BOOK OF ABSTRACTS

2012 International Power Modulator and High Voltage Conference

June 3 - 7, 2012

San Diego, CA

Sponsored by:

Technically Co-Sponsored by:

ii EXHIBITORS

5S Components, Inc. Barth Electronics Inc. 630 Fifth Ave 1589 Foothill Drive East McKeesport, PA 15035 USA Boulder City, NV 89005 USA Phone: 412-967-5858 Phone: 702-293-1576 Fax: 412-967-5868 Fax: 702-293-7024 http://www.5scomponents.com/ http://www.barthelectronics.com Behlke Power Electronics, LLC Diversified Technologies, Inc. 5 Alexander Road, Suite 2 35 Wiggins Avenue Billerica, MA 01821-5032 USA Bedford, MA 01730 USA Phone: 978-362-3118 Phone: 781-275-9444 Fax: 978-362-3122 Fax: 781-275-6081 http://www.behlke.com http://www.divtecs.com General Atomics Electronics Systems, Inc. Genvolt 4949 Greencraig Lane New Road, Highley, San Diego, CA 92123 USA Bridgnorth, Shropshire, WV16 6NN, UK Phone: 858-522-8300 Phone: +44 (0) 1746 862555 Fax: 858-522-8301 Fax: +44 (0) 1746 862666 http://www.ga-esi.com http://www.genvolt.co.uk HVCA, CKE HVR Advanced Power Components (Products by Dean Technology, Inc.) 1307 Military Rd. P.O. Box 700968 Tonawanda, NY 14217 USA Dallas, TX 75370 USA Phone: 716-693-4700 Phone: 972-248-7691 Fax: 716-693-4774 Fax: 972-381-9998 http://www.hvrapc.com http://www.hvca.com Magnetic Metals Corp Pearson Electronics, Inc. 1900 Hayes Avenue 4009 Transport Street Camden, NJ 08105 USA Palo Alto, CA 94043 USA Phone: 856-964-7842 Phone: 650-494-6444 Fax: 856-963-8569 Fax: 650-494-6716 http://www.magmet.com http://www.pearsonelectronics.com Powerex Inc. Pulse Power & Measurement Ltd. 173 Pavilion Lane 65 Shrivenham Hundred Business Park Yongwood, PA 15697 USA Watchfield Phone: 724-925-7272 Swindon, Wiltshire SN6 8TY, UK Fax: 724-925-4393 Phone: +44 (0)1793 784389 http://www.pwrx.com Fax: +44 (0) 1793 784391 http://www.ppm.co.uk/ Pulsed Technologies, LTD. RFI Corporation Yablochkova 5 100 Pine Aire Drive Ryazan 390023 RUSSIA Bay Shore, New York 11706 USA Phone: +7(4912)24 92 17 Phone: 631-231-6400 Fax: +7(4912)24 05 19 Fax: 631-231-6465 http://www.pulsetech.ru http://www.rficorp.com/ ScandiNova Systems AB SLAC National Accelerator Laboratory Ultunaallén 2A 2575 Sand Hill Road, MS 49 75651 UPPSALA SWEDEN Menlo Park, CA 94025 USA Phone: +46 (0)18 480 59 00 Phone: 650-926-2602 Fax: +46 (0)18 480 59 99 Fax: 650-926-3588 http://www.sc-nova.com http://www.slac.stanford.edu/

iii EXHIBITORS (cont.)

Stangenes Industries, Inc. TDK-Lambda Americas High Power Division 1052 East Meadow Circle 405 Essex Rd Palo Alto, CA 94303-4230 USA Neptune, NJ 07753 USA Phone: 650-493-0814 Phone: 732-922-9300 Fax: 650-855-9926 Fax: 732-922-1441 http://www.stangenes.com http://www.us.tdk-lambda.com/hp Tera Analysis Ltd. - Producers of QuickField TMD Technologies LTD Canadian Representative Office Swallowfield Way Phone: +1 905 597 4133 or +1 877 215 8688 Hayes, Middlesex UB3 1DQ, UK Cell: +1 416 838 6434 Phone: +44 (0)20 8573 5555 e-mail: [email protected] Fax: +44 (0)20 8569 1839 http://www.quickfield.com http://www.tmd.co.uk TREK, Inc. Ultravolt, Inc. 11601 Maple Ridge Road 1800 Ocean Avenue, FRNT Medina, NY 14103 USA Ronkonkoma, NY 11779 USA Phone: 585-7983140 Phone: 631-471-4444 Fax: 585-798-3106 Fax: 631-471-4696 http://www.trekinc.com http://www.ultravolt.com

iv WELCOME,

On behalf of the International Power Modulator and High Voltage Conference (IPMHVC) Executive Committee and the Conference and Technical Program Committees, we welcome you to the 2012 IEEE IPMHVC. This year we have received a record number of >300 abstract submissions from 865 authors and co-authors. Almost 60% of these were sent in from our international colleagues in 26 different countries, which emphasize the international character of this conference. Significant participation came from China, India, Japan, United Kingdom, Korea, Germany, Russia, France, and Brazil. The most popular technical topics were Solid State Modulators, Components, and Switches and Dielectrics and Breakdown followed by Biological, Medical, and Environmental Applications; High Voltage Testing and Diagnostics; High Power Microwaves, Radiating Structures, and Electromagnetic Propagation; and Compact Pulsed Power Systems. Abstracts were also collected in several other areas including Power Electronics and Power Supplies; Analytical Methods, Modeling, and Simulation; Plasma Opening and Closing Switches; High Voltage Design and Analysis; High Current Systems and EM Launchers; Accelerators, Radar, and RF Applications; Power Conditioning and Pulse Shaping; etc. The technical program of the 2012 IEEE IPMHVC is being held at the conference hotel, the Hilton San Diego Bayfront. The Hilton Bayfront is the newest waterfront hotel on San Diego Bay and is located within minutes of several attractions including the San Diego harbor, San Diego Padre’s PETCO Park stadium, Coronado island, and the vibrant Gaslamp Quarter of the downtown area which boasts more than 16 square blocks and more than 150 restaurants, shops, and nightclubs. The social program opens with the welcome reception on Sunday evening in the Exhibitors area, followed by a “night out” dinner at the USS Midway Museum on Monday evening, and a reception and conference awards banquet on Tuesday evening (Hilton Bayfront). The conference is fully sponsored by the IEEE Dielectrics and Electrical Insulation Society and technically co-sponsored by the IEEE Nuclear and Plasma Sciences Society and the IEEE Electron Devices Society. We gratefully acknowledge the sponsorship from government, university, and industry, and the support from exhibitors. We encourage you to visit the booths and talk to the exhibitors. We would like to express our sincere gratitude to the entire Conference Organizing Committee for all their efforts and we extend our sincere thanks to all the members of the Technical Program Committee for their hard work in reviewing the abstract submissions and defining an outstanding technical program. Finally, we thank all of the presenters and attendees for contributing to the ongoing success of this conference and we look forward to seeing you in Denver Colorado in 2014.

Richard M. Ness 2012 IPMHVC General Conference Chair

Juergen Kolb 2012 IPMHVC Technical Program Chair

v 2012 IPMHVC COMMITTEE CHAIRS AND STAFF

General Conference Chair Richard Ness Ness Engineering, Inc. Technical Program Chair Juergen Kolb INP Greifswald Conference Treasurer Mark Kemp SLAC National Accelerator Laboratory Publications Chair Frank Hegeler Naval Research Laboratory/CTI Publicity Chair Robert Saethre Oak Ridge National Laboratory Exhibits Chair Mike Mazzola Mississippi State University Exhibits Coordinator Debi Brewington Mississippi State University Sponsors Chair Greg Dale Los Alamos National Laboratory Industrial Advisory Committee Chair Larry Cagle Dean Technology, Inc. Professional Awards Chair Steve Calico Lockheed Martin Student Awards/ Travel Grant Chair Jon Mayes Applied Physical Electronics LC Visa Assistance Enis Tuncer GE Global Research

vi Overseas Conf. Attendance Chair Bucur Novac Loughborough University Employment Assistance Chair Raymond Allen Naval Research Laboratory Short Course Chair Chunqi Jiang University of Southern California Conference Webmaster Robert Saethre Oak Ridge National Laboratory IEEE DEIS Meetings Chair Resi Lloyd Qualitrol Corp Executive Committee Chair Hulya Kirkici Auburn University

TECHNICAL PROGRAM COMMITTEE MEMBERS

Hidenori Akiyama Kumamoto University Raymond Allen Naval Research Laboratory Matthew Aubuchon General Atomics Stephen Bayne Texas Tech University Ronny Brandenburg INP Greifswald Larry Cagle Dean Technology Steve Calico Lockheed Martin Hao Chen Cymer, Inc. Yeong-Jer Chen Old Dominion University Randy Cooper Cooper Consulting Services, Inc. Joerg Ehlbeck INP Greifswald Wolfgang Frey Karlsruhe Inst. of Technology Allen Garner General Electric Marcel Gaudreau Diversified Technologies, Inc. Mike Giesselmann Texas Tech University Greg Dale Los Alamos National Laboratory Werner Hartmann Siemens AG Frank Hegeler Naval Research Laboratory/CTI Brett Huhman Naval Research Laboratory Marcus Iberler University of Frankfurt Naz Islam University of Missouri Joachim Jacoby University of Frankfurt

vii Chunqi Jiang University of Southern California Weihua Jiang Nagaoka University of Technology Richard Johnson JPA, Inc. Ravindra Joshi Old Dominion University Hulya Kirkici Auburn University Susumu Kono Ariake National College of Technology Scott Kovaleski University of Missouri Andras Kuthi University of Southern California Markus Loeffler Fachhochschule Gelsenkirchen Mark Kemp SLAC National Accelerator Laboratory Juergen Kolb INP Greifswald Jon Mayes Applied Physical Electronics, L.C. Mike Mazarakis Sandia National Laboratories Georg Michel Max-Planck-Inst. for Plasma Physics Harry Moore CIV USA AMC Sang Hoon Nam Pohang Accelerator Laboratory Andreas Neuber Texas Tech University Bucur Novac Loughborough University Steve Pronko General Atomics Vladislav Rostov Inst. of High Current Electronics Tomsk Dan Schweickart US Air Force Wright Patterson Mark Sinclair AWE Aldermaston Ivor Smith Loughborough University Emil Spahn French-German Research Inst. Robert Stark Diehl BGT Defense Claus Strowitzki MLase AG Yaohong Sun Chinese Academy of Science Enis Tuncer GE Global Research Rene Vezinet CEA Adriaan Welleman Astrol Electronics AG David Wetz University of Texas, Arlington Shu Xiao Old Dominion University Michael Yalandin Inst. of Electrophysics Ekaterinburg Chen-Guo Yao Chonqing University Luigi Zeni Second University of Naples Kai Zhou G&W Electric Co.

SESSION ORGANIZERS AND CHAIRS

Plenary Session Chairs Craig Burkhart SLAC National Accelerator Laboratory Hulya Kirkici Auburn University Juergen Kolb INP Greifswald

viii Oral Session Chairs Raymond Allen Naval Research Laboratory Matthew Aubuchon General Atomics Steve Calico Lockheed Martin Allen Garner General Electric Marcel Gaudreau Diversified Technologies, Inc. Werner Hartmann Siemens AG Brett Huhman Naval Research Laboratory Chunqi Jiang University of Southern California Mike Mazarakis Sandia National Laboratories Andreas Neuber Texas Tech University Dan Schweickart US Air Force Wright Patterson Shu Xiao Old Dominion University

Poster Session Chairs Hao Chen Cymer Inc. Randy Cooper Cooper Consulting Services Inc. David Wetz University of Texas, Arlington

IPMHVC EXECUTIVE COMMITTEE

Larry Cagle Dean Technology Greg Dale Los Alamos National Laboratory Mike Giesselmann Texas Tech University Frank Hegeler Naval Research Laboratory/CTI Richard Johnson JPA, Inc. Hulya Kirkici Auburn University Juergen Kolb INP Greifswald Mike Mazarakis Sandia National Laboratories Marshall Molen Mississippi State University Harry Moore CIV USA AMC Richard Ness Ness Engineering, Inc. Bucur Novac Loughborough University Sol Schneider Consultant Daniel Schweickart US Air Force Wright Patterson Jim Thompson University of Missouri Enis Tuncer GE Global Research Ryan Umstattd US Air Force Los Angeles

ix CONFERENCE SPONSORS AND SUPPORTERS

Exhibitors Gigawatt Sponsors: General Atomics Electronic Systems HVR Advanced Power Components TDK-Lambda Americas High Power Division Megawatt Sponsors: Barth Electronics, Inc. / Pulse Power & Measurement Ltd. Behlke Power Electronics LLC Dean Technology Stangenes Industries, Inc. TMD Technologies Limited Kilowatt Sponsors: ABB Semiconductors / 5S Components Inc. Diversified Technologies, Inc. Genvolt Magnetic Metals Corp. Pearson Electronics Powerex Pulsed Technologies Ltd. RFI Corporation ScandiNova Systems AB SLAC National Accelerator Laboratory Tera Analysis Ltd. TREK, Inc. UltraVolt, Inc.

Government and University Sponsors Air Force Office of Scientific Research INP Greifswald Naval Research Laboratory Office of Naval Research Sandia National Laboratories

Corporate Sponsors Dean Technology General Atomics Electronic Systems GE Global Research Center HVR Advanced Power Components L-3 – Applied Technologies, Inc. Lockheed Martin Ness Engineering, Inc.

x GENERAL INFORMATION

Onsite Conference Registration Desk Sapphire West Foyer, Hilton San Diego Bayfront Sunday, June 3, 2012 2:00 PM - 8:00 PM Monday, June 4, 2012 7:30 AM - 5:30 PM Tuesday, June 5, 2012 7:30 AM - 5:30 PM Wednesday, June 6, 2012 7:30 AM - 3:30 PM

Exhibit Times Sapphire CDGH - Exhibits Area, Hilton San Diego Bayfront Sunday, June 3, 2012 6:00 PM - 8:00 PM Monday, June 4, 2012 7:30 AM - 12 PM and 1:30 PM - 5:30 PM Tuesday, June 5, 2012 7:30 AM - 12 PM and 1:30 PM - 5:30 PM Wednesday, June 6, 2012 7:30 AM - 12 PM and 1:30 PM - 3:30 PM

Companion Program TBD, please see the registration desk and the conference website for more information

Short Courses Aqua 306/308, Hilton San Diego Bayfront Thursday, June 6, 2012 8:00 AM - 2:45 PM Breakfast for short course attendees starts at 7:15 AM

Technical Tour Tour of the General Atomics DIII-D National Fusion Facility Thursday, June 6, 2012 1:30 PM - 4:00 PM

Social Events Welcome Reception Sapphire CDGH - Exhibits Area, Hilton San Diego Bayfront Sunday, June 3, 2012 6:00 PM - 8:00 PM Off-site dinner at the USS Midway Monday, June 4, 2012 6:30 PM - 10:00 PM Buses will depart from the Conference Hotel, Level 1, starting at 6:15 PM. Conference Awards Dinner Tuesday, June 5, 2012, Hilton San Diego Bayfront Reception (Sapphire CDGH - Exhibits Area) 6:30 PM - 7:30 PM Dinner (Sapphire KLOP) 7:30 PM - 10:00 PM For conference registrants only Sapphire CDGH - Exhibits Area, Hilton San Diego Bayfront Monday, Tuesday, and Wednesday Continental Breakfast 7:15 AM - 8:15 AM Coffee Break 9:30 AM - 10:00 AM Afternoon Break 3:00 PM - 3:30 PM

xi 2012 IEEE IPMHVC SCHEDULE-AT-A-GLANCE Location: Hilton San Diego Bayfront, San Diego, CA (unless otherwise noted)

Sunday, June 3, 2012 2:00 – 8:00 PM Registration Sapphire West Foyer 6:00 – 8:00 PM Welcome reception Sapphire CDGH - Exhibits Area

Monday, June 4, 2012 7:15 – 8:15 AM Breakfast (registrants only) Sapphire CDGH - Exhibits Area 8:15 – 8:30 AM Welcome Sapphire KLOP 8:30 – 9:30 AM Plenary 1 Sapphire KLOP 9:30 – 10:00 AM Break Sapphire CDGH - Exhibits Area 10:00 – 12:00 PM Oral Session 1 Solid State Modulators, Components and Switches 1 Sapphire OP 10:00 – 12:00 PM Oral Session 2 Dielectrics and Breakdown Sapphire KL 12:00 – 1:30 PM Lunch (on your own) 1:30 – 3:00 PM Poster Session 1 Solid State Modulators, Components Switches, Dielectrics, Breakdown, and Power Electronics and Power Supplies Aqua 306/308 3:00 – 3:30 PM Break Sapphire CDGH - Exhibits Area 3:30 – 5:30 PM Oral Session 3 Solid State Modulators, Components and Switches 2, Power Electronics and Power Supplies Sapphire OP 3:30 – 5:30 PM Oral Session 4 Biological, Medical, and Environmental Applications Sapphire KL 6:15 PM Bus shuttle to the Midway. Departs on Level 1 of the conference hotel. 6:30 – 10:00 PM Night Out dinner at the USS Midway

xii Tuesday, June 5, 2012 7:15 – 8:15 AM Breakfast (registrants only) Sapphire CDGH - Exhibits Area 8:15 – 8:30 AM Conference Updates Sapphire KLOP 8:30 – 9:30 AM Plenary 2 Sapphire KLOP 9:30 – 10:00 AM Break Sapphire CDGH - Exhibits Area 10:00 – 12:00 PM Oral Session 5 Plasma Opening and Closing Switches, Lasers and other Radiation Sources Sapphire KL 10:00 – 12:00 PM Oral Session 6 High Voltage Testing and Diagnostics Sapphire OP 12:00 – 1:30 PM Lunch (on your own) 1:30 – 3:00 PM Poster Session 2 Biological, Medical, and Environmental Applications, Plasma Opening and Closing Switches, Lasers and Other Radiation Sources, High Voltage Testing and Design, Compact Pulsed Power, and Power Conditioning and Pulse Shaping Aqua 306/308 3:00 – 3:30 PM Break Sapphire CDGH - Exhibits Area 3:30 – 5:30 PM Oral Session 7 Compact Pulsed Power Systems Sapphire OP 3:30 – 5:30 PM Oral Session 8 High Voltage Design and Analysis, Accelerators, Radar, and RF Applications, Reliability and Transient Suppression Sapphire KL 6:30 – 7:30 PM Reception Sapphire CDGH - Exhibits Area 7:30 – 10:00 PM Conference Awards Banquet Sapphire KLOP

xiii Wednesday, June 6, 2012 7:15 – 8:15 AM Breakfast (registrants only) Sapphire CDGH - Exhibits Area 8:15 – 8:30 AM Conference Updates Sapphire KLOP 8:30 – 9:30 AM Plenary 3 Sapphire KLOP 9:30 – 10:00 AM Break Sapphire CDGH - Exhibits Area 10:00 – 12:00 PM Oral Session 9 High Current Systems and EM Launchers Sapphire KL 10:00 – 12:00 PM Oral Session 10 High Power Microwaves, Radiating Structures, and Electromagnetic Propagation Sapphire OP 12:00 – 1:30 PM Lunch (on your own) 1:30 – 3:00 PM Poster Session 3 High Voltage Design and Analysis, Accelerators, Radars, and RF Applications, Reliability and Transient Suppression, High Current Systems and EM Launchers, High Power Microwaves, Radiating Structures, and Electromagnetic Propagation, Analytical Methods, Modeling, and Simulation, Prime Power and Power Systems, Energy Storage Devices and Components, High Energy Systems Aqua 306/308 3:00 – 3:30 PM Break Sapphire CDGH - Exhibits Area 3:30 – 5:30 PM Oral Session 11 Analytical Methods, Modeling, and Simulations Sapphire KL 3:30 – 5:30 PM Oral Session 12 Power Conditioning and Pulse Shaping, Energy Storage Devices and Components Sapphire OP

xiv Thursday, June 7, 2012 7:15 – 8:00 AM Breakfast for Short Course Attendees Aqua 306/308 8:00 – 12:00 PM Short Course 1: An Overview of Electric Power Systems Engineering Dr. Charles A. Gross Auburn University Aqua 306A 8:00 – 12:15 PM Short Course 2: Power Electronics Dr. Craig Burkhart SLAC National Accelerator Laboratory Aqua 308 8:00 – 2:45 PM Short Course 3: RF and HPM Sources Dr. Bruce Carlsten Los Alamos National Laboratory Aqua 306B 11:45 – 1:15 PM Lunch Break for Short Course 3 attendees (on your own) 1:30 – 4:00 PM Technical Tour of the General Atomics DIII-D National Fusion Facility Please see the registration desk and the conference website for more information

xv 2012 IEEE IPMHVC ABSTRACT LISTING

Plenary 1 Session Chair: Hulya Kirkici, Auburn University PL1 HIGH VOLTAGE, BIOFUELS, AND CO-PRODUCTS 1 TAKING HIGH VOLTAGE TO THE (FARM) FIELD Robert Hebner University of Texas, Austin

Oral Session 1: Solid State Modulators, Components and Switches 1 Session Chair: Marcel Gaudreau, Diversified Technologies, Inc. 1O1,2 COMPACT SILICON SGTO MODULE FOR PULSE SWITCHING BEYOND 6 KV, 2 (Invited) 100 KA Heather O'Brien1, Aderinto Ogunniyi1, William Shaheen2, Victor Temple3, Charles Scozzie1 1U.S. Army Research Laboratory Adelphi, MD, USA, 2Berkeley Research Associates Beltsville, MD, USA, 3Silicon Power Corp. Clifton Park, NY, USA 1O3 SPICE ANALYSIS OF AN INNOVATIVE SOLID-STATE MARX TOPOLOGY 3 UTILIZING A BOOST REGULATOR CIRCUIT TO GENERATE MILLISECOND PULSES WITH LOW DROOP Christopher Yeckel , Richard Cassel Stangenes Industries Inc. Palo Alto, CA, USA 1O4 A HIGH POWER CASCODE SWITCH FOR RAPID, EFFICIENT ENERGY 4 TRANSFER AT HIGH REPETITION RATES Jason M. Sanders, Andras Kuthi, Martin A. Gundersen University of Southern California, Electrical Engineering - Electrophysics, Los Angeles, CA, USA 1O5 NEW CONCEPTS FOR PULSED POWER MODULATORS: IMPLEMENTING A 5 HIGH VOLTAGE SOLID-STATE MARX MODULATOR Floyd Arntz1, Kevin Ostlund1, Michael Kempkes1, Jeffrey Casey2 1Diversified Technologies, Inc. Bedford, MA, USA, 2Rockfield Research, Inc. Las Vegas, NV, USA 1O6 HIGH AVERAGE POWER HIGH VOLTAGE MODULATOR USING A DUAL 6 PULSE TRANSFORMER CIRCUIT Werner Hartmann1, Norbert Grass2, Klaus-Dieter Rohde1, Martin Schwendner2 1Siemens AG, CT T DE HW4, Erlangen, Germany, 2Georg-Simon-Ohm University Nuremberg, Germany 1O7 THE SLAC P2 MARX 7 Mark Kemp, Andrew Benwell, Craig Burkhart, David MacNair, Minh Nguyen SLAC National Accelerator Laboratory Menlo Park, CA, USA 1O8 DESIGN OF A 20 KHZ MAGNETIC PULSE COMPRESSOR 8 Dongdong Zhang1, Yuan Zhou4, Wenfeng Li3, Jiayu xu3, Jue Wang1, Yaohong Sun1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China, 3Graduate School of Chinese Academy of Sciences Beijing, China, 4Tianjin University of Technology and Engineering Tianjin, China

xvi Oral Session 2: Dielectrics and Breakdown Session Chair: Raymond Allen, Naval Research Laboratory 2O1 SURFACE FLASHOVER MECHANISM ON THE LIQUID IMMERSED 9 DIELECTRICS Jouya Jadidian1, Markus Zahn1, Nils Lavesson2, Ola Widlund2, Karl Borg2 1Massachusetts Institute of Technology Cambridge, MA, USA, 2ABB Corporate Research Västerås, Sweden 2O2 THE STATISTICAL AND FORMATIVE TIMES FOR BREAKDOWN AT A 10 POLYMER-OIL INTERFACE Mark Wilson1, Martin Given1, Igor Timoshkin1, Scott MacGregor1, Tao Wang1, Mark Sinclair2, Ken Thomas2, Jane Lehr3 1University of Strathclyde, Electronic & Electrical Engineering, Glasgow, United Kingdom, 2AWE Aldermaston, Hydrodynamics Division, Reading, United Kingdom, 3Sandia National Laboratories, Exploratory Pulsed Power, Albuquerque, NM, USA 2O3 INITIATION MECHANISM OF NEGATIVE PULSED DISCHARGE IN 11 SUPERCRITICAL CARBON DIOXIDE Tomohiro Furusato, Takeshi Ihara, Tsuyoshi Kiyan, Sunao Katsuki, Masanori Hara, Hidenori Akiyama Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan 2O4 SPATIALLY-RESOLVED SPECTRAL OBSERVATIONS OF PULSED SURFACE 12 FLASHOVER PLASMA IN A NITROGEN ENVIRONMENT Andrew Fierro, George Laity, Andreas Neuber, Lynn Hatfield, James Dickens Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA 2O5 INVESTIGATION OF VACUUM UV ABSORPTION DURING LOW- 13 TEMPERATURE PLASMA FORMATION IN N2/H2 MIXTURES AT ATMOSPHERIC PRESSURE George Laity1, Andrew Fierro1, Lynn Hatfield1, Andreas Neuber1, James Dickens1, Klaus Frank1,2 1Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA, 2Friedrich – Alexander University at Erlangen - Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen, Germany 2O6 SIMULATION OF HIGH-VOLTAGE DC BREAKDOWN FOR ANGLED 14 DIELECTRIC INSULATORS INCLUDING SPACE-CHARGE AND GAS- COLLISION EFFECTS Manuel P. Aldan1, John P. Verboncoeur2 1University of California at Berkeley, Nuclear Engineering, Berkeley, CA, USA, 2Michigan State University, Electrical and Computer Engineering, East Lansing, MI, USA

2O7 REINFORCED INSULATION PROPERTIES OF EPOXY RESIN/ SIO2 15 NANOCOMPOSITES BY ATMOSPHERIC PRESSURE PLASMA MODIFICATION Wei Yan1, Toan Phung1, Zhaojun Han2, Kostya (Ken) Ostrikov2 1University of New South Wales, School of Electrical Engineering and Telecommunications, Sydney, Australia, 2CSIRO Material Science and Engineering, Plasma Nanoscience Centre Australia, Lindfield, Australia 2O8 FLASHOVER PHENOMENA ACROSS SOLID DIELECTRICS IN VACUUM: 16 MECHANISM AND SUPPRESSION Guan-Jun Zhang, Jiang-Yang Zhan, Xue-Zeng Huang, Hai-Bao Mu Xi'an Jiaotong University, School of Electrical Engineering, Xi'an, China

xvii Poster Session 1: Solid State Modulators, Components Switches, Dielectrics, Breakdown, and Power Electronics and Power Supplies Session Chair: Randy Cooper, Cooper Consulting Services Inc. 1P1 FAST OPENING SWITCH APPROACH FOR HIGH-VOLTAGE VACUUM TUBE 17 PROTECTION APPLICATION

Wolfhard Merz1, Monty Grimes2 1DESY, MKK7, Hamburg, Germany, 2Behlke Power Electronics LLC Billerica, MA, USA 1P2 HYBRID OPTIONS FOR UPGRADE OF THE LHC ENERGY EXTRACTION 18 SWITCHGEAR Knud Dahlerup-Petersen, Gert-Jan Coelingh, Bozhidar Panev CERN, TE, Geneva, Switzerland 1P3 SENSITIVITY ANALYSIS FOR THE CLIC DAMPING RING INDUCTIVE ADDER 19 Janne Holma, Michael Barnes

CERN, TE/ABT/FPS, Geneva, Switzerland 1P4 DESIGN AND TEST OF A MODULAR TRIGGER GENERATOR FOR OVER- 20 VOLTAGE TRIGGERING OF MARX GENERATORS

Martin Sack, Georg Mueller Karlsruhe Institute of Technology, IHM, Eggenstein-Leopoldshafen, Germany 1P5 PARAMETRIC MEASUREMENTS OF SWITCHINGS LOSSES OF IGBT´S IN 21 PULSED POWER APPLICATIONS Claus Strowitzki, Matthias Dahlke MLase AG, Development, Germering, Germany 1P6 A 5KV, 3MHz SOLID-STATE MODULATOR BASED ON THE DSRD SWITCH 22 FOR AN ULTRA-FAST BEAM KICKER

Andrew Benwell1, Craig Burkhart1, Anatoly Krasnykh1, Tao Tang1, Alexei Kardo-Sysoev2 1SLAC National Accelerator Laboratory, Electrodynamics, Menlo Park, CA, USA, 2Ioffe Physical Technical Institute St. Petersburg, Russia 1P7 SOLID STATE FAST TRANSITION KICKER MODULATOR FOR 23 ACCELERATOR APPLICATIONS

Steven Glidden, Howard Sanders, Daniel Warnow Applied Pulsed Power, Inc. Freeville, NY, USA 1P8 NEXT GENERATION, FAST CURRENT RISE-TIME, LASER PUMPED 5kV 24 SILICON THYRISTOR SWITCH

Steven Glidden, Howard Sanders, Daniel Warnow Applied Pulsed Power, Inc. Freeville, NY, USA 1P9 GROUND BASED RADAR MODULATOR SOLID-STATE UPGRADE 25 Sherry Hitchcock1, Paul Holen1, Magne Stangenes1, Mike Garbi1, Chris Rivers1, Harry

Anamkath1, Randy Ross1, Lill Runge1, Alan Gardner2, Jurgen Terry2 1Stangenes Industries, Inc Palo Alto, CA, USA, 2Raytheon Technical Services El Segundo, CA, USA 1P10 AN OVERVIEW OF CONTEMPORARY SOLID-STATE MODULATOR 26 TOPOLOGIES AND THEIR PRACTICAL PARAMETER SPACE

Sherry Hitchcock, Richard Cassel, Magne Stangenes Stangenes Industries, Inc Palo Alto, CA, USA

xviii 1P11 OPTIMUM TERA HERTZ PULSE AMPLITUDE IN LOW TEMPERATURE 27 GROWN GALLIUM ARSENIDE PHOTOCONDUCTIVE SWITCHES FOR POWER

APPLICATIONS Omar Ibrahim1, Haitham Al Saif1, Ashwani Sharma2, Clay Mayberry2, P. Kirawanich3, N. E. Islam1 1University of Missouri - Columbia, Department of Electrical and Computer Engineering, Columbia, MO, USA, 2AFRL/RSVE Albuquerque, NM, USA, 3Mahidol University, Department of Electrical Engineering, Nakhon Pathom, Thailand 1P12 DESIGN AND TESTING OF WIDE BANDGAP CURRENT LIMITING DEVICES 28 Nathaniel Kinsey1, Randy Curry1, Robert Druce1, Heikki Helava2

1University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA, 2Helava Systems Inc. Deer Park, NY, USA 1P13 DEVELOPMENT OF AN AUTOMATED TEST SETUP FOR LONG TERM 29 SYSTEMATIC EVALUATION OF EXPERIMENTAL GATE-TURN-OFF

THYRISTORS IN HIGH ENERGY PULSE APPLICATIONS Shelby Lacouture1, Kevin Lawson1, Stephen Bayne1, Michael Giesselmann1, Heather O'Brien2, Aderinto Ogunniyi2, Charles Scozzie2 1Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA, 2U.S. Army Research Laboratory Adelphi, MD, USA 1P14 FIBER OPTIC SYSTEM FOR 50 MHZ BURST OPERATION OF A SILICON 30 CARBIDE PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH

Daniel Mauch, Cameron Hettler, William Sullivan III, James Dickens Texas Tech University, Center for Pulsed Power and Electronics, Lubbock, TX, USA 1P15 DV/DT IMMUNITY AND RECOVERY TIME CAPABILITY OF 1.0 CM2 SILICON 31 CARBIDE SGTO

Aderinto Ogunniyi1, Heather O'Brien1, Charles Scozzie1, William Shaheen2, Anant Agarwal3, Lin Cheng3, Victor Temple4 1U.S. Army Research Laboratory Adelphi, MD, USA, 2Berkeley Research Associate Beltsville, MD, USA, 3Cree, Inc Durham, NC, USA, 4Silicon Power Corporation Clifton Park, NY, USA 1P16 IGBT GATE DRIVER UPGRADES TO THE HVCM AT THE SNS 32 Dennis Solley, David Anderson, Gunjan Patel, Mark Wezensky

Oak Ridge National Laboratory, Research Accelerator Division, Oak Ridge, TN, USA 1P17 HVCM TOPOLOGY ENHANCEMENTS TO SUPPORT A POWER UPGRADE 33 REQUIRED BY A SECOND TARGET STATION AT SNS.

Dennis Solley, David Anderson, Gunjan Patel, Mark Wezensky Oak Ridge National Laboratory, Research Accelerator Division, Oak Ridge, TN, USA 1P18 ULTRA-COMPACT 100 KV SOLID-STATE SWITCH DEVELOPMENT FOR SUB- 34 MICROSECOND DISCHARGES

R.J. Richter-Sand1, G. Parker1, M. Kostora1, S. Heidger2, M. Domonkos2, E. Loree3 1SAIC Albuquerque, NM, USA, 2AFRL Albuquerque, NM, USA, 3Loree Engineering Albuquerque, NM, USA 1P19 AN ULTRA FAST HYBRID TOTEM POLE MOSFET/DRIVER MODULE FOR 35 HIGH REPETITION RATE OPERATION

Tao Tang, Craig Burkhart SLAC National Accelerator Laboratory Menlo Park, CA, USA 1P20 A COMPACT SOLID STATE MODULATOR FOR ACCELERATOR 36 APPLICATIONS

Kongyin Gan, Hepin Hu, Tao Li, Zhiyuan Tan Institute of the Applied Electronics, China Academy of Engineering Physics Miangyang, China

xix 1P21 LONGEVITY OF HIGH POWER GAAS PCSS AT DC BIAS VOLTAGE 37 Liu Hongwei, Liu Jinfeng, Yuan Jianqiang, Zhao Yue, Li Hongtao, Xie Weiping

China Academy of Engineering Physics, The institute of Fluid Physics, Mianyang, China 1P22 DESIGN OF REPETITIVE HIGH VOLTAGE RECTANGULAR WAVEFORM 38 PULSE ADDER

Liuxia Li, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources, Shanghai, China 1P23 ON-STATE RESISTANCE COMPARISON OF SEMI-INSULATING 6H-SIC 39 PHOTOCONDUCTIVE SEMICONDUCTOR SWITCHES

Jianqiang Yuan, Hongwei Liu, Jinfeng Liu, Hongtao Li, Weiping Xie China Academy of Engineering Physics, Institute of Fluid Physics, Mianyang, China 1P24 PRELIMINARY RESEARCHES ON A PLANE-BOARD EXPLOSIVE OPENING 40 SWITCH

Shirong Hao, Yingmin Dai, Minhua Wang, Nanchuan Zhang, Wenhui Han, Youcheng Wu Hydro-physics Research Institute, Academy of Engineering Physics, Si Chuan Province, Mianyang, China 1P25 INFLUENCE OF HYDROSTATIC PRESSURE AND TEMPERATURE ON THE 41 WATER DIELECTRIC STRENGH AND ON THE DYNAMIC PRESSURE WAVE

Justin Martin1, Thierry Reess1, Antoine De Ferron1, Robert Ruscassie1, Franck Rey- Bethbeder2 1University of Pau, SIAME, PAU, France, 2TOTAL PAU, France 1P26 MODELING OF THE DIELECTRIC RECOVERY OF 42 HOT AIR IN INSULATING NOZZLES

Andreas Kurz, Paul Gregor Nikolic, Daniel Eichhoff, Armin Schnettler RWTH Aachen University, Institute for High Voltage Technology, Aachen, Germany 1P27 INVESTIGATIONS ON THE DIELECTRIC STRENGTH OF CARBON DIOXIDE 43 AND CARBON DIOXIDE MIXTURES FOR THE APPLICATION IN GAS

INSULATED SWITCHGEAR Paul Gregor Nikolic, Andreas Kurz, Matthias Hoffacker, Armin Schnettler RWTH Aachen University, Institute for High Voltage Technology, Aachen, Germany 1P28 THE INFLUENCE OF CONCENTRATED HEAT FLUX ON THE DIELECTRIC 44 PROPERTIES OF SYNTHETIC AND NATURAL ESTERS.

Pawel Rozga Technical University of Lodz, Institute of Electrical Power Engineering, Lodz, Poland 1P29 INVESTIGATION OF AC DISCHARGES WITH WATER DROPLETS ON SOLID 45 DIELECTRIC LAYERS

Alper Kara, Ozcan Kalenderli, Kevork Mardikyan Istanbul Technical University, Electrical-Electronics Faculty, Istanbul, Turkey 1P30 ON THE MEASUREMENTS OF THE DIELECTRIC CONSTANT AND 46 DISSIPATION FACTOR OF VARIOUS ELASTOMERS

L. Nastrat1, R.M. Sharkawy2 1South Valley University, Electrical Power and Machines Engineering, Aswan, Egypt, 2AASTMT, Electrical and Control Engineering, Cairo, Egypt 1P31 CONDUCTION AND BREAKDOWN IN SYNTHETIC AND NATURAL ESTER 47 FLUIDS

Igor Timoshkin1, Yi Jing1, Martin Given1, Mark Wilson1, Tao Wang1, Scott MacGregor1, Jane Lehr2 1University of Strathclyde, EEE, Glasgow, United Kingdom, 2Sandia NL Albuquerque, NM, USA

xx 1P32 PULSED HIGH-VOLTAGE BREAKDOWN OF THIN FILM PARYLENE-C 48 Juan Elizondo-Decanini, Evan Dudley

Sandia National Laboratories Albuquerque, NM, USA 1P33 HIGH FIELD CONDUCTION IN HEAT RESISTANT POLYMERS AT ELEVATED 49 TEMPERATURE

Janet Ho, T. Richard Jow US Army Research Laboratory Adelphi, MD, USA 1P34 ELECTRICAL CHARACTERISTICS OF MICROPLASMA DEVICES WITH 50 CARBON-NANOTUBES (CNT) AS THE CATHODE

Huirong Li, Chung-Nan Tsai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA 1P35 SURFACE FLASHOVER OF NANODIELECTRICS WITH VARYING 51 ELECTRODE ARCHITECTURES IN PARTIAL VACUUM

Zhenhong Li, Huirong Li, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA 1P36 TO ELECTRICALLY LOCATE GATE-OXIDE DEFECTS IN DUAL-GATE 52 TECHNOLOGIES FOR VARIOUS HIGH-VOLTAGE DOMAINS

Lieyi Sheng, John Leith, Eddie Glines ON Semiconductor, Quality, Pocatello, ID, USA 1P37 MECHANISM FOR STIMULATED ACOUSTIC EVENTS ASSOCIATED WITH 53 PARTIAL DISCHARGE

Aleta T. Wilder The University of Texas, Cockrell School of Engineering, Austin, TX, USA 1P38 HIGH TEMPERATURE CAPACITORS WITH HIGH ENERGY DENSITY 54 Chen Zou, Nanyan Zhang, Douglas Kushner, Raymond Orchard, Charles Mi, Shihai Zhang

Strategic Polymer Sciences, Inc., Capacitor Division, State College, PA, USA 1P39 EXPERIMENTAL STUDY ON SURFACE FLASHOVER CHARACTERISTICS OF 55 INSULATING METERIAL IN VACUUM

Ling Dai, Fuchang Lin, Xiangyu Shi, Zhiwei Li, Cheng Su Huazhong University of Science and Technology , State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China

1P40 SPACER FLASHOVER CHARACTERISTICS IN SF6 UNDER REPETITIVE 56 NANOSECOND-PULSES

Huijuan Ran 1, Tao Wang 1, Jue Wang 1, Chengyan Ren 1, Ping Yan 1, Dongdong Zhang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Graduate University of Chinese Academy of Sciences Beijing, China, 3Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China 1P41 STUDY ON SURFACE FLASHOVER AND GAS DESORPTION OF SOLID 57 INSULATION MATERIALS IN VACUUM

Chengyan Ren1, Li Xiao1, Jue Wang1, Ping Yan1, Dongdong Zhang1, Yaohong Sun1, Tao Shao1, Tao Wang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China 1P42 EXPERIMENTAL STUDY OF NANOSECOND-PULSE DIELECTRIC BARRIER 58 DISCHARGE IN OPEN AIR

Tao Shao12, Cheng Zhang1, Yang Yu1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

xxi 1P43 STUDY ON THE DC SPACE CHARGE CHARACTERISTICS OF THE MULTI- 59 LAYER OIL-PAPER INSULATION MATERIAL USED IN POWER

TRANSFORMER Chao Tang College of Engineering and Technology, Southwest University, Chongqing, China 1P44 POLLUTION FLASHOVER PERFORMANCE OF INSULATORS WITH 60 SEMICONDUCTIVE SIR

Xiaoxing Wei, Zhidong Jia, Zhenting Sun, Zhicheng Guan Tsinghua University, Graduate School at Shenzhen, Shenzhen, China 1P45 FLASHOVER PERFORMANCE ALONE POLLUTED SURFACE OF 220KV GLASS 61 INSULATOR STRINGS COVERED WITH NON UNIFORM PRTV COATINGS

Chuyan Zhang1, Shuwei Wan1, Bao Feng2, Zhiyong Wang2, Liming Wang1, Zhicheng Guan1 1Tsinghua University, Graduate School at Shenzhen, Shenzhen, China, 2Guangdong Power Grid Company, China Southern Power Grid, Zhongshan Power Grid Corporation, Zhongshan, China 1P46 NANOSECOND-PULSE DIFFUSE DISCHARGE AT ATMOSPHERIC PRESSURE 62 Cheng Zhang1, Tao Shao12, Victor F. Tarasenko3, Hao Ma1, Dongdong Zhang1, Ping Yan1,

Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA, 3Institute of High Current Electronics, Russian Academy of Sciences Tomsk, Russia 1P47 RESEARCH ON SURFACE FLASHOVER PROPERTIES OF POLYMER 63 MODIFIED BY ION IMPLANTATION

Rong Xu1, Ping Yan1, Jue Wang1, Chengyan Ren1, Tao Shao1, Yaohong Sun1, Dongdong Zhang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drives, Beijing, China 1P48 THEORETICAL ANALYSIS OF TREEING PROCESS IN MICRO AND NANO 64 COMPOSITE INSULATORS

Kavitha Dhinesh1, Sindhu T Krishnan2, T N Padmanabhan Nambiar1 1Amrita Vishwa Vidyapeetham, Electrical and Electronics Engineering, Coimbatore, India, 2National Institute of Technology Calicut, Electrical Engineering, Kozhikode, India 1P49 PERFORMANCE IMPROVEMENT OF GAS INSULATED SUBSTATIONS BY 65 REDUCING THE CONTAMINATED METALLIC PARTICLE MOVEMENT

Parthasarathy P.1, Amarnath Jinka2, Singh B.P.3 1Guru Nanak Engineering College, Department of Electrical and Electronics Engineering, Hyderabad, India, 2JNTUH College of Engineering, Department of Electrical and Electronics Engineering, Hyderabad, India, 3St.Martin's Engineering College , Department of Electrical and Electronics Engineering, Hyderabad, India 1P50 IMAGE CHARGE EFFECT ON METALLIC PARTICLE MOVEMENT IN A 66 SINGLE PHASE GAS INSULATED BUSDUCT (GIB) WITH DIELECTRIC

COATED ENCLOSURE USING CHARGE SIMULATION METHOD Narapareddy Ramarao1, Jinka Amarnath2 1Nigama Engineering College, Department of Electrical and Electronics Engineering, KARIMNAGAR, India, 2JNTUH College of Engineering, Department of Electrical and Electronics Engineering, HYDERABAD, India

xxii 1P51 ESTIMATION OF LIFT OFF FIELD OFF AND MAXIMUM MOVEMENT 67 PATTERN OF METALLIC CONTAMINANTS IN A 600 KV THREE PHASE

COMMMON ENCLOSURE GAS INSULATED BUSDUCT USING MONTE-CARLO TECHNIQUE Padmavathi Devasetty1, Kamakshaiah Saprams2, Amarnath Jinka3, Mani Kuchibhatla4 1Vignana Bharathi Institute , EEE, Hydeabad, India, 2JNTUH, EEE, Hyderabad, India, 3JNTUH, EEE, Hyderabad, India, 4Vignana Bharathi Institute of Technology, EEE, Hyderabad, India 1P52 HIGH VOLTAGE POWER AMPLIFIER UTILIZING SERIES-CONNECTED 68 TRANSISTORS TO CONTROL THE OUTPUT

J.F. Tooker, P. Huynh P.O. Box 85608, General Atomics, San Diego, CA, USA 1P53 A CAPACITIVE LEVEL-SHIFTER FOR HIGH VOLTAGE (2.5KV) 69 Thomas Andersen, Michael A. E. Andersen, Ole C. Thomsen

Technical University of Denmark, Elektro, Lyngby, Denmark 1P54 BATTERY POWERED HIGH OUTPUT VOLTAGE BI-DIRECTIONAL FLYBACK 70 CONVERTER FOR LINEAR DEAP ACTUATOR

Lina Huang, Prasanth Thummala, Zhe Zhang, Michael Andersen Technical University of Denmark, Electrical Engineering, Kongens Lyngby, Denmark 1P55 ANALYSIS OF DIELECTRIC ELECTRO ACTIVE POLYMER ACTUATOR AND 71 ITS HIGH VOLTAGE DRIVING CIRCUITS

Prasanth Thummala, Lina Huang, Zhe Zhang, Michael Andersen Technical University of Denmark, Electrical Engineering, Kongens Lyngby, Denmark 1P56 COMPACT HIGH-VOLTAGE CAPACITOR CHARGER 72 SungRoc Jang1, HongJe Ryoo1, Gennadi Goussev1, SukHo Ahn2, SeungBok Ok2

1Korea Electrotechnology Research Institute , Electric Propulsion Research Center, Changwon, Korea, 2University of Science & Technology , Dept. of Energy Conversion Technology, Daejeon, Korea 1P57 DEVELOPMENT OF THE INVERTER HVPS FOR MODULATOR SYSTEM AT 73 PAL-XFEL

Soung-soo Park, Sang-hee Kim, Sei-jin Kwan, Byeong-jun Lee, Yong-jo Moon, Heung-su Lee, Heung-sik Kang, Jung-yun Hwang Pohang Accelerator Laboratory, Accelerator, Pohang, Korea 1P58 NEW 13-SPACE VECTOR DIAGRAM FOR THE THREE-PHASE SIX-SWITCHES 74 VOLTAGE SOURCE INVERTER

Mohamed Saied Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt 1P59 AN ADJUSTABLE HVDC POWER SUPPLY USING INTEGRATED HIGH 75 VOLTAGE TRANSFORMER WITH SOME PROTECTIVE & CONTROLLING

FEATURES. Muhammad Muktadir Rahman American Intl. University- Bangladesh, Electrical and Electronic Engineering, DHAKA, Bangladesh 1P60 A REPETITIVE MICROSECOND-PULSE GENERATOR FOR PLASMA JET 76 APPLICATION

Wenfeng Li1, Tao Shao12, Weiming Huang1, Cheng Zhang1, Dongdong Zhang1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

xxiii 1P61 HIGH-FREQUENCY HIGH-VOLTAGE DC POWER SUPPLY BASED ON 77 PARALLEL RESONANT TECHNOLOGY AND PHASE SHIFTED CONTROL

Kun Liu1, Yinghui Gao1, Ping Yan2, Dongdong Zhang1, Yaohong Sun1 1Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China, 2Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing, China 1P62 AN EFFICIENT ALL SOLID-STATE NANOSECOND PULSED GENERATOR FOR 78 PULSED DISCHARGES

Junfeng Rao, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources, Shanghai, China 1P63 RESEARCH ON THE RELIABLE THERMAL DESIGN OF HIGH FREQUENCY 79 HIGH VOLTAGE CHARGING POWER SUPPLY

Xiaoxia Shi1, Yinghui Gao1, Dongdong Zhang1, Yaohong Sun1, Ping Yan1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China 1P64 DC POWER SOURCE OF ONLINE MONITORING EQUIPMENTS FOR 80 OVERHEAD CONDUCTORS

Ji Yang Chongqing Electrical Power Company, Dianjiang Branch, Chongqing, China 1P65 R&D OF 14KV/25A DC HIGH VOLTAGE POWER SUPPLY FOR TETRODE 81 AMPLIFIER

Wei Wang Nanjing Institute of Electronic Technology, Nanjing, China 1P66 OUTPUT FAULT PROTECTION AND INTERMEDIATE OVERLOAD DIAGNOSIS 82 IN A "REGULATED HIGH VOLTAGE POWER SUPPLY" (80 KV, 130A)

Paresh Patel1, Sumod C. B.1, D. P. Thakkar1, L. N. Gupta1, V. B. Patel1, L. K. Bansal1, K. Qureshi1, V. Vadher1, N. P. Singh2, U .K. Barua1 1Institute for Plasma Research, Neutral Beam Injector Group, SST-1, Gandhinagar, India, 2ITER-India, Power Supply Group, ITER, India, Gandhinagar, India 1P67 REDUCED COMMON MODE VOLTAGE IN DIRECT TORQUE CONTROLLED 83 INDUCTION MOTOR DRIVES USING NEAR STATE PWM TECHNIQUE

Vuyyuru Anantha Lakshmi1, T. Bramhananda Reddy1, Munagala Surya Kalavathi2, VC Veera Reddy3 1G.Pulla Reddy Engineering College, E.E.E , Kurnool, India, 2J.N.T.U College of Engineering, E.E.E , Hyderabad, India, 3S.V.U College of Engineering, E.E.E , Tirupathi, India 1P68 A NOVEL HYBRID PWM ALGORITHM FOR REDUCED COMMON MODE 84 VOLTAGE IN DIRECT TORQUE CONTROLLED INDUCTION MOTOR DRIVES

Vuyyuru Anantha Lakshmi1, T. Bramhananda Reddy1, Munagala Surya Kalavathi2, VC Veera Reddy3 1G.Pulla Reddy Engineering College, E.E.E, Kurnool, India, 2J.N.T.U College Of Engineering, E.E.E, Kurnool, India, 3S.V.U College Of Engineering, E.E.E, Kurnool, India 1P69 IMPLEMENTATION OF DIRECT TORQUE CONTROL OF INDUCTION MOTOR 85 WITH SPACE VECTOR MODULATION

Sushama Malaji JNTU Hyderabad, Electrical & Electronics Engineering, Hyderabad, India

xxiv 1P70 REDUCTION OF COMPUTATIONAL COMPLEXITY IN "EKF" FOR 86 SENSORLESS INDUCTION MOTOR DRIVE

Kamal Basha1, B.Ravindhra Nath Reddy2, Suryakalavathi Muganal3 1MITS, EEE, Madanapalle, India, 2JNTUH, EE, Hyderabad, India, 3JNTUH, Electrical, Hyderabad, India 1P71 PERFORMANCE EVALUATION OF CLASSICAL AND FUZZY LOGIC 87 CONTROL TECHNIQUES FOR BRUSHLESS DC MOTOR DRIVE

M. Surya Kalavathi1, C. Subba Rami Reddy2 1JNTU Hyderabad, Electrical and Electronics Engineering, Hyderabad, India, 2K.S.R.M College of Engineering, Electrical and Electronics Engineering, Kadapa, India 1P72 FAULT DIAGNOSIS AND TESTING OF INDUCTION MACHINE USING 88 BACK PROPAGATION NEURAL NETWORK Rajeswaran Nagalingam1, Madhu Tenneti2, Suryakalavathi Munagala3 1SNS College of Technology, ECE, Coimbatore, India, 2Swarnandhra Institute of Engineering and Technology, PRINCIPAL, Narasapur, India, 3Jawaharlal Nehru Technological University, EEE, Hyderabad, India

Oral Session 3: Solid State Modulators, Components and Switches 2, Power Electronics and Power Supplies Session Chair: Werner Hartmann, Siemens AG

3O1 PERFORMANCE AND OPTIMIZATION OF A 30 KV SILICON CARBIDE 89 PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH FOR PULSED POWER APPLICATIONS Cameron Hettler, William Sullivan III, James Dickens, Andreas Neuber Texas Tech University, Department of Electrical and Computer Engineering, Lubbock, TX, USA

3O2 REDUCING TURN-ON DISSIPATION OF RSD FROM APPLICATION 90 Lin Liang, Quan Wei, Wu Hong, Xueqing Liu, Yuehui Yu Huazhong University of Science & Technology, Department of Electronic Science & Technology, Wuhan, China 3O3 ENHANCED VOLTAGE RECOVERY OF HIGH VOLTAGE SEMICONDUCTOR 91 SWITCHES J. R. Cooper1, E. Loree2, T. Konopelski3, M. Hope3, R. D. Curry4 1Cooper Consulting Services, Inc. San Diego, CA, USA, 2Loree Engineering Albuquerque, NM, USA, 3M7 Electro-optics St. Louis, MO, USA, 4The University of Missouri Columbia, MO, USA 3O4 THE EFFECTS OF SUB-CONTACT NITROGEN DOPING ON SILICON CARBIDE 92 PHOTOCONDUCTIVE SEMICONDUCTOR SWITCHES W. W. Sullivan III, C. Hettler, J. Dickens Texas Tech University, Electrical and Computer Engineering, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA 3O5 PULSE-TO-PULSE VOLTAGE REPRODUCIBILITY EFFICIENT PREDICTION 93 METHOD FOR HIGH PRECISION KLYSTRON MODULATOR DESIGN Rudi Soares, Davide Aguglia CERN - European Organization for Nuclear Research, Technology Dept., Geneva, Switzerland

xxv 3O6 DESIGN OF AN 80KV, 40A RESONANT SWITCHMODE POWER CONVERTER 94 FOR PULSED POWER APPLICATIONS Paul Nonn, Andrew Seltzman, Jay Anderson University of Wisconsin, Physics, Madison, WI, USA 3O7 DESIGN OF A COMPACT, BATTERY-POWERED REP-RATE CHARGER FOR A 95 88-KJ CAPACITOR BANK FOR EML APPLICATIONS Brett Huhman, Jesse Neri US Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA 3O8 REGULATED HIGH VOLTAGE POWER SOURCES UTILISED FOR FAST 96 DYNAMIC LOADS LIKE NEUTRAL BEAMS, RF HEATING SYSTEMS AND FAST ACCELERATORS Paresh Patel1, Sumod C.B.1, D.P. Thakkar1, L.N. Gupta1, V.B. Patel1, L.K. Bansal1, K. Qureshi1, V. Vadher1, N.P. Singh2, U.K. Barua1 1Institute for Plasma Research, Power Supplies and DAC division, Neutral Beam Injector Group, Gandhinagar, India, 2ITER, India, Power Supply Group, Gandhinagar, India

Oral Session 4: Biological, Medical, and Environmental Applications Session Chair: Allen Garner, General Electric 4O1,2 COMPARISON BETWEEN MONOPOLAR AND BIPOLAR µs RANGE PULSED 97 (invited) ELECTRIC FIELDS IN ENHANCEMENT OF APPLE JUICE EXTRACTION Paula S. Brito1, Hiren Canacsinh1, João Mendes1, Luís M. Redondo1, Marcos T. Pereira2 1Instituto Superior de Engenharia de Lisboa, ADESPA, Lisbon, Portugal, 2Lusoforma, Industria e comercio d embalagens Mem Martins, Portugal 4O3 HIGH VOLTAGE PULSE GENERATOR BASED ON TPI-THYRATRONS FOR 98 PULSED ELECTRIC FIELD MILK PROCESSING Victor Bochkov1, Dmitry Bochkov1, Igor Gnedin1, Yaroslav Makeev1, Gleb Vasiliev2, Sergey Zhdanok2 1Pulsed Technologies Ltd. Ryazan, Russia, 2A.V. Luikov Heat & Mass Transfer Institute National Academy of Sciences of Belarus Minsk, Belarus 4O4 CHARACTERISTICS OF CAVITATION BUBBLES AND SHOCK WAVES 99 GENERATED BY PULSED ELECTRIC DISCHARGES WITH DIFFERENT VOLTAGE AMPLITUDES Daiki Oshita1, S.H.R Hosseini2, Yuta Okuda1, Yuta Miyamoto1, Hidenori Akiyama1,2 1Kumamoto Univercity, Graduate school of science and technology, Kumamoto, Japan, 2Kumamoto Univercuty, Bioelectrics research center, Kumamoto, Japan 4O5 PULSED ELECTRIC FIELD INDUCED DIELECTRIC EVOLUTION OF 100 MAMMALIAN CELLS Jie Zhuang1,2, Yu Jing1, Juergen F. Kolb2 1Frank Reidy Research Center for Bioelectrics, Old Dominion University Norfolk, VA, USA, 2Leibniz Institute for Plasma Science and Technology Greifswald, Germany 4O6 INVESTIGATING THE ROLE OF PULSE REPETITION RATE IN MODULATING 101 CELLULAR RESPONSE TO HIGH VOLTAGE, NANOSECOND ELECTRIC PULSES Stefania Romeo1, Luigi Zeni1, Anna Sannino2, Maria Rosaria Scarfì2, P. Thomas Vernier3, Olga Zeni2 1Second University of Naples, Department of Information Engineering, Aversa, Italy, 2National Research Council, Institute for Electromagnetic Sensing of Environment - IREA, Napoli, Italy, 3University of Southern Californiano, Ming Hsieh Department of Electrical Engineering, Los Angeles, CA, USA

xxvi 4O7 NON-THERMAL AND TRANSIENT THERL EFFECT OF PULSED ELECTRIC 102 FIELDS ON HELA CELLS Kazunori Mitsutake1, Shinya Moriyama1, Yumi Kishita1, Sunao Katsuki2, Hidenori Akiyama1, Tsuyoshi Shuto3, Hirofumi Kai3 1Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan, 2Kumamoto University, Bioelectrics Research Center, Kumamoto, Japan, 3Kumamoto University, Faculty of Life Science,, Kumamoto, Japan 4O8 ANALYSIS OF CORONA DISCHARGES IN CYLINDRICAL TOPOLOGY AND 103 PARTICLE CHARGING MECHANISMS FOR OPTIMISATION OF PRECIPITATION EFFICIENCY Igor Timoshkin, Athanasios Mermigkas, Martin Given, Tao Wang, Mark Wilson, Scott MacGregor University of Strathclyde, EEE, Glasgow, United Kingdom

Plenary 2 Session Chair: Craig Burkhart, SLAC National Accelerator Laboratory PL2 THE EVOLUTION OF PULSED MODULATORS FROM THE MARX 105 GENERATOR TO THE SOLID STATE MARX MODULATOR AND BEYOND Richard Cassel Stangenes Industries Inc.

Oral Session 5: Plasma Opening and Closing Switches, Lasers and other Radiation Sources Session Chair: Chunqi Jiang, University of Southern California 5O1,2 DESIGN AND PERFORMANCE OF A HIGH-PRESSURE, FLOWING LIQUID 106 (Invited) DIELECTRIC PEAKING SWITCH Rainer Bischoff French-German Research Institute of Saint-Louis (ISL) Saint-Louis, France 5O3 TRIGGERED OPERATION OF A CORONA CONTROLLED CASCADE SWITCH 107 AT ELEVATED PRESSURES Martin J Given1, Long Li1, Mark P Wilson1, Igor V Timoshkin1, Tao Wang1, Scott J Macgregor1, Jane M Lehr2 1Strathclyde University, Electronic and Electrical Eng, Glasgow, United Kingdom, 2Sandia National Laboratories Albuquerque, NM, USA 5O4 LOW JITTER, HIGH VOLTAGE, REPETITIVE LASER TRIGGERED GAS 108 SWITCHES Frank Hegeler2, Matthew C. Myers1, Matthew F. Wolford1, John D. Sethian1, Andrew M. Fielding2, John L. Giuliani1 1Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2Commonwealth Technology, Inc. Alexandria, VA, USA 5O5 DISCUSSION OF BREAKDOWN MECHANISM IN TRIGATRON SPARK GAP 109 Li Cai, Fuchang Lin, Lee Li, Xiangdong Qi, Chaobing Bao HuaZhong University of Science and Technology (HUST), State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China 5O6 PERFORMANCE OF A CORONA-STABILISED SWITCH ACTIVATED BY FAST- 110 RISING TRIGGER PULSES Mark Wilson1, Igor Timoshkin1, Martin Given1, Scott MacGregor1, Tao Wang1, Jane Lehr2 1University of Strathclyde, Electronic & Electrical Engineering, Glasgow, United Kingdom, 2Sandia National Laboratories, Exploratory Pulsed Power, Albuquerque, NM, USA

xxvii 5O7 EFFECT OF CURRENT PULSE WIDTH ON THE XENON Z-PINCH DISCHARGE 111 PLASMA FOR EXTREME ULTRAVIOLET SOURCE Peng Lu, Tetsuya Watanabe, Sunao Katsuki, Takashi Sakugawa, Hidenori Akiyama Kumamoto university, Graduate School of Science and Technology, Kumamoto, Japan 5O8 X-RAY EMISSION FROM A TABLE-TOP X-PINCH DEVICE 112 Ran Zhang, Xinlei Zhu, Shen Zhao, Haiyun Luo, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing, China

Oral Session 6: High Voltage Testing and Diagnostics Session Chair: Dan Schweickart, US Air Force Wright Patterson 6O1 EXPERIMENTAL IMPULSE RESPONSE OF GROUNDING SYSTEMS 113 Malone Castro, Euler Macedo, Edson Costa, Raimundo Freire, Maria Rodrigues, Luana Gomes Campina Grande Federal University , Electrical Engineering, Campina Grande, Brazil 6O2 THE EFFECTS OF TEMPERATURE, MOISTURE, TESTING VOLTAGE AND 114 TIME DURATION ON DIELECTRIC RESPONSE OF TRANSFORMER INSULATION OIL Maziar Shareghi, Toan Phung, Mohammad Salay Naderi, Trevor Blackburn The University of New South Wales, School of Electrical Engineering and Telecommunications, Sydney, Australia 6O3 A LASER DIAGNOSTIC FOR DETECTING INTERNAL ELECTRIC FIELD AND 115 MECHANICAL STRAIN IN A RESONANT PIEZOELECTRIC TRANSFORMER Peter Norgard1, Scott Kovaleski1, Greg Dale2 1University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA, 2Los Alamos National Laboratory Los Alamos, NM, USA 6O4 THE EVOLUTION OF IEC 60034-18-41 FROM TECHNICAL SPECIFICATION TO 116 STANDARD: PERSPECTIVES FOR MANUFACTURERS AND END USERS Gian Carlo Montanari1, Andrea Cavallini1, Luca Fornasari2 1University of Bologna, DEI, Bologna, Italy, 2Techimp HQ Spa, R&D, Zola Predosa, Italy 6O5 RADIOMETRIC LOCATION OF ELECTRICAL DISCHARGE ACTIVITY 117 Martin Judd1, Rachel Harris1, Alistair Reid2 1University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, United Kingdom, 2Glasgow Caledonian University, School of Engineering and Built Environment, Glasgow, United Kingdom 6O6 A FILTER BANK APPROACH FOR EXTRACTING FEATURES FOR THE 118 CLASSIFICATION OF PARTIAL DISCHARGE SIGNALS IN HIGH VOLTAGE XLPE CABLES R. Ambikairajah, B. T. Phung, J. Ravishankar, T. R. Blackburn University of New South Wales, School of Electrical Engineering & Telecommunications, Sydney, Australia 6O7 GENERATION, MEASUREMENT AND APPARENT CHARGE ESTIMATION OF 119 PARTIAL DISCHARGE SIGNALS Diego Araújo1, Euler Macêdo1, Edson Costa1, Raimundo Freire1, José Maurício Neto1, Waslon Lopes1, Warner Barros1, Ian Glover2 1Federal University of Campina Grande, Electrical Engineering and Informatic Center, Campina Grande, Brazil, 2University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, Scotland

xxviii 6O8 APPLICATION HILBERT-HUANG TRANSFORM ON PARTIAL DISCHARGE 120 PATTERN RECOGNITION OF GAS-INSULATED SWITCHGEAR Hong-Chan Chang1, Feng-Chang Gu1, Cheng-Chien Kuo2 1National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan, 2Saint John's University, Electrical Engineering, Taipei, Taiwan

Poster Session 2: Biological, Medical, and Environmental Applications, Plasma Opening and Closing Switches, Lasers and Other Radiation Sources, High Voltage Testing and Design, Compact Pulsed Power, and Power Conditioning and Pulse Shaping Session Chair: Hao Chen, Cymer Inc. 2P1 OZONE PRODUCTION BY BARRIER DISCHARGE TYPE CONCENTRIC 121 CYLINDER ELECTRODE USING PULSED DISCHARGE

Fumiaki Fukawa, Yuuya Satoh, Kotaro Rokkaku, Susumu Suzuki, Haruo Itoh Chiba Institute of Technology, Electrical, Electronics and Computer Engineering, Narashino, Japan 2P2 INVESTIGATION OF NON-HEATING STERILIZATION METHOD OF PACKED 122 FRESH FOODS BY PULSED ELECTRIC FIELD

Takato Higuchi, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan Yonezawa, Yamagata 992-8510, Japan 2P3 INVESTIGATION OF QUANTITY OF ACTIVE SPECIES GENERATED BY 123 PULSED STREAMER DISCHARGES IN THE AREA WITH DROPLETS FOR

WATER TREATMENT Takashi Saito, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan 2P4 SPECTROSCOPIC OBSERVATION OF MICRO PLASMA JETS GENERATED BY 124 PULSED POWER

Makoto Inokuchi, Takashi Sakugawa, Hidenori Akiyama Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan 2P5 BURST ELECTROMAGNETIC WAVE FOCUSING SYSTEM FOR MEDICAL 125 APPLICATION

Hidetoshi Ishizawa, Masanori Hashimoto, Takashi Tanabe, Hammid Hosseini, Sunao Katsuki, Hidenori Akiyama Kumamoto University, Guraduate School of Science and Technology, Kumamoto, Japan 2P6 INVESTIGATION OF OZONE PRODUCTION USING NANOSECOND PULSED 126 POWER FOR DENSE OZONE

Ryo Mabuchi, Tatsuya Kageyama, Kenji Teranishi, Naoyuki Shimomura The University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima, Japan 2P7 DECOMPOSITION OF HUMATE USING PULSED DISCHARGE IN BUBBLES 127 Yuuya Satoh, Fumiaki Fukawa, Kotaro Rokkaku, Susumu Suzuki, Haruo Itoh

Chiba Institute of Technology, Electrical, Electronics and Computer Engineering, Narashino, Japan 2P8 DEVELOPMENT OF TECHNIQUES APPLYING NANOSECOND PULSE 128 ELECTRIC FIELDS ON SOLID TUMOR

Naoyuki Shimomura, Yoshihiro Magori, Masataka Nagahama, Kenji Teranishi, Yoshihiro Uto, Hitoshi Hori The University of Tokushima, Institute of Technology and Science, Tokushima, Japan

xxix 2P9 APPLICATION TO WATER TREATMENT OF PULSED HIGH-VOLTAGE 129 GENERATOR USING SEMICONDUCTOR OPENING SWITCH

Taichi Sugai1, Akira Tokuchi1, Weihua Jiang1, Yasushi Minamitani2 1Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan, 2Yamagata University, Department of Electrical Engineering, Yonezawa, Japan 2P10 PORE DYNAMICS INDUCED BY nsPEF: A COMPARISON BEETWEEN 130 EXPERIMENTAL AND THEORETICAL RESULTS

Patrizia Lamberti1, Stefania Romeo3, Maria Rosaria Scarfì2, Vincenzo Tucci1, Olga Zeni2 1University of Salerno, Dept. of Electronic and Computer Engineering, Fisciano (SA), Italy, 2CNR, Institute for Electromagnetic Sensing of Environment (IREA), Napoli, Italy, 3Second University of Naples, Dept. of Information Engineering, Aversa (CE), Italy 2P11 NON-INVASIVE PULSED ELECTRIC FIELD FOOD PROCESSING: PROOF- 131 OF0PRONCIPLE EXPERIMENTS

Bucur Novac1, Fahd Banakhr1, Ivor Smith1, Laurent Pecastaing2, Robert Ruscassie2, Antoine de Feron2, Pascal Pignolet2 1Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom, 2University de Pau, SIAME, Equipe Genie Electrique, Heliopare Pau, France 2P12 HIGH BLOOD SUGAR CONCENTRATION RESPONSE TO 850 MHz 132 ELECTROMAGNETIC RADIATION USING GTEM CELLS

Nattaphong Boriraksantikul1, Naz Islam1, Kiran Bhattacharyya2, John Viator2, Phumin Kirawanich3 1University of Missouri-Columbia, Department of Electrical and Computer Engineering, Columbia, MO, USA, 2University of Missouri-Columbia, Department of Biological Engineering, Columbia, MO, USA, 3Mahidol University, Department of Electrical Engineering, Nakhon Pathom, Thailand 2P13 COMPACT PULSER POWER FOR PLATELET AGGREGATION AND GROWTH 133 FACTOR RELEASE

Yeong-Jer Chen, Barbara Hargrave, Shu Xiao, Karl Schoenbach Old Dominion University, Bioelectrics, Norfolk, VA, USA 2P14 MODELING OF DELIVERY OF SUBNANOSECOND ELECTRIC PULSES INTO 134 BIOLOGICAL TISSUES

Shu Xiao12, Fei Guo1, Fei Li2, Jiang Li2, Gene Hou3 1Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, USA, 2Old Dominion University, Department of Electrical and Computer Engineering, Norfolk, VA, USA, 3Old Dominion University, Department of Mechanical and Aerospace Engineering, Norfolk, VA, USA 2P15 CONCRETE SURFACE SCRAPING WITH HIGH VOLTAGE PULSED POWER 135 GENERATOR

Alexander Nashilevskiy1, Gennady Kanaev2, Vladimir Kukhta3, Vladimir Lopatin1, Gennady Remnev1, Kensuke Uemura3, Ivan Egorov1 1National Research Tomsk Polytechnic University, Institute of High-Technology Physics, Tomsk, Russia, 2National Research Tomsk Polytechnic University, Institute of Physics and Technology, Tomsk, Russia, 3Nagata Seiki Co., Ltd. Niigata,Tsubame , Japan 2P16 STUDY OF THE EFFICIENCY OF A PULSED ELECTRIC FIELD SYSTEM FOR 136 LIQUID STERILIZATION: A STATISTICAL APPROACH

Eduardo Araujo, Ivan Lopes Federal University of Minas Gerais , Electrical Engineering , Belo Horizonte, Brazil

xxx 2P17 EXPERIMENTAL STUDY ON CHARGES TRANSPORTATION IN 137 NANOSECOND-PULSED SURFACE DIELECTRIC BARRIER DISCHARGE

Hui Jiang1, Tao Shao12, Cheng Zhang1, Wenfeng Li1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA 2P18 HYDROPHOBIC IMPROVEMENT OF PMMA SURFACE TREATED BY A 138 NANOSECOND-PULSE PLASMA JET

Zheng Niu1, Cheng Zhang1, Tao Shao12, Jiayu Xu1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA 2P19 A NOVEL METHOD TO CALCULATE THE SHOCK WAVE PROPAGATION AND 139 OPTIMIZATION OF PRESSURE RELIEF IN SF CIRCUIT BREAKERS 6 Mahdi Khanali1, Kaveh Niayesh2 1University of Waterloo, ECE, Waterloo, ON, Canada, 2University of Tehran, ECE, Tehran, Iran 2P20 A HIGH CURRENT LOW INDUCTANCE MULTI-GAP MULTI-CHANNEL 140 SWITCH FOR MICROSECOND LINEAR TRANSFORMER DRIVER, WORKING

UNDER ATMOSPHERIC DRY AIR INSULATION AT 80KV, 250KA LEVEL Francis Lassalle, Bernard Roques, Arnaud Loyen, Alain Morell CEA DAM GRAMAT, F-46500, Gramat, France 2P21 DEVELOPMENT OF A HIGH CURRENT GAS-SWITCH FOR THE MAGNETIC 141 HORN OF THE FAIR P-BAR-EXPERIMENT

Christian Hock, Marcus Iberler, Joachim Jacoby, Gregor Loisch, Andreas Schönlein, Jörg Wiechula Goethe University , Institute of Applied Science, Frankfurt, Germany 2P22 RESEARCH AND DEVELOPMENT OF DRIVERS FOR PSEUDOSPARK 142 SWITCHES

Victor Bochkov1, Dmitry Bochkov1, Yaroslav Makeev1, Piotr Bak2, Alexey Panov2, Chris Pihl 3, Sam Andreason3 1Pulsed Technologies Ltd. Ryazan, Russia, 2Budker Institute of Nuclear Physics Novosibirsk, Russia, 3Pulse Power Solutions LLP Mill Creek, WA, USA 2P23 POWER TRIGGERED VACUUM SWITCH FOR 50 HZ NETWORKS 143 Vladimir Sidorov, Dmitriy Alferov, Roman Bunin, Dmitriy Evsin, Valeriy Ivanov

Russian Electrotechnical Institute Moscow, Russia 2P24 PARALLEL OPERATION OF FOUR SPARK GAPS IN A PULSER SYSTEM 144 Hasibur Rahaman1, Byung-Joon Lee1, Jong Woo Nam1, Sang Hoon Nam1, Jae Woon Ahn2,

Seung Whan Jo2, Hae Ok Kwon2 1POSTECH, Pohang Accelerator Laboratory, Pohang, South Korea, 2Hanwha Corporation, R & D Department, Gumi, South Korea 2P25 CRITICAL CIRCUIT PARAMETERS IN PRODUCING A TOROIDAL AIR 145 PLASMA

Adam Lodes1, Randy Curry1, W. Brown2, M. Schmidt2 1University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA, 2Applied Research Associates Arlington, VA, USA 2P26 SELECTIVELY GROWN CARBON NANOTUBES(CNTs): CHARACTERIZATION 146 AND FIELD EMISSION PROPERTIES

Chung-Nan Tsai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

xxxi 2P27 NONLINEAR FOWLER-NORDHEIM PLOTS OF CARBON NANOTUBES UNDER 147 VACUUM AND PARTIAL PRESSURES

Rujun Bai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA 2P28 AN ATMOSPHERIC PRESSURE GAS SWITCH TRIGGERED BY ARRAY 148 MICROHOLLOW CATHODE DISCHARGE

Yaqing Teng, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources,, Shanghai, China 2P29 EXPERIMENTAL RESEARCH OF HIGH STABILITY GAS DISCHARGING 149 SWITCH

Xueling Yao, Jingliang Chen, Yingbiao Shao Xi'an Jiaotong University, Electrical Engineering, Xi'an, China 2P30 EXPERIMENTAL RESEARCH OF ROD-SHAPED GAS DISCHARGING SWITCH 150 Xueling Yao, Jingliang Chen, Yuxi Wang

Xi'an Jiaotong University, Electrical Engineering, Xi'an, China 2P31 DEVELOPMENT OF A COLLIDING PLASMA EXPERIMENT AS AN UV/VUV 151 RADIATION SOURCE

Andreas Schönlein, Christian Hock, Marcus Iberler, Joachim Jacoby, Johanna Otto, Tim Rienecker, Christian Teske, Sero Zaehter Goethe University, Institute of Applied Physics, Frankfurt, Germany 2P32 X-RAY BACKLIGHTING OF SINGLE-WIRE AND MULTI-WIRE Z-PINCH 152 Xinlei Zhu, Ran Zhang, Haiyun Luo, Shen ,Zhao, Xiaobing Zou, Xinxin Wang

Tsinghua University, Department of Electrical Engineering, Beijing, China 2P33 TIMING OF THE X-RAY BURST FROM PARALLELED X-PINCHES 153 Shen Zhao, Haiyun Luo, Xinlei Zhu, Ran Zhang, Xiaobing Zou, Xinxin Wang

Tsinghua University, Department of Electrical Engineering, Beijing, China 2P34 EVALUATION OF TAPE-BASED STRESS GRADING COATINGS BY INFRARED 154 THERMOGRAPHY

Fermin P. Espino-Cortes, Tomas I. Asiain Olivares, Pablo Gomez Instituto Politecnico Nacional, SEPI ESIME Electrical Department , Mexico City, Mexico 2P35 DETECTION AND LOCATION OF ARCING FAULTS IN DISTRIBUTION 155 NETWORKS USING A NON-CONTACT APPROACH

Rachel Harris1, Philip Moore2, Martin Judd1 1University of Strathclyde, High Voltage Technologies Research Group, Glasgow, United Kingdom, 2Elimpus Ltd Bellshill, United Kingdom 2P36 ASSESSMENT OF DIELECTRIC DEGRADATION BY MEASUREMENT, 156 PROCESSING AND CLASSIFICATION OF PARTIAL DISCHARGES

Euler C. T. Macedo1, Juan M. Villanueva2, Diego B. Araujo2, Edson G. da Costa2, Raimundo C. S. Freire2, José M. R. de Souza Neto2, Ian A. Glover3 1Para´ıba Federal University, Alternative and Renewable Energy Center, João Pessoa, Brazil, 2Campina Grande Federal University , Electrical Engineering and Informatics Center, Campina Grande, Brazil, 3University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, Scotland

xxxii 2P37 ITAIPU´S EXPERIENCE IN THE ACCEPTANCE TESTS FACTORY CARRIED 157 OUT ON HIGH VOLTAGE ELECTRICAL EQUIPMENTS (EMPHASIS ON

TRANSFORMERS AND BUSHINGS): RELEVANT FACTS OCCURRED DURING VFT - VERY FAST TRANSIENT TEST, PARTIAL DISCHARGES MEASUREMENT, DISPLACEMENT/DEFORMATION CORE OF POWER TRANSFORMER AND GENERAL CONDITIONS OF HIGH VOLTAGE LABORATORIES Cláudio Morais1, Domingues Gonzalez2, Juliano Silva3, Luiz Pisa3 1Itaipu Binacional, Inspection, Foz do Iguaçu, Brazil, 2Itaipu Binacional, Engineering, Ciudad del Este, Paraguay, 3Itaipu Binacional, Engineering, Foz do Iguaçu, Brazil 2P38 PERFORMANCE EVALUATION OF A NEW SYSTEM GROUNDING 158 Maria Alice Rodrigues, Edson Costa, Malone Castro

Federal University of Campina Grande (PB-Brazil), Electrical Engineering Department, Campina Grande, Brazil 2P39 A STUDY ON RELIABILITY BASED ASSESSMENT ALGORITHM FOR HIGH 159 VOLTAGE INDUCTION MOTOR STATOR WINDINGS

Chang Jeong-Ho1, Lee Heung-Ho2 1Korea Water Resources Coraporation, Green Technology Research Center, Daejeon, Korea, 2Chungnam National University, Electrical Engineering, Daejeon, Korea 2P40 DETERMINING ECONOMIC LIFE CYCLE FOR POWER TRANSFORMER 160 BASED ON LIFE CYCLE COST ANALYSIS

Sun Hun Lee1, An Kyu Lee1, Jin O Kim2 1Korea Water Resources Corporation, K-Water Institute, Deajeon, Korea, 2Hanyang University, Dept. of Electrical Engineering, Seoul, Korea 2P41 REAL-TIME INSULATION STATUS ASSESSMENT OF UNDERGROUND CABLE 161 JOINTS BASED ON STANDARD DEVIATION

RuayNan Wu, ChienKuo Chang National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan 2P42 DETERIORATION TREND ON ELECTRICAL TREEING OF UNDERGROUND 162 CABLE INSULATION

RuayNan Wu, ChienKuo Chang National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan 2P43 RESEARCH OF NANOSECOND PULSE RESISTIVE DIVIDER 163 Jingliang Chen, Xueling Yao, Shaolin He, Tianyu Lin

1Xi'an Jiaotong University, Electrical Engineering, Xi'an, China 2P44 RESEARCH ON ROGOWSKI COIL FOR MEASURING 10/350ΜS PULSE 164 CURRENT

Jingliang Chen1, Xueling Yao1, Antong Chen2, Xiaoqing Xu1 1State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Electrical Engineering, Xi'an, China, 2Vanderbilt University, Electrical Engineering and Computer Science, Nashville, TN, USA 2P45 RESEARCH OF TRANSFORMER CONDITION ASSESSMENT SYSTEM BASED 165 ON RISK EVALUATION

Lu Guo-jun, Li Gang, Qin Yu, Huang Yan-guang Guangzhou Power Supply Bureau, Tests and Research Institute, Guangzhou, China

xxxiii 2P46 MEASUREMENT AND ANALYSIS OF INSULATION RESISTANCE OF 166 METALIZED POLYPROPYLENE FILM CAPACITOR UNDER HIGH ELECTRIC

FIELD Hua Li, Zhiwei Li, Fuchang Lin, Yaohong Chen, De Liu Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China 2P47 A STUDY OF OVER-VOLTAGE MONITORING DEVICE BASED ON COUPLING 167 CAPACITANCE SENSORS

Qi Wang1, Chen-guo Yao1, Yan Mi1, Jian Wang2 1Chongqing University, State Key Laboratory of Transmission & Distribution Equipment and Power System Safety and New Technology, Chongqing, China, 2State Gird Corporation of China, EHV Transmission &Substation Company, Chengdu, China 2P48 THE LIGHTNING PROTECTION TESTS FOR THE RADOME IN Z11 168 HELICOPTER OF CHINA Duan Zemin Hefei Hangtai Electrophysics Co.,Lt Hefei, China 2P49 PROTECTION OF 132 KV TRANSFORMER AGAINST LIGHTNING BY 169 EFFECTIVE PLACEMENT OF SURGE ARRESTER

Radhika Goru1, Suryakalavathi Mungala2 1Vnr Vjiet, Eee, Hyderabad, IN, India, 2Jntuh, Eee, Hyderabad, IN, India

2P50 A COMPACT LOW INDUCTANCE PULSE ENERGY DRIVER SYSTEM FOR 170 PULSE POWER APPLICATIONS

Kum Sang Low1, Albert Ng1, Chee Hoong Low1, Chin Yang Chia1, Kum Wan Low1, David Mahadevan1 1Specscan Sdn. Bhd. Petaling Jaya, Malaysia, 2University of Malaya, Department of Physics, Kuala Lumpur, Malaysia 2P51 GENERATORS OF HIGH-POWER HIGH-FREQUENCY PULSES BASED ON 171 SEALED-OFF DISCHARGE CHAMBERS WITH HOLLOW CATHODE

Victor Bochkov1, Vladmir Ushich1, Alexander Dubinov2, Inna Kornilova2, Igor L'vov2, Sergey Sadovoy2, Victor Selemir2, Dmitry Vyalykh2, Victor Zhdanov2 1Pulsed Technologies Ltd. Ryazan, Russia, 2Russian Federal Nuclear Center – All-Russian Research Institute for Experimental Physics Sarov, Russia 2P52 SOLID-STATE PULSED POWER SYSTEM FOR GAS TREATMENT 172 APPLICATIONS

Seung-Bok Ok1, Hong-Je Ryoo2, Sung-Roc Jang2, Gennadi Goussev2 1University of Science and Technology, Energy Conversion Technology, Daejeon, South Korea, 2Korea Electrotechnology Research Institute, Electric Propulsion Research Center, Changwon, South Korea 2P53 COMPACT HV HIGH POWER CAPACITOR CHARGER 173 Willy Debache, Michael Teboul

TECHNIX, Development, CRETEIL, France 2P54 COMPACT 600 KV MULTI-PRIMARY WINDINGS RESONANT TRANSFORMER 174 TO DRIVE AN ELECTROMAGNETIC SOURCE

Romain Pecquois1, Laurent Pécastaing1, Marc Rivaletto1, Antoine de Ferron1, Jean-Marc Duband2, Laurent Caramelle2, René Vézinet3 1Université de Pau, SIAME EGE, Pau, France, 2HI PULSE Pont de Pany, France, 3DAM, CEA GRAMAT, Gramat, France

xxxiv 2P55 HIGH REPETITION RATE PICOSECOND FID PULSE GENERATORS FOR UWB 175 APPLICATIONS

Vladimir Efanov, Mikhail Efanov, Alexander Komashko, Pavel Yarin FID GmbH Burbach, Germany 2P56 DEVELOPMENT OF A RF BURST PULSE GENERATOR USING A NON-LINEAR 176 TRANSMISSION LINE FOR CANCER TREATMENT

Yuichi Abe, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, Department of Electrical Engineering, 4-3-16 Jonan, Yonezawa, Yamagata 992-0026, Japan 2P57 A 600V, 1KA COMPACT LTD MODULE USING POWER MOSFETS 177 Pravin Iyengar1, Tee Chong Lim1, Stephen Finney1, Mark Sinclair2

1University of Strathclyde, Electronic and Electrical Engineering, Glasgow, United Kingdom, 2Atomic Weapons Establishment, Pulsed Power Group, Aldermaston, United Kingdom 2P58 STATUS OF PROTOGEN THE FIRST INTEGRATION OF GENESIS 178 TECHNOLOGIES

Steven Glover1, Forest White2, Gary Pena1, Peter Foster3, Larry Schneider1 1Sandia National Laboratories Albuquerque, NM, USA, 2SAIC Albuquerque, NM, USA, 3Defense Nuclear Facilities Safety Board Washington, DC, USA 2P59 STATUS AND EXPERIMENTS WITH THE 1-MA WATER-INSULATED 179 MYKONOS LTD VOLTAGE ADDER

Michael Mazarakis1, Mark Savage1, William Fowler1, William Stygar1, Scott Roznowski1, Alexander Kim2 1Sandia National Laboratories, 1671, Albuquerque, NM, USA, 2High Current Electronic Institute, Pulsed Power, Tomsk, Russia 2P60 LINEAR TRANSFORMER DRIVER (LTD) WITH SQUARE PULSE OUTPUT 180 Michael Mazarakis2, Alexander Kim1, Alexander Sinebbryukhov1, S. Volkov1, S. Kondratief1,

Frederic Bayol3, Gauthier Demol3, V. Alexcenco1, William Stygar2 1Institute of High Current Electronics, Russian Academy of Sciences ,Pulsed Power, Russian Academy of Sciences, Tomsk 634055, Russia, 2Sandia National Laboratory, 1671, Albuquerque, NM, USA, 33International Technologies for High Pulsed Power, Pulsed Power, Thegra 46500, France 2P61 MODIFICATIONS TO A COMPACT MARX GENERATOR 181 Kim Morales

NSWC Dahlgren, Q, Dahlgren, VA, USA 2P62 RAPID CAPACITOR CHARGING POWER SUPPLY FOR AN 1800J PFN 182 Travis Vollmer, Michael Giesselmann

Texas Tech University, Center for Pulsed Power & Power Electronics, Lubbock, TX, USA 2P63 A SHORT-RISE-TIME PULSE GENERATOR USING LASER TRIGGERED SPARK 183 GAP SWITCH

Yuan Li, Jin Li, Xin Li, Debiao Chen, Hui He, Zhi Zhou, Mao Chen, Fuxin Zhou Institute of Fluid Physics, Department of Accelerator Physics and Applications, Mianyang, China 2P64 DEVELOPMENT OF BRAUNBECK COILS FOR PULSED MAGNETIC FIELD 184 GENERATOR FOR BIOMEDICAL EXPOSURE

Yan Mi, Chun Jiang, Longxiang Zhou, Chenguo Yao, Chengxiang Li Chongqing University, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing, China

xxxv 2P65 THE PERFORMANCE OF A PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH 185 TRIGGERED BY A LASER DIODE

Baojie Wang, Kefu Liu, Liuxia Li, Jian Qiu Fudan University, Electric Light Sources, Shanghai, China 2P66 AN NS RISETIME GAS SWITCH WITH A MOVABLE ELECTRODE AND A 186 FIXED ELECTRODE

Xiaobing Zou, Kun Huang, Xinxin Wang, Ran Zhang, Xinlei Zhu, Shen Zhao Tsinghua University, Department of Electrical Engineering, State Key Laboratory of Control and Simulation of Power System and Generation Equipment, Beijing, China 2P67 EXPERIMENTS ON COMPACT PULSE FORMING LINE USING WATER 187 DIELECTRIC HELICAL TRANSMISSION LINE

Pankaj Deb, Surender Sharma, Biswajit Adhikhari, Rohit Shukla, T. Prabaharan, Partha Banerjee, Rishi Verma, Anurag Shyam Bhabha Atomic Research Centre, Department of Atomic Energy, Vishkapatnam, India 2P68 OPERATIONAL RESULTS OF PULSE SHAPING TECHNIQUES FOR THE HIGH 188 VOLTAGE CONVERTER MODULATOR

Gunjan Patel, David Anderson, Dennis Solley, Mark Wezensky Oak Ridge National Laboratory, Spallation Neutron Source, Oak Ridge, TN, USA 2P69 DESIGN AND TEST OF INDUCTION VOLTAGE ADDER DERIVED BY 3 189 BLUMLEIN PFLS

Hoon Heo1, Oh Ryoung Choi1, Sang Hoon Nam1, Jong Won Yang2, Jong Hyo Won3 1Pohang Accelerqator Laboratory Pohang, Korea, 2ADD Daejeon, Korea, 3LIG Nex1 Seongnam, Korea 2P70 HIGH-VOLTAGE VACUUM ELECTRONIC SWITCHES FOR POWER 190 ELECTRONICS

Vladimir Perevodchikov, Pavel Stalkov, Ivan Trukhachev, Valentina Shapenko, Alexander Scherbakov Federal State Unitary Enterprise "All-Russian Electrotechnical Institute named after V.I.Lenin" (FGUP VEI) Mosow, Russia 2P71 ELECTRIC EXPLOSIVE OPENING SWITCH TECHNOLOGY 191 Wu Youcheng, Hao Shirong, Yang Yu, Geng Lidong, Wang Minhua, Zhang Nanchuan

Institute of Fluid Physics, High Pulsed Power Technology and Application, Mianyang, China

Oral Session 7: Compact Pulsed Power Systems Session Chair: Mike Mazarakis, Sandia National Laboratories 7O1,2 COMMISSIONING AND POWER FLOW STUDIES OF THE 2.5-MEV URSA 192 (invited) MINOR LTD Josh Leckbee1, Tim Pointon1, Steve Cordova1, Bryan Oliver1, Martial Toury2, Michel Caron2 1Sandia National Laboratories, Advanced Radiographic Technologies, Albuquerque, NM, USA, 2Commissariat a l'Energie Atomique Pontfaverger, Moronvilliers, France 7O3 SOLID-STATE LTD TECHNOLOGY FOR COMPACT PULSED-POWER 193 DEVELOPMENT Weihua Jiang, Akira Tokuchi Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan 7O4 DEVELOPMENT OF THE 1 MV/100 kA FAST LTD GENERATOR 194 Lin Chen, Wenkang Zou, Liangji Zhou, Meng Wang, Weiping Xie Institute of Fluid Physics, Pulsed Power Laboratory, Mianyang, China

xxxvi 7O5 REPETITIVE TESLA-CHARGED PFL AND BLUMLEIN PULSED POWER 195 GENERATORS Bucur Novac, Ivor Smith, Peter Senior Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom 7O6 SOLID DIELECTRIC TRANSMISSION LINES FOR PULSED POWER 196 Matt Domonkos1, Susan Heidger1, Darwin Brown2, Tommy Cavazos2, Alan Devoe3, Fatih Dogan4, Don Gale2, Jim O'Loughlin1, Jerald Parker2, Dan Sandoval2, Kirk Slenes5, Wayne Sommars2, Jack Watrous6 1AFRL Kirtland AFB, NM, USA, 2SAIC Albuquerque, NM, USA, 3Presidio Components San Diego, CA, USA, 4Missouri University of Science and Technology Rolla, MO, USA, 5TPL, Inc. Albuquerque, NM, USA, 6NumerEx, LLC Albuquerque, NM, USA 7O7 A COMPACT, PHASEABLE MW-CLASS HIGH POWER MICROWAVE SYSTEM 197 USING AN INTEGRATED PHOTOCONDUCTIVE SWITCH AND NONLINEAR TRANSMISSION LINE Cameron Hettler, James-William Bragg, William Sullivan III, Daniel Mauch, James Dickens, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA 7O8 COMPACT PICOSECOND PULSE GENERATORS WITH GIGAWATT PEAK 198 POWER Vladimir Efanov, Mikhail Efanov FID GmbH Burbach, Germany

Oral Session 8: High Voltage Design and Analysis, Accelerators, Radar, and RF Applications, Reliability and Transient Suppression Session Chair: Andreas Neuber, Texas Tech University 8O1 PRELIMINARY NUMERICAL STUDY ON DIELECTRIC MIXTURES UNDER 199 LIGHTNING IMPULSE CONDITIONS Enis Tuncer, Chris Calebrese, Weijun Yin GE Global Research, Dielectrics & Electrophysics Lab, Niskayuna, NY, USA 8O2 EVOLUTION OF PLASMA DENSITY GENERATED BY HIGH POWER 200 MICROWAVES Sterling Beeson, James Dickens, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA 8O3 BEHAVIOR OF HV CABLE AT SHORT CIRCUIT AND RELATED PHENOMENA 201 Alex Pokryvailo, Cliff Scapellati Spellman High Voltage Electronics Corp. Hauppauge, NY, USA 8O4 FLEXIBLE 50-OHM HIGH-VOLTAGE NANOSECOND PULSE GENERATOR 202 Sophie Kohler, Saad El Amari, Vincent Couderc, Delia Arnaus-Cormos, Philippe Leveque University of Limoges, XLIM UMR 6172 CNRS, Limoges, France 8O5 COMPACT 110-MW MODULATOR FOR C-BAND HIGH GRADIENT 203 ACCELERATOR Takahiro Inagaki1, Chikara Kondo1, Katsutoshi Shirasawa1, Tatsuyuki Sakurai1, Yuji Otake1, Tsumoru Shintake2 1RIKEN, SPring-8 Center, Hyogo, Japan, 2OIST Okinawa, Japan 8O6 SOME CONSIDERATIONS TO THE ITER SNUBBERS 204 Ge Li Institute of Plasma Physics, Chinese Academy of Sciences Hefei, China

xxxvii 8O7 A NEW TRIGGERING TECHNOLOGY BASED ON INDUCTIVE TRANSFORMER 205 FOR LTD SWITCHES Yu Lei, Kefu Liu, Jian Qiu, Zhuolin Tu Fudan University, Electric Light Sources, Shanghai, China 8O8 SUSCEPTIBILITY OF ELECTRO-EXPLOSIVE DEVICES TO HIGH PULSED 206 ELECTRIC FIELDS David Reale, John Mankowski, James Dickens Texas Tech University, Center for Pulsed Power & Power Electronics, Lubbock, TX, USA

Plenary 3 Session Chair: Juergen Kolb, INP Greifswald PL3 PLS-II AS THE LEADING KOREAN ACCELERATOR PROJECT AND ITS ROLE 207 FOR MEGA-SCIENCE ACCELERATOR PROJECTS IN KOREA Sang Hoon Nam Pohang Accelerator Laboratory, Pohang, Korea

7Oral Session 9: High Current Systems and EM Launchers Session Chair: Brett Huhman, Naval Research Laboratory 9O1 THE COLLIDING TORI FUSION REACTOR: PROOF OF PRINCIPLE 208 EXPERIMENT Michael Anderson1, Vitaly Bystritskii1, Ivan Isakov1, Vasily Matvienko1, Francesco Giammanco2, Tommaso Del Rosso2, Michl Binderbauer1, Lucia Bonelli3, Hiroshi Gota1, Frank Jauregui1, Cheryl Johnson1, Enrico Paganini3, Mark Rouillard1, George Strashnoy1, William Waggoner1, Kurt Walters1 1Tri Alpha Energy, Inc., Pulsed Power Physics, Foothill Ranch, CA, USA, 2University of Pisa, Physics, Pisa, Italy, 3ENEL Pisa, Italy 9O2 ATMOSPHERIC ELECTROMAGNETIC PLASMADYNAMIC SYSTEM FOR 209 INDUSTRIAL APPLICATIONS Yuri Chivel1, Victor Bochkov2, Dmitry Bochkov2, Yury Gryshin 3, Valery Suslov 3, Vladimir Vermel 4 1MerPhotonics Saint Etienne, France, 2Pulsed Technologies Ltd. Ryazan, Russia, 3Pulsed Technologies Ltd. Ryazan, Russia, 4Bauman University Moscow, Russia, 5Bauman University Moscow, Russia, 6TsAGI Moscow, Russia 9O3 PROGRESS TOWARD A SELF-CONTAINED RAPID CAPACITOR CHARGER 210 FOR A SMALL RAILGUN IN BURST MODE OPERATION AT 3 RPS Raymond Allen1, Craig Boyer2, Jesse Neri1, Michael Veracka3, Brett Huhman1 1Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2L3 Communications/Titan Group Reston, VA, USA, 3Naval Research Laboratory, Tactical Electronic Warfare Division, Washington, DC, USA 9O4 ANALYSIS AND SIMULATION OF ELECTROMAGNETIC COIL LAUNCH 211 SYSTEM Jiange Zhang1, Zan Lu1, James E. Thompson2, Naz E. Islam1 1University of Missouri-Columbia, Electrical & Computer Engineering, Columbia, MO, USA, 2University of Missouri-Columbia, College of engineering, Columbia, MO, USA 9O5 MEASUREMENT OF SOLID ARMATURE'S IN-BORE VELOCITY USING B-DOT 212 PROBES IN AUGMENTED RAILGUN Song Shengyi, Cheng Cheng, Guan Yongchao, He Yong Institute of Fluid Physics, CAEP, Laboratory for Pulsed Power Technology, Mianyang, China

xxxviii 9O6 EXPERIMENTAL RESULTS FROM THE DESTRUCTIVE TESTING OF MULTI- 213 LAYER PZT FERROELECTRIC GENERATORS Allen Stults US Army, AMRDEC, Redstone Arsenal, AL, USA 9O7 EXPERIMENTAL AND THEORETICAL STUDIES OF A FLYER-PLATE 214 ELECTROMAGNETIC ACCELERATOR Kaashif Omar1, Neal Graneau1, Mark Sinclair1, Bucur Novac2, Ivor Smith2, Peter Senior2 1AWE, Hydrodynamics Department, Aldermaston, United Kingdom, 2Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom 9O8 OPTIMIZATION OF NONUNIFORM TRANSMISSION LINE WITH A GAUSSIAN 215 IMPEDANCE PROFILE BY CIRCUIT SIMULATION Rui Zhang, Chongyang Mao, Kun Hunag, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing , China

Oral Session 10: High Power Microwaves, Radiating Structures, and Electromagnetic Propagation Session Chair: Steve Calico, Lockheed Martin 10O1 VIRTUAL PROTOTYPING A MEGAWATT CLASS CONVENTIONAL 216 MAGNETRON Michael Lambrecht, Timothy Fleming, Peter Mardahl Air Force Research Laboratory, Directed Energy Directorate, Kirtland AFB, NM, USA 10O2 RECIRCULATING PLANAR MAGNETRON EXPERIMENTS AND SIMULATIONS 217 Ronald Gilgenbach1, Matthew Franzi1, Yue-Ying Lau1, David Chalenski1, David Simon1, Brad Hoff2, David French2, Geoff Greening2, John Luginsland3 1University of Michigan, Nuclear Eng. & Radiological Sciences , Ann Arbor, MI, USA, 2Air Force Research Lab, Directed Energy Directorate, Kirtland AFB, NM, USA, 3Air Force Office of Scientific Research, Plasma & Electroenergetic Physics, Arlington, VA, USA 10O3 SERIAL ARRANGEMENT OF FERRIMAGNETIC NONLINEAR TRANSMISSION 218 LINES James-William Bragg, Christopher Simmons, James Dickens, Andreas Neuber Center for Pulsed Power and Power Electronics, Texas Tech University, Department of Electrical and Computer Engineering, Lubbock, TX, USA 10O4 GENERATING OSCILLATING PULSES USING NONLINEAR CAPACITIVE 219 TRANSMISSION LINES Ngee Siang Kuek1, Ah Choy Liew1, Edl Schamiloglu2, Jose Osvaldo Rossi3 1National University of Singapore, Department of Electrical & Computer Engineering, Singapore, Singapore, 2University of New Mexico, Department of Electrical & Computer Engineering, Albuquerque, NM, USA, 3National Institute for Space Research, Associated Plasma Laboratory, Sao Jose dos Campos, Brazil 10O5 3D FDTD SIMULATION OF A NLTL USING FERROELECTRIC MATERIALS IN 220 RECTANGULAR WAVEGUIDE Byron Caudle, Michael Baginski, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA 10O6 GAS EVOLUTION OF NICKEL, STAINLESS STEEL 316, AND TITANIUM 221 ANODES IN VACUUM SEALED TUBES Jonathan Parson, James Dickens, Andreas Neuber, John Walter, Magne Kristiansen Texas Tech University, Electrical and Computer Engineering, Lubbock, TX, USA

xxxix 10O7 THREE-DIMENSIONAL PARTICLE-IN-CELL SIMULATION OF SUB- 222 TERAHERTZ HIGH-POWER GYROTRON Koyu Ito, Weihua Jiang Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan 10O8 A DIELECTRIC RESONATOR ANTENNA BASED ON HIGH DIELECTRIC 223 CONSTANT COMPOSITES FOR HIGH POWER, UHF ANTENNA APPLICATIONS Kevin O'Connor, Randy Curry University of Missouri-Columbia, Center for Physical and Power Electronics, Columbia, MO, USA

Poster Session 3: High Voltage Design and Analysis, Accelerators, Radars, and RF Applications, Reliability and Transient Suppression, High Current Systems and EM Launchers, High Power Microwaves, Radiating Structures, and Electromagnetic Propagation, Analytical Methods, Modeling, and Simulation, Prime Power and Power Systems, Energy Storage Devices and Components, High Energy Systems Session Chair: David Wetz, University of Texas, Arlington 3P1 PULSED VOLTAGE DRIVEN ELECTROSPRAY 224 Daichi Obata1, Asuki Nakamura1, Sunao Katsuki2, Hidenori Akiyama1

1Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan, 2Kumamoto University, Bioelectrics Research Center, Kumamoto, Japan 3P2 OPTIMIZATION OF CORONA RING DESIGN FOR COMPOSITE INSULATOR 225 STRINGS USING KRIGING METAMODELING AND DIRECT ALGORITHMS

Hanyu Ye, Markus Clemens Universität Wuppertal, Chair of Electromagnetic Theory, Wuppertal, Germany 3P3 DEVELOPMENT OF SMALL DIMENSION HIGH-VOLTAGE ELECTRONIC 226 VACUUM DEVICES

Victor Bochkov1, Dmitry Bochkov1, Vladimir Nicolaev1, Vasiliy Teryoshin1, Piotr Panov1, Alexandr Batrakov2, Konstantin Karlik2, Grigory Ozur2, Dmitry Proskurovsky2 1Pulsed Technologies Ltd Ryazan, Russia, 2Institute of High Current Electronics RAS Tomsk, Russia 3P4 OPTIMIZATION OF A CATHODE CONFIGURATION IN GAS INSULATED 227 SWITCHGEAR WITH A PERMITTIVITY GRADED INSULATOR

Chi-Wuk Gu, Jae-Ho Rhee, Heung-Jin Ju, Kwang-Cheol Ko Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea 3P5 INTERRUPTING CAPABILITY OF VACUUM INTERRUPTER BY VARIOUS 228 PARAMETERS

Chi-Wuk Gu1, Kun-A Lee1, Heung-Jin Ju1, Kwang-Cheol Ko1, Cheol-Kyou Lee2 1Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea, 2Vitzrotech Co., Ltd. Ansan, South Korea

xl 3P6 EFFECTS OF CAPACITIVE VERSUS RESISTIVE LOADING ON HIGH 229 TRANSFORMATION RATIO PIEZOELECTRIC TRANSFORMERS FOR

MODULAR DESIGN CONSIDERATIONS James VanGordon1, Brady Gall1, Peter Norgard1, Scott Kovaleski1, Emily Baxter1, Baek Kim1, Jae Kwon1, Gregory Dale2 1University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA, 2Los Alamos National Laboratory, Accelerator Operations and Technology - High Power Electrodynamics, Los Alamos, NM, USA 3P7 DEVELOPMENT OF 100kV BIPOLAR CAPACITOR CHARGING SYSTEM 230 Yinghui Gao1, Kun Liu1, Yaohong Sun1, Dongdong Zhang1, Ping Yan1

1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China

3P8 DESIGN AND TEST OF 2250KV SEMI-FLEXIBLE SF6 INSULATED HIGH 231 VOLTAGE IMPULSE TRANSMISSION LINE

Kun Wang1, Xupeng Song2, Jingbo Zhang2, Gensheng Lu2, Kefu Liu1 1Fudan University, Institute of Electric Light Sources, Shanghai, China, 2China Electronic Technology Group Corporation , No.23 Research Institute, Shanghai, China 3P9 FDTD ANALYSIS OF LIGHTNING TRANSIENT ELECTROMAGNETIC FIELD 232 ON THE TRANSMISSION LINE

Hao Wu, Chen-guo Yao, Qian-bo Xiao, Yan Mi, Chen-xiang Li, Jian Li State Key Laboratory of Power Transmission Equipment ＆ System Security and New technology, College of Electric Engineering Chongqing University, Chongqing, China 3P10 NUMERICAL MODELING OF UHV LABORATORY TO EVALUATE THE 233 RATING OF HV EQUIPMENT

Adusumilli Pradeep1, Shreeharsh Mallick2, H S Jain1 1Bharat Heavy Electricals Limited, High Voltage Engineering, Hyderabad, India, 2University of Florida, Lightning Research Group, Gainesvile, FL, USA 3P11 STUDY OF LIGHTNING INDUCED OUTAGE IMPROVEMENT FOR A 220KV 234 TRANSMISSION LINE.

Goru Radhika1, Mungala Suryakalavathi2 1VNR VJIET, EEE, Hyderabad, India, 2JNTU, EEE, Hyderabad, India 3P12 ELECTRIC FIELD STRESS ANALYSIS ON THE SURFACE OF A COMPOSITE 235 CONE TYPE SPACER IN GAS INSULATED SUBSTATION FOR A FIXED

SPHERICAL AND A WIRE LIKE PARTICLE Duvvada Deepak Chowdary1, Jinka Amarnath2 1Dr.L.B.College of Engineering For Women, Electrical & Electronics Engineering, Visakhapatnam, India, 2Jawaharlal Nehru Technological University, Electrical & Electronics Engineering, Hyderabad, India 3P13 ANALYSIS TO CORE SNUBBER BASED ON DELTAMAX 236 Fei Xie12, Hongwen Yuan1, Ge Li1, Desheng Cheng1, Jinling Chen1, Qiangjian Chen1

1Chinese Academy of Sciences, Institute of Plasma Physics, Anhui, China, 2Shunde Polytechnic, Department of Electronic and Information Engineering, Shunde, China 3P14 MHz-LEVEL REPETITIVE MODULATORS FOR ACCELERATOR 237 APPLICATIONS

Weihua Jiang, Akira Tokuchi Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan

xli 3P15 DEVELOPMENT OF HIGH PERFORMANCE ELECTRON BEAM SWITCHING 238 SYSTEM FOR SWISS FREE ELECTRON LASER AT PAUL SCHERRER

INSTITUTE Martin Paraliev, Christopher Gough Paul Scherrer Institute, Large research facilities , Villigen PSI, Switzerland 3P16 A STABILITY OF LCLS LINAC MODULATORS 239 Anatoly Krasnykh, Franz-Josef Decker, Ben Morris, Minh Nguyen

SLAC National Accelerator Lab Menlo Park, CA, USA 3P17 SNS LEBT CHOPPER PULSE WIDTH LIMITATION 240 Vladimir Peplov, Robert Saethre

ORNL Oak Ridge, TN, USA 3P18 KLYSTRON MODULATOR DESIGN FOR THE LOS ALAMOS NEUTRON 241 SCIENCE CENTER ACCELERATOR

William Reass, David Baca, Daniel Rees, Edward Partridge Los Alamos National Laboratory, AOT-RFE, Los Alamos, NM, USA 3P19 INJECTOR SYSTEM FOR THE POLISH SYNCHROTRON RADIATION 242 FACILITY 'SOLARIS'

Piotr Tracz1, C.J. Bocchetta1, P. Goryl1, L. Walczak1, A. Wawrzyniak1, M. Eriksson2, D. Kumbaro2, L. Malmgren2, J. Mooder2, S. Thorin2 1The Jagiellonian University, SOLARIS, Krakow, Poland, 2The Lund University, MAX-lab, Lund, Sweden 3P20 A HIGH-REPETITION RATE PULSED ELECTRON ACCELERATOR 243 Gennady Remnev, Ivan Egorov, Marat Kaikanov, Evgeny Lukonin, Victor Esipov, Artem

Poloskov Tomsk Polytechnic University, High Technology Physics Institute, Tomsk, Russia 3P21 30 KV COAXIAL PULSED PLASMA ACCELERATOR FOR DIAGNOSTICS AND 244 APPLICATIONS OF MATERIAL PROCESSING

Anuar Zhukeshov, Assem Amrenova, Asylgul Gabdullina Kazakh National University, Physics Faculty, Almaty, Kazakhstan 3P22 SNS LEBT CHOPPER FAILURE MODES AND IMPROVEMENTS 245 Robert Saethre, Vladimir Peplov

Oak Ridge National Laboratory, Research Accelerators Division, Oak Ridge, TN, USA 3P23 EMI NOISE REDUCTION IN INTEGRATED 6 KHZ SOLID STATE PULSED 246 POWER SYSTEM

Hao Chen, Byron Yakimow, Paul Melcher Cymer Inc San Diego, CA, USA 3P24 METHOD OF CURRENT TRANSFORMER METROLOGICAL PROPERTIES 247 ESTIMATION FOR TRANSFORMATION OF DISTORTED SIGNALS

Michal Kaczmarek Technical Univeristy of Lodz, Instytute of Electrical Power Engineering, Lodz, Poland 3P25 ANALYSIS OF THE INFLUENCE OF THE LEVEL OF SIGNAL DISTORTION ON 248 CURRENT ERROR AND PHASE DISPLACEMENT OF INDUCTIVE CURRENT

TRANSFORMERS Kaczmarek Michal Technical Univeristy of Lodz, Instytute of Electrical Power Engineering, Lodz, Poland 3P26 AN EMPIRICAL STUDY ON EVALUATION METHOD FOR AGING MEDIUM 249 LARGE POWER TRANSFORMER

Chang Jeong-Ho1, Lee Sung-Hun1, Oh Seung-Chan2, Lee Hyo-Sung3, Lee Heung-Ho3 1Korea Water Resources Corporation, Daejeon, Korea, 2Corporation Korea Atomic Energy Research Institute, , Daejeon, Korea, 3Chungnam National University Daejeon, Korea

xlii 3P27 INVESTIGATIONS INTO NON-DESTRUCTIVE MODIFICATION OF 250 CAPACITOR BANK OUTPUT INDUCTANCE AT THE NRL MATERIALS

TESTING FACILITY Brett Huhman1, Richard Cairns2, Scott Douglass2, Jess Neri1 1US Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2Soterra Defense, Inc, Crofton, MD, USA 3P28 SHOCK COMPRESSION OF GAS-IMPREGNATED SOLIDS 251 David Rice, Scott Kovaleski, John Gahl

University of Missouri, Electrical Engineering, Columbia, MO, USA 3P29 EXPERIMENTAL RESULTS OF EXTREMELY COMPACT FERROELECTRIC 252 GENERATOR BASED PULSED SYSTEMS

Allen Stults1, Sergey Shkuratov2, Jason Baird2 1US Army, AMRDEC, Redstone Arsenal, AL, USA, 2Loki Rolla, MO, USA 3P30 ANALYSIS TO THE EAST NBI TRANSMISSION LINES 253 Cheng Desheng, Li Ge, Cao Lei, Xie Fei

1Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China 3P31 AN ACTIVE JITTER DAMPER OF SWITCHES OF LTD BASED ON 254 TRANSFORMER COUPLING EFFECT

Yue Zhao, Liangji Zhou, Lin Chen, Meng Wang China Academy of Engineering Physics, Institute of Fluid Physics, Mianyang, China 3P32 COMPACT ELECTRIC POWER SYSTEM FOR TOKAMAK 255 Ge Li

Institute of Plasma physics, Chinese Academy of Sciences Hefei, China 3P33 SOME PROBLEMS OF SLIDING CONTACT IN RAILGUN ("VELOCITY SKIN- 256 EFFECT" AND HALL-EFFECT IN MICRO-PLASMA)

Volodymyr Chemerys National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia 3P34 THE PRINCIPLE OF MAGNETIC FLUX COMPRESSION IN THE PULSED 257 ELECTROMECHANICAL GENERATORS AND ITS IMPLEMENTATION IN

DESIGN Volodymyr Chemerys National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia 3P35 EFFECTS OF ELECTROMAGNETIC PULSES ON A SYSTEM WITH MULTIPLE 258 LAYERS OF DIFFERENT MATERIALS

Antonio Upia1, Daniel Muffoletto1, Mark Muffoletto1, Brett Bowman1, Kevin Burke1, Jennifer Zirnheld1, Harry Moore2, Hardev Singh2, Thomas DeAngelis3 1The University at Buffalo, Energy Systems Institute, Buffalo, NY, USA, 2US Army Military, ARDEC, Picatinny Arsenal, NJ, USA, 3SciTech Services, Inc. Havre de Grace, MD, USA 3P36 FREQUENCY AGILITY OF A FERRITE-LOADED, NONLINEAR TRANSMISSION 259 LINE

Christopher Simmons, James-William Bragg, James Dickens Texas Tech University, Department of Electrical And Computer Engineering, Lubbock, TX, USA 3P37 PROSPECTS OF BUILDING CAPACITIVE NONLINEAR LINES USING 260 CERAMIC PZT FOR HIGH-FREQUENCY OPERATION

Jose Osvaldo Rossi1, Fernanda Sayuri Yamasaki1, Lauro Paulo da Silva Neto1, Edl Schamiloglu2 1INPE, Associated Plasma Laboratory, Sao Jose dos Campos, Brazil, 2UNM, ECE Dept, Albuquerque, NM, USA

xliii 3P38 X-BAND RELATIVISTIC BACKWARD WAVE OSCILLATOR WITH TWO- 261 SPIRAL CORRUGATED BRAGG REFLECTOR

A. Elfrgani, M. Fuks, S. Prasad, E. Schamiloglu University of New Mexico, Electrical and Computer Engineering, Albuquerque, NM, USA 3P39 ELECTRIC CIRCUIT MODELING METHODS OF ELECTROMAGNETIC SHOCK 262 WAVE IN AIR FOR HIGH POWER MICROWAVE PROPAGATION

Kun-A Lee, Jong-Yoon Park, Kwang-Cheol Ko Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea 3P40 OPEN TRANSVERSE ELECTROMAGNETIC (TEM) CELL AS APPLICATOR OF 263 HIGH-INTENSITY NS PEFs AND ELECTRO-OPTIC MEASUREMENTS

Sophie Kohler1, Thao Vu1, Thomas Vernier2, Delia Arnaud-Cormos1, Philippe Leveque1 1University of Limoges, XLIM UMR 6172 CNRS, Limoges, France, 2Information Sciences Institute, MOSIS, California, CA, USA 3P41 A PIEZOELECTRICALLY DRIVEN ION DIODE NEUTRON SOURCE FOR 264 ACTIVE INTERROGATION

Peter Norgard, Scott Kovaleski, James VanGordon, Emily Baxter, Brady Gall, Jae Kwon, Baek Kim University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA 3P42 CARRIER DYNAMICS AND ELECTRON ENERGY DISTRIBUTION FUNCTION 265 OF A TRANSBERSE VIRCATOR

Shen Shou Max Chung1, Yien Chieh Huang2, Ci Ling Pan1 1National Tsing Hua University, Department of Physics, Hsinchu, Taiwan, 2National Tsing Hua University, Institue of Photonics Technologies, Hsinchu, Taiwan 3P43 SHAPES OF GRATINGS AND BEAM ENERGY RELATIONSHIP IN A 100 MEV 266 SMITH-PURCELL DEVICE

Shen Shou Max Chung1, Yien Chieh Huang2, Ci Ling Pan1 1National Tsing Hua University, Department of Physics, Hsinchu, Taiwan, 2National Tsing Hua University, Institue of Photonics Technologies, Hsinchu, Taiwan 3P44 INNOVATIVE SOLUTIONS TO HPM TESTING 267 Russell Blundell

White Sands Missile Range, Survivability Vulnerability & Assessment Directorate, White Sands, NM, USA 3P45 INVESTIGATIONS INTO THE POTENTIAL FOR SURFACE FLASHOVER ON 268 METAMATERIAL STRUCTURES IN AN HPM ENVIRONMENT

Patrick Kelly, John Mankowski, Stephen Bayne Center for Pulsed Power and Power Electronics, Electrical and Computer Engineering, Lubbock, TX, USA 3P46 COMPARISON OF CSI COATED CARBON VELVET AND ALUMINUM 269 CATHODES OPERATED AT CURRENT DENSITY ON THE ORDER OF 300A/CM2

Curtis Lynn, John Walter, Andreas Neuber, James Dickens, Magne Kristiansen Texas Tech University, Electrical Engineering, Lubbock, TX, USA 3P47 AN ARBITRARY-GEOMETRY PULSED RF SOURCE ARRAY SYSTEM BASED 270 ON GPS TIMING

John Walter, Christopher Lutrick, Scott Clark, Shad Holt, David Reale, Patrick Kelly, James Dickens, John Mankowski Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

xliv 3P48 STOCHASTIC MODEL OF METAL OXIDE SURGE ARRESTERS BASED ON 271 SYSTEM IDENTIFICATION

Pablo Bezerra Vilar, George Rossany Soares Lira, Tarso Vilela Ferreira, Edson Guedes da Costa Federal University of Campina Grande, Department of Electric Engineering , Campina Grande, Brazil 3P49 PSPICE MODELING OF SILICON CARBIDE MOSFETS AND DEVICE 272 PARAMETER EXTRACTION

Argenis Bilbao, Stephen Bayne Texas Tech University, Electrical and Computer Engineering, Lubbock, TX, USA 3P50 PULSED POWER SWITCH MODELING FOR BROAD OPERATION 273 Steven Glover1, Peter Foster2, Dillon McDaniel1, Forest White3, Gary Pena1, Larry

Schneider1 1Sandia National Laboratories Albuquerque, NM, USA, 2Defense Nuclear Facilities Safety Board Washington, DC, USA, 3SAIC Albuquerque, NM, USA 3P51 ANALYTIC SOURCES USING POLYNOMIAL SHAPED PARTICLES IN THE LTP 274 METHOD

Robert Jackson1, John Verboncoeur2 1Calabazas Creek Research, Inc. San Mateo, CA, USA, 2Michigan State University, Electrical and Computer Engineering, East Lansing, MI, USA 3P52 ANALYSIS OF CURRENT-DIVIDING POST-HOLE CONVOLUTES FOR SIX 275 LINES DRIVING THREE TRIODES ON SATURN

E. A. Madrid1, D. V. Rose1, C. L. Miller1, V. Harper-Slaboszewicz2 1Voss Scientific Albuquerque, NM, USA, 2Sandia National Laboratories, Albuquerque, NM, USA 3P53 REPETITIVE PULSE TESTING AND MODELING OF A HIGH POWER CERAMIC 276 RESISTOR

Daniel Muffoletto, Kevin Burke, Jennifer Zirnheld University at Buffalo, Energy Systems Institute, Buffalo, NY, USA 3P54 DYNAMIC BIFURCATION ANALYSIS OF ADVANCED AIRCRAFT ELECTRIC 277 POWER SYSTEM (AAEPS) WITH NONLINEAR LOADING

Hadi Ebrahimi, Hassan El-Kishky The University of Texas at Tyler, Electrical Engineering, Tyler, TX, USA 3P55 A NOVEL GENERALIZED AVERAGING TECHNIQUE FOR THE MODELING OF 278 CONTROLLERS IN AN AAEPS MULTI-CONVERTER SYSTEM

Hadi Ebrahimi, Hassan El-Kishky The University of Texas at Tyler, Electrical Engineering, Tyler, TX, USA 3P56 AN EMI MODEL OF HIGH FREQUENCY AND HIGH VOLTAGE CAPACITOR 279 CHARGING POWER SUPPLY CONSIDERING TRANSIENT SWITCHING

INTERFERENCE BASED ON SABER Xiao Han3, Yinghui Gao1, Dongdong Zhang2, Yaohong Sun1, Ping Yan2 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China, 3Chinese Academy of Sciences, Graduate School, Beijing, China 3P57 MODELING AND SIMULATION OF MULTIPACTOR DISCHARGE ON 280 DIELECTRIC WINDOW UNDER HPM IN VACUUM

Guan-Jun Zhang, Bai-Peng Song, Xi-Wei Hao Xi'an Jiaotong University, School of Electrical Engineering, Xi'ab, China

xlv 3P58 SIMULATION OF PULSED ELECTROMAGNETIC PROCESSES IN MULTI- 281 LAYER PACKAGE OF INDUCTOR CORE OF INDUCTION ACCELERATORS OF

ELECTRONS Volodymyr Chemerys, Iren Borodiy National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia 3P59 HIGH VOLTAGE DIRECT CURRENT TRANSMISSION – A REVIEW, PART I 282 Mohamed Saied

Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt 3P60 HIGH VOLTAGE DIRECT CURRENT TRANSMISSION – A REVIEW, PART II – 283 CONVERTER TECHNOLOGIES

Mohamed Saied Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt 3P61 CPF, TDS BASED VOLTAGE STABILITY ANALYSIS USING SERIES, SHUNT 284 AND SERIES–SHUNT FACTS CONTROLLERS FOR GENERATOR OUTAGE

CONTINGENCY Surya Kalavathi1, Naveen Kumar2 1JNTUH, EEE, Hyderabad, India, 2VNRVJIET, EEE, Hyderabad, India 3P62 OPTIMAL LOCATION AND PARAMETER SETTING OF UPFC FOR POWER 285 SYSTEM VOLTAGE STABILITY ENHANCEMENT USING DIFFERENTIAL

EVOLUTION(DE) ALGORITHM Suryakalavathi Munagala1, Balachennaiah Pagidi2 1JNTUH, EEE Department, Hyderabad, India, 2A.I.T.S, EEE Department, Rajampet, India 3P63 OPTIMAL POWER FLOW ANALYSIS OF ANDHRA PRADESH STATE GRID IN 286 DEREGULATED ENVIRONMENT

Sunilkumar Chava1, Amarnath Jinka2, Subramanyamps3 1CVR COLLEGE OF ENGINEERING, EEE, HYDERABAD, India, 2JNTUH, EEE, HYDERABAD, India, 3VBIT, EEE, HYDERABAD, India 3P64 ROLE OF FACTS DEVICES ON ZONAL CONGESTION MANAGEMENT 287 ENSURING VOLTAGE STABILITY UNDER CONTINGENCY

Jami Sridevi1, Jinka Amarnath2, Gade Govinda Rao3 1Gokaraju Rangaraju Institute of Engineering And Technology, Electrical and Electronics Engineering, Hyderabad, India, 2Jawaharlal Nehru Technological University, Electrical and Electronics Engineering, Hyderabad, India, 3Gayatri Vidya Parishad College of Engineering, Electrical and Electronics Engineering, Hyderabad, India 3P65 INFLUENCE OF HEAT TREATMENT ON PROPERTIES OF HIGH-CURRENT 288 METALLIZED FILM CAPACITORS

Kong Zhonghua, Xu Bei, Tong Chunya, Lou Zaifei School of Electronic and Information Engineering, Ningbo University of Technology, Ningbo, China 3P66 DEVELOPMENT AND PERFORMANCE OF HIGH TEMPERATURE POWER 289 CONVERSION CAPACITORS

J. R. MacDonald, J. B. Ennis, M. A. Schneider General Atomics Electronic Systems, Inc., Capacitor Research and Development, San Diego, CA, USA 3P67 DROOP RELATED LIFETIME REDUCTION OF POLYPROPYLENE FILM 290 CAPACITOR IN A PULSED POWER APPLICATION

Tao Tang1, Mark Kemp1, Craig Burkhart1 1SLAC National Acclerator Laboratory Menlo Park, CA, USA, 2SLAC National Acclerator Laboratory, RF Accelerator Research and Enegineering, Menlo Park, CA, USA

xlvi 3P68 LIFETIME TESTING OF AIRIX ACCELERATING UNITS 291 Alain Georges, Hervé Dzitko, Marc Mouillet, Rémi Nicolas, Denis Reynaud

CEA, DIF, ARPAJON, France 3P69 A MOBILE HIGH-POWER, HIGH-ENERGY PULSED-POWER SYSTEM 292 Bucur Novac1, Michael Parker1, Ivor Smith1, Peter Senior1, Gerasimos Louverdis2

1Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom, 2Dstl, Security Sciences Department, Sevenoaks, United Kingdom 3P70 CAPACITOR DROOP COMPENSATION WITH SOFT SWITCHING FOR HIGH 293 VOLTAGE CONVERTER MODULATOR

Michael Bland1, William Reass1, Alex Scheinker1, Ji Chao2, Pericle Zanchetta2, Alan Watson2, Jon Clare2 1Los Alamos National Laboratory, AOT-RFE, Los Alamos, NM, USA, 2The University of Nottingham, Electrical & Electronic Engineering, Nottingham, United Kingdom 3P71 COHERENCE EFFECTS 294 Lutfi Oksuz, Ali Gulec, Erdogan Teke, Ferhat Bozduman Suleyman Demirel Universitesi, Fizik Bolumu, Isparta, Turkey

Oral Session 11: Analytical Methods, Modeling, and Simulations Session Chair: Matthew Aubuchon, General Atomics 11O1,2 LINEAR-INDUCTION-ACCELERATOR BEAM-ENERGY-SPREAD 295 (Invited) MINIMIZATION: CELL MODELS AND TIMING OPTIMIZATION C. R. Rose, C. Ekdahl, M. Schulze Los Alamos National Laboratory, WX-5, Los Alamos, NM, USA 11O3 THERMAL MODELING OF HIGH TEMPERATURE POWER CONVERSION 296 CAPACITORS J. R. MacDonald General Atomics Electronic Systems, Inc., Capacitor Research and Development, San Diego, CA, USA 11O4 FDTD MODELING OF FAST TRANSIENT CURRENTS IN HIGH VOLTAGE 297 CABLES Xiao Hu, Martin D. Judd, Wah H. Siew University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, United Kingdom 11O5 ELECTROMAGNETIC MODELLING OF HIGH PRESSURE SPARK GAP 298 PEAKING SWITCH Mrunal Parekh, Bindu Sreedevi, H.A. Mangalvedekar VJTI, VJTI-SEIMENS HIGH VOLTAGE LAB, Mumbai, India 11O6 ESTIMATIONS OF THE ENERGY AVAILABLE TO A BREAKDOWN CHANNEL 299 AS IT PROPAGATES THROUGH A DIELECTRIC MEDIUM

Martin J Given1, Igor V Timoshkin1, Yiming Gao1, Mark P Wilson1, Tao Wang1, Scott J Macgregor1, Jane M Lehr2 1University of Strathclyde, Electronic and Electrical Eng, Glasgow, United Kingdom, 2Sandia National Laboratories Albuquerque, NM, USA 11O7 PREVENTING BREAKDOWN BY DIRECT OPTIMIZATION APPROACH 300 Zoran Andjelic1, Salih Sadovic2, Jean-Claude Mauroux3 1ABB Corporate Research Baden, Switzerland, 2Sadovic Consulting Paris, France, 3ABB Corporate Research Zuerich, Switzerland

xlvii 11O8 A SIMULATION OF BREAKDOWN PARAMETERS OF HIGH POWER 301 MICROWAVE INDUCED PLASMA IN ATMOSPHERIC GASES Patrick Ford, John Krile, Hermann Krompholz, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

Oral Session 12: Power Conditioning and Pulse Shaping, Energy Storage Devices and Components Session Chair: Shu Xiao, Old Dominion University 12O1 HIGH TEMPERATURE CAPACITOR PERFORMANCE IN A HIGH POWER, 302 HIGH FREQUENCY CONVERTER Kevin Bray1, Hiroyuki Kosai1, Daniel Schweickart2, Biswajit Ray3 1UES, Inc Dayton, OH, USA, 2Air Force Research Laboratory, RZPE, Dayton, OH, USA, 3Bloomsburg University of Pennsylvania Bloomsburg, PA, USA 12O2 GLASS DIELECTRICS FOR POWER CAPACITORS 303 Mohan Manoharan1, Mike Lanagan1, Douglas Kushner2, Chen Zou2, Shihai Zhang2, Takashi Murata3 1The Pennsylvania State University, Materials Research Institute, University Park, PA, USA, 2Strategic Polymer Sciences, Inc., Capacitor Division, State College, PA, USA, 3NEG, Glass Division, Shiga, Japan 12O3 ELECTRICAL BREAKDOWN IN CAPACITOR DIELECTRIC FILMS: SCALING 304 LAWS AND THE ROLE OF SELF-HEALING M. A. Schneider, J. R. MacDonald, M. C. Schalnat, J. B. Ennis General Atomics-Electronic Systems, Inc. San Diego, CA, USA 12O4 PULSED CURRENT LIMITATIONS OF HIGH POWER ELECTROCHEMICAL 305 ENERGY STORAGE DEVICES David Wetz, Biju Shrestha, Peter Novak University of Texas at Arlington, Electrical Engineering Department, Arlington, TX, USA 12O5 STATUS UPDATE OF THE POWER CONDITIONING SYSTEM IN THE 306 NATIONAL IGNITION FACILITY Bruno Le Galloudec1, Phil Arnold1, Glen James1, Dave Pendleton1, Dave Petersen1, Geoff Arellano-Womack2, Javier Cano3, Allen Harkey2, Norris Lao2, Manuel Magat1, Michael McIntosh2, Quang Ngo2, Seth Robison2, David Schwedler2, Mark Lopez2 1Lawrence Livermore National Laboratory, Engineering/LSEO, Livermore, CA, USA, 2AKIMA Infrastructure Services LLC Livermore, CA, USA, 3NSTEC Livermore, CA, USA 12O6 DESIGN AND CONSTRUCTION OF A 250 KV, 100 HZ REPETITIVE VIRCATOR 307 TEST STAND Kelton Clements, Randy Curry, Robert Druce University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA 12O7 EXPERIMENTATION AND SIMULATION OF HIGH CURRENT DENSITY 308 SURFACE COATED ELECTRO-EXPLOSIVE FUSES Jacob Stephens, Andreas Neuber, James Dickens, Magne Kristiansen Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock , TX, USA 12O8 ANALYSIS ON STRAY PARAMETERS IN A SOLID-STATE MARX PULSED 309 POWER MODULATOR Jian Qiu, Kefu Liu, Liuxia Li Fudan University, Electric Light Sources, Shanghai, China

xlviii

MONDAY

B Plenary Session 1 HIGH VOLTAGE, BIOFUELS, AND CO-PRODUCTS TAKING HIGH VOLTAGE TO THE (FARM) FIELD Robert Hebner University of Texas, Austin

A revolution is underway regarding how the world acquires what has traditionally been called “fossil fuel” or “petrochemicals”. Our present approach is to extract the results of nature converting plants to a hydrocarbon over millions of years. A daunting challenge is to compete with what nature has provided. To be competitive, one must grow the product and extract the relevant chemicals at a cost competitive with the cost of extracting from the earth the result of millions of years of natural processes using a century of extraction optimization. And it must be done in days or months, not centuries. But the rewards are great. On the financial side, bioprocessing has the potential to open more of the world to producing its own fossil fuel, thus helping to diversify supply and stabilize prices. On the environmental side, growing biofuels extracts CO2, while using them liberates CO2. Because these are done in such close temporal proximity, the net effect on the atmosphere is expected to be significantly less than that of fossil fuels. The technical challenge is to drive down cost, and electric fields are proving to be very cost effective in some aspects of processing compared to the more conventional chemical methods. Our research has made advances in four important areas of processing: electroporation, electromechanical cell disruption, electroflocculation, and electrophorisis. Electroporation is the process of creating pores in a cell membrane. In the processing application, these pores allow solvents to enter the intracellular region and material to diffuse out. The pores are created by applying a sufficiently high electric field across the cell membrane. Electromechanical cell disruption requires that the pulse be long enough to induce mechanical motion in the cell, but short enough that the field is applied in a time short compared to the difference between the effective time constants of the intracellular and the extracellular material. This process opens the cell so that oil can be removed. For algae growth in particular, a challenge is to separate the material from the growth medium since even very green algae ponds are typically only about 0.1% algae. One approach to concentration is to apply a metal that helps eliminate the normal electrostatic repulsion between algae cells, leading to flocculation. Electroflocculation is the use of an electric field to produce the flocculation sites from sacrificial electrodes. Electrophorisis is the use of an electric field to achieve separation by exploiting the natural charge state of the algae. This process has an effect, but it is confounded by the drag forces on the cells and the presence of simultaneous electroflocculation. All of these technologies have been evaluated and some have been used successfully in commercial products and in field demonstrations. Success in the integration of high voltage technology into the biofuels efforts is opening the door to additional potential applications.

1 1O1,2 (Invited) COMPACT SILICON SGTO MODULE FOR PULSE SWITCHING BEYOND 6 KV, 100 KA Heather O'Brien1, Aderinto Ogunniyi1, William Shaheen2, Victor Temple3, Charles Scozzie1 1U.S. Army Research Laboratory Adelphi, MD, USA, 2Berkeley Research Associates Beltsville, MD, USA, 3Silicon Power Corp. Clifton Park, NY, USA

In a continuing effort to reduce the weight and volume of high-power pulse switches, the U.S. Army Research Laboratory and Silicon Power have developed new Super-GTO-based switch modules that out-perform the previous designs while maintaining compact size. These switch modules have recently been demonstrated at a 50% increase in hold-off voltage and 40% increase in pulse current (compared to switches presented at PMC 2006) while utilizing the same area of silicon in the same volume packaging. Each switch module is composed of eight parallel 3.5 cm2 silicon Super-GTOs, for a total silicon area of 28 cm2 and a package volume of 0.14 L. The pulse performance at the individual Super-GTO device level was improved by modifying the emitter layout and metallization to reduce on-state resistance and maximize current-spreading across the silicon area. Switch modules were evaluated under a 125-microsecond wide pulse condition, with a 10-90% rise time of 10 microseconds. They were switched at a single-shot rate up to peak current capability, as determined by linearity on the on-state voltage drop and repeatability of each pulse without any perceived degradation to the switch. Modules were pulsed up to 112 kA for over 400 pulses with slight (5%) change in on-state voltage and consistent pulse performance. Compared to separate single-chip evaluations, these eight-chip Super-GTO modules are derated by 13% on current based on experimental data. This paper will include further information on the evaluation strategy, test bed design, and measurement techniques.

2 1O3 SPICE ANALYSIS OF AN INNOVATIVE SOLID-STATE MARX TOPOLOGY UTILIZING A BOOST REGULATOR CIRCUIT TO GENERATE MILLISECOND PULSES WITH LOW DROOP Christopher Yeckel, Richard Cassel Stangenes Industries Inc. Palo Alto, CA, USA

High-power solid-state modulators are emerging as reliable, tunable, and cost-effective alternatives to current spark gap and thyratron technologies. The persistent improvement of the power, speed, and availability of solid-state components is generating increased commercial interest in their development. Solid state pulsed systems are optimal for technologies demanding stringent and stable pulse shapes, high repetition rates, ultra-long lifetimes, and performance redundancy. Solid-state Marx modulators operate by charging capacitors in parallel and discharging them in series. The charge and discharge cycles are generated by IGBT switches altering the circuit in a precisely controlled pattern. During the discharge cycle the Marx erects and energy stored in the capacitors is pulsed into the load. The transient voltage drop across the pulse associated with the discharge of the capacitor, or voltage droop, limits the effective pulse width. By incorporating a boost regulator circuit in parallel with the discharge circuit, the effective pulse width can be increased from microseconds to milliseconds. SPICE simulations indicate that a 30-stage solid-state Marx modulator utilizing a novel boost circuit topology can generate a 3 ms long megawatt pulse at 20-Hz with a voltage droop of less than 1%. The boost regulator operates by boosting the discharging capacitor with matched boost capacitors. Both the discharge and boost capacitors are charged to the same voltage, so a simpler power supply topology is required. A feedback circuit controls the operation of the boost IGBTs, increasing the efficiency of the circuit by limiting the current through the boost inductor. Additional controls prevent overcharging of the discharge capacitor in the case of fluctuating load impedance. This paper describes SPICE simulations justifying the use of a boost regulator circuit in parallel with a discharge circuit to increase the effective pulse width of a Marx modulator. The effect of circuit impedances on system efficiency as well as trade-offs between parameters are investigated. Based on the positive results generated by the SPICE simulations, construction of a prototype system has begun at Stangenes Industries.

3 1O4 A HIGH POWER CASCODE SWITCH FOR RAPID, EFFICIENT ENERGY TRANSFER AT HIGH REPETITION RATES Jason M. Sanders, Andras Kuthi, Martin A. Gundersen University of Southern California, Electrical Engineering - Electrophysics, Los Angeles, CA, USA

In recent years, the number of applications that are enabled or enhanced by high peak power, nanosecond pulses has expanded. There are numerous reasons for this, key among them the advancement in fabricating and designing devices and architectures capable of rapidly transferring and shaping electrical pulses [1]. Published and ongoing research has reported that gains are realized in a number of these applications when the pulses are applied in quick succession. Examples include plasma assisted combustion and cellular membrane electropermeabilization, each of which is enhanced in specific ways by high pulse repetition rates [2, 3]. Unfortunately, most of these experiments have been unable to explore fully the effects of high repetition rates because they are limited by the maximum rate of the pulsed power supply. Rapid pulsing from high voltage, high current supplies (10-70 kV, 50 – 350 A) is challenging for a number of reasons, chief among them the lack of solid state switches capable of switching sufficiently high voltage and current with fast turn on and turn off times. To address this issue, a switch composed of power MOSFETs arranged in a cascode configuration has been developed. Proper layout results in maximum ratings of 500 V at 1 kA and dI/dt approaching 1×109 A/s. Turn-on time is less than 10 ns, and with proper thermal management, the switch can achieve a burst mode repetition rate of 1 MHz. In spite of added complexity, this switching system is well suited for real world applications that require high power switching from a reliable, efficient unit that has a long lifetime. The initial prototype has been assembled on a 6.5" × 3.5" PCB, and, though larger than a commercially available semiconductor switch, its size and weight are minimal compared to switches with competing specs, all of which are gas discharge based and require additional high voltage or laser triggering systems and high current heating circuits. Development of the next iteration of this prototype is underway, and emphasis will be placed on enhancing usability. This fully shielded "black box" unit will be easily integrated into the front end switching system of existing pulsed power supplies, featuring only an input, an output, and a trigger channel. [1] D. Singleton, A. Kuthi, J. M. Sanders, A. Simone, S. Pendleton, M. A. Gundersen , "Low energy compact power modulators for transient plasma ignition," Dielectrics and Electrical Insulation, IEEE Transactions on , vol.18, no.4, pp.1084-1090, August 2011. [2] I. V. Adamovich, I. Choi, N. Jiang, J.-H. Kim, S. Keshav, W. R. Lempert, E. Mintusov, M. Nishihara, M. Samimy, and M. Uddi, "Plasma assisted ignition and high-speed flow control: non- thermal and thermal effects," Plasma Sources Science and Technology, vol. 18, p. 034018, 2009. [3] P. T. Vernier, Y. Sun, and M. A. Gundersen. 2006. Nanoelectropulse-driven membrane perturbation and small molecule permeabilization. BMC Cell Biol. 7:37.

4 1O5 NEW CONCEPTS FOR PULSED POWER MODULATORS: IMPLEMENTING A HIGH VOLTAGE SOLID-STATE MARX MODULATOR Floyd Arntz1, Kevin Ostlund1, Michael Kempkes1, Jeffrey Casey 1Diversified Technologies, Inc. Bedford, MA, USA, 2Rockfield Research, Inc. Las Vegas, NV, USA

Marx Modulator Design: The International Linear Collider (ILC) program is expected to require up to 650 pulse modulators, each of which will nominally provide at 120 kV, 120 A, 1.5 milliseconds, 5 Hz cathode pulses for the multi-beam klystrons (MBKs). Diversified Technologies Inc. (DTI) recently developed a Solid-State Marx Modulator under an SBIR program funded by the DOE. The objective was to build a full-scale Marx modulator for the ILC, and deliver it to SLAC. The modulator demonstrates a new technology for compact and economic ILC class performance. The theory of the Marx modulator design is to charge an array of capacitors in parallel (at low to medium voltage), and then erect these capacitors in series to achieve a high-voltage output. The parallel charging of the capacitors can be accomplished in a number of ways. For a very low duty cycle, resistive isolation can suffice. Similarly, for short pulses, inductive isolation is ideal. For the long pulses required of the ILC, these are not suitable. Instead, each capacitor requires two separate switches – one for charging, and one for pulsing. DTI's Marx modulator consists of the buck regulating power supplies, a set of twenty core modules, which deliver the bulk of the energy to the load, and sixteen correcting modules which compensate for the drop in voltage as the core modules' capacitors droop over the pulsewidth. By using solid-state switches, the capacitors serve as energy storage units, rather than fully discharging during each pulse. The opening capability of DTI's switches provides arc protection of the load, exactly as would a hard-switch, eliminating the need for a crowbar. The architecture provides system flexibility; it has the capability to switch additional modules onto the modulator output, providing voltage regulation with reduced energy storage. System Performance: The Marx modulator has met all design goals, and is more compact and economical than other technologies. Two expensive components of a hard switch modulator are the regulated power supply, and the large capacitor bank. The Marx significantly reduces the stored energy requirement. The ability to directly regulate output voltage eliminates the need for an external, regulated DC power supply. This enables the modulator to be powered by directly rectifying medium voltage AC power. We estimate that this class of modulator can be built for ~ $300k (in ILC quantity), with essentially no additional cost for a power supply. The combination of these factors makes the solid-state Marx bank the optimal approach to constructing ILC modulators and power supplies. Operation of this unit at SLAC will provide additional insight into potential operating refinements, as well as the inherent reliability and performance of the Marx design in combination with prototype ILC klystrons.

5 1O6 HIGH AVERAGE POWER HIGH VOLTAGE MODULATOR USING A DUAL PULSE TRANSFORMER CIRCUIT Werner Hartmann1, Norbert Grass2, Klaus-Dieter Rohde1, Martin Schwendner2 1Siemens AG, CT T DE HW4, Erlangen, Germany, 2Georg-Simon-Ohm University Nuremberg, Germany

Pulsed power technology and, in particular, high average power high-voltage modulators, are an essential component of modern environmentally friendly processes for air and water treatment, odor removal, soil remediation and the like. Most state-of-the-art power modulators use all-solid- state technology, employing magnetic switching techniques for pulse compression in single-stage or two-stage pulse compression schemes. For the generation of short high voltage pulses at high pulse repetition rates, it is common to start at a moderate voltage level in the primary stage, and achieve a sufficiently high voltage level with a step-up transformer. Pulse compression is either performed before the transformer – easing the voltage isolation requirements - , or after the transformer, which reduces the size of the magnetic switch cores but leads to increasing insulation requirements for the magnetic switches. We report on a novel concept using two step- up transformers in series, with an intermediate pulse compression stage. This concept has advantages in terms of minimizing the insulation requirements and core sizes in every stage, as well as minimizing stray capacitances and inductances, respectively. Hence, although this scheme requires an additional component (the second pulse transformer), the overall setup can be optimized in terms of core sizes, insulation requirements, and energy efficiency as compared to standard circuits. Thus, it is possible to start from a comparatively low primary stage of only 1 kV, using standard IGBT switches and off-the-shelf capacitors, in order to achieve pulse amplitudes of over 50 kV at pulse widths of the order of 150 ns and pulse repetition rates of the order of kHz. The modulator design is discussed in detail and experimental results of a prototype device are reported.

6 1O7 THE SLAC P2 MARX Mark Kemp, Andrew Benwell, Craig Burkhart, David MacNair, Minh Nguyen SLAC National Accelerator Laboratory Menlo Park, CA, USA

The SLAC P2 Marx has been under development at SLAC National Accelerator Laboratory for application to the International Linear Collider klystron modulator. Nominal operating parameters are 120kV, 140 A, 1.6 ms pulse width, 5 Hz, and a flat top of +/-0.5%. The modulator utilizes solid state switching, an oil-free enclosure, and includes robust real-time diagnostic access. Full- modulator developmental testing will have completed by early 2012. This paper summarizes the development of this modulator including the power electronics design, the control system, and final performance characteristics. In detail, we will focus on the experimental results of the modulator in key performance areas such as the flat-top and the DC to pulse efficiency. Finally, we will discuss how the Marx can be straightforwardly modified to be utilized in proposed future accelerator applications.

7 1O8 DESIGN OF A 20 KHZ MAGNETIC PULSE COMPRESSOR Dongdong Zhang1, Yuan Zhou4, Wenfeng Li3, Jiayu xu3, Jue Wang1, Yaohong Sun1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China, 3Graduate School of Chinese Academy of Sciences Beijing, China, 4Tianjin University of Technology and Engineering Tianjin, China

Presented is a compact high repetition-rate pulse generator with adjustable output amplitude based on magnetic pulse compressor (MPC). The pulse compressor makes use of commercially available insulated gate bipolar transistors (IGBT) switching a capacitor bank into a Mn-Zn transformer together with a voltage doubling circuit. The capacitor bank is charged to 800V maximum by a current resonant boost-chopper. The basic operation of the boost-chopper will be introduced and analyzed here. The output of the pulse generator is controlled by the boost- chopper. Pulses with a width of 100ns can be generated with repetition rates up to 20 kHz. The amplitude can be controlled from 9 kV to 45 kV into a 500 Ω load. As repetition rate increases, losses become increasingly important. Magnetization losses in the MPC cores lead to core heating which degrades switching performance. An efficiency design strategy for MPC is introduced, in which the total losses are minimized with respect to the individual core gains, and the resulting compression design has a lower overall loss and a better distribution of losses through the system. By optimizing the distribution of the compression ratio at each stage, the maximum energy transfer efficiency of the one-stage MPC system was 83%.

8 2O1 SURFACE FLASHOVER MECHANISM ON THE LIQUID IMMERSED DIELECTRICS Jouya Jadidian1, Markus Zahn1, Nils Lavesson2, Ola Widlund2, Karl Borg2 1Massachusetts Institute of Technology Cambridge, MA, USA, 2ABB Corporate Research Västerås, Sweden

Surface flashover mechanism on the interface of the insulators immersed in the liquid dielectrics has been studied. Modeling results have been presented as streamer shape, velocity, distributions of electric field, volume charge density and surface charge density for different liquid-solid and liquid-gas interfaces. The relative permittivity (εr) of the liquid has been set to 2.2, which represents transformer oil, while immersed dielectrics are examined having permittivities 2.1, 4.4, 1 and 1.1 which represent polytetrafluoroethylene (PTFE), pressboard, air and Sulfur- hexafluoride (SF6 at 5 bars), respectively. A two-dimensional axisymmetric hydrodynamic model, which has been previously used for modeling streamers initiated from a sharp needle electrode in the oil only dielectric system is appropriately modified to satisfy the new physics and boundary conditions. Experimental evidence has shown that streamer propagation is dramatically altered when the streamer comes in contact with another dielectric surface. The surface can either assist or impede streamer propagation depending on the orientation of the interfacial surface with respect to the direction of the main electric field component. For the case where the surface orientation is parallel to the primary direction of the main electric field component, the interface accelerates streamer propagation and aids in breakdown for both solid and gaseous dielectric interfaces by increasing the streamer velocity by 48 to125 percent depending on the permittivity difference between dielectrics and the polarity of the applied voltage. However, the opposite is true when the interface is oriented perpendicularly to the direction of the main electric field component such that streamer growth is impeded as it travels with 45 to 74 percent slower velocity along the perpendicular interface. The underlying assumption for our two-phase model is that the immersed insulator has zero conductivity, since for the sub-microsecond time-constants of interest in this paper, the conduction through the interface cannot contribute to the charge transport between electrodes if no breakdown occurs in the immersed insulator (ε/σ>>1 μs). Consequently, the conduction current in the dielectric immersed in the liquid is ignored, and the total current density in the immersed dielectric is only displacement current. At the interfacial surface, a set of boundary conditions account for the surface charge density whose time derivative is equal to the difference in normal conduction currents on either side of the interface. At the same time, the local surface charge density is always equal to the local jump in the normal component of displacement field across the interface. The maximum electric field and streamer velocity on the surface increase with increasing applied voltage peak and immersed insulator permittivity, while the streamer thickness decreases significantly on the insulator surfaces with higher permittivity. Filamentary positive streamers propagate almost two times faster on the interfacial surface than the bushy negative streamers, which have been confirmed by the model as general properties of streamers also in the oil-only system.

9 2O2 THE STATISTICAL AND FORMATIVE TIMES FOR BREAKDOWN AT A POLYMER-OIL INTERFACE Mark Wilson1, Martin Given1, Igor Timoshkin1, Scott MacGregor1, Tao Wang1, Mark Sinclair2, Ken Thomas2, Jane Lehr3 1University of Strathclyde, Electronic & Electrical Engineering, Glasgow, United Kingdom, 2AWE Aldermaston, Hydrodynamics Division, Reading, United Kingdom, 3Sandia National Laboratories, Exploratory Pulsed Power, Albuquerque, NM, USA

At the present time there is a requirement to increase the energy density of pulsed-power machines, either through driving existing or upgraded machines at elevated voltages, or by designing new, more compact, pulsed-power systems. For this approach to be effective, information about the breakdown behavior of system components, in terms of the time to breakdown as a function of voltage and rate of voltage rise, is required by the designers and operators of these machines. The time to breakdown is frequently divided into two parts, modelling the different stages involved in electrical breakdown: the statistical time associated with initiation of breakdown; and the formative time associated with the propagation of the discharge across the gap. If the von Laue approach is used, it is assumed that: the distribution of the statistical time is exponential; the formative time follows a normal distribution; and the formative time is longer than the statistical time. The von Laue distribution can be regarded as a special case of the three-parameter Weibull distribution, where the shape parameter has been set to one. It has the advantage over the more general Weibull distribution that the assumption of a normal distribution in the formative time has been confirmed experimentally in gases. This paper reports on the results for the statistical time and the average value of the formative time, derived by applying the von Laue approach to a large data set obtained during an investigation of breakdowns along a polymer-oil interface, under impulse conditions. In this investigation, five polymers with different electrical properties relevant to pulsed-power systems were used: polypropylene; low-density polyethylene; ultra-high-molecular-weight polyethylene; Rexolite; and Torlon. The times to breakdown for the polymers were measured using three different geometries, designed to create discharges across the polymer-oil interface. The validity of applying the von Laue approach to the data sets and the possible errors in deriving the statistical and formative times are discussed. The dependence of the values for the statistical time and the average formative time on the experimental geometry and the properties of the solid polymer are examined, and values for the average streamer propagation velocity are derived and discussed.

10 2O3 INITIATION MECHANISM OF NEGATIVE PULSED DISCHARGE IN SUPERCRITICAL CARBON DIOXIDE Tomohiro Furusato, Takeshi Ihara, Tsuyoshi Kiyan, Sunao Katsuki, Masanori Hara, Hidenori Akiyama Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan

The initiation mechanism of an electrical discharge in high density mediums is complex and has been the subject of extensive research for many years. Studies have shown that the initiation process is associated with the chemical composition and physical properties of the dielectric medium, the medium state, electric field distribution, and the waveform of the applied voltage, and that it involves very complex phenomena. Current theories of the discharge initiation mechanism in non-uniform field gaps in high density medium can be divided into two categories: (1) the so-called bubble triggered ionization mechanism; and (2) the direct ionization model. In our preceding study [1], results were presented of positive streamer initiation mechanism in a point-to-plane gap in compressed CO2 under ns pulsed voltage by using Schlieren and photomultiplier techniques. The results showed that direct ionization by free electrons is the dominant mechanism in positive streamer initiation. In the present study, the initiation process of an electrical discharge in a negative point-to-plane gap in supercritical phase was investigated experimentally with the same experimental setup, measurement, and observation techniques as the previous study. Experimental results show that the structure and process of a negative discharge at the initial stage are strikingly different from that of the positive one. [1] T. Ihara, T. Furusato, S. Kameda, T. Kiyan, S. Katsuki, M. Hara and H. Akiyama, "Initiation Mechanism of Positive Streamer in Pressurized Carbon Dioxide up to Liquid and Supercritical Phases with Nanosecond Pulsed Voltages", J. Phys. D: Appl. Phys. (in Press)

11 2O4 SPATIALLY-RESOLVED SPECTRAL OBSERVATIONS OF PULSED SURFACE FLASHOVER PLASMA IN A NITROGEN ENVIRONMENT Andrew Fierro, George Laity, Andreas Neuber, Lynn Hatfield, James Dickens Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

The mechanisms leading to the development of an atmospheric low temperature plasma along a surface under pulsed conditions, rise time ~ 50 ns, applied voltage ~ 40 kV, is of current interest. In the early plasma phase, high energy photons are a contributing factor to the process of generating electron avalanches resulting in surface flashover. Since only photons in the VUV regime are energetic enough to cause step-ionization or direct ionization of atmospheric gases, an experiment has been set up to allow observations of photons between the wavelengths of 115 nm and 800 nm. The self-produced radiation emitted by the developing plasma is transmitted from the atmospheric side through the MgF2 window into vacuum and focused by two off-axis parabolic mirrors onto the entrance slit of a spectrograph. VUV-sensitive optical diagnostics include a nanosecond rise-time photomultiplier tube and fast gated ICCD camera. A low voltage TTL pulse is used to synchronize the optical and electrical diagnostics providing an overall apparatus resolution of three nanoseconds. Spatially-resolved measurements of self-produced radiation with nanosecond temporal resolution in a high purity nitrogen environment were conducted. Detailed investigations of the anode triple-point (for gap distances between 3.75 mm and 8.75 mm) indicate that VUV production originates from this region as early as 60 ns before flashover for the larger gap cases. Prior to voltage collapse, the anode region exhibits a decrease in VUV intensity while VUV production at locations closer to the cathode begins to increase. This data suggests that peak VUV emission before breakdown occurs near the streamer heads due to the field enhancement created from positive-ion space charge. Further time-resolved emission spectroscopy measurements of the entire electrode region demonstrate the presence of atomic nitrogen emission lines in the VUV regime as well as the second positive system from molecular nitrogen in the UV. The dynamics of the second positive system when compared to the lifetime of VUV emission from excited atoms will add additional insight into the electro-physics of the transition from streamer to spark discharge.

Work supported by the Air Force Office of Scientific Research (AFOSR) with additional student fellowship support provided by the National Physical Science Consortium (NPSC) in partnership with Sandia National Laboratories.

12 2O5 INVESTIGATION OF VACUUM UV ABSORPTION DURING LOW- TEMPERATURE PLASMA FORMATION IN N2/H2 MIXTURES AT ATMOSPHERIC PRESSURE George Laity1, Andrew Fierro1, Lynn Hatfield1, Andreas Neuber1, James Dickens1, Klaus Frank1,2 1Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA, 2Friedrich – Alexander University at Erlangen - Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen, Germany

This paper describes recent advances in the study of self-generated emission of vacuum ultraviolet (VUV) radiation which is produced during the early time-period leading to high voltage breakdown at atmospheric pressure. Specific interest exists in understanding the role of this high energy (>10 eV) radiation in the photo-dissociation and photo-ionization processes of nano-second gas discharges. These studies are key in enabling new technologies which utilize fast (<100 ns) low-temperature plasma generation (in the form of self-contained streamers) at atmospheric pressures. Spectral measurements were performed of dielectric surface flashover events triggered between two stainless steel electrodes (field enhancement factor ~10) resting on a polished MgF2 window surface. Diagnostics include fast-shutter intensified CCD cameras, photomultipliers with VUV sensitivity, Rogowski current monitors, and optically-isolated high voltage probes. Previous studies of air breakdown showed the presence of 121.5 nm radiation which is released from de-excitation of hydrogen atoms, HI. Since this Lyman-α line is self- absorbed, it enabled inferring various plasma parameters from recording emission spectra from 115 – 135 nm for species of HI and NI. For instance, measurements in H2/N2 mixtures have revealed that the highest amount of absorption via HI atoms occurs in the high field region near the anode, implying that significant H2 dissociation for radiation-trapping is occurring in this zone. Selective spatial measurements further showed that the apparent VUV emission centers (i.e. streamer heads) move away from the anode and the mechanisms leading to line broadening (i.e. Stark effect from space charge) are a function of streamer position. Therefore estimates are presented on the electron temperature (~10 eV), density (~1019 cm-3 confined within the streamer head), and dissociation percentage (~10-5 along the streamer path) as a function of plasma location. Furthermore, the line broadening mechanisms exhibit a distinct dependence on the N2/H2 concentration, which is a current area of study. The presented self-absorption mechanisms are essential in quantitatively understanding the role of VUV radiation transport via absorption for photo-ionization during streamer breakdown, in which re-absorption of high energy photons is inherently a requirement.

Work supported by the U.S. Air Force Office of Scientific Research (AFOSR), with additional student fellowship support from NASA / Texas Space Grant Consortium, the Directed Energy Professional Society, the National Defense Industrial Association, and the IEEE Dielectrics and Electrical Insulation Society.

13 2O6 SIMULATION OF HIGH-VOLTAGE DC BREAKDOWN FOR ANGLED DIELECTRIC INSULATORS INCLUDING SPACE-CHARGE AND GAS- COLLISION EFFECTS Manuel P. Aldan1, John P. Verboncoeur2 1University of California at Berkeley, Nuclear Engineering, Berkeley, CA, USA, 2Michigan State University, Electrical and Computer Engineering, East Lansing, MI, USA

We report on 2D Particle-In-Cell (PIC) simulations of a Bergeron geometry with steady-state fields in a semi-infinite, two-electrode system separated by an angled dielectric in either vacuum or background gas. We include a number of models neglected in recent theory, such as space charge effects, dielectric surface charging, spatial and temporal distributions of particles, and the shape of the secondary-emission curve [1]. This work employs and extends an improved PIC model by Taverniers, et al., which was developed to reduce numerical grid errors at the dielectric [2]; additional enhancements include improved modeling of secondary emission from metals and dielectrics [3], improved modeling of multiple finite-thickness electrodes, and the inclusion of a triple-point emitter modeled after Schächter's theoretical developments [4]. Simulation parameters are dielectric insulator material, dielectric angle, gap width, applied voltage, and gas type and pressure. Vacuum simulations focus on DC multipactor breakdown initiated by a triple- point source. Single-surface multipactor breakdown in vacuum is defined as bulk population multiplication with an average secondary-emission coefficient (δavg) greater than unity at the onset of anodic current. Due to space charge saturation, a current can develop at the anode equal to the seed current without a bulk population multiplication; this condition is characterized as a dark-current with δavg less than unity at the onset of anodic current. The introduction of gaseous species into the system significantly alters space charge, and can lead to additional phenomena associated with gas ionization. It is observed that multipactor breakdown is dominant at very low pressures (~1 mTorr) and gaseous species do not significantly change breakdown characteristics, e.g. breakdown voltage and time to breakdown. Increased pressure (~1 Torr) exhibits additional avalanche effects. A study on the role of the seed-current initial conditions and type will be presented, along with a detailed analysis of the influence of background gas. Breakdown voltage as a function of dielectric angle will be presented from vacuum through atmospheric pressure, taking particular care to distinguish dominant effects within specific pressure regimes. Comparisons with theory and existing gas-breakdown experiments will be made when possible. Finally, a study on the influence of multiple finite-thickness electrodes will be presented. [1] Jordan, N.M., et al., "Electric field and electron orbits near a triple point," J. Appl. Phys., 102, 2007. [2] Taverniers, S., et al., "2D Particle-In-Cell Modeling of Dielectric Insulator Breakdown," ICOPS 2009 Proceedings, 2009. [3] Vaughan, J.R.M., "A New Formula for Secondary Emission Yield," IEEE Trans. Electron Dev., Vol. 36, No. 9, 1989, pp.1963-1967. [4] L. Schächter, "Analytic expression for triple-point electron emission from an ideal edge", Appl. Phys. Lett., Vol. 72, No. 4, pp. 421 – 423, 1998.

This work is supported by an AFOSR grant on the Basic Physics of Distributed Plasma Discharges.

14 2O7

REINFORCED INSULATION PROPERTIES OF EPOXY RESIN/ SIO2 NANOCOMPOSITES BY ATMOSPHERIC PRESSURE PLASMA MODIFICATION Wei Yan1, Toan Phung1, Zhaojun Han2, Kostya (Ken) Ostrikov2 1University of New South Wales, School of Electrical Engineering and Telecommunications, Sydney, Australia, 2CSIRO Material Science and Engineering, Plasma Nanoscience Centre Australia, Lindfield, Australia

Nanocomposite dielectrics hold a promising future for the next generation of insulation materials because of the optimized properties on their relative permittivity, space charge distribution, partial discharge characteristics and electrical breakdown strength. The reinforced ageing resistance against variety of stresses also allows such materials to perfectly fit the requirement of outdoor and high voltage insulation applications. However, poor interaction and compatibility between the nanoparticle fillers and the host materials lead to degradation of the overall performance of the synthesized material, because they significantly dominate the characteristics of the interfacial region between the organic and the inorganic phases, which usually take up to a few tens of percents of the totally volume. To solve this problem, we aim to improve the surface reactivity of the nanoparticles so that to create strong chemical bonds in the interface while remaining good dispersion uniformity by taking the advantage of the plasma technology. In the presented study, SiO2 nanoparticles are treated with atmospheric pressure non-equilibrium Helium plasma prior to being added into the epoxy resin host. Fourier transform infrared spectroscopy (FTIR) results reveal that the effects of the plasma process on the surface functional groups of the treated nanoparticles, as well as the reactions of the interfacial region between the nanoparticles and the polymer matrix. Scanning electron microscopy (SEM) results show that the plasma-treatment improves the dispersion uniformity of nanoparticles in the host polymer. In the respect of the insulation performance, the partial discharge (PD) resistivity of the plasma-treated specimen is improved as a higher inception voltage and a lower PD magnitude is found compared with those shown by the untreated nanocomposite. Weibull plots suggest that the breakdown strength of the nanocomposite is improved by around 5%. Furthermore, approximately 20% increase of the lifetime for the plasma-treatment sample is indicated from the endurance test under an extreme electric field.

15 2O8 FLASHOVER PHENOMENA ACROSS SOLID DIELECTRICS IN VACUUM: MECHANISM AND SUPPRESSION Guan-Jun Zhang, Jiang-Yang Zhan, Xue-Zeng Huang, Hai-Bao Mu Xi'an Jiaotong University, School of Electrical Engineering, Xi'an, China

Surface flashover in vacuum is a great limitation of electrical and electronic system, since it typically takes place on the surface region of an insulating material at applied electric stress much lower than the bulk breakdown strength of the material, which is closely related to multiple factors such as the applied waveform, the included angle between electrode and the surface, the elements of desorbed gas, the kinds of material, the surface roughness, the temperature, the gas pressure, the electrical pre-stress and so on. Essentially we consider it is a kind of complicated surface and interface physical phenomenon. Based on the concurrent optical and electrical measurements and microscopic observations, the research works of our group concentrate on the relationship between flashover and surface/interface condition of insulating materials. The experimental results reveal that, under low electric field, prior to field electron emission from the cathode triple junction, electroluminescence phenomena occur due to the radiative recombination of electrons and holes injected into the surface states from the electrodes. There are some different optical phenomena detected from the surface of alumina and polymers, and we attribute the preflashover phenomena to the differences between the surfaces of different insulating materials. According to the results, the phenomena mentioned above are related to the trapping parameters in the surface layer of a material. This work is a contribution to the traditional secondary electron emission avalanche (SEEA) model. A novel machinable ceramic is developed for vacuum insulation system, which has excellent machinable performance and good surface electrical capability. Moreover, different preparation technologies with doping and hydrofluoric acid (HF) etching treatment were investigated. The experimental results show that, the glass phase on the surface of machinable ceramics is an important factor for the largely existing shallow traps, and the shallow traps bring disadvantage in the flashover characteristics. By eroding off the glass phase in the sample with hydrofluoric acid treatment, the shallow traps can be reduced, thus its flashover stability can be greatly improved and its scattering phenomenon is significantly reduced.

16 1P1 FAST OPENING SWITCH APPROACH FOR HIGH-VOLTAGE VACUUM TUBE PROTECTION APPLICATION Wolfhard Merz1, Monty Grimes2 1DESY, MKK7, Hamburg, Germany, 2Behlke Power Electronics LLC Billerica, MA, USA

The operation of high-power, high-frequency vacuum tubes requires an appropriate protection method to avoid significant damages during arcing. Fast closing switches like spark gaps, thyratrons, ignitrons and semiconductors acting as charge-diverting bypass switches are the most commonly used protection method. These "crowbar" switches cause hard transient conditions for all subcomponents involved and usually result in a significant post-fault recovery period. The availability of fast high-voltage semiconductor devices, with flexible on/off control function, makes opening switch topologies possible and attractive to improve this situation. This paper describes a circuit topology to protect an Inductive Output Tube which is expected to operate within RF subsystems for accelerator applications. The topology is characterized by using a commercial available high voltage MOSFET switch with direct liquid cooling and completed with essential snubber extensions. The advantages of the opening switch approach are faster action, smaller fault energy, faster recovery, and more compact design. Initial test results of this topology are presented.

17 1P2 HYBRID OPTIONS FOR UPGRADE OF THE LHC ENERGY EXTRACTION SWITCHGEAR Knud Dahlerup-Petersen, Gert-Jan Coelingh, Bozhidar Panev CERN, TE, Geneva, Switzerland

The high current switching in the more than 230 energy extraction facilities for rapid discharge of the superconducting circuits in CERN's LHC collider is presently based on specifically adapted, electro-mechanical DC switchgear. The experience from more than two years of operation confirms the high reliability of these systems with no observed opening failures and a calculated, single failure probability of 2.5% for a 20-year operations period. However, meticulous adjustments and sustained maintenance of the DC breakers, required because of degradations occurring during commutation (even in the presence of capacitor commutation assistance), is an essential activity of every shutdown of the machine. Consequently, CERN is now considering a replacement of at least a part of the existing systems by new hybrid facilities in which IGCTs are used as static switches in combination with the more classical gear. The paper describes the philosophy behind the choices for topology and component selection for both low- to medium current, bi-polar circuits (double IGCT's with blocking diodes and a series-connected, classical opening breaker as back-up, only activated in case of a double IGCT release failure) and for bi- polar, high-current applications (13 kA) with traditional DC breakers paralleled by a double IGCT switch, which basically serve as an efficient snubber system. The driver circuits and the protection features are also described. The detailed design of a hybrid bi-polar, +/-600A extraction system is presented, including a compact, heat-transfer-liquid cooled 500 kJ extraction absorber with adjustable resistance.

18 1P3 SENSITIVITY ANALYSIS FOR THE CLIC DAMPING RING INDUCTIVE ADDER Janne Holma, Michael Barnes CERN, TE/ABT/FPS, Geneva, Switzerland

The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat, high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than +/-0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. PSpice has been utilised to carry out a sensitivity analysis of the predicted output pulse to the value of both individual and groups of circuit components: these results are used to define component performance requirements, nominal values and tolerances. This paper reports the simulation results as well as tests and measurements of the various candidate components, including semiconductor switches, pulse capacitors and transformer cores.

19 1P4 DESIGN AND TEST OF A MODULAR TRIGGER GENERATOR FOR OVER- VOLTAGE TRIGGERING OF MARX GENERATORS Martin Sack, Georg Mueller Karlsruhe Institute of Technology, IHM, Eggenstein-Leopoldshafen, Germany

Over-voltage triggering of a spark gap enables a synchronized operation of several Marx generators in repetitive operation without an increased wear of the electrodes. The trigger pulses are generated by means of a pulse generator consisting of several stacked stages, which are equipped with IGBTs as opening switches. A pulse transformer serves as intermediate energy storage. It replaces one charging coil between the first and second stage of the Marx generator and couples the trigger pulses into the Marx circuit causing an over-voltage across the 1st stage's spark gap. The number of stages of the trigger generator can be varied in order to adapt the trigger generator to different Marx generator designs with varying stray capacitance and breakdown voltage of the spark gap. The paper describes the design of the trigger generator and presents the results of tests.

20 1P5 PARAMETRIC MEASUREMENTS OF SWITCHINGS LOSSES OF IGBT´S IN PULSED POWER APPLICATIONS Claus Strowitzki, Matthias Dahlke MLase AG, Development, Germering, Germany

IGBT´s are the working horse in Power Electronics. Due to improvements of the IGBT´s they find also many applications in the field of Pulsed power. The switching losses of an IGBT are normally given from the supplier, but for typical converter applications. These Data are not valid for Pulsed Power applications. In this paper parametric measurements of switching losses are shown for IGBT`s in typical pulsed power application.

21 1P6 A 5KV, 3MHZ SOLID-STATE MODULATOR BASED ON THE DSRD SWITCH FOR AN ULTRA-FAST BEAM KICKER Andrew Benwell1, Craig Burkhart1, Anatoly Krasnykh1, Tao Tang1, Alexei Kardo- Sysoev2 1SLAC National Accelerator Laboratory, Electrodynamics, Menlo Park, CA, USA, 2Ioffe Physical Technical Institute St. Petersburg, Russia

A solid-state modulator has been developed at the SLAC National Accelerator Laboratory for ultra-fast broadband beam deflection. The modulator design is based on an opening switch topology that uses Drift Step Recovery Diodes (DSRDs) as the opening switches. The modulator provides nano-second length pulses into a 50 Ω load, i.e. a strip line kicker. The rise and fall time of the kicker is primarily determined by the switching characteristic of the DSRD and has been measured as approximately 1ns with a 5kV output voltage. A robust pumping circuit for the DSRD kicker has been developed and tested at a 3MHz repetition rate. The design and results of the modulator development are discussed.

22 1P7 SOLID STATE FAST TRANSITION KICKER MODULATOR FOR ACCELERATOR APPLICATIONS Steven Glidden, Howard Sanders, Daniel Warnow Applied Pulsed Power, Inc. Freeville, NY, USA

Kicker requirements have become more complicated with each new accelerator design. This paper will describe a fast transition electrostatic kicker modulator. This electrostatic kicker modulator achieves a 20 kV transition on a 2 m strip-line within 250 ns from trigger at a maximum transition frequency of 40 kHz, using less than 8 kW at full power. The electrostatic kicker modulator operates using a fast resonant charge circuit combined with a slow maintenance circuit in a push-pull configuration operating at ±10 kV. The rise time of the voltage change is less than 100 ns, and either state can be maintained indefinitely. The system uses four 32 kV MOSFET switches that operate at peak currents of 100 amps, switching 1 MW of peak power.

23 1P8 NEXT GENERATION, FAST CURRENT RISE-TIME, LASER PUMPED 5KV SILICON THYRISTOR SWITCH Steven Glidden, Howard Sanders, Daniel Warnow Applied Pulsed Power, Inc. Freeville, NY, USA

Lasers have been used to control semiconductor switching devices either by laser gating or laser triggering. Laser gating requires the optical source to generate all charge carriers, which would be prohibitively expensive in terms of optical power to use with high current devices. Laser triggering only generates charge carriers in the gate region of the device, still resulting in a slow turn-on time, as those charges create conducting channels between the anode and cathode. Laser pumping is an alternative that combines these two concepts, seeding all of the initial charge carriers using optical power while using thyristor action to maintain conduction. By selecting the appropriate wavelength, the charge carries can be generated throughout the bulk of the thyristor. This significantly reduces the costs of the optical power while still providing a very fast turn-on, as the limit of the turn-on time is not the rate at which the initial charge carriers can be generated but how quickly the device can be seeded with photo-generated charge carriers. Building on previous work, a new generation of silicon thyristors specifically designed for laser pumping were manufactured with an upgraded manufacturing process to improve metalization, passivation, and breakdown voltage. Also a new high power compact laser source was developed which was designed for lower cost. This paper will describe the significant switching speed performance- demonstrated by the laser pumped thyristor switches as compared to conventional switches.

This work has been supported in part by DOE Grant DE-FG02-08ER85188

24 1P9 GROUND BASED RADAR MODULATOR SOLID-STATE UPGRADE Sherry Hitchcock1, Paul Holen1, Magne Stangenes1, Mike Garbi1, Chris Rivers1, Harry Anamkath1, Randy Ross1, Lill Runge1, Alan Gardner2, Jurgen Terry2 1Stangenes Industries, Inc Palo Alto, CA, USA, 2Raytheon Technical Services El Segundo, CA, USA

A ground based radar modulator driving a Klystron microwave amplifier has been designed, built and tested. It is a solid-state upgrade replacing a thyratron based line-type modulator including a shunt regulated resonant charge power supply and a pressurized SF6 insulated pulse transformer tank. The upgraded modulator is a high-current thyristor based line-type modulator with a command charge switching power supply and an oil-filled pulse transformer and socket assembly tank. The modulator produces an 117 kV, 80 A, 7.1 us flat top pulse with 25 kW average beam power and is driven by a 400 Hz 208 V generator. The modulator is compact and the design is modular and interlocked for ease of maintenance and improved safety. This paper will provide details of modulator performance including operating data, output waveforms and environmental test results.

25 1P10 AN OVERVIEW OF CONTEMPORARY SOLID-STATE MODULATOR TOPOLOGIES AND THEIR PRACTICAL PARAMETER SPACE Sherry Hitchcock, Richard Cassel, Magne Stangenes Stangenes Industries, Inc Palo Alto, CA, USA

With the advent of improved switching devices like high-current thyristors and high voltage IGBT's , solid-state modulators have significantly evolved over the past 50 years. The improved performance of these devices have enabled development of solid-state modulators in the mid power range (10 kW to 150 kW) that are suitable for radar, research, inspection and medical applications. This paper will look at the key components that are needed for each of the topologies and the demonstrated operating parameters and identify the topologies that are optimum with respect to reliability, cost, size and weight within a variety of parameter spaces.

26 1P11 OPTIMUM TERA HERTZ PULSE AMPLITUDE IN LOW TEMPERATURE GROWN GALLIUM ARSENIDE PHOTOCONDUCTIVE SWITCHES FOR POWER APPLICATIONS Omar Ibrahim1, Haitham Al Saif1, Ashwani Sharma2, Clay Mayberry2, P. Kirawanich3, N. E. Islam1 1University of Missouri - Columbia, Department of Electrical and Computer Engineering, Columbia, MO, USA, 2AFRL/RSVE Albuquerque, NM, USA, 3Mahidol University, Department of Electrical Engineering, Nakhon Pathom, Thailand

Electromagnetic waves are radiated when the signal from a generator is propagated through a transmission line to reach the antenna, where radiations occur. In generating THz radiation from a photo conductive semiconductor switch (PCSS) using femto-second laser pulses, however, the substrate of the PCSS acts both as the signal generator as well as the transmission line while the metallic contacts act as the antenna. The shape of the radiated wave depends on the carriers generated in the substrate that accelerate towards the contacts1. Thus the substrate properties (as well as the contact shape) determine the antenna radiation characteristics for PCSS based THz radiators2. The PCSS material itself is grown through the compensation process, where a defect state which acts as a donor or an acceptor is compensated through a shallow donor or acceptor. The material therefore is a trap-filled region. As a result the pulse rise time and amplitude depends largely on the interactions (trapping/de-trapping) of the generated carriers with these trap sites during the collection process. Thus in applications where the pulse amplitude and rise-time play a central role, the material property needs careful evaluation. The objective of this research is to establish a link between the pulse amplitude and the substrate material characteristics and to determine how the substrate conditions can be optimized for high amplitude pulse generation. Specifically, the substrate material characteristics such as compensation mechanisms, traps properties, that determine E-fields, recombination rate, photo generation pulse shape and current conduction in a low temperature Gallium Arsenide (LT-GaAs) grown semi-insulating material is studied3. High amplitude signal is desirable in many applications. In communications, for example, an increase in the amplitude of the transmitted signal will result in a nonlinear increase in the received signal to noise ratio and also an improved communication link which would enable providers to use multi-level coding, thus increasing the data rate4. [1] P. Kirawanich, S. J. Yakura, and N. E. Islam, "Study of High Power Wideband Terahertz- pulse Generation Using High –Speed Photoconductive Semiconductor Switches," IEEE Transactions on Plasma Sciences Vol 37, No. 1, pp219, 2009. [2] S. J. Yakura, C. E. Baum and N. E. Islam, "Analyzing enhanced terahertz-pulse power and frequency using a field-carrier transport approach," IEEE Antennas and Wireless Propagation Letters, IEEE Antennas And Wireless Propagation Letters, VOL. 7, 2008 725. [3] Naz E. Islam, Edl Schamiloglu, Jon S. H. Schoenberg, and R. P. Joshi, "Compensation Mechanisms and the Response of High Resistivity GaAs Photoconductive Switches During High- Power Application," IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 5, OCTOBER 2000. [4] M. A. Richards, "Fundamentals of Radar Signal Processing," McGraw-Hill, New York, 2005.

27 1P12 DESIGN AND TESTING OF WIDE BANDGAP CURRENT LIMITING DEVICES Nathaniel Kinsey1, Randy Curry1, Robert Druce1, Heikki Helava2 1University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA, 2Helava Systems Inc. Deer Park, NY, USA email: [email protected]

The University of Missouri in collaboration with Helava Systems Inc. developed a concept and shown in experiments a solid state switch based on the photoconductive properties of a semiconductor to be used in pulsed power systems. A device geometry was subsequently designed which would allow for matched microwave off-state transmission but provide substantial attenuation of the signal in the on-state (illuminated) condition. Several possible device geometries were designed and optimized in a CST Microwave Studio®. Each design was simulated and the results compared allowing for the best possible geometry to be chosen. The chosen design allowed for greater than 99% off-state transmission and an on-state limiting of less than 7% of the incident signal. Initial experimental tests to determine the semiconductor's effectiveness to act as a photoconductive switch were investigated using highly conductive silver paint. Once initial data was taken and the responses better understood, the designed geometry was fabricated with the semiconductor. These devices were then subjected to testing and the results compared with simulated calculations in CST and MATLAB. The University of Missouri has demonstrated the ability of aluminum gallium nitride (AlGaN) to act as a photoconductive switch when illuminated with 355-nm light. Experiments show a greater than two orders of magnitude drop in semiconductor channel resistance upon illumination. While further investigation into the ability of the device to obtain sub-ohm resistance levels is needed, initial tests and calculations confirm the ability of AlGaN materials to act as a current limiting device with the geometry designed by the University of Missouri.

28 1P13 DEVELOPMENT OF AN AUTOMATED TEST SETUP FOR LONG TERM SYSTEMATIC EVALUATION OF EXPERIMENTAL GATE-TURN-OFF THYRISTORS IN HIGH ENERGY PULSE APPLICATIONS Shelby Lacouture1, Kevin Lawson1, Stephen Bayne1, Michael Giesselmann1, Heather O'Brien2, Aderinto Ogunniyi2, Charles Scozzie2 1Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA, 2U.S. Army Research Laboratory Adelphi, MD, USA

One of the main issues with implementing a new technology into any system is understanding the lifetime and failure modes of that technology. The test setup developed at Texas Tech University is designed specifically to evaluate experimental high energy switches during continuous operation and monitor device characteristics to determine when the device is going to fail. The devices that are tested on this setup are both high energy silicon and silicon carbide gate-turn-off thyristors capable of switching pulsed currents up to 6 kA. The silicon devices were developed by silicon power and the silicon carbide devices were designed by Cree Inc. The test bed incorporates two different operating modes; pulsed operation and curve tracing mode. The pulsed operating mode utilizes a 1.8 kJ 10-stage pulse forming network (PFN) to provide a square current pulse through the device under test with a peak current of 6 kA and a pulse width of 100 µs. The PFN is charged by a rapid capacitor charger (developed at Texas Tech University) capable of charging at 3.6 kJ/s in order to achieve a max repetition rate of one pulse per second. The system is matched to a 0.5 Ω load so that a peak current of 6 kA can be achieved with a charging voltage of 6 kV which is below the avalanche breakdown point of the device under test. The system will simultaneously monitor the gate voltage, gate current, on-state voltage, and cathode current. This information will be used to determine if the characteristics are changing during operation and stop testing if the device is degrading. Periodically throughout testing the setup will switch into the second operating mode; curve tracing mode. This mode will control multiple systems to measure four different I-V curves for the various junctions within the device. The forward conduction I-V curve trace will monitor the DC characteristics of the device up to 100 A. This trace will provide valuable information for the turn-on voltage and on-state resistance. The forward blocking I-V curve will trace the blocking characteristics out to the onset of avalanche breakdown, around 8 kV determining the critical information on the leakage current of the device and breakdown voltage. The third trace will measure the forward gate I-V curve to determine the gate turn-on voltage and the gate on-state resistance. The final trace will evaluate the reverse gate I-V curve to determine the gate leakage current. All of these traces will be analyzed to determine if the DC characteristics of the device is degrading during the course of the test.

29 1P14 FIBER OPTIC SYSTEM FOR 50 MHZ BURST OPERATION OF A SILICON CARBIDE PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH Daniel Mauch, Cameron Hettler, William Sullivan III, James Dickens Texas Tech University, Center for Pulsed Power and Electronics, Lubbock, TX, USA

A fiber optic system was constructed to demonstrate high frequency operation of a silicon carbide photoconductive semiconductor switch. The goal was to transform a single high-power laser pulse into a train of pulses by adding static delays into a multimode fiber bundle. The individual optical fibers comprising the fiber bundle were divided equally into groups with differing length. These groups incrementally add an additional 20 ns of flight time to the light in their respective portion of the total fiber bundle. The end result is a train of pulses with 20 ns between each pulse. A frequency tripled Nd:YAG laser (10 ns FWHM) generating up to 300 mJ of light at 355 nm is coupled from free space into the fiber light guide. Experimental results examining the collection and transmission efficiency, and temporal and spatial output are presented.

30 1P15 DV/DT IMMUNITY AND RECOVERY TIME CAPABILITY OF 1.0 CM2 SILICON CARBIDE SGTO Aderinto Ogunniyi1, Heather O'Brien1, Charles Scozzie1, William Shaheen2, Anant Agarwal3, Lin Cheng3, Victor Temple4 1U.S. Army Research Laboratory Adelphi, MD, USA, 2Berkeley Research Associate Beltsville, MD, USA, 3Cree, Inc Durham, NC, USA, 4Silicon Power Corporation Clifton Park, NY, USA

The silicon carbide SGTO is a future switching component technology of interest to the Army for various pulsed power applications. This research investigates the dV/dt immunity and recovery 2 time (Tq) capability of 1.0 cm silicon carbide (SiC) super gate turn-off thyristors (SGTOs). The 1.0 cm2 SiC SGTO is the first of its kind. . The SiC SGTO was designed by SPCO and Cree, while the fabrication was done by Cree. This device has a mesa area of 0.73 cm2 and a drift region thickness of 90 um and capable of holding off voltage greater than 9 kV. The dV/dt evaluation implemented on the SiC SGTO is an analysis used to determine the device hold-off capability when subjected to very fast voltage transient in the off-state. This analysis is essential because the switches used in pulse power systems for the Army will be exposed to very noisy environments. The recovery time (Tq) evaluation determines the amount of delay time required for the switch to transition from the on-state to the off-state with confidence that the device will not abruptly switch on. Pulse evaluation results suggest that the SiC SGTO did not require assisted gate turn-off and obtained a recovery time less than 25 μs after a 1-ms pulse-width current of 1.7 kA, corresponding to an action level of 1.445 x 103 A2s. Furthermore, the SiC SGTO was evaluated for dV/dt immunity with an instantaneous rise time greater than 9 kV/μs. This paper will include detailed information on circuit topology used for both dv/dt and recovery time analysis, pulse evaluation approach used to acquire electrical characteristics of SiC SGTO, pulse evaluation results of the SiC SGTO. The performance of the 1.0 cm2 SiC SGTO will also be compared with previous evaluations of Si SGTOs and smaller die area SiC SGTOs.

31 1P16 IGBT GATE DRIVER UPGRADES TO THE HVCM AT THE SNS Dennis Solley, David Anderson, Gunjan Patel, Mark Wezensky Oak Ridge National Laboratory, Research Accelerator Division, Oak Ridge, TN, USA

The SNS at ORNL has been fully operational since 2006 and in September 2009, the design goal of 1MW of sustained beam power on target was achieved. Historically, the high voltage converter modulators (HVCM)s have been a known problem area and, in order to reach another SNS milestone of ≥90% availability, a new gate driver was one of several areas, targeted to improve the overall reliability of the HVCM systems. Both the drive capability and fault protection of the large IGBT modules in the HVCM were specifically addressed to improve IGBT switching characteristics and provide enhanced troubleshooting and monitoring capabilities for the critical IGBT/driver pair. This paper outlines the work involved, and results obtained, while completing this driver upgrade and documents the driver's long-term performance. Enhanced features, designed to be used in conjunction with a new controller presently under development, will also be discussed.

ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05- 00OR22725

32 1P17 HVCM TOPOLOGY ENHANCEMENTS TO SUPPORT A POWER UPGRADE REQUIRED BY A SECOND TARGET STATION AT SNS. Dennis Solley, David Anderson, Gunjan Patel, Mark Wezensky Oak Ridge National Laboratory, Research Accelerator Division, Oak Ridge, TN, USA

This paper discusses the topology used in the HVCMs at SNS to process power for both the cold and warm linac sections of the klystron gallery in support of extended operations at the megawatt level. In anticipation of a second target station and higher anticipated power levels, an enhancement to the present topology is being investigated. SPICE circuit simulations and preliminary experimental data will be presented.

33 1P18 ULTRA-COMPACT 100 KV SOLID-STATE SWITCH DEVELOPMENT FOR SUB-MICROSECOND DISCHARGES R.J. Richter-Sand1, G. Parker1, M. Kostora1, S. Heidger2, M. Domonkos2, E. Loree3 1SAIC Albuquerque, NM, USA, 2AFRL Albuquerque, NM, USA, 3Loree Engineering Albuquerque, NM, USA

Compact pulse power applications require switching components that offer kA-level current conduction, high voltage operation of 100 kV, a low inherent inductance necessary to achieve >1010 di/dt, and triggering mechanisms to produce repetition-rate discharges. Development of a prototype 10 kV, 6 kA, 200 nanosecond solid-state triggered switches with low repetitive rate capabilities and scalable attributes to a 100 kV module is presented. Project application engineers are using bare voltage-controlled (VC) wafers from Silicon Power Corporation in a volumetrically small stack (3 cm3) with the performance attributes necessary to achieve the technical milestones for a 100 kV arrangement. Wafer testing, Simulation Program with Integrated Circuit Emphasis (SPICE) circuit modeling, and the triggering system design are discussed. Assembly of the stacked wafer elements required the development of a custom assembly fixture and precise temperature control during switch element fabrication. The circuit designs employ the derivative of a negative bias for each of the stack VC solid-state wafers and a reliable fiber optic mechanism to trigger each 10 kV module in a 100 kV stack. Testing includes dissipation measurements and monitoring of failure mechanisms that affect and ultimately limit achieving a technical milestone of a 10 Hz (micro-burst or continuous with limited life). Performance characteristics are compared to a commercial solid-state thyratron replacement unit from Applied Pulsed Power Inc.

Work is sponsored by Air Force Research Laboratory (AFRL)/RDHP, Kirtland Air Force Base, under FA9451-08-D-0170.

34 1P19 AN ULTRA FAST HYBRID TOTEM POLE MOSFET/DRIVER MODULE FOR HIGH REPETITION RATE OPERATION Tao Tang, Craig Burkhart SLAC National Accelerator Laboratory Menlo Park, CA, USA

The proposed Project X MEBT (Medium Energy Beam Transport) line needs a chopper that has the capability to remove an arbitrary bunch pattern from the 162.5MHz H- beam bunch train. The chopper driver needs to provide ±500V pulses with ~1ns rise and fall time at an average repetition rate of 33MHz. A Hybrid MOSFET/driver Switch Module (HSM) has been demonstrated at the SLAC National Accelerator Laboratory, which with a 1 kV charging voltage is capable of delivering a 30A pulse with a 1 ns rise time into a 30 ohm load [1]. The design and performance of a new HSM with a totem pole output stage, as is needed for this high repetition rate application, is presented. [1] T. Tang, C. Burkhart, "Hybrid MOSFET/Driver for ultra-fast switching", IEEE Trans. on Dielectrics and Electrical Insulation, Aug. 2009.

Work supported by the US Department of Energy under contract DE-AC02-76SF00515.

35 1P20 A COMPACT SOLID STATE MODULATOR FOR ACCELERATOR APPLICATIONS Kongyin Gan, Hepin Hu, Tao Li, Zhiyuan Tan Institute of the Applied Electronics, China Academy of Engineering Physics Miangyang, China

In order to develop the compact microwave power source for the accelerator applications, a compact solid state modulator was developed basing the traditional 1:55 pulse transformer and IGBT switches in parallel in our laboratory. It can output the 45kV pulse to the magnetron when the input voltage is about 840V, the rise time of the output pulse is less than 1us when the load of the modulator is a 450 ohms pure resistor, its weight is less than 120 kilograms. This solid state modulator has been used to drive the 5193 magnetron now.

36 1P21 LONGEVITY OF HIGH POWER GAAS PCSS AT DC BIAS VOLTAGE Liu Hongwei, Liu Jinfeng, Yuan Jianqiang, Zhao Yue, Li Hongtao, Xie Weiping China Academy of Engineering Physics, The institute of Fluid Physics, Mianyang, China

Lifetime of high power GaAs PCSS at DC bias voltage has been studied. The joule heating process of PCSS shows a pivotal factor of the lifetime at primary test results. Theoretical analysis shows that joule heating comes from discharge process and leakage current may constrain the work electric of the switch and the value is much less than flashover electric field of it. Based on the joule heating process two improved aspects include changing of the work medium and erect direction of the laser has been tested. And then tested more than 5×105 times has achieved using a single PCSS with electrode gap of 15 mm under a DC bias of 19 kV, current of 0.9 kA,full-width at half-maximum of 10 ns and repetition of 20 Hz.

37 1P22 DESIGN OF REPETITIVE HIGH VOLTAGE RECTANGULAR WAVEFORM PULSE ADDER Liuxia Li, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources, Shanghai, China

In this paper, a repetitive high voltage pulse adder is described, which can generate rectangular pulse even in the case of capacitive load. This pulse adder is based on solid state switches, and each stage contains two power MOSFETs, in which one outputs voltage and another cuts off wave. With this technique, we obtain nearly rectangular pulse. By test at different type of loads, this characteristic of the pulse adder is well maintained. At the same time, a FPGA is used to control all system, which provides a convenient operation interface, so we can easily adjust output pulse voltage, repetitive rate and pulse width. In our present work , a 40-stage modulator has been built and successfully operate at output voltage of 30 kV with repetitive rate of 20 kHz, both rise time and fall time less than 250ns, and minimum pulse width of 5μs. This facility has been applied for the experiment research of dielectric barrier discharge (DBD) and pulse plasma discharge.

38 1P23 ON-STATE RESISTANCE COMPARISON OF SEMI-INSULATING 6H-SIC PHOTOCONDUCTIVE SEMICONDUCTOR SWITCHES Jianqiang Yuan, Hongwei Liu, Jinfeng Liu, Hongtao Li, Weiping Xie China Academy of Engineering Physics, Institute of Fluid Physics, Mianyang, China

In order to investigate on-state resistance of 6H-SiC photoconductive semiconductor switches (PCSSs), two kinds of 6H-SiC materials with different dark resistivity and process have been used to fabricate the PCSSs. The experimental results show that the SiC PCSS operates in linear mode. The switch made from 6H-SiC with a dark resistivity of 6×105 ohm•cm can only sustain an operating voltage of 4.2 kV, and its minimum on-state resistances can achieve tens of ohms, which are about two orders of magnitude higher than that of GaAs PCSS. Another switch made from 6H-SiC with a dark resistivity of 2×1010 ohm•cm can sustain an operating voltage of 30 kV, but its minimum on-state resistances can be as high as several kilo ohms, which are totally unacceptable for pulsed power system. The numerical analyses are presented and compared with experimental results, and the influencing factors of the minimum on-state resistance are discussed, which shows that increasing the optical energy of incident laser, carrier mobility and carrier lifetime can reduce the minimum on-state resistance. From the comparison of different 6H-SiC PCSSs, several methods to reduce on-state resistance are proposed.

Work supported by the National Natural Science Foundation of China under Grant 50837004 and 51007085.

39 1P24 PRELIMINARY RESEARCHES ON A PLANE-BOARD EXPLOSIVE OPENING SWITCH Shirong Hao, Yingmin Dai, Minhua Wang, Nanchuan Zhang, Wenhui Han, Youcheng Wu Hydro-Physics Research Institute, Academy of Engineering Physics, Si Chuan Province, Mianyang, China

A plane-board explosive opening switch and its preliminary reasearch results are presented in this paper. The opening switch consists of an explosive network board，a folded metal foil and insulating slots. When used as opening switch in inductive energy storage system, it can transfer pulse current with tens of kilo-ampere and more than 20μs rise time from primary energy source to a 50nH load in less than 2μs.The conversion efficiency is more than 90%.

40 1P25 INFLUENCE OF HYDROSTATIC PRESSURE AND TEMPERATURE ON THE WATER DIELECTRIC STRENGH AND ON THE DYNAMIC PRESSURE WAVE Justin Martin1, Thierry Reess1, Antoine De Ferron1, Robert Ruscassie1, Franck Rey- Bethbeder2 1University of Pau, SIAME, PAU, France, 2TOTAL PAU, France

The paper presents experimental results for breakdown voltage in water gaps as a function of water hydrostatic pressure and temperature. Low applied electric field and high switching energy ensure the development of subsonic electrical discharges. For these discharges, the vapour bubbles involved during the pre-breakdown phase are initiated by joule heating effect. The dependencies of the U50 breakdown voltage on hydrostatic pressure up to 5MPa and on the temperature up to 90°C are investigated. The pre-breakdown phase of the discharge is characterised by the different power consumption behaviours and by the energy losses according to hydrostatic pressure and temperature. A minimum threshold value of the discharge energy losses can be highlighted. Experimental measurements concerning the shock wave generated by the subsonic discharges are presented. Results point out that the dynamic wave is not dependent from the hydrostatic pressure. On the other hand, for a constant energy at breakdown time, the dynamic pressure wave increases with the temperature. These results will allow the optimization of the electrical energy ratio converted into acoustic energy.

41 1P26 MODELING OF THE DIELECTRIC RECOVERY OF HOT AIR IN INSULATING NOZZLES Andreas Kurz, Paul Gregor Nikolic, Daniel Eichhoff, Armin Schnettler RWTH Aachen University, Institute for High Voltage Technology, Aachen, Germany

In standard gas circuit breakers -important safety elements in today's power grids-, a small surface layer of polytetrafluoroethylene (PTFE) vaporizes at the extreme high temperatures occurring in the arcing zone during the high current phase of the interruption process. This ablation continues even some hundred microseconds after the arc has been quenched and it actually changes the total gas composition as well as the temperature profile in the arcing zone. Therefore it hinders the fast cooling of the arcing zone, which is necessary to prevent dielectric failures. The experimental determination of the dielectric recovery of hot air in insulating nozzles is already subject of previous investigations which focus on the substitution of SF6 (sulfur hexafluoride) in circuit breakers for future power grids. Thus the intention of the investigations presented here is the determination of a physical model for the calculation of the previously measured recovery characteristics. Therefore CFD simulations (computational fluid dynamics) are performed in order to derive the relevant physical properties of the decaying quenching gas (density, temperature etc.). These properties serve as input parameters for the developed model. Based on the gas properties resulting from the CFD simulations it is possible to calculate the effective ionization coefficients and thus the breakdown voltage applying the streamer criterion. Afterwards the calculated breakdown voltages are compared to the measured recovery characteristics. The comparison shows a qualitatively good agreement between the measurements and the calculation.

42 1P27 INVESTIGATIONS ON THE DIELECTRIC STRENGTH OF CARBON DIOXIDE AND CARBON DIOXIDE MIXTURES FOR THE APPLICATION IN GAS INSULATED SWITCHGEAR Paul Gregor Nikolic, Andreas Kurz, Matthias Hoffacker, Armin Schnettler RWTH Aachen University, Institute for High Voltage Technology, Aachen, Germany

Nowadays SF6 (sulphur hexafluoride) is used in circuit breakers and gas insulated switchgear due to its outstanding arc quenching and dielectric properties. Nevertheless SF6 is a strong greenhouse gas with a global warming potential of 22800 CO2 (carbon dioxide) mass equivalents. Furthermore toxic decomposition products resulting from the interruption process in circuit breakers require protective equipment for the personnel and special gas handling. Beside the emission restrictions for SF6 denoted in the Kyoto protocol recent investigations on SF6 emissions in the field of electrical power supply as well as other sectors of industry show that a future increase of the total SF6 emissions is due. Therefore it is still beneficial to search for alternative insulation and quenching gases. Previous studies showed that the dielectric strength CO2 is about one third of SF6. Additionally a decrease of its dielectric strength in case of contamination with metal particles is observed. Thus in this paper the dielectric strength of CO2 is investigated. Measurements are performed in a test arrangement which is dimensioned according to a real gas insulated switchgear geometry. A metal needle is installed in the test setup in order to simulate a particle disturbance. The investigations are performed using a lightning impulse with constant amplitude under atmospheric pressure. During the investigations the improvement possibilities of CO2 in case of particle contamination by admixture of non-toxic gases are investigated and compared to each other. Additionally high speed camera photographs of the breakdown path are taken. From the comparison of the experimental investigations results a statement on the dielectric strength of CO2 under non-uniform field conditions and on the enhancement of this dielectric strength by the admixture of additional gaseous components. These results can serve as a means for the dielectric design of a SF6-free gas insulated switchgear.

43 1P28 THE INFLUENCE OF CONCENTRATED HEAT FLUX ON THE DIELECTRIC PROPERTIES OF SYNTHETIC AND NATURAL ESTERS Pawel Rozga Technical University of Lodz, Institute of Electrical Power Engineering, Lodz, Poland

In recent years, a growing numbers of researchers focused their interest on the insulating fluids, which, in the situations where the decisive meaning is the environment protection and fire prevention, could replace the mineral oil in the power transformers. Such fluids are the specially manufactured synthetic and natural esters. From the environment protection point of view, these esters, in relation to conventional mineral oils, are characterized by the high level of biodegradability reaching even 95%. Whereas, when it comes to the fire prevention, these esters have more then twice higher temperature of flash point. The assessment of dielectric properties and the mechanisms of initiation and propagation of discharges (prebrakdown phenomena) in insulating fluids based on esters, has been taken occasionally and such incomplete results have not been allowed on the fully comparison the esters with the typical mineral oils. Apart from the few works concerning the problem of breakdown in esters, mainly, the fundamental physical- chemical and electrical properties are described. In this paper, the problem connected with the using the synthetic and natural esters as an insulating fluids in the power transformers, will be raised. This problem was observed during the production phase in one of the Polish power transformer factory. It concerns the one of the fundamental dielectric parameter characterizing the insulating material – dielectric loss factor tgδ. It has been noticed that the both esters show the susceptibility to action of the concentrated heat flux generated by the heaters of the heating system of the insulating fluid. This flux causes the violent growth of tgδ when it acts with large intensity. It means that the using the same, as in the case of mineral oil, parameters of the heat treatment of the fluid (using the unit surface load on the level of 2 W/cm2) is not possible, because such treatment causes the deterioration of dielectric properties of the esters to the level disqualifying these esters from the using as a insulating medium of power transformer. The above-described problem will be presented on the basis of investigations performed in the specially prepared experimental system. The research assumption, the experimental system giving the possibility to realization of the research programm, and the results of the analysis of the influenece of the concentrated heat flux on the dielectric parameters of two biodegradable insulating fluids (synthetic and natural ester), will be desribed in the article. The results will be presented as the diagrams showing mainly the changing of the dielectric loss factor versus the unit surface load.

44 1P29 INVESTIGATION OF AC DISCHARGES WITH WATER DROPLETS ON SOLID DIELECTRIC LAYERS Alper Kara, Ozcan Kalenderli, Kevork Mardikyan Istanbul Technical University, Electrical-Electronics Faculty, Istanbul, Turkey

This paper describes the AC discharge characteristics of air when water droplets are on solid dielectric layers floating between the electrodes. Identical planar electrodes are used to examine the breakdown voltage during the tests. In the experiments, single water droplet positioned in the center of horizontal dielectric layers is assumed to be conductive. Dielectric layers are made up of silicone rubber and polyvinyl chloride that have the same diameter with the electrodes. Tests are both conducted with positive and negative high direct voltage. The dielectric behaviors of insulating layers are investigated in the presence of water droplets in various air gaps up to 50 mm.

45 1P30 ON THE MEASUREMENTS OF THE DIELECTRIC CONSTANT AND DISSIPATION FACTOR OF VARIOUS ELASTOMERS L. Nastrat1, R.M. Sharkawy2 1South Valley University, Electrical Power and Machines Engineering, Aswan, Egypt, 2AASTMT, Electrical and Control Engineering, Cairo, Egypt

Polymeric insulators can especially be susceptible since they are mostly organic. It has always been of practical interest to study the electrical properties of polymeric insulators [1]. Elastomers have emerged relatively recently as a novel group of the constructional polymers and their characteristics are a subject of intensive studies undertaken by several research teams world wide[2]. Elastomer materials are extensively used in many insulation applications, because they show an excellent electrical performance. At one time, when natural rubber and a few synthetic rubbers constituted the primary type of rubberlike materials in use, the term rubber was predominantly used to describe this group of materials. However, with developments in the field of polymer chemistry, numerous other rubberlike materials have been developed whose chemical composition bears no resemblance to the chemical composition of the natural or the early synthetic rubbers. Also, these newer materials often exhibit vast improvements over the early rubbers in many respects while still being basically rubberlike or elastic in character. Therefore, the term elastomer came to be used to encompass the broadened range of rubberlike materials. The ASTM definition of an elastomer is "a material which at room temperature can be stretched repeatedly to at least twice its original length and upon immediate release of the stress will return with force to its approximate original length". Currently, there are over a dozen recognized classes of elastomers, a number of which are useful in electronic assemblies [3,4]. In present work, four different types of elastomer such as; Puna N, Nitrile (NBR), Hypalon (CSM), Ethylene Propylene (EPR) and Hexafluor (FPM) were examined. There were main dielectric parameters tested for the types of elastomer, i.e. dielectric constant and dissipation factor. The results indicated that the highest dielectric constant was 13 at 1 KHz for NBR elastomer, and the lowest dissipation factor was 0.0066 at 1 KHz for EPR elastomer. Also, during this work, a mathematical model is depicted, thus devising a suitable function approximation for the frequency dependent tabulated data obtained for the adopted measurement of various elastomers. [1] Raji Sundararajan, Victor Godinez and Muhammad Amin, "Performance of Thermoplastic Elastomeric and Thermoset Insulators under Accelerated Acid Rain Multistress Conditions", 15th National Power Systems Conference (NPSC), Bombay, Dec. 2008. [2] Pawer Andruszkiewicz, Marta Piatek, Ryszard Ukielski, "Electrical Properties of Thermoplastic Elastomers Copoly (Amide-Block-Amide)s, Physics and Chemistry of Solid State, V. 7, No. 1, 2006, p. 7-10. [3] H. Deng, R. Hackam, in: IEEE Annual Report-Conference on Electr. Insul. Diel. Phen., San Francisco, 1996, pp. 20-23. [4] Hans-Jorg Winter, Jens Lambrecht, and Roland Barsch, "On the Measurement of the Dielectric Strength of Silicon Elastomers", UPEC, 2010.

46 1P31 CONDUCTION AND BREAKDOWN IN SYNTHETIC AND NATURAL ESTER FLUIDS Igor Timoshkin1, Yi Jing1, Martin Given1, Mark Wilson1, Tao Wang1, Scott MacGregor1, Jane Lehr2 1University of Strathclyde, EEE, Glasgow, United Kingdom, 2Sandia NL Albuquerque, NM, USA

Dielectric liquids used for insulation in power and pulsed power systems include conventional mineral oils, synthetic and natural esters. Insulating liquids in power systems are subjected to high electric transient fields which could cause catastrophic dielectric breakdown. Natural esters have the potential to be used as an environmentally-friendly alternative to traditional mineral oils, as they are made from renewable sources, they are readily biodegradable and non-toxic. Consequently, an understanding of dielectric behaviour of ester liquids stressed with electric fields will be important for the reliable usage of these liquids in power and pulsed power applications. The present paper is focused on investigation of pre-breakdown conduction currents and conduction mechanisms in synthetic and natural ester liquids. Pre-breakdown currents in highly non-uniform electric fields produced in a point-plane electrode system have been measured and the current-voltage characteristics have been analysed. Three regions of the I-V characteristics can be attributed to different conduction regimes: Ohmic conduction; space charge saturation conduction;, and conduction controlled by Fowler-Nordheim charge injection. Using experimental I-V curves, apparent negative-charge mobilities for the ester fluids have been obtained and compared with charge mobilities for mineral oils available from previous studies and data in the literature. Breakdown characteristics of ester liquids stressed with AC and impulsive regimes have been measured in point-plane and sphere-sphere electrode topologies in accordance with ASTM International standards. The present paper discusses breakdown characteristics and pre-breakdown behavior of ester fluids and compares the dielectric behavior of these liquids with traditional mineral oils. This information will help in the determining the suitability of these ester liquids for use in practical pulsed power and power systems.

47 1P32 PULSED HIGH-VOLTAGE BREAKDOWN OF THIN FILM PARYLENE-C Juan Elizondo-Decanini, Evan Dudley Sandia National Laboratories Albuquerque, NM, USA

Measurements of polymer dielectric high-voltage (HV) strength at thicknesses in the 1 to 10 µm range have always been difficult to validate and repeat. We report results of experiments done using Parylene-C films of 2-, 4-, and 6-µm thickness in a series of configurations intended to determine the high-voltage breakdown (HVB) of the material itself with a minimum of externally undefined parameters. The experiments used an alumina substrate coated with a conductive gold film with Parylene-C film deposited on top of the lower gold film. One edge of the lower gold film was exposed to provide electrical connection, and a triangular or circular gold electrode was deposited on the surface of the Parylene-C. The intent was to test the dielectric breakdown strength of bare Parylene-C as well as to evaluate the effects of field enhancements produced by the two electrode shapes.

48 1P33 HIGH FIELD CONDUCTION IN HEAT RESISTANT POLYMERS AT ELEVATED TEMPERATURE Janet Ho, T. Richard Jow US Army Research Laboratory Adelphi, MD, USA

Improved high temperature polymeric dielectrics are in demand for applications such as hybrid vehicles, advance aircraft, wide-band gap semiconductor power electronics, and deep oil-well drilling. Metallized polymeric film capacitors have the advantage of graceful failure as a result of self-healing. As no dielectrics are perfect insulators, trace amount of electrical conduction is always present, especially at high electric field and/or elevated temperature. In this work, high field conductivity and conduction mechanisms of various heat resistant polymers were investigated. Such information is valuable not only for better understanding of transport mechanisms of the charge species at high field but also for gaining insight relevant to improved breakdown strength.

49 1P34 ELECTRICAL CHARACTERISTICS OF MICROPLASMA DEVICES WITH CARBON-NANOTUBES (CNT) AS THE CATHODE Huirong Li, Chung-Nan Tsai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

The experimental results of glow discharge in the microplasma arrays are presented. The microplasma device is based on hollow cathode structure with carbon-nanotubes (CNT) grown inside the cathode cavity. The hollow structure is fabricated on silicon wafer by etching and CNTs are grown using chemical vapor deposition (CVD) method inside the hollow structure, whose shape is either cylindrical or rectangular. The anode is a metal deposited on to the surface of the silicon. It is shown that the CNT has a lower ignition voltage at the first stage of breakdown, due to the enhanced field emission characteristics of CNTs [1]. It is also shown that the CNT performs relatively well in partial pressure [2]. The device is operated in 1 to 100 torr range under DC and high frequency unipolar fields at 20 kHz and the results are compared with the one without CNT in the hollow cathode structure. The device is fabricated in house using micro-fabrication technology. The comparison of the DC and pulsed operating characteristics of the device are presented. The optical diagnostics with a spectrometer are performed along with the help of V-I curve as a function of pressure. [1] S.J. Park, K. H. Park and J. G. Eden, "Integration of carbon nanotubes with microplasma device cathodes: reduction in operating and ignition voltages", Electronics letters 29th April 2004 Vol. 40 No.9. [2] R. Bokka and H. Kirkici, "Field emission degradation of carbon nanotubes", Power Modulator and High Voltage Conference (IPMHVC) 2010 IEEE International.

50 1P35 SURFACE FLASHOVER OF NANODIELECTRICS WITH VARYING ELECTRODE ARCHITECTURES IN PARTIAL VACUUM Zhenhong Li, Huirong Li, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

Solid insulators have been widely employed in power systems and partial vacuum, especially in space power systems. However, the holdoff capability of an insulator in vacuum is limited by the surface flashover problem due to the cathode 'triple-junction' effect [1] [2]. In this work, the surface flashover characteristics of nanodielectrics cast epoxy resin with varying electrode architectures in partial vacuum are studied. All of the samples except the control samples are made by adding nanoscale Al2O3 or TiO2 powder into the epoxy resin with known properties. The samples are in cylindrical shape, and the weight ratios between the powder and epoxy are 1:50 (2%) and 1:16.6 (6%). In a vacuum chamber, the surface flashover of the samples is investigated using DC and 20 kHz pulsed unipolar signals separately. 1 cm thick cylindrical samples are sandwiched between two parallel plate electrodes, and the voltage, current, and light emission waveforms during the flashover events are recorded and analyzed. Lateral pillar electrodes are also used in the studies and comparisons to the parallel plate case are made. Data on the voltage, current and optical emission will be presented in this paper. [1] Miller, H. C., "Flashover of insulators in vacuum: review of the phenomena and techniques to improved holdoff voltage," IEEE Transactions on Electrical Insulation, vol.28, no.4, pp.512-527, Aug 1993. [2] Fang Li, Hulya Kirkici, "Nanodielectric surface flashover studies under kHZ range pulsed fields in partial vacuum," Power Modulator and High Voltage Conference (IPMHVC), 2010 IEEE International, vol., no., pp.453-456, May 2010.

51 1P36 TO ELECTRICALLY LOCATE GATE-OXIDE DEFECTS IN DUAL-GATE TECHNOLOGIES FOR VARIOUS HIGH-VOLTAGE DOMAINS Lieyi Sheng, John Leith, Eddie Glines ON Semiconductor, Quality, Pocatello, ID, USA

High-quality gate oxides free from defects have been diligently pursued for ensuring reliable semiconductor products. However, clarifying the source of defects in degrading the gate-oxide integrity (GOI) often turns to be a daunting task in both development and manufacturing. A variety of defective sources, from starting material to process integration, were attributed to deteriorate gate oxides. Furthermore, the added process complexities of integrating dual/multiple gates, tunnel oxide for memory cells, and high-voltage (HV) devices cause more difficulties in identifying the root cause involved. For a thin layer of gate oxide, various types of defects can intricately occur along the bottom or the top interface, or be largely embedded inside. Typically, they are point defects, fairly small in size, or even invisible using conventional inspection tools. Moreover, the failure analysis efforts at nondestructively visualizing a gate-oxide defect often fail, because an electrical analysis, even delicately processed, can easily destroy the defect due to structural burst or meltdown. Consequently, a most common approach of searching a defective source has been to experimentally explore a wide range of suspected steps in the front-end-of-line (FEOL) and even further in the back-end-of-line (BEOL) processing. This paper will present for the first time a comprehensive methodology of electrically locating gate-oxide defects within the highly integrated schemes of several dual-gate processes. These technologies were developed for different voltage domains from 1.2V up to dozens of volts in realizing various applications from high-performance core circuit blocks with high-voltage I/O drivers to specific high-voltage and high-power environments (including automotive, and military/aerospace applications). During the early phase of development, conventional V-ramp and TDDB (time-dependent-dielectric- breakdown) tests revealed modestly higher defective levels on both low- and high-voltage gate- oxides as well as on the tunnel oxide when integrated. Therefore, big efforts have been made for identifying the defective sources and implementing process improvements. It has been consistently proven that the gate-oxide defects in dual-gate processes, despite their increased complexity in integration, can be more readily located than in single-gate ones. The matrix of electrical responses of defects in thin- and thick-gate oxides (and tunnel oxide if applicable) provides a unique insight of quickly getting to know the physical location of the defects, thus significantly relieves the efforts of identifying a defective source in processing. In this paper, the defects incorporated with a wide range of gate oxides from 2 nm up to 45 nm in thickness will be extensively examined. By clarifying the various types of detrimental mechanisms and defective sources, the approach of synthesizing the electrical responses for locating gate oxide defects in dual-gate processes has been well verified.

52 1P37 MECHANISM FOR STIMULATED ACOUSTIC EVENTS ASSOCIATED WITH PARTIAL DISCHARGE Aleta T. Wilder The University of Texas, Cockrell School of Engineering, Austin, TX, USA

A mechanism is proposed for Stimulated Acoustic Events (SAE) observed as associated with Partial Discharge (PD) events. The mechanism is based on the formation of a transverse horizontal wave within a dielectric gap and propagating along the high voltage electrode – dielectric interface. The excitation of a longitudinal wave in the electrode and a large acoustic impedance mismatch at the electrode - dielectric interface are required (as first described at the 2006 IPMHVC). The dilatational frequencies in the ultrasound of both the fundamental and harmonic components of the observed SAE are predicted. The spatial shear displacement due to the transverse horizontal wave has been estimated and will be described. The maximum displacement occurs in the dielectric, close to the high voltage electrode. The possibility that cyclic displacement resulting from SAE could enlarge voids that could then excite PD under voltage stress is explored.

53 1P38 HIGH TEMPERATURE CAPACITORS WITH HIGH ENERGY DENSITY Chen Zou, Nanyan Zhang, Douglas Kushner, Raymond Orchard, Charles Mi, Shihai Zhang Strategic Polymer Sciences, Inc., Capacitor Division, State College, PA, USA

Power electronics are a key technology for hybrid and plug-in electric drive vehicles (EDV) and represent 20% of the material costs. DC bus capacitors are one of the critical components in EDV power inverters and they can occupy ~35% of the inverter volume, contribute to ~23% of the weight, and add ~25% of the cost. Current polypropylene (PP) film capacitors have dielectric constant K of 2.2 and temperature stability lower than 105 °C. We recently developed a modified polytetrafluoroethylene (PTFE) which combines high dielectric constant, low dielectric loss, low leakage current, high dielectric breakdown strength, and high temperature stability. The modified PTFE capacitor film also has graceful failure feature which is critical to applications demanding high reliability and long lifetime. The thermoplastic nature of the modified PTFE ensures that they can be processed into thin capacitor film using inexpensive melt extrusion and biaxial orientation process. In this report, extensive high voltage test results of the novel capacitor film will be presented.

54 1P39 EXPERIMENTAL STUDY ON SURFACE FLASHOVER CHARACTERISTICS OF INSULATING METERIAL IN VACUUM Ling Dai, Fuchang Lin, Xiangyu Shi, Zhiwei Li, Cheng Su Huazhong University of Science and Technology , State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China

This paper devotes itself to the experimental study on surface flashover characteristics of insulating material, which is closely connected to the compact pulse power system operating in vacuum. The rated voltage of the pulse power source is several kV and the peak current is several kA. To simulate the actual operating condition and possible failure mode of pulsed power system, a series of experiments are performed to validate the adaptability of high pulsed power device in vacuum. This paper concentrates on the mechanism of surface flashover in vacuum and corresponding influence factors. Different metal electrode materials, different surface insulation materials are tested, and the interference effect of hot plasma has been studied specially. Research indicates that cleanliness and roughness of electrode surface and insulating materials have great influence on flashover voltage. Moreover, external hot plasma plays a key role in the formation of surface flashover. In medium vacuum (10-3-1 Pa), the surface flashover voltage of 3mm surface distance on organic glass is above 17kV；But if there is external hot plasma source, the flashover voltage would reduce significantly with the increase of plasma quantity; flashover voltage would rush to 1 kV or lower. Based on the experiment study, some measures are taken on the 8 kV / 100 kA pulse power system produced in prior work. The device can operate stably in the vacuum of 10-3Pa.

55 1P40

SPACER FLASHOVER CHARACTERISTICS IN SF6 UNDER REPETITIVE NANOSECOND-PULSES Huijuan Ran 1, Tao Wang 1, Jue Wang 1, Chengyan Ren 1, Ping Yan 1, Dongdong Zhang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Graduate University of Chinese Academy of Sciences Beijing, China, 3Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China

Very Fast Transient Overvoltages (VFTO) might result insulation failures inside or outside Gas Insulated Switchgears (GIS), and most of them are lead by the spacer flashovers on the basis of operational experiences. To get a better understanding of the discharge progress, an experimental study on spacer flashovers under nanosecond-pulse in compressed SF6 gases is presented. The source of nanosecond-pulse is a solid-state pulse generator SPG200N, which the pulse rise-time and pulse-width are 15 ns and 30~40 ns respectively, and the pulse repetition frequency varies from 1 Hz to 1 kHz. The material of spacer is epoxy resin, which is a common material of spacers in GIS. The test electrodes are plane-plane electrodes to simulate the near-uniformly field in GIS, which are 80mm in diameter. In this research, the parameters affecting flashover characteristics such as voltage-current waveforms, repetitive pulse stress time and applied pulse number are measured, and the affections about the flashover characteristics are analyzed. The experimental results show that the repetitive pulse stress time decreases with the increasing of the applied electric field and the pulse repetition frequency. At the last, the comparison about the characteristics between the spacer flashover and gap breakdown is presented.

56 1P41 STUDY ON SURFACE FLASHOVER AND GAS DESORPTION OF SOLID INSULATION MATERIALS IN VACUUM Chengyan Ren1, Li Xiao1, Jue Wang1, Ping Yan1, Dongdong Zhang1, Yaohong Sun1, Tao Shao1, Tao Wang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China

The relation of desorbed gases and surface discharge in vacuum is a complex problem without reliable theory. The vacuum experimental platform of direct current and nanosecond pulse source was built, and the quadrupole mass spectrometer connected to vacuum cavity was used to analysis the out-gassing characteristics of insulation materials. Then the vacuum surface discharge experiments were done and the out-gassing characteristics were measured in the process. By comparing the mass spectrograms before discharges with ones after discharges, we obtained the out-gassing composition of several insulation materials. Meanwhile we analyzed the probable sources of different gases. The results show that the high polymer surface may decompose and the dissolved gases may be extracted besides gas desorption in discharges. The flashover voltage of insulation materials has direct effect on their out-gassing characteristics. We'll thoroughly research their relation in subsequent work.

57 1P42 EXPERIMENTAL STUDY OF NANOSECOND-PULSE DIELECTRIC BARRIER DISCHARGE IN OPEN AIR Tao Shao12, Cheng Zhang1, Yang Yu1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

Dielectric barrier discharge (DBD) is an important method to produce non-thermal plasma in atmospheric air, which is widely used in a variety of industrial fields. In this paper, the discharge is generated in atmospheric air using a magnetic compression solid-state pulsed power generator. The output pulse can be up to 30 kV with a rise time of about 40 ns and a full width at half maximum of 70 ns. The characteristics are studied by the measurement of voltage and current waveforms, discharge images, and optical emission spectroscopy. The experimental results show that when the air gap is less then 3 mm, no filaments are observed and the DBD is diffuse in the whole discharge regime. The rotational and vibrational temperatures of the DBD are calculated according to the emission band of the nitrogen second positive system near 380.5 nm. The relationship between the emission intensity and the rotational temperature with the applied voltage and driving frequency are investigated and discussed. The experimental results show that the emission intensity is sensitive to the applied voltage and driving frequency, and the rotational temperature indicates insensitivity to the applied voltage and driving frequency.

58 1P43 STUDY ON THE DC SPACE CHARGE CHARACTERISTICS OF THE MULTI- LAYER OIL-PAPER INSULATION MATERIAL USED IN POWER TRANSFORMER Chao Tang College of Engineering and Technology, Southwest University, Chongqing, China

The fast development in HVDC transmission projects has enlightened the significance of the research on space charge behaviors in oil-paper insulation, which is widely used in power transformers and cables as a low cost but reliable insulation system. However, the dynamics and behaviors of space charge in oil-paper insulation, especially after thermal ageing, are not well understood. In this paper, space charge behaviors in multi-layer oil-paper insulation system after accelerated thermal ageing have been investigated using the pulsed electroacoustic (PEA) technique. A series of measurements were carried out when the insulation materials of different ageing degrees were subjected to different applied DC voltages at different temperatures. Charge behaviors in the insulation system have been analyzed and some key parameters such as threshold voltage, maximum charge density, residual electrical field, and charge accumulation/decay patterns were discussed. The test results showed that homocharge injection takes place under all the test conditions after thermal ageing, the injected charges move faster into oil-paper. Particularly the positive charge, the initial amount of charge injection, charge injection depth and accumulation increase evidently.

59 1P44 POLLUTION FLASHOVER PERFORMANCE OF INSULATORS WITH SEMICONDUCTIVE SIR Xiaoxing Wei, Zhidong Jia, Zhenting Sun, Zhicheng Guan Tsinghua University, Graduate School at Shenzhen, Shenzhen, China

Icing problems threaten the security of the power system heavily. Many methods were proposed to reduce the ice accretion on the transmission conductors, but effective ways for anti-icing or de- icing for insulators are still yet to be determined. Some researchers came up with a method about insulator anti-icing basing on the semiconductive SIR, which using the heating effect of the leakage current. The coating was painted on the bottom side of the insulator, but left no coating on the upper surface. With the application of this active method, ice accretion can be relatively reduced. However, the pollution flashover performance was challenged owing to the conductive coating. In this paper, experiments on the pollution flashover characteristics about the new method were carried out. Three kinds of samples were tested, pure insulators, bottom coated ones with RTV coatings and bottom coated ones with semiconductive ones. Test results indicated that the pollution flashover voltage of the semiconductive ones is almost twice of the pure ones, but a little lower than the RTV ones. The primary causes of high pollution flashover voltage are the hydrophobicity and the drying effect generated by the leakage current.

60 1P45 FLASHOVER PERFORMANCE ALONE POLLUTED SURFACE OF 220KV GLASS INSULATOR STRINGS COVERED WITH NON UNIFORM PRTV COATINGS Chuyan Zhang1, Shuwei Wan1, Bao Feng2, Zhiyong Wang2, Liming Wang1, Zhicheng Guan1 1Tsinghua University, Graduate School at Shenzhen, Shenzhen, China, 2Guangdong Power Grid Company, China Southern Power Grid, Zhongshan Power Grid Corporation, Zhongshan, China

The PRTV coating material has perfect performance of anti-pollution flashover for porcelain and glass insulators because of the surface hydrophobicity caused by the coating. Usually, the whole strings of insulators were coated with PRTV coatings in engineering application. However, this paper had investigated the pollution flashover performance for 220kV glass insulator strings covered with non uniform PRTV coatings. Conclusions were carried out by vast artificial contamination tests under AC voltage that, the flashover voltage can be enhanced greatly by covering non uniform PRTV coatings and the leakage current can be reduced. Compare with the whole string of insulators covered with PRTV coatings, the outdoor insulation performance shown little difference for 220kV glass insulator strings. The work can provide theoretical support for external insulation's maintenance and design of 220kV AC transmission lines.

61 1P46 NANOSECOND-PULSE DIFFUSE DISCHARGE AT ATMOSPHERIC PRESSURE Cheng Zhang1, Tao Shao12, Victor F. Tarasenko3, Hao Ma1, Dongdong Zhang1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA, 3Institute of High Current Electronics, Russian Academy of Sciences Tomsk, Russia

Nanosecond pulsed discharges have various discharge forms. The dense diffuse discharge, for example, is closely related to x-ray radiation and runaway electron beams. In this paper, a two- stage magnetic compression solid-state pulse generator is used to produce repetitive nanosecond pulses for the excitation of nanosecond-pulse diffuse discharges. The output pulse of the generator has a rise time of about 25 ns and a full width at half maximum of 40 ns. A diffuse discharge is obtained in a point-to-plane gap in open air. Electrical characteristics and the transition of the discharge mode of a nanosecond-pulse discharge in atmospheric air are studied based on the current-voltage waveforms, discharge images, and emission spectrum. The experimental results show that a large-scale and stable diffuse discharge can be obtained at atmospheric pressure, and the corresponding optical spectrum reveals a low level of light emission. Air gap spacing, pulse repetition frequency, and pulse polarity affect the mode transition and emission intensity of the diffuse discharge. The diffuse discharge occurs for an appropriate air gap, high electric field with positive pulse, and fast rise time.

62 1P47 RESEARCH ON SURFACE FLASHOVER PROPERTIES OF POLYMER MODIFIED BY ION IMPLANTATION Rong Xu1, Ping Yan1, Jue Wang1, Chengyan Ren1, Tao Shao1, Yaohong Sun1, Dongdong Zhang1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drives, Beijing, China

Surface characteristics of Insulator effect its surface flashover performance obviously, appropriate surface treatment can increase the surface flashover voltage. Ion implantation technology is an effective surface modification tool, it can change the roughness, resistivity and adsorbability on the insulator surface. Polytetrafluoroethylene (PTFE) and nylon were modified by C ion and nitrogen ion with a dose ranging from 1 ×1016 to 2×1017cm-2 using a ion source. The surface flashover voltage were measured on the experimental platforms of surface characteristics in vacuum before and after modification, Also the characteristies and microstructure of the implanted layer were studied by using the SEM and XPS and find the influencing factors on surface flashover properties of Polymer modified byion implantation.

63 1P48 THEORETICAL ANALYSIS OF TREEING PROCESS IN MICRO AND NANO COMPOSITE INSULATORS Kavitha Dhinesh1, Sindhu T Krishnan2, T N Padmanabhan Nambiar1 1Amrita Vishwa Vidyapeetham, Electrical and Electronics Engineering, Coimbatore, India, 2National Institute of Technology Calicut, Electrical Engineering, Kozhikode, India

One of the important reasons for the breakdown of a solid insulator is the 'treeing' process which is initiated by the partial discharges. The polymeric insulators which are very widely used in recent times as insulator have very high breakdown strength and low permittivity. It is widely reported in the literature that, the addition of nanoparticles to the polymer base increases the breakdown strength of the insulator. Many experiments show that nanoparticles with a few weight percentages have much advantage over micron size particles in increasing the breakdown strength. Here the attempt is made to analyze theoretically the effect of micron and nanosize particles in delaying the tree propagation. The analyses are done using ANSYS tool. The electric field patterns in epoxy resin insulator in the presence of micron and nanosized particles are plotted. The field non uniformity and the treeing process are done theoretically in the presence of void.

64 1P49 PERFORMANCE IMPROVEMENT OF GAS INSULATED SUBSTATIONS BY REDUCING THE CONTAMINATED METALLIC PARTICLE MOVEMENT Parthasarathy P.1, Amarnath Jinka2, Singh B.P.3 1Guru Nanak Engineering College, Department of Electrical and Electronics Engineering, Hyderabad, India, 2JNTUH College of Engineering, Department of Electrical and Electronics Engineering, Hyderabad, India, 3St.Martin's Engineering College , Department of Electrical and Electronics Engineering, Hyderabad, India

Demand for electrical power has become one of the major challenges faced by the developing countries. Considering the relatively low per capita power consumption, there is a constant need for power capacity addition and technological upgradation whereas non-conventional energy systems have proved to be good alternative sources for energy. In developing countries like India most of the additional power has been met by conventional electric sources. Hence, the emphasis has shifted towards improving the reliability of transmission and distribution systems and ensuring that the innovations are not harmful to the environment. SF6 is generally found to be very sensitive to field perturbations such as those caused by conductor surface imperfections and by conducting particle contaminants. A study of CIGRE group suggests that 20% of failure in GIS is due to the existence of various metallic contaminations in the form of loose particles. The presence of contamination can therefore be a problem with gas insulated substations operating at high fields. If the effects of these particles could be eliminated, then this would improve the reliability of compressed gas insulated substation. It would also offer the possibility of operating at higher fields to affect a potential reduction in the GIS size with subsequent savings in the cost of manufacture and installation. The purpose of this paper is to develop techniques, which will formulate the basic equations that will govern the movement of metallic particles like aluminum, copper in a coated as well as uncoated busduct.

65 1P50 IMAGE CHARGE EFFECT ON METALLIC PARTICLE MOVEMENT IN A SINGLE PHASE GAS INSULATED BUSDUCT (GIB) WITH DIELECTRIC COATED ENCLOSURE USING CHARGE SIMULATION METHOD Narapareddy Ramarao1, Jinka Amarnath2 1Nigama Engineering College, Department of Electrical and Electronics Engineering, KARIMNAGAR, India, 2JNTUH College of Engineering, Department of Electrical and Electronics Engineering, HYDERABAD, India

Present paper analyses the effect of image charge on the movement of free conducting particles inside a single phase Gas Insulated Busduct(GIB) with epoxy dielectric coating on inner side of outer enclosure. A mathematical model has been derived by considering all the forces like gravitational, drag and the electrostatic, acting on the metallic particle for ascertaining the movement pattern in a Gas Insulated Busduct. These forces are functions of particle geometric parameters, electrostatic charge acquired by the metallic particle and the electric field at the particle location, the drag coefficient and Reynold's number. The second order differential equation for the particle motion is solved iteratively and coefficient of restitution of particle was considered at every impact with the enclosure of Gas Insulated Busduct. Electric fields at the instantaneous particle locations due to live inner conductor and its image charge were computed using the Charge Simulation Method (CSM). The movements of metallic particle without image charge effect are compared with movements of metallic particle with image charge effect. It is observed from results, the movement with image charge effect is more than the movement without image charge effect. The simulation is carried out for various bus configurations with different aluminium and copper particles inside are 100kV, 145kV, 175kV and 220kV class. The results have been analyzed and presented in this paper.

66 1P51 ESTIMATION OF LIFT OFF FIELD OFF AND MAXIMUM MOVEMENT PATTERN OF METALLIC CONTAMINANTS IN A 600 KV THREE PHASE COMMMON ENCLOSURE GAS INSULATED BUSDUCT USING MONTE- CARLO TECHNIQUE Padmavathi Devasetty1, Kamakshaiah Saprams2, Amarnath Jinka3, Mani Kuchibhatla4 1Vignana Bharathi Institute , EEE, Hydeabad, India, 2JNTUH, EEE, Hyderabad, India, 3JNTUH, EEE, Hyderabad, India, 4Vignana Bharathi Institute of Technology, EEE, Hyderabad, India

The reliability of power transmission and the introduction of higher voltages to the center of big cities have been the two key features in the history of GIS. Coping with the requirement in power systems, three-phase enclosure type GIS had been developed as a practical means to realize a GIS with higher reliability in more compact size. The presence of metallic contaminant on enclosure may lead to the breakdown of Gas insulation medium. In this paper different types of metallic contaminants are considered and their movement pattern is obtained using Monte-Carlo technique. The critical voltage for different type of material leading to flash over is obtained. Presently SF6 Gas is used as the dielectric medium but, future usage of SF6 has been debated through out the world as it is a green house Gas. In this paper the performance of Gas insulated substation with mixture of SF6+N2 gases is obtained in the presence of metallic particles. The Simulation results are incorporated in this paper for validation.

67 1P52 HIGH VOLTAGE POWER AMPLIFIER UTILIZING SERIES-CONNECTED TRANSISTORS TO CONTROL THE OUTPUT J.F. Tooker, P. Huynh P.O. Box 85608, General Atomics, San Diego, CA, USA

The design of a high voltage power amplifier is being developed that uses series-connected transistors to control the output. Although having many potential applications, this high voltage power amplifier is being designed to meet at a minimum, the requirements of one of the power supplies required for depressed collector gyrotrons being used in electron cyclotron systems on machines performing experiments for fusion energy. The output voltage is required to vary up to 35 kV with at least 200 mA of peak current. In addition, square-wave modulation at up to 5 kHz is required. Although the required continuous operating current for a gyrotron is on the order of a few tens of milliamps, the amplifier is capable of continuous currents up to 50 mA. Because of the reasonably low power dissipation, a linear control topology for the design was selected for the amplifier. Series-connected transistors are used to meet the output voltage requirement. The transistors are configured in modules and the design is easily scalable for different levels of output voltage. The design of transistor modules for the amplifier was developed, and prototype modules were successfully built and tested to verify the performance of the topology at an output of 2 kV. The design of the complete amplifier is now being developed. The description of the design of the modules, the test results of the prototype modules, and an overview of the final design of the amplifier will be presented.

68 1P53 A CAPACITIVE LEVEL-SHIFTER FOR HIGH VOLTAGE (2.5KV) Thomas Andersen, Michael A. E. Andersen, Ole C. Thomsen Technical University of Denmark, Elektro, Lyngby, Denmark

A capacitive level-shifter as a part of a high voltage half-bridge gate driver is presented in this work. The level-shifter utilizes a differential capacitor pair to transfer the information from low side to high side. A thorough evaluation of the critical parts of the level-shifter is presented with focus on low power consumption as well as low capacitive load on the floating half-bridge node (output capacitance). The operation of the level-shifter is tested and verified by measurements on a prototype. Results conclude stabile operation at 2.44kV, 50kHz with a current consumption of 0.5mA. Operation voltage was limited by test equipment. Total output capacitance is [email protected].

69 1P54 BATTERY POWERED HIGH OUTPUT VOLTAGE BI-DIRECTIONAL FLYBACK CONVERTER FOR LINEAR DEAP ACTUATOR Lina Huang, Prasanth Thummala, Zhe Zhang, Michael Andersen Technical University of Denmark, Electrical Engineering, Kongens Lyngby, Denmark

DEAP (Dielectric Electro Active Polymer) consists of a soft silicone polymer, sandwiched between two compliant metallic electrodes. When a voltage is applied, the polymer will compress in thickness and expand in area due to the electric field; therefore, DEAP can be used as an actuator. The similar structure to a capacitor enables DEAP to be fundamentally considered as a capacitive load. Compared to traditional electro-magnetic, pneumatic or hydraulic actuators, the capacitive actuator possesses many advantages, such as high power density, fast and direct actuation, high actuating precision, extremely low steady-state power consumption, etc. However, one of the difficult issues in facing the capacitive actuators is the requirement of relatively very high driving voltage. For the current DEAP material, the stimulating voltage is of several thousand volts (~2.5 KV DC). Because of the simple design and immense applicable occasions, linear DEAP actuator, which only performs linear motion, will be an effective replacement for many conventional actuators. So it is essential to carry out the research for the linear DEAP actuator driving circuits. In some portable or autonomous applications, battery will be the only power source for the whole system; therefore, a DC-DC converter which can convert low input voltage to high output voltage will be necessary. Combined with the capacitive property of DEAP material and the requirement to extend the lifetime of the battery, a bi-directional flyback converter is a good choice, which not only can boost the input voltage to several thousand volts from a battery, but also can recover energy when the DEAP actuator is released. Because of its simple topology, the flyback based driver can be realized in small size, which is vital in the portable or autonomous systems. In the final paper, the capacitive property of DEAP material will be proved and analyzed. The structure of the linear DEAP actuator will be shown, and the working principle of the bi-directional flyback converter which can boost the output voltage to 2.5 KV from a 3V battery will be analyzed in detail, including the analysis of the energy transfer and recovery processes. In addition, the control strategy for the capacitive load is also different from that of the resistive-inductive load, so the control for the bi-directional flyback converter will be addressed and analyzed. For validating the correctness of the proposed topology and its control, a simulation has been done and the critical waveforms will be illustrated for both energy transfer and recovery processes. In addition, the experimentation of a flyback converter for the linear DEAP actuator is under progress, so the experiment measurements may also be presented in the final paper.

70 1P55 ANALYSIS OF DIELECTRIC ELECTRO ACTIVE POLYMER ACTUATOR AND ITS HIGH VOLTAGE DRIVING CIRCUITS Prasanth Thummala, Lina Huang, Zhe Zhang, Michael Andersen Technical University of Denmark, Electrical Engineering, Kongens Lyngby, Denmark

The Dielectric Electro Active Polymer (DEAP) material is a very thin elastomer film with a compliant electrode layer on both sides. Using the capacitive behavior of the polymer, DEAP can be used as an actuator, mechano-electrical sensor, as well as energy harvester to generate electricity. For such kind of tasks, DEAP show unique properties, such as very low electrical power consumption, no noise, flexibility, high power density, large bandwidth, higher performance than competing technologies and light weight. The current DEAP technology has a wide potential in applications such as wind turbine flaps, heating valves, unmanned aerial vehicles (UAVs), wave energy harvesting and loudspeakers. This paper focuses on application of DEAP technology as an actuator. The varying loads on the wind turbine blades may cause them to oscillate and collide with the tower. So it is very important to control these blade loads, to protect the turbine from being damaged using aerodynamic control devices such as flaps. The flaps may also be used to increase the energy output of a wind turbine. The current heating valve actuators in the market are thermal actuators, being noiseless but consuming significant power, and electrical gear motors which are relatively energy efficient, but inherently prone to noise issues. The unique properties of the DEAP material makes it technically viable that the trailing edge flaps for the wind turbine blades will result in improved blade efficiency and, reduced loads and fatigues on the blades and turbine. Also the compact in-line heating valves based on DEAP will make better, cheaper and noiseless valves without mechanical parts. For the control of DEAP actuators a special high voltage power electronic (HVPE) converters are necessary, driving this kind of actuators at high voltages and typically low currents. The main focus of this paper to develop high voltage power supply for driving the DEAP actuator, which is of capacitive in nature fundamentally, and to provide different structures of the actuators (for both wind turbine flap and the heating valve application). For the wind flap application the specifications are: Input voltage Vin = 24 VDC (from the battery) or Vin = 400 VAC (from the wind turbine), Output voltage Vout = 2500 VDC. For the heating valve application the specifications are: Input voltage Vin = 3 VDC (from the battery), Output voltage Vout = 2500 VDC. The capacitance of DEAP actuator for both applications is C = 150 nF. The theoretical analysis and simulations have done. In the final paper we will present different high voltage (HV) switch mode power supply topologies, such as flyback or full bridge and their control techniques. We will also present the modeling (electrical and electro-mechanical) and different structures of the DEAP actuators for both wing flap and heating valve applications.

71 1P56 COMPACT HIGH-VOLTAGE CAPACITOR CHARGER SungRoc Jang1, HongJe Ryoo1, Gennadi Goussev1, SukHo Ahn2, SeungBok Ok2 1Korea Electrotechnology Research Institute , Electric Propulsion Research Center, Changwon, Korea, 2University of Science & Technology , Dept. of Energy Conversion Technology, Daejeon, Korea

This paper describes the design, implementation and experiment of a 28 kJ/s high-voltage capacitor charging power supply (CCPS) based on series-parallel resonant converter that provides high-efficiency and high-power density. Soft-switching based single phase resonant converter which has advantages of reduced switching as well as conduction loss of semiconductor switches was designed for 48 kW (12 kV, 4 A) peak power operation. In addition, the compact design of input filter without bulky components such including DC reactor and electrolytic capacitor allows high-power density, high-power factor, and low-cost. And the voltage control loop was optimized with fast response time in order to compensate the low frequency ripple of input voltage due to the reduced filter component. Experiments of developed charger were carried out with both resistor and capacitor load for measuring not only efficiency and power factor with respect to the output power but also charging time to estimate average charging current. The experimental results with resistor load showed 95% and 0.96 of maximum efficiency and power factor at a full- load condition, respectively. From the measured charging time of a 206 uF capacitor, 360 ms for 10 kV charging, the average charging current was estimated as 5.5 A. Finally, it was experimentally confirmed that the developed CCPS shows high-performance in view point of efficiency and power factor with high power density (700 W/Liter).

72 1P57 DEVELOPMENT OF THE INVERTER HVPS FOR MODULATOR SYSTEM AT PAL-XFEL Soung-soo Park, Sang-hee Kim, Sei-jin Kwan, Byeong-jun Lee, Yong-jo Moon, Heung-su Lee, Heung-sik Kang, Jung-yun Hwang Pohang Accelerator Laboratory, Accelerator, Pohang, Korea

The Pohang Accelerator Laboratory (PAL) has been starting the 10 GeV PAL-XFEL projects since 2011. The PAL-XFEL needs a stable electron beam. The stable charging energy in the modulator system is essential to provide the stable acceleration field for an electron beam. The stability of CCPS(Capacitor Charging Power Supply) is very important since short-term stability will be determined by a minimum resolution of a charging system. This paper shows detailed hardware R&D and test results to get the target stability.

This work is supported by MEST (Ministry of Education, Science and Technology) and POSCO (Pohang Steel and Iron Company).

73 1P58 NEW 13-SPACE VECTOR DIAGRAM FOR THE THREE-PHASE SIX- SWITCHES VOLTAGE SOURCE INVERTER Mohamed Saied Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt

This paper presents a new switching strategy control-ing the most-common, simple, and well- known three-phase six-switch voltage source inverter (VSI). Via this strategy, each one of the six transistors conducts for 150o, instead of the known 180o or 120o conduction-modes, resulting in a new space voltage-vector diagram (SVD). For a wye-load connected to the VSI, the known 6 active and 2 zero voltage-vectors, coincided in the origin, construct the classical 7-SVD. Using the new controling strategy, new different 6 non-zero voltage-vectors are primarily introduced to the literature and added to the former ones conistituting an innovated 13 space vector diagram (13-SVD) for the inverter, instead of the conventional 7-SVD. The output phase-voltage becomes a 7-level, 12-step waveform, and a 50% reduction of the total harmonic distortion is obtained. Comprehensive study for the new switching strategy and the resulting voltage vectors is proposed, and comparisons with other VSI topologies; like neutral point clamped (NPC) and multilevel inverters (MLI) were also carried out. Simulation and experimen-tal results show the contribution of the proposed technique. Index Term- voltage source inverters, space voltage- vectors, switching strategy, space vector modulation, 150o conduction-mode, 12-Step waveform, two-level inverter, total harmonic distortion.

74 1P59 AN ADJUSTABLE HVDC POWER SUPPLY USING INTEGRATED HIGH VOLTAGE TRANSFORMER WITH SOME PROTECTIVE & CONTROLLING FEATURES. Muhammad Muktadir Rahman American Intl. University- Bangladesh, Electrical and Electronic Engineering, DHAKA, Bangladesh

We can produce variable/adjustable HVDC with a little arrangement using Fly back Transformer (IHVT), Tesla coil, car ignition coil & other type of step-up auto transformer found in microwave oven, X-ray units & in similar devices. This arrangement of circuitry is very reliable & lightweight. In our experiment we made a power supply using Integrated High Voltage Transformer & try to give it several protective & controlling features to its driver circuitry to increase the longevity of the power supply. As far as the general run of small-scale electronics is concerned, EHT(extra high tension)/HVDC power supplies are used mainly for cathode ray tube (CRT) anodes and for some specialized purposes such as Geiger-Muller counters and photomultipliers. None of these applications calls for a large current drain. As an example, X-ray equipment may require 100 kVDC at a current of less than 1 A. Some of these EHT supplies such as those used for radio transmitters or particle accelerators demand very substantial currents. As an example, large radio transmitters may call for a 20 kVDC supply at several amperes of current.

75 1P60 A REPETITIVE MICROSECOND-PULSE GENERATOR FOR PLASMA JET APPLICATION Wenfeng Li1, Tao Shao12, Weiming Huang1, Cheng Zhang1, Dongdong Zhang1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

A plasma jet excited by pulsed power is a promising approach for producing non-thermal plasmas at atmospheric pressure. Pulsed power generators vary widely in performance and should be selected according to the requirements of each application. In this paper, a repetitive microsecond-pulse generator is constructed using cascading power modules where solid-state switches are the key units. The generator is capable of providing repetitive pulses with a voltage up to 10 kV, pulse duration of a few microseconds, and repetition frequency of up to 5 kHz. The output pulse voltage can be adjusted by varying the ac input voltage, and the pulse width and frequency can be changed by the driving signal of the IGBTs. This generator has been successfully used for plasma jet applications.

76 1P61 HIGH-FREQUENCY HIGH-VOLTAGE DC POWER SUPPLY BASED ON PARALLEL RESONANT TECHNOLOGY AND PHASE SHIFTED CONTROL Kun Liu1, Yinghui Gao1, Ping Yan2, Dongdong Zhang1, Yaohong Sun1 1Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China, 2Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing, China

High-voltage DC power supply is widely used in areas of engineering applications and experimental researches, such as voltage-withstand test for electrical equipment, electrostatic dust-elimination for environment manipulation, numeric imaging of X-ray for medical use, radar transmitter for military, etc. In this paper a high-voltage DC power supply, which use the parallel resonant technology of switching mode power supply and the phase shifted control technology of inverter, was designed. The output voltage of this supply could be controlled by regulating the drive signals' phases of the switch devices. By calculation and simulation of the main circuit, the work principle, the circuit parameter, and the advantages and disadvantages were presented. The working conditions and output waveforms of every moment in the phase shifting process were introduced in detail. The high-voltage was obtained by high-frequency high-voltage transformer and voltage quadrupled rectifier, which were packaged in one tank. The control strategy was realized by the digital signal processing technology. The output voltage was used as the feedback signal of closed-loop control, and the digital PI algorithm was adopted in order to make the output voltage more stable. To guarantee the experimenters' safety, the computer control software was developed as the remote controller, which could real-time monitoring and controlling the power supply. The experimental results show that the power supply can regulate the output voltage efficaciously, and it can be adaptive in the high-voltage and small-current applications.

77 1P62 AN EFFICIENT ALL SOLID-STATE NANOSECOND PULSED GENERATOR FOR PULSED DISCHARGES Junfeng Rao, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources, Shanghai, China

In this paper, an efficient all solid-state nanosecond pulsed generator consisting of a MARX generator, Blumlein transmission lines and one magnetic switch (MS) for DBD is designed. Blumlein transmission lines are charged by MARX generator and discharged by MS. The operation principle of the generator is described in detail. For comparisons experiments were carried out using three loads including matched resistor, air gap and DBD load. Experimental results have been given. This generator is capable of providing pulses with voltage up to 20 kV and duration of 220 ns on the matched load of a 100 ohm resistor at the efficiency of 90.8%. With the air gap load, current presents bipolar square-wave attenuation oscillation with duration of 220 ns. Special emphasis is given to the DBD load. It's found out that there are over ten discharges under a single-shot condition, which considerably improves the discharge efficiency and indicates great potential value for industrial applications.

78 1P63 RESEARCH ON THE RELIABLE THERMAL DESIGN OF HIGH FREQUENCY HIGH VOLTAGE CHARGING POWER SUPPLY Xiaoxia Shi1, Yinghui Gao1, Dongdong Zhang1, Yaohong Sun1, Ping Yan1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China

High frequency high voltage charging power supply has been widely used in the pulsed power technology. With the development of modern power electronics technology and advanced manufacturing techniques, the power density of the power supply is continuously improving, however, the high power density results in high heat flux, and the heat is difficult to be dissipated in a limited size, the thermal design is facing with austere challenge. Combined with the principle and the intermittent working condition of the power supply, the power losses of the main power devices is calculated, and the design of the heat structure and cooling method is introduced, as well as the CFDesign software simulation of the cooling model. The design results have been verified by the experimental results on a 30kW/50kHz charging power supply. Finally, the fundamental principles and thermal design method are presented.

79 1P64 DC POWER SOURCE OF ONLINE MONITORING EQUIPMENTS FOR OVERHEAD CONDUCTORS Ji Yang Chongqing Electrical Power Company, Dianjiang Branch, Chongqing, China

This paper presents a DC power source of online monitoring equipment for overhead conductors. Analytical expression of output power of draw-out current transformer (DCT) which is related to overhead-line current, parameters of magnetic core and number of secondary winding turns is derivated and discussed first. Then, combinative powering scheme which integrate power supply based on DCT with Li-battery-powered power supply is proposed. In this scheme, according to the results of comparison between secondary current of DCT measured by current detection resistor and the upper and lower limit current set in sluggish comparator (Schmitt circuit), the relay automatically change number of secondary winding turns to adjust output power and increase suitability of DCT under wide range alteration of overhead-line current. Li-battery group in parallel with draw-out power supply functions as energy-storage power supply (when line- current is large enough) and hot standby power supply (when line-current is too small). Moreover, decrease of charge/discharge times and alternative discharge between two Li-batteries are achieved by another sluggish comparator. Experiments show that the layout of combinative power source is reasonable and it makes the output voltage and power stable.

80 1P65 R&D OF 14KV/25A DC HIGH VOLTAGE POWER SUPPLY FOR TETRODE AMPLIFIER Wei Wang Nanjing Institute of Electronic Technology, Nanjing, China

A deuteron RFQ has been designed for neutron generator. It adopted a Tales tetrode TH781 as CW amplifier which could deliver RF power up to 200kW under 200MHz. In order to achieving high stability and low ripple anode voltage, a new type all-switch DC HVPS has been developed. Compared to conventional large power line-frequency high voltage source, it doesn’t require huge line-frequency transformer, high stability and dynamic responsibility also are some advantages of this design. The design study of power supply’s topology, high frequency inverter and IGBT driver will be presented in this paper.

81 1P66 OUTPUT FAULT PROTECTION AND INTERMEDIATE OVERLOAD DIAGNOSIS IN A "REGULATED HIGH VOLTAGE POWER SUPPLY" (80 KV, 130A) Paresh Patel1, Sumod C. B.1, D. P. Thakkar1, L. N. Gupta1, V. B. Patel1, L. K. Bansal1, K. Qureshi1, V. Vadher1, N. P. Singh2, U .K. Barua1 1Institute for Plasma Research, Neutral Beam Injector Group, SST-1, Gandhinagar, India, 2ITER-India, Power Supply Group, ITER, India, Gandhinagar, India

Regulated High Voltage Power Supplies (RHVPS) have been developed and being utilized at Institute for Plasma Research (IPR) for Neutral beam and RF heating applications of Steady- state Superconducting Tokamak (SST-1) up to 80 kV, 130 A rating. They are developed in-house and also being delivered at different research institutes for various applications. RHVPS are meant to deliver power to various loads at megawatt level. These loads have very low fault energy tolerance; thereby protection of load from fault is mandatory. In addition to this, at each stage of power transformation/conversion, special diagnosis is necessary to protect power supply components. Also, output fault protection is to be done in such a manner that fault energy is not more than 10J. In fault conditions, output is to be turned off within 2µSec. Having these requirements, an output fault protection system is developed with suitable sensors and managing fast turn off choosing appropriate components. Multi-secondary transformers (2 nos., each at 5.6 MVA rating with 40 outputs) are used at front end of RHVPS. They may get damaged even for overload at any one of their secondary, while remaining secondaries carry very less current or no current. Such a localized overload is not sufficient for tripping the main circuit breaker whose tripping level is set to an actual overload of transformer. Special technique is applied to sense and diagnose this fault in addition to routine overload sensing. Differentiation of such typical fault from a real overload condition is done by sensing and monitoring primary current of transformer with reference to different operating scenarios. Electronic means are used for fast detection and isolating RHVPS from utility supply. The presented system effectively protects transformer from fault at any one of its 40 secondaries as well as actual overload. This paper describes overall RHVPS power scheme along with output fault protection and internal fault diagnosis system and test results thereof.

82 1P67 REDUCED COMMON MODE VOLTAGE IN DIRECT TORQUE CONTROLLED INDUCTION MOTOR DRIVES USING NEAR STATE PWM TECHNIQUE Vuyyuru Anantha Lakshmi1, T. Bramhananda Reddy1, Munagala Surya Kalavathi2, VC Veera Reddy3 1G.Pulla Reddy Engineering College, E.E.E , Kurnool, India, 2J.N.T.U College of Engineering, E.E.E , Hyderabad, India, 3S.V.U College of Engineering, E.E.E , Tirupathi, India

This paper presents a simplified near state PWM algorithm (NSPWM) for the reduction of common mode voltage (CMV) in direct torque controlled induction motor drives. In the proposed PWM algorithm instead of using zero voltage vectors, active voltage vectors are utilized for composing the reference voltage vector, So that the CMV changes from +Vdc/6 or -Vdc/6 due to application of active voltage vectors. As the proposed algorithm is 1200 bus clamping PWM algorithm, it reduces the switching frequency and switching losses of the inverter. To validate the proposed algorithm, simulation studies have been carried out using MATLAB-Simulink and results have been presented.

83 1P68 A NOVEL HYBRID PWM ALGORITHM FOR REDUCED COMMON MODE VOLTAGE IN DIRECT TORQUE CONTROLLED INDUCTION MOTOR DRIVES Vuyyuru Anantha Lakshmi1, T. Bramhananda Reddy1, Munagala Surya Kalavathi2, VC Veera Reddy3 1G.Pulla Reddy Engineering College, E.E.E, Kurnool, India, 2J.N.T.U College Of Engineering, E.E.E, Kurnool, India, 3S.V.U College Of Engineering, E.E.E, Kurnool, India

This paper presents a novel hybrid pulse width modulation (HPWM) technique for the reduction of common mode voltage (CMV) in direct torque controlled induction motor drives based on the concept of imaginary switching times. In the proposed approach, different active zero state PWM (AZPWM) sequences are considered in which the actual switching times are calculated based on the instantaneous values of phase voltages. So, it does not require sector identification and angle information. Moreover for the reduction of CMV, AZPWM sequences utilize active voltage vectors for composing the reference voltage vector instead of using zero voltage vectors, So that the CMV changes from +Vdc/6 or -Vdc/6 due to application of active voltage vectors. Though these AZPWM methods reduce the computational burden involved in calculation, they still suffer from steady state ripples in torque, flux and current. To reduce the ripples in steady state, a HPWM technique is developed in which stator flux ripple analysis is done for all the AZPWM sequences in terms of actual switching times, dc link voltage (Vdc), sampling time period (Ts). As AZPWM2, AZPWM3 exhibit same ripple characteristics only AZPWM3 is considered in this paper. Then by comparing AZPWM1, AZPWM3, AZPWM4 sequences with respect to each other sequences at various modulation indices the sequence with minimum flux ripple is obtained. This sequence is then fed to DTC based induction motor drive. As all the sectors are symmetric, the mean square flux ripple characteristics for a period of 600 are plotted. To validate the proposed PWM algorithm, numerical simulation studies have been carried out using MATLAB- Simulink and results are presented and compared.

84 1P69 IMPLEMENTATION OF DIRECT TORQUE CONTROL OF INDUCTION MOTOR WITH SPACE VECTOR MODULATION Sushama Malaji JNTU Hyderabad, Electrical & Electronics Engineering, Hyderabad, India

With the DTC scheme employing a Voltage Source Inverter (VSI), it is possible to control directly the stator flux linkage and the electromagnetic torque by the optimum selection of inverter switching vectors. The selection of inverter switching vector is made to restrict the flux and torque errors within the respective flux and torque hysteresis bands. In low-speed drives Direct Torque Control has serious ripples in flux disorder of the switching frequency. In this paper, Direct Torque Control of an Induction Motor with Space Vector Modulation (SVM) will be used. The modelling and simulation of an induction motor drive are performed using MATLAB/SIMULINK Software.

85 1P70 REDUCTION OF COMPUTATIONAL COMPLEXITY IN "EKF" FOR SENSORLESS INDUCTION MOTOR DRIVE Kamal Basha1, B.Ravindhra Nath Reddy2, Suryakalavathi Muganal3 1MITS, EEE, Madanapalle, India, 2JNTUH, EE, Hyderabad, India, 3JNTUH, Electrical, Hyderabad, India

In this paper, an effective algorithm is presented to reduce the computational complexity for estimate the speed of induction motor drive. In this proposed method, a modified extended kalman filter (EKF) method will be utilized to estimate the speed of the induction motor drive based on wavelet algorithm. This method offers less number of iterations in the EKF method. To achieve this, initially the mathematical model of the induction motor is generated and then the speed of the motor is estimated for a particular model. The quadrature and direct axis voltage and current are taken as the input parameters to the modified EKF. From the simulation results it is found that the proposed EKF scheme impressively reduced the computational complexity for estimate the speed of induction motor drive when compared with conventional EKF method.

86 1P71 PERFORMANCE EVALUATION OF CLASSICAL AND FUZZY LOGIC CONTROL TECHNIQUES FOR BRUSHLESS DC MOTOR DRIVE M. Surya Kalavathi1, C. Subba Rami Reddy2 1JNTU Hyderabad, Electrical and Electronics Engineering, Hyderabad, India, 2K.S.R.M College of Engineering, Electrical and Electronics Engineering, Kadapa, India

The brushless DC (BLDC) motor is becoming widely used as a small horse power control. High efficiency due to reduced losses, low maintenance and low rotor inertia of the BLDC motor have increased the demand of BLDC motors in high power servo and robotic applications. The marvelous increase in the popularity of the BLDC motor among engineers bears testimony to its industrial usefulness in terms of superior performance and relative size. Fuzzy logic has been developed about forty years. During the past several years, fuzzy logic control technology has been widely and successfully utilized in numerous industrial applications and consumer products. Since fuzzy logic with human like but systematic property can convert the linguistic control rules based on expert knowledge into automatic control strategy, it can be well applied to control the systems with uncertain or unmodelled dynamics. On the basis of these properties of fuzzy logic, this paper proposes three types of fuzzy logic controllers for brushless dc (BLDC) motor drive using advanced simulation model and presents a comparative study of performance specifications of classsical PI and PID controllers and three fuzzy logic controllers. The three fuzzy logic controllers considered are PI-like fuzzy logic controller (FLC), Hybrid fuzzy logic controller (HFLC) and integrated fuzzy logic controller (IFLC). The steady state and dynamic characteristics of speed and torque are effectively monitored and analyzed using the proposed model. The aim of fuzzy logic controllers is to obtain improved performance in terms of disturbance rejection or parameter variation than obtained using classical controllers. In the HFLC, the proportional term of the traditional PID controller is replaced with an incremental fuzzy logic controller. For the PI-Like FLC, the output of the controller is modified by a rule base with the error and change of error of the controlled variable as the inputs. The IFLC is constructed by using Fuzzy logic controller and PID controller. A performance comparison of classical and fuzzy logic controllers has been carried out by several simulations at different speeds and different load conditions. The performance comparison of all the five controllers is given based on the integral of the absolute value of the error (IAE), the integral of the squared error (ISE), the integral of the time-weighted absolute error (ITAE), the integral of the time- weighted squared error (ITSE), settling time, steady state error and peak over shoot . The simulation results show that the fuzzy logic controllers can well adapt to speed changes as well as sudden speed reduction besides fast recovery from load torque and parameters variation and show remarkable improvement compared to classical PI and PID controller.

87 1P72 FAULT DIAGNOSIS AND TESTING OF INDUCTION MACHINE USING BACK PROPAGATION NEURAL NETWORK Rajeswaran Nagalingam1, Madhu Tenneti2, Suryakalavathi Munagala3 1SNS College of Technology, ECE, Coimbatore, India, 2Swarnandhra Institute of Engineering and Technology, PRINCIPAL, Narasapur, India, 3Jawaharlal Nehru Technological University, EEE, Hyderabad, India

The recent developments with AI (Artificial Intelligence) are extremely intricate and increasing in complexity, which are required for use in wide range of domestic and industrial applications. This AI technique is used to control the speed of an induction motor. The main problem in induction motor drives is the variable speed and is a severe constraint in the real time environment. The electrical and mechanical faults can impose unacceptable conditions and protective devices are therefore provided to quickly disconnect the motor from grid. In order to ensure that electrical machines receive adequate protection, extensive testing is performed to verify the high quality of assembly. In this paper we focused on the fault diagnosis and testing of induction machine with various load conditions and verified it by using Field Programmable Gate Array (FPGA). Back Propagation Neural (BPN) Network is used to calculate the error and correct/regulate the induction motor. BPN and FPGA based this technique is increased the speed and improve the fault coverage area of the induction machine.

88 3O1 PERFORMANCE AND OPTIMIZATION OF A 30 KV SILICON CARBIDE PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH FOR PULSED POWER APPLICATIONS Cameron Hettler, William Sullivan III, James Dickens, Andreas Neuber Texas Tech University, Department of Electrical and Computer Engineering, Lubbock, TX, USA

A 30 kV silicon carbide photoconductive semiconductor switch (PCSS) is presented. The SiC PCSS device is fabricated from semi-insulating 4H-SiC in a newly-proposed rear-illuminated, radial switch structure. The improved structure reduces the peak electric field within the switch, extending the blocking voltage to over 30 kVdc. Electrostatic field simulations of the PCSS are presented along with experimental blocking curves. The PCSS demonstrated low on-state resistance, delivering over 10 MW of peak power into a 50 Ω load. Device modeling was performed to further optimize the switch for peak efficiency when illuminated with 355 nm light, a common laser wavelength. The switch structure was modified for peak operation at 355 nm and the experimental and theoretical results are compared.

89 3O2 REDUCING TURN-ON DISSIPATION OF RSD FROM APPLICATION Lin Liang, Quan Wei, Wu Hong, Xueqing Liu, Yuehui Yu Huazhong University of Science & Technology, Department of Electronic Science & Technology, Wuhan, China

Reversely switched dynistor (RSD) is a kind of switches especially applied in pulsed power area proposed by the Russian scientists in 1980s. Due to special operating principle its di/dt capability can reach 105A/μs. The work reducing turn-on dissipation from application done in our group is reported this paper. The first way is to over pre charge. An analytical expression for the critical value of pre-charge has been acquired by the Russian scientists. However, the actual pre-charge amount reversely injected into RSD in experiments is always much higher than the critical value. By establishing the two-dimensional numerical model of RSD, considered the influence of carrier Auger combination and extraction current from the emitter on the injected charges in the triggering process, we find that the extra charge amount in the p and n base region is only about 24.75% of the integral value of current at the end of triggering. The result illuminates that the RSD should be over pre charged. It will reduce the turn-on voltage and the also the turn-on dissipation. The second way is to turn on by a two-step method, which is to trigger the RSD by a low current, then let a low main current flow through RSD and then the high main current pass through. Because a low main current flows firstly, the requirement for triggering current is reduced. When the high current pass through later, the RSD has reached a high level of conductance modulation and the turn-on dissipation will be low. Both the simulation and experimental results show that the turn-on characteristics of RSD are better by the two-step method than the traditional discharge method. The third way is to well controlling the triggering time. It has been found by experiment that as the triggering time increases, the turn-on voltage of RSD decreases firstly and then increases at the definite triggering electric charge amount, i.e. it exists a minimum for the turn-on voltage at a certain triggering time. We have tried explained the phenomenon from the carrier combination effect inside RSD. At present the RSDs we develop have successfully pass through the peak current of 171 kA in single pulse.

90 3O3 ENHANCED VOLTAGE RECOVERY OF HIGH VOLTAGE SEMICONDUCTOR SWITCHES J. R. Cooper1, E. Loree2, T. Konopelski3, M. Hope3, R. D. Curry4 1Cooper Consulting Services, Inc. San Diego, CA, USA, 2Loree Engineering Albuquerque, NM, USA, 3M7 Electro-optics St. Louis, MO, USA, 4The University of Missouri Columbia, MO, USA

Semiconductor switches such as FETs, IGBTs, and BiMOSFETs are often required to transition from a state in which they have no voltage applied or have reverse current flowing through their anti-parallel diodes, to a state in which they are holding off a large voltage in the forward direction. This transition is often driven to occur on a timescale of 10's to 100's of nanoseconds. Under these conditions, solid state switches can pass large surge currents before recovering their full voltage hold off capability. These surge currents can adversely affect the circuit performance, increase the losses in the device, and potentially damage the device as well, especially under repetitive duty. This paper discusses the switch performance in a specific circuit in which an IXBK55N300 BiMOSFET switch transitions from both a state in which there is no voltage across the switch and also from a state in which the anti-parallel diodes are conducting on the order of 10 A, to a state in which a high voltage is applied across the switch in a few 10's of nanoseconds. In both of these cases, a relatively large current surge is generated that passes through the device. The paper describes both an active and a passive circuit connected to the BiMOSFET that minimize the current surge associated with the device's recovery of its forward voltage hold off. The measured performances of the active and the passive circuits in mitigating the current surge are compared with one another and with the unmitigated surge current for the device under the same conditions.

91 3O4 THE EFFECTS OF SUB-CONTACT NITROGEN DOPING ON SILICON CARBIDE PHOTOCONDUCTIVE SEMICONDUCTOR SWITCHES W. W. Sullivan III, C. Hettler, J. Dickens Texas Tech University, Electrical and Computer Engineering, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

Forming non-rectifying (ohmic) contacts to wide band gap semiconductors such as silicon carbide (SiC) requires a heavily doped subsurface layer to reduce the Schottky barrier height and allow efficient electron injection. Nitrogen, a common n-type dopant in SiC, was incorporated into a SiC sample using a laser enhanced diffusion process in which an impurity is incorporated into the semiconductor to very high surface concentrations (> 1020 cm-3) and very shallow depths (<200 nm) with the use of a pulsed 266 nm laser. This paper evaluates the effects of nitrogen introduced through laser enhanced diffusion on the contact formation and the efficiency of silicon carbide photoconductive switches at low and high injection levels under different biasing conditions. Nine intrinsically triggered lateral switches were fabricated on a high purity semi-insulating 4H- SiC sample; three with no sub-contact doping, three with sub-contact doping on only one contact, and three with sub-contact doping on both contacts. Results are presented for tests under pulsed 355 nm laser illumination with sub-contact doping on only the anode, only the cathode, neither, and on both of the contacts.

92 3O5 PULSE-TO-PULSE VOLTAGE REPRODUCIBILITY EFFICIENT PREDICTION METHOD FOR HIGH PRECISION KLYSTRON MODULATOR DESIGN Rudi Soares, Davide Aguglia CERN - European Organization for Nuclear Research, Technology Dept., Geneva, Switzerland

This paper presents a design tool in the framework of the R&D program on klystron modulators required for the Compact Linear Collider (CLIC), a new linear electron-positron collider under study. This 50km long accelerator needs roughly 300MW of average power for feeding the 1638 required klystron modulators of the drive beam (DB). The voltage specifications for the DB klystrons are extremely tight and bring a new set of challenges to the design of power converters. A 150kV voltage pulse with a flat-top length of 140μs, rise & fall times of 3μs for a pulsed power of 24MW is required. In terms of precision the flat-top stability must be better than 10-3 and the pulse-to-pulse-reproducibility (PPR) must be better than 10-5. Such an extremely tight PPR specification was never met before, therefore an important R&D program is ongoing to breakthrough this challenge. PPR in Switch Mode Power Converters (SMPC) can be affected by random phenomena such as switches jitter, external electromagnetic perturbations, thermal fluctuations, etc. Although many phenomena influence the PPR, one of the most important and more predictable is the switches jitter. All the other phenomena are common to all SMPC; however switches jitter influences the PPR differently depending on the converter topology (since the switches arrangement is different). In order to take topological design decisions considering this challenging specification, it is necessary to have an efficient method for estimating the PPR of any SMPC as a function of the switches jitter. Such a methodology is presented in this paper, and it allows the derivation of the PPR versus the expected jitter of each switch (driver and switch). The method is analytical and flexible, offering excellent calculation speed, precision, and the possibility to apply the tool to any kind of SMPC. This paper presents the methodology, which is based on advanced harmonics analyses, and its numerical validation through circuit simulations (Pspice and MatLab). An experimental analysis, on a 10kW test bench, of existing commercial drivers and switches, in the range of 1.7kV – 1kA is presented as well in order to characterize the technical state of the art of switches jitter. Starting from these experimental jitter measurements the paper finally presents realistic PPR estimations for different basic topologies cells, such as buck or H-Bridge converters. Results show that drivers' jitters must be reduced with dedicated design objectives and that the choice of different combination of basic topologies cells, series and/or parallel connections, has a great impact on the PPR of the SMPC. This is why the presented method is an essential tool for the design process of such highly reproducible klystron modulators.

93 3O6 DESIGN OF AN 80KV, 40A RESONANT SWITCHMODE POWER CONVERTER FOR PULSED POWER APPLICATIONS Paul Nonn, Andrew Seltzman, Jay Anderson University of Wisconsin, Physics, Madison, WI, USA

A unique switchmode power converter has been designed to supply a stable 80kV, 40A, 10ms pulse to a klystron tube presenting an 1800 ohm load. The supply is powered from a 900v, 0.5F electrolytic capacitor bank capable of sourcing the required input current over the pulse duration. The supply uses a low inductance IGBT network to switch power from the capacitor bank into the primaries of a three phase resonant transformer system. The resonant transformer assembly utilizes three magnetically separate microcrystalline iron cores in order to provide suitable volt- seconds and low magnetic loss at switching frequencies of 18.5 to 25kHz. The transformers are driven by independent full H-bridges with a 100% duty cycle square wave of variable frequency and corresponding phase offset. The use of a full duty cycle square wave in conjunction with a resonant transformer allows soft switching during the current zero crossing in the transformer primary. The subsequent reduction in junction heating allows operation of the IGBT network at higher then rated current without damage during the output pulse. Each transformer has a large leakage inductance secondary of 1.36mH with a parallel 50nF capacitor resonator, providing a boost ratio in excess of 60:1 at resonance and rated load while using a turns ratio of 13.5:1. The primary consists of a parallel pair of open air 10 turn helical copper straps around both sides of a square type core, while the secondaries consist a parallel pair of oil insulated coils, each with two 135 turn layers connected in parallel. The secondaries of the three transformers are connected in a wye configuration to a doubling rectifier, boosting the output to 80kV. The high switching frequency in addition to an LC harmonic filter provides a stable output and a reduction in filter capacitance allowing large values of dv/dt during the leading and trailing edge of the pulse. Ramp up times to 80kv of <0.5ms have been measured during operation. Due to the resonant nature of the secondaries, the boost ratio is strongly dependent on load and switching frequency. This provides a measure of safety to the connected klystron since a load change due to an output fault or arc will rapidly drop output power by offsetting resonance and reducing boost ratio. Further, the voltage output of the power supply may be directly controlled by adjusting switching frequency. A microprocessor PID feedback control system provides a stable output by varying the switching frequency toward resonance in order to increase the boost ratio as the capacitor bank discharges.

94 3O7 DESIGN OF A COMPACT, BATTERY-POWERED REP-RATE CHARGER FOR A 88-KJ CAPACITOR BANK FOR EML APPLICATIONS Brett Huhman, Jesse Neri US Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA

The Materials Testing Facility (MTF) at the U.S. Naval Research Laboratory (NRL) is developing a battery-powered, rep-rate charger for a 88-kJ capacitor bank. The goal is to charge a 7000-µF capacitor to 5-kV in three seconds for a fifty shot burst. A bank of LiFePO4 batteries is used with a full H-bridge converter, a transformer, and a rectifier to transform the 450V battery voltage to 5-kV secondary voltage. A key parameter is to minimize the converter weight and volume; therefore the switching frequency needs to be as high as possible to reduce the size of filter components and transformers. However, as the frequency increases, switching losses will begin to dominate and a practical limit will be reached before the device switching maximum is reached. In addition to the design of stable battery packs, most of the work has been focused on switch design and driver optimization, utilizing techniques such as resonate switching and active feedback control systems. This paper will present simulation data and results from experiments.

Work supported by the US Office of Naval Research and the Naval Research Laboratory Base Program

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

95 3O8 REGULATED HIGH VOLTAGE POWER SOURCES UTILISED FOR FAST DYNAMIC LOADS LIKE NEUTRAL BEAMS, RF HEATING SYSTEMS AND FAST ACCELERATORS Paresh Patel1, Sumod C.B.1, D.P. Thakkar1, L.N. Gupta1, V.B. Patel1, L.K. Bansal1, K. Qureshi1, V. Vadher1, N.P. Singh2, U.K. Barua1 1Institute for Plasma Research, Power Supplies and DAC division, Neutral Beam Injector Group, Gandhinagar, India, 2ITER, India, Power Supply Group, Gandhinagar, India

High power heating and current drive systems for any Tokomaks as well as for accelerators use Regulated High Voltage Power Sources (RHVPS) as main subsystems. These RHVPSs are to be designed to meet parameters like fast dynamics, good ripple and regulation performance. Microsecond order fault clearing time is most important parameter from load safety point of view since only few Joules of energy is permitted to the fault. The development of a series of RHVPS ranging from 14 kV to 100 kV with a maximum of 130A are being used for the RF and NB heating systems of the SST-1 Tokomak and a design thereof is presented here. Extensive tests on an 80kV, 75A power supply were done and this RHVPS is regularly used on a Neutral Beam Injector. A 100kV, 25 A RHVPS is being installed for accelerator application including a klystron operation. The system uses the pulse step modulation technique for control of the series switches of each switched power module fed from multi-secondary transformer. A special switching signal array controls the series switches with which the rise/fall slope control could be programmed from few µS to hundreds of mS range. The fast protection clears any over current fault in less than 2 µS; fault energy has been measured to be less than 5 Joules. In addition to these major features, the presentation describes novel subsystem level design and results from fault conditions.

96 4O1,2 (invited) COMPARISON BETWEEN MONOPOLAR AND BIPOLAR µs RANGE PULSED ELECTRIC FIELDS IN ENHANCEMENT OF APPLE JUICE EXTRACTION Paula S. Brito1, Hiren Canacsinh1, João Mendes1, Luís M. Redondo1, Marcos T. Pereira2 1Instituto Superior de Engenharia de Lisboa, ADESPA, Lisbon, Portugal, 2Lusoforma, Industria e comercio d embalagens Mem Martins, Portugal

Exposure of living cells to pulsed electric fields (PEF) can cause cell membranes disorder causing a so called electroporation phenomenon, where transmembrane potential is the key variable to achieve the desired results after PEF application and control of pulse parameters such as pulse width, pulse number and applied electric field are crucial for the reversible or irreversible disruption of cell membranes. Nowadays PEF applications in biomedical and food industry fields are numerous and pulse shape may have significant influence in performance and productivity in many of those applications. One interesting point is that bipolar pulses may defy permeabilisations asymmetries due to hidden transmembrane potentials and may also increase the odds of electroporation since cells are nor perfectly spherical. In this work, the effect of monopolar and bipolar shaped pulses in additional yield of apple juice extraction is evaluated. Considering the relative low voltages involved in the laboratory experiments, an H-bridge topology was used, capable of deliver monopolar and bipolar pulses into the load where the switches hold-off the voltage of the power supply. Applied electric field, pulse width and number of pulses are assessed for each pulse type and divergences are analyzed. Variation of electric field is ranged from 100 V/cm to 1000 V/cm, pulse width from 20 µs to 300 µs and number of pulses from 10 to 275, at frequency of 200Hz. Two trains separated by 1 second are applied to apple cubes. Results are plotted against reference untreated samples for all assays. Energy consumption is calculated for each experiment as well as qualitative indicators for apple juice of total soluble dry matter and absorbance at 390 nanometers wavelength. Bipolar pulses demonstrated higher efficiency and energetic consumption has a threshold where higher inputs of energy do not result in higher juice extraction. Total soluble dry matter and absorbance results do not illustrate significant differences between application of monopolar and bipolar pulses but all values are inside the limits proposed for apple juice intended for human consumption. A manufactured treatment chamber with 503 cm3 is used and an adapted pressurizing system guaranteed a constant pressure of 5 bar for all assays of the apple juice production.

97 4O3 HIGH VOLTAGE PULSE GENERATOR BASED ON TPI-THYRATRONS FOR PULSED ELECTRIC FIELD MILK PROCESSING Victor Bochkov1, Dmitry Bochkov1, Igor Gnedin1, Yaroslav Makeev1, Gleb Vasiliev2, Sergey Zhdanok2 1Pulsed Technologies Ltd. Ryazan, Russia, 2A.V. Luikov Heat & Mass Transfer Institute National Academy of Sciences of Belarus Minsk, Belarus

Development of cutting-the-edge electric field processing methods for liquid products, in particular, milk, fruit juice and so on is in progress all over the world. The non-thermal technology was designed using effect of super-power pulse electric filed with electric strength of 35 -100 kV/cm, short pulse duration of 10 – 1000 ns and repetition rate up to 1000 Hz [1, 2]. In this technology the liquid product is flushed through the electrode system without heating, chemical reagents and hazardous radiation. Common technologies for the electric pulse treatment are based on solid state switches. Relatively low operating voltages of single switches dictate necessaty to use assemblies which complicate circuitry and make the technology pretty expensive. For example, one installation for 400 litres/hour costs $250 000 [2]. These drawbacks seriously complicate expansion of the technology on the market. Meantime the achieved characteristics are a challange for pulsed power system designers to search for solutions reducing cost and improving reliability of installations. TPI-thyratrons designed in the beginning of 2000s do have doubtless advantages over the hot cathode thyratrons, trigger spark-gaps, vacuum gaps and solid-state devices for high pulsed power applications. This allowed building and testing a system "UPME" for milk processing with average productivity up to 1000 litres/hour based on TPI1-10 k/50 thyratron with operating voltage up to 50 kV. As a result of the tests energy losses, reliability as well as environmental safety, biological effectiveness and cost-effectiveness of the chosen method were estimated. Complex investigations and biological evaluation of the milk quality was made on a prototype installation in Minsk (Belarus) in cooperation with universities, biological institutes and accredited labs. Target cost of the UPME installation is 50 000 $US approximately. [1] Schoenbach K.H. et al. Bacterial Decontamination of Liquids with Pulsed Electric Field, IEEE Trans. Dielectrics and Elec. Ins., 7, pp.637-645, (2000) oshi, R.H. Stark, F. Dobbs, and S.J. Beebe, [2] M. Gaudreau, T. Hawkey, J. Petry, M. Kempkes, SOLID-STATE POWER SYSTEMS FOR PULSED ELECTRIC FIELD (PEF) PROCESSING, www.divtecs.com [3] P. A. Bokhan, D. E. Zakrevsky, M. A. Lavrukhin, et al, «Development Of Gas-Discharge Lasers Using TPI-Type Pseudospark Switches», 17th IEEE International Pulsed Power Conference, Washington DC, pp. 1303-1308, 2009

98 4O4 CHARACTERISTICS OF CAVITATION BUBBLES AND SHOCK WAVES GENERATED BY PULSED ELECTRIC DISCHARGES WITH DIFFERENT VOLTAGE AMPLITUDES Daiki Oshita1, S.H.R Hosseini2, Yuta Okuda1, Yuta Miyamoto1, Hidenori Akiyama1,2 1Kumamoto Univercity, Graduate school of science and technology, Kumamoto, Japan, 2Kumamoto Univercuty, Bioelectrics research center, Kumamoto, Japan

In the cases that underwater pulsed electric discharges should be applied with high repetition rates, such as medical applications, characteristic of the generated cavitation bubble and shock waves should be considered. In our previous research, underwater shock waves focusing by pulsed discharges using a magnetic pulse compression unit (MPC) were studied. In this paper, effects of pulsed electric discharge parameters, like voltage amplitude and pulse duration, on the characteristic of cavitation bubbles and shock waves were visualized and analyzed. Pulsed discharge shock waves and cavitations were produced by using a MPC unit. The water was degassed by a vacuum pump in order to eliminate the influence of dissolved air. In order to prevent electrical discharge oscillation and to increase the electrode life time, degassed saline electrolyte was used. The whole sequences of shock wave generation by discharge plasma, bubble growth, bubble collapse, and secondary shock wave generation near the electrode were visualized by time-resolved high speed shadowgraph method. Using the visualization results and image analysis, radius and collapse time of cavitation bubbles and their shock waves pressures were evaluated.

99 4O5 PULSED ELECTRIC FIELD INDUCED DIELECTRIC EVOLUTION OF MAMMALIAN CELLS Jie Zhuang1,2, Yu Jing1, Juergen F. Kolb2 1Frank Reidy Research Center for Bioelectrics, Old Dominion University Norfolk, VA, USA, 2Leibniz Institute for Plasma Science and Technology Greifswald, Germany

Pulsed electric field above a certain threshold of amplitude and duration can permeabilize live mammalian cells and trigger various bioelectric effects. These conformational and functional changes lead to modifications in the dielectric properties of corresponding cellular structures. Hence, time-resolved measurement of cellular dielectric properties following pulsed electric field exposure helps to understand the underlying interaction mechanisms. Moreover, cell specific differences might eventually permit us to design exposure conditions to preferentially target cells, such as cancer. To this end, we have investigated the dielectric properties of two mammalian cancer cell lines, Jurkat cells and B16F10 cells, after exposure to microsecond and nanosecond pulsed electric fields by means of time domain dielectric spectroscopy. Cell suspensions of 10% volume fraction were exposed to 8 pulses of 100 μs, 300 ns and 60 ns duration with different amplitude. Results show that conductivities of the both cell suspensions increased significantly following microsecond or nanosecond exposure. Further analysis, based on the combination of a Maxwell-Wagner mixture model and a single shell cell model, shows increases in conductivities of suspending medium and plasma membrane, indicating that membrane poration has occurred. This was confirmed by membrane integrity markers. The dielectric parameters of a nucleus, obtained by a double shell model, show significant changes after nanosecond pulsed electric field exposure, indicating that nanosecond pulses had affected intracellular structures. The induced changes were significantly different for different cell lines and regimens with same electrical energy, suggesting differences in membrane charging and pore formation. A strong correlation was found between the plasma membrane conductivity 30 minutes after exposure and the long term cell survival 24 hours after exposure, suggesting the possibility of employing dielectric spectroscopy as a noninvasive means to evaluate and predict the efficacy of pulsed electric field treatment.

100 4O6 INVESTIGATING THE ROLE OF PULSE REPETITION RATE IN MODULATING CELLULAR RESPONSE TO HIGH VOLTAGE, NANOSECOND ELECTRIC PULSES Stefania Romeo1, Luigi Zeni1, Anna Sannino2, Maria Rosaria Scarfì2, P. Thomas Vernier3, Olga Zeni2 1Second University of Naples, Department of Information Engineering, Aversa, Italy, 2National Research Council, Institute for Electromagnetic Sensing of Environment - IREA, Napoli, Italy, 3University of Southern Californiano, Ming Hsieh Department of Electrical Engineering, Los Angeles, CA, USA

Although it is well established that cell functions are affected by exposure to high voltage, nanosecond electric pulses, the basic mechanisms for these effects remain unclear. Moreover, the correspondence between experimental findings and theoretical models that could allow prediction of effects under specific pulsing conditions is still lacking [1]. One of the key pulse parameters is the pulse repetition rate (PRR) whose impact on bio-effects has given rise to contradictory results. In a recent paper, Pakhomova and co-workers specifically investigated the role of PRR in membrane permeabilization and cell killing, and they demonstrated that both the total duration of the treatment and the PRF are critical factors in the sensitization of cells to lethal effects of pulse exposure [2]. In the present study we investigated the role of PRR in modulating cellular responses. Relatively mild exposure conditions were applied in order to minimize the complexity of the biological response. We focused on different cellular endpoints (plasma membrane permeabilization, apoptosis, cell viability, and proliferation) to explore whether different cellular targets can exhibit different dependencies on PRR, and to seek an explanation for the conflicting results reported in the literature. In preliminary experiments human lymphoblastoid T cells were exposed to 60 ns duration and 2.5 MV/m amplitude pulses with varying number and repetition rates. Electric pulses were generated by means of a coaxial-cable-based Blumlein pulse-forming network matched to standard electroporation cuvettes, in which cell suspensions were placed for exposures. Preliminary results on human lymphoblastoid T cells indicate that high pulse repetition rates enhance plasma membrane permeabilization and apoptosis while reducing cell viability immediately after the pulse exposure and over time. [1] Joshi RP and Schoenbach KH, Critical reviews in biomedical engineering, 38(3): 255-304, 2010. [2] Pakhomova ON et al., PLoS ONE 6(2): e17100, 2011.

101 4O7 NON-THERMAL AND TRANSIENT THERL EFFECT OF PULSED ELECTRIC FIELDS ON HELA CELLS Kazunori Mitsutake1, Shinya Moriyama1, Yumi Kishita1, Sunao Katsuki2, Hidenori Akiyama1, Tsuyoshi Shuto3, Hirofumi Kai3 1Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan, 2Kumamoto University, Bioelectrics Research Center, Kumamoto, Japan, 3Kumamoto University, Faculty of Life Science,, Kumamoto, Japan

The primary biological effects of intense electrical pulses are physical effects that are divided into non-thermal effect based on a dielectric stress and transient thermal effect (TTS) based on the Joule heating. The primary effects are likely to trigger various secondary biological responses such as mitochondrial membrane potential drop, calcium release from endoplasmic reticulum, caspase activation, etc. While most published studies on pulse electric fields have dealt with non- thermal effects, we have been investigating the TTS effect on organism. Our previous study [1] using HeLa cells has demonstrated the superposition of TTS on non-thermal loading enhances the apoptotic activity significantly. Here, we compare the biological effects of non-thermal, transient thermal loads and their combination, with respect to the viability, apoptotic activity and stress responses in HeLa cells. In addition, we are interested in the difference between the TTS and conventional hyperthermia. Intense Burst Alternating Current Electric Field (IBACF) was used as a narrow frequency band pulsed field to be given to the cells. The IBACF generator consists of a pulse generator , a signal generatorand a high power radio-frequency amplifier . The thermal load was adjusted mainly by a pulse duration and an interval of the repetitive pulses. Even with small field less than 100 V/cm, the temperature jump of cell-suspending medium can be 50 K within 1 s, which is TTS. Cells were placed in the 2 or 4 mm gap cuvette and exposed to the IBACF (<10 kV/cm). The voltage across the cuvette was monitored. The instantaneous temperature of the cell-suspending medium was monitored using a fast-response radiation thermometer. HeLa cells were treated by various electrical pulse sequences with a field strength between 0.25 and 4 kV/cm and with a temperature jump up to 60 K. Morphological and statistical analysis of the cells were conducted by using a fluorescent microscopy and a flow cytometer, respectively. The cell viability depends on both the temperature jump and the electric field strength. The synergic effect of the TTS with the non-thermal effect enhances the apoptotic activity. Presently, we have been analyzing the gene expression and protein phosphorylation to investigate the cellular mechanisms leading to apoptosis. [1] S. Katsuki, K. Mitsutake, et al., "Non-thermal and Transient Thermal Effects of Burst 100 MHz Sinusoidal Electric Fields on Apoptotic Activity in HeLa Cells", IEEE TDEI, Vol. 17, 678- 684, 2010.

102 4O8 ANALYSIS OF CORONA DISCHARGES IN CYLINDRICAL TOPOLOGY AND PARTICLE CHARGING MECHANISMS FOR OPTIMISATION OF PRECIPITATION EFFICIENCY Igor Timoshkin, Athanasios Mermigkas, Martin Given, Tao Wang, Mark Wilson, Scott MacGregor University of Strathclyde, EEE, Glasgow, United Kingdom

In the recent work [1] an impulsive micro-electrostatic precipitation technology has been investigated. This technology combines a DC high voltage with sub-microsecond high voltage impulses to energise the electrodes of the precipitator. The present paper examines corona discharges in cylindrical topologies for optimisation of the electrostatic precipitation process. Analytical analysis of the corona discharges has been conducted and the space-charge saturated current in the cylindrical topology has been obtained using the Poisson and the continuity equations. The Peek's phenomenological approach has been used for calculations of the corona ignition voltage and evaluation of the depth of the ionisation zone in the cylindrical reactor. Analysis of charging of micron and sub-micron particles with different conductivies has been conducted using the analytical Cochet approach which takes into account the field and diffusion charging mechanisms. Based on these data, the particle migration velocities and efficiency of precipitation of particulate matter have been calculated. This analysis shows that problematic particles with dimensions in the range 100-1000 nm have minimum velocities which results in the reduction in their precipitation efficiency. Analytical results are compared with the experimental data which confirms a lower efficiency for 400-650nm particles. The paper discusses potentials solutions which will help to improve efficiency of electrostatic precipitation of sub-micron particles as these particles attracted attention due to environmental and health risks which they pose. These solutions include impulsive energisation of high voltage electrodes and double-stage precipitation reactors. [1] A. Mermigkas, I. Timoshkin, S. MacGregor, M. Given, M. Wilson, T. Wang, "Superposition of DC voltage and sub-μs impulses for energisation of electrostatic precipitators", IEEE Transactions on Plasma Science, Special Issue on Pulsed Power, 2012, to be published.

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104

TUESDAY

B Plenary Session 2 THE EVOLUTION OF PULSED MODULATORS FROM THE MARX GENERATOR TO THE SOLID STATE MARX MODULATOR AND BEYOND Richard Cassel Stangenes Industries Inc.

The pulsed modulator has evolved from the early spark gap Mark Generators thru many different design forms to the present in which the Marx design returns using Solid State switches. The paper will chronicle the different types of pulsed modulator, including hard tube/switched modulators, pulse forming network modulators, induction/fractional turn modulators and Marx type modulators. The use of the various types of modulators for short and long pulse operation is reviewed. The advantages and disadvantages of the different types of modulators are evaluated and there possible use in present requirements and future applications is discussed. In addition, the paper speculates on the possibility evolutional direction in which modulators might change or develop in the future.

105 5O1,2 (Invited) DESIGN AND PERFORMANCE OF A HIGH-PRESSURE, FLOWING LIQUID DIELECTRIC PEAKING SWITCH Rainer Bischoff French-German Research Institute of Saint-Louis (ISL) Saint-Louis, France

A repetitive, high-voltage liquid dielectric switch for high-power microwave (HPM) applications is currently being developed and investigated at the French-German Research Institute of Saint- Louis (ISL). The switch was designed to be implemented in existing coaxial pulse line structures and is being driven by compact modular Marx generators at rise times less than 5 ns and output voltages up to 400 kV. A pumping system consisting of a gear pump and a piston diaphragm pump was installed, which allowed the operation of the switch at flow rates up to 100 ml/s and pressures up to 1800 kPa. Galden, a perfluoro-polyether, was chosen as the liquid dielectric. Computational fluid dynamics (CFD) simulations of liquid flow through the switch were carried out. The results led to an optimized electrode geometry with an asymmetric radial inflow between the concave copper-tungsten electrodes and an axial outflow through a bore hole inside the earth electrode, in order to minimize the risk of a turbulent flow through the switch. The measurements of the achievable breakdown field strength showed a significant dependency on the pressure and on the type of the Galden fluid used. A Galden fluid with a high boiling temperature is to be preferred, as it has the least tendency to contain micro gas bubbles. A maximum breakdown field strength of 9.3 MV/cm at a pressure of 1570 kPa and a gap distance of 0.30 mm is reported using Galden HT270. This represents an increase of 240% in comparison to the breakdown field strength of 3.8 MV/cm at atmospheric pressure. The typical switch rise time was 0.46 ns; the achieved voltage rise time was 5·1014 V/s. Initial two-pulse experiments were carried out to investigate the achievable pulse repetition rate by charging the switch directly with a high-voltage capacitor charger at a charging voltage of 50 kV and a charging time of 210 µs. The measured 90% recovery time of 4.0 ms at a pressure of 320 kPa shows the potential of the liquid dielectric switch to operate at frequencies above 200 Hz.

106 5O3 TRIGGERED OPERATION OF A CORONA CONTROLLED CASCADE SWITCH AT ELEVATED PRESSURES Martin J Given1, Long Li1, Mark P Wilson1, Igor V Timoshkin1, Tao Wang1, Scott J Macgregor1, Jane M Lehr2 1Strathclyde University, Electronic and Electrical Eng, Glasgow, United Kingdom, 2Sandia National Laboratories Albuquerque, NM, USA

Corona stabilised switches are known to have the advantages of low jitter and high repetition rates [1]. However the operating voltage of a single stage switch is relatively limited, with a maximum of ~40 kV. It has been shown that it is possible to setup a cascade switch using corona stabilised stages that can operate at much higher voltages [2]. The concepts involved in this basic cascade have been developed, and it has been shown that by changing the profiles of the corona emission electrodes in the cascade gaps, it is possible to control the voltage distribution across the cascade stages using air at atmospheric pressure [3]. The triggered behaviour of individual gaps in the cascade and also of the full cascade were investigated using air at atmospheric pressure and it was shown that the expected switching time and jitter of the cascade could be predicted from the voltage distribution for the cascade, determined by the corona emission characteristics of the cascade electrodes, and the measured triggered breakdown behaviour of the individual gaps in the cascade.[4, 5]. This paper describes work performed to investigate the behaviour of the cascade in air over a range of pressures. The corona emission characteristics, the triggered behaviour of the individual elements, and the triggered behaviour of the cascade over a range of voltages and pressures are reported. The implications of this data on the design of a practical corona controlled cascade switch operating in air are also discussed. [1] J. M. Koutsoubis, and S.J. MacGregor, "Effect of gas type on high repetition rate performance of a triggered, corona stabilised switch", IEEE Trans. Dielectr. Electr. Insul., Vol. 10, pp. 245- 255, 2003. [2] J. R. Beveridge, S. J. MacGregor, M. J. Given, I. V. Timoshkin and J. M. Lehr. "A Corona- stabilised Plasma Closing Switch", IEEE Trans. Dielectr. Electr. Insul., Vol. 16, pp 948–955, 2009. [3] M.J.Given, I.V. Timoshkin, M.P. Wilson, S.J. MacGregor. "A Novel Design for a Multistage Corona Stabilised Closing Switch. IEEE Trans. Dielectr. Electr. Insul., Vol. 18, pp 983–989, 2011. [4] M. J. Given, M.P. Wilson, I.V. Timoshkin, S.J. MacGregor, T. Wang and J.M. Lehr "The Triggered Behaviour of a Controlled Corona Stabilised Cascade Switch" Proccedings IEEE Int. Pulse Power Conference. Chicago (2011). [5] M. J. Given, M.P. Wilson, I.V. Timoshkin, S.J. MacGregor, T. Wang and J.M. Lehr "The Triggered Behaviour of a Controlled Corona Stabilised Cascade Switch" Submitted IEEE Transactions on Plasma Science. (2012).

107 5O4 LOW JITTER, HIGH VOLTAGE, REPETITIVE LASER TRIGGERED GAS SWITCHES Frank Hegeler2, Matthew C. Myers1, Matthew F. Wolford1, John D. Sethian1, Andrew M. Fielding2, John L. Giuliani1 1Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2Commonwealth Technology, Inc. Alexandria, VA, USA

The krypton fluoride (KrF) laser facility, Electra, is a repetitively pulsed, electron beam pumped laser system at the Naval Research Laboratory, which is focused on meeting the scientific and technical requirements of a durable driver for Inertial Fusion Energy (IFE). The main laser amplifier includes two identical pulsed power systems that generate 500 kV, 110 kA, 140 ns pulses to opposing diodes. Each pulsed power system charges two parallel pulse forming lines (PFL) up to 1.2 MV, and the energy is switched into the electron beam diode load with laser triggered spark gaps at the end of each line. The switches are triggered by a quadrupled ND:YAG laser, with pulse length 11 nsec. Energies of 11 mJ with a focal diameter of 0.3 mm are typical for each switch. The two parallel, sulfur-hexafluoride filled spark gaps should fire within a few nsec of each other in order to apply the a smooth, fast rising and fast falling power pulse to the cathode. (Failure to achieve this results in undesired voltage reflections that compromise the durability of the electron beam components.) This in turn requires low jitter and by inference, relatively short switch runtimes between the trigger laser and switch closure. The switches should sustain reliable performance at repetition rates of up to 5 pps for at least 100,000 continuous pulses without maintenance. This paper evaluates the switch performance for hemispheric and flat shape electrodes, discusses electrode erosion, and provides the switch jitter and runtime for voltages ranging from 0.675 – 1.17 MV, SF6 pressures from 50 – 83 psia at 7 SCFM, and trigger laser energies from 1 – 19 mJ at 266 nm. Fused silica, CaF2, and sapphire windows are examined as laser trigger optical ports of the SF6 switch. The switch reliability improves with flat shaped electrodes, with CaF2 windows, and at high trigger laser energies. At 1.15 MV and an electrode gap of 5 cm, 2 σ switch jitters of <3 nsec are achieved for laser energies >5 mJ, and SF6 switch pressures ranging from 55 to 66 psia. The useable electrode lifetime has been extended from 40,000 shots (hemispheric design) to at least 200,000 shots (flat shape design).

Work supported by DOE/NNSA.

108 5O5 DISCUSSION OF BREAKDOWN MECHANISM IN TRIGATRON SPARK GAP Li Cai, Fuchang Lin, Lee Li, Xiangdong Qi, Chaobing Bao HuaZhong University of Science and Technology (HUST), State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China

Development of a three-electrode spark gap is discussed in this paper. Two modes of the breakdown mechanism, i.e., fast-breakdown mode (FBM) and slow-breakdown mode (SBM), are proposed to explain the breakdown in the trigatron gap. Raether criterion can distinguish these two modes. Some important factors influencing the operation mechanism have been discussed, such as the undervoltage ratio, trigger voltage and gap distance. Then, the mathematical model time delay determined by operation mechanism could be calculated. Moreover, the quantitative relationship between electric field and time delay was also discussed by considering the trigger energy. The experimental results show that how the working parameters affect on the breakdown mechanism. Then the experimental results demonstrate that there are three regions divided by two inflection points in time delay and optimization operation could be attained with selection of working parameters.

109 5O6 PERFORMANCE OF A CORONA-STABILISED SWITCH ACTIVATED BY FAST-RISING TRIGGER PULSES Mark Wilson1, Igor Timoshkin1, Martin Given1, Scott MacGregor1, Tao Wang1, Jane Lehr2 1University of Strathclyde, Electronic & Electrical Engineering, Glasgow, United Kingdom, 2Sandia National Laboratories, Exploratory Pulsed Power, Albuquerque, NM, USA

Plasma closing switches used in pulsed-power applications have traditionally been insulated with sulphur hexafluoride (SF6) due to its high dielectric strength at relatively low pressures. Widespread recognition of SF6 as a damaging greenhouse gas however has resulted in the implementation of local and international legislation governing the recovery of SF6, translating to increased running costs for users of the gas. As a consequence, alternative gases are being investigated to determine their suitability to replace SF6, both as internal insulation as a switching medium, and as external insulation to prevent flashover within other pulsed-power components and systems. In a previous paper, the authors described the characterisation of a triggered corona- stabilised (TCS) closing switch in terms of delay time and jitter, firstly in SF6 to provide reference data, and secondly in dry air as a potential replacement for SF6. Over the available operational pressure range for each gas, jitter was found to vary from 1.0 µs to 5.1 µs in dry air, compared with 0.7 µs to 2.9 µs in SF6. The trigger pulse utilised in this work had peak magnitude of 35 kV, rise-time of 30 µs, and full width at half-maximum (FWHM) pulse duration of 80 µs. The triggering range in dry air was found to be very narrow for this trigger pulse, with a range of only 4-5 kV between the self-breakdown voltage and the trigger threshold over a 3-bar pressure range, compared to a maximum triggering range of 19 kV in SF6. The same TCS closing switch has now been re-characterised with faster-rising trigger pulses, with rise-time of the order of 100 ns, and peak voltages up to 40 kV. The trigger pulses were provided by a 2-stage, pulse- forming network (PFN) Marx generator, with the stages being formed from 25-m sections of URM67 coaxial cable. The results obtained for delay time and jitter are presented, and compared with those found previously for the slower triggering regime.

110 5O7 EFFECT OF CURRENT PULSE WIDTH ON THE XENON Z-PINCH DISCHARGE PLASMA FOR EXTREME ULTRAVIOLET SOURCE Peng Lu, Tetsuya Watanabe, Sunao Katsuki, Takashi Sakugawa, Hidenori Akiyama Kumamoto university, Graduate School of Science and Technology, Kumamoto, Japan

Extreme ultraviolet (EUV) lithography is considered the most promising candidate for next generation semiconductor manufacturing of the half-pitch 22 nm node and beyond. 13.5nm in- band (2% bandwidth) EUV light source is still one key issue for the industrial application of EUV lithography. Previously, we have reported the characteristics of both xenon and tin plasma EUV light source developed in our group. The performance of EUV light radiation and dynamics of plasma has been studied. Z-pinch plasma movement along axial direction enlarges the size of EUV-emitting plasma. In the EUV lithography system, due to the limited etendue of the optical system of the EUV scanner, the smaller the EUV-emitting plasma size can allow the larger collectable angle of the source optics at the certain etendue. In this paper, we have studied the possibility of reducing the EUV-emitting plasma size by shortening the current pulse width in the xenon z-pinch EUV source. The current pulse duration was shortened by decreasing the inductance of discharge circuit. Current pulses with the duration of 85-ns and 120-ns were applied across the short capillary to drive the Z-pinch plasma. The EUV light emission and plasma dynamics have been compared for two different pulse duration. Temporal plasma behavior was visualized by the time-resolved visible light and EUV light (11-18nm) imaging. The electron density of Z-pinch plasma was measured using the interferometer. The effect of current pulse width on the xenon z-pinch plasma EUV source is discussed.

111 5O8 X-RAY EMISSION FROM A TABLE-TOP X-PINCH DEVICE Ran Zhang, Xinlei Zhu, Shen Zhao, Haiyun Luo, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing, China

X-pinch plasma is produced with a high and pulsed current flowing through two or more fine wires that cross and touch at a single point, forming an "X"-shaped structure. A subnanosecond pulsed x-ray point source is usually formed at the crossing point of the wires. X-pinches have been used as x-ray sources for backlighting of high density plasmas such as wire-array Z-pinch plasma and for phase-contrast imaging of soft biological objects that could not be imaged by the conventional x-ray radiography. For the purpose of the clinical or biological application of X- pinch as x-ray source, a table-top X-pinch device was constructed based on a compact (2m×1m×1.5m) pulsed current generator (~ 100 kA, 60ns). The whole device was put on a platform under which there are four wheels and thus it can be easily moved by a single person. The current flowing through the X-pinch load was measured with a Rogowski coil and it was almost unchanged for X-pinches made using different wires (5mm, 8mm, 10mm and 13mm Wu wire, 13mm and 25mm Mo wire), which means that the contribution of the wires to the total impedance of the X-pinch load is very small. The characteristics of the x-ray emission from the X-pinch were investigated. The time-resolved x-ray emission was measured with photoconducting detectors (PCDs) and the pattern of the x-ray source was recorded with a pinhole camera. When the above mentioned wires were used as two-wire X-pinches, X-ray pulses from the X-pinches were always observed. As the mass of the two wires increases, the time delay of the x-ray emission relative to the beginning of the current increases. The X-ray pulse consists of single peak or two overlapping peaks of subnanosecond pulsewidth. Two X-ray pulses with a time interval on the order of 10 ns were often observed for an X-pinch of a relatively small mass when the current is high enough. The appearance of the second X-ray pulse is attributed to the second pinch of the plasma. The total energy of the x-ray emission, obtained by the integration of the x-ray pulse over time, changes significantly from shot to shot and is in the range of 0.1J ~ 1J for x-rays of hn > 1.5 keV. The x-ray spectrum was obtained with PCDs covered with different filters and the major part of the x-rays is with hn <2.5 keV. The x-ray source is usually one point or two partly overlapping points, which is consistent with the measurement of x-ray pulse. The x- ray point source has a size ranging from 5 mm to 50 mm. The experimental results show that the table-top X-pinch is suitable to be used as x-ray source for phase-contrast imaging of soft biological objects.

112 6O1 EXPERIMENTAL IMPULSE RESPONSE OF GROUNDING SYSTEMS Malone Castro, Euler Macedo, Edson Costa, Raimundo Freire, Maria Rodrigues, Luana Gomes Campina Grande Federal University, Electrical Engineering, Campina Grande, Brazil

Grounding systems are important part of the power system that protect power lines and power apparatus from severe ground faults and lightning currents. The grounding systems should have sufficiently low impedance and current-carrying capacity to prevent the buildup of voltages that may result in undue hazard to connected equipments and to persons. Many studies describe experiments, empirical formulas, analytical or numerical methods to predict the behavior of grounding systems when impulse currents discharge to earth. These studies produce realistic results for very simple electrodes or for impulse currents having small amplitude but, in general, they fail where complex systems have to be analyzed when soil breakdown occurs (i.e., when the system is excited by high impulse currents). Is shown in this article a development experimental methodology applied in the evaluation of the grounding system response to high current impulse. A grounding system can substantially reduce the damage caused by lightning, but it is necessary to know the electrical model of the grounding system to be able to design power system installations and make corrections during the maintenance phase. The aim of this paper is to present a methodology for developing experimental models of these grounding systems. After the development of models, the results of this work are useful also in validating simulations. Experimental studies with high current impulses require adequate area and strict safety equipment. Because of these difficulties, the number of experimental works is not large. In recent years, it was intensified the use of simulation, using computational methods. Initial experimental procedure was performed using a high current pulse generator, a four-channel oscilloscope, ground rods, cables and connectors. Pulses were generated with waveform 8/20 µs and peak voltage from 10 to 40 kV. The current impulse injection in the soil was through a conventional grounding rod, made of steel coated with copper. Current values were acquired at several radial distances in the soil to evaluate the spread of the impulse. Final work will present a new test-set and provide a satisfactory data to evaluation and an accurate analysis of the ground systems.

113 6O2 THE EFFECTS OF TEMPERATURE, MOISTURE, TESTING VOLTAGE AND TIME DURATION ON DIELECTRIC RESPONSE OF TRANSFORMER INSULATION OIL Maziar Shareghi, Toan Phung, Mohammad Salay Naderi, Trevor Blackburn The University of New South Wales, School of Electrical Engineering and Telecommunications, Sydney, Australia

Reliability of a power transformer is determined by aging state of the insulation. As the conductivity of both oil and pressboard can extensively vary during the life of transformers due to the factors such as moisture and temperature, condition monitoring is of great importance to predict the remaining lifetime of a transformer. Dielectric diagnosis with polarisation and depolarisation currents (PDC) which employs the dielectric response of system in time domain has been used in this research to find the differences between the PDC patterns produced by two types of transformer insulating fluids, mineral and bio-degradable oil. The mineral oil used is Shell Diala BX, and the biodegradable one is Envirotemp FR3 which is ester-based, and a relatively new transformer insulating fluid that is recently being considered as an environmentally-friendly alternative to conventional mineral oil. The DC conductivity of the two oil types has been obtained under the effects of various temperature and moisture levels. The experiment is conducted for two levels of moisture when temperature factor has been changed from ambient to 90 °C. The oil water content measurement has been conducted using Karl- Fischer-Titration. Also, an attempt was made to investigate the effects that different testing voltages and time durations have on the polarisation and depolarisation spectrum. A range of DC voltages up to 1000V, and time durations from 1000 to 10000 seconds have been applied. Finally, all the PDC patterns obtained under the effect of mentioned factors are evaluated.

114 6O3 A LASER DIAGNOSTIC FOR DETECTING INTERNAL ELECTRIC FIELD AND MECHANICAL STRAIN IN A RESONANT PIEZOELECTRIC TRANSFORMER Peter Norgard1, Scott Kovaleski1, Greg Dale2 1University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA, 2Los Alamos National Laboratory Los Alamos, NM, USA

Piezoelectric transformers are simple devices that are used to produce high voltages for applications where portable high voltage, low current sources are required. Early evaluations of piezoelectric transformers (PTs) suggested that the very small resonance bandwidth required to achieve the desired extremely high voltage gain can be easily spoiled by resistive loading such as might occur if a resistive divider network were used to measure the output voltage. A diagnostic technique was developed that used a laser to probe the first-order electrooptic response of the resonant PT. Tests conducted with a resonantly driven PT indicated that the electrooptic response alone was insufficient to predict the measured behavior, and that a correct response could only be obtained if the elastooptic effects were considered as well. Results from the mathematical development are presented as well as experimental data collected on a resonantly driven PT. The experimental evidence indicates that as the internal electric fields climb within the PT, the response from a photodetector changes in a linearly correlated fashion.

Work supported by Nuclear Regulatory Commission, Qynergy, and Los Alamos National Laboratory.

115 6O4 THE EVOLUTION OF IEC 60034-18-41 FROM TECHNICAL SPECIFICATION TO STANDARD: PERSPECTIVES FOR MANUFACTURERS AND END USERS Gian Carlo Montanari1, Andrea Cavallini1, Luca Fornasari2 1University of Bologna, DEI, Bologna, Italy, 2Techimp HQ Spa, R&D, Zola Predosa, Italy

The IEC 60034-18-41 is undergoing a radical revolution: born as a technical specification is going to become a standard for wire-wound rotating machines. One of the points that will influence most strikingly machine manufacturer/customer relations is the concept of impulse rated voltage (IRV). IRV will be printed on the machine nameplate as a number specifying the stress category for which the machine has been qualified (1: Benign, 2: Moderate, 3: Severe, 4: Extreme): the larger the IRV the more reliable the machine when operated by a converter. Indeed, a machine with IRV equal to, e.g., 2 will withstand without problems converter surges in the stress category 1 or 2, while it will probably fail in shorter-than-design time under surges in the stress category 3 or, worst, 4. In order to clarify the implications that these changes will have on the electrical industry, it is important to emphasize the concept of stress category (that is going to change with respect to the previous edition of IEC 60034-18-41) and IRV. Also, as wire-wound insulation systems are qualified or not depending on the fact that partial discharges are incepted or not during qualification tests, it is important to face the challenge of partial discharge detection under repetitive surge voltages. According to the above, this paper will first summarize the main changes in the IEC 60034-18-41. After that, a short description of a system able to detect partial discharge under repetitive voltage surges and its application on complete stators will be presented and measurement examples reported.

116 6O5 RADIOMETRIC LOCATION OF ELECTRICAL DISCHARGE ACTIVITY Martin Judd1, Rachel Harris1, Alistair Reid2 1University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, United Kingdom, 2Glasgow Caledonian University, School of Engineering and Built Environment, Glasgow, United Kingdom

Hertz's original validation of Maxwell's theory of electromagnetic waves involved the transmission and reception of an electrical transient. The fact that the experiment was based on electrical breakdown across a spark gap is not surprising, since the radiation of electromagnetic energy becomes more effective as the rate of change of electric current increases. In a spark, electrons are accelerated very rapidly, particularly in the regions where an insulating medium is undergoing initial ionization. In present times, now that the detection and measurement of signals in the GHz range is possible using low-cost hardware, the radiation of electromagnetic transients from electrical discharges is increasingly being used for condition monitoring and diagnostics on power equipment in high voltage electrical supply networks. This paper describes a number of embodiments of the radiometric method for monitoring discharges, such as arcing in power systems and partial discharges in electrical plant. Results presented include an evaluation of the use of RF methods to locate faults on a wide-area distribution network and the use of UHF sensors to locate partial discharges in power transformers. Frequency band selectivity can even allow partial discharges to be detected in the UHF frequency range in the presence of rapid high voltage switching. In comparatively small scale structures with air insulation, PD location accuracies of typically better than 30 cm can be achieved using 4 UHF sensors and timing resolutions of about 1 ns. The techniques described in this paper may be applicable to insulation breakdown studies in pulsed power devices and systems, both for characterization of intended operation and diagnosis of defects that may degrade performance.

117 6O6 A FILTER BANK APPROACH FOR EXTRACTING FEATURES FOR THE CLASSIFICATION OF PARTIAL DISCHARGE SIGNALS IN HIGH VOLTAGE XLPE CABLES R. Ambikairajah, B. T. Phung, J. Ravishankar, T. R. Blackburn University of New South Wales, School of Electrical Engineering & Telecommunications, Sydney, Australia

There are increasing demands to manage the high voltage cables of the electricity supply industry, which in turn calls for the implementation of online diagnosis and condition monitoring of these assets. The detection of partial discharge (PD) signals and classifying its patterns is an area of interest in the analysis of defects in high voltage cables. Either time or frequency domain features can be extracted from a PD signal for PD classification. This paper investigates a filter- bank based approach to extract frequency domain based features to represent a PD signal. The PD events are recorded in the lab and on-site over an entire AC cycle of 20ms. By applying the Fast Fourier Transform to the PD signal, the sampled PD signal is mapped into equivalent discrete frequency bins. These bins are grouped into equal sub-bands and also into octave sub-bands, for comparison. As the PD signal is generally corrupted by noise, a signal boosting technique is applied to each sub-band to de-noise the signal. The energy corresponding to each sub-band is then calculated using the magnitude of the Fast Fourier Transform and these energies are used as N dimensional features for classification, where N is the number of sub-bands. Three classes of signals, namely surface discharge, corona discharge and internal discharge, are measured in a laboratory environment with the voltage being steadily increased and decreased. The data obtained is then divided into training and testing sets for classification purposes. The robustness of these features, using equal and octave sub-bands, is compared with three different classifiers: probabilistic neural network, support vector machine and the sparse representation classifier. The performance of these classifiers is also discussed in this paper. Results show that the proposed features are robust and provide a strong classification accuracy of PD signals that can be used in online condition monitoring systems. In addition, the optimal number of sub-bands and minimum number of features required for high accuracy classification of PD signals is also investigated.

118 6O7 GENERATION, MEASUREMENT AND APPARENT CHARGE ESTIMATION OF PARTIAL DISCHARGE SIGNALS Diego Araújo1, Euler Macêdo1, Edson Costa1, Raimundo Freire1, José Maurício Neto1, Waslon Lopes1, Warner Barros1, Ian Glover2 1Federal University of Campina Grande, Electrical Engineering and Informatic Center, Campina Grande, Brazil, 2University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, Scotland

Partial discharge (PD) measurement has long been used as a test to evaluate different insulation system designs, and as a quality control test for new equipment. However, in the past 20 years, PD measurement has been widely applied to diagnose the condition of electrical insulation in operating apparatus such as switchgear, transformers, cables, etc. PD is characterized by high frequency current pulses that occur in High Voltage (HV) electrical equipments originating gas ionization process when damaged insulation is submitted to high values of electric field. The importance of estimate the apparent charge of HV equipments in operation is to verify if it is respecting the PD limit established by IEC 60270. In cases when HV apparatus exceeds the apparent charge level, it must be periodically monitored or must be taken off operation because it has a large probability to insulation fail. The degree of insulation damage may be related to the charge involved in each PD event. Thus, many commercial PD instruments integrate the current (or voltage analog) of each PD event to generate a charge response quantified in picocoulombs (pC). The IEC 60270 standardizes apparent charge measurements and levels. However, the standard does not provide recommendations for ultra wide-band detectors, as the High Frequency Current Transforms (HFCT) PD sensors largely used nowadays. In addition many sources of noise (radio transmissions, commutator noise from rotating machines, power electronics switching circuits, etc) can directly affect the PD estimation. A HFCT connected to a high acquisition rate oscilloscope were used to measure the PD signals from a potential transformer (13.8 kV class) and from a acrylic cell with separable electrodes which enable the use of different arrangements of artificial defective dielectrics. A MATLAB routine was developed to de-noise the PD signals based on wavelet transform and also estimate the apparent charge of each PD signal, comparing the result with the apparent charge of a commercial PD monitoring and diagnosis system. In the final version of this paper, will be described the de-noised signals and apparent charge estimation of PD signals measured using the Ultra Wide Band (UWB) inductive sensors. Experimental tests will be performed using HV apparatus and a PD apparent charge estimation methodology will be proposed.

119 6O8 APPLICATION HILBERT-HUANG TRANSFORM ON PARTIAL DISCHARGE PATTERN RECOGNITION OF GAS-INSULATED SWITCHGEAR Hong-Chan Chang1, Feng-Chang Gu1, Cheng-Chien Kuo2 1National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan, 2Saint John's University, Electrical Engineering, Taipei, Taiwan

This study proposes gas-insulated switchgear (GIS) partial discharge (PD) pattern recognition based on the Hilbert–Huang transform (HHT). First, this study establishes four common defect types of 15 kV GIS and uses a commercial high-frequency current transformer (HFCT) sensor to measure the electrical signals caused by the PD phenomenon. The HHT can represent instantaneous frequency components through empirical mode decomposition, and then transform into a 3D Hilbert energy spectrum. Finally, this study extracts the energy feature parameters from the 3D Hilbert spectrum using a neural network for PD recognition. To demonstrate the effectiveness of the proposed method, this study examines its identification ability using 160 sets of field-tested PD patterns generated by GIS. The result shows that the proposed method can separate various defect types easily. The method can also be employed by the construction unit to verify the GIS quality and determine the GIS insulation status.

120 2P1 OZONE PRODUCTION BY BARRIER DISCHARGE TYPE CONCENTRIC CYLINDER ELECTRODE USING PULSED DISCHARGE Fumiaki Fukawa, Yuuya Satoh, Kotaro Rokkaku, Susumu Suzuki, Haruo Itoh Chiba Institute of Technology, Electrical, Electronics and Computer Engineering, Narashino, Japan

Ozone has many applications in various fields with an advantage of low environmental load, i.e., sterilization, deodorization, bleaching, etc. A part of industrial applications of ozone have been already put in practical use. While the barrier discharge is mainly used for commercial production of ozone, the various discharge methods have been studied to achieve higher yield and higher concentration in recent years. In this study, a Blumlein type pulse forming network (B-PFN) is provided and the ozone production experiment is conducted. The reactor is concentric cylinder electrode. The inner electrode is stainless steel and pulsed voltage is applied. The external electrode is earth electrode and glass lining of the dielectric is carried out inside. This reactor gives ozone yield of about 350 g/kWh for discharge efficiency. Since arc discharges are controlled due to using pulsed discharge on barrier discharge type reactor, a higher electric field is obtained. The condition of high yield ozonizer is reported in detail.

121 2P2 INVESTIGATION OF NON-HEATING STERILIZATION METHOD OF PACKED FRESH FOODS BY PULSED ELECTRIC FIELD Takato Higuchi, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan Yonezawa, Yamagata 992-8510, Japan

Currently, foods have been mainly sterilized using chemicals, heating and ultraviolet rays. However, these methods have some problems, for example, the change of the taste and constituent of fresh foods, the risk of the residual chemicals and low efficiency. To solve these problems, the sterilization by the pulsed electric field has been proposed. When the pulsed electric field is applied to a bacterium or fungus, the voltage concentrates to the membrane of it. If the membrane has over 1V of the voltage, breakdown occurs in the membrane. As a result, a pore is made on the membrane and it is sterilized. However, in the case of packed food, since a packing plastic bag is an insulator, the electric field didn't be applied to the bacteria and fungi. In the sterilization by the pulsed electric field, a cell can be written as equivalent circuits by capacitors and resistors. The membrane is the capacitor and the cytoplasm is the resistor. Also the foods can be written as equivalent circuits by capacitors and resistors and a packing plastic bag is written as the capacitor. Therefore, the intensities of the electric field applying to the cell and the bag are changed by the frequency of applying pulsed electric field. This work focuses on sterilization of the packed fresh foods by the pulsed electric field. In this study, we have investigated the sterilization ratios of E. coli packed by a plastic film for the voltage pulses of several frequencies.

122 2P3 INVESTIGATION OF QUANTITY OF ACTIVE SPECIES GENERATED BY PULSED STREAMER DISCHARGES IN THE AREA WITH DROPLETS FOR WATER TREATMENT Takashi Saito, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan

Water pollution that is one of the environmental problems is caused by organic matters discharged in the river and the ocean. Therefore, currently, the method of improving the water quality by bacteria and chemicals is used as a waste water treatment technology. However, the organic matters that are difficult to decompose in the biological treatment exist. If those organic matters are discharged in the environment, there is a possibility of influencing the ecosystem harmfully as a environmental hormone. Therefore, as advanced water treatment, we are studying a method by pulsed discharge generated in the area with atomized waste water. The active speciessuch as O3 and hydroxyl radical that have high oxidizing power are generated by the discharge, and those can decompose effectively the organic matters that are difficult to decompose. Therefore, improvement of the treatment speed and the treatment efficiency can be expected. In this method,quantity of hydroxyl radical generated in the discharge area is important. Therefor we have investigated the quantity of hydroxyl radical generated by pulsed streamer discharges in the area with droplets for water treatment.

123 2P4 SPECTROSCOPIC OBSERVATION OF MICRO PLASMA JETS GENERATED BY PULSED POWER Makoto Inokuchi, Takashi Sakugawa, Hidenori Akiyama Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan

Atmospheric pressure micro plasma jets have been developed for industrial and medical applications, such as the dental treatment, inner surface treatment of capillaries, stimuli of microorganisms and local cleaning of semiconductor devices. An advantage of atmospheric pressure air micro plasma jets is a capability to irradiate plasma to a narrow area, and also is not to require vacuum devices with the ultra-portable and miniaturized size. In this paper, the pulsed power generated micro plasma jets are compared with the DC generated micro plasma jets. Especially, the spectroscopic observation of micro plasma jets is reported comparing two kinds of plasma jets.

124 2P5 BURST ELECTROMAGNETIC WAVE FOCUSING SYSTEM FOR MEDICAL APPLICATION Hidetoshi Ishizawa, Masanori Hashimoto, Takashi Tanabe, Hammid Hosseini, Sunao Katsuki, Hidenori Akiyama Kumamoto University, Guraduate School of Science and Technology, Kumamoto, Japan

Inducing apoptosis in malignant cells and controlling ES cell differentiation by using subnanosecond high voltage pulses have been investigated. These results stimulate authors to develop a high power burst electromagnetic wave focusing system for the apoptosis induction of cancer cells. This system consists of a transmitting antenna, and an ellipsoidal reflector which focuses radiation waves. The ellipsoidal reflector has the characteristic of focusing the burst electromagnetic waves radiated from the first focal point on the second focal point. Therefore, the electric field is enhanced at the second focal point. This system is immersed in heated water to avoid the mismatch of permittivity between a living body and the medium in which electromagnetic waves propagate. Thereby, the reflection and the refraction at the surface of a living body are reduced, and the burst electromagnetic waves are focused on the target more accurately. This paper shows the experimental and simulated results to optimize the antenna and reflector geometry to radiate the burst electromagnetic wave to a living body.

125 2P6 INVESTIGATION OF OZONE PRODUCTION USING NANOSECOND PULSED POWER FOR DENSE OZONE Ryo Mabuchi, Tatsuya Kageyama, Kenji Teranishi, Naoyuki Shimomura The University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima, Japan

Ozone has been used as an oxidizing agent with low environmental load. The consumption of ozone is increasing and will furthermore increase. Then, the improvement of efficiency of ozone production is required. Dielectric barrier discharge (DBD) has been used to produce ozone in industrial ozonizers since non-thermal plasma as streamer discharge can be readily obtained to produce ozone effectively. The efficiency of ozone production with the DBD is, however, not so high. Meanwhile, ozone production using pulsed power has been studied and the high efficiency has been achieved. The use of pulsed power can bring the streamer discharge without dielectric barrier layer. In using pulsed power, concentration of produced ozone is relatively low and improvement of concentration is indispensable to develop for practical use. We have introduced nanosecond pulsed powers for ozone production since higher efficiency of production is expected. Here, fundamental research using nanosecond pulsed power to ozone production has been done in order to consider the mechanism and configuration to produce dense ozone. Although a short separation between discharge electrodes in reactor is important for ozone production with higher concentration, spark discharge or arc discharge should be controlled at the same time. Since the dense streamer discharges were obtained by shortening separation between the electrodes, production of dense ozone could be expected. On the other hand, the frequent occurrence of the spark discharges would cause an elevation of temperature of gas and electrodes so that disassociation of ozone molecules was accelerated.

126 2P7 DECOMPOSITION OF HUMATE USING PULSED DISCHARGE IN BUBBLES Yuuya Satoh, Fumiaki Fukawa, Kotaro Rokkaku, Susumu Suzuki, Haruo Itoh Chiba Institute of Technology, Electrical, Electronics and Computer Engineering, Narashino, Japan

Pulsed discharge in bubbles generated by pulsed generator is applied to the water treatment containing persistent substances, which are mainly organic substances in water and have recently resulted in environmental damage. Humic acid is one of the persistent substances. A Blumlein type pulse forming network (B-PFN) is provided in the study. The discharge reactor is constructed by a cylinder equipped with a pair of electrode, which are injection needle and spiral electrode. The gas used for bubbles are helium, oxygen and nitrogen. In this study, the absorbance and total carbon concentration in the humate solution is measured by a photo absorbance spectrometer and a total organic carbon analyzer. From the results, the decomposition of humate is observed from the temporal variation of gradient of absorbance curves. The decomposition rate of the humate by pulsed discharge in nitrogen bubble is larger than the pulsed discharge in helium and oxygen bubbles. Especially, the organic carbon concentration has decreased remarkably by the pulsed discharge in nitrogen bubble. Ozone and ultraviolet irradiation by pulse discharge has influenced in the decomposition.

127 2P8 DEVELOPMENT OF TECHNIQUES APPLYING NANOSECOND PULSE ELECTRIC FIELDS ON SOLID TUMOR Naoyuki Shimomura, Yoshihiro Magori, Masataka Nagahama, Kenji Teranishi, Yoshihiro Uto, Hitoshi Hori The University of Tokushima, Institute of Technology and Science, Tokushima, Japan

Many studies have started to apply pulse electric fields on tumor with an expectation for cancer therapy. In this study, we introduce the embryonated chick assay to the experiment applying nanosecond pulse electric fields (nsPEF) on solid tumor. The experiment using the embryonated chick assay, which is generically classified as in vivo, has several advantages. Many species of virus or rickettsia are available since the protective immunity is low. In some conditions, angiogenesis would be yielded; the cancer tissue in body was well simulated. To preparation of many specimen materials, with large incubator, is easier than that for laboratory animal such as mice and rats. The tumor cells: EMT6/KU (mouse breast adenocarcinoma cells) adopted for the experiment, are transplanted before several days of the test in advance. Nanosecond pulse electric fields are applied on a solid tumor on the chorioallantoic membrane in an egg with needle electrodes. A pulsed power generator whose output pulse length is 1.5 ns is used in this experiment. The needle electrode to apply nsPEF consists of a stainless wire of 1 mm in diameter with a rubber sleeve. The tip of the needle electrode is round or steeple. The two or four needle electrodes are inserted into the egg through a window on shell so as to tack the tumor in them. The tumors are retrieved from the eggs a few days after nsPEF application test and are weighed. The control eggs without nsPEF application are also processed as the same procedure. Rejection- test, F-test and t-test are used for significant test on application of pulsed electric fields. The significant difference between weight of the tumor with nsPEF application and that of control was confirmed with the significant tests. The difference increased with the charging voltage of pulsed power generator. In using steeple needles, a type of discharges is frequently observed in the eggs. The effect of the discharge was not clear for growth of the tumors. The tumor with four needles would be lighter than that with tow needles.

128 2P9 APPLICATION TO WATER TREATMENT OF PULSED HIGH-VOLTAGE GENERATOR USING SEMICONDUCTOR OPENING SWITCH Taichi Sugai1, Akira Tokuchi1, Weihua Jiang1, Yasushi Minamitani2 1Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan, 2Yamagata University, Department of Electrical Engineering, Yonezawa, Japan

Water treatment using pulsed streamer discharge in water has been studied currently. The pulsed streamer discharge in water generates active species that decompose organic compounds in water. We have studied the method spraying water droplets into discharge space in air. The method is higher energy efficiency than other methods using the discharge [1]. For this treatment way, we are trying to develop a pulsed high-voltage generator which can raise treatment efficiency more. To realize it, pulsed voltage of faster rise time and short width, higher repetition rate and higher energy transfer efficiency from the input to the output are needed. Additionally, the pulsed high- voltage generator has to be low cost to enable practical application. A pulsed high-voltage generator using Semiconductor Opening Switch (SOS diode) [2] outputs the pulse of fast rise time and short width and is low cost and compact size. The realization of high energy transfer efficiency of that generator enables the highest treatment efficiency in the world for the water treatment using the streamer discharge. Therefore, we have aimed that realization. The circuit of the generator consists of capacitors, a pulse transformer, inductors and a SOS diode. Main cause of the energy loss was the loss of the SOS diode and a switch in primary side and coupling of the pulse transformer. The improvement of these problems was carried out by investigating the characteristic of the SOS and changing circuit elements. After that, water treatment was carried out, and the generator using SOS was compared to other pulsed power generator from a point of view of the treatment velocity and the energy efficiency of the treatment. [1] M. A. Malik, "Water purification by plasmas: Which reactors are most energy efficient?", Plasma Chem. Plasma Process Vol. 30, pp.21-31, 2010. [2] Tomoyuki Yokoo, Kunihiko Saiki, Kazuaki Hotta, and Weihua Jiang "Using Semiconductor Opening Switch for Atmospheric Discharge", IEEE Transactions on Plasma Science, Vol. 36, NO.5, pp.2638-2643 (2008).

129 2P10 PORE DYNAMICS INDUCED BY NSPEF: A COMPARISON BEETWEEN EXPERIMENTAL AND THEORETICAL RESULTS Patrizia Lamberti1, Stefania Romeo3, Maria Rosaria Scarfì2, Vincenzo Tucci1, Olga Zeni2 1University of Salerno, Dept. of Electronic and Computer Engineering, Fisciano (SA), Italy, 2CNR, Institute for Electromagnetic Sensing of Environment (IREA), Napoli, Italy, 3Second University of Naples, Dept. of Information Engineering, Aversa (CE), Italy

Although electroporation is a well know technique with applications spanning from drug delivery to cancer therapy, the mechanisms involved in the phenomenon are still not well understood [1, 2]. In a recent study, we found that human lymphoblastoid Jurkat cells under a single, 60 ns, 2.5 MV/m pulsed electric field, exhibited differential uptake of the dyes YO-PRO1 and PI, right after pulse and over time, due to their molecular configuration [3]. The present study aims to compare the results of a 3D Finite Element Method numerical solution of the phenomenon with experimental findings, in order to validate the model and to increase the information about the involved mechanism. The proposed approach is based on a literature available model assuming that the pore dynamics is governed by an asymptotic form of the Smoluchosky equation [4], while the ionic flux through the electrically induced pores can be modelled by means of a suitable current source. The non linear dynamics of the electric responses of the membrane can be obtained by considering a cell model immersed in an electric field obtained by the Electro Quasi Static formulation of the Maxwell equations coupled with the ordinary differential equation describing the electroporation of the plasma membrane by means of a specific pore density population, N(r,VM(t),P) (r = pore radius, t = time, VM= voltage across the membrane and P = particular point on the membrane) [5]. The non linear equations system is then solved numerically in the time domain by means of a commercial software based on the Finite Element Method. The variables VM and N are used in order to check the activation of electroporation. The phenomenon is assumed to be activated when, upon the application of a nanosecond pulsed electric field (nsPEF), VM reaches a critical value and the pore density significantly overrides its equilibrium status. In order to associate numerical to experimental results, in a preliminary approach the model is implemented by assuming a fixed pore radius, whereas the hypothesis of the confluence of different pores in a greater, more stable pore will be subsequently explored. [1] Breton M and Mir LM, Bioelectromagnetics 2011, doi: 10.1002/bem.20692 [2] Joshi RP and Schoenbach KH, Critical Reviews in Biomedical Engineering, 2010, 38 (3): 255-304 [3] Romeo S, et al, PLoS ONE, 2011, 6(12): e28419. [4] DeBruin K and Krassowska W, Biophys. J., 1999, 77: 1213–1224. [5] S. Elia, P. Lamberti and V. Tucci, IEEE T Nanobioscience, 2010, 9 (3): 204-212.

130 2P11 NON-INVASIVE PULSED ELECTRIC FIELD FOOD PROCESSING: PROOF- OF0PRONCIPLE EXPERIMENTS Bucur Novac1, Fahd Banakhr1, Ivor Smith1, Laurent Pecastaing2, Robert Ruscassie2, Antoine de Feron2, Pascal Pignolet2 1Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom, 2University de Pau, SIAME, Equipe Genie Electrique, Heliopare Pau, France

Two essentialrequirements arise before any proposed and novel non-invasive pulsed electric field (PEF) food processing technique can be implemented in industrially meaningful systems. These are the reliable measurement of the intense fast transient electric fields generated in water close to metallic electrodes and a convinging proof-of-principle demonstration of the technique. Both of these milestones have recently been very successfully achieved in a joinr research programme in progress at Loughborough University (UK) and the University de Pau (France). The paper will report on final results from electro-optic experiments that dtermine the Kerr constant for water at various temperatures, using water samples probed by lasers and subjected to a homogeneous transient electric field strength exceeding 360 kV/cm. In addition, very successful proof-of- principle, non-invasive processing experiments will be discussed, in which only extremely small displacement currents flow in the water samples. The electic field in the samples was monitoted using Kerr effect based sensors and a 6 log reduction was obtained in the Escherichia coli initially present. Brief comments will be made on the possible future of the novel technology.

131 2P12 HIGH BLOOD SUGAR CONCENTRATION RESPONSE TO 850 MHZ ELECTROMAGNETIC RADIATION USING GTEM CELLS Nattaphong Boriraksantikul1, Naz Islam1, Kiran Bhattacharyya2, John Viator2, Phumin Kirawanich3 1University of Missouri-Columbia, Department of Electrical and Computer Engineering, Columbia, MO, USA, 2University of Missouri-Columbia, Department of Biological Engineering, Columbia, MO, USA, 3Mahidol University, Department of Electrical Engineering, Nakhon Pathom, Thailand

The use of electronic devices such as microwaves, mobile phones etc. have expanded dramatically over the last decade or so. As a result, there are increased concerns about the health risks of electromagnetic radiation on biological subjects, and research in this area is the focus of study for many. The effects of cellular phone radiation on carcinogenic1, blood-brain barrier connections2, cell toxicity3 are a few examples of many such studies. Diabetes related works include research in cell susceptibility4, blood dielectric properties5 and the effects of cell phone radiations on brain glucose metabolism6. In this presentation we report on the results of GTEM cell generated electromagnetic radiation on sugar-laden human blood. The response characteristics of the blood samples at two different power levels representing two different sources are reported. The 2 W 850 MHz GTEM signal represents a handset cell phone while a cell phone tower radiation source is represented by the 60 W, 850 MHz signal. Response parameters include blood plasma properties such as glucose level, and red blood cell and white blood cell counts. 1. I. Yakymenko, and E. Sidorik, "Risk of carcinogenesis from electromagnetic radiation of mobile telephony devices," Experimental Oncology, vol. 32, no. 2, 2010, pp. 54-60. 2. G. D. Lapin, "The EMF to BBB connection", Engineering in Medicine and Biological Magazine, IEEE, vol. 15, No. 4, 1996, pp. 57-60. 3. D. Brusick, R. Albertini, D. McRee, D. Peterson, G. Williams, P. Hanawalt, and J. Preston, "Genotoxicity of Radiofrequency Radiation," Environmental and Molecular Mutagenesis, vol. 32, 1998, pp. 1-16. 4. M. Havas, "Dirty Electricity Elevates Blood Sugar Among Electrically Sensitive Diabetics and May Explain Brittle Diabetes," Electromagnetic Biology and Medicine, vol. 27, 2008, pp. 135- 146. 5. S. Abdalla, "Effect of Erythrocytes Oscillations on Dielectric Properties of Human Diabetic- blood," American Institute of Physics, vol. 1, No. 012104, 2011. 6. N. D. Volkow, D. Tomasi, G. –J. Wang, P. Vaska, J. S. Fowler, F. Telang, D. Alexoff, J. Logan, and C. Wong, "Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism," The Journal of the American Medical Association, vol. 305, No. 8, 2011, pp 808- 813.

132 2P13 COMPACT PULSER POWER FOR PLATELET AGGREGATION AND GROWTH FACTOR RELEASE Yeong-Jer Chen, Barbara Hargrave, Shu Xiao, Karl Schoenbach Old Dominion University, Bioelectrics, Norfolk, VA, USA

Current work is conducted to develop a compact, portable, pulse delivery system to maximize the quantity of platelet gel activation and provide practical use for on-site wound healing. The use of pulse electric fields to stimulate Ca2+ release from the ER, thus inducing platelet activation, has been shown. Preliminary studies of a prototype AC powered 300 ns, 30 kV/cm system has shown reproducible success of aggregating platelets and producing platelet gel from platelet rich plasma with certain pulse parameters. Several essential issues are described for the next generation pulser for platelet gel activation. These include being battery powered for remote operations, size reduction for easy transportation, component design considerations to minimize effort from the preparation to the application of the platelet gel, and increased volume of platelet gel produced in a single batch for large wound treatments.

133 2P14 MODELING OF DELIVERY OF SUBNANOSECOND ELECTRIC PULSES INTO BIOLOGICAL TISSUES Shu Xiao12, Fei Guo1, Fei Li2, Jiang Li2, Gene Hou3 1Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, USA, 2Old Dominion University, Department of Electrical and Computer Engineering, Norfolk, VA, USA, 3Old Dominion University, Department of Mechanical and Aerospace Engineering, Norfolk, VA, USA

Delivery of subnanosecond pulses into biological tissue (for example, in the brain) can be undertaken by an impulse radiating antenna (IRA) [Baum et al.]. Previous analysis shows that it is important to add a dielectric lens, which reduces the abrupt change of dielectric constant from the air to the tissue and therefore increases the transmission of the pulses. The electric-field induced neurological response can potentially be used for neurostimulation, an increasingly-used therapy in areas where conventional pharmacological approaches become ineffective, such as in treating refractory pain, Parkinson disease, dystonia, and obsessive compulsive disorder. As a proof of concept of such delivery, we have modeled subnanosecond pulsed radiation focused into a dummy brain which consists of homogeneous, hemisphere tissues (3-D electromagnetic solver, CST Microwave Studio). The modeling of an IRA in conjunction of a lens indicates the subnanosecond pulses can be focused 6 cm below the surface with a spot diameter less than 1 cm. The focal point coincides with the geometric focus of the IRA. However, this result is only valid for a tissue with a low conductivity (s=0.3 S/m). For more lossy tissues, the electric field decreases from the surface monotonically as the subnanosecond pulses penetrate in depth. Similar trend was found in the electromagnetic modeling of a brain (CST's HUGO). Recently, it was shown that time-reversal technique can be used to focus the impulse into the brain. This technique solves a forward problem by placing an electromagnetic source at the desired focal point. The signals emitted from that source are collected by the multiple receiving antennas placed on the surface. The received signals are reversed in time and resent to the antennas, resulting in a focusing at the initial source. Practically, this technique may encounter the difficulty of coordinating the large number of antennas and inevitably is limited to low-power delivery. Therefore, its applicability in biological applications which require high field intensities (such as kV/cm) becomes restricted. We propose to use a dielectric lens to replace these antennas. The dielectric lens will be fed only by one source, a prolate-spheroidal reflector antenna (IRA), therefore eliminating the problem arising from using multiple receiving-transmitting antennas and still having the ability of high power radiating from the IRA. The time reversal will be conducted by the lens consisting of a number of dielectrics. The dielectric constants of the dielectrics are the objects to be optimized. The results of a 2-D modeling will be presented in this paper. This research intends to establish a patient-specific model for electromagnetic delivery.

This research has been supported by U.S. Air Force Office of Scientific Research (AFOSR) and Old Dominion University, 2012 Multidisciplinary Seed Funding.

134 2P15 CONCRETE SURFACE SCRAPING WITH HIGH VOLTAGE PULSED POWER GENERATOR Alexander Nashilevskiy1, Gennady Kanaev2, Vladimir Kukhta3, Vladimir Lopatin1, Gennady Remnev1, Kensuke Uemura3, Ivan Egorov1 1National Research Tomsk Polytechnic University, Institute of High-Technology Physics, Tomsk, Russia, 2National Research Tomsk Polytechnic University, Institute of Physics and Technology, Tomsk, Russia, 3Nagata Seiki Co., Ltd. Niigata,Tsubame , Japan

The design of a high voltage pulsed generator with an output voltage of ≥350 kV is described. The generator operates in the nanosecond range of pulse durations (~300 ns) at a repetition rate of up to 10 pulses/s in a continuous mode and is intended for electric discharge technologies, specifically for removing of the concrete surface. The energy stored in the generator is ~600 J, and the energy released in the output pulse is ≥300 J. The requirement to the concrete surface scraping with the high voltage power generator, the advantage of applying the high voltage pulse power generator and the result of the concrete surface scraping are represented.

135 2P16 STUDY OF THE EFFICIENCY OF A PULSED ELECTRIC FIELD SYSTEM FOR LIQUID STERILIZATION: A STATISTICAL APPROACH Eduardo Araujo, Ivan Lopes Federal University of Minas Gerais, Electrical Engineering, Belo Horizonte, Brazil

The application of pulsed electric fields for liquid food sterilization is an emergent and promising technology potentially applicable in the industrial sterilization of fruit juices, water, milk and other beverages. This paper reports the results of a computational investigation on the influence of different parameters, such as the number and intensity of the high voltage pulses and the electric field distribution inside the treatment chamber, on the survival rate of microorganisms. Experimental data reported in the literature of the influence of the number of pulses and electric field intensity on the survival rate of two different microorganisms is the basis for the statistical investigation. The numerical analysis is based on a non-homogeneous tridimensional electric field modeling, using Finite Element Method. The field distribution inside the treatment chamber, combined with statistical models, is used to statistically evaluate the overall system treatment efficiency. Different electrode arrangements and microorganisms are considered. The energy consumption and the maximum electric field inside the treatment chamber are also analyzed. Additionally, two prediction models proposed by Peleg-Fermi and by Hulsheguer & Niemann are applied and compared. The overall results of the study show that the combination of different power supply parameters, such as the number and intensity of the electric pulses, besides different electrode arrangements, applied to different microorganisms can be adequately adjusted to reach a certain statistical survival rate that leads to acceptable system efficiency depending on the application needs.

136 2P17 EXPERIMENTAL STUDY ON CHARGES TRANSPORTATION IN NANOSECOND-PULSED SURFACE DIELECTRIC BARRIER DISCHARGE Hui Jiang1, Tao Shao12, Cheng Zhang1, Wenfeng Li1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

Surface dielectric barrier discharges excited by high nanosecond voltage pulses are a promising approach for producing plasma required by flow control. Charge transport is an important parameter of discharge characteristics, and the discharge energy can be obtained using a gap voltage - electric charge Lissajous figure. Based on the in-house developed repetitive nanosecond-pulse generator, the influences of voltage amplitude, repetition frequency, the electrode gap and width on the surface DBD charge transport characteristics are investigated in this paper. Results show that the amount of charge transported per pulse increases with the increase in applied voltage and electrode width. There is an optimal electrode gap to obtain the largest value of charge transported per pulse, and the influence of pulse repetition frequency is minimal on charge transport.

137 2P18 HYDROPHOBIC IMPROVEMENT OF PMMA SURFACE TREATED BY A NANOSECOND-PULSE PLASMA JET Zheng Niu1, Cheng Zhang1, Tao Shao12, Jiayu Xu1, Ping Yan1, Edl Schamiloglu2 1Institute of Electrical Engineering, Chinese Academy of Science Beijing, China, 2Department of Electrical & Computer Engineering, University of New Mexico Albuquerque, NM, USA

Cold atmospheric-pressure plasma is rich in a variety of active particles, with good physical and chemical properties. It has a wide range of applications in areas as surface modification of materials, and biomedical and environmental protection. A dielectric barrier discharge is a traditional way to generate cold plasma, but its confined discharge gap limits some applications. The plasma jet is a method to produce plasma in a concentrated volume, and uses relatively simple electrode structures. It can be applied in a narrow space and on complex surfaces. In this paper, a single needle electrode is used to generate a plasma jet that is driven by unipolar repetitive nanosecond pulses with rise time of 25 ns and a full width at half maximum of 40 ns. The characteristics under different experimental conditions are observed. On the basis of previous work of hydrophilic treatment, surfaces of PolymethylMethacrylate (PMMA) are modified and hydrophobic results are achieved.

138 2P19 A NOVEL METHOD TO CALCULATE THE SHOCK WAVE PROPAGATION AND OPTIMIZATION OF PRESSURE RELIEF IN SF6 CIRCUIT BREAKERS Mahdi Khanali1, Kaveh Niayesh2 1University of Waterloo, ECE, Waterloo, ON, Canada, 2University of Tehran, ECE, Tehran, Iran

An optimized design of pressure relief is made possible via simulation of electrical arc in SF6 circuit breaker, considering exact geometry of interruption chamber and discovering pressure profile and shock wave propagation curves. To prevent circuit breaker explosion and its side damages, pressure relief equipment on one hand must function in cases of inextinguishable arcs, e.g. when an open circuit breaker is imposed to very high lightning overvoltages, on the other hand it is not supposed to function during the short circuit current interruption process. For this purpose, pressure variation pattern and pressure wave must be recognized in regard of reaching proper function. Thus the main point is finding pattern in both cases and designing the equipment for proper function at both of them. This problem is solved by combining fluid dynamic and electromagnetic equations in arc column and fluid dynamic in surrounding area and assessing the impact of produced pressures and shock waves on the deformation / explosion of the pressure relief. Assuming arc as a pulsed source of energy may result in estimation of mentioned parameters which is used for switchgears in some researches, but according to complication, large amount of parameters dealing with arc and size of interruption chamber it seems not to be an accurate and precise method for this application. One of the advantages of this investigation is applying real geometry and specific dimensions of circuit breaker arrangement as well as considering practically used materials. Based on the proposed simulations, optimized design and best location and size of the pressure relief are presented for some typical circuit breaker geometries with different voltage levels and short circuit currents are presented.

139 2P20 A HIGH CURRENT LOW INDUCTANCE MULTI-GAP MULTI-CHANNEL SWITCH FOR MICROSECOND LINEAR TRANSFORMER DRIVER, WORKING UNDER ATMOSPHERIC DRY AIR INSULATION AT 80KV, 250KA LEVEL Francis Lassalle, Bernard Roques, Arnaud Loyen, Alain Morell CEA DAM GRAMAT, F-46500, Gramat, France

Linear transformer driver (LTD) is a modular technology used to develop high current or high voltage drivers, by connecting several LTD stages in series and/or in parallel. The switch is a pivotal component of a LTD stage. A Multi-gap, multi-channel gas spark switch allows low inductance high current commutation, with accurate triggering and good reliability. We present here experimental and circuit simulation studies of a 7 gaps, 8 channels switch working with atmospheric dry air insulation. Switch design and test bed results are presented. Analysis and improvement of triggering and of multi-channel behaviour are discussed. In this test bed configuration and with a 80kV charging voltage of the capacitor, a 250kA, 600ns rise time current is switched into a matched resistive load.

140 2P21 DEVELOPMENT OF A HIGH CURRENT GAS-SWITCH FOR THE MAGNETIC HORN OF THE FAIR P-BAR-EXPERIMENT Christian Hock, Marcus Iberler, Joachim Jacoby, Gregor Loisch, Andreas Schönlein, Jörg Wiechula Goethe University, Institute of Applied Science, Frankfurt, Germany

The planed Facility for Antiproton and Ion Research (FAIR) is a new accelerator laboratory at the GSI in Darmstadt, Germany. To produce Antiprotons (3GeV) ) in the facility, Protons (29GeV) will be shot on a target (e.g. Iridium). In order to focus these Antiprotons for further experiments, a strong magnetic field will be applied by a so called Magnetic Horn. The Pulsforming Network (PFN) has to handle a peak current of 400kA with a pulse length of 20μs to generate this magnetic field. Currently the only possibility to handle this high current is the application of mercury filled Ignitrons. The working group plasma physics at the University of Frankfurt develops a mercury free switch, which is able to replace the Ignitrons in the PFN of the experiment. The main task for switching such high currents is to reduce the local electrode erosion. For that we propose a gas switch that generates an accelerated plasma to minimize the attrition. The experimental setup of the switch consists of coaxial electrodes, similar to the geometry used for plasma focus devices; the inner electrode is surrounded by an outer electrode. To reach a high holding voltage, the setup is designed for the left hand side of the paschen branch. The main discharge between the coaxial electrode system will be initiated by a trigger predischarge. After the ignition of the main discharge between the coaxial electrode system and due to the interaction of the induced radial magnetic field with the plasma, the gas discharge will be accelerated to the open end of the coaxial electrode system. This acceleration of the plasma sheet is due to the Lorentz force. The switch will be therefore called as Lorentz Drift Switch (LDS). For a further reduction of erosion and to provide enough charged particles for the current transport, several of these coaxial devices will be stacked together in a parallel, multiple electrode system. The outer electrodes will be connected with each other to synchronize the single plasma sheets of every device. With the introduced setup we hope to provide a real alternative for the application of common Ignitrons at FAIR. Due to the simple setup and the reduction of erosion we will introduce a low cost, and rugged high current switch for applications in further high energy experiments.

This work is funded by a HIC for FAIR and a HGS-HIRe scholarship.

141 2P22 RESEARCH AND DEVELOPMENT OF DRIVERS FOR PSEUDOSPARK SWITCHES Victor Bochkov1, Dmitry Bochkov1, Yaroslav Makeev1, Piotr Bak2, Alexey Panov2, Chris Pihl 3, Sam Andreason3 1Pulsed Technologies Ltd. Ryazan, Russia, 2Budker Institute of Nuclear Physics Novosibirsk, Russia, 3Pulse Power Solutions LLP Mill Creek, WA, USA

Data related to design and development of trigger and heater drivers for pseudospark switches (thyratrons TPI- and TDI-type) are presented. The drivers (trigger and heater units) are made using up-to-date solid-state and gas-discharge switching elements only and have both manual and remote control with CAN, RS-485 or Ethernet interface. The drivers for TDI-thyratrons are made with a single or several outputs, so that the device is capable of triggering up to 4 thyratrons. Trigger/heater drivers with high-voltage insulation for applications with transient high-voltages appearing on cathode and hydrogen reservoir of the switch are available. Test results for hollow anode TDI-thyratrons (operating voltage: 45, 75 and 150 kV, peak current up to 200 kA) with the voltage insulated trigger/heater drivers in pulsed magnetic systems [1] are described. Though TPI-type thyratrons are a more recent development than the TDI series, they are already well established in a variety of pulsed power systems. Several triggering techniques meeting various switching requirements have been developed and tested. These are the simplest circuit on non- linear elements, advanced techniques with the primary discharge circuit triggered via single, double or triple pulse triggering techniques. For applications requiring low jitter (less than 0.4 ns), high peak currents, and long life (5-10 years), triple-pulse triggering has proven to be a preferred method. The circuitry of the BZ-TP/10 trigger unit utilized on the LIU-2 accelerator [2] is also described. [1] J. Slough, C. Pihl, V. D. Bochkov, et al, “Prospective Pulsed Power Applications Of Pseudospark Switches”, 17th IEEE International Pulsed Power Conference (2009), pp. 255-259. [2] A.V.Akimov, P.V.Logachev, V.D. Bochkov, et al, “Application of TPI-thyratrons in a Double-pulse Mode Power Modulator with Inductive-Resistive Load”, IEEE Trans. on Dielec. and Electr. Insul., Vol. 17, Issue 3, pp. 718-722, 2010.

142 2P23 POWER TRIGGERED VACUUM SWITCH FOR 50 HZ NETWORKS Vladimir Sidorov, Dmitriy Alferov, Roman Bunin, Dmitriy Evsin, Valeriy Ivanov Russian Electrotechnical Institute Moscow, Russia

Triggered vacuum switches owing to high switching capacities are widely used in pulse power and pulse technologies. High current triggered vacuum switch (TVS) has been developed for switching of current in AC networks. New TVS-53 has rod electrode system which forms axial magnetic field due to ac current flow. Experimental researches of making and breaking ability of new TVS are carried out at various parameters of the main current. It is shown, that TVS is capable to switch repeatedly a 50 Hz current from units up to tens kA. Characteristics of developed high current TVS-53 are resulted. 50 Hz network application of TVS defines specific demands to triggering devices. Requirements to triggering device are defined, the technical characteristics of various triggering devices are presented.

143 2P24 PARALLEL OPERATION OF FOUR SPARK GAPS IN A PULSER SYSTEM Hasibur Rahaman1, Byung-Joon Lee1, Jong Woo Nam1, Sang Hoon Nam1, Jae Woon Ahn2, Seung Whan Jo2, Hae Ok Kwon2 1POSTECH, Pohang Accelerator Laboratory, Pohang, South Korea, 2Hanwha Corporation, R & D Department, Gumi, South Korea

Spark gaps are widely used switches for the development of high power pulser systems because of their simplicity and fast switching capability. The rate of plasma de-ionization and subsequent cooling of the de-ionized plasma between switching pulses restrict the recovery time of the spark gaps, thereby reducing their pulse repetition rate. Therefore, authors have developed a pulser system employing a single microplasma-assisted spark gap to increase the repetition rate up to 1 MHz [1]. However, insufficient recovery time at such high repetition rate decreases breakdown voltage as well as charging efficiency of the spark gap. The breakthrough of this problem is achieved by a parallel operation of two spark gaps in the pulser system by reducing the repetition rate or increasing the recovery time of each spark. The charging circuit system and operating parameters are configured for the efficient operation of the pulser system with relatively increased breakdown voltage of the spark gaps compared to the single spark gap pulser system. Finally, the pulser system operates four spark gaps in parallel in a non-synchronized mode with increasing recovery time or voltage recovery of each spark gap. In this manner, the sum of the repetitive switching of four spark gaps reaches close to that of the single spark gap pulser system. [1] H. Rahaman, S.H. Nam, J.W. Nam, B.J. Lee, K. Frank, "Application of Microplasma Discharge in a Spark Gap for High Repetitive Switching," App. Phy. Letter, Vol. 96, 141502, 2010.

144 2P25 CRITICAL CIRCUIT PARAMETERS IN PRODUCING A TOROIDAL AIR PLASMA Adam Lodes1, Randy Curry1, W. Brown2, M. Schmidt2 1University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA, 2Applied Research Associates Arlington, VA, USA email: [email protected]

A multi-millisecond duration, toroidal air plasma with electron density of at least 1014 -1015/cm3 has been developed at the University of Missouri Columbia. An exploding wire is used to first form the plasma and a secondary discharge region is used to further heat and impart momentum to the plasma. Using this method of post discharge heating, we have been able to produce a self- confined, self-stabilized, toroidal air plasma, or TAP. A study of circuit parameters has been conducted to better understand the critical factors in the formation and evolution of the TAP. Circuit inductance, load resistance, and wire material has been varied to determine the critical aspects of the formation of the TAP. A full diagnostic suite of pressure sensors, high speed photography, as well as current and voltage measurements, have been utilized to observe the TAP. Results from these experiments as well as the experimental set up including the high voltage driving circuits, are presented.

This work was supported by The Office of Naval Research under contract number S- 000296.00001. UMC Curry Applied Research Associates

145 2P26 SELECTIVELY GROWN CARBON NANOTUBES (CNTS): CHARACTERIZATION AND FIELD EMISSION PROPERTIES Chung-Nan Tsai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

Carbon nanotubes (CNTs) are considered as one of the promising electron-emitting materials available for use in cold cathode applications such as flat-panel displays and vacuum microelectronic devices. It has been known that due to its high aspect ratio (small diameter and relatively long length), it is possible to obtain electron emission at low applied electric field. This property plays an important role when CNTs are used as cathode material in plasma device [1]. In this work the growth mechanism and the experimental results of field emission characteristics of CNTs fabricated using Chemical Vapor Deposition (CVD) are presented. We investigated the field emission characteristics of patterned selectively grown random and vertically-aligned multi- walled CNTs (MWNTs). To synthesize the patterned MWNTs on plain silicon (n-type 100) substrates, a thin catalyst (Fe) film is first deposited by DC magnetron sputtering. High-quality films of MWNTs are grown in a thermal CVD furnace in gases mixture of acetylene and argon, after lithographic lift-off patterning of a metal catalyst layer on the wafer. The measurement results indicate that both vertically aligned and randomly oriented CNTs have significant field emission capabilities to be used as cold cathode emitters in plasma devices. [1] Haitao Zhao, Hulya Kirkici (2010). Effects of impurity on field emission of carbon nano- tubes. Proceedings of 29th IEEE International Power Modulator and High Voltage Conference. Atlanta, GA., U.S.A., May 2010.

146 2P27 NONLINEAR FOWLER-NORDHEIM PLOTS OF CARBON NANOTUBES UNDER VACUUM AND PARTIAL PRESSURES Rujun Bai, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

Carbon nanotubes (CNTs) known to have excellent field electron emission characteristics and they have been used as cold cathodes in pseudospark switches [1]. In this work carbon nanotubes are studied in order to develop cold cathode material with efficient field emission characteristics. Randomly aligned Multi-Walled carbon nanotubes (MWNTs) are fabricated using chemical vapor deposition method (CVD) under different growth conditions by varying sputtering times of the catalyst and growth times of CNTs [2]. These nanotubes are then tested for their field emission characteristics at different pressures ranging from 5x10-7 Torr to 20x10-3 Torr. The experiments were carried out in different background gases of Helium and dryair. Effects of different gases at different pressures on the field emission properties of carbon nanotubes are studied and results are presented. Fowler-Norheim (FN) plots revealed a nonlinear slops for all the samples tested under different background pressure. It is known that the slop of the FN plots gives information about the field enhancement factor of the surface. Therefore, the nonlinearity is attributed to the nonlinear field enhancement factor. In this paper, we present the effects CNT growth conditions, background pressure and other factors on the field enhancement factor. This data is used in determining a proper cold cathode material to be used as trigger electrode for pseudospark switch. [1] Haitao Zhao, Design and Construction of Carbon NanoTubes (CNTs) Triggered Pseudospark Switch, PhD Dissertation, Auburn University, May 2012. [2] Ramsh Bokka, Carbon Nanotube Cold Cathodes for Applications under Vacuum to Partial Pressure in Helium and Dryair, MS Thesis, Auburn University, August 2011.

147 2P28 AN ATMOSPHERIC PRESSURE GAS SWITCH TRIGGERED BY ARRAY MICROHOLLOW CATHODE DISCHARGE Yaqing Teng, Kefu Liu, Jian Qiu Fudan University, Institute of Electric Light Sources,, Shanghai, China

The structure of microhollow cathode is two electrodes divided by about 200μm thick dielectric and threaded by about 100μm hollow. Array microhollow cathode discharge (MHCD) was operated at atmospheric with 2.5kV pulse voltage of 20ns rise time and current up to 100A, which is supplied by the charged capacitance of power supply. Triggered by a MHCD, a gas switch operated under voltage of 50kV with 30ns fall time and current of 1kA with 15ns rise time was fabricated with a 2nF capacitance and a 50Ω resistance. The switch characteristics such as the range of switch working voltage, on-resistance, delay time and jitter are given. The influences of the rise time of trigger voltage and the value of trigger current on switch performance is mainly discussed in this paper. The advantages of the switch lie in lower trigger voltage with simply trigger circuit and multipoint discharge and fast fall time. An electrical model including stray capacitances is set up and the modeled results agree very well with the measured currents and voltages.

148 2P29 EXPERIMENTAL RESEARCH OF HIGH STABILITY GAS DISCHARGING SWITCH Xueling Yao, Jingliang Chen, Yingbiao Shao Xi'an Jiaotong University, Electrical Engineering, Xi'an, China

The gas discharging switch is one of the most important components of pulsed power technology and Pulsed power system. The gas discharging switch with adjusted air pressure is designed and the experimental setup is established for testing its characteristics in this paper. The experimental law between the characteristics of gas discharging switch and all influencing factors, these factors include gas pressure, gap distance and trigger pulse voltage etc.. Under the condition of gap distance of 5 mm and the gas pressure of 0.4MPa, the average DC breakdown voltage is 45 kV. The Gauss fitting method is adopted and the self-breakdown probability is 6.36×10-9 at operating voltage of 35kV. When trigger pulse voltage is 12 kV, the minimum operating voltage is 1.4 kV, so the operating voltage scope is from 3.1%~94.7%. At the operating voltage of 75 % of its self- breakdown voltage, the discharging delay time and jitter are 2.3 μs and 184.4 ns respectively. The experimental setup for test the synchronous controlling accuracy of two gas switches and the experimental results showed that the sequence control error of two gas switches is within ±2 μs under the trigger pulse voltage of 12 kV and operating voltage at 75% of their self-breakdown voltage. As for the pulse current with hundreds of microsecond duration time, the controlling accuracy is high than 5‰. The designed gas switch can be used in the circumstance fro test xenon lamp and other similar circumstances.

149 2P30 EXPERIMENTAL RESEARCH OF ROD-SHAPED GAS DISCHARGING SWITCH Xueling Yao, Jingliang Chen, Yuxi Wang Xi'an Jiaotong University, Electrical Engineering, Xi'an, China

The gas discharging switch is one of the most important components of pulsed power technology and Pulsed power system. The rod-shaped triggering gas switch insists of two main electrodes and a trigger electrode. Two main electrodes are placed parallel each other, the trigger electrode is located on the orthogonal plane to main electrodes and is mounted in the middle of two main electrodes and the distance is 1mm to surface of the main electrodes. The experimental circuit is setup and the trigger characteristics are researched. The experimental results show that when the gap distance is 6.65 mm, the self-breakdown voltage is 10.2 kV. When trigger pulse voltage of 14.6 kV, the operating voltage of rod-shaped gas switch is from 48.0% to 85.7%, and the discharging delay time changes from 21.6 µs to 2.66 µs and the delay jitter changes from 4.25 µs to 0.49 µs accordingly. At the same time, the pulse arc running and electrode erosion are also observed, it is found that the electrode erosion tracking is mainly decided by the amplitude of pulse current, and with the increase of pulse current, the erosion spots change form circular to ellipse and the erosion track gets longer along the inner electrode orientation, and the erosion spot cover the whole electrode surface gradually, this is the effect of Lorentz force caused by pulse current. Because of arc running on the inner surface of main electrodes, the using life of the designed rod-shaped gas switch can be prolonged greatly.

150 2P31 DEVELOPMENT OF A COLLIDING PLASMA EXPERIMENT AS AN UV/VUV RADIATION SOURCE Andreas Schönlein, Christian Hock, Marcus Iberler, Joachim Jacoby, Johanna Otto, Tim Rienecker, Christian Teske, Sero Zaehter Goethe University, Institute of Applied Physics, Frankfurt, Germany

In our working group we are optimizing a coaxial plasma accelerator (PA) for a colliding plasma experiment to investigate an intense UV/VUV radiation source. PAs and colliding plasmas are also helpful to study astrophysical phenomena, like astrophysical jets or galactic collisions. The coaxial PAs used in this experiment consist of massive copper outer and inner electrodes which are electrical isolated by PEEK. A high voltage applied to the PA leads to the ignition of a discharge which results in a current flow that generates a magnetic field. Due to the generation of a magnetic field a lorentz force appears. This force leads to an acceleration of the plasma sheet and drags the neutral gas out of the PA. Hence the magnetic field functions as a magnetic piston. The plasma movement can be described by the snowplow model (SPM). Due to the acceleration of the plasma sheet to high velocities (km/s) a preceding shockwave is formed. The plasma collision will be caused by two identical PA facing each other. Both PA have a stored energy of 1kJ. To optimize the collision and the UV/VUV radiation several criteria have to be met. The two PAs have to be operated simultaneously. For that, a pulsed power network is necessary. Another important criteria is to create a high temperature plasma within the collision zone. Therefor high velocities of the plasma sheet should be reached. A further demand is a low inductance of the setup to get a high current rise time and according to the SPM a high plasma sheet velocity. For the analysis of the experiment multiple diagnostics will be applied. A fast shutter camera is used to trace the propagation of the plasma sheets in the vacuum chamber and to determine the velocity. In addition the velocity can be measured by a photodiode assembly. For UV/VUV diagnostics AXUV diodes and a VUV-Monochromator are available.

This work is funded by HGS-HIRe and EMMI (ExtreMe Matter Institute).

151 2P32 X-RAY BACKLIGHTING OF SINGLE-WIRE AND MULTI-WIRE Z-PINCH Xinlei Zhu, Ran Zhang, Haiyun Luo, Shen ,Zhao, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing, China

The development of single-wire and multi-wire Z-pinch were investigated by X-ray backlighting using an X-pinch as the soft X-ray source. The experiments were carried out on the pulsed power generator PPG-I (400kA/500kV/100ns) which was designed and constructed by Department of Electrical Engineering of Tsinghua University. The source X-pinch and object single-wire or multi-wire Z-pinch are installed in the place of a current-return rod or the center between the anode and the cathode, respectively. The X-ray films with high resolution and high sensitivity were used to record the results. A resistive current probe and a Rogowski coil of our own design were used to monitor the current, and a step wedge filter was designed to measure the mass ablation rate of the thin wire. By a large number of imaging experiments, the physical images of the coronal plasma formation, the interwire plasma merging, and the development of plasma instabilities of Z-pinch and some important parameters like mass ablation rate and core expansion rate were obtained.

152 2P33 TIMING OF THE X-RAY BURST FROM PARALLELED X-PINCHES Shen Zhao, Haiyun Luo, Xinlei Zhu, Ran Zhang, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing, China

As a point x-ray source produced at the crossing point of two fine wires through which a pulsed and high current flows, X-pinch has been used for backlighting of wire-array Z-pinch plasmas. In order to obtain two time-resolved images in a single shot of Z-pinch discharge, a wire-array z- pinch as the object to be imaged was placed between the anode and the cathode of a vacuum diode connected to a pulsed power generator. The anode plate was normally mounted on return- current rods, but here two of these rods were replaced by two X-pinches as the x-ray backlighting sources. Controlling the timing of the x-ray burst from an X-pinch with respect to the start of the current pulse is important for getting the time-resolved images. It was found that the x-ray burst for a given X-pinch load occurs at a roughly reproducible time and value of the current flowing through the X-pinch from pulse to pulse and that the timing of the x-ray burst scales linearly with the mass per unit length of X-pinch load. However, these results are not enough to control the timing of the x-ray burst from two paralleled X-pinches since the current flowing through each X- pinch is unknown. Thus, we need to know how the total current is distributed among the paralleled return-current rods and X-pinches. For this purpose the currents flowing through these two paralleled X-pinches were measured with two Rogowski coils. It was found no strong influence of the wire diameter and material on the currents flowing through the paralleled X- pinches. In order to explain this phenomenon, the following researches were carried out. The current and the voltage of an X-pinch were measured. The inductance of the X-pinch was assumed to be a constant and estimated by the calculation of the magnetic field based on the well- known Biot-Savart's Law. The voltage of the inductance was calculated with L·di/dt and subtracted from the measured voltage of the X-pinch. Then, the resistance of the X-pinch was determined and the following results were obtained. At the start of the current the resistance of the exploding wires is several tens of Ohms, one order of magnitude higher than the metallic resistance of the wires at room temperature, and then it falls down quickly to about 1Ω, which reflects the physical processes occurring in the electrical exploding wires, i.e., a current transition from the overheated and highly resistive wire core to the highly conductive plasma. The resistance is only a little bit lower than the impedance, indicating that the resistance predominates over the inductance in determining the voltage across the X-pinch. For the wires we used, it seems no strong influence of the wires on the resistance, which may be explained by the fact that the current flows through the plasma rather than the metallic wires itself.

153 2P34 EVALUATION OF TAPE-BASED STRESS GRADING COATINGS BY INFRARED THERMOGRAPHY Fermin P. Espino-Cortes, Tomas I. Asiain Olivares, Pablo Gomez Instituto Politecnico Nacional, SEPI ESIME Electrical Department, Mexico City, Mexico

In medium voltage rotating machines, stress grading (SG) at the ends of coils are used to avoid partial discharges (PDs) on the surface of the coil. SG coatings are usually applied as tapes with certain length and thickness. These dimensions depend on the nominal voltage and the type of material used. The good performance of the SG coating depends mainly on its correct design and application. Commonly, problems become evident when the coils are tested for long term evaluation of insulation systems or once the coils are in service. For example, during voltage endurance (VE) tests, when the voltage applied to the coils is about three or more times the nominal line-to-ground voltage hot spots or partial discharges in the SG coatings led to early failures of these coatings and with time, the complete failure of the insulation system. If the stress grading composites are not correctly applied or designed, modification of the SG coatings would be required to pass the test. In this work, infrared thermography is used to analyze the manufacture quality of tape-based stress grading coatings. The hot spots that can make the systems fail either in service or in voltage endurance tests are related to the tape disposition and defects. By this inspection procedure problems with the manufacture process of the coating can be early detected and corrected.

154 2P35 DETECTION AND LOCATION OF ARCING FAULTS IN DISTRIBUTION NETWORKS USING A NON-CONTACT APPROACH Rachel Harris1, Philip Moore2, Martin Judd1 1University of Strathclyde, High Voltage Technologies Research Group, Glasgow, United Kingdom, 2Elimpus Ltd Bellshill, United Kingdom

A novel approach to detecting and locating arcing-faults in an electrical distribution system is presented in this paper. The location of faults in the transmission system (66 kV and above) is readily achieved using the distance-to-fault function typically provided with numeric-type distance relays. However, the same approach cannot be applied when locating faults in the distribution system (11 – 33 kV) due to a number of factors, e.g. the circuits are protected by overcurrent rather than distance relays and do not always have VTs or station batteries, the multiple lateral spurs extending from rural medium voltage circuits will mislead most distance-to- fault algorithms and a communications infrastructure which would allow a distance-to-fault result to be accessed often does not exist. In addition, the cost per circuit of retrofitting monitoring equipment would be very high and would require contact to be made with the distribution system itself, bringing with it the risk of interruption of the electricity supply. The approach presented here overcomes these difficulties by making use of the fact that when an electrical fault induces an arc it is accompanied by the radiation of electromagnetic transients that are detectable as a signal which propagates in the RF band. By capturing this radiometric discharge at geographically separate locations, the location of the arc origin can be calculated using the differences in the times of arrival at each of the monitoring locations (a method that has already been proven effective for lightning strike location). Detection, capture and timestamping of these signals can be achieved using off the shelf components and, crucially, this approach requires no direct connection to the distribution network. A network of four monitoring stations covering a section of the distribution network north-east of Glasgow, UK was commisioned and installed. GPS steered timestamping equipment allowed a common, accurate, timestamp source to be received at each station. Timestamps were stored with each wavefront that met the criterion for capture so that any time-differences-of-arrival could be obtained and comparison between signal time-of-capture and events in utility fault records made. Using this monitoring network, radiometric emissions were captured from a number of fault-induced-arcs, although none at more than one monitoring station. Lightning captures were made simultaneously at two or more stations and accurately located using the time-differences-of-arrival, demonstrating that the data captured was sufficient to allow signal origins to be calculated. Future work will consider in more detail the propagation distance of these radiometric emissions in particular the manner in which these signals attenuate with distance from their origin, along with the effect on detection rate of alternative monitoring station layouts.

155 2P36 ASSESSMENT OF DIELECTRIC DEGRADATION BY MEASUREMENT, PROCESSING AND CLASSIFICATION OF PARTIAL DISCHARGES Euler C. T. Macedo1, Juan M. Villanueva2, Diego B. Araujo2, Edson G. da Costa2, Raimundo C. S. Freire2, José M. R. de Souza Neto2, Ian A. Glover3 1Para´ıba Federal University, Alternative and Renewable Energy Center, João Pessoa, Brazil, 2Campina Grande Federal University , Electrical Engineering and Informatics Center, Campina Grande, Brazil, 3University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, Scotland

Failure of insulation in power systems plant may be caused by manufacturing defects or by electrical, mechanical, thermal and chemical process which occur during operation. Such processes create defects, such as voids in solid insulation or particle contamination in gas insulation, which locally reduces the dielectric strength of the insulation. Electrical discharge may occur in these regions of reduced dielectric strength but not in the regions of un-degraded insulation. The resulting process is referred to a partial discharge (PD) since the discharge does not bridge the entire gap between electrodes. PD is normally characterized by low-level current pulses with fast rise-time and short duration; typically no more than a few hundred nanoseconds. The detailed structure of the PD 'signal' varies depending on insulation defect type, PD sensor type, insulation characteristics and physical connection. PD data collected in the field are often contaminated by electrical noise arising. The proper analysis of such data generally, therefore, requires the application of sophisticated signal processing methods. If PD is found in insulating systems then it is important to identify its character, i.e. internal discharge, surface discharge, corona etc. For many years PD recognition was performed by observation, and (human) expert interpretation, of PD patterns on the power frequency ellipse displayed using an oscilloscope. The aim of this paper is present a methodology for the assessment of insulation degradation using the measurement, processing, analysis and classification of PD signals. Internal PD, caused by voids in solid insulation, has been generated under a range of well-defined, and reproducible, conditions using a specially designed test cell. (In the full paper the test cell will be described in sufficient detail to allow its replication.) Test cell PD has been recorded using two widely employed measurement techniques; (i) the IEC 60270 'classical' method and (ii) using a wideband high frequency current transformer (HFCT). For each specific insulation defect the wavelet transform is applied to the raw data to suppress interference. The resulting pre-processed patterns of PD activity are then subject to statistical feature extraction using discharge asymmetry, phase asymmetry, correlation, skew and kurtosis. Full details of the feature extraction algorithm will be given in the final paper. Finally, a neural network was used to classify the PD as one of several types using a feature set derived from PD caused by known defects. The assessment of insulation degradation in HV apparatus by the measurement, processing, analysis and classification of PD signals has been demonstrated.

156 2P37 ITAIPU´S EXPERIENCE IN THE ACCEPTANCE TESTS FACTORY CARRIED OUT ON HIGH VOLTAGE ELECTRICAL EQUIPMENTS (EMPHASIS ON TRANSFORMERS AND BUSHINGS): RELEVANT FACTS OCCURRED DURING VFT - VERY FAST TRANSIENT TEST, PARTIAL DISCHARGES MEASUREMENT, DISPLACEMENT/DEFORMATION CORE OF POWER TRANSFORMER AND GENERAL CONDITIONS OF HIGH VOLTAGE LABORATORIES Cláudio Morais1, Domingues Gonzalez2, Juliano Silva3, Luiz Pisa3 1Itaipu Binacional, Inspection, Foz do Iguaçu, Brazil, 2Itaipu Binacional, Engineering, Ciudad del Este, Paraguay, 3Itaipu Binacional, Engineering, Foz do Iguaçu, Brazil

This paper presents important points that were observed by the Itaipu [1] inspection / engineering team from the point of view of quality during the factory witnessing of the high-voltage electrical equipment recently acquired by Itaipu, both in Brazil and Europe Three cases will be examined : i) The first case refers to the VFT - very fast transient overvoltage test carried out on high voltage transformers and bushings . The very fast transients are generated during switching operation of Itaipu SF6 gas insulated substation (GIS). The transformers and bushings must withstand the overvoltages from this characteristic. In 2010, Itaipu had acquired two high voltage step-up transformers [256 MVA/550kV ]. They were the first in the world submitted to VFT tests . The same way, were acquired 12 high voltage bushings, rated voltage 550 kV, type OIP – oil impregnated paper . These bushings were manufactured and tested in Europe. This paper will present the development of VFT tests carried out in these transformers and bushings, the method and type of device which was chosen for obtaining the standard wave 1.5 µs / 50 µs , the chopping wave in SF6 gas and the spark gap system adopted. The Itaipu´s technical requirements concerning the VFT are showed too. The difficulties found to obtain the curve voltage x SF6 pressure during the chopping wave SF6 are related. ii) The second case presents the Itaipu´s experience concerning the partial discharging PD measurement carried out on factory in the bushings type SF6 /air and OIP – oil impregnated paper, 550 kV, about the following points : - Problems and technical conditions found in the high voltage laboratories both Brazil and Europe to perform the PD tests, in accordance with the Itaipu´s specification and to the pertinent technical standards; - Difficulties found in high voltage laboratories to obtain the parameters of noise level in accordance with the standard IEC 60.270; in this stage, many improvements in the test circuit were done for avoiding/solving interferences and disturbance. iii) The third case refers to the accident on core transformer [ 241.5 kV ; 470 MVA ] , in which was observed displacement / elastic deformation when it was being moved through the factory, before the core assembling on the active part of power transformer. It will be related the actions which was taken of re-work of core in factory, the total disassembling , total re-stacking, and all the verifications and tests which were performed for avoiding hot points in the future and this way to assure quality and reliability to the transformer useful life. [1] Itaipu is the largest hydroelectric power plant in the world as regards the generation of energy. Itaipu generated 92,2 milion megawatts-hour (MWh) last 2011.

157 2P38 PERFORMANCE EVALUATION OF A NEW SYSTEM GROUNDING Maria Alice Rodrigues, Edson Costa, Malone Castro Federal University of Campina Grande (PB-Brazil), Electrical Engineering Department, Campina Grande, Brazil

The use of grounding electrodes involved by a concrete coating is presented as a viable technique to decrease the resistance values of grounding grids in electrical systems. The effectiveness of bentonite, a material of low resistivity, as a reducing agent of the grounding resistance, used to fill the soil around grounding electrodes, it is also proven by researchers. From these two principles, this paper studies the performance of three types of grounding grids, all composed by three copper electrodes (120 mm length, 10 mm diameter), arranged as an equilateral triangle of 2.5 m of side. However, the three grids differed by the material evolving the electrodes: in the first grid, the electrodes were involved with common concrete; in the second grid, the electrodes were involved with bentonite doped concrete; in the third grid, naked (without coating) electrodes were employed. All rods were manufactured in the High Voltage Laboratory of the Federal University of Campina Grande (Paraíba - Brazil), and the process involved polyvinyl chloride (PVC) tubes, employed as molds (diameter of 50 mm). The employed bentonite is commercially known as Brasgel PA. After applying the concrete to the electrodes, all rods passed through a curing process, in order to give the structure greater strength. The grounding resistance of the three grids were periodically measured, aiming to evaluate the effectiveness of the technique. Current impulses, with waveform 8/20 μs and voltage intensity loading ranging between 10 and 60 kV have been applied to the grids, using a current impulse generator and a digital oscilloscope, for signal acquisition. Then, it was possible to evaluate both the supportability of concrete structures for high current impulse and the behavior of the signals of voltages and currents, during the current injection in the soil. The impulsive impedance was also calculated, so it was possible to compare the performance of the three proposed arrangement. The concrete mechanical strength was satisfactory for current impulses up to 8.9 kA. There was a reduction of the grounding resistance in both coated cases, when compared to the naked copper rods. The current and voltage waveforms revealed differences in terms of load flow for the three types of grounding grids in the analysis.

158 2P39 A STUDY ON RELIABILITY BASED ASSESSMENT ALGORITHM FOR HIGH VOLTAGE INDUCTION MOTOR STATOR WINDINGS Chang Jeong-Ho1, Lee Heung-Ho2 1Korea Water Resources Coraporation, Green Technology Research Center, Daejeon, Korea, 2Chungnam National University, Electrical Engineering, Daejeon, Korea

Today, the high voltage motor widely used and played significant role in various area. So, Failures of water supply motors can have large impact of the operation reliability of water supply network. However In spite of their importance, the power equipments have several problems in its maintenance system. For example, Excess expenditure of maintenance cost according to the fiscal year that is depend on the time-base maintenance technique and increase of insufficient scientific asset management at equipments repair or replacement. So we need more reliability improvement of power utility through reducing fault occurrence rate and standardization of diagnosis about high voltage motor. The primary goal of this paper is to develop a standard algorithm for an efficient condition evaluation of high voltage induction motor stator windings in the technical aspects. Make use of this result, the equipment decided to be replace or repair otherwise on service. The technical tests were included measurements of AC current (ΔI), dissipation factor (tanδ), partial discharge (PD) magnitude, and Polarization Index(P.I). In addition, the AC current test was performed on the stator windings of water supply pump motor under operation to confirm insulation strength. The algorithm suggested in this study which developed from CBM(Condition Based Risk Management) method, makes a significant contribution to reliability assessment of the condition of high voltage Induction motor stator windings.

159 2P40 DETERMINING ECONOMIC LIFE CYCLE FOR POWER TRANSFORMER BASED ON LIFE CYCLE COST ANALYSIS Sun Hun Lee1, An Kyu Lee1, Jin O Kim2 1Korea Water Resources Corporation, K-Water Institute, Deajeon, Korea, 2Hanyang University, Dept. of Electrical Engineering, Seoul, Korea

Today, the power utilities are setting on the slow load growth and the aging of power equipment, and then could spend the efforts on the stability of system performance. Under structure of vertically integrated power industry, great cost has been spent to enhancing reliability of such power utilities. In Korea, lots of the power equipments were built up in the 70s and 80s. Due to this reason most of them increasingly reach their aged life time. In this case, asset management is a great way to fulfill the economic investment and the stability of system performance. The asset management is separated by three parts of essential elements: management, engineering and information. The corporate of these parts should be practiced that seek to balance. This paper presents the principle calculation of determining economic life cycle on the power transformer from economic aspect of asset management. Economic life cycle is calculated by life cycle cost analysis performed in accordance to IEC 60300-3-3. Annual equivalent cost analysis is used to model cost function in life cycle cost analysis. Economic life cycle is defined by the term minimizing the overall annual equivalent cost occurring for owning and operating power facility. Accordingly, annual equivalent cost analysis can be referred to as capital cost and operating cost are essential in economic evaluation. 1) Capital cost: Capital cost commonly consists of initial cost and salvage value. Initial cost is indicated as the purchase price of power facility. Normally, capital cost becomes the declining function on increasing according to year. 2) Operating cost: Operating cost of power facility consists of operating and maintenance cost. When such operating cost is assumed to be increased in every year, operation cost of power facility becomes increasing function. Especially operating cost can be difficult to obtain data due to a long time operation. Thus, the method is performed by annual equivalent cost analysis with estimating operating cost using numerical method. This paper shows the application of effective asset management considering the economic evaluation determining economic life cycle for power transformer in Korea's hydro-generation. Economic evaluation is performed by annual equivalent cost with estimating operating cost using numerical method. The proposed method will be expected to play an important role in investment decision making considering economic evaluation.

160 2P41 REAL-TIME INSULATION STATUS ASSESSMENT OF UNDERGROUND CABLE JOINTS BASED ON STANDARD DEVIATION RuayNan Wu, ChienKuo Chang National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan

A real-time insulation status assessment of underground cable joint is presented. The cable joint with an artificial defect was subjected to the voltage higher than partial discharge inception voltage (PDIV) until the insulation breakdown. In the meantime, partial discharge (PD) measurement was carried out with a fixed time interval. Furthermore, the characteristics of PD activity were extracted from each measured data. The characteristics sequences, refresh by each measurement, were calculated to the standard deviation probability distribution. According to each evolution of standard deviation, some outliers were appealed while the characteristics sequences contained a catastrophe phenomenon. The catastrophe of characteristic might relate to the serious change of insulation. Hence, the method of outlier detection with three times standard deviation was proposed as the real-time insulation status assessment.

161 2P42 DETERIORATION TREND ON ELECTRICAL TREEING OF UNDERGROUND CABLE INSULATION RuayNan Wu, ChienKuo Chang National Taiwan University of Science and Technology, Electrical Engineering, Taipei, Taiwan

The evolution of PD characteristics due to electrical tree growth in XLPE was investigated to analyze the status of insulation. Many point-to-plane electrode specimens were carried out using XLPE as the insulation material of underground cable. These specimens were conducted under 14 kV to 17 kV voltage. At the meantime, PD phase resolved data acquisitions were in progress by means of a computer-based measurement system. Each PD phase resolved data was transferred into several characteristics and accumulated into sequences until insulation breakdown. As the result, some characteristics shows the simple trend including increasing, transition and decreasing. Hence, this paper proposed the curve fitting to represent the trend of PD sequence. The slope of fitting curve identified the insulation status. If the slope of curve closes to zero, it means the trend of PD entering the transition stage which was suggested to alarm operators to prevent non-expectable breakdown.

162 2P43 RESEARCH OF NANOSECOND PULSE RESISTIVE DIVIDER Jingliang Chen, Xueling Yao, Shaolin He, Tianyu Lin 1Xi'an Jiaotong University, Electrical Engineering, Xi'an, China

In this paper, the distributed parameter circuit model of pulse resistive divider is established for researching its steep response characteristics. The experimental results show that the steep response time or speed of the pulse resistive divider is influenced by many factors which including high voltage resistance, low voltage resistance, equivalent inductance of resistance and distributed capacitance. It is found that the response time can be lessened by the design method of adding a "middle electrode" between high voltage electrode and low voltage electrode, which can change the electric field distribution and compensate the influence of distributed capacitance and improve the steep response characteristics of pulse resistive divider. The pulse resistive divider is designed, whose high voltage resistance is 10.2 kΩ and low voltage resistance is 10.2Ω, the scale factor is 1000:1. The steep response characteristics of pulse resistive divider are measured by using a steep voltage source whose front time of is 1.4 ns and duration time is about 600 ns, and the experimental results showed that the partial response time of pulse resistive divider is less than 1.6ns. To calibrate the measuring accuracy of pulse resistive divider, the calibrated Tektronix P6015A is adopted. The comparing results show that the withstand voltage of the pulse resistive voltage divider is high than 40kV and the measuring accuracy is better than 1%.

163 2P44 RESEARCH ON ROGOWSKI COIL FOR MEASURING 10/350ΜS PULSE CURRENT Jingliang Chen1, Xueling Yao1, Antong Chen2, Xiaoqing Xu1 1State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Electrical Engineering, Xi'an, China, 2Vanderbilt University, Electrical Engineering and Computer Science, Nashville, TN, USA

Taking into consideration the high-frequency components of the rapidly rising part and the low- frequency components of the long duration time of the 10/350μs pulse current waveshape, the self-integral Rogowski coil with a core is designed. Based on the energy frequency spectral analysis of the waveshape, it is observed that the frequency components are mainly distributed from 100Hz to 200kHz. The 10/350 μs crowbar pulse current circuit was then set up and experiments were carried out. The experimental results show that the designed Rogowski coil has excellent characteristics for measuring 10/350 μs pulse current parameters including front time, duration time, and peak current. At the same time, compared with the calibrated shunt and Pearson current monitor of type 1018 within the peak of 100 kA of the waveshape, the experimental results show that: (1) The measurements obtained using the designed Rogowski coil are similar as the measurements obtained using the calibrated shunt, while the measurements by the Pearson current monitor show significant distortion when the current peak reaches 80kA. (2) Compared with the calibrated shunt, the designed Rogowski coil outperforms by reaching the measurement error of less than 1% on the peak and less than 5% on the half-value time. The results have shown that the Rogowski coil can provide precise measurements to the 10/350μs pulse current and other similar circumstances, and is an effective alternative to the standard techniques.

164 2P45 RESEARCH OF TRANSFORMER CONDITION ASSESSMENT SYSTEM BASED ON RISK EVALUATION Lu Guo-jun, Li Gang, Qin Yu, Huang Yan-guang Guangzhou Power Supply Bureau, Tests and Research Institute, Guangzhou, China

Over the years, TBM (Time-Based Maintenance) is the main method which was applied in power system. The implementation of preventive repair strategy of transformer can not determine the status of transformers between the maintenance cycles, and a series of problems, such as lack of maintenance, excessive maintenance, waste of maintenance resources and even reliability reduction will be brought out. In this paper, one kind of transformer condition assessment system was designed, and it could evaluate the risk of transformers and provide maintenance strategies. In this system, detailed data of transformers which were composed of parameter informations, maintenance records, test data, defects or faults, load variation, environment were analyzed synthetically to diagnose the conditions of transformers. Different points and factors were defined to different parameters, and the final results would be calculated and indicated the status and risk of transformers. The result was showed in currency form, and condition maintenance strategies could be designed to optimize investment. This system was developed and applied in all the 500kV transformers in Guangzhou. Results proved that this system could provide a reliable basis for asset lifecycle management.

165 2P46 MEASUREMENT AND ANALYSIS OF INSULATION RESISTANCE OF METALIZED POLYPROPYLENE FILM CAPACITOR UNDER HIGH ELECTRIC FIELD Hua Li, Zhiwei Li, Fuchang Lin, Yaohong Chen, De Liu Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan, China

Metalized polypropylene film capacitor has characteristics of high energy density and high reliability due to its self-healing capability. The operating electric field of high energy density capacitor applied to pulsed power system is really high. Each such occasion,voltage drop of capacitor resulting from dielectric absorption and leakage would exert negative influence on the efficiency of the pulsed power system. The insulation resistance (IR) of capacitor applies a leakage path through the dielectric. As a parameter of capacitor independent of capacitance, equivalent IR is commonly equal to a time constant or product of the IR and capacitance, whose unit is MΩ×μF (second). Measurement of IR under high electric field is feasible for the self- healing capability. This paper mainly concentrates on leakage phenomenon in metalized polypropylene film capacitor by the measurement and analysis of IR. A measuring system is established to measure IR under various temperatures and high electric fields. A set DC voltage is applied to capacitor and sampling resistance series circuit and the steady voltage of capacitor and sampling resistance are recorded. The testing time is so long that the influence of dielectric polarization and absorption current can be neglected. Under electric field ranging from 250V/μm ~ 450V/μm, self-healing in capacitor is inevitable and random. So the IR in this paper is the comprehensive results of both dielectric leakage and self-healing capability, and is close to operation condition. Measurement data of IR is characterized by great dispersion even under unified test conditions. So a lot of experimental data are required and data fitting is carried to analyze IR according to the theory of dielectric electric conductive mechanism of polypropylene under high electric field. The results indicate that the IR is extremely sensitive to electric field and temperature. The IR decreases rapidly with the increasing electric field, and the descending trend will gradually slow down because of the self-healing capability under high electric field.For example, at 20°C, IR is on the order 105 MΩ×μF under 250V/μm and on the order 104MΩ×μF under 450V/μm; and it also decreases rapidly with the increasing operating temperature at 20°C~50°C, and the descending trend will also gradually slow down. At last, theoretical calculation of capacitor IR based on electric conduction in dielectric under electric field is carried, and it suggests that the difference of IR between capacitor and polypropylene dielectric is significant under high electric field.

166 2P47 A STUDY OF OVER-VOLTAGE MONITORING DEVICE BASED ON COUPLING CAPACITANCE SENSORS Qi Wang1, Chen-guo Yao1, Yan Mi1, Jian Wang2 1Chongqing University, State Key Laboratory of Transmission & Distribution Equipment and Power System Safety and New Technology, Chongqing, China, 2State Gird Corporation of China, EHV Transmission &Substation Company, Chengdu, China

The over-voltage monitoring plays an critical role in power system security area. Developing the effective monitoring of online research on the over-voltage characteristics can facilitate to get the over-voltage characteristics, analysis the accident and improve insulation. In this paper, a simple and promising method based on coupling capacitance sensors is proposed for overhead transmission-line monitoring. The sensor is noncontactable and its installation is simple. By the frequency and lightning impulse voltage experiment, the performance and measurement accuracy of the sensor has been proved. Using the sensor and the date acquisition devices and software platform, the overhead transmission line monitoring system has been realized.

167 2P48 THE LIGHTNING PROTECTION TESTS FOR THE RADOME IN Z11 HELICOPTER OF CHINA Duan Zemin Hefei Hangtai Electrophysics Co.,Lt Hefei, China

The lightning protection tests which are simulated by power modulator and high voltage technology are used the radome system in the Z11 helicopter of China, it is presented in the paper. The radome system is composed of the radome, the lightning diverters, the air data probe and a long 0.5m metal structure which simulated a part of the helicopter body. The test facilities and the test results are introduced. Based on the tests, the radome system performance preventing lightning destruction is improved by optimizing the diverters. Finally, the optimized radome system passed the ground simulated lightning tests successfully by the Chinese CCAR27 (equal to FAR27) and the standard of lightning protection of aircraft HB6129-87.

168 2P49 PROTECTION OF 132 KV TRANSFORMER AGAINST LIGHTNING BY EFFECTIVE PLACEMENT OF SURGE ARRESTER Radhika Goru1, Suryakalavathi Mungala2 1Vnr Vjiet, Eee, Hyderabad, IN, India, 2Jntuh, Eee, Hyderabad, IN, India

Lightning interference occurs mainly on overhead lines and has been a problem since the early days of electricity supply. Over voltages which occur on the lines, travel towards the terminal or substation, and can damage, particularly the expensive equipment such as power transformers. Lightning traveling waves are produced in the system and cause temporary increase in voltage in the transmission line system. The increase in voltage is harmful for the insulator of lines and devices connected to the transmission line. Therefore, it is necessary to analyze such increase in voltage in order to design the surge arrester suitable for the investment, the good performance of the system and the reliability of transmission line.In this work Metal-Oxide Surge Arrester is used. The objective of this paper is to protect the power system equipments from lightning and to determine the effective placement of surge arrester. This will be done by comparing the voltage level measured close to the transformer with the suggested basic insulation level (BIL) 650KV used in this work. A powerful electrical tool to simulate the power system model is electromagnetic transient program PSCAD/EMTDC is used in this work. Here we present a proposed model of a three phase 132KV transmission system with over voltage which shows that the lightning surge of 10KA, 8 x 20µs can be very dangerous even at low value of current if there is no surge arrester is in operating or used for protection. This over voltage is reduced by using the Metal-Oxide Surge Arrester. Hence Arrester rating calculated to be 109KV and parametric determination for a one column arrester with an overall length of 1.45 meters is done, the discharge voltage for this arrester is 248kV for a 10kA, 8 x 20µs current wave shape. The outcome of this paper shows the placement of arrester at 90m, 60m and 30m from the transformer in terms of voltage levels measured at particular points and overall simulation results will demonstrated the importance of having a right location of surge arrester placement as fail to do so will cause a significant damage to the equipment.

169 2P50 A COMPACT LOW INDUCTANCE PULSE ENERGY DRIVER SYSTEM FOR PULSE POWER APPLICATIONS Kum Sang Low1, Albert Ng1, Chee Hoong Low1, Chin Yang Chia1, Kum Wan Low1, David Mahadevan1 1Specscan Sdn. Bhd. Petaling Jaya, Malaysia, 2University of Malaya, Department of Physics, Kuala Lumpur, Malaysia

In recent years, there have been various developments of high-current discharge drivers used in pulsed-power technologies including linear transformer drivers and impedance-matching transformers. As the discharge current scales up, it becomes crucial to optimize the input energy requirements. A new system was designed to provide a scalable low inductance current driver suitable for pulse-power applications including z-pinch, plasma-focus, and other direct current drive applications. This paper explores the development of a new current driver for a system with a z-pinch load using six (6) modular units of low inductance integrated multiple-capacitor assemblies developed by Specscan Sdn. Bhd. Each of these modular units comprise four (4) folded aluminum foil and dielectric film capacitors arranged in a two-stage LC-inversion circuit. Six (6) of these modular multi-capacitor assemblies were connected to a pair of hexagon-shaped transmission plates of 1 meter in diameter with a z-pinch load located in the center to form a voltage-discharge loop for an estimated loop circuit inductance of 6.36nH. Six (6) individual spark-gap switches were connected to the voltage inversion loops of the multi-capacitor assemblies. Voltages of +6.75kV and -6.75kV were applied across the switches to charge the capacitors requiring 280J of total input energy. The switches were then triggered simultaneously to generate a voltage-inversion that provides a near-quadruple increase in voltage across the transmission plates to form a pulse-energy driver system. A peak voltage of approximately 24.4kV was obtained at the z-pinch load with a peak current of 210kA and a quarter-wave rise rime of 110ns. The system generated 4.6GW of peak power with a corresponding efficiency of 16.5MW/J. This development illustrates a concept of an efficient scalable direct high current driver system for various pulse power applications using relatively low voltages. One particular interest in the future is the possibility of scaling these drivers to operate in the mega-amperes range. This can be achieved if: a) the charging voltages are increased; and b) if the transmission plates are enlarged to accommodate a greater number of modular multi-capacitor units. This paper will describe how the existing z-pinch system operates and the results obtained. Projections will then be made on its potential current scaling while maintaining its input energy efficiencies.

170 2P51 GENERATORS OF HIGH-POWER HIGH-FREQUENCY PULSES BASED ON SEALED-OFF DISCHARGE CHAMBERS WITH HOLLOW CATHODE Victor Bochkov1, Vladmir Ushich1, Alexander Dubinov2, Inna Kornilova2, Igor L'vov2, Sergey Sadovoy2, Victor Selemir2, Dmitry Vyalykh2, Victor Zhdanov2 1Pulsed Technologies Ltd. Ryazan, Russia, 2Russian Federal Nuclear Center – All- Russian Research Institute for Experimental Physics Sarov, Russia

In pulse high-voltage low-pressure gas-discharges with hollow cathode a full modulation of discharge voltage can occur at the frequency in a range of some hundreds of Megahertz. This phenomenon can be used to generate high-power high-frequency pulses [1]. One of the factors, limiting application of such generators is a vacuum system itself, gas-filling system and chamber pressure control. Application of sealed-off gas-discharge chambers makes the high-frequency generators smaller and more mobile [2]. Similar generators can be used e.g. to test electromagnetic field influence on radio-electronic equipment. The results of development and tests of repetitively pulsed generator of high-power high-frequency pulses based on sealed-off discharge chambers with hollow cathode enclosed into a metal-ceramic envelope and maximal dimensions of 37 mm in diameter, length of 125 mm and weight of 250 gram are described. Pulses with burst duration up to 1300 ns and peak power up to 1 MW at frequency of 120 MHz with repetition rate of 100 Hz were obtained using the chamber of similar design and equipped with a nitrogen (or hydrogen) source. [1] D. Arbel, Z. Bar-Lev, J. Felsteiner, A. Rosenberg, and Y. Z. Slutsker, "Highpower radio frequency generation in a hollow-cathode discharge," Appl. Phys. Lett., vol. 66, no. 10, pp. 1193– 1195, Mar. 1995. [2] A.E.Dubinov, I.Y.Kornilova, I.L.L'vov, S.A.Sadovoy, et al, IEEE Trans. on Plasma Sci., vol.38, no.11, pp. 3105-3108, Nov. 2010.

171 2P52 SOLID-STATE PULSED POWER SYSTEM FOR GAS TREATMENT APPLICATIONS Seung-Bok Ok1, Hong-Je Ryoo2, Sung-Roc Jang2, Gennadi Goussev2 1University of Science and Technology, Energy Conversion Technology, Daejeon, South Korea, 2Korea Electrotechnology Research Institute, Electric Propulsion Research Center, Changwon, South Korea

This paper deals with a solid-state pulsed power system for gas treatment applications. It consists of a solid-state pulsed power modulator and a plasma reactor. To be specific, the developed pulsed power modulator is based on a high voltage capacitor charger and pulse generator part including a series of connected 24 pieces power cells. In addition, the specifications of the developed pulsed power modulator are as follows: pulsed output voltage 40 kVmax; pulsed output current 150 Amax; pulse width 0.5~5 µs; pulse repetition rates (PRR) 3 kHzmax, and average maximum output power of 13 kW. For the optimal experimental conditions, the pulsed-power system was analyzed with an equivalent electrical circuit model. Finally, the reliability and the robustness of the proposed pulsed power system are verified through the experimental results.

172 2P53 COMPACT HV HIGH POWER CAPACITOR CHARGER Willy Debache, Michael Teboul TECHNIX, Development, CRETEIL, France

We realized the design of one 45 kV compact High Power Capacitor Charger. With a peak power of 40 kW, its weight is 25 kgs for a volume of 25 liters. Based on double resonant technology, the charger can be supplied either by one 300 V battery or an external DC power supply. It is controlled via an optic fiber interface. For providing such a light and compact charger, each part was deeply considered with a particular emphasis on the transformer which represents the heart of the system. The oil tank, which is containing most of the parts, is also used as a heat sink for reducing volume and weight. Final paper will include photos, diagrams and measurements, simulation and more details about heat losses and the results obtained with different DC input voltages.

173 2P54 COMPACT 600 KV MULTI-PRIMARY WINDINGS RESONANT TRANSFORMER TO DRIVE AN ELECTROMAGNETIC SOURCE Romain Pecquois1, Laurent Pécastaing1, Marc Rivaletto1, Antoine de Ferron1, Jean- Marc Duband2, Laurent Caramelle2, René Vézinet3 1Université de Pau, SIAME EGE, Pau, France, 2HI PULSE Pont de Pany, France, 3DAM, CEA GRAMAT, Gramat, France

Modern pulsed power applications of high power microwave technology require compact power- amplifier. In each case, the high pulsed power generator is made up of a primary energy source and a load, separated by the power-amplification system that forwards the energy from this source to the load. Usually a Marx generator or a Tesla transformer is used as the power- amplifier. Our structure uses an innovating and very compact resonant transformer to drive a dipole antenna. Our complete pulsed power source, named MOUNA, is composed of a set of batteries, a dc/dc converter to charge four capacitors, four synchronized spark gap switches, a resonant transformer generating 600 kV/265 ns pulses, an oil peaking switch and a dipole antenna. The device must transmit waveforms with a wide frequency band and a high figure-of- merit. The paper describes the compact 600 kV multi-primary windings resonant transformer developed in common by Université de Pau and Hi Pulse Company. The resonant transformer is made of four primary windings, two secondary windings in parallel and a Metglas® 2605SA1 amorphous iron magnetic core. An innovating biconic specific geometry makes it possible to optimize the leakage inductance. The transformer mechanical characteristics are: 6 kg weight, 3.4 liters volume, 20 cm diameter and 11 cm width. Design details are explained accurately. Each feature is justified. Calculations of leakage inductance and stray capacitance between primary and secondary windings are presented. Core losses and saturation induction are studied. An LTspice- based study of the power-amplifier is proposed. Finally, the results from two experimental studies are presented. Firstly, the resonant power-amplifier loaded by a compact capacitive charge associated to a homemade capacitive voltage probe specially developed is studied. Secondly, an integrated V-dot probe measures the power-amplifier output inside the electromagnetic source. To conclude, the experimental results are compared to the LTspice simulations and discussed.

174 2P55 HIGH REPETITION RATE PICOSECOND FID PULSE GENERATORS FOR UWB APPLICATIONS Vladimir Efanov, Mikhail Efanov, Alexander Komashko, Pavel Yarin FID GmbH Burbach, Germany

A series of high voltage pulse generators and pulse power modules with picosecond pulse duration and pulse repetition rate of megahertz range has been developed. Combination of megawatt peak power and megahertz PRF permit production of radiating systems with unique set of specifications. The most important parameter for many UWB radiating systems is maximum pulse repetition rate that permits reaching high average values of radiated power and in certain limits adjust output spectrum. FID GmbH has developed a series of high repetition rate pulse generators that permit operation into a wide variety of antennas and having highreliability, compact size and energy efficiency. Modular pulse generator FPM10-100PNK has maximum amplitude 10 kV into 50 Ohm. Rise time is 80-100 ps, pulse width at half amplitude 200-300 ps, maximum PRF of 100 kHz with power consumption of about 200 W. Approximate size of module is 200x170x50mm, weight of 3 kg. Pulser FPG 10-10PHF has an output amplitude of 10 kV into 50 Ohm with pulse repetition rate of 10 MHz. Output pulse has rise time of 150-200ps and duration of 500 ps FWHM. With peak power of 2 MW average power to load is 5 kW. Pulse generator permits creation of sequences of output pulses set by computer control with possibility to vary PRF in burst from zero to 10 MHz. Maximum pulse repetition rate has pulse generator FPG 1-500PHF. In burst mode the achieved PRF is 500 MHz with burst duration of up to 10 microseconds and average repetition frequency of 1 MHz. Rise time of this type of pulsers is 150- 200 ps, pulse duration at half amplitude is 300-500 ps. Pulsers can form a computer controlled sequence of pulses with PRF inside such burst up to 500 MHz. Operation of high power picosecond pulse generators in radiating systems requires high stability and EMI-proof power supplies and control systems. FID GmbH has developed a series of such power supplies with output power from tens of watts to tens of kilowatts. Digital control blocks permit operation of tens of pulsers with accuracy of 10-20 ps. Optical lines permit controls to be placed hundreds of meters away from radiating point and set the necessary operation mode via computer interface. In most cases cooling of high repetition rate pulse generators and modules is done by forced air, however amplitudes higher than 10 kV usually require liquid cooling system.

175 2P56 DEVELOPMENT OF A RF BURST PULSE GENERATOR USING A NON- LINEAR TRANSMISSION LINE FOR CANCER TREATMENT Yuichi Abe, Yasushi Minamitani Graduate School of Science and Engineering, Yamagata University, Department of Electrical Engineering, 4-3-16 Jonan, Yonezawa, Yamagata 992-0026, Japan

Nanosecond and sub-nanosecond high voltage pulses can provide new applications. A cancer treatment by an ultra-short pulse high electric field is one of them. High power pulsed electromagnetic wave has been proposed to apply the high electric field for that treatment. This work focuses on the design of a compact high power burst pulse electromagnetic wave generator using a nanosecond pulsed power generator for the cancer treatment. In previous study, we have used a LC inversion circuit as a power supply of the pulse electromagnetic wave generator. The LC inversion circuit is useful in order to output efficiently electromagnetic wave by the antenna. However, since the LC inversion circuit outputs the voltage waveform with damping oscillation, the duration of the burst pulse is under 100ns. Therefore, we focus on a ferrite-filled coaxial non- linear transmission line. Nonlinear transmission line is capable of generating sharp pulses and shock wave. The non-linear coaxial line has the advantage of simple structure and low cost in comparison with the non-linear transmission line using a non-linear element. Therefore we have developed the burst pulse generator using the ferrite-filled coaxial non-linear transmission line in order to extend the duration of the burst oscillation for the cancer treatment. In the experiment, we have investigated the pulse duration time and frequency for various conditions of the input pulse shape and the magnetic cores.

176 2P57 A 600V, 1KA COMPACT LTD MODULE USING POWER MOSFETS Pravin Iyengar1, Tee Chong Lim1, Stephen Finney1, Mark Sinclair2 1University of Strathclyde, Electronic and Electrical Engineering, Glasgow, United Kingdom, 2Atomic Weapons Establishment, Pulsed Power Group, Aldermaston, United Kingdom

The presented work forms our first steps towards the research and development of MOSFET and IGBT based Inductive Voltage Adder (IVA) pulsed power systems for Flash radiography at AWE Aldermaston, UK. In [1], it is shown that MOSFET based IVA/ LTDs can be applied for compact pulsed power generation. Evidently, this technology has not reached the maturity towards Megawatt level applications. However, there is potential to develop smaller flash radiography systems. The present challenges that need to be tackled are to optimise semiconductor switching, reduce packaging size and component count to achieve compactness and higher power density. Also, there is a need for further attention towards improving synchronisation of modules and fault protection as the technology matures towards higher energy applications. This paper presents a compact, high density LTD module using power MOSFETs. The LTD module consists of two MOSFET drivers driving four MOSFETs each, film capacitors and a magnetic core. An enhanced MOSFET gate driver [2] was designed specifically for this application. The MOSFET driver is capable of driving multiple MOSFETs without compromising the performance of each individual device. Overall, the module features easy synchronisation, higher power density, and fast switching times. The MOSFET DE475-102N21A, 1kV, 144A pulse was chosen for this system. The LTD module has been tested at 600V in a single shot and low rep rated (10Hz) operation. Currents of up to 1kA were achieved across a ~ 0.6 Ω load with pulse widths of 100ns and <10 ns rise and fall times. Manufacturer's do not provide sufficient device performance information for short pulse conditions, therefore testing is necessary. Experimental results demonstrate that the rds(ON) of the MOSFETs increase linearly as the current and effectively, the junction temperature of the devices increase. However, due to the lack of information in data sheets it is difficult to estimate this change. This variation in the rds (ON) of the MOSFET is analysed and also factors which affect the choice of number of drivers and devices per module have further been discussed in this paper. [1] Weihua Jiang, "Solid state LTD module using Power MOSFETs", IEEEtransactions on plasma science, 2010, Volume38, Issue 10 part 1, Page(s) 2730-2733. [2] Iyengar, P; Fletcher, J.E; Bittlestone, D.J; et al, "Enhanced MOSFET gate driver for Pulsed Power IVA module", Presented at the 18th IEEE International Pulsed Power Conference, Chicago, 2010.

177 2P58 STATUS OF PROTOGEN THE FIRST INTEGRATION OF GENESIS TECHNOLOGIES Steven Glover1, Forest White2, Gary Pena1, Peter Foster3, Larry Schneider1 1Sandia National Laboratories Albuquerque, NM, USA, 2SAIC Albuquerque, NM, USA, 3Defense Nuclear Facilities Safety Board Washington, DC, USA

Advancements of technologies to enable ultra-low impedance pulsers at lower pressures has resulted in the design of a system called Genesis for dynamic materials experiments. A prototype demonstration called Protogen includes interfaces for up to twelve modules and can be operated in a rep-rate mode to generate reliability data. Initial operation of Protogen is focusing on the integration of key technologies and dielectric lifetime. Multiple configurations of Protogen have already been tested demonstrating the flexibility of Genesis technology. This paper expands on previously published results paying particular attention to versatility, reliability, and modeling of the Protogen system.

178 2P59 STATUS AND EXPERIMENTS WITH THE 1-MA WATER-INSULATED MYKONOS LTD VOLTAGE ADDER Michael Mazarakis1, Mark Savage1, William Fowler1, William Stygar1, Scott Roznowski1, Alexander Kim2 1Sandia National Laboratories, 1671, Albuquerque, NM, USA, 2High Current Electronic Institute, Pulsed Power, Tomsk, Russia

The LTD technological approach can result in very compact devices that can deliver very fast, high current and high voltage pulses straight out of the cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. Because the output pulse rise time and width can be easily tailored (pulse shaped) to the specific application needs, the load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. Ten 1-MA LTD cavities were originally designed and built to run in a vacuum or Magnetic Insulated Transmission Line (MITL) voltage adder configuration, and after successful operation in this mode, we were currently modifying and make them capable to operate assembled in a deionized water insulated voltage adder. Special care is being taken to deaerate the oil of the cavities and water of the voltage adder and eliminate air bubbles. Our motivation is to test the advantages of water insulation compared to the MITL transmission approach. The desired effect is that the vacuum sheath electron current losses and pulse front erosion would be avoided without any new difficulties caused by the de-ionized water insulator. Presently, we are assembling two modified cavities with more robust components and special for water insulation "O" rings and grooves. In addition we are replacing the polyethylene insulators, which are absorbing a lot of oil and change dimensions, with polyurethane ones. Lifetime experiments of the voltage adder will be done with a matched liquid resistor load. Experimental results will be presented and compared with circuit codes simulations.

179 2P60 LINEAR TRANSFORMER DRIVER (LTD) WITH SQUARE PULSE OUTPUT Michael Mazarakis2, Alexander Kim1, Alexander Sinebbryukhov1, S. Volkov1, S. Kondratief1, Frederic Bayol3, Gauthier Demol3, V. Alexcenco1, William Stygar2 1Institute of High Current Electronics, Russian Academy of Sciences ,Pulsed Power, Russian Academy of Sciences, Tomsk 634055, Russia, 2Sandia National Laboratory, 1671, Albuquerque, NM, USA, 33International Technologies for High Pulsed Power, Pulsed Power, Thegra 46500, France

The LTD technological approach can result in relatively compact devices that can deliver fast, high current and high voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling) top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks.

180 2P61 MODIFICATIONS TO A COMPACT MARX GENERATOR Kim Morales NSWC Dahlgren, Q, Dahlgren, VA, USA

Marx generators have been built with a wide span of physical size and output capability, ranging from circuit-board scale devices of a few stages up to systems capable of producing many Megavolts and occupying entire buildings. Our focus in this poster is the development of a capability to explore Compact Marx Generator (CMG) devices, where we arbitrarily define a CMG to be an apparatus consuming less than 0.5 m3 (excluding the charging and control systems). We report the development of a laboratory system that incorporates a shielded test stand with battery-powered high voltage charging supplies and a computer based control system with a graphical user interface. We will briefly discuss a demonstration of the test bed capability with results from a compact, modular CMG.

181 2P62 RAPID CAPACITOR CHARGING POWER SUPPLY FOR AN 1800J PFN Travis Vollmer, Michael Giesselmann Texas Tech University, Center for Pulsed Power & Power Electronics, Lubbock, TX, USA

The RCC (rapid capacitor charger) previously developed at the P3E Center [1] has been adapted to charge an 1800 J PFN (pulse forming network) for rep-rated operation. The entire automated system to test and evaluate SGTOs (Super Gate turn-off Thyristors) runs at a 1 Hertz repetition rate; thus requiring a power supply to charge the PFN within 500 ms and have a 3.6 kJ/s average power capability to allow for data acquisition and storage between shots. The hard-switching H- bridge topology with 10 kW burst mode handling capability is very well suited for this compact table top system design. The control of the RCC has been shifted to a PIC controller responsible for PFN charging. Charging parameters include: an adjustable charging time from 50 to 500 ms, high voltage monitoring with adjustable voltage level, and RCC Go/shut-off. All charging parameters are determined by the main CPU handling the automation process and are sent to the PIC controller before each PFN charging event. With the addition of forced air cooled heat-sink for the IGBT modules, enough heat can be removed to allow continuous automated operation. [1] Vollmer, Travis; Giesselmann, Michael, "Rep-Rated Operation of a Modular Compact HV- Capacitor Charger", Proceedings of the 18th IEEE International Pulsed Power Conference, Chicago, Illinois, June 19-23, 2011.

182 2P63 A SHORT-RISE-TIME PULSE GENERATOR USING LASER TRIGGERED SPARK GAP SWITCH Yuan Li, Jin Li, Xin Li, Debiao Chen, Hui He, Zhi Zhou, Mao Chen, Fuxin Zhou Institute of Fluid Physics, Department of Accelerator Physics and Applications, Mianyang, China

A high voltage device capable of producing 150 kV short rise time pulse with less than 2 nanoseconds has been constructed and tested. As the key part, a spark gap switch has been designed to meet the requirement of reliability and stability by using an ultraviolet laser as the trigger device. The optimized structure of the switch can minimize the switch inductance and at the same time guarantee insulation capability. The performance of the gap under conditions of different kinds of insulation gas has also been investigated.

183 2P64 DEVELOPMENT OF BRAUNBECK COILS FOR PULSED MAGNETIC FIELD GENERATOR FOR BIOMEDICAL EXPOSURE Yan Mi, Chun Jiang, Longxiang Zhou, Chenguo Yao, Chengxiang Li Chongqing University, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing, China

Current coil is often used as a key part of a pulsed magnetic field generator for cancer treatment. For biomedical exposure such as cancer cells experiment in vitro, current coil has to meet two basic requirements: low inductance and big magnetic uniform area. So, a new coil system with four coils, which is called Braunbeck coils, is proposed to replace the traditional Helmholtz coils for a bigger magnetic uniform area. The coil geometric parameters and central magnetic induction were calculated firstly. Then, the internal magnetic field distribution was simulated and analyzed using finite element simulation software COMSOL Multiphysics. At last, an actual device of Braunbeck coils with red copper was developed, and the bigger diameter (D) and height (H) of the Braunbeck coils were 50cm and 40.8cm, respectively. The actual magnetic field distribution measurement of Braunbeck coils was performed using magnetic field sensor (B-24, PRODYN) and the result showed that its magnetic uniform area with uniformity of 95% was a cylinder with the diameter of 0.72D and the height of 0.83H, which was bigger than that of Helmholtz coils. All in all, the Braunbeck coils meets the requirements, and it will make contribution to future biomedical experiments for cancer treatment.

184 2P65 THE PERFORMANCE OF A PHOTOCONDUCTIVE SEMICONDUCTOR SWITCH TRIGGERED BY A LASER DIODE Baojie Wang, Kefu Liu, Liuxia Li, Jian Qiu Fudan University, Electric Light Sources, Shanghai, China

The photoconductive semiconductor switches (PCSS) have unique advantages such as ultrafast rise-time, low jitter, good synchronization and high dielectric strength. Its performance is strongly affected by the optical pulse. In this paper, a research about the performance of high gain GaAs PCSS triggered by laser diode is described. A laser diode can beam different shapes of optical pulse from different drivers. The goal of our work is to study the performance of PCSS how to be affected by the energy, the rise edge of the optical pulse and the same energy with different shapes of optical pulse, such as high peak power but short pulse width and low peak power but long pulse width. The test circuit is a single transmission line discharged into a matched load, and the PCSS was immersed in the transformer oil with laser diode. The trigger energy changes from 3uJ to 12uJ when PCSS works at 12kV/cm to 40kV/cm. The experimental results show that the minimum energy to trigger PCSS is 3uJ and increasing the energy has no effect on the performance. At present the experiments have been demonstrated that the PCSS had achieved 750ps rise-time, 6.9kV output at 16kV bias-voltage, and the 200ps jitter. The experimental results are discussed at last.

185 2P66 AN NS RISETIME GAS SWITCH WITH A MOVABLE ELECTRODE AND A FIXED ELECTRODE Xiaobing Zou, Kun Huang, Xinxin Wang, Ran Zhang, Xinlei Zhu, Shen Zhao Tsinghua University, Department of Electrical Engineering, State Key Laboratory of Control and Simulation of Power System and Generation Equipment, Beijing, China

The voltage risetime of a pulse generator with pulse forming line (PFL) and gas switch is mainly determined by the performance of the gas switch. Recently, we developed a small scale gas switch composed of a movable electrode driven by electromagnetic force and a fixed electrode. For a fixed voltage on PFL, the risetime of this switch is tested to be 1~1.5ns, while the risetime of a switch with two fixed electrodes is about 5-10ns. As we know, both an increase of gas density and a decrease of gap length under a certain applied voltage can shorten the switch risetime due to the enhancement of the breakdown field strength. In order to explain why the movable electrode results in a much faster risetime, A Mach-Zehnder laser interferometer is now being used to take time-resolved pictures of the discharge gap between the movable electrode and the fixed electrode. Interferogramms would tell us if the gas density between electrodes has an increase resulting from the fast movement of electrode, or if the length of gap at the time of self- breakdown is decreased even if gas density keeps unchanged as electrode moves.

186 2P67 EXPERIMENTS ON COMPACT PULSE FORMING LINE USING WATER DIELECTRIC HELICAL TRANSMISSION LINE Pankaj Deb, Surender Sharma, Biswajit Adhikhari, Rohit Shukla, T. Prabaharan, Partha Banerjee, Rishi Verma, Anurag Shyam Bhabha Atomic Research Centre, Department of Atomic Energy, Vishkapatnam, India

Pulse forming lines using transmission lines are used to generate rectangular pulses for wider range of application such as electron beam generation, x-ray generation, high power microwave generation. The helical pulse forming line produces a pulse longer than a coaxial pulse forming line with a same size. So a high voltage pulse in a small length can be produced. The helical pulse forming line (PFL) having transmission line characteristics is constructed. The inner conductor of pulse forming line is helical winding shape which increases the pulse length without changing its shape. The length of outer conductor of PFL is 800 mm. The helical PFL has inductance of 3 microhenry. The helical pulse forming line has impedence of 23 ohm and capacitance of 5.6 nF. Water is used as a dielectric in the pulse forming line due to its high value of relative permittivity (~80 ) and high breakdown strength. To prevent the water breakdown deionsed water having resistivity 2 MΩcm is used. The helical PFL is charged with a pulse transformer to 180 kV in 3.5 microsecond. The PFL is discharged into a 20 ohm resistive load through a low inductance coaxial spark gap switch. The spark gap switch is pressurized to 2 bar with N2 gas. The total voltage measured across 20 ohm load is 76 kV. The pulse duration of 260ns is measured across the load. So the compactness of PFL is achieved with helical water line as compared to coaxial PFL. The helical PFL will be used as a driver for electron beam generation. The detailed design of the system with experiment results will be presented in the paper.

187 2P68 OPERATIONAL RESULTS OF PULSE SHAPING TECHNIQUES FOR THE HIGH VOLTAGE CONVERTER MODULATOR Gunjan Patel, David Anderson, Dennis Solley, Mark Wezensky Oak Ridge National Laboratory, Spallation Neutron Source, Oak Ridge, TN, USA

The High Voltage Converter Modulators (HVCMs) are used to convert power for RF klystron used throughout the accelerator systems at the Spallation Neutron Source (SNS). The output voltage of the HVCM has significant droop and ripple which, combined with LLRF system limitations affects the performance and efficiency of the accelerator cavities. In conjunction with the progress in development of the new HVCM controller, different pulse modulation techniques were implemented and studied in the HEBT test modulator. This paper discusses the results of implementation of frequency modulation, phase modulation and start pulse modulation on the output pulse and performance of the HVCM. Operational data, including full average power operation, from the test modulator is also discussed. Future plans for the new modulation scheme will be presented.

ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

188 2P69 DESIGN AND TEST OF INDUCTION VOLTAGE ADDER DERIVED BY 3 BLUMLEIN PFLS Hoon Heo1, Oh Ryoung Choi1, Sang Hoon Nam1, Jong Won Yang2, Jong Hyo Won3 1Pohang Accelerqator Laboratory Pohang, Korea, 2ADD Daejeon, Korea, 3LIG Nex1 Seongnam, Korea

We designed an induction voltage adder with 3 cells. Each induction cell is derived a Blumlein pulse forming lines. The Blumlein pulse forming lines have gas switches triggered by a compact Marx generator. We used amorphous metal tape cores for the induction cells because of its large flux swing. The induction voltage adder was tested for a copper sulfate liquid resistor. We present the features of design and the preliminary test results.

189 2P70 HIGH-VOLTAGE VACUUM ELECTRONIC SWITCHES FOR POWER ELECTRONICS Vladimir Perevodchikov, Pavel Stalkov, Ivan Trukhachev, Valentina Shapenko, Alexander Scherbakov Federal State Unitary Enterprise "All-Russian Electrotechnical Institute named after V.I.Lenin" (FGUP VEI) Mosow, Russia

Vacuum switching tubes are effective for the high-voltage electronic equipment. They have a number of advantages in comparison with semi-conductor and gas-discharge switches. There are high level of a rated voltage of the individual device, high operational speed and full controllability. The current proceeding through the device is defined by the grid potential, instead of processes in an anode contour. There are some more advantages of the device in service. They are ability to dissipate great power on the anode, stability to short circuit currents in loading and in the tube, independence on electromagnetic radiation. The basic lack of vacuum electronic switches is the big power losses during conducting period and limitation of current value. Our group develops high efficiency electronic switches. It's arrived due to using high potential on an operating electrode and lower anode potential during conducting period. Developed devices have received the name of Electron Beam Valves (EBV) due to careful formation of electron beams. Three groups of EBV for a various parity of a switching voltage and current are presented: · EBV with rated voltage up to 200 kV and current in a continuous operation mode 2A. They are intended for power supplies of the devices working in the short-circuit current operation mode: powerful high-voltage electron beam welding equipment and power supplies for dust precipitators. · EBV with rated voltage up to 60 kV and direct current 8 A (pulse current 50 A) which are intended for power supply systems of powerful radio-electronic devices. In particular, special modulators of average output power 150 kW with pulse duration impulses operatively changing from micro seconds up to milliseconds. · EBV with rated voltage up to 80-100 kV with direct current 30-50 A and pulse current 500 A which can be used for power supply of gyratrons for fusion reactors plasma heating. They also can be used in power supplies of pulse gas- discharge devices for clearing industrial effluence from oxides in atmospheric emissions. Ways of switching tubes efficiency increase by reduce of anode potential and perspective of high-voltage electronic switches using in power electronics are considered. Results of experimental researches of pulse-width modulation on frequency up to 2 kHz for 50 Hz invertors are resulted. Development of experimental three-phase converter of power 1-2 MW intended for reactive power control in AC electric networks with rated voltage up to 35 kV is described. On our opinion, use of effective, high-voltage electronic switching tubes has grate prospects in high- voltage powerful electronics.

190 2P71 ELECTRIC EXPLOSIVE OPENING SWITCH TECHNOLOGY Wu Youcheng, Hao Shirong, Yang Yu, Geng Lidong, Wang Minhua, Zhang Nanchuan Institute of Fluid Physics, High Pulsed Power Technology and Application, Mianyang, China

Electric explosive opening switch (EEOS) can be used in pulsed power source because of its capability of cutting rapidly the current. In order to optimize EEOS metal wires of several materials were studied, including Al, Cu, Ag, and Au. The material with best capability among above materials was found according to the results of calculation and experiments. Based on EEOS technology a multi-pulse generator was developed. The generator consisted of a capacitor bank used as the primary energy source and an EEOS which was made up of wire arrays with different lengths and different cross-sections. The number of pulses was decided by the number of steps of wire arrays. The interval between the pulses and the amplitudes of the pulses could be adjusted by changing parameters of the wire arrays and charging voltage of the capacitor. Two pulses with peak voltage of 250kv or three pulses with peak voltage of 200kv were gained on a load with about 10Ω in one shot. Moreover, inductive energy storage pulsed power source with output peak power of more than 50GW was developed. This source was composed of a Marx generator with two capacitors, a unit for charging capacitors, an EEOS and a resistance load. One capacitor had 2μF capacitance. According to the results of calculation and experiments, the parameters of the EEOS and energy storage inductor were optimized. When charging voltage of capacitors was above 90kv, the peak of output power was more than 50GW on a 10Ω load. If an equivalent capacitor replaces the Marx generator, a compact high pulsed power source will be developed, including a compact charging unit and a compact EEOS.

191 7O1,2 (invited) COMMISSIONING AND POWER FLOW STUDIES OF THE 2.5-MEV URSA MINOR LTD Josh Leckbee1, Tim Pointon1, Steve Cordova1, Bryan Oliver1, Martial Toury2, Michel Caron2 1Sandia National Laboratories, Advanced Radiographic Technologies, Albuquerque, NM, USA, 2Commissariat a l'Energie Atomique Pontfaverger, Moronvilliers, France

The Linear Transformer Driver (LTD) is a compact type of inductive voltage adder (IVA) with the primary energy storage inside the IVA cells. Recently, the 2.5-MeV URSA Minor LTD was commissioned at Sandia National Laboratories. It is designed to drive a magnetically insulated transmission line (MITL) and electron beam diode load. Control of the electron power flow in the MITL (e.g. early time loss currents) is paramount to efficient operation. Results from experimental testing and 2-D particle-in-cell (PIC) simulations of magnetic insulation and electron loss in the MITL will be presented. On URSA Minor, currents are measured in the cathode and anode conductors at four axial locations along the MITL. Measured currents and inferred voltages will be compared to the simulations. Because of reliability issues, initial testing of the 21-cell URSA Minor was limited to charge voltages of +/- 75 kV and generated less than 2 MeV at the load. Recent improvements to the LTD cells have increased the reliability at higher charge voltage. A review of the changes to the cells and a report on results from and simulations of recent experiments at +/- 75 kV charge and +/- 90 kV charge will be presented.

192 7O3 SOLID-STATE LTD TECHNOLOGY FOR COMPACT PULSED-POWER DEVELOPMENT Weihua Jiang, Akira Tokuchi Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan

Compact pulsed power generators based on linear transformer driver (LTD) scheme are being developed for industrial applications. Power semiconductor devices are used as switches in contrast to spark gap switches employed in large LTDs. The solid-state switching devices allow high repetition rate and turning-off capability. In addition, the LTD scheme allows real-time impedance control during the pulse. For this reason, compact LTDs are expected to have a variety of industrial applications. This paper concentrates on a demonstration system which is a 10- module MOSFET-based LTD stack. It uses a total number of 350 power MOSFETs as switches. It is capable of generating peak output voltage of 9 kV and peak output current of 175 A, with pulse length of ~ 40 ns and repetition rate of 1 kHz. This test system has been used to demonstrate the practicability of solid-state LTD and to explore the possibility of output waveform shaping and impedance control by using LTD scheme. The design details and experimental results will be reported at the conference.

This work is supported by National Natural Science Foundation of China under Grant 50837004.

193 7O4 DEVELOPMENT OF THE 1 MV/100 KA FAST LTD GENERATOR Lin Chen, Wenkang Zou, Liangji Zhou, Meng Wang, Weiping Xie Institute of Fluid Physics, Pulsed Power Laboratory, Mianyang, China

The 1 MV/100 kA fast LTD generator was constructed and tested successfully whose designation was based on the 100 kV/100 kA-LTD stage prototype which had been developed in 2008. The generator consists of 10 LTD stages connected in series, and runs in a magnetically insulated transmission line (MITL) voltage adder configuration. There are 10 bricks, i.e., 20 capacitors (100 kV/20 nF) and 10 multi-gap switches for each stage. The outer diameter of the generator is about 1.5 m, at a length of 2.2 m. At the charge voltage of ±90 kV, the generator can delivers 1.1 MV fast pulse with rise time of 53 ns and FWHM of 146 ns into a 9.4 Ohm diode load. In addition, the preliminary test results are reported for flash X-ray radiography applications.

194 7O5 REPETITIVE TESLA-CHARGED PFL AND BLUMLEIN PULSED POWER GENERATORS Bucur Novac, Ivor Smith, Peter Senior Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom

The paper describes the development of repetitive 0.5 MV Tesla-charged, water-filled pfl and oil- filled Blumlein pulsed power generators, both with an overall efficiency of 84%. Details will be given of the filamentary modelling technique and the electroststic analysis that were used to determine the main parameters of the Tesla transformer, including the self-inductance of the primary and secondary windings, their mutual inductance and the capacitance between them. All resistance and inductance calculations take full account of both skin and proximity effects. The design procedure for both generatos will be presented, together with details of the fast embedded sensors that were used in analysing the dynamic characteristics of the two generator systems. Experimental results obtained during this major experimental programme will be compared with theoretical predictions.

195 7O6 SOLID DIELECTRIC TRANSMISSION LINES FOR PULSED POWER Matt Domonkos1, Susan Heidger1, Darwin Brown2, Tommy Cavazos2, Alan Devoe3, Fatih Dogan4, Don Gale2, Jim O'Loughlin1, Jerald Parker2, Dan Sandoval2, Kirk Slenes5, Wayne Sommars2, Jack Watrous6 1AFRL Kirtland AFB, NM, USA, 2SAIC Albuquerque, NM, USA, 3Presidio Components San Diego, CA, USA, 4Missouri University of Science and Technology Rolla, MO, USA, 5TPL, Inc. Albuquerque, NM, USA, 6NumerEx, LLC Albuquerque, NM, USA

This paper documents recent work developing solid dielectric transmission lines for sub- microsecond, 100 kV class compact pulsed power systems. Polymer-ceramic nanocomposite materials have demonstrated sub-microsecond discharge capability in parallel plate capacitors and transmission lines [1],[2]. With a dielectric constant of approximately 50, the propagation velocity is 2.5 cm/ns, necessitating lines of several meters length to achieve > 100 ns pulse lengths. By folding the line in a fashion analogous to ceramic multilayer capacitors, the physical length of the line can be significantly shorter than the electrical length. We present the results of an experimental effort to develop a folded transmission line using a polymer-ceramic nanocomposite dielectric. The pulse length was somewhat shorter than expected based on a simple calculation using the geometry and the dielectric constant. Fully 3-D electromagnetic calculations were used to examine the role of the edges in curtailing the pulse length. Dielectric breakdown in this device occurred below the electric field threshold demonstrated in the prior work [1], and post-mortem analysis is ongoing. Improvements in the large scale fabrication of TiO2 have opened the possibility for producing single layer high voltage devices. Given a dielectric constant approaching 140, transmission lines using TiO2 can be considerably shorter than with other materials. Relatively thick, flat sheets of TiO2 have been fabricated for high voltage testing. Several transmission lines, employing a serpentine electrode geometry, have been manufactured and tested. Low voltage testing has confirmed the operation of the lines according to the design. As expected, the triple point between the TiO2, electrode, and insulating medium has proven difficult to manage for high voltage operation. Several techniques to mitigate the effects of the triple point, including resistive grading at the edges of the electrodes, are under active investigation. Fully 3-D electromagnetic modeling is also being employed to examine the effects of electrode geometry and composition on the performance of the lines. [1] M.T. Domonkos, S. Heidger, D. Brown, J. Parker, C.W. Gregg, K. Slenes, W. Hackenberger, S. Kwon, E. Loree, and T. Tran, "Sub-Microsecond Pulsed Power Capacitors Based on Novel Ceramic Technologies," IEEE Transactions on Plasma Science, Vol. 38, Issue 10, Part 1, Oct. 2010, pp. 2686 – 2693. [2] M.T. Domonkos , S. Heidger, D. Brown , T. Cavazos, A. Devoe , F. Dogan , D. Gale, J. O'Loughlin, J. Parker, D. Sandoval, K. Slenes , W. Sommars, J. Watrous, "Compact Pulsed Power Using Solid Dielectric Transmission Lines," IEEE Pulsed Power Conference 2011, Chicago, IL, June 2011.

196 7O7 A COMPACT, PHASEABLE MW-CLASS HIGH POWER MICROWAVE SYSTEM USING AN INTEGRATED PHOTOCONDUCTIVE SWITCH AND NONLINEAR TRANSMISSION LINE Cameron Hettler, James-William Bragg, William Sullivan III, Daniel Mauch, James Dickens, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

A high power microwave system consisting of a single 30 kV silicon carbide photoconductive semiconductor switch (PCSS) and a ferrite-loaded nonlinear transmission line (NLTL) is demonstrated. The optically-triggered 4H-SiC PCSS is capable of delivering up to 18 MW of peak electrical power into the saturated 50 Ω NLTL. The PCSS is illuminated by a tripled Nd:YAG laser (355 nm) with a pulse width of 7 ns and pulse energy of up to 10 mJ. The PCSS generates a 15 ns pulse width, 1.5 ns rise time voltage pulse that is fed into an axially-biased NLTL. The NLTL transforms the fast-rising voltage pulse from the PCSS directly into microwave oscillations. The 1 meter long NLTL consists of a 3 mm inner conductor loaded with 3 mm x 6 mm (IDxOD) ferrites and a 9.75 mm outer conductor. Through axial and azimuthal field interaction, damped gyromagnetic precession occurs in the ferrimagnetic material producing microwave oscillations with peak conversion efficiency approaching 60%. The static biasing field resets the magnetic material to the same induction level allowing sub-nanosecond jitter at high operating frequencies. A fiber optic system was used to generate a train of laser pulses to operate the system in burst mode at MHz frequencies. The overall system jitter and the potential for implementation into a phased array is discussed.

197 7O8 COMPACT PICOSECOND PULSE GENERATORS WITH GIGAWATT PEAK POWER Vladimir Efanov, Mikhail Efanov FID GmbH Burbach, Germany

A series of compact high voltage picosecond pulse power modules with amplitude of up to 500 kV and peak power of up to 10 GW has been developed. These pulse generators have a rise time of 100-150 ps and a pulse duration of 200-500 ps. Size of 200-300kV module with an amplitude of 200-300 kV into 50 Ohm are about 220x170x70 mm, weight about 3 kg. Jitter of the output pulse relative to triggering pulse is about 20ps. Maximum pulse repetition frequency is up to 1 kHz. Compact pulse power modules can operate into any load from short to open circuit. Consumed power of 200kV pulser is about 500 W at 1 kHz. Accelerator laser and radar applications require high voltage pulses with an amplitude of hundreds of kilovolts with pulse duration from 100 ps to several nanoseconds. FID GmbH has developed a new class of solid-state compact pulser modules that at the same time provide gigawatt peak power, picosecond pulse duration and high timing stability. Moreover new compact modules are highly reliable and have high efficiency. Successful tests of compact pulse power module with maximum output amplitude of 200 kV and pulse duration of 250 ps have been performed in short and open circuit modes. Compact pulser modules have been developed using new series of FID switches capable of switching currents of tens of kiloamperes in less than 100 ps. A series of compact picosecond pulse generators operating into 10-100 Ohm with maximum output voltage of 100, 200, 300, 400 and 500 kV has been developed. Modular pulser FPG 200-1PM has approximate size of 220x170x70 mm and weight of about 3 kg. Maximum output amplitude is 200 kV into 50 Ohm. Rise time is about 150 ps and pulse duration is 250 ps at half amplitude. Maximum pulse repetition rate is 1 kHz at which pulse consumes about 500W. Operation of pulse generator requires external power of about 1000 V and triggering pulse of about 100 V. Modular pulser FPG 500-1PM has maximum output voltage of 500 kV into 50 Ohm with rise time of about 150 ps and pulse duration of 300 ps FWHM. This pulser operates at 1 kHz. Its approximate size about 500x200x180mm and weight is about 10 kg. Power consumption is about 2 kW. Operation of generator requires input power of about 2 kV and triggering pulse with amplitude of about 100 V. At 100 Hz pulser can operate for significant time without external cooling. FID GmbH is now performing development o compact pulse power modules with amplitude of 1-2 megavolts and pulse duration of 200-300 ps. Measurement of operating specifications of gigawatt picosecond pulsers and compact pulse power modules special high voltage attenuators with bandwidth of up to 2 GHz and directional couplers with bandwidth of 10 GHz have been developed.

198 8O1 PRELIMINARY NUMERICAL STUDY ON DIELECTRIC MIXTURES UNDER LIGHTNING IMPULSE CONDITIONS Enis Tuncer, Chris Calebrese, Weijun Yin GE Global Research, Dielectrics & Electrophysics Lab, Niskayuna, NY, USA

High voltage devices and systems are designed using different rules depending on various parameters i.e., selection of materials. One of the important parts of the design process is the insulation coordination, which is employed to select the necessary insulation material(s) and determine sufficient insulation characteristics of the equipment to retain reliable operation under normal voltages and overvoltages of various origins. It determines the continuous operation of the device and system for the design lifetime. Lightning impulse (LI) is one of the overvoltages that can be experienced in the energy distribution system. Response of insulation materials under overvoltage conditions would be important to understand in order to improve selection of materials and also tailoring novel materials. In this contribution, we construct ideal structures to imitate particle filled composites and apply the finite element method to solve electrical potential distribution under LI waveform. The particle as well as matrix electrical properties are altered to study the response of the dielectric mixture under LI conditions. Results of simulations are presented using dimensional and electrical parameters. Numerical simulations improve our understanding of materials under unipolar high electrical fields, and contribute to design novel devices for high voltage technology.

199 8O2 EVOLUTION OF PLASMA DENSITY GENERATED BY HIGH POWER MICROWAVES Sterling Beeson, James Dickens, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

The relaxation time of pulsed rf-generated plasma is investigated. A 3 MW, 3 μs width, 50 ns risetime HPM pulse is transmitted through a dielectric window that terminates a WR- 284 waveguide filled with insulating gas. The investigated plasma is formed across the dielectric window on the atmospheric side. This produces electron densities on the order of 1013 to 1012 cm-3 for 60 to 145 torr in air, respectively. In the same pressure range, initial attenuation (~ 0.5 dB) of the microwaves is observed after tens to hundreds of nanoseconds with final attenuation values approaching -40 to -10 dB, respectively. To determine plasma relaxation times after the HPM pulse terminates a multi-standard waveguide coupler (X/S-band) was designed to inject a low power 10 GHz signal used for probing the surface plasma. The coupler was designed to have high coupling coefficients (> -5 dB) for the specific narrowband around 10 GHz (BW ~ 10 MHz) along with negligible insertion loss of the HPM propagation. From the measured attenuation and reflection of the 10 GHz probe signal, the evolution of the electron density is inferred. Further, attachment rates, diffusion lengths, and recombination rates of various reactants are used to elucidate the chemical and kinetic behavior of the ion/electron densities. Presented here are the design parameters of the multi-standard waveguide coupler along with the experimental and calculated data for N2, air and argon gases at pressures from 5 to 400 torr. It is shown, for instance, that the electron density falls 4 orders of magnitude within 50 μs for 10 torr N2.

200 8O3 BEHAVIOR OF HV CABLE AT SHORT CIRCUIT AND RELATED PHENOMENA Alex Pokryvailo, Cliff Scapellati Spellman High Voltage Electronics Corp. Hauppauge, NY, USA

Discharges in many HV loads are unavoidable at voltages close to their operational limits. Such loads may be vacuum gaps, e.g., X-ray tubes. The discharge characteristics depend not only on the state of the load, but, in the case of a vacuum gap, on external circuitry [1]. In cabled connections, the cable length is critical. The latter is mostly overlooked in literature. In this paper, we consider two cases. In the first, the cable shield is connected to ground on both sides. Then the processes in it can be described by conventional transmission line equations. We show the pattern of traveling waves developing at short-circuit conditions and overvoltages at the power supply side as a function of the cable and power supply parameters. Means of increasing the breakdown voltage by circuit modification are described. In the second case, the shield at the power supply side is grounded, and at the load side it is floating (open termination). It is shown that the transmission line model is no longer applicable. PSpice equivalent circuits with lumped parameters are developed and analyzed. It is shown that the cable insulation is overstressed at the load side. Experimental results obtained on low-voltage models are presented. [1] Slivkov I.N. "Electrical Breakdown of Vacuum". Energoatomizdat, Moscow, 1972. In Russian. [2] Pokryvailo, A., Vlasov, K.K., Magdin, Yu.A. and Starchikov, A.N., "On the Electromagnetic Compatibility of High Voltage Power Supplies for X-Ray Analytical Apparatus Operating under Conditions of High Voltage Discharges", Instrumentation and Methods of X-Ray Analysis", Vol. 40, pp. 151-158, 1990. [3] Pokryvailo, A, Carp, C., and Scapellati, C., "Comparative Testing of Simple Terminations of High Voltage Cables", IEEE Electrical Insulation Magazine, vol. 26, No. 1, 2010, pp. 7-17.

201 8O4 FLEXIBLE 50-OHM HIGH-VOLTAGE NANOSECOND PULSE GENERATOR Sophie Kohler, Saad El Amari, Vincent Couderc, Delia Arnaus-Cormos, Philippe Leveque University of Limoges, XLIM UMR 6172 CNRS, Limoges, France

Over the last decade, high-voltage pulsed techniques have been employed in a variety of fields such as medicine, biology, food processing, environmental science and defense. In bioengineering, many studies have shown the ability of nanosecond pulsed electric fields (nsPEFs) in the MV/m range to affect the structure and functions of biological cells. The observed effects are dependent on the pulse parameters e.g. shape, duration and amplitude. High-voltage (HV) nanosecond pulse generators with adjustable and easily monitored pulse parameters are well suited for investigating dose-effect relationships [1]. We previously reported versatile microstrip-based HV pulse generators [2]. In this paper, a new 50-Ohm coaxial-based high-voltage (up to 20 kV) pulse generator is described and characterized. The pulse forming line of the generator is based on the frozen wave generator concept. Two photo-conductive semiconductor switches (PCSS) are embedded in a 2-port and 3-port coaxial structure, respectively. The two structures are connected by a coaxial cable through THT connectors. The 2- port structure is terminated by a short circuit. The 3-port structure is also connected to a 12-GHz oscilloscope for the data acquisition and a HV power supply for charging the line. Apertures in both structures allow optical triggering of the switches by a high-energy mode-locked Nd:YAG laser operating at 1064 nm. The laser source generates 35-ps pulses at a frequency rate of 20 Hz. The DC polarization is set to 16 kV. With a delivered optical energy of 8 mJ per pulse, rectangular monopolar pulses of 12-ns duration and a maximum amplitude of 6.9 kV were measured. The rise and fall times were 1.1 ns and 1.3 ns respectively. By varying the optical energy, it was possible to control the maximum output voltage. Modification in the illumination time delay of the switches allowed generating balanced and unbalanced bipolar pulses with various frequency contents and a maximum peak-to-peak amplitude of 13 kV. Pulse with adjustable durations (2 to 100 ns) can be easily obtained by changing the length of the line connecting the two coaxial structures. In conclusion, a robust HV nanopulse generator with adjustable pulse parameters in terms of shape, amplitude and duration is proposed. Using coaxial technology, instead of the previously reported microstrip structure, improves the voltage limits of the generator. This generator opens new perspectives for establishing dose-response relationships in nanopulse bioexperiments. It also allows investigation of the role played by the pulse spectral content in nonthermal biological effects. [1] J. F. Kolb, S. Scarlett, J. Cannone, J. Zhuang, C. Osgood, and K. H. Schoenbach, "Nanosecond Pulse Generator with Variable Pulse Duration for the Study of Pulse Induced Biological Effects," Proceedings of the 2008 Power Modulator Conference, Las Vegas, NV, pp. 61-64, 2008. [2] S. El Amari, M. Kenaan, C. Merla, D. Arnaud-Cormos, P. Leveque, and V. Couderc, "Microwave subnanosecond pulse generation and shaping by using infrared optoelectronic switching,"IEEE International Power Modulator and High Voltage Conference 2010, Atlanta, GA, pp.391-392, 2010.

202 8O5 COMPACT 110-MW MODULATOR FOR C-BAND HIGH GRADIENT ACCELERATOR Takahiro Inagaki1, Chikara Kondo1, Katsutoshi Shirasawa1, Tatsuyuki Sakurai1, Yuji Otake1, Tsumoru Shintake2 1RIKEN, SPring-8 Center, Hyogo, Japan, 2OIST Okinawa, Japan

The X-ray free electron laser (XFEL) facility SACLA (SPring-8 angstrom compact free electron laser) is a compact and low cost XFEL facility based on a C-band (5.7 GHz) 8-GeV electron accelerator. In order to generate higher accelerating field as high as 35 MV/m, the accelerating structures have to driven by very high peak RF power at shorter intervals. We need to place 64 klystron modulators in each 4 m spacing along to the accelerator, therefore the modulator has to be very compact. The free electron laser in X-ray wavelength requests very tight tolerances on intensity and phase of the accelerating field, which is related to a special beam-dynamics with non-crest acceleration, i.e., the electron beam is not only accelerated but also receiving energy slope, which is utilized to compress the bunch length. Typical requirement is 100 ppm (rms) on RF amplitude, and 0.2 degree (rms) of 5.7 GHz on phase. In order to meet these requirements, we have developed an extremely stable, compact, oil-filled modulator with 110 MW (350 kV, 315 A) peak output power. We employed a conventional line-type modulator with a novel architecture design. All the high voltage components, including 16 series of PFN circuit, a thyratron, a pulse transformer, and reverse protection circuits, are installed in a single steel tank (1.7 m x 1 m x 1 m), filled with insulation oil. This design provides good EM noise-shield performance, and superior operational stability against environmental temperature variation and humidity. In order to charge the PFN capacitor up to 50 kV, an inverter-type precise high voltage charger has been developed. The pulse-to-pulse stability of the charging voltage as low as 10 ppm (rms) has been achieved, as a result, the accelerating voltage and the phase fluctuations have been drastically reduced. Since February 2011, all the modulators have been continuously operated for the accelerator commissioning, with the superior performance. The accumulated operation time is about 5,000-6,000 hours. In this presentation we report the design concept and the operational performance of the compact modulator.

203 8O6 SOME CONSIDERATIONS TO THE ITER SNUBBERS Ge Li Institute of Plasma Physics, Chinese Academy of Sciences Hefei, China

Recent studies on ITER snubber suggest its present reference design could not stand well by historically reviewing the snubber works mathematically. Initially ITER will use two 1 MeV heating neutral beams (NB) and one 100 keV diagnostic NB. In the heating NB system, Two Snubbers based on SF6 gas insulation are presently configured as functional passive protection devices to be inserted between ITER ion source and its 1 MV acceleration power supply for absorbing the stored energy in their respective transmission lines (TML) to attenuate the peak fault arc currents and quench them when shorting occurs. The present reference design is based on flux matching method developed in JAEA. The capacitance parameters in TML1 and in TML2 are respectively valued as 3.724 nF and 1.2 nF, where the TML1 is one 120 m 1 MV coaxial conductor to be used to connect the power supply yard and the high voltage deck (HVD), the TML2 is used to connect the HVD and the beam source. Another snubber design method is developed by Fink, Baker and Owren (FBO), who integrate the time varing resistances of the core snubber layers and assuming that the snubber core never saturates, which gives the analysis solution to the design of core snubber. The FBO method is an empirical design method and successfully used in the design of DIII-D snubbers, which could give compact snubber design, is being further discussed in the paper and used for analyzing the present ITER snubbers. The conditions of snubber design are derived from FBO method, which suggest the reference design for ITER snubbers could not protect the ITER NB reliably well even with the advanced snubber operation scenario developed in Experimental Advanced Superconducting Tokamak (EAST), Institute of Plasma Physics Chinese Academy of Sciences (ASIPP). Modified design for ITER Snubbers is suggested based on this work in EAST, ASIPP. Its inner bore diameter must be scaled up with the present reference Finemet material or more advanced design should be developed for safe ITER operation.

204 8O7 A NEW TRIGGERING TECHNOLOGY BASED ON INDUCTIVE TRANSFORMER FOR LTD SWITCHES Yu Lei, Kefu Liu, Jian Qiu, Zhuolin Tu Fudan University, Electric Light Sources, Shanghai, China

A new triggering technology is proposed based on reversed-LTD principle, which is named LTD- trigger. It has a similar structure to LTD device, but it operates reversely relative to LTD. LTD- trigger is an inductive voltage divider contrast to LTD based on inductive voltage adder in principle. Its input port and output port is opposite to LTD configuration. With one primary high- voltage pulsed power supply of LTD-trigger, multichannel fast triggering pulsed voltages can be obtained by the linear inductive transformer (magnetic core) to trigger corresponding LTD switches. It reduces the delay and jitter time due to the intrinsic advantages from coaxial configuration over the conventional triggering method. With careful design, LTD-trigger can match the time sequence of triggered switches in the different cavities of LTD. The paper analyzed the working principle of LTD-trigger by establishing a circuit model and simulation. Taking some fault factors into consideration, the results showed that the LTD-trigger is reliable. A prototype with 20 channels of triggering pulse and 20kV trigger voltage in each channel had been designed and tested.the jitter of all trigger pulse is less than 1ns. The experimental results showed that they agreed with the simulation.

205 8O8 SUSCEPTIBILITY OF ELECTRO-EXPLOSIVE DEVICES TO HIGH PULSED ELECTRIC FIELDS David Reale, John Mankowski, James Dickens Texas Tech University, Center for Pulsed Power & Power Electronics, Lubbock, TX, USA

Commercially available Electro-Explosive Devices (EED), such as Blasting Caps, use electrical current to initiate a primary charge. Various detonators are available including bridge wire, match-type, exploding bridge wire, and slapper. The basic operating principle of the match-type device is to heat the ignition element causing a reaction that then detonates the primary charge. The normal operation current profiles, both constant current and pulsed excitation, are well known as is the ignition temperature. However, as safety and reliability are of great concern, both in the operation and storage of EEDs, the susceptibility of these devices to transient or spurious fields is of interest. Previous work has investigated the susceptibility of match-type EEDs to high magnetic fields [1]. This work was extended to investigate the effects of high pulsed electric fields. A Finite Element Method (FEM) simulation is used to determine the heating of the bridge wire element due to applied field levels. Several situations are investigated including EEDs in conductive and non-conductive media, leads open or terminated in a high impedance representing operational situations, and leads shorted representing storage. [1] J. Parson, et al., "Pulsed magnetic field excitation sensitivity of match-type electric blasting caps," Rev. Sci. Inst., vol. 81, pp. 105115-1-105115-7, Oct. 2010.

206

WEDNESDAY

B Plenary Session 3 PLS-II AS THE LEADING KOREAN ACCELERATOR PROJECT AND ITS ROLE FOR MEGA-SCIENCE ACCELERATOR PROJECTS IN KOREA Sang Hoon Nam Pohang Accelerator Laboratory, Pohang, Korea

The Pohang light source II (PLS-II) is a new 3rd generation synchrotron light source, which was constructed in 2011 and opened to users on March 2012. The PLS-II is fully renovated from the old PLS that had been operated for fifteen years from 1995 in Pohang, Korea. The PLS-II project had taken 3years from 2009 to 2011 at a cost of about 100M$. It is consisted of a full energy injector linac and a storage ring (SR). The linac has sixteen high power pulsed 200MW modulators and 80 MW klystrons to generate 2856 MHz microwave energy, which is used to accelerate electron beams. The high energy electron beams are injected to the SR with a high power pulsed kicker modulator. Major specifications of the PLS-II SR are 3 GeV energy, 400 mA stored current, 5.8 nm-rad beam emittance, 12 double band achromat (DBA) superperiods with 281 m circumference, and 20 available straight sections for insertion devices. Total 30 beamlines were ready for user services in March 2012. The PLS was the first large scale accelerator project, and there were several other mega-science projects have been initiated after the success of the PLS in Korea. Current accelerator based mega-science projects in Korea are Proton Engineering Frontier Project (PEFP), Korea Rare Isotope Accelerator (KoRIA), and PAL X-ray Free Electron Laser (XFEL), and Korea Heavy Ion Medical Accelerator (KHIMA). The PEFP is a project to construct a 100 MeV, 200 mA proton accelerator, mainly for industrial applications. The KoRIA is a 200 MeV/u accelerator facility to produce rare isotope beams with both ISOL and in-flight fragmentation. The PAL XFEL is a project to produce 0.1 nm hard x-ray free electron laser with tens of femto-second pulse-width by using a 10 GeV electron linear accelerator. The KHIMA will be the first heavy ion therapy system in Korea. These projects will be briefly introduced and the role of PLS-II construction team who has in-depth experience for such large projects will be discussed. Technical experiences in pulse power, high voltage, and power electronics will be emphasized.

207 9O1 THE COLLIDING TORI FUSION REACTOR: PROOF OF PRINCIPLE EXPERIMENT Michael Anderson1, Vitaly Bystritskii1, Ivan Isakov1, Vasily Matvienko1, Francesco Giammanco2, Tommaso Del Rosso2, Michl Binderbauer1, Lucia Bonelli3, Hiroshi Gota1, Frank Jauregui1, Cheryl Johnson1, Enrico Paganini3, Mark Rouillard1, George Strashnoy1, William Waggoner1, Kurt Walters1 1Tri Alpha Energy, Inc., Pulsed Power Physics, Foothill Ranch, CA, USA, 2University of Pisa, Physics, Pisa, Italy, 3ENEL Pisa, Italy

This report provides a brief conceptual overview, machine parameters, a description of the diagnostics suite, and initial results of the Colliding Tori Fusion Reactor - Proof of Principle (CTFR-POP) experiment. The CTFR-POP machine (10MA, 2MJ, 0.25TW) was constructed to explore the parameter space between Magnetic Confinement and Magnetized Target Fusion. CTFR-POP relies on empirical knowledge gained from past experiments [1,2,3], mature pulsed power driver technology [4] and peristaltic theta-pinch techniques [5,6] to create a traveling magnetic wave that forms, accelerates, collides and compresses compact plasma tori to high 23 -3 densities (n > 5x10 m ) and temperatures (Ttot > 5keV) with plasmoid lifetimes > 1-10us. [1] A. Hoffman, et al., "Field Reversed Configuration Lifetime Scaling Based on Measurements from the Large s Experiment," Nuclear Fusion vol. 33, no.1, p. 27-38, (1993). [2] F.H. Coensgen, et al., "Multistage Magnetic Compression of Highly Ionized Plasma," Physics of Fluids vol. 4, no. 4, p. 350-361, (1959). [3] D.R. Wells, et al., "Hydrodynamic Confinement of Thermonuclear Plasmas: TRISOPS VIII (Plasma Liner Confinement)," Fusion Technology, vol.9, p. 83-96 (1986). [4] T.C. Grabowski, "Directed Energy HPM, PP, & PPS Efforts: Magnetized Target Fusion – Field Reversed Configuration," Air Force Research Laboratory Report, AFRL-DE-PSTR-2006- 1086, (2006). [5] G.P. Boicourt, "Engineering Feasibility Evaluation of a Peristaltic Pinch," Los Alamos National Laboratory Report, LA-6766-MS, (1977). [6] M. Binderbauer, et al., "Dynamic formation of a hot field reversed configuration with improved confinement by supersonic merging of two colliding high-β compact toroids," Physics Review Letters, vol. 105, no. 4, p. 045003 (2010).

208 9O2 ATMOSPHERIC ELECTROMAGNETIC PLASMADYNAMIC SYSTEM FOR INDUSTRIAL APPLICATIONS Yuri Chivel1, Victor Bochkov2, Dmitry Bochkov2, Yury Gryshin 3, Valery Suslov 3, Vladimir Vermel 4 1MerPhotonics Saint Etienne, France, 2Pulsed Technologies Ltd. Ryazan, Russia, 3Pulsed Technologies Ltd. Ryazan, Russia, 4Bauman University Moscow, Russia, 5Bauman University Moscow, Russia, 6TsAGI Moscow, Russia

Electromagnetic plasmadynamic systems are one of the most promising systems for a number of applications: surface hardening, thermal spraying, surface modifications. On the surface these systems provide the same action parameters (i.e., power density, exposure time) as technological lasers, but they have advantages - large action spots, up to ten square centimeters and combined thermal and shock action. These systems are capable of accelerating powder particles at the 3 velocity up to (2.5-3)·10 m/s. Using these systems the unique coatings from B4,C, Si and WC are formed. Such high particles velocity is not attainable by other spraying. But normally these systems operate at low pressure of ambient gas (102 -103 Pa) only and with a low frequency of operation <0.1 Hz, which constitutes major problems for industrial application. Attempts to obtain high-energy pulsed plasma flows at atmospheric pressure are confronted with difficulties to produce homogeneous discharges in the plasma accelerator channel. A new hybrid two-stage electromagnetic plasmadynamic system with the first stage in the form of a DC plasma torch with flow temperature ~ 3000 К – 4000 К at atmospheric pressure, and with the second stage in a form of a coaxial plasma accelerator has been devised. Plasma of DC torch fills the accelerated channel. A high-voltage impulse is applied to the accelerating gap situated in the beginning of the channel and representing its narrowest zone. As a result, a breakdown occurs, and the plasma current shell is formed. The originated plasma current shell is accelerated by electromagnetic Lorents force along the axis of the accelerator. At the exit of the accelerator, a large-diameter underexpanded plasma flow is formed which is characterized by high velocity as great as (3- 5)·103 m/s with the diameter of plasma flow up to 2 cm and length up to 10 cm. The persistence of intense air plasma flow radiation varies between 120 and 200 µs and plasma brightness temperature ranges up to 1.5·103 K. Frequencies up to 1-4 Hz are realized at energy of pulsed flow 3-4.5 kJ. As a high energy switch Pulsetech's a water-cooled thyratron TDI1-200k/25H with maximum DC current of 10 A is used. This hybrid plasma source has future prospects for industrial applications due to a number of advantages such as: large area of processing; high plasma velocity and temperature, high frequencies of operation, no reduced pressure; no dangerous and harmful gases, low noise. The results are presented on the use of the this pulsed- periodic atmospheric plasmadynamic system for surface layer modification and its possibility for particles acceleration have been investigated.

209 9O3 PROGRESS TOWARD A SELF-CONTAINED RAPID CAPACITOR CHARGER FOR A SMALL RAILGUN IN BURST MODE OPERATION AT 3 RPS Raymond Allen1, Craig Boyer2, Jesse Neri1, Michael Veracka3, Brett Huhman1 1Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2L3 Communications/Titan Group Reston, VA, USA, 3Naval Research Laboratory, Tactical Electronic Warfare Division, Washington, DC, USA

In previous work, one module of a battery powered rapid charger was created which was able to charge the capacitor bank of a low velocity railgun [1] to 2 kV at 1 Hz in burst mode [2][3]. A second module has recently been added to the system which has demonstrated how these modules can be combined in parallel to increase both the power and energy available. Also, some additions to the circuit have improved the robustness of the system. Further improvements to the railgun now allow us to reduce the required charge voltage to 1.8 kV although the capacitance of the bank will increase to keep the stored energy the same. The rapid charger has now demonstrated 2 RPS operation. Methods to further increase the charge rate are discussed. Research into alternative battery types reveals that our current dry-cell lead-acid batteries compare favorably to newer battery types. [1] J. M. Neri and J. S. Kim, "Initial Operation, Modeling and Optimization of a Low-Velocity Augmented Railgun," 13th International Pulsed Power Conference, June 15-19, 2003, pp. 1103- 1106. [2] R. J. Allen and J. M. Neri, "A Battery Powered, 200-kW Rapid Capacitor Charger for a Portable Railgun in Burst Mode Operation at 3 RPS," 16th International Pulsed Power Conference, June 17-22, 2007. [3] R.J. Allen, C.N. Boyer, J.M. Neri, and M. Veracka, "Development of a 150-KW, Battery Powered, Rapid Capacitor Charger for a Small Railgun in Burst Mode Operation at 3 RPS," Proceedings of the 2008 International Power Modulators and High Voltage Conference, May 27- 31, 2008, pp. 106-108.

This work is supported by the Naval Research Laboratory Base Program.

210 9O4 ANALYSIS AND SIMULATION OF ELECTROMAGNETIC COIL LAUNCH SYSTEM Jiange Zhang1, Zan Lu1, James E. Thompson2, Naz E. Islam1 1University of Missouri-Columbia, Electrical & Computer Engineering, Columbia, MO, USA, 2University of Missouri-Columbia, College of engineering, Columbia, MO, USA

Compared with the conventional method or technology to launch the tactical missile, electromagnetic coil launcher or coilgun technology has distinct good points. In contrast to classic launch system, the presentation discusses the technical characteristics of the EM coil launch system for missile and introduces the systematic structure of the EM coil launcher, such energy storage subsystem, current conversion subsystem, control subsystem and launcher subsystem. Based on specific requirements such as load mass of 500kg and muzzle speed of 30m/s, the basic design of the EM launch system, including the calculation of the overall parameters, composition of the subsystems and the selection of the major components is also discussed. In addition, the electrical and mechanical models of the system, upon which the electromagnetic and dynamic simulations of the system have been conducted to optimize the parameters of the launching coils is also discussed. Finally some problems and concerns that need specific attentions and their possible solutions is also discussed in the presentation. [1] Skurdal, B.D.; Gaigler, R.L.; Multimission Electromagnetic Launcher Magnetics, IEEE Trans actions on Volume: 45 , Issue: 1 , Part: 2, Page((s): 458 – 461,2009. [2] M. S. Aubuchon et al., "Results from Sandia National Laboratories/Lockheed Martin electrom agnetic missile launcher (EMML)," in Proc.15th IEEE Int. Pulsed Power Conf., 2005, pp. 75–78. [3] R. J. Kaye, "Operational requirements and issues for coilgun electromagnetic launchers," IEE E Trans. Magn., vol. 41, no. 1, pp. 194–199, Jan. 2005. [4] R. L. Gaigler,M. R. Alberding, and L. S. Basak, "Unitary Electro Magnetic Coil Launch Tube, " U.S. Patent Application 20080006144, Jan.10, 2008. [5] B. M. Marder, "SLINGSHOT A coilgun design code," Sandia National Lab., Albuquerque, NM, Sandia National Laboratories Report SAND2001-1780, Sep. 2001.

211 9O5 MEASUREMENT OF SOLID ARMATURE'S IN-BORE VELOCITY USING B-DOT PROBES IN AUGMENTED RAILGUN Song Shengyi, Cheng Cheng, Guan Yongchao, He Yong Institute of Fluid Physics, CAEP, Laboratory for Pulsed Power Technology, Mianyang, China

The waveform of solid armature's displacement and in-bore velocity can be obtained by arranging B-dot probe arrays along the barrel of a series augmented railgun. The moment of armature arrive can be determined by an evident change in the differential signal from B-dot probe while armature passing by. However, for a railgun it is difficult or even impossible to directly pick up the arrive moment from the signal because of not only armature movement but also rail current contributed to the change of differential signal, especially for the series augmented railgun where all the time there are currents both on outer rails and connecting conductors to probably be induced by the B-dot probe. To eliminate the influence of current variety the ratio function has been introduced, which is the ratio of the differential signal integral to the current. The ratio function of armature probe aimed at armature current will reach a maximum at the moment of armature arrive, while the one at rail current will reach the median. Three shots with same initial conditions were carried on a series augmented railgun, each of which had adopted armature probe, rail probe and VISAR, respectively. The well agreement with each other about displacement and velocity waveforms by B-dot probes indicated that method and measurement were valid. The accuracy of B-dot method is mainly affected by probe size and position, railgun current distribution and electromagnetic noise.

212 9O6 EXPERIMENTAL RESULTS FROM THE DESTRUCTIVE TESTING OF MULTI-LAYER PZT FERROELECTRIC GENERATORS Allen Stults US Army, AMRDEC, Redstone Arsenal, AL, USA

Ferroelectric generators have shown significant improvement with better availability of materials. To date, most improved designs for these explosive generators have been in the use of the generators as high voltage devices. As an alternative, these devices can be used as high current devices. In order to make high current devices, a multiple layer approach has been pursued where conductive leads have been alternated with dielectric ceramics within the active block of material. As a start in learning how to make such multi-layer materials, many samples, 120, have been produced. These samples, while not optimal, are considered suitable for explosive loading to gather voltage and current results from firing into loads of low inductance and varying resistances. These results are presented and a simple model of ferroelectric generators as current devices has been empirically determined. The results of these 120 experiments are given in order that a baseline data set can be used by interested researchers for further study.

213 9O7 EXPERIMENTAL AND THEORETICAL STUDIES OF A FLYER-PLATE ELECTROMAGNETIC ACCELERATOR Kaashif Omar1, Neal Graneau1, Mark Sinclair1, Bucur Novac2, Ivor Smith2, Peter Senior2 1AWE, Hydrodynamics Department, Aldermaston, United Kingdom, 2Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom

A joint programme involving the study and practical performance of a flyer plate electromagnetic accelerator has recently been initiated by AWE, Aldermaston and Loughborough University Two electromagnetic accelerating systems have been developed as part of the programme: AMPERE, based on a 120 kJ/40 kV capacitor bank mounted at AWE and QUATTO, based on a 100 kJ/22 kV capacitor bank and operated at Loughborogh Pulsed Power Laboratory. Both 0-D and 2-D numerical models for the foil-flyer accelerator have been developed. The 0-D model is used primarily for parametric design studies and the 2-D model for accurately calculating the 2-D distribution of the current, velocity, acceleration and temperature of the flyer, together with the complete distribution of the magnetic and electric fields generated during a shot. Recently, a novel form of inductive sensor has been installed and successfully used to detect the current distribution in the flyer, although the probe can also be used with any parallel-plate transmission line. The paper will present the most relevant experimental data obtained during the first phase of the joint programme and compare this with theoretical predictions.

214 9O8 OPTIMIZATION OF NONUNIFORM TRANSMISSION LINE WITH A GAUSSIAN IMPEDANCE PROFILE BY CIRCUIT SIMULATION Rui Zhang, Chongyang Mao, Kun Hunag, Xiaobing Zou, Xinxin Wang Tsinghua University, Department of Electrical Engineering, Beijing, China

In 1997 a breakthrough in Z-pinch research was achieved by Sandia Laboratories in PBFA-Z project. One of the reasons for this breakthrough was thought to be the use of PBFA accelerator (20 MA, 100 ns) as Z-pinch driver. Recently, a number of architectures have been proposed in the literatures for the design of future pulsed power Z-pinch drivers. In the architectures monolithic radial-transmission-line impedance transformers were used to combine the outputs of several- hundred terawatt-level pulse generators to produce a petawatt-level pulse. It was usually proposed to use the radial transformers with an exponential impedance profile since they are more efficient than those with a linear impedance profile and easier to treat theoretically. However, it appears that the impedance profile that optimizes the performance of a transmission-line transformer is not known. Lewis and Wells suggested that the performance of a Gaussian transformer may be superior to that of an exponential transformer. In this paper, an optimization of nonuniform transmission line with a Gaussian impedance profile was carried out by circuit simulation with Pspice code. Based on a recently published design of a petawatt-class Z-pinch driver, the following parameters of a water-insulated Gaussian line were used. The input and output impedance are 0.203 Ω and 2.16 Ω, respectively. The length of the line is 33.83 m. The input voltage is half-sine shape with an angular frequency of 1.4×107 s-1, corresponding to pulse width (FWHM) of 150 ns. The only unknown parameter for the Gaussian line was h. The optimized value of h that gives the highest power transmission efficiency was determined by iterative numerical circuit simulation. The power transmission efficiency of the optimized Gaussian line was compared with that of the exponential line under same conditions (input and output impedance, line length, input voltage).

215 10O1 VIRTUAL PROTOTYPING A MEGAWATT CLASS CONVENTIONAL MAGNETRON Michael Lambrecht, Timothy Fleming, Peter Mardahl Air Force Research Laboratory, Directed Energy Directorate, Kirtland AFB, NM, USA

Researchers at the Air Force Research Laboratory's (AFRL) Directed Energy Directorate have designed a conventional magnetron via virtual prototyping. The strapped magnetron design delivers 1 to 4 MW peak power output with corresponding input voltages of 40-60 kV, a 0.18-0.3 T confinement field, and efficiencies between 85-88%. The source was virtually prototyped using AFRL's state-of-the-art computer simulation software package, the Improved Concurrent Electromagnetic Particle In Cell (ICEPIC) code, a highly parallelized full-wave electromagnetic PIC code that is capable of running on thousands of processors in parallel. Many design variants were explored including 14, 16, and 18 vanes, strap placement and configuration, axial length, number of RF extraction rods, cathode radii, and an upstream RF choke. The process has yielded an optimum design that consistently oscillates in the π mode with no mode competition. Additionally, the device operates in a regime predicted by single particle Buneman- Hartree analysis. Analysis shows that electric field stresses remained below the Kilpatrick limit for simulations using input voltages below 52 kV, with maximums observed between the straps and anode as well as between the straps. The primary power loss mechanisms were found to be particle collisions with the slow wave structure and cathode, which accounted for a loss of nearly 10% of the input power.

216 10O2 RECIRCULATING PLANAR MAGNETRON EXPERIMENTS AND SIMULATIONS Ronald Gilgenbach1, Matthew Franzi1, Yue-Ying Lau1, David Chalenski1, David Simon1, Brad Hoff2, David French2, Geoff Greening2, John Luginsland3 1University of Michigan, Nuclear Eng. & Radiological Sciences, Ann Arbor, MI, USA, 2Air Force Research Lab, Directed Energy Directorate, Kirtland AFB, NM, USA, 3Air Force Office of Scientific Research, Plasma & Electroenergetic Physics, Arlington, VA, USA

A new type of high power microwave (HPM) magnetron has been experimentally demonstrated. The Recirculating Planar Magnetron (RPM) is based on two, linear magnetron-sections connected by recirculating- bends in a racetrack configuration. [1,2]. The magnetron sections are immersed in an axial magnetic field with a transverse electric field. The RPM has numerous advantages for High Power Microwave generation: 1) high currents at moderate current densities from large-area cathodes, 2) improved heat management on anode structures, 3) more efficient than linear magnetrons because electrons are recycled, and 4) scalable to higher powers and frequencies. An experimental RPM has been designed and constructed utilizing two-arrays of 6-cavities each at a pi-mode resonant frequency of 1-GHz. The RPM is driven by the MELBA generator at parameters: V = -300 kV, I = 1-20 kA, and pulselength = 0.3-1 microsecond. Initial experiments have shown 1-GHz microwave oscillation at currents exceeding 2 kA for hundreds of ns. Microwave power calibrations are underway. [1] R.M. Gilgenbach, Y.Y. Lau, D.M. French B.W. Hoff, J.W. Luginsland, and M. Franzi, "Crossed Field Device", US Patent pending [2] Ronald M. Gilgenbach, Yue-Ying Lau, David M. French, Brad W. Hoff, Matthew Franzi and John Luginsland, "Recirculating-Planar-Magnetrons for High Power, High-Frequency Radiation Generation", IEEE Trans. Plasma Science, V39, p980-987 (2011).

Research Supported by AFOSR, AFRL and L-3 Communications

217 10O3 SERIAL ARRANGEMENT OF FERRIMAGNETIC NONLINEAR TRANSMISSION LINES James-William Bragg, Christopher Simmons, James Dickens, Andreas Neuber Center for Pulsed Power and Power Electronics, Texas Tech University, Department of Electrical and Computer Engineering, Lubbock, TX, USA

Nonlinear transmission lines (NLTLs) utilizing ferrimagnetic materials for microwave generation have been realized as a possible solid-state replacement to traditional high power microwave (HPM) sources. The nonlinearities present in the material, along with interaction between pulsed, azimuthal magnetic fields and static, axial-biasing magnetic fields provide microwave (mesoband) generation with peak powers approaching 10 MW at 4 GHz center frequency. Additionally, an incident pulse of several nanoseconds is sharpened to hundreds of picoseconds. This study focuses on a serial arrangement of two NLTLs with 5 ns electrical length separation. Multiple NLTLs have been designed with varying length and material in order to achieve increased time of microwave generation. Additionally, two tested materials are known to produce two different operational frequency bands and the serial arrangement may provide a means to achieve increased bandwidth or dual band operation. A 40 kV incident voltage is applied to the setup with varying bias levels for each NLTL structure. The lines are terminated into a 50 Ω matched load. Measurements taken before and after each NLTL provide insight to the behavior of the travelling pulse. Results regarding peak output power, efficiency, and frequency of operation are discussed.

218 10O4 GENERATING OSCILLATING PULSES USING NONLINEAR CAPACITIVE TRANSMISSION LINES Ngee Siang Kuek1, Ah Choy Liew1, Edl Schamiloglu2, Jose Osvaldo Rossi3 1National University of Singapore, Department of Electrical & Computer Engineering, Singapore, Singapore, 2University of New Mexico, Department of Electrical & Computer Engineering, Albuquerque, NM, USA, 3National Institute for Space Research, Associated Plasma Laboratory, Sao Jose dos Campos, Brazil

A nonlinear lumped element transmission line (NLETL) that consists of cascading series linear inductors and parallel nonlinear capacitors can be used to produce oscillating pulses. This paper describes the implementation of such high voltage nonlinear capacitive lines (NLCL) using commercial-off-the-shelf (COTS) components. Instead of using complex pulse forming networks or pulse forming lines, a storage capacitor and a fast semiconductor switch are used to provide an input pulse into the cascading LC-elements of the NLCL with good approximation for rectangular pulse-shape characteristic. The design of the NLCL is based on the NLETL circuit model that has been developed in-house. Experimental results are compared with the simulated ones predicted by the NLETL model. The voltage modulation and the frequency content of the output pulses are analyzed. The conventional single NLCL produces a signal with a DC offset and a decoupling capacitor is needed at the end of the line to extract the AC component before injecting into a load such as an antenna. A novel method of directly extracting the AC component without the use of a decoupling capacitor is proposed and investigated. Results of this direct AC extraction, which show the possibility of better performance, are discussed.

219 10O5 3D FDTD SIMULATION OF A NLTL USING FERROELECTRIC MATERIALS IN RECTANGULAR WAVEGUIDE Byron Caudle, Michael Baginski, Hulya Kirkici Auburn University, Electrical and Computer Engineering, Auburn, AL, USA

This research describes the characterization of the transient peak pulse power propagation in an X-band waveguide filled with typical nonlinear ferroelectric dielectric. A three dimensional FDTD analysis served as the basis for the investigation where Maxwell's curl equations were solved explicitly using a first order backward difference method. The effect of the transient's voltage input magnitude and temporal signature were investigated with special focus given to the behavior of field propagation near saturation. Typical pulse propagation in linear materials results in the pulse undergoing attenuation and dispersion and the peak pulse power decaying as the wave propagates. However, nonlinear materials and the initial pulse may be selected to enhance the peak pulse power via spatial compression of the pulse. The initial results of the research clearly indicate a significant peak power enhancement. Additionally, this work will provide the framework for a power optimization algorithm that will focus on maximizing the peak pulse power of the transient.

220 10O6 GAS EVOLUTION OF NICKEL, STAINLESS STEEL 316, AND TITANIUM ANODES IN VACUUM SEALED TUBES Jonathan Parson, James Dickens, Andreas Neuber, John Walter, Magne Kristiansen Texas Tech University, Electrical and Computer Engineering, Lubbock, TX, USA

This paper presents a study on gas evolution of three different anode materials in vacuum sealed tubes. The system consists of a 200 kV, 80 J, low impedance Marx Generator and a triode- geometry vircator at a vacuum level on the scale of 10-9 torr. It was observed that the primary and secondary emissions form regions of localized plasma between the A-K gap that negatively affect tube operation: the gap impedance is lowered, the microwave performance suffers, and the low vacuum within the sealed tube is spoiled over time. The three anode materials tested are of nickel (Ni), stainless steel 316 (SS316), and titanium (Ti). To help identify the primary source for outgassing (anode or cathode), the cathode material, aluminum (Al), was kept the same for all experiments. Pre-conditioning treatments of the anodes consisted of surface smoothing by sand blasting, vibratory bathing, chemical baths and temperature bake-out at 300oC. The Ni, SS316 and Ti anodes were additionally treated by electro-polishing processes. All cathodes were treated by chemical bathing and high-temperature bake-out. Scanning electron microscope (SEM) images and energy-dispersive x-ray spectroscopy (EDAX) analysis were conducted on the anodes and cathodes before and after the experiments were completed. Gas evolution during the explosive emission processes was measured using a residual gas analyzer (RGA). In order to better resolve the gas evolution process time-resolved images of each anode / cathode combination of the primary and secondary emission were taken and are included in the discussion. These images reveal the instance in time when explosive emission occurs with respect to the corresponding voltage and current waveforms. The RGA results point to cracking patterns for nitrogen, carbon-monoxide, methane and hydrogen as the main outgassing species, and have been found to increase background vacuum to 10-5 - 10-6 torr. Traces of argon, hydrogen deuteride and carbon-dioxide were also collected by the RGA. As expected, the SEM and EDAX analysis reveal pitting and surface composition alterations to both anode and cathode.

Distribution A: Approved for public release

221 10O7 THREE-DIMENSIONAL PARTICLE-IN-CELL SIMULATION OF SUB- TERAHERTZ HIGH-POWER GYROTRON Koyu Ito, Weihua Jiang Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan

High power sub-terahertz pulsed gyrotrons are being developed for collective Thomson scattering (CTS) diagnostics of fusion plasmas. The typical target parameters are: output power 100~200 kW, operation frequency 300 GHz, and pulsed length > 10 us. In order to support experimental development, numerical simulations have been carried out by using three- dimensional particle-in-cell (PIC) code, "MAGIC". The oscillation mode of the electromagnetic radiation has been selected as TE15,2, for which the beam parameters and cavity dimensions have been determined accordingly. So far, the simulation results have shown maximum power of ~ 148 kW at oscillation frequency of 292.8 GHz, with conversion efficiency of ~ 22.84 %.

222 10O8 A DIELECTRIC RESONATOR ANTENNA BASED ON HIGH DIELECTRIC CONSTANT COMPOSITES FOR HIGH POWER, UHF ANTENNA APPLICATIONS Kevin O'Connor, Randy Curry University of Missouri-Columbia, Center for Physical and Power Electronics, Columbia, MO, USA

Dielectric resonator antennas incorporating newly developed high dielectric constant composite materials have been investigated as compact high power antennas for VHF and UHF operation. The dimensions of dielectric resonators can generally be reduced by the inverse of the square root of the dielectric constant. Through this fundamental relationship, low profile designs are possible with significantly lower volume and weight requirements than traditional antennas. By combining the benefits of the composite materials' high dielectric constants and their ability to be manufactured to the required size and shape of the resonator geometry, the frequency range of dielectric resonator antennas can be reduced below the conventional bands of operation of solid dielectric resonator antennas. The resonators are coupled with a microstrip feed, enabling the antenna input impedance and operating voltage to relatively easily be designed through the microstrip parameters. The paper provides an analysis of the use of high dielectric constant composite materials in microstrip-coupled dielectric resonator antennas, and the potential for high power operation at frequencies below 1 GHz is discussed. An overview of the design of a dielectric resonator antenna incorporating the high dielectric constant composite materials developed at the University of Missouri is given along with theoretical and experimental data on its performance.

Funding for this program was provided by the Office of Naval Research N00014-08-1-0267.

223 3P1 PULSED VOLTAGE DRIVEN ELECTROSPRAY Daichi Obata1, Asuki Nakamura1, Sunao Katsuki2, Hidenori Akiyama1 1Kumamoto University, Graduate School of Science and Technology, Kumamoto, Japan, 2Kumamoto University, Bioelectrics Research Center, Kumamoto, Japan

Electrospray is a method to produce fine droplets from liquid materials, which are commercially used for painting, pesticide spraying, ionizing target materials in mass spectrometry, etc. The formation of Taylor cone, which is the key issue in electrospray, depends on the hydrodynamic and electrical properties such as viscosity, surface tension and electric conductivity. For example, Taylor cone is not formed in conductive materials because the charge relaxation occurs in a characteristic time τcr = ε/4πσ, where ε and σ are permittivity and conductivity, respectively. For this reason, many kinds of conductive liquid materials are not applicable to spray by the conventional electrospray, which is driven by a direct current (DC) voltage. We are trying to use pulsed voltages superposed on DC in order to deliver plenty of electrical charge to the liquid within τcr, which is expected to result in the expansion of the range of materials to spray. Ethanol or water with a variety of conductivities was delivered to a stainless steel nozzle with inner and outer diameters of 80 and 200 μm, respectively, where the negative high voltages with various pulse durations were applied. The voltage applied to and the current flowing to the nozzle were monitored using a high voltage probe (Tektronix, P6015A) and a 1 MΩ shunt resister, respectively. The formations of Taylor cone and micro-droplets were observed using high-spatial- resolution shadow graph and light scattering methods, respectively. Our experiments show that dynamics of the liquids varies with the duration of the pulsed voltage. We have experimentally demonstrated the possibility of spraying liquid materials that cannot be sprayed by DC driven electrospray.

224 3P2 OPTIMIZATION OF CORONA RING DESIGN FOR COMPOSITE INSULATOR STRINGS USING KRIGING METAMODELING AND DIRECT ALGORITHMS Hanyu Ye, Markus Clemens Universität Wuppertal, Chair of Electromagnetic Theory, Wuppertal, Germany

High electric field intensities along a composite insulator surface, in particular at the high voltage end fitting, can result in electrical discharges on the silicone rubber surface. This is one of the important factors of degradation of the insulating material. One way of reducing this effect is to use of geometric field grading techniques such as corona rings to locally reduce the electric field and minimize the corona discharges. The improvement highly depends on the geometry of the corona ring, i.e., its design parameters. In this paper three parameters are considered in an optimization procedure: the ring radius, the radius of the ring tube and the distance between the ring and the energized end fitting. The 3D-FEM-Simulation Code MEQSICO [1] is used to accurately calculate electric field distribution along the insulator for the various corona ring design parameters. However, the 3D-simulations of large-scale high-resolution insulator models that realistically take into account coupling capacitances [2] are very time-consuming. Thus a global optimization scheme is adopted that uses a one-then-two stage Kriging metamodel [3] and the DIRECT (=DIViding RECTangles) optimization algorithm. This reduces the total number of 3D-simulations for the evaluation of given parameter sets and hence speeds up the optimization. The results are compared to other global algorithms without meta-models (such as genetic algorithms, DIRECT algorithm). [1] T. Steinmetz, M. Helias, G. Wimmer, L.O. Fichte, M. Clemens, "Quasistatic Electric Field Computations with Discrete Electromagnetism Formulations", IEEE Trans. Magn., Vol. 42, No. 4, pp. 755-758, April 2006. [2] D. Stefanini, M. Clemens, J.M. Seifert, "Three Dimensional FEM Electric Field Calculations for EHV Composite Insulator Strings", 2010 IEEE International Power Modulators and High Voltage Conference (IPMHVC 2010), 23.-27.05.2010, Atlanta, USA, pp. 238-242. [3] G. Hawe, J. K. Sykulski, "A hybrid one-then-two stage algorithm for computationally expensive electromagnetic design optimization", COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Vol. 26, No.2, pp. 236- 246, April 2007.

225 3P3 DEVELOPMENT OF SMALL DIMENSION HIGH-VOLTAGE ELECTRONIC VACUUM DEVICES Victor Bochkov1, Dmitry Bochkov1, Vladimir Nicolaev1, Vasiliy Teryoshin1, Piotr Panov1, Alexandr Batrakov2, Konstantin Karlik2, Grigory Ozur2, Dmitry Proskurovsky2 1Pulsed Technologies Ltd Ryazan, Russia, 2Institute of High Current Electronics RAS Tomsk, Russia

A reliability of high-voltage electron vacuum and gas-discharge devices – X-Ray tubes, neutron tubes, gyrotrons, thyratrons, accelerators, is mostly limited by hold-off voltage capability of the tubes. However the known manufacturing technologies do not allow to achieve a high hold-off voltage in a compact design. In order to cope with the problem it is essential to consider the whole lot of issues emerging when designing and manufacturing the devices and in particular interaction of processes on surface of high voltage electrode system, on surface and in the volume of dielectric envelope as well as processes outside the envelope. X-Ray tubes are typical representatives of high-voltage vacuum and gas-discharge devices. Therefore the work on creation of reliable compact X-Ray tube completely reflects basic trends of our investigations: Reduction of intensity of charged particles parasitic emission and improvement of vacuum insulation dielectric strength. For this purpose we use technology of modification of electrode surface structure and condition by thermo-processing with high-current (up to 30 kA) pulse (duration ~5 µsec), low-energy (up to 35 keV) large-area electron beam irradiation electronic beam down to the depth from 30 nm to 30 µm [1]. Improvement of hold-off voltage capability owing to influence of dielectric elements, in particular, tube envelope [2]. We use a specially- designed technology for coating of envelope internal surface by multi-layers consisting of metal oxides crystals, when each particle of the layer has on the surface a nano-layer of inert non- organic material – silicon oxide. · Development of impregnated and field-emission (carbon- graphite or metal-ceramic) nanostructure-based cathodes. · Application of methods for tube oil cooling without mechanical drive owing to electro-hydrodynamic effects. · Improvement of reliability of external medium in which the device is operated, in particular dielectric strength of transformer oil. In the report results of investigations of X-Ray ceramic-metal tubes for anode voltages of 160 kV and 250 kV with length of 150 mm and diameter of 55 mm are presented. The proposed solutions reduce intensity of charged particle parasitic emission and prevent high density charge accumulation inside the tube, thus providing sound reduction of dielectric envelope through-breakdowns possibility and high hold-off voltage capability. [1] Ozur G.E., Proskurovsky D.I., Rotshtein V. P., Markov A.B., Production and application of low-energy, high-current electron beams. Laser & Particle Beams, 2003, vol. 21, No. 2, pp. 157- 174. [2] Bochkov V.D. and Pogorel'skii M.M., "Study of the charge distribution over insulating envelope in a high-voltage vacuum device", Journal of Technical Physics (Russian), Vol. 69, No. 6, 1999, pp. 30-35.

226 3P4 OPTIMIZATION OF A CATHODE CONFIGURATION IN GAS INSULATED SWITCHGEAR WITH A PERMITTIVITY GRADED INSULATOR Chi-Wuk Gu, Jae-Ho Rhee, Heung-Jin Ju, Kwang-Cheol Ko Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea

An application of a functionally graded material (FGM) to the solid spacer in gas insulated switchgears (GISs) can reduce the electric field intensity [1]. Especially, the location of the high electric field concentration moves from the anode to the interface between the spacer and the gas, when the FGM spacer is used. However, the electric field stress near the triple junction of the cathode with a rounded shape, which remarkably affects the insulation capability of a GIS, increases reversely [2, 3]. Therefore, in order to prevent this, it is necessary to modify the cathode geometry in the common C-GIS. In this research, we dug a groove in the cathode near the triple junction, and performed the optimization of this cathode configuration by using the design of experiments (DOE). Additionally, the permittivity graded spacer with the permittivity variation of a reverse direction distribution unlike that of the existing unidirectional [2] or bidirectional [3] distribution was applied. Consequently, both the maximum electric field intensity generating near the inflection point of the spacer geometry and the electric field stress near the triple junction of the cathode can be efficiently reduced by using the FGM spacer and designing the optimal cathode shape. [1] M. Kurimoto, K. Kato, M. Hanai, Y. Hoshina, M. Takai, and H. Okubo, "Application of Functionally Graded Material for Reducing Electric Field on Electrode and Spacer Interface", IEEE Trans. Dielectr. Electr. Insul., Vol. 17, pp. 256, 2010. [2] H. J. Ju, K. C. Ko, and S. K. Choi, "Optimal Design of a Permittivity Graded Spacer Configuration in a Gas Insulated Switchgear", J. Korean Phys. Soc., Vol. 55, pp. 1803, 2009. [3] H. J. Ju, B. Kim, and K. C. Ko, "Optimal Design of an Elliptically Graded Permittivity Spacer Configuration in Gas Insulated Switchgear", IEEE Trans. Dielectr. Electr. Insul., Vol. 18, pp. 1268, 2011.

227 3P5 INTERRUPTING CAPABILITY OF VACUUM INTERRUPTER BY VARIOUS PARAMETERS Chi-Wuk Gu1, Kun-A Lee1, Heung-Jin Ju1, Kwang-Cheol Ko1, Cheol-Kyou Lee2 1Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea, 2Vitzrotech Co., Ltd. Ansan, South Korea

Vacuum interrupter (VI) has been commercially available in medium voltage switching equipment. Recently, the development of the VI is focused to reduce the size. Thus, it is necessary to comprehend the interruption phenomenon and moving speed of contact for aiming at applying to a smaller size contact. In this paper, we investigated the interruption behavior in the real VI with two different contact size of the transverse magnetic field (TMF) type which is widely used for interrupting the arc current in vacuum. Additionally, we investigated the interrupting capability according to the change of opening speed by using contact with the lower interrupting performance obtained from earlier tests. In our experiment, CuCr25 contact was applied, Weil-Dobke voltage superposition circuit was used for a short circuit current test. Through the correlation between the contact size and opening speed, we could design a smaller VI, and it was applied to 17.5kV 25kA vacuum circuit breaker (VCB).

228 3P6 EFFECTS OF CAPACITIVE VERSUS RESISTIVE LOADING ON HIGH TRANSFORMATION RATIO PIEZOELECTRIC TRANSFORMERS FOR MODULAR DESIGN CONSIDERATIONS James VanGordon1, Brady Gall1, Peter Norgard1, Scott Kovaleski1, Emily Baxter1, Baek Kim1, Jae Kwon1, Gregory Dale2 1University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA, 2Los Alamos National Laboratory, Accelerator Operations and Technology - High Power Electrodynamics, Los Alamos, NM, USA

Piezoelectric transformers (PTs) can be useful as compact, high-voltage supplies. However, PTs cannot be fully utilized if the associated circuitry does not allow for the desired transformation ratio to be maintained. At the University of Missouri, the effects of adding capacitive and/or resistive loads to a PT are being studied. Experiments and modeling suggest that the highest transformation ratios are achieved when both the resistive and reactive load elements are optimized, rather than only the magnitude of the impedance. Specifically, these effects are being studied to modularize the PT as a compact, high-voltage power supply for a variety of applications. This paper will analyze these loading effects and suggest a coupling method for maintaining high transformation ratios from Rosen-type PTs comprised of rotated y-cut lithium niobate.

Work supported by Nuclear Regulatory Commission, Qynergy, and Los Alamos National Laboratory.

229 3P7 DEVELOPMENT OF 100KV BIPOLAR CAPACITOR CHARGING SYSTEM Yinghui Gao1, Kun Liu1, Yaohong Sun1, Dongdong Zhang1, Ping Yan1 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China

Linear transformer driver technology is a newly developed pulsed power technology in recent years. Bipolar high-voltage switch is an important device in the linear transformer driver system. In order to do the aging test of the switch, a bipolar capacitor charging system was developed based on the high-frequency inverter technology. The output voltage of the system is ±100kV, and the difference between the positive voltage and the negative voltage is less than 2%. Generally such system is implemented through a bipolar transformer, but the difference of the positive and negative output voltage can not be adjusted through control mode once the transformer was manufactured, especially in high-frequency high voltage system in which the distributed parameters of the transformer is more difficult to control. In this paper a high- frequency bipolar capacitor charging system was developed by using two charging unit, one outputs positive voltage and another outputs negative voltage, both of them adopt the series resonant circuit and H-bridge phase shift control mode. The adjustment of the voltage difference is realized by controlling the charging rate of each charging unit, and the charging rate is controlled through the phase shift control of the H-bridge inverter. When the charging time and the preset voltage are input in the user interface and the start signal is sent out, each charging unit charges the capacitor according to the same charging curve to ensure the voltage difference is under the requirement. Experimental results are presented and discussed.

230 3P8

DESIGN AND TEST OF 2250KV SEMI-FLEXIBLE SF6 INSULATED HIGH VOLTAGE IMPULSE TRANSMISSION LINE Kun Wang1, Xupeng Song2, Jingbo Zhang2, Gensheng Lu2, Kefu Liu1 1Fudan University, Institute of Electric Light Sources, Shanghai, China, 2China Electronic Technology Group Corporation , No.23 Research Institute, Shanghai, China

An SF6 insulated high voltage impulse transmission line is described which is used in high power microwave and high power impulse technology. According to total request of system, transmission line adopt SF6 gas with 2.5MPa pressure as insulation and polyphenyleneoxide(PPO) as support between inner and outer conductor which use corrugated structure with some depth to improve the flexibility. For safety in application, stainless steel material is used as tension component. Test verified that loss of transmission is 0.016dB/m when transmitting a signal with 3ns impulse width, 1kHz repetition frequency. Characteristic impedance of transmission line is 48.2Ω.furthermore flange and transition connecter is discussed in the paper for application. In the following work, breakdown strength of SF6 gas with different pressure under impulse high voltage will be studied in order to compare to data under AC and DC situations, so as to achieve breakdown theory of SF6 gas under some impulse high voltage situations.

231 3P9 FDTD ANALYSIS OF LIGHTNING TRANSIENT ELECTROMAGNETIC FIELD ON THE TRANSMISSION LINE Hao Wu, Chen-guo Yao, Qian-bo Xiao, Yan Mi, Chen-xiang Li, Jian Li State Key Laboratory of Power Transmission Equipment ＆ System Security and New technology, College of Electric Engineering Chongqing University, Chongqing, China

Lightning has become one of the major reasons which cause the power grid failures. Lightning parameters measurement of the transmission line is the foundation of lightning protection research. It can supply the original accurate data to study the lightning characteristics, analyze the reason of the lightning accident, identify the responsibility of the lightning accident and design the insulation of the transmission line. So, it plays a very important role. In this paper, the distribution of the lightning transient electromagnetic field around the transmission tower is simulated by the finite-difference time-domain (FDTD) method based on an established model reference to an actual 500kV transmission tower. The magnetic field signal obtained by setting a series of detection points has been compared to the signal's current flowing on the transmission lines. The analysis results stimulated and calculated show that when lightning striking on phase of wires, waveform of the magnetic field strength at the detection points are the same as the current flowing on the lines, and the amplitude of the magnetic field exhibits a stabile linear relationship with the current. Additionally, all the detection points located in the space around the tower can completely get current waveform flowing on the transmission lines. Moreover, the amplitude and the polarity of the waveform at the detection points have different characteristics when the different phase of wires has been stroked by the lightning. At last, a lightning fault pattern recognition method which can figure out the lightning fault phase accurately is established based on the magnetic field waveform characteristics obtained from the detection points.

232 3P10 NUMERICAL MODELING OF UHV LABORATORY TO EVALUATE THE RATING OF HV EQUIPMENT Adusumilli Pradeep1, Shreeharsh Mallick2, H S Jain1 1Bharat Heavy Electricals Limited, High Voltage Engineering, Hyderabad, India, 2University of Florida, Lightning Research Group, Gainesvile, FL, USA

The design of a high voltage laboratory depends on a number of factors viz. maximum test voltage level, size of test equipment and clearances between the live terminals and grounded structures such as walls, ceiling, and other non-energized test equipment. The energy requirements of the test equipment depend on the loading conditions (test object, voltage divider, and stray capacitances). The stray capacitances play an important role in determining the field distribution in the laboratory and also in evaluating the specifications of HV equipment. Owing to the large structure of UHV laboratory it is very important to optimize the design of the test laboratory to accommodate all the equipment with required safety margin and economic considerations. Bharat Heavy Electricals Ltd. (BHEL), Corporate R&D, Hyderabad, India recently established an indoor UHV laboratory, to test Gas-Insulated Switchgears (GIS) and other power apparatus during the in-house development process for equipment up to 765 kV voltage class. Initial studies were carried out to determine the specifications of test equipment (primarily impulse voltage generator or IVG) and corresponding UHV laboratory dimensions. Studies were also done to verify the performance of the IVG under different loading conditions (for both lightning and switching impulse tests), keeping into account the effect of stray capacitance. Based on the evaluated results, the laboratory dimensions were chosen for appropriate switching impulse ceiling-wall clearances. In this paper, the authors describe the modeling and simulations carried out to arrive at the optimum values for the specification of IVG and the dimension of the laboratory. A 3D numerical model of the laboratory configuration was used to calculate stray capacitances and a PSPICE simulation was carried out to study the effect of stray capacitance on performance of the IVG. Experiments will be carried out to validate the calculated values obtained from modeling/simulation in the design process.

233 3P11 STUDY OF LIGHTNING INDUCED OUTAGE IMPROVEMENT FOR A 220KV TRANSMISSION LINE Goru Radhika1, Mungala Suryakalavathi2 1VNR VJIET, EEE, Hyderabad, India, 2JNTU, EEE, Hyderabad, India

High Voltage Electric Power Transmission is the bulk transfer of electrical energy, from generating plants to substations located near to population centers. It is essential for the designers of transmission network to reduce the number of outages and preserve the continuity of service and electric supply. Lightning has been one of the important problems for insulation design of power systems and it is still the main cause of outages of transmission and distribution lines. A Lightning flash generally consists of several strokes which lower charges, negative or positive, from the cloud to the ground. The lightning surge causes the traveling waves and the temporary increase in voltage in the transmission line system. Lightning is the most harmful for destroying the transmission line and setting devices so it is necessary to study and analyze the temporary increase in voltage for designing and setting the surge arrester. When a direct lightning stroke occurs on a tower, the tower has to carry huge impulse currents. If the tower footing resistance is considerable, the potential of the tower rises to a large value, steeply with respect to the line and consequently a flashover may take place along the insulator strings. This is known as back flashover. Back flashovers account for a large share of the faults experienced by high voltage transmission lines (TL). The prediction of back flashover is a complex task due to the interaction of random multiparameters. The objective of this paper, is to design a 220kV transmission model, which includes all the components of the Transmission line i.e phase and ground conductors, insulator strings, line towers associated grounding systems and a surge of 100KA, 4/10 µs. The transmission tower with one OHGW was found to give high over voltage across insulator compared to two OHGW. So tower with two OHGW was taken in this work. Back flash over mechanism is modeled and triggered to the existing system by an external control module with powerful electrical tool PSCAD/EMTDC. Metal Oxide transmission line arresters were used in this work as a solution for the back flashover. However, considering acceptable probabilistic failure as one outage per year per 100km line length, and suggested basic insulation level (BIL) of 1050KV, the arrester rating was calculated to be 196KV and its parametric determination for a one column arrester with an overall length of 1.45 meters is done. Simulation is carried out by placing Metal Oxide Arrester on each line and compared in terms of voltage levels, Arresters being placed in all the three phases. The overall simulated results will demonstrate the importance of having transmission line arresters for protection against back flashovers.

234 3P12 ELECTRIC FIELD STRESS ANALYSIS ON THE SURFACE OF A COMPOSITE CONE TYPE SPACER IN GAS INSULATED SUBSTATION FOR A FIXED SPHERICAL AND A WIRE LIKE PARTICLE Duvvada Deepak Chowdary1, Jinka Amarnath2 1Dr.L.B.College of Engineering For Women, Electrical & Electronics Engineering, Visakhapatnam, India, 2Jawaharlal Nehru Technological University, Electrical & Electronics Engineering, Hyderabad, India

The shape of a spacer, used in the Gas Insulated Substation (GIS) as a supporting insulator between the inner conductor and outer enclosure, plays a critical role for obtaining uniform field along its surface. Shape control, is a technique to obtain uniform stress field distribution along spacer surface. In GIS, triple junction formed by electrode, insulator and gas is considered to be one of the critical point at which electric field stress will be high. Metal inserts and recessed electrodes are employed to mitigate the effects of field stress at anode and cathode triple junctions. Insulation integrity of compressed GIS may be affected due to the presence of metallic particles adhering on to the surface of the spacer. Knowledge of Electric field stress distribution along the surface of the spacer in the presence of conducting particle gives a better insight about the dielectric performance of the system. In this paper first a composite cone type spacer is designed geometrically to obtain uniform field stress distribution. Metal Inserts and recessed electrodes are incorporated to reduce the electric field stress at anode and cathode triple junctions. Field stresses on the surface of the spacer and at the anode and cathode triple junctions are computed in the presence and absence of metal inserts and recessed electrodes while the spherical and wire like particles are considered to be present on the surface and at the triple junctions. Finite Element Method (FEM), one of the proven numerical method, is used for computing the electric fields at various points under consideration.

235 3P13 ANALYSIS TO CORE SNUBBER BASED ON DELTAMAX Fei Xie12, Hongwen Yuan1, Ge Li1, Desheng Cheng1, Jinling Chen1, Qiangjian Chen1 1Chinese Academy of Sciences, Institute of Plasma Physics, Anhui, China, 2Shunde Polytechnic, Department of Electronic and Information Engineering, Shunde, China

Deltamax material is a kind of magnetic material for core snubber which has high flux density swings as well as high magnetic permeability below 1MHz. The theory for core snubber is developed by Fink, Baker and Owen (FBO model) in 1980 which considers only the snubber resistance effects and gives the snubber design under saturation condition. Core snubber is one of the most important devices in EAST(Experimental Advanced Superconducting Tokamak) NBI which select Deltamax as its candidate core material. This device is designed to protect the neutral beam injector system during the period of high voltage breakdown. The paper proposes an approach to limit the high voltage breakdown effects, based on the concepts of the equivalent resistance and inductance in parallel mode implemented with Deltamax cores. The fault peak current is higher than the original FBO model after take it into account, so the introduction of coefficient instead of parallel inductance can amend the original design model. After that, the EAST NBI circuit fault simulation code is primarily established which could simulate fault conditions with above time-varying resistance and inductance. The code is calibrated with the test results. Based on above work, the ion source snubber is designed with Deltamax. This snubber is tested at 80.6 kV with 4nF discharged capacitor. After that, 50kV experimental validation in real NBI system is tested, the peak short current is within 300A which has larger gradient capacitor. The results show that it can protect ion source within 50kV, and can protect the ion source in 100kV reliability if being configured with double snubber architecture, together with the filament snubber for the whole NBI line.

236 3P14 MHZ-LEVEL REPETITIVE MODULATORS FOR ACCELERATOR APPLICATIONS Weihua Jiang, Akira Tokuchi Nagaoka University of Technology, Extreme Energy-Density Research Institute, Nagaoka, Japan

Highly repetitive pulsed high-voltage modulators are being developed for accelerator applications. They use power semiconductor devices as switches combined with inductive-energy storage scheme. Typical operation parameters are: peak output voltage 1~10 kV, peak output current 20~200 A, pulse width (FWHM) 3~10 ns, maximum repetition rate 3 MHz (burst of 1000 pulses with repetition frequency of 50 bursts per second). The circuit design details and test results will be reported at the conference. This work is partially supported by High Energy Accelerator Research Organization (KEK).

237 3P15 DEVELOPMENT OF HIGH PERFORMANCE ELECTRON BEAM SWITCHING SYSTEM FOR SWISS FREE ELECTRON LASER AT PAUL SCHERRER INSTITUTE Martin Paraliev, Christopher Gough Paul Scherrer Institute, Large Research Facilities, Villigen PSI, Switzerland

A compact X-ray Free Electron Laser (SwisFEL) project is under development at the Paul Scherrer Institute. Its goal is to meet the demand in applied science for shorter and higher brightness X-ray pulses. To increase facility efficiency the main linac will operate in two electron bunch mode. The two bunches are separated in time by 28 ns and sent to two undulator lines. The combination of two beam lines should produce short X-ray pulses covering wavelength range from 1 to 70 Å with submicron position stability. To separate the two bunches, a novel electron beam switching system is being developed. The total deflection is achieved with a combination of high Q-factor resonant deflector magnet, followed by a DC septum magnet. The shot-to-shot deflection stability of the entire switching system should be better than +/-10 ppm in amplitude and +/-100 ps in time, values which present severe measurement difficulties. Deflection magnets requirements, development and results of the kicker prototype are presented.

238 3P16 A STABILITY OF LCLS LINAC MODULATORS Anatoly Krasnykh, Franz-Josef Decker, Ben Morris, Minh Nguyen SLAC National Accelerator Lab Menlo Park, CA, USA

To mitigate a jitter specification for LCLS user run, a pulse-to-pulse data acquisition of energy and bunch length measurements is employed. This system allows be happy most of the LCLS users. However to understand of main sources of the pulse to pulse jitter in the multi distributed LCLS system is needed for further perfection. As it is shown in [1] our current LCLS components under consideration are processes in the high power RF loads which terminate the unused accelerating RF power and 6575 modulators. Efforts concerning to RF load issues will be presented on LINAC2012. Subjects concerning the modulator stability will be discussed on this conference. We will discuss three approaches which had been experimentally studied. An evidence of a 0.033 rms RF phase pulse-to-pulse jitter will be shown. [1] F.-J. Decker et. al. "Indentifying Longitudinal Jitter Sources in the LCLS Linac", IPAC 2010, May 2010.

239 3P17 SNS LEBT CHOPPER PULSE WIDTH LIMITATION Vladimir Peplov, Robert Saethre ORNL Oak Ridge, TN, USA

In the SNS linac the beam shall be chopped in the manner which supports accumulation of protons in the accumulating ring and then accurate extraction of charged particles from the ring to send them to the SNS target. The Low Energy Beam Transport (LEBT) chopper system uses four identical pulsed power supplies (pulsers) to create the required series of bipolar HV pulses to four chopper electrodes to deflect the beam. Each pulser supplies a +/- 3 kV pulse or ground to an electrostatic einzel lens split into four quadrants to deflect the beam for 200 ns to 1 us. The SNS linac timing system provides a series of input trigger signals of different widths to drive the pulser's MOSFET switches. The width of the pulser's output pulse should be variable for multiple purposes such as change of average beam energy delivered to the target or for a beam study processes. Lower and upper pulse width limits for the chopper system depend on the characteristics of the pulsers, LEBT load, beam energy, extraction kicker and timing system. This paper presents estimations of timing limits for the existing chopping system and the possible ways to increase a range of used pulse widths are discussed.

240 3P18 KLYSTRON MODULATOR DESIGN FOR THE LOS ALAMOS NEUTRON SCIENCE CENTER ACCELERATOR William Reass, David Baca, Daniel Rees, Edward Partridge Los Alamos National Laboratory, AOT-RFE, Los Alamos, NM, USA

This paper will describe the design of the 44 modulator systems that will be installed to upgrade the Los Alamos Neutron Science Center (LANSCE) accelerator RF system. The klystrons operate at 85 kV with a nominal 32 Amp beam current and up to a 120 Hz repetition rate at a 15% duty cycle. The klystrons are a mod-anode design. The modulator is designed with analog feedback control to ensure the klystron beam current is flat-top regulated. To achieve fast switching whilst maintaining linear feedback control, a grid-catch, totem-pole modulator configuration is used with an "on" deck and an "off" deck. The on and off deck modulators are of identical design and utilize a cascode connected planar triode, cathode driven with a high speed MOSFET. The derived feedback is connected to the planar triode grid to enable the flat-top control. Although modern design approaches suggest solid state designs may be considered, the planar triode (Eimac Y-847B) is very cost effective, is easy to integrate with the existing hardware, and provides a simplified linear feedback control mechanism. The design is vary compact and fault tolerant. This paper will review the complete electrical design, operational performance, and system characterization as applied to the LANSCE installation.

241 3P19 INJECTOR SYSTEM FOR THE POLISH SYNCHROTRON RADIATION FACILITY 'SOLARIS' Piotr Tracz1, C.J. Bocchetta1, P. Goryl1, L. Walczak1, A. Wawrzyniak1, M. Eriksson2, D. Kumbaro2, L. Malmgren2, J. Mooder2, S. Thorin2 1The Jagiellonian University, SOLARIS, Krakow, Poland, 2The Lund University, MAX-lab, Lund, Sweden

The injector system for SOLARIS, the new synchrotron radiation facility being built in Krakow Poland, will be presented. SOLARIS will be equipped with a linear injector and a storage ring operated at an electron beam energy of 1.5 GeV. The SOLARIS injector will be constructed in a modular way. It will be divided into three RF stations. Each station consist of S-band klystron with a solid-state pulse power modulator, followed by a SLED unit and a power divider. The modulator delivers RF power of 35 MW with a pulse length of 4,5 µs and will have a repetition rate that can be up to 100 Hz. The three RF stations will feed six S-band linear accelerating structures each giving an energy gain of 100 MeV. The electron source will be a 3 GHz thermionic RF-gun and a magnetic energy filter will be used. The SOLARIS injector will initially be operated at the electron beam energy of 550 MeV with options for a full energy (1.5GeV) upgrade with the supplementary RF stations and accelerating structures. The SOLARIS synchrotron radiation facility is based on a copy of the 1.5 GeV storage ring being concurrently built for the MAX-IV project in Lund, Sweden.

242 3P20 A HIGH-REPETITION RATE PULSED ELECTRON ACCELERATOR Gennady Remnev, Ivan Egorov, Marat Kaikanov, Evgeny Lukonin, Victor Esipov, Artem Poloskov Tomsk Polytechnic University, High Technology Physics Institute, Tomsk, Russia

A new 50 Hz high-intensity electron beam accelerator with the beam ejection into the atmosphere has been developed for radiation technology application. A high-voltage nanosecond pulse generator of the accelerator is based on a low-inductance pulse transformer. The energy stored in the primary capacitor bank is 80J. A cold cathode thyratron is used as a switcher. The diode consists of a metal-ceramic cathode which provides a high delay time in the plasma formation. The electron beam current pulse duration at half height is 80 ns. The kinetic energy of the electron beam is 400 keV. The cooling system of the anode is used, which makes it possible to extract en electron beam with a current density of 30 A/cm2 into the atmosphere. The accelerator is capable to operate in a long-term-repetition rate producing 50 pulses per second is possible due to the use of a built-in system of regeneration and cooling of the transformer oil. The results of studies of the stability of beam parameters in the frequency mode are presented. The use of the accelerator as a source of pulsed X-ray radiation is considered.

243 3P21 30 KV COAXIAL PULSED PLASMA ACCELERATOR FOR DIAGNOSTICS AND APPLICATIONS OF MATERIAL PROCESSING Anuar Zhukeshov, Assem Amrenova, Asylgul Gabdullina Kazakh National University, Physics Faculty, Almaty, Kazakhstan

The pulsed plasma accelerator (PPA) with energy storage capacity 70 uF, 30 kV created for obtaining of powerful plasma flows. High power fluxes (up to 60 J/cm2, 14 us) generated by PPA, have been used in different applications such as surface erosion, spraying and modification. The performance of a PPA strongly depends on the geometry of its electrode system as well as on the mode of its operation. In this work investigate the "continuously filled" mode, and then the working gas fills all space between to coaxial electrodes (diameter 9 and 3 cm, length 50 cm). The mainly plasma parameters are: maximum flow velocity 9,6 cm/us, electron temperature ~ 10 eV, density of plasma ~1015 cm-3. The researches are shown, that the plasma parameters and the plasma formation peculiarities depended on initial gas pressure. So, when the pressure in the chamber below 10-1 Torr the distribution of current has diffused type and plasma has the maximum parameters specified above. At higher pressure current distributed predominantly in radial direction, but the plasma have significantly lower parameters. Studies using high voltage dividers and magnetic probes have shown that in accelerator there are HF fluctuations which have a significant influence on the process of acceleration. We investigated the role of inside electric fields on plasma formation process and it accelerating, too. The parts of researched devoted to problem of material processing and modification of it properties. As same case, the microhardness of common steels, irradiated by plasma fluxes, improved up to 5-7 times, and the depth of modification up to 200 um.

244 3P22 SNS LEBT CHOPPER FAILURE MODES AND IMPROVEMENTS Robert Saethre, Vladimir Peplov Oak Ridge National Laboratory, Research Accelerators Division, Oak Ridge, TN, USA

The Low Energy Beam Transport (LEBT) [1] Chopper for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory has experienced failures of the power semiconductors within the Tri-state pulsed power supplies. These power supplies produce a +/- 3 kV pulse or ground to an electrostatic einzel lens split into four quadrants to deflect the beam for 200 ns to 1 us. The four power supplies are ac coupled to the lens and a -50 kV dc supply for steering offset. This paper discusses the failure modes and improvements to mitigate future failures.

245 3P23 EMI NOISE REDUCTION IN INTEGRATED 6 KHZ SOLID STATE PULSED POWER SYSTEM Hao Chen, Byron Yakimow, Paul Melcher Cymer Inc San Diego, CA, USA

Solid state pulsed power systems have been designed and implemented in Cymer's Deep Ultraviolet (DUV) lithography light source products for over 20 years. Product reliability is critical for semiconductor photolithography processing and is driven by a host of factors including reliable operations of the solid state pulsed power and control systems. The reliability of the integrated system depends not only on its dedicated pulsed power designs (for example, charging system, magnetic compression pulse forming network (PFN), thermal management, etc.), but also on the impact of the electro-magnetic interference (EMI) to its internal sensors and the communication of the control system. Unfortunately, at times, the conventional EM noise suppression designs may prove to be insufficient to ensure robust operations of the integrated systems in the harsh environment created by high voltage pulse transient discharges. Additional effort to identify the noise sources and mitigate their adverse effects may be required. Recent design changes to the saturable reactor assembly within the Cymer's pulsed power system yielded improvement to its long-term sustainability. Thus how to enhance the noise filtering and grounding designs of the reactor thermal sensor control loop and make it compatible in the new environment is an interesting topic. This paper presents the recent investigation of EMI from the 6 kHz pulsed power system and displays the viable solutions and designs for reducing the noise susceptibility of the integrated system.

246 3P24 METHOD OF CURRENT TRANSFORMER METROLOGICAL PROPERTIES ESTIMATION FOR TRANSFORMATION OF DISTORTED SIGNALS Michal Kaczmarek Technical Univeristy of Lodz, Instytute of Electrical Power Engineering, Lodz, Poland

In low power quality conditions instrument transformers are transforming distorted signals. For distorted currents / voltages some constructions of instrument transformers in certain operating conditions are characterized by significantly worst metrological properties. Standardization recommendations concerning instrument transformer do not specify requirements for estimation of their accuracy of distorted signals transformation and limiting values. Therefore, it is necessary to develop and test appropriate measuring methodology and standardization recommendations of current transformer metrological properties estimation for transformation of distorted currents. Accuracy of instrument transformers for the transformation of distorted signals can be carried out based on direct measurements of current or voltage harmonics r.m.s. value or phase angle regarding the primary harmonics of transformed signal. However, this method is still not sufficiently precise and require complex and expensive measuring system, which allows simultaneous measurement of the r.m.s. values and phase shifts of particular harmonics of primary and secondary signals. Estimation of instrument transformer metrological characteristics during the transformation of distorted signals with the content of higher harmonics of conductive disturbances from selected frequency range can be also conducted on the basis of the designation of the accuracy of transformation for sinusoidal signals from the same frequency range. This paper presents a new method for evaluating the metrological characteristics of current transformers during the transformation of distorted currents based on the determination of the composite error. As defined in IEC 60044-1 for steady-state conditions the composite error is the r.m.s. value of the difference between the instantaneous values of the primary current, and the instantaneous values of the actual secondary current multiplied by the rated transformation ratio. The numeric value of the composite error will never be less than the vector sum of the current error and the phase displacement. Consequently, the composite error always indicates the highest possible value of current error or phase displacement. Accepted accuracy classes for tested CTs are same as requirement in IEEE C57.13 for the current transformer correction factor measured in condition of secondary winding load power factor equal 1.0 for 10% and 100% of rated primary current.

247 3P25 ANALYSIS OF THE INFLUENCE OF THE LEVEL OF SIGNAL DISTORTION ON CURRENT ERROR AND PHASE DISPLACEMENT OF INDUCTIVE CURRENT TRANSFORMERS Kaczmarek Michal Technical Univeristy of Lodz, Instytute of Electrical Power Engineering, Lodz, Poland

Current / voltage error and phase displacement in accordance with the instrument transformer standard C57.13 are measured for sinusoidal signals of frequency 50 Hz. Due to increased level of conductive disturbances in currents and voltages of the power network accurate transformation of distorted signals and especially its main harmonics - 50 Hz in such conditions through instrument transformer is demanded. To determine the metrological properties of instrument transformer in condition of distorted signals transformation, as a total difference between primary and secondary signals, composite error may be used. If accuracy of higher harmonics transformation by tested instrument transformer is not important, just for 50 Hz main harmonic of the transformed signal, the change in current / voltage error and phase displacement in relation to their value in condition of sinusoidal signal of frequency 50 Hz transformation may be measured. In some operating conditions conductive disturbances causes an increase of some constructions of current transformer (CT) current error and phase displacement, but even then, for main harmonic, CT should met the requirements of corresponding accuracy class. The aim of the research is to determinate the influence of conductive disturbances on errors of the inductive CTs of current ratios 300 / 5 A and 100 / 5 A. During the laboratory studies to the supplying voltage of the tested CTs primary winding additional conductive disturbances are brought. Their level from the programmable power supply is selected in order to the proper value of the THDU factor. During the laboratory studies for the load of the tested CTs resistors are used. Analysis of the results from the laboratory studies shows, that conductive disturbances in the CT primary current, in some measuring conditions, cause increase of its current error and phase displacement and decrease of accuracy for 50 Hz main harmonic. One of the solutions to this problem is the decrease of the tested CT secondary winding rated load in relation to the conditions when CT is used for transformation of sinusoidal current of frequency 50 Hz. The main reason of this phenomena is the change of the magnetic circuit properties of the current transformer for distorted current in relation to its properties for sinusoidal current.

248 3P26 AN EMPIRICAL STUDY ON EVALUATION METHOD FOR AGING MEDIUM LARGE POWER TRANSFORMER Chang Jeong-Ho1, Lee Sung-Hun1, Oh Seung-Chan2, Lee Hyo-Sung3, Lee Heung- Ho3 1Korea Water Resources Corporation, Daejeon, Korea, 2Corporation Korea Atomic Energy Research Institute, Daejeon, Korea, 3Chungnam National University Daejeon, Korea

Today, a new water supply project is setting on the slow growth of construction and the aging of power equipment has been increased, so we need more efforts to sustain the stability of system performance. Therefore, a reasonable asset management of power equipment has become a necessity. Asset management is great way to fulfill the economic investment and the stability of system performance. The asset management is separated by three parts of essential elements: management, engineering and information. The corporate of these parts should be practiced that seek to balance. This Study presents a standard algorithm for an efficient condition evaluation of oil-immersed power transformer in the technical aspects. Make use of this result, the equipment will be decided to be replace or repair otherwise on service. This application of effective asset management considering technical evaluation such as condition assessment and aging evaluation makes a significant contribution to reliability assessment of the condition of oil-immersed power transformer.

249 3P27 INVESTIGATIONS INTO NON-DESTRUCTIVE MODIFICATION OF CAPACITOR BANK OUTPUT INDUCTANCE AT THE NRL MATERIALS TESTING FACILITY Brett Huhman1, Richard Cairns2, Scott Douglass2, Jess Neri1 1US Naval Research Laboratory, Plasma Physics Division, Washington, DC, USA, 2Soterra Defense, Inc, Crofton, MD, USA

The Materials Testing Facility (MTF) at the U.S. Naval Research Laboratory (NRL) has experimented with inductor modifications to maximize the output performance of a capacitor bank, the configuration of which is discussed in [1]. NRL was provided the opportunity to replace a standard 80-µH inductor on a capacitor bank with a combination of two 33-µH inductors to form an effectively lower inductance of 65-µH. To install these inductors, substantial design modifications were made and the effect of the modified capacitor bank was noticeable on load testing. The resistance of the two smaller inductors is high enough that the modified capacitor bank acts like a resistor modification similar to [2] has been installed on the bank. While the L/R time has not been reduced as much as [2], it is still sufficiently higher than the stock MTF capacitor bank to affect the load, significantly lowering the current at the end of the test pulse. The effect of the resistance will be shown at various power levels and the resulting effect on switch action, capacitor voltage reversal, and output current will be demonstrated. Computer modeling of the modifications will also be discussed. The objective of a second modification was much simpler, which involved changing the effective inductance of a standard MTF inductor by inserting a metal tube inside the coil. The inductance was lowered to increase the current output, thereby increasing the utility of the existing hardware. By using an easily adjustable tube, the inductance can be tuned without needed to purchase new inductors or restrict experimental operations by using extensive modifications. Discussion will include computer modeling of the tube design and comparison of experimental data to circuit models. [1] B.M. Huhman, J.M. Neri. "Effect of Fuse Resistance on EML Capacitor Bank Solid-State Switching," Proc. IEEE Intl. Power Modulators and High Voltage Conf., 2008, pp.89-92. [2] B.M. Huhman, J.M. Neri, and T.L. Lockner. "Effect of Resistance Modification on EML Capacitor Bank Performance," in Proc. IEEE Intl. Pulsed Power Conf., 2009, pp.757-762.

Work supported by the US Office of Naval Research and the Naval Research Laboratory Base Program.

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

250 3P28 SHOCK COMPRESSION OF GAS-IMPREGNATED SOLIDS David Rice, Scott Kovaleski, John Gahl University of Missouri, Electrical Engineering, Columbia, MO, USA

Research is being conducted at the University of Missouri to assess the effects of shock waves on gas-impregnated solids. A test stand has been constructed to deliver capacitively stored energy to a copper foil load. When the copper foil vaporizes and expands, a flyer plate is launched and collides with a gas-impregnated target. An RLC circuit was designed to minimize the effects of non-critical damping and variable impedance of the vaporizing copper foil while delivering the energy needed to accelerate the flyer plate. Velocity data was collected with a framing camera and correlated with the mass of the flyer plate and the charge voltage. This data makes it possible to determine the velocity in future experiments when the target is blocking the line of sight of the framing camera. This paper will discuss the RLC circuit design and suggest techniques to minimize the effects of an underdamped circuit.

251 3P29 EXPERIMENTAL RESULTS OF EXTREMELY COMPACT FERROELECTRIC GENERATOR BASED PULSED SYSTEMS Allen Stults1, Sergey Shkuratov2, Jason Baird2 1US Army, AMRDEC, Redstone Arsenal, AL, USA, 2Loki Rolla, MO, USA

Independent government verification testing was conducted at Redstone Arsenal as part of an on- going development of a ferroelectric generator based, extremely compact explosive pulsed power system. Electric field measurements at ten meters in both horizontal and vertical polarization were recorded. A total of fifteen shots were made with very good results. Data gathered confirmed that the Loki design could provide a broadband pulse at the design to 400 MHz in excess of 50kV/m peak-to-peak.

252 3P30 ANALYSIS TO THE EAST NBI TRANSMISSION LINES Cheng Desheng, Li Ge, Cao Lei, Xie Fei 1Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China

EAST neutral beam injector (NBI) is a special pulsed load under high-voltage and high-power, there is about 6 MW electric power to be transferred into the EAST NBI by transmission lines floating at 100kV high potentials with aluminum shield. The maximum loading mode is 100s on and off for 300s. In the Stage of beam extracting the breakdown phenomenon is occurred frequently. The fault is often attenuated with snubber whose design is based on the stray capacitance of the NBI system. On the other hand, Due to the huge transferred currents, the heat sink of the transmission line will have great effect on the state of EAST-NBI system. Therefore, some design requirements should be analyzed for safety work of the transmission lines under normal and fault conditions, the major work of this article is as follow: 1) The stray capacitance of transmission lines is analyzed by analysis and simulation method, it will provide design basis for the protection device to absorb the storage energy in the capacitor. 2) Electromagnetic environment is analyzed for transmission lines, which gives the structure, the shield and the ground of the transmission line. 3) The heat stabilization due to the voltage drop is analyzed for the transmission line under above load mode, which gives the primary design of EAST NBI transmission lines. Key words: EAST (Experimental Advanced Superconducting Tokamak); Neutral Beam Injector (NBI); Transmission lines, Stray Capacitance.

253 3P31 AN ACTIVE JITTER DAMPER OF SWITCHES OF LTD BASED ON TRANSFORMER COUPLING EFFECT Yue Zhao, Liangji Zhou, Lin Chen, Meng Wang China Academy of Engineering Physics, Institute of Fluid Physics, Mianyang, China

The Linear-Transformer-Driver is gaining importance with regard to its unique merits. Such as low impedance, fast rise time, well compatibility with magnetically insulated transmission line and robustness. The LTD is fact of a kind of Inductive-Voltage-Adder, which is based on multiple discharge branches. Each branch consists of an energy storage capacitor and a switch. All branches are isolated by an unsaturated magnetic core. When switches are triggered, all capacitor discharge in parallel simultaneously. Synchronization of massive switches of LTD is a huge challenge. In the paper, source of jitter of spark-switches is discussed. It is supposed that switch delays fit normal distribution, the waveform's rise time and peak current are related with jitter by numerical simulation. A transformer coupling device is developed for jitter damping is presented. Jitter of switches is suppressed less than sub-nanosecond with a multi-wing transformer, but the number of branches is limited by the dimensions of transformer core, and the disposal is inconvenience. So we developed a novel transformer coupling device that includes a number of transformer ,which is equal to number of branches, each transformer has only one primary and secondary coil. The dotted terminal of transformer is connection in parallel or in series has enormous impact on waveform's rise time and current peak value. It is proved that the transformer coupling device with series dotted terminal connection is properly for massive switches jitter damping by numerical simulated analysis.

254 3P32 COMPACT ELECTRIC POWER SYSTEM FOR TOKAMAK Ge Li Institute of Plasma physics, Chinese Academy of Sciences Hefei, China

The International Thermonuclear Experimental Reactor (ITER) is now implemented with Tokamak which requires about 1 GVar reactive power to compensate its power system for superconducting magnets where about 0.25GVar is transferred from France Electrical Power Network, the other 0.75GVar is generated by the system of Reactive Power Compensation and Harmonic Filtering, the standard VSC configuration. ITER can experimentally generate 500MW fusion thermal power in 400s long pulse mode with about its one half construction area for its power suppliers. It could only generate about 500MW/3=167 MWe active electric power if it is to be configured with pressured water reactor due to that it is only about 1/3 conversion efficiency from thermal energy to electric energy. For such fusion machine, the requirement for reactive power is much larger than the active power it generates. Based on this requirement, one efficiency and compact pulsed synchronous generator is suggested for this purpose. It can not only generate the fundamental reactive power to compensate and stabilize the power network, but also the active power for outputting power to the network. Due to its two purposes in one device configuration, it becomes cheap and reliable by implement it in the design of future fusion power plant for demonstration. Some consideration has been done to the special synchronous generator, which is intended for the concept design of Chinese Experimental Reactor, targeting the compact Electric Power System for superconducting Tokamak.

255 3P33 SOME PROBLEMS OF SLIDING CONTACT IN RAILGUN ("VELOCITY SKIN-EFFECT" AND HALL-EFFECT IN MICRO-PLASMA) Volodymyr Chemerys National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia

The high current sliding contact of railgun borns the set problems at using of this accelerator. The global problem is a damage of the contact surface destruction at the rails in result of the micro- zones melting at the points of the current density concentration. In spite of the armature manufacturing in the form of V-similar body (as it was done in the many test experiments) the contact surface of armature with each rail is not uniform and feels the action of different physical factors which are able to violate the normal operation of sliding contact. First of them is non-ideal state of contact surfaces and, as result, a micro-dot character of current transfer across the contact border with local melting electrode's material up to creation the micro-plasma portions. In addition, non-perfect properties of contact transition lead to the growth of the field diffusion velocity along the contact surface with possible asymmetry of current way picture from rail to rail. In turn, such asymmetry causes the permanent transversal electromagnetic pressure directed to one of rails is a method to improve the symmetry of both contact resistances between the rails and armature. With respect to the micro-plasma behavior, beside of its role in the process of electrodes local melting, due to presence of the strong magnetic field the tensor conductivity of plasma occurs with reduction of transversal conductivity of contact layers. Another main problem of sliding contact operation is a big difference between armature motion velocity and the electromagnetic field diffusion into the rails material. Equalizing of these magnitudes as it would be possible by the proper choice of the rail material is the real way to improve the current distribution along the contact surface. The paper contains the brief theoretical characteristics all mentioned phenomena. Special attention has granted to Hall-effect and field diffusion into electrodes as the main factors of influence on the current density distribution in contact. The field in the contact zones is considered taking into account the longitudinal component of current density due to Hall-effect. Theoretical discussion is illustrated by the results of numerical simulation with using 2D model of processes with a tensor conductivity of contact layers. Data of numerical investigation of contact process show the ability to avoid extra-concentration of current density at the surface of contact. Information presented in the paper can be useful for prognosis of needed properties of electrodes material to avoid a crisis of contact stipulated by "velocity skin- effect" at armature velocity near 1 up to 10 km/s.

256 3P34 THE PRINCIPLE OF MAGNETIC FLUX COMPRESSION IN THE PULSED ELECTROMECHANICAL GENERATORS AND ITS IMPLEMENTATION IN DESIGN Volodymyr Chemerys National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia

Rotational electromechanical generators belong to the most effective sources of pulsed power at millisecond range of the pulse duration [1], [2]. In the paper the set of real machines built in different countries including Russia and Ukraine has been considered. Jointly with traditional structure of machine (outer stator) the inverted machine has been tested (outer rotor). The base of theory for the pulse generation is described in comparison with popular magneto-cumulative generators of linear motion. The special theory of the transient processes in application to the rotational pulsed generators is more productive than classical theory of shock machines due to distinguishing approach. The principal difference of operational process for the rotational machine has been discussed in connection with re-connection of coils before the flux compression. The question about the field distribution and electromagnetic energy density per unit of volume is considered as for the stage of initial excitation of magnetic field and for the stage of the field compression. Specifics of the machines with non-magnetic core of rotor [3] and with completely air core have been analyzed. The tendency of magnetic energy amplification change along with increase of the energy density at initial excitation has been investigated. The role of the flux scattering around the slots containing the active conductors of windings is under special attention in the paper, as well as the calculation of the leakage inductance and practical methods for the leakage reduction which are others than traditional compensation [4]. The characteristics of computer algorithm for the operational characteristics prognosis of compression generator are given in the paper taking into account the specifics of design. The examples of cascade connection of winding for great increase of current amplification are described in the paper. There is presented the useful useful analysis and generalization of the known information as well as the own experience of author in the area of the pulsed power generation using rotational machines. [1] A.S.Druzhynin, V.G.Kuchinsky, B.A.Larionov, "Compression generators," in: Physics and engineering of powerful pulsed systems, Energoatomizdat, Moscow,1987, pp.280 – 295 (in Russian). [2] M.D.Driga, S.B.Pratap, W.F.Weldon, "Advanced compulsator design," IEEE Transaction on Magnetics, 1989, v.25, No.1, pp.142 – 146. [3] V.T.Chemerys, Yu.N.Vaskovsky, "The parameters and energy amplification of compression generator with iron-free rotor defined by the magnetic field simulation," 12th IEEE Intern. Pulsed Power Conference, Digest of technical papers, vol.1, pp.437 – 440. [4] S.B.Pratap, and M.D.Driga, "Compensation in pulsed alternators," IEEE Transactions on Magnetics, vol.35, No.1, Jan.1999, pp.372 – 377.

257 3P35 EFFECTS OF ELECTROMAGNETIC PULSES ON A SYSTEM WITH MULTIPLE LAYERS OF DIFFERENT MATERIALS Antonio Upia1, Daniel Muffoletto1, Mark Muffoletto1, Brett Bowman1, Kevin Burke1, Jennifer Zirnheld1, Harry Moore2, Hardev Singh2, Thomas DeAngelis3 1The University at Buffalo, Energy Systems Institute, Buffalo, NY, USA, 2US Army Military, ARDEC, Picatinny Arsenal, NJ, USA, 3SciTech Services, Inc. Havre de Grace, MD, USA

Electromagnetic pulses (EMP) can be very destructive and protecting against them is crucial. This paper discusses a method to determine the effects an intentional EMP would have on a system with multiple layers of different materials by simulating in ANSYS HFSS the exposure to electromagnetic waves. Worst case scenarios are tested by applying wavelengths that result in a resonant frequency through the object. The results of the simulations show the current densities throughout the object induced by the EMP waves. The impact of the waves can be determined by reviewing the current densities through the object with respect to the physical properties of the materials.

258 3P36 FREQUENCY AGILITY OF A FERRITE-LOADED, NONLINEAR TRANSMISSION LINE Christopher Simmons, James-William Bragg, James Dickens Texas Tech University, Department of Electrical and Computer Engineering, Lubbock, TX, USA

A nonlinear transmission line (NLTL) provides a solid-state means of generating high power, microwave pulses. The NLTLs in this study are coaxial transmission lines whose center conductor is encapsulated by ferrite beads. Operational frequency can be controlled by varying the dimensions of the ferromagnetic material, which affects azimuthal magnetic fields and material losses. This research demonstrates frequency agility of an NLTL by documenting the design, construction, and testing of a 2 GHz NLTL and comparing the results to a previously fabricated 4 GHz NLTL. The NLTL will be one meter long, and to test for frequency agility, ferrites with dimensions ranging from 3 mm x 6 mm (inner diameter x outer diameter) up to 15 mm x 25 mm will be loaded onto the NLTL. Incident voltage levels range from 30 kV to 60 kV with magnetic biasing fields from zero to 50 kA/m.

259 3P37 PROSPECTS OF BUILDING CAPACITIVE NONLINEAR LINES USING CERAMIC PZT FOR HIGH-FREQUENCY OPERATION Jose Osvaldo Rossi1, Fernanda Sayuri Yamasaki1, Lauro Paulo da Silva Neto1, Edl Schamiloglu2 1INPE, Associated Plasma Laboratory, Sao Jose dos Campos, Brazil, 2UNM, ECE Dept, Albuquerque, NM, USA

The attempts to obtain oscillating pulses at frequencies above 500 MHz up to 1 GHz using barium/strontium titanate (BST) ceramics in nonlinear lumped lines have been unsuccessful due to the loss in the dielectric material that limits the operating frequencies to below 100 MHz. The analysis of these results also indicates that the use of nonlinear dielectrics with lower permittivities would be very good for achieving higher frequencies in nonlinear capacitive lines (NLCLs). On the other hand, de-poled PZTs have been studied in terms of their nonlinearity properties and dielectric breakdown. Although PZTs are less nonlinear (17%) and present lower breakdown strength (5 kV/mm) compared to BST dielectric ceramics (50% and 10 kV/mm, respectively), they have lower dielectric constant (about 1000 or less, than one fifth of BSTs), which could be very useful for obtaining higher frequencies in NLCLs as mentioned above. Moreover, as their piezoelectric properties are removed (de-poled) they present negligible hysteresis loss in this case, which limits the dielectric loss. Therefore, the main idea of this paper is to present the tests made with a NLCL built with de-poled PZTs to verify the prospects for better performance in terms of the generation of high frequency oscillating pulses.

260 3P38 X-BAND RELATIVISTIC BACKWARD WAVE OSCILLATOR WITH TWO- SPIRAL CORRUGATED BRAGG REFLECTOR A. Elfrgani, M. Fuks, S. Prasad, E. Schamiloglu University of New Mexico, Electrical and Computer Engineering, Albuquerque, NM, USA

Backward wave oscillators are typically known to radiate in the TM01 mode. A two-spiral corrugated Bragg reflector has been used downstream of the cathode in an X-band relativistic Backward wave oscillator (RBWO) to radiate a TE11 mode at the output. Simple analytical formulas were used to design the basic parameters of the Bragg reflector, which were later optimized numerically since there is no exact closed form solution for the electromagnetic fields within a periodic waveguide structure or cavity. The fully electromagnetic, fully relativistic particle-in-cell code MAGIC was used to simulate the problem. The RBWO was driven by a voltage pulse that has a half sine wave-like shape, amplitude 460 kV, and FWHM duration of 12 ns. A uniform static magnetic field of 2T was applied throughout the simulation volume. With these parameters a microwave power of 230 MW at a frequency of 9.8 GHz in a clean TE11 mode pattern was detected at the output.

261 3P39 ELECTRIC CIRCUIT MODELING METHODS OF ELECTROMAGNETIC SHOCK WAVE IN AIR FOR HIGH POWER MICROWAVE PROPAGATION Kun-A Lee, Jong-Yoon Park, Kwang-Cheol Ko Hanyang University, Dept. of Electrical Engineering, Seoul, South Korea

In recent years, as RF systems have been increasing rapidly, there is a growing need for studies about disturbance of electromagnetic shock wave propagation generated by high voltage pulse. Through front-door or back-door, electromagnetic shock wave can cause a upset or a lockup, that is, unsteady state in RF systems, and even cause a latchup or a burnout, which is permanent breakdown of the RF systems. Numerically, electromagnetic wave propagation can be analyzed by FDTD and FEM [1]. However, it is difficult to calculate the entire high power microwave system using FDTD and FEM. Therefore, the purpose of this paper is to simulate the propagation of electromagnetic shock wave by using the electric circuit modeling methods without complicated calculations. In this paper, a concept of tapered transmission line is adopted as the electric circuit modeling methods. The tapered transmission line is used for impedance matching, and impedances of the tapered transmission line depend on the location [2]. Because of its characteristic, the electromagnetic wave in the tapered transmission line is reflected and refracted while it is propagated. The electromagnetic shock wave propagation in air is expected by a reflection and a reflection coefficient in the tapered transmission line, and then we can simulate the electric circuit models with load by using EMTP (Electro-Magnetic Transient Program). We can describe the various electric circuit models of the electromagnetic shock wave in air. By using these models we can deduce the behavior of high power microwave propagation. [1] Dan Yang, Cheng Liao, Jian Fang and Yunlin Liu, Numerical analysis and simulation of high power microwave pulses propagation in the atmosphere using FDTD method, APMC 2005, (2005) p.4. [2] James Benford, John A. Swegle, Edl Schamiloglu, High Power Microwaves, Taylor & Francis, (2006) p.34~p.37.

262 3P40 OPEN TRANSVERSE ELECTROMAGNETIC (TEM) CELL AS APPLICATOR OF HIGH-INTENSITY NS PEFS AND ELECTRO-OPTIC MEASUREMENTS Sophie Kohler1, Thao Vu1, Thomas Vernier2, Delia Arnaud-Cormos1, Philippe Leveque1 1University of Limoges, XLIM UMR 6172 CNRS, Limoges, France, 2Information Sciences Institute, MOSIS, California, CA, USA

Ultrashort high-intensity pulsed electric fields applied to biological cells have gained increased attention over the last decade. Pulsed electric fields in the nanosecond range (4-300 ns) and of intense amplitude (50-400 kV/cm) have been demonstrated to be effective in triggering cell death in cancer cells. As the pulse duration is further decreased and the pulse rise time increased, the electric field can directly interact with intracellular structures [1]. A hyperband antenna has been reported to deliver subnanosecond pulses [2]. In this study, a setup based on a transverse electromagnetic (TEM) cell has been experimentally and numerically characterized. The setup is used for exposing biological samples to nanosecond pulsed electric fields (nsPEFs) with subnanosecond rise time. The experimental characterization was conducted using a pulse generator based on an optoelectronic switch triggered by a compact solid-state laser. Monopolar and bipolar pulses of 1.6 kV-amplitude and only 1.2-ns duration were delivered to an open TEM cell (220(L)*85(W)*20(H) mm). Connection between devices was made through 50-Ohm impedance coaxial cables. The target was a 3-mL water solution contained in a 35-mm Petri dish placed in the center of the TEM cell. For measuring the incident and reflected pulses at the TEM cell input, a 3-port high-voltage tap-off was inserted between the generator and the TEM cell. Pulses were displayed on a 12-GHz oscilloscope. The spatio-temporal voltage inside the Petri dish was numerically computed using a FDTD-based custom code. The experimental results show that only a very small part of the incident energy is reflected back by the TEM cell for both monopolar and bipolar pulses. Contrary to Gigahertz TEM cells, the TEM cell does not cause pulse distortion. This is explained by the smaller cross section of the TEM cell and thus its larger bandwidth. The return loss (S11 parameters) of the empty TEM cell and the TEM cell containing the Petri dish were indeed measured to be less than -10 dB up to 3 GHz. The numerical simulations show that the distribution of the electric field is homogeneous in the center of the Petri dish with hot spots near the walls. In conclusion, the experimental and numerical investigations show the ability of the TEM cell to deliver high-intensity nsPEFs. During the conference, results of in situ electric field measurements using a millimeter-sized fiber-coupled electro-optic probe inserted into the center of the water volume will also be shown. [1] K. Schoenbach et al., "The Effect of Intense Subnanosecond Electrical Pulses on Biological Cells," IEEE Trans. Plasma Sci., vol.36, pp. 414-422 , April 2008. [2] P. Kumar, C.E. Baum, S. Altunc, J. Buchenauer, S. Xiao, C.G. Christodoulou, E. Schamiloglu, K.H. Schoenbach, "A Hyperband Antenna to Launch and Focus Fast High-Voltage Pulses Onto Biological Targets," IEEE Trans. Microw. Theory Tech., vol. 59, no. 4, pp. 1090- 1101, April 2011.

263 3P41 A PIEZOELECTRICALLY DRIVEN ION DIODE NEUTRON SOURCE FOR ACTIVE INTERROGATION Peter Norgard, Scott Kovaleski, James VanGordon, Emily Baxter, Brady Gall, Jae Kwon, Baek Kim University of Missouri, Electrical and Computer Engineering, Columbia, MO, USA

The University of Missouri is conducting research and development into the production of neutrons from a piezoelectric transformer power source. The neutrons generated by the piezoelectric transformer (PT) may eventually be used for portable active interrogation technologies or gas and oil well diagnostics. The University of Missouri program ties together several independent areas of focus, including ion source development, PT characterization and optimization, and PT-compatible high voltage diagnostics. The neutron source was based on the well known D-D collision interaction, during which free energy and a neutron are released. An ion source is under development that optimizes ion emission current through structural changes in the emission surface characteristics. A PT-based accelerator is under development to evaluate ion beam characteristics and circuit dynamics under resonant operating conditions. A suite of diagnostics are under development to directly and indirectly measure circuit parameters including voltage and current, as well as parameters accessible using optical techniques.

Work supported by Nuclear Regulatory Commission, Qynergy, and Los Alamos National Laboratory.

264 3P42 CARRIER DYNAMICS AND ELECTRON ENERGY DISTRIBUTION FUNCTION OF A TRANSBERSE VIRCATOR Shen Shou Max Chung1, Yien Chieh Huang2, Ci Ling Pan1 1National Tsing Hua University, Department of Physics, Hsinchu, Taiwan, 2National Tsing Hua University, Institue of Photonics Technologies, Hsinchu, Taiwan

Pulse shortening and low efficiency has been the disadvantages of Vircator, despite considerable experiments has been conducted, explanations still inconclusive. We tag the electrons emitted by cathode with different colors in time, and trace carrier dynamics while observing EEDF in a MAGIC simulation of transverse Vircator. The initial EEDF is assumed to be a Gaussian distribution instead of commonly used fixed beam energy in explosive emission model, and FFT is performed on critical intervals, before the grid, Vircator formation, and HPM oscillation, to show the modes evolutions during each stage. The time and EEDF for virtual cathode to form and the main oscillation to occur are documented. We hope to illustrate the roles of lead and late electrons in Vircator formation and main HPM oscillation.

265 3P43 SHAPES OF GRATINGS AND BEAM ENERGY RELATIONSHIP IN A 100 MEV SMITH-PURCELL DEVICE Shen Shou Max Chung1, Yien Chieh Huang2, Ci Ling Pan1 1National Tsing Hua University, Department of Physics, Hsinchu, Taiwan, 2National Tsing Hua University, Institue of Photonics Technologies, Hsinchu, Taiwan

Smith-Purcell (SP) radiator is an interested device for THz generation, which attracts many attentions due to its relatively new applications in biology, security, and spectroscopy. Present sources like BWO produces higher THz power than microwave photonics techniques, but SP device is potentially capable of tunable very short pulses and powerful THz radiation, which is particularly useful in understanding the time evolution of many processes. A common problem of SP radiator is electron beam colliding with the grating due to their proximity. A high energy beam can move away from the grating while still remain interactions with it. In this paper we simulate the beam-grating interaction with PIC code, and evaluate the fields radiated by different grating shapes with a 100 MeV beam. For super-radiance to occur, coherent bunching is required.

266 3P44 INNOVATIVE SOLUTIONS TO HPM TESTING Russell Blundell White Sands Missile Range, Survivability Vulnerability & Assessment Directorate, White Sands, NM, USA

The requirement to provide system level HPM testing has really come to fruition over the past five to ten years. Initially the HPM test capability was not mature enough to support the system level HPM testing. However, with the increase in technology and the ever increasing red and blue threats it became apparent that the U.S. would need to significantly invest in HPM threat test sources. These HPM threat sources would enable the U.S. to determine the susceptibility of our military systems before they were sent to theater. The HPM threat sources were developed and White Sands Missile Range (WSMR) operates and maintains ~80% of the Department of Defense's HPM capabilities. Because of the capability and the capacity of the HPM environments located at WSMR we very quickly came to the conclusion that it was taking much too long to test these military systems. Because of this, WSMR submitted several proposals to the DoD Test & Evaluation, Science and Technology program. The instrumentation designed and built that stemmed from these proposals such as the slow wave structure for X-Band capability, the Rotating Step-Twist Polarizer, and the Rotary Attenuator are all examples of the innovative solutions used to streamline the HPM testing at WSMR. All three of these designs are highly effective and will be covered in greater detail during this brief.

267 3P45 INVESTIGATIONS INTO THE POTENTIAL FOR SURFACE FLASHOVER ON METAMATERIAL STRUCTURES IN AN HPM ENVIRONMENT Patrick Kelly, John Mankowski, Stephen Bayne Center for Pulsed Power and Power Electronics, Electrical and Computer Engineering, Lubbock, TX, USA

Electromagnetic metamaterials (MTMs) have recently shown experimental success in achieving a negative index of refraction leading to a highly directive radiation pattern and increase in gain. MTM's are designed to be effectively homogenous by having a cell size less than one-quarter wavelength of the incident microwave radiation. For microwave frequencies, this corresponds to structures with relatively small dimensions, on the order of several millimeters and less. MTM structures are typically placed inside a waveguide prior to some radiating element to increase the directivity and gain of the far-field radiation pattern. In an HPM environment, high field levels within the waveguide can cause surface flashover across the small gap dimensions of MTM structures and lead to a reduction in transmitted microwave power. This paper examines efforts to develop metamaterial structures which have been designed to reduce the potential for surface flashover in an HPM environment. Ansoft's HFSS was used to determine peak E-Field locations in a variety of MTM structures. Based upon these simulations, changes were made to the structures to reduce E-field enhancement and thus the potential for breakdown. Results from experimental testing utilizing a 2.85 GHz testbed capable of producing 4 MW at a pulsewidth of 3 µs and risetime less than 50 ns are presented. Additionally, the parameters at which flashover will occur on common metamaterials structures are presented.

268 3P46 COMPARISON OF CSI COATED CARBON VELVET AND ALUMINUM CATHODES OPERATED AT CURRENT DENSITY ON THE ORDER OF 300A/CM2 Curtis Lynn, John Walter, Andreas Neuber, James Dickens, Magne Kristiansen Texas Tech University, Electrical Engineering, Lubbock, TX, USA

Many high power microwave devices employ the use of explosive or flashover electron emission cathodes in order to generate the electron beam. These diodes are simple to operate, requiring no heater or other external systems. However, they generally suffer from non-uniform emission, anode heating, out-gassing, and pulse shortening due to anode and cathode plasma expansion. The ability to rep-rate such diodes is generally limited by anode heating and out-gassing which are both affected by beam uniformity at the anode. The diodes under investigation have an emission area of 20 cm2 and an A-K gap of 8 mm, operate at a current density of 300 A/cm2 at an accelerating voltage of approximately 200 kV, and can be operated as a > 100 MW class vircator. Following high temperature bake-out, the background base vacuum level is on the order of 10-9 torr. Since each pulse causes the pressure to rise to about 10-8 torr, gas is pumped by a small integrated sputter ion pump to restore the pressure to 10-9 torr range before applying a subsequent pulse. The vircator is operated as a sealed tube and no pumping is required until the device is operated. Two diodes are compared in this work. One is a machined aluminum cathode, which is made from solid aluminum with 250 mm by 250 mm square protrusions, about 250 mm tall, machined into the surface. The protrusions are not de-burred after machining, in order to create emission centers. The carbon velvet cathode is made from 1 mm carbon fibers with a PVD CsI coating. Time resolved images of the emission centers were taken for the carbon velvet cathodes. Also, time integrated scintillator images of the electron beam at the anode were taken for both the carbon fiber and the aluminum cathodes. Data sets of over 1000 shots were recorded with each cathode. The data is analyzed for statistical variation in the voltage and current waveforms as well as the perveance of the diodes. Additionally the lifetimes of the cathodes are compared. The lifetime of the aluminum cathode was exceeded by 1,300 shots whereas the carbon velvet cathode showed no degradation in operation. Additionally, modeling was performed to further investigate the emission mechanism of the CsI coated carbon velvet diode. Particle in cell simulations were executed in an attempt to determine whether time resolved emission centers can be used to model diode perveance, or if space charge limited field emission best describes the perveance behavior of the CsI coated carbon velvet diode.

Distribution A: Approved for public relea

269 3P47 AN ARBITRARY-GEOMETRY PULSED RF SOURCE ARRAY SYSTEM BASED ON GPS TIMING John Walter, Christopher Lutrick, Scott Clark, Shad Holt, David Reale, Patrick Kelly, James Dickens, John Mankowski Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

High-power pulsed RF sources have been explored for use in many different applications, such as directed energy weapons and ground penetrating radar. The efficacy of these sources in most applications is directly linked to the available RF power as well as other pulse characteristics. The available power levels and output waveform flexibility can be significantly increased by arraying multiple sources together. Extending the array concept to many sources spread over a geographic area has potential advantages, but involves the difficult tasks of determining the relative positions of all of the array members and synchronizing their firing times. An effort is underway at Texas Tech University to investigate the theoretical performance limits and the practical implementation issues of a distributed array of pulsed RF sources. In the experimental system under development, arbitrarily-located individual pulsed RF sources are wirelessly linked together into an array. A controller at each source utilizes a GPS receiver to determine its position and to synchronize its local time base relative to the other units. This allows precisely coordinated triggering at separate locations spread over a limited area (i.e. over distances ranging up to 100's of meters). Additionally, photo-conductive silicon carbide switches are evaluated as a trigger source for such a system. Experimental results, including the measured firing jitter for an array of multiple radiating sources, are presented.

270 3P48 STOCHASTIC MODEL OF METAL OXIDE SURGE ARRESTERS BASED ON SYSTEM IDENTIFICATION Pablo Bezerra Vilar, George Rossany Soares Lira, Tarso Vilela Ferreira, Edson Guedes da Costa Federal University of Campina Grande, Department of Electric Engineering, Campina Grande, Brazil

Metal Oxide Surge Arresters (MOSA) are devices widely used to protect systems against internal or external surge voltages. An accurate model of such device is very important in simulations for studies involving: insulation coordination, energy absorption capability, diagnosis, correct selection and others. When subjected to standard current impulses MOSA behaves as a non-linear resistance therefore a non-linear resistor was originally used to model it. However, previous works have shown that the MOSA impulse response, when an impulse with crest time inferior to 8µs is applied, presents a frequency dependent behavior characterized by a time delay between the peaks of voltage and current. This behavior cannot be simply represented by the non-linear resistance model. Many different models where developed to represent this dependency. The general idea of the developed models was to use circuits with linear passive elements elements and non-linear inductances and resistances to achieve the time delay between voltage and current. Some parameters of the circuit were calculated with physical data of the MOSA such as its height or the rated residual voltage for standard impulses and others are adjusted in recursive a procedure to match results of the model and experiments. In terms of system identification this procedure can be classified as white box identification, which is based on previous knowledge about the system, in this case circuits theory, constitution and characteristics of MOSA. This work proposes a new approach to the problem: MOSA is subjected to different impulses, and the system is identified based on its responses using stochastic techniques. The main advantages of such approach is its robustness to noise in measurements and the fact that determination of the parameters of the model do not require a recursive procedure, which is common in models based on circuits knowledge. The result of stochastic identification is not an electric circuit, which is the common form of presenting a model for MOSA, but a mathematical model such a difference equation or state variables which also can be use to simulate MOSA behaviors.

271 3P49 PSPICE MODELING OF SILICON CARBIDE MOSFETS AND DEVICE PARAMETER EXTRACTION Argenis Bilbao, Stephen Bayne Texas Tech University, Electrical and Computer Engineering, Lubbock, TX, USA

The goal of this research is to develop device models for Silicon Carbide (SiC) MOSFETs. Parameters are extracted and used to create PSPICE models that can be utilized for circuit simulation. Two silicon carbide power MOSFETs made available by CREE Semiconductor are considered. The first silicon carbide power MOSFET tested is the CMF20120A64410. This MOSFET features a 1200V drain-to-source breakdown voltage and 30A continuous current capacity. The second device tested is an experimental MOSFET that is still not available in the market as of the date of this paper. The experimental MOSFET features a 1200V drain-to-source breakdown voltage and 80A continuous current capability. Custom made circuits are developed for extracting some of the parameters. In some cases where the tests only require low drain current, a HP B1505A curve tracer is used to aid the development of the model. The effect of temperature over the gate threshold voltage is also looked at. By externally increasing and monitoring the die temperature of the SiC MOSFETs, new device parameters can be extracted and modeled. Once the parameters are extracted they are converted into a PSPICE model. The model is tested and compared to the real device to verify accuracy. This is achieved using custom switching circuits with both inductive and resistive loads and software suites like MATLAB.

272 3P50 PULSED POWER SWITCH MODELING FOR BROAD OPERATION Steven Glover1, Peter Foster2, Dillon McDaniel1, Forest White3, Gary Pena1, Larry Schneider1 1Sandia National Laboratories Albuquerque, NM, USA, 2Defense Nuclear Facilities Safety Board Washington, DC, USA, 3SAIC Albuquerque, NM, USA

Dynamic materials properties research at Sandia National Laboratories has resulted in research that is advancing capabilities in precision programmable Pulsed Power systems operating in multi-mega amp regimes. Programmable pulse shaping capabilities require the gas switches in these systems to perform over a large range of dynamic operating conditions. Runtime, jitter, and the number of channels formed are all impacted by the conditions of these switches at the time of trigger. This paper provides a model and analysis of a 200 kV gas switch designed for linear transformer drivers operating at percentages of self break ranging from 45% to 100%. This work expands on the research performed by T.H. Martin and S.I. Braginskii.

273 3P51 ANALYTIC SOURCES USING POLYNOMIAL SHAPED PARTICLES IN THE LTP METHOD Robert Jackson1, John Verboncoeur2 1Calabazas Creek Research, Inc. San Mateo, CA, USA, 2Michigan State University, Electrical and Computer Engineering, East Lansing, MI, USA

The Local Taylor Polynomial (LTP) method treats fields and sources as local analytic polynomials for rapid numerical solution of PDE's. Knowledge of the source polynomial would allow sources to be treated analytically in LTP formulas, since the derivatives follow directly for polynomial forms. Aside from idealized cases, such information is seldom available; however, use of macro-particles with finite polynomial shape functions for charge and current deposition can make analytic treatment possible for general cases. The macro-particle polynomial coefficients can be used directly in LTP solution formulas. This scheme allows one to choose a representation of particles that enables high fidelity with fewer particles compared to traditional particle methods, since the polynomials can include information such as transverse profile information from a beam, for example. This paper presents a simple polynomial form for representing macro-particles in numerical simulations. The particle shape must be continuous and differentiable to a specified order, bounded in size and magnitude, zero in magnitude and derivatives at the edges, symmetric, positive definite, with analytic coefficients. Two key properties for use in LTP will be demonstrated: zero derivatives at the particle boundary and analytically computable coefficients.

274 3P52 ANALYSIS OF CURRENT-DIVIDING POST-HOLE CONVOLUTES FOR SIX LINES DRIVING THREE TRIODES ON SATURN E. A. Madrid1, D. V. Rose1, C. L. Miller1, V. Harper-Slaboszewicz2 1Voss Scientific Albuquerque, NM, USA, 2Sandia National Laboratories, Albuquerque, NM, USA

Post-hole convolutes are traditionally utilized as current adders in pulsed power accelerators, joining multiple transmission lines in parallel into a single load-driving transmission line. A new configuration for the Saturn accelerator at Sandia National Laboratories uses a cathode- post/anode-hole convolute scheme to divide the current from two incoming lines into six output lines driving electron beam loads. A fully electromagnetic and relativistic 3D simulation model has been developed to study electron power flow in this convolute configuration. The simulation model is run in both steady-state and linearly-rising voltage drive configurations to assess loss currents. Comparisons between the simulation results and experimental current measurements will be presented.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin company, for the United States Department of Energy's National Nuclear Security Administration, under contract DE-AC04-94AL85000.

275 3P53 REPETITIVE PULSE TESTING AND MODELING OF A HIGH POWER CERAMIC RESISTOR Daniel Muffoletto, Kevin Burke, Jennifer Zirnheld University at Buffalo, Energy Systems Institute, Buffalo, NY, USA

In an effort to understand the failure mechanisms of ceramic resistors when used above their stated limits, a series of pulsed load profiles were applied to two different types of epoxy coated ceramic resistors. The load profiles that cause failure are evaluated and compared to the results of a lumped element numerical model, which models the thermal characteristics of such a resistor under test and allows for the heating profiles during operation to be predicted.

276 3P54 DYNAMIC BIFURCATION ANALYSIS OF ADVANCED AIRCRAFT ELECTRIC POWER SYSTEM (AAEPS) WITH NONLINEAR LOADING Hadi Ebrahimi, Hassan El-Kishky The University of Texas at Tyler, Electrical Engineering, Tyler, TX, USA

In this article a comprehensive dynamic bifurcation analysis of the Variable Speed Constant Frequency (VSCF) Advanced Aircraft Electric Power System (AAEPS) corresponding to Boeing 767 is performed. A complete set of state space differential equations describing the aircraft electric system's dynamics are derived. The developed mathematical equations are utilized to verify the aircraft electric power system stabilities under various loading configurations. In order to investigate the system's sustainability to any foreigner chaos, different loading conditions are studied by using the load demands as bifurcation parameters. Furthermore, changes in the operating frequency, due to variation in the rotational speed of the Synchronous Generator (SG) is studied. For variations of one of the loads, it is shown that the equilibrium point undergoes different bifurcation behaviors. Finally, the developed equations are implemented in Matlab, and the accuracy of obtained results is verified by exact time-domain simulations of a study model in the PSIM9 SW environment, and two-dimensional (2-D) bifurcation diagrams, which can assist engineers in identifying regions of preferred or undesired operations are presented for each case study.

277 3P55 A NOVEL GENERALIZED AVERAGING TECHNIQUE FOR THE MODELING OF CONTROLLERS IN AN AAEPS MULTI-CONVERTER SYSTEM Hadi Ebrahimi, Hassan El-Kishky The University of Texas at Tyler, Electrical Engineering, Tyler, TX, USA

This work develops a comprehensive set of Generalized State Space Averaging (GSSA) representative models for the non-linear control signals in the multi-converter system of an Advanced Aircraft Electric Power System (AAEPS). Due to the switching operation and variation in loading conditions in the aircraft system under study, the pulse-width modulation (PWM) interconnected converters show inherent time-variant behaviors with totally non-linear control signals to keep the system's operation within IEEE/military standards. Therefore, the proposed models can be applied to derive the key features of the non-linear switching functions under investigation, hence, can be treated as the basic modeling framework of some specific converters in the advanced aircraft power electronic system with closed-loop controllers. For instance, modeling and visualization of the multi-converter system including: full-bridge 12-pulse rectifier interacting with constant-voltage, constant current and constant-power buck converters with feedback control system is achieved via applicability of this technique. Finally, the models of multi-converter circuits representing Boeing 767 power electronic system are analyzed and simulation results are presented. To verify the accuracy of obtained results, a study model has been implemented in PSIM9 SW environment.

278 3P56 AN EMI MODEL OF HIGH FREQUENCY AND HIGH VOLTAGE CAPACITOR CHARGING POWER SUPPLY CONSIDERING TRANSIENT SWITCHING INTERFERENCE BASED ON SABER Xiao Han3, Yinghui Gao1, Dongdong Zhang2, Yaohong Sun1, Ping Yan2 1Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing, China, 2Chinese Academy of Sciences, Key Laboratory of Power Electronics and Electric Drive, Beijing, China, 3Chinese Academy of Sciences, Graduate School, Beijing, China

In this paper, a mathematical analysis of the CMI(Common-mode Interference) and the DMI(Differential-mode Interference)for a 20kHz/10kV capacitor charging power supply in frequency-domain is presented, and a related circuit model considering the transient switching interference based on SABER is proposed. Due to the high working frequency of the full bridge inverter and the device-switching transitions in rectifiers and the inverter, the conducted EMI (Electromagnetic Interference) caused by the charging circuit which flows forth to the signal acquisition circuit or control circuit includes the harmonics of grid frequency, working frequency and device-switching transition frequencies. Thus under certain working conditions such as multiple power supplies charging capacitor in parallel, the interference may cause charging failure. To solve this problem, a mathematical analysis of the CMI and the DMI in frequency- domain is presented, and a method of multiple slope approximation of the device-switching transition is applied in the SABER-based simulation model. Afterwards, various EMI mitigation techniques for the power supply could be simulated and compared, and provide further details for the realization of EMI reduction in high frequency and high voltage capacitor charging power supply.

279 3P57 MODELING AND SIMULATION OF MULTIPACTOR DISCHARGE ON DIELECTRIC WINDOW UNDER HPM IN VACUUM Guan-Jun Zhang, Bai-Peng Song, Xi-Wei Hao Xi'an Jiaotong University, School of Electrical Engineering, Xi'ab, China

Multipactor discharges on dielectric window seriously limits the generation and transmission of high power microwaves (HPM), which blocks the development of microwave technology. In order to understand its physical mechanism deeply, a simulation model based PIC Monte Carlo is built in this paper. The influences of microwave electromagnetic field and dielectric surface electrostatic field are considered in this model. During simulation, the realistic secondary electron yield curves as input are used, and the distributions in the emission velocities and emission angles of the secondary electrons are also took into account. The movement trajectories of electron under complex field are obtained by simulation. The influences of different emergence angles and microwave electromagnetic parameters to electron movement are also considered. It is found that the emergence angles of electron have significant effect on the movement of electron, and impact energy will be increased and return time will be reduced as the increase of electric field amplitude, and the impact energy and return time will oscillate with cycles for the change of the phase of electric field. The change of multipactoring electrons number and electrostatic field are also studied by simulation. The result shows that electrons number and electrostatic field both oscillate with twice microwave frequencies periodically for the change of time. The reason of this phenomena is explained.

280 3P58 SIMULATION OF PULSED ELECTROMAGNETIC PROCESSES IN MULTI- LAYER PACKAGE OF INDUCTOR CORE OF INDUCTION ACCELERATORS OF ELECTRONS Volodymyr Chemerys, Iren Borodiy National Aviation University of Ukraine, Theoretical Physics, Kyiv, Ukrenia

Induction accelerators of electron beams can use the inductor systems which consist of individual sections with a ferromagnetic core, especially as the range of pulses duration of power supply near 50 – 300 ns. Due to using of amorphous band materials as Metglas the power losses for re- magnetization in the wounded circular core of inductor can be reduced significantly in comparison with other classical ferromagnetic materials. Nevertheless the high initial magnetic permeability of amorphous ferromagnetics jointly with resistivity of material is the reason of finite speed on magnetic field diffusion into the cross-section of core. That is why at the inductor design that is necessary to check the time of field penetration into the core to compare it with a time of electron beam acceleration. Authors have developed the methods of 1D and 2D simulation of the field diffusion using equivalent parameters stratified medium at its artificial "homogenization". The way of these parameters obtaining was controlled by the simulation of real two-component (ferromagnetic plus insulator) layered package. The special principles of the field diffusion similarity has been developed for drawing of big scale model of package which indeed consists of sheets with thickness 12 – 20 micrometers for ferromagnetics and 4 – 6 micrometers for insulator band. Non-linearity of magnetization curve was inseted into the simulating program. It was applied software "ELCUT" for this research (English version is "QuickField"). In result of implementation of described approaches it was possible to get time- variation distribution of magnetic induction across the core cross-section at the field excitation by the current pulses of duration 100 – 150 ns. Really, sometimes designer can meet a non-uniform distribution of magnetic field up to zero in the center of core. Beside of problem of finite time of the field diffusion in the multi-layer amorphous cores we meet the problem of the wave process influence on the field penetration. Main peculiarities of the wave processes in the cores have been investigated using the 2D model of ideal magneto-dielectrics. Some interpolation of this result can be done concerning of real package of core. Main conclusion about role of the wave processes can be formulated as the need of pulse duration to be long enough for the front of wave passage at least up to the center of core cross section. The real speed of electromagnetic wave for medium with equivalent parameters must be taken into attention for such estimation.

281 3P59 HIGH VOLTAGE DIRECT CURRENT TRANSMISSION – A REVIEW, PART I Mohamed Saied Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt

Major milestones in the development of high voltage direct current (HVDC) technologies and concepts were achieved in 1950s. Thanks to the high power thyristor switches (1960-70s), the HVDC technologies reached a significant degree of maturity in 1980s. The classical HVDC uses thyristor-based current-sourced line-commutated converter (LCC) technology. The advent of power semiconductor switches in 1980-90s, with turn on-off capabilities, especially, the IGBTs and IGCTs, and the on-going progress in this field have introduced the conventional (two-level) voltage-source converter (VSC) technology and its variety of configurations, e.g. multi-level and multi-module VSCs, also as viable converter technologies for power system applications. The DC system is experiencing significant degree of re-emergence due to its potential to either directly address, or to facilitate resolving a large number of existing and anticipated interconnected AC power system steady-state and dynamic issues. HVDC technology made possible to transfer bulk power over long distances. This paper in it's part I presents comparative evaluations, studies, and review of HVDC versus HVAC transmission systems. Applications, different schemes of HVDC systems are also outlined.

282 3P60 HIGH VOLTAGE DIRECT CURRENT TRANSMISSION – A REVIEW, PART II – CONVERTER TECHNOLOGIES Mohamed Saied Abu Qir Fertilizers & Chemical Industries Company (AFC) Alexandria, Egypt

This paper is the second part of the review titled "High Voltage Direct Current Transmission - A Review, Part I" The main converter technologies and HVDC systems' components will be discussed in this complementary paper.

283 3P61 CPF, TDS BASED VOLTAGE STABILITY ANALYSIS USING SERIES, SHUNT AND SERIES–SHUNT FACTS CONTROLLERS FOR GENERATOR OUTAGE CONTINGENCY Surya Kalavathi1, Naveen Kumar2 1JNTUH, EEE, Hyderabad, India, 2VNRVJIET, EEE, Hyderabad, India

Voltage stability is of major concern in power systems stability. Main reason for the cause of voltage instability is the sag in reactive power at various locations in an interconnected power system. Improving the systems reactive power handling capacity via FACTS devices during a Generator outage categorized under large disturbance voltage instability is the idea behind this work. Various Series, Shunt and Series–Shunt FACTS controllers are used to improve the reactive power profile which is tested on an IEEE 14-bus system. The implementation of the present contingency can be explained as follows. We run the CPF for the base case and introduce the contingency i.e., the Generator outage and rerun the CPF routine to know the deterioration of voltages at various buses. Now, using the search technique, various series, shunt and Series-Shunt FACTS controllers are introduced at appropriate places with chosen VAR ratings to improvise the maximum loadability limit of the system to take it back to the pre-disturbance values (or) near pre-disturbance values. Now, Time Domain simulation (TDS) is run to observe the generator oscillations for voltage stability at various generators. The technique used here is called the search technique where in the weakest of all the buses is selected and the device is placed near that bus. The KAVR rating to be given as input to the FACTS is also selected from various values of KVAR range based on the search technique. A comparison is made amongst the five FACTS controllers to choose the optimum device in terms of KVAR requirement and cost. Earlier works reported a comparison of only four of the above FACTS devices where in attempts were made to make an improvement in voltage profile only and not considering any contingency. This works mainly focused on a contingency based stability analysis. The work presented here focuses on the usage of search technique for optimal location of FACTS controllers for Generator outage contingency with an improvement in loading parameter and voltage magnitude. The future work includes operating the FACTS efficiently along with their optimal location for voltage stability enhancement using AI techniques.

284 3P62 OPTIMAL LOCATION AND PARAMETER SETTING OF UPFC FOR POWER SYSTEM VOLTAGE STABILITY ENHANCEMENT USING DIFFERENTIAL EVOLUTION (DE) ALGORITHM Suryakalavathi Munagala1, Balachennaiah Pagidi2 1JNTUH, EEE Department, Hyderabad, India, 2A.I.T.S, EEE Department, Rajampet, India

The problem of voltage stability is one of the main concerns in the operation of power systems. Location of the FACTS device Such as the UPFC is an important for the enhancement of practical power systems voltage stability. In this paper, a Differential Evolution (DE) algorithm is used to solve a mixed continuous-discrete multi-objective optimization problem in order to find optimal location of UPFC. Various objectives are considered, namely Voltage Stability improvement, real power loss minimization and load Voltage Deviations minimization. Simulations are performed on IEEE 14 test system for optimal location and size of FACTS device. Analysis of the initial conditions to determine the voltage stability margins and a contingency analysis to determine the critical outages with respect to the voltage stability margin are also examined in order to evaluate their effect on the location analysis. The obtained results show that with the allocation of FACTS device with the proposed method, the voltage stability is considerably enhanced in both normal state and critical contingencies.

285 3P63 OPTIMAL POWER FLOW ANALYSIS OF ANDHRA PRADESH STATE GRID IN DEREGULATED ENVIRONMENT Sunilkumar Chava1, Amarnath Jinka2, Subramanyamps3 1CVR COLLEGE OF ENGINEERING, EEE, HYDERABAD, India, 2JNTUH, EEE, HYDERABAD, India, 3VBIT, EEE, HYDERABAD, India

In the past, the electricity industry was government-controlled and also monopolistic. However over the past decade, the industry in many countries had undergone significant changes and was restructuring for a free market, also known as deregulation. This led to a competitive market whereby customers are able to choose their electricity supply from a number of generating companies and retailers. In this deregulated market, it is essential for generating companies to plan their operations efficiently, so as to minimize operating costs while maximizing their profit margins. There are many factors involved in the successful operation of a power system. The system is expected to have power instantaneously and continuously available to meet power demands. It is also expected that the voltage supplied will be maintained at or near the nominal rated value. Not only must the demands be met at all times, the public and employees should not be placed in hazard by operations of the system. At the same time proper operating procedures must be observed to avoid damage to equipment or other facilities of the system. All of these operating requirements must be achieved simultaneously. In this paper, important factors that may affect generating companies' profit margins through wholesale electricity trading are discussed. These factors include generators' efficiencies and capabilities, types of generators owned, fuel costs, transmission losses and settling price variation. It demonstrates how proper analysis of these factors using the solutions of Optimal Power Flow (OPF), can allow companies to maximize overall revenue. And through this OPF analysis, companies will be able to determine, for example, which generators are most economical to run, best locations for generators to be situated at, and also the scheduling of generators as demand changes throughout the day. It illustrates how solutions of OPF can be used to maximize companies' revenue under different scenarios. In this paper above tasks are demonstrated on 124-bus real life Indian utility system of Andhra Pradesh State Electricity Board (APSEB) and results have been presented and analyzed.

286 3P64 ROLE OF FACTS DEVICES ON ZONAL CONGESTION MANAGEMENT ENSURING VOLTAGE STABILITY UNDER CONTINGENCY Jami Sridevi1, Jinka Amarnath2, Gade Govinda Rao3 1Gokaraju Rangaraju Institute of Engineering And Technology, Electrical and Electronics Engineering, Hyderabad, India, 2Jawaharlal Nehru Technological University, Electrical and Electronics Engineering, Hyderabad, India, 3Gayatri Vidya Parishad College of Engineering, Electrical and Electronics Engineering, Hyderabad, India

Congestion management is one of the most important issues for secure and reliable system operations in deregulated electricity market.In the competitive electricity market, it is not always possible to discharge all of the contracted power transactions due to congestion in the transmission lines. In most cases, Independent System Operator tries to remove congestion by rescheduling output power of the generators.This paper presents an optimal allocation method for flexible ac transmission system (FACTS) devices for market-based power systems considering congestion relief and voltage stability. In this paper, transmission congestion distribution factors based on sensitivity of line real power have been proposed to identify the congestion clusters. The system operator can identify the generators from the most sensitive congestion clusters to reschedule their generation optimally to manage transmission congestion based on generator sensitivity efficiently. The role of Thyristor controlled series Capacitor and Static Var Compensator have been investigated for reducing the transmission congestion cost ensuring voltage stability after locating it optimally in the system based on improved performance index. The effectiveness of the proposed method has been carried out on a 62 bus Indian Utility System and 124 bus Indian Utility System.

287 3P65 INFLUENCE OF HEAT TREATMENT ON PROPERTIES OF HIGH-CURRENT METALLIZED FILM CAPACITORS Kong Zhonghua, Xu Bei, Tong Chunya, Lou Zaifei School of Electronic and Information Engineering, Ningbo University of Technology, Ningbo, China

As a high energy density capacitor, the metallized film capacitor was used in pulsed power device at first, while its energy density increase quickly. With the development of pulsed power technology, it requires respectively high-current energy density metallized film capacitor. Manufacturing process of metallized film capacitor plays a dominant role in its performance. With difference process and parameters, the capacitor products have difference qualities in different conditions. Currently, there's few study on the performance of heat treatment for high- current metallized film capacitors at home and abroad. This paper discusses the influence of heat- treatment on the performance of high-current metallized film.

288 3P66 DEVELOPMENT AND PERFORMANCE OF HIGH TEMPERATURE POWER CONVERSION CAPACITORS J. R. MacDonald, J. B. Ennis, M. A. Schneider General Atomics Electronic Systems, Inc., Capacitor Research and Development, San Diego, CA, USA

Military and commercial applications require capacitors that can operate at high temperatures, high energy densities, with long lifetimes. This paper describes life testing of capacitors with energy densities as high as 0.2 J/cc at >125°C. Capacitors using the same dielectrics but with a higher packing factor design can achieve the same performance but with energy densities >0.3 J/cc at 100°C. Data on equivalent series resistance, power dissipation, peak and root mean square current ratings, and other performance parameters are presented. This work was sponsored by the US Army Research Laboratory.

289 3P67 DROOP RELATED LIFETIME REDUCTION OF POLYPROPYLENE FILM CAPACITOR IN A PULSED POWER APPLICATION Tao Tang1, Mark Kemp1, Craig Burkhart1 1SLAC National Acclerator Laboratory Menlo Park, CA, USA, 2SLAC National Acclerator Laboratory, RF Accelerator Research and Enegineering, Menlo Park, CA, USA

Self-healing film capacitors composed of high crystalline polypropylene (HCPP) film patterned with high ohm/square aluminum metallization are used as the primary energy storage/discharge capacitors in a Marx-topology klystron modulator under development for the International Linear Collider (ILC). The lifetime of these capacitors was expected to be 100,000 hours, which was validated by accelerated aging tests at elevated voltage. However, capacitor failures occurred after less than 1000 hours of modulator operation. Subsequent experimental investigations demonstrated an additional aging mechanism not correlated with electric field magnitude nor film heating within the operating conditions of the modulator. Although the capacitor design was based on a dc model, there is a significant ac component; the ripple ratio is as large as 0.4, which is believed to underlie the accelerated aging mechanism. Our aging model suggests alternative capacitor construction materials and design that should be impervious to this mechanism. Preliminary results with the new capacitor design are presented.

Work supported by the US Department of Energy under contract DE-AC02-76SF00515.

290 3P68 LIFETIME TESTING OF AIRIX ACCELERATING UNITS Alain Georges, Hervé Dzitko, Marc Mouillet, Rémi Nicolas, Denis Reynaud CEA, DIF, ARPAJON, France

Airix is a linear accelerator producing a 60ns, 2kA, 19MeV electron beams. It is operated in a single shot mode by CEA for radiographic purposes. It is based on inductive cells technology, which increases the beam energy step by step. Usually each accelerating unit (a cell and its driver) delivers a 100ns impulsion of 250kV amplitude to the beam. The test bench is used to determine the behaviour over time of the cells, the driver (high voltage generator) and the links between them (high voltage cables). We try different configurations and deal with ensuing problems. In this paper, we describe the test-bed in use, the problems we have met and how we dealt with them, and we establish the reliability performances we now expect from the accelerating units for the next decades.

291 3P69 A MOBILE HIGH-POWER, HIGH-ENERGY PULSED-POWER SYSTEM Bucur Novac1, Michael Parker1, Ivor Smith1, Peter Senior1, Gerasimos Louverdis2 1Loughborough University, School of Electronic, Electrical and Systems Engineering, Loughborough, United Kingdom, 2Dstl, Security Sciences Department, Sevenoaks, United Kingdom

A high-power, high-energy, pulsed-power generator, based on a 415 kJ/22 kV capacitor bank has recently been developed and tested indoors at Loughborough University. The generator can drive a load with a resistance between 10 ohms and 40 ohms and a self-inductance between 10 microH and 30 microH, generating a total electrical power of many GW, while depositing a Joule energy of many tens of kJ. The arrangement is based on an inductive storage technique that includes a 600 kV high-voltage transformer, two closing switches and an opening switch. The high- Coulomb closing switch in the primary circuit is activated using detonators, while the closing switch mounted in the secondary circuit to condition the load output, uses a high-pressure gas self-breakdown closing switch. The opening switch in the primary circuit is an exploding wire array made thom thick copper wire fired in quartz sand. The entire system, including its command and control unit, has recently been mounted in two ISO containers, where iti s powered by diesel generators. Thr paper will describe the resulting mobile system and provide details of its performance capabilities.

292 3P70 CAPACITOR DROOP COMPENSATION WITH SOFT SWITCHING FOR HIGH VOLTAGE CONVERTER MODULATOR Michael Bland1, William Reass1, Alex Scheinker1, Ji Chao2, Pericle Zanchetta2, Alan Watson2, Jon Clare2 1Los Alamos National Laboratory, AOT-RFE, Los Alamos, NM, USA, 2The University of Nottingham, Electrical & Electronic Engineering, Nottingham, United Kingdom

High Voltage Converter Modulators (HVCM) offer significant performance advantages over conventional modulator technologies for long pulse applications. One of the key advantages of HVCM technology is the ability to compensate for capacitor bank droop. Achieving droop compensation without incurring significant additional switching loss has not been possible in existing designs. This paper presents an analysis of the "Y-point" variant of the HVCM topology using the Combined Phase and Frequency Modulation (CPFM) technique. This combined with the addition of 'lossless' snubber capacitors enables droop compensation while achieving soft switching over the whole pulse. The rise time and overshoot of the output voltage is optimized using an iterative extreme seeking algorithm. The optimization reduces the rise time from 100us to <50us with no overshoot. This will lead to an increase in overall system efficiency. Waveforms showing the IGBT soft switching phenomena over the full pulse width will be presented. An analysis of the operating range for soft switching will be presented. Recommendations for optimized design of the next generation of HVCMs will be given.

293 3P71 COHERENCE EFFECTS Lutfi Oksuz, Ali Gulec, Erdogan Teke, Ferhat Bozduman Suleyman Demirel Universitesi, Fizik Bolumu, Isparta, Turkey

Most high power microwave (HPM) devices are generating radiation over certain frequency bandwidth. In this paper it will be shown that this effect can be related to the Heisenberg uncertainty principle. We will also demonstrate that it is necessary to determine the FWHM of the FFT of the signal and to evaluate the time period of the signal in order to understand better the coherence phenomenon. It is believe that the coherence phenomenon can be related to the pulse shortening observed in the HPM devices. The current theoretical model examines the formulation given in Ref. 1. [1] M. M. Kekez, "Details of HPM generation in atmospheric air using the laser and klystron terminology" (to be published in IEEE Trans. Plasma Sci.,)

294 11O1,2 (Invited) LINEAR-INDUCTION-ACCELERATOR BEAM-ENERGY-SPREAD MINIMIZATION: CELL MODELS AND TIMING OPTIMIZATION C. R. Rose, C. Ekdahl, M. Schulze Los Alamos National Laboratory, WX-5, Los Alamos, NM, USA

The second axis (Axis II) of the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL) is a linear induction accelerator (LIA) using 74 cells, each driven by a separate pulse-forming network (PFN). The summation of the injector and 74 cell voltages is the overall energy spread. The ability to perform precise multipulse radiography is heavily influenced by the temporal beam energy spread, related beam motion, and other focusing and target factors. Beam loading affects both the shape and magnitude of each cell’s voltage during the pulse. Ideally, each PFN/Cell pair is tuned such that the loaded-cell voltage is flat with minimal amplitude variation during the pulse. However, changes in operating parameters on Axis II (beam current, operating cell voltage) have altered the amount of flattop variation resulting in more energy spread than when commissioned. In this paper, we present an optimization method which minimizes the beam’s temporal energy spread by adjusting the timing of PFN/cell voltages, either advancing or retarding them, such that the injector voltage plus the summed cell voltages in the LIA result in a flatter energy profile. The method accepts as inputs the beam current, injector voltage, and cell-voltage waveforms. It optimizes cell timing per user-selected groups of cells and outputs timing adjustments, one for each of the selected groups. Simulations and experimental data for both unloaded and loaded-cell timing optimizations are presented. For the unloaded cells, the pre-optimization baseline energy spread was reduced by over 30 % as compared to baseline. For the loaded-cell case, the measured energy spread was reduced by 49% compared to baseline. Additionally, this paper describes the DARHT Axis-II loaded-cell models used to determine optimum cell timing. The models include PFN parameters (e.g., voltage, output impedance), cell parameters (e.g., impedance, losses, saturation volt-second products), and beam-current magnitude and timing. Results are presented as to the accuracy of the models with beam loading and the reduction in energy spread which can be obtained by optimizing the timing of the cells.

295 11O3 THERMAL MODELING OF HIGH TEMPERATURE POWER CONVERSION CAPACITORS J. R. MacDonald General Atomics Electronic Systems, Inc., Capacitor Research and Development, San Diego, CA, USA

There is an ever increasing need for power conversion capacitors that are capable of operating at higher energy densities, higher temperatures, and longer lifetimes. Unfortunately, an increase in energy density or temperature will necessitate significant de-rating of lifetime. The operating temperature of the capacitor is one of the most important parameters for long life, since an 8°C increase in temperature will reduce the lifetime by half. The current the capacitor is exposed to is important for determining the operating temperature, because power is dissipated in the electrode and dielectric in the form of heat. It is necessary to understand the thermal behavior of power conversion capacitors in order to optimize their design. This work presents a thermal model of a power conversion capacitor, examines the temperature rise in the capacitor with a variety of geometries and current load, and compares the results with experimental data.

This work was sponsored by the US Army Research Laboratory.

296 11O4 FDTD MODELING OF FAST TRANSIENT CURRENTS IN HIGH VOLTAGE CABLES Xiao Hu, Martin D. Judd, Wah H. Siew University of Strathclyde, Department of Electronic and Electrical Engineering, Glasgow, United Kingdom

Research into the modeling of sub-nanosecond partial discharge (PD) phenomena in high voltage cables is presented in this paper in order to illustrate the capabilities of the finite-difference time- domain (FDTD) simulation method for modeling transients and their effects measured at a distance. FDTD modeling is numerically intensive because it computes the three-dimensional electric and magnetic fields throughout the simulation volume. However, this has the advantage that time-varying quantities such as conducted currents and voltages can be recorded in addition to the vector field components at any point. For modeling PDs in cables, a current source can be introduced within the insulating medium and its time-domain waveform defined using digitally sampled data from an actual PD current pulse measurement. In the field, high frequency current transformers (HFCTs) are the most commonly used transducers for detecting and locating insulation defects in HV distribution cables with PD activity. The HFCT itself is not amenable to being modeled directly using FDTD because its geometrical detail (particularly the winding) is too fine to be mapped onto the FDTD mesh. However, a hybrid model can be implemented by recording magnetic (H) field values in a rectangular path around a conductor and applying Ampere's circuital law in a post-processing stage. In this way, the measured responses of real HFCTs that have been characterized experimentally can be implemented. Similar techniques could be applied to much larger insulation breakdown currents, for example, in gas switches. In this paper, the method for simulating localized insulation breakdown is presented, showing how this can be used to launch a PD pulse into a typical 11 kV cable model and predict the output response of an HFCT some distance away. This process is illustrated through a parametric study of variations in the PD source parameters and by comparison of the data with the measured propagation properties of PD signals in an 11 kV EPR-insulated cable sample that incorporates semiconducting layers with frequency-dependent properties. Examples are also given in which the FDTD software is used to model time-domain reflectometry measurements that can be useful for locating damage within the same type of HV cable.

297 11O5 ELECTROMAGNETIC MODELLING OF HIGH PRESSURE SPARK GAP PEAKING SWITCH Mrunal Parekh, Bindu Sreedevi, H.A. Mangalvedekar VJTI, VJTI-SEIMENS HIGH VOLTAGE LAB, Mumbai, India

Ultra-fast gaseous breakdown is an important phenomenon in pulsed power related to ultra wideband systems, plasma limiters, and ultra fast switches. The objective of this thesis being reduction in the rise time of the output pulse it is essential to minimize the inductance of the spark gap channel. This can be achieved by smaller inter electrode gap spacing. Therefore the design of switch requires modeling of field as well as circuit conditions to decide the electrode gap distance, configuration, gas pressure etc. The modeling of switch is carried out using the Finite element method to understand the Electric field and potential distribution in the switch geometry. Using the above quantities the switch is then modeled by obtaining resistance, inductance and capacitance parameters. With this developed model rise time of the voltage is calculated when the switch is connected to the load (Antenna).The field computation is carried out using FEMM (Finite element method magnetic) and the circuit calculation is done with MATLAB.

298 11O6 ESTIMATIONS OF THE ENERGY AVAILABLE TO A BREAKDOWN CHANNEL AS IT PROPAGATES THROUGH A DIELECTRIC MEDIUM Martin J Given1, Igor V Timoshkin1, Yiming Gao1, Mark P Wilson1, Tao Wang1, Scott J Macgregor1, Jane M Lehr2 1University of Strathclyde, Electronic and Electrical Eng, Glasgow, United Kingdom, 2Sandia National Laboratories Albuquerque, NM, USA

As a breakdown channel propagates through a dielectric medium, the energy required in changing the channel from its original state to an ionised gas or plasma will come from the electrostatic energy stored in the dielectric. As the channel propagates, the field distribution and thus the electrostatic energy stored will change. If these can be calculated then, insights into the development of the discharge channel should be obtained. The electrostatic energy density we for 2 a given value of field E is given by we = eE /2 If the electric field is known over the volume of the insulator, the electrostatic energy can be calculated by integrating the electrostatic energy density over the volume of the insulator V. The electric field produced by the discharge channel can be approximated assuming that the profile of the channel is a confocal hyperboloid and analytical forms exist for the resulting field. This approach allows the changes in energy stored in the system as the discharge channel propagates to be calculated. An alternative approach is to use charge simulation. In this method the electric field associated with a conductor can be calculated by summing the field produced by a series of charges. The magnitude of these charges can be calculated by defining the voltage at a series of points along the profile of the conductor and solving the resulting set of equations. The field resulting from a rod-plane electrode geometry can be simulated using a point charge and a series of line charges arranged on the axis of the rod electrode, with a corresponding set of image charges to establish a plane at potential zero corresponding to the earth plane. The advantage of this method is, that as the charges all lie on the axis of the electrode, the electrostatic energy in the system can be found by simply calculating the work done in separating each pair of charge and image charge from an initial position at the earth plane to the positions required to establish the required voltage profile. This paper will report on the results obtained by using the analytical technique based on integration of the field and by using the charge simulation method on the rate at which electrostatic energy is supplied to a discharge channel as it propagates through a dielectric medium. The validity of the charge simulation approach will be tested by examining the sensitivity of the model to changes in the location and magnitude of the charge distribution and also by comparing the field predicted by the charge simulation method with those calculated using Quickfield®.

299 11O7 PREVENTING BREAKDOWN BY DIRECT OPTIMIZATION APPROACH Zoran Andjelic1, Salih Sadovic2, Jean-Claude Mauroux3 1ABB Corporate Research Baden, Switzerland, 2Sadovic Consulting Paris, France, 3ABB Corporate Research Zuerich, Switzerland

The ultimate goal when designing the HV apparatus is to prevent the breakdown appearance during the operational conditions. In this paper we present the modelling approach for the optimal design of HV devices. Here we combine several tools that in an automatic iterative loop converge to the final, breakdown-free design. The integrated framework contains the module for BEM- based field computation, advanced tool for free-form optimization of the real-world problems and the controlling tool for breakdown criteria evaluation. In each iteration step after calculating the field distribution, the new instance of the possible final design is proposed by the module for the free-form optimization and checked by tool for the automatic control of the breakdown appearance. In the full paper we give detailed description of the techniques used within the integrated framework (simulation / optimization / controlling). Special attention is paid to the optimization approach. Here we use the gradient-less free-form optimization approach for both direct (sensitivity-less) and indirect (simple sensitivity-based) optimization. The procedure is illustrated by some examples of the optimization of the real-world apparatus (switches, circuit breakers). The optimal design proposed by the simulation is verified by the laboratory tests.

300 11O8 A SIMULATION OF BREAKDOWN PARAMETERS OF HIGH POWER MICROWAVE INDUCED PLASMA IN ATMOSPHERIC GASES Patrick Ford, John Krile, Hermann Krompholz, Andreas Neuber Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

Surface flashover induced by a High Power Microwave (HPM) fast rise-time pulse causes a significant drop in transmitted power, along with reflections that can damage the source. Momentum transfer collision rates in the range of 100s of GHz (for pressures exceeding 5 kPa) lead to low plasma conductivity, corresponding to absorption levels of up to 60 % of the incident power. A simulation algorithm was developed using the finite-difference time-domain (FDTD) method in order to model the growth and transport of the electron density near a dielectric surface, and the resulting interaction with the microwave pulse. The time-dependent plasma parameters are governed by empirical and simulated scaling laws for ionization and collision rates, along with diffusion coefficients; the resulting frequency-dependent plasma permittivity is transformed to a discrete algorithm to describe the spatially resolved plasma in the FDTD algorithm. A plasma thickness of up to 2 mm is simulated that compares with side-on ICCD imaging of surface flashover. Breakdown parameters, such as delay times and breakdown electric fields, in nitrogen, air and argon, are compared with experimental data on surface flashover across a polycarbonate window at atmospheric pressures. The flashover experiments are utilize an S-band magnetron producing a 2.5 MW peak power, 50 ns rise-time, 3 µs long pulse at a 2.85 GHz center frequency. The simulated results correlate well with measured, and the model exhibits low computational complexity when simulating a pulse on the order of microseconds, making it a good alternative to standard particle-in-cell codes.

This research is supported by an AFOSR grant on the Basic Physics of Distributed Plasma Discharges.

301 12O1 HIGH TEMPERATURE CAPACITOR PERFORMANCE IN A HIGH POWER, HIGH FREQUENCY CONVERTER Kevin Bray1, Hiroyuki Kosai1, Daniel Schweickart2, Biswajit Ray3 1UES, Inc Dayton, OH, USA, 2Air Force Research Laboratory, RZPE, Dayton, OH, USA, 3Bloomsburg University of Pennsylvania Bloomsburg, PA, USA

Evolutionary increases in the demand on electrical power systems have resulted in the need to develop the next generation of compact, power dense, electrical systems. These systems will utilize robust and efficient high voltage power devices that are operable over an extended temperature range (-55 oC to 250 oC). Recent advances in SiC power devices and high temperature magnetic and insulation materials have stimulated the development of compact, high switch rate power system components that can operate at higher temperatures. These effects have highlighted the need to develop capacitor technology for high power, high frequency power filter applications, which can cylce over a wide range of temperatures. In this study, capacitor properties were evaluated with respect to temperature and geometry, up to 200 oC. These capacitors were then inserted as the output filter capacitors in an interleaved DC-DC converter. A thermally insulated converter was constructed to evaluated the temperature effects of the capacitors on the overall converter performance. All components were maintained at room temperature while the capcitors were exposed to ambient temperatures up to 200 oC. Capacitor performance in the converter was correlated with observations in the capacitor properties. A SPICE simulation was also developed to evaluate the performance of different capacitors in an interleaved DC-DC boost converter model. The experimental performance of the capacitors in the boost converter was related to the input parameters in the model. Both predicted electrical properties and the empirical data were utilized to asses the performance of the capacitors under extreme conditions. This approach has provided a basic understanding of how capacitor architecture, its electrical properties, and the themal stability affect its performance as a filtering device in high power, high frequency applications.

302 12O2 GLASS DIELECTRICS FOR POWER CAPACITORS Mohan Manoharan1, Mike Lanagan1, Douglas Kushner2, Chen Zou2, Shihai Zhang2, Takashi Murata3 1The Pennsylvania State University, Materials Research Institute, University Park, PA, USA, 2Strategic Polymer Sciences, Inc., Capacitor Division, State College, PA, USA, 3NEG, Glass Division, Shiga, Japan

Thin glass sheet production has grown substantially because of the strong demand from the flat panel display industry and a large investment in the development of new glass fabrication methods. Alkali-free glass is a promising material for high temperature and high power capacitors because of its low dielectric loss and high breakdown strength. Several glass compositions are commercially offered with a permittivity range of 5 to 7 and low dielectric loss (tan delta <0.5%) values up to temperatures of 200°C. Glass ribbon is available with thicknesses between 50 and 200 µm and the thickness may be reduced to 5 µm by etching. Intrinsic breakdown strengths between 5 and 10 MV/cm have been measured for small-volume samples and the breakdown strength decreases as glass thickness and electrode area increase. The decrease in breakdown strength is attributed to the onset of a thermal breakdown mechanism. Large areas aluminum electrodes were evaporated on 80 mm by 80 mm glass sheets and the capacitance, loss and high electric field properties will be presented.

303 12O3 ELECTRICAL BREAKDOWN IN CAPACITOR DIELECTRIC FILMS: SCALING LAWS AND THE ROLE OF SELF-HEALING M. A. Schneider, J. R. MacDonald, M. C. Schalnat, J. B. Ennis General Atomics-Electronic Systems, Inc. San Diego, CA, USA

The study of insulating materials has garnered renewed interest over the past decade, particularly with the rise of nanodielectrics. Energy storage dielectrics are no exception and a number of results have been published claiming very impressive breakdown strengths and energy densities for a wide variety of materials. Unfortunately, many of these materials are evaluated solely with very short duration voltage withstand tests on very small sample areas, typically on the order of a few seconds and a few square centimeters of active dielectric area. Particularly with energy storage capacitor dielectrics, reported results can be significantly misleading as full-scale devices have very long operational lifetimes on the order of years, and dielectric areas as much as one hundred to several million times as large, the combination of which necessitates significant derating of the operating electric field of a full-scale device. Practical components must also include additional material such as electrodes, major insulation, and packaging, resulting in packing factors much less than 100%. The result of taking area scaling, life scaling, and packing factor into account often reduces practical energy densities by one to two orders of magnitude. Here we review test methodologies for evaluation of dielectric breakdown strength, highlighting contrasts with real world operating conditions. A review of failure statistics for dielectric materials is presented drawing on literature, experimental results ad Monte-Carlo simulations in order to demonstrate the critical need for investigation of materials targeting realistic conditions. Additionally we review scaling laws for capacitor materials, discussing the scalability of certain results with regard to developing full-scale capacitors. Finally an analysis of self-healing and its effect on these statistics is provided, demonstrating the necessity to tolerate dielectric breakdown in order to further the state-of-the-art for high energy density capacitors.

304 12O4 PULSED CURRENT LIMITATIONS OF HIGH POWER ELECTROCHEMICAL ENERGY STORAGE DEVICES David Wetz, Biju Shrestha, Peter Novak University of Texas at Arlington, Electrical Engineering Department, Arlington, TX, USA

Recently manufacturers of electrochemical energy storage devices have produced cells that are more power dense then previously available. The types of cells include lithium-ion batteries (LIBs), electric-double-layer capacitors (EDLCs), and lithium-ion capacitors (LICs) among others. The higher power capability has vastly increased the application space for which these types of devices can be used to source the prime power. Many pulsed power sources that draw their prime power form electrochemical energy storage devices have already been developed and their capabilities will only improve as the energy storage technologies advance. Though many manufacturers list peak pulsed current limitations on their datasheets, the values listed are often limited by the experimental hardware used to extract current from the cells and not always the cells themselves. In order to experimentally validate the pulsed current limitations of some of the newest electrochemical cells, a low impedance test stand, capable of extracting high pulsed current from individual cells has been developed. The impedance of the stand, less than 1 milli- Ohm, is such that in most cases, the impedance of the cell dominates the discharge current. A description of the test stand and the current limitations of many of the cells tested thus far will be presented.

305 12O5 STATUS UPDATE OF THE POWER CONDITIONING SYSTEM IN THE NATIONAL IGNITION FACILITY Bruno Le Galloudec1, Phil Arnold1, Glen James1, Dave Pendleton1, Dave Petersen1, Geoff Arellano-Womack2, Javier Cano3, Allen Harkey2, Norris Lao2, Manuel Magat1, Michael McIntosh2, Quang Ngo2, Seth Robison2, David Schwedler2, Mark Lopez2 1Lawrence Livermore National Laboratory, Engineering/LSEO, Livermore, CA, USA, 2AKIMA Infrastructure Services LLC Livermore, CA, USA, 3NSTEC Livermore, CA, USA

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory operates the world's largest and most energetic laser. The facility supports studies of high energy density physics with the ultimate goals of achieving ignition and energy gain for the first time in a laboratory setting. The success of its mission depends heavily on key subsystems like the power conditioning system (PCS), where near 100% availability is required in supporting 24/7 laser operation. The 192 modules of PCS store and then deliver approximately 400 MJ of electrical energy to the laser amplifiers. The sheer number of modules coupled with the aggressive shot schedule present a challenge for both preventive maintenance and the implementation of engineering changes. Because the system comes into play very late during the shot process, it is extremely important to minimize the number of occurrences and duration of reactive maintenance activities. In this presentation we will discuss PCS performance, training and maintenance strategies, along with a series of development and upgrades that will help assure long-term system reliability and availability while supporting NIF's missions.

This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-520240.

306 12O6 DESIGN AND CONSTRUCTION OF A 250 KV, 100 HZ REPETITIVE VIRCATOR TEST STAND Kelton Clements, Randy Curry, Robert Druce University of Missouri, Center for Physical and Power Electronics, Columbia, MO, USA email: [email protected]

The Center for Physical and Power Electronics (CPPE) at the University of Missouri, Columbia is investigating the applicability of utilizing two separate Vircators simultaneously for multipulse testing. To facilitate this research, we have designed and constructed a versatile modulator to drive the HPM sources that allow us to drive two Vircators in parallel. The modulator consists of a thyratron-switched capacitor bank that pulse charges a water transmission line through a pulse transformer. The water transmission line is then switched into a voltage adder by a pressurized oil switch with an output risetime of 20ns. The capacitor bank is charged to 30 kV by a bank of power supplies delivering up to 40kJ/s and switched by a thyratron into the pulse transformer. The 1:10 pulse transformer charges the water line to 300 kV in approximately 2.5μs. When driven by the pulse line, the 250 kV output voltage is utilized to simultaneously drive the two, 32 Ω Vircators in parallel or a 16 Ω load with a 70 ns long pulse. We will present details of the design, including electromagnetic simulations using CST Microwave Studio and SPICE circuit simulations of the Vircator design and modulator design, as well as construction details. The test results will be presented, and the power output of the Vircators under various operating conditions will be discussed.

307 12O7 EXPERIMENTATION AND SIMULATION OF HIGH CURRENT DENSITY SURFACE COATED ELECTRO-EXPLOSIVE FUSES Jacob Stephens, Andreas Neuber, James Dickens, Magne Kristiansen Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, TX, USA

The primary objective of the research discussed in this paper is to develop a compact electro- explosive fuse (EEF) for a flux compression generator (FCG) power conditioning system, capable of rapidly obtaining and maintaining high impedance. It was observed that significant gains in EEF performance are introduced with the application of an insulating coating to the surface of the EEF wire. A 2 kA small scale test bed has been designed to provide a single wire EEF with similar current density (~107 A/cm2), voltage gradient (~7 kV/cm), and timescale (~8 μs) as to what is seen by and EEF utilized in a HPM generating FCG system [1]. With the small scale test bed EEF performance data was rapidly obtained at a significantly lower cost than equivalent full scale FCG experiments. High speed imaging of the EEF opening process revealed that the gains in performance associated with surface coated EEFs are a result of suppression of plasma development at the wire surface. Using the small scale test bed, EEFs were tested in quartz sand and various pressures of nitrogen or sulfur hexafluoride to determine the effect of wire environment on EEF performance for both bare wire and insulated wire. A one-dimensional finite difference model coupled with the Los Alamos National Laboratory SESAME Equation-of-State database was utilized to simulate the resistive behavior of the single wire EEFs in each of these environments. Further, a large scale test bed, designed to provide a similar current action as to what is seen by an FCG was used to test 18 wire EEF arrays at the 40 kA level. With this system both compact and non-compact EEF arrays with bare and insulated wire were tested. Data taken from the experiments is used along with the model output to elucidate the observed performance enhancement provided by the application of a surface coating to the compact FCG power conditioning EEF. [1] A. Young, A .Neuber, M. Elsayed, J. Korn, J. Walter, S. Holt, J. Dickens, M. Kristiansen, L. Altgilbers, "COMSED 1 – A Compact, Gigawatt Class Microwave Source Utilizing Helical Flux Compression Generator Based Pulsed Power," 2010 IEEE International Power Modulator and High Voltage Conference, Atlanta, GA, May 23 - 27, 2010.

Distribution A: Approved for public release

308 12O8 ANALYSIS ON STRAY PARAMETERS IN A SOLID-STATE MARX PULSED POWER MODULATOR Jian Qiu, Kefu Liu, Liuxia Li Fudan University, Electric Light Sources, Shanghai, China

In many pulsed power applications, high voltage and high frequency square pulses are needed. Traditional Marx type modulators based on solid-state switches often couldn't meet the requirements, especially on frequency and waveform. To solve the problems,a noval solid-state pulsed power mudulator based on charging and driving by magnetic ring transformers is introduced in the paper. In order to obtain pulses with steep voltage edges on various kinds of loads, half bridges formed by IGBT switches are used in the mudulator. The usage of magnetic rings makes the stray capacitance become one of the most important aspects to distort the output voltage waveforms.The effect of stray parameters on output waveforms is analysed in detail by Pspice simulation and verified by the experiments in this paper.According to the analysis, this paper deals with a design of the pulsed power mudulator with isolated recharge for dielectric barrier discharge (DBD) research, In order to design much more suitable pulsed modulators, some methods are described to reduce the influence of the stray parameters.

309 AUTHOR INDEX

A Barnes, Michael ...... 19 Abe, Yuichi...... 176 Barros, Warner...... 119 Adhikhari, Biswajit...... 187 Barua, U .K...... 82, 96 Agarwal, Anant...... 31 Basha, Kamal ...... 86 Aguglia, Davide ...... 93 Batrakov, Alexandr...... 226 Ahn, Jae Woon...... 144 Baxter, Emily ...... 229, 264 Ahn, SukHo...... 72 Bayne, Stephen ...... 29, 268, 272 Akiyama, Hidenori...... 11, 99, 102, 111, Bayol, Frederic...... 180 ...... 124, 125, 224 Beeson, Sterling ...... 200 Al Saif, Haitham ...... 27 Benwell, Andrew ...... 7, 22 Aldan, Manuel P...... 14 Bhattacharyya, Kiran ...... 132 Alexcenco, V...... 180 Bilbao, Argenis ...... 272 Alferov, Dmitriy ...... 143 Binderbauer, Michl ...... 208 Allen, Raymond ...... 210 Bischoff, Rainer ...... 106 Amari, Saad El...... 202 Blackburn, Trevor...... 114, 118 Amarnath, Jinka .....65, 66, 67, 235, 286, 287 Bland, Michael...... 293 Ambikairajah, R...... 118 Bocchetta, C.J...... 242 Amrenova, Assem...... 244 Bochkov, Dmitry...... 98, 142, 209, 226 Anamkath, Harry...... 25 Bochkov, Victor...... 98, 142, 171, 209, 226 Andersen, Michael ...... 69, 70, 71 Bonelli, Lucia...... 208 Andersen, Thomas ...... 69 Borg, Karl ...... 9 Anderson, David ...... 32, 33, 188 Boriraksantikul, Nattaphong...... 132 Anderson, Jay ...... 94 Borodiy, Iren...... 281 Anderson, Michael...... 208 Bowman, Brett ...... 258 Andjelic, Zoran ...... 300 Boyer, Craig...... 210 Andreason, Sam ...... 142 Bozduman, Ferhat...... 294 Araújo, Diego...... 119, 156 Bragg, James-William...... 197, 218, 259 Araujo, Eduardo...... 136 Bray, Kevin...... 302 Arellano-Womack, Geoff ...... 306 Brito, Paula S...... 97 Arnaud-Cormos, Delia...... 202, 263 Brown, Darwin...... 196 Arnold, Phil...... 306 Brown, W...... 145 Arntz, Floyd ...... 5 Bunin, Roman ...... 143 Burke, Kevin...... 258, 276 Burkhart, Craig ...... 7, 22, 35, 290 B Bystritskii, Vitaly...... 208 Baca, David...... 241 Baginski, Michael ...... 220 Bai, Rujun ...... 147 C Baird, Jason...... 252 Cai, Li ...... 109 Bak, Piotr ...... 142 Cairns, Richard ...... 250 Banakhr, Fahd...... 131 Calebrese, Chris ...... 199 Banerjee, Partha ...... 187 Canacsinh, Hiren...... 97 Bansal, L. K...... 82, 96 Cano, Javier...... 306 Bao, Chaobing...... 109 Cao, Lei...... 253 Caramelle, Laurent...... 174

310 Caron, Michel ...... 192 Dai, Yingmin...... 40 Casey, Jeffrey ...... 5 Dale, Greg...... 115, 229 Cassel, Richard ...... 3, 26, 105 De Ferron, Antoine ...... 41, 131, 174 Castro, Malone...... 113, 158 DeAngelis, Thomas...... 258 Caudle, Byron ...... 220 Deb, Pankaj...... 187 Cavallini, Andrea ...... 116 Debache, Willy ...... 173 Cavazos, Tommy ...... 196 Decker, Franz-Josef ...... 239 Chalenski, David...... 217 Del Rosso, Tommaso...... 208 Chang, ChienKuo...... 161, 162 Demol, Gauthier...... 180 Chang, Hong-Chan ...... 120 Devoe, Alan ...... 196 Chang, Jeong-Ho...... 159, 249 Dhinesh, Kavitha...... 64 Chao, Ji ...... 293 Dickens, James...... 12, 13, 30, 89, 92, 197, Chemerys, Volodymyr...... 256, 257, 281 ...200, 206, 218, 221, 259, 269, 270, 308 Chen, Antong ...... 164 Dogan, Fatih...... 196 Chen, Debiao...... 183 Domonkos, Matt ...... 34, 196 Chen, Hao ...... 246 Douglass, Scott ...... 250 Chen, Jingliang ...... 149, 150, 163, 164 Druce, Robert...... 28, 307 Chen, Jinling ...... 236 Duband, Jean-Marc...... 174 Chen, Lin...... 194, 254 Dubinov, Alexander...... 171 Chen, Mao...... 183 Dudley, Evan...... 48 Chen, Qiangjian ...... 236 Dzitko, Hervé...... 291 Chen, Yaohong ...... 166 Chen, Yeong-Jer ...... 133 E Cheng, Cheng...... 212 Ebrahimi, Hadi...... 277, 278 Cheng, Desheng ...... 236, 253 Eddie, Glines...... 52 Cheng, Lin...... 31 Efanov, Mikhail ...... 175, 198 Chia, Chin Yang...... 170 Efanov, Vladimir...... 175, 198 Chivel, Yuri...... 209 Egorov, Ivan...... 135, 243 Choi, Oh Ryoung ...... 189 Eichhoff, Daniel...... 42 Chowdary, Duvvada Deepak ...... 235 Ekdahl, C...... 295 Chung, Shen Shou Max ...... 265, 266 Elfrgani, A...... 261 Clare, Jon ...... 293 Elizondo-Decanini, Juan...... 48 Clark, Scott ...... 270 El-Kishky, Hassan...... 277, 278 Clemens, Markus ...... 225 Ennis, J. B...... 289, 304 Clements, Kelton...... 307 Eriksson, M...... 242 Coelingh, Gert-Jan ...... 18 Esipov, Victor ...... 243 Cooper, J. R...... 91 Espino-Cortes, Fermin P...... 154 Cordova, Steve...... 192 Evsin, Dmitriy...... 143 Costa, Edson ...... 113, 119, 156, 158, 271 Couderc, Vincent ...... 202 Curry, Randy...... 28, 91, 145, 223, 307 F Feng, Bao ...... 61 Ferreira, Tarso Vilela...... 271 D Fielding, Andrew M...... 108 Dahlerup-Petersen, Knud...... 18 Fierro, Andrew ...... 12, 13 Dahlke, Matthias...... 21 Finney, Stephen...... 177 Dai, Ling ...... 55 Fleming, Timothy ...... 216

311 Ford, Patrick...... 301 Gu, Chi-Wuk...... 227, 228 Fornasari, Luca ...... 116 Gu, Feng-Chang...... 120 Foster, Peter ...... 178, 273 Guan, Yongchao ...... 212 Fowler, William ...... 179 Guan, Zhicheng...... 60, 61 Frank, Klaus...... 13 Gulec, Ali...... 294 Franzi, Matthew ...... 217 Gundersen, Martin A...... 4 Freire, Raimundo ...... 113, 119, 156 Guo, Fei...... 134 French, David...... 217 Gupta, L.N...... 82, 96 Fukawa, Fumiaki...... 121, 127 Fuks, M...... 261 H Furusato, Tomohiro...... 11 Han, Wenhui ...... 40 Han, Xiao ...... 279 G Han, Zhaojun...... 15 Gabdullina, Asylgul ...... 244 Hao, Shirong ...... 40, 191 Gahl, John ...... 251 Hao, Xi-Wei...... 280 Gale, Don ...... 196 Hara, Masanori...... 11 Gall, Brady...... 229, 264 Hargrave, Barbara...... 133 Gan, Kongyin...... 36 Harkey, Allen...... 306 Gao, Yiming...... 299 Harper-Slaboszewicz, V...... 275 Gao, Yinghui...... 77, 79, 230, 279 Harris, Rachel ...... 117, 155 Garbi, Mike...... 25 Hartmann, Werner...... 6 Gardner, Alan...... 25 Hashimoto, Masanori...... 125 Geng, Lidong ...... 191 Hatfield, Lynn...... 12, 13 Georges, Alain ...... 291 He, Hui...... 183 Giammanco, Francesco...... 208 He, Shaolin...... 163 Giesselmann, Michael...... 29, 182 He, Yong...... 212 Gilgenbach, Ronald...... 217 Hebner, Robert ...... 1 Giuliani, John L...... 108 Hegeler, Frank...... 108 Given, Martin...... 10, 47, 103, 107, 110, 299 Heidger, Susan ...... 34, 196 Glidden, Steven...... 23, 24 Helava, Heikki ...... 28 Glover, Ian ...... 119, 156 Heo, Hoon...... 189 Glover, Steven...... 178, 273 Hettler, Cameron...... 30, 89, 92, 197 Gnedin, Igor ...... 98 Higuchi, Takato...... 122 Gomes, Luana ...... 113 Hitchcock, Sherry ...... 25, 26 Gomez, Pablo...... 154 Ho, Janet ...... 49 Gonzalez, Domingues...... 157 Hock, Christian ...... 141, 151 Goru, Radhika...... 169 Hoff, Brad ...... 217 Goryl, P...... 242 Holen, Paul...... 25 Gota, Hiroshi...... 208 Holma, Janne...... 19 Gough, Christopher...... 238 Holt, Shad ...... 270 Goussev, Gennadi ...... 72, 172 Hong, Wu...... 90 Graneau, Neal ...... 214 Hope, M...... 91 Grass, Norbert...... 6 Hori, Hitoshi ...... 128 Greening, Geoff ...... 217 Hosseini, Hammid...... 125 Grimes, Monty ...... 17 Hosseini, S.H.R...... 99 Gryshin, Yury ...... 209 Hou, Gene ...... 134

312 Hu, Hepin...... 36 Judd, Martin ...... 117, 155, 297 Hu, Xiao...... 297 Huang, Kun...... 186 K Huang, Lina...... 70, 71 Kaczmarek, Michal...... 247, 248 Huang, Weiming...... 76 Kageyama, Tatsuya...... 126 Huang, Xue-Zeng...... 16 Kai, Hirofumi...... 102 Huang, Yan-guang ...... 165 Kaikanov, Marat ...... 243 Huang, Yien Chieh...... 265, 266 Kalavathi, Munagala Surya...... 83, 84, 87 Huhman, Brett...... 95, 210, 250 Kalavathi, Surya...... 284 Hunag, Kun...... 215 Kalenderli, Ozcan ...... 45 Huynh, P...... 68 Kamakshaiah, Saprams...... 67 Hwang, Jung-yun ...... 73 Kanaev, Gennady...... 135 Kang, Heung-sik ...... 73 I Kara, Alper...... 45 Iberler, Marcus...... 141, 151 Kardo-Sysoev, Alexei...... 22 Ibrahim, Omar...... 27 Karlik, Konstantin...... 226 Ihara, Takeshi...... 11 Katsuki, Sunao ...... 11, 102, 111, 125, 224 Inagaki, Takahiro ...... 203 Kelly, Patrick ...... 268, 270 Inokuchi, Makoto...... 124 Kemp, Mark ...... 7, 290 Isakov, Ivan...... 208 Kempkes, Michael ...... 5 Ishizawa, Hidetoshi...... 125 Khanali, Mahdi ...... 139 Islam, Naz ...... 27, 132, 211 Kim, Alexander...... 179, 180 Ito, Koyu ...... 222 Kim, Baek ...... 229, 264 Itoh, Haruo ...... 121, 127 Kim, Jin O...... 160 Ivanov, Valeriy ...... 143 Kim, Sang-hee...... 73 Iyengar, Pravin...... 177 Kinsey, Nathaniel...... 28 Kirawanich, Phumin ...... 27, 132 J Kirkici, Hulya ...... 50, 51, 146, 147, 220 Jackson, Robert...... 274 Kishita, Yumi...... 102 Jacoby, Joachim ...... 141, 151 Kiyan, Tsuyoshi ...... 11 Jadidian, Jouya...... 9 Ko, Kwang-Cheol ...... 227, 228, 262 Jain, H S...... 233 Kohler, Sophie ...... 202, 263 James, Glen...... 306 Kolb, Juergen F...... 100 Jang, Sung-Roc ...... 72, 172 Komashko, Alexander...... 175 Jauregui, Frank...... 208 Kondo, Chikara...... 203 Ji Yang ...... 80 Kondratief, S...... 180 Jia, Zhidong...... 60 Kong, Zhonghua ...... 288 Jiang, Chun ...... 184 Konopelski, ...... 91 Jiang, Hui ...... 137 Kornilova, Inna ...... 171 Jiang, Weihua...... 129, 193, 222, 237 Kosai, Hiroyuki...... 302 Jing, Yi...... 47 Kostora, M...... 34 Jing, Yu...... 100 Kovaleski, Scott ...... 115, 229, 251, 264 Jo, Seung Whan ...... 144 Krasnykh, Anatoly ...... 22, 239 Johnson, Cheryl...... 208 Krile, John...... 301 Jow, T. Richard...... 49 Krishnan, Sindhu T ...... 64 Ju, Heung-Jin ...... 227, 228 Kristiansen, Magne ...... 221, 269, 308

313 Krompholz, Hermann ...... 301 Li, Hongtao ...... 37, 39 Kuek, Ngee Siang ...... 219 Li, Hua ...... 166 Kukhta, Vladimir ...... 135 Li, Huirong...... 50, 51 Kumar, Naveen ...... 284 Li, Jian...... 232 Kumbaro, D...... 242 Li, Jiang...... 134 Kuo, Cheng-Chien ...... 120 Li, Jin ...... 183 Kurz, Andreas ...... 42, 43 Li, Lee...... 109 Kushner, Douglas...... 54, 303 Li, Liuxia...... 38, 185, 309 Kuthi, Andras...... 4 Li, Long...... 107 Kwan, Sei-jin ...... 73 Li, Tao...... 36 Kwon, Hae Ok ...... 144 Li, Wenfeng ...... 8, 76, 137 Kwon, Jae...... 229, 264 Li, Xin...... 183 Li, Yuan ...... 183 L Li, Zhenhong...... 51 Lacouture, Shelby ...... 29 Li, Zhiwei...... 55, 166 Laity, George ...... 12, 13 Liang, Lin...... 90 Lakshmi, Vuyyuru Anantha...... 83, 84 Liew, Ah Choy...... 219 Lamberti, Patrizia...... 130 Lim, Tee Chong ...... 177 Lambrecht, Michael ...... 216 Lin, Fuchang ...... 55, 109, 166 Lanagan, Mike ...... 303 Lin, Tianyu...... 163 Lao, Norris ...... 306 Lira, George Rossany Soares...... 271 Lassalle, Francis...... 140 Liu, De ...... 166 Lau, Yue-Ying ...... 217 Liu, Hongwei ...... 37, 39 Lavesson, Nils...... 9 Liu, Jinfeng ...... 37, 39 Lawson, Kevin ...... 29 Liu, Kefu...... 38, 78, 148, 185, 205, 231, 309 Le Galloudec, Bruno...... 306 Liu, Kun ...... 77, 230 Leckbee, Josh...... 192 Liu, Xueqing ...... 90 Lee, An Kyu...... 160 Lodes, Adam...... 145 Lee, Byeong-jun...... 73 Loisch, Gregor ...... 141 Lee, Byung-Joon...... 144 Lopatin, Vladimir...... 135 Lee, Cheol-Kyou...... 228 Lopes, Ivan...... 136 Lee, Heung-Ho...... 159, 249 Lopes, Waslon...... 119 Lee, Heung-su...... 73 Lopez, Mark...... 306 Lee, Hyo-Sung ...... 249 Loree, E...... 34, 91 Lee, Kun-A ...... 228, 262 Lou, Zaifei...... 288 Lee, Sun Hun ...... 160 Louverdis, Gerasimos ...... 292 Lee, Sung-Hun ...... 249 Low, Chee Hoong ...... 170 Lehr, Jane...... 10, 47, 107, 110, 299 Low, Kum Sang ...... 170 Lei, Yu ...... 205 Low, Kum Wan...... 170 Leith, John...... 52 Loyen, Arnaud ...... 140 Leveque, Philippe ...... 202, 263 Lu, Gensheng ...... 231 Li, Chengxiang...... 184 Lu, Guo-jun...... 165 Li, Chen-xiang ...... 232 Lu, Peng ...... 111 Li, Fei...... 134 Lu, Zan...... 211 Li, Gang ...... 165 Luginsland, John...... 217 Li, Ge ...... 204, 236, 253, 255 Lukonin, Evgeny...... 243

314 Luo, Haiyun ...... 112, 152, 153 Montanari, Gian Carlo ...... 116 Lutrick, Christopher...... 270 Mooder, J...... 242 L'vov, Igor...... 171 Moon, Yong-jo...... 73 Lynn, Curtis ...... 269 Moore, Harry...... 258 Moore, Philip ...... 155 M Morais, Cláudio...... 157 Ma, Hao...... 62 Morales, Kim ...... 181 Mabuchi, Ryo...... 126 Morell, Alain...... 140 MacDonald, J. R...... 289, 296, 304 Moriyama, Shinya...... 102 Macêdo, Euler...... 113, 119, 156 Morris, Ben ...... 239 MacGregor, Scott.10, 47, 103, 107, 110, 299 Mouillet, Marc ...... 291 MacNair, David...... 7 Mu, Hai-Bao ...... 16 Madrid, E. A...... 275 Mueller, Georg...... 20 Magat, Manuel ...... 306 Muffoletto, Daniel...... 258, 276 Magori, Yoshihiro...... 128 Muffoletto, Mark...... 258 Mahadevan, David ...... 170 Muganal, Suryakalavathi ...... 86 Makeev, Yaroslav ...... 98, 142 Munagala, Suryakalavathi...... 88, 169, 285 Malaji, Sushama...... 85 Murata, Takashi ...... 303 Mallick, Shreeharsh ...... 233 Myers, Matthew C...... 108 Malmgren, L...... 242 Mangalvedekar, H.A...... 298 N Mani, Kuchibhatla...... 67 Naderi, Mohammad Salay ...... 114 Mankowski, John ...... 206, 268, 270 Nagahama, Masataka ...... 128 Manoharan, Mohan...... 303 Nagalingam, Rajeswaran ...... 88 Mao, Chongyang...... 215 Nakamura, Asuki ...... 224 Mardahl, Peter...... 216 Nam, Jong Woo ...... 144 Mardikyan, Kevork ...... 45 Nam, Sang Hoon...... 144, 189 Martin, Justin ...... 41 Nambiar, T N Padmanabhan...... 64 Matthias Hoffacker ...... 43 Nashilevskiy, Alexander...... 135 Matvienko, Vasily...... 208 Nastrat, L...... 46 Mauch, Daniel...... 30, 197 Neri, Jesse ...... 95, 210, 250 Mauroux, Jean-Claude ...... 300 Neto, José Maurício ...... 119, 156 Mayberry, Clay ...... 27 Neto, Lauro Paulo da Silva ...... 260 Mazarakis, Michael...... 179, 180 Neuber, Andreas ...... 12, 13, 89, 197, 200, McDaniel, Dillon ...... 273 ...... 218, 221, 269, 301, 308 McIntosh, Michael ...... 306 Ng, Albert ...... 170 Melcher, Paul ...... 246 Ngo, Quang...... 306 Mendes, João...... 97 Nguyen, Minh ...... 7, 239 Mermigkas, Athanasios...... 103 Niayesh, Kaveh...... 139 Merz, Wolfhard...... 17 Nicolaev, Vladimir...... 226 Mi, Charles...... 54 Nicolas, Rémi...... 291 Mi, Yan ...... 167, 184, 232 Nikolic, Paul Gregor ...... 42, 43 Miller, C. L...... 275 Niu, Zheng ...... 138 Minamitani, Yasushi...... 122, 123, 129, 176 Nonn, Paul...... 94 Mitsutake, Kazunori...... 102 Norgard, Peter...... 115, 229, 264 Miyamoto, Yuta ...... 99 Novac, Bucur ...... 131, 195, 214, 292, 305

315 O Pendleton, Dave ...... 306 Obata, Daichi ...... 224 Peplov, Vladimir...... 240, 245 O'Brien, Heather ...... 2, 29, 31 Pereira, Marcos T...... 97 O'Connor, Kevin ...... 223 Perevodchikov, Vladimir ...... 190 Ogunniyi, Aderinto ...... 2, 29, 31 Petersen, Dave...... 306 Oh, Seung-Chan...... 249 Phung, Toan ...... 15, 114, 118 Ok, Seung-Bok...... 72, 172 Pignolet, Pascal...... 131 Oksuz, Lutfi ...... 294 Pihl, Chris ...... 142 Okuda, Yuta ...... 99 Pisa, Luiz...... 157 Olivares, Tomas I. Asiain ...... 154 Pointon, Tim ...... 192 Oliver, Bryan...... 192 Pokryvailo, Alex ...... 201 O'Loughlin, Jim ...... 196 Poloskov, Artem ...... 243 Omar, Kaashif...... 214 Prabaharan, T...... 187 Orchard, Raymond...... 54 Pradeep, Adusumilli...... 233 Oshita, Daiki ...... 99 Prasad, S...... 261 Ostlund, Kevin ...... 5 Proskurovsky, Dmitry...... 226 Ostrikov, Kostya (Ken)...... 15 Otake, Yuji...... 203 Q Otto, Johanna ...... 151 Qi, Xiangdong...... 109 Ozur, Grigory...... 226 Qin, Yu...... 165 Qiu, Jian ...... 38, 78, 148, 185, 205, 309 P Qureshi, K...... 82, 96 Padmavathi, Devasetty...... 67 Paganini, Enrico...... 208 R Pagidi, Balachennaiah...... 285 Radhika, Goru...... 234 Pan, Ci Ling ...... 265, 266 Rahaman, Hasibur...... 144 Panev, Bozhidar ...... 18 Rahman, Muhammad Muktadir...... 75 Panov, Alexey...... 142 Ramarao, Narapareddy ...... 66 Panov, Piotr...... 226 Ran, Huijuan ...... 56 Paraliev, Martin...... 238 Rao, Gade Govinda...... 287 Parekh, Mrunal...... 298 Rao, Junfeng ...... 78 Park, Jong-Yoon ...... 262 Ravishankar, J...... 118 Park, Soung-soo ...... 73 Ray, Biswajit...... 302 Parker, G...... 34 Reale, David...... 206, 270 Parker, Jerald...... 196 Reass, William ...... 241, 293 Parker, Michael...... 292 Reddy, B.Ravindhra Nath...... 86 Parson, Jonathan ...... 221 Reddy, C. Subba Rami...... 87 Parthasarathy, P...... 65 Reddy, T. Bramhananda ...... 83, 84 Partridge, Edward ...... 241 Reddy, VC Veera...... 83, 84 Patel, Gunjan...... 32, 33, 188 Redondo, Luís M...... 97 Patel, Paresh...... 82, 96 Rees, Daniel ...... 241 Patel, V.B...... 82, 96 Reess, Thierry ...... 41 Pawel Rozga...... 44 Reid, Alistair...... 117 Pecastaing, Laurent...... 131, 174 Remnev, Gennady...... 135, 243 Pecquois, Romain ...... 174 Ren, Chengyan...... 56, 57, 63 Pena, Gary...... 178, 273 Rey-Bethbeder, Franck ...... 41

316 Reynaud, Denis...... 291 Scherbakov, Alexander...... 190 Rhee, Jae-Ho...... 227 Schmidt, M...... 145 Rice, David ...... 251 Schneider, Larry...... 178, 273 Richter-Sand, R.J...... 34 Schneider, M. A...... 289, 304 Rienecker, Tim...... 151 Schnettler, Armin ...... 42, 43 Rivaletto, Marc ...... 174 Schoenbach, Karl ...... 133 Rivers, Chris ...... 25 Schönlein, Andreas ...... 141, 151 Robison, Seth ...... 306 Schulze, M...... 295 Rodrigues, Maria...... 113, 158 Schwedler, David...... 306 Rohde, Klaus-Dieter ...... 6 Schweickart, Daniel ...... 302 Rokkaku, Kotaro...... 121, 127 Schwendner, Martin...... 6 Romeo, Stefania...... 101, 130 Scozzie, Charles...... 2, 29, 31 Roques, Bernard...... 140 Selemir, Victor...... 171 Rose, C. R...... 295 Seltzman, Andrew...... 94 Rose, D. V...... 275 Senior, Peter...... 195, 214, 292 Ross, Randy ...... 25 Sethian, John D...... 108 Rossi, Jose Osvaldo ...... 219, 260 Shaheen, William...... 2, 31 Rouillard, Mark...... 208 Shao, Tao ...... 57, 58, 62, 63, 76, 137, 138 Roznowski, Scott ...... 179 Shao, Yingbiao...... 149 Runge, Lill ...... 25 Shapenko, Valentina ...... 190 Ruscassie, Robert...... 41, 131 Shareghi, Maziar...... 114 Russell Blundell...... 267 Sharkawy, R.M...... 46 Ryoo, Hong-Je ...... 72, 172 Sharma, Ashwani ...... 27 Sharma, Surender...... 187 S Sheng, Lieyi ...... 52 Sack, Martin...... 20 Shi, Xiangyu ...... 55 Sadovic, Salih ...... 300 Shi, Xiaoxia...... 79 Sadovoy, Sergey ...... 171 Shimomura, Naoyuki ...... 126, 128 Saethre, Robert...... 240, 245 Shintake, Tsumoru ...... 203 Saied, Mohamed ...... 74, 282, 283 Shirasawa, Katsutoshi...... 203 Saito, Takashi...... 123 Shkuratov, Sergey...... 252 Sakugawa, Takashi ...... 111, 124 Shrestha, Biju...... 305 Sakurai, Tatsuyuki ...... 203 Shukla, Rohit...... 187 Sanders, Howard...... 23, 24 Shuto, Tsuyoshi...... 102 Sanders, Jason M...... 4 Shyam, Anurag ...... 187 Sandoval, Dan...... 196 Sidorov, Vladimir ...... 143 Sang Hoon Nam...... 207 Siew, Wah H...... 297 Sannino, Anna...... 101 Silva, Juliano...... 157 Satoh, Yuuya...... 121, 127 Simmons, Christopher...... 218, 259 Savage, Mark ...... 179 Simon, David ...... 217 Scapellati, Cliff ...... 201 Sinclair, Mark ...... 10, 177, 214 Scarfì, Maria Rosaria ...... 101, 130 Sinebbryukhov, Alexander ...... 180 Schalnat, M. C...... 304 Singh, B.P...... 65 Schamiloglu, Edl...... 58, 62, 76, 137, 138, Singh, Hardev ...... 258 ...... 219, 260, 261 Singh, N. P...... 82, 96 Scheinker, Alex...... 293 Slenes, Kirk...... 196

317 Smith, Ivor ...... 131, 195, 214, 292 Thomsen, Ole C...... 69 Soares, Rudi ...... 93 Thorin, S...... 242 Solley, Dennis...... 32, 33, 188 Thummala, Prasanth ...... 70, 71 Sommars, Wayne ...... 196 Timoshkin, Igor....10, 47, 103, 107, 110, 299 Song, Bai-Peng ...... 280 Tokuchi, Akira ...... 129, 193, 237 Song, Shengyi ...... 212 Tong, Chunya...... 288 Song, Xupeng...... 231 Tooker, J.F...... 68 Sreedevi, Bindu...... 298 Toury, Martial...... 192 Sridevi, Jami ...... 287 Tracz, Piotr...... 242 Stalkov, Pavel ...... 190 Trukhachev, Ivan ...... 190 Stangenes, Magne ...... 25, 26 Tsai, Chung-Nan...... 50, 146 Stephens, Jacob...... 308 Tu, Zhuolin ...... 205 Strashnoy, George...... 208 Tucci, Vincenzo ...... 130 Strowitzki, Claus...... 21 Tuncer, Enis ...... 199 Stults, Allen...... 213, 252 Stygar, William...... 179, 180 U Su, Cheng...... 55 Uemura, Kensuke...... 135 Subramanyamps...... 286 Upia, Antonio...... 258 Sugai, Taichi ...... 129 Ushich, Vladmir...... 171 Sullivan III, William ...... 30, 89, 92, 197 Uto, Yoshihiro...... 128 Sumod, C.B...... 82, 96 Sun, Yaohong...... 8, 57, 63, 77, 79, 230, 279 Sun, Zhenting...... 60 V Sunilkumar, Chava...... 286 Vadher, V...... 82, 96 Suryakalavathi, Mungala ...... 234 VanGordon, James...... 229, 264 Suslov, Valery...... 209 Vasiliev, Gleb ...... 98 Suzuki, Susumu ...... 121, 127 Veracka, Michael ...... 210 Verboncoeur, John ...... 14, 274 Verma, Rishi ...... 187 T Vermel, Vladimir ...... 209 Tan, Zhiyuan...... 36 Vernier, P. Thomas ...... 101, 263 Tanabe, Takashi ...... 125 Vézinet, René...... 174 Tang, Chao...... 59 Viator, John...... 132 Tang, Tao ...... 22, 35, 290 Vilar, Pablo Bezerra...... 271 Tarasenko, Victor F...... 62 Villanueva, Juan M...... 156 Teboul, Michael ...... 173 Volkov, S...... 180 Teke, Erdogan...... 294 Vollmer, Travis...... 182 Temple, Victor ...... 2, 31 Vu, Thao ...... 263 Teng, Yaqing...... 148 Vyalykh, Dmitry ...... 171 Tenneti, Madhu...... 88 Teranishi, Kenji...... 126, 128 Terry, Jurgen...... 25 W Teryoshin, Vasiliy...... 226 Waggoner, William...... 208 Teske, Christian ...... 151 Walczak, L...... 242 Thakkar, D.P...... 82, 96 Walter, John ...... 221, 269, 270 Thomas, Ken...... 10 Walters, Kurt...... 208 Thompson, James E...... 211 Wan, Shuwei...... 61

318 Wang, Baojie...... 185 Y Wang, Jian...... 167 Yakimow, Byron...... 246 Wang, Jue...... 8, 56, 57, 63 Yamasaki, Fernanda Sayuri ...... 260 Wang, Kun ...... 231 Yan, Ping...... 56, 57, 58, 62, 63, 77, Wang, Liming ...... 61 ...... 79, 137, 138, 230, 279 Wang, Meng...... 194, 254 Yan, Wei ...... 15 Wang, Minhua...... 40, 191 Yang, Jong Won...... 189 Wang, Qi...... 167 Yang, Yu...... 191 Wang, Tao...... 10, 47, 56, 57, 103, Yao, Chen-guo ...... 167, 184, 232 ...... 107, 110, 299 Yao, Xueling...... 149, 150, 163, 164 Wang, Wei ...... 81 Yarin, Pavel...... 175 Wang, Xinxin...... 112, 152, 153, 186, 215 Ye, Hanyu ...... 225 Wang, Yuxi...... 150 Yeckel, Christopher ...... 3 Wang, Zhiyong ...... 61 Yin, Weijun...... 199 Warnow, Daniel ...... 23, 24 Yu, Yang...... 58 Watanabe, Tetsuya...... 111 Yu, Yuehui ...... 90 Watrous, Jack...... 196 Yuan, Hongwen ...... 236 Watson, Alan...... 293 Yuan, Jianqiang...... 37, 39 Wawrzyniak, A...... 242 Wei, Quan ...... 90 Wei, Xiaoxing...... 60 Z Wetz, David ...... 305 Zaehter, Sero...... 151 Wezensky, Mark ...... 32, 33, 188 Zahn, Markus ...... 9 White, Forest...... 178, 273 Zanchetta, Pericle...... 293 Widlund, Ola...... 9 Zemin, Duan ...... 168 Wiechula, Jörg ...... 141 Zeni, Luigi...... 101 Wilder, Aleta T...... 53 Zeni, Olga ...... 101, 130 Wilson, Mark ...... 10, 47, 103, 107, 110, 299 Zhan, Jiang-Yang...... 16 Wolford, Matthew F...... 108 Zhang, Cheng...... 58, 62, 76, 137, 138 Won, Jong Hyo ...... 189 Zhang, Chuyan...... 61 Wu, Hao ...... 232 Zhang, Dongdong ...... 8, 56, 57, 62, 63, 76, Wu, RuayNan...... 161, 162 ...... 77, 79, 230, 279 Wu, Youcheng ...... 40, 191 Zhang, Guan-Jun...... 16, 280 Zhang, Jiange ...... 211 Zhang, Jingbo...... 231 X Zhang, Nanchuan ...... 40, 191 Xiao, Li ...... 57 Zhang, Nanyan...... 54 Xiao, Qian-bo...... 232 Zhang, Ran...... 112, 152, 153, 186 Xiao, Shu...... 133, 134 Zhang, Rui...... 215 Xie, Fei...... 236, 253 Zhang, Shihai ...... 54, 303 Xie, Weiping...... 37, 39, 194 Zhang, Zhe ...... 70, 71 Xu, Bei ...... 288 Zhao, Shen ...... 112, 152, 153, 186 Xu, Jiayu ...... 8, 138 Zhao, Yue...... 37, 254 Xu, Rong...... 63 Zhdanok, Sergey ...... 98 Xu, Xiaoqing...... 164 Zhdanov, Victor ...... 171 Zhou, Fuxin...... 183 Zhou, Liangji...... 194, 254

319 Zhou, Longxiang...... 184 Zhukeshov, Anuar...... 244 Zhou, Yuan ...... 8 Zirnheld, Jennifer...... 258, 276 Zhou, Zhi...... 183 Zou, Chen...... 54, 303 Zhu, Xinlei ...... 112, 152, 153, 186 Zou, Wenkang...... 194 Zhuang, Jie...... 100 Zou, Xiaobing ...... 112, 152, 153, 186, 215

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