M^^bi^_ ANNUAL ?*g^MM@^^^ REPORT Princeton Plasma Physics Laboratory fes. *;.>-. Tokamak Physics Experiment PPPL-Q-51 Cover: Artist rendering of the Tokamak Physics Experiment (TPX). The TPX mission is to develop the scientific basis for a more compact, continuously operating, lower-cost fusion reactor. The TPX Project is a national project with a team of physicists and engineers from national laboratories, industry, and universities across the United States responsible for its design and construction. The Project is being performed under the auspices of the U.S. Department of Energy (DOE), Office of Fusion Energy, with DOE project management provided through the DOE Chicago Operations Office and the Princeton Area Office. The TPX will be built at the Princeton University Plasma Physics Laboratory and operated as a national research facility. Cover Design: Karen Jackson Funding for the color cover was provided by nonappropriated funds. No Department of Energy funds were used. AnnUcll R©pOrt Covering the Period October 1,1992 to September 30,1993 Princeton University Plasma Physics Laboratory Princeton, New Jersey 08543 PPPL-Q-51 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi• bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer• ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom• mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Unless otherwise designated, the work in this report is funded by the United States Department of Energy under contract DE-AC02-76-CHO-3073. Printed in the United States of America OflteimOK QT THIS DOCUMENT IS UNUJSgfllSF DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. Contents Preface i Principal Parameters of Experimental Devices for Fiscal Year 1993 iii Tokamak Fusion Test Reactor 1 Princeton Beta Experiment-Modification 39 Current Drive Experiment-Upgrade 51 Tokamak Physics Experiment 57 International Thermonuclear Experimental Reactor 73 International Collaboration 77 Plasma Processing Research 81 Pure Electron Plasma Experiments 87 Theoretical Studies 91 Divertor Modeling 109 High-Field Magnet Project 111 Engineering Department 113 Environment, Safety, and Health and Quality Assurance 127 Technology Transfer 137 Office of Human Resources and Administration 141 PPPL Invention Disclosures for Fiscal Year 1993 149 Office of Resource Management 151 Graduate Education: Plasma Physics 159 Graduate Education: Program in Plasma Science and Technology 163 Science Education Program 165 Section Coordinators 169 Princeton Plasma Physics Laboratory Reports for Fiscal Year 1993 171 Glossary of Abbreviations, Acronyms, Symbols 179 Preface The Tokamak Fusion Test Reactor (TFTR) scales long compared with current-relaxation and project is in the final stages of preparations for its plasma-wall equilibration times. Favorable results long-planned deuterium-tritium (D-T) program, from TPX are essential to further development of with the objective to derive the maximum amount an attractive tokamak fusion reactor and will also of experimental data on the behavior of tokamak benefit the operation of the International Thermo• plasmas containing a significant population of nuclear Experimental Reactor (ITER). energetic alpha particles. The programmatic ob• The TPX program builds on the foundation of a jectives of the D-T experiments are threefold: (1) to vigorous tokamak concept improvement program maximize D-T fusion power in the 10-MW range, that is already a primary focus of the U.S. fusion (2) to investigate confinement in D-T plasmas, and effort. The scientific elements of this program are (3) to obtain regimes with strong alpha-driven threefold: (1) magnetohydrodynamic (MHD) collective effects. Specific physics topics for near- stability in regimes with high plasma pressure and term experimental study include: (1) confinement self-generated current, (2) confinement and exhaust and heating in D-T plasmas, including isotopic mass of plasma energy and particles, and (3) control of effects; (2) application and evaluation of alpha steady-state plasmas. The role of TPX will be to diagnostics; (3) production of measurable alpha combine these elements and extend them to true heating of electrons; (4) energetic alpha transport; steady-state conditions. This step will be a crucial (5) alpha-driven collective instabilities; (6) alpha ash transition from pulsed-operating modes that are accumulation; and (7) radio-frequency-heated D-T strongly influenced by initial conditions to con• plasmas. An overriding consideration has been the tinuous modes fully controlled by the tokamak's need to implement the D-T experiments safely and operators. without impacting the environment. Consensus has been reached on the physics Preparations are well-advanced for the Opera• parameters and engineering approach for TPX, and tional Readiness Reviews necessary to proceed to the project team has now completed the conceptual D-T operations. The first shipment of tritium design. Appropriate roles for industry in the arrived at PPPL in April, 1993. It is anticipated engineering design and construction of TPX have that experimental tests using trace tritium (i.e., a been defined. On the basis of a briefing to the 2% mixture of tritium in deuterium gas) will begin Energy Systems Acquisition Advisory Board in July, early in the new fiscal year and will provide both 1992, and a subsequent review by the Secretary of physics information on the behavior of tritium in Energy's Advisory Board, approval of Key Decision deuterium plasmas and operational information on 0 (mission need) and Key Decision 1-A (start of Title- functioning of the tritium systems. If successfully 1 design, subject to satisfactory completion of a implemented, these tests can be followed quite Conceptual Design Review) was given by the quickly by experiments with approximately 50-50 Department of Energy (DOE) in November, 1992. mixtures of tritium and deuterium. Following a successful Conceptual Design The overall programmatic mission of the Toka• Review in March, 1993, the TPX Project is preparing mak Physics Experiment (TPX) is to develop the to begin Preliminary (Title I) Design in October, scientific base for a compact, continuously operating 1993. and economical tokamak fusion reactor. It will do The Princeton Beta Experiment-Modification this by demonstrating both the physics and (PBX-M) device resumed operations in the summer technology needed to extend tokamak operation into of 1993 with 2 MW of lower-hybrid current drive the steady-state regime and advances in funda• (LHCD) and 2 MW of ion-Bernstein wave heating mental tokamak performance parameters on time (IBWH), as well as its original 6 MW neutral-beam Princeton Plasma Physics Laboratory Fiscal Year 1993 Annual Report I Preface injection system. The PBX-M has an extensive set of the national Numerical Tokamak Project. The of programmatically targeted plasma diagnostics. divertor modeling effort has continued to be in• As well as an array of motional-Stark-effect polari- volved prominently in multi-institutional and meters for obtaining the q(r) profile and a tangential international divertor activities, as well as in the hard-X-ray imaging diagnostic for energetic- design studies of TPX and ITER. electron profile measurements, the PBX-M has now In regard to the ITER Engineering Design also been equipped with two electron-cyclotron- Activities, the Laboratory representation on the emission diagnostics for additional suprathermal Joint Central Team (JCT) is improving, in addition electron measurements and with several fluctuation to substantial involvement in Home Team activities. diagnostics. Two Laboratory physicists have recently been ap• The emphasis of the PBX-M 1993 experimental pointed to the JCT's Physics Integration Unit at program was to demonstrate the effectiveness of the San Diego Joint Work Site, and one Laboratory the LHCD power for tailoring the current profile engineer is already at the Naka Joint Work Site. and to determine the distribution and transport of The Laboratory also provides the Chair of the ITER fast electrons. The major results were: (1) that the Technical Advisory Committee. LHCD can be deposited either centrally or at The small Current Drive Experiment-Upgrade intermediate radius, (2) that the energetic electrons (CDX-U) device continues to pursue innovative are well localized in radius except when MHD current-drive techniques. activity is present, and (3) that the current profile The Laboratory's major involvements in inter• can be modified sufficiently to raise q(0) from 0.9 to national fusion collaborations have continued. 1.1, with the higher q(0) value sustained by LHCD. Moreover, discussions with prospective host insti• The IBWH program has been successful in creating tutions and with DOE have been initiated