DOCSLIB.ORG

Spectroscopic and Langmuir Probe Diagnostic Analysis of Plasma in GLAST-III Spherical Tokamak

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Spectroscopic and Langmuir Probe Diagnostic Analysis of Plasma in GLAST-III Spherical Tokamak 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Spectroscopic and Langmuir probe Diagnostic Analysis of Plasma in GLAST-III Spherical Tokamak A. Qayyum, F. Deeba, M. U. Naseer, S. Hussain, and GLAST team National Tokamak Fusion Program 3329, Islamabad Outline • Initial Plasma Formation • GLAST-II • GLAST-III (upgrade) • Development of TLP • Plasma Characterization • Langmuir probe • Photodiode array • Ocean spectrometer • Camera 2 ECR pre-ionization assisted startup (2.45 GHz, I kW) Vacuum Vessel = Pyrex Major radius = 15 cm Minor radius = 9 cm IP = 5 kA BT = 0.1 T Pictorial illustration of GLAST-II 3 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Optimization of compensation coils ECRH assisted plasma current in GLAST-II 4 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Development and subsequent decay of plasma discharge 5 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Langmuir probes •Triple probe (b) Plasma P2 P1 P3 g e n i b t o a r o l p I F - + + - Vd2 Vd3 (fixed) Oscilloscope Oscilloscope 6 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria ECR pre-ionization assisted startup (2.45 GHz, I kW) Vacuum vessel = Pyrex Major radius = 20 cm Minor radius = 10 cm IP = 5 kA BT = 0.2 T Available Diagnostics: Langmuir probe HR4000 Spectrometer Photodiodes (OPTODIODES) PMT array A photographic image of GLAST-III with PD array and TLP system 7 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria GLAST-III, ECRH pre-ionization (MW+TF) 14 0 -3 a a, 8x10 mbar 12 -3 b b, 6x10 mbar -3 e c, 4x10 mbar c 10 -3 -1 d d, 2x10 mbar -4 e, 9x10 mbar d 8 e c [eV] [V] e T -2 6 floating V -3 a, 8x10 mbar b 4 -3 b, 6x10 mbar -3 a -3 c, 4x10 mbar 2 -3 d, 2x10 mbar -4 e, 9x10 mbar 0 1 2 3 4 5 6 7 8 -4 t [ms] 1 2 3 4 5 6 7 8 t [ms] Plasma current formation (MW+TF+OH) 40 10 20 -4 2x10 mbar 0 9 -3 35 2 x 10 mbar Photodiode 16 8 30 -2 7 12 6 25 8 5 [V] -4 [V] 20 4 4 Loop [kA] p floating V I 3 V 15 -6 0 2 Light emission (arb.u) emission Light 1 10 Floating probe -4 -8 0 5 -1 -8 -2 0 -10 -12 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1.0 1.5 2.0 2.5 3.0 3.5 4.08 t[ms] t[ms) Effect of vertical field ECR pre-ionization assisted 9 10 11 12 Development of Plasma Diagnostics NATIONAL TOKAMAK FUSION PROGRAM Year 2011-13 2014-16 2016-18 2018-to date Electrostatic Triple Probe Emissive Probe Fast Sweep Probe Rake Probe Probes Development i) Probe head i) Emissive filament i) Cylindrical probe tip i) Multi-tip probe head ii) Biasing circuit ii) Resistive heating ii) Sweeping voltage ii) Biasing circuit ii) Measuring circuit circuit source iii) Measuring circuit ii) Measuring circuit ii) Measuring circuit Achievement i) Floating potential Direct measurement i) Time-resolved (I-V) Radial profiles of ii) Electron temperature of plasma potential characteristics i) Floating potential iii) Electron density ii) Electron ii) Electron temperature Publication Temperature iii) Electron density Publications Plasma iii) Electron density Time-resolved Measurement of Plasma Measurements in Data has been recorded during ECR Parameters by Means of Triple Probe Pulse Discharge Publication assisted pre-ionization discharge in Rev. Sci. Instrum. 84 (2013) with Resistively A sweep Langmuir Probe metallic vessel spherical tokamak Triple-probe diagnostic measurements Heated Emissive System for Temporal and analysis is in progress to in plasma of GLAST Spherical Tokamak Probe Measurements in Time- determine electron temperature Journal of Fusion Energy 35 (2016) 205 High Temperature, varying Plasmas and electron density for different 54 (2016) 905 Physics of Plasmas radial positions (submitted) 13 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Development of Plasma Diagnostics Year 2011-14 2014-16 2016-18 2018-to date Emission USB 4000 Spectrometer HR2000+ Spectrometer HR 2000+ Spectrometer H-alpha Spectroscopy Spectroscopy BPX Photodiode BPX photodiode Photodiode array H-beta Spectroscopy (OPTODIODE ) Development i) Line of sight i) Positioning of optical fibers i) 8-channel line of sight i) Narrow band filters adjustment system ii) Mounting of photodiodes optical system ii) Photodiodes ii) Data acquisition system ii) Signal acquisition iii) PMT array Achievement i) Discharge quality in Optimization of microwave i) Movement of ECR layer Temporal profiles of GLAST-II pre-ionization and current ii) Plasma fluctuations i) H-beta ii) Identification of formation phases in GLAST-III iii) Stark broadening of H- ii) H-alpha Impurities in the alpha iii) Electron temperature by Line- discharge Publication ratio method Electrical and Optical Publication Publications Measurements in the Early A photodiode array and Data has been recorded during Initial Plasma Formation Hydrogen Discharge of GLAST- Langmuir probe for optimization of ECR assisted pre- in the GLAST-II Spherical III characterizing plasma in ionization discharge and analysis is Tokamak Plasma Sci. Technol. 19 (2017) GLAST-III tokamak device in progress to determine electron Journal of Fusion Energy 085103 Measurement, 125 (2018) temperature using line-ratio method 35 (2016) 529-537 56-62 14 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria 15 thanks 16.
Load more

Recommended publications
  • GLAST Science Glossary (PDF)
    GLAST SCIENCE GLOSSARY Source: http://glast.sonoma.edu/science/gru/glossary.html Accretion — The process whereby a compact object such as a black hole or neutron star captures matter from a normal star or diffuse cloud. Active galactic nuclei (AGN) — The central region of some galaxies that appears as an extremely luminous point-like source of radiation. They are powered by supermassive black holes accreting nearby matter. Annihilation — The process whereby a particle and its antimatter counterpart interact, converting their mass into energy according to Einstein’s famous formula E = mc2. For example, the annihilation of an electron and positron results in the emission of two gamma-ray photons, each with an energy of 511 keV. Anticoincidence Detector — A system on a gamma-ray observatory that triggers when it detects an incoming charged particle (cosmic ray) so that the telescope will not mistake it for a gamma ray. Antimatter — A form of matter identical to atomic matter, but with the opposite electric charge. Arcminute — One-sixtieth of a degree on the sky. Like latitude and longitude on Earth's surface, we measure positions on the sky in angles. A semicircle that extends up across the sky from the eastern horizon to the western horizon is 180 degrees. One degree, therefore, is not a very big angle. An arcminute is an even smaller angle, 1/60 as large as a degree. The Moon and Sun are each about half a degree across, or about 30 arcminutes. If you take a sharp pencil and hold it at arm's length, then the point of that pencil as seen from your eye is about 3 arcminutes across.
    [Show full text]
  • The Fairy Tale of Nuclear Fusion L
    The Fairy Tale of Nuclear Fusion L. J. Reinders The Fairy Tale of Nuclear Fusion 123 L. J. Reinders Panningen, The Netherlands ISBN 978-3-030-64343-0 ISBN 978-3-030-64344-7 (eBook) https://doi.org/10.1007/978-3-030-64344-7 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland When you are studying any matter or considering any philosophy, ask yourself only what are the facts and what is the truth that the facts bear out.
    [Show full text]
  • Nuclear Fusion: How Are Elements Created in Stars?
    Nuclear Fusion How are elements created in sta rs? Abo ut the Activity This simple and engaging activity explains nuclear fusion and how radiation is gen erated by stars, using marshmallows as a model. Topics Covered • What is cosmic radiation and where does it come from? • How are the elements in the universe generated? Participants Activities are appropriate for families, the general public, and school groups ages 10 and up. Any number of visitors may participate. Materials Needed Location and Timing • Marshmallows (mini multi-colored This activity can be used at or before a ones are best. White and full-sized star party, in a classroom, with youth marshmallows also work.) Or groups or the general public. It takes substitute small balls of playdough. about 5 – 8 minutes. • Uncooked salad pasta • Bowls for the marshmallows and hard pasta • A Periodic Table of the Elements (provided below) • (Optional) Copies of the Electromagnetic Spectrum for advanced audiences (See Activity Description for a link) • (Optional) Napkins for the marshmallows Included in This Packet Page Detailed Activity Description 2 Helpful Hints 7 Background Information 7 Periodic Table 8 © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Detailed Activity Description Nuclear Fusion Leader’s Role Participants’ Role (Anticipated) Objective: Allow visitors to have an introduction to nuclear fusion and the energy it releases. To Do: Display the Table of Elements side of the banner and/or pass out the Table of Elements handouts. To say: Throughout its life, a star generates new elements by fusing atoms together in its core, What’s fuse mean? Join together.
    [Show full text]
  • Towards Multi-Wavelength Observations of Relativistic Jets from General Relativistic Magnetohydrodynamic Simulations a Dissertat
    TOWARDS MULTI-WAVELENGTH OBSERVATIONS OF RELATIVISTIC JETS FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS A DISSERTATION SUBMITTED TO THE DEPARTMENT OF PHYSICS AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Richard Jude Anantua August 2016 © 2016 by Richard Anantua. All Rights Reserved. Re-distributed by Stanford University under license with the author. This work is licensed under a Creative Commons Attribution- Noncommercial 3.0 United States License. http://creativecommons.org/licenses/by-nc/3.0/us/ This dissertation is online at: http://purl.stanford.edu/sh254xw9430 ii I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Roger Blandford, Primary Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Steven Allen I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Grzegorz Madejski Approved for the Stanford University Committee on Graduate Studies. Patricia J. Gumport, Vice Provost for Graduate Education This signature page was generated electronically upon submission of this dissertation in electronic format. An original signed hard copy of the signature page is on file in University Archives. iii Abstract A methodology for reverse engineering current and anticipated observations of astrophysical rel- ativistic jets using self-consistent, general relativistic magnetohydrodynamic (GRMHD) simulations is detailed from data-hosting and manipulation to mimicking instrument-specific properties such as point spread function convolution.
    [Show full text]
  • Relativistic Proton Production During the 2000 July 14 Solar Event: the Case for Multiple Source Mechanisms D
    The Astrophysical Journal, 644:565–574, 2006 June 10 # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. RELATIVISTIC PROTON PRODUCTION DURING THE 2000 JULY 14 SOLAR EVENT: THE CASE FOR MULTIPLE SOURCE MECHANISMS D. J. Bombardieri,1 M. L. Duldig,2 K. J. Michael,1,3 and J. E. Humble2,4 Received 2005 November 8; accepted 2006 January 15 ABSTRACT Protons accelerated to relativistic energies by transient solar and interplanetary phenomena caused a ground-level cosmic-ray enhancement on 2000 July 14, Bastille Day. Near-Earth spacecraft measured the proton flux directly, and ground-based observatories measured the secondary responses to higher energy protons. We have modeled the arrival of these relativistic protons at Earth using a technique that deduces the spectrum, arrival direction, and anisotropy of the high-energy protons that produce increased responses in neutron monitors. To investigate the acceleration processes involved we have employed theoretical shock and stochastic acceleration spectral forms in our fits to spacecraft and neutron monitor data. During the rising phase of the event (10:45 and 10:50 UT) we find that the spectrum between 140 MeVand 4 GeV is best fitted by a shock acceleration spectrum. In contrast, the spectrum at the peak (10:55 and 11:00 UT) and in the declining phase (11:40 UT) is best fitted with a stochastic acceleration spectrum. We propose that at least two acceleration processes were responsible for the production of relativistic protons during the Bastille Day solar event: (1) protons were accelerated to relativistic energies by a shock, pre- sumably a coronal mass ejection (CME); and (2) protons were also accelerated to relativistic energies by stochastic processes initiated by magnetohydrodynamic (MHD) turbulence.
    [Show full text]
  • 3Rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis
    3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis 27–31 May 2019 Vienna, Austria IAEA Scientific Secretary International Atomic Energy Agency Vienna International Centre Wagramer Straße 5, PO Box 100 Ms. Sehila Maria Gonzalez de Vicente A-1400 Vienna, Austria NAPC Physics Section Tel: +43-1-2600-21753 Fax: +43-1-26007 E-mail: [email protected] International Programme Advisory Committee Chair: D. Mazon (France) M. Churchill (USA), A. Dinklage (Germany), R. Fischer (Germany), N. Howard (USA), S. Kajita (Japan), S. Kaye (USA), D. McDonald (UK), A. Murari (EUROfusion/EU), J. Vega (Spain), J. Stillerman (USA), G. Verdoolaege (Belgium), M. Xu (China) Administrative Secretary Ms. Marion Linter International Atomic Energy Agency Vienna International Centre Wagramer Straße 5, PO Box 100 A-1400 Vienna, Austria NAPC Physics Section Tel.: +43-1-2600-25119 Fax: +43-1-26007 E-mail: [email protected] Meeting Website: https://nucleus.iaea.org/sites/fusionportal/Pages/Data%20Processing/2019/info.aspx 1 2 Topics I. Uncertainty Propagation of Experimental Data in Modelling Codes II. Data Analysis Lessons Learnt, Best Practices and Proposals for ITER III. Regression Analysis: Profiles, Scaling and Surrogate Models IV. Learning in Non-Stationary Conditions for Experimental Design and Predictions V. Inverse Problems VI. Image Processing VII. Causality Detection in Time Series VIII. Synthetic Diagnostics, Integration, Verification and Validation IX. Deep Learning 3 Schedule Monday, 27 May 2019 Meeting Room C2. Building C, Floor 7 1:30-2:00 Registration and Welcome 2:00-3:15 Opening Address Verdoolaege G. A Brief Overview of Probability Theory in Data Science 4 Tuesday, 28 May 2019 Meeting Room C2.
    [Show full text]
  • ID 530 JAVED.Pdf
    Integrated Data Acquisition, Storage and Retrieval for Glass Spherical Tokamak (GLAST) Muhammad Aqib Javed, M. A. Naveed, Shahid Hussain & GLAST Team National Tokamak Fusion Program (NTFP), Pakistan. 1 / 29 Outline • Introduction to GLAST • Systems & Diagnostics • Evolution of Data Acquisition System • Future Directions of GLAST Data Acquisition & Control System 2 / 29 Introduction GLAss Spherical Tokamak (GLAST) is a series of small Spherical Tokamaks with an insulating vacuum vessel of major and minor radius as tabulated below: Major Radius (cm) Minor Radius (cm) GLAST I 15 9 GLAST II 15 9 GLAST III 20 10 3 / 29 GLAST I • Steel pipe at center • Chamber dia. = 50 cm • Aspect ratio = 1.5 4 / 29 GLAST I • Neon Gas Pressure = 3 micro bar • Frame Rate = 480 fps • Total Discharge Time = 8msec 5 / 29 GLAST II • Glass pipe at center • Chamber dia. = 50 cm • Aspect ratio = 1.6 6 / 29 Temporal Formation of Plasma in GLAST II 5k fps (1 Frame = 0.2msec) 7 / 29 GLAST III • Glass pipe at center • Chamber dia. = 60 cm • Aspect ratio = 2 8 / 29 Plasma formation in GLAST III Plasma Current = 5-7kA for 1msec 9 / 29 GLAST Systems • Power Supply System To energize different magnetic coil systems and microwaves • Microwave System • Magnetic Coils System Toroidal Field Coils System, Central Solenoid Coil System, Poloidal Field Coil System 10 / 29 GLAST Systems • Glow Discharge Cleaning (GDC) System • Timing Center & Trigger System On site developed system for synchronized & precise triggering of different capacitor banks and instrumentation. It has been developed using PIC-18F4550 Microcontroller. • Data Acquisition System 11 / 29 GLAST Diagnostics • Electromagnetic Diagnostics Rogowski coils, Magnetic probes, Plasma flux loops etc.
    [Show full text]
  • 15Th Latin American Workshop on Plasma Physics (LAWPP 2014) and 21St IAEA TM on Research Using Small Fusion Devices (RUSFD)
    15th Latin American Workshop on Plasma Physics (LAWPP 2014) and 21st IAEA TM on Research Using Small Fusion Devices (RUSFD) Journal of Physics: Conference Series Volume 591 San Jose, California, USA 27 - 31 January 2014 ISBN: 978-1-5108-0213-1 ISSN: 1742-6588 Printed from e-media with permission by: Curran Associates, Inc. 57 Morehouse Lane Red Hook, NY 12571 Some format issues inherent in the e-media version may also appear in this print version. Copyright© by the Institute of Physics All rights reserved. Printed by Curran Associates, Inc. (2015) For permission requests, please contact the Institute of Physics at the address below. Institute of Physics Dirac House, Temple Back Bristol BS1 6BE UK Phone: 44 1 17 929 7481 Fax: 44 1 17 920 0979 [email protected] Additional copies of this publication are available from: Curran Associates, Inc. 57 Morehouse Lane Red Hook, NY 12571 USA Phone: 845-758-0400 Fax: 845-758-2634 Email: [email protected] Web: www.proceedings.com Table of contents Volume 591 15th Latin American Workshop on Plasma Physics (LAWPP 2014) and 21st IAEA TM on Research Using Small Fusion Devices (RUSFD) 27–31 January 2014, San José, Costa Rica Accepted papers received: 9 February 2015 Published online: 24 March 2015 Preface 011001 15th Latin American Workshop on Plasma Physics (LAWPP 2014) and 21st IAEA TM on Research Using Small Fusion Devices (RUSFD) OPEN ACCESS V I Vargas-Blanco, J J E Herrera-Velázquez 011002 Lists of committees OPEN ACCESS 011003 Peer review statement OPEN ACCESS Papers Tokamaks 012001 Report on recent results obtained in TCABR OPEN ACCESS R M O Galvão, C H S Amador, W A H Baquero, F Borges, I L Caldas, N A M Cuevas, V N Duarte, A G Elfimov, J I Elizondo, A M M Fonseca, T M Germano, G G Grenfell, Z O Guimarães- Filho, J L Jeronimo, Yu K Kuznetsov, M A M Manrique, I C Nascimento, C J A Pires, P G P Puglia, A P Reis, G Ronchi, L F Ruchko, W P de Sá, R J F Sgalla, E K Sanada, J H F Severo, V C Theodoro and D L Toufen pg.
    [Show full text]
  • Non-Thermal Emission from Relativistic MHD Simulations of Pulsar Wind Nebulae: from Synchrotron to Inverse Compton
    A&A 485, 337–349 (2008) Astronomy DOI: 10.1051/0004-6361:200809424 & c ESO 2008 Astrophysics Non-thermal emission from relativistic MHD simulations of pulsar wind nebulae: from synchrotron to inverse Compton D. Volpi1,L.DelZanna1,E.Amato2, and N. Bucciantini3 1 Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 2, 50125 Firenze, Italy e-mail: [email protected] 2 INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy 3 Astronomy Department, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720-3411, USA Received 18 January 2008 / Accepted 28 March 2008 ABSTRACT Aims. We develop a set of diagnostic tools for synchrotron-emitting sources, presented in a previous paper, to include a computation of inverse-Compton radiation from the same relativistic particles that give rise to the synchrotron emission. For the first time, we then study the gamma-ray emission properties of Pulsar Wind Nebulae, in the context of the axisymmetric jet-torus scenario. Methods. We evolve the relativistic MHD equations and the maximum energy of the emitting particles, including adiabatic and synchrotron losses along streamlines. The particle energy distribution function is split into two components: one corresponds to radio-emitting electrons, which are interpreted to be a relic population that is born at the outburst of the supernova, and the other is associated with a wind population that is continuously accelerated at the termination shock and emits up to the gamma-ray band. The inverse Compton emissivity is calculated using the general Klein-Nishina differential cross-section and three different photon targets for the relativistic particles are considered: the nebular synchrotron photons, photons associated with the far-infrared thermal excess, and the cosmic microwave background.
    [Show full text]
  • FY 2009 Congressional Budget Request
    DOE/CF-027 Volume 4 Department of Energy FY 2009 Congressional Budget Request Science February 2008 Office of Chief Financial Officer Volume 4 DOE/CF-027 Volume 4 Department of Energy FY 2009 Congressional Budget Request Science February 2008 Office of Chief Financial Officer Volume 4 Printed with soy ink on recycled paper Volume 4 Table of Contents Page Appropriation Account Summary.............................................................................................................3 Appropriation Language ...........................................................................................................................5 Overview...................................................................................................................................................7 Funding by Site.......................................................................................................................................27 Basic Energy Sciences ............................................................................................................................65 Advanced Scientific Computing Research ...........................................................................................153 Biological and Environmental Research...............................................................................................181 High Energy Physics.............................................................................................................................225 Nuclear Physics.....................................................................................................................................277
    [Show full text]
  • EX/P4-22 First Plasma Formation in Glass Spherical Tokamak (GLAST)
    EX/P4-22 First Plasma Formation in Glass Spherical Tokamak (GLAST) S Hussain1, G M Vorobyov2 and GLAST Team3 1,3National Tokamak Fusion Program (NTFP), P.O. Box 3329, Islamabad, Pakistan; 2Saint Petersburg University, Saint Petersburg Russia [email protected] Abstract: The first plasma formation in GLAST is presented. GLAST is a small spherical tokamak having vacuum vessel of dielectric material with aspect ratio of 1.7. A plasma current of 2kA was produced for about 0.5msec using ECR assisted plasma startup. A small vertical field was then added to enhance the peak of plasma current up to 5kA. The variation of plasma current with the applied vertical field was also studied and the optimum values of the vertical magnetic field were experimentally determined to be between 40-50 gauss. A high speed camera was used to study the plasma behavior during the whole discharge scenario. The diagnostic systems such as Rogowski coil, flux loop, fast photo-diode, and spectrometers were also used to record the signatures of plasma current and to estimate some plasma parameters. The edge electron temperature was estimate to be 13eV from the measurement of the variation in the loop voltage during the plasma current formation. 1. Introduction In spherical tokamaks there is limited space available for the central solenoid due to their low aspect ratio. This reduces the availability of induced toroidal electric field required for the production of initial plasma. In addition, the presence of eddy currents in the vacuum vessel further suppress the generation of induced electric field. Therefore, in spherical tokamaks the effect of eddy currents has great concern while evaluating the induced electric field for breakdown.
    [Show full text]
  • Plasma Science: Advancing Knowledge in the National Interest Plasma 2010 Committee, Plasma Science Committee, National Research Council
    Plasma Science: Advancing Knowledge in the National Interest Plasma 2010 Committee, Plasma Science Committee, National Research Council ISBN: 0-309-10944-2, 280 pages, 7 x 10, (2007) This free PDF was downloaded from: http://www.nap.edu/catalog/11960.html Visit the National Academies Press online, the authoritative source for all books from the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council: • Download hundreds of free books in PDF • Read thousands of books online, free • Sign up to be notified when new books are published • Purchase printed books • Purchase PDFs • Explore with our innovative research tools Thank you for downloading this free PDF. If you have comments, questions or just want more information about the books published by the National Academies Press, you may contact our customer service department toll-free at 888-624-8373, visit us online, or send an email to [email protected]. This free book plus thousands more books are available at http://www.nap.edu. Copyright © National Academy of Sciences. Permission is granted for this material to be shared for noncommercial, educational purposes, provided that this notice appears on the reproduced materials, the Web address of the online, full authoritative version is retained, and copies are not altered. To disseminate otherwise or to republish requires written permission from the National Academies Press. Plasma Science: Advancing Knowledge in the National Interest http://www.nap.edu/catalog/11960.html Plasma 2010 Committee Plasma Science Committee Board on Physics and Astronomy Division on Engineering and Physical Sciences Copyright © National Academy of Sciences.
    [Show full text]