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Title: An ITPA joint experiment to study runaway electron generation and suppression

Recent results from an ITPA joint experiment to study the onset, growth, and decay of relativistic electrons (REs) indicate that loss mechanisms other than collisional damping may play a dominant role in the dynamics of the RE population, even during the quiescent I{sub p} flattop. Understanding the physics of RE growth and mitigation is motivated by the theoretical prediction that disruptions of full-current (15 MA) ITER discharges could generate up to 10 MA of REs with 10–20 MeV energies. The ITPA MHD group is conducting a joint experiment to measure the RE detection threshold conditions on a number of tokamaks under quasi-steady-state conditions in which V{sub loop}, n{sub e}, and REs can be well-diagnosed and compared to collisional theory. Data from DIII-D, C-Mod, FTU, KSTAR, and TEXTOR have been obtained so far, and the consensus to date is that the threshold E-field is significantly higher than predicted by relativistic collisional theory, or conversely, the density required to damp REs is significantly less than predicted, which could have significant implications for RE mitigation on ITER.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [3] ;  [9] ;  [10]
  1. MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)
  2. ENEA Unità, Tecnica Fusione, C.R. Frascati, Via E. Fermi 45, 00044-Frascati, Roma (Italy)
  3. National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)
  4. (Korea, Republic of)
  5. Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, 52425 Jülich (Germany)
  6. ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance (France)
  7. Universidad Carlos III de Madrid, Avenida de la Universidad 30, 28911-Madrid (Spain)
  8. Oak Ridge Institute for Science and Education (ORISE), Oak Ridge Tennessee 37831 (United States)
  9. General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States)
  10. Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, Hefei, Anhui 230031 (China)
Publication Date:
OSTI Identifier:
22304090
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DAMPING; DOUBLET-3 DEVICE; ITER TOKAMAK; MAGNETOHYDRODYNAMICS; MEV RANGE 10-100; RELATIVISTIC RANGE; RUNAWAY ELECTRONS; TEXTOR TOKAMAK