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Title: Helium transport in enhanced confinement regimes on the TEXTOR and DIII-D tokamaks

Conference ·
OSTI ID:10162239
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  1. Oak Ridge National Lab., TN (United States)
  2. Association Euratom-Kernforschungsanlage Juelich GmbH (Germany)
  3. General Atomics, San Diego, CA (United States)
  4. Associatie Euratom-Belgische Staat, Ecole Royale Militarie, Brussels (Belgium)
  5. National Inst. for Fusion Science, Nagoya (Japan)
  6. California Univ., Los Angeles, CA (United States)
  7. California Univ., Berkeley, CA (United States)

Comparisons of helium (He) transport and exhaust in L-mode and in an enhanced confinement regime (H-mode), which is induced by a polarizing electrode, have been made for the TEXTOR tokamak. The results show an increased tendency for He accumulation when bulk plasma energy and particle confinement are improved during the polarization induced H-mode. Since these results imply that a high He pumping efficiency may be necessary for H-mode burning plasmas, we have begun exploring He transport in a divertor H-mode, similar to that proposed for International Thermonuclear Experimental Reactor (ITER). A collaborative program has been initiated to measure He transport and scaling on DIII-D during L-mode, H-mode, and ELMing H-mode plasma conditions. To simulate the presence of He ash in DIII-D, a 25 ms He puff is injected into a DIII-D plasma resulting in a He concentration of {approx}5%. The time dependence of the He{sup 2+} density profiles in the plasma core is measured by charge-exchange recombination spectroscopy at 11 radial locations.

Research Organization:
General Atomics, San Diego, CA (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC03-89ER51114; AC05-84OR21400
OSTI ID:
10162239
Report Number(s):
GA-A-20901; CONF-920311-20; ON: DE92016247
Resource Relation:
Conference: 10. international conference on plasma-surface interactions in controlled fusion devices,Monterey, CA (United States),30 Mar - 3 Apr 1992; Other Information: PBD: Apr 1992
Country of Publication:
United States
Language:
English