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Title: Investigation of He–W interactions using DiMES on DIII-D

Here, tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225–850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in the surface of W buttons after only a single DIII-D (3 s, ~150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04–0.1 MJ m–2.
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [4] ;  [6] ;  [6] ;  [2] ;  [5] ;  [7] ;  [4] ;  [7]
  1. Univ. of California, San Diego, CA (United States). Center for Energy Research
  2. General Atomics, San Diego, CA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Australian National Univ., Canberra, ACT (Australia). Research School of Physics and Engineering
  5. ITER Organization, Saint Paul-Lez-Durance (France)
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  7. Univ. of Wisconsin, Madison, WI (United States)
Publication Date:
OSTI Identifier:
1319233
Grant/Contract Number:
FG02-07ER54917; FG02-89ER53296; FG02-08ER54999; FG02-07ER54912; AC52-07NA27344; AC05-00OR22725; FC02-04ER54698
Type:
Accepted Manuscript
Journal Name:
Physica Scripta
Additional Journal Information:
Journal Volume: 2016; Journal Issue: T167; Journal ID: ISSN 0031-8949
Publisher:
IOP Publishing
Research Org:
Univ. of California, San Diego, CA (United States); Univ. of Wisconsin, Madison, WI (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Contributing Orgs:
ITER Organization, Saint Paul-Lez-Durance (France); Australian National Univ., Canberra, ACT (Australia)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; tungsten; helium; DIII-D