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Title: An initial measurement of a fast neutral spectrum for ion cyclotron range of frequency heated plasma using two-channel compact neutral particle analyzers in KSTAR

The accurate measurement of fast neutral particles from high energy ion tails is very important since it is a measure of ion cyclotron range of frequency (ICRF) or neutral beam (NB) ion heating. In KSTAR, fast neutral measurements have been carried out using a compact neutral particle analyzer based on the silicon photo diode since 2010. As a result, the fast neutral spectrum was observed consistent with the ion temperature, diamagnetic energy, and neutron flux in 2011. However, there was fast neutral count beyond the injected neutral beam energy in NB-only heating. Since it is difficult to expect the count unless the temperature is high enough to diffuse the fast ions beyond the beam energy it was required to identify what it is. During the 2012 campaign, the two-channel diode detectors with and without a particle stopper were used to distinguish fast neutral counts and other counts by a hard X-ray or neutrons. As a result, it was confirmed that the high energy component beyond the beam energy originated from a hard X-ray or neutrons. Finally, it was observed that faster neutrals are generated by ICRF heating and enhanced by electron cyclotron heating compared to NB-only heating.
Authors:
; ;  [1] ;  [2]
  1. Nuclear Fusion Engineering and Technology Development Center, KAERI, Daejeon 305-353 (Korea, Republic of)
  2. Nuclear Fusion Plasmas Research Center, NFRI, Daejeon 305-806 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22220327
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 84; Journal Issue: 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAMS; COMPARATIVE EVALUATIONS; CYCLOTRONS; ECR HEATING; ELECTRON TEMPERATURE; HARD X RADIATION; ICR HEATING; ION CYCLOTRON-RESONANCE; ION TEMPERATURE; NEUTRAL PARTICLE ANALYZERS; NEUTRON FLUX; NEUTRONS; NIOBIUM IONS; PHOTODIODES; PLASMA BEAM INJECTION; PLASMA DIAGNOSTICS; SILICON; SPECTRA; TOKAMAK DEVICES