Spectrum response and analysis of 77-GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas
Spectrum response and analysis of 77-GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas
复制标题
LHD 等离子体中体离子和快离子的 77 GHz 频带集体汤姆森散射诊断的频谱响应和分析
DOI：
10.1088/0029-5515/54/2/023006
复制
发表时间：
2014
期刊：
影响因子：
3.3
通讯作者：
M. Salewski
中科院分区：
文献类型：
--
作者：
M. Nishiura;S. Kubo;K. Tanaka;R. Seki;S. Ogasawara;T. Shimozuma;K. Okada;S. Kobayashi;T. Mutoh;K. Kawahata;T. Watari;LHD experiment group;T. Saito;Y. Tatematsu;S. B. Korsholm;M. Salewski
集体汤姆逊散射（CTS）诊断的开发和用于测量体和快离子起源于180 keV的中性束在大螺旋装置（LHD）。在77 GHz的回旋管与1兆瓦的功率输出功能的电磁波作为探头和电子回旋加热束。为了阐明回旋管在77 GHz频段的诊断适用性，我们研究了等离子体中探测器和接收器束轨迹的相关性，其中等离子体具有高电子密度（4-5）× 10 19 m− 3和低电子密度（1-2）× 10 19 m− 3。在高密度下，在CTS光谱中观察到杂散辐射分量，而在低密度下杂散辐射分量小得可以忽略。在使用光束扫描的原位光束对准之后测量和分析CTS光谱。定性地，CTS谱图显示对于（1-2）× 10 19 m− 3的电子密度和2-4 keV的电子温度，对1-2 keV的离子温度的一致响应。所测得的CTS光谱显示在180 keV的快离子注入过程中的体离子区域的脚的不对称形状。这种形状由速度空间（v）中的快离子分布来解释||，v_（max））的蒙特卡罗模拟结果。利用CTS谱的分析方法，从测量的CTS数据中估计了离子温度和快离子速度分布。
A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron cyclotron heating beam. To clarify the diagnostic applicability of the gyrotron in the 77 GHz frequency band, we investigated the dependence of the probe and receiver beam trajectories in plasmas with high electron densities of (4–5)× 10 19 m− 3 and low electron densities of (1–2)× 10 19 m− 3. At high density, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1–2 keV for electron densities of (1–2)× 10 19 m− 3 and electron temperatures of 2–4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v||, v⊥) based on Monte Carlo simulation results. The analysis method of the CTS spectra is used to evaluate the ion temperature and fast-ion velocity distribution from the measured CTS data.