Edge Plasma Diagnostics on Tore Supra Tokamak

在法国Cadarache的Tore Supra托卡马克上，研究了束探针光谱在边缘等离子体诊断中的适用性。通过在Tore Supra边缘部分操作遍历分流器，预计将产生高达10^<14> cm^<-3>的电子密度，需要开发一种能够以高达1cm的空间分辨率测量如此高密度的诊断技术。束探针光谱学是本课课组最初开发的一种利用等离子体粒子与注入的束原子之间的各种原子和辐射过程，用于等离子体诊断的方法。通过与Cadarache课课组的讨论发现，由于注入的中性锂束衰减强，原计划使用的中性锂束不适用于如此高的电子密度测量，但测量注入等离子体的中性氢或氦束不同跃迁对应的两条谱线的强度比，将得到电子密度分布图。因为强度比是局部电子密度的函数。然而，在真空紫外区制备光检测系统是必要的。在使用氢的情况下，可以利用Tore Supra上现有的氢诊断束，但需要准备一个新的氦诊断束。在现有的氢诊断光束中加入掺氦光束也是可行的。本文将完成Tore Supra边缘等离子体电子密度分布诊断系统的设计。

Applicability of the beam probe spectroscopy to the edge plasms diagnostics on the Tore Supra tokamak in Cadarache, France, has been investigated. It is expected that electron density as high as 10^<14> cm^<-3> will be produced by operating an ergodic divertor in edge part of Tore Supra, and a diagnostic technique which could measure such high density with spatial resolution as high as 1cm is required to be developed. The beam probe spectroscopy which has originally been developed in our research group utilizes various atomic and radiative processes between plasma particles and beam atoms injected, and is used for plasma diagnostics. It has been found through the discussion with research group in Cadarache that the use of neutral lithium beam originally planned is not proper for such a high electron density measurement because of strong attenuation of the beam injected, but the measurement of the intensity ratio of two spectral lines corresponding to different transitions from the neutral hydrogen or helium beam injected into the plasma will give an electron density profile, since the intensity ratio is a function of local electron density. It is, however, necessary to prepare the light detection system in the Vacuum Ultraviolet region. In the case of using hydrogen, an existing diagnostic beam of hydrogen on Tore Supra could be utilized, but it will be necessary to prepare a new diagnostic beam for helium. A doped beam of helium in the existing hydrogen diagnostic beam would also be applicable. A design of the diagnostic system for electron density profile in the Tore Supra edge plasma is going to be completed.