Glass F, Carlstrom T N, Du D, McLean A G, Taussig D A, Boivin R L
General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA.
Rev Sci Instrum. 2016 Nov;87(11):11E508. doi: 10.1063/1.4955281.
A design to extend the unique divertor Thomson scattering system on DIII-D to allow measurements of electron temperature and density in high triangularity plasmas is presented. Access to this region is selectable on a shot-by-shot basis by redirecting the laser beam of the existing divertor Thomson system inboard - beneath the lower floor using a moveable, high-damage threshold, in-vacuum mirror - and then redirecting again vertically. The currently measured divertor region remains available with this mirror retracted. Scattered light is collected from viewchords near the divertor floor using in-vacuum, high temperature optical elements and relayed through the port window, before being coupled into optical fiber bundles. At higher elevations from the floor, measurements are made by dynamically re-focusing the existing divertor system collection optics. Nd:YAG laser timing, analysis of the scattered light spectrum via polychromators, data acquisition, and calibration are all handled by existing systems or methods of the current multi-pulse Thomson scattering system. Existing filtered polychromators with 7 spectral channels are employed to provide maximum measurement breadth (T in the range of 0.5 eV-2 keV, n in the range of 5 × 10-1 × 10 m) for both low T in detachment and high T measurement up beyond the separatrix.
提出了一种扩展DIII-D上独特的偏滤器汤姆逊散射系统的设计，以实现对高三角形等离子体中电子温度和密度的测量。通过使用可移动的、高损伤阈值的真空内反射镜将现有偏滤器汤姆逊系统的激光束向内引导至下层地板下方，然后再次垂直引导，可逐次选择进入该区域。当该反射镜缩回时，当前测量的偏滤器区域仍然可用。散射光通过真空内的高温光学元件从偏滤器地板附近的视线上收集，并通过端口窗口中继，然后耦合到光纤束中。在离地板较高的高度，通过动态重新聚焦现有偏滤器系统的收集光学器件进行测量。钕钇铝石榴石激光定时、通过多色仪对散射光谱进行分析、数据采集和校准均由当前多脉冲汤姆逊散射系统的现有系统或方法处理。现有的具有7个光谱通道的滤波多色仪用于为脱离时的低温度和高于磁分界面的高温度测量提供最大测量范围（温度范围为0.5 eV至2 keV，密度范围为5×10至1×10 m）。
