A multichannel spectroscopic diagnostic based on the Stark effect on helium lines was developed and implemented in IShTAR (Ion Cyclotron Sheath Test ARrangement) to measure the spatial distribution of electric fields across the radio frequency sheaths of the ion cyclotron antenna. Direct measurements of the DC electric fields in the antenna sheaths are an important missing component in understanding the antenna-plasma edge interactions in magnetically confined fusion plasmas since they will be used to benchmark theoretical models against real antenna operation. Along with the high-resolution Czerny-Turner monochromator and a detector with an intensifier, the hardware relies on the 2 chained set of linear-to-linear fiber bundles that provide seven optical channels capable of resolving an 8.4 mm region in the vicinity of the antenna's box. The diagnostic is supported with local helium gas puff, enabling it to operate in nonhelium plasmas. Spatially resolved electric field was measured for two discharge configurations, one with and one without the ICRF antenna. The results show a clear difference in the shape of the DC electric field's spatial profile for the two cases studied, with the elevated values when the ICRF antenna was operating. This demonstrates the ability of the diagnostic to measure even small relative changes in the intensity of the electric field.

中文翻译：

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用于空间分辨测量 ICRF 天线鞘中电场的偏振斯塔克光谱

在 IShTAR（离子回旋加速器护套测试装置）中开发并实施了基于斯塔克效应对氦线的多通道光谱诊断，以测量穿过离子回旋加速器天线射频护套的电场空间分布。天线护套中直流电场的直接测量是理解磁约束聚变等离子体中天线 - 等离子体边缘相互作用的重要缺失部分，因为它们将用于根据实际天线操作对理论模型进行基准测试。除了高分辨率的 Czerny-Turner 单色器和带有增强器的检测器外，硬件还依赖于 2 组链式线性到线性光纤束，这些光纤束提供了七个能够解析 8.4 mm 区域附近的光通道天线盒。诊断由局部氦气喷射支持，使其能够在非氦等离子体中运行。测量了两种放电配置的空间分辨电场，一种带有 ICRF 天线，另一种不带有 ICRF 天线。结果表明，对于所研究的两种情况，直流电场空间分布的形状存在明显差异，ICRF 天线运行时值升高。这证明了诊断测量电场强度的微小相对变化的能力。所研究的两个案例的空间剖面图，当 ICRF 天线运行时值升高。这证明了诊断测量电场强度的微小相对变化的能力。所研究的两个案例的空间剖面图，当 ICRF 天线运行时值升高。这证明了诊断测量电场强度的微小相对变化的能力。