Comparison of Optical Emission Spectroscopy and Cavity Ring‐Down Spectroscopy in Large‐Scaled Negative‐Ion Source
Comparison of Optical Emission Spectroscopy and Cavity Ring‐Down Spectroscopy in Large‐Scaled Negative‐Ion Source
复制标题
大型负离子源中发射光谱与光腔衰荡光谱的比较
DOI：
10.1063/1.3637407
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Y. Takeiri
中科院分区：
文献类型：
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作者：
K. Ikeda;H. Nakano;K. Tsumori;U. Fantz;O. Kaneko;M. Kisaki;K. Nagaoka;M. Osakabe;Y. Takeiri
光学发射光谱（OES）和腔环下光谱（CRDS）系统安装在美国国家聚变科学研究所的一个1/3比例的负氢离子源测试台上，以研究等离子体栅格附近提取区氢离子的动力学。在低偏置电压下，离子束提取后，氢离子密度的信号形式迅速下降。OES测量的氢巴尔默线发射强度也出现了类似的信号下降，这是由H−和H+相互中和作用产生的氢原子减少引起的。射束电流的变化趋势与提取区的H -密度和Hα/Hβ相似，在Cs播种后立即增加了两倍。我们观察到H−密度与Hα/Hβ的倾斜度之间存在线性相关关系，从而可以将OES测量结果与CRDS测量结果进行实验基准比对。因此，该方法可用于在负离子源中用OES估计高电子离子的H -密度。
Optical emission spectroscopy (OES) and cavity ring‐down spectroscopy (CRDS) systems are installed in a 1/3‐scaled negative hydrogen‐ion source at the National Institute for Fusion Science testbed to investigate the dynamics of H− ions in the extraction region near the plasma grid. The signal form of the H− ion density rapidly drops after beam extraction on applying a low‐bias voltage. A similar signal drop appears in the intensity of the hydrogen Balmer‐line emission measured by OES and is caused by decreasing atomic hydrogen produced by mutual neutralization effects between H− and H+. Shot trend of the beam currents are similar to the H− density and Hα/Hβ in the extraction region, which increases twice as large immediately after Cs seeding. We observe a linear correlation between the H− density and the inclination of Hα/Hβ which allows for experimentally benchmarking the OES measurement with that of CRDS. Thus, this approach is used for estimating the H− density by OES in negative‐ion sources for high‐e...