Abstract INTF (Indian Test Facility) is a negative hydrogen ion source based neutral beam test facility to characterise 100 keV,60 A Diagnostic Neutral Beam (DNB), conceptualised for ITER. Several diagnostics are under development to monitor and characterise the performance of ion source and the beam properties. Doppler Shift Spectroscopy (DSS) diagnostics shall be used to estimate the beam divergence, beam inhomogeneity and the stripping losses of the extracted H− ion beam. In this work, the conceptualisation of the DSS diagnostics and the performance evaluation of the proposed system is presented. A forward model is developed to predict the signal strength and signal to noise ratio for various beam operation scenarios and for different optical setups. The model also estimates the expected error in the line width analysis carried for estimating the beam divergence. To reduce the error in the estimated beam divergence, a study on the error propagation was carried out by considering a range of viewing angles, different types of light collection systems and optical instruments. An optimum viewing angle, the light collection system and the instrumentation is chosen accordingly. An endoscopic design concept for each LOS has been adopted and the mechanical assembly of the same is presented in this work. The present work also reports that for a focused divergent beam, using conventional methods of line width analysis might lead large errors and impacts the beam divergence measurements obtained by DSS. A suitable algorithm has been developed to deconvolve the beam focusing spectral width contribution, thereby improving the preciseness of the beam divergence estimation.

中文翻译：

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INTF 多普勒频移光谱诊断的概念设计

摘要 INTF（印度测试设施）是一种基于负氢离子源的中性束测试设施，用于表征 100 keV、60 A 诊断中性束 (DNB)，为 ITER 概念化。几种诊断方法正在开发中，以监测和表征离子源的性能和束特性。应使用多普勒频移谱 (DSS) 诊断来估计提取的 H- 离子束的束发散度、束不均匀性和剥离损失。在这项工作中，提出了 DSS 诊断的概念化和拟议系统的性能评估。开发了一种前向模型来预测各种光束操作场景和不同光学设置的信号强度和信噪比。该模型还估计了为估计光束发散而进行的线宽分析中的预期误差。为了减少估计光束发散度的误差，通过考虑一系列视角、不同类型的光收集系统和光学仪器，对误差传播进行了研究。相应地选择最佳视角、光收集系统和仪器。每个 LOS 都采用了内窥镜设计概念，并在这项工作中介绍了相同的机械组装。目前的工作还报告说，对于聚焦发散光束，使用传统的线宽分析方法可能会导致较大的误差并影响 DSS 获得的光束发散测量。已经开发了一种合适的算法来解卷积光束聚焦谱宽贡献，