强流负离子源光腔衰荡光谱系统研究

High power negative ion source has broad applications. Generally the beam current density of high power negative ion source is an order of magnitude lower than positive ion source. Reliable diagnostic techniques are core works of neutral beam injection based on high power negative ion source, especially for negative ion source with meter-scale extraction area. This project is aimed at developing Cavity Ring-down Spectroscopy for H- density diagnostic of high power negative ion source. Cavity Ring-down Spectroscopy has no pollution and interference to plasma and is not subject to interference from surrounding electromagnetic field, also CRDS doesn't need other plasma parameters. The main research contents of this project include: the matching of laser pulse duration and signal ring-down time, the entire design of CRDS diagnostic system for high power negative ion source; to adjust and maintain the alignment of the cavity under complex vibration source and to develop the technique of aligning and maintaining meter-cavity; the transforming and amplifying of the fast small optical signal and to build a reliable data acquisition system. The successful implementation of this project will provide a good diagnostic support for high power negative ion source and promote the development of high power negative ion source for neutral beam injection.

强流负离子源具有广泛的应用。通常其负离子束流引出密度比正离子束流引出密度低约一个量级，特别对于大面积（引出系统线度在米量级）负离子源，可靠的负离子密度诊断是其研究的核心工作。本项目的目标是发展用于测量强流负离子源氢负离子密度的光腔衰荡光谱诊断方法，该方法具有对等离子体无污染、无干扰、不受外部电磁场信号干扰、不需要已知其他等离子体参数的优点。其主要研究内容包括：研究激光器工作脉宽与信号衰荡时间的匹配关系，开展强流负离子源光腔衰荡光谱诊断系统的设计；解决聚变实验室振动源多样性给光学谐振腔调试、维持带来的问题，发展米量级共焦光学谐振腔的调试与维持技术；解决聚变实验室复杂电磁环境对快速微弱光信号转换、放大、提取的干扰问题，发展可靠的信号采集系统。本项目的成功实施可为强流负离子源的发展提供良好的诊断支撑，推动中性束用强流负离子源的研究进展。

本项发展了用于测量强流负离子源氢负离子密度的光腔衰荡光谱诊断方法，该方法具有对等离子体无污染、无干扰、不受外部电磁场信号干扰、不需要已知其他等离子体参数的优点。其主要研究成果包括：完成了强流负离子源光腔衰荡光谱诊断系统的设计；解决了聚变实验室振动源多样性给光学谐振腔调试、维持带来的问题，发展了米量级共焦光学谐振腔的调试与维持技术；实现了聚变实验室复杂电磁环境对快速微弱光信号转换、放大、提取，发展了可靠的信号采集系统。本项目的研究成果为强流负离子源的发展提供良好的诊断支撑，推动中性束用强流负离子源的研究进展。