Abstract:

Improvement of the traditional plasma diagnostic with Fabry-Perot cavity was made. A method that can diagnose the rapidly varying plasma was put forward. The experiment proved that the velocity of measuring the variation of signal phase by the vector network analyzer is fast enough when it works in CW sweep mode, and is comparable to the velocity of plasma sheath and wake variation. So the method can be adopted to diagnose plasma sheath and wake. The performance of the novel diagnostic device was evaluated. The evaluation shows that the device has good real-time performance and the measurable plasma electron density varies between  10-1~1015m-3which is a wide range.

Key words: Fabry-Perot resonator, Plasma sheath and wake, Real-time diagnostic, Plasma diagnostic

摘要：

对准光学谐振腔诊断等离子体的传统诊断方法进行了改进，提出一种可用于诊断瞬态等离子体的实时诊断方法。通过实验证明，矢量网络分析仪点频测试(CW Sweep)对信号相位变化的测量速度足够快，可以跟上等离子体鞘套和尾迹的变化速度，因此利用该方法诊断等离子体鞘套和尾迹是可行的。通过对诊断系统性能的评估，表明诊断装置具有较高的实时性，对等离子体电子浓度有较宽的测量范围，测量范围可达10-1~1015m-3。

关键词: 准光学谐振腔, 鞘套和尾迹, 实时诊断, 等离子体诊断