介绍了激光干涉技术用于诊断等离子体的基本原理、实验装置及图像处理方法等,通过Mach-Zehnder激光干涉仪诊断了空气开关等离子体。结果表明,该实验装置能够获得高质量的干涉图。通过对干涉图的数值处理,重建了等离子体电子密度的三维分布。空气开关放电后75 ns时刻,等离子体的平均电子密度为2×10 ¹⁸ cm ^-3,电子温度为0.11 eV,等离子体半径为1.1 mm,扩散速度为1.4×10 ⁴ m/s。

Herein, a technique for plasma diagnosis via laser interference is described in terms of basic principles, experimental setup, and image-processing methods. Air-switch plasma is diagnosed using a Mach-Zehnder laser interferometer. The results show that the experimental device can record high-quality interferograms. Through numerical processing of these interferograms, the three-dimensional electron density distribution in plasma is reconstructed. After the air switch is ignited for 75 ns, the average electron density in plasma reaches 2×10 18 cm -3, the electron temperature is 0.11 eV, the plasma radius is 1.1 mm, and the diffusion velocity is 1.4×10 4 m/s.