高真空激光等离子体的同步移相干涉诊断及仿真  

Simultaneous phase-shifting interferometer diagnosis and simulationof high vacuum laser plasma

作　　者：许贝贝 陆健[1] 张宏超[1] 高楼 唐懋 XU Beibei;LU Jian;ZHANG Hongchao;GAO Lou;TANG Mao(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学理学院,南京210094

出　　处：《激光技术》2024年第1期14-19,共6页Laser Technology

基　　金：国家自然科学基金资助项目(11774176)。

摘　　要：为了解决在高真空环境下,等离子体膨胀迅速、外围羽流引起的条纹偏移小、单幅干涉条纹图难以检出的问题,采用同步移相干涉测试技术得到了1.333×10-4 Pa和1.333×10-3 Pa真空度下激光诱导铝等离子体电子密度分布;同时采用2维轴对称流体动力学模型,对高真空环境下激光诱导等离子体的膨胀过程进行了数值仿真,得到了电子密度的2维分布,并分析了数值仿真结果存在偏差的原因及改进方法。结果表明,等离子体的中心电子密度在50 ns时下降至1.4×1020 cm-3;数值仿真结果与实验结果吻合较好,验证了模型的正确性。该研究为高真空下激光等离子体的研究提供了一定的参考。In order to solve the problem of rapid plasma expansion and small fringe offset caused by peripheral plumes in the high vacuum environment,it was difficult to detect a single interference fringe pattern.The electron density distributions of the laser-induced aluminum plasma under 1.333×10-4 Pa and 1.333×10-3 Pa pressure were obtained by using simultaneous phase-shifting interference.At the same time,the expansion process of laser-induced plasma under a high vacuum environment was simulated numerically by using a 2-D axis ymmetric fluid dynamics model,and the two-dimensional distribution of electron density was obtained and analyzed for the reasons for the deviation of numerical simulation results and the improvement methods.The results show that the central electron density of plasma decreases to 1.4×1020 cm-3 at 50 ns.The numerical simulation results are in good agreement with the experimental results,which verifies the reliability of the model.This research provides some reference for the study of laser plasma under high vacuum.

关 键 词：激光技术 激光诱导等离子体 高真空 同步移相 电子密度 数值仿真 

分 类 号：O439[机械工程—光学工程] TN249[理学—光学]