Application of multi-pulse optical imaging to measure evolution of laser-produced counter-streaming flows  

作　　者：袁大伟 李玉同 朱保君 李彦霏 仲佳勇 魏会冈 刘畅 原晓霞 张喆 梁贵云 王菲鹿 李芳 赵家瑞 华能 朱宝强 朱健强 江少恩 杜凯 丁永坤 赵刚 张杰 

机构地区：[1]Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences [2]National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences [3]School of Physical Sciences, University of Chinese Academy of Sciences [4]Collaborative Innovation Center of IFSA(CICIFSA), Shanghai Jiaotong University [5]Department of Astronomy, Beijing Normal University [6]National Laboratory on High Power Lasers and Physics [7]Research Center for Laser Fusion, China Academy of Engineering Physics [8]Key Laboratory for Laser Plasmas(Ministry of Education)and Department of Physics and Astronomy,Shanghai Jiao Tong University

出　　处：《Chinese Physics B》2017年第5期165-169,共5页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China(Grant No.2013 CBA01501/3);the National Natural Science Foundation of China(Grant Nos.11503041,11135012,11375262,11573040,11574390,and 11220101002);China Postdoctoral Science Foundation(Grant No.2015M571124)

摘　　要：A counter-streaming flow system is a test-bed to investigate the astrophysical collisionless shock（CS） formation in the laboratory. Electrostatic/electromagnetic instabilities, competitively growing in the system and exciting the CS formation, are sensitive to the flows parameters. One of the most important parameters is the velocity, determining what kind of instability contributes to the shock formation. Here we successfully measure the evolution of the counter-streaming flows within one shot using a multi-pulses imaging diagnostic technique. With the technique, the average velocity of the high-density-part（ne ≥ 8–9 × 10^19cm^-3） of the flow is directly measured to be of ～ 10^6cm/s between 7 ns and 17 ns.Meanwhile, the average velocity of the low-density-part（ne ≤ 2 × 10^19cm^-3） can be estimated as ～ 10^7cm/s. The experimental results show that a collisionless shock is formed during the low-density-part of the flow interacting with each other.A counter-streaming flow system is a test-bed to investigate the astrophysical collisionless shock（CS） formation in the laboratory. Electrostatic/electromagnetic instabilities, competitively growing in the system and exciting the CS formation, are sensitive to the flows parameters. One of the most important parameters is the velocity, determining what kind of instability contributes to the shock formation. Here we successfully measure the evolution of the counter-streaming flows within one shot using a multi-pulses imaging diagnostic technique. With the technique, the average velocity of the high-density-part（ne ≥ 8–9 × 10^19cm^-3） of the flow is directly measured to be of ～ 10^6cm/s between 7 ns and 17 ns.Meanwhile, the average velocity of the low-density-part（ne ≤ 2 × 10^19cm^-3） can be estimated as ～ 10^7cm/s. The experimental results show that a collisionless shock is formed during the low-density-part of the flow interacting with each other.

关 键 词：streaming counter interacting exciting instability determining diagnostic colors distinguish gamma 

分 类 号：P14[天文地球—天体物理] TN24[天文地球—天文学]