Application of multi-pulse optical imaging to measure evolution of laser-produced counter-streaming flows
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 i...
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| Published in | Chinese physics B Vol. 26; no. 5; pp. 165 - 169 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
01.05.2017
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| Subjects | |
| Online Access | Get full text |
| ISSN | 1674-1056 2058-3834 |
| DOI | 10.1088/1674-1056/26/5/054206 |
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| Summary: | 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. |
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| Bibliography: | streaming counter interacting exciting instability determining diagnostic colors distinguish gamma Dawei Yuan1, Yutong Li2,3,8, Baojun Zhu2, Yanfei Li2, Jiayong Zhong4,8, Huigang Wei1, Chang Liu4, Xiaoxia Yuan4, Zhe Zhang2, Guiyun Liang1, Feilu Wang1, Fang Li2, Jiarui Zhao2, Neng Hua5, Baoqiang Zhu5, Jianqiang Zhu5, Shaoen Jiang6, Kai Du6, Yongkun Ding6, Gang Zhao1, Jie Zhang7,8（1 Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China ; 2National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China ; 3 School of Physical Sciences, University of Chinese Academy of Sciences, Bering 100049, China ; 4Department of Astronomy, Beijing Normal University, Beijing 100875, China; 5National Laboratory on High Power Lasers and Physics, Shanghai 201800, China ; 6Research Center for Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China ; 7 Key Laboratory for Laser Plasmas （Ministry of Education） and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China ;8 Collaborative Innovation Center of IFSA （CICIFSA）, Shanghai Jiaotong University, Shanghai 200240, China） 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. 11-5639/O4 |
| ISSN: | 1674-1056 2058-3834 |
| DOI: | 10.1088/1674-1056/26/5/054206 |