Implementation of a large-aperture Thomson scattering system for diagnosing driven ion acoustic waves on Shenguang-III prototype laser facility
Implementation of a large-aperture Thomson scattering system for diagnosing driven ion acoustic waves on Shenguang-III prototype laser facility
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DOI：
10.1088/1748-0221/17/05/p05017
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发表时间：
2022-05
影响因子：
1.3
通讯作者：
C. Chen;T. Gong;Z. Li;H. Zhao;D. Yang;X. Jiang;Y. Liu;S. Jin;R. Zhao;S. Li;L. Guo;Q. Li;K. Pan;F. Wang
中科院分区：
文献类型：
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作者：
C. Chen;T. Gong;Z. Li;H. Zhao;D. Yang;X. Jiang;Y. Liu;S. Jin;R. Zhao;S. Li;L. Guo;Q. Li;K. Pan;F. Wang
在神光III原型激光装置靶室底部安装了一套大口径（f/3）汤姆逊散射诊断系统，用于测量受激布里渊散射驱动的离子声波。当4ω（263.3nm）探测光束沿水平面入射靶室时，该系统能够探测到3ω（351 nm）相互作用光束驱动的离子声波的汤姆逊散射光。对于给定的电子密度，来自驱动离子声波的汤姆逊散射光在特定方向上发射。诊断系统的f/3孔径允许测量电子密度高达4×1021 cm-3的等离子体中的驱动离子声波，这覆盖了神光III原型实验中感兴趣的典型密度范围。由于驱动汤姆逊散射光谱通常比伴随的热汤姆逊散射光谱强几个数量级，为了记录这两种信号，在系统中使用半面积滤波器，其将较强的信号抑制到与较弱的信号相当的水平。通过减小系统孔径，可以阻挡来自驱动离子声波的汤姆逊散射光。因此，该系统也可用于探测热离子声波的汤姆逊散射光，用于等离子体参数的测量。在最近的实验与充气黑腔，汤姆逊散射光谱的驱动和热离子声波已被诊断。
A large-aperture (f/3) Thomson scattering diagnostic system, for measuring the ion acoustic waves driven by stimulated Brillouin scattering, has been recently implemented at the bottom of the target chamber on Shenguang-III prototype laser facility. With a 4ω (263.3 nm) probe beam entering the target chamber in the horizontal plane, this system is capable of detecting the Thomson scattered light off ion acoustic waves driven by a 3ω (351 nm) interaction beam. The Thomson scattered light off a driven ion acoustic wave emits at a specific direction, for a given electron density. The f/3 aperture of the diagnostic system allows measurement of driven ion acoustic waves in plasmas with electron densities up to 4×1021 cm-3, which covers the typical density range of interest in experiments on Shenguang-III prototype. Since the driven Thomson scattered spectrum is usually orders of magnitude stronger than the accompanying thermal Thomson scattered spectrum, to record both signals, a half area filter is used in the system, which suppress the stronger signal to a comparable level with the weaker one. By reducing the system aperture, Thomson scattered light off driven ion acoustic waves can be blocked. Therefore, this system can be also used to detect the Thomson scattered light off thermal ion acoustic waves for measurement of plasma parameters. In recent experiments with gas-filled hohlraums, Thomson scattered spectra off both driven and thermal ion acoustic waves have been diagnosed.