Methods of Generation and Detailed Characterization of Millimeter-Scale Plasmas Using a Gasbag Target

• Published in: Chinese physics letters Vol. 28; no. 12; pp. 125202 - 1-125202-4
• Main Authors: Li, Zhi-Chao (志超李), Zheng, Jian (坚郑), Jiang, Xiao-Hua (小华蒋), Wang, Zhe-Bin (哲斌王), Yang, Dong (冬杨), Zhang, Huan (欢章), Li, San-Wei (三伟李), Wang, Feng (峰王), Peng, Xiao-Shi (晓世彭), Yin, Qiang (强尹), Zhu, Fang-Hua (芳华朱), Guo, Liang (亮郭), Yuan, Peng (鹏袁), Liu, Shen-Ye (慎业刘), Ding, Yong-Kun (永坤丁)
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2011
• Subjects: Density; Electron density; Electron temperature; Inertial confinement fusion; Laser beams; Lasers; Pinhole cameras; Plasmas
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/28/12/125202

Gasbag targets are useful for the research of laser-plasma interactions in inertial confinement fusion, especially in the laser overlapping regime. We report that on the Shenggnang-II laser facility, millimeter-scale plasmas are successfully generated by four 0.35 mu m laser beams using a gasbag target. Multiple diagnostics are applied to characterize the millimeter-scale plasmas in detail. The images from the x-ray pinhole cameras confirm that millimeter-scale plasmas are indeed created. An optical Thomson scattering system diagnoses the electron temperature of the CH filling plasmas by probing the thermal ion-acoustic fluctuations, which indicates that the electron temperature has a 600 eV flat roof in 0.7-1.3 ns. Another key parameter, i.e. the electron density of the millimeter-scale plasmas, is inferred by the spectrum of the back stimulated Raman scattering of an additional 0.53 mu m laser beam. The inferred electron density keeps stable at 0.1n sub(c)in early time consistent with the controlled filling pressure and splits into a higher density in late time, which is attributed to the blast wave entering into the SRS interaction region