基于神光Ⅲ原型的背向散射实验技术研究

激光与等离子体相互作用研究是惯性约束聚变 (ICF) 研究中的重要研究内容. 为了定量研究神光III原型实验中激光与等离子体互作用产生的散射光能量和光谱, 研制了全孔径和近背向散射诊断系统, 并介绍了全孔径和近背反测量系统的光路结构. 对采用连续相位板技术后引起的激光焦斑变化进行了分析. 介绍了采用全孔径和近背向散射诊断系统在神光III原型上完成的考核束匀滑实验效果的实验, 对比了使用束匀滑前后背向散射系统获得的散射光份额和散射光谱分布. 实验发现, 在神光III原型使用800J能量 8束打靶的条件下, 使用束匀滑后背向散射光份额可以降低到5%以下, 其散射光谱也更加集中. 这些数据为黑腔能量学等研究的进一步发展起到重要的促进作用. 关键词： 激光散射 连续相位板 黑腔 光谱

Backscattered Light diagnostic technique on Shen Guang-III prototype Laser Facility

Laser and plasma interaction (LPI) is the important part for the study of inertial confinement fusion (ICF). In order to have an investigation for the energy and spectrum of scattered light produced by laser-plasma interaction in Shen Guang-III prototype laser facility, a backscattered light diagnostic system was developed. This paper introduces the design and the damping factor of this system. The laser focus shape after using the coherent phase plate (CPP) has been analyzed. Experimental results with the energy and spectrum of backscattered light have been provided and compared after adding the CPP on the laser beam. It is found that the fraction of backscattered light can be reduced to below 5% under the laser condition 8×800 J after using the CPP. And the spectrum range with CPP is narrower than that without CPP on laser beam. These experimental data can improve the research on hohlraum energy.
Keywords： laser scattering coherent phase plate hohlraum spectrum