Yield degradation due to laser drive asymmetry in D3He backlit proton radiography experiments at OMEGA

Mono-energetic proton radiography is a vital diagnostic for numerous high-energy-density-physics, inertial-confinement-fusion, and laboratory-astrophysics experiments at OMEGA. With a large number of campaigns executing hundreds of shots, general trends in D3He backlighter performance are statistically observed. Each experimental configuration uses a different number of beams and drive symmetry, causing the backlighter to perform differently. Here, we analyze the impact of these variables on the overall performance of the D3He backlighter for proton-radiography studies. This study finds that increasing laser drive asymmetry can degrade the performance of the D3He backlighter. The results of this study can be used to help experimental designs that use proton radiography.

单能质子放射成像（mono-energetic proton radiography）是OMEGA激光装置开展诸多高能量密度物理（high-energy-density-physics）、惯性约束聚变（inertial-confinement-fusion）及实验室天体物理（laboratory-astrophysics）实验的核心诊断手段。当前已有大量实验批次累计完成数百发打靶，科研人员已通过统计分析观测到D³He背光源（D³He backlighter）性能的整体变化规律。由于不同实验配置所采用的激光束数目与驱动对称性存在差异，D³He背光源的性能表现也会有所不同。本文针对上述变量对质子放射成像研究中D³He背光源整体性能的影响展开了系统性分析。本研究发现，增大激光驱动不对称性会劣化D³He背光源的性能。本研究结果可用于指导开展质子放射成像相关的实验设计。