激光聚变靶丸冰层折射率与粗糙度表征技术研究  

Simultaneous Diagnosis of Refractive Index and Roughness of Ice Layer in Laser Fusion Targets

作　　者：徐兆锐 刘东[1] 彭韶婧 李欣明 严天亮 白剑[1] 沈亦兵[1] 吴兰[1] 刘崇[1] Xu Zhaorui;Liu Dong;Peng Shaojing;Li Xinming;Yan Tianliang;Bai Jian;Shen Yibing;Wu Lan;Liu Chong(State Key Laboratory of Extreme Photonics and Instrumentation,College of Optical Science and Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]浙江大学光电科学与工程学院极端光学技术与仪器全国重点实验室,浙江杭州310027

出　　处：《光学学报》2024年第16期155-162,共8页Acta Optica Sinica

基　　金：极端光学技术与仪器全国重点实验室创新项目(EPI2023ZD01)。

摘　　要：惯性约束聚变装置对靶丸燃料层的均匀性要求严苛,检测系统需要具备折射率、厚度与粗糙度等参数的高精度表征能力。搭建了一套基于干涉与背光阴影成像技术的振镜扫描靶丸同步表征系统,并基于代数重构算法重建了靶丸冰层轮廓粗糙度与三维折射率分布。仿真与实验结果表明,轮廓粗糙度表征的相对误差优于2.2%,本文系统对多种靶丸结构三维折射率的重建结果平均值的相对误差均小于0.16%,这证明了表征技术的可靠性,为聚变靶丸制备工艺提供了有效的支撑。Objective Inertial confinement fusion(ICF)is a promising fusion energy research technique that involves subjecting a tiny fuel target,typically a pellet containing a mixture of deuterium and tritium,to extreme temperatures and pressures,causing the fuel to undergo nuclear fusion.Achieving uniformity in the fuel layer within the target is critical for a successful fusion reaction,necessitating precise measurement and control of various parameters such as refractive index,thickness,and surface roughness.Any deviation from the ideal uniformity can lead to instability during the implosion process,significantly reducing fusion reaction efficiency.Recent advancements in ICF research have introduced various methods for characterizing the fuel layer,including X-ray imaging for density measurements,liquid refractive index matching for optical profiling,and confocal microscopy for surface analysis.Despite these innovations,challenges remain,particularly in adapting these methods in a vacuum environment and achieving the precision necessary for accurate characterization.To address these challenges and provide comprehensive guidance for the ICF target fabrication process,there is an urgent need to develop a characterization system capable of in situ synchronous detection of the roughness and refractive index of the target’s ice layer within a vacuum chamber.Methods We establish a characterization model for optical path difference and light deflection based on Mach-Zehnder(M-Z)interferometry and backlight shadow imaging techniques.By integrating interferometric detection and backlight shadow technology,a synchronous measurement method for refractive index and thickness is applied,allowing precise iteration to obtain the average thickness and refractive index of the ICF target’s ice layer.Utilizing an optical projection tomography approach,a mirror-scanning synchronous characterization system for the target is constructed,which synchronously measures the average thickness and refractive index of the target’s ice layer un

关 键 词：激光聚变靶丸 振镜扫描 干涉检测 背光阴影 粗糙度表征 三维折射率分布 

分 类 号：O436.1[机械工程—光学工程]