激光等离子体诊断用串列式十六通道X射线KB系统研究

The multi-channel Kirkpatrick-Baez (KB) microscope is the precise x-ray imaging instrument used for time-resolved diagnostics in laser inertial confinement fusion (ICF) research. The present eight-channel and sixteen-channel KB microscopes with parallel optical structure in LMJ and OMEGA laser facility require the high accuracy on optical components and system assembly, and many laser beams, which limits their practical application in ICF experiments . Based on the urgent demand for developing high-quality x-ray imaging diagnostics in domestic laser facility and the above problems of parallel multi-channel KB microscope, the project proposes the novel multi-channel KB microscope with its mirrors successively arranged along with optical axis. This tandem optical structure is easy to implement and reduces the required backlighter size, meanwhile the image spacing can be accurately controlled. The project is planned to carry out the research on the overall scheme of sixteen-channel KB microscope with tandem optical structure, and focuses on the basic technical issues in optical design and precise system assembly. The research is of great significance for enriching laser ICF diagnostic methods and promoting the precision level of laser ICF diagnostics in China.

多通道Kirkpatrick-Baez（KB）显微镜是激光惯性约束聚变(ICF)研究进行高质量X射线时空诊断的重要成像设备。LMJ和OMEGA等强激光ICF装置在研的八通道及十六通道KB系统为并列式光路结构，存在着元件加工精度要求高、物镜装配难度大和所需背光源路数多等制约其实际应用的瓶颈问题。基于我国激光ICF装置开展高质量X射线时空诊断的迫切需求和并列式多通道KB系统存在的上述问题，本项目提出了一种各物镜元件沿光轴依次顺序排列的多通道KB结构。这种串列式多通道KB系统的光路结构易于实现，降低了对背光源尺寸的要求，同时可以准确调控像点间距。本项目将开展基于串列式光路结构的十六通道KB系统总体方案研究，并重点解决其光学设计和精密物镜装配等基础性技术问题。本项目的研究成果对于丰富激光ICF诊断方法，提高我国激光ICF诊断研究的精密化水平具有重要意义。

多通道Kirkpatrick-Baez（KB）显微镜是激光惯性约束聚变(ICF)研究进行高质量X射线时空诊断的重要成像设备，NIF、LMJ和OMEGA等强激光ICF装置在研的并列式物镜排布的八通道和十六通道KB系统存在着元件加工精度要求高、物镜装配难度大和像点间隔控制困难等制约其实际应用的瓶颈问题。基于我国激光ICF装置开展高质量X射线时空诊断的迫切需求，针对并列式十六通道KB系统存在的上述问题，项目研究和探索了基于串列式光路排布的多通道KB结构，解决了光学结构设计、多层膜元件研制、精密物镜装配等制约多通道KB系统应用的基础性关键技术。基于高精度支撑锥芯配合X射线实时成像装调的方法，实现了多通道KB系统的精密物镜装配，在实验室离线条件完成了串列式八通道和十六通道KB样机的演示验证。基于模拟定位球配合高精度直线导轨的物像精确指示方法，实现了多通道KB系统由实验室离线条件至强激光装置在线条件的准确切换。项目为我国激光ICF精密化多通道KB诊断系统的应用奠定理论和技术基础。基于上述研究成果，国际上首次实现了串列式八通道和十六通道高分辨KB系统在强激光装置的诊断应用，分别于2015年和2016年在神光II升级装置对快点火锥壳靶的低能区自发光进行了高分辨的动态X射线成像。