探测器阵列靶散射取样衰减单元设计

探测器阵列靶是测量激光强度时空分布的常用设备，为实现到靶激光参数高精度测量，取样衰减方式是其关键。针对探测器阵列靶散射取样衰减技术，基于双向透射分布函数对毛玻璃等材料透射散射光特性进行研究，推导出散射到探测器感光面激光强度衰减倍率的计算公式。设计了毛玻璃与工程漫射体组合的散射取样衰减单元，结合ABg散射模型，利用TracePro建立仿真模型。结果表明，设计的取样衰减结构可以承受功率密度2 000 W/cm2激光辐照20 s；散射出射角在±5.44°范围内，探测面取样不均匀性约为3.34%；衰减倍率仿真设计结果与实验测量误差约为0.805%。该种散射取样衰减方式具有抗激光损伤能力强、光斑匀化效果好、光强定量衰减及宽光谱响应等优点，具有很好的应用前景。

Design of scattering sampling attenuation unit for detector array target

The detector array target is a common equipment for measuring the spatial and temporal distribution of laser intensity. In order to achieve high-precision measurement of target laser parameters, the sampling attenuation method is its key point. Aiming at scattering sampling attenuation technology for detector array target, based on the bidirectional transmission distribution function, the transmission and scattering characteristics of ground glass and other materials were studied. And the calculation formula of the laser intensity attenuation magnification which was scattered to the photosensitive surface of the detector was deduced. The scattering sampling attenuation unit combined with ground glass and engineering diffuser was designed. Combined with the ABg scattering model, the simulation model of scattering sampling attenuation materials were established by TracePro software. The results show that the designed sampling attenuation structure is able to withstand the power density of 2 000 W/cm2 laser irradiation for 20 s; within the scattering emission angle of ±5.44°, the sampling unevenness of the detection surface is about 3.34%; the attenuation magnification simulation design result and experimental measurement error is about 0.805%. The scattering sampling attenuation method has the advantages of strong resistance to laser damage, better spot homogenization effect, quantitative attenuation of laser intensity and broad spectral response. This manner has a good application prospect.