D3He爆推靶质子源优化模拟研究

为了在百kJ高功率激光装置上建立D3He质子照相平台，采用一维辐射流体程序Helios-CR对D3He爆推靶质子产生进行了模拟，综合考虑多种因素给出在百千焦高功率激光装置上开展质子照相所需要的激光和靶球建议参数。结合激光装置现有条件，分析了在1015 W/cm2左右激光强度下D3He质子产额随靶球半径、激光强度、充气压力和SiO₂球壳厚度等参数的变化规律，给出了靶球半径300 μm，内充D3He气体压强1.8 MPa，SiO₂球壳厚度3.5 μm左右等优化参数，预计此条件下D3He质子产额可达109～1010。通过模拟得到的质子产额变化规律，为质子照相平台的正式建立和实验参数选取提供了参考。

Optimized simulation of D3He proton source for exploding pusher target

To establish a monochromatic high-energy proton photography platform on high power laser device with hundreds of kilojoules, D3He gas-filled spherical SiO₂ glass pellets, irradiated by an absorbed laser intensity of 1015 W/cm2 have been considered and the exploding pusher target simulation has been conducted with Helios-CR to design an optimum target, which couples to the incident laser light more effectively to produce the optimum number of protons. By varying the inner radius of the target, the laser intensity and the thickness of the spherical shell, the optimal laser conditions and target parameters for photography under the condition of our laser device are obtained. The simulation results give a suitable experimental parameter of 300 μm target ball radius, 1.8 MPa filled D3He gas and 3.5 μm SiO₂ spherical shell thickness. In addition, we also considered the influence of laser driving symmetry and kinetic effect on the simulation results. Taking the optimal parameters obtained by simulation as the input, it is expected that 109–1010 proton yield can be obtained experimentally. The law of proton yield variation obtained through simulation provides a reference for the formal establishment of the proton photography platform and the selection of experimental parameters.