基于广义惠更斯-菲涅耳衍射积分公式,推导出在激光间接驱动聚变装置腔柱内和腔柱内靶面上相干叠加的多束激光束投影焦斑光强度的解析表达式。着重分析了轴向距离、离焦量、入射角和聚焦F数等因素对投射在腔内部横截面上的光斑光强分布的影响,以及离焦量、入射角、F数和腔径大小对辐照在靶壁上的焦斑光强分布的影响。仿真结果表明,增大离焦量和聚焦F数,辐照在腔柱内靶面上和垂直于腔轴切面上各投影光斑的光强变化变得平缓,且腔靶内表面上的光强分布均匀性变差,且增大聚焦F数或增大离焦量,会使投影焦斑尺寸呈现减小的趋势。在腔壁上要获得均匀性比较好的光斑,跟腔径值和注入角度的选取有比较密切的联系。 Based on the generalized Huygens-Fresnel diffraction integral formula, the analytical expression of the intensity of the multi-beam laser beam focal spot intensity coherently superimposed on the target surface of the laser indirectly driven fusion device cavity column is derived. The effects of axial distance, defocus amount, incident angle and focal F number on the light intensity distribution of the light spot projected on the internal cross section of the cavity are analyzed emphatically, and the relationship between the defocus amount, incident angle, F number and cavity size Effect of irradiation on focal intensity distribution of target on the target wall. The simulation results show that with increasing the defocus amount and focusing F-number, the light intensity changes of each projection spot on the target surface in the cavity column and perpendicular to the cavity axis become gentle, and the light intensity on the inner surface of the cavity target The distribution uniformity becomes worse, and increasing the focal F number or increasing the defocus amount tends to decrease the projection focal spot size. In the cavity wall to get a better uniformity of the spot, with the cavity diameter and injection angle of the more closely linked.