Optimization of beam configuration for direct-driven fusion based on ICF indirect-driven laser facility

To increase the flexibility of ICF laser facility and meet the requirements of indirect-driven and direct-driven fusions, the beam configuration should be optimized. This paper takes the Shenguang Ⅲ as an example facility which was originally designed for indirect-driven fusion. The beam configuration for direct-driven fusion is optimized through spherical-harmonic mode and three-dimensional irradiation field analysis. The optimization results show that the irradiation uniformity of the sphere target surface is less than 1%. Then irradiation uniformity and coupling efficiency are calculated with different laser profiles. The small and steep spot which direct-driven fusion requires is also obtained based on the beam configuration.