Investigation of a gallium alloy liquid metal mirror for application in inertial fusion energy systems

The final optic in future inertial fusion energy plants must maintain high performance and survivability under gigashot laser irradiation while exposed to fusion byproducts. Although no practical solution has been demonstrated, a self-healing final turning mirror based on a grazing-incidence liquid metal mirror has been theoretically explored. This work investigates the suitability of a gallium alloy. The experimental system simulates key conditions, including vacuum exposure and 10-Hz, 355-nm, 6-ns laser pulses. Experiments address reflectivity, damage, and response as a function of pressure. Results highlight the potential of liquid metal gallium alloys for robust final optics in laser-based fusion power plants and inform non-traditional optics for intense laser systems.