7th International Conference on Matter and Radiation at Extremes (ICMRE2024)

The interaction of ultrashort laser pulses with solid targets has the potential to produce high-energy ion beams via the target normal sheath acceleration (TNSA) mechanism. With suitable surface modulation structures on the target, the quality of the accelerated ion beam can be significantly optimized. By comparing the simulation results of different modulation structures on the target surface, it becomes evident that the cone structure target exhibits the most optimal ion beam yield. Based on random walk sampling algorithm, the target structure is designed under the TNSA mechanism driven by a 10²⁰ W/cm² linear-polarized Gaussian laser pulse. The front surface of the target features a modulation structure comprising 24 independent parameters, optimized through random walk sampling specifically tailored to the cone structure. This method enables rapid optimization of target structure parameters, resulting in enhanced hot electron temperature and yield. Additionally, it forms a stronger longitudinal sheath electric field, ultimately leading to an ion beam yield that is 34% higher compared to that achieved with manually configured cone structure targets. This method possesses significant potential for target design applications in the laser-driven ion acceleration experiments.

laser-driven ion acceleration,random walk,ion beam yield