The use of targets with surface structures for laser-driven particle acceleration has potential to significantly boost the particle and radiation energies because of enhanced laser absorption. We investigate, via experiment and particle-in-cell simulations, the impact of micron-scale surface-structured targets on the spectrum of electrons and protons accelerated by a picosecond laser pulse at relativistic intensity. Our results show that, compared with flat-surfaced targets, structures on this scale give rise to a significant enhancement in particle and radiation emission over a wide range of laser–target interaction parameters. This is due to the longer plasma scale length when using micro-structures on the target front surface. We do not observe an increase in the proton cutoff energy with our microstructured targets, and this is due to the large volume of the relief.

中文翻译：

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由高强度皮秒激光脉冲照射的微结构目标产生快速粒子的特征

由于增强的激光吸收，使用具有表面结构的目标进行激光驱动的粒子加速具有显着提高粒子和辐射能量的潜力。我们通过实验和细胞内粒子模拟研究了微米级表面结构目标对由皮秒激光脉冲以相对论强度加速的电子和质子光谱的影响。我们的结果表明，与平面目标相比，这种规模的结构在广泛的激光-目标相互作用参数范围内显着增强了粒子和辐射发射。这是因为在目标前表面上使用微结构时等离子体尺度长度更长。我们没有观察到我们的微结构目标的质子截止能量增加，