Emission of high energy gamma rays via the non-linear inverse Compton scattering process (ICS) in interactions of ultra-intense laser pulses with thin solid foils is studied using particle-in-cell simulations. It is shown that the angular distribution of the ICS photons has a forward-oriented two-directional structure centred at an angle $\vartheta = \pm 30^\circ$, a value predicted by a theoretical model based on a standing wave approximation to the electromagnetic field in front of the target, which only increases at the highest intensities due to faster hole boring, which renders the approximation invalid. The conversion efficiency is shown to exhibit a super-linear increase with the driving pulse intensity. In comparison to emission via electron-nucleus bremsstrahlung, it is shown that the higher absorption, further enhanced by faster hole boring, in the targets with lower atomic number strongly favours the ICS process.

中文翻译：

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从固体靶逆康普顿散射照射通过在10超短激光脉冲²² - 10 ²³瓦/厘米²制度

使用细胞内粒子模拟研究了在超强激光脉冲与薄固体箔相互作用中通过非线性逆康普顿散射过程 (ICS) 发射的高能伽马射线。结果表明，ICS光子的角分布具有以角度$\vartheta=\pm 30^\circ$为中心的前向双向结构，该值由基于驻波近似的理论模型预测目标前方的电磁场，由于更快的钻孔，仅在最高强度时增加，这使得近似无效。显示转换效率随着驱动脉冲强度呈现超线性增加。与通过电子-核轫致辐射的发射相比，表明更高的吸收，