In this study, we investigate the generation of twin γ ray beams in the collision of an ultrahigh intensity laser pulse with a laser wakefield accelerated electron beam using a particle-in-cell simulation. We consider the composed target of a homogeneous underdense preplasma in front of an ultrathin solid foil. The electrons in the preplasma are trapped and accelerated by the wakefield. When the laser pulse is reflected by the thin solid foil, the wakefield accelerated electrons continue to move forward and pass through the foil almost without influence from the reflected laser pulse or foil. Consequently, two groups of γ ray flashes, with tunable time delay and energy, are generated by the wakefield accelerated electron beam interacting with the reflected laser pulse from the foil as well as another counter-propagating petawatt laser pulse behind the foil. Additionally, we study the dependence of the γ photon emission on the preplasma densities, driving las...

中文翻译：

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超高强度激光脉冲与激光尾场加速电子束相互作用产生的两阶段γ射线发射

在这项研究中，我们使用粒子内模拟研究了超高强度激光脉冲与激光尾场加速电子束的碰撞中双γ射线束的产生。我们考虑在超薄固体箔片前均匀均质的预质子的组成目标。等离子体中的电子被尾场捕获并加速。当激光脉冲被薄的固体箔片反射时，被场加速的电子继续向前移动并穿过箔片，几乎不受反射的激光脉冲或箔片的影响。因此，两组γ射线闪烁，具有可调的时间延迟和能量，由场加速电子束与来自箔片的反射激光脉冲以及箔片后面的另一个反向传播的petwatt激光脉冲相互作用产生的电子。此外，我们研究了γ光子发射对等离子体前体密度的依赖性，从而驱动激光...