Luo Wen, Liu Wei-Yuan, Yuan Tao, Chen Min, Yu Ji-Ye, Li Fei-Yu, Del Sorbo D, Ridgers C P, Sheng Zheng-Ming
School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China.
SUPA, Department of Physics, University of Strathclyde, Glasgow, G40NG, United Kingdom.
Sci Rep. 2018 May 30;8(1):8400. doi: 10.1038/s41598-018-26785-8.
Upcoming ultrahigh power lasers at 10 PW level will make it possible to experimentally explore electron-positron (ee) pair cascades and subsequent relativistic ee jets formation, which are supposed to occur in extreme astrophysical environments, such as black holes, pulsars, quasars and gamma-ray bursts. In the latter case it is a long-standing question as to how the relativistic jets are formed and what their temperatures and compositions are. Here we report simulation results of pair cascades in two counter-propagating QED-strong laser fields. A scaling of QED cascade growth with laser intensity is found, showing clear cascade saturation above threshold intensity of ~10 W/cm. QED cascade saturation leads to pair plasma cooling and longitudinal compression along the laser axis, resulting in the subsequent formation of relativistic dense ee jets along transverse directions. Such laser-driven QED cascade saturation may open up the opportunity to study energetic astrophysical phenomena in laboratory.
即将出现的10拍瓦级超高功率激光器将使通过实验探索电子-正电子（ee）对级联以及随后相对论性ee喷流的形成成为可能，这些现象被认为发生在诸如黑洞、脉冲星、类星体和伽马射线暴等极端天体物理环境中。在后一种情况下，相对论性喷流是如何形成的以及它们的温度和组成是什么，这是一个长期存在的问题。在此，我们报告了在两个反向传播的量子电动力学强激光场中对级联的模拟结果。发现了量子电动力学级联增长与激光强度的标度关系，表明在约10 W/cm的阈值强度以上出现明显的级联饱和。量子电动力学级联饱和导致对等离子体冷却并沿激光轴纵向压缩，从而在横向形成随后的相对论性致密ee喷流。这种激光驱动的量子电动力学级联饱和可能为在实验室研究高能天体物理现象提供机会。
