Faure J C, Tordeux D, Gremillet L, Lemoine M
CEA, DAM, DIF, 91297 Arpajon, France.
Université Paris-Saclay, CEA, LMCE, 91680 Bruyères-le-Châtel, France.
Phys Rev E. 2024 Jan;109(1-2):015203. doi: 10.1103/PhysRevE.109.015203.
We simulate, using a particle-in-cell code, the chain of acceleration processes at work during the Compton-based interaction of a dilute electron-ion plasma with an extreme-intensity, incoherent γ-ray flux with a photon density several orders of magnitude above the particle density. The plasma electrons are initially accelerated in the radiative flux direction through Compton scattering. In turn, the charge-separation field from the induced current drives forward the plasma ions to near-relativistic speed and accelerates backwards the nonscattered electrons to energies easily exceeding those of the driving photons. The dynamics of those energized electrons is determined by the interplay of electrostatic acceleration, bulk plasma motion, inverse Compton scattering and deflections off the mobile magnetic fluctuations generated by a Weibel-type instability. The latter Fermi-like effect notably gives rise to a forward-directed suprathermal electron tail. We provide simple analytical descriptions for most of those phenomena and examine numerically their sensitivity to the parameters of the problem.
我们使用粒子模拟程序，模拟了稀薄电子 - 离子等离子体与极高强度、非相干γ射线通量相互作用时发生的一系列加速过程，该γ射线通量的光子密度比粒子密度高几个数量级。等离子体电子最初通过康普顿散射在辐射通量方向上被加速。反过来，感应电流产生的电荷分离场将等离子体离子向前驱动至近相对论速度，并将未散射的电子向后加速至轻易超过驱动光子能量的能量。这些被加速电子的动力学由静电加速、整体等离子体运动、逆康普顿散射以及由韦贝尔型不稳定性产生的移动磁涨落引起的偏转之间的相互作用决定。后一种类似费米的效应显著地产生了一个向前的超热电子尾。我们为这些现象中的大多数提供了简单的解析描述，并通过数值方法研究了它们对问题参数的敏感性。
