ELI Beamlines Facility, The Extreme Light Infrastructure ERIC, Za Radnicí 835, Dolní Břežany, 25241, Czechia.
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague 2, 12116, Czechia.
Sci Rep. 2023 Jan 30;13(1):1701. doi: 10.1038/s41598-023-28753-3.
The emergence of petawatt lasers focused to relativistic intensities enables all-optical laboratory generation of intense magnetic fields in plasmas, which are of great interest due to their ubiquity in astrophysical phenomena. In this work, we study generation of spatially extended and long-lived intense magnetic fields. We show that such magnetic fields, scaling up to the gigagauss range, can be generated by interaction of petawatt laser pulses with relativistically underdense plasma. With three-dimensional particle-in-cell simulations we investigate generation of magnetic fields with strengths up to [Formula: see text] G and perform a large multi-parametric study of magnetic field in dependence on dimensionless laser amplitude [Formula: see text] and normalized plasma density [Formula: see text]. The numerical results yield scaling laws that closely follow derived analytical result [Formula: see text], and further show a close match with previous experimental works. Furthermore, we show in three-dimensional geometry that the decay of the magnetic wake is governed by current filament bending instability, which develops similarly to von Kármán vortex street in its nonlinear stage.
太瓦级激光聚焦到相对论强度的出现使人们能够在等离子体中全光学地产生强磁场，由于它们在天体物理现象中普遍存在，因此引起了极大的兴趣。在这项工作中，我们研究了空间扩展和长寿命强磁场的产生。我们表明，通过太瓦级激光脉冲与相对论欠密等离子体的相互作用，可以产生高达千兆高斯范围的这种磁场。通过三维的粒子模拟，我们研究了高达[Formula: see text]G 的磁场的产生，并对磁场强度与无量纲激光幅度[Formula: see text]和归一化等离子体密度[Formula: see text]的依赖关系进行了大型多参数研究。数值结果得出的标度律与推导的解析结果[Formula: see text]非常吻合，并且与以前的实验工作也非常吻合。此外，我们在三维几何中表明，磁场尾流的衰减由电流丝弯曲不稳定性控制，该不稳定性在其非线性阶段类似于 von Kármán 涡街发展。
