Magnetized high energy density physics offers new opportunities for observing magnetic field-related physics for the first time in the laser-plasma context. We focus on one such phenomenon, which is the ability of a laser-irradiated magnetized plasma to amplify a seed magnetic field. We performed a series of fully kinetic 3D simulations of magnetic field amplification by a picosecond-scale relativistic laser pulse of intensity $4.2\times 10^{18}$ W/cm$^2$ incident on a thin foil. We observe axial magnetic field amplification from an initial 0.1 kT seed to 1.5 kT over a volume of several cubic microns, persisting hundreds of femtoseconds longer than the laser pulse duration. The magnetic field amplification is driven by electrons in the return current gaining favorable orbital angular momentum from the seed magnetic field. This mechanism is robust to laser polarization and delivers order-of-magnitude amplification over a range of simulation parameters.

中文翻译：

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通过携带轨道角动量的返回电流电子在激光照射的薄无碰撞等离子体靶中产生磁场

磁化高能量密度物理学为首次在激光等离子体背景下观察磁场相关物理学提供了新的机会。我们关注这样一种现象，即激光照射磁化等离子体放大种子磁场的能力。我们通过入射在薄箔上的强度为 $4.2\times 10^{18}$W/cm$^2$ 的皮秒级相对论激光脉冲对磁场放大进行了一系列全动力学 3D 模拟。我们观察到轴向磁场在几立方微米的体积内从最初的 0.1 kT 种子放大到 1.5 kT，持续时间比激光脉冲持续时间长数百飞秒。磁场放大由返回电流中的电子驱动，从种子磁场中获得有利的轨道角动量。