Gu Yan-Jun, Murakami Masakatsu
Institute of Laser Engineering, Osaka University, Suita, Osaka, 565-0871, Japan.
Sci Rep. 2021 Dec 8;11(1):23592. doi: 10.1038/s41598-021-02944-2.
Spontaneous magnetic field generation plays important role in laser-plasma interactions. Strong quasi-static magnetic fields affect the thermal conductivity and the plasma dynamics, particularly in the case of ultra intense laser where the magnetic part of Lorentz force becomes as significant as the electric part. Kinetic simulations of giga-gauss magnetic field amplification via a laser irradiated microtube structure reveal the dynamics of charged particle implosions and the mechanism of magnetic field growth. A giga-gauss magnetic field is generated and amplified with the opposite polarity to the seed magnetic field. The spot size of the field is comparable to the laser wavelength, and the lifetime is hundreds of femtoseconds. An analytical model is presented to explain the underlying physics. This study should aid in designing future experiments.
自发磁场产生在激光与等离子体相互作用中起着重要作用。强准静态磁场会影响热导率和等离子体动力学，特别是在超强激光的情况下，洛伦兹力的磁场部分变得与电场部分一样显著。通过激光辐照微管结构对千兆高斯磁场放大进行的动力学模拟揭示了带电粒子内爆的动力学过程以及磁场增长的机制。产生了一个与种子磁场极性相反的千兆高斯磁场并对其进行放大。该磁场的光斑尺寸与激光波长相当，寿命为数百飞秒。提出了一个解析模型来解释其基本物理原理。这项研究应有助于设计未来的实验。
