Magnetic field amplification driven by the gyro motion of charged particles

TL;DR

This paper investigates how charged particles' gyro motion in laser-irradiated microtubes can spontaneously generate and amplify giga-gauss magnetic fields, affecting plasma dynamics in high-intensity laser interactions.

Contribution

It presents kinetic simulations and an analytical model demonstrating magnetic field amplification mechanisms in laser-plasma interactions with microstructures.

Findings

Giga-gauss magnetic fields are generated and amplified with opposite polarity to initial seed fields.

The magnetic field's spot size is comparable to the laser wavelength.

The magnetic field persists for hundreds of femtoseconds.

Abstract

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.