Micron-Scale Mapping of Megagauss Magnetic Fields in Petawatt Laser-Solid Interactions

TL;DR

This paper presents high-resolution measurements of megagauss magnetic fields produced during petawatt laser-solid interactions, revealing electron beam filamentation signatures and validated by hybrid simulations.

Contribution

It introduces spatially and temporally resolved optical polarimetry techniques to map magnetic fields in laser-solid interactions, providing new insights into electron dynamics.

Findings

Detection of megagauss magnetic fields at the target rear

Observation of electron beam filamentation signatures

Validation of measurements with hybrid simulations

Abstract

We report spatially and temporally resolved measurements of magnetic fields generated by petawatt laser-solid interactions with high spatial resolution, using optical polarimetry. The polarimetric measurements map the megagauss magnetic field profiles generated by the fast electron currents at the target rear. The magnetic fields at the rear of a 50 $\mu$m thick aluminum target exhibit distinct and unambiguous signatures of electron beam filamentation. These results are corroborated by hybrid simulations.