Laser-driven strong magnetostatic fields with applications to charged beam transport and magnetized high energy-density physics

TL;DR

This paper demonstrates the generation of ultra-strong magnetic fields using laser-driven plasma processes, enabling enhanced charged particle transport and advancing applications in high-energy-density physics and laboratory astrophysics.

Contribution

It introduces a method to produce over 0.5 kT magnetic fields via laser-driven currents, with detailed experimental characterization and applications to relativistic electron transport.

Findings

Generated magnetic fields >0.5 kT using laser-driven currents.

Achieved 5-fold enhancement in energy-density flux in magnetized targets.

Demonstrated control of magnetic field evolution via laser irradiance.

Abstract

Powerful laser-plasma processes are explored to generate discharge currents of a few $100\,$kA in coil targets, yielding magnetostatic fields (B-fields) in excess of $0.5\,$kT. The quasi-static currents are provided from hot electron ejection from the laser-irradiated surface. According to our model, describing qualitatively the evolution of the discharge current, the major control parameter is the laser irradiance $I_{\mathrm{las}}\lambda_{\mathrm{las}}^2$. The space-time evolution of the B-fields is experimentally characterized by high-frequency bandwidth B-dot probes and by proton-deflectometry measurements. The magnetic pulses, of ns-scale, are long enough to magnetize secondary targets through resistive diffusion. We applied it in experiments of laser-generated relativistic electron transport into solid dielectric targets, yielding an unprecedented 5-fold enhancement of the energy-density flux at $60 \,\mathrm{\mu m}$ depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetized high-energy density physics investigations, related to laser-generated secondary sources of radiation and/or high-energy particles and their transport, to high-gain fusion energy schemes and to laboratory astrophysics.