Study of filamentation instability on the divergence of ultraintense laser-driven electrons

TL;DR

This study uses collisional PIC simulations to analyze how filamentation instability affects the divergence of relativistic electron beams generated by ultraintense lasers, revealing increased divergence due to magnetic fields in collisional plasmas.

Contribution

It demonstrates the role of filamentation instability in enhancing electron beam divergence in collisional plasmas, with implications for optimizing laser-driven electron applications.

Findings

Filamentation instability generates strong magnetic fields in collisional plasmas.

RE divergence increases with laser intensity and target charge state.

Using low-Z materials may improve electron beam control in applications.

Abstract

Generation of relativistic electron (RE) beams during ultraintense laser pulse interaction with plasma targets is studied by collisional particle-in-cell (PIC) simulations. Strong magnetic field with transverse scale length of several local plasma skin depths, associated with RE currents propagation in the target, is generated by filamentation instability (FI) in collisional plasmas, inducing a great enhancement of the divergence of REs compared to that of collisionless cases. Such effect is increased with laser intensity and target charge state, suggesting that the RE divergence might be improved by using low-Z materials under appropriate laser intensities in future fast ignition experiments and in other applications of laser-driven electron beams.