Simulation study of a passive plasma beam dump using varying plasma density

TL;DR

This study investigates a modified passive plasma beam dump using gradient or stepped plasma profiles, demonstrating improved energy absorption over uniform plasma through particle-in-cell simulations.

Contribution

It introduces a novel plasma profile design that enhances energy loss efficiency in plasma beam dumps compared to traditional uniform plasma schemes.

Findings

Gradient and stepped plasma profiles increase decelerating gradients.

Simulations show improved energy absorption with non-uniform profiles.

Enhanced plasma beam dump performance for laser wakefield acceleration parameters.

Abstract

A plasma beam dump uses the collective oscillations of plasma electrons to absorb the kinetic energy of a particle beam. In this paper, a modified passive plasma beam dump scheme is proposed using either a gradient or stepped plasma profile to maintain a higher decelerating gradient compared to a uniform plasma. The improvement is a result of the plasma wavelength change preventing the re-acceleration of low energy particles. Particle-in-cell simulation results show that both stepped and gradient plasma profiles can achieve improved energy loss compared to a uniform plasma for an electron bunch of parameters routinely achieved in laser wakefield acceleration.