Plasma lens-based beam extraction and removal system for Plasma Wakefield Acceleration experiments

TL;DR

This paper proposes a novel plasma lens-based system combining collimators and discharge-capillaries to effectively extract the witness bunch and remove the driver in plasma wakefield acceleration, supported by theoretical analysis and simulations.

Contribution

It introduces an innovative plasma lens system for efficient beam extraction and driver removal in plasma wakefield acceleration experiments, addressing a key challenge in the field.

Findings

The system can successfully extract and transport the witness bunch.

It effectively removes the depleted driver while preserving beam quality.

Numerical simulations confirm the system's feasibility across various configurations.

Abstract

Plasma Wakefield Acceleration represents one of the most promising techniques able to overcome the limits of conventional RF technology and make possible the development of compact accelerators. With respect to the laser-driven schemes, the beam-driven scenario is not limited by diffraction and dephasing issues, thus it allows to achieve larger acceleration lengths. One of the most prominent drawback, conversely, occurs at the end of the acceleration process and consists of removing the depleted high-charge driver while preserving the main features (emittance and peak current) of the accelerated witness bunch. Here we present a theoretical study demonstrating the possibility to reach these goals by using an innovative system consisting of an array of beam collimators and discharge-capillaries operating as active-plasma lenses. Such a system allows to extract and transport the accelerated and highly divergent witness bunch and, at the same time, provides for the removal of the driver. The study is completed by a set of numerical simulations conducted for different beam configurations. The physics of the interaction of particles with collimator is also investigated.