A final focus system for injection into a laser plasma accelerator at the ARES linac

TL;DR

This paper presents the design and simulation of a final focus system with permanent magnetic quadrupoles for injecting ultra-short electron bunches from ARES into laser plasma accelerators, considering space-charge effects and errors.

Contribution

It introduces a novel final focus system design optimized for ARES, integrating space for diagnostics and laser transport, and includes comprehensive simulation of beam focusing and error effects.

Findings

Effective focusing of electron bunches into LPA demonstrated

Space-charge effects significantly influence beam transport

Error simulations inform system robustness and stability

Abstract

ARES (Accelerator Research Experiment at SINBAD) is a linear accelerator at the SINBAD (Short INnovative Bunches and Accelerators at DESY) facility at DESY. ARES was designed to combine reproducible beams from conventional RF-based accelerator technology with novel but still experimental acceleration techniques. It aims to produce high brightness ultra-short electron bunches in the range of sub fs to few fs, at a beam energy of 100-150 MeV, suitable for injection into novel acceleration experiments like Dielectric Laser Acceleration (DLA) and Laser driven Plasma Acceleration (LPA). This paper reports the conceptual design and simulations of a final focus system for injecting into a LPA experiment at ARES, including permanent magnetic quadrupoles (PMQ), sufficient longitudinal space for collinear laser and electron transport, space for required diagnostics and a LPA setup. Space-charge effects play a significant role and are included. Simulation results on the focusing of the ARES electron bunches into and their transport through the laser-driven plasma are presented. The effects of several errors have been simulated and are reported.