Numerical Studies for EuPRAXIA@SPARC\_LAB Plasma Beam Driven Working Point

TL;DR

This paper presents simulation studies to identify optimal plasma and beam parameters for EuPRAXIA@SPARC_LAB, achieving high gradients and low emittance suitable for soft x-ray FELs.

Contribution

It provides a detailed analysis of plasma density and driver-witness separation to optimize beam quality and stability in plasma-based accelerators.

Findings

Achieved >1kA peak current with <0.1% energy spread for the witness beam.

Maintained approximately 1 GV/m accelerating gradient in the plasma.

Identified stability requirements for RF and plasma parameters.

Abstract

The realization of a plasma based user facility on the model of EuPRAXIA@SPARC\_LAB requires to design a working point for the operation that allows to get an high accelerating gradient preserving a low emittance and low energy spread of the accelerated beam. Such beam is supposed to pilot a soft x-ray free electron laser with a wavelength of 2-\SI{4}{\nano\meter}. In this work several simulation scans are presented, varying at the same time the plasma density and driver-witness separation in order to show that, in a realistic working point for EuPRAXIA@SPARC\_LAB, it is possible to find an ideal compromise for a witness with a peak current >1kA that allows to preserve the energy spread of the core (80\% of the charge) below 0.1\%, while maintaining an accelerating gradient inside the plasma module around of 1 GV/m. The study is completed with a parametric analysis with the aim of establishing the stability requirements of the RF working point and the plasma channel in order to preserve the energy jitter at the same level of the energy spread.