A spectral unaveraged algorithm for free electron laser simulations

TL;DR

This paper introduces a spectral unaveraged numerical algorithm for simulating free electron laser emissions, enabling detailed 3D or axisymmetric modeling of short-wavelength amplification with improved accuracy.

Contribution

The paper presents a novel spectral unaveraged algorithm for FEL simulations, allowing full 3D or axisymmetric modeling of electromagnetic interactions without averaging approximations.

Findings

The algorithm accurately models free electron laser emissions.

Simulation results agree with established FEL codes.

The method is adaptable for broader resonant field-particle interaction problems.

Abstract

We propose and discuss a numerical method to model electromagnetic emission from the oscillating relativistic charged particles and its coherent amplification. The developed technique is well suited for free electron laser simulations, but it may also be useful for a wider range of physical problems involving resonant field-particles interactions. The algorithm integrates the unaveraged coupled equations for the particles and the electromagnetic fields in a discrete spectral domain. Using this algorithm, it is possible to perform full three-dimensional or axisymmetric simulations of short-wavelength amplification. In this paper we describe the method, its implementation, and we present examples of free electron laser simulations comparing the results with the ones provided by commonly known free electron laser codes.