Analysis and Simulation on the Enhancement of the CSR Effects

TL;DR

This paper investigates how non-Gaussian charge distributions in particle bunches can significantly amplify CSR effects, leading to greater emittance growth and energy modulation than previously predicted, through analytical and numerical methods.

Contribution

It introduces a model demonstrating that charge concentration within bunches enhances CSR effects beyond Gaussian-based predictions.

Findings

Charge concentration increases CSR self-interaction.

Enhancement level depends on local charge density.

Non-Gaussian distributions can cause significant CSR effects.

Abstract

Recent measurements of the coherent synchrotron radiation (CSR) effects indicated that the observed beam emittance growth and energy modulation are often bigger than previous predictions based on Gaussian longitudinal charge distributions. In this paper, by performing a model study, we show both analytically and numerically that when the longitudinal bunch charge distribution involves concentration of charges in a small fraction of the bunch length, enhancement of the CSR self-interaction beyond the Gaussian prediction may occur. The level of this enhancement is sensitive to the level of the local charge concentration.