CSR induced microbunching gain estimation including transient effects in transport and recirculation arcs

TL;DR

This paper extends a semi-analytical Vlasov solver to include transient CSR effects in transport and recirculation arcs, providing more accurate microbunching gain estimates for high-brightness electron beams.

Contribution

It introduces a method to incorporate entrance and exit transient effects into microbunching gain calculations, improving upon previous steady-state models.

Findings

Enhanced microbunching gain estimation accuracy.

Comparison with particle tracking simulations validates the extended model.

Insights into the physics of transient CSR effects.

Abstract

The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport or recirculation arcs, may result in the microbunching instability ({\mu}BI). To accurately quantify the direct consequence of this effect, we further extend our previously developed semi-analytical Vlasov solver [C. -Y. Tsai et al., FEL Conference 2014 (THP022)] to include more relevant coherent radiation models than the steady-state free-space CSR impedance, such as the entrance and exit transient effects derived from upstream beam entering to and exiting from individual dipoles. The resultant microbunching gain functions and spectra for our example lattices are presented and compared with particle tracking simulation. Some underlying physics with inclusion of these effects are also discussed.