Transverse Microwave Convective Instability at Transition Crossing

TL;DR

This paper presents an analytical model for transverse microwave convective instability during transition crossing in synchrotrons, predicting the intensity threshold with good agreement to CERN data without fitting parameters.

Contribution

It introduces a simple formula for the instability threshold in the microwave case with strong space charge effects, validated against experimental data.

Findings

The model accurately predicts the intensity threshold.

Good agreement with CERN PS data without fitting parameters.

Applicable to low and medium energy synchrotrons.

Abstract

An analytical model of transverse convective instability of a bunch at transition crossing is presented for the microwave case, when the wake is sufficiently short compared with the bunch length. The space charge is assumed to be strong, as it typically is for the low and medium energy synchrotrons. A simple formula for the intensity threshold is obtained and its prediction is compared with available CERN PS data; without a single fitting parameter, a good agreement is demonstrated.