Model of e-cloud instability in the Fermilab Recycler

TL;DR

This paper develops a simple model of electron cloud instability in the Fermilab Recycler, explaining how the cloud amplifies injection errors in bunched proton beams and aligns well with experimental data.

Contribution

The paper introduces a novel simple model of electron cloud instability that accounts for nonlinearity and matches experimental observations.

Findings

Model accurately predicts instability growth.

Good correlation with experimental data.

Highlights importance of nonlinearity in e-cloud effects.

Abstract

Simple model of electron cloud is developed in the paper to explain e-cloud instability of bunched proton beam in the Fermilab Recycler. The cloud is presented as an immobile snake in strong vertical magnetic field. The instability is treated as an amplification of the bunch injection errors from the batch head to its tail. Nonlinearity of the e-cloud field is taken into account. Results of calculations are compared with experimental data demonstrating good correlation.