Electron cloud observations at the ISIS Proton Synchrotron

TL;DR

This paper reports the first observations of electron clouds at the ISIS Proton Synchrotron using a novel MCP-based detector, highlighting their potential impact on beam stability and accelerator performance.

Contribution

Development of a new MCP-based electron cloud detector and its application to first measurements at ISIS Proton Synchrotron.

Findings

Electron clouds were successfully detected at ISIS.

Signals correlated with beam position and loss monitors.

The detector's high dynamic range improved measurement sensitivity.

Abstract

The build up of electron clouds inside a particle accelerator vacuum chamber can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the behaviour of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which allows energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. This paper presents the first electron cloud observations at the ISIS Proton Synchrotron. These results are compared against signals from a beam position monitor and a fast beam loss monitor installed at the same location.