Electron Cloud Density Measurements in Accelerator Beam-pipe Using Resonant Microwave Excitation

Abstract

An accelerator beam can generate low energy electrons in the beam-pipe, generally called electron cloud, that can produce instabilities in a positively charged beam. One method of measuring the electron cloud density is by coupling microwaves into and out of the beam-pipe and observing the response of the microwaves to the presence of the electron cloud. In the original technique, microwaves are transmitted through a section of beam-pipe and a change in EC density produces a change in the phase of the transmitted signal. This paper describes a variation on this technique in which the beam-pipe is resonantly excited with microwaves and the electron cloud density calculated from the change that it produces in the resonant frequency of the beam-pipe. The resonant technique has the advantage that measurements can be localized to sections of beam-pipe that are a meter or less in length with a greatly improved signal to noise ratio.

10 pages, 10 figures, re-submitted to Nuclear Instruments and Methods in Physics Research A

References in corpus (2)

• Simulation and Analysis of TE Wave Propagation as a Probe for Electron Clouds in Particle Accelerators
• TE Wave Measurement and Modeling

Cited by in corpus (4)

• In-Situ Measurements of the Secondary Electron Yield in an Accelerator Environment: Instrumentation and Methods
• Measurements of Electron Cloud Growth and Mitigation in Dipole, Quadrupole, and Wiggler Magnets
• The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 3: Electron Cloud Diagnostics
• Simulation and Analysis of TE Wave Propagation as a Probe for Electron Clouds in Particle Accelerators