BNL, Upton, Long Island, New York, USA
NSLS-II storage ring is shielded for full injected beam loss around injection point, with the remainder shielded for significantly lower losses. To insure these design levels aren't exceeded, a Loss Control and Monitoring system (LCM) was designed. The LCM will control and monitor beam losses in the injection region and monitor injection losses outside that region. In order to measure quantitative charge losses, development of new beam loss monitors using Cerenkov light produced by the electron component of the shower induced by beam particles penetrating the vacuum chamber. These Cerenkov beam loss monitors (CBLM) measure the light from electrons passing through ultra-pure fused silica rods placed close to the inner edge of the VC. These rods will give sufficient light signal to monitor beam losses from several particles lost per turn to a major fraction of the 500mA beam in one to a few turns, about a 9 decade dynamic range of signal. Design and measurements of the prototype CBLM system will be presented. Although designed for light sources, CBLMs will provide quantitative beam loss measurements for accelerators with continuous high energy electron beams, such as ERLs.
Work presented is contributed by the NSLS-II Loss Control and Monitoring Working Group.
