Beam lifetime study based on momentum acceptance restriction by movable beam scraper

The beam lifetime of the SAGA-LS electron storage ring was experimentally investigated using a movable beam scraper installed in a dispersive section. In addition to physical aperture restriction, the scraper could be used to reduce the momentum acceptance of the storage ring, enabling the evaluation of the Touschek effect. Lifetime measurements were performed with scraper scans, and the individual contributions of gas scattering and the Touschek effect were clarified. Our results confirm that the present method provides a basic understanding of lifetime limiting effects in the storage ring.