Multi-Disciplinary Simultaneous Top-Up Injection at KEK Electron Positron Injector LINAC

Abstract

The electron-positron injector at KEK has been delivering beams for both particle physics and synchrotron radiation science experiments for many years. To increase the efficiency of these experiments, we have been developing simultaneous top-up injection with fast beam switching. In particular, to meet the stringent beam conditions required for the SuperKEKB B-Factory project, a large number of pulsed-operated devices have been developed over a long period of time. These devices are coordinated by a high-speed wide-area event synchronization mechanism, enabling beam switching 50 times per second. During the full-scale beam commissioning of SuperKEKB in 2019, simultaneous top-up injection into five multipurpose storage rings was achieved. This led to more than 200% increase in the efficiency of particle physics experiments and improved the stability of the stored beam current of synchrotron radiation experiments to less than 0.1% fluctuation. The concept and development details of this project are described.