High-Speed RF Switch Electronics for Picking Up of Electron–Positron Beam Bunches

Abstract

Beam diagnostics is important to guarantee good quality of beam in a particle accelerator. Both the electron and positron run in the tunnel in some modern electron–positron colliders such as circular electron–positron collider (CEPC) to be built and Beijing Electron–Positron Collider II (BEPC II). To measure the electron and positron beams, picking-up these two different bunches in real time is a notable concern. As the time interval between adjacent electron and positron bunches is quite small, for example, 6 ns in CEPC, high-speed switch electronics is required. This paper presents the prototype design of a high-speed radio frequency (RF) electronics that can pick up nanosecond positron–electron beam bunches with a switching time of fewer than 6 ns. Fast separation of electron and positron is achieved based on RF switches and precise delay adjustment of the controlling signals (∼10 ps). Initial tests have been conducted in the laboratory to evaluate the performance of electronics; the results indicate that this circuit can successfully pick up the bunch signal within a time interval of 6 ns, which makes it possible to further measure the electron and positron beams simultaneously.