Development of Beam Chopper Based on 100 MeV Compact High-intensity Proton Cyclotron

A beam chopper based on the 100 MeV highintensity proton cyclotron built by the China Institute of Atomic Energy (CIAE) was optimized through theoretical analysis and simulation. To get the best solution, two sets of beam chopper were developed at the same time for actual measurement and comparison. The waveform applying to the chopper system is 2.8 MHz sine wave, which is the 16 frequency division of the cyclotron’s RF system. The beam chopper has advantages in aspects of compact structure, helical resonator with relatively high Q value, high chopping voltage, low power loss, and no need for water cooling structure. Meanwhile, a set of beam selection device with square aperture was developed. Finally, the pulsed proton beams with the energy of 100 MeV and repetition frequency of 5.6 MHz were successfully obtained at the experimental terminal. The successful development of the beam chopper not only meets the application requirements of nuclear data measurement, but also greatly promotes the development of beam pulse technology based on the cyclotron.