Development of sawtooth waveform beam buncher for medical cyclotron accelerator.

This article focuses on the design, development, and testing of a sawtooth waveform beam buncher for medical cyclotron accelerators, aimed at improving beam current intensity by efficiently bunching ion beams. The system employs a heterodyne combiner to synthesize a high-voltage sawtooth waveform from three narrowband radio frequency (RF) power amplifiers operating at the fundamental frequency and its second and third harmonics, combined with a broadband matching network and meshed wire electrodes. Testing demonstrated that the buncher achieves over 1250 V bunching voltage with more than 65% effective bunching segment and less than 5% non-linearity, indicating enhanced bunching efficiency and transmission compared to two-harmonic systems. The design simplifies amplifier requirements, avoids bulky resonant cavities, and shows promise for efficient, low-cost operation in cyclotron injection lines.