Development of a compact X-band dual-mode medical linac based on a pulse compressor

摘要: In this study, a compact X-band dual-mode electron linear accelerator (linac) was developed for medical radiotherapy applications, which is capable of generating both 100 mA / 6 MeV beams for X-ray radiotherapy (low-energy mode) and 10 mA / 13.5 MeV beams for electron radiotherapy (high-energy mode). The dual-mode linac leveraged a 3 MW multi-beam X-band klystron as the power source, with a total length of 1.5 m. A novel spherical SLED pulse compressor was specially designed for the high-energy mode to achieve flat-top output, with a gain factor of 2.2. Mode switching between the two operating configurations is realized through dynamic tuning of the pulse compressor’s resonant frequency. Furthermore, a standing-wave (SW) bi-periodic accelerating structure operating in π/2 mode was developed, which enables effective bunching and acceleration of electron beams under both energy modes. A comprehensive experimental platform has been established for the linac, and high-power RF tests have been conducted. The experimental results validate the feasibility of the dual-mode linac, demonstrating its potential for versatile radiotherapy applications with optimized spatial compactness.