Speaker
Description
Five sets of 240 MeV superconducting proton cyclotrons (SC240) have been successfully developed by Hefei CAS Ion Medical and Technical Devices Co., Ltd. (HFCIM) in collaboration with the Institute of Plasma Physics, Chinese Academy of Sciences. Two of these SC240 have been installed and are currently operational at dedicated proton therapy system in Hefei and Wuhan. The SC240 employs superconducting magnet technology capable of generating a maximum coil field of 4.3 T, delivering a 240 MeV proton beam with currents exceeding 500 nA for proton therapy applications. The cyclotron features a yoke with a diameter of 3 meters and a weight of approximately 70 tons. Two dedicated RF cavities, operating at a frequency of 77.8 MHz and providing up to 100 kV of accelerating voltage, are used to accelerate the proton beam. Three magnetic channels guide the beam from the deflector to the external cyclotron. Specific first-harmonic field compensation has been designed for the first and second magnetic channels. Both the deflector and the magnetic channels are equipped with remotely controlled positioning systems. The maximum beam extraction efficiency of the SC240 has been demonstrated to reach 84% in tests. At customer sites, the extracted beam current consistently exceeds 500 nA. This article presents the key design features of the SC240 cyclotron, including its injection and extraction systems, and provides experimental results from the fourth SC240 unit.
Footnotes
*responding author (Kaizhong Ding, email: kzding@ipp.ac.cn). Authors want to thank the team of Ionetix Inc. and Huazhong University of Science and Technology.
