Design of 50 MeV proton microbeam based on cyclotron accelerator
摘要: High-energy proton microbeam facilities are powerful tools in space science, biology, and cancer therapystudies. The primary limitationsof the 50 MeV proton microbeam system are the poor beam quality provided by the cyclotron and the problem of intense scattering in the slit position. Here, we present an optical design for a cyclotron-based 50 MeV high-energy proton microbeam system with a micron-sized resolution. The microbeam system,which hasan Oxford triplet lens configuration,has relatively small spherical aberrations and is insensitive to changes in the beam divergence angle and momentum spread. In addition, the energy filtrationincluded in the system can reducethe beam momentum spread from 1% to 0.02%. The effects of lens parasitic aberrations and the lens fringe fieldon the beam spot resolution are also discussed. In addition, owing to the severe scattering of 50 MeV protons in slit materials, a slit system model based on the Geant4 toolkit enables the quantitative analysis of scattered protons and secondary particles. For the slit system settings under a 10-micron final beam spot, very few scattered protons can enter the quadrupole lens system and affect the focusing performance of the microbeam system, but thesecondary radiation of neutrons and gamma rays generatedat the collimationsystem should be considered for the 50 MeV protonmicrobeam. These data demonstrate thata 50 MeV proton microbeam system with a micron-sized beam spot based on a cyclotron is feasible.
Mou, Hongjin,Mao, Guangbo,Zhang, Jinquan,Zhao, Can,Guo, Jinlong,Liu, Wenjintg,Wu, Ruqun,Shen, Cheng,Zhang, Lei,Li, Junshuai,Du, Guanghua.(2023).Design of 50 MeV proton microbeam based on cyclotron accelerator.中国科学院科技论文预发布平台.doi:10.12074/202306.00028V1