Design and Control of Vacuum System for SC200 Superconducting Proton Cyclotron Beam Transmission

The irregularly-shaped vacuum system was developed for the superconducting proton medical irradiation equipment(SC200),comprising the densely installed parts including the dipole/quadrupole/correction magnets and stopper/measurement/control subunits of proton-beam.The discussions focused on:i)The vacuum design of the four subunits,including the energy selectable section,constant energy section,transmission section and bending section of the proton beam;ii)The control/measurement subunits,such as the local/remote/manual/digital control algorithms;and iii)The fabrication,installation and maintenance of the vacuum system.The self-built vacuum system,65 m in total length and with a dynamic base pressure of below 5×10^-4 Pa,was tested.The results show that the self-developed SC200 transmission vacuum system satisfies well all the stringent requirements for the proton beam therapy.