title: Conceptual design of the superconducting magnet for the 250 MeV proton cyclotron.
abstract: BACKGROUND
  The superconducting cyclotron is of great importance to treat cancer parts of the body. To reduce the operation costs, a superconducting magnet system for the 250 MeV proton cyclotron was designed to confirm the feasibility of the superconducting cyclotron.
  
  
  RESULTS
  The superconducting magnet system consists of a pair of split coils, the cryostat and a pair of binary high temperature superconductor current leads. The superconducting magnet can reach a central magnetic field of about 1.155 T at 160 A. The three GM cryocooler with cooling capacities of 1.5 W at 4.5 K and 35 W at 50 K and one GM cryocooler of 100 W at 50 K were adopted to cool the superconducting magnet system through the thermosiphon technology.
  
  
  CONCLUSIONS
  The four GM cryocoolers were used to cool the superconducting magnet to realize zero evaporation of the liquid helium.
authors.affiliation: Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PO Box 1126, Hefei, 230031 Anhui People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PO Box 1126, Hefei, 230031 Anhui People's Republic of China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PO Box 1126, Hefei, 230031 Anhui People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
keywords: Cryostat; HTS current lead; Proton cyclotron; Superconducting magnet