Magnet Design of an 800 MeV High Power Proton Cyclotron

The high-power proton beam has wide applications in neutron and neutrino physics, radioactive ion-beam production, ADS systems, proton radiography, and nuclear data measurement, etc. Cyclotrons are intrinsic in continuous-wave beam mode, which has the characteristics of high efficient power conversion rate, compact structure, and relatively low construction cost. A high-power 800-MeV proton cyclotron was proposed by CIAE, and the prestudy on the cyclotron was carried out since the year of 2009. The main magnet is among the most crucial and challenging subsystems. In contrast to low beam current cyclotron, the main magnet system of high beam current cyclotron needs to provide very strong vertical focusing force to avoid the beam blowup caused by dangerous resonances and space charge effects. In this paper, the 3-D modeling and optimizing work on this large-scale magnet system are presented in detail.