Studies on single turn extraction for a superconducting cyclotron

Feasibility of single turn extraction in a high-field separated sector cyclotron has been accessed. Three key requirements are: (1) larger last-turn separation than the beam width, (2) preservation of beam quality throughout the acceleration, and (3) phase space matching at injection. To enlarge separation of the last-turn orbital precession will be induced at the injection. Traversal of the ν_r=1.5 resonance can affect the radial beam width of light nuclei accelerating to the energy above 300 MeV/u. Tolerance to the gradient field of third harmonic, which causes the half-integer resonance in lowest order, was estimated to be 0.1 gauss/cm. The effects of vertical resonances were also evaluated, and the result was used in the yoke design. Moreover, longitudinal space charge forces were computed for a realistic charge distribution of beam on the estimation of the limiting current