Development of high field dipole and high current pulse power supply for compact proton synchrotron

A small dipole magnet of 3 T is developed with its pulse power supply feeding 200 kA at maximum for the table-top proton synchrotron which is now under development for the radiotherapy. The experimental field distribution is consistent with the 3D dynamic field simulation results satisfying the required beam aperture. The dipole field was measured at an interval of 2 msec with 15 tiny search coils aligned accurately to the radial direction in the pole gap. The dipole is excited by the discharge current of the capacitor bank of 53 kJ with the rise time of 5 msec. Transverse beam behavior is also simulated using a time dependent beam optics code under the influence of the RF acceleration field to estimate the required beam apertures. Performances of the dipole and power supply will be treated in detail in conjunction with the numerical simulations.