Multibeam cavity for low energy beam acceleration

In order to accelerate high intensity ion beams, it is necessary to suppress a defocusing force by the space charge effect. The function of the defocusing force is extremely strong in the low energy region. One of the solutions is the relaxation of the defocusing force by dividing the high intensity beam into several beams. We then propose a high intensity injector system with a multibeam IH type radio frequency quadrupole (IH–RFQ) linac, and simulated the resonance frequency and the electromagnetic field distributions in the multibeam type IH–RFQ linac. We report the design of the multibeam type IH–RFQ linac.