Features of a Deutron Accelerator Based on the RFQ Structure

During acceleration of particles with a charge-to-mass ratio of 1 : 2, the length of a cavity is practically doubled compared to that of a proton accelerator for the same energy. At an output energy exceeding 1.0 MeV per nucleon, the cavity length becomes large, L cav ≈ 3λ, where λ is the wavelength of the TE211 operating mode. This leads to a critically small frequency separation between the operating TE211 quadrupole mode and the TE11n dipole modes. For mode separation, it is proposed to use coupling windows in the electrodes between neighboring structure segments, which in turn change the field distribution along the structure. Field uniformity is restored with the insertion of plungers into the four segments between the electrodes through the RFQ shell. The result of the simulation is a tuned RFQ accelerating structure with the following main parameters: the ion type is deuterons D + or alpha particle He ++ , the operating frequency is 202 MHz, the injection voltage is 75 kV, the length is 4.3 m, the peak RF power is not higher than 300 kW, the energy of accelerated ions is 1.25 MeV/nucleon, and the peak current is 50 mA for D + and 10 mA for He ++ . The result is the design of the RFQ structure based on the performed electrodynamics and beam dynamics simulation.