Beam dynamics studies on a 200 mA proton radio frequency quadrupole accelerator

The Frankfurter Neutron-Quelle am Stern-Gerlach-Zentrum (FRANZ) Facility, a planned pulsed neutron source at Frankfurt University, will use a 175 MHz, 200 mA proton radio frequency quadrupole (RFQ) accelerator as a driver. To design such an intense-beam RFQ subjected to the strict constraints on the beam quality and the structure length, two unconventional design strategies, the new four-section procedure and the longitudinal-rotation measure, have been developed and applied. The performances and the safety of the optimum design are analyzed.