Design approach for a 325 MHz, 3 MeV, 70-100 mA proton radio-frequency quadrupole accelerator with low emittance transfer

摘要

Radio Frequency Quadrupole (RFQ) accelerators often need to face the challenges of space charge effects from high beam currents. This study investigated how to reach an efficient beam dynamics design for a 325 MHz, 3 MeV, 70-100 mA proton RFQ with not only high beam transmission and short structure length but also high beam quality simultaneously. To avoid emittance transfer which can lead to beam instabilities, a so-called epsilon(l)/epsilon(t) (ratio of the longitudinal and transverse emittances) = 1.0 design guideline is being proposed. In this paper, the application of this design guideline integrated with the "New Four-Section Procedure" and the corresponding design results are presented.