Conceptual Design of a 50-MHz, 300-keV/u CW Heavy Ion RFQ

摘要

We designed a radio frequency quadrupole (RFQ) that can accelerate 10-keV/u heavy ion beams (hydrogen molecules to uranium) from an ion source and can inject the 300-keV/u beam into a superconducting linac. We chose 50 MHz for the rf frequency and used the PARMTEQM code to create a RFQ structure and to simulate the beam dynamics through the RFQ. The length of the RFQ IS 6 pt.1.3 m, and the transmission rate is 84% for a uranium ion beam. For the structure of a heavy ion RFQ, we can consider a four-vane-type structure, winch is efficient; for protons, a four-rod-type structure which is compact for heavy ions, and a four-vane-type structure with windows, which is intermediate type. We chose the four-vane-type structure with windows to operate the RFQ in the CW mode.