Development of room temperature accelerating structures for the RIA

The proposed Rare-Isotope Accelerator Facility (RIA) includes a driver linac and a post-accelerator based on superconducting cavity technology. The exceptional sections of the RIA accelerators are front ends that comprise normal-conducting continuous wave accelerating structures to obtain particle velocities acceptable for further acceleration by superconducting cavities. The front ends for both accelerators are based on RFQ technology. An engineering design of a 57.5 MHz RFQ for the driver linac has been developed. A cold model of the 57.5 MHz RFQ has been fabricated. The post-accelerator consists of a conventional RFQ operating at 12 MHz and two sections of a hybrid RFQ (H-RFQ) operating at 12 and 24 MHz. A 1:2 scale cold model of the 12 MHz H-RFQ has been built and studied to determine the final specifications for the full power hybrid RFQ. This paper reports on the present development status of these accelerating structures.