Development of RFQs at J-PARC

Kondo, Yasuhiro   ; Morishita, Takatoshi  

In this paper, we present the performance and RFQs at J-PARC. In the summer of 2014, we replaced the frontend system of the J-PARC linac for beam current upgrade. An RF driven ion source (IS) and a radio frequency quadrupole linac (RFQ III) are newly developed to make the linac be capable for 50 mA peak current operation. Prior to the installation to the accelerator tunnel, we conducted an off-line beam test at an RFQ test stand, and confirmed the basic performance of the IS and RFQ as their design. The 50 mA peak current was demonstrated at this test stand and we also succeeded the 50 mA operation in the actual linac. The used RFQ (RFQ I) replaced by RFQ III will be used for beam test of laser charge exchange system for the ADS project and beam scraper and so on. The other RFQ developed as a spare of RFQ I will be used for world first muon acceleration experiment. The status of these RFQs is also shown.