ACS cavity for J-PARC LINAC

Ao, Hiroyuki; Asano, Hiroyuki; Ouchi, Nobuo ; Tsubota, Naoaki; Hasegawa, Kazuo; Hirano, Koichiro  ; Morishita, Takatoshi  ; Takata, Koji*; Naito, Fujio*; Yamazaki, Yoshishige

The energy upgrade of the J-PARC linac was started from March 2009. In this project 20 Annular Coupled Structure (ACS) modules will be fabricated. The resonant frequency of the ACS module has to be tuned with mechanical machining before the final brazing. Therefore the test cells were fabricated to accumulate frequency tuning parameters. We fixed the final dimensions and the machining amount of the frequency tuning using these results. So far, the cell parts for the five ACS modules were tuned within 71.93 0.05 MHz. At the moment the first ACS module is being assembled and it will be completed in autumn 2010.