Fabrication status of acs accelerating modules of J-PARC LINAC

We have been fabricated the several ACS modules step by step: the first buncher, the second buncher, the low-beta accelerating module, and so on. This paper reports the improvement of the frequency and summarizes these RF measurement results. The data of the frequency fluctuation from brazing or stacking have been accumulated, and then the second buncher could be tuned correctly, although the frequency of the first buncher was lower than the target design. In the present fabrication process, about 0.1 to 0.2 MHz fluctuation should be corrected at each measurement step. As the result, the frequency could be tuned to the range of the movable tuner.