Study of influence of radial matcher section endshape on RFQ cavity frequency

To investigate the feasibility of using a form cutter to machine the Radial Matcher Section （RMS） of tile Radio Frequency Quadrupole （RFQ） for the Accelerator Driven System （ADS） project at Institute of Modern Physics, Chinese Academy of Sciences （IMP, CAS）, the influence of RMS end shape on the RFQ cavity frequency is studied. The results indicate that using a form cutter to machine the RMS of an RFQ will indeed influence the cavity frequency. The RMS end shape will give more influence to a shorter RFQ cavity. For the 4.2 m ADS RFQ, the influence is negligible, which means that a form cutter can be used to machine the RMS.