Du, H. Kong, Q.Y. Li, Z.S. Wang, K.D. Yin, X. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-194-6 10.18429/JACoW-LINAC2018-TUPO004 English 329-331 TUPO004 DTL cavity linac simulation quadrupole Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-LINAC2018-TUPO004 http://jacow.org/linac2018/papers/tupo004.pdf An interdigital H-mode drift tube linac (IH-DTL) will be constructed as a postinjector linac for the Heavy Ion Medical Machine (HIMM). Its resonant frequency, injec-tion and final energies are determined from beam dynamics and hardware parameters considerations of the entire machine to be 162.5MHz, 600keV/u and 4MeV/u, respectively. The beam duty cycle of the injector linac is less than 0.1% based on the injection requirements of the synchrotron. Beam dynamics and RF structure design and optimize of the IH-DTL has been finished. The maximum surface electric field is less than 2.0-times the Kilpatric limit for accelerating C⁴⁺ beam. This IH-DTL contains 42 accelerating gaps and two focusing quadrupole triplets. In order to examine the field distribution of the IH-DTL which reaches the length of 3.17m, an aluminum alloy 1:1 cold model cavity with 4 moveable tuners and 2 empty focusing magnet shell was constructed. The relative intertube-distance errors are less than ±50μm. The measurements show that the gap voltage values can match the CST-MWS simulating results within relative difference of ±3% by adjusting the 4 moveable tuners.