Mechanical analysis of low β 162.5 MHz taper HWR cavity

Peking University is designing a superconducting taper-type half-wave resonator (HWR) with frequency of 162.5 MHz and of 0.09 for high current proton beam (about 100 mA) and deuteron beam (about 50 mA) acceleration. For this kind of SRF cavity, mechanical analysis is important to predict the frequency shift caused by the cavity deformation. ANSYS codes are used to analyse the frequency shift caused by helium bath pressure and Lorentz force, and the tuning range. Simulation results show that this HWR cavity has pressure sensitivity as low as 31.1 Hz/kPa and Lorentz force detuning coefficient of －0.41 Hz/(MVm-1)2. The tuning range of the cavity is 177 kHz which is wide enough for compensating the possible frequency shift. The mechanical property of the cavity permits the cavitys stable operation.