Nuclotron-based Ion Collider fAcility (NICA) is an accelerator complex under construction in JINR, in which superconducting linac-injector can accelerate protons up to 20 MeV and light ions to 7.5 MeV/u. To achieve this design target, a 325 MHz, beta = 0.21 niobium half-wave resonator (HWR) called HWR1 was developed jointly by IMP and JINR. This paper optimizes the electromagnetic design of NICA cavity, designs the mechanical structure (including helium jacket) and gives the results of multi-physical studies. Simulation results show that Epk/Eacc = 6.29, the coefficients of df/dp and LFD are 4.96 Hz/mbar and -1.28 Hz/(MV/m)^2, respectively. In addition, the niobium cavity has been fabricated and vertically tested, the magnetic shield and helium jacket are in the process of electron beam welding, and the cryomodule will be assembled in the next 1~2 months.

A 325 MHz, optimal beta = 0.40 niobium half-wave resonator (HWR) called HWR040 for the superconducting driver linac of the China initiative Accelerator-Driven subcritical System (CiADS) has been designed and analysed at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). The linac requires 60 HWR040s to accelerate protons from 45 MeV to 175 MeV. This paper mainly presents the multi-physics studies of the HWR040, include electromagnetic optimization, mechanical structure design and heat transfer simulation of the cavity, to predict the behaviour of the cavity under practical operating process.

HIAF is a heavy ion accelerator facility in China for nuclear physics research. The superconducting LINAC was used to accelerating beam energy up to 17MeV/u, then injecting to a Booster Ring. The linac are under construction since 2021, which includes 30 quarter-wave resonator (QWR) and 66 half-wave resonator (HWR). The first-batch production of cavity system have been completed. And the cavity's auxiliaries, such as coupler and tuner are ready too for first two cryomodules. This paper will present the current status of the HIAF SC cavity system.