The ADS (Accelerator Driven Sub-system) Proton Linac Injector I was successfully commissioned up to 6.05MeV at the pulse beam current of 10.4mA with seven superconducting (SC) cavities on October 27th, 2015.

The 5MeV test stand of ADS accelerator Injector I is composed of an ion source, a low energy beam transport line, a 325MHz RFQ (room temperature), a medium energy beam transport line, a cryogenic module (CM1) of seven SC spoke cavities (β=0.12) , seven SC solenoids, seven cold BPMs and a beam dump. During the beam commissioning, the high intensity proton beam is accelerated by the RFQ to the energy of 3.2MeV, and then by the seven SC spoke012 cavities to the energy of 6.05MeV, the beam current measured at the beam dump is above 10.4mA. CM1 runs stably with the transmission efficiency of over 99%.

The above technologies applied in Injector I RFQ, SC cavities, SC magnets and cryogenics, and the LLRF control system are all developed independently by IHEP and the domestic manufacturers, laying a solid foundation for building a large SC linac with high energy and high intensity proton beam in the future.

This is the first time in the world that a SC spoke accelerating facility with the lowest beta cavities was successfully commissioned. Its performance is good in the field of ADS studies and high intensity proton SC linac technologies, marking an innovative step forward by the Chinese scientists.

ADS (Accelerator Driven Sub-system) Proton Linac Injector I (image by IHEP)