Compact cryomodule for mobile stand-alone superconducting industrial accelerators

Superconducting RF (SRF) accelerators have the potential to be more profitable in comparison with normally conducting accelerators, as long they can be made compact, achieve operational simplicity, autonomy, transportability, satisfactory energy efficiency, as well as have reasonable costs. The development of SRF technologies such as Nb₃Sn coating, conductively-cooled resonators, and high-capacity liquid-helium-free cryocoolers made SRF accelerators mobile and energetically and economically efficient at a beam power of tens of kW. One of the key elements of such an accelerator is the cryomodule, which must have minimal thermal losses to enable operation from low power cryoheads and enable conductive cooling of SRF resonator. In this paper we present the design and test results of a compact cryomodule for an industrial stand-alone SRF linear accelerator prototype, based on 650 MHz elliptical resonators, being developed at Fermi National Accelerator Laboratory.