Stand-Alone Cryomodule with Low-Loss Peripheral Components

Currently, superconducting accelerators are relatively large complex systems requiring a central refrigeration system and complex piping to distribute liquid helium and nitrogen to the accelerator. Stand-alone systems are of high interest to both scientific facilities and industrial applications as they do not require massive and expensive cryogenic facilities and trained specialists. However, the cryomodule for a stand-alone system needs to be designed to minimize the heat losses to the liquid helium so that commercial self-contained cryocoolers can handle the thermal load. In response to this problem, we propose to develop and build a stand-alone cryomodule based on commercially available cryocoolers for a dressed 72 MHz quarter-waver resonator (QWR). The careful optimization of the peripheral components will allow reaching accelerating voltages of up to 2 MV at a cost much lower than stationary cryogenic system. In Phase I, we will optimize the peripheral components to reduce conductive thermal transfer, with a focus on optimizing the design of coupler to reduce the static heat load while maintaining high conductivity. Another goal will be to reduce radiative heat transfer to < 0.1 W/m2 via development of multi-shield radiation coolers. The cryomodule prototype can be immediately used at the ATLAS facility as a re-accelerator in the general purpose beamline, as a de-buncher cavity the Argonne In-flight Rare Isotope Separator (AIRIS), and as a high-performance buncher before a beam switch yard. The technology developed in this project can be further adapted for other types of cavities and used for industrial (ion implantation), security (cargo-inspection) and medical (ion therapy) applications.