APT CRYOMODULE ASSEMBLY AND THE USEFULNESS OF THE MOCKUP MODEL

The cryomodule for the APT β=0.64 high-energy accelerator incorporates either two or three radiofrequency cavities, two sets of magnetic shields, one active heat shield, multi-layer insulation blankets, cryogenic plumbing for the shields and cavities, power couplers, cavity spokes, and cavity frequency tuners. Maintaining cavity cleanliness is the most important aspect of the cryomodule assembly. The clean assembly of the cryomodule is performed in a class-100 clean room. The final assembly, such as tungsten inert gas welding used to join the cryogenic plumbing, is performed in a controlled environment. To address overall design concerns and assembly issues early in the design process, a full-scale mock-up of the entire cryomodule was fabricated. The mock-up also enabled us to determine the effect of the magnetic shielding and provides a clear representation of the problems that exist. In this paper we describe the assembly process and the benefits the mockup has provided.