ASSEMBLY, INSTALLATION, AND COMMISSIONING OF THE ATLAS UPGRADE CRYOMODULE

A new cryomodule containing seven low‐beta superconducting radio frequency (SRF) cavities has been added to the ATLAS heavy ion linac, providing an additional 15 MV accelerating potential to the existing accelerator. We describe the final stages of cryomodule assembly, commissioning, and installation in the ATLAS accelerator. The clean techniques used to achieve low‐particulate rf surfaces are presented, as are the module design features which enable clean assembly and reliable high‐gradient operation. The thermal performance of the cryomodule is described, along with performance data for the SRF cavities. Details on subsystem performance including helium and nitrogen systems, vacuum systems, thermal and magnetic shields, slow and fast tuners, and survey/alignment systems are given.