MECHANICAL DESIGN OF THE CRYOGENIC SUB-SYSTEMS FOR ReA6 QUARTER WAVE RESONATOR CRYOMODULE

The driver linac for the Facility for Rare Isotope Beams (FRIB) consists of 49 cryomodules operated at 2 K utilizing 4 different types of superconducting resonators and 2 solenoid lengths which in turn requires 7 individual cryomodule configurations. The mechanical design requirements of the internal cryogenics of an FRIB cryomodule are determined by the piping and instrumentation diagram, which is discussed in the paper based on the FRIB quarter wave cryomodule type. In addition, heat load requirements and spatial constraints of other cryomodule sub-systems influence the cryomodule cryogenics design. The paper describes detailed design choices for the cryogenic headers and piping, a 2 K heat exchanger inside the cryomodule, solenoid current leads, and the bayonet connections to the cryogenic distribution system inside the accelerator tunnel. Different operating modes, which influence the cryogenic design, are summarized.