Stand-alone cryomodule with low-loss peripheral components

Technical Report · Thu May 28 00:00:00 EDT 2020

OSTI ID:1631034

Kutsaev, Sergey

In this project, RadiaBeam Systems in collaboration with Argonne National Laboratory has significantly improved the design of a stand-alone cryomodule, based on a commercially available cryocooler, for the dressed 72.75 MHz quarter-wave resonator (QWR) for the ATLAS intensity upgrade project. By the development of low-loss peripheral components we were able to reduce the losses and the cost to make it more widely applicable. In the Phase I of this project we have optimized all the components to reduce the conductive thermal transfer Focus was given to components such as the mechanical hangers for the liquid helium bath and cavity. More time was also taken to perform a thorough radiative analysis and the thermal shielding was tuned to be more effective. One of the major improvements was to reduce the number of 4K cryoheads to two, with a 5W capacity, each. Second major improvement was done for an RF power coupler to reduce the dynamics heat load while maintaining low static losses. Another achievement was to reduce the radiative heat transfer to < 0.1 W/m2 via development of multi-shield radiation coolers. Totally, we were able to reduce static losses to LHe by almost factor of 2.5 (60%)! We have also significantly optimized the engineering design to account for realistic operational conditions such as a deeper focus into typical operational concerns such as cavity quenches due to power failure. The liquid helium bath had its cavity expanded to allow greater reaction time if the cryocoolers shut down or increased boil off occurred. Other concerns addressed include temperature monitoring of the chamber along with safe heating to bring the chamber back up to room temperature as needed. Finally, we have performed structural analysis required for safety operation in National Labs.

• Research Organization: RadiaBeam Technologies, Santa Monica, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: sc0019666
• OSTI ID: 1631034
• Type / Phase: SBIR (Phase I)
• Report Number(s): DOE-RBS-19666
• Country of Publication: United States
• Language: English