Innovative bottom-up design of 0.085 cryomodule validated and mature for FRIB production

FRIB’s 0.085 cryomodule prototype has been fully tested and validated. This is an important milestone in the technical construction of FRIB as it is the first validation of a cryomodule that has been constructed with a bottom-up design.

The FRIB cryomodule design has three specific features:

Bottom-up support to facilitate assembly and maintenance and to improve the alignment tolerance

Local magnetic shielding to reduce fabrication cost while improving the magnetic-shielding performance, and

Cavity 2K operation to enhance cavity performance.

While the FRIB team has accumulated cryomodule fabrication and assembly experience through ReA and ReA3 cryomodule productions, those designs are different from the FRIB cryomodule design: They feature top-down assembly and 4K operation. Thus, the FRIB cryomodule design had to be thoroughly validated before production.

For a year, the FRIB team has worked on a prototype of an FRIB β=0.085 cryomodule (ReA6-1 CM). The team also equipped one FRIB liquid helium distribution line. They successfully validated the FRIB cryomodule design and the helium distribution line in May 2015.

In June, most of the mechanical design effort for the cryomodule focused on the cryogenics within the module. The design of the cryogenics progressed very rapidly throughout the month, due largely to the fact that three engineers were assigned to handle the design. Assigning one engineer to each of the main circuits within the cryomodule allowed for greater attention and care to be given to each circuit.

The next goal of the FRIB team is to complete a full FRIB 0.085QWR cryomodule by the end of 2015.