Performance Testing of FRIB Early Series Cryomodules

Construction of a new accelerator for nuclear physics research, the Facility for Rare Isotope Beams (FRIB), is underway at Michigan State University (MSU). The FRIB linac will use superconducting resonators at an operating temperature of 2 K to accelerate ions to 200 MeV per nucleon. The linac requires 106 quarter wave resonators (80.5 MHz, β = 0.043 and 0.086) and 248 half wave resonators (322 MHz, β = 0.29 and 0.54), all made from sheet Nb. Production resonators being delivered to MSU by cavity vendors. At MSU, the resonators are etched, rinsed, and tested in MSU's certification test facility. Certification testing is done before the installation of the high-power input coupler and the tuner. After certification, the resonators are tested in the cryomodule before installation into the FRIB tunnel. The cryomodule test goals are to verify integrated operation of the resonators, RF couplers, tuners, RF controls, and superconducting solenoids. To date, 10 cryomodules out of 48 have been fabricated, and 8 of the cryomodules have been certified. Cryomodule test results are presented in this paper. Construction of a new accelerator for nuclear physics research, the Facility for Rare Isotope Beams (FRIB), is underway at Michigan State University (MSU). The FRIB linac will use superconducting resonators operating at a temperature of 2 K to accelerate ions to 200 MeV per nucleon. The linac requires 104 quarter wave resonators (80.5 MHz, = 0.041 and 0.085) and 220 half wave resonators (322 MHz, = 0.29 and 0.53), all made from sheet Nb. Production resonators are being fabricated by cavity vendors; the resonators are etched, rinsed, and tested in MSU’s certification test facility. Cavity certification testing is done before the installation of the high-power input coupler and tuner. After certification and cryomodule assembly, the resonators are tested in the cryomodule before installation into the FRIB tunnel. The cryomodule test goals are to verify integrated operation of the resonators, RF couplers, tuners, RF controls, and superconducting solenoids. To date, 12 out of 46 cryomodules have been completed, and 9 have been certified. Cavity and cryomodule certification test results are presented in this paper.