FRIB, East Lansing, USA
INFN/LNL, Legnaro (PD), Italy
KEK, Ibaraki, Japan
ANL, Argonne, Illinois, USA
TRIUMF, Vancouver, Canada
JLab, Newport News, Virginia, USA
The Facility for Rare Isotope Beams (FRIB), under con-struction at Michigan State University, will utilize a driver linac to accelerate stable ion beams from protons to ura-nium up to energies of >200 MeV per nucleon with a beam power of up to 400 kW. Superconducting technology is widely used in the FRIB project, including the ion sources, linac, and experiment facilities. The FRIB linac consists of 48 cryomodules containing a total of 332 superconducting radio-frequency (SRF) resonators and 69 superconducting solenoids. We report on the design and the construction of FRIB cryomodules.
FRIB, East Lansing, USA
The original Fundamental Power Coupler (FPC) of Half-Wave Resonator (HWR) for the Facility of Rare Isotope Beams (FRIB) requires multipacting conditioning at operating RF power which is up to 5 kW Continue Wave (CW). Conditioning takes a lot of time and RF power, and its elimination is highly desirable. To significantly shorten the RF conditioning, we developed a multipacting-free coupler design. This paper reports the latest progress in the optimization and prototype tests of multipacting-free coupler. The choke structure is removed and coupler geometry is further modified to protect the coupler RF window from the electron bombardment. The comparison result of multipacting-free coupler with original coupler was performed on automatic conditioning system, which showed significantly time reducing for RF conditioning.
FRIB, East Lansing, USA
INFN/LNL, Legnaro (PD), Italy
ANL, Argonne, Illinois, USA
The driver linac for the Facility for Rare Isotope Beams (FRIB) will require the production of 48 cryomodules (CMs). In addition to the β=0.085 quarter-wave CM, FRIB has completed the design of a β=0.53 half-wave CM as a pre-production prototype. This CM will qualify the performance of the resonators, fundamental power couplers, tuners, and cryogenic systems of the β=0.53 half-wave design. In addition to the successful systems qualification; the β=0.53 CM build will also verify the FRIB bottom up assembly and alignment method on a half-wave CM type. The lessons learned from the β=0.085 pre-production CM build including valuable fabrication, sourcing, and assembly experience have been applied to the design of β=0.53 half-wave CM. This paper will report the design of the β=0.53 half-wave CM as well as the CM interfaces within the linac tunnel.
FRIB, East Lansing, USA
The driver linac for the Facility for Rare Isotope Beams (FRIB) comprises four kinds of cavities (=0.041, 0.085, 0.29, and 0.53) and six types of cryomodules including matching modules. FRIB has started the fabrication of a β=0.53 preproduction cryomodule, which is the first prototype for a half-wave (=0.29 and 0.53) cavity. This paper describes the fabrication progress and the lessons learned from the β=0.53 preproduction cryomodule.
FRIB, East Lansing, Michigan, USA
Cryogenic magnetic shielding (A4K) is generally used in SRF cryomodules which is much more expensive than mu-metal used in room temperature. In order to reduce the cost, FRIB QWR and HWR magnetic shieldings were redesign to improve the shielding performance so that mu-metal can be implemented as an alternative shielding material. The magnetic shielding of first FRIB β=0.085 cryomodule was made up of 50% by A4K and 50% by mu-metal. Cavities were tested in 4K and 2K, the results showed that the Q0 of cavities were similar for both shielding materials, which is a success as a validation test for mu-metal magnetic shielding.