FRIB, East Lansing, Michigan, USA
Fermilab, Batavia, Illinois, USA
INFN/LNL, Legnaro (PD), Italy
KEK, Ibaraki, Japan
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
IMP/CAS, Lanzhou, People's Republic of China
The Facility for Rare Isotope Beams (FRIB) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.
NSCL, East Lansing, Michigan, USA
FRIB, East Lansing, Michigan, USA
Major work centers of the new SRF Highbay are fully installed and in use for FRIB pre-production SRF quarter-wave and half-wave resonators, including inspection area, high temperature vacuum furnace for cavity degassing, chemical etching facility and processing and assembly cleanrooms. Pre-production activities focus on optimizing workflow by reducing process time, tracking part status and related data, and identifying bottlenecks. Topics discussed may include; buffered chemical polish (BCP) etching for cavity frequency control, degassing time reduction, automated high pressure rinse, particle control against field emission, pre-production cavity test results and implementation of workflow status programs
FRIB, East Lansing, Michigan, USA
The local magnetic shield design and cryogenic magnetic shielding material for the FRIB QWR cryomodule was validated in a two cavity, one solenoid prototype cryomodule. The magnetic fields were measured inside and outside the magnetic shielding before, during, and after operation of an 8 T superconducting solenoid. The effect of demagnetization cycles of the solenoid was also examined. The magnetic field at the cavity’s high RF magnetic field area, inside the magnetic shield and with the solenoid off, was measured using a single-axis fluxgate to be less than 0.3 μT (3 mG) after cool down of the cryomodule. A 3.07 μT (30.7 mG) residual field was observed at high magnetic field area after conclusion of solenoid operation. This was attributed to the persistent currents circulating in the superconducting solenoid. Demagnetization cycles were therefore determined to be unnecessary for FRIB cryomodules, as long as the solenoid is normal conducting when the cavity is cooled through the superconducting critical temperature.
S.K. Chandrasekaran currently at Fermi National Accelerator Laboratory, Batavia, IL, USA.
FRIB, East Lansing, Michigan, USA
FRIB, East Lansing, Michigan, USA
INFN/LNL, Legnaro (PD), Italy
The driver linac for the Facility for Rare Isotope Beams (FRIB) will require the production of 48 cryomodules. FRIB has completed the fabrication and testing of a β=0.085 quarter-wave cryomodule as a pre-production prototype. This cryomodule qualified the performance of the resonators, fundamental power couplers, tuners, and cryogenic systems of the β=0.085 quarter-wave design. In addition to the successful systems qualification; the ReA6 cryomodule build also verified the FRIB bottom up assembly and alignment method. The lessons learned from the ReA6 cryomodule build, as well as valuable fabrication, sourcing, and assembly experience are applied to the design and fabrication of FRIB production cryomodules. This paper will report the results of the β=0.085 quarter-wave cryomodule testing, fabrication, and assembly; production implications to future cryomodules will also be presented. Authors: