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TY - CPAPER AU - Chandrasekaran, S.K. AU - Saito, K. TI - Validation of Local Magnetic Shielding for FRIB Using a Prototype Cryomodule J2 - Proc. of International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 AB - 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. PB - JACoW CY - Geneva, Switzerland SP - 857 EP - 860 KW - solenoid KW - cavity KW - operation KW - shielding KW - cryomodule DA - 2015/12 PY - 2015 SN - 978-3-95450-178-6 DO - 10.18429/JACoW-SRF2015-TUPB102 UR - http://srf2015.vrws.de/papers/tupb102.pdf ER -