Characterization of large area photomutipliers under low magnetic fields: design and performances of the magnetic shielding for the Double Chooz neutrino experiment

This paper describes the characterization studies under low magnetic fields of the Hamamatsu R7081 photomultipliers that are being used in the Double Chooz experiment. The design and performances of the magnetic shielding that has been developed for these photomultipliers are also reported.