B-RAD: a radiation survey meter for operation in intense magnetic fields

B-RAD is a hand-held radiation survey meter, specifically designed for operation in regions of strong magnetic field. The instrument has been jointly developed by CERN Radiation Protection group and the Department of Energy of the Polytechnic of Milan (POLIMI), originally to perform measurements of the residual radioactivity (radiation surveys) in the experimental areas of CERN Large Hadron Collider (LHC) and inside the ATLAS detector without switching the magnetic field off. B-RAD is based on a scintillating crystal coupled to Silicon Photomultipliers, and its operation is unaffected by magnetic field intensity up to 3 T. Five engineered prototype units were built and made available for routine use at CERN. The design of the instrument has subsequently been licenced to a company in order to industrialise it. This paper describes the CERN-POLIMI engineered version of the instrument, discusses its characterization in details and provides an overview of the commercial unit.