Device for measuring the amount of beryllium in a radioactive object

A device for measuring an amount of beryllium in a radioactive object, including: a hollow cylinder of a first piece made of a material to thermalize neutrons emitted by the radioactive object and a metal piece to mitigate a dose rate on the radioactive object, the first piece having a hollow cylinder shape deprived of a wall fraction, the metal piece including a solid part inserted in a space which corresponds to the deprived wall fraction of the first piece and a recessed part which is an extension of the solid part and is accommodated within the wall of the first piece, in contact with the first piece; a gamma radiation source accommodated in an indentation of the recessed part of the metal piece; and at least one neutron detector placed in a bulk of the first piece.