Neutron spectroscopy with ~6LiF bolometers

摘要

A compact and semi-portable neutron detector has been built based on the bolometric technique. Its unique features open new possibilities for the radioprotection survey of fast neutrons at nuclear installations and the investigations of background problems of sensitive neutron scattering instruments. This cryogenic detector, operated at 300-400 mK, consists of a 0.5 g LiF 95% 6Li enriched crystal read out by a NTD-Ge sensor and is based on the ~6Li(n,a)~3H neutron capture reaction. It is used to define the energy of neutrons up to 5 MeV. Measurements with 252Cf source have been performed to determine the energy resolution of the detector. We report the first results obtained with this neutron detector. From developments made in view of the ROSEBUD (Rare Objects SEarch with Bolometers UndergrounD) collaboration we suggest a possible further improvement of the neutron detector by employing a combined heat and light detection. In the case of dark matter experiments, such a detector would allow to monitor the residual fast neutron component.