Search

We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal grains in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5'' \times 5'', containing 1% crystal by mass and with the crystal grains having a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to have an intrinsic fast fission neutron efficiency of 0.4% and a gamma sensitivity < 4.93 \times 10^-9, while the nonscintillating detector had a neutron efficiency of 0.6 or 0.7%, depending on analysis integration limits, with gamma sensitivity < 4.93 \times 10^-9 and (3.25 \pm 2.84) \times 10^-7, respectively. We determine that increasing the neutron detection efficiency by a factor of 5–6 will make the detector competitive with moderated ^3He tubes, and we discuss several simple and straightforward methods for obtaining or surpassing such an improvement. We end with a discussion of possible applications, both for the scintillating-plastic and nonscintillating-plastic detectors. [ABSTRACT FROM PUBLISHER]

The main purpose of the Cryogenic Underground Observatory for Rare Events (CUORE) experiment is the search for the Neutrinoless Double Beta Decay (0νDBD) of 130Te reaching a sensitivity on Majorana mass better than 50 meV. Cuoricino represents not only the first stage of CUORE, but also the most massive 0νDBD experiment presently running. Present results and future planning of these experiments will be described in the paper. [ABSTRACT FROM AUTHOR]

We report the performance of two prototype TeO2 macrobolometers, operated at ∼25 mK, able to identify events due to energy deposited at the detector surface. This capability is obtained by thermally coupling thin Ge active layers to the main energy absorber of the bolometer, and is demonstrated by irradiating the detectors with α particles. The temperature variations of the main absorber and of the active layer are measured independently with doped Ge thermistors. These results show clearly that an intrinsic limitation of monolithic low temperature calorimeters, e.g., the impossibility to give information about event position, can be efficiently overcome using composite structures. [ABSTRACT FROM AUTHOR]