Application of Silicon Drift Detectors for the Readout of a CdWO4 Scintillating Crystal.

In this paper, an application of silicon drift detectors (SDDs) as photodetectors for large inorganic scintillators is presented. In particular, a $2.3\times 2.3\times 1.5$ cm3 CdWO4 crystal has been coupled to a $3\times 2$ matrix of $8\times 8$ mm2 SDDs both cooled at 125 K, obtaining a scintillation detector whose performances are tested by measuring the $\gamma $ rays emitted by a 228Th source. The SDDs, characterized by high quantum efficiency and low electronic noise, are suitable candidates as photodetectors for high-resolution gamma-ray spectroscopy detectors. On the other hand, CdWO4 is an interesting crystal for the study of rare nuclear decays, such as the possible neutrinoless double beta decay ( $0\nu \beta \beta $ ) of 116Cd. With this prototype, a full-width at half-maximum resolution of 3.09 ± 0.05% at 2615 keV has been measured. This result provides a first validation of the application of this technology to rare event searches. [ABSTRACT FROM AUTHOR]