GAMMA-RAY SPECTROMETER ASSEMBLED FROM 9xCeBr(3)-NaI(Tl) PHOSWICH DETECTORS

The technique of using a cluster of 9xCeBr(3)-NaI(Tl) phoswich detectors as a Compton suppression spectrometer for detecting low-energy E gamma < 4 MeV gamma-radiation is investigated. The characteristics of a phoswich detectors cluster and a High-Purity Germanium detector (HPGe) with a BGO shield are compared. The main characteristics of gamma-ray spectrometer: the energy resolutions Delta E, the total registration efficiency epsilon gamma and the peak efficiency epsilon PEAK, depending on the energies E gamma of the registered gamma-rays and on the distances to the source, are presented. It is shown that the Compton suppression coefficient values of both spectrometers are the same, while the peak efficiency of the phoswich cluster is three times higher than in the HPGe detector. The Compton suppression mode of the phoswich cluster is supposed to be used for studying beta-delayed gamma-decay processes, particularly direct gamma-decay of Pygmy resonances.