A highly efficient alpha, beta, gamma-spectrometer with low background

A highly efficient low-background spectrometer based on phoswich detector design and characteristics are described. The spectrometer allows measurements in a broad energy range of alpha-, beta- and gamma-radiation emitted from the natural radionuclides to be carried out. The phoswich detector consists of a fast scintillator based on the doped p-terphenyl single crystal and a slow CWO scintillator. Separate detection of each type of radiation is made possible by means of signal discrimination over the pulse shape. The minimum detectable activity of /sup 90/Sr+/sup 90/Y equal to 1 Bq was achieved. Advantages of the proposed spectrometer are discussed, and quantitative data on the minimum detectable activities for each type of radiation are presented.