Photopeak efficiency determination in low energy γ-ray region using volume reference sources

By using volume reference sources (matrix: perlite, alumina, manganese dioxide) which contain nine nuclides 109Cd, 57Co, 139Ce, 51Cr, 85Sr, 137Cs, 54Mn, 88Y, 60Co), the photopeak efficiency curve related to linear attenuation coefficient for a n-type germanium detector was obtained. As a result, a smooth curve was obtained in the low energy region below 88 keV, regardless of matrix. And the mass attenuation coefficient was expressed by one function for various materials in the energy region from 10 keV to 2 MeV. By using these curves, nuclides emitting low energy gamma-and/or X-rays can be determined quantitatively within about 10% of error. (author)