Absolute measurement of 166mHo radioactivity and development of sealed sources for standardization of γ-ray emitting nuclides

Holmium-166m has a long half life (1200 yr) and emits a large number of γ-rays between 80 and 1400 keV. These characteristics are very suitable for γ-ray calibration sources, therefore, the absolute activity of 166mHo was measured and several sealed sources were produced to be used as reference sources for the secondary standardization systems for γ-ray emitting nuclides. In this project, seven metal sealed sources and ten point sources were produced and several of these sources were transferred to the secondary standard laboratories to complete the traceability scheme.