A study on the gamma-decay of Mo-99

In this study, the decay form of 99Mo which is supplied by KAERI had been investigated from the analysis of γ-ray energy spectrum radiating from the radioactive element 99Mo. The γ-ray energy spectrum was obtained using NaI(T1) scintillation detector and multichannel pulse height analyser. The calibration curve and formula for γ-ray energy versus channel number were made from the two photopeaks of standard radioactive source 22Na, 140 and 314 channel corresponding to the γ-ray energy of 511 keV and 1275 keV, respectively. The γ-ray energies from 99Mo were detected at the same condition with the standard source, and compared with standard energies of 99Mo. Experimental results show that the γ-ray energies from the sample are in good agreement with the values of standard source within energy error of 2 keV, which means that the 99Mo supplied by the KAERI can be used as a standard radioactive source. (Author)