Specific Activity Measurement of ¹³¹I and ¹³³Ba by Anti-coincidence Method

¹³¹I is a very important nuclide applied in nuclear medicine. ¹³³Ba, an EC decay nuclide, plays a significant role in the efficiency calibration of HPGe detector. The activity measurement method for the above two kinds of nuclides was studied by the 4πβ(PPC)-γ(HPGe) anti-coincidence counting. The specific activity measurement result for 131I sample is 1 794.8（1±0.6%）kBq•g^-1（k=1）and for 133Ba is 502.8（1±0.6%）kBq•g^-1(k=1). Compared with the results measured by 4πβ(PC)-γ(NaI(Tl)) coincidence efficiency extrapolation methods at the same reference time, 1 797.6（1±0.5%）kBq•g^-1（k=1）and 504.9（1±0.6%）kBq•g^-1（k=1）, it is in good agreement within the uncertainties.