Abstract:
The plane source of
210Po was used for verification of gas-flow proportional counter gross alpha and gross beta measure instruments, and it was needed to be replaced by new
210Po plane source because of its short half-life (138.4 d). High purity
210Po solution was extracted from raw
210Pb solution containing
210Bi and
210Po by resin before electroplating and its purity was confirmed by high purity germanium gamma spectrometer. The morphology of electroplating plane source of
210Po was checked by microscope and characterized by alpha spectrometer. There was a unique alpha peak in its alpha spectrum which was satisfied with the requirements well. The primary standard for 2πα and 2πβ particles emission rate was employed to verify the 2πα and 2πβ particle emission rate. The result is between 1.0×10
4 to 2.0×10
5 min
-1 and the expanded uncertainty is less than 3%(
k=2), which show that the prepared standard plane source of
210Po meet the requirements of verification regulation well. A new approach of preparation of
210Po standard plane sources from
210Pb is established and the goal of supplying
210Po standard plane source constantly is achieved.