[ RadSafe ] Ac-227 and Pa-231

[Franz Schönhofer]

Dear collegues,

 

Finally a question not related to SI-units or global warming (sorry, I
should write politically correctly „climate change”).......

 

I received today a question from a good friend, asking whether I have
experience for the determination of Ac-227. There is also interest in the
determination of Pa-231, with Ac-227 being the far more important one. 

 

Concern for contamination with Ac-227 is especially for rare-earth
concentrates and among them of course lanthanum. We know well about the
possibility to perform gamma-spectrometry of daughter products in this
particular case, but a direct measurement, preferably using the beta
activity of Ac-227 because of the much higher efficiency. The method should
be rather quick, because results are necessary to maintain the mass flow in
a factory. Furthermore the contamination of products produced from the
concentrates has to be controlled as well. One good question is the possible
interference of the naturally occurring radioactive isotope of lanthanum-138
in spite of its very low abundance. 

 

Checking google for hours I have besides gamma-spectroscopy found only one
short description of determination of Ac-227 in water by LSC, giving an
outline but no details.

 

Any hints, preferably to electronic sources, will be appreciated very much. 

 

Franz

 

Franz Schoenhofer, PhD

MinRat i.R.

Habicherg. 31/7

A-1160 Wien/Vienna

AUSTRIA