Freeze-drying applied to radioactive source preparation.
In the framework of R&D studies for the improvement of radioactive source efficiencies prepared on thin films for 4pibeta-gamma coincidence counting, a comparative study on two drying methods has been undertaken in our laboratory (BNM-Laboratoire National Henri Becquerel, France). The standard method of evaporation at atmospheric pressure and a method based on freeze-drying using commercial equipment are compared. The preliminary results of this study obtained with 65Zn sources are presented and a significant improvement of the detection efficiencies to the electron emission for freeze-dried sources is shown. In the course of validation of this method, other radionuclides were studied and, up to now, the results confirm the better crystallization homogeneity achieved for freeze-dried sources.
de Sanoit
J
J
CEA-BNM Laboratoire National Henri Becquerel, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France. jacques.desanoit@cae.fr
Leprince
B
B
Bobin
Ch
Ch
Bouchard
J
J