An improved method for α-source preparation using neodymium fluoride coprecipitation

Coprecipitation on neodymium fluoride of actinides is a well known method for the production of sources intended for α-spectrometry. The procedure is based on the fact that trivalent neodymium fluoride complexes form microprecipitates in hydrochloric acid. This precipitate is membrane filtered and retained on a filter. Fluoride complexes of the measured actinides are kept in another hydrochloric acid solution. When the latter solution is filtered, the actinide complexes are retained onto the neodymium fluoride. The filters are placed on planchet trays and spectra are measured using a semiconductor detector in a vacuum chamber. According to the literature, the standard filtration method is vacuum filtration. In this work, a method based on plastic filter holders and disposable syringes operated by a direct current motor has been developed. Control of the filtrate flow rate and the use of disposable equipment are attractive features of the method. Sources produced with this method have been compared with sources prepared both by using vacuum filtration and by using electrodeposition. The results show that the method has a high and reproducible yield. In addition, spectrawith good resolution quality are obtained.