Alpha spectrometry of thick radioactive sources. I

Using various methods of alpha spectrometry a series of spectra have been obtained from thick sources. It is shown that the form of the spectra depends very much on the method used and that the analysis methods of Guery (CEA-M-1145 (1969)) may not be applicable. To overcome these difficulties two semi-empirical methods, the straight incline method and the exponential incline method have been developed, applicable according to the form of the spectra, which provide acceptable results and which have the advantage of being more generally applicable and independent of the type of sample. Results are presented for samples of uranium, thorium oxide and pitchblende. (UK)