NUCLIDE ANALYSIS ON LOW-STATISTICS ALPHA-PARTICLE SPECTRA - AN EXPERIMENTAL-VERIFICATION FOR PU ISOTOPES

In spectrometry with low-activity alpha-particle sources, deconvolutio n of multiplet:; which usually have poor statistics is a problem. In t he present work, apeak-fitting model that is used successfully in metr ology of alpha-particle spectrometry has been applied to the low-level case to identify problems and limitations, The method consists of mea suring relative peak areas and peak positions in spectra of the single isotopes of interest. They serve to subsequently optimize (in the lea st-squares sense using constraints) the isotopic ratio in the spectra from the mixed-isotope sources. It is found that the method can perfor m reasonably well provided all sources have about the same thickness. Source thickness and the large solid angle produce peak deformation an d increase coincidence summing with conversion electrons. At present t hey limit the application of the peak-fitting model.