Study of the energy resolution in alpha-particle spectra from electrodeposited radium sources

Electrodeposited 226Ra sources were prepared and measured in order to perform a detailed study of the energy resolutions attained with two recent electrodeposition procedures for preparing spectrometric radium sources. The values of the energy resolution for the high-energy emission of 226Ra and for the single-emissions of 210Po and 222Rn were calculated by fitting the data with a curve formed by the convolution of two left-handed exponentials with a Gaussian function. Significant differences between the energy resolutions for the aforementioned radionuclides were observed. The 210Po energy resolutions were, in general, somewhat better than those obtained for 226Ra. On the contrary, the energy resolutions found for 222Rn were notably poorer than those obtained for 226Ra and 210Po. These discrepancies can be satisfactorily explained by taking into consideration the distribution of these nuclides in the sources and the effect of radon diffusion involved in this type of thin deposit. (author)