LAUSR

The alpha emission spectrum of electrodeposited thin film 232Th and depleted uranium sources, including the alpha emitting 232Th decay chain daughters and 238U daughter nuclide 234U, have been measured using a thin film 4H–SiC alpha detector. The energy resolution of this detector was proved suitable for the identification of many of the major characteristic alpha emissions associated with the 232Th daughter isotopes. The identification of the lower energy daughter isotopes made from the 4H–SiC detector measurements was confirmed using a silicon surface barrier detector. A depleted uranium source was fabricated using electrodeposition in a molten salt and the alpha spectrum was acquired with a 4H–SiC detector. The 234U/238U activity ratio and atomic enrichment of 234U in the sample were determined. A method of determining the 235U enrichment in the product stream of the enrichment process used to produce the depleted uranium source was developed. This method makes use of the 234U and 235U waste stream enrichments, as indicated by the depleted uranium source, and a mass balance equation to determine the product 235U enrichment. Since the 235U spectrum was obscured in the electrodeposited source by peak broadening of 238U and 234U, a table of common 235U waste enrichment values was used to compute 235U product enrichments, thereby resulting in a plausible identification of the enrichment process as a Department of Energy HEU enrichment process.