Use of Secondary Ion Mass Spectrometry in Nuclear Forensic Analysis for the Characterization of Plutonium and Highly Enriched Uranium Particles

Abstract

The application of secondary ion mass spectrometry (SIMS) analysis is described for the characterization of plutonium and highly enriched uranium (HEU) particles with a diameter to 10 μm. Applying a method previously described, particles of HEU could be detected in a scrap material, together with natural uranium. The isotopic composition of the particles was measured with a typical accuracy and precision of 0.5%. The spectrum of the trace elements in the uranium particles was also recorded. From the results it was possible to deduce that the uranium oxide, as UO2, was produced via a pyrochemical process. In a sample consisting of a mixture of three different species of particles, two of these were identified as plutonium particles. They were characterized according to their isotopic ratio 239/240 as well as to their dimension and shape. The results obtained by SIMS for the isotopic ratio were compared with those obtained analyzing the particles by Thermal Ionization Mass Spectrometry (TIMS). The shape and dimensions were confirmed by the analysis with Scanning Electron Microscopy (SEM). In both the cases the results obtained by SIMS were in good agreement with those from TIMS and SEM.

Evaluation of the Homogeneity of the Uranium Isotope Composition of NIST SRM 610/611 by MC-ICP-MS, MC-TIMS, and SIMS

“…Microanalytical techniques including secondary ion mass spectrometry (SIMS) and laser ablation inductively-coupled mass spectrometry (LA-ICP-MS) have made high precision, spatially resolved analysis of U isotope ratios possible, which has yielded new insights into complex materials [8][9][10][11]. For example, the isotopes of U in glassy fallout debris from a historical nuclear test have been shown to be heterogeneously distributed [12,13].…”

RIMS analysis of ion induced fragmentation of molecules sputtered from an enriched U3O8 matrix

“…The increasing threat of nuclear weapons development has prompted the use of a number of mass spectrometry techniques charged with the task of determining the isotopic composition of trace amounts of radionuclides from a diverse set of materials [1][2][3][4][5][6][7]. A major focus for these types of measurements is on improving the sensitivity for the detection of uranium and transuranic isotopes in the presence of isobaric interferences without the need for complex and time-consuming sample preparation methods.…”

Precise and accurate isotopic analysis of microscopic uranium-oxide grains using LA-MC-ICP-MS

“…235 U 1 H on 236 U, but this can be minimised by the use of a desolvating nebuliser. Secondary ion mass spectrometry (SIMS) has been used in the nuclear forensics context for the precise analysis of uranium and plutonium isotope ratios directly from particulates [29][30][31] .…”