Abstract
Analysis of post-nuclear detonation materials provides information on the type of device and its origin. Compositional analysis of trinitite glass, fused silicate material produced from the above ground plasma during the detonation of the Trinity nuclear bomb, reveals gross scale chemical and isotopic heterogeneities indicative of limited convective re-homogenization during accumulation into a melt pool at ground zero. Regions rich in weapons grade Pu have also been identified on the surface of the trinitite sample. The absolute and relative abundances of the lanthanoids in the glass are comparable to that of average upper crust composition, whereas the isotopic abundances of key lanthanoids are distinctly non-normal. The trinitite glass has a non-normal Nd isotope composition, with deviations of −1.75 ± 0.60 ε (differences in parts in 104) in 142Nd/144Nd, +2.24 ± 0.75 ε in 145Nd/144Nd, and +1.01 ± 0.38 ε in 148Nd/144Nd (all errors cited at 2σ) relative to reference materials: BHVO-2 and Nd-Ames metal. Greater isotopic deviations are found in Gd, with enrichments of +4 ± 1 ε in 155Gd/160Gd, +4.19 ± 0.75 ε in 156Gd/160Gd, and +3.48 ± 0.52 ε in 158Gd/160Gd compared to BHVO-2. The isotopic deviations are consistent with a 239Pu based fission device with additional 235U fission contribution and a thermal neutron fluence between 1.4 and 0.97 × 1015 neutrons/cm2.
Original language | English |
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Pages (from-to) | 57-67 |
Number of pages | 11 |
Journal | Journal of Radioanalytical and Nuclear Chemistry |
Volume | 302 |
Issue number | 1 |
DOIs | |
State | Published - Oct 2014 |
Funding
Acknowledgment We would like to thank the Smithsonian National Museum of Natural History for the trinitite sample, A. Fahey for discussion over trinitite properties and sample analysis techniques, and Savannah River National Laboratory for the use of their mass spectrometer. NS adds a special thanks to Dr. Mignerey for her assistance in understanding neutron and fission interactions. Funding was provided by the Plasma Lab at the University of Maryland, the Department of Geology, and the University of Maryland.
Keywords
- Laser-ablation and solution inductively coupled mass spectrometry
- Nd and Gd isotopic ratios
- Nuclear forensics
- Trinitite