Quantitative Analysis Of Uranium And Plutonium Using Microcalorimeter Decay Energy Spectroscopy

Year
2020
Author(s)
Mark Croce - Los Alamos National Laboratory, Los Alamos
Chandler Smith - Los Alamos National Laboratory, Los Alamos
Aidan Tollefson - Los Alamos National Laboratory, Los Alamos
Katrina Koehler - Los Alamos National Laboratory
Matthew Carpenter - Los Alamos National Laboratory, Los Alamos
Andrey Bosko - International Atomic Energy Agency, Seibersdorf, Austria
Abstract

By placing a small nuclear material sample inside a microcalorimeter detector, the total decay energy for each alpha-decaying nuclide can be measured with nearly 100% detection efficiency. This new category of radiometric measurement is under development for nuclear safeguards applications because of its potential to accurately determine the composition of uranium, plutonium, and other actinide isotopes in a small sample with 1 Bq or less of alpha activity. This activity corresponds to 0.4 nanograms of 239 Pu or 12 micrograms of 235 U. We have demonstrated the first high-resolution decay energy spectroscopy measurements on uranium and plutonium certified reference materials. For uranium samples, 234 U, 235 U, 236 U, and 238 U were resolved. For plutonium samples, 238 Pu, 239 Pu, 240 Pu, and 241 Am were resolved. We will present quantitative analysis results and discuss potential applications of decay energy spectroscopy.