Dark Matter Search with Plutonium-241 Beta Decays

Geonbo Kim | 23-LW-043

Executive Summary

We will measure high-precision plutonium 241 beta decay spectra using a decay energy spectrometry technique that we have developed for plutonium assay for nuclear safeguards, to search for a keV-scale sterile neutrino that is one of the most promising dark matter candidates and one of the top priorities in research needs for high energy physics. This project will be the most competitive experiment searching for the keV sterile neutrino dark matter, as well as benefits ongoing nuclear safeguards and nuclear forensics programs by providing accurate spectral shape of plutonium 241 and thus improving accuracy on plutonium 241 fraction in nuclear samples.

Publications, Presentations, and Patents

Boyd, Stephen, et al. 2023. "Development of Fast Decay-Energy Spectroscopy with Magnetic Microcalorimeters." IEEE Transactions on Applied Superconductivity, vol. 33, no. 5, pp. 1-5 (2023).

Kim, Geonbo. 2023. "MAGNETO-ν: Searching for keV-scale sterile neutrino in 241 Pu beta decays." Bulletin of the American Physical Society (2023).

Zhang, Xianyi, Alexander Kavner, and Geonbo Kim. 2023. "Analysis of MAGNETO-ν data and a preliminary limit to keV-sterile neutrino mixing." Bulletin of the American Physical Society (2023).

Alexander Kavner, et al, "Efficiency studies for Magneto-v Experiment“ (Presentation, 20th Workshop on Low Temperature Detectors, Daejeon, South Korea, 2023).

Geon-Bo Kim, “Magnetic Microcalorimeter Applications at LLNL" (Presentation, First Workshop on Microcalorimetry and Nuclear Data, Washington, D.C., 2023).

Geon-Bo Kim,“Magnetic Quantum Sensors for NNSA Programs " (Presentation, Quantum Sensing Workshop, Berkeley, CA, 2023).

Geon-Bo Kim, “MAGNETO: Low Mass Dark Matter Search with Fast Metallic Magnetic Calorimeters" (20th workshop on low temperature detectors, Daejeon, South Korea, 2023).