NIST quantum sensors measure X-rays from uranium, neptunium and plutonium — more accurate assessment of nuclear material
On 10 September 2026 NIST reported that a team including its researchers measured X-ray emissions from plutonium, uranium and neptunium with unprecedented accuracy in the energy range where they overlap with the elements’ gamma-ray emissions. This allows the X-ray background to be filtered out when nuclear material is assessed from gamma-ray spectra.
- The measurements used an array of about 250 transition-edge sensors (TES) developed at NIST — superconducting films held a fraction of a degree above absolute zero whose resistance rises in proportion to the energy of an absorbed photon.
- According to NIST, the results support international nuclear safeguards through more precise accounting of material in nuclear facilities, including the measurement of isotope ratios, and the sensors may also help increase efficiency and reduce costs at nuclear power plants.
- The paper “Measured and Theoretical Kα X-Ray Emission Linewidths of U, Np, and Pu” was published in Physical Review Letters on 10 September 2026; co-authors include researchers from NIST, the University of Colorado Boulder, Los Alamos National Laboratory, Houghton University and the Kastler Brossel Laboratory (Sorbonne University).
Source: NIST — NIST-Developed Quantum Sensors Improve Nuclear Monitoring (10.09.2026)