Sub-eV uncertainties on gamma-ray energies using a magnetic microcalorimeter—potential new reference energies
Year: 2026
Type: article
Abstract: We present new measurements of 27 gamma-ray energies ranging from 14 keV to 136 keV, obtained using magnetic microcalorimeters for energy-dispersive spectrometry. The spectrometer has eight pixels and achieves a high energy resolution between 15 eV and 30 eV across the entire energy range. It faces a cryogenic source sampler with four movable sources, each containing a mixture of radionuclides, including 169 Yb and 57 Co. Four gamma-ray lines from 169 Yb and one from 57 Co were used to calibrate the spectrometer and correct for its non-linearity in the energy range 14 keV–130 keV. The gamma-ray energies, emitted through the decay of 57 Co, 109 Cd, 133 Ba, 153 Gd, 154 Eu, 155 Eu, 169 Yb, 170 Tm, 210 Pb, 239 Np, 241 Am and 243 Am, have been reassessed. This work significantly reduces the uncertainties upon previously reported gamma energies obtained by energy-dispersive spectrometry using semiconductor detectors: the lowest absolute uncertainty achieved is 0.13 eV at 105.3 keV, which corresponds to a relative uncertainty of 1.3 ppm. With respect to the available literature, among the 27 measured gamma-ray lines, the uncertainties of 10 energies were reduced by a factor of 5, while those of 4 additional energies were reduced by more than one order of magnitude.
Source: Metrologia
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,325
OpenAlex ID: W7203484112