Precise ⁹²Rb and ⁹⁶Y yields for thermal-neutron-induced fission of ²³⁵U and ^239,241Pu determined using calorimetric low-temperature detectors

The novel technology of calorimetric low-temperature detectors (CLTDs) was applied to determine isotopic yields of fission fragments using the passive absorber method for thermal-neutron-induced fission reactions at the LOHENGRIN mass spectrometer at the Institut Laue-Langevin in Grenoble, France. Precise yields were determined for( 92)Rb and Y-96. These fission products are the dominant contributors to the high-energy portion of the reactor antineutrino spectra. Our new measurements resolve inconsistencies between previous yield measurements and fission data libraries and reduce the nuclear data uncertainties in the computation of reactor antineutrino spectra by the summation method.