Experimental Validation of Calorimetric Electron Capture Spectral Theory with 193Pt

Using microcalorimeters, a high statistics, high-resolution calorimetric spectrum of electron capture in 163 Ho can be used to determine the neutrino mass. The spectral shape can be calculated from first principles with various assumptions and approximations. To determine the validity of these choices, the theoretical calculations must be compared to data from multiple isotopes. New calorimetric data for a 193 Pt-in-Pt absorber measured with a transition edge sensor are presented and compared to theoretical calculations and values from the literature.