Corrections for Exchange and Screening Effects in Low-energy Beta Decays

Xavier Mougeot (1) , Marie-Martine Bé (1) , Charlène Bisch (1) , Martin Loidl (1)

1 LNHB - Laboratoire National Henri Becquerel

The beta spectra of 241Pu and 63Ni have been recently measured using metallic magnetic calorimeters. This powerful experimental technique allows theoretical beta spectra calculations to be tested at low energy with an accuracy never before achievable. Their comparison with classical beta calculations exhibits a significant deviation below 4 keV for 241Pu and 8 keV for 63Ni. The atomic exchange effect explains the main part of this deviation in the 63Ni beta spectrum. This effect has a significant contribution, equivalent to the magnitude of the screening, in the 241Pu beta spectrum.

Keywords: Beta spectrum; 241Pu; 63Ni; Metallic magnetic calorimeters; metrology; ionizing radiations

Domains: Physics [physics]; Nuclear Experiment [nucl-ex]

Xavier Mougeot, Marie-Martine Bé, Charlène Bisch, Martin Loidl. Corrections for Exchange and Screening Effects in Low-energy Beta Decays. Nuclear Data Sheets, 2014, 120, pp.129 - 132. ⟨10.1016/j.nds.2014.07.026⟩. ⟨cea-01848991⟩