Speaker
Description
The nuclear isomer $^\textrm{83m}$Kr is used at many experiments for calibrations. At the neutrino mass experiment KATRIN, monoenergetic conversion electrons from the 32.2-keV transition of $^\textrm{83m}$Kr are regularly used to investigate inhomogeneities in the electric potential inside the tritium source and to calibrate the energy scale. The absolute precision of this energy scale is limited by the uncertainty (0.5$\,$eV) on the transition energy --- a limitation which impacts the important comparison of the measured beta spectrum endpoint with the $^3$He-$^3$H mass difference determined in Penning trap measurements. The poster presents a novel method for precisely determining the transition energies of $^\textrm{83m}$Kr by leveraging the existence of conversion electrons from the direct transition. The method uses precision electron spectroscopy of conversion electrons from all three transitions (9.4$\,$keV, 32.2$\,$keV, and 42.6$\,$keV). These measurements are to be performed under the same conditions at the KATRIN experiment, made possible by the ppm-precise retarding high voltage defining the relative energy scale.
We acknowledge the support of Helmholtz Association (HGF); Ministry for Education and Research BMBF (05A17PM3, 05A17PX3, 05A17VK2, 05A17PDA, 05A17WO3, 05A20VK3, 05A20PMA and 05A20PX3); Helmholtz Alliance for Astroparticle Physics (HAP); the doctoral school KSETA at KIT; Helmholtz Young Investigator Group (VH-NG-1055); Max Planck Research Group (MaxPlanck@TUM); Deutsche Forschungsgemeinschaft DFG (Research Training Group grant nos. GRK 1694 and GRK 2149); Graduate School grant no. GSC 1085-KSETA and SFB-1258 in Germany; Ministry of Education, Youth and Sport (CANAM-LM2015056, LTT19005) in the Czech Republic; the Department of Energy through grants DE-FG02-97ER41020, DE-FG02-94ER40818, DE-SC0004036, DE-FG02-97ER41033, DE-FG02-97ER41041, DE-SC0011091 and DE-SC0019304; and the Federal Prime Agreement DE-AC02-05CH11231 in the USA. This project has received funding from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation programme (grant agreement no. 852845). We thank the computing cluster support at the Institute for Astroparticle Physics at Karlsruhe Institute of Technology, Max Planck Computing and Data Facility (MPCDF), and National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory.
| Collaboration | KATRIN |
|---|
