Erice: INTERNATIONAL SCHOOL OF NUCLEAR PHYSICS, 47th COURSE

The KATRIN experiment aims at a direct kinematic measurement of the absolute neutrino mass with an expected sensitivity below 300 meV (90% CL), achieved through high-resolution, high-statistics spectroscopy of tritium beta decay. To reach this sensitivity, systematic effects that modify the measured electron spectrum must be modeled and controlled via dedicated calibration measurements. One key systematic effect is related to the starting potential of electrons in the gaseous molecular tritium source, which behaves as a cold plasma in a tesla-scale magnetic field. In this talk, after introducing the starting-potential-related effects, we present the analysis of calibration measurements using gaseous krypton-83m. Steps toward a robust source-potential description are discussed and the impact on the neutrino mass analysis is evaluated.
This work is supported by the Helmholtz Association and by the Ministry of Research, Technology and Space BMFTR (grant numbers 05A23PMA, 05A23PX2, 05A23VK2 and 05A23WO6).