Göttingen 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
T: Fachverband Teilchenphysik
T 102: Neutrino Physics IX
T 102.5: Vortrag
Freitag, 4. April 2025, 10:00–10:15, VG 3.104
Determination of the absolute nuclear transition energies of 83mKr using the gaseous krypton source of KATRIN — •Benedikt Bieringer and Matthias Böttcher for the KATRIN collaboration — Institut für Kernphysik, Universität Münster
The KATRIN experiment aims to measure the electron neutrino mass mν with 0.3 eV/c2 (90% C.L.) sensitivity after 1000 measurement days in 2025, by measuring the T2 β spectrum near its endpoint E0 and performing a fit including parameters E0 and mν2. Since these are highly correlated, systematic effects influencing the obtained mν will also manifest in E0 and the derived T2 Q value. Comparing this with the T−3He mass difference from Penning-trap measurements is therefore a valuable for cross checks of our experimental procedure. Determining the KATRIN Q value with high precision requires calibration of the experimental energy scale with 83mKr conversion electrons. This is limited by knowledge of 83mKr nuclear transition energies, being known to 0.3 eV precision in the literature. The excited nucleus of 83mKr decays via a two-step cascade of 32.2 keV and 9.4 keV highly converted γ transitions, and a weak direct transition. With a gaseous Kr source, a measurement of conversion electrons from all three transitions was performed in 2023 at KATRIN. Following the method described in ref. EPJ C 82 (2022) 700 the nuclear transition energies can be determined, which can allow for a reduction of the T2 Q value uncertainty to 0.1 eV. In this talk, we present the analysis of the measurement. This work is supported by the Helmholtz Association and BMBF (grant numbers ErUM-Pro 05A23PMA, 05A23PX2, 05A23VK2 and 05A23WO6).
Keywords: Neutrino mass; Calibration; Krypton; Conversion electron spectroscopy; KATRIN