%0 Generic
%A Rischka, Alexander
%D 2018
%F heidok:25153
%R 10.11588/heidok.00025153
%T The First Direct Q_EC Measurement in 163Ho  and the Development of the High-Precision  Mass Spectrometer PENTATRAP for Neutrino  Physics
%U https://archiv.ub.uni-heidelberg.de/volltextserver/25153/
%X An improvement of the upper limit of the electron neutrino mass to a sub eV/c2 level is the goal of the ECHo collaboration. The upper limit of the  neutrino mass will be determined with cryogenic microcalorimetry from the analysis of the atomic de-excitation spectrum of 163Dy after the EC in  163Ho. To check for systematic errors an independent measurement of the Q-value of the EC in 163Ho is required. For the first phase of ECHo the issue  with the discrepancy between the latest microcalorimetry measurements of the Q-value and its literature value needed to be fixed. For this, a first direct  measurement of the Q-value of the EC in 163Ho with the Penning-trap mass  spectrometer SHIPTRAP was accomplished in the context of this thesis using  the novel PI-ICR technique. Within the uncertainty, it agrees with the  latest microcalorimetry measurements. Furthermore, the achieved precision  is sufficient for ECHo-1k to be able to improve the upper limit of the electron  neutrino mass to 10 eV/c2 (95% C.L.). For further improvements on the  neutrino mass, the Q-value needs to be improved, too. For this, the novel  high precision Penning-trap mass spectrometer PENTATRAP has been developed  and commissioned. PENTATRAP will utilize five Penning traps to  test new measurement schemes, which could make it possible to reach unv  certainties in the 10^12 regime. Currently, first mass-ratio measurements of  the nuclei pair 132Xe and 131Xe with known masses were carried out to test  the performance of PENTATRAP.