TY  - GEN
Y1  - 2020///
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/27340/
AV  - public
ID  - heidok27340
N2  - The goal of the ECHo collaboration is to reach a sub-eV sensitivity on the effective
electron neutrino mass by the analysis of the high energy resolution and high
statistics 163Ho electron capture spectrum measured with metallic magnetic micro
calorimeters. Within this thesis several measurements have been performed for detector
optimization and for a study of the spectral shape of the 163Ho . In a first
measurement the heat capacity of Ho-ions implanted in gold absorbers was measured.
It was found that an implanted activity per pixel of a = 10 Bq does not
compromise in a noticeable way the performance of the detector at T = 20 mK. To
test the performance of MMC detectors shielded by rock and to check this option
of operation for future ECHo phases, an experiment was performed in an underground
lab. This measurement allowed for the first time a detailed investigation
of the 163Ho spectral shape. Furthermore, was a first high statistic 163Ho spectrum
acquired. The analysis allows for a determination of the Q-value of the 163Ho EC
with Q = 2.837 +- 0.005 (stat) +- 0.005 (syst) keV and to perform a first analysis of the end
point region of the spectrum to extract an effective electron neutrino mass.
TI  - Measurement of a high energy resolution and high
statistics 163Ho electron capture spectrum for the
ECHo experiment
A1  - Velte, Clemens
CY  - Heidelberg
ER  -