Inhalt

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   Zusammenfassung
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   Abstract
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   Acknowledgments
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   Contents
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  1 Introduction
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  1.1 Neutrino physics
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   1.1.1 Brief history of neutrino
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   1.1.2 Motivation for neutrino mass determination
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   1.1.3 Towards the absolute scale of neutrino masses
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   1.2 Process of internal conversion
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   Thesis outline
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  2 The KATRIN experiment
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   2.1 Tritium beta-decay
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   2.2 The MAC-E filter technique
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   2.3 Brief overview of the KATRIN experimental setup
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   2.4 Systematic and statistical uncertainties
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  3 Stability monitoring and calibration of the energy scale in KATRIN
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   3.1 Motivation for continuous monitoring and absolute calibration of the energy scale
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   3.2 Concept of monitoring of the KATRIN energy scale stability
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   3.2.1 High precision high voltage divider
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  3.3 Candidates for quasi-monoenergetic electron sources for KATRIN
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   3.3.1 Photoelectrons from 241Am/Co
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   3.3.2 Conversion electrons from 83mKr
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   4 Solid 83Rb/83mKr electron sources for KATRIN
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  4.1 Vacuum-evaporated sources
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   4.1.1 Vacuum evaporation of 83Rb
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   4.1.2 Samples investigated in this work
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  4.2 Ion-implanted sources
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   4.2.1 Basic processes of ion implantation
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   4.2.2 Ion implantation of 83Rb at the ISOLDE facility
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   4.2.3 Samples investigated in this work
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  4.3 Conversion electrons from solid 83Rb/83mKr sources
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   4.3.1 Shifts of electron binding energies
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   4.3.2 Shake-up and shake-off effects
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   4.3.3 Inelastically scattered electrons
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  5 Mainz MAC-E filter used for conversion electron spectroscopy
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  5.1 Experimental setup
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   5.1.1 MAC-E filter
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   5.1.2 Source section
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   5.1.3 Detector section
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   5.1.4 Vacuum system
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   5.1.5 High voltage system
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   5.1.6 Control and data acquisition system
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   5.2 Data analysis
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   5.2.1 Typical measurement and data treatment
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   5.2.2 Energy scale corrections
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   5.2.3 Dead time correction
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   5.2.4 Expected count rate of zero-energy-loss electrons
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   5.2.5 Transmission function
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   5.2.6 Description of the conversion electron line shape
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   5.2.7 Cross-correlation method
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   5.2.8 Comparison of cross-correlation and many-parameters fit methods
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   6 Long-term measurements of the conversion electrons energy stability at Mainz MAC-E filter
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  6.1 Pilot studies of the energy stability of the 83Rb/83mKr sources
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   6.1.1 Proof of principle
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   6.1.2 Measurements with vacuum-evaporated sources mounted onto CKrS setup
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   6.2 First measurement phase: single vacuum-evaporated source
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   6.2.1 Systematic measurements of the long-term drifts
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   6.2.2 Sudden unexpected shift of the high voltage scale
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   6.2.3 Measurements with the shifted high voltage scale
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   6.2.4 Influence of the source position on the K-32 line
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  6.3 Second measurement phase: one ion-implanted and two vacuum-evaporated sources investigated simultaneously
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   6.3.1 Comparison of drifts of individual sources
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   6.3.2 Changes of vacuum conditions due to breakdowns and bake-out
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   6.3.3 Tests with deliberate venting of the vacuum setup
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   6.3.4 Sudden unexpected change of the high voltage divider scale factor
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   6.3.5 Influence of the source position on the K-32 line at two different spectrometer resolutions
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   6.3.6 Background and transmission properties of Mainz MAC-E filter
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   6.4 Third measurement phase: four ion-implanted sources investigated simultaneously
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   6.4.1 Comparison of drifts of individual sources
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   6.4.2 Change of residual gas composition in spectrometer vessel resulting from vacuum breakdown
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  6.5 Summary of results
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   6.5.1 Energy stability of conversion electrons emitted by the solid sources
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   6.5.2 Overview of systematic effects
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   7 Conversion electron spectrum of 83mKr in solid sources
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   7.1 Choice of data and estimate of analysis precision
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  7.2 Shapes of the conversion electron lines
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   7.2.1 Description of the conversion lines of the vacuum-evaporated sources with a singlet
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   7.2.2 Doublet structure of the conversion lines of the ion-implanted sources
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   7.2.3 Verification of the many-parameters fit procedure
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   7.2.4 Discussion of amplitude and background of the conversion electron lines
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   7.3 Absolute kinetic energies of the conversion electrons from solid sources
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   7.3.1 Conversion electrons of the 9.4keV gamma transition
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   7.3.2 Conversion electrons of the 32keV gamma transition
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   7.3.3 Influence of 83mKr atom environment on the electron binding energy
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   7.3.4 Energy difference of the 9.4keV and 32keV gamma transitions
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  7.4 Hypotheses for the explanation of the asymmetry and splitting in the 83mKr conversion electron spectra of the ion-implanted 83Rb/83mKr sources
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   7.4.1 Different environments of the 83Rb atoms
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   7.4.2 Surface plasmons
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   7.4.3 Electron-hole interaction in metals
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   7.4.4 Strong electric fields in polycrystalline foils
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   7.4.5 Internal conversion at neighboring atoms
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   7.5 Electron energy loss spectra of the solid sources
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   8 Conclusions and outlook
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   A Electron binding energies of gaseous krypton
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  B Evaluation of the energy shifts of the 83mKr conversion lines resulting from abrupt changes of vacuum conditions
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   B.1 Second measurement phase
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   B.2 Third measurement phase
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   C Investigation of different environments of the 83Rb atoms in the ion-implanted 83Rb/83mKr sources with the XPS method
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   Bibliography