File:Masterthesis Schaller 2016.pdf

The low temperature properties of glasses are governed by atomic tunnelling systems. These tunnelling systems can couple resonantly to electric fields and can be studied by phase coherent methods such as dielectric polarisation echo measurements using microwave resonators. The obtained results are described by the standard tunnelling model, however several extensions are necessary to treat the nuclear effects and the interactions between tunnelling systems. In the framework of this thesis a new automated data acquisition and analysing system for the measurement of two-pulse polarisation echoes at GHz frequencies was built. The new setup reduces the necessary measuring expenditure by constantly calculating the signal to noise ratio and logging the thermalisation process. Furthermore high data quality is ensured due to the single shot data acquisition including an extended error investigation. A network analyser was added to the electronic circuit of the setup which allows for readjusting the drive frequency to the resonance frequency of the resonator for every temperature step. Measurements carried out on the glass BK7 show the functionality of the new readout and analysis routines.