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Abstract

In this work, the scintillation properties of liquid and gaseous xenon are investigated.^83mKr is used as an internal calibration source in xenon dual-phase time projection chambers (TPC) and decays via an intermediate step and thus produces two direct ultraviolet scintillation signals in close coincidence and at low energies of 32.1 and 9.1 keV. Since the relative size of these two signals depends on the applied electric field, their ratio can be used to reconstruct the field in the detector. Furthermore, the size of the second decay signal depends on its time proximity to the first signal. In this thesis, the ^83mKr decay signals for electric fields in the range of (2 - 1200) V/cm are investigated. The dependence of the light signals ratio on the electric field is confirmed. However, the values obtained here deviate from earlier studies. As part of this work, for the first time, the infrared scintillation light of xenon gas is studied together with its ultraviolet signal. Infrared light measured in a TPC makes it possible to obtain further information about the processes happening in xenon. In order to examine its properties in detail, an infrared-sensitive photomultiplier tube was used, which enables a precise time resolution. The pressure and gas purity dependence is investigated. No significant pressure dependence could be observed in the range of 800-1050 mbar, which is compatible with previous measurements. A dependency on gas purity could be observed for the IR signal, which is in contrast to earlier measurements.