Development of a high-resolution liquid xenon detector for gamma-ray astrophysics

It has been shown here that liquid xenon is one of the most promising detector media for future gamma-ray detectors, owing to an excellent combination of physical properties. The feasibility of the construction of a high resolution liquid xenon detector as a gamma-ray detector for astrophysics has been demonstrated. Up to 3.5 liters of liquid xenon has been successfully purified and using both small and large volume prototypes, the charge and the energy resolution response of such detectors to gamma-rays, internal conversion electrons and alpha particles have been measured. The best energy resolution measured was 4.5% FWHM at 1 MeV. Cosmic ray tracks have been imaged using a 2-dimensional liquid xenon multiwire imaging chamber. The spatial resolution along the direction of the drifting electrons was 180 {dollar}mu{dollar}m rms. Experiments have been performed to study the scintillation light in liquid xenon, as the prompt scintillation signal in the liquid is an excellent trigger for a high resolution liquid xenon detector. To obtain a better overview of noble liquid detectors general, and liquid xenon in particular, experiments have also been performed with liquid krypton ionization detectors. The average energy to produce an electron-ion pair in liquid krypton was measured for the first time with a pulsed ionization chamber to be 18.4 {dollar}pm{dollar} 0.3 eV.