Development of liquid xenon detectors for gamma ray astronomy

The application of liquid xenon in high-resolution detectors for gamma-ray astronomy is being investigated. Initial results from a pulse-shape analysis of ionization signals in a liquid-xenon gridded chamber indicate that it is possible to achieve the necessary liquid purity for the transport of free electrons with simple techniques. The energy resolution has been measured as a function of applied electric field, using electrons and γ=rays from a ²⁰⁷Bi source. At a field of 12 kV/cm the noise-subtracted energy resolution of the dominant 569-keV γ-ray line is 34 keV FWHM (full width at half maximum). This value is mostly determined by recombination of electron-ion pairs on delta-electron tracks