Development of imaging high pressure xenon gas scintillation drift chambers for use in gamma ray burst astronomy

This thesis describes the development of the Scintillation Imaging Gas-filled Hard X-ray Telescope (SIGHT), a balloon-borne instrument designed to make astronomical observations in the 35-300 keV energy range. The telescope utilizes a high pressure xenon gas scintillation drift chamber (GSDC) as the X-ray detector sitting behind a coded aperture mask. The GSDC offers {dollar}sim{dollar}2% FWHM energy resolution over the entire region of operation, coupled with {dollar}sim{dollar}200 {dollar}mu{dollar}m position resolution that gives the telescope a mapping angular resolution of about 1.5 arcminutes and a strong source localization capability better than 10 arcseconds. These attributes combined in a single instrument can provide a wealth of information on galactic X-ray sources, including high resolution measurements of features in the spectra of binary X-ray pulsars and nuclear decay lines in the spectra of supernova remnants. These objects can be observed without contamination from other sources since SIGHT can map the sky. This thesis studies the particular improvements to gamma ray burst astronomy that SIGHT could make. These burst sources are a mystery, with the distance to their sources unknown. SIGHT or related instruments built around GSDCs could make high resolution searches for low energy features that have been reported in the spectra of these bursts but not confirmed. The instrument could also localize bursts on the sky and search for bursts associated with nearby galaxies. The specific observational advantages SIGHT enjoys are due to its waveshifter fiber readout of the scintillation light. The details of the design optimization of this readout are presented. The development of plane parallel proportional counters with CsI photocathodes for the detection of vacuum ultraviolet light is also reported. These devices have gains of more that 10{dollar}sp6{dollar} and quantum efficiencies of more than 30% for the detection of xenon scintillation light peaked around 170 nm. The proportional counters could replace SIGHT's waveshifter fiber readout with a more robust, more efficient readout. They will also prove useful anywhere an inexpensive, imaging instrument capable of detecting single vacuum ultraviolet photons is needed.