Progress on the Scintillation Imaging Gas-filled Hard X-ray Telescope (SIGHT)

We are building a new type of hard X-ray detector (35-300 keV) for astronomical observations, a high pressure (20 atmospheres) imaging xenon gas scintillation drift chamber. This detector combines the concepts of the gas scintillation chamber and the time projection chamber, utilizing waveshifting fibers to read out the scintillation light. This detector will be the focal plane instrument of the Scintillation Imaging Gas-filled Hard X- ray Telescope (SIGHT), a balloon-borne instrument which promises to combine high sensitivity (2.2 x 10-5 (gamma /cm2sec for narrow lines and 4 x 10-6 (gamma /cm2sec/keV continuum at 70 keV), very good energy resolution (2.6% FWHM 122 keV), and outstanding imaging (1.5 arcminute map pixels). We summarize the capabilities of SIGHT and present recent technical innovations and construction status of the detector.