| A Charge Coupled Device (CCD) coupled with a pixellated inorganic scintillator (such as segmented CsI) can provide high position resolution (∼300 mum). However, standard CCDs are integrating devices typically operating no faster than video rates. For a balloon-borne gamma-ray telescope capable of measuring the energy of individual photons, the CCD must have a time resolution better than the average time interval between cosmic ray events on the veto shield (∼10 kHz). A Fast Timing Bi-Directional CCD has better than 10 mus time resolution and 50 mum position resolution. We describe the CCD readout architecture, the ASIC readout design, the present status of the development, and the application to a gamma-ray astronomy telescope suitable for a 100-day Ultra Long Duration Balloon mission. |
