Position resolution performance of prototype segmented CdZnTe arrays

The Burst and All Sky Imaging Survey (BASIS) is a proposed mission to provide ±3 arc-second locations of an estimated 90 Gamma-Ray Bursts (GRBs) per year. The BASIS coded aperture imaging system requires a segmented detector plane able to detect the position of photon absorption to less than 100 microns. To develop prototype detector arrays with such fine position resolution we have fabricated many 15 mm × 15 mm × 2 mm 100 micron pitch CdZnTe strip detectors. A 2 × 2 prototype 100 micron CdZnTe strip detector array has been fabricated and has been used to test the capabilities of the BASIS imaging system. Preliminary shadowgrams of a 1 mm wide gap between two tungsten straight edges indicate that our position resolution is on the order of 69 μm. Both the array and imaging tests will be described. A 6 × 6 element CdZnTe detector array is also being fabricated at GSFC. The assembly of this flight prototype array will be discussed as well as applications for BASIS.