Development of edge-on type CdTe detector module for gamma camera

The detector module using CdTe with edge-on configuration was developed. The pixel pitch is 1.4 mm, and 1024 pixels constitute the field of view of 45 mm square. The CdTe crystals sandwich thin circuit boards to form CdTe cards, and 16 CdTe cards are mounted on the module. The intrinsic energy resolution of 4.4% (FWHM) was achieved with Tc-99m at CdTe temperature of 25 °C. It remains 5.1% at 40 °C, which implies the possibility of air-cooling system. Uniformity and count-rate performance were also evaluated.