Abstract
We developed a prototype of TlBr semiconductor detector array for high resolution PET scanner with less than 1mm FWHM. We obtained an energy resolution of similar to 20% FWHM for 511 keV and a coincidence time resolution of similar to 50nsec FWHM at a detector bias 100V. This result expects the capability of application of TlBr detector array to a high resolution PET scanner. The TlBr detector arrays with the present time resolution performance can be applied to a small PET scanner for the PET study using small animals such as rats and mice.