Lead tungstate crystals of high light yield for medical imaging

Because of their high stopping power and fast scintillation, lead tungstate crystals have attracted much attention in the high energy physics and nuclear physics communities. The use of lead tungstate, how ever, is limited by its low light output. An effort has been made at the Shanghai Institute of Ceramics to improve this. The results indicate that a factor often increase of the light output, mainly in the microsecond decay component, may be achieved. The X-ray diffraction pattern, photoluminescence spectrum, light output, decay kinetics and transmittance spectrum of new samples are presented. Longitudinal uniformity of a sample of 22 radiation lengths is studied. This new type of lead tungstate crystals has attracted broad interest in the field of medical imaging.