Bismuth Germanate (BGO) Optimisation for Energy Resolution and Purity

Investigations are described which are being carried out into quality criteria for polycrystalline BGO for the production of crystals to be used in large high energy physics calorimeters. The objective is the definition of a material specification which can ensure that the bars are of high quality and reproducibility and have been manufactured in the most cost effective manner. Results are presented on the effect of selected impurities on the performance of bars made from materials of controlled composition.