Status of the PWO crystal preproduction from Russia for CMS-ECAL

Since September 1998, the CMS electromagnetic calorimeter has entered into its construction phase. Since that time, 3500 PbWO4 (PWO) crystals of excellent quality have been produced by Bogoroditsk Techno-Chemical Plant (BTCP) in Russia and analysed at the CERN regional centre. Most crystals show mechanical and optical properties well within the specification limits, together with excellent production homogeneity. Also, the radiation hardness characteristic of those crystals fulfils the requirements of the future LHC collider. An overview on the characteristics of these large series production crystals will be presented.