Speaker
            
    Victor Zhilich
            
                (BINP)
        
        
    Description
The KEDR Tagging System is designed to enhance the detector ability  to  study   the  two-photon processes e⁺e⁻ → e⁺e⁻X. The collider magnetic elements (dipoles and lenses) form a magnetic spectrometer for the scattered  electrons and positrons. Its energies are  measured with 8 coordinate blocks which are placed beside of the vacuum chamber. In the double--tag mode an invariant mass of the system  X  can be measured with resolution  3-15  MeV for  Winv=300÷3000 MeV depending on the mass and the beam energy. The  changes of the  beam energy cause the small changes in the magnetic structure  and the beam orbit. This cause   systematic shifts of the  e± energy  which  is  measured with  the coordinate blocks. These different shifts leads to degradation of the Winv resolution.   The complex calibration system was constructed  to allow  the calibration for all tagger blocks with the necessary accuracy.
            Primary author
        
            
                
                
                    
                        Victor Zhilich
                    
                
                
                        (BINP)
                    
            
        
    
        