Beam stability of undulator and dipole radiation on BESSY II obtained by synchrotron radiation monitors

The determination of the position and the emission angle of the radiation from the BESSY II synchrotron radiation light source and of their reproducibility and stability is an essential requirement for successful experimentation. To this end, both imaging and non-imaging monitors have been developed here. For the individual beamlines, each front end has been equipped with non-imaging monitors which provide continuous, on-line information for the users. These systems are described here and detailed data on the performance of the machine obtained over two years of operation to date are presented.