With the refurbishment completed, the optical beamline delivers all the required diagnostics. This paper reports on their status focusing in particular on the R&D beamline branch. The additional branch is equipped with programable mirror and lens position controllers allowing elaborate optical optimisation. This system is used for educational purposes and for improving the source point imaging system through the study of polarisation characteristics. Test systems for an ultra-fast diode and a THz detector are equipped with CMOS cameras and polarisation filters. Furthermore the R&D branch complements the existing diagnostics to measure bunch lengths and investigate non-linear beam dynamics.

This paper describes the optical beam diagnostics available at the BESSY II booster synchrotron. For the first time, diagnostics are established to investigate the distribution of the electron beam in all three dimension. A permanent installation of a source-point imaging system aided by a telescope optic depicts the transverse properties of the electron beam. Additionally, the bunch length is measured using a streak camera with a resolution in the picosecond range. Both systems can work in parallel and are able to observe the non-equilibrium beam dynamics over the entire booster ramp.