R&D on third generation multi-segmented piezoelectric bimorph mirror substrates at Spring-8

An innovative active X-ray mirror which incorporates the bending mechanism in the mirror substrate itself has been developed during the last few years: the multi-segmented Piezoelectric Bimorph Mirror (PBM). This paper reports on the current status of a third generation multi-segmented PBM which is currently being manufactured for the 8 GeV storage ring SPring-8. After successful validation of the conceptual design by the manufacturing, installation and commissioning of three prototype mirrors at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, the R&D effort is now focused on pushing the reflecting surface quality to the limits of currently available polishing and metrology technology.