Recoil polarimetry in meson photoproduction at MAMI

The nucleon excitation spectrum remains poorly known, with the masses, widths, EM couplings and even existence of many states not well established. A program of experiments using meson photoproduction off the nucleon is being carried out to improve this situation A new large acceptance recoil polarimeter has been developed by the Edinburgh group for use in such reactions with the Crystal Ball at MAMI. This work summarizes the procedure used to measure recoil polarization with the new device and presents some preliminary results for the double polarization observable C-tau in the reaction gamma p -> p pi(0), compared to the current, partial wave analysis.