Double pion photoproduction in the second resonance region

Double pion photoproduction from threshold up to the second resonance region (Egamma > 820 MeV) was investigated in a series of experiments carried out with the TAPS-detector at the Mainz MAMI accelerator. Data for double pidegrees-photoproduction were taken for the proton, the deuteron and heavy nuclei. The pi(+) pidegrees final state was studied for the free proton. In case of the proton and deuteron targets the kinematics were completly defined so that in addition to total cross sections invariant mass distributions of the pion-pion and pion-nucleon pairs could be obtained. The invariant mass distributions are crucial for the understanding of the reaction mechanisms.