Nuclear structure studies using photonuclear reactions with quasi-monoenergetic photon beams at HIγS

Photons provide a particular clean probe to study a variety of nuclear structure phenomena. Their interaction with the atomic nucleus is described by the electromagnetic interaction enabling the almost model-independent separation of the nuclear response from the details of the reaction mechanism. In this talk, recent developments and experimental results obtained from photonuclear reaction studies with quasi-monoenergetic photon beams at HIγS are discussed in view of contradictory data sets when comparing data from real-photon scattering and particle-induced reactions. In addition, a model-independent approach is presented that allows the determination of photon strength functions in the photoabsorption and photon-emission channel in a single experiment testing the concept of the Brink-Axel hypothesis in the energy region below the neutron separation threshold.