Instrumentation for Δ photoproduction experiments on nuclei with high-energy resolution

A technique has been developed to perform photo-induced experiments in the region of the Δ(1232) resonance with a sufficiently good energy resolution to separate excited states of the final nucleus. The technique utilizes developments in accelerator technology (high-duty factor electron beams), target technology (multi-layer waterfall targets), and detector technology (diffusely reflective aerogel Cherenkov systems). Taken together, these developments have enabled studies of the reaction 16 O( γ , π − p) with an energy resolution of less than 1 MeV. This represents an order of magnitude improvement in energy resolution over previous experiments of this kind.