The existing Nuclear Resonance Fluorescence (NRF) setup at the HI{\gamma}S facility at the Triangle Universities Nuclear Laboratory at Duke University has been extended in order to perform {\gamma}-{\gamma} coincidence experiments. The new setup combines large volume LaBr3:Ce detectors and high resolution HPGe detectors in a very close geometry to offer high efficiency, high energy resolution as well as high count rate capabilities at the same time. The combination of a highly efficient {\gamma}-ray spectroscopy setup with the mono-energetic high-intensity photon beam of HI{\gamma}S provides a worldwide unique experimental facility to investigate the {\gamma}-decay pattern of dipole excitations in atomic nuclei. The performance of the new setup has been assessed by studying the nucleus \sulfur at 8.125 MeV beam energy. The {\gamma}-decay branching ratio from the 1+ level at 8125.4 keV to the first excited 2+ state was determined to 15.7(3)%.
@article{arxiv.1304.6270,
title = {The high-efficiency {\gamma}-ray spectroscopy setup {\gamma}3 at HI{\gamma}S},
author = {Bastian Löher and Vera Derya and Thomas Aumann and Jacob Beller and Nathan Cooper and Marc Duchene and Janis Endres and Enrico Fiori and Johann Isaak and John Kelley and Michael Knörzer and Norbert Pietralla and Christopher Romig and Marcus Scheck and Heiko Scheit and Joel Silva and Anton P. Tonchev and Werner Tornow and Henry Weller and Volker Werner and Andreas Zilges},
journal= {arXiv preprint arXiv:1304.6270},
year = {2015}
}