SuN: Summing NaI(Tl) gamma-ray detector for capture reaction measurements

High demand for nuclear reaction cross-section measurements relevant for astrophysical processes requires the development of new experimental techniques that allow for investigation of, often very low, cross-sections. For this purpose, a new 4π4πSumming NaI(Tl) detector (SuN) has been constructed, which is an 8-fold segmented NaI(Tl) barrel read by 24 photomultipliers. The design of the detector will be presented and detailed results of the commissioning experiments utilizing standard calibration sources and known Al27(p,γ)Si28 resonances will be discussed.