Fe with DAPPER Using Forward Analysis*

The photon strength function (PSF) describes the average photon emission probabilities of excited states within the continuum.  The PSF thus is important in understanding radiative neutron capture reactions.  Experiments have shown an enhancement in the PSF at low energy for some nuclei.  Low energy enhancement (LEE) theoretically has a large effect on r-process nucleosynthesis, where many nuclei with unmeasured neutron capture cross sections are produced in nature. Previous experiments have shown a LEE in both ⁵⁶Fe and ⁵⁷Fe. A measurement of ⁵⁸Fe’s PSF would determine if this trend continues. In addition, doing a measurement of ⁵⁸Fe’s PSF helps to prepare for a future measurement of ⁶⁰Fe’s PSF, which will require a radioactive beam. DAPPER (Detector Array for Photons, Protons, and Exotic Residues) probes PSFs using inverse kinematics (d,p) reactions. DAPPER consists of 128 BaF₂ detectors, to detect the gamma rays with high efficiency, and one S3 Annular Silicon detector, to detect the recoiled proton. Preliminary results on the measurement of ⁵⁸Fe’s PSF using a Forward method as well as the performance of the DAPPER array will be discussed.