New Method for Self-Absorption: Demonstrating Utility of a Polarized Beam

A newly proposed self-absorption experiment was performed following nuclear resonance fluorescence (NRF) of ²⁴Mg at the High-Intensity γ-Ray Source using photon beam energies of 9.82, 9.97, and 10.71 MeV. For this project, preparatory analysis was carried out focusing on determining the efficiency of the 32 clover-detector channels of the Clover Array and the analysis of NRF spectra, important steps toward extracting photoabsorption cross sections. Data from a radioactive source were analyzed, in order to optimize the simulation of the entire Clover Array setup such that computed efficiencies match measured ones. This experiment turned out to be very sensitive to weak decay branches of the states produced by NRF. Thus far, three new, weak decay branches, not reported in the literature, have been observed.