New Short-Lived Fission Product Yield Experiment at Oregon State University*

A new experimental setup at the Oregon State University (OSU) TRIGA reaction is being designed, with the goal of measuring short-lived fission product yields and investigating discrepancies in fission product $\gamma$-ray branching ratios. ${}^{238}$U cumulative fast fission product yields were recently measured using Godiva-IV. The fission product yields were extracted by analyzing fission product $\gamma$-rays which rely on $\gamma$-ray branching ratios. This method relies on the accuracy of $\gamma$-ray branching ratios, some of which may not be reliable. Measurements at Godiva-IV are limited to begin $\sim$1 hour post-irradiation. The OSU rabbit system allows the rapid transport of samples from the core to the counting setup within 3 seconds. The new setup will consist of four Compton-suppressed HPGe clover detectors providing high efficiency for $\gamma$-ray detection, and the high segmentation of the array will increase the $\gamma$-$\gamma$ coincidence detection efficiency and enable the investigation of gamma-ray branching ratios. Results from a preliminary proof-of-principle measurement at the OSU TRIGA reactor will be presented along with the current status of preparations for the future campaign.