Ir Radionuclei Production Cross Section

Iridium plays a critical role as a radiochemical detector for the measure of neutron energy spectra through activation.  Iridium is unique in that it can provide a measure of neutron energy spectra over three important energy regimes; thermal/epithermal, fission, and fast.  Currently, there is a large discrepancy between (n,n’) cross section data, indirect gamma-ray absence cross section data, and theory.  This presentation will describe a new experimental effort to provide an improved measure of the radionuclei production cross section of ¹⁹³Ir(n,n’)^193mIr needed for radiochemical detection.  The new measurement makes use of precision targets and silicon drift detectors for low-energy x-ray detection of ^193mIr as well as advances in making monoenergetic neutron sources.  In addition, a new experimental setup for performing (n,n’) to metastable states using the recently commissioned Notre Dame Neutron Irradiation Station will be discussed.