Physics Colloquium: Prof. Anna Simon, University of Notre Dame

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Location: zoom

Neutron capture reactions for nuclear astrophysics and national security applications

Prof. Anna Simon
Department of Physics, University of Notre Dame

High-accuracy neutron capture cross sections are required not only for nuclear astrophysics modeling, but also for a variety of applications ranging from nuclear energy, stockpile stewardship to national security. Frequently, those reactions pose a challenge for direct measurements, thus indirect techniques are employed to extract the cross sections. One of the methods, the Oslo methods, allows for extracting the nuclear statistical properties from the experimental data. Those are then used to calculate the capture cross sections through the Hauser-Feshbach statistical approach.

This talk will focus on the measurements performed at Texas A&M using the Hyperion array to employ the Oslo technique. Here, the Oslo method was for the first time employed to investigate rare-earth nuclei and unraveled a new feature, the low-energy upbend, in the gamma-ray strength function for these nuclei. Systematic measurements show that this feature is present in all nuclei, regardless of their shape and has a significant impact on the cross section. Cross sections obtained from the measured statistical properties will be presented, with experimental uncertainties propagated using Monte Carlo approach.

All interested persons are invited to attend remotely—email physics@nd.edu for information.