Speaker
Description
Improved $(\alpha,n)$ cross section measurements are needed for a range of applications such as nuclear astrophysics, neutrino physics, geophysics, nuclear energy, and weapons research. While they are sometimes focused on different energy regions, all benefit from a improved measurements over a wide energy range. The connection is further strengthened through the use of $R$-matrix analysis for the evaluation of the data in all cases. The shared desire for an improved characterization of the cross sections makes it clear that a comprehensive $R$-matrix analysis will be the most consistent method, as opposed to piecemeal ones, that sample only a fraction of the data and energy range.
At the University of Notre Dame we have pursued an improvement $(\alpha,n)$ cross section evaluation both by making new experimental measurements and $R$-matrix analyses. In this talk I will give an overview of several $(\alpha,n)$ experimental projects that are planned or underway, with a focus on the $^{13}$C$(\alpha,n)^{16}$O reaction. These new measurements focus on thin target, high energy resolution, differential measurements of partial cross sections using neutron and secondary $\gamma$-ray spectroscopy, the type of data most directly implemented into an $R$-matrix analysis. On the $R$-matrix side, I'll discuss efforts to construct an analysis of the $^{17}$O system using the code AZURE2, and new methods of performing Bayesian uncertainty analysis to determine probability distributions for observables and to calculate covariance matrices for fit parameters.
