Measurements of the $^{96}$Zr($\alpha$,n)$^{99}$Mo cross section for astrophysics and applications

• Main Authors: Hamad, Gula, Brandenburg, Kristyn, Meisel, Zach, Brune, Carl R, Carter, Don E, Ingram, David C, Jones-Alberty, Yenuel, Massey, Thomas N, Saxena, Mansi, Soltesz, Doug, Subedi, Shiv K, Voinov, Alexander V
• Format: Journal Article
• Language: English
• Published: 12-08-2022
• Subjects: Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.2208.06239

The reaction $^{96}$Zr($\alpha$,n)$^{99}$Mo plays an important role in
$\nu$-driven wind nucleosynthesis in core-collapse supernovae and is a possible
avenue for medical isotope production. Cross section measurements were
performed using the activation technique at the Edwards Accelerator Laboratory.
Results were analyzed along with world data on the $^{96}{\rm Zr}(\alpha,n)$
cross section and $^{96}{\rm Zr}(\alpha,\alpha)$ differential cross section
using large-scale Hauser-Feshbach calculations. We compare our data, previous
measurements, and a statistical description of the reaction. We find a larger
cross section at low energies compared to prior experimental results, allowing
for a larger astrophysical reaction rate. This may impact results of
core-collapse supernova $\nu$-driven wind nucleosynthesis calculations, but
does not significantly alter prior conclusions about $^{99}{\rm Mo}$ production
for medical physics applications. The results from our large-scale
Hauser-Feshbach calculations demonstrate that phenomenological optical
potentials may yet be adequate to describe $(\alpha,n)$ reactions of interest
for $\nu$-driven wind nucleosynthesis, albeit with regionally-adjusted model
parameters.