Nuclear Structure 2022

Gamma-Particle Coincidence Studies of 93Sr(d,p)94Sr via the Surrogate Reaction Method

14 Jun 2022, 16:30

20m

Berkeley, CA

Oral Oral Presentations NS2022 Plenary

Speaker

Andrea Richard (Lawrence Livermore National Laboratory, Facility for Rare Isotope Beams)

Description

Neutron-capture cross sections play a vital role in our understanding of heavy element nucleosynthesis. In astrophysical processes such as the intermediate neutron-capture process and rapid neutron-capture process, element formation occurs in neutron-rich environments and involves short-lived isotopes for which capture cross sections cannot be measured via direct techniques. Instead reaction rates in these regions rely on calculations that have uncertainties up to a few orders of magnitude. Recent measurements of the $\beta$-decay of ${}^{94}$Rb [1], which compared the neutron-to gamma-ray-branching ratio of state decays above the neutron separation energy in ${}^{94}$Sr, suggest an enhanced $\gamma$-ray branch which would in turn lead to an unexpectedly large ${}^{93}$Sr(n,$\gamma$) cross section. If confirmed, such an enhancement could have a strong impact on our understanding of nucleosynthesis processes involving nuclei in this region. In order to investigate this potential enhancement of the ${}^{93}$Sr(n,$\gamma$) cross section, an experiment was performed at TRIUMF using an 8~MeV/u ${}^{93}$Sr beam impinging on a CD${}_2$ target. The (d,p$\gamma$) coincidence data was measured using the SHARC and TIGRESS arrays. Experimental details from the measurement of ${}^{93}$Sr(d,p)${}^{94}$Sr will be presented along with preliminary gamma-particle coincidence analysis using the Surrogate Reaction Method [2,3].

*This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

[1]. J. L. Tain, et al. Phys. Rev. Lett. 115, 062502 (2015).
[2]. J. Escher, et al., Phys. Rev. Lett. 121, 052501 (2018).
[3]. A. Ratkiewicz, et al., Phys. Rev. Lett. 122, 052503 (2019).

Presentation materials

ARichard_NS2022.pdf