Speaker
Description
The nucleosynthesis of approximately half of the elements heavier than iron is attributed to the r-process. A key input for modeling the r-process is the neutron-capture cross-section of neutron-rich nuclei. However, astrophysical sensitivity studies suggest that uncertainties in these cross-sections significantly impact the predicted abundances. In particular, in the A=140 region, calculations underproduce the observed abundances by nearly an order of magnitude. The main sources of uncertainty in neutron-capture cross-sections calculations come from the Nuclear Level Density (NLD) and Gamma-Ray Strength Function ($\gamma$SF).
Here, we present the results from the analysis of $^{142}\text{Ba}(n,\gamma)^{143}\text{Ba}$ using the $\beta$-Oslo method. The compound nucleus $^{143}\text{Ba}$ was populated via $\beta$-decay of $^{143}\text{Cs}$ beams at the Argonne National Laboratory. The emitted $\gamma$-rays were detected using the segmented total absorption calorimeter: the Summing NaI(Tl) (SuN) detector. The segmented scintillator allows us to measure the individual $\gamma$-rays as well as the excitation energy of the populated states in the compound nucleus. Using the $\beta$-Oslo method, we extract the NLD and $\gamma$SF of $^{143}\text{Ba}$, which are then used to constrain the neutron-capture cross-section. The results of the NLD and $\gamma$SF will be presented.