Experiments probing clustering effects in explosive nucleosynthesis

Abstract

Nuclear clustering affects the nucleosynthesis occurring in a number of astrophysical environments. Highly-clusterized nuclear states typically occur near particle thresholds and therefore can produce dramatic impacts on the nuclear reaction rates. This is especially true for astrophysical explosions that are driven by the consumption of helium as fuel. Such burning can occur in X-ray bursts, supernovae type Ia, and core-collapse supernovae for instance. This article will focus on the explosive astrophysical events in which nuclear clustering is most important, will discuss the types of information and tools necessary to estimate the astrophysical reaction rates, and will discuss example experiments at Notre Dame and other facilities that have or will be performed to measure the critical nuclear data needed for such estimates.

Alpha clustering in 41, 45, 49Ca* nuclei formed in neutron induced reactions

“…The observed gradual decrease in the cross-section with increasing neutron number of Sn nuclei explicates that with evolution of neutron-skin, the α-cluster formation gets supressed in heavy nuclei. Such an interplay between neutron-skin and α-clustering in light nuclei needs to be investigated as these light exotic nuclei exhibit an important role in the nucleosynthesis and the degree of α-clustering can significantly affect the astrophysical reaction rates [5]. Therefore, it is intriguing to examine the isotopic dependence of α-clustering in light nuclei and Ca isotopic chain with magic proton number Z = 20 act as an ideal ground to probe aforementioned interplay.…”