Alpha decay of thermally excited nuclei

Abstract

One of the prominent decay modes of heavy nuclei which are produced in astrophysical environments at temperatures of the order of $10^9$ K is the $\alpha$ (${}^4$He) decay. Thermally enhanced $\alpha$ decay rates are evaluated within the standard scheme of a tunneling decay where the $\alpha$ particle tunnels through the potential barrier formed by its interaction with the daughter nucleus. Following the observation that there exist several excited levels with the possibility of an $\alpha$ decay when the daughter nucleus is at a shell closure, we focus in particular on decays producing daughter nuclei with the neutron number, N = 126. Within a statistical approach we find that the half-lives, $t_{1/2}(T)$, for temperatures ranging from $T$ = 0 to 2.4 GK can decrease by 1 - 2 orders of magnitude with the exception of the decay of ${}^{212}$Po which decays to the doubly magic daughter ${}^{208}$Pb, where $t_{1/2}(T)$ decreases by 5 orders of magnitude. The effect of these thermally enhanced $\alpha$ decays on the $r$-process nucleosynthesis can be significant in view of the mass build up at the waiting point nuclei with closed neutron shells.

arXiv comment18 pages, 1 figure

References in corpus (28)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Multi-messenger Observations of a Binary Neutron Star Merger
• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
• Effect of a High Opacity on the Light Curves of Radioactively Powered Transients from Compact Object Mergers
• The Combined Ultraviolet, Optical, and Near-Infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. IV. Detection of Near-infrared Signatures of r-process Nucleosynthesis with Gemini-South
• Kilonovae
• Universal decay law in charged-particle emission and exotic cluster radioactivity
• Neutron Star Mergers and Nucleosynthesis of Heavy Elements
• Radioactivity and thermalization in the ejecta of compact object mergers and their impact on kilonova light curves
• Neutron Star Mergers Might not be the Only Source of r-Process Elements in the Milky Way
• Neutrino-driven wind simulations and nucleosynthesis of heavy elements
• SkyNet: A modular nuclear reaction network library
• Critical view of WKB decay widths
• Databases and tools for nuclear astrophysics applications BRUSsels Nuclear LIBrary (BRUSLIB), Nuclear Astrophysics Compilation of REactions II (NACRE II) and Nuclear NETwork GENerator (NETGEN)
• Impact of nuclear mass uncertainties on the $r$-process
• Kilonovae across the nuclear physics landscape: The impact of nuclear physics uncertainties on r-process-powered emission
• A novel manifestation of $\alpha$-clustering: new '$\alpha$ + ${}^{208}$Pb' states in ${}^{212}$Po revealed by their enhanced E1 decays
• Statistical approach for supernova matter
• Formation of hot heavy nuclei in supernova explosions
• Radioactive Heating and Late Time Kilonova Light Curves
• Bayesian Estimation of Thermonuclear Reaction Rates
• Alpha Clustering from the Quartet Model
• Critical view of nonlocal nuclear potentials in alpha decay
• Signature of the N=126 shell closure in dwell times of alpha-particle tunneling
• $\alpha$-cluster structures above double shell closures via double-folding potentials from chiral effective field theory
• Manifestation of deformation and nonlocality in $\alpha$ and cluster decay

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