The electron screening puzzle and nuclear clustering

Abstract

Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak, show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. In this letter we show that instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.

Strong screening effects on resonant nuclear reaction23Mg (p, γ)24Al in the surface of magnetars

“…Following the works of Fushiki et al (1989), we will reinvestigate the electron Fermi energy in SMFs, and derived new results for SES theory and the screening rates for nuclear reaction in SMFs, based on the Thomas-Fermi-Dirac approximations. Secondly, our discussions also differs from that of Spitaleri & Bertulani (2015), which analyzed the influence of the SES only in the case without SMFs. Finally, Potekhin, & Chabrier, (2013) also discussed the electron screening effect on stellar thermonuclear Fusion.…”

“…The related discussions were provided by Liolios et al (2000), Liolios et al (2001), Kravchuk et al (2014) and Liu (2013). Very recently, Spitaleri & Bertulani (2015) also discussed the electron screening and nuclear clustering puzzle. Their results show that the large screening potential values is in fact due to clusterization effects in nuclear reactions, especially in reaction involving light nuclei.…”