ملخص: The electronic screening effect on the penetrability of the Coulomb barrier is evaluated for 6Li(p, 3He)4He and 7Li(p, [alpha])4He fusion reactions through the so-called enhancement factor [function of (italic small f)]. The [function of (italic small f)]s experimental values of [function of (italic small f)] for the two reactions involving solid targets are extracted from published cross sections. For the two inverse reactions involving gaseous targets [function of (italic small f)]g values are also extracted. A model of interacting p and Li in a solid medium which predicts theoretical [function of (italic small f)]s values is presented. Numerical evaluations of [function of (italic small f)]s are made for the astrophysical energy range under numerous assumptions. Analytical two-parameter fits are derived. Values of the electron screening potential energy U0 are evaluated and compared to those deduced from experimental data.

لغة: إنجليزية