Search for electron screening of nuclear reactions at sub-coulomb energies

Abstract

The reaction 3He(d, p) 4 He has been investigated for E = 6 to 42 keV with the use of D projectiles and 3He atomic gas target nuclides as well as with 3He projectiles and D 2 molecular gas target nuclides. These studies show for the first time the predicted effects of electron screening on low-energy fusion cross sections, i.e. a nearly exponential enhancement of the cross sections compared to the case of bare nuclei. The enhancement is about a factor 2 smaller for the case d( 3He, p) 4He due to the molecular nature of the D 2 target nuclides. The reactions 6Li(p, α) 3He and 7Li(p, α 4He have also been studied for E = 10 to 65 keV with the use of solid LiF targets. The results also indicate an exponential enhancement due to the effects of electron screening.