Energy loss, electron screening and the astrophysical 3He(d, p)4He cross section☆

We reanalyze the low-energy ^3He(d, p)^4He cross section measurements of Engstler et al. using recently measured energy loss data for proton and deuteron beams in a helium gas. Although the new ^3He(d, p)^4He astrophysical S-factors are significantly lower than those reported by Engstler et al., they clearly show the presence of electron screening effects. From the new astrophysical S-factors we find an electron screening energy in agreement with the adiabatic limit.