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The electron screening effect was studied in the 1H(7Li,α)4He, 1H(19F,αγ)16O and 2H(19F,p)20F nuclear reactions on two different hydrogen-containing palladium foils. In one of the targets we did not detect a large enhancement of the cross section due to electron screening, and in the second one we measured a high electron screening potential for all three reactions, up to an order of magnitude above the theoretical models. Contrary to the predictions given by the available theories, the data suggest that the reason behind this difference is linked to a dependence of the electron screening potential on the host's crystal lattice structure and the location of the target nuclei in the metallic lattice.

Proton–deuteron fusion reaction has been studied using a proton beam with an energy of 260 keV and a deuterium-implanted graphite target. The reaction product, 3He, usually de-excites by γ-ray emission. However, instead of a γ ray, 3He can emit an electron with a discrete energy of 5.6 MeV, due to electron screening in graphite. Such electrons were identified with the ΔE–E technique. The emission of fast electrons shows that electron screening causes the electrons to approach the nuclei during the reaction very closely. Different behavior of nuclear reactions at low and high energies was also demonstrated. Keywords: Nuclear astrophysics, Electron screening, Internal conversion, Fusion reactions, Radiative capture