ELECTRON SCREENING IN THE D-3 FUSION REACTION(HE)

Cross section measurements of the d(He-3, p) He-4 reaction have been e xtended to an energy as low as E(cm) = 5.4 keV. The data have an impro ved accuracy compared with previous work and confirm the existence of electron screening. The combined analysis of the present and previous data leads to an electron screening potential of U(e) = 123 +/- 9 eV. A similar analysis of previous data for He-3(d, p) He-4 leads to U(e) = 186 +/- 9 eV. Both screening potentials differ due to the molecular and atomic aggregate state of the targets involved in these investigat ions and are significantly larger than expected from available atomic physics models, supporting the general trend in studies of electron sc reening.