The direct force on electromigrating hydrogen isotopes

The present understanding of the magnitude of the direct force on hydrogen and its isotopes deuterium and tritium is discussed in the light of new exp erimental data and existing theoretical formulations. By this it is proven, that the direct valence of hydrogen can be significantly different from th e unscreened jellium value of unity. Furthermore, a more detailed interpret ation of a resistivity dependent direct valence is given, which clarifies t he controversy around that subject. Selfconsistent calculations of the elec tronic charge density at and around an interstitial, at all positions along its electromigration jump path, are required to come to a more complete un derstanding of the measured results. (C) 1999 Elsevier Science S.A. All rig hts reserved.