Proton-bombardment--induced blistering of vanadium

Samples of annealed and severely cold-rolled vanadium were bombarded at room temperature with 150-keV H+ ions at fluxes from 1.2 x 10/sup 15/ to 1.2 x 10/sup 16/ H+/cm2 sec to doses of from 3.6 x 10/sup 17/ to 3.2 x 10/sup 19/ H+/cm2. All samples irradiated to doses greater than 1.1 x 10/sup 19/ H+/cm2 exhibited blistering in spite of the fact that temperatures never exceeded the peak miscibility gap temperatures below which vanadium hydride is stable with respect to gaseous hydrogen even at low hydrogen partial pressures. Niobium also blistered under similar conditions. This unexpected observation must be reconciled by any acceptable theory of radiation blistering