The effect of thermal cycles of negative magnitude upon the 222Rn permeation in Au which had been pre-annealed at various temperatures was studied at 150C, after prolonged equilibration at the same temperature. It was found that the thermal cycling enhanced the permeability, and reduced the activation energy for permeation. The results were explained in terms of the capture of vacancies by large diffusing 222Rn atoms and/or by the opening-up of small so-called channels having atomic dimensions. These defects tended to annihilate during prolonged isothermal holding at ambient temperatures.

Effects of Thermal Cycles on 222Rn Permeability in Au. S.K.Bhattacharyya, S.K.Pabi: Journal of Nuclear Materials, 1999, 275[2], 206-10