An investigation was made of the diffusivity of Ar, in Ar-saturated silica fibres, by using a modified version of Seivert’s method. This furnished results which were in good agreement with previous data. At 500 to 905C, the diffusivity of Ar in vitreous silica was described by:

D (cm2/s) = 5.06 x 10-5 exp[-26.9(kcal/g-atom)/RT]

G.S.Nakayama, J.F.Shackelford: Journal of Non-Crystalline Solids, 1990, 126[3], 249-54