An investigation was made of the diffusion of 39Ar and 41Ar in single crystals at temperatures where non-ideal diffusion predominated. It was shown that all or most of the Ar atoms were trapped in crystal defects after irradiation with neutrons. The mechanism for the release of the atoms was sensitive to variations in the irradiation dose, and could be attributed to an activation energy of 2.4eV, but only for the lowest doses (table 56). After irradiation to low doses, non-ideal release occurred at 250 to 400C; after irradiation to a dose of 1018/cm2 at 400 to 550C.

Non-Ideal Diffusion of Argon in Potassium Chloride. P.Schmeling: Physica Status Solidi B, 1967, 20[2], 597-603

Table 57

Diffusion of Ar in Single Crystals of KCl

(doped with 0.02mol%K2S and

irradiated to a dose of 9 x 1013/cm2)