Measurements were made of post-irradiation inert-gas release from single crystals of pure and U-doped material. Upon using an irradiation dose and time that did not cause irradiation damage which could affect the diffusion behavior, the diffusion of 37Ar and 41Ar in the pure samples could be described by:

D (cm2/s) = 106 exp[-3.54(eV)/kT]

Noble Gases in Solids. Diffusion of Noble Gases in Calcium Fluoride. J.Biersack, A.Brenner: Nukleonik, 1967, 10[5], 264-7