Measurements were made of the release of 41Ar and 39Ar from fast neutron-irradiated single crystals. The results for 425 to 625K could be described by:

D (cm2/s) = 7 x 108 exp[-1.80(eV)/kT]

The results for 625 to 1015K could be described by:

D (cm2/s) = 2 x 10-3 exp[-0.36(eV)/kT]

F.W.Felix: Proceedings of the British Ceramic Society, 1967, 9, 273-7