The trapping of helium in α-tridymite was studied at 236 to 336K. The diffusion coefficients could be represented by:

D(cm2/s) = 7.7 x 10-4 exp-[12000/RT]

R.M.Barrer, D.E.W.Vaughan: Transactions of the Faraday Society, 1967, 63, 2275-90