A study was made of the release kinetics of radioactive Xe atoms from single crystals, following neutron irradiation. The results for undoped material, at temperatures ranging from 940 to 1320C, could be described by:

D (cm2/s) = 1 x 104 exp[6(eV)/kT]

The results for U-doped material, at temperatures ranging from 700 to 940C, could be described by:

D (cm2/s) = 1010 exp[6(eV)/kT]

F.W.Felix, S.Y.T.Lagerwall: Physica Status Solidi A, 1971, 4[1], 73-9