Fundamental mechanisms of 3He relaxation on glass

We present a model of 3He relaxation on the surface of borosilicate glass which accurately predicts observed relaxation rates and their temperature dependence. Above room temperature 3He dissolves into Pyrex, where interactions with Fe3+ ions result in a relaxation time of ≈1 ms. Gas exchange across the glass surface of an enclosed vessel leads to T1−1=A/V(3.9±1.4)×10−2 cm/h at room temperature, where A/V is the surface-to-volume ratio. The activation energy for relaxation is 13.7±0.7 kJ/mol and is dominated by the activation energy of 3He diffusion in glass. This is the first successful confirmation of predicted 3He relaxation rates in glass vessels.