Tunnel detrapping of self‐trapped positronium in SrF2 single crystal

We develop a model to explain the temperature dependence of the delocalized Ps fraction in SrF2. The model accounts for both classical and tunnel detrapping mechanisms. We show that it is this model that reproduces the available experimental data well throughout the entire temperature range, thus demonstrating an important role of the temperature activated tunnel detrapping for the self-trapped Ps in SrF2. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)