A more accurate model of wetting transitions with liquid helium

Up to now the analysis of the liquid helium prewetting line on alkali metal substrates have been made using the simple model proposed by Saam et al. Some improvements on this model are considered within a mean field, sharp kink model. The temperature variations of the substrate-liquid interface energy and that of the liquid density are considered, as well as a more realistic effective potential for the film-substrate interaction. A comparison is made with the experimental data on rubidium and cesium