Dynamics of Liquid Helium Wetting on Real Surfaces

Interest about wetting properties of liquid helium on weakly binding substrates was recently focused on dynamical properties. The motion of liquid film border near prewetting transitions has been investigated, as well as meniscus edge dynamical properties. Depending on substrate quality, an hysteretic dynamics is observed due to line pinning. It may interfere with the observation of the transition, in addition to the intrinsic thermal hysteresis associated with its first order nature. Experimental results and models put forward to explain them will be discussed.