Decrease in the amplitude of helium II–vapor interface oscillations at addition of monodisperse backfill in a U-shaped channel filled with superfluid helium

The paper considers experimental data of superfluid helium dynamics in a U-shaped cylindrical channel filled with a backfill of metal balls. An experimental cell is presented and the results of study are shown in the form of a time dependence for the position of vapor–liquid interface. The differences between the oscillations in a free channel and in confined conditions are discussed. For a channel with a finely dispersed porous structure, the oscillation amplitude significantly reduces and a stationary state of the interfacial surface is possible.