A SHELL MODEL OF POSITIVE IONS IN 3He-RICH LIQUID HELIUM

Nous proposons un modèle de coquille pour ions positifs dans 3He dilué dans 4He liquide. En raison de leur masse plus grande, les atomes 4He forment une coquille complète autour de la boule de neige. En se basant sur ce modèle on peut donner une explication de la mobilité multiple des ions positifs récemment découverte dans 3He normal.We propose a shell model for positive ions in 3 liquid containing dilute 4He.Due to their heavier mass 4He atoms should tend to form a closed shell structure around the snowball. Based on this model, an explanation is given for the recently discovered multiple positive-ionic mobility in normal 3He

Low-frequency conductivity of a two-dimensional Wigner solid coupled to surface excitations of liquid helium

The line-shape and broadening of coupled phonon-ripplon resonances of Wigner-solid conductivity are studied using the memory function formalism. The analytic properties of the memory function permit coordinating the approximations of the secular equation for the coupled phonon-ripplon modes and the line-broadening of these resonances. Special attention is paid to the description of the strong-coupling regime realized for surface electrons on superfluid helium. For this case it is shown that the line-broadening is much smaller than and the line-shape is different from those found previously using the weak-coupling theory. Different theoretical approaches are compared with available experimental data