Vortex dimples at charged helium interfaces

We have investigated theoretically the profile of electrically charged helium interfaces in the presence of a superfluid vortex line perpendicular to the interface. The free surface of superfluid³He-B as well as the interface between phase-separated³He and⁴He mixtures have been considered. The superflow-induced dimple profile around the vortex line was calculated within the linear theory assuming a weak curvature of the interface. Our results show that the depth of the dimple increases strongly with an external electric field as the critical value of the electrohydrodynamic surface instability is approached. The chances of observing these charge-enhanced dimples are also discussed.