Diffusion transport of negative ions through the interface between cryogenic liquids

A theory of electron bubble transport through the interface between cryogenic liquids is developed based on a new approach to calculating the potential of interaction of a bubble with the interface. The theory is in good agreement with experiments on the electric-field dependence of the potential barrier near the interface between liquid ⁴He, ³He, and vacuum, as well as at the interface between ³He and ⁴He saturated solutions. It is found that the interaction potential dependence on the distance between the electron bubble and the interface is isotopically invariant to three versions of such an interface. The dependence of the lifetime of negative ions in ⁴He and ³He on the temperature and electric field has been determined using the Kramers theory.