Proceedings of the Royal Society of London A Mathematical and Physical Sciences
Stochastic theory of the interaction of ions and quantized vortices in helium II
Russell James Donnelly, Paul Harry Roberts
Abstract
Abstract The interaction of ions and quantized vortex lines in helium II is treated by imagining that the motion of the superfluid near a vortex line acts on an ion so as to produce a potential well. The ion itself is looked upon as a Brownian particle immersed in a gas of quasi-particles. The capture of ions is pictured as a process of sedimentation into the well. The escape of the ions from the well is treated as a problem of the escape of a Brownian particle over a potential barrier. A solution of the Fokker-Planck equation for a two-dimensional well is given. Comparison of the theory with a variety of experiments is presented.