3^He A-B Transition in Finite Geometries

TL;DR

This paper presents a hydrodynamic theory explaining how finite cell geometries influence the 3He A-B transition rate by introducing a pressure discontinuity caused by lateral wall drag, a factor previously overlooked.

Contribution

It introduces a new hydrodynamic model accounting for finite geometries' effects on the 3He A-B transition, emphasizing the role of lateral wall drag.

Findings

Pressure discontinuity across the interface due to wall drag

Finite geometry effects are crucial for understanding transition rates

Hydrodynamic theory incorporating boundary effects is developed

Abstract

The measured rate of the 3^He A-B transition depends on the diameter of the experimental cell. Theoretically, this can only be explained by a direct drag on the interface exerted by the lateral walls, leading to a pressure discontinuity across the interface. This has not been considered before, either here or in similar circumstances. The general hydrodynamic theory that includes the influence of finite geometries is presented.