Strong Interaction of Vortices with Attractive Point Defects, and Applicationto Neutron Star Rotation

The rate of energy transfer to Kelvin waves is obtained for a slowly moving vortex interacting strongly with a point defect distribution. Vortices are trapped by attractive point defects for relatively long time intervals: a critical vortex velocity below which pinning occurs can be defined in terms of the interaction time. An expression is found for the dissipative force at higher velocities and applied here to superfluid neutron vortices in a neutron star, with reference to the recovery of the spin-down rate change in pulsar glitches.