Physical Review Letters
Spatial Distribution of Superfluid Vortices
D. Scott Shenk, James B. Mehl
Abstract
We report accurate measurements of the increase, due to rotation, of the attenuation of second sound in an annulus. The measurements can be explained in detail by a vortex-free-region model in close agreement with theory, assuming a vortex-core parameter of 10 \AA{} at 1.65 K. The range of agreement extends from the vorticity threshold to relatively high angular velocities.