Visualization of Superfluid Helium Flow
Abstract
We discuss an experimental technique to visualize the motion in the bulk of superfluid He by tracking micron-sized solid hydrogen tracers. The behavior of the tracers is complex since they may be trapped by the quantized vortices while also interacting with the normal fluid via Stokes drag. We discuss the mechanism by which tracers may be trapped by quantized vortices as well as the dependencies on hydrogen volume fraction, temperature, and flow properties. We apply this technique to study the dynamics of a thermal counterflow. Our observations serve as a direct confirmation of the two-fluid model as well as a quantitative test of the normal fluid velocity dependence on the applied heat flux.
Cite
@article{arxiv.0808.1977,
title = {Visualization of Superfluid Helium Flow},
author = {Matthew S. Paoletti and Ralph B. Fiorito and Katepalli R. Sreenivasan and Daniel P. Lathrop},
journal= {arXiv preprint arXiv:0808.1977},
year = {2009}
}
Comments
7 pages, 7 figures, to appear in J. Phys. Soc. Japan