Year: 2015
Type: article
Abstract: We describe a technique, using thin lines of triplet-state $\mathrm{He}_{2}^{*}$ molecular tracers created by femtosecond-laser field ionization of helium atoms, for visualizing the flow of the normal fluid in superfluid $^{4}\mathrm{He}$, together with its application to thermal counterflow in a channel. We show that, at relatively small velocities, where the superfluid is already turbulent, the flow of the normal fluid remains laminar, but with a distorted velocity profile, while at a higher velocity there is a transition to turbulence. The form of the structure function in this turbulent state differs significantly from that found in types of conventional turbulence. This visualization technique also promises to be applicable to other fluid dynamical problems involving cryogenic helium.
Source: Physical Review B
Authors: A. Marakov, J. Gao, W. Guo, S. W. Van Sciver, G. G. Ihas, D. N. McKinsey, W. F. Vinen
Language: Latvian
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Collaborative Research: Materials World Network: Collaborative Research on Simple Forms of Quantum Turbulence - Production, Decay and Visualization, Materials World Network: Collaborative Research on Simple Forms of Quantum Turbulence - Production, Decay and Visualization, RECOVERY ACT LIQUID HELIUM FLUID DYNAMICS STUDIES, Collaborative Research: Materials World Network: Collaborative Research on Simple Forms of Quantum Turbulence - Production, Decay and Visualization
OpenAlex ID: W2090404151