Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 22: Symposium Quantum Fluids
TT 22.3: Hauptvortrag
Dienstag, 28. März 2006, 16:00–16:30, HSZ 304
The Transition in the Vortex Dynamics of Superfluid 3He-B — •V.B. Eltsov, R. Blaauwgeers, R. de Graaf, J. Kopu, and M. Krusius — Low Temperature Laboratory, Helsinki University of Technology, FIN-02015 HUT, Finland
In recent years the field of vortex dynamics in quantum
fluids has wittnessed a flurry of important advances. In superfluid 3He-B quantum turbulence has been investigated from the lowest temperatures up to 0.6 Tc, the temperature of the transition from turbulent dynamics at low temperatures to the superconductor-like highly dissipative dynamics at high temperatures. We have studied the evolution of vortex loops injected in vortex-free flow in a rotating cylindrical bucket of 3He-B and have traced with NMR a complete path to the final lowest energy configuration of rectilinear vortex lines stretched parallel to the rotation axis. With decreasing mutual friction damping injected loops become unstable towards formation of new vortices. Depending on vortex density this process proceeds either through rapid turbulent vortex multiplication due to inter-vortex interactions or via growth and reconnection to the boundary of Kelvin wave excitations on individual vortex lines. In the final stage a bundle of vortex lines expands along the rotating column into the vortex-free regions in the form of a propagating vortex front followed by a helically twisted cluster of vortex lines.