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Graduate Student Seminar - 03/27/2015

"Superfluid Helium Vortex Dynamics"

by David Meichle

Friday, March 27, 2015 -- 12:00 p.m.
Large Conference Room, 1207 Energy Research Facility

Advisor:  Professor Daniel Lathrop

Liquid helium obtains superfluid properties when cooled below the Lambda transition temperature of 2.17 Kelvin. Superfluid, a partial Bose Einstein condensate, has many exotic properties including that it flows freely without friction and supports ballistic instead of diffusive heat transport. A superfluid is also uniquely characterized by the presence of quantized vortices, dynamical line-like topological phase defects around which all circulation in the flow is constrained. This talk will review both microscopic and macroscopic models of the vortex dynamics and how our work, both numerical and experimental, has vetted sometimes contradictory theoretical predictions. Recent advances in our experimental capabilities and their relevance to novel experimental tests will also be discussed. The advances include both the ability to disperse fluorescent nanoparticles directly into the superfluid for use as robust optical tracers and the development of a world-first 3D stereographic microscope for time-resolved tracking of tracer particles and quantum vortices fully in three dimensions.

For additional information about the IREAP Graduate Student Seminars, contact Joe Garrett, David Somers or Joe Murray.

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