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Graduate Student Seminar - 09/25/2015

"Vortex Dynamics in Superfluid Helium: Experimental Frontiers and Challenges"

by Peter Megson

Friday, September 25, 2015 -- 12:00 p.m.
Large Conference Room, 1207 Energy Research Facility

Advisor:  Professor Daniel Lathrop

Liquid helium, when cooled below to 2.17 K, undergoes a phase transition and becomes partially superfluid. Superfluid helium exhibits many exotic physical properties, including flow-without-friction and ballistic heat transport. Superfluid helium also contains line-like vortices of quantized circulation -- so-called quantum vortices. These vortices have a deep theoretical background, but there is no complete model that describes their motion in superfluid. This owes partially to the fact that direct observation of quantum vortices was not possible until recently. This talk describes an experiment that uses fluorescent nanoparticles and 3D microscopy to visualize vortex dynamics in three dimensions. In particular, we will focus on current experimental challenges with regards to nanoparticle quality and dispersion, as well as data analysis, with an eye towards our ultimate goal of comparing our experimental observations to available models.

For additional information about the IREAP Graduate Student Seminars, contact Peter Megson.

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