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Center for Nonlinear Studies |
Several significant questions regarding turbulence in quantum fluids, such as superfluid helium, remain unanswered owing to the inability to directly probe the local velocity in a manner quite common in the study of classical fluid turbulence. By implementing a novel visualization technique that allows us to directly measure the local velocity field, we experimentally characterize fundamental processes in turbulent superfluid helium. A mixture of hydrogen and helium gas is directly injected into the bulk of the fluid, which produces a polydisperse distribution of micron-sized hydrogen tracer particles that are visualized with a camera and individually tracked. The tracer particles allow us to examine the two-fluid nature of superfluid helium, identify and characterize tens of thousands of individual reconnection events, and probe the local velocity statistics of turbulent quantum fluids for the first time.
Host: Robert Ecke