We have measured the mobility and limiting terminal velocity of electron bubbles sliding along vortex lines in superfluid 4He for a broad range of temperatures (0.1 - 1 K). This allows dissipative processes at small length scales to be probed, which can include drag exerted by an excess density of excitations in the vicinity of the vortex core; the scattering and generation of Kelvin waves and solitons; condensation of 3He impurity atoms onto vortex cores. We have also used this technique to probe the dynamics of agitated vortex arrays and the corresponding timescales for relaxation back towards a rectilinear array, providing new insight into the decay of quantum turbulence at short length scales.

Add to my calendar

Back to listing