Dr David Schmoranzer (Charles University) gives a webinar on “Experiments on Inhomogeneous Quantum Turbulence in Superfluid ⁴He”.

In this talk we will examine experimental evidence on two types of flows generating inhomogeneous quantum turbulence: spherically symmetrical thermal counterflow and flow due to submerged oscillators. In both experiments, quantum turbulence was detected by the second sound attenuation technique, giving a spatially weighted average vortex line density. Specifics of the two flows will be introduced and discussed, together with their eventual role in determining the structure of the observed turbulence, as inferred from the experiments. Finally, we will consider the use of local mechanical detectors in similar experiments and their expected response to externally driven turbulent flows, with some implications for ongoing measurements with nanomechanical devices.