Statistical properties of homogeneous and isotropic turbulence in He II measured via particle tracking velocimetry

It is demonstrated for the first time that by combining Eulerian and Lagrangian flow analyses of tracer particle trajectories in a nearly homogeneous and isotropic turbulence (HIT) in superfluid helium-4 (He II), the turbulence statistics at all length scales can be resolved. The spatial velocity structure functions of the HIT in He II exhibit classical Kolmogorov scaling at large length scales together with anomalous deviations at small scales. Our technique paves the way for future quantitative studies of the similarities and differences between quantum and classical turbulence.