A beam of quasiparticles from a black-body radiator is directed at a localized region of quantum turbulence generated by a vibrating wire resonator driven at super-critical velocity. We are able to measure directly the fraction of the incident quasiparticle beam which is retro-reflected from the turbulence by Andreev processes. Combining these measurements with previous measurements on the spatial extent of the turbulence may allow us to infer the vortex line density.
Describes the first direct imaging of a quantum turbulent tangle by the Andreev reflection of a beam of quasiparticle excitations, a novel technique leading to further discoveries in quantum fluids research (see above). Bradley devised and supervised all aspects of this experiment. RAE_import_type : Journal article RAE_uoa_type : Physics