Heat transport in a flowing complex plasma in microgravity conditions

Heat transport in a three-dimensional complex (dusty) plasma was experimentally studied in microgravity conditions using a Plasmakristall-4 (PK-4) instrument on board the International Space Station (ISS). An extended suspension of microparticles was locally heated by a shear flow created by applying the radiation pressure force of the manipulation-laser beam. Individual particle trajectories in the flow were analyzed, and from these, using a fluid heat transport equation that takes viscous heating and neutral gas drag into account, the complex plasma's thermal diffusivity and kinematic viscosity were calculated. Their values are compared with previous results reported in ground-based experiments with complex plasmas.