Heat transport in a flowing complex plasma in microgravity conditions

TL;DR

This study experimentally investigates heat transport in a three-dimensional complex plasma under microgravity conditions on the ISS, analyzing particle trajectories to determine thermal diffusivity and viscosity.

Contribution

It provides new measurements of thermal diffusivity and viscosity of complex plasma in microgravity, using a novel laser heating and particle tracking method.

Findings

Thermal diffusivity and viscosity values were obtained for complex plasma in microgravity.

Results are compared with ground-based experiments, highlighting differences due to microgravity conditions.

The study demonstrates the feasibility of analyzing heat transport in complex plasmas in space environments.

Abstract

Heat transport in a three-dimensional complex (dusty) plasma was experimentally studied in microgravity conditions using 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 analysed 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.