Plasmakristall-4 laboratory for research of complex (dusty) plasma on board of the International Space Station

The scientific equipment «Plasmakristall-4» («PK-4») is designed to study complex (dusty) plasma under microgravity conditions aboard the International Space Station (ISS) and is a joint project of the European Space Agency (ESA) and Roscosmos. Scientific equipment «PK-4» is integrated into «European physiological modules» (EPM) rack, in the European laboratory module Columbus. Experiment control - automated, software-interactive, or manual from an on-board laptop and/or from a terminal in the ground control center. A low-pressure direct current discharge in noble gases in a glass tube is used to create a plasma at scientific equipment «PK-4». Microparticles of a given size are injected into the discharge to obtain a complex plasma. Two digital video cameras allow to trace individual microparticles inside the tube in phase space, which makes a complex plasma to be a good model for studying classical phenomena in condensed matter at the kinetic level. To monitor the plasma conditions, an integrated spectrometer and another video camera are used allowing to observe emission from the plasma at different wavelengths. To study the reaction of microparticles to external forces, they can be exposed to radiation from a powerful laser, a gas stream, and also to thermophoretic force, i.e., by producing a given temperature gradient.