‘PK‐4’ — Laser‐driven shear flow in a DC discharge complex plasma

Flows, shear flows, laminar and turbulent flows on the microscopic scales are one of the fundamental issues in fluid dynamics. Due to their special properties, complex plasmas provide an excellent opportunity to study these flows, even on the scale of individual particles. To this end, experiments were conducted in the ‘Plasmakristall 4’ (PK‐4) experimental device that uses the positive column of a high voltage DC discharge to produce complex (dusty) plasmas. The linear geometry of PK‐4 provides the opportunity to study all these kinds of flow phenomena as well as waves and collisions. Since gravity distorts most of the effects to be studied with PK‐4, the facility is planned to be operated onboard the International Space Station ISS from 2008. In order to generate a high‐velocity shear flow PK‐4 is now upgraded with a 20W manipulation laser system.