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PK4 Neon "Plasma crystal (PK) 4"

A DC-plasma for the ISS

The PK4 (Plasmakristallexperiment 4) project is a continuation of the successful PKE Nefedov experiment on board the International Space Station ISS and its successor, PK3 Plus. As with these experiments, PK4 will allow us to study complex ('dusty') plasmas (made up of ions, electrons, neutral gas and micron sized 'dust' particles) in a weightless or microgravity environment. Only under these conditions stress-free plasma crystal systems can exist and provide us with unique and new insights into the physics of complex plasmas.

Plasma inside PK4 prototype: the 'positive
column' of a DC glow discharge.
The dark space inside the 'cathode fall' - left
hand side, the 'positive column' starts.
(Note the totally different geometric proportions compared
to the formerly used RF plasma chambers!)

With PK4, for the first time a DC operated plasma chamber with an observable length of 30 cm and a diameter of 3 cm will be used to study effects that can not be seen with the PKE Nefedov and PK3-Plus RF chambers. The main difference of a DC chamber compared to a RF discharge is the elongated geometry of the chamber that allows to study more fluid systems than static plasma crystals like the RF setups. The tubular design provides a high accessibility for watching and recording the experiment, and also for manipulation with additional RF fields or intense laser beams. The well known physics of glow discharges helps to change and to control the plasma parameters because they mainly depend on pressure, current and geometry. The effects that are planned to be studied on the kinetic level are: Laminar and turbulent flow; the transition between both; thermodynamics and self-organisation of complex plasma flows; solitons and shocks; interfaces and plasma instabilities; agglomeration and disagglomeration. For low-frequency excitation and confining particles modulated RF coils and high-voltage supplies are foreseen.

Instability ("Striations") in the PK4 plasma.
View into the tube with the plasma.

The expected results will be of fundamental interest for the understanding of complex plasmas, but also for the physics of condensed matter (crystalization) and fluid dynamics. Further applications might be in the field of semiconductor production and astrophysics (planetary formation).

Zur PK4-Homepage!
Visit also the PK4 homepage!

Updated: 2004-10-29
Contact: Michael Kretschmer mail
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