for homogeneous, void-free complex plasma, while the neon glow distribution unexpectedly
resulted in a big void for identical gas and electrical parameters. The physical reason for this
difference was not clear. There are a number of important differences between complex
plasma parameters in neon and argon, eg, different ion mass and mean free path, different
plasma density, different electron temperature, etc.
PK-3 Plus showed that the “void” in the center of the complex plasma cloud could be easily
closed under certain conditions, thus providing a much better homogeneity of the complex
plasma, a feature that was hardly achievable before. This is very promising as it is essential for
many precision studies and enables new manipulation possibilities for future experiments.
Instabilities in the plasma (eg, heartbeat instability that causes continuous contraction and
expansion of the void, which the microparticles follow) appeared at high microparticle densities
and were strongly related to changes in the plasma glow. However, even though homogeneous
and void-free plasma is advantageous for modelling solid (crystalline), fluid and gas phases and
transitions between different phases, the reason for the void appearance in the neon
distribution, has created an interesting field of study for the future by itself.
PUBLICATION(S)
Petrov OF, Fortov VE. Collective phenomena in strongly coupled dissipative systems of charged
dust: From ground to microgravity experiments. Contributions to Plasma Physics. December
2013;53(10):767-777. doi: 10.1002/ctpp.201310052.
Worner L, Ivlev AV, Couëdel L, et al. The effect of a direct current field on the microparticle
charge in the plasma afterglow. Physics of Plasmas. 2013;20(12):123702. doi:
10.1063/1.4843855.
Fortov VE, Morfill GE. Strongly coupled dusty plasmas on ISS: Experimental results and
theoretical explanation. Plasma Physics and Controlled Fusion. December 1,
2012;54(12):124040. doi: 10.1088/0741-3335/54/12/124040.
Du C, Sutterlin KR, Jiang K, et al. Experimental investigation on lane formation in complex
plasmas under microgravity conditions. New Journal of Physics. July 31, 2012;14(7):073058. doi:
10.1088/1367-2630/14/7/073058.
Zhukhovitskii DI, Fortov VE, Molotkov VI, et al. Nonviscous motion of a slow particle in a dust
crystal under microgravity conditions. Physical Review E. 2012;86(1-2):016401.
Schwabe M, Jiang K, Zhdanov SK, et al. Direct measurement of the speed of sound in a complex
plasma under microgravity conditions. EPL (Europhysics Letters). December 2011;96(5):55001.
doi: 10.1209/0295-5075/96/55001.
Kretschmer M, Konopka U, Zhdanov SK, et al. Particles inside the void of a complex plasma. IEEE
Transactions on Plasma Science. November 2011;39(11):2758-2759. doi:
10.1109/TPS.2011.2135383.