Stability of a dust cloud in the radio frequency low-pressure gas discharge
V. N. Naumkin, D. I. Zhukhovitskii, A. M. Lipaev, A. V. Zobnin, A. D. Usachev, O. F. Petrov, H. M. Thomas, M. H. Thoma, O. I. Skripochka, and A. A. Ivanishin
Joint Institute of High Temperatures, Russian Academy of Sciences, Izhorskaya ul. 13, Bd. 2, Moscow, 125412 Russia
Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow Region 141700, Russia
Institut für Materialphsyik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Münchener Str. 20, 82234 Weßling, Germany
Physikalisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany
Gagarin Research and Test Cosmonaut Training Center, Star City, Moscow Region 141160, Russia
Abstract—We report observation of the dust ionization waves (DIWs) excited by an external oscillating electric field on the Plasma Kristall-4 facility under microgravity conditions. It is shown that at the smallest excitation amplitude, the waves are linear, and the dispersion relation can be
deduced from the experimental data. The microparticle oscillations are represented as a superposition of two longitudinal waves propagating
in the opposite directions. In the investigated range of excitation frequency, the wavenumber is not directly proportional to the frequency,
and the phase velocity is almost proportional to the frequency. We propose an interpretation of DIW assuming that the microparticle effect
on the recombination rate rather than the microparticle subsystem compressibility is responsible for the wave propagation. The calculated
phase velocity of DIW is compatible with the experimental one.