Dusty Plasma under Microgravity Conditions: Experiments onboard Space Station MIR and ISS
- Paper number
IAC-07-A2.6.05
- Author
Prof. Vladimir Fortov, Institute for High Energy Densities, Russian Academy of Sciences, Russia
- Coauthor
Prof. Oleg Petrov, Joint Institute for High Temperatures of the Russian Academy of Sciences, Russia
- Coauthor
Dr. Olga Vaulina, Institute for High Energy Densities, Russian Academy of Sciences, Russia
- Coauthor
Dr. Vladimir Molotkov, Institute for High Energy Densities, Russian Academy of Sciences, Russia
- Coauthor
Mr. Andrey Lipaev, Institute for High Energy Densities, Russian Academy of Sciences, Russia
- Coauthor
Dr. Hubertus Thomas, Max-Planck-Institut for Extraterrestrial Physic, Germany
- Coauthor
Dr. Alexey Ivlev, Germany
- Coauthor
Mr. Nikolay Sevastiyanov, S.P. Korolev Rocket and Space Corporation Energia, Russia
- Coauthor
Mr. A. Ivanov, S.P. Korolev Rocket and Space Corporation Energia, Russia
- Coauthor
Prof. Gregor Morfill, Max-Planck-Institut for Extraterrestrial Physic, Germany
- Year
2007
- Abstract
The dusty plasma is a partly ionized gas that contains negatively or positively charged dust particles of micron size. The particles in the dusty plasma may form quasi-stationary plasma-dust structures similar to a liquid or a solid. Dusty plasma is affected by gravity, depending on the size of the solid particles gravity can be the dominating force. Under microgravity conditions in space much weaker forces become important and other new phenomena not achievable on Earth can be observed.
The experiments were performed in dusty plasma under ground bounded and microgravity conditions. The results of the experimental studies of the diffusion of dust, charged by a photoemission in microgravity conditions are presented. The data were obtained during investigations of dusty plasma induced by solar radiation (space station "Mir"), which shown that under action of intensive solar radiation the micron-size particles may acquire the considerable positive electric charges. The complex measurements of velocity distributions, temperatures, friction coefficient and diffusion constants of macroparticles in dusty plasma were carried out. The comparison of experimental data and theoretical estimates has shown that the dynamic behavior of macroparticles for t < 10-15 s was determined by process of the ambipolar diffusion.
The formation of ordered structures in DC discharge dusty plasma was also studied in microgravity experiments carried out aboard the Mir space station. Experiments were made in neon with pressure 2.0 Torr. The dust grains used in our experiments are bronze particles of 70-180 µm diameter. Pair correlation functions obtained revealed a short-distance order with a first maximum at 700 µm.
Effective structural and transport characteristics of the system of macroparticles in dusty plasma were measured in a set of experiments in RF gas-discharge plasmas in microgravity conditions on the board of International Space Station. A number of different phenomena were studied including self-excitation of dusty waves, formation of plasma crystal and plasma liquid regions, different vortices of charged dust grains. The experimental studies of the viscosity of a dust-plasma liquid were carried out. The results of analysis of the obtained data made it possible to estimate the coefficient of dynamic viscosity of a dust-plasma liquid. Results were given of experimental investigation of three-particle correlation for liquid plasma-dust structures. The obtained three-particle correlation functions for experimental and numerical data are analyzed and compared with the superposition approximation.
- Abstract document