1. Measurement of the speed of sound by observation of the Mach cones in a complex plasma under microgravity conditions
- Author
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Andrey M. Lipaev, V. N. Naumkin, Mierk Schwabe, D. I. Zhukhovitskii, Vladimir E. Fortov, Hubertus M. Thomas, Alexei V. Ivlev, Gregor Morfill, and Vladimir Molotkov
- Subjects
Physics ,soft matter ,Projectile ,ISS ,Buffer gas ,FOS: Physical sciences ,chemistry.chemical_element ,Mechanics ,Acoustic wave ,Plasma ,Condensed Matter Physics ,microgravity ,Physics - Plasma Physics ,Plasma Physics (physics.plasm-ph) ,Discontinuity (linguistics) ,symbols.namesake ,Neon ,Mach number ,chemistry ,Physics::Plasma Physics ,Speed of sound ,symbols ,plasma crystal ,Forschungsgruppe Komplexe Plasmen ,complex plasma - Abstract
We report the first observation of the Mach cones excited by a larger microparticle (projectile) moving through a cloud of smaller microparticles (dust) in a complex plasma with neon as a buffer gas under microgravity conditions. A collective motion of the dust particles occurs as propagation of the contact discontinuity. The corresponding speed of sound was measured by a special method of the Mach cone visualization. The measurement results are incompatible with the theory of ion acoustic waves. The estimate for the pressure in a strongly coupled Coulomb system and a scaling law for the complex plasma make it possible to derive an evaluation for the speed of sound, which is in a reasonable agreement with the experiments in complex plasmas., 5 pages, 2 figures, 1 table
- Published
- 2015