Measurement of the speed of sound by observation of the Mach cones in a complex plasma under microgravity conditions

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.

arXiv comment5 pages, 2 figures, 1 table

References in corpus (3)

• Freezing and melting of 3D complex plasma structures under microgravity conditions driven by neutral gas pressure manipulation
• Nonviscous motion of a slow particle in the dust crystal under microgravity conditions
• A scaling law for the dust cloud in radio frequency discharge under microgravity conditions

Cited by in corpus (6)

• Density distribution of a dust cloud in three-dimensional complex plasmas
• Dust acoustic waves in three-dimensional complex plasmas with a similarity property
• Interaction of a supersonic particle with a three-dimensional complex plasma
• Theory of a cavity around a large floating sphere in complex (dusty) plasma
• Penetration of a supersonic particle at the interface in a binary complex plasma
• Ionization equation of state for the dusty plasma including the effect of ion--atom collisions