0372-400Х (Edition in Ukrainian)
2071-0186 (Edition in English)
2071-0194 (in electronic form)
Abbreviated key title: Ukr. J. Phys.
Current issue Ukr. J. Phys. 2014, Vol. 59, N 4, p.385-395
Zhukhovitskii D.I.1, Fortov V.E.1, Molotkov V.I.1, Lipaev A.M.1, Naumkin V.N.1, Thomas H.M.2, Ivlev A.V.2, Morfill G.E.2
1 Joint Institute of High Temperatures, Russian Academy of Sciences
(Bd. 2, 13, Izhorskaya Str., Moscow 125412, Russia; e-mail: email@example.com)
2 Max-Planck-Institut f¨ur Extraterrestrische Physik
(Giessenbachstrasse, 85748 Garching, Germany)
Subsonic Motion of Projectile in a Fluid Complex Plasma under Microgravity Conditions
Section: Plasmas and gases
Abstract: Subsonic motion of a large particle moving through the bulk of a dust crystal formed by negatively charged small particles is investigated, by using the PK-3 Plus laboratory on the board of the International Space Station. Tracing the particle trajectories shows that the large particle moves almost freely through the bulk of a plasma crystal, while dust particles move along characteristic α-shaped pathways near the large particle. We develop a theory of the nonviscous motion of dust particles near a large particle and calculate particle trajectories. The deformation of a cavity around a large projectile moving with subsonic velocity in the cloud of small dust particles is investigated with a due regard for the friction between dust particles and atoms of a neutral gas. The pressure of a dust cloud at the surface of a cavity around the projectile can become negative, which entails the emergence of a considerable asymmetry of the cavity, i.e., the cavity deformation. The corresponding threshold velocity is calculated, which is found to decrease with increasing the cavity size. A good agreement with experiment validates our approach.
Key words: dusty plasma, plasma crystal, nonviscous motion, cavity deformation.