TY - JOUR AU - Zhukhovitskii, D. I. AU - Fortov, V. E. AU - Molotkov, V. I. AU - Lipaev, A. M. AU - Naumkin, V. N. AU - Thomas, H. M. AU - Ivlev, A. V. AU - Morfill, G. E. PY - 2018/10/19 Y2 - 2024/03/29 TI - Subsonic Motion of a Projectile in a Fluid Complex Plasma under Microgravity Conditions JF - Ukrainian Journal of Physics JA - Ukr. J. Phys. VL - 59 IS - 4 SE - Plasmas and gases DO - 10.15407/ujpe59.04.0385 UR - https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2018458 SP - 385 AB - <p>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 a-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.</p> ER -