SEARCH-PK-3-2
Search-PK-3-2 conducts baseline experiments in the Plazmenniy Kristall 3 Plus science unit in
which the parameters for plasma containing particles vary throughout virtually the entire
range.
EARTH BENEFITS
The experiment has great importance for fundamental science, because microgravity opens up
possibilities for discovering entirely new effects in plasma with charged solid macroparticles.
RESULTS
MACH CONES-PK
The effectiveness of directly measuring the speed of sound in a 3-D plasma dust system was
demonstrated by measuring the mach angle that comprises the half-angle of the mach cone
solution. The speed of the large particle exceeded 35 mm/s. The speed of sound measured was
20-30 mm/s, ie, the large particle traveled in supersonic mode at a mach number ranging from
2.8-1.3.
PROJECTILE-PK
Trajectories of small particles were studied in detail and a theory of their motion was
developed based on hydrodynamic
approximation. A comparison of the particle
trajectories calculated on the basis of a
classical solution with those obtained in the
experiment demonstrates that motion of
dust particles corresponds to the case of
their non-viscous flow of a spherical Wigner-
Seitz cell around a large particle in which the
transfer of impulse moment between the
environment and the outflowing medium
did not occur. This situation explained the
effect of drag force disappearing from the
dust crystal.
PHASE TRANSITIONS-PK-1
The phase transition isotropic medium-chain
structure in ER plasma was studied in
microgravity. Particles remained in a
disordered liquid phase while the amplitude
of the alternating field applied was lower
than a given threshold. The subsequent
increase of the field led to a reorganization of the particles. The particles became more and
more ordered until well-defined chains along the field were formed. The transition between
isotropic and chain liquid states was entirely reversible; a decrease in the field returned the
particles back to an isotropic state.
Photograph of the dust particle cloud obtained with a
quadrant camera with a field of view of 35.7х26.0 mm.
On the left, a short path is observed in the large
particle’s leading edge section in the dust cloud. As can
be seen in the photograph, the movement of the
particle is accompanied by the appearance of a Mach
cone. The cones shown in the figure were obtained by
superimposing two sequential video footage frames. It
is clear that the projection of the double cone on the
plane deviates somewhat from the straight lines.
Roscosmos image.