PHASE TRANSITIONS-PK-2
For Phase Transitions-PK-2, 3.4-micron particles penetrated the stable structure of large
particles and traveled to the center of the plasma chamber. During observations, it was
established that in the external area, when the speed of the penetrating particles was fairly
high, the penetration of the small particles resulted in the formation of chains. The large
particles also structured into chains and formed lanes. The formation of such structures is
observed in nature, when 2 streams of particles move towards each other under the impact of
a certain force. The phenomenon observed was a non-equilibrium transition, and was
dependent upon the specific characteristics and dynamics of the particle interaction. It is of
interest for various fields of physics. With experiments involving dust plasma in microgravity, it
is possible to enable the movement of individual particles and study the dynamics of the
transition.
PHASE TRANSITION-PK-3
The increase in distance
between particles (ie, the
decrease in density of the
dust component) was the
main factor responsible
for the fusion of the
plasma dust system with
the increase in pressure
of the inert gas. Similarly,
the decrease in pressure
resulted in compression
of the dust system and
stimulated crystallization. The interaction energy as a function of pressure was maximal with
the lowest pressure p ≈ 11 Pa for both of the plasma dust systems studied. The increase in inert
gas pressure resulted in the decrease in interaction energy between dust particles, as well as
the decrease in pressure of the gas causing an increase in interaction. An analysis of the phase
state of the plasma dust system observed (based on assessing the phase trajectories of the
system in an equilibrium phase diagram) showed that when pressure increases both systems
move in the direction of the fusion curve. The plasma dust system of small-size particles
crossed the phase border at high pressures.
CRYSTALLIZATION FRONT-PK
The formations of a crystallization front and domains with varying orientations were
discovered.
SEARCH-PK-3-2
In the PK-3 Plus unit, three ways of closing off an area free of microparticles were successfully
demonstrated, decreasing high frequency discharge power to the minimum possible level,
using a symmetrical flow of gas and effect of an external low-frequency electrical field.
Penetration of dust particles 3.4 microns in diameter into a structure of
particles 9.2 microns in diameter in an argon plasma at a pressure of 30
Pa. The formation of chains and lanes is visible. Frames were obtained
by superimposing sequential images: small particles are identified in the
form of long bands, and large particles appear as points. Roscosmos
image.