PLASMA CRYSTAL EXPERIMENT – NEFEDOV (PKE-NEFEDOV)
Research Area: Plasma Physics
Expedition(s): 1-11
Principal Investigator(s): ● Gregor Morfill, Max Planck Institute for Extraterrestrial Physics,
Garching, Germany
● Vladimir E. Fortov, the Russian Academy of Sciences, Moscow,
Russia
RESEARCH OBJECTIVES
PKE-Nefedov is designed for long-term investigations
of complex plasmas in weightlessness. Complex
plasmas contain ions, electrons, neutral atoms (or
molecules), and small solid particles normally in the
micrometer range. These microparticles attract
thousands of elementary charges in the plasma and
interact with each other via a screened Coulomb
potential. Complex plasmas are of special interest
because they can behave as liquid and crystalline
states and are observable at the kinetic level. Thus,
they form a new model system for strongly coupled
states.RESULTS
During the 4.5 years of operation of the PKE-
Nefedov laboratory on the International Space
Station, 45 successful complex plasma experiment
sessions in microgravity (typically 90 min each)
were completed. The scientific outcome was very
broad and fundamental. It covered many aspects of
physics, like solid state and fluid physics, wave
phenomena, physics of binary systems, particle
growth, decharging of particles in the afterglow
plasma, coagulation of charged particles in a neutral
gas, additional to pure complex plasma
phenomena like the study of the ion drag force and
the void formation. The scientific yield counts more
than 30 publications in international journals.
PUBLICATION(S)
Ivlev AV, Kretschmer M, Rubin-Zuzic M, et al. Decharging of complex plasmas: First kinetic
observations. Physical Review Letters. February 2003;90(5):055003. doi:
10.1103/PhysRevLett.90.055003.
Arrival of PKE-Nefedov aboard the International
Space Station. NASA image.Side view of a plasma crystal in the laboratory.
Dust particles are suspended in an argon plasma
above a high-frequency electrode (bottom). The
horizontal field of view is 2 cm. Max Planck
Institute for Extraterrestrial Physics image.