Space station crew helps scientists analyze complex plasmas

Aug. 7 (UPI) -- Experiments carried out on the International Space Station are helping scientists better understand how dust particles behave inside complex plasmas.

In addition to electrons, ions and gas atoms, complex plasmas, or dusty plasmas, contain an array of microparticles, including dust grains. Inside the plasma, these particles become highly charged and interact with one another in unusual ways, sometimes behaving like liquid or crystalline molecules.

Scientists are keen to better understand the behavior of microparticles in plasma, but gravity distorts plasma experiments on Earth.

On the space station, under microgravity conditions, European Space Station astronauts and Roscosmos cosmonauts trapped a microparticle cloud in plasma before allowing the cloud to drift -- all while being supplied with a constant direct current. Scientists observed the cloud as it formed self-excited wave patterns.

After being allowed to drift, the experimenters reversed the polarity of the current. The experiment results revealed a bifurcation in the wave patterns in response to the flipped discharge.

"The most interesting finding was the velocity of these waves strongly depends on the electric field, which is exciting the waves," Mikhail Pustylnik, a researcher at the German Aerospace Center's Institute of Materials Physics, said in a news release. "We expect to encounter these types of waves in astrophysical situations where you might have dust -- in a cometary tail, for example."

Scientists hope the findings, detailed this week in the journal Physics of Plasmas, will help astronomers, cosmologists and planetary scientists better understand a variety of phenomena.

The research could also fuel breakthroughs in advanced electronics.

"Many plasma processes are also used in the semiconductor industry," Pustylnik said.

Dust particles can damage silicon wafers during manufacturing. By switching the polarity of the electric discharge surrounding a silicon wafer, researchers could potentially protect the technology from interfering microparticles.