Plasma Experiments Anniversary

Anniversary for plasma experiments

Small anniversary on the ISS: These days the 25 series of experiments run for the Physics of Complex Plasmas on the International Space Station. The experimental facility has also now get a place in the new Russian module Poisk research that had docked to the ISS in November last year.

The newest addition to the ISS, the Russian module MIM-2, called “Poisk” (search). It is now the experiment facility housed PK-3 Plus for the study of complex plasmas. Photo: NASA

From 27 to 29 January 2010, the Russian cosmonaut Oleg Kotov starts the 25 series of experiments on the physics of complex plasmas on the International Space Station. The German Aerospace Center (DLR) has financially supported both the development of the experimental equipment and research. For the anniversary, the plasma experimental facility PK-3 Plus from their previous place between the Russian station parts Zarya and Zvezda in the small Russian research module MIM-2 with the name Poisk (Search) is moved, which is docked to the ISS since November 2009. Therefore the operating time of PK-3 Plus has been extended by two years until the end of 2011 at the same time.

At its old place had PK-3 Plus as well as the previous PKE-Nefedov knew the 2001–2005 their service on the ISS are degraded and tucked between the series of experiments. With the move to the new ISS module, the experimental setup has found a permanent home on the space station after five years of operation. This saves valuable future Cosmonaut time. Time that can be invested in research and science. The wear parts of the plant, such as hoses, fasteners and connections are protected by the permanent installation. Each year, scientists regularly lead by two to three series of experiments.

Plasmas are electrically charged gases and apply in addition to solid, liquid and gas as the fourth, the ungeordnetste state of matter. They are the stuff consist of the lightning and auroras. In our daily lives, they have plasma lamps and fluorescent glow. Complex plasmas containing plasmas, in contrast to simple addition dust particles. In the experiments, the ISS, the plasma is an inert gas, argon or neon, in an electric field generated between two electrodes.

In this particles are injected plastic, having only a few microns in diameter. The particle load in the plasma of the same sign. Their effort, then take the greatest possible distance from each other, leading to their structural order up to the formation of a crystal structure similar to that of many metals and is referred to as “plasma crystal”. By changing the electric field and the gas pressure in the plasma chamber, the scientists can melt and solidify the plasma crystal and investigate such aggregate transitions.

The special feature here is that such transactions are much slower than “normal” substances and the change in position of each dust particle can be tracked with the camera. Scientists look directly into the matter. So they can observe, among other things, the interaction between the particles in the propagation of waves, turbulent flows and the segregation of different types of particles. The need for large three-dimensional, complex plasmas can be realized only in weightlessness. For under the influence of Earth’s gravity drop the dust down, and the complex plasma forms only a thin layer. From the scientific data obtained in microgravity more than 40 internationally recognized publications in scientific journals have emerged to date.

With the microgravity experiments could be shown that complex plasmas the class of soft matter can be assigned. These include colloids, gels and granules. They consist of molecules, particles, droplets or bubbles in the millimeter to nanometer range, which are dispersed in a liquid or a gas. In everyday life, soft matter meets us everywhere: milk, foam, toothpaste and sand are also included. Common is that they are like a solid or a liquid can behave. Sand, for example, flow like water in a vessel and take the form, but a large heavy stone lying on sand as on a solid surface and does not sink in. The physics of soft matter and especially the predictability of properties for the development of designer materials are therefore highly relevant for many industries.

From the development of devices for space and the experiments a very interesting spin-off for the medicine has shown, namely the development of the so-called “plasma torch”. This is a small medical device that can be created with the cold plasmas for sterilization and treatment of chronic, antibiotic-resistant wounds. It is already being tested in a clinical study of more than 100 patients.

Each series of experiments for the Physics of Complex Plasmas typically contains about three 90-minute experiment runs that are performed on three consecutive days. Developed and conducted the research program of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching and the Institute for High Energy Densities is (JIHT) of the Russian Academy of Sciences in Moscow.