By a News Reporter-Staff News Editor at Journal of Technology -- Investigators discuss new findings in Plasma Science. According to news reporting originating from Madrid, Spain, by VerticalNews correspondents, research stated, "BETs is a three-year project financed by the Space Program of the European Commission, aimed at developing an efficient deorbit system that could be carried on board any future satellite launched into Low Earth Orbit (LEO). The operational system involves a conductive tape-tether left bare to establish anodic contact with the ambient plasma as a giant Langmuir probe."
Our news editors obtained a quote from the research from Madrid Polytechnic University, "As a part of this project, we are carrying out both numerical and experimental approaches to estimate the collected current by the positive part of the tether. This paper deals with experimental measurements performed in the IONospheric Atmosphere Simulator (JONAS) plasma chamber of the Onera-Space Environment Department. The JONAS facility is a 9-m(3) vacuum chamber equipped with a plasma source providing drifting plasma simulating LEO conditions in terms of density and temperature. A thin metallic cylinder, simulating the tether, is set inside the chamber and polarized up to 1000 V. The Earth's magnetic field is neutralized inside the chamber. In a first time, tether collected current versus tether polarization is measured for different plasma source energies and densities. In complement, several types of Langmuir probes are used at the same location to allow the extraction of both ion densities and electron parameters by computer modeling (classical Langmuir probe characteristics are not accurate enough in the present situation). These two measurements permit estimation of the discrepancies between the theoretical collection laws, orbital motion limited law in particular, and the experimental data in LEO-like conditions without magnetic fields. In a second time, the spatial variations and the time evolutions of the plasma properties around the tether are investigated. Spherical and emissive Langmuir probes are also used for a more extensive characterization of the plasma in space and time dependent analysis. Results show the ion depletion because of the wake effect and the accumulation of ions upstream of the tether."
According to the news editors, the research concluded: "In some regimes (at large positive potential), oscillations are observed on the tether collected current and on Langmuir probe collected current in specific sites."
For more information on this research see: Drifting Plasma Collection by a Positive Biased Tether Wire in LEO-Like Plasma Conditions: Current Measurement and Plasma Diagnostic. IEEE Transactions on Plasma Science, 2013;41(12):3380-3386. IEEE Transactions on Plasma Science can be contacted at: Ieee-Inst Electrical Electronics Engineers Inc, 445 Hoes Lane, Piscataway, NJ 08855-4141, USA. (Institute of Electrical and Electronics Engineers - www.ieee.org/; IEEE Transactions on Plasma Science - ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=27)
The news editors report that additional information may be obtained by contacting J.M. Siguier, Madrid Polytechnic University, E-28040 Madrid, Spain. Additional authors for this research include P. Sarrailh, J.F. Roussel, V. Inguimbert, G. Murat and J. SanMartin.
Keywords for this news article include: Spain, Madrid, Europe, Plasma Science
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