Experimental Investigation of Dust Density Waves and Plasma Glow
| Autor: | O. Arp, K. O. Menzel, Alexander Piel, John Goree, D. Caliebe |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Physics
Nuclear and High Energy Physics Dusty plasma Brightness Number density Plasma Electron Condensed Matter Physics Ion Physics::Popular Physics Physics::Plasma Physics Excited state Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Atomic physics Astrophysics::Galaxy Astrophysics Excitation |
| Zdroj: | IEEE Transactions on Plasma Science. 38:842-846 |
| ISSN: | 1939-9375 0093-3813 |
| DOI: | 10.1109/tps.2009.2034312 |
| Popis: | Dust density waves (DDWs) are compressional modes that are often excited by subsonic ion flows in dusty plasmas. Previous experiments relying on imaging of only the dust revealed that they can propagate parallel to the ion flow direction or at an oblique angle. An experiment was performed using microgravity conditions on parabolic flights with video imaging of both the dust and the plasma glow. Glow arises from electron-impact excitation of neutral gas atoms, and it serves as a signature of energetic electrons. Averaging over time, it was found that the presence of dust enhances the glow brightness everywhere in the plasma. Resolving the time variation, a spontaneously excited DDW was observed at 3.9 Hz. It was characterized not only by a compression of the dust number density but also by a modulation of the glow intensity. The correlation between the wave and the glow is analyzed by Fourier methods. We found an unexpected phase relation between the plasma glow and the DDW of 118o. A glow maximum is followed by a dust density maximum. |
| Databáze: | OpenAIRE |
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