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The retrograde motion of arc cathode spots in vacuum
| Content Provider | Scilit |
|---|---|
| Author | Jüttner, Burkhard Kleberg, Ingmar |
| Copyright Year | 2000 |
| Description | Journal: Journal of Physics D: Applied Physics Experiments are reported on the retrograde arc spot motion on copper and tantalum cathodes in vacuum in the presence of a magnetic field. The spots are imaged with time and space resolutions of <100 ns and <10 µm, respectively. The magnetic flux density amounted to B = 0.4 T and the arc currents to 2-100 A. For times <1 µs random displacement occurs on a time scale <100 ns. At intervals of about 4 µs, jumps of the spot are observed over distances of 50-300 µm in the retrograde direction, thus yielding macroscopic velocities of about 50 m $s^{-1}$. The jumps are preceded by the ejection of plasma jets in the retrograde direction, having average velocities of about v = 5 km $s^{-1}$. New spots are formed exactly in the jet direction. The jets are explained by instabilities in the magnetically confined spot plasma, and the spot formation by electric fields = × within the jets. The jets are ejected in periods of enhanced plasma production caused by the inner spot processes, i.e., by the dynamics of fragments and cells, having diameters of ≤20 and ≤10 µm, respectively. No reversal of the motion has been observed at elevated temperatures up to 2100 K. |
| Related Links | http://iopscience.iop.org/article/10.1088/0022-3727/33/16/315/pdf |
| Ending Page | 2036 |
| Page Count | 12 |
| Starting Page | 2025 |
| ISSN | 00223727 |
| e-ISSN | 13616463 |
| DOI | 10.1088/0022-3727/33/16/315 |
| Journal | Journal of Physics D: Applied Physics |
| Issue Number | 16 |
| Volume Number | 33 |
| Language | English |
| Publisher | IOP Publishing |
| Publisher Date | 2000-08-07 |
| Access Restriction | Open |
| Subject Keyword | Journal: Journal of Physics D: Applied Physics Astronomy and Astrophysics Magnetic Field Electric Field |
| Content Type | Text |
| Resource Type | Article |
| Subject | Surfaces, Coatings and Films Acoustics and Ultrasonics Condensed Matter Physics Electronic, Optical and Magnetic Materials |
