Instabilities of prebreakdown currents in vacuum I: late breakdowns
| Autor: | B. Juttner, M. Lindmayer, Gerd Düning |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Acoustics and Ultrasonics
Chemistry business.industry Time constant Electron Plasma Condensed Matter Physics Cathode Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Optics law Deposition (phase transition) Breakdown voltage Particle Transient (oscillation) Atomic physics business |
| Zdroj: | Journal of Physics D: Applied Physics. 32:2537-2543 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/0022-3727/32/19/310 |
| Popis: | Prebreakdown electron emission between extended metal electrodes is experimentally studied with time resolution of 100 ns. Switching to higher emission levels is observed and could be provoked by mechanical shocks. This is found to be analogous to spontaneous switching effects. Elementary time constants of current jumps are 1-3 µs while the whole switching process lasts up to 40 ms, thus ruling out impact of macroparticles. The breakdown voltage is found to be correlated with the emission level. Therefore, switching on electron emission can explain breakdowns with delay times >1 ms. Still longer times are found at the deposition of metal vapour plasma originating from neighbouring arc gaps. In some cases, transient increases of the emission occur that last several seconds. Therefore, in vacuum interrupters late breakdowns after current zero can be caused by mechanical shocks without particle impact and also by deposition of residual vapour at the cathode. |
| Databáze: | OpenAIRE |
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