Electric discharge
A-D dark discharge
A-B: non-self-sustaining discharge and collection of spontaneously generated ions.
B-D: theTownsend region,where the cascade multiplication ofcarrierstakes place.
D-Iglow discharge
D-E: transition to a glow discharge, breakdown of the gas.
E-G: transition to a normal glow; in the regions around G, voltage is nearly constant for varying current.
G-I: represents abnormal glow, as current density rises
I-Karc discharge.
Inelectromagnetism,anelectric dischargeis the release and transmission of electricity in an appliedelectric fieldthrough a medium such as agas(i.e., an outgoing flow ofelectric currentthrough a non-metalmedium).[1]
Applications
[edit]The properties and effects of electric discharges are useful over a wide range of magnitudes. Tiny pulses of current are used to detectionizing radiationin aGeiger–Müller tube.A low steady current can illustrate the gas spectrum in agas-filled tube.Aneon lampis an example of agas-discharge lamp,useful both for illumination and as avoltage regulator.Aflashtubegenerates a short pulse of intense light useful forphotographyby sending a heavy current through a gas arc discharge.Corona dischargesare used inphotocopiers.
Electric discharges can convey substantial energy to the electrodes at the ends of the discharge. Aspark gapis used in internal combustion engines to ignite the fuel/air mixture on every power stroke. Spark gaps are also used to switch heavy currents in aMarx generatorand to protect electrical apparatus. Inelectric discharge machining,multiple tiny electric arcs erode a conductive workpiece to a finished shape.Arc weldingis used to assemble heavy steel structures, where the base metal is heated to melting by the arc's heat. Anelectric arc furnacesustains arc currents of tens of thousands of amperes and is used for steelmaking and the production of alloys and other products.
Examples
[edit]Examples of electric discharge phenomena include:
- Brush discharge
- Dielectric barrier discharge
- Corona discharge
- Electric glow discharge
- Electric arc
- Electrostatic discharge
- Electric discharge in gases
- Leader (spark)
- Partial discharge
- Streamer discharge
- Vacuum arc
- Townsend discharge
- St. Elmo's fire
- Lightning
- Electric organ
See also
[edit]References
[edit]- ^American Geophysical Union, National Research Council (U.S.). Geophysics Study Committee (1986)The earth's electrical environment.National Academy Press, Washington, DC, p. 263.ISBN9780309036801
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