Arc initiation in cathodic arc plasma sources
Abstract
A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. Themore »
- Inventors:
-
- Albany, CA
- Issue Date:
- Research Org.:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- OSTI Identifier:
- 874809
- Patent Number(s):
- 6465793
- Assignee:
- The Regents of the University of California (Oakland, CA)
- Patent Classifications (CPCs):
-
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05H - PLASMA TECHNIQUE
- DOE Contract Number:
- AC03-76SF00098
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- initiation; cathodic; plasma; sources; triggerless; method; apparatus; based; simply; switching; supply; voltage; electrodes; anode; cathode; neither; mechanical; trigger; electrode; nor; flashover; required; conducting; path; provided; allows; hot; spot; form; location; connects; conductive; eroded; action; deposition; ensures; ongoing; repair; achieved; applying; power; 500; v-1; kv; insulator; coated; layer; current; layer-cathode; interface; concentrated; contact; local; density; sufficient; production; surface; graphite; material; deposited; formed; separates; mechanism; explosive; destruction; caused; joule; heating; flow; coating; occurs; power supply; current flow; surface layer; power density; joule heating; supply voltage; /250/
Citation Formats
Anders, Andre. Arc initiation in cathodic arc plasma sources. United States: N. p., 2002.
Web.
Anders, Andre. Arc initiation in cathodic arc plasma sources. United States.
Anders, Andre. Tue .
"Arc initiation in cathodic arc plasma sources". United States. https://www.osti.gov/servlets/purl/874809.
@article{osti_874809,
title = {Arc initiation in cathodic arc plasma sources},
author = {Anders, Andre},
abstractNote = {A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. The current flow between the thin insulator coating and cathode occurs at only a few contact points so the current density is high.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 2002},
month = {Tue Jan 01 00:00:00 EST 2002}
}