Recovery of vacuum gaps after arcing

Technical Report · Thu Jun 11 04:00:00 EDT 1987

DOI:https://doi.org/10.2172/6348304· OSTI ID:6348304

Miller, H C

This paper reviews the recovery of vacuum gaps: i.e., the return of the voltage holdoff capability of a vacuum gap after it has ceased to sustain a vacuum arc. After a brief description of vacuum arcs, the paper discusses cathode and anode arc phenomena as they affect recovery. Finally, various experimental results pertinent to recovery are presented and discussed. During conduction a vacuum gap contains electrons, ions, neutral atoms (vapor), and macroparticles of electrode material. At current zero the production of electrons, ions, and macroparticles ceases immediately. If an anode spot is present it will take tens of microseconds to milliseconds for significant production of neutral vapor to cease; the time depending upon the rate at which the anode spot cools, which in turn depends upon the anode material and upon the size and depth of the anode spot at current zero. Early recovery is controlled by ions, later recovery by neutral atoms. The ultimate recovery voltage is a function of electrode surface properties. Magnetic fields may be used to promote recovery by helping to clear the vacuum gap of ions and electrons and by preventing the formation of anode spots or moving them before current zero. The most important requirement in obtaining the fastest recovery times is to design the vacuum gap to avoid the formation of anode spots, thus insuring that only cathode recovery phenomena are significant. 60 refs., 6 figs., 5 tabs.

• Research Organization: General Electric Co., Largo, FL (USA). Neutron Devices Dept.
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-76DP00656
• OSTI ID: 6348304
• Report Number(s): GEPP-TIS-963A; ON: DE87013852
• Country of Publication: United States
• Language: English

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CURRENTS
DATA
ELECTRIC ARCS
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
ELECTRICAL EQUIPMENT
EQUIPMENT
EXPERIMENTAL DATA
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