Accession Number : AD0710838

Title :   UEBER DIE KATHODISCHE VERDAMPFUNG IN FUNKENENTLADUNGEN (On the Cathode Vaporization in Spark Discharges),

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V STUTTGART-VAIHINGEN (WEST GERMANY)

Personal Author(s) : Mailaender,Martin ; Krauss,Lutz

Report Date : 13 DEC 1969

Pagination or Media Count : 9

Abstract : By means of current measurements and time-resolved intensity measurements of a spectral line of the electrode material in a spark discharge it is possible to put up a differential equation which connects mutually intensity and current. The selection of an appropriate spectral line was done under the point of view that its intensity is proportional to the vaporization rate of the electrodes. Generally this is the case if the normalized temperature of the line is equal to the temperature of the spark axis, which varies only slowly. The differential equation and its integral are in good agreement with the experimental results, which are based on the following measurements: the time-intensity curve of a certain line, the time of maximum intensity and the maximum intensity in dependence on frequency, the modulation and phase of the intensity curve, the total intensity (time integral). These results yield a model for the vaporization of the electrode surface: the cathode spot of the spark starts at an arbitrary point of the surface, heats it up to boiling temperature and moves on to the adjacent area element, until boiling temperature is reached too, and so on. During the anode phase of the electrode and after the end of the current flow the vaporization decreases with a time constant which is independent of the discharge parameters but dependent on the electrode material.

Descriptors :   (*ELECTRIC DISCHARGES, CATHODES), (*CATHODES, VAPORIZATION), ELECTRIC CURRENTS, INTENSITY, DIFFERENTIAL EQUATIONS, WEST GERMANY

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE