Acta Physica Academiae Scientiarum Hungaricae 13. (1961)

1960 / 3. szám - G. Lakatos - J. Bitó: Time Dependence of Some Parameters of A. C. Discharges

2 TIME DEPENDENCE OF SOME PARAMETERS OF A. C. DISCHARGES* By G. Lakatos and J. Bitó INDUSTRIAL RESEARCH INSTITUTE FOR TELECOMMUNICATION TECHNIQUE, BUDAPEST (Presented by G. Szigeti. — Received 21. II. 1961) The time dependence of the various discharge parameters in a hot-cathode a. c. low pressure mercury vapour argon discharge was investigated. The authors applied Fajt and Koncz’s a. c. probe measurement method based on the Langmuir probe theorem. They describe the time dependence of the field strength, electron temperature, electron concentration, recombination velocity, cathode- and anode-fall. In the experiments the cathode was not heated by any external source. Introduction The plasma of the low pressure, d. c. gas discharge has often been examined by means of the Langmuir probe measuring principle [1] in mercury vapour and in a mixture of mercury vapour and argon [2]. Langmuir’s method has been used by some workers also in case of an a. c. gas discharge [3, 4, 5]. The authors examined the time dependence of some parameters of the a. c. gas discharge in a mixture of mercury vapour and argon of 3 mm Hg pressure, at an ambient temperature of 22,5—24 °C. In all measurements an oxide-coated cathode was used which was heated by the discharge only, no external heating being applied. From the probe characteristics they obtained the time dependence of the axial field strength, the electron temperature, the electron concentration, the recombination velocity and the cathode- and anode-fall. Measuring method and arrangement Langmuir [1] obtained in case of an increasing probe-potential an increasing electron current on the probe, according to the equation: ie = 1/4 • e ■ ne vef ■ exp eV(1) * A report on research conducted under contract with the United Incandescent Lamp and Electrical Co. Ltd. Acta Phys. Hung. Тот. XIII. Fasc. 3.

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