Acta Technica 68. (1970)

1-2. szám - Bitó, J. F.: On the Time Dependence of the Parameters on the Cathode Side

J. F. BITÓ a half period. The field strength of the positive column changes, corre­sponding to the tube voltage. The time dependence of the anode fall corre­sponds as regards its character to the curve, describing the time dependence of the cathode fall [2]. For the sake of control we determined the momentary tube voltage of the discharge tube at a deliberately chosen time, and examined whether the result of our calculation coincided with the momentary tube voltage value to be gained experimentally, in an additive way. With the application of the connection Vrih) = VkÍH) + VA{h) + íp(<i) ‘ Ep{h)-> (1) where Fj-Oi) tube voltage in the moment t,; F/c(h) cathode fall in the moment q; Va(1i) ano<le fall in the moment q; lp(tj) length of the positive column in the moment q; Ep(fxf) ‘ef 1 strength of the positive column, measured in the moment q. As the measurements were extended, apart from the Faraday dark space to all discharge spaces, if they were right, then also the connection (1) must have been valid. According to the controls, performed at different times [1], the right side of the equation was, in general, by 0,5 —1,5 V less than the tube voltage. This was attributed to the neglected transient spaces and to the inaccuracy in the measurement. With the aid of a stroboscopic measurement [1] it would be shown that the boundaries of the cathode spaces were not constant, further we have taken the time dependence of the axial dimension of the two cathode spaces, characteristic for the arc discharges with oxide coated cathodes. The results are shown in Fig. 1. l [mm] Fig. 1. The time dependence of the axial length of the cathode light and of the Faraday dark space with (............) and without ( _ ) auxiliary electrodes (1 Faraday dark space, 2 cathode light; l* anodic half period) Acta Technica Academiae Scientiarum Hungaricae 68, 1970

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