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涂氧化物阴极由于其在低工作温度下具有高发射效率而被广泛应用于电子管中。由于焦耳效应造成的打火或过热限制,氧化物阴极的直流发射最大极限考虑为0.5安/厘米~2。在1000°K的工作温度及从1.0至4.0安/厘米~2电流密度的情况下,我们成功地实验了具有相当长寿命的氧化物阴极。在平板二极管和三极管中进行了不同类型的氧化物阴极实验。发现,三极管中氧化物阴极的工作极限远比二极管中苛刻得多。进行了直流大电流密度二极管实验,同时,在直流、高频及脉冲条件下完成了三极管实验。在二极管中进行的大电流密度氧化物阴极实验表明,当前采用的阴极材料的某些极限仅大于4.0安/厘米~2。在目前阴极材料的极限为2.0安/厘米~2的三极管中出现了一些有趣的效应。由很小的极间距离造成的栅极过载及聚束效应产生了阳极表面的侵入作用及阴极污染。试验了各种栅极材料并对其结果进行了比较。在约为1.0安/厘米~2的平均电流密度下进行了大功率高频振荡器的三极管实验。在此工作模式中,栅极的设计及其材料是限制因素。在此模式中,栅极材料的蒸发可能使管子受到突然的严重破坏。在高频工作期间,沉积在绝缘子上的栅极材料使管子破裂。对实验进行的讨论表明,通过适当地选择材料可以避免产生此种结果。
Oxide cathodes are widely used in electron tubes due to their high emission efficiency at low operating temperatures. Due to the sparking or overheating limitation caused by the Joule effect, the maximum DC emission limit of the oxide cathode is considered to be 0.5 A / cm2. With an operating temperature of 1000 ° K and from 1.0 to 4.0 Amps / cm 2 current density, we succeeded in experimenting with oxide cathodes that have a relatively long lifetime. Different types of oxide cathode experiments were conducted in flat-panel diodes and triodes. Found that the working limit of the oxide cathode in the transistor is far more demanding than the diode. Conducted a DC high current density diode experiment, at the same time, in the DC, high frequency and pulse conditions completed triode experiments. High current density oxide cathode experiments conducted in diodes indicate that some of the limits currently used for cathode materials are only greater than 4.0 A / cm2. In the current cathode material limit of 2.0A / cm ~ 2 transistor has some interesting effects. The gate overloading and the focusing effect caused by the very small inter-electrode distance create the intrusion of the anode surface and the cathode pollution. Various gate materials were tested and their results were compared. Transistor experiments of high power high frequency oscillators were performed at an average current density of about 1.0 A / cm 2. In this mode of operation, the design of the gate and its material are the limiting factors. In this mode, evaporation of the gate material can expose the tube to sudden severe damage. During high-frequency operation, the gate material deposited on the insulator ruptures the tube. The discussion of the experiment shows that such a result can be avoided by proper selection of materials.