(一) 引言所有的电子管都要在高度的真空下,阴极发射的电子才能在各个电极电场作用下进行正常的运动。若因某种因素使真空度下降,则管子性能就变差,甚至失效了。值得注意的是,管内真空度的高低即管内气体动态平衡,不仅仅决定于排气最后封离时的真空度,而且和各个电极零件(尤其是阳极、二栅)所用的材料和它们的处理工艺(清洗、 (A) Introduction All of the tubes must be in a high degree of vacuum, the cathode emits electrons in the electrode under the action of the normal electric field. If some factor to reduce the degree of vacuum, the tube performance will deteriorate, or even failure. It is worth noting that the level of vacuum in the tube, ie, the dynamic balance of the gas in the tube, depends not only on the degree of vacuum at the final seal of the exhaust gas but also on the material used for the individual electrode parts, especially the anode and secondary grids, and their treatment Technology (cleaning,