一、引言约在1905年,Wehuelt首先发现阴极“中间层”的存在. 由于中间层的导电性能比阴极氧化物涂层导电性能差得多,在1100°K时,Ba_2SiO_4中间层导电率比涂层要小约10~3倍以上,因此造成电子管参数变化和工作点的偏移,产生负反馈.当工作于脉冲态时,发现脉冲电流衰落以及产生火花现象.1952年,W.W.Lindemann和A.Van der Ziel等逐渐新发现中 I. INTRODUCTION Wehuelt first discovered the presence of a cathode “middle layer” in about 1905. Since the conductivity of the middle layer is much worse than that of the cathode oxide coating, the conductivity of the Ba 2 SiO 4 interlayer at 1100 ° K Layer about 10 to 3 times smaller, resulting in changes in the parameters of the tube and the work point of the offset, resulting in negative feedback when working in the pulse state, the pulse current fading and sparks found in 1952, WWLindemann and A. Van der Ziel, etc. gradually new discovery