High voltage breakdown phenomena in RF window, electron gun and RF cavities in 250 kW CW C band klystron and their preventive measures

The paper describes voltage break down phenomenon and preventive measures in components of 250 KW CW, C band klystron under development at CEERI Pilani. The klystron operates at a beam voltage of 50 kV and delivers 250 kW RF power at 5GHz frequency. The klystron consists of several key components and regions, which are subject to high electrical stress. The most important regions of electrical breakdown are electron gun, the RF ceramic window and output cavity gap area. In the critical components voltage breakdown considered at design stage by proper gap and other techniques. All these problems discussed, as well as solution to alleviate this problem. The electron gun consists basically of cathode, BFE and anode. The cathode is operated at a voltage of 50 kV. In order to maintain the voltage standoff between cathode and anode a high voltage alumina seal and RF window have been designed developed and successfully used in the tube.