Advances in high power CW traveling-wave tubes

Progress is reported on the use of beryllia heat sinks in ring and bar traveling-wave tubes, and on the practical application of collector voltage depression for efficiency enhancement in high power CW tubes. A ring and bar traveling-wave tube has been developed which gives a CW power output of more than 6 kw in the 6 GHz band, with a large-signal gain of 30 dB and a power bandwidth to 1 dB points of 10%. The slow wave structure is machined from high conductivity copper tube and brazed to beryllia posts which provide good thermal connection to a water-cooled copper jacket. Particular care has been taken in the design to combine good mechanical reproducibility with ease of construction and to minimize circuit mismatches. The tube has a new electromagnet which gives excellent beam transmission, with low power consumption and convenience in handling.