A cathode-ray switch tube with 11 channels of electron multiplication

An 11-channel switch tube with 5 stages of electron multiplication has been developed. In some applications the switch tube will replace the camera-oscilloscope system for recording the rise times of electrical signals. This tube will be used to convert wide-band information from a single channel into eleven channels of lower bandwidth information which can be transmitted over standard telephone cables for telemetering operations. Venetian-blind dynodes are used for the multiplier structure. Each channel is defined by a pair of louvers on the dynode disk. U-shaped shields, which just straddle the louver edge of the preceding dynode, are used to minimize crosstalk. The channel width is 0.120 inch or a total length of 1.32 in for the 11 channels. The collector system provides a method for equalizing the gain of all the channels. The switch tube is 3 in in diameter and 24 in in length. Operating at a 4-kv beam potential with 2-µa beam current, the tube provides 20 ma of output current, with less than 5 per cent crosstalk to adjacent channels. The electron optics and the performance of the tube are described.