A high-sensibility cathode-ray tube for millimicrosecond transients

A high-sensibility cathode-ray tube has been developed for the photographic recording of transients in the millimicrosecond region. The new cathode-ray tube uses a traveling-wave deflection system with magnetic focusing and attains a spot diameter of 0.001 inch. The first models have a sensibility of 0.026 volt/trace width and a writing speed of 10
¹¹
trace widths/second. Improved production models are expected to have sensibilities of less than 0.02 volt/trace width. In this particular application, sensibility in volts per trace width and writing speed in trace widths per second are the significant performance characteristics. Analysis of the dependency of these on several important parameters in the general cathode-ray tube design shows that the use of a much smaller spot and display than is conventional results in large gains in sensibility. Analysis also indicates that maximum sensibility is achieved with the deflection plates located in the lens region. Magnetic focusing is used to permit this optimum deflection plate location. To allow the choice of long plates with short effective transit time, a traveling-wave deflection system is employed. Postdeflection acceleration is introduced to obtain high writing speeds.