"A new high-sensibility cathode ray tube for millimicroseconds transients"

A high sensibility sealed display tube for the photographic recording of transients in the millimicrosecond region presents a specialized problem in CRT design. 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 CRT design shows that the use of a much smaller spot and display than is conventional results in large gains in sensibility and writing speeds. Analysis also indicates that maximum sensibility is achieved with the deflection plates located in the lens region. Magnetic focusing is used to permit this positioning. To allow the choice of long plates with short effective transit time, the traveling wave deflection system of Pierce is employed. Post acceleration is introduced to obtain high writing speeds. This adds a thick lens to the electron optical system which is not easily taken into account in a simple analysis. Its general effect, however, is to reduce deflection sensitivity and also spot size, where the latter is not already limited by the screen resolution. The new tube uses a traveling wave deflection system with a magnetic focusing and attains a spot diameter of .001". The field-tested research model had a sensibility of 0.05 volts/trace width and a writing speed of 10 trace widths/sec. The production models are expected to have sensibilities of 0.02 volts/trace width due largely to improvements in the post acceleration system.