A barrier-grid tube for binary digital storage

An improved electrostatically focused and deflected barrier-grid tube for high speed random access binary digital storage is reported. The tube has a high resolution electron gun incorporating a dual focus lens and dual interdeflection plate shields. The barrier-grid Consists of a four-layer stack of tungsten wire grids (wound at 450 turns per inch). A gold coating on the grid wires provides a uniform secondary emission ratio. The useful storage area of the target is . The tube is used in a system to store 16,384 bits with a performance error rate of less than 1 in 10¹⁰operations. The cycle time is 2.5 microseconds per bit with a single read or write operation requiring 0.7 microsecond. Under these conditions the read-around number exceeds 300 for an average output amplitude change of 10 percent.