Improved barrier-grid storage tube

The development of a radically new barrier-grid storage tube is described. The tube utilizes a spherically-curved target assembly 4.5 inches in diameter with a 4.5 inch radius of curvature in which the barrier grid is fused to the dielectric surface. The center of deflection of the electrostatically focused and deflected electron gun is essentially coincident with the center of curvature of the target; thus, the beam strikes the target at normal incidence throughout. The total deflection angle of the electron beam is 60° and means are provided for concentrating 10 µa of beam current into an 8-mil spot (measured at the 5% points on the current density distribution curve) and for dynamic focusing of the beam throughout the target area involving dynamic correction of the deflection defocusing. Either collector or target readout may be employed. The collector section of the tube is designed to uniformly and efficiently collect the signal electrons from the target so that the signal shading is negligible. Contact to the collector is made by a coaxial lead through the bulb wall. The target end of the tube is designed so that contact to the target is with a coaxial lead in which the barrier grid is connected to the outer shield of the coax. Techniques for depositing a uniform porcelain enamel layer on the spherically-curved target bowl and for forming and fusing the barrier grid to the insulator surface are described. In addition, the design of the electron gun is described in detail.