Electron optical properties of a postdeflection acceleration lens in cathode-ray tubes for oscilloscopes of high-bandwidth capability

A postdeflection acceleration lens (PDAL) for use in high-sensitive fast-writing CRTs is described. The lens achieves a vertical scan magnification of about 2.8 and a horizontal of about 2.2. After a discussion of the principle of operation a detailed investigation of defection linearity and distortion is given. A computer was used to calculate deflection linearity and distortion whereas experimental CRTs were evaluated to establish tube parameters which result in a vertical deflection sensitivity of 3 V/cm and a writing speed of 3 cm/ns.