Analysis on electrostatic pattern yoke camera tubes

To investigate the features of electron-beam systems in electrostatic deflecting camera tubes, a method for calculating the deflection field of the twisted curved-arrow pattern yoke is presented using the method of separation of variables. In spite of three-dimensional analysis, field values at 2000 points can be calculated at 10^-3accuracy within 1 min using a HITAC-M200H computer. Distributions of deflection field also are given. Furthermore, deflection aberrations of electron beams are analyzed in the magnetic focusing and electrostatic deflecting (MS) systems. It is revealed that the favorable features of MS beam systems can be realized only by utilizing a nonuniform magnetic field. It is also seen that deflection aberrations and landing error are very dependent on a twist in the pattern yoke.