Electron Optics for CRT's: Computer Modeling

The performance of electron guns can be improved with the aid of accurate visual models of the gun and beam, including thermal spreading and space charge effects, as previously described in the literature. To effectively model a CRT-type of electron gun, a "scaled" approach is outlined in which the region of the cathode and control grid is treated with greater accuracy than are the succeeding regions of the lens and field-free space. Using computer-drawn plots of the gun structure, field, and beam, the five steps needed to imploment this "scaled" approach are summarized.