Analysis of magnetic plates attached to a deflection yoke with a hybrid method

Deflection yokes require several kinds of magnetic plates to correct the misconvergence of three beams. The effects of magnetic plates attached to a deflection yoke were simulated with a computer program. In this program the magnetic fields were computed with a hybrid method combining the surface-charge and finite-difference methods using Fourier transformation. The misconvergence pattern changed by a silicon steel plate attached to a deflection yoke was calculated by this program. Although the calculated vertical misconvergence changes were larger than those measured, the horizontal misconvergence changes agreed with the measured misconvergence changes within the experimental errors. This result shows that the computer program would be efficient for designing the deflection yokes with optimum magnetic plates