Development of an electron optics simulator to consider the 3-D magnetic deflection field in CRTs

We have developed an electron optics simulator which can take the three-dimensional magnetic deflection field in CRTs into account. The magnetic field is calculated by the combination of an integral equation method (IEM) and a multipole field expansion method considering the exact shape and winding pattern of saddle-saddle coils of a deflection yoke (DY) for the CRTs. The simulator analyzes misconvergence by following an electron trajectory in the magnetic field by using the Runge-Kutta-Gill method. The combined method reduced the CPU time to 145 compared with the method which uses only the IEM. The relations between the misconvergence and the tilt angle of the DY away from the CRT axis are calculated and they agree well within the measurement error.