Magnetic Focusing and Electrostatic Deflecting Camera Tubes with Twisted Pattern Yokes

Abstract

Magnetic focusing and electrostatic deflecting (MS) camera tubes have been investigated concerning a twist angle of the Pattern yoke and the shielding electrode for deflection field near the electron gun by calculating the deflection electrostatic field using the variable separation method.
It was found that a twist in the pattern yoke by 30 degrees reduces the beam spreads due to deflection aberrations and improve the resolution uniformity over the raster. It was also found that the shielding electrode is efficient for improving resolution.
The 2/3 inch MS camera tubes based on the calculation are fabricated and show good resolution. The performances of the tubes are found to be in very good agreement with calculations. Cameras using the tubes are also fabricated. The optimization of the MS electron beam systems have been established.