After-Acceleration and Deflection

Deflection sensibility of a cathode-ray tube is defined as reciprocal of the change in deflecting voltage or current required to move the spot one spot diameter on the screen. By deflecting the electron beam in a region of low potential, deflection sensibility can be increased in the case of electrostatic deflection, but cannot be increased in the case of magnetic deflection. Any improvement achieved by after-acceleration is due only to the lowering of the potential in the region of deflection, and not to the peculiar electron-optical properties of the particular scheme employed.