Final answer:
Electrons in an image intensification tube are accelerated by an electric field, not the input phosphor. In CRTs, electrons accelerated by high voltages can produce light and X-rays when they hit a metal target.
Step-by-step explanation:
When electrons are produced in an image intensification tube, they are not accelerated by the input phosphor. Instead, the input phosphor converts X-rays into a visible light image. The electrons are accelerated by an electric field created by a high voltage applied within the tube. In Cathode Ray Tubes (CRTs), such as those used in some older television models, electrons are accelerated by an approximately 30-kV potential and directed towards the screen. Upon striking the phosphor-coated screen, they produce light to form images.
X-rays can also be produced if the electron energy is sufficient when they strike a target, as seen in X-ray tubes. In CRTs, when high-voltage discharges accelerate electrons to strike a metal plate like copper, the high energy can ionize atoms and emit X-rays. However, CRTs are generally designed to minimize X-ray emission for safety reasons.