Final answer:
Electrons in image intensification tubes are accelerated by electrostatic lenses towards a phosphor screen to create an image. X-rays can be produced when electrons strike a target with enough energy, but CRTs like in old TVs are not designed to create X-rays and usually don't produce them at levels of concern.
Step-by-step explanation:
In image intensification tubes, electrons are indeed accelerated toward the output phosphor by electrostatic lenses. In the context of cathode-ray tubes (CRTs), which are a type of vacuum tube formerly used in older television sets, a high-voltage (approximately 30-kV) accelerating potential propels electrons toward the screen. These electrons then collide with a phosphor coating on the inside of the screen, causing the phosphor to emit light and create the visible image.
When considering whether X-rays might also be generated in this process, it is important to note that X-ray production requires a significant energy transfer from electrons to atomic nuclei. In the case of CRTs, while the 30-kV accelerating potential is substantial, it is generally not high enough to produce X-rays efficiently. However, some amount of X-ray emission can occur at these voltages, especially if the electrons strike high atomic number materials, but CRTs are designed to minimize this effect. For instance, the glass screen absorbs most of the soft X-rays produced.
The first method of X-ray production, as illustrated in scientific figures, occurs when an electron is accelerated in a vacuum and then strikes a metal plate. At sufficiently high voltages, these interactions can produce X-rays as the electron energies are high enough to ionize atoms in the metal target. This process is intentionally used in X-ray tubes, which operate on a similar principle but at higher voltages and with materials optimized for X-ray production.