Final answer:
A phosphor suitable for use in an intensifying screen must have high efficiency in converting X-rays to light to ensure enough brightness and lower doses of radiation, enhancing image quality and safety.
Step-by-step explanation:
To be suitable for use in an intensifying screen, a phosphor should have the characteristic of high efficiency in converting X-rays to light. This is because an intensifying screen is designed to work by absorbing X-rays and then re-emitting the energy as visible light, which is then captured on the photographic film or detected by other sensors. High-efficiency conversion ensures that the screen provides enough brightness for an image with lower doses of radiation, enhancing patient safety and improving the quality of diagnostic images. Phosphors with low efficiency would not produce sufficient light, resulting in poor image quality.
Furthermore, when considering the use of phosphors in CRTs (Cathode Ray Tubes), such as in some television tubes, they are stimulated by electrons to emit light that forms pictures. Although a 30-kV accelerating potential used in a CRT might suggest the possibility of X-ray creation, it is generally below the threshold necessary to produce significant quantities of X-rays. Heavy elements such as tungsten are needed, with accelerating potentials of at least 72.5 kV to produce characteristic X-rays.