What type of radiation does the input screen in an image intensifier respond to?

The input screen in an image intensifier is specifically designed to respond to X-rays. When X-rays enter the input screen, they interact with the material, typically made of a scintillating phosphor, converting the X-ray photons into visible light. This process is crucial for fluoroscopy because it allows for the visualization of internal structures in real-time. The input screen amplifies the signal, enabling the conversion of the X-ray image into a more easily interpretable format, improving the overall diagnostic quality.

In contrast, alpha particles, beta particles, and gamma rays do not play a direct role in the function of the input screen of an image intensifier. Alpha particles are heavy and positively charged, making them less penetrating and not relevant to this specific application. Beta particles, which are either electrons or positrons, are less commonly used in imaging and have differing interactions within materials. Gamma rays, while they are similar to X-rays in their electromagnetic nature, do not interact with the input screen in the same manner as X-rays do, which are the primary radiation type utilized in conventional fluoroscopic procedures.