What happens when x-rays strike the input phosphor?

When x-rays strike the input phosphor, they are converted into visible light. The input phosphor is typically made of materials such as cesium iodide or sodium iodide, which have the ability to absorb the high-energy x-ray photons and subsequently re-emit energy in the form of visible light photons. This conversion is a critical step in the functioning of devices like image intensifiers, as it enables the transformation of x-ray images into a visible format that can be further processed, viewed, or recorded.

The conversion process is essential for creating a clear and high-contrast image for the observer. It aids in maximizing the efficiency of the imaging system by enhancing the visibility of structures within the body while minimizing radiation exposure to the patient. The quality of the visible light produced directly impacts the overall image quality, making this conversion process fundamental to radiographic and fluoroscopic imaging techniques.