Which device in the fluoroscopic system is responsible for converting light photons to an electronic signal?

The photocathode is a crucial component of the fluoroscopic system, specifically responsible for converting light photons into an electronic signal. When the input phosphor, which receives the X-ray photons, is excited, it produces visible light. The photocathode then absorbs this visible light and emits electrons as a result. This process is vital in the functioning of fluoroscopy because the emitted electrons are subsequently focused and intensified, allowing the formation of a video signal that is then processed to create real-time images.

The function of the photocathode is essential as it bridges the gap between the light produced by the phosphors and the electronic signals needed for imaging, making it a cornerstone of the fluoroscopic imaging process.