Which detector component converts x-rays to light?

• A. storage capacitor
• B. scintillation layer
• C. capture area
• D. TFT

Answer: (B)

The detector converts x-rays to light in the scintillation layer. This material (often cesium iodide or gadolinium oxysulfide) absorbs x-ray photons and re-emits visible light. That light is then picked up by the photodetector layer and converted into an electrical signal for readout. The storage capacitor holds the signal, the capture area gathers charge, and the thin-film transistor (TFT) controls the readout, but the essential step of turning x-rays into light is performed by the scintillation layer.