output phosphor of image intensifier

The output phosphor of an X-ray image intensifier is a luminescent screen that converts the accelerated electron image back into a visible light image. Its most common material composition is zinc cadmium sulfide activated with silver (ZnCdS:Ag), though alternatives like gadolinium oxysulfide activated with terbium (Gd₂O₂S:Tb) also exist.

Key Material and Design Details
Primary Material: Historically and commonly, the output phosphor uses a ZnS or (Zn, Cd)S host material, often activated by elements such as silver (Ag) or copper (Cu). A specific designation sometimes referenced is P20, which has a peak emission around 530 nm (green light).

Alternative Material: Some designs utilize Gd₂O₂S:Tb as the phosphor layer. In these cases, up to 80% zinc cadmium sulfide can be added, and the layer is often covered with a thin aluminum reflective layer to direct light toward the output.

Function: Electrons, after being accelerated and focused by the tube’s electrodes, strike this phosphor layer to produce the final bright visible image.

If you need more specific technical parameters (such as thickness or conversion efficiency) for a particular application or intensifier generation, feel free to ask.

Author:Image Intensifier