Which material is NOT commonly used in CT detectors?

The material that is not commonly used in CT detectors is iron. In the context of CT (Computed Tomography) imaging, the detectors must have specific characteristics that allow for the accurate detection of X-rays and the efficient conversion of those X-rays into electrical signals.

Germanium, cadmium, and silicon are semiconductor materials known for their effective detection capabilities in various imaging technologies. Germanium, for instance, is often utilized in applications requiring high energy resolution, while cadmium compounds, such as cadmium telluride, are known for their high atomic number which improves X-ray detection efficiency. Silicon is widely used in many types of electronic devices, including in the formation of CT detectors, due to its abundance and favorable electronic properties.

Iron, however, is primarily used for other purposes in technology and is not typically utilized as a detector material in CT imaging. Its characteristics do not align well with the requirements for efficient X-ray detection, making it unsuitable for this application. Thus, the selection of iron as a detector material is not congruent with the modern standards and technologies employed in CT systems.