radiation detector

A device in which incident radiation produces a measurable effect. If this effect is a rise in temperature it is called a thermal detector. If it is a rise in pressure it is called a photoacoustic detector. In the case where an electrical signal is produced it is called a photoelectric detector. Photoelectric detectors can be classified as photo-emissive detectors and semiconductor detectors. Where the radiation produces a chemical reaction, it is termed a photochemical detector. A detector yielding an output signal that is independent of the wavelength of the radiation over a specific region is called a nonselective detector. Where it is wavelength specific it is a selective detector. A detector having a quantum efficiency independent of the wavelength is a nonselective quantum counter. Certain detectors are able to distinguish between different quantum energies. This property is described by the energy resolution and the energy resolving power. These detectors are called energy dispersive detectors. In X-ray spectroscopy, the reciprocal is often used but this is discouraged.