Source:http://linkedlifedata.com/resource/umls/id/C2955691
UMD: Devices designed for accurate sensing of ionizing radiation in an enclosed chamber. These chambers typically consist of an electrically closed spherical or cylindrical vessel that usually works as the cathode and an internal electrode (e.g., a rod) that is the anode. The presence of radiation from any source causes charged particles to traverse the gas inside the ionization chamber, producing ionization of the gas (i.e., creating ionized pairs). The impinging particles might be alpha or beta particles from a radioactive source and/or gamma or x-rays. When an electric potential is applied between the wall of the chamber and the anode the ionization produced by radiation is collected in the form of a current. The current is typically measured using an external electrometer; some ionization chambers include pre-amplifiers to amplify the generated current before delivering it for external measurement. Ionizing chambers are used in detectors, counters, monitors, dosimeters and other instruments intended for m