What type of detector is an ionization chamber classified as?

An ionization chamber is classified as a gas-filled detector because it operates based on the principle of ionization of gas molecules. When ionizing radiation passes through the chamber, it interacts with the gas, creating ion pairs—positive ions and free electrons. These ion pairs are then collected by an applied electric field, leading to a measurable electric current that correlates to the amount of radiation present.

Gas-filled detectors, such as ionization chambers, are widely used in radiation detection because they can accurately measure high radiation doses, like those encountered in radiography and certain types of radiation therapy. This classification distinguishes them from other types of detectors, such as solid-state detectors that utilize semiconductor materials or liquid-filled detectors that use a liquid medium to detect radiation.

The other types mentioned, including liquid-filled and photoelectric detectors, involve different mechanisms of detection and are not applicable in this context. Thus, classifying an ionization chamber as gas-filled is accurate and reflects its operational characteristics.