Which gas filled detector is typically used in beta gamma survey monitors?

The ion chamber is typically utilized in beta-gamma survey monitors due to its ability to measure high radiation exposure rates accurately. This type of detector responds to ionizing radiation by producing ion pairs in a gas-filled chamber; as radiation passes through the gas, it ionizes the atoms, creating free electrons and positive ions. The electric field within the chamber then collects these charges, generating a measurable current that correlates directly with the radiation intensity.

Ion chambers are particularly advantageous for monitoring higher dose rates, such as those found in beta and gamma radiation fields, and they provide a fairly steady response over a range of radiation energies. They have a linear response to radiation exposure, meaning that the output is directly proportional to the radiation levels, making them ideal for use in survey monitors where accurate quantification of radiation exposure is needed.

While other detectors like the Geiger-Muller (GM) detector and scintillation counters also detect beta and gamma radiation, they serve different functions and have distinct operational characteristics. The GM detector is sensitive to lower levels but can saturate at high radiation doses, which may lead to inaccurate readings in intense fields. Scintillation counters are efficient and sensitive, often used in laboratory settings rather than field surveys due to their complex operational requirements and the need