Radiation Safety Practice Exam

What type of gas is commonly used in the chamber of RADIAC instruments?

1. Oxygen

2. Inert gas

3. Carbon dioxide

4. Nitrogen

The correct answer is: Inert gas

RADIAC instruments, which are used for the detection and measurement of ionizing radiation, commonly employ an inert gas in their chambers. Inert gases, such as argon or neon, are advantageous because they are chemically non-reactive and do not form compounds under normal conditions. This characteristic allows them to provide a stable environment within the detection chamber, ensuring that the measurements of radiation exposure are not affected by interactions with the gas itself. When ionizing radiation passes through the chamber filled with inert gas, it ionizes some of the gas molecules, leading to the creation of electron-ion pairs. These pairs can then be collected to produce an electrical signal that is proportional to the amount of radiation detected. The stability and non-reactivity of the inert gas contribute to the reliability and accuracy of the RADIAC instruments. In contrast, the other gases mentioned would not be suitable for use in these instruments due to their reactive properties or the potential for creating complications in the measurement process.