Radiation Safety Practice Exam

How do RADIAC instruments detect ionizing radiation through the principle of ionization?

1. By measuring electric current only

2. By light energy being released

3. Through gas being pumped into the chamber

4. By absorbing sound waves

The correct answer is: By light energy being released

The detection of ionizing radiation by RADIAC instruments is based on the principle of ionization, specifically through the interaction of radiation with gas within a chamber. When ionizing radiation passes through a gas-filled detector, it ionizes the gas molecules, creating positive ions and free electrons. This ionization results in a measurable electric current when the ions migrate toward the electrodes within the chamber, allowing the instrument to quantify the level of radiation. The reasoning behind the correct choice lies in the fact that ionization is the fundamental mechanism at work in these instruments. The generated ionization leads to the formation of free charge carriers (electrons and ions), which can then be measured as electrical signals. Thus, the direct relationship between detected radiation and the electric current produced through ionization provides a reliable means of measuring radiation levels. In contrast, while the release of light energy can occur in processes like scintillation detection, RADIAC instruments specifically rely on the ionization of gas and the resultant electrical signals to indicate radiation levels. Hence, light energy being released is not the primary detection mechanism for RADIAC instruments. Additionally, pumping gas into the chamber is not necessary for the principle of ionization itself, and sound waves are not involved in the detection of ionizing