Radiation Safety Practice Exam

How do RADIAC instruments that utilize ionization detect ionizing radiation?

1. By measuring sound waves generated

2. By analyzing chemical reactions

3. By collecting and measuring ion pairs created during interaction with matter

4. By detecting temperature changes in the detector

The correct answer is: By collecting and measuring ion pairs created during interaction with matter

RADIAC instruments that utilize ionization detect ionizing radiation through the process of collecting and measuring ion pairs created during interactions with matter. When ionizing radiation passes through the detector, it interacts with the gas within the ionization chamber, leading to the ionization of gas molecules. This results in the creation of positive ions and free electrons, which are known as ion pairs. These ion pairs are then collected by applying an electric field within the detector, allowing for the measurement of the resulting electric current. The amount of current generated is proportional to the number of ion pairs formed, which correlates to the intensity of the ionizing radiation present. This method is effective for identifying and quantifying various types of ionizing radiation, making it a valuable tool in radiation safety and monitoring. In contrast, the other options describe mechanisms that do not apply to the functioning of RADIAC instruments using ionization. For example, measuring sound waves or analyzing chemical reactions does not pertain to ionization detection, and detecting temperature changes would relate to different types of detectors not focused on ionization processes.