Radiation Safety Practice Exam

What material is commonly used in gamma and X-ray scintillation probes to enhance interaction detection?

1. Cadmium sulfide

2. Sodium iodide

3. Zinc oxide

4. Lead iodide

The correct answer is: Sodium iodide

Sodium iodide is a widely used scintillation material for gamma and X-ray detection because of its effective performance in converting incident radiation into detectable light signals. When gamma rays or X-rays interact with sodium iodide, they excite the crystal's atoms, leading to the emission of scintillation light, typically in the visible spectrum. This property makes sodium iodide particularly valuable in applications requiring sensitive detection of high-energy photons. Its high atomic number and density also contribute to a greater probability of interaction with incoming radiation, which enhances the overall efficiency of detection. Additionally, sodium iodide crystals can be easily doped with thallium (NaI(Tl)), which further improves their scintillation efficiency and allows for better energy resolution in detecting different radiation levels. Thus, sodium iodide is recognized as one of the optimal materials for creating scintillation probes used in radiation safety and detection applications.