CDPH Lead Inspector/Assessor California State Practice Exam

XRF using a 109Cd source emits what type of energy?

1. X-ray

2. Gamma ray

3. Beta particle

4. Ultraviolet light

The correct answer is: Gamma ray

The correct answer is that XRF (X-ray fluorescence) using a 109Cd source emits gamma rays. The 109Cd source specifically emits gamma radiation as part of its decay process, which is utilized in the XRF technique to excite the electrons in the materials being analyzed. When the gamma rays from the 109Cd interact with the atoms in the sample, they cause the ejection of inner-shell electrons. As outer-shell electrons fill these vacancies, they release energy in the form of characteristic X-rays. This process is crucial for the analysis of elemental composition, as the energy levels of the emitted X-rays can be used to identify the specific elements present in the material. Understanding the nature of the radiation emitted by the 109Cd source helps in grasping the fundamental workings of XRF technology, which is essential for lead inspection and assessment practices.