The fundamental unit of matter is the atom, which is composed of a nucleus consisting of protons and neutrons surrounded by a cloud of electrons. This module discusses the basics of radioactivity and how the decay rate can be described by Poisson statistics. All detectable gamma radiation from earth materials come from the natural decay products of only three elements at the surface ground, These elements, uranium (U), thorium (Th), and potassium (K), can be measure, whether directly or indirectly. We discuss the decay mechanisms of the important radioisotopes for gamma ray surveying. We introduce the concept of disequilibrium. The properties of gamma rays are summarized.
After completing this module, participants will come to understand:
- The fundamentals of radioactivity,
- Be able to describe the different types of radioactive decay,
- Discuss the statistical nature of radioactive decay and Poisson distributions,
- Have an understanding of the natural sources of radiation,
- Learn the importance of disequilibrium, and
- Have a summary of the properties of gamma rays and how they interact with matter.