Natural Radioactivity

**3**

**Chapter 1**

**Abstract**

Applications

cal, food, or building materials.

**1. Introduction**

detectors, annual effective dose, absorbed dose

*Lubna A. Al-Asadi*

Gamma Background Radiations

This chapter deals with gamma background radiation that is exposed to two major natural sources: normal sources that are earthly gamma rays and astronomical rays. Earthbound gamma rays from radionuclide elements such as thorium, potassium, and uranium. Also, in building and enhancing materials such as medical plants, building purposes, some vegetables and fruits commonly used in markets and soil. The measurements of gamma background radiation differ according to the purpose. So, there are many instruments used such as HPGe detector, NaI (TI) detector, CR-39, a dosimeter, and SSNDT detector. This research will explain in detail the studies and the mechanism for each detector and how it works and the application (practical) studies for each one. The purpose of calculating gamma background radiation is to be in the safe side for human being according to the international union specified with a standard limitation of world average value or with a specific value ranged (standard values) according to the case study in medi-

**Keywords:** terrestrial gamma rays, natural gamma ray, background radiation,

How do γ-rays compare with other types of radiation? "Radiation" in common language describes "energy packages" that travel on straight paths. "Electromagnetic radiation" is characterized by variations of electric and magnetic fields in space and time. Another type of "radiation" is "cosmic rays," very energetic particles discovered early in the twentieth century in the upper atmosphere of the Earth and known to pervade interstellar space. These particles are called "cosmic radiation" because with their high energies they propagate at the speed of light and

Gamma radiation represents the most energetic part of the electromagnetic spectrum (**Figure 1**). Therefore, it is natural that it provides information about the

In general, there are three noteworthy sources: earthly radiation, grandiose radiation, and interior radiation due to the admission of regular radionuclides through inward breath (for the most part radon) and ingestion. Additionally, the most three radionuclide components are thorium (232Th), potassium (40K), and

in certain aspects behave like photons of similar energies [1].

liveliest procedures and wonders in the universe [2].

and Measurements with
