Abstract

This basic modes of radioactive decay review "Gamma Rays" reviews some topics related to radiation, its classification and importance. In general, gamma rays interfere with our life, so we need to comprehend radiation as fact around us all the time and all the time. We live in a naturally radioactive world, but to what extent do physicians, nurses, and medical technicians, who may have to deal with urgent cases of a radiation, know about it? This chapter will address what radiation is and what is its role. This chapter will guide us toward the knowledge of ionizing radiation and its certain forms such as alpha particles, beta particles, gamma rays, and X-rays. as well as it will review on radioactive decay (nuclear decay) as well as help us learn about radioactivity and radiation, in addition to the types of decays, which are divided into beta decay, gamma decay, electron capture, positron decay, and alpha decay. This chapter will focus on radioactive decay, the activity and units of radioactive activity, and half-life of it. The last part of this chapter discusses attenuation as the reduction in the intensity of gamma ray or X-ray beam. The most important subtitles that are scattered from attenuation are HVL mean free path, the linear attenuation coefficient, pair production, and photoelectric scattering.

Keywords: activity, alpha particle, beta particle, decay (radioactive), electron capture, electromagnetic radiation, electron, emissions, energy, electron volt (eV), gamma rays, gray (Gy), half-life (radiological), ionizing radiation, isotopes, molecule, nonionizing radiation, nucleus (of an atom), nuclide, photon, positron, positron emission, proton, radiation, radionuclide, X-ray

## 1. What is radiation?

Radiation is a form of energy that is released as electromagnetic waves or particles, moves through space, and may be able to penetrate or interact with different materials.

Radiation-caused changes in materials depend on the origin, type of radiation, and the deposited energy [1].

#### 1.1 Classification of radiations

Radiation is classified into ionizing and nonionizing radiation. Ionizing radiation is divided into direct ionizing and indirect ionizing (as shown in Figure 1).

#### 1.1.1 Ionizing radiation

Ionization radiation refers to the capability of ionizing material either directly or indirectly because of their higher energy such as X-rays, γ-rays, energetic neutrons, electrons, protons, and heavier particles (as shown in Figure 2).

Use of Gamma Radiation Techniques in Peaceful Applications

• This consists of charged particles, such as electrons, protons, α particles,

◦ Energy can be deposited by directly ionizing radiation in the medium through direct coulomb interaction between the directly

ionizing charged particles and orbital electrons of atoms.

• This consists of neutral particles, photons (X-ray and γ-rays), and

Alpha, beta, neutron particles, gamma rays and X-rays are each caused by unstable atoms, either through the overabundance of vitality or mass (or both of them). To reach a steady state, they must discharge that additional vitality or mass

Alpha particles (α particle): positive charged particles (+2), which are released in the radioactive decay of some nuclei. An alpha is a particle which is emitted from the nucleus of an atom, which consists of (+2) protons and (2) neutrons with mass number (4) (Helium atom). It is strong ionizing with low penetration power and

Beta particles (β+ or β-): They are particles with electric charge ((+) or ()) emitted from the nucleus during radioactive decay. They take the form of either an electron or a positron (a particle with the size and mass of an electron, but with a

• Electrons or positrons have small mass and variable energy. Electrons are formed when a neutron transforms into a proton and an electron.

a photon of energy, which is released from an unstable nucleus of an atom.

released sometimes, so they provide their exceed energy to the electron in the atomic orbit; this process usually happens to the nearest nucleus (as shown in

that they originate from the electron shell. This is generally caused by energy

higher to a lower state of the energy by emitting gamma ray.

Gamma rays: are different from alpha or beta rays, because they do not contain any particles, as they are used in electromagnetic radiation. Instead, they consist of

Isomeric transition: It occurs when the excited atomic nucleus changes from a

Internal conversion electron: This process occurs when the gamma rays are not

X-rays: They are similar to gamma radiation; the only one primary difference is

neutrons) in the medium through two steps:

protons or heavier particles).

orbital electrons of the atoms.

◦ Energy can be deposited by indirectly ionizing radiation (photons or

1.First step: a charged molecule is transmitted in the medium (photons discharge electrons or positrons; neutrons discharge

2.The second step: the produced charged particles store vitality to the medium through direct Coulomb interaction with the

and heavy ions.

DOI: http://dx.doi.org/10.5772/intechopen.85502

Basic Modes of Radioactive Decay

ii. Indirectly ionizing radiation

1.2.1 Ionizing radiation takes a few forms

within the frame of radiation.

short range.

Figure 3).

25

positive charge).

neutrons.

### Figure 1.

Classification of radiations.

