The Four Basic Types of Ionizing Radiation cont'd

DOE-HDBK-1130-98

Module 1: Radiological Fundamentals

Instructor's Notes

Ionizing radiation

EO4 Define ionizing

radiation.

Ionizing radiation is energy (particles or rays) emitted from

radioactive atoms, and some devices, that can cause

ionization. Examples of devices that emit ionizing radiation

are X-ray machines, accelerators, and fluoroscopes.

It is important to note that exposure to ionizing

radiation does not necessarily result in contamination

of the worker.

Radiation is a type of energy, and contamination is

radioactive material that is uncontained and in an

unwanted place.

Non-ionizing radiation

EO5 Distinguish between

ionizing radiation and non-

ionizing radiation.

energy to ionize an atom is called "non-ionizing

radiation."

Examples of non-ionizing radiation are radar waves,

microwaves, and visible light.

C. The Four Basic Types of Ionizing Radiation

The four basic types of ionizing radiation of concern in the

DOE complex are alpha particles, beta particles, gamma or X

rays, and neutrons.

Alpha particles

EO6 Identify the four basic

types of ionizing radiation

Physical characteristics

and the following for each:

The alpha particle has a large mass and consists

Physical characteristics

of two protons, two neutrons, and no electrons.

Range

Shielding

It is a highly charged particle (charge of plus two)

that is emitted from the nucleus of an atom.

Sources

The positive charge causes the alpha particle (+)

to strip electrons (-) from nearby atoms as it

passes through the material, thus ionizing these

atoms.