The Four Basic Types of Ionizing Radiation

DOE-HDBK-1130-98

Module 1: Radiological Fundamentals

Instructor's Notes

The positively charged atom and the negatively charged

electron are called an "ion pair."

Ionization should not be confused with radiation. Ions (or ion

pairs) produced as a result of the interaction of radiation with

an atom allow the detection of radiation.

EO4 Define ionization.

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,

without exposure to radioactive material, will not result in

contamination of the worker.

EO4 Define ionizing

radiation.

Radiation is a type of energy, and contamination is radioactive

material that is uncontained and in an unwanted place.

Non-ionizing radiation

Electromagnetic radiation that doesn't have enough energy to

ionize an atom is called "non-ionizing radiation."

EO5 Distinguish between

ionizing radiation and non-

ionizing radiation.

Examples of non-ionizing radiation are radar waves,

microwaves, and visible light.

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

Alpha particles

Physical characteristics

1) The alpha particle has a large mass and consists of two protons,

two neutrons, and no electrons.