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.
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
Radiation is a type of energy, and contamination is radioactive material that is
uncontained and in an unwanted place.
Electromagnetic radiation that doesn't have enough energy to ioniz e an atom is called
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.
The alpha particle has a large mass and consists of two protons, two neutrons, and
It is a highly charged particle (charge of plus two) that is emitted from the nucleus
of an atom.
The positive charge causes the alpha particle (+) to strip electrons (-) from nearby
atoms as it passes through the material, thus ionizing these atoms.
The alpha particle deposits a large amount of energy in a short distance of travel.
This large energy deposit limits the penetrating ability of the alpha particle to a very
Range in air is about 1-2 inches.