The Four Basic Types of Ionizing Radiation cont'd

DOE-HDBK-1130-98

Module 1: Radiological Fundamentals

Instructor's Notes

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

emitted from the nucleus of an atom.

EO6 Identify the four basic

types of ionizing radiation

and the following for each:

a. Physical characteristics

b. Range

c. Shielding

d. Biological hazards

e. Sources

3) The positive charge causes the alpha particle (+) to strip

electrons (-) from nearby atoms as it passes through the

material, thus ionizing these atoms.

Range

1) The alpha particle deposits a large amount of energy in a short

distance of travel.

2) This large energy deposit limits the penetrating ability of the

alpha particle to a very short distance.

3) Range in air is about 1-2 inches.

Shielding

Most alpha particles are stopped by a few centimeters of air, a sheet

of paper, or the dead layer (outer layer) of skin.

1) Alpha particles are not considered an external radiation hazard.

This is because they are easily stopped by the dead layer of

skin.

2) Internally, the source of the alpha radiation is in close contact

with body tissue and can deposit large amounts of energy in a

small volume of living body tissue.

Sources

(Insert facility-specific information.)