Section 3: Basic radiation
concepts
Definitions
The
classical Physics definition of radiation is,
“The process in which energy is transferred by means of
electromagnetic
waves.” This includes visible light, infrared,
microwaves and
heat.
In
this training we will only be concerned with forms of electromagnetic radiation
that are ionizing,
such as x-rays and gamma rays. We will
discuss
ionization and other types of ionizing radiation later in Section 4.
The NRC
defines ionizing radiation
as, “…alpha
particles, beta particles, gamma rays, X-rays, neutrons, high-speed
electrons,
high-speed protons and other particles capable of producing ions
– does not
include non-ionizing radiation, such as radio- or micro waves, or
visible,
infrared, or ultraviolet light.”
 Health
Physics books
define radioactivity
as, “Spontaneous
nuclear transformations that result in the formation of new
elements.” What a
concept! One element can change into another! That
sounds like the
old
Alchemists who vainly attempted to convert lead into gold through
chemical
means. Little did they know that it was much easier to convert gold to
lead,
through radioactive transformations. These transformations involve the nucleus
of unstable atoms and are totally independent of any chemical and
physical
states. They occur by alpha, beta, positron emission, or by electron
capture,
but may or may not include gamma radiation. We’ll explain how
they happen in a
bit.
|
UW
Home
