The defined area in which the
Protective barrier. A barrier of radiation-attenuating
exposure of persons to radiation is supervised by a
material used to give the required protection from
Radiation Protection Officer. Controlled areas require
control of access, occupancy, and working conditions.
Qualified expert. With reference to radiation protection,
Half-value layer (HVL).
Thickness of a specified
a person having the knowledge and training to advise
substance which, when introduced into the path of a
regarding radiation protection needs, to measure ionizing
given beam of radiation, reduces the exposure rate by
radiation, and to evaluate safety techniques; a person
having relevant certification from the American Board of
Radiology or American Board of Health Physics, or
Kilovolt (kV). A unit of electrical potential difference
equal to 1000 volts.
With reference to shielding design, a person having
Kilovolt peak (kVp). The crest value in kilovolts of the
particular knowledge and training in the field of medical
potential difference of a pulsating potential generator.
x-ray and gamma-ray shielding.
When only one-half of the wave is used, the value refers
Radiation (Ionizing). Any electromagnetic or particulate
to the useful half of the cycle.
radiation capable of producing ions, directly or indirectly,
by interaction with matter, specifically x-rays and
expressed in an equivalent thickness of lead.
Million electron volts (MeV). Energy equal to that
Radiation protection survey. An evaluation of the
acquired by a particle with one electronic charge being
radiation safety in and around an installation.
accelerated through a potential difference of 1 million
Radiation protection officer.
The person directly
responsible for radiation protection.
Any space not meeting the
. Radiation that has been deviated
definition of controlled area.
in direction during passage through matter.
Occupiable area. Any room or other space, indoors or
Secondary protective barrier. Barrier sufficient to
outdoors, that is likely to be occupied during irradiation
attenuate stray or secondary radiation to the required
by any person, either regularly or periodically during the
course of his/her work, habitation, or recreation.
Radiation that passes through the
. Radiation arising directly from the
window, aperture, cone, or other collimating device of the
target of an x-ray tube or from a radioactive source.
source housing. Sometimes called "primary beam."