OO€.
cE.
Escort destroyer.
Destroyer escort.
debris {radioactive).
See weapon debris.
decay (radioactive). The decrease in activity 3f any radicactive material with the passage of time cue to
the spontareaus emission from the atomic nuclei of either alpha or beta particles, sometimes accompanied by gamma radiation, or by gamma photons alone.
Every decay process has a definite half-life.
decontamination. The reduction or removal of contaminating radioactive material from a structure, area,
object, or person.
Decontamination may be accomplished by (1) treating the surface to remove or
decrease the contamination; (2) letting the mater +a] stand so that the radioactivity 1s decreased as
a result of natural cecay; and (3) covering the contamination in order to attenuate tne ~adiation
emitted.
device.
Nuclear fission and fusion materials, together with tneir arming, fizing, firing, chemicalaxplostve, and effects-measuring campanents, that have not reached the development status of an
operational weapon.
ny
OM.
Minelayer destroyer.
300.
Oepartment af Defense.
The Federal executive agency responsible for the defense of the United
tates.
Includes the four services and special joint defense agencies. Reports to the President
through the Secretary of Defense.
dose.
A general term denoting the quantity of ionizing radiation absorbed.
The unit of absorbed dose is
the rad (whicn see).
In soft body tissue the absorbed dose in rads is essentially equal to the exposure in roentgens.
The bialogical dose (also called the RBE dose) in rems is a measure of biological
effectiveness of the absorbed radiation. Dosage is used in older literature as well as exposure dose
and simply exposure, and care should be exercised in their use.
See also exposure.
dose rate.
As a general
Converted destroyers designed to conduct high-speed minelaying operatians.
rule,
the amount of
fonizing (or nuclear)
radiation that an
individual
or material
would receive per unit of time.
It is usually expressed as rads (or rems) per hour or multiples or
divisions of these units such as millirads per hour. The dose rate is commonly used to indicate the
level af radioactivity tm a contaminated area.
See survey meter.
dosimeter. An instrument for measuring and registering the total accumulated dose of (or exposure to) ionizing radiation.
[Instruments worn or carried by individuals are called persanne! dosimeters.
dosimetry.
The measurement and recording of radiation doses and dose rates.
[t is concerned with the use
of various types of radiation instruments with which measurements are made.
See also dosimeter, survey meter.
OPM,
Disintegrations per minute, a measure of radioactivity, literally atoms disintegrating per minute.
Oifficult to directiy compare with roentgens per hour for mixtures of radionuciides.
OTMB.
Oavid Taylor Model Basin, Carderock, Maryland (Navy).
dynamic
pressure.
Blast wave.
EG&G.
Air pressure that results from the mass air flow (or wind) behind the shock front of a
Edgerton, Germeshausen & Grier, Boston, Massachusetts (now EG&G, Inc.).
vided timing and firing electronics and technical film caverage.
Am AEC contractor.
Pro-
electromagnetic radiation.
Electromagnetic radiations range from X-rays and gamma rays of Short wave
ength (high frequency), through the ultraviolet, visible, and infrared regions, to radar and radio
waves of relatively longa wavelength.
elliptical approximations.
Method of predicting fallout areas.
Data received that have the same values
are plotted from a vertical slice of the atmosphere. The equal or near-equal conditions are generally
found to form a closed path that appears roughly elliptical im shape. The elliptical approximation
is the ellipse drawn through these data points having nearly the same values. The ellipse is drawn
so that the set af data comes closest to the curve.
EQODU.
Explosive Ordnance Disposal Unit (Navy}.
Estimated time of arrival.
ETO.
Estimated time of departure.
m
ETA,
475