Radiation COPY Flashcards
One Curie is that quantity of a radioactive material that will have how many disintegrations in one second
37 billion
A unit of exposure to x or gamma rays
Roentgen
A roentgen is that amount of radiation that will produce in air a given electrical charge per_____of air
Kilogram
What is the unit of absorbed dose in any substance
Radiation absorbed dose (RAD)
What is the unit of dose equivalent for any type of ionizing radiation sorted by body tissue in terms of its biological effect
Roentgen equivalent man
The REM is defined as the dose in RAD multiplied by the appropriate _____
Quality factor
REM = RAD x QF
What was designed so that all branches of science could use a single set of interrelated measurement units
System Internationale (SI)
Known formerly as the Curie this unit is used to measure radioactivity. It is the quantity of a radioactive material that will have one disintegration in one second
Becquerel
Formerly the RAD it is the unit used to measure absorbed dose for any type of radiation and any material. Equal to 100 RAD
Gray
Formerly the REM it relates the absorbed dose in human tissue to the effective biological damage of radiation. it is the equivalent to 100 REM
The sievert.
Primarily of galactic origin consisting of high-energy protons helium ions electrons, and photons. Interaction with an atmosphere by these particles produces most of the observed cosmic radios
Cosmic radiation
The intensity of cosmic radiation varies with what?
Latitude and elevation.
Higher elevations receive greater exposures.
Naturally occurring radioactive isotopes are a form of what type of radiation?
Terrestrial radiation
Terrestrial radiation consists of either isotopes produced by what
or
isotopes with _____ which have been present on earth since it’s creation
Interaction of cosmic rays
Long half lives
Direct terrestrial radiation dose varies with what
Location
What type of radiation occur is with building material such as concrete, brick, and stone, which contain quantities of uranium
Terrestrial radiation
Inhaled Radon 222, ingested potassium 40, carbon-14, etc are forms of what radiation
Natural radioactivity within the body, inhaled radioactivity
What are the most common type of man-made background radiation sources
Isotopic sources
They are intentionally produced by reading material with neutron beams from Excelerators IE cesium 137 which is used to check Radiac calibration
These sources make up the largest variety of radiation sources they can be classified as accelerators or reactors
Machine sources
What are the most common type of Excelerator source
X-ray machines
X-rays are high-energy photons that are how much more energetic than visible light?
1000 to 1,000,000
What is an example of a reactor type source
Nuclear reactor
A typical reactor may produce intensities up to how many RAD/Hr
1 billion
A person living near a nuclear reactor facility might receive an additional exposure of how many mR/yr
0.1 to 1.0 MR/yr
The average exposure from all backgrounds sources in the United States is approximately how many MR/year
203.3 MR/year
What is defined as the amount of time calculated to a sure that Personnel exposures do not exceed A predetermined level
Staytime
What is the best safety factor
Distance
If you double the distance from the source the intensity is reduced to _____of the original intensity
One quarter
What absorbs part or all of the various types of radiation
Shielding
X-ray shielding is based on the same mechanism as what
X-ray matter interaction
At a lower energies materials of high atomic number provide the attenuation at lower or higher barrier weight
Lower
All shield barrier material shall be a shored what what and what
Quality, uniformity, and permanency
In lead barriers joint should be in contact with how much of an overlap or twice the thickness, whichever is greater
One half inch overlap
What is the sole reason for concern about the effects of ionizing radiation
Interaction of radiation with matter particularly the human body
What is the term for any electromagnetic or particulate radiation capable of producing ion pairs in its passage through matter
Ionizing radiation
Ionizing radiation can be divided into two general categories what are they
Directly ionizing radiation and indirectly ionizing radiation
What type of radiation carries a charge and can deposit energy directly into an absorber
Directly ionizing radiation
What are the three major mechanisms which account for the energy deposition by charged particles in an absorber
Ionization, excitation, and bremsstrahlung
What occurs when an incident charged particle exerts a sufficient force of attraction or repulsion on the atomic orbital electron to completely remove one or more electrons from the atom. The positively charged atom from which the electron was removed and the removed electrons are referred to as what?
Ionization. Ion pair
What occurs when incident charged particles exert force on atoms to raise orbital electron to higher energy state but not enough force to completely remove them from their atom. the excited atom will emit photons when the electrons return to the ground state
Excitation