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rad
rad and matter
Question | Answer |
---|---|
5 ways x-rays interact with matter? | coherent scattering, comptom effect, photelectric effect, pair production, photodisintegration |
2 most important ways that x-rays interact with matter in producing x-rays are? | compton effect, photoelectric |
higher energy x-rays result in _________ wave lengths | short |
do x-rays have long or short wavelengths? | short |
moderate engery x-rays interact with _________ | electrons |
high energy x-rays interact with __________ | nuclei |
two other names for coherent scattering? | classical scattering, thompson scattering |
type of scattering were there is no change in energy but a change in direction | coherent scattering |
type of scattering with no ionization | coherent scattering |
which direction is commonly seen in coherent scattering? | forward direction |
type of effect with ionization of the target atom, change in x-ray direction and reduction of energy? | compton effect |
how is scatter x-ray absorbed in the compton effect? | photoeletrically |
what effect is it when eletrons are emitted from matter after the absorption | photelectric effect |
partial absorption and scattering | compton effect |
form of ionizing radiation and as such can be dangerous | X-Rays |
type of electromagnetic radiation with wavelengths | X-Rays |
When radiation is only scattered by one localized scattering center, this is called? | single scattering |
It is very common that scattering centers are grouped together, and in those cases the radiation may scatter many times, which is known as? | multiple scattering |
the decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, when it interacts with matter? | compton effect |
The amount the wavelength increases by is called? | compton shift |
scattering where the photon gains energy (decreasing in wavelength) upon interaction with matter | inverse comtpton scattering |
emitted electrons can be referred to as | photoelectrons |
Two sources of ionizing radiation to which everyone is exposed? | Natural environmental (background radiation) Man-made radiation |
Examples of natural environmental (background) radiation? | Cosmic radiation from the sun and stars Radioactive elements in the earth (uranium, radium, thorium) Radio-potassium and radiocarbon (found in foods, drinking water, and the air) |
Man made radiation sources? | Fallout from nuclear weapons testing and effluents from nuclear power plants Radioactive materials used in industry Medical and dental exposures |
ALARA | As Low As Reasonably Achievable |
The amount of radiation needed, when applied to the skin, to make it turn temporarily red? | erythema dose |
A unit of gamma radiation measured by the amount of ionization in air. In non-bony biological tissue 1 roentgen delivers a dose approximately equal to 1 rad? | Roentgen |
one ______ equal to the absorption of radiation energy per gram of matter. It has been replaced by the gray? | Rad |
Roentgen equivalent man, a unit used in radiation protection to measure the amount of damage to human tissue from a dose of ionizing radiation? | Rem |
A unit of radioactivity that represents the amount of radioactivity associated with one gram of radium? | Curie |
basis for the NCRP’s establishment of policies and procedures for radiation exposures | ALARA |
Radiation workers are limited by a maximum of Effective Dose Equivalent of? | 5 rem per year |
General public is allowed a dose limit of? | .5 rem per year |
Anyone less than 18 years old should receive no more than? | 0.1 rem whole-body dose in 1 year |
Pregnant woman should not receive no more than? | .5 rem per year |
SOURCES OF EXPOSURE Two sources of medical radiation exposure are? X-rays (external source) Radionuclides (internal source) | X-rays (external source) Radionuclides (internal source) |
Ways in which mutations can manifest themselves are? | Miscarriages Physical birth defects Metabolic or biologic changes causing a predisposition to disease or premature death |
Dose is measured in? | grays (Gy) or sievert (Sv) |
REM measures? | radiation equivlalent |
radiation absorption is measured by? | RAD, radiation absorption dose |
100 RAD = how many Gy? | 1 |
what is the unit of radioactive activity? | becquerel |
What does EDE stand for? | effective dose equivalent |
there is no energy transfer at a deflection of how many degrees? | zero |
which has a higher frequency, hard or soft x-rays? | hard |
which has a shorter wavelength hard x-rays or soft x-rays? | hard |
what is it called when electrons are emitted from matter after the absorption of energy from electromagnetic radiation? | photoelectric |
what effect is it when electrons are emitted from matter after the absorption of energy from electromagnetic radiation? | hertz effect |
the theory of an elecctromagnetic wave scattered by charged particles? | thompson scattering |
the wavelength of the incident x-ray is _________ the wavelength of the scattered x-ray? | equal to |
most coherently scattered x-rays are scattered in what direction? | forward |
decrease in energy (increase in wavelength) of a x-ray or gamma ray photon when it interacts with matter is called? | compton scattering |
in this type of scattering the photon gains energy (wavelength gets shorter) as it interacts with matter? | inverse compton scattering |
amount a wavelength changes is know as? | compton shift |
what type of effect is it if a photon has low energy but still has sufficient enough energy to eject an electron from its host atom? | photoelectric effect |
when higher energy photons bombard the nucleus and cause an electron and positron to be formed it is called? | pair production |