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135 terms

radiation units

occupies space and has mass-made of molecules
fundamental unit of matter
smallest part of a substance that retains the same properties of the substace-composed of two or more atoms
when matter is altered, _______ results
composition, arrangement, orbiting electrons
Identification of atom is determined by the __________ of its nucleus and __________ of _________ _________
amount of different atoms in existance
atomic number
the number of protons
protons + neutrons
neutral atom
protons = electrons
number of neutrons are different
gamma rays
substances made up of only one type of atom
unbalanced atom, electron ejected from shell
emission and propagation of energy through space or substance in the form of waves or particles without a physical carrier
radiation, ionization
some _________ can cause ___________
transfer of electrons or by sharing of electrons
molecules are formed by:
ionization, energy, electrostatic, nucleus
__________ requires sufficient ______ to overcome the _____________ force that binds the electrons to the ________
man-made, naturally
radiation can be ________ or occur _________
electromagnetic radiation
movement of energy through space
electrical and magnetic forces, travel in waves, no mass or weight, travels at the speed of light
characteristics of electromagnetic radiation
x-rays, man-made, gamma rays (radioative sources), cosmic rays (sunlight)
types of ionizing radiation
visible light, microwaves, radio/tv
types of non-ionizing radiation
electromagnetic spectrum
listed according to their energy strength
electromagnetic and particle
types of radiation
corpusclar radiation
another name for particle radiation
kinetic energy (moving), has mass and weight,can not reach speed of light, travel in straight lines
characteristics of particle radiation
electrons (beta particles and cathode rays), alpha particles, protons, neutrons
four types
beta particles
high speed electrons; radioactive nucleus
cathode rays
high speed electrons, within x-ray tube
alpha particles
heavy metals; only protons and neutrons
accelarated particles; mass = 1, positive charge
accelerated particles; mass = 1, no charge
discrete bundles of energy
crest to crest or trough to trough
waves are measure from
penetrating, ionizing
shorter waves are more ___________ or ________
waves are measured in
electric, magnetic forces
electromagnetic radiation is caused by ________ and ___________ ______
number of wavelegnths that pass a given point
penetrate matter, produce a latent image, produce fluorescence in certain materials, produces ionization of matter, pure energy without mass or charge, are a portion of the electromagnetic spectrum, can adversely affect the biological tissues
properties of x-rays
flow of electrons through a wire
electrical pressure of force that moves electrons between 2 electrical charges
dentistry uses _________
1,000 volts
kilovolt peak, max. kV's
quality of electrons
kV controls the ________ __ _________
amperage or ampere
measure of electrical current
dentistry uses _____________ to measure electrical current
1/1000 ampere
milliampere denotes ______ ______
quantity of electrons
mA controls ________ __ ________
prevents leakage, supports x-ray tube, prevents electric shock
purpose for metal housing
leaded glass envelope in vacuum tube, surrounds electrodes, has window for emission of x-rays
properties of x-ray tube
surrounds x-ray tube, cooling system, and thermal conductor/electrical insulator
purpose for insulating oil
step-up transformer
step-down transformer
regulates electrical voltage
down, milliamperage, quantity, coils, secondary, coil
Step -____ transformer controls _____________ or _______; less turns or _____ in the _________ coil than in the primary ____
up, kilovoltage, quality, more, turns, primary coil
Step- __ transformer controls ________ or _______; ____ _____ or coils in the secondary coil than in the _______ _____
autotransformer, maintains, voltage, step-up
_______________ regulates and _________ the _______ coming in through the ______ transformer
has 2 circuits, cathode, tungsten filament, focusing cup, directs electrons
left side of x-ray tube (vaccum/cathode tube)
high voltage and low voltage
two circuits contain
has negative charge
source of electrons when heated
tungsten filament
metal with negative charge, focusing cup
anode, tungsten target, copper sleeve
right side of x-ray tube
has positive charge
piece of metal embedded into copper stem
tungsten target
target, angled, 20, focal
tungsten ______ is ______ about __ degrees to produce a _____ spot
3373* C
high atomic number and high melting point
kinetic energy, electrons, photons
tungsten target converts ______ ______ of ________ into x-ray _______
good conductor, heat
cooper sleeve is a ____ _________ of ____
dissapates, target
heat _________ from tungsten ______
1%, generates, x-rays
__ of energy _________ into _____
eliminates non useful rays
aluminum filter
diaphragm or collimater
restricts size of primary beam, made of lead
cylinder or rectangular, different lengths
PID, Positioning Indicating Device
turn on unit, set mA's and kVp, select exposure time, thermionic emission produces electron cloud, electron cloud moves from cathode to anode when button is pushed, focusing cup focuses electron cloud towards the target
the sequence of the production of x-rays
cathode ray
electron cloud that moves from cathode to anode by the force of kV's when button is pushed
thermionic emission
removal of electrons by the tungsten filament
electron, formed, removed, turn, on
the ________ cloud is ______ by the _______ electrons, this happens when you ____ the unit __
general radiation
electrons, break, veers
in bremsstrahlung _______ _____ and _____ away
x-ray photon
slowing or stopping of electron creates a _____ _______
bremsstrahlung, break, electron, atom, energy, atom
in ____________, electrons _____ and veer away, after its slowed down or stopped, creating a x-ray photon, the same _______ moves to another ____, giving up ______ as it moves from atom to ____
no ionization occurs
when electrons breaks off and veers, energy expressed in x-rays and heat
bremsstrahlung (general radiation)
the primary source of x-ray photons (70%)
electron hits the nucleus
2nd type of Bremsstrahlung (rare)
one, creates, photon
____ electron ______ one x-ray ______
electrons, electron, tungsten, knocks
_______ hits an _______ in the_______ atom and _____ it loose
energy of movement creates an x-ray photon
cascading affect
electron, energy, electrons, atom, 70 kVp
entering _______ has higher ______ level than _______ in tungsten ____, at least __ ___
photons only, ionization
energy expressed as ______ ____, creating __________
produces small amount of x-rays
characteristic radiation
x-rays, weightless, energy, photons, electrical, waves, frequency, speed
_____ can be defined as ________ bundles of ______ or _______ without an________ charge that travels in ______ with a specific ________ at the _____ of light
photons, materials, ionization
x-ray _______ interact with the ________ they penetrate and cause _________
energy, wave length
x-rays differ in ______ and ____ ______
primary radiation
the penetrating x-ray beam that is produced at the target of the anode and that exits the tubehead
secondary radiation
x-radiation that is created when the primary beam interacts with matter
_________ radiation is less penetrating than primary radiation
scatter radiation
a form of secondary radiation and is the result of an x-ray that has been deflected from its path by the interaction with matter
scatter, deflected, tissues, body, dental
_______ radiation is _________ in all direction by the patients ______ and travels to all parts of the patient's ____ and to all areas of the ______ operatory
x-ray photon, matter, interaction
it is possible for an ____ ______ to pass through ______ or the tissues of a patient without any ___________
photons, interaction, producing densities, radiography
the x-ray _______ that pass through a patient with any ___________ are responsible for _________ _________ on film and make dental ___________ possible
x-ray, completely absorbed, tissues
it is possible for an _____ photon to be __________ ________ within matter or the ________ of a patient
refers to the total transfer of energy from the x-ray photon to the atoms of matter through which the x-ray beam passes
energy, beam, composition, absorbing
absorption dependes on the _______ of the x-ray _____ and the __________ of the _________ matter or tissues
atomic, absorption, photoelectric
at the ______ level _________ occurs as a result of the ____________ effect
photoelectric, ionization
in the ____________ effect, __________ takes place
photoelectric effect
an x-ray photon collides with a tightly bound, inner-shell electron and gives up all its energy to eject the electron from its orbit; the x-ray photon imparts all its kinetic energy to the orbiting electrons, is absorbed, and ceases to exist, 30% of all interactions
ejected, photoelectron, negative
the ______ electron is termed a ___________ and has a ________ charge
deflected, path, passage
it is possible for an x-ray photon to be ___________ from its ______ during its __________ through matter
atomic, compton, scatter
at the ______ level, the _______ effect accounts for most of the _______ radiation
compton scatter
ionization takes place, an x-ray phonton collides with a loosely bound outer-shell elctron and gives up part of its energy to eject the electron from its orbit; the x-ray photon loses energy and continues in a different direction at a lower energy level, incident photon still exists
new, weaker, photon, atoms, energy
the ___, ______ x-ray ______ interacts with other _____ until all its ______ is gone
ejected, compton electron, recoil, negative, positvely
the _______ electron is termed ______ _______ or _____ electron, and has a _______ charge, the remaining atom is _________ charged
62%, diagnostic
compton scatter accounts for ___ of the scatter that occurs in __________ radiography
coherent, unmodified
another type of scatter radiation that may take place when x-rays interact with matter is known as ________ scatter, or _________ scatter
coherent scatter
involves an x-ray photon that has its path altered by matter; occurs when a low energy x-ray photon interacts with an outer-shell electron; no change in the atom occurs, and x-ray photon of scattered radiation is produced, no ionization occurs
coherent scatter, x-ray, direction, incident, no, energy, ionization
in ________ ______ the ____ photon is scattered in a different _________ than the ________ photon, __ loss of ______ and no _________ occurs
8%, interactions, dental, beam
coherent scatter accounts for ___ of the __________ of matter with the ______ x-ray ____
when alternating current is made to flow in one direction
the purpose of filtration
to remove long, soft or non-penetrating waves
inherent filtration
anything included by the manufacturer
added filtration
required by state regulation
collimation, exposure, quality, minimizes
___________ reduces patient _________ and increases _______ and _________ scatter radiation
aborption, tissues, energy, composition
_________ by _______ depends on ______ of x-ray beam and ___________ of absorbing matter
incident photon
the photon that comes form the PID and interacts with matter
pass through
no interatction, no effect on tissues, 9% of x-ray photons during bitewing examination
overall blackness on film
difference of degree in overall blackness
low contrast
lots of black/white, long gray scale, best for perio disease and PA lesions
high contrast
black/white, short gray scale, best for caries detection
increased density, darker film
increased kVp
decreased density, lighter film
decreaed kVp
film contrast
controlled by kVp, absorption of energy
beam intensity
combination of mA, kVp, area exposed, time of exposure