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RadTherapy
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What do the properties of electromagnetic energy include?
- frequency
- wave length
- velocity
- amplitude
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Ever present all around us is a field or state of energy called
electromagnetic energy
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Electromagnetic energy exists over a wide range called and energy______
continuum
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What is a continuum?
An uninterrupted (continuous) ordered sequence
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An atom of light is a
photon
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A _____ is the smalles qty of any type of electromagnetic energy, just as an ____ is the samllest qty of an element
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A photon may be pictured as a small bundle of energy, sometimes called a ______, that travels thru space at the speed of light.
quantum
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An x-ray photon is a _____ of electromagnetic energy
quantum
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James Clerk Maxwell showed that visible light has both electric and magnetic properties, hence the term _____ ______
electromagnetic energy
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What are energy disturbances that move through space at the speed of light?
Photons
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The velocity of all electomagnetic radiation is
- C=3x10^8 m/s
- speed of light
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The gravitational field governs the interaction of different masses, the electric field governs the interaction of electrostatic charges and the magnetic field governs the interaction of magnetic poles, this variation is called a
Sine wave
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____ _____ can be described by a mathematical formula and therefore have many applications in physics
sine waves
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_______ is 1/2 the range from crest to valley over which the since wave varies
Amplitude
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Higher the amp, the _____ the wave
weaker
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The sine wave model of electromagnetic energy describes cariations in the electric and magentic fields as the photon travels with velocity c. The important properties of this model are ______ represented by __ and ____ ____ represented by the ____
- frequency, rep by f
- wave length, rep by the greek letter lambda (insert funky letter from page 46 here)
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The rate of rise and fall is
frequency
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what is usually identified as cycles per second?
frequency
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___ hertz is = to 1 cycle per second?
1
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Frequency is = to the # of _____ and ______ that pass the point of an observer per unit of time.
crests and valleys
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the ___________is the distance from one crest to another, from one valley to another, or from any point on the sine wave to the next corresponding point.
wave length
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the wave length is the distance from one _____to another, from one ________ to another, or from any point on the _____ _____ to the next corresponding point.
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Three wave parameters are needed to describe electromagnetic energy, what are they?
- veolcity
- frequency
- wave length
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At a given velocity, wavelength, and frequency are ___ ____
inversely proportional
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A simple mathematical formula, called the ____ _____ expresses this interrelationship of how the 3 parameters associated with a sine wave are related
wave equation
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What is the wave equation used for
both sound and electromagnetic energy
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Sound waves are OR are not very different from electromagnetic photons?
are
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For electromagnetic energy, _____ and _____ are inversely proportional
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As the _______ _____ increases, the _______ decreases and vice versa
- eletromagnetic energy
- wavelength
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What includes the entire range of electromagnetic energy
electromagnetic spectrum
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what is not part of the electromagnetic spectrum?
diagnostic ultrasound
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The energy of a photon is directly proportional to its
frequency
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Although photons of visible light travel in straight lines, their course can be deviated when they pass from one transparent medium to another. This deviation in line of travel is called
refraction
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The deviation in line of travel called ______, is the cause of many peculiar but familiar phenomena, such as a rainbow or the apparent bending of a straw in a glass.
refraction
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communiaction broadcasts are usually identified by their frequency of transmission and are called
radiofrequency emissions (RF)
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An _____ _____ contains considerably more energy than a visible light photon or an RF photon.
x-ray
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An xray photon contains considerably more energy than a ______ ______ _____ or an ___ ______
- visible light photon
- RF photon
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The frequency of x-radiation is much _______ and the wave length is much _______ than for other types of electromagnetic energy
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The frequency of _______ is much higher and the ______ is much shorter than for other types of electromagnetic radiation.
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It is sometimes said that gamma rays have ( higher OR lower) energy than xrays
higher
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Gamma rays are found where?
in the nucleus of an atom
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Xrays are found where?
outer shells of an atom
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The only diff between xrays and gamma rays is
their origin
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What are emitted from the electron cloud of an atom that has been stimulated artificially>
xrays
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Visible light is identified by
wavelength
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radiofrequency is identified by
frequency
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xrays are identified by
energy
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A photon of x-radiation and a photon of visible light are fundamentally the same except
that xradiation has much higher frequency and hence a shorter wavelength, than visible light
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A photon of ______ and a photon of ____ ____ are fundamentally the same except that xradiation has much higher frequency and hence a shorter wavelength, than visible light
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The differences between photon of xradiation and photon of visible light result in differences in the way these photons
interact with matter
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Visible light photons tend to behave more like _____ than _____
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xray photons behave more like _____ than _____
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When both types of photons exhibit wave and particle behaviors, this is known as
wave-particle duality
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Photons interact with matter most easily when the matter is approx the same size as the ____ _____
photon wavelength
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What behave as those they are particles?
xrays
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Narrow portion of the enormous spread of the electromagnetic spectrum is called
visible light
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visible light behaves like a
wave
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_______ _______ attenuation is the reduction in intensity that results from scattering and absorbtion.
electromagnetic energy
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Electromagnetic energy attenuation is the reduction in intensity that results from ______ and ______
scattering and absorbtion
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visible light can interact with matter, _____ from the silvered surface of a mirror is common
reflection
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When light waves are absorbed, the energy deposited in the absorber reappears as
heat
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When ____ ____ are absorbed, the energy deposited in the absorber reappear as heat.
light waves
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______ and ______ are used routinely in xray diagnosis to describe the visual appearances of anatomical structures
radiopaque and radiolucent
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Structures that absorb xrays are called
radiopaque
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structures that transmit xrays are called
radiolucent
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Is bone radiolucent or radiopaque?
radiopaque
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Is lung tissue radiopaque or radiolucent?
radiolucent
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The decrease in intensity is ____ ______ to the square of the distance of the object from the source.
inverselty proportional
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The decrease in ________is inversely proportional to the square of the _______ of the object from the source.
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The decrease in intensity is inversely proportional to the square of the distance of the object from the source and is called the
inverse square law
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Note:
Electromagnetic energy (radiation) intensity is inversely related to the square of the distance from the source.
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What can be applied to distances greater than 7 times the longest dimension of the source?
inverse square law
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To apply the inverse square law, you must know 3 of the 4 parameters which consists of
2 distances and 2 intensitys
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The ____ photon is a discrete bundle of energy
xray
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what are created with the speed of light (c) and exist with velocity (c) or they do not exist at all?
xrays
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what is directly proportional to photon frequency?
photon energy
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Photon energy is _____proportional to photon frequency
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The constant of proportionality of photon energy and photon frequency is known as
Planck's constant and symbolized as h
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Matter can be neither created or destroyed, a law known as the
law of conservation of matter
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What is an example of the conversion of energy into mass>
pair production
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