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10 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is attenuation?
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The process where radiation is reduced in intensity with passing through material
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What is the range of beta particles most effected by?
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The maximum distance is strongly dependent on the number of absorber electrons in the particles path, not so much on the atomic number
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What is the difference between elastic and inelastic collisions?
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inelastic: some of the kinetic energy is transferred to the other particle and both move
elastic: all of the kinetic energy is transferred to other particle |
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What is specific ionization?
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same as LET in radiobiology, # of ion pairs created per unit of length traveled
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What is bremsstrahlung radiation?
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when an electron changes velocity near dense nucleus it gives off x-rays
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Why is the range of alpha particles in a material very predictable?
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absorption is flat because alpha is monoenergietic
What is the average energy loss of traveling alpha particle? |
35 eV per ion pair created
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What is the exponential absorption equation for gamma or x-rays?
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I = I0e-ut
I0 = initial intensity I = reduced intensity u = linear attenuation coefficient, cm-1 t = absorber thickness, cm |
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The reduction in intensity of gamma rays are dependent on 2 factors, what are they?
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the amount of energy and material
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What is a half value layer (HVL)?
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The thickness of a given material at a specific energy level needed to reduce the intensity by half
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What is photoelectric effect and why is it important for imaging?
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inner shell electrons removed and photons produced, higher Z numbers favor this, so most of the energy is deposited in crystal without scatter in scans
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