Physics Bushong

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Author:
RadiationTherapy
ID:
180108
Filename:
Physics Bushong
Updated:
2014-01-03 16:05:38
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Radiation therapy physics rad science
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Radiation Physics Test 10/29
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  1. Structures that absorb X-rays
    • Radiopaque
    • (ie. bone)
  2. Structures that transmit X-rays
    • Radiolucent
    • (ie. soft tissue)
  3. The Inverse Square Law can be applied to distances greater than _________ times the longest dimension of the source
    The inverse square law can be applied to distances greater than  SEVEN times the longest dimension of the source.
  4. States that the intensity of radiation at a location is inversely proportional to the square of its distance from the source.
    • The Inverse Square Law
  5. A discrete bundle of energy
    the x-ray photon
  6. Photon energy is directly proportional to
    photon frequency
  7. Photon energy is ____________ proportional to photon wavelength
    Photon energy is INVERSELY proportional to photon wavelength.
  8. X-rays exist:
    at the speed of light or not at all
  9. E=hf
    Planck's Quantum Equation
  10. The longer the wavelength, the _____________ the energy of each photon.
    • Lower
    • (longer=lower)
  11. The law of conservation of mass & energy states:
    Energy & Matter can neither be destroyed or created
  12. The properties of elctromagnetic radiation include:
    (4)
    • frequency
    • wavelength
    • velocity
    • amplitude
  13. Electromagnetic energy exists over a wide range called:
    an energy continuum

    A continuum is an uninterrupted (continuous) ordered sequence.
  14. An atom of light
    Photon
  15. The smallest quantity of any type of electromagnetic energy
    photon
  16. A photon may be pictured as a small bundle of energy, sometimes called a
    Quantum
  17. A quantum of electromagnetic energy
    an x-ray photon
  18. Energy disturbances that move through space at the speed of light
    photon
  19. Mass of a photon
    • Photons have NO MASS
    • but they do have electric and magnetic fields
  20. Speed of light
    • 3x108 m/s
    • The speed of light (c)
  21. The velocity of electromagnetic radiation
    3 x 108 m/s
  22. Variations of amplitude over time
    Sine wave
  23. One-half the range from crest to valley over which the sine wave varies
    • Amplitude
  24. The number of wavelengths that pass a point of observation per second
    • Frequency (f)
    • measured in Hertz (Hz)
  25. The rate of rise and fall
    Frequency (f)
  26. What is frequency measured in?
    • Hertz (Hz)
    • One hertz is equal to one cylce per second
    • ie. 20 cycles in 10 sec is 2 Hz
  27. The distance from one crest to another, one valley to another or from any point on the sine wave to the next corresponding point
    Wavelength 
  28. What are the 3 parameters needed to describe electromagnetic energy?
    • Velocity (v- measured in m/s)
    • Frequency (f- measured in Hz)
    • Wavelength 
  29. At a given velocity _______________ & ______________ are inversely proportional
    wavelength & frequency
  30. For electromagnetic energy, frequency and ____________ are inversely proportional
    wavelength
  31. The deviation of course that occurs when photons of visible light traveling in straight lines pass from one transparent medium to another
    Refraction
  32. ________ light consists of photons with wavelengths longer than visible light but shorter than microwaves
    Infrared light
  33. ___________ light is between visible light & ionizing radiation on the spectrum
    Ultraviolet light
  34. An x-ray photon contains ___________ energy than a visible light photon or an RF photon
    considerably more
  35. The frequency of x-radiation is much _________ and the wavelength is much _________ than for other types of electromagnetic energy
    • Higher (frequency)
    • Shorter (wavelength)
  36. Where are x-rays produced?
    Outside of the nucleus of excited atoms; emitted from the electron cloud
  37. Where are gamma rays produced?
    Inside the nucleus of the atom
  38. A photon of x-radiation & a photon of visible light are fundamentally the same except that x-radiation has ________ frequency & hence a _________ wavelength
    • Higher (frequncy)
    • Shorter (wavelength)
  39. X-rays are identified by
    Energy
  40. Visible light tends to behave more like
    Waves
  41. X-ray photons tend to behave more like
    Particles
  42. The reduction in intesnsity that results from scattering and absorption
    Attenuation
  43. Transfer of energy from an electromagnetic field to matter.

    Removal of x-rays from a beam via the photoelectric effect.
    Absorption
  44. Return or re-entry of an x-ray
    Reflection
  45. Passage of an x-ray beam through an anatomical part with no interaction with anatomical structures
    Transmission

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