Electromagnetic Radiation

1
Electromagnetic Radiation
2
Photon

• The smallest quantity of any type of
  electromagnetic radiation
• May be called a quantum

3
Sine Waves

• Amplitude
• One half the range from crest to valley over
  which the sine wave varies
• (crest top , valley bottom)
• Frequency
• The number of wavelengths passing a point per
  second
• (measured in Hz)
• Wavelength
• The distance from one point on the sine wave to
  the next corresponding point
• (crest to crest or valley to valley etc.)

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The Wave Equation

• At a given velocity, frequency and wavelength are
  inversely proportional.
• Velocity Frequency x Wavelength

5
Electromagnetic Spectrum

• A chart that describes the energies, frequency
  and wavelengths of electromagnetic energy.

6
Wave particle duality

• When the photon behaves both as a particle and a
  wave.
• Photons interact with matter most easily when the
  matter is approximately the same size as the
  photon wavelength

7
Characteristics of wave forms

• Attenuation
• The reduction in the total number of x-ray
  photons remaining in the beam after passing
  through a given thickness of material
• Reflection
• X-ray photons that bounce off matter in the same
  direction that it was interacted with
• Absorption
• X-ray photons that are totally absorbed by matter

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Characteristics of x-ray absorption

• Radiopaque
• Structures that absorb x-rays
• Radiolucent
• Structures that attenuate x-rays

9
Inverse Square Law

• Radiation intensity is inversely related to the
  square of the distance from the source
• I 1 (d2)2
• I 2 (d1)2

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Matter and Energy

• Law of conservation of matter
• Matter cannot be created or destroyed
• Law of conservation of energy
• Energy cannot be created or destroyed
• (Energy may be transferred to matter and vice
  versa)