Waves and Particles Nuclear Physics

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Waves and ParticlesNuclear Physics
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Waves and Particles

• Wave Particle Duality
• Black Body Radiation
• The Photo-electric Effect
• The Compton Effect
• De Broglie Wavelength
• Heisenberg Uncertainty Principle

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Wave - Particle Duality

• Waves exhibit particle-like characteristics
• Particles exhibit wave-like characteristics
• Youngs Double-Slit Experiment using a stream of
  electrons showed a similar deflection pattern to
  light wave

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Blackbody Radiation

• All bodies radiate electromagnetic waves.
• Blackbodies are objects that absorb all
  electromagnetic waves that fall on them.
• Materials that are good absorbers are good
  emitters.
• Materials that are good reflectors (like polished
  silver) are poor emitters.
• Max Planck stated that objects emit energy at
  integer multiples of the frequency of the wave
  emitted.

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Plancks Equation

• E n h f
• Where E is energy, n 0,1,2,3,, f is the
  frequency of the wave and h is Planks Constant,
• Plancks Constant(h) 6.6260688 X 10-34 Js
• These energy packets have a value hf

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• Plancks equation verifies Einsteins earlier
  claim that light consists of energy packets
• He received the Nobel Prize in 1918 for his work
  on Quantum Theory.

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The Photoelctric Effect

• Photons hit metal surface with sufficient
  frequency
• Energy from photons creates a current
• Photo cells are commonly used in various
  detection systems (garage doors, alarm systems,
  etc.)

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The Compton Effect Aurthur Compton

• Decrease in energy (increasing wavelength l) when
  photons interact with matter.
• Compton used x-rays and gamma rays to prove
  Einsteins Photoelectric Effect/Photon theories.
• Inverse Compton Effect occurs when photons gain
  energy from their interaction with matter.

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Compton Effect
Arthur Compton Nobel Prize 1927

• Mathematical Explanation
• h f h f KE
• Energy of incident energy of
  Kinetic Energy gained
• Photon scattered photon by scattered
  electron.

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DeBroglie and the Wave Nature of Matter

• Using the wave-particle duality work done by
  Einstein and Planck, De Broglie stated that ALL
  objects that move have a wavelength similar to a
  wave associated with them.

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The De Broglie Wavelength

• De Broglie stated that the wavelength of any
  particle or object is inversely proportion to its
  momentum (p).
• l h / p
• Where l wavelength
• h Plancks Constant
• p Momentum (m v)

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De Broglie Wavelength

• Verified experimentally by several physicists in
  the U.S. and in Europe
• The De Broglie Wavelength is only observable for
  very small masses (protons, neutrons, electrons,
  etc)
• Because the l for larger masses would be very
  small, diffraction and interference cannot be
  observed. (See example 5 in book)

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The Heisenberg Uncertainty Principle
Werner Karl Heisenberg Nobel Prize 1932

• Limits the accuracy with which momentum and
  position of a particle can be described
  simultaneously
• These limits are imposed by nature and cannot or
  of the quality of the equipment used)
• Heisenbergs Principle describes uncertainty
  between position and momentum as well as energy
  and time.

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The Heisenberg Uncertainty PrincipleMomentum and
Position
Momentum and Position (Dpy)(Dy) __h__
4 p Where Dy
uncertainty in the particles y direction Dpy
uncertainty in the vertical component of the
particles momentum. h Plancks Constant
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The Heisenberg Uncertainty PrincipleEnergy and
Time
Momentum and Position (DE)(Dt) __h__
4 p Where DE
uncertainty in the particles energy when in a
certain state. Dt Time interval that
the particle is in that state h Plancks
Constant
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Congratulations!!
If you understood all of this I am impressed
because. This is tougher than Rocket Science!!!