19.9 nuclear fusion

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19.9 nuclear fusion

• light nuclei combine to give a more stable heavy
  nucleus plus possibly several neutrons, and
  energy is released.
• Used in hydrogen bombs.
• Powers the sun and stars. (H atoms fuse to form
  helium atoms and release intense energy.)
• Sustainable fusion reactions require temperatures
  of about 100 million oC.
• Exists as a plasma (not solid, liquid, or gas)
• Difficult to make positive nuclei fuse together.

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Advantages of fusion

• More easily available
• Doesnt cause pollution to mine it
• Not easily made into bombs
• Waste products are much less radio active and
  have shorter half lives
• Releases 3-10 times the amount of energy as
  fission

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magnetic fusion reactor

• Figure 21.20 Plasma confinement in a tokamak
  reactor. Courtesy of Princeton Plasma Physics
  Laboratory.