Dusty plasmas with magnetized dust

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Dusty plasmas with magnetized dust
Auburn University ? October 19, 2009

• Bob Merlino
• University of Iowa

Full text available at http//www.physics.uiowa.e
du/rmerlino/Dusty20Plasmas.htm
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Why?

• New dusty plasma physics to study
• Astrophysical and planetary dusty plasmas have
  magnetized dust
• Much theoretical work on waves in magnetized
  dusty plasmas has been done

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Criteria for magnetized dust

• 1. dust gyroradius ltlt transverse
  plasma dimension
• 2.
• dust gyrofrequency gtgt dust-neutral
• collision frequency

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Magnetic field strengthvs. device size

• Criteria can be satisfied with high B and
  moderate size device, or
• Moderate B and very large device
• Cost trade-off ??

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Dust size consideration

• Both criteria are satisfied more easily with
  small dust grains
• But, grains that are too small are not easily
  imaged
• Another issue ? diagnostics ??

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Plasma source considerations

• Not easy to make uniform and stable plasmas in
  high B fields
• Discharge sources require neutral gas, and the
  dust-neutral collision frequency pressure
• Probably need plasma source that operates at
  pressures below 10-5 torr

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Parameter scalings (a dust radius)
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Dust gyroradius vs. B
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questions

• Should the particles be large enough to be
  imaged?
• How will we diagnose this dusty plasma?
• What type of plasma source should be used?
• What dusty plasma physics should be studied