Sonoluminescence

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Sonoluminescence

• By
• Mark Cartagine

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Outline

• What Is Sonoluminescence?
• Sonoluminescence Process, Features,
  Peculiarities
• Theories
• Shockwave
• Jet
• Interesting Research

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What is Sonoluminescence?

• The Equipment

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Result
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Sonoluminescence Process

• Bubble trapped between nodes of 25 kHz sound
  waves
• Expands4µm to 40µm during rarefaction (V? x
  1000) near Vacuum
• Collapses to van der Waals hard core (0.5µm)
  during compression
• VCollapse 1.4 km/s,
• Mach 4

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Process Contd

• Reboundaccel 1011g
• Bubble Emits Light, Sound _at_ min. radius
• Light is Broad Spectrum
• UVgtBluegtRed Equivalent to 70,000K Plasma

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Sonoluminescence Features

• Flash duration 50 pico-sec.
• Interval between flashes 35 millisec
• Energy Concentration 1012

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Peculiarities

• Intensity Inversely Proportional to Temperature
• Radius Discontinuity
• Works best when doped w/ Noble Gas (Helium,
  Argon, Xenon)

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Theories

• Shock Wave
• Jet
• Neither is Totally
• Accepted

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Shock Wave

• Bubble walls collapse Mach 4
• Bubble attains hard core radius
• Shock Wave Continues to Concentrate Energy
• Spherical shock wave hits center and rebounds

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Shock Wave Theory Explained

• Combines Adiabatic Heating Shock Wave Heating
• Ratio of Shockwave Temperatures to Mach No.2
• Mach No. Increases as Walls Collapse
• Two Shock Waves
• Ionization Occurs
• Light Emitted as Electrons Collide w/ Ions
• Max Temp 3x108 K (Theoretical)

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Theory Strengths, Weaknesses

• Explains
• Spectrum (Instant Heating)
• Flash Interval, Duration
• Temperature Effect (Vapor ? with Temp )
• Microphones Near Bubble Hear Pop
• Cannot Explain
• Noble Gas Effect
• Discontinuity
• Critically Dependent on Bubble Symmetry

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Alternative Jet Theory

• Bubble Jitters
• Asymmetric Collapse
• Creates Jet
• Propelled toward Opposite Wall at Mach Speeds
• Shattered Water Emits Fracto-luminescence
• Max Temp 104 K

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Jet Theory Strengths Weaknesses

• Explains
• Noble Gas ? Disrupts Crystalline Form
• Temperature Relation Lower Temps ? More Hydrogen
  Bonds ? Greater Water Rigidity
• Cannot Explain
• Discontinuity
• Spectrum
• Models Noble Gas Effect as Random Process

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Interesting Research

• Taleyarkhan et al., 2002
• Used Deuterated Acetone (C3D6O)
• Injected Neutrons into Bubble _at_ max Radius
• Claims
• Temps 107 K
• Production of Tritium Nucleus Proton
• Helium-3 Nucleus 2.45 MeV Neutron

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In Short

• Fusion!

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Colleagues Reaction To the News

• Shapira Saltmarsh (2002) Repeated
• Taleyarkhan Experiment
• Results
• at least three orders of magnitude fewer neutrons
  than the fusion of deuterium into helium-3 should
  generate, even though their neutron detector is
  more efficient than Taleyarkhans
• Experimental Results not Reproducible

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In Short Your Research . . .
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Taleyarkhans Rebuttal

• Shapira Saltmarsh grossly overestimated
  detector efficiency
• We have been able to reproduce the results, many
  times
• In Short,

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Recent Developments

• Mild Support (Flannigan Suslick, 2005)
• Able to Obtain Plasma
• "A plasma is a prerequisite but certainly not a
  sufficient condition for fusion"
• Maybe we could have fusion with molten salts or
  liquid metals . . .
• Sonoluminescence Remains a Phenomenon in Search
  of an Explanation

?
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References

• Didenko, Y.T. K.S. Suslick (2002). The Energy
  Efficiency of Formation of Photons, Radicals, and
  Ions During Single-Bubble Cavitation. Nature
  418, 394-397
• Glanz, J. (1996). The Spell of Sonoluminescence.
  Science 274, pp. 718-719
• Pool, R. (1994). Can Sound Drive Fusion in a
  Bubble? Science 266, p. 1804
• Putterman, S.J. (1995). Sonoluminescence - Sound
  into Light. Scientific American. 272, pp. 32-37
• Putterman, S.J. (1198). Star in a Jar. Physics
  World. 11, pp. 38-42
• Shapira, D., M.J. Saltmarsh (2002). Comments
  on The Possible Observation of d-d Fusion in
  Sonoluminescence. Physics Division, Oak Ridge
  National Laboratory.
• Taleyarkhan, R.P., C.D. West, J.S. Cho, R.T.
  Lahey Jr., R.I Nigmatulin, R.C. Block (2002).
  Evidence for Nuclear Emissions During Acoustic
  Cavitation. Science 295, pp. 1868-1873
• Taleyarkhan, R.P., R.C. Block, C.D. West, , R.T.
  Lahey Jr., (2002). Comments on the Shapira
  Saltmarsh Report. Physics Division, Oak Ridge
  National Laboratory.