1 / 21

Sonoluminescence

By: Mark Cartagine. Sonoluminescence. Outline. What Is Sonoluminescence? Sonoluminescence: Process, Features, Peculiarities Theories Shockwave Jet Interesting Research. What is Sonoluminescence?. The Equipment. Result. Sonoluminescence: Process.

upton
Download Presentation

Sonoluminescence

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. By: Mark Cartagine Sonoluminescence

  2. Outline • What Is Sonoluminescence? • Sonoluminescence: Process, Features, Peculiarities • Theories • Shockwave • Jet • Interesting Research

  3. What is Sonoluminescence? • The Equipment

  4. Result

  5. Sonoluminescence: Process • Bubble trapped between nodes of 25 kHz sound waves • Expands:4μm 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

  6. Process Cont’d • Reboundaccel ≈ 1011g • Bubble Emits Light, Sound @ min. radius • Light is Broad Spectrum • UV>Blue>Red: “Equivalent to 70,000K Plasma”

  7. Sonoluminescence: Features • Flash duration: 50 pico-sec. • Interval between flashes: 35 millisec • Energy “Concentration” ~ 1012

  8. Peculiarities • Intensity Inversely Proportional to Temperature • Radius Discontinuity: • Works best when “doped” w/ Noble Gas (Helium, Argon, Xenon)

  9. Theories • “Shock Wave” • “Jet” Neither is Totally Accepted

  10. “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

  11. 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)

  12. 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

  13. 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

  14. 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

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

  16. In Short: • Fusion!

  17. 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 Taleyarkhan’s • Experimental Results not Reproducible

  18. In Short: Your Research . . .

  19. Taleyarkhan’s Rebuttal • Shapira & Saltmarsh “grossly overestimated detector efficiency” • We have been able to reproduce the results, “many times” In Short,

  20. 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 ?

  21. 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.

More Related