1. Sonoluminescence
By:
Mark Cartagine

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, 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 max Radius
Claims:
Temps ≈ 107 K
Production of Tritium Nucleus + Proton
Helium-3 Nucleus 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,
Glanz, J. (1996). The Spell of Sonoluminescence. Science 274, pp
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
Putterman, S.J. (1198). Star in a Jar. Physics World. 11, pp
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
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.