Single Bubble Single Bubble SonoluminescenceSonoluminescence

Senior Thesis to partially fulfill the requirements for the Honors Degree in Physics

at the University of Alaska Fairbanks

Denis Seletskiy

SonoluminescenceSonoluminescence

- Introduction- Brief History- Parameters- Existing Theories- My Experiment- Calculations- Conclusion

IntroductionIntroduction

• What is Sonoluminescence (SL)?

• Single bubble SL (SBSL) and multiple bubble SL (MBSL)

Brief HistoryBrief History• Pre-discovery period - Lord Rayleigh (cavitation 1917)

• Discovery of MBSL (1934) - Frenzel and Schultes (photo plates)

• Discovery of SBSL (1988) - Gaitan ( Flynn’s formulation)

• Subsequent developments - Flash duration, flash spectrum, timing,

temperature, bubble radius, bubble stability (Putterman et al.; Weninger et al.)

ParametersParameters

• Radius of the Bubble in Time• Flash Duration• Spectrum and Temperature• Intensity and Temperature• Effect of Bubble Gas on Emissions• Dipole Emissions

Radius of the BubbleRadius of the Bubble

From : S. Putterman, Sonoluminescence: Sound into Light, Scientific American, 272 (1995)

Flash DurationFlash Duration

From: M.Moran et al., Observations of Single-Pulse Sonoluminescence

(from LLNL e-preprint server www-phys.llnl.gov)

• Streak camera images

• SBSL < 6ps

• Limited by fast streak camera resolution of 2ps

Spectrum and Spectrum and TemperatureTemperature

From: R.Hiller et al., Spectrum of Synchronous Picosecond Sonoluminescence, Phys. Rev. Letters, 69 (1992)

• Solid – blackbody spectrum (T=25000K)

Dotted – SL

• No spectral lines on 1nm resolution scale, (compare to MBSL)

• Note: UV absorption

Intensity and TemperatureIntensity and Temperature

Reducing T results in: a) Intensity increase

b) UV shift in spectrumFrom: R.Hiller et al, Spectrum of Synchronous Picosecond Sonoluminescence,

Phys. Rev. Letters, 69 (1992)

Effect of Gas on EmissionsEffect of Gas on Emissions

From: R. Hiller et al, Effect of Noble Gas Doping in Single Bubble

Sonoluminescence, Science 266, (1994)

• Noble Gas Doping

• Intensity normalized to emissions of air

• Most efficient at 1% doping

Ar) 1% ,N %70( 2

Dipole Emission PatternDipole Emission Pattern

• Bubble eccentricity ~ .01

• Less stable than spherical emissions

Figure shows intensity due to refraction of light from a point source through an elliptical interface (non-spherical bubble)

From:  K. Weninger et al, Angular correlations in sonoluminescence: Diagnostic

for the sphericity of a collapsing bubble, Phys. Rev. E 54, (1996)

Existing TheoriesExisting Theories

• Shock Wave Theory (UCLA) Putterman et al. - as discussed before on the Radius slide - shortcomings: dI/dT >0; noble gas doping; stability - atomic emission timescale ~ ns = 1000x flash timescale

• High Pressure Gas Scintillator (Duke) Tornow - agreement with gas doping and UV spectrum peak

- shortcomings: fails to explain the picosecond flash duration

• Jet Formation Theory (John Hopkins) Prosperetti

- jet fracturing of the wall of the bubble – produces light

- manages to explain almost all of the properties

My ExperimentMy Experiment

•

CellCell• 100 ml Kimax flask with radius 3.05 cm

• Resonant frequency (27.0±0.3) kHz

• Two driving and one sensor

piezoelectric transducers

TransducersTransducers

• Piezo-electric with intrinsic polarization:

P = 3.3 V/nm C = 750 pF

• Curie point 300 °C

• Displacement 195 nm p-p at maximum drive

Electrical CircuitElectrical Circuit

• RLC circuit with variable inductance; tune to match the mechanical resonance frequency

Inductance MatchInductance Match

• In resonant condition voltage swing across the transducers was about 650 V p-p

OUT OF PHASE IN PHASE

Sonoluminescent Flash Sonoluminescent Flash

•

• Digitally photographed using a f=20 cm lens

photons 6106)(5

Digitally EnhancedDigitally Enhanced

• 16X magnification of previous image

• Note: the edge is brighter, suggesting hollow sphere

• Note: dipole-like emission?

ComparisonComparison

• Good agreement with my picture

• Note: radius of glowing bubble is about 10 µm

From: M.Moran et al, Observations of Single-Pulse Sonoluminescence,

www-phys.llnl.gov

CalculationsCalculations

ConclusionConclusion

Black

Thank you