Single Bubble Sonoluminescence Senior Thesis to partially fulfill the requirements for the Honors...

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