1. Observation of Fluorescence Emission from Single-Bubble Sonoluminescence in Water doped with Quinine
Institute of Physics, Academia Sinica SL Group
J.Q. Lu , F.K. Lin, H.I. Leong, T.K. Wong
2006/01/16

2. OUTLINE Why the ultra-violet radiations are so important?!
How can we measure the ultra-violet radiations?!
What are the results we have got?!
Summary

3. WHY ?!
The light emission mechanism of the collapsing bubble (sonoluminescence) is still unknown.
Is there any high energy photons emitted ??
 The most important thing in single bubble sonoluminescence (SBSL) is
temperature

4. That’s why we are so interesting in
temperature.

5. Only “visible light” (300nm~800nm) can penetrate the water.
So, we can get the
temperature of SBSL
is through fitting
“the blackbody radiation
curve”.
Water absorption spectrum
25,000K
Blackbody radiation curve

6. OUR GOAL: Doing the FIRST observation of ultra-violet radiations in single-bubble sonoluminescence.
And we find an experimental method to do the wavelength shifting of the high energy photons into the “visible light”, by
Using Scintillator

7. HOW ?! How scintillator works ??
 slower decay curve (ns) compare to prompt SL curve (ps)
Fluorescence (FL)

8. RIGHT SCINTILLATOR
Quinine is a strongly fluorescent compound in dilute acid solution with two excitation wavelengths (250 and 350 nm) and a fluorescence emission at 450 nm.

9. Experimental Set-Up

10. Two components of Quinine SL
Pure sonoluminescence (SL) Waveform
Pure Fluorescence (FL) Waveform

11. Fitting
= = = 1
=(1-a) a
Hep-physics/ , Ultrasonics, in press (2006)

12. Temperature of the surface of bubble
Planck’s law:
Number of photons:
= = _
What does FLcoeff a means? a

13. FLcoeff a is a function of T
a = f(T)
A new method to determine the temperature of the surface of bubble.

14. Future work
X-axis is T, Y-axis is the value of FLcoeff
Question:
It seems that the value of y is invariable, whether it is and what it means?
If we change the parameters, what will happen?
How about the photons with higher energy (λ<250nm)?

15. ~ Thank You ~