1. Start-Up of a Research Program in Sonoluminescence
Overview of Group
Research Directions & Facilities
Observation of Fluorescence Emissions in Sonoluminescence on Water doped with Dye
Status and Plans
Henry T. Wong /王子敬
Academia Sinica /

2. Collaborating Groups:
AS(台灣中央研究院), CIAE(北京原子能院), NCU(台灣中央大學), NCCU(台灣中正大學), NJU(南京大學), Slovakian Academy of Science
Inter-disciplinary : expertise in particle physics, nuclear physics, optics .....
(BUT -- NO previous experience in acoustics, ultrsoncis ….. Etc.)
A smaller-scale activities in parallel with our core program

3. Approaches: Research Directions:
Study processes that shed light to the underlying physics mechanism of SBSL
Explore possibilities of emissions of high energy radiations in SBSL
Approaches:
Adopt and adapt techniques used in nuclear and particle physics experimentations (high energy radiation detectors, electronics, data acquisition, data analysis ….)

4. Resonators:

5. Liquid & Gas Systems

6. Data Acquisition System
VME Crate
PMTs
VME-PCI Bus …
Gate
PZT-driver
Synchronous
Output
Delay
ADC
TDC
FADC
2.5 GHz
Oscilloscope
PMT PC
Linux & Windows
USB-GPIB

7. Observation of Fluorescence Emissions in Sonoluminescence
Motivations:
SL emissions <200 nm not been observed due to self-absorption in water
UV+HE spectra may provide information on the temperature for black-body emissions
May help to differentiate black-body from other non-equilibrium emissions models
Photon yields ratio between UV+HE & Optical is a convenient gauge of the relative temperature achieved in varying SBSL conditions.

8. Goal: devise an event-by-event analytical method to probe the UV+HE parts of the spectra
Strategy: dope water with fluorescent materials, wavelength-shifted HE SL emissions to optical and differentiate it from prompt SL via pulse shape analysis

9. Quinine is a strongly fluorescent compound in dilute acid solution
Choice of Dopant: Most scintillators are soluable only in organaic solvents  Need one that dissolves in water
Quinine is a strongly fluorescent compound in dilute acid solution
Absorption and Fluorescence
~250nm 400nm
Visible light

10. Set-Up: Quinine in 0.9% dilute sulphuric acid in water
Plastic scintillator panel for capturing cosmic rays which gives pure fluorescent emissions
Digitize pulse with 2.5 GHz oscilloscope interfaced to PC event-by-event
Temperature ranges : 2oC – 25oC

11. Average of 1000 events:
Pure SL from SBSL in water(0.9% sulphuric acid)
Pure FL from cosmic rays
Mixed SL+FL from SBSL in Quinine-doped water

12. Items to study on SL+FL emissions :
Evolve from qualitative to quantitative
Measure UV/HE photon energy
Derivation of temperatures assuming black body emissions, after calibration (light yield  energy output) procedures
Improved DAQ system from Oscilloscope-GPIB to FADC at VME-Linux
Distributions of (a,b) with large event samples
Variations of (a,b) with ambient conditions and SBSL light yield

13. Other Research Program:
Fast DAQ Sampling (achieved 18 kHz) to study timing structures of SBSL events
Repeat/Set Up “neutron detection experiment” to look for possible neutron emissions in SL (i.e. study of SL at high acoustic pressure)
Devise techniques to measure SBSL pulse shapes, towards event-by-event modes , possibly towards HBT analysis

14. Preparation towards repeating neutron experiment at CIAE Neutron Facilities:
CIAE Pulsed Neutron Source
14 MeV or 3 MeV
1.5 ns spill length, repetitive rate 1.5 MHz
1010 neutrons per spill
Beamline
The small pipe side by side is for alpha measurement.

15. DAQ : tag neutrons with both PSD ToF
Neutron Detector :
NE213 liquid scintillator
Sensitive Area: Φ180mm×50 mm
PSD capabilities for (n,g) separation
DAQ : tag neutrons with both PSD ToF