HOW TO:

First you must get a couple things.
*Sine Generator- that can provide over 25kHz. The generator that we are using is an older oscillator. I'm talking vacuum tubes. The reason for the older type is many of the newer sine generators make a sine wave by taking parabolas and attaching them while the older (oscillator) provides a clean sine wave at a low distortion rate.

*Amplifier- almost any amp. that provides enough power will work. We are using a kenwood car amp. that is powered by 2 deep cycle batteries. The reason for the batteries is to provide enough current for the amp. As long as the amplifier is putting out above 40 volts peak to peak you should be pushing enough drive amplitude. This can be checked with an oscilloscope.

*2 oscilloscopesthat are two trace. One for the RLC circuit and the other for the Microphone.

*2 piezoceramic transducers(drivers, speakers) The transducers and the microphone can be ordered from:
Channel Industries Inc.
Santa Barbara, CA.
(805)967-0171
They may be ordered as a set for roughly 100 dollars.

*1 piezoceramic transducer (microphone)

*Three finger clamp

*Laboratory stand (with a large diameter ring stand)

*Flask: 100 mL Pyrex spherical flask with a small neck

*Lead wire- this is for attaching the piezos to the coaxial cables. Around 36 AMG (coated).

*Inductor(s)- We are presently using a variable inductor that is set at 26.7 mH (our flask resonance), that is where our resonance at 25 kHz in the RLC lies. This is the very best idea due to the fact that the inductance needs to be set very close to get the RLC circuit in phase. You might be limited in resources and have to work with a couple inductors to find the circuit resonance of 25 kHz. They add together like resistors: add together in series and with the reciprocal in parallel. (1/total L)= (1/L)+(1/L) .......
We ordered ours from:
Electronics Plus Inc.
823 Fourth Street
San Rafael, CA. 94901
(415)457-0466

*Resistors- 1M, 10k, 1R

*Coaxial cable

*5 Minute epoxy(for gluing the piezos to the flask)

*Eyedropper

*Degassed distilled water- We degassed our water by using a vacuum dome with the water in a Ernmeyer flask.

*A Bubble and some luck

O.K. so your all ready to go. Well here it is.

First about the RLC circuit. It is very critical that the circuit is made correctly to be able to achieve the proper 25 kHz plus or minus 5 kHz. Douglas Manning, my research partner made this RLC circuit. What your looking at below is the actual diagram of our wood-mounted RLC circuit. We epoxied everything down and used BNC connectors to enable the apperatus to be portable.

Resonator:

Now about the resonator.
Since you have now your 100 mL flask check the flask for anyimpurities or chemicals left in the flask from prior experiments. It is very important that the flask is very clean if it isn't new.

Also go ahead and cut portions of the 36 AMG coated wire. About 2 inches should be enough. Make sure that when you remove the coating that the wire is not tarnished. If the wire is cut into while the de-coating of the wire it will either reduce the signal through the lead or weaken the lead enough to break later on (most likely after it is soldered to the PZT's).

Now about the Piezoelectric Ceramic Transducers (PZT's).
This is most important part of the apparatus. If you ordered the transducers from Channel Industries what you have is Navy type 1 which is relatively impervious to water. The ceramic has a permanent polarization, which is provided by heating the PZT's above their "Curie Point" around 450C and then cooled. This polarization will remain unless the piezo is heated again above it's Curie Point. The polarization defines positive and negative as marked on the PZT's. When a DC current is passed through the PZT's the ceramic tends to expand or contract, depending on the polarity. When wiring the drive piezos to the amplifier they should be in parallel. You should triple check that the drive piezos are wired with the same polarity to enable you to have phase in the circuit.

Why so much info. on the PZT's? Well here's the fun part: 60-40 tin-lead solder (recommended) liquifies at 400 to 500 degrees C. Remember the Curie point?

Soldering the PZT's:
When soldering the piezos first you must find a very good flux. A good flux base helps speed the soldering process. On allof the piezos you must clean them with a pencil eraser to remove the oxidation. After removing the oxidation you are now ready to solder. We used a "heat sink" with our soldering. Our heat sink was a round piece of aluminum about 2 inches thick that was cooled to around 10 degrees C. Aluminum is notorious for its specific heat capacity and ability to pull heat from other objects.
-Now tin the ends of the lead wires.
-Place the piezo on the heat sink and solder three dots on each drive piezo making sure that they are soldered on the same polarization marked side. Go ahead and dot the microphone piezo in three spots also. Now place one dot on the other side of each of the piezo (this is the side that will be pointing away from the flask). BE SURE TO WORK FAST. Don't spend over a couple secondswith the soldering iron on the piezo. The dots should be just large enough to connect the small 36 AMG to them.
-Dip your lead in some flux. Now with the tinned lead lay it across one of the dots and with the soldering iron heat up the dot until the lead wire flows into it.
-After you have all the leads soldered to the piezos check the connections and then clean the residual flux off with a q-tip and alcohol.
-Now your ready to do some mounting. With five minute epoxy mount the drive piezos roughly 180 degrees apart and centered on the flask. The side that is mounted on the flask should be the side with the three leads in case one breaks. Go ahead and mount the small mic. piezo on the bottom of the flask also with the three lead side toward the flask. (see below)

-Now connect (solder) the leads from the drive piezos to the to the coax (it's a good idea to strap the coax to the three finger clamp to reduce the stress on the leads).
-Connect the microphone leads to the coax running to the second o-scope.

-Now your looking at the upper diagram and probrably thinking what the heck. O.k the sine waves you see above is what you should be looking at when your system is in phase. This is most likely at the 25 kHz depending on your resonator and set-up.
-Below that is a model of how you bubble will react to various power settings. This a very important part in the deduction of where your at while trying to get a sonoluminescencing bubble. I have found that the very best way to find that "glowing bubble" is to:

1) Set the power low but still high enough to lock a bubble in the center.
2) Set the frequency at the point where some noise is picked up in the microphone PZT.
3) Now raise the power level very slowly until the bubble completely collapses.
4) Now you are just barely over the sonoluminscencing level "power-wise". It's now time to reduce the power level a small amount and inject another bubble.
5) If the bubble disappears then the power is still to high. If you now have a stable bubble at this reduced power relative to the upper-level just found; you are in business.
6) At this point the frequency should be set to a point where the noise through the microphone PZT is at it's greatest.
7) Now turn off all the lights. At this point I found that taking a small Mag. flashlight and focusing on the bubble and then slowly moving the light away enables you to find that glow more easily. Also at this point you might have to manipulate the frequency to find that perfect spot. When that frequency/powerlevel is found the bubble will appear just like flipping a switch.

-Please forgive the absence of numbers with this description. I have found that with various set-ups the numbers differ somewhat. So the importance lies in the observation of the bubble's behavior and not so much in duplication of numbers.
-Now it is time to marvel at this phenomenon and partake in the theory behind the mechanism of this great and yet unexplained anomaly of nature. Good luck and above all enjoy yourself!

[IMAGE]

-At this point I would like to thank some people. --Above all thanks goes to Tom Masulis my more than generous physics professor. Without his acceptance of my curiosity and endless patience upon being barged by many questions, Doug and I would not have been so lucky.
-My partner in this project who without his guidance and even-keel I would have surely been over my head. Douglas Manning.
-Dr. Robert Hiller for answering everyone of my questions and providing many valuable insights.
-And last but far from least Joe Polen (physics professor) for volunteering his time and resources to the project.
-Also Shasta College for employing these great professors and providing the resources when needed.
I hope that you are as lucky as I with the project and also teachers. Without the constant resolve and belief that Tom and Joe have shown in Doug and I along with many other students we all would be less fortunate.

Questions, Comments? cpeter2001@aol.com

Good Luck!!!