Just right, Beth. Build a big enough one and you wouldn't need fireworks. I am not sure that would be safer, though.
Long ago I worked on spark and wire chambers. I even helped with a needle chamber. In those cases we wanted to see the track of any charged particle, so we had a chamber of a noble gas. This ionized and the spark followed the ionized trail. This simple detector is a great little project. Now all we need is a cirsuit to count the particles. Next project?
A counter circuit would be very easy to implement. A Geiger counter works in an identical way, except that there is some gas inside a Geiger tube. There is both analog and digital means to do the job. Of course, without a known standard, you couldn't calibrate it. Although this is a cool gadget to play around with and for educational purposes, does it have any practical use? I understand that skin, and even paper stops alpha particles. That's why an alpha source (Americium, I think) is used in smoke detectors.
Why publish something so useless? Your alpha source would need to be actually sitting on the metal plate to show activity. Alpha particles, even high energy particles, are stopped by our surface layer of dead skin. If you've ever used a cloud chamber you would know that alpha particles are stopped by a few inches (the size of the project) of air.
Ouch Sparky! Well if you must have a visual show I suggest abandoning the dangerous HV and going for a Cloud Chamber. They are easy to build and the thickness of the vapor trail makes it easy to distinguish between alpha, beta or gamma (cosmic) radiation. As a child I saw my first cloud chamber at a Russian technology exhibit at the New York Coliseum back in the late 1950's. Both the Soviet Union and that NY exhibition hall are long gone.
They love sparks and noise and yes a little danger. This project is a great way to introduce the alpha partical. Inserting paper between the alpha source and the detector would be a good demonstration of the size of the alpha.
While a cloud chamber is certainly a good demonstration tool, its use is more difficult because dry ice is required. In addition, cloud chamber has a limited field of view and difficult to see at a distance. Using the "spark detector", in a darkened room, the entire class could see the effect.
"Useless" is a relative word and is very inappropriate for this forum. Establishing the uselessness of a demonstration, experiment or idea is impossible - if the demonstration inspires just one person to build off of it somehow, it is not useless.
In a related story, apparently some in Pakistan don't think finding the "God particle" is all that amazing or important. It is a very useless endeavor in their minds. Heck,some members of our own Congress think that scientific data is useless and that science has no role in public policy.
So bravo to John Iovine for taking the time to investigate and build a device that addressed his curiosity.
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