Hi JJJ,
Thanks for the post.
In the 1970's, one of my favorite books was "The Scientific American Book of
Projects for The Amateur Scientist" by C.L. Stong. It was a series of reprints
from the famous "The Amateur Scientist" section of the monthly magazine,
Scientific
American.
One of the projects was "Build your own Cloud Chamber" and the author described
how you could obtain a speck of radioactive material by simply writing to him and
enclosing a self-addressed envelope.
C.L. Stong replied to me with an apology in a very humorous letter that had
been hand-typed on some ancient typewriter. He was getting on in years by then.
He had been a barnstorming pilot in the bi-plane era and had become an Electrical
Engineer in 1926. Unfortunately, he explained, due to postal regulations, he could
no longer send radioactive samples in the mail. However, he explained the samples were
specks of radium paint - the same type that was used to paint glow-in-the-dark
watch and clock dials at the time. As these were ubiquitous in the 1970's, a sample
was readily obtained by just scraping the paint from the hands of a broken
alarm clock.
One of the best cloud chambers I ever encountered was in the Science Museum
in London in the late 1980's. It was quite large and a beautiful thing to watch the
particles streaming through it.
Here is a YouTube video of someone's cloud chamber in action using a Thorium 232
source.
http://www.youtube.com/watch?v=UIDYH...eature=related
In another article in the same book by C.L. Stong, you could build your own
Homemade Atom Smasher "for less than the average cost of a set of golf clubs".