Re: Cloud chambers

[Dan MacIsaac <Dan.MacIsaac@NAU.EDU>]

Ludwik:

I also build these with teachers.  Recent manufacture Coleman
lantern mantles no longer contain Thorium, so I use radioactive
rocks I grabbed in AZ (Carnotite), or the commercial needle
sources, or recent Chinese manufacture lantern mantles.

The NAS has a site that discusses tips for making cheap
and nasty cloud chambers work at
<http://www2.ans.org/pi/teachers/reactions/2001-06-02.html>

Dan M

On Sep 23, 2004, at 5:57 PM, Ludwik Kowalski wrote:
> Question:  I am a junior high Science teacher.  For the
> past two years I have tried to help my students build
> cloud chambers.  We use small plastic dishes with
> black felt on the bottom and a black paper ring around
> the inside edge.  We use Coleman lantern mantles and
> 91% isopropyl  alcohol.  We place this in a Wendy's
> salad container along with vermiculite and dry ice.
> And we wait, and wait.  The room is darkened.  The
> children use flashlights to see into the chamber.  And
> they see nothing.  I know I have seen this experiment
> work.  It has worked for me in the past...but not these
> last two years. What am I doing wrong? Does anyone
> have any suggestions? Help! I would really like to do
> this -- but with success.
Dan MacIsaac, Assistant Professor of Physics, SUNY-Buffalo State College
222SCIE BSC, 1300 Elmwood Ave , Buffalo NY 14222 USA 716-878-3802
<macisadl@buffalostate.edu>  <http://PhysicsEd.BuffaloState.edu>