Demonstrations of Half-Life

[Mark Hanlon <MarkH@nch.edu.au>]

Dear Colleagues,

Thank you for the many useful replies I received to my request for
a way to demonstrate the concept of a half-life, in a practical way. 

For this specific request, the criteria were that the demonstration
should be very practical, and that it should be easily grasped by
people with a limited education and a non-English-speaking
background. One or two suggestions were really good, but
require equipment that I don't have access to (and can't, at the
moment, buy).  A few suggestions didn't quite meet these criteria,
but were quite good, and can be used with other audiences.

Some suggestions : 

Air Sampling   -  this is a very practical demonstration of a true   
half-life; 

Barium generator - measuring decay of the barium;

Chemical lights - these fade over time

Flashlight  - flattening batteries over time

There were also a number of good analogies - but some of these
could be as hard to express as the actual half-life concept, to a
non-English-speaking background group. 

The two suggestions which were made with, by far, the greatest
frequency, were : 

Coins - variations on the "heads and tails" game, with removal of
one category after every toss.  There were many variations of this
suggestion. 

Popcorn - while we would all appreciate that cooking popcorn is
not a technically accurate analogy to radioactive decay, this form
of demonstration brings a bit of fun to what is a very "dry"
subject for this audience.  It has a great deal of appeal.  

Well, backed up by the expert opinions of my esteemed
 international colleagues from Radsafe, I will inform management
that I need a popcorn cooker as a training aid, and I'll set up an
elegant series of experiments to determine the most appropriate
operating parameters. (I wonder what the annual dose limit for
popcorn is, anyway ?).

Thanks to all, for the excellent ideas, all of which I will use with the
appropriate people.

Mark Hanlon,
Radiation Safety Officer,
New Children's Hospital,
P.O. Box 3515,
PARRAMATTA, NSW, 2124
Australia

Phone  61 2 9845 3324      FAX  61 2 9845 0831

email  markh@nch.edu.au


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