training -Reply

[FRAMEP@ORAU.GOV]

Emilie Lamothe wrote in part:

>We want to cover basics such as what is radiation and a half-life, a
>bit about dosimetry and environmental monitoring, possibly something
>on health effects, and because of the nearby nuclear generating
>station, emergency preparedness.  Does anyone have any suggestions?

Some random off-the-top of my balding head thoughts:

Basics:

Its nice to have a familiar alpha-beta-gamma source eg. a gas lantern
mantle. Using a pancake gm which responds to all three you can show a
piece of paper stops some counts (those from the alphas), a hand
stops more (those from betas) and some counts continue (those due to
gammas). It would probably take several mantles to generate
sufficient gammas to do this properly.

Demo the americium source in a smoke detector and explain how it
works i.e. via ionization of the air - the same principle at work in
the gm. Also get a cheap cloud chamber if you have dry ice/ liquid
nitrogen readily available to demo ionization.

Decay:

Obtain a Cs-Ba generator. These are cheap and easy to come by or
make. Milk off the barium -137 onto a planchet and you have a
material with a nice short half life to measure.  As a bonus you can
simultaneously show the decrease in activity on the column as the
barium is milked off and then watch it grow back. This combination of
decay and ingrowth was part of the evidence that Rutherford and Soddy
used to prove their theory of transmutation. 

Radon daughters can be collected on a filter via a pump and/or vacuum
cleaner and their decay can be monitored. This is a multicomponent
curve however. 

Dosimetry:

To demonstrate thermoluminescent dosimetry irradiate some NaCl to ca
100,00 rad (less might be fine, do what you can and try a test). The
ANS used to sell this stuff for 10 bucks or so. In the dark, sprinkle
it on a hot plate and the thermoluminescence will be readily visible.
You could also use LiF etc. Remark that the amber color of the
irradiated salt represents a change in the absorption spectrum
brought about by the trapped energy (and energy absorption is what
dosimetry is about).

As part of this demo you could heat up and decolorize some amethyst-
the purple color of which is radiation induced.

Environmental monitoring:

Tough to do something easy. You could measure with a gm the
radioactivity of wood ash from a stove. The elevated counts are due
to members of the uranium and thorium decay series as well as K-40
all of which have been concentrated by burning. There is some  Cs-137
in there too, but its small potatoes relative to the other stuff.

Health effects.

Tough to deal with cancer but try irradiating some seeds anywhere
from 100 rad up to 100,000 rad. Rye is nice because you can germinate
a lot of seeds in small containers and it has a single blade making
it easy to measure the growth of. Seeds soaked in water are more
sensitive and this could be taken to indicate the effect of free
radical production (maybe). Could also try bubbling oxygen through
the solution as the seeds are soaked. Some science supply places like
Carolina Biological  carry irradiated seeds (as well as cloud
chambers).

Best of luck

Paul Frame
Professional Training Programs
Oak Ridge Associated Universities
framep@orau.gov