re:low background thesis

[Zack Clayton <zack.clayton@epa.state.oh.us>]

Sorry for posting this to the whole RADSAFE list, but the private address is blocked
from here and the medlist server rejects me as not a subscriber.

Some comments on this from reading what's been posted.

Reduction of background will be difficult.  the idea of running a "control" set of about 4
times background is suspicious however.  The control set should probably be run in
an area of high background if possible.  The 4 times background set could then be
used as an additional data point.   The reduced background set will probably need to
be run in a physically distant location simultaneously with the first.    

High background could include: 
high altitude (less atmospheric shielding),  granite or other igneous bedrock close to
or at the surface, granite walled buildings,  Brick made with a high thorium or uranuim
content clay, or an area with a high Chernobyl deposition.  There are others you will
probably think of with this list as a start.

Low background could include:  Sea level or  below ground rooms in a non igneous
rock, such as a limestone or sandstone.  Stay away from high organic sediments as
these may have high uranium content.  Wooden buildings or limestone block.  check
with geologists to see what is underlaying the area,  in Ohio we have a high organic
shale that lies from near surface to several hundred feet down, but it still gives high
radon readings over the map area as uranium daughters migrate up though joints and
fissures.  (Uranium seems to accumulate in oranic rich sediments and areas of high
phosphate, something to do with the environments of deposition but I'm not sure
why.)

Good luck, it sounds like a good thesis or dissertation topic that should get
international notice when complete.  But very difficult to eliminate background.


Zack Clayton
zclayton@epa.state.oh.us

A day without radiation would be a day without sunshine.