RE: neutron flux in space

["Fulmer, Philip" <philip.fulmer@cplc.com>]

Scott,

I was enjoying the thread (your humor wasn't wasted); however, I'm now
more curious about an answer to the original question regarding
activation.  I suspect that the question wasn't meant to be limited to
strictly neutron activation but also possibly photoactivation, charged
particle reactions, spallation, etc., all processes that produce
radioactive atoms.  Would the total activity caused by these events
still be overshadowed by amounts as small as check sources?

Philip

__________________________
Philip C. Fulmer, PhD, CHP 
Carolina Power & Light Company
Harris Energy and Environmental Center
3932 New Hill-Holleman Road
P. O. Box 327
New Hill, NC 27562-0327
philip.fulmer@cplc.com
(919) 362-3363      

>----------
>From: 	Scott D. Kniffin[SMTP:Scott.D.Kniffin.1@gsfc.nasa.gov]
>Sent: 	Wednesday, May 06, 1998 2:42 PM
>To: 	Multiple recipients of list
>Subject: 	Re: neutron flux in space
>
>Hi again,
>
>I grant that neutrons are there, just that in comparison to all the other
>stuff hitting you in space, the neutron term is rather less significant
>than any of the others.  Besides, at 10eV, they're getting soaked up by the
>outter (probably aluminum) skin of your spacecraft and the resultant
>activation product is not around very long in terms of what's coming back
>at earth in hte event of a disaster. Plus there's scattering/reflection and
>the decay products of the activated Al (2.6MeV beta and 1.8MeV gamma) still
>has to go into the spacecraft.  The cosmic rays are much worse in terms of
>what damage they do to electronic components, fortunately these are also
>(except in certain orbits) minimal as well.  
>I hadn't meant to turn this into a mess, I thought I was pointing out a
>humorous glitch (which after further review, what I wrote wasn't as funny
>as it sounded before I had my hot chocolate) in a note reminding us to
>watch what we say.  Sorry for the confusion, I'll slap myself a few times
>in the morning before I reply from now on, I promise. ;)
>
>Scott Kniffin
>
>mailto:Scott.D.Kniffin.1@gsfc.nasa.gov
>RSO, Unisys Corp. @ Lanham, MD
>CHO, Radiation Effects Facility, GSFC, NASA, Greenbelt, MD
>
>The opinions expressed here are my own.  They do not necessarily represent
>the views of Unisys Corporation or NASA.  This information has not been
>reviewed by my employer or supervisor.  
>
>At 13:16 05/06/98 -0500, you wrote:
>>Depending on the circumstances this parameter can change dramatically
>since many more neutrons are produced by the very high energy cosmic rays
>(ions) when they interact with matter (e.g., the air containment shell of
>your space vehicle).  The NCRP meeting this year had lots of neat data on
>this topic.
>>
>><color><param>0000,ffff,ffff</param>Disclaimer:  the above are the
>>personal musings of the author, and do not represent any past, present,
>>or future position of NIST, the U.S. government, or anyone else who might
>>think that they are in a position of authority.
>>
>></color><color><param>8080,0000,0000</param>Lester Slaback, Jr. 
>>[Lester.Slaback@NIST.GOV]
>>
>>NBSR Health Physics
>>
>>Center for Neutron Research
>>
>>NIST
>>
>>Gaithersburg, MD  20899
>>
>>301 975-5810</color>
>>
>>
>