RE: neutron shielding

["Ayers, Rex G" <Rex.Ayers@TycoHealthcare.com>]

I have some scatter coming out from under some shield doors of our

cyclotrons. The angle is such that the steel box would work well and give me

a greater cross-section of paraffin.



Thanks for the suggestions.



Rex Ayers, CHP



-----Original Message-----

From: JPreisig@AOL.COM [mailto:JPreisig@AOL.COM]

Sent: Wednesday, June 26, 2002 7:37 PM

To: radsafe@list.vanderbilt.edu

Subject: Re: neutron shielding





Hi Radsafers:



     This is from   jpreisig@aol.com    .



     Interesting stuff:  paraffin encased in steel.  Depending on the

neutron

energy, you might want to re-think your plans.  Below 20 MeV, you might get 

away

with what you are trying to do.  Above 20 MeV,  neutrons can go through 

steel quite easily (there is a hole in the steel cross-section for

neutrons). 

 You

need to find out in what energy range this hole exists.  You might shield 

well

with the paraffin and still have the neutrons stream in along the steel

edges.  Bummer.



    At particle accelerators (intermediate energy and I think, high energy)

(proton machines) one has inner walls of iron/steel, and materials like

that.

Outside of the steel/iron, one has concrete without much (or any???) 

steel/iron

reinforcing.  The concrete stops the neutrons, not any steel/iron inside of

it.  The internal  wall steel/iron stops charged particles (i.e. protons).  

Different 

shielding situations are shielded differently than this.



     Good Luck with your work.







                                          Joe Preisig, Ph.D.





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