Does Neutron Radiation affect Ferrite/Ceramic Magnets? 1

[cermag]

Does anybody know if neutron bombardment of Ferrite/Ceramic permanent magnetic material will cause any irreversible/irrecoverable loss in the magnetic field. If so why?

 

[EdStainless]

There were DoD papers written in the 50's and 60's on this subject. They took magnets of every known type (at the time) and put them into high neutron flux situation. Some were even exposed in actual bomb tests.
If you have trouble finding the information you could try the U of Dayton magnetics department or the Air Force materials group at Wright Patterson (also in Dayton OH).

I don't remember. Some materials were damaged and some were not.

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http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[MagMike]

Those DoD papers are extremely informative, but a challenge to track down.

A few months ago I came across a paper by a group at Fermi National Acccelerator Lab. They exposed strontium ferrite magnets (Ceramic 8) to proton & gamma radiation. They only noticed normal thermal flucuations.

Moskowitz's book reports a lowered remanence after exposing Barium ferrite/ceramic (not used much nowadays) magnets to over 10e19 neutrons and 275degC. He doesn't quantify the amount of loss. However, given that temperature, I suspect most of the loss was due to thermal effects.

The link for the Fermilab report is:

http://tdserver1.fnal.gov/tdlibry/TD-Notes/1997

Tech Notes/TD-97-064.pdf

 

[MagMike]

I noticed the link I just posted didn't work correctly. The spaces between 1997 Tech and Notes caused a problem.

I recommend pasting the complete text of that link into the address field of your browser. I just tried it that way in it works.

 

[janas21]

I am not quite sure but neutron is not affect magnets, since we need fluxes of great velocity. For protons the results should be bigger because of the collision that are created inside the lattice and produce temperature. Except the defects that are produced it might due to thermal creation to expand the curie temperature which indicates no more function as a magnets.

but i am not sure. what i mentioned have to do with pure physics theory but not with real life problems

 

[IRstuff]

Don't forget that the original Space Shuttles and other older spacecraft flew with magnetic core memories specifically for radiation hardness.

TTFN

 

[cermag]

Thank you all for your input. I now have the basic information I was looking for.