Neutron focussing arrangements

[johnf]

Enjoy





Edit have fixed file name

[Doug Coulter]

Wow, I knew this was possible (though I got a ton of crap for mentioning that on that other forum) but this is sure a nice implementation of the idea. Am I correct in supposing this only works with relatively slow neutrons (under 20 eV or so)? I don't have eV to angstroms in my head as a conversion. My books on "fast neutron physics" mention being able to do this up to about that energy with a tight-lattice xtal of LiF for example, but this is a much smarter way of going about it I think. Nice mechanical design. I guess this also implies that you could have a long beam pipe with low losses if it were made like this?

FWIW -- most Linux machines won't easily eat a filename with more than one period in it (implies an extension on an extension and/or a hidden system file) so I had to gyrate a bit to get this downloaded. Would you rename it for us? I can do it (logged in as owner), but I am morally opposed to editing other's posts in any way if there's not a need to.

Edit -- thanks for fixing the name, but I'll leave this up for others to note about strange filenames. It works fine now.

neutronMagLens.pdf

Neutron Mag Lens

(884.16 KiB) Downloaded 338 times

Here's the only other thing I've seen on directing neutrons. It somehow didn't turn me on much, but....maybe I missed something. It does happen

The one you put up here -- does this imply that they made that thing out of all one orientation of crystal lattice to get total reflection (Bragg style)? If so, I'm really impressed.
This seems to say that one might concentrate the neutrons from a source effectively so as to do better activation with less of a good source, does it not?

[johnf]

Well yes focussing does make a weak source appear better

besides it stops wasting them in ones own body

now for a pun

"everything in moderation"

[Steven Sesselmann]

Hi guys,

On thge subject of neutron guides, the ANSTO Opal research reactor in Sydney has a number of large guides, to direct thermal neutrons through channels to various experiments.

I have seen these guides first hand, made from layers of class with mirror coatings on the inside.

http://www.ansto.gov.au/discovering_ans ... pabilities

Steven

[Doug Coulter]

I believe that someone recently saw something other than the usual neutron diffraction (bragg scattering at low angles, only works with slow neutrons) with one of the new carbon forms, maybe diamond? I'll go searching on it, but some one reported that they got high angle reflections off something strange that were some other mechanism. Boy, we we could do full energy neutrons from a fusor, we get us a camera that can image where the neutrons are coming from, and learn a heck of a lot more than almost anyone else knows now. Someone made a one pixel camera (a daunting enough task, my first attempt failed) and tried, but it's just not the same...OR crap, maybe that was gammas. Well, high angle scattering of either is big news.

As things sit, you can't even make a pinhole camera for neutrons, as for that to work, the pinhole has to be in something of negligible thickness compared to the hole.

I really want a neutron camera...