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Gold/Mining/Energy : A New Age In Gold Refining -- Ignore unavailable to you. Want to Upgrade?

To: Bill Jackson who wrote (487)	1/21/1998 8:37:00 AM
From: Chuck Bleakney	Read Replies (2) \| Respond to of 672

Yes, you can make a portable neutron source and its quite easy to do, all you need is an alpha emitter with a high enough energy alpha and mix it very finely with berylium... Berylium emits a neutron after it accepts an alpha (energetic helium nucleus). Alpha emitters abound in nature, Uranium, Thorium are 2 that I know of off the cuff. Most of the really good ones are man made (Plutonium). I just wouldnt want to be the one carying it around, neutrons are difficult to shield and a single absorbed neutron does a lot more damage than ordinary radiation. Unlike radiation which is attenuated by dense materials, neutrons actually pass right through dense materials like they were transparent. We had as part of our reactor a neutron colliminator. This was simply a tube that terminated close to the core. Some neutrons would make it this far and would travel down the tube to be absorbed by a special absorber in a block at the end. We had a device that could put samples into this beam. Our common samples would be a chunk of lead with a small piece of plastic behind it (viewed from the neutron source side) then a paper thin sheet of a absorber material that would also activate but had a very short half life (hours to a day). We would expose the sample for about 30 min and then remove the absorber sheet and tape it to a sheet of unexposed film. The next day we would develop that film. It was like an x-ray, only what you were viewing was exactly opposite... the dense material was transparent while the less dense material would cause a shadow. The reason for this was very simple... neutrons are only eliminated from the beam by either being absorbed or scattered, and lighter materials have much better scattering efficiencies. Of course an absorber placed in the path would have created an even darker shadow. Chuck