[Rockhounds] P=holes and detectors

[J Bryan Kramer]

Be is a target, not a source. The alpha particles from the Ra or Am strike
the Be and knock off neutrons. This converts Be-9 to Be-8 plus a neutron.

Another weird aspect to the story was the cobalt control rods. Why control
rods? This lash up could never approach criticality. And if you want neutron
shielding the you want something with lots of hydrogen. Polystyrene is
commonly used. A hydrogen nucleus is almost exactly the same mass as a
neutron, being a single proton, and it stops neutrons handily. Collisions
transfer energy most efficiently when the two masses are equal. Military
control rods are Hafnium, which I admit would be difficult to find. But
Carbon is the common substitute. It was used in the original Chicago stadium
reactor and the Russians still use it. Boron works well too and is a good
neutron shield as well. You can find all the boraxo you want at the local
supermarket too.

Cobalt is something you normally want to keep out of reactors since it
converts to Co-60 which is a very hot gamma emitter. The Navy eliminated all
cobalt alloy valve seats from their systems to eliminate this problem.

BK

On Feb 3, 2008 12:48 PM, Flint Smith <flint...smith at sbcglobal.net> wrote:

> Erb offered David tips on isolating certain radioactive elements, provided
> a list of isotopes that can sustain a chain reaction, and imparted a piece
> of information that would soon prove to be vital to David's plans: "Nothing
> produces neutrons … as well as beryllium."
>
>
> I don't know that much about reactor design, but in bombs (I'm pretty
> sure) beryllium is used as a moderator, not a "neutron source" so this part
> sounds wrong.  Any of you have radioactive beryllium mineral samples?
>
> Later, when they talk about the need to slow down the neutrons, beryllium
> was left off the list of choices.
>
>
> Pmodreski at aol.com wrote:
> Ulli,
>
> Check out these articles--this came from the Rockhound listserv.  I  read
> these, then read them again & did a little searching on the
>  internet--trying to
> figure out if this was "real", true story or fiction.   Apparently, it is
> indeed real--one of the more remarkable stories I've ever  heard.  I had
> never
> heard of this before...the story dates from back about  10 years ago.
>
> (P.S., just got home (read this earlier today), I need to go out in a few
> minutes, so, I won't have a chance to download pictures till later, so you
> can
> see mine, probably in the morning.)
>
> Have a good evening!
>
> Pete
>
>
> In a message dated 2/2/2008 9:09:07 AM Mountain Standard Time,
> jerrybs at frii.com writes:
>
> interesting  story
> http://www.harpers.org/archive/1998/11/0059750
>
> more  info
> http://en.wikipedia.org/wiki/David_Hahn
>
> Jerry
> WA
>
>
>
>
>
>
>
>
> **************Biggest Grammy Award surprises of all time on AOL Music.
> (
> http://music.aol.com/grammys/pictures/never-won-a-grammy?NCID=aolcmp003000000025
> 48)
>
>
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-- 
"I know I shall be castigated by a large group of people today, but I
was trained to assume that art related to the elusive quality of beauty and
that the purpose of art was concerned with the elevation of the spirit"
Ansel Adams


J Bryan Kramer
North Florida, USA
photos at:
http://pbase.com/photoburner


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