....
I extracted the following.
"Not sure where the americium was located, he wrote to an electronics firm
in Illinois. A customer-service representative wrote back to say she'd be
happy to help out with "your report." Thanks to her help, David extracted
the material. He put the americium inside a hollow block of lead with a tiny
hole pricked in one side so that alpha rays would stream out. In front of
the block he placed a sheet of aluminum, its atoms absorb alpha rays and
kick out neutrons. His neutron gun was ready.
The mantle in gas lanterns, the small cloth pouch over the flame, is coated
with a compound containing thorium-232. When bombarded with neutrons it
produces uranium-233, which is fissionable. David bought thousands of
lantern mantles from surplus stores and blowtorched them into a pile of ash.
To isolate the thorium from the ash, he purchased $1000 worth of lithium
batteries and cut them in half with wire cutters. He placed the lithium and
thorium ash together in a ball of aluminum foil and heated the ball with a
Bunsen burner. This purified the thorium to at least 9000 times the level
found in nature, and up to 170 times the level that requires NRC licensing.
But David's americium gun wasn't strong enough to transform thorium into
uranium."
Note. alpha emitters are generally easily shielded. The alpha likes to stop
by bremstrahlung breaking and emits a bit of X-Rays and some electrons which
all stop very quickly. These are dangerous when inhaled in small particles,
and this is the danger in atomized plutonium. I never heard of making an
alpha source into a neutron source by the described conversion. I am not
expert in all this but this does sound a bit fishy to me based on my general
knowledge of neutron sources (which I thought were generally driven by high
energy protons), and alpha shielding. However, depackaging an alpha emitter
is a very uncool idea, rather akin to pulverizing asbestos. And
concentrating this known danger several hundred times by quantity, as well,
seems like a lousy way to make neutrons even if it does work. A small proton
accelerator would, I think, do the job quite nicely. Isn't that what the
nukes use? That's the source tube that causes the bomb to detonate at max
compression and is the tube that is unusual enough that it got some folk
arrested for trying to sell em to the Iraqi's around 10 years ago, as I
recall.
The thorium does, I think, carry a number of radioactive isotopes in it's
natural state. Not something you want to concentrate, and chemically rather
nasty (I think it is quite poisonous) Lithium? Other than being strongly
chemically active, I don't recall any really nasty chemical junk. I thought
lithium absorbed neutrons and gave off heat. Not exactly a good moderator
for a neutron multiplication chain reaction. I seem to recall a neutron
thorium chain reaction, so perhaps this could work if you had a good neutron
source and a good neutron reflector around it, and perhaps something to
thermalize the neutrons, like paraffin, or water. You do know that even if
he obtained no neutrons at all in this process, his chemical process is very
very nasty. Wow. And I thought I was bad making up rocket fuels in my
misspent youth.
