Neutron sources, alpha sources, pulling dragon's tail

[Brad Dolan <bdolan@well.sf.ca.us>]

Various comments on this thread, all lumped into an easy-to-ignore wad:



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From:   IN%"werewolf@io.org"
To:     IN%"cypherpunks@toad.com"
CC:     
Subj:   RE: Nuclear Weapons Material

> 
> iqg1550 says:
> > Let's all rejoice at the birth of the latest member of The Horsemen of
> > The Criminal Apocalypse -- The Nuclear Weapons Material Smuggler.  
> > I'm sure his four siblings will make plenty of room for their baby brother.
> 
> I will point out, of course, that anyone who can afford the tens of
> millions to hundreds of millions the smugglers are reportedly charging
> for critical masses worth of Plutonium and Uranium, odds are that they
> can afford to buy un-escrowed secure communications equipment...

Not to mention the fact that without tritium, the "trigger" for nuclear
weapons (and extremely expensive and rare at $ 100m a gram) all you have
is a radioactive paperweight.

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This misconception was put to rest by a number of postings such as the 
following:


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From:   IN%"psmarie@cbis.com"
To:     IN%"werewolf@io.org"
CC:     IN%"cypherpunks@toad.com"
Subj:   Nuclear Weapons Material

> Not to mention the fact that without tritium, the "trigger" for nuclear
> weapons (and extremely expensive and rare at $ 100m a gram) all you have
> is a radioactive paperweight.

The "trigger" isn't tritium.  Tritium (along with lithium 6) is used
in fusion bombs.  A fission-only device, ala Hiroshima or Nagasaki,
doesn't require any.

The trigger in the center of the plutonium core is a neutron source,
polonium if memory serves correctly.  Tritium is a beta emitter.

        --Paul

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From:   IN%"ghio@chaos.bsu.edu"  "Matthew Ghio"
To:     IN%"cypherpunks@toad.com"
CC:     
Subj:   RE: Nuclear Weapons Material

pstemari@bismark.cbis.com (Paul J. Ste. Marie) wrote:
> Mark Terka wrote:
> > Not to mention the fact that without tritium, the "trigger" for nuclear
> > weapons (and extremely expensive and rare at $ 100m a gram) all you have
> > is a radioactive paperweight.
>
> The "trigger" isn't tritium.  Tritium (along with lithium 6) is used
> in fusion bombs.  A fission-only device, ala Hiroshima or Nagasaki,
> doesn't require any.
>
> The trigger in the center of the plutonium core is a neutron source,
> polonium if memory serves correctly.  Tritium is a beta emitter.

A neutron source is usually a light element with a high neutron/proton
ratio, coupled with an alpha emitter.  I believe the Nagasaki bomb used
beryllium-9.  An alpha particle impacting a beryllium nucleus will fuse
with it, forming carbon-12, and the binding energy will eject a neutron.
I think aluminum and a few other light elements will undergo similar
reactions to release neutrons in the presence of alpha particles.

Polonium is primarilly an alpha emitter.  It would work as part of a
neutron source, but it is not a particularily good choice because its
half-life is only 138.4 days (polonium-210).  This makes it expensive
to obtain, and impractical to store.
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Plutonium itself is a decent alpha emitter.  Seems like I've been around
a Pu-Be neutron source somewhere ( but not too close!)

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From:   IN%"ecarp@netcom.com"
To:     IN%"ghio@chaos.bsu.edu"
CC:     IN%"cypherpunks@toad.com"
Subj:   RE: Nuclear Weapons Material

> Polonium is primarilly an alpha emitter.  It would work as part of a
> neutron source, but it is not a particularily good choice because its
> half-life is only 138.4 days (polonium-210).  This makes it expensive
> to obtain, and impractical to store.


They used to use polonium in static eliminators in darkrooms - don't know 
if they use them anymore, though.
-- 
Ed Carp, N7EKG                          Ed.Carp@linux.org, ecarp@netcom.com
Finger ecarp@netcom.com for PGP 2.5 public key          an88744@anon.penet.fi
If you want magic, let go of your armor.  Magic is so much stronger than
steel!        -- Richard Bach, "The Bridge Across Forever"

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You can still buy those neat little brushes intended to remove dust from
negatives.  Each comes with a polonium source to help kill the static
charge holding the dust.  I've got one right next to my Sunshine Health
Mine radon-emitting pillow.
 
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From:   IN%"ecarp@netcom.com"
To:     IN%"perry@imsi.com"
CC:     IN%"werewolf@io.org", IN%"cypherpunks@toad.com"
Subj:   RE: Nuclear Weapons Material

> Mark Terka says:
> > Not to mention the fact that without tritium, the "trigger" for nuclear
> > weapons (and extremely expensive and rare at $ 100m a gram) all you have
> > is a radioactive paperweight.
> 

> This is sheer ignorance. First of all, tritium is not nearly that
> expensive. Its quite cheap, in fact, and can be manufactured without
> that much trouble. Second of all, tritium is not a necessary component
> of non-thermonuclear (i.e. hydrogen) bombs. Third, tritium isn't a
> "trigger". Lastly, an ordinary A-bomb is just a way to bring together
> a critical mass of a fissionable material, like U-235 or Plutonium.
> Once a critical mass is in one place the chain reaction will handle
> the rest.

Quite true.  All you really need for a fission bomb is a casing to hold 
everything together, 2.2 kilos (or so) of U-235 (or a sufficient quantity 
of critical mass other stuff <grin>), and something that will hold it 
together long enough for it to fission.

And no, Taylor, holding them together in your hands won't work 
(unfortunately)... hehehe :)   [...]
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Well, you can do it - only you just get a pffutt instead of a bang.
A couple of folks at Los Alamos have tried it.  Regrettably, they're
no longer with us.  I think the practice was called, "pulling the
dragon's tail."
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bdolan@well.sf.ca.us