Neutron sources, alpha sources, pulling dragon's tail

[Brad Dolan]

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



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From:   IN%"werewolf at io.org"
To:     IN%"cypherpunks at 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 at cbis.com"
To:     IN%"werewolf at io.org"
CC:     IN%"cypherpunks at 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 at chaos.bsu.edu"  "Matthew Ghio"
To:     IN%"cypherpunks at toad.com"
CC:     
Subj:   RE: Nuclear Weapons Material

pstemari at 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 at netcom.com"
To:     IN%"ghio at chaos.bsu.edu"
CC:     IN%"cypherpunks at 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 at linux.org, ecarp at netcom.com
Finger ecarp at netcom.com for PGP 2.5 public key          an88744 at 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 at netcom.com"
To:     IN%"perry at imsi.com"
CC:     IN%"werewolf at io.org", IN%"cypherpunks at 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 at well.sf.ca.us