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From: throopw@dg_rtp.UUCP (Wayne Throop)
Newsgroups: net.politics,net.sci
Subject: Re: Small Nuclear Bombs
Message-ID: <355@dg_rtp.UUCP>
Date: Thu, 22-May-86 16:41:12 EDT
Article-I.D.: dg_rtp.355
Posted: Thu May 22 16:41:12 1986
Date-Received: Sat, 24-May-86 05:50:13 EDT
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> gsmith@brahms.BERKELEY.EDU (Gene Ward Smith)
>> throopw@dg_rtp.UUCP (Wayne Throop)
>>> rb@ccird1.UUCP (Rex Ballard)

>>> Reguarding plutonium vs. water vapor risks, remember that it
>>> only takes a few ounces of plutonium to trigger the fusion bomb.

>>Ounces, schmounces.  Even the smallest thermonuclear weapon needs
>>several *pounds* (not ounces) of plutonium to trigger fusion.

>>> Some tactical weapons [...] are about the size
>>> of a ping-pong ball and are therefore easy to deliver but hard
>>> to shoot down.

>> "Size of a ping-pong ball?" Just a supercritical mass of
>>plutonium itself is about the size of a softball [...]
>>Granted, tactical nukes can be the size, say, of a
>>toaster.... but a *ping* *pong* *ball*?  Get real.

>     I was talking to an ex-LLL physicist once who told me that there 
> is an isotope of Californium with a *very small* critical mass (a few
> grams, I think it was). This opened the theoretical possibility of a
> hand grenade sized nuclear weapon.

*First* of all, I was talking about plutonium.  *Second*, when somebody
says "theoretically", they mean "not really".  *Third*, a ping-pong ball
is quite a bit smaller than a hand grenade.  (Trust me... I've seen
both.)

There are several reasons to suppose that californium wouldn't make a
practical material for weapons production, among them the fact that
those with the smallest critical mass also have the greatest thermal
neutron production (and thus must be sheilded the most, and ought to
have short shelf-life due to neutron activation of the trigger).

Note that I agree that a multi-kiloton fission weapon *can* be made the
size of a ping-pong ball in *theory*.  It is merely far, far beyond
current engineering practice (well, I'm pretty sure it is).  In theory,
it is possible to make a multi-gigaton weapon that size (antimatter),
maybe even a planet-buster (anti-neutronium, or maybe
anti-just-short-of-black-holium).  Or let's get *really* freaky, several
unstable quantum black holes in a time-stassis.  Again, there is a
little matter of implementation...
-- 
Wayne Throop      <the-known-world>!mcnc!rti-sel!dg_rtp!throopw