Re: [Phys-l] 0.55 kt fizzle ??

[Chuck Britton <cvbritton@earthlink.net>]

The US did an underground blast in Mississippi that was less than 
this 0.55 yield.
(local folks remember their wells being muddy for quite some time)

The first detonation, to form the cavity, code-named Salmon, took place
in 1964 using a 5.3 kiloton bomb, placed at the bottom of a sealed 2,710
foot shaft. The second nuclear blast, a relatively small 0.38 kilotons
yield shot code-named Sterling, was exploded within Salmon's 110 foot
diameter cavity more than two years later

http://www.clui.org/clui_4_1/ludb/sites/MS3126.html

but this sub-critical mass needs a good tamper/reflector.
I'd wager that this was a fizzle rather than a sophisticated tiny device.
This means that they will be testing another one soon - fix things.


At 5:10  -0400 on 10/9/06, John Denker wrote concerning [Phys-l] 0.55 
kt fizzle ?? :
> The wire services are carrying the following quote:
>
>    "It amounts to detonating 550 tons of trinitrotoluene, or TNT, at once,"
>     said Park Chang-soo, a spokesman of the Korea Institute of Geoscience
>     and Mineral Resources.
>
> Hmmmm.
>   1) The report from Mr. Park could be a misquotation.
>   2) Mr. Park could have mis-estimated the yield.  For example, it 
> is possible,
>    with some clever work, to "decouple" an explosion so as to reduce 
> its seismic
>    signature.
>   3) A 0.55 kt result might represent a triumph, namely the world's first
>    mini-nuke.  See below.
>   4) Or it might represent a fizzle, perhaps 20x less than what they were
>    expecting.
>   5) Or ... maybe a pile of TNT dolled up to look like a nuke???
>
>
> We're talking about a chain reaction here.  Critical mass is critical
> mass.  The yield you naturally get from critical mass is on the order
> of 10 kt.  The Hiroshima weapon yielded 15 kt.  If you design for less
> than that, you are likely to get nothing at all;  a decaying exponential
> is qualitatively different from a growing exponential in the chain
> reaction!
>
> I'm not alone in thinking so;  here's a 2001 FAS report on mini-nukes:
>   http://www.fas.org/faspir/2001/v54n1/weapons.htm
> Search for the part about "finely-tuned".
>
> =======================
>
> Once again I am astonished by some reporters' ability to circulate
> "facts" without bothering to think whether they make sense or not.
>
> _______________________________________________
> Forum for Physics Educators
> Phys-l@carnot.physics.buffalo.edu
> https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l