[sci.military] waterlogged nuclear bomb; Progressive

wrf@mab.ecse.rpi.edu (Wm Randolph Franklin) (11/07/90)

From: wrf@mab.ecse.rpi.edu (Wm Randolph Franklin)

There  was an objection to my  statement that you couldn't compress bomb
components under water fast enough  for an explosion.  Of  course  water
can transmit a pressure wave.  However I really doubt that as the pieces
of U or Pu are coming together they can push the water in front  of them
out of the way without slowing down.  Slowing  down would cause a squib.
The same objection  would apply to  any  conventional focused explosive.
It wouldn't seem that its shock wave could focus properly in water.

If the  bomb were in a pressure  container so  that the components could
come together in a vacuum or at most a  low pressure  gas then the above
doesn't apply.  That didn't seem to be the case in the movie.


P.s. one of the neat things about the  Progressive case was how much you
could guess from such a little input.  At  one  point a judge classified
certain  underlinings in  an  encyclopedia  article on  comets.  What do
comets have to  do with H-bombs?  Aha!   They used to think that comets'
tails  were swept back  by  light   pressure.  So one classified  H-bomb
principle must be radiation pressure!

I think  that one thing that  enhances the radiation pressure  effect is
that  the outer  coating of U238 is  many thin  layers.    As each layer
vaporizes from the radiation it doesn't reflect, the next  layer becomes
available.  This is  an interesting  contrast  to  the proper design  of
armor plate, where one thick sheet is better.

Another  enhancement is that the U238  may form   an ellipsoid with  the
fission bomb at one focus and the D-T at the other.  Not sure  about the
details, though.
-- 
						   Wm. Randolph Franklin
Internet: wrf@ecse.rpi.edu (or @cs.rpi.edu)    Bitnet: Wrfrankl@Rpitsmts
Telephone: (518) 276-6077;  Telex: 6716050 RPI TROU; Fax: (518) 276-6261
Paper: ECSE Dept., 6026 JEC, Rensselaer Polytechnic Inst, Troy NY, 12180