From: mbk@lyapunov.ucsd.edu (Matt Kennel)
Newsgroups: sci.physics.fusion
Subject: Re: The H-Bomb secret is out
Date: 1 Oct 1992 00:02:59 GMT
Organization: Institute For Nonlinear Science, UCSD
NNTP-Posting-Host: lyapunov.ucsd.edu
X-Newsreader: Tin 1.1 PL3

jac@ds8.scri.fsu.edu (Jim Carr) writes:
: Plutonium proved more difficult, but the first test worked. 
: 
: Fusion was difficult.  Very smart people had, history shows, some 
: very wrong ideas.  Now it is true that calculation showed them to 
: be wrong, but they proceeded with a (pointless) test anyway.  In 
: the meantime (after working on the problem for almost a decade), 
: a solution was found that worked on the first try.  This suggests 
: that it is more a matter of creative invention (where the invention 
: is not immediately obvious from one's experience) than engineering. 

All the documents that I've seen say that there was in fact a
"new insight" into the design of an H-Bomb between say 1950 and 1954.

Remember, there was an original thermonuclear bomb exploded in something
like 1951, and nothing else for a few years more.

Here's a few comments from an article Bethe wrote in 1954, but which
wasn't declassified until 82. 

"The H-bomb was suggested by teller in 1942.  Active work on it was pursed
in the summer of 1942 by Oppenheimer, Teller, myself and others...."

"Teller, working on the H-bomb at Los Alamos discovered a major difficulty.
This discovery made it clear that it would be a very hard problem to
make a 'classical super work' as this type of H-bomb was called.  I shall
refer to the classical super as Method A."

..

"Two new methods of designing a thermonuclear weapon were invented (Methods
B and C).  Both inventions were due to Teller.  Method B was invented
in 1946, Method C in 1947....  However at the time, there seemed to
be no way of putting Method B into practice.  Teller himself wrote
a most pessimistic report on the feasibility of this method.

Method C is different from all the others in that themonuclear reactions
are used in only a minor way, for weapons of relatively small yield.
This method seemed quite primising from the start, and as early as
the summer of 1948 it was added to the devices to be tested in the
Greenhouse tests."  {This is simply the adding of fusion materials
to the core of an implosion fusion weapon as a booster to make more neutrons.}

"Theoretical work on the classical super, Method A, proceeded continually,
since this method was considered the most important of all thermonuclear
devices."  {Goes on to say how the calculations were very difficult
and they didn't have good enough computers}.

"To accomplish Method A, two major problems had to be solved which I shall
call Part 1 and Part 2.  Part 1 seemed to be reasonably well in hand
according to calculations by Teller's group from 1944 to 1946 although
nobody had been able to perform a really convicing calculation, as
discussed in the paragraph above.  Teller now believed he had a solution for
Part 2."

..

The major feature of the year 1950, was however, the discover that Part 1
of Method A was by no means under control.  While Teller and
most the LANL were busy preparing the Greenhouse test, a number of
persons in the theoretical division had continued to consider the various
problems posed by Part 1.  In particular, Dr. Ulam on his own initiative
had decided to check the feasibilty of aspects of Part 1 without the
aid of high speed computing euqipment.  He and Dr Everett who assisted
him soon found that the calculations of Teller's group of 1946 were wrong.
Ulam's calculations showed that an extraordinarily large amount of
tritium would be necessary... In the summer of 1950 further calculations
by Ulam and Fermi showed further difficulties with part 1."

..

"Between January and May 1951, the 'new concept was devveloped'."

"On March 9, 1951...Teller and Ulam published a paper which contained one-half
of the new concept.  Ulam, by the way, made his discovery while studying
some aspects of fission weapons.  This shows once more how the
important ideas may not come from a straightfoward attack on the
main problem."

"Within a month, the very important second half occured to Teller...This
immediately became the main focus of attention of the thermonuclear
design program."

{Here's where it gets good}

"It is difficult to describe to a non-scientist the novelty of the new
concept.  I was entirely unexpected from the previous development.
It was also not anticipated by Teller, as witness his despair immediately
preceeding the new concept.  ....  The new concept was to me, who
had been rather closely associated with the program, about as surprising
as the discovery of fission had been to physicists in 1939.  Before 1939
scientists had a vague idea that it might be possible to release
nuclear energy but nobody could even thing remotely of a way to do it.
If physicists had tried to discover a way to release nuclear energy before
1939, they would have worked on anything else rather than the field which
finally led to the discovery of fission, namely radio chemistry.  At that
time, concentrated work on any 'likely' way of releasing nuclear energy
would have led nowhere.  Similarly concentrated work on method A would
have never led to method D.  The Greenhouse test had a vague connection with
method D but one that nobody, including Teller, could have forseen or
did forsee when that test was planned ....  .. The scientists who had
shown good judgement concerning the technical feasibility of method A 
were now suddenly proved wrong, whereas Teller, who had been wrong in
interpreting his own calculations was suddenly right."

: I think this must be referring to the very real problems of building 
: a fission bomb.  I think there was a story in Analog that parodied 
: the process.  The problem in the case of both weapons is assembling 
: the "special nuclear materials".  Not easily done unless your basement 
: is the size of the Hanford reservation.  


Apparently there is more than that to fusion bombs.


So, who else besides the U.S. has fusion bombs, and how do *theirs* work?

: 
: --
: J. A. Carr                                    |  "The New Frontier of which I  
: jac@gw.scri.fsu.edu                           |  speak is not a set of promises
: Florida State University  B-186               |  -- it is a set of challenges."
: Supercomputer Computations Research Institute |   John F. Kennedy (15 July 60)

--
-Matt Kennel  		mbk@inls1.ucsd.edu
-Institute for Nonlinear Science, University of California, San Diego
-*** AD: Archive for nonlinear dynamics papers & programs: FTP to
-***     lyapunov.ucsd.edu, username "anonymous".