English: Page 4 of classified scientific paper by US nuclear physicists Edward Teller and Stanislaw M. Ulam March 9, 1951 On Heterocatalytic Detonations I: Hydrodynamic Lenses and Radiation Mirrors, at US nuclear weapon design facility Los Alamos Scientific Laboratory, Los Alamos, New Mexico, which contains their historic breakthrough idea for how to build a practical thermonuclear weapon, staged implosion, generally referred to as the "secret of the hydrogen bomb". This concept, which may have been independently invented by scientists in other countries, is thought to be the design used in all modern thermonuclear weapons, which includes virtually all nuclear weapons in the stockpiles of major "nuclear" nations. This declassified version is heavily redacted; out of 20 pages only a few paragraphs are not blacked out. Only pages with text remaining have been uploaded here.

• This is part of the introductory paragraphs that state the basics of the idea; that by the explosion of one or more "auxiliary" fission bombs they hoped to ignite a reaction in a "principal" assembly of either fission or fusion fuel outside the bombs. These paragraphs explain the jargon that they used for this idea: "heterocatalytic", appearing in the title. This is in contrast to the "autocatalytic" action of a fission bomb, which ignites fuel inside itself. These terms are no longer used.
• This paper, titled On Heterocatalytic Detonations I was apparently part one of a two-part series. The top paragraph states what will be in the 2nd part; estimates of the all-important compression of the fusion fuel that can be achieved by their design, which will determine whether a fusion "burn" can take place. I have never heard reference to this sequel in open literature, it would be interesting to know whether any part of it has been declassified.