Weapon Development

In the immediate postwar period a small number of Los Alamos Scientific Laboratory's staff were responsible for theoretical work on fusion weapons.

There were incomplete and inaccurate mathematical treatments of the "Super", an idea first proposed by Teller and Fermi, and one of the most difficult problems in physics of the postwar period. Stanislaw Ulam, Edward Teller, and Richard Garwin designed the U.S. hydrogen bomb in 1951. The "George" test as part of Operation Greenhouse became the first thermonuclear proof of principle test while the first successful testing of a thermonuclear device, the "Mike" shot, at Enewetok Atoll was conducted in 1952.

Improving the Primary Stage

A remarkable set of improvements occurred from 1952 to 1956 in the physics, design, and engineering of the primary stage of a nuclear weapon.

The diameter of the primary stage decreased by more than a factor of three and weight decreased by more than a factor of 30. Collectively, these improvements allowed the nation to rapidly expand the flexibility and utility of its nuclear stockpile. The improved stockpile made possible multiple delivery platforms, including ballistic missiles and tactical applications, and facilitated the shift of national policy from massive retaliation and targeting of cities and populous areas to a flexible response strategy designed to deer and counter Soviet war-fighting capabilities.

Dry, Solid Thermonuclear Fuel

In 1954 the Laboratory successfully demonstrated the feasibility of dry, solid thermonuclear fuel for thermonuclear weapons. This development greatly simplified the weaponization and engineering of all subsequent generations of thermonuclear weapons. The first thermonuclear bomb containing solid fusion fuel was the Castle-Bravo shot.

Plastic-Bonded Explosives

Los Alamos demonstrated the first use of plastic-bonded explosives in a nuclear explosion in 1956. This development allowed the shift from precision machined cast explosives to formulations containing high concentrations of high-energy density compounds with reduced sensitivity, more uniformity, and better mechanical characteristics. Pressed, plastic-bonded explosives are the key energetic materials in today's enduring stockpile.