Search results
Results from the WOW.Com Content Network
The pits of the first nuclear weapons were solid, with an urchin neutron initiator in their center. The Gadget and Fat Man used pits made of 6.2 kg of solid hot pressed plutonium-gallium alloy (at 400 °C and 200 MPa in steel dies – 750 °F and 29,000 psi) half-spheres of 9.2 cm (3.6 in) diameter, with a 2.5 cm (1 in) internal cavity for the initiator.
A hollow plutonium pit was the original plan for the 1945 Fat Man bomb, but there was not enough time to develop and test the implosion system for it. A simpler solid-pit design was considered more reliable, given the time constraints, but it required a heavy U-238 tamper, a thick aluminium pusher, and three tons of high explosives. [citation ...
The advantage of a hollow design is possibly managing a smaller size while retaining reliability. The short half-life of polonium (138.376 days) required frequent replacement of initiators and a continued supply of polonium for their manufacture, as their shelf life was only about 4 months. [6] Later designs had shelf life as long as 1 year.
The more sophisticated testing will allow the lab to ensure the new plutonium pits it plans to manufacture to equip warheads will be effective — and whether any adjustments in design or shape ...
Feb. 19—Los Alamos National Laboratory reached what federal officials say is a key milestone in developing its first plutonium pit that can be placed in a nuclear warhead as it seeks to produce ...
Apr. 22—The head of U.S. Strategic Command in rounds of congressional testimony this week described renewed plutonium pit production efforts as vital to the nation's nuclear arsenal and, as a ...
It is unknown though possible to make a composite design using high grade plutonium in the bullet only. After it was discovered that the "Thin Man" program would not be successful, Los Alamos redirected its efforts into creating the implosion-type plutonium weapon: "Fat Man". The gun program switched completely over to developing a uranium bomb.
“Cleanup at Los Alamos is long delayed,” Coghlan said, adding that annual spending for the plutonium pit work has neared $2 billion in recent years while the cleanup budget for legacy waste is ...