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 ...
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 ...
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 ...
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 ...
The hemispheres were nickel-plated and the outer surface was coated in gold and 30 curies (1.1 TBq) of polonium. The 2.0-centimeter (0.79 in) initiator, which was hot to the touch, fitted neatly inside the 20-millimeter (0.8 in) hole in the center of the plutonium pit. [45]
Plutonium–gallium alloy (Pu–Ga) is an alloy of plutonium and gallium, used in nuclear weapon pits, the component of a nuclear weapon where the fission chain reaction is started. This alloy was developed during the Manhattan Project .