Nuclear weapons using plutonium-239 (an alternative to uranium-235) are triggered by an implosion mechanism in which a spherical assembly of conventional high explosives compresses a subcritical core of a plutonium compound to supercritical density. Load More. As well as Pu239 you also get Pu-240, Pu-241, etcetera. Little boy the bomb used in Hiroshima was a uranium fission bomb. An implosion device employs not only less fissile material than a gun assembly device (in absolute respects), but it also more efficiently uses the material. Fat man the bomb dropped over Nagasaki was a plutonium implosion type bomb. Index A number of famous scientists working at Los Alamos including Richard Tolman John von Neumann and Edward Teller contributed to this design. "Fat Man" was the second plutonium, implosion-type bomb. 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. The primary advantages of implosion are: a. high insertion speed - this allows materials with high spontaneous fission rates (i.e. Fat Man: Implosion-Type Bomb. Without either a plutonium gun bomb or implosion weapon, the burden would fall entirely on uranium and the less efficient gun method. The chain reaction lasts about a microsecond. A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force from nuclear reactions , either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb). “Fat Man” was the second plutonium, implosion-type bomb. As the plutonium was produced in the nuclear reactors at Hanford, Washington, it was discovered that the plutonium was not as pure as the initial samples from Lawrence's Radiation Laboratory. This implosion technique was used in the first plutonium bomb test at Alamogordo and in the Nagasaki bomb, each with an explosive power of about 20 kilotons of TNT. Both bomb types release large quantities of energy from relatively small amounts of matter. The Pu240 is a problem because this nucleus has a fairly high rate of spontaneous fission. plutonium) to be used; b. high density achieved, leading to a very efficient bomb, and allows bombs to be made with relatively small amounts of material; Implosion thus considerably increases a bomb's efficiency. This creates enough force to increase the density of the sphere of plutonium to the point where it is super-critical. The first was the “Gadget” detonated at the Trinity site on July 16, 1945. An implosion fission weapon with an explosive yield of one kiloton can be constructed with as little as 1 to 2 kg (2.2 to 4.4 pounds) of plutonium or with about 5 to 10 kg (11 to 22 pounds) of highly enriched uranium. To obtain a given yield, considerably less fissile material is needed for an implosion weapon than for a gun-assembly device. plutonium) high density becomes achieved. The Israelis can almost certainly build very good plutonium implosion bombs, probably including boosted-fission devices of up to ~50 kiloton yield. The main advantages of implosion are: high assembly speed - this permits the use of materials with high spontaneous fission rates (i.e. Oppenheimer directed a major reorganization of Los Alamos in July 1944 that prepared the way for the final development of an implosion bomb. The initial design for the plutonium bomb was also based on using a simple gun design (known as the "Thin Man") like the uranium bomb. Vanunu reconstructed a plauisble schematic of a small “Layer Cake” device that they could probably get to work right the first time; that would probably squeeze 100 kT into a Jericho. In the implosion-type device, a core of sub-critical plutonium is surrounded by several thousand pounds of high-explosive designed in such a way that the explosive force of the HE is directed inwards thereby crushing the plutonium core into a super-critical state.