Nuclear fission Mexico, which was the scientific hub for research on bomb development and design. Other sites, notably the Berkeley Radiation Laboratory and the Metallurgical Laboratory at the University of Chicago, played important contributing roles. Overall scientific direction of the project was managed by the physicist J. Robert Oppenheimer. In July 1945, the first atomic explosive device, dubbed "Trinity", was detonated in the New Mexico desert. It was fueled by plutonium created at Hanford. In August 1945, two more atomic devices – "Little Boy", a uranium-235 bomb, and "Fat Man", a plutonium bomb – were used against the Japanese cities of Hiroshima
Mark 36 nuclear bomb tamper-pusher which would undergo fission during the second stage fusion burn, doubling the weapon yield. Chuck Hansen wrote in Swords of Armageddon (1995) that Mark 36 nuclear bomb was produced in two yield versions, clean and dirty. He stated that clean version of Mark 36 had a yield of 6 megatons and that dirty version of Mark 36 had a design of maximum yield of 19 megatons. Mark 36 nuclear bomb The Mark 36 was a heavy high-yield United States nuclear bomb designed in the 1950s. It was a thermonuclear bomb, using a multi-stage fusion secondary system to generate yields