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
B41 nuclear bomb of 50 or 100 megatons of TNT, depending on its own configuration as a "clean" (lead encased) or dirty (uranium encased) bomb. However even at the Tsar Bomba's theoretical maximum yield of 100 megatons, it would still only achieve a yield to weight ratio of ~ 3.7 Megaton/tonne, thus the B-41 is the most efficient, highest yield to weight ratio, weapon ever created. However, since neither full yield versions of the B-41 nor "Tsar Bomba" were ever demonstrably tested, the B-41's high efficiency is merely theoretical; the most efficient tested and proven nuclear physics package is the W56. If detonated