Nuclear weapons testing: The Castle Bravo, a 15-megaton hydrogen bomb, is detonated on Bikini Atoll in the Pacific Ocean, resulting in the worst radioactive contamination ever caused by the United States.
Nuclear weapons testing
Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of their explosion. Over 2,000 nuclear weapons tests have been carried out since 1945. Nuclear testing is a sensitive political issue. Governments have often performed tests to signal strength. Because of their destruction and fallout, testing has seen opposition by civilians as well as governments, with international bans having been agreed on. Thousands of tests have been performed, with most in the second half of the 20th century.
Castle Bravo
Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of Operation Castle. Detonated on 1 March 1954, the device remains the most powerful nuclear device ever detonated by the United States and the first lithium deuteride-fueled thermonuclear weapon tested using the Teller–Ulam design. Castle Bravo's yield was 15 megatons of TNT [Mt] (63 PJ), 2.5 times the predicted 6 Mt (25 PJ), due to unforeseen additional reactions involving lithium-7, which led to radioactive contamination in the surrounding area.
TNT equivalent
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. A ton of TNT equivalent is a unit of energy defined by convention to be 4.184 gigajoules. It is the approximate energy released in the detonation of a metric ton of trinitrotoluene (TNT). In other words, for each gram of TNT exploded, 4.184 kilojoules of energy are released. This convention intends to compare the destructiveness of an event with that of conventional explosive materials, of which TNT is a typical example, although other conventional explosives such as dynamite contain more energy. A related concept is the physical quantity TNT-equivalent mass, expressed in the ordinary units of mass and its multiples: kilogram (kg), megagram (Mg) or tonne (t), etc.