Greenhouse George

Greenhouse George was an American nuclear test conducted on May 8, 1951, as part of Operation Greenhouse. It was the first instance of thermonuclear fusion brought about by humans, i.e. energy release from atomic nuclei colliding at very high temperatures. It yielded 225 kilotons TNT equivalent. The Cylinder device was designed for probing the thermonuclear reaction. It was a test of the radiation implosion principle that was key to the recently theorized Teller-Ulam design. The vast majority of its yield derived from fission. The energy output from the thermonuclear fusion in this test was insignificant in comparison.