The electromagnet for the world's first major cyclotron enabled Professor Ernest O. Lawrence and others to perfect cyclotron technology. Originally a 27-inch cyclotron, it was converted to a 37-inch instrument in 1937. Weighing 85 tons, it led the world in atomic particle energies from 1932 until 1939 and opened new frontiers in nuclear research. Its many discoveries included radioisotopes such as iodine-131 and the first man-made element, technetium. After modification, the magnet first showed in 1941-42 that uranium-235 could be separated magnetically on a large scale. In 1945 it became the pioneer synchrocyclotron, confirming for the first time the theory of phase stability, the principle governing the operation of the great accelerators built since, and it became a major stepping-stone in the history of science.
