In 1930, Lawrence left Yale for Berkeley, and two years later at the age of 29 he became the youngest full professor in the Berkeley faculty.
In 1930 at Berkeley, Ernest O. Lawrence invented the cyclotron, the first circular accelerator. Lawrence often operated the early cyclotrons throughout the night to produce medical isotopes for research and treatment.
Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideröe on high-energy accelerators. It is an article in a German electrical engineering journal on the multiple acceleration of positive ion.
In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston, constructed a 13-cm diameter model that had all the features of early cyclotrons, accelerating protons to 80,000 volts using less than 1,000 volts on a semi-circular accelerating electrode, now called the "dee.”
Following the discovery by J. D. Cockcroft and E. T. S. Walton of how to produce larger currents at higher voltages, Lawrence constructed the first two-dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. The 27-Inch Cyclotron was used extensively in early investigations of nuclear reactions involving neutrons and artificial radioactivity. In 1939, working with William Brobeck, Lawrence constructed the 60-Inch (150-cm) Cyclotron, which accelerated deuterons to 19 MeV.
The cyclotron takes advantage of the relationship between the magnetic force needed to bend the path of a particle in a circle, the radius of the circle and the speed of the particle, to whizz particles around a loop and accelerate them to formerly unattainable velocities.
In the next decade, Lawrence’s invention proved to be a spectacularly useful machine. The doctoral candidates and postdocs he assembled into teams at Berkeley discovered scores of new isotopes, including carbon-14, which made its mark as a tool for carbon dating. Other isotopes created by cyclotron bombardment became the foundation of the new science of nuclear medicine and the sources of new cures.
First particle accelerator in United States
