It sounds rather like an exercise bicycle from the 1950s but the cyclotron is actually the grandfather of today's most powerful particle accelerators. Having originally studied chemistry, Ernest Lawrence (1901-1958) switched to physics and received his PhD from Yale University in 1925. At this time, scientific insights into the nature of matter were starting to yield interesting results. In Cambridge, England, Ernest Rutherford had been using atomic particles as projectiles with which to bombard atoms. By 1919 he had succeeded in bombarding the nucleus of a nitrogen atom and getting it to absorb a helium nucleus, creating oxygen.
This kind of work, however, was reaching a technical limit. The atomic particles from naturally radioactive materials were too few and did not have the energy required to pursue the experiments that Rutherford wanted to perform. In 1927 he issued a plea to physicists to find methods to produce a "copious supply" of high-energy particles.
Lawrence answered the call and, just two years later, in 1929, came up with the idea that would quickly become the cyclotron. He was inspired to experiment with a magnetic field that would force charged particles to travel in a circular trajectory. This would make the particles pass through the same accelerating magnetism over and over again. In 1931 his first model was ready for production. His first cyclotron was a relatively simple device, measuring just a few inches across,that could accelerate hydrogen ions to much higher energies than were achievable before by any method. The new field of high-energy physics had finally arrived.
