synchrocyclotrons

A synchrocyclotron is a type of particle accelerator that accelerates charged particles, such as protons or ions, to high energies. It is a variation of the cyclotron, which uses a constant radio frequency to accelerate particles. In a synchrocyclotron, the radio frequency is varied during the acceleration process. This variation is necessary because as particles gain energy, their mass increases due to relativistic effects. A constant frequency would no longer be synchronized with the particles' orbital period, causing them to be accelerated less efficiently or even stop accelerating altogether. By decreasing the frequency of the applied electric field in step with the increasing mass of the particles, synchronization is maintained throughout the acceleration cycle.

The synchrocyclotron consists of two D-shaped electrodes, called dees, placed in a vacuum chamber. A strong magnetic field is applied perpendicular to the plane of the dees, causing charged particles to move in a spiral path. An alternating voltage is applied across the gap between the dees. Particles are injected into the center of the dees and are accelerated each time they cross the gap. As they gain energy, they spiral outwards. The frequency of the alternating voltage is modulated downwards as the particles gain energy, ensuring they are always in sync with the accelerating electric field. Once the particles reach the desired energy, they are extracted from the accelerator. Synchrocyclotrons were an important step in the development of particle accelerators, allowing for the study of nuclear physics and the production of medical isotopes.