Phazotrons

A phazotron is a type of particle accelerator, specifically a cyclic accelerator, that was developed in the mid-20th century. It is a variation of the cyclotron but with a significant modification to overcome the relativistic mass increase of particles as they are accelerated to high energies. In a standard cyclotron, the constant magnetic field and radiofrequency electric field cause particles to spiral outwards. However, as particles approach the speed of light, their mass increases, causing them to fall out of sync with the accelerating electric field.

The phazotron, also known as a synchrocyclotron, addresses this issue by varying either the magnetic field or, more commonly, the frequency of the accelerating electric field. In a synchrocyclotron, the radiofrequency is modulated, decreasing as the particles gain energy and mass. This decreasing frequency ensures that the particles remain in resonance with the accelerating field throughout their trajectory, allowing them to reach higher energies than a conventional cyclotron.

The magnetic field in a phazotron is typically uniform over the entire area where the particles orbit. The accelerated particles are extracted from the accelerator when they reach the desired energy. Phazotrons were important in the development of nuclear physics and particle physics research, enabling the study of nuclear reactions and the discovery of new particles. While more advanced accelerators like synchrotrons have largely superseded phazotrons for very high-energy physics, they remain a historically significant and effective type of particle accelerator.