A betatron is a type of cyclic particle accelerator used to accelerate electrons to high energies. It was first proposed by Donald Kerst in 1940 and built by him and his team at the University of Illinois in 1945. Betatrons were the first cyclic accelerators to be built, and were the primary source of high-energy electrons in physics experiments until the development of the linear accelerator in the 1950s.

A betatron uses a magnetic field to accelerate electrons in a circular path. The magnetic field is created by a coil of wire that surrounds the electron beam, and is varied rapidly using an oscillator to keep the electrons moving in a circular path. As the electrons pass through the magnetic field, they are accelerated and emit synchrotron radiation, which can be used to study the properties of materials and subatomic particles.

Betatrons are capable of accelerating electrons to energies of several GeV (billion electron volts), making them useful for a wide range of applications, including medical imaging and radiation therapy, materials science, and particle physics research. However, they have some limitations, including a relatively low beam intensity compared to other types of accelerators, and a difficulty in producing electron beams with a wide range of energies.

Betatrons have largely been replaced by other types of accelerators, such as linear accelerators and synchrotrons, which are better suited to some applications. However, they remain an important tool in some areas of research, and several betatron facilities are still in operation around the world. Read More about Fee Management.