Cyclotron is a device used to accelerate charged particles to high energies. It was devised by Lawrence.
Cyclotron works on the principle that a charged particle moving normal to magnetic field experiences magnetic Lorentz force due to which the particle moves in a circular path.
(i) Maintaining a uniform magnetic field over a large area of the Deesis difficult.
(ii) At high velocities, relativistic variation of mass of the particle upsets the resonance condition.
(iii) At high frequencies, relativistic variation of mass of the electron is appreciable and hence electrons cannot be accelerated by cyclotron.