CBSE Class 12-science Answered

Cyclotron is a particle accelerator. It is used to accelerate charged particles to high velocities by making them to pass repeatedly through the same accelerating region.

In a cyclotron charged particles are accelerated to very high energy using comparatively small electric field, by making the charged particle to cross the electric field again and again using a strong magnetic field.

A cyclotron consist of two semicircular boxes D ₁ and D ₂ called dees enclosed in a chamber kept between the poles of a powerful electromagnet, so that a uniform magnetic field acts perpendicular to the plane of the dees. An alternating voltage is produced in the gap between the dees by using a high frequency oscillator.

The ions inside a cyclotron are subjected to a uniform magnetic field, perpendicular to the velocity of the ions. The magnetic Lorentz force acting on the ions keep them in circular orbits in two evacuated hollow semicircular dees. The radius of the orbit increases as the ions are accelerated by the potential difference between the dees which reverses at the orbital frequency of the ions.

Hence we can say that in a cyclotron the magnetic field is used to make the charged particle move in circular orbit repeatedly.