Question

What are the functions of magnetic field and electric field in a cyclotron?

Answer 1

A cyclotron is a type of particle accelerator. It uses electric and magnetic fields to accelerate a charged particle and to make it follow a spiral path. With each complete orbit the velocity of the particle increases

Complete step by step solution:
A cyclotron uses electric and magnetic fields to accelerate charged particles. When a charge moves in a magnetic field, it experiences a force, this concept is the basic principle that a cyclotron works on.
It consists of two equal semicircle sections, called the “D’s”, joined together at their diameters. The cyclotron is set up inside a large electromagnet, which maintains a uniform magnetic field B inside it. The charged particle is first launched from the center of the cyclotron. Here, a high voltage electric field is applied to it, which causes the charge to move forward. The direction of the magnetic field is perpendicular to the motion of the charge, it causes it to move in a circular path.
Therefore, the charged particle moves in a path which is a semicircle, as it enters the other D, the direction of the electric field is reversed. This causes the particle to experience a push from the electric field again, and it covers a semicircular path around the other D too.
With each push the charge experiences a force that increases the radius of its rotation. This also causes the path of the particle to look like a spiral. The time taken by the charged particle is the same for all radii covered by it, therefore the charge accelerates inside a cyclotron.
Thus, in a cyclotron electric field is responsible for increasing the velocity of the charged particle whereas the magnetic field is responsible for the circular motion of the charged particle inside the D’s.

Note In order to provide electrical force to the particle in the exact time when it reaches the other D, the frequency of the electric field is set equal to the “resonant frequency of the cyclotron”. Which depends on the charge of the particle, mass of the particle and the Magnetic field inside the cyclotron.