What role does the magnetic field play in a cyclotron?

The magnetic field in a cyclotron is crucial for ensuring the circular motion of a charged particle, such as an ion. When a charged particle enters the magnetic field, it experiences a magnetic force that acts perpendicular to both the direction of its velocity and the magnetic field itself. This results in the particle undergoing circular motion, as the magnetic force continuously acts as a centripetal force that keeps the particle moving along a curved path.

The strength of the magnetic field determines the radius of the circular motion, and for a given speed and charge of the particle, a stronger magnetic field will result in a smaller radius of curvature. This characteristic enables the cyclotron to accelerate particles to high speeds while maintaining their circular trajectory. Therefore, the primary role of the magnetic field in a cyclotron is to keep charged particles in a circular path, allowing for effective acceleration and manipulation of the particles in a controlled manner.