Cyclotron

At the center of a cyclotron, a source emits a charged particle, such as a proton, which is immediately accelerated by a voltage. The proton travels through a magnetic field that curves its path into a spiral as it continues to accelerate. Eventually, it spirals out of the cyclotron at a high speed. The protons are directed down a beam line to collide with a target. In proton therapy that target is a tumor.