How Does a Cyclotron Work?

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A cyclotron is a particle accelerator that uses electrical power to accelerate charged particles in a spiral path. The collision of particles produces certain radioactive isotopes for medicine, industry and scientific research.

Cyclotrons contain two hollow D-shaped electrodes, called dees, in a vacuum chamber between the poles of a powerful electromagnet. This vacuum chamber is flat and sits in a narrow gap between poles of an electromagnet, which creates a perpendicular magnetic field. A high-frequency alternating voltage is applied across the electrode to accelerate the charged particles fed into the center of the chamber.

As particles gain more energy from the accelerating voltage, they spiral outwards until they reach the outer edge of the chamber. The size of the vacuum chamber determines the spiral path of each particle and the amount of energy attained from the cyclotron. The direction of the spiral can also be reversed by connecting the dee to an AC voltage source that reverses direction at regular intervals.

The most common use for a cyclotron is for positron emission tomography scans. PET scans use gamma rays and radioisotopes produced by cyclotrons to help medical professionals diagnose medical conditions. A PET scanner can detect gamma rays in the human body and create a 3-D image of the organ being studied.