Cyclotron Facts For Kids
A cyclotron is a special machine invented by Ernest O. Lawrence that accelerates charged particles to high speeds, used in medical and scientific applications.
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Photos of Cyclotron
Lawrence's original 4.5-inch (11 cm) cyclotron
Lawrence's 60-inch (150 cm) cyclotron at Lawrence Radiation Laboratory, University of California, Berkeley, California, constructed in 1939. The magnet is on the left, with the vacuum chamber between its pole pieces, and the beamline which analyzed the particles is on the right.
Diagram of a cyclotron. The magnet's pole pieces are shown smaller than in reality; they must actually be at least as wide as the accelerating electrodes ("dees") to create a uniform field.
Diagram of cyclotron operation from Lawrence's 1934 patent. The hollow, open-faced D-shaped electrodes (left), known as dees, are enclosed in a flat vacuum chamber which is installed in a narrow gap between the two poles of a large magnet (right).
Vacuum chamber of Lawrence 69 cm (27 in) 1932 cyclotron with cover removed, showing the dees. The 13,000 V RF accelerating potential at about 27 MHz is applied to the dees by the two feedlines visible at top right. The beam emerges from the dees and strikes the target in the chamber at bottom.
The trajectory followed by a particle in the cyclotron approximated with a Fermat's spiral
In isochronous cyclotrons, the magnetic field strength B as a function of the radius r has the same shape as the Lorentz factor γ as a function of the speed v.
A French cyclotron, produced in Zürich, Switzerland in 1937. The vacuum chamber containing the dees (at left) has been removed from the magnet (red, at right).
A modern cyclotron used for radiation therapy. The magnet yoke is painted yellow.