What does cyclotron mean?
A cyclotron is a machine designed to accelerate charged particles—such as protons, deuterons, or alpha particles—to very high speeds. Invented by American physicist Ernest O. Lawrence around 1929–1930, it works by applying a steady magnetic field that bends the particle's path into a circle, combined with an alternating electric field that repeatedly boosts the particle's energy. As the particles gain speed, their orbits widen into an expanding spiral until they are finally steered out of the machine and aimed at a target. Cyclotrons played a central role in the birth of nuclear physics, enabling the artificial production of radioactive isotopes and fundamental discoveries about the atomic nucleus. Smaller versions remain valuable today, particularly for generating radioisotopes used in medical imaging such as PET scans. The term also appears in physics descriptions of charged-particle behaviour in magnetic fields, as in cyclotron frequency and cyclotron resonance.
nounA cyclotron is a type of particle accelerator that uses a constant magnetic field and a rapidly alternating electric field to propel charged particles, such as protons or deuterons, outward along a spiral path to very high energies.
- A machine for accelerating charged particles in a spiral path using a constant magnetic field and alternating electric field.
- (Physics) The characteristic motion or resonance of charged particles in a magnetic field, as described by 'cyclotron frequency' or 'cyclotron resonance'.
"The physicists fired up the cyclotron and watched the beam of protons spiral toward its target."
"The medical isotopes used in PET scans are produced inside hospital-based cyclotrons."
"Cyclotron resonance occurs when a charged particle orbits at a frequency matching the applied electric field."
Standard plural; used when referring to multiple machines or installations.
"Several university laboratories operate small cyclotrons for isotope production."
Invented in 1929 by 27-year-old Ernest Lawrence, the cyclotron was so compact he built the first one out of a kitchen phonograph — and it won him the Nobel Prize.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cyclotron
The word cyclotron was coined in English in the early 1930s, shortly after Ernest O. Lawrence developed the device at the University of California, Berkeley. It combines the Greek-derived element 'cyclo-', meaning circle or wheel (from Greek 'kyklos'), with '-tron', a suffix commonly used for scientific instruments and electron devices. Related words sharing the 'cyclo-' root include bicycle, cyclone, and cyclical.
How cyclotron is actually used
A technical term used mainly in physics, engineering, and related scientific contexts; rarely encountered in everyday conversation. The word carries no strong connotation beyond its association with mid-20th-century nuclear research.
Easily confused with cyclotron
A synchrotron varies its magnetic field strength to keep particles on a fixed-radius circular path, whereas a cyclotron uses a constant magnetic field and lets the particle's orbit spiral outward.
A betatron accelerates electrons using an changing magnetic field in a fixed circular orbit, while a cyclotron accelerates charged particles in an expanding spiral path.