A radio frequency quadrupole ("RFQ", pictures available here) is a linear accelerator component generally used at low beam energies, roughly 50keV to 3MeV. It is similar in concept to a quadrupole mass analyser but its purpose is to accelerate a single-species beam (rather than perform mass spectrometry on a multiple-species beam).

The RFQ is a combined-function component that both accelerates and focusses the beam of charged particles.

Invented by Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

physicists Kapchinsky and Teplyakov in 1970, the RFQ is presently used as an injector by major laboratories and industries throughout the world for radiofrequency linear accelerators.