Ion Cyclotron Resonance

Abstract

A CHARGED particle of mass m and charge e crossing a uniform magnetic field of strength H will describe a circular path with angular frequency ω = eH/mc, independently of the particle's energy (c is the velocity of light). If such a particle is subjected to an alternating electric field, at the cyclotron frequency, perpendicular to the magnetic field, then absorption of energy from the electric field may be expected. A measurement of the frequency at which absorption takes place should therefore enable the mass of the resonating particle to be determined, given e, H and c, while the amount of absorption should provide information on the number of resonating particles present.