ECR

The plasma in the Electron Cyclotron Resonance ion source is confined in a magnetic trap formed by the electric currents flowing in the solenoids (axial confinement) and by the radial magnetic field produced by the hexapole magnet, which is made of permanent magnets or superconducting coils. The electrons in the plasma are resonantly accelerated when they pass the resonance zone where their girofrequency equals the frequency of the microwave injected into the plasma chamber. The originally neutral gas or metal vapor atoms are ionized in step-by-step collisions with the fast electrons. The produced ions are extracted with an extraction electrode system through a hole in the positively biased plasma chamber.