ECR ion source


An electron cyclotron resonance ion source (ECRIS) uses the functional principle of resonant heating plasma by microwave irradiation. Electrons in a magnetic field move in circles due to the Lorentz force, with a frequency depending on the magnetic field strength. If the frequency of the incoming microwave radiation is approximately equal to the gyration frequency of the rotating electrons, resonance resulting in the heating of the electrons is observed. The heating of the free electrons generates ions via electron impact ionization, which in turn generates additional free electrons. This snowball effect produces a plasma confined by the magnetic field, which is generated by permanent magnets. Ions can be extracted from the plasma by applying an electric gradient.  
Depending on the operating parameters, ECR ion sources are able to produce multi-charged ions or lowly charged ions at ion beam currents of µA up to mA.

Scheme illustrating the principle of operation of an electron cyclotron resonance ion source (ECRIS).
Figure 1: Schematic illustrating the principles of operation of an electron cyclotron resonance ion source (ECRIS).

Source and Extraction Assembly, RIBS-2.45


ECR ion source.


  • highly modularized design for optimum integration into existing facilities
  • capable of producing ions of a wide range of elements
  • comparatively high ion current output of up to hundreds of microamperes
  • operates with a 2.45 GHz microwave frequency effectively generating a stable plasma
  • reliable operation