Surface Plasma Negative Ion Sources

The Surface Plasma Source (SPS) is a particular type of negative ion source that uses cesium or other materials to enhance negative ion production. The BTG surface plasma heavy negative ion source (SPHNIS) is based on negative ion formation by secondary emission of negative ions enhanced by cesium catalyst admixture to the discharge. The main features of the negative ion sources developed by BTG are:

  • High current,
  • High electrical efficiency
  • High gas efficiency and
  • Compact size
  • Long lifetime


Negative ion source developed by BTG

The main applications of these ion sources are as injectors into tandem accelerators, cyclotrons, LINACs and neutral beam devices. The BTG surface plasma negative ion sources are designed for high brightness and high gas and power efficiency. Several versions have been successfully designed and tested.


High power negative hydrogen ion source developed by BTG