An Electron Beam Ion Trap (EBIT) provides highly charged ions (HCI) for spectroscopy and other experiments. To this end, a nearly monoenergetic electron beam is used. In interactions with the electrons from the beam, neutral atoms or positively charged ions can be stripped of bound electrons by means of electron impact ionization.

The electron beam originates at a so-called “electron gun”, is accelerated towards the trap center, and dumped at a so-called “collector”. The electron beam is guided and compressed by a strong magnetic field.

The positively charged ions are attracted and trapped radially by the negatively charged electron beam. Longitudinal trapping is achieved by electrostatic potentials applied to a set of cylindrical drift tubes around the beam axis.

Once trapped, HCIs interact with the electron beam and emit X-rays, which can give insights into a wide range of atomic processes, of interest for plasma physics, astrophysics and fundamental research.

The electron beam ion trap S-EBIT I, developed by Physics and Technology LLC (Livermore, California, USA), was set up at the AlbaNova University Center in Stockholm Sweden. It then was transferred to GSI, where it is now operated in the X4 cave. S-EBIT I demonstrated its capability of producing and trapping HCI for use in spectroscopy, by being used for high-resolution X-ray spectroscopy and for testing equipment for experiments at storage rings.

S-EBIT II was developed as an upgrade for S-EBIT I. It is located at HITRAP, allowing it to function as a local ion source. That way, it will allow for additional beamtime, beyond what is available from the GSI accelerator facilities, supporting experiments at HITRAP.