Production of highly charged ions inside a cryogenic Penning trap by electron-impact ionisation

We have built and operated a cryogenic Penning trap arrangement that allows for the efficient production, selection, and long-term storage of highly charged atomic ions. In close similarity to an electron-beam ion trap it works by electron-impact ionisation of atoms inside a dedicated confinement region. The electrons are produced by field emission at liquid-helium temperature and are subsequently accelerated to the keV energy range. The electron beam is reflected through the trap multiple times to increase the ionisation efficiency. We show a characterisation of the system and measurements with argon and tungsten ions up to Ar16+ and W27+, respectively.

Automated summary

We have constructed and operated a cryogenic Penning trap setup that enables efficient production, selection, and long-term storage of highly charged atomic ions. Similar to an electron-beam ion trap, it functions by electron-impact ionization of atoms within a designated confinement region. The electrons are generated by field emission at liquid-helium temperature and subsequently accelerated to the keV energy range. The electron beam undergoes multiple reflections in the trap to enhance ionization efficiency. We present a characterization of the system and measurements with argon and tungsten ions up to Ar16+ and W27+, respectively.