Ultracold Electron and Ion Sources

The development of laser cooling and trapping made a whole new temperature regime accessible to experiments. Among others, this led to the creation of new states of matter such quantum gases and ultracold plasmas. In our research, we use atom trapping to create a new class of charged particle sources, featuring ultracold electrons (10K) and ions (1mK). Such sources offer a new route toward high brightness by virtue of a high angular intensity. This is in contrast to needle sources (such as the liquid-metal ion source or carbon nanotube electron emitters), which optimize current density. As a result, ultracold sources suffer less from space-charge effects, in particular in pulsed mode.

Applications of the ultracold sources that we are intersted in are ultrafast electron diffraction and focused-ion beam instrumentation.

Our research on ultracold electron and ion sources is divided in two subprojects:

  • Ultracold electron bunches
  • Laser-cooled focused ion beams