Application of leak-out-spectroscopy to exotic hydrogen-helium cations

Leak-out-spectroscopy (LOS) is a rather novel ion-trap-based action spectroscopy method. LOS exploits the fact that vibrational energy of a laser-excited ion can be converted into kinetic energy in a collision with a suitable neutral molecule or atom. The ions are thus accelerated and may leave the trap towards a detector. By counting the "leaked-out" ions as a function of the laser wavelength, a spectrum is generated. The invention of LOS has boosted the spectroscopy of molecular ions, as it is a universal and close-to background-free technique, with many recent applications to astrophysically relevant cations.

In this presentation, I will focus on the application of LOS to exotic ions consisting only of helium and hydrogen. Such systems are not only believed to be astrochemically relevant, but also consist of only a few particles and therefore serve as a testing ground for high-level theoretical treatments. First results for the linear cations He-H⁺-He and D₂He⁺ will be presented.