An Ion Mobility Mass Spectrometry Cryogenic Ion Trap Instrument Coupled To The Fritz Haber Institute Infrared Free Electron Laser

The coupling of ion mobility with mass spectrometry (IM-MS) allows for the selection of isolated, gas-phase molecular ions with defined mass/charge as well as geometrical size/charge ratios. When coupled to cryogenic ion traps, those molecular ions can be tagged with atoms or molecules to allow for action spectroscopy of very well defined cold species, and several instruments to do so have been developed in laboratories worldwide. We recently upgraded our drift tube IM-MS instrument that is coupled to the Fritz Haber Institute FEL to perform IR multiple photon dissociation spectroscopy with a cryogenic ion trap to allow for messenger atom/molecule action spectroscopy. The cryogenic ion trap itself implements a novel concept by having a segmented trap consisting of a high and a low pressure region. Ions can be injected cw or at a high repetition rate into the high pressure region, portions of the ions can then be transferred at a variable rate to the low pressure region from which they are ejected to the laser interaction region at a rate, matched to the laser repetition rate and independent from the injection rate into the trap. First results on the IR spectroscopy of biological molecules will be presented