Florian Simke

• This thesis develops and characterizes digitally driven quadrupole mass filters (QMFs) and linear Paul traps for mass-selection and bunching of large ion packets. Rectangular driving waveforms are analyzed and stability regions are mapped to show how mass filtering by mass-to-charge ratio can be controlled via frequency and duty cycle. Experimentally, a Digital Ion Trap (DIT) module is built for the MS-SPIDOC project. The used QMF attains a resolving power of about 100, with the expected trade-off of reduced transmission. The encapsulated Paul trap employs additional pin electrodes to shape an axial potential well and, after buffer-gas cooling, produces dense ion bunches with a full width at half maximum (FWHM) of ~1 µs. As functional tests, Cesium-Iodide clusters are mass-selected, stored, and ejected as ion bunches. By mass-selecting hemoglobin charge states and by storing and ejecting a GroEL protein complex, the module is shown to preserve biomolecules in their native state. In the second part, a MagneTOF detector is calibrated by single-ion counting and area integration of the measured transient, enabling quantification of ion bunches up to the detector’s technical saturation (~6×10⁴ ions per 1-µs bunch). In addition, the saturation of another Paul trap is extrapolated to the 10⁶–10⁷-ion range.