Measurements of exotic calcium isotopes by multi reflection time of flight mass spectrometry and further developments and applications ISOLTRAP Multi reflection time of flight mass spectrometry magic number mass separation neuron rich calcium isotopes precision mass measurements short lived nuclides voltage stabilization This thesis describes mass measurements at ISOLTRAP ISOLDE CERN in the region of the neutron rich calcium isotopes. For the less exotic and more abundantly produced isotopes 51Ca and 52Ca the Penning trap based ToF ICR technique could be used to validate the available mass data and to improve their precision. For the isotopes 53Ca and 54Ca a Multi Reflection Time of Flight Mass Spectrometer (MR ToF MS) was used to determine the mass of these exotic isotopes for the first time experimentally. This also represents the first time an MR ToF MS was applied to derive the masses of previously unknown radioactive ions from the high precision time of flight data that can be gathered with the device. The mass data was then used to benchmark the strength of the N=32 neutron subshell closure and at the same time to compare to state of the art shell model calculations. Furthermore the capability of the MR ToF device to deliver isobarically pure beams to a subsequent experiment was developed further and studied in detail. The new technique is based on the in trap lift which is normally used to in and eject ions into and from the device. With this new selective ejection technique after separation of the ion ensemble in the MR ToF trap no external components are required. Additionally a new stabilization system for voltages supplies based on a PI algorithm was developed and thoroughly tested. The stabilized voltage supply was then used to supply the most sensitive mirror voltage ...