Control of the environmental inluences on THe-Trap on the example of the determination of the mass ratio of carbon-12 to oxygen-16

Tritium-Helium-3-Trap (THe-Trap) is a Penning-trap setup dedicated to measure the 3H to 3He mass ratio with a relative uncertainty of better than 10-11. This is 40 times more precise than the currently adopted value and, thus, will help to investigate possible systematic uncertainties of the Karlsruhe Tritium Neutrino experiment (KATRIN). To achieve the desired level of uncertainty, several environmental influences such as atmospheric pressure shifts and magnetic field fluctuations have to be suppressed. With the implemented stabilization system, the relative magnetic field drift could be reduced to a few 10-12/h for a time span of several weeks. Within the context of this thesis a mass ratio measurement of 12C4+ to 16O5+ was performed to characterize systematic effects. This measurement yielded a statistical uncertainty of 6.3 x 10-11, which can easily be improved with more statistics, i.e. a longer measurement time. While the systematic uncertainty for 12C4+-ions were under control at the 10-11 level, the systematic shifts could not be quantified for 16O5+ due to poor vacuum conditions. Without these corrections, a systematic uncertainty of 1.2.10-10 could be achieved for the 12C/16O mass ratio measurement.