This thesis was performed in the context of the Karlsruhe Tritium Neutrino (KATRIN) experiment which aims to determine the effective mass of the electron antineutrino with an unprecedented sensitivity of 200 meV/c^2 (90% C.L.). The main goals of this thesis were to perform large scale Monte Carlo simulations of signal electrons to model the properties of the response function of the experiment with great precision as well as to determine the transmission properties of the main spectrometer
