Monte Carlo simulations of the detector response to low energy electrons for KATRIN

Abstract The Karlsruhe Tritium Neutrino experiment (KATRIN) derives the mass of the electron anti-neutrino with a sensitivity of 0.2 eV/c 2 (90% C.L.) in a model-independent way from the measured energy spectrum of tritium β -decay electrons. The focal plane detector (FPD) is a large silicon PIN diode detecting the electrons transmitted by a large MAC-E spectrometer. To model the detector response to low-energy electrons, a full Monte Carlo simulation was developed and benchmarked.