Neutrino mass measurements and heavy sterile neutrino detection by time-of-flight measurements at KATRIN

The KATRIN experiment aims at a measurement of the anti νe mass with 0.2 eV sensitivity using an integrating spectrometer of MAC-E filter type. In this talk the alternative idea of determining the mass with a non-integrating Time-of-Flight (TOF) spectroscopy mode on a MAC-E filter is discussed. Simulations show that it can in principle improve the statistical sensitivity on the parameter m(νe)2 by up to a factor 5, provided a sufficiently precise start signal is available for the TOF measurement. An already successfully applied method utilizes periodic cut-offs of the electron beam but is uncertain to reach the necessary sensitivity. That method, however, might be useful for detecting heavy sterile neutrinos in the keV range. These could possibly contribute to a large fraction of the dark matter observed in the universe and can in principle be measured due to their mixing with the electron neutrino.