The KATRIN Neutrino Mass Experiment
  The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the mass of electron neutrinos from beta-decay of tritium with an unprecedented sensitivity of 0.2 eV/c^2 improving present limits by one order of magnitude. The decay electrons will originate from a 10 m long windowless, gaseous tritium source. Super-conducting magnets guide the electrons through differential and cryogenic pumping sections to the electro-static tandem spectrometer (MAC-E-filter), where the kinetic energy will be measured. The experiment is presently being built at the Forschungszentrum Karlsruhe by an international collaboration of more than 120 scientists. The largest component, the 1240 m^3 main spectrometer, was delivered end of 2006 and first commissioning tests have been performed. This presentation describes the goals and technological challenges of the experiment and reports on the progress in commissioning first major components. The start of first measurements is expected in 2012. 
J. Wolf (for the KATRIN collaboration)