KATRIN
![Transport of the main spectrometer to the Karlsruhe Institute of Technology.](/Images/godic/202501/22/Ortsdurchfahrt-Leopoldshafen1808.jpg")
![Energy spectrum of the electrons emitted in tritium beta decay. Three graphs for different neutrino masses are shown. These graphs differ only in the range near the high-energetic end-point; the intersection with the abscissa depends on the neutrino mass. In the KATRIN experiment the spectrum around this end-point is measured with high precision to obtain the neutrino mass.](/Images/godic/202501/22/KATRIN_Spectrum.svg1808.png")
KATRIN is a German acronym (Karlsruhe Tritium Neutrino Experiment) for an undertaking to measure the mass of the electron antineutrino with sub-eV precision by examining the spectrum of electrons emitted from the beta decay of tritium. The core of the apparatus is a 200-ton spectrometer, which has been built by MAN DWE GmbH in Deggendorf and was shipped to Karlsruhe via an 8600 km route involving the Black Sea, the Mediterranean Sea, the Atlantic Ocean and the Rhine. This detour was necessary as shorter routes (the shortest route on land would have been only 350 km) could not been used due to the tank's size. The construction is proceeding well with several of the major components being already on-site. The main spectrometer test program will start in 2013 and the complete system integration is planned for 2014. The experiment is located at the former Forschungszentrum Karlsruhe, now Campus Nord of the Karlsruhe Institute of Technology.