•Klaus Eitel für die KATRIN-Kollaboration
Forschungszentrum Karlsruhe, Institut für Kernphysik

The determination of the absolute neutrino mass scale, which is not accessible by neutrino oscillation experiments, is of fundamental importance in particle physics and cosmology. The KArlsruhe TRItium Neutrino experiment addresses this task by investigating spectroscopically the electron spectrum from the Tritium b decay ³H ® ³He + e^-+ [`(n)]_e near its kinematical endpoint of 18.6 keV. With a strong molecular windowless gaseous Tritium source and an electrostatic filter of unprecedented energy resolution of DE = 1 eV, KATRIN will allow a direct model-independent measurement of neutrino masses in the sub-eV range relevant for structure formation in the early universe.

We present an overview of the experimental configuration as well as a status report of the ongoing construction and conclude with detailed analyses of the expected neutrino mass sensitivity of 0.2 eV (90% CL).

Funded in part by the German BMBF Förderschwerpunkt Astroteilchenphysik under 05CK1VK1/7 und 05CK1UM1/5.