Probing the neutrino mass scale with KATRIN
Kathrin Valerius (KIT, Karlsruhe)

The mass scale of neutrinos remains one of the fundamental open questions in modern physics, with far-reaching implications from particle physics to cosmology.
Precision measurements of the kinematics of weak interactions, in particular tritium beta decay and electron capture in 163Ho, offer the only model-independent (direct) approach to access the neutrino mass scale in a laboratory experiment.
The currently most mature technique relies on the spectroscopy of tritium beta decay near its kinematic endpoint at 18.6 keV. The KArlsruhe TRItium Neutrino experiment (KATRIN) is targeted at improving the sensitivity of this method by an order of magnitude to 200 meV (90% C.L.). To this end, KATRIN utilises an ultra-luminous windowless gaseous tritium source and a high-resolution electrostatic spectrometer.
In this talk I will present results of the “First Tritium” campaign in which the full 70-m long beam line of KATRIN was successfully inaugurated in summer 2018, demonstrating the precision spectroscopy performance and stability of the overall system. I will furthermore report on the current final steps of preparing the KATRIN apparatus and the analysis chain for first neutrino-mass measurements starting next spring.