The Karlsuhe Tritium Neutrino Experiment (KATRIN) is seeking to determine the neutrino mass in a purely kinematic and therefore model-independent way. It does this by measuring the endpoint region of the molecular tritium beta decay spectrum. KATRIN sets the currently most stringent model-independent upper limit on the neutrino mass, at 0.45 eV (90 % CL).
Important for KATRIN's success is the careful characterization and mitigation of systematics. Particularly important is the characterization of electron energy losses due to scattering, for which a pulsed photo-electron source is used, providing additional energy information via time-of-flight analysis. Additionally, using 83mKr for an absolute calibration of the energy scale enables an important cross-check of the results by comparing the Q-value result from KATRIN to the 3He-3H mass difference determined in Penning trap measurements.
After successful systematics mitigation and a full analysis of the available dataset, KATRIN's final sensitivity is expected to reach below 0.3 eV. However, very likely, the neutrino mass value will remain out of reach for KATRIN's sensitivity and new experiments employing improved technology are going to be necessary.
One key improvement would be switching from a molecular to an atomic tritium source. Such a source can be constructed by trapping mK-cold atoms in a magneticfield. Within the Karlsruhe Mainz Atomic Tritium Experiment (KAMATE), a collaboration of the TLK and the JGU Mainz, we are bench-marking different types of atomic dissociators and aim to demonstrate the primary cooling stages with tritium.
The talk will summarize the KATRIN results so far, as well as highlight efforts to mitigate systematics of the KATRIN setup. It will also touch on some of the work done in the context of KAMATE.