Development of technologies for a future neutrino mass experiment at KATRIN

The Karlsruhe Tritium Neutrino (KATRIN) experiment determines the neutrino mass by electron spectroscopy of the tritium beta-decay spectrum. After a total measurement time of 1000 days in 2025, a final sensitivity better than 0.3 eV/c2 (90% C.L.) is anticipated.

Ultimately, determining the neutrino mass may require constructing experiments with sensitivities as low as the lower boundaries obtained by neutrino oscillation experiments (40 meV/c2 in case of inverted ordering, or 8 meV/c2 for normal ordering). To reach those sensitivities, we are developing new technologies such as a differential detector with sub-eV resolution, and an atomic tritium source.

For the differential detector, we are currently testing quantum sensors, more precisely, µm-sized cryogenic (10 mK) calorimeters. We aim to build a demonstrator where we couple a large quantum-sensor array of up to 106 channels to the existing KATRIN beamline.

Additionally, we are building a first-of-its-kind setup for creating tritium atoms. We plan to make it part of another demonstrator – after solving key challenges for future atomic sources (mK-cooling, storing of atoms) in cooperation with the global community (e.g. ... mehrProject 8).

Both technology demonstrators will be paramount for the design of the ultimate neutrino mass experiment.

This work is supported by the Helmholtz Association and BMBF (grant numbers 05A23PMA, 05A23PX2, 05A23VK2, and 05A23WO6).