KATRIN++ - Development of New Detector Technologies for a Future Neutrino Mass Experiment with Tritium

Currently, the tightest constraints on the absolute scale of neutrino mass from a direct, model-independent approach, are obtained by the KATRIN experiment, giving an upper limit on the mass of the electron anti-neutrino of 0.45 eV (https://doi.org/10.48550/arXiv.2406.13516), with final projected sensitivity below 0.3 eV. Going beyond this limit, and probing the inverted mass ordering (and beyond), will be the task for future neutrino mass experiments. In this regard, development of new detector technologies is of utmost importance, with quantum sensor arrays currently being the front runners due to their exceptional performance and excellent energy resolution. We report on our R&D efforts aiming to demonstrate the feasibility of developing and operating large quantum sensor arrays for detection of external electrons in a KATRIN-like setup, as a basis for the next generation neutrino mass experiments with tritium.