The KATRIN (Karlsruhe Tritium Neutrino) experiment investigates the kinematic endpoint of the tritium beta-decay spectrum to determine the effective mass of the electron anti-neutrino. The collaboration reported its first limit on the neutrino mass in fall 2019 with mν <1.1 eV (90% CL) followed by the first sub-eV limit in March this year. Its unprecedented tritium source luminosity and spectroscopic quality make it a unique instrument to also search for physics beyond the stan- dard model such as sterile neutrinos.
The TRISTAN project aims at detecting a keV-sterile neutrino signature by measuring the en- tire tritium beta-decay spectrum with an upgraded KATRIN detection and read-out system. One of the greatest challenges is to handle the high signal rates generated by the strong activity of the KATRIN tritium source while keeping a good energy resolution and stability over time. Therefore, a novel multi-pixels silicon drift detector and read-out are being designed to handle rates up to 100 MHz with an energy resolution of 200 eV (FWHM) at 10 keV.
During my talk, the KATRIN experiment and its latest results will be introduced. Then the TRISTAN project, the assembly and the commissioning of the first module will be presented, focusing on the latest results from a 47-pixels module inserted in the KATRIN Monitor Spectrometer. The challenges of modeling the entire tritium spectrum to look for a sterile neutrino signature will be discussed. Finally, the possibility of using the TRISTAN detector to look for solar axions in the IAXO experiment will be mentioned.