The new detector section for KATRIN for the keV sterile neutrino search

At the Karlsruhe Institute of Technology (KIT) a full-scale replica of the KATRIN experiment's detector system was developed to pretest the innovative TRISTAN detectors. The replica system facilitates comprehensive testing and calibration of currently three TRISTAN detectors under controlled conditions, ensuring their optimal performance prior to integration into the KATRIN beamline in 2026 which will enhance KATRIN's sensitivity in the search for keV-scale sterile neutrinos. Critical operational parameters, including energy resolution, count rate capabilities, and data aquisition, are meticulously evaluated. Preliminary results indicate that the TRISTAN modules achieve exceptional high-resolution beta spectroscopy, essential for precise neutrino mass measurements and the exploration of potential new physics. This presentation will discuss the setup, detailed test procedures and initial results that emphasize the central role of the TRISTAN upgrade in advancing neutrino research.