Speaker
Description
The KATRIN experiment aims at the direct measurement of the neutrino mass scale via precision endpoint spectroscopy of tritium β-decay. The current upper limit on the neutrino mass set by KATRIN is 0.8 eV/c² (90% C.L.) (Nature Physics 18, 160–166 (2022)). Despite advances in background reduction, the elevated background level prohibits to achieve its target sensitivity of 0.2 eV/c² (90% C.L.).
Our investigations showed that the special nature of the background allows in principle differentiating background (small pitch angles) from β-decay electrons (large pitch angles). Therefore, one option to reduce the background is by implementing an “active Transverse Energy Filter” (aTEF, Eur. Phys. J. C 82, 922 (2022)), which discriminates electrons at the detector based on their pitch angle. First aTEF prototypes fabricated at the University of Münster show the expected angular-selective electron detection.
This contribution presents the concept of an active Transverse Energy Filter, its fabrication process and the performance of current prototypes in a test setup. It furthermore gives an outlook on the potential for background reduction and the related sensitivity improvement from an implementation of an aTEF at KATRIN.
This work is supported by BMBF under contract number 05A20PMA and Deutsche Forschungsgemeinschaft DFG (Research Training Group GRK 2149) in Germany.
