Penning trap induced background in the KATRIN experiment

The KArlsruhe TRItium Neutrino (KATRIN) experiment is a largescale experiment with the objective to determine the effective electron anti-neutrino mass with an unprecedented sensitivity of 0.2 eV/c2 at 90% CL in a model-independent way based on precision β-decay spectroscopy of molecular tritium. KATRIN is currently in the middle of several physics measurement campaigns and so far has improved the upper bound on the effective electron-neutrino mass to 0.8 eV at a 90% confidence level.
A Penning trap located between the KATRIN spectrometers, in combination with a large flux of β-decay electrons in this area, produces a scan-step-duration-dependent background which is one of the leading systematic uncertainties of KATRIN. This background was successfully mitigated with an optimized configuration of the voltages in the KATRIN beamline and is not present anymore in recent measurement campaigns. This talk will present measurements and a background model to describe the Penning trap induced background.
This work is supported by the Helmholtz Association, the Ministry for Education and Research BMBF (05A17PM3, 05A17PX3, 05A17VK2, and 05A17WO3), the Helmholtz Alliance for Astroparticle Physics (HAP), and the Helmholtz Initiative and Networking Fund (W2/W3-118).