Measurement of the electric potential and the magnetic field in the shifted analysing plane of the KATRIN experiment

Aker, M et al. [KATRIN Collaboration]

Abstract

The projected sensitivity of the effective elec- tron neutrino-mass measurement with the KATRIN experi- ment is below 0.3 eV (90 % CL) after 5 years of data acqui- sition. The sensitivity is affected by the increased rate of the background electrons from KATRIN’s main spectrometer. A special shifted-analysing-plane (SAP) configuration was developed to reduce this background by a factor of two. The complex layout of electromagnetic fields in the SAP config- uration requires a robust method of estimating these fields. We present in this paper a dedicated calibration measurement of the fields using conversion electrons of gaseous 83m Kr, which enables the neutrino-mass measurements in the SAP configuration.