The wire electrode system for the KATRIN main spectrometer

Aims. KATRIN is a neutrino mass experiment based on the kinematics of tritium β -decay. This work presents the methods employed at KATRIN to reduce the spectrometer-related background. s. The electrode system of the main spectrometer includes a modular double-layer wire grid for electrostatic screening of background. The key features of the wire electrode and the underlying design criteria of the optimisation procedure are described. . Fabrication of the wire electrode modules is completed and installation into the KATRIN main spectrometer has started.