  NEXT-100 is currently being constructed at the Laboratorio Subterr\'aneo de
Canfranc in the Spanish Pyrenees and will search for neutrinoless double beta
decay using a high-pressure gaseous time projection chamber (TPC) with 100 kg
of xenon. Charge amplification is carried out via electroluminescence (EL)
which is the process of accelerating electrons in a high electric field region
causing secondary scintillation of the medium proportional to the initial
charge. The NEXT-100 EL and cathode regions are made from tensioned hexagonal
meshes of 1 m diameter. This paper describes the design, characterization, and
installation of these parts for NEXT-100. Simulations of the electric field are
performed to model the drift and amplification of ionization electrons produced
in the detector under various EL region alignments and rotations. Measurements
of the electrostatic breakdown voltage in air characterize performance under
high voltage conditions and identify breakdown points. The electrostatic
deflection of the mesh is quantified and fit to a first-principles mechanical
model. Measurements were performed with both a standalone test EL region and
with the NEXT-100 EL region before its installation in the detector. Finally,
we describe the parts as installed in NEXT-100, following their deployment in
Summer 2023.

Instrumentation and Detectors