  The focal-plane detector system for the KArlsruhe TRItium Neutrino (KATRIN)
experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout
electronics, two superconducting solenoid magnets, an ultra high-vacuum system,
a high-vacuum system, calibration and monitoring devices, a scintillating veto,
and a custom data-acquisition system. It is designed to detect the low-energy
electrons selected by the KATRIN main spectrometer. We describe the system and
summarize its performance after its final installation.
