The KLOE drift chamber

The tracking detector of the KLOE experiment is 4 m diameter, 3.3 m length drift chamber, designed to contain a large fraction of the decays of low-energy KL produced at the Frascati DAΦNE φ-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering inside the sensitive volume. The tracking information is provided by 58 layers of stereo wires defing 12,582 cells, 2×2 cm2 in size in the 12 innermost layers and 3×3 cm2 in the outer ones. Details of the chamber design, calibration procedure and tracking performances are presented.