Performance of the scintillating fibre detector in the upgraded UA2 detector

A large scintillating fibre detector consisting of ≈ 60 000 scintillating plastic fibres of 1 mm diameter and 2.4 m length has been used successfully as a tracking and preshower detector in the UA2 experiment at CERN. The detector readout, the pattern recognition algorithm and the results from the pp data taking run are described.