The upgrade of BABAR Muon Detector

The muon system is critical for the long-term BaBar physics program. The original muon detector using the Resistive Plate Chambers (RPCs) has been degrading rapidly. In 2002 the Limited Streamer Tube (LST) technology was chosen for the upgrade of the barrel part of the muon detector. The design, production, quality control (QC) and installation of the LSTs will be discussed. The gas system, high voltage system and the readout system of the LST detector will be described. The data taking experience with the partially installed LST system in 2005 will be presented in several aspects such as the detector performance and the impact on physics.