SEMINAR     Monday, January 9 h. 15.00  Seminar room         Antonio Pellegrino, NIKHEF          Tracking with straw tubes in the LHCb experiment             Abstract The tracking system of LHCb experiment consists of two elements: a small silicon detector at high rapidity in the highest particle flux region and a gaseous straw tube detector, the Outer Tracker (OT), covering most of the LHCb acceptance. The OT consists of ~55,000 straw tubes, covering in total an area of 360 m2. The detector design is modular and each module consists of two staggered mono-layers of straw tubes. All detector modules have been constructed and fully tested under the supervision of the NIKHEF LHCb group. During module production, stringent quality criteria were applied to the wire tension and the HV behaviour of each wire. The experience gained by the NIKHEF group in producing straw tubes has grown in these years so that during the construction no modules were rejected. This experience is now mature to be transferred to other groups wishing to build such kind of devices. The detector installation at CERN is foreseen to begin in March 2006. An overview of all the problems faced during the design and construction phases will be given