Design, construction and test results of the ZEUS forward tracking detector

Abstract The design and construction of the ZEUS forward tracking detector is described. The detector consists of three large planar drift chambers mounted in the forward direction with respect to the proton beam and a smaller rear detector of the same type. Test beam measurements performed at DESY show a single wire spatial resolution of 105 μm and a d E d x resolution of 8.8%. The resolution of the three-dimensional track coordinates and slopes provided by one chamber are found to be 90 μm and 2.7 mrad, respectively.