A drift chamber vertex detector for intersecting storage rings

Abstract

A cylindrical drift chamber detector for use in a high p T experiment at the CERN ISR is described. The sense wires (total of 3444) are grouped in 42 layers at radii between 20 cm and 80 cm and are used to provide determination of 42 space points along tracks passing through all wire layers. The high redundance of space points provides improved pattern recognition for complex events, good momentum resolution when the detector is placed in a magnetic field, and some particle identification via sampling of d E/d x. Results of tests performed with a smaller chamber are presented. In a direction perpendicular to the sense wires, the accuracy of measurement is given by fwhm = 0.5 mm, while fwhm = 9 mm for the coordinate along the wire direction, obtained by the “charge division” method.