A.M. Goodall

e+- identification using the drift chambers and transition radiators of the H1 forward track detector

The status of the operation and performance of the H1 Forward Track Detector at the HERA ep storage rings for the detection of electrons (e−) and positrons (e+) is reported. Events with charged particles produced at small angles (7° 3 GeV. Transition radiation X-rays, produced in polypropylene foil radiators immediately upstream of each radial wire drift chamber, are detected in the latter as ionisation charge additional to the usual dEdx contribution. Progress towards achieving the design eπ discrimination of better than 10% π contamination for 90% e± acceptance, which has been established with single tracks, in the complex multi-track environment of ep events at HERA, is reported.

Electron identification in the H1 radial wire drift chambers

Abstract Tests of a radial wire drift chamber for the H1 experiment at the HERA ep-collider were performed at a test beam at the CERN SPS. These types of chambers, part of the H1 forward track detector, are designed to determine accurate vector track segments and to identify electrons by means of d E d x and transition radiation (TR) detection. The electron/pion discrimination has been evaluated at particle momenta from 5 to 50 GeV/c using gas mixtures containing 15 to 30% xenon. Methods and results of this analysis are presented.

Spatial precision of H1 radial wire drift chambers using gas mixtures suitable for transition radiation detection

Abstract Results are presented from calibration and tests of a radial wire drift chamber for the H1 experiment at the HERA ep collider. The chambers form part of the H1 forward track detector (FTD) and are designed both to determine accurate vector track segments and to identify simultaneously electrons by means of d E d x measurement and transition radiation (TR) detection. The spatial reconstruction accuracy (from drift timing and charge division) has been investigated using gas mixtures suitable for TR X-ray detection. A novel technique for enhancing the precision of determination of the radial (non-drift) coordinate of each track using the drift cell geometry is evaluated. A brief summary of the performance of the three radial wire chambers in the FTD is given.