Author/Authors :
Albrecht، نويسنده , , H. and Bauer، نويسنده , , T.S. and Beck، نويسنده , , M. and Berkhan، نويسنده , , K. and Bohm، نويسنده , , G. M. Bruinsma، نويسنده , , M. and Buran، نويسنده , , T. and Capeans، نويسنده , , M. and Chen، نويسنده , , B.X. and Deckers، نويسنده , , H. and Dong، نويسنده , , X. and Eckmann، نويسنده , , R. and Emeliyanov، نويسنده , , D. and Evgrafov، نويسنده , , G. and Golutvin، نويسنده , , I. and Hohlmann، نويسنده , , M. and H?p، نويسنده ,
Abstract :
In this paper we describe the operation and performance of the HERA-B Outer Tracker, a 112 674 channel system of planar drift tube layers. The performance of the HERA-B Outer Tracker system fullfilled all requirements for stable and efficient operation in a hadronic environment, thus confirming the adequacy of the honeycomb drift tube technology and of the front-end readout system. The detector was stably operated with a gas gain of 3 × 10 4 in an Ar / CF 4 / CO 2 (65:35:5) gas mixture, yielding a good efficiency for triggering and track reconstruction, larger than 95% for tracks with momenta above 5 GeV / c . The hit resolution of the drift cells was 300– 320 μ m and the relative momentum resolution can be described as: σ ( p ) / p [ % ] = ( 1.61 ± 0.02 ) + ( 0.0051 ± 0.0006 ) · p [ GeV / c ] . At the end of the HERA-B running no aging effects in the Outer Tracker cells were observed.
Keywords :
Gas gain , Calibration , Drift chamber , efficiency , ALIGNMENT , RESOLUTION
