H. Neal

The lead-liquid argon sampling calorimeter of the SLD detector

Abstract The lead-liquid argon sampling calorimeter of the SLD detector is one of the largest detectors employing cryogenic liquids now in operation. This paper details the design and performance considerations, the mechanical and cryogenic systems, the absorber design and tower segmentation, the data acquisition electronics, and the control systems of the detector. The initial operational performance of the device is discussed. Detailed resolution studies will be presented in a later paper.

Performance of the SLD Central Drift Chamber

We report for the first time on the performance of the Central Drift Chamber (CDC) of the Stanford Linear Collider Large Detector (SLD), which has been recording data since 1992. The low mass of the chamber and the use of a gas characterized by both a low drift velocity and low diffusion constant help to minimize the drift-distance measurement errors. We describe some of the calibrations and corrections applied to the data, and report on the resolutions achieved thus far. We measure an intrinsic drift resolution of 55-110 /spl mu/m in the region of uniform field. Analysis of the full drift-pulse waveform allows for efficient double-hit resolution of about 1 mm. Momentum resolution is characterized by the formula (dp/sub t//p/sub t//sup 2/)/sup 2/=0.0050/sup 2/+(0.010/p/sub t/)/sup 2/, where p/sub t/ is expressed in units of GeV/c. Used in conjunction with the SLD vertex detector, the CDC permits measurements of impact parameters of high-momentum tracks to the level of 10 /spl mu/m in the r-/spl phi/ plane and 36 /spl mu/m in the r-z plane. A resolution of 6.4% is achieved in the measurement of dE/dx for the electrons in Bhabha scattering events. >

Performance of the SLD central drift chamber

Abstract The central drift chamber (CDC) of the Stanford Linear Collider Large Detector (SLD) has been recording data since 1992. The low mass of the chamber and the use of a gas characterized by both a low drift velocity and low diffusion constant help to minimize multiple scattering and drift-distance measurement errors. We describe some of the calibrations and corrections applied to the data, and report on the resolutions achieved thus far. We measure an intrinsic drift resolution of 55–110 μm in the region of uniform field. Analysis of the full drift-pulse waveform allows for efficient double-hit resolution of about 1 mm. Transverse momentum resolution is given by the formula ( σ(p t ) p t 2 ) 2 = 0.0050 2 + ( 0.010 p t ) 2 , where p t is in GeV/ c . Used in conjunction with the SLD vertex detector, the CDC permits measurements of impact parameters of high-momentum tracks to 10 μm in the r - φ plane and 36 μm in the r - z plane.