L. Mathys

Performance of the CRID at SLD

Abstract This paper describes the performance of a large 4π Cherenkov Ring Imaging Detector (CRID) in the SLD experiment at the SLC at SLAC. We compare the most recent SLD results with those obtained during the R&D period, discuss various design features, and highlight some specific lessons derived from three years of operation.

Development and construction of the SLD Cherenkov ring-imaging detector☆

Abstract We report on the development and construction of the Cherenkov ring-imaging detector (CRID) for the SLD experiment at the SLAC linear collider. In particular, we outline recent progress in the construction and results from testing the first components of the barrel CRID, including the drift boxes, liquid radiator trays and mirror system. We also review progress in the construction of the barrel CRID gas radiator vessel, the liquid radiator recirculator system, and the electronic readout system. The development of a comprehensive monitor and control system - upon which the stable operation and physics efficacy of the CRID depend — is also described.

Production of 400 mirrors with high VUV reflectivity for use in the SLD Cherenkov ring imaging detector

Abstract The Stanford Large Detector for experimental particle physics detection at the SLAC Linear Collider contains a Cherenkov ring imaging detector (CRID). The barrel CRID mirrors have been successfully produced and installed. The industrial mirror production process, the quality control of the mirrors produced, and the results of the vacuum ultraviolet (VUV) reflectivity and mirror-shape accuracy are described. An average reflectivity of at least 80% for light at 160 nm and 85% for light in the 180–230 nm wavelength range has been achieved in the production of over 400 mirrors of a typical size of 30 by 30 cm. The surface roughness and optical distortion measurements imply that the light loss due to scattering is a few percent of the incident light and the angular error due to shape distortion is less than 1 mrad.

Monitor and control systems for the SLD Cherenkov ring-imaging detector

To help ensure the stable long-term operation of a Cherenkov Ring Imaging Detector at high efficiency, a comprehensive monitor and control system is being developed. This system will continuously monitor and maintain the correct operating temperatures, and will provide an on-line monitor of the pressures, flows, mixing, and purity of the various fluids. In addition the velocities and trajectories of Cherenkov photoelectrons drifting within the imaging chambers will be measured using a pulsed UV lamp and a fiberoptic light injection system.

Development of the CRID single-electron wire detector☆

Abstract We describe the R&D effort to define the design parameters, method of construction and experimental results of single-electron wire detectors. These detectors will be used for particle identification using Cherenkov ring-imaging techniques in the SLD experiment at SLAC. We present measurements of pulse heights for several gases as a function of gas gain, charge division performance on a single-electron signal using both 7 and 33 μm diameter carbon wires, photon feedback in TMAE-laden gas, average pulse shape, and its comparison with the predicted shape and cross-talk. In addition, we present results of wire aging tests and other tests associated with construction of this unusual type of wire chamber.

The fluid systems for the SLD Cherenkov Ring Imaging Detector

The design and operation of the fluid delivery, monitor, and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID) are described. The systems deliver drift gas (C/sub 2/H/sub 6/+TMAE), radiator gas (C/sub 5/F/sub 12/+N/sub 2/), and radiator liquid (C/sub 6/F/sub 14/). Measured critical quantities such as electron lifetime in the drift gas and ultraviolet (UV) transparencies of the radiator fluids, together with the operational experience, are reported. >

Cherenkov Ring Imaging Detector front-end electronics

The front-end electronics of the Cerenkov Ring Imaging Detector (CRID) used in the Stanford Large Detector (SLD) spectrometer at the Stanford Linear Accelerator Center (SLAC) Linear Collider is described. The Plessey process provides a straightforward and low-cost path toward system miniaturization. System tests show good noise performance, calibration precision, system linearity, and signal shape uniformity over the full dynamic range. >

Obtaining physics results from the SLD CRID

Abstract We describe the likelihood ratio method used for particle identification in the SLD CRID, which allows the use of the entire momentum range covered by the liquid and gas radiators, including the threshold regions. Its application to two preliminary physics analyses is also described.

Construction and testing of the SLD Cerenkov Ring Imaging Detector

The construction of the Cherenkov Ring Imaging Detector (CRID) for the SLD (Stanford Linear Collider Large Detector) experiment at the SLAC (Stanford Linear Accelerator Center) Linear Collider and the testing of its components is reported. Results are included from testing the drift boxes, liquid radiator trays, and mirrors for the barrel CRID. The development of the support systems essential for the operation of the CRID, namely, gas and liquid recirculation systems and monitoring, are discussed. >

Operational status and performance of the SLD CRID

Abstract The operation and performance of the SLD CRID achieved during the recently completed 1994–1995 run of the SLC will be discussed. Stable operation of liquid (C6F14) and gas (85% C5F12 and 15% N2) radiators with good UV transparency has been achieved. Our expectations for the future SLD physics program will also be briefly discussed.