The DELPHI time projection chamber

The central tracking device of the DELPHI experiment is a time projection chamber (TPC) with an active volume of 2*1.34 m in length and 2.22 m in diameter. Since spring 1988 the TPC has undergone extensive tests in a cosmic ray setup. It has been equipped with its final readout electronics for one complete sector ( approximately 2000 channels) and has been operated since with cosmic rays as well as with the laser system and all the other calibration devices. First results indicate that the TPC behaves as expected, but more work and analysis is needed to quote final numbers. It will be installed in the LEP tunnel by early 1989. The authors describe the construction, the readout electronics, and the contribution of the TPC to the Delphi trigger. Emphasis is given to novel features which are not used in similar detectors.<
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