The performance of limited streamer drift tubes

Abstract

These notes summarize a program of drift tube tests which has been done at LPNHE. The final aim of the work is to build a track detector for the DELPHI experiment, approved for LEP. This device is known as the “Outer Detector” of DELPHI and will consist of a 2 m radius cylinder with the beam line as axis. It is required to satisfy two main requirements: (a) precise measurement of track position in a plane normal to the beam line. This would be achieved by drift time determination. (b) fast measurement of track position in the direction parallel to the beam. This would be achieved by a fast charge division in less than 200 ns. The chosen solution relies on drift tubes operated in the limited streamer mode. There will be 6000 tubes arranged in six layers. This solution allows for modularity, simplicity and safety, all important properties for a device which must be installed in the central part of Delphi.