Author/Authors :
Brand، نويسنده , , C and Buzzi، نويسنده , , C and Foeth، نويسنده , , H and Hessing، نويسنده , , T.L and Reid، نويسنده , , D and Hajduk، نويسنده , , Z and Michalowski، نويسنده , , J and Booth، نويسنده , , P.S.L and Bowcock، نويسنده , , T.J.V and Galloni، نويسنده , , A and Last، نويسنده , , I and McNulty، نويسنده , , R and Thornhill، نويسنده , , J، نويسنده ,
Abstract :
A straw tube detector has been built as part of the 1995 upgrade for the DELPHI experiment at LEP. The detector is cylindrical in design, with inner wall and outer wall radii of 25 cm and 30 cm respectively. It consists of 960 straws in 5 layers, with a length of 2.1 m, running at atmospheric pressure with a 50:50 argon-ethane gas mixture. The efficiency and spatial resolution arising from the measurement of the drift time have been measured in a test beam. Preliminary results with a full scale prototype and a 2:1 argon-isobutane gas mixture at a gain of 2 × 104 give a coordinate resolution of 99 μm per straw, a resolution for a track element in the detector of 49 μm and an efficiency per straw of more than 99%.
