Author/Authors :
Aguillion، نويسنده , , G. and Anderson، نويسنده , , B. and Attree، نويسنده , , D.J. and Ball، نويسنده , , A.H. and Bard، نويسنده , , R. and Bentvelsen، نويسنده , , S. and Betts، نويسنده , , S.T. and Boutemeur، نويسنده , , M. G. Caron، نويسنده , , B. and Charalambous، نويسنده , , A. and Chatelain، نويسنده , , J.P. and Colmer، نويسنده , , J. and Courarie، نويسنده , , P. and Cresswell، نويسنده , , M. and Davis، نويسنده , , R. and Dum، نويسنده ,
Abstract :
Arrays of thin scintillating tiles with embedded wavelength shifting fibre readout have been installed in the OPAL endcaps to improve trigger performance, time resolution and hermeticity for experiments at LEP II. The arrays were required to have high single-particle detection efficiency, uniform response, low noise and good time resolution. Limited space for the detector, and a strong magnetic field in the endcap region, resulted in a need for high light output per unit thickness of scintillator, and remote readout. In addition, because of limited space for readout cables, a high light yield per embedded fibre was required. This paper describes the design and construction of a tile array that satisfies these requirements. A light yield of 14 photoelectrons per minimum ionizing particle and a time resolution of 3 ns were obtained during 1997 LEP operation.
Keywords :
Tile , fibre , scintillator , opal
