Author/Authors :
Bartolomé، نويسنده , , E and Boix، نويسنده , , G and Casado، نويسنده , , M.P. and Chmeissani، نويسنده , , M and Clemente، نويسنده , , S and Fern?ndez، نويسنده , , E and Garrido، نويسنده , , L and Lorenz، نويسنده , , E and Mart??nez، نويسنده , , M and Merino، نويسنده , , G and Riu، نويسنده , , I and S?nchez، نويسنده , , F and Wright، نويسنده , , A، نويسنده ,
Abstract :
Avalanche Photo-Diodes (APDs) are being used as optical readout elements in a sampling electromagnetic calorimeter made of alternate layers of tungsten and plastic scintillators. The calorimeter serves as a small-angle luminosity monitor in the stray magnetic field of the ALEPH detector at LEP (CERN). Its scintillators are coupled both to APDs and conventional PMTs simultaneously via wavelength shifter fibres. In this paper we present results on the overall performance of the APDs, including gain and stability versus time and energy, based on the direct comparison of the two photosensitive devices.
Keywords :
APD , Em-calorimeter , aleph , PMT
