Author/Authors :
Kirn، نويسنده , , Th. and Schmitz، نويسنده , , D. and Schwenke، نويسنده , , J. and Flügel، نويسنده , , Th. and Renker، نويسنده , , D. and Wirtz، نويسنده , , H.P.، نويسنده ,
Abstract :
New types of Hamamatsu avalanche photodiodes (APD) have been investigated for the readout of PbWO4 crystals. The results presented cover quantum efficiency measurements of APD prototype A-E, which is passivated by a SiO2 layer or a Si3N4 layer, before and after exposure to a 5.5 Mrad dose of60Co photons. The measurements of the gain and of the excess noise factor as a function of the wavelength are also presented and compared to analytic calculations based on a simple model for the internal APD structure.
ork was performed within the frame of the CMS ECAL group.
