  The application of reach-through avalanche photodiodes (R'APD) as a
photodetector for scintillator tiles has been investigated. The light collected
by WLS fibers (0.84mm and 1mm diameter) embedded in the scintillator has been
transmited to the 0.5mm2 active surface of APD by clear optical fibers and
optical connectors. A low noise charge sensitive preamplifier (approximately
400 electrons equivalent noise charge) has been used to gain the photodiode
signal. Various configurations of tile-fibre systems, suitable for CMS and LHCb
experiments at LHC have been studied using cosmic muons and muon beam at SPS at
CERN. In order to optimize the performance of APD, measurments in the
temperature range from -10C to +25C have been done. The MIP detection
efficiency and electron/MIP separation have been estimated in order to
determine applicability of the readout for LHCb preshower.
