Signal Reconstruction of the ATLAS Hadronic Tile Calorimeter: implementation and performance

TileCal, the central hadronic section of the ATLAS Calorimeter, is a sampling calorimeter made of steel and scintillating tiles. The TileCal front-end electronics reads out about 10,000 photo-multipliers at 40 Msps measuring energies ranging from ≃ 30 MeV to ≃ 2 TeV. The read-out system is designed to provide the ATLAS High Level Trigger with reconstructed PMT signals within the time budget allowed by the First Level Trigger (LVL1) running at a maximum trigger rate of 75 KHz. The signal amplitude, time and a reconstruction quality factor are obtained for each PMT using optimal filtering techniques implemented in the Digital Signal Processors (DSP).