Design of the Front-End Readout Electronics for ATLAS Tile Calorimeter at the sLHC

Abstract

We present a detailed upgrade design of the analog front-end electronics for the ATLAS Tile Calorimeter (TileCal) at the sLHC. Here we use the latest commercial off-the-shelf (COTS) components. We believe that with the latest technology based COTS devices, significant improvements in radiation tolerance are possible. The front-end analog electronics provides 17-bit dynamic range for readout of the PMT signals. Each PMT signal is processed with a 7-pole passive LC shaper, followed by a pair of bi-gain amplifiers and two 40 Msps sampling ADCs. The readout system is capable of measuring energy deposition from <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\sim$</tex></formula> 220 MeV to 1.3 TeV in a single calorimeter cell and providing input to a fully digital Level-1 trigger. Other on-board features include a slow current integrator used for detector calibration with a cesium source to normalize the PMT gains and charge injectors for calibrating linearity and dynamic range of the readout electronics. A total of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\sim$</tex> </formula> 10, 000 upgraded readout channels are needed to replace the current system at the LHC.