CERN Accelerating science

ATLAS Slides
Report number	ATL-LARG-SLIDE-2012-246
Title	Upgraded readout electronics for the ATLAS LAr Calorimeter at the Phase I of LHC
Author(s)	Stärz, S (Technische Universität Dresden)
Corporate author(s)	The ATLAS collaboration
Submitted to	12th Pisa Meeting on Advanced Detectors: Frontier Detector for Frontier Physics, La Biodola, Isola d'Elba, Italy, 20 - 26 May 2012
Submitted by	[email protected] on 18 May 2012
Subject category	Detectors and Experimental Techniques
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Abstract	The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards (LTDBs) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies a digital filtering and identifies significant energy depositions in each trigger channel. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. This poster presents the general concept of the upgraded LAr calorimeter readout together with the various electronics components to be developed for such a complex system. The R&D activities and architectural studies undertaken by the ATLAS LAr Calorimeter group will be described.