Development of the Trigger Readout System for Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to 10^34 cm^-2s^-1. An LHC upgrade is planned to enhance the luminosities to 2-3 x 10^34 cm^-2 s^-1 and to deliver an integrated luminosity of about 300 fb^-1 during Run 3 from 2019 through 2021. In order to improve the identification performance for electrons, photons, taus, jets, missing energy at high background rejection rates, an improved spatial granularity of the trigger primitives has been proposed. Therefore, a new trigger readout system is being designed to digitize and process the signals with higher spatial granularity. A demonstrator system has been developed and installed on the ATLAS detector to evaluate the technical and performance aspects. Analog signal parameters including noise and cross-talk have been analyzed. The performance of the new readout system is being measured and experience will be gained for the development and construction of the full trigger readout system during the data taking run starting 2015. The performance of the demonstrator system in the data taking run will be presented. Based on the demonstrator system, the next generation of prototypes for the trigger readout system is being developed. In this talk, research and development of radiation tolerant custom ASICs for the final trigger readout system will be discussed.