Author/Authors :
Garvey، نويسنده , , Richard J. and Hillier، نويسنده , , S. and Mahout، نويسنده , , G. and Staley، نويسنده , , R. and Watkins، نويسنده , , P. and Watson، نويسنده , , Willi A. and Achenbach، نويسنده , , R. and Hanke، نويسنده , , P. and Hinderer، نويسنده , , W. and Kaiser، نويسنده , , D. and Kluge، نويسنده , , E.-E. and Meier، نويسنده , , K. and Nix، نويسنده , , O. and Penno، نويسنده , , Richard K. and Schmitt، نويسنده , , K. and Bauss، نويسنده , , B. and Dahlhoff، نويسنده , , A. and Jakobs، نويسنده , , K. and Mahboubi، نويسنده , , K. and Schنfer، نويسنده , , U. Able-Thomas، نويسنده , , J. and Trefzger، نويسنده , , T. and Eisenhandler، نويسنده , , E. and Landon، نويسنده , , M.P.J. and Mills، نويسنده , , D. and Moyse، نويسنده , , E. and Apostologlou، نويسنده , , P. and Barnett، نويسنده , , B.M. and Brawn، نويسنده , , I.P. and Davis، نويسنده , , A.O. and Edwards، نويسنده , , J. and Gee، نويسنده , , C.N.P. and Gillman، نويسنده , , A.R. and Hatley، نويسنده , , R. and Perera، نويسنده , , V.J.O. and Bohm، نويسنده , , David C. and Hellman، نويسنده , , S. and Silverstein، نويسنده , , S.B.، نويسنده ,
Abstract :
At the full LHC design luminosity of 1034 cm−2 s−1, there will be approximately 109 proton–proton interactions per second. The ATLAS level-1 trigger is required to have an acceptance factor of ∼10−3. The calorimeter trigger covers the region |η|⩽5.0, and φ=0 to 2π. The distribution of transverse energy over the trigger phase space is analysed to identify candidates for electrons/photons, isolated hadrons, QCD jets and non-interacting particles. The Cluster Processor of the level-1 calorimeter trigger is designed to identify transverse energy clusters associated with the first two of these. The algorithms based on the trigger tower energies which have been designed to identify such clusters, are described here. The algorithms are evaluated using an FPGA. The reasons for the choice of the actual FPGA being used are given. The performance of the FPGA has been fully simulated, and the expected latency has been shown to be within the limits of the time allocated to the cluster trigger. These results, together with the results of measurements made with real data into a fully configured FPGA, are presented and discussed.
