Upgrades to the ATLAS Level-1 Calorimeter Trigger

ABSTRACT: 2015 the Large Hadron Collider will run with increased center-of-mass energy and luminosity. To maintain trigger efficiency against increased pileup rates, event topology information will be added to the ATLAS Level-1 real time data path and processed by a new Topology Processor (L1Topo). In phase-I, a new digital readout for the Liquid Argon calorimeters will provide finer granularity and depth segmentation in the electromagnetic layer to new Level-1 feature extractors (FEX) for improved EM, tau and jet identification. We present the topology and phase-I trigger upgrades to the ATLAS Level-1 trigger.