An FPGA based demonstrator for a topological processor in the,future ATLAS L1-Calo trigger (“GOLD”)

The existing ATLAS trigger consists of three levels. The level 1 (L1) is an FPGAs based custom designed trigger, while the second and third levels are software based. The LHC machine plans to bring the beam energy to the nominal value of 7 TeV and to increase the luminosity in the coming years. The current L1 trigger system is therefore seriously challenged. To cope with the resulting higher event rate, as part of the ATLAS trigger upgrade, a new electronics module is foreseen to be added in the L1-Calo electronics chain: the topological processor. Such processor is provided with fast optical I/O and large bandwidth capability, in order to use the information on the cluster position in space (i.e. jets in the calorimeters or muons in the muon detectors) and improve the purity of the L1 triggers streams by applying topological cuts within the latency budget. In this talk, an overview of the adopted tecnological solutions and the R&D activities on the demonstrator (“GOLD”) are presented.