The ATLAS Muon to Central Trigger Processor Interface Upgrade for the Run 3 of the LHC

To cope with the higher luminosity and physics cross-sections for the third run of the Large Hadron Collider (LHC) and beyond, the Trigger and Data Acquisition (TDAQ) system of the ATLAS experiment at CERN is being upgraded. Part of the TDAQ system, the Muon to Central Trigger Processor Interface (MUCTPI) receives muon candidates information from each of the 208 barrel and endcap muon trigger sectors, counts muon candidates for each transverse momentum threshold and sends the result to the Central Trigger Processor (CTP). The MUCTPI takes into account the possible overlap between trigger sectors in order to avoid double counting of muon candidates. A full redesign and replacement of the existing MUCTPI is required in order to provide full-granularity muon position information at the bunch crossing rate to the Topological Trigger processor (L1Topo) and to be able to interface with the new sector logic modules. State-of-the-art FPGA technology and highdensity ribbon fibre-optic transmitters and receivers arebeing used to implement the MUCTPI in a single AdvancedTCA blade, compared to 18 9U VMEbus cards in the existing system. The upgraded MUCTPI featuresover 270 multi-gigabit optical inputs/outputs with an aggregate bandwidth of over 2 Tbit/sec. This work presents the hardware design, results from the validation of the first prototype, the testing of the optical interfaces, and integration tests with the muon sector logic.