TY - JOUR AU - ATLAS Collaboration (Aad, G. et al AU - Aparisi Pozo, J. A. AU - Bailey, A. J. AU - Cabrera Urban, S. AU - Castillo, F. L. AU - Castillo Gimenez, V. AU - Cerda Alberich, L. AU - Costa, M. J. AU - Escobar, C. AU - Estrada Pastor, O. AU - Ferrer, A. AU - Fiorini, L. AU - Fullana Torregrosa, E. AU - Fuster, J. AU - Garcia, C. AU - Garcia Navarro, J. E. AU - Gonzalez de la Hoz, S. AU - Gonzalvo Rodriguez, G. R. AU - Guerrero Rojas, J. G. R. AU - Higon-Rodriguez, E. AU - Lacasta, C. AU - Lozano Bahilo, J. J. AU - Madaffari, D. AU - Mamuzic, J. AU - Marti-Garcia, S. AU - Martinez Agullo, P. AU - MiƱano, M. AU - Mitsou, V. A. AU - Moreno Llacer, M. AU - Poveda, J. AU - Rodriguez Bosca, S. AU - Rodriguez Rodriguez, D. AU - Ruiz-Martinez, A. AU - Salt, J. AU - Santra, A. AU - Sayago Galvan, I. AU - Soldevila, U. AU - Sanchez, J. AU - Valero, A. AU - Valls Ferrer, J. A. AU - Vos, M. PY - 2020 DA - 2020// TI - Operation of the ATLAS trigger system in Run 2 T2 - J. Instrum. JO - Journal of Instrumentation SP - P10004 - 59pp VL - 15 IS - 10 PB - Iop Publishing Ltd KW - Data acquisition concepts KW - Data reduction methods KW - Online farms and online filtering KW - Trigger concepts and systems (hardware and software) AB - The ATLAS experiment at the Large Hadron Collider employs a two-level trigger system to record data at an average rate of 1 kHz from physics collisions, starting from an initial bunch crossing rate of 40 MHz. During the LHC Run 2 (2015-2018), the ATLAS trigger system operated successfully with excellent performance and flexibility by adapting to the various run conditions encountered and has been vital for the ATLAS Run-2 physics programme For proton-proton running, approximately 1500 individual event selections were included in a trigger menu which specified the physics signatures and selection algorithms used for the data-taking, and the allocated event rate and bandwidth. The trigger menu must reflect the physics goals for a given data collection period, taking into account the instantaneous luminosity of the LHC and limitations from the ATLAS detector readout, online processing farm, and offline storage. This document discusses the operation of the ATLAS trigger system during the nominal proton-proton data collection in Run 2 with examples of special data-taking runs. Aspects of software validation, evolution of the trigger selection algorithms during Run 2, monitoring of the trigger system and data quality as well as trigger configuration are presented. SN - 1748-0221 UR - https://arxiv.org/abs/2007.12539 UR - https://doi.org/10.1088/1748-0221/15/10/P10004 DO - 10.1088/1748-0221/15/10/P10004 LA - English N1 - WOS:000577278000004 ID - ATLASCollaborationAad_etal2020 ER -