1290345 SzGeCERN 20161219115516.0 oai:cds.cern.ch:1290345 cerncds:CERN DOI 10.1016/j.nima.2009.06.114 SPIRES 8762058 Inspire 866136 eng Scannicchio, D A CERN ATLAS trigger and data acquisition Capabilities and commissioning 2010 4 p The ATLAS trigger system is based on three levels of event selection that selects the physics of interest from an initial bunch crossing rate of 40 MHz to an output rate of View the MathML source compatible with the offline computing power and storage capacity. During nominal LHC operations at a luminosity of View the MathML source, decisions must be taken every 25 ns. The LHC is expected to begin operations with a peak luminosity of View the MathML source with far fewer number of bunches, but quickly ramp up to higher luminosities. Hence, the ATLAS Trigger and Data Acquisition system needs to adapt to the changing beam conditions preserving the interesting physics and detector requirements that may vary with these conditions. SzGeCERN Detectors and Experimental Techniques CERN ARTICLE CERN LHC ATLAS on behalf of the ATLAS TDAQ Collaboration PH-EP 306-309 1-3 Nucl. Instrum. Methods Phys. Res., A 617 2010 h 201037 a2010 13 20100908 1659 CER01 20100908 1128651 306-309 labiodola20090524 PUBLIC 002917166CER ARTICLE ConferencePaper