Author/Authors :
Aielli، نويسنده , , G. and Andrei، نويسنده , , V. and Achenbach، نويسنده , , R. and Adragna، نويسنده , , P. and Aloisio، نويسنده , , A. and Alviggi، نويسنده , , M.G. and Antonelli، نويسنده , , S. and Ask، نويسنده , , S. and Barnett، نويسنده , , B.M. and Bauss، نويسنده , , B. and Bellagamba، نويسنده , , L. and Ben Ami، نويسنده , , S. and Bendel، نويسنده , , M. and Benhammou، نويسنده , , Y. and Bergé، نويسنده , , D. and Bianco، نويسنده , , M. an، نويسنده ,
Abstract :
The ATLAS detector at CERNʹs Large Hadron Collider (LHC) will be exposed to proton–proton collisions from beams crossing at 40 MHz. At the design luminosity of 10 34 cm - 2 s - 1 there are on average 23 collisions per bunch crossing. A three-level trigger system will select potentially interesting events in order to reduce the readout rate to about 200 Hz. The first trigger level is implemented in custom-built electronics and makes an initial fast selection based on detector data of coarse granularity. It has to reduce the rate by a factor of 10 4 to less than 100 kHz. The other two consecutive trigger levels are in software and run on PC farms. We present an overview of the first-level trigger system and report on the current installation status. Moreover, we show analysis results of cosmic-ray data recorded in situ at the ATLAS experimental site with final or close-to-final hardware.
Keywords :
Cosmic-ray data , Trigger system , ATLAS , Installation and commissioning
