CERN Accelerating science

ATLAS Slides
Report number	ATL-DAQ-SLIDE-2015-028
Title	The Evolution of the Region of Interest Builder in the ATLAS Experiment
Author(s)	Blair, Robert (Argonne National Laboratory) ; Crone, Gordon Jeremy (Department of Physics and Astronomy, University College London) ; Green, Barry (Department of Physics, Royal Holloway and Bedford New College) ; Love, Jeremy (Argonne National Laboratory) ; Proudfoot, James (Argonne National Laboratory) ; Rifki, Othmane (Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma) ; Panduro Vazquez, Jose Guillermo (Department of Physics, Royal Holloway and Bedford New College) ; Zhang, Jinlong (Argonne National Laboratory)
Corporate author(s)	The ATLAS collaboration
Submitted to	121st LHCC Meeting, CERN, Geneva, Switzerland, 4 - 5 Mar 2015
Submitted by	[email protected] on 26 Feb 2015
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Free keywords	RoIB ; RobinNP ; HLTSV
Abstract	ATLAS is a general purpose particle detector at the Large Hadron Collider (LHC) at CERN designed to measure the products of proton collisions. Given their high interaction rate (1GHz), selective triggering in real time is required to reduce the rate to the experiment’s data storage capacity (1KHz). To meet this requirement, ATLAS employs a combination of hardware and software triggers to select interesting collisions for physics analysis. The Region of Interest Builder (RoIB) is an integral part of the ATLAS detector Trigger and Data Acquisition (TDAQ) chain where the coordinates of the regions of interest (RoIs) identified by the first level trigger (L1) are collected and passed to the High Level Trigger (HLT) to make a decision. While the current custom RoIB operated reliably during the first run of the LHC, it is desirable to have the RoIB more operationally maintainable in the new run, which will reach higher luminosities with an increased complexity of L1 triggers. We are responsible for migrating the functionality of the multi-card VME based RoIB into a single PCI-Express card in a commodity PC. In our testbed, we are reading out 12 channels with fragment size of 128 32 bit words at 150 KHz.