Title :
ALICE HLT high speed tracking and vertexing
Author :
Gorbunov, S. ; Aamodt, K. ; Alt, T. ; Appelshäuser, H. ; Arend, A. ; Becker, B. ; Böttger, S. ; Breitner, T. ; Büsching, H. ; Chattopadhyay, S. ; Cleymans, J. ; Das, I. ; Djuvsland, ø ; Erdal, H. ; Fearick, R. ; Haaland, ø S. ; Hille, P.T. ; Kalcher, S. ;
Author_Institution :
ALICE collaboration, CERN, Geneva, Switzerland
Abstract :
The on-line event reconstruction in ALICE is performed by the High Level Trigger, which should process up to 2000 events per second in proton-proton collisions and up to 200 central events per second in heavy-ion collisions, corresponding to an input data stream of 30 GB/s. In order to fulfil the time requirements, a fast on-line tracker has been developed which can optionally use GPU hardware accelerators. The algorithm combines a Cellular Automaton method being used for a fast pattern recognition and the Kalman Filter method for fit of found trajectories and for the final track selection. A fast estimate of the vertex position is based on measurements from the Silicon Pixel Detector. The vertexer is used for the on line monitoring of the ALICE interaction point.
Keywords :
Kalman filters; cellular automata; coprocessors; heavy ion-nucleus reactions; high energy physics instrumentation computing; particle calorimetry; pattern recognition; proton-proton interactions; transition radiation detectors; ALICE HLT high speed tracking; ALICE HLT vertexing; ALICE High Level Trigger; GPU hardware accelerators; Kalman filter method; Silicon Pixel Detector; cellular automaton method; fast online tracker; fast pattern recognition; final track selection; heavy-ion collisions; online event reconstruction; proton-proton collisions; trajectoy fitting; vertex position; Detectors; Graphics processing unit; Instruction sets; Physics; Pixel; Silicon; Trajectory;
Conference_Titel :
Real Time Conference (RT), 2010 17th IEEE-NPSS
Conference_Location :
Lisbon
Print_ISBN :
978-1-4244-7108-9
DOI :
10.1109/RTC.2010.5750344
