Parts | Days | Selection | Search | Downloads | Help

HK: Fachverband Hadronen und Kerne

HK 9: Accelerators and Instrumentation I

HK 9.4: Talk

Monday, March 16, 2009, 15:00–15:15, H-ZO 80

The ALICE High-Level Trigger — •Jochen Thäder — Kirchhoff-Institut für Physik, Universität Heidelberg

The High-Level Trigger (HLT) for the heavy ion experiment ALICE is a PC cluster of several 100 nodes, which has to reduce the data rate of up to 25 GB/s to at most 1.25 GB/s before permanent storage. For the ongoing commissioning of the ALICE detector and the first year LHC injection tests, the HLT has installed the first 100 nodes, consisting of a group of front-end processor nodes which receive the data from the front-end electronics and a group of computing nodes, as well as the HLT management infrastructure.

During the ALICE commissioning in 2008, the HLT itself was commissioned as a part of of the whole ALICE data-taking system. It was performing online first and second level reconstruction, online data compression and calibration as well as providing online event visualization for the DiMuon, PHOS, SDD, TPC and TRD detectors. Online raw data compression and reconstruction for SDD and PHOS detectors were performed during the first LHC runs.

The experiences made during the commissioning of the HLT itself, the ALICE cosmic runs as well as the first LHC runs will be presented in this talk.

Work on the ALICE High-Level Trigger has been financed by the German Federal Ministry of Education and Research (BMBF) as part of its program "Förderschwerpunkt Hadronen- und Kernphysik - Großgeräte der physikalischen Grundlagenforschung".