Heidelberg 2015 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HK: Fachverband Physik der Hadronen und Kerne

HK 50: Instrumentation 15

HK 50.1: Group Report

Thursday, March 26, 2015, 14:30–15:00, M/HS1

The CBM First-level Event Selector — •Jan de Cuveland and Volker Lindenstruth for the CBM collaboration — Frankfurt Institute for Advanced Studies, Goethe University, Frankfurt, Germany

The CBM experiment currently under construction at GSI/FAIR is designed to study QCD predictions at high baryon densities. The CBM First-Level Event Selector (FLES) is the central event selection system of the experiment. Designed as a high-performance computer cluster, its task is an online analysis of the physics data including full event reconstruction at an incoming data rate exceeding 1 TByte/s.

The CBM detector systems are free-running and self-triggered, delivering time-stamped data streams. As there is no inherent event separation, traditional approaches for global event building and event selection are not directly applicable. Instead of event building, the FLES combines the data from approximately 1000 input links to self-contained, overlapping processing intervals and distributes them to compute nodes. It employs a high-bandwidth InfiniBand network as well as dedicated custom FPGA input boards providing time-addressed access to buffered data. Subsequently, specialized event selection algorithms analyze these processing intervals in 4–D, identify events, and select those relevant for storage depending on the chosen CBM setup and selection scenario.

This presentation outlines the design of the CBM First-level Event Selector and summarizes the results from first prototype systems.