The Compressed Baryonic Matter Experiment – Timing and Fast Control
The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD (quantum chromodynamics) phase diagram in the region of high baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state of nuclear matter at high densities, and the search for the deconfinement and chiral phase transitions.
In case of a collision of two nuclei at the target, different kinds of particles and radiation are emitted. A magnetic field bends the trajectory of the particles depending on their mass. In order to distinguish the particles from each other and analyze their properties, different detectors are positioned after the target (STS… ECAL).
The detector elements are interfaced to sensor electronics, producing in total terabits of data. In order to handle this amount of data, the frontend electronics is connected to a very large number of FPGAs (~1000) which preprocess and forward the acquired data to the server farm via fiber links which performs the track reconstruction.
A special property of the CBM experiment is the way data is being recorded at the frontend. Compared to experiments like LHCb at CERN which uses triggered detector readout electronics (synchronized bunches of recorded data), the CBM electronics is operated self-triggered, i.e. the electronics decides when to record data and the data acquisition (DAQ) has to handle a continuous data stream.
A consequence of this is the requirement to accurately synchronize the data taking in both time and frequency, in order to be able to bring the acquired data of a single detector frontend ASIC into the context of the data of both a complete detector but also all other detectors for each point in time. Without a properly synchronized readout chain, there is no way of reconstructing particle tracks at the server farm with a reasonable amount of effort, especially at this high data rates.
ITIV contributes to the CBM experiment with the design of the Timing and Fast Control system which is in charge of controlling this integral part of the detector readout.
German Project partners:
- GSI Helmholtzzentrum für Schwerionenphysik, Darmstadt
- Bereich Computer Science, Konrad-Zuse-Zentrum für Informationstechnik, Berlin
- Institut für Technische Informatik, Universität Heidelberg
- Institute for Computer Science (IRI), Goethe-Universität Frankfurt
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt am Main
- Lehrstuhl für Experimentalphysik, Technische Universität, München
- Institut für Kernphysik, Technische Universität, Darmstadt
- Institut für Kernphysik, Johann Wolfgang Goethe-Universität, Frankfurt am Main
- Institut für Kernphysik, Westfälischen Wilhelm-Universität, Münster
- II. Physikalisches Institut, Justus-Liebig-Universität, Gießen
- Physikalisches Institut, Eberhard Karls Universität, Tübingen
- Institut für Theoretische Physik, Ruprecht-Karls-Universität, Heidelberg
- Fakultät für Mathematik und Naturwissenschaften, Bergische Universität, Wuppertal
- L. Meder, M. Dreschmann, O. Sander, J. Becker
A signal distribution board for the timing and fast control master of the CBM experiment
In Topical Workshop on Electronics for Particle Physics (TWEPP) 2015, Band 11, S. 9, 2015
- Nandor Szirmak, “Analysis of Interconnection and System Concepts for the Construction of a TFC-System”, October 2014 – April 2015
- Juri Lebedev, “Design of a system for synchronizing a distributed FPGA system”, November 2015 – May 2016
Project Webpage: https://www.gsi.de/work/forschung/cbmnqm/cbm.htm
Group photo from the 26th Collaboration Meeting in Prague, autumn 2015
Group photo from the 25th Collaboration Meeting at GSI, Darmstadt, spring 2015