Mainz 2014 – wissenschaftliches Programm
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T: Fachverband Teilchenphysik
T 71: DAQ, Trigger, Elektronik 3
T 71.6: Vortrag
Dienstag, 25. März 2014, 18:00–18:15, GFH 01-731
ROI Selection with the Belle II PXD DAQ System — •David Münchow, Thomas Gessler, Wolfgang Kühn, Jens Sören Lange, Klemens Lautenbach, and Björn Spruck for the Belle II collaboration — University Gießen
The DEPFET (DEPleted Field Effect Transistor) pixel detector at the future Belle II experiment will consist of ∼8·106 channels. We expect a data rate of ∼22 GB/s which is ∼10× more data than the remaining subdetectors. To achieve the specifications of the event builder a reduction factor >30 is needed. The data rate is reduced on 32 FPGA based Compute Nodes (CN) developed by IHEP Beijing and JLU Gießen. Each node is equipped with a Xilinx Virtex-5 FX70T FPGA, 2×2 GB DDR2 RAM, GBit Ethernet and 4×6.25 Gb/s optical links.
To fulfill the required data reduction, background is rejected using Regions of Interest (ROI). These are calculated by separate systems using tracks extrapolated from outer detectors. The ROI selection and the memory management for the incoming data are implemented in VHDL.
The incoming data are stored in RAM for further processing. This allows a latency of >1 s at the tracking system. The ROI selector decodes the binary data format on the FPGA in a pipelined manner and processes the ROI selection parallelized in the number of ROIs.
In the first DAQ test at DESY in May 2013 we recorded >108 events with a trigger rate of up to 4 kHz. Results from a test beam with online ROI selection, high level trigger (HLT) and event building at DESY in January 2014 will be presented.
This work is supported by BMBF (05H12RG8)