Jun 9 – 15, 2018
Woodlands Conference Center
America/New_York timezone
**** See you at Real Time 2020 ****

Initial performance of Belle II High Level Trigger and Back End Processing in the Beam Commissioning

Jun 12, 2018, 2:40 PM
1h 30m
Woodlands Conference Center

Woodlands Conference Center

159 Visitor Center Dr, Williamsburg, VA 23185
Poster presentation Processing Farms Poster 1


Ryosuke ITOH


The Belle II experiment, a new generation B-factory experiment, is
about to start data taking from April this year. The data acquisition
system (DAQ) is now ready and waiting for the beam commissioning.

The data are processed by the High Level Trigger(HLT) equipped with
1600 cores. A high granurality parallel processing is
performed to keep up with the L1 trigger up to 30kHz with a typical
event size of 100kB. A full event reconstruction is performed on HLT
for the software trigger, and also the track information is fed back
to the pixel readout to reduce the data size down to 1/10 by the
matching with the track. The data are merged with the HLT output and
stored in high speed RAID arrays. The merged data are also fed into a
PC cluster called ExpressReco at a reduced rate for the monitoring
purpose. ExpressReco is equipped with 160 cores for the fine event
reconstruction with the pixel data and the detailed data monitoring is
performed. The beam colliding position is obtained and is fed back
to the accelerator.

This contribution reports the initial performance of HLT and
ExpressReco in the beam commissioning, together with the various
experience on the whole Belle II DAQ system during the commisioning

Minioral Yes
Speaker Ryosuke ITOH
Country Japan
Description backend processing
Institute KEK

Primary authors

Ryosuke ITOH Mikihiko Nakao (KEK) Soh Suzuki Satoru Yamada (KEK) Tomoyuki Konno (Tokyo Metropolitan University) Prof. Zhen-An Liu (IHEP,Chinese Academy of Sciences (CN)) Jingzhou Zhao (IHEP.Beijing) Thomas Hauth (KIT - Karlsruhe Institute of Technology (DE)) Chunhua Li

Presentation materials

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