Speaker
Description
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
period.
| Minioral | Yes |
|---|---|
| Description | backend processing |
| Speaker | Ryosuke ITOH |
| Institute | KEK |
| Country | Japan |
