Upgrading the backend of the pipeline readout system for Belle II
The Belle II experiment at KEK will be a successor to the Belle experiment. Belle II will start operation from 2015, searching for subatomic particles beyond the standard model. The pipeline readout system for the Belle experiment will be unable to satisfy the requirements of Belle II, because the luminosity of the SuperKEKB accelerator will be about 40 times higher than that of KEKB. We have moved the digitizer to front-end electronics and upgraded the back-end part, as well as replacing the processor on the readout module. We report here the upgrade plan and the throughput of the back-end part.
The BELLE DAQ system
Abstract We built a data acquisition system for the BELLE experiment. The system was designed to cope with the average trigger rate up to 500 Hz at the typical event size of 30 kB. This system has five components: (1) the readout sequence controller, (2) the FASTBUS-TDC readout systems using charge-to-time conversion, (3) the barrel shifter event builder, (4) the parallel online computing farm, and (5) the data transfer system to the mass storage. This system has been in operation for physics data taking since June 1999 without serious problems.
Belle DAQ system upgrade at 2001
Abstract We renewed the data acquisition system for the Belle experiment. Previous data acquisition system, which has been used since December 1998, did not have level 2 trigger facility. To improve the data reduction factor and total throughput, we replaced event builder, online computer farm and the storage system. The event builder and online computer farm are unified into one system. This event building farm uses commodity hardware and newly appended level 2 trigger functionality. This data acquisition system started its operation since last autumn and is very stable. We took 36 fb −1 with new DAQ system, it had already overtaken 30 fb −1 that is total amount of previous DAQ system.