Title :
The T2K near detector data acquisition systems
Author :
Thorpe, M. ; Angelsen, C. ; Barr, G. ; Metelko, C. ; Nicholls, T. ; Pearce, G. ; West, N.
Author_Institution :
STFC Rutherford Appleton Lab., Didcot, UK
Abstract :
T2K is a second generation long-baseline experiment in Japan, designed to perform precision studies of neutrino oscillations. A neutrino beam originating at the J-PARC facility is sampled by two near detectors, approximately 280m distant from the source and directed towards the Kamioka underground facility, 295km distant, where the Super-Kamiokande water Cerenkov detector is situated. Both the on-axis (INGRID) and off-axis (ND280) near detectors employ the MIDAS framework for their data acquisition systems. Events are selected via a flexible hardware trigger, which allows mixed operating modes incorporating beam spill, cosmic and calibration triggers. Data are acquired from the front-end electronics over optical gigabit Ethernet links by custom MIDAS front-end applications distributed over a cluster of Linux computers. Event fragments from all sub-detectors are merged and logged on a central backend processor and then copied to remote storage for longterm archival. The system is also designed to allow flexible partitioning of sub-detectors for standalone diagnostics and calibration. We present the design of the DAQ system and report on experience gathered during early operation of the near detectors.
Keywords :
Cherenkov counters; data acquisition; high energy physics instrumentation computing; local area networks; multiprocessing systems; neutrino oscillations; nuclear electronics; trigger circuits; DAQ system design; INGRID near detector; J-PARC facility; Kamioka underground facility; Linux computer cluster; MIDAS framework; MIDAS front end applications; ND280 near detector; Super-Kamiokande water Cerenkov detector; T2K near detector data acquisition systems; beam spill; calibration triggers; central back end processor; cosmic ray triggers; flexible hardware trigger; flexible subdetector partitioning; front end electronics; mixed operating modes; neutrino beam; off axis near detector; on axis near detector; optical gigabit Ethernet links; precision neutrino oscillation studies; second generation long baseline experiment; stand alone calibration; stand alone diagnostics; Clocks; Data acquisition; Detectors; Monitoring; Neutrino sources; Optical fiber communication; Oscillators;
Conference_Titel :
Real Time Conference (RT), 2010 17th IEEE-NPSS
Conference_Location :
Lisbon
Print_ISBN :
978-1-4244-7108-9
DOI :
10.1109/RTC.2010.5750358
