Speaker
Alec Habig
(Univ. of Minnesota Duluth)
Description
The NOvA experiment studies neutrino oscillations with 2 functionally
identical detectors separated by a baseline of 810km. The 14 kT far
detector in Ash River, Minnesota, comprises 344,064 channels of liquid
scintillator detection cells read out via wavelength-shifting fiber into
32-channel Avalanche Photo Diodes (APD). A custom designed Front End
Board (FEB) continuously digitizes and zero-supresses the output signals
from each APD. The smaller near detector located at Fermilab has 20,192
channels that are readout in an identical manner. Both detectors are
internally synchronized by a GPS-based timing system with maintains a
readout-to-readout synchronization to better than 15.6 ns across the full
detector. The timing system also provides a universal time base, which is
used provide synchronization and correlation between the geographically
separated detectors and the Fermilab accelerator complex.
The NOvA Data Acquisition (DAQ) system for the far detector comprises
168 powerPC-based custom computers for reading out and collating data from
FEBs, a farm of 196 COTS linux nodes for buffering data for trigger decisions and
event building, another 10 for dedicated DAQ functions such as run control, data
logging, and DAQ system monitoring. Data is transferred between the detector
and the DAQ computing via a multiple bandwidth multilayer networks and fabric routing.
The performance of the recently completed DAQ on the full near and far
detectors will be reviewed. The scaling characteristics of the network
data flow, event building systems, and DDS based message passing layers
will be covered in detail highlighting the computing and operational
challenges of bringing the full DAQ and readout system online.
Author
Dr
Peter Shanahan
(Fermilab)
Co-authors
Abbey Waldron
(Oxford/T2K)
Alec Habig
(Univ. of Minnesota Duluth)
Andrew Norman
(Fermilab)
Evan Niner
(Indiana University)
Holger Meyer
(Wichita State University)
Jonathan Paley
(Argonne National Laboratory)
Mark Messier
(Indiana University)
Prof.
Mathew Muether
(Witchita State University)
Steve Magill
(Argonne National Laboratory)
Susan Kasahara
(University of Minnesota)
