  The Data Acquisition System of the LZ experiment, the 10-tonne dark matter
detector to be installed at the Sanford Underground Research Facility (SURF),
will collect signals from 788 photomultiplier tubes (PMTs). Because the signals
from the time projection chamber PMTs will be passed through dual-gain
amplifiers, the DAQ system will collect waveforms from a total of 1276
channels, using custom built, 32-channel, FPGA-based digital signal processors.
The appropriately conditioned signals will be digitized at 100 MHz with 14-bit
resolution. Based on actual measurements with a small-scale prototype system,
the LZ DAQ is expected to be able to handle a maximum sparsified data rate of
~1500 MB/s. During calibrations, it is estimated that only 33% of the system
resources are utilized. The digital filters that are used for data selection
operate with an aggregate throughput in excess of 595,000 MB/s. Data selection
decisions are based on, for example, the amount of scintillation (S1) and
photoluminescence S2 light, S1 and S2 hit-patterns, and total energy
deposition.
