NuMi Off-Axis Neutrino Appearance - NOVA Document Database ...

detailed design work, but is not considered a large risk. The detector package includes a thermoelectric
cooler whose reliability might be an issue. First estimates show that as many as three
packages would have to be replaced every day. The devices are readily accessible, but
accelerated tests are planned to understand the failure rate under the more benign NOνA
operating conditions. The cooler is necessary to operate the APDs at -15 o C to achieve a signalto-noise
ratio of 10:1.
Front-End Board: This is a straight-forward board with a custom Integrated Circuit
designed by Fermilab, a 12-bit ADC (Analog to Digital Converter) and an FPGA. The ASIC is
based on an existing design that was adapted for NOνA. A first prototype was received and
measurements are being performed. A second prototype iteration is in the project schedule in
case modifications are required. The signals from the detector are continuously digitized and
processed in the FPGA. Only signals above threshold are packaged with a time-stamp and
channel identification and forwarded to the DAQ system. Data rates of