A radiation tolerant readout link and control board for the Phase-II upgrade of the ATLAS Hadronic Tile Calorimeter

This work presents performance and radiation test results for the updated prototype of a radiation tolerant read-out link and control Daughterboard (DB) for the Phase-II upgrade of the ATLAS Hadronic Tile Calorimeter (TileCal) front-end electronics for high-luminosity LHC. In the upgraded system, photomultiplier signals are ampli ed, shaped and digitized by the front-end electronics and a Mainboard (MB), while the DB collects and transmits the digitized data to the off-detector over multigigabit optical links. The DB provides a bi-directional interface between the front-end and off-detector electronics, receiving con figuration, control and LHC-synchronous timing over two 4.8 Gbps downlinks to a pair of CERN GBTx ASICs, and providing high-speed readout off-detector over two redundant 9.6 Gbps uplinks, each driven by one of two Xilinx Kintex Ultrascale FPGAs. The DB design is double redundant to minimise single-point failure modes, and the FPGA fi rmware uses strategies including TMR, FEC and CRC to minimize the effects of single-event upsets and damage from hadronic and minimum ionizing radiation. The DB is expected to receive approximately 0.2 krad of total ionizing and 2.44 neutrons / $cm^{2}$ of non-ionising radiation over a 10 year period, so the prototype board and components have undergone TID, NIEL and SEE with large safety factors in order to be radiation quali ed for high-luminosity LHC operations.