Radiation hardening techniques for neutron digital imaging FPGA

In neutron digital imaging experiments, field programmable gate array (FPGA) is an important logic control unit for imaging. However, neutron irradiation can not only cause single event effects of FPGA, but also bring noises to neutron imaging. It is necessary to take measures to reduce the effects of neutron irradiation on FPGA imaging. In this paper, based on the periodical characteristics of images, a method of two vote from three instead of triplet modular redundancy is adopted to judge imaging key signals. The noises which are caused by many reasons including the single event upset(SEU) in RAM area can be smoothed by using median filter algorithm with hardware implementation. The simulation results show that two techniques and methods used in this paper not only achieve the resource redundancy and cost saving of FPGA, but also get good anti-radiation filtering effect, while preserving image details. Timing simulation and hardware platform have verified the correctness of the design.