{"@context":"https://schema.org","@type":"ScholarlyArticle","headline":"FPGA-Based Digital Architecture for Ex-Core Neutron Flux Monitoring in Nuclear Reactors","author":[{"@type":"Person","name":"Heehun Yang"},{"@type":"Person","name":"Yujin Eom"},{"@type":"Person","name":"Geon Shin"},{"@type":"Person","name":"Soyeon Choi"},{"@type":"Person","name":"Hoyoung Yoo"}],"datePublished":"2025","isPartOf":{"@type":"Periodical","name":"IEEE Transactions on Instrumentation and Measurement"},"identifier":"https://doi.org/10.1109/TIM.2025.3629880","description":"This article presents the efficient digital ex-core neutron flux monitoring system (ENFMS) based on a field programmable gate array (FPGA), designed to precisely measure reactor power levels across a wide operational range from

$10^{-8}$

% to

$10^{2}$

%. Conventional analog-based ENFMS inherently suffers from low system performance, complex maintenance, susceptibility to environmental noise, and issues related to chip obsolescence. To address these challenges, the proposed system employs FPGA-based digital signal processing, implementing three optimized measurement modes, namely, pulse, mean square value (MSV), and current, to effectively cover the entire operational range. A linear interpolation algorithm also provides smooth and continuous transitions between overlapping modes. Furthermore, the system-on-chip (SoC) architecture integrates all signal-processing functions onto a single FPGA chip, significantly reducing system size, complexity, and power consumption. Experimental evaluations performed on a Xilinx Kintex UltraScale FPGA platform demonstrated a short latency of approximately 3.49

$\\mu $

s at a 500-MHz clock frequency, high data throughput of 8.0 GB/s, and power consumption of about 6.3 W. Moreover, the system exhibited excellent measurement accuracy with a low root mean square (rms) error of 0.0197 V throughout the entire operational range. Consequently, the proposed digital ENFMS significantly improves potential applicability, accuracy, and maintainability, making it well-suited not only for existing nuclear instrumentation systems but also for emerging reactor technologies such as small modular reactors (SMRs).","url":"https://innscience.ca/en/community/literature/4c0b6b59-b3f7-41b6-a343-7a9c2b7a8345"}