@article{9244,
  author = {A. J.H. Donné and Y. Zhu},
  title = {A Brief History and Evolution of Electron Cyclotron Emission Imaging (ECEI) Systems},
  abstract = {This paper presents the history and evolution of Electron Cyclotron Emission Imaging (ECEI) systems, from its first applications in the mid 1990-ies until the present. ECEI has emerged as a transformative diagnostic tool for magnetically confined fusion plasmas, providing 2D measurements of electron temperature fluctuations with high resolution (centimeter-scale, and microsecond). Deployed globally on major fusion devices (e.g., ASDEX-Upgrade, DIII-D, KSTAR, EAST), ECEI has enabled critical studies of plasma instabilities, including sawtooth crashes, edge-localized modes (ELMs), and energetic particle driven instabilities. Recent breakthroughs with millimeter-wave system-on-chip technology applications have significantly enhanced ECEI performance, achieving 400× higher signal gain, 85% lower noise, and a 2000x footprint reduction. The 2024 development of radiation-hardened GaN-based receiver chips further ensures compatibility with reactor harsh environments. Additionally, AI-driven analysis has expanded ECEI’s diagnostic capabilities, enabling early disruption prediction, plasma shape detection, and locked mode identification with greater accuracy than the conventional diagnostics. These advancements position millimeter-wave diagnostics as the key for next-generation fusion reactors, meeting demands for compact integration, neutron tolerance, and real-time stability control. Future developments will focus on further optimizing ECEI for Fusion Pilot Plant (FPP) applications, solidifying its role in enabling stable, high-performance plasmas.},
  year = {2025},
  journal = {Proceedings of 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2025)},
  volume = {50},
  pages = {1-2},
  address = {Helsinki, Finland},
  doi = {10.1109/IRMMW-THz61557.2025.11319801},
  note = {2025/08/22},
  language = {eng},
}