Development and preliminary results of 270 GHz microwave forward scattering diagnostic system on the experimental advanced superconducting tokamak (EAST)

作者：P. J. Sun, Xiaoliang Li, Y. Ren, Xiaofeng Han, X. Liu, Jing Qian, Yilun Zhu, C. W. Domier, Ke Yao, Xinhang Xu, Jon Dannenberg, R. Chen, Guosheng Xu, Neville C. Luhmann · 发表于：Plasma Physics and Controlled Fusion · 年份：2025 · DOI：10.1088/1361-6587/adfa41 · 被引用次数：4 · 研究领域：Magnetic confinement fusion research、Superconducting Materials and Applications、Particle accelerators and beam dynamics

Abstract To measure localized (intermediate, high) poloidal wavenumber electron density fluctuations, a tangential millimeter-wave collective scattering system has been designed and successfully developed on the experimental advanced superconducting tokamak (EAST). This innovative system employs a 270 GHz mm-wave probe beam, emitted from the mid-plane of Port K and directed towards Port P after passing through a combination of two in-vessel mirrors. Here these two ports are located on the EAST device’s midplane and are 110° apart. The downward scattered signals pass through two in-vessel mirrors, and exit through the P window. The received multi-channel separated scattering signals are arranged along the poloidal direction. This optical arrangement makes the monitored turbulent wave number is poloidal dominant and up to 40 cm −1 . The tangential microwave scattering scheme enables this diagnostic to monitor local density fluctuations, with typically a radial spatial resolution △ R = 5 cm, and a wavenumber resolution of △ k = 0.4 cm −1 . The scattering system underwent comprehensive laboratory testing in 2023, with installation finalized in 2024. The system features steerable launch and receiver optics, allowing remote control to position the scattering volume from normalized radius ρ –0 to the pedestal region on a shot-by-shot basis. Effective experimental data, characterized by distinct off-center spectral peaks, have been successfully obtained in neutral beam-heated plasmas...