Millimeter-wave high-wavenumber scattering diagnostic developments on EAST and NSTX-U

作者：P. J. Sun, X. Liu, Y. Ren, Guosheng Xu, R. Chen, Jing Qian, Xiaoliang Li, C. W. Domier, Jon Dannenberg, Ke Yao, Yilun Zhu, Neville C. Luhmann · 发表于：Review of Scientific Instruments · 年份：2024 · DOI：10.1063/5.0219393 · 被引用次数：10 · 研究领域：Magnetic confinement fusion research、Superconducting Materials and Applications、Particle accelerators and beam dynamics

A pioneering 4-channel, high-k poloidal, millimeter-wave collective scattering system has been successfully developed for the Experimental Advanced Superconducting Tokamak (EAST). Engineered to explore high-k electron density fluctuations, this innovative system deploys a 270 GHz mm-wave probe beam launched from Port K and directed toward Port P (both ports lie on the midplane and are 110° part), where large aperture optics capture radiation across four simultaneous scattering angles. Tailored to measure density fluctuations with a poloidal wavenumber of up to 20 cm-1, this high-k scattering system underwent rigorous laboratory testing in 2023, and the installation is currently being carried out on EAST. Its primary purpose lies in scrutinizing ion and electron-scale instabilities, such as the electron temperature gradient (ETG) mode, by furnishing measurements of the kθ (poloidal wavenumber) spectrum. This advancement significantly bolsters the capacity to probe high-k electron density fluctuations within the framework of EAST. Beam tracing and data interpretation modules developed for both EAST and NSTX-U high-k scattering diagnostics are described.