The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D Doppler backscattering (DBS) experiments on MAST. SAMI actively probes the plasma edge using a wide (+-40 degrees vertical and horizontal) and tuneable (10-35.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24 degrees FWHM at 10-34.5 GHz. This capability is unique to SAMI and is an entirely novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial measurements of phenomena observed on conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.
A Doppler backscattering diagnostic for the EXL-50U spherical tokamak: plasma considerations and preliminary quasioptical design
A*STAR Research Entities(新加坡科学研究局);Imperial College London(帝国理工学院);Nanyang Technological University(南洋理工大学);UCLA(加州大学洛杉矶分校);ENN Science & Technology Development Co., Ltd(新奥科技发展有限公司)
Forecasting the first Edge Localized Mode (ELM) after LH-transition with a neural network trained on Doppler Backscattering data from DIII-D
Agency for Science, Technology and Research (A*STAR)(科学技术研究局);Nanyang Technological University(南洋理工大学);University of California, Los Angeles(加州大学洛杉矶分校);Tohoku University(东北大学)
Conceptual study on using Doppler backscattering to measure magnetic pitch angle in tokamak plasmas
Future Energy Acceleration and Translation Programme, Agency of Science, Technology and Research (A*STAR)(未来能源加速与转化计划,科学与技术研究局);Department of Physics, University of Oxford(牛津大学物理系);Department of Physics and Astronomy, University of California, Los Angeles(加州大学洛杉矶分校物理与天文学系);Lawrence Livermore National Laboratory(劳伦斯利弗莫尔国家实验室);Department of Physics, National University of Singapore(新加坡国立大学物理系);Commonwealth Fusion Systems(联邦聚变系统);Princeton Plasma Physics Laboratory(普林斯顿等离子体物理实验室);Rudolf Peierls Centre for Theoretical Physics, University of Oxford(牛津大学鲁道夫·佩尔斯理论物理中心)
Using Convolutional Neural Networks to detect Edge Localized Modes in DIII-D from Doppler Backscattering measurements
Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR)(高性能计算研究所,科学与技术研究局);School of Physical and Mathematical Sciences, Nanyang Technological University(南洋理工大学物理与数学科学学院);Department of Physics and Astronomy, University of California, Los Angeles(加州大学洛杉矶分校物理与天文学系);AIP, RIKEN(理化学研究所应用物理部);Department of Physics, University of Oxford(牛津大学物理系)
Beam-Tracing-Based Quantitative Reconstruction of Density Fluctuations in QUEST Using Doppler Backscattering
Research Institute for Applied Mechanics, Kyushu University(九州大学应用力学研究所);National Institute for Fusion Science(国立研究开发法人核融合科学研究所);Future Energy Acceleration & Translation (FEAT), Agency for Science, Technology and Research (A*STAR)(科学技术研究局未来能源加速与转化中心)