Article
Physics, Fluids & Plasmas
M. H. Li, S. G. Baek, G. M. Wallace, B. J. Ding, C. B. Wu, G. H. Yan, P. T. Bonoli, M. Wang, L. Liu, L. M. Zhao, Z. G. Wu, H. Yang, S. Y. Lin, Q. Zang, N. Yan, H. L. Zhao, J. Huang, X. M. Zhai, X. X. Li, X. J. Zhang, X. Z. Gong
Summary: LHCD experiments were conducted in EAST L-mode plasmas with line-averaged density up to 5.1 x 10(19) m(-3). The results showed that the LHCD density limit can be increased with higher wave source frequency and higher magnetic field. The mechanisms responsible for the LHCD density limit differ between 2.45 GHz and 4.6 GHz waves.
Article
Optics
Ashish Varma, Asheel Kumar
Summary: This paper presents a scheme for the excitation of lower hybrid wave by beating of two counterpropagating cosh Gaussian laser beams in a magnetized plasma. The results show the importance of beam parameters in shifting the characteristics of peaks and discuss the convective losses, escaping, and trapping conditions of waves in the magnetized plasma.
Article
Nuclear Science & Technology
M. Wang, L. Liu, L. M. Zhao, M. H. Li, W. D. Ma, H. C. Hu, Z. G. Wu, J. Q. Feng, Y. Yang, L. Zhu, M. Chen, T. A. Zhou, H. Jia, J. Zhang, L. Cao, L. Zhang, R. R. Liang, B. J. Ding, X. J. Zhang, J. F. Shan, F. K. Liu, A. Ekedahl, M. Goniche, J. Hillairet, L. Delpech
Summary: In recent years, improvements have been made to the 2.45 GHz and 4.6 GHz lower hybrid (LH) systems, including upgrading the guard limiters of the LH antennas to tungsten material, upgrading the launcher of the 2.45 GHz system, and changing the location of the ICRF launcher. These improvements have enhanced the power capability and coupling effect of the systems.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Nuclear Science & Technology
Dan Du, Guan Jin Qiao, Guang Zu Pan, Kai Jian Yang, Dong Xiang, Xue Yu Gong
Summary: This paper presents numerical simulation results showing that under certain conditions, a double-saddle antenna can excite helicon modes which resonate with the driving frequency in a nonuniform toroidal plasma. The resonant standing helicon waves can separate or coexist in the toroidal plasma. The power absorption of the resonant standing waves is much larger than the power absorption of nonresonant eigenmodes, and it accounts for most of the RF power deposited into the plasma.
FUSION ENGINEERING AND DESIGN
(2022)
Article
Physics, Fluids & Plasmas
C. B. Wu, B. J. Ding, S. G. Baek, M. H. Li, G. M. Wallace, Y. C. Li, G. H. Yan
Summary: This study investigates the effect of density fluctuations on the probability distribution of LH wave refractive index at the LCFS in the plasma scrape-off layer. The results show that scattering probability and scattering angle distribution are the main factors affecting the spectral broadening. Additionally, the density, density fluctuation, and fluctuation correlation length can significantly modify the LH wave current profile.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
M. H. Li, H. D. Xu, X. J. Wang, M. Wang, B. J. Ding, C. B. Wu, G. H. Yan, L. Liu, L. M. Zhao, Z. G. Wu, W. Y. Xu, D. J. Wu, L. Y. Zhang, Y. Y. Tang, H. Li, G. M. Wallace, S. G. Baek, P. T. Bonoli, Q. Zang, S. Y. Lin, L. Y. Meng, H. L. Zhao, L. Q. Xu, M. R. Wang, X. J. Zhang, J. Huang, J. P. Qian, X. Z. Gong
Summary: This paper presents the progress in the long-pulse operation of the electron cyclotron (EC) system and the achievements in high-electron temperature plasmas by the combined EC and lower hybrid (LH) waves heating since the EC system was built in 2015. The heating effect strongly depends on the location of EC power deposition. H-mode plasmas with solely EC wave auxiliary heating have been obtained for the first time. The higher electron temperature produced by EC wave is found to reduce the LH power loss in the scrape-off layer.
Article
Physics, Fluids & Plasmas
Guanghui Zhu, Qing Li, Xuan Sun, Jianyuan Xiao, Jiangshan Zheng, Hang Li
Summary: In this study, we used first-principles electromagnetic-kinetic simulations to investigate the interaction between a phased antenna array and deuterium plasmas in the lower hybrid range of frequency. Our results showed good agreement with theoretical predictions in terms of wave accessibility and resonance. We also found that the power spectrum of the antenna changed when the plasma was present, indicating wave coupling and plasma absorption. Our findings provide valuable insights for the engineering design of wave heating experiments using phased antenna arrays.
PLASMA SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
G. Khojeh, A. Abdoli-Arani
Summary: In this study, the resonant frequency of a toroid cold plasma covered with a dielectric layer is calculated for two different polarizations of the incident electric field. The electrical field inside the plasma is also calculated. The results show that the resonant frequency is dependent on the geometry and dielectric constant.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
W. Bin, C. Castaldo, F. Napoli, P. Buratti, A. Cardinali, A. Selce, O. Tudisco
Summary: Kinetic instabilities driven by runaway electrons have gained attention in the fusion community. Experiments at FTU have identified different families of waves associated with these instabilities. These findings contribute to understanding and monitoring the early stages of plasma.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Fluids & Plasmas
W. Kong, X. Y. Wang, Y. Lin, L. Chen
Summary: Parametric decay instability of lower hybrid waves is studied using the GeFi particle simulation model, which includes both electron and ion kinetics. Three types of parametric decay processes are observed and the dependencies of growth rates on various parameters are investigated. The simulation results agree well with existing theories. The importance of electron and ion nonlinearity and the electron E x B drift in the three-wave interaction process is confirmed.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Applied
Xiaodong Li, Veit Grosse, Dongbin Song, Wenjiang Yang, Rafael Macian-Juan
Summary: The development of rare-earth barium copper oxide (REBCO) coated conductors with high critical current density has opened up possibilities for large-scale fusion under ultra-high fields. The latest technology, such as cable-in-conduit conductors, has shown outstanding current-carrying capacities. However, the mechanical behavior of the ceramic superconductor is limited when twisted or folded, hindering their potential in ultra-high-field applications. The use of non-twisted cables offers a possible solution by protecting mechanical properties and decreasing the influence of perpendicular fields on critical currents.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Physics, Multidisciplinary
A. Matsuyama, R. Sakamoto, R. Yasuhara, H. Funaba, H. Uehara, I. Yamada, T. Kawate, M. Goto
Summary: Experimental observations show that adding a small fraction of neon to hydrogenic pellets enhances core density assimilation and reduces outward transport for low magnetic-field side injection.
PHYSICAL REVIEW LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Xu Liu, Lunjin Chen, Qianli Ma
Summary: In this study, the global distribution of lower hybrid (LH) waves in the inner magnetosphere was statistically studied using Van Allen Probes observations from 2012 to 2018. It was found that LH waves are commonly observed near the magnetic equator with typical amplitudes of 0.02-0.2 mV/m and occurrence rates up to 10%. The waves extend to inner L regions with increasing amplitudes as AE* increases, and weaker waves are observed at the nightside inside the plasmapause while moderate and strong waves are observed at the nightside and noon inside the plasmapause. They extend to all magnetic local times inside the plasmapause and dawnside outside the plasmapause with increasing AE*.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Physics, Fluids & Plasmas
Y. Ko, N. Tsujii, A. Ejiri, O. Watanabe, S. Jang, K. Shinohara, K. Iwasaki, Y. Peng, Y. Lin, Y. Shirasawa, T. Hidano, F. Adachi, Y. Tian
Summary: A new outer-off-midplane lower hybrid wave launcher was developed to improve core absorption in the TST-2 spherical tokamak. The experiment confirmed that the new launch scenario resulted in improved core electron heating and reduced LH wave driven fast electron losses, while also making it easier to maintain the optimal electron density level.
Article
Geosciences, Multidisciplinary
Shan Wang, Daniel B. Graham, Xin An, Li Li, Qiu-Gang Zong, Xu-Zhi Zhou, Wen-Ya Li, Zhi-Yang Liu
Summary: This study investigates electrostatic waves in a magnetopause reconnection event, specifically focusing on their coupling with lower-frequency electromagnetic waves. The anisotropy of energized electrons in the reconnection exhaust excites whistler waves, which in turn modulates parallel electron beam-mode waves near the current sheet mid-plane. In the separatrix region, parallel propagating electrostatic waves associated with field-aligned electron beams and perpendicular propagating electron cyclotron harmonic waves with loss cone distributions exhibit modulation frequencies in the lower-hybrid wave frequency range. These findings enhance our understanding of the characteristics and mechanisms of electrostatic waves in reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Xianzu Gong, Liqing Xu, Jinping Qian, Juan Huang, Rui Ding, A. M. Garofalo, Annika Ekedahl, Long Zeng, Erzhong LI, Bin Zhang, Shiyao Lin, Biao Shen, Mao Wang, Handong Xu, Xinjun Zhang, Miaohui LI, Guizhong Zuo, Qing Zang, Haiqing Liu, Bo Lyu, Liang Wang, Youwen Sun, Guosheng Xu, Jiansheng Hu, Damao Yao, Yu Wu, Liqun Hu, Bingjia Xiao, Nong Xiang, Kun Lu, Yuntao Song, Baonian Wan, Jiangang LI
Summary: In 2021, EAST achieved a steady-state long pulse of over 100 seconds with a core electron temperature of over 10 keV. This operation successfully addressed key issues such as active control of wall conditioning, long-duration fully noninductive current, and divertor heat/particle flux. The fully noninductive current was generated using pure radio frequency waves and electron cyclotron resonance heating. This experimental platform provides a valuable opportunity to study multiscale instabilities, electron-dominant transport, and plasma-wall interactions under weak collisionality on a timescale of hundreds of seconds.
PLASMA SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
K. Li, X. Lin, Z. Yang, Q. Yang, G. Xu, L. Meng, Y. Wang, H. Lan, B. Zhang, L. Xu, K. Wu, T. He, J. Xu, J. Wu, F. Ding, Y. Duan, S. Mao, Q. Zang, L. Zhang, T. Zhang, F. Wang, L. Wang, G. -N. Luo
Summary: Achieving simultaneous exhaust of excessive transient and steady-state heat fluxes on the divertor target for the divertor protection in the future fusion reactors is necessary. In EAST, sustained large ELM control and stable partial detachment have been achieved concurrently with argon (Ar) or neon (Ne) seeding. With Ne seeding, stable ELM-free state was obtained with a decrease in the electron temperature and an improvement of plasma confinement. With Ar seeding, while initially suppressing large ELMs, it transitioned to type-III ELMs with a high frequency, correlated with energy confinement degradation.
Article
Physics, Fluids & Plasmas
T. Q. Jia, J. P. Qian, D. L. Chen, D. Moreau, B. Shen, B. Zhang, X. Z. Gong, J. Huang, J. Y. Zhang, X. D. Yang, R. R. Liang, Y. C. Hu, L. X. Chen, Y. F. He, Y. Tao, Z. H. Wang, L. Zeng, Y. W. Sun
Summary: This paper describes the scaling characteristics of the H-mode confinement database of NBI-LHW and ECRH-LHW plasmas in the EAST tokamak. The scaling models τE,EAST,H,NBI LHW and τE,EAST,H,ECRH LHW are obtained for the thermal energy confinement time. The scaling τE,EAST,H,NBI LHW shows a similar dependency on plasma current and power loss, a lower dependency on plasma density and elongation, but a stronger dependency on toroidal field than the scaling τth,98y2.
Article
Geosciences, Multidisciplinary
Tengjiao Sun, Xiaoping Luo, Wentian Mi, Adam Woods, Domenico Chiarella, Hairuo Qing, Yongsheng Ma, Xueling Kou, Zhongmin Shen, Guosheng Xu, Haifeng Yuan, Jiaju Liang, Fanghao Xu, Hao Wang, Xiaoxing Gong, Jian Luo, Tingfu Jin, Xiaowei Lv
Summary: This study focuses on the characteristics of the ultra-deeply buried Middle Triassic Leikoupo marine carbonate petroleum system in the Western Sichuan Depression, China. It is found that the reservoir is charged with compound gases from four different source rock units. The research results have important implications for similar sedimentary basin studies and indicate the potential for abundant deeply buried marine carbonate hydrocarbon resources in China and elsewhere in the future.
MARINE AND PETROLEUM GEOLOGY
(2023)
Correction
Geosciences, Multidisciplinary
Tengjiao Sun, Xiaoping Luo, Wentian Mi, Adam Woods, Domenico Chiarella, Hairuo Qing, Yongsheng Ma, Xueling Kou, Zhongmin Shen, Guosheng Xu, Haifeng Yuan, Jiaju Liang, Fanghao Xu, Hao Wang, Xiaoxing Gong, Jian Luo, Tingfu Jin, Xiaowei Lv
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Y. Zhang, X. D. Zhang, Q. L. Qiu, J. Zhang, B. Li, L. Chen, Z. P. Luo, J. P. Qian, L. Wang, H. Q. Liu, L. Y. Meng, X. Liu, B. Zhang, B. Shen, Q. P. Yuan, B. J. Xiao, X. Z. Gong, G. S. Xu, J. S. Hu, K. Lu, X. C. Wu, Y. T. Song
Summary: This paper proposes a novel divertor concept, the fish tail divertor, for reducing the surface temperature on the tokamak divertor plate and the temperature caused by edge localized modes. Experimental results demonstrate the capability of strike point sweeping on the plate at a frequency range of 10 to 100 Hz using an oscillating magnetic field. By applying a coil current of several percent of plasma current, a strike point movement of 5-6 cm is achieved, leading to a significant reduction of divertor surface temperature. The concept shows potential application in fusion reactors.
Article
Physics, Fluids & Plasmas
Yuehao Ma, Bin Zhang, Jian Bao, Z. Lin, Wenlu Zhang, Huishan Cai, Ding Li
Summary: This study investigates the electrostatic turbulence properties in the internal transport barrier (ITB) region of an Experimental Advanced Superconducting Tokamak discharge (#93890) based on first-principles nonlinear gyrokinetic simulations. It is found that the growth rate and frequency of the ion temperature gradient (ITG) mode significantly increase due to resonant excitation by trapped electrons in the linear stage. The non-adiabatic effect of trapped electrons enhances the heat conductivity of ions and the turbulence intensity, leading to a weakening of the zonal flow intensity and an enhancement of the turbulent transport.
Article
Physics, Fluids & Plasmas
Y. Q. Chu, B. S. Zhang, P. Li, X. D. Yang, H. Q. Liu, Y. X. Jie, C. B. Wu, W. M. Zhang, K. D. Li, T. F. Zhou, L. He, Q. Zang, H. Lian, F. B. Zhong, R. J. Zhu, L. F. Zhang, K. Hanada
Summary: Improved confinement caused by Ne injection is investigated in EAST. The safety factor q profile and electron-scale turbulence are studied with a polarimeter-interferometer system and CO2 laser collective scattering system in a series of Ne injection experiments in EAST. Ne with a suitable injection rate can lead to negative magnetic shear in the plasma core, which promotes electron-scale turbulence suppression. The continuous injection of Ne under the reversed shear condition further reduces the electron-scale turbulence intensity. Core electron temperature increase and confinement improvement are observed.
Article
Physics, Fluids & Plasmas
G. F. Ding, R. Chen, Y. Ye, G. S. Xu, X. Q. Wu, Q. Q. Yang, L. Yu, L. Y. Meng, L. Wang, X. Lin, P. Wang, H. Lan
Summary: Different types of edge low-frequency fluctuations with distinct characteristics are observed in various detached divertor states. The characteristics of three specific types of fluctuations, namely low-frequency quasi-coherent fluctuation (LFCF), low-frequency broadband frequency fluctuation (LFBF), and low -n X-point mode (LNXM), on the Experimental Advanced Superconducting Tokamak (EAST) are examined. The occurrence of LFCF is related to the energy detachment and a large electron temperature gap between the inner and outer strike points, while LFBF occurs when the inner strike point is energy detached and the outer strike point is nearly energy detached or attached. The underlying physical mechanisms of these fluctuations are proposed. Rating: 8/10.
Article
Physics, Fluids & Plasmas
Erzhong Li, Y. Chen, H. Qu, T. Zhou, F. Chen, L. Zhang, H. Wang, Y. Duan, H. Liu, B. Shen
Summary: Recently, magneto-hydrodynamic instabilities have been observed in various experimental scenarios using a gas electron multiplier (GEM) camera installed on the Experimental Advanced Superconducting Tokamak (EAST). The GEM camera, placed outside the EAST vacuum chamber, records x-ray photons through a beryllium window, providing valuable data for the analysis of neoclassical tearing mode (NTM) onset and plasma disruption dynamics in the presence of magnetic islands. Although not directly compared to theory and simulations, the GEM camera, in conjunction with other diagnostics, reveals the significance of electron dynamics in NTM and plasma disruption. This is meaningful for understanding and modeling the disruption instability of fusion plasmas.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Fluids & Plasmas
Wenbin Liu, Kangning Geng, Long Zeng, Weiwen Xiao, Kaixuan Ye, Tao Zhang, Bin Cao, Xiang Zhu, Tian Tang, Haiqing Liu, Ang Ti, Hailin Zhao, Zhe Gao, Yi Tan, Chu Zhou, Ah Di Liu, Muquan Wu, Baolong Hao, Hang Li, Guoqiang Li, Xiang Gao
Summary: A coherent mode (CM) induced by SMBI was observed in Ohmic plasmas of EAST tokamak, which existed in the fluctuation spectra of electron temperature and density but not in the Mirnov fluctuation spectrum. The CM had multiple discrete frequencies between 5 to 20 kHz, occasionally dominated by a single frequency. It was found to be correlated to a high local transport level but did not have a clear influence on global confinement.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Fluids & Plasmas
Y. F. Wang, K. Hanada, D. Sakurai, H. Q. Liu, T. Lan, X. Gao, X. H. Wu
Summary: This study aims to solve the fringe jump problem in the polarimeter-interferometer (POINT) diagnostics system of the Experiment Advanced Superconducting Tokamak (EAST) by proposing a support vector machine model for electron density fringe jump detection and correction. The established model efficiently classifies the fringe jump data from the raw measurement data, corrects it, and greatly improves the correction efficiency and precision of electron density data from the POINT system. It is expected to be embedded into the plasma control system for more accurate real-time electron density feedback control.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Fluids & Plasmas
Guosheng Xu, Xingquan Wu, Youjun Hu
Summary: We found that the previously derived perturbed Lagrangian from the drift-kinetic equation was inconsistent with the ordering for the low-frequency large-scale MHD. In this study, we rederived the expression for the perturbed Lagrangian using the ordering system for the low-frequency large-scale MHD in a low-beta plasma within the framework of nonideal MHD. This finding is significant as the perturbed Lagrangian is widely used to understand the kinetic driving and dissipative mechanisms of MHD instabilities and plasma response in fusion plasmas.
PLASMA SCIENCE & TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Shanshan Pan, Yanmin Duan, Liqing Xu, Yan Chao, Hailin Zhao, Haiqing Liu, Shouxin Wang, Ling Zhang, Yuqi Chu, Wenmin Zhang, Kaixuan Ye, Liqun Hu
Summary: Accumulation of high-Z impurities in the plasma core can adversely affect plasma performance and trigger sawtooth crashes and tearing modes (TMs) in EAST. Experimental observations in the EAST tokamak show that a large sawtooth crash can trigger m/n = 3/2 and m/n = 2/1 TMs under the condition of high-Z impurity accumulation. This study focuses on the relationship between impurities, sawtooth crashes, and TMs, revealing that impurity transport after a sawtooth crash plays a crucial role in the destabilization of TMs.
Article
Engineering, Aerospace
Gang Wang, Guosheng Xu, Yukun Wang, Yimeng Yao, Kun Wang, Xi Hu, Heyao Sun, Jingwang Liu
Summary: This paper proposes three deployment modes, synchronous deployment, fixed-axis-non-fixed-axis stepwise deployment, and non-fixed-axis-fixed-axis stepwise deployment, to obtain the optimal deployment scheme of the orthogonal biaxial folding wing of UAVs at different airspeeds. The aerodynamic model of the folding wing is established using the Lagrange method and the Fluent simulation software is used to analyze the influence of the UAV deployment mode and airspeed on the driving torque of the folding wing. The simulation results show that the optimal deployment mode is synchronous deployment when the airspeed is less than 40 m/s, and non-fixed-axis-fixed-axis stepwise deployment when the airspeed is greater than or equal to 40 m/s. The accuracy of the folding wing aerodynamics model is proven through comparison with theoretical results.
