Article
Physics, Fluids & Plasmas
J. Zhou, A. Dominguez-Vazquez, P. Fajardo, E. Ahedo
Summary: This paper introduces an axisymmetric fluid model to simulate electrodeless plasma thrusters. Numerical simulations are conducted to study plasma transport and discuss particle and energy fluxes of electrons. The results indicate that wall losses greatly affect the thrust efficiency of these thrusters, and a sensitivity analysis shows that the performance is underestimated due to incomplete electron expansion in finite plumes.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
A. Shuvaev, V. M. Muravev, P. A. Gusikhin, J. Gospodaric, A. Pimenov, I. Kukushkin
Summary: The experimental discovery of superluminal electromagnetic 2D plasma waves in a high-quality GaAs/AlGaAs two-dimensional electron system on a dielectric substrate is reported. The study shows a strong hybridization between plasma and Fabry-Perot light modes at large two-dimensional densities, and the plasma resonance split into two modes in the presence of a perpendicular magnetic field, each corresponding to a specific sense of circular polarization. The experimental results are in good agreement with the theory.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Fluids & Plasmas
Zhiyuan Chen, Kunlong Wu, Yibai Wang, Junxue Ren, Peng Wu, Guangchuan Zhang, Min Li, Haibin Tang
Summary: A kinetic particle-in-cell model was used to study the detachment processes of electrons in a magnetic nozzle. The detachment direction, mechanisms, and contribution to plasma flux were found to differ significantly between the upstream and downstream regions.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
A. Caldarelli, F. Filleul, C. Charles, R. W. Boswell, J. E. Cater, N. Rattenbury
Summary: To improve the efficiency of radio-frequency magnetic nozzle plasma thrusters, it is crucial to understand the coupling between plasma expansion and the magnetic field. This study investigates the effects of magnetic field strength and orientation on plasma expansion in a magnetic nozzle. The results show that the magnetic field lines interacting with the antenna dictate the local plasma profiles downstream from the magnetic nozzle, regardless of magnetic field strength and orientation.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Aerospace
Zhihong Wang, Chunguang Wang, Weiping Tian
Summary: In this study, the flow characteristics of a nozzle with large expansion ratio and its impact on nozzle force were investigated through ground cold flow test research and fluid-structure coupling simulation analysis. The research found that the pressure fluctuation after separation is much larger than before separation, indicating the occurrence of flow separation. The research also explored the structural deformation characteristics of the nozzle under separation conditions.
Article
Physics, Applied
Nanya Zhong, Gang Fu, Junjun Li, Chen Lian, Wenqi Chen, Kama Huang
Summary: A novel two-dimensional atmospheric pressure plasma jet device is proposed and validated through analysis of plasma parameters and establishment of an experimental system.
PLASMA PROCESSES AND POLYMERS
(2022)
Article
Multidisciplinary Sciences
Kazunori Takahashi
Summary: Development of a magnetic nozzle radiofrequency plasma thruster involves rf plasma source and magnetic nozzle, where thrust is affected by rf power transfer efficiency and plasma acceleration. Improving engine efficiency and obtaining larger thrust through configuration modification has been successful in this study.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Jin Tang, Yaodong Wu, Lingyao Kong, Weiwei Wang, Yutao Chen, Yihao Wang, Y. Soh, Yimin Xiong, Mingliang Tian, Haifeng Du
Summary: This study used differential phase contrast scanning transmission electron microscopy to investigate nanoscale magnetic objects in Kagome ferromagnet Fe3Sn2 nanostructures, revealing that these magnetic objects can be attributed to the integral magnetizations of two types of complex 3D magnetic bubbles with depth-modulated spin twisting. While magnetic configurations obtained using high-resolution TEM are generally considered as two-dimensional, the results suggest the importance of the integral magnetizations of underestimated 3D magnetic structures in 2D TEM magnetic characterizations.
NATIONAL SCIENCE REVIEW
(2021)
Article
Physics, Fluids & Plasmas
N. Shukla, K. Schoeffler, J. Vieira, R. Fonseca, E. Boella, L. O. Silva
Summary: This research investigates the nonlinear evolution of electromagnetic instabilities driven by the interpenetration of electron and positron plasma clouds using ab initio kinetic plasma simulations. The study shows that the plasma clouds slow down due to electromagnetic fields generated by oblique and Weibel effects, with the plasma flow expected to decrease by a factor close to root 1/3, providing important insights into the fluid dynamics of plasmas.
Article
Mechanics
Lukas Babor, Hendrik C. Kuhlmann
Summary: This study investigates the Lagrangian transport in the laminar incompressible flow in a two-dimensional square cavity driven by a harmonic tangential oscillation of the lid, covering a wide range of Reynolds and Strouhal numbers. The topology of fluid trajectories is analyzed by stroboscopic projections, revealing the co-existence of chaotic trajectories and regular Kolmogorov-Arnold-Moser (KAM) tori. The structure of pathlines strongly depends on the Reynolds number and the oscillation frequency of the lid.
Article
Physics, Fluids & Plasmas
Kazuma Emoto, Kazunori Takahashi, Yoshinori Takao
Summary: Fully kinetic simulations of magnetic nozzle acceleration show that electrons in the nozzle gain axial momentum primarily due to the Lorentz force, while ions are accelerated by the electrostatic force. The axial momentum gain of electrons significantly increases with higher magnetic field strength and becomes dominant in the magnetic nozzle, leading to a significant increase in thrust and exhaust velocity due to electron momentum conversion from radial to axial direction.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Jann-Yenq Liu, Tsung-Yu Wu, Chi-Yen Lin, Loren C. Chang
Summary: This study utilizes ionospheric GNSS radio occultation soundings to demonstrate the global three-dimensional structures and dynamics of ionospheric lunar tides for the first time. It reveals that the double-bulge amplitude of ionospheric lunar tides varies at the equator and +/- 35 degrees magnetic latitude.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Yoon Jang Chung, K. A. Villegas Rosales, K. W. Baldwin, P. T. Madathil, K. W. West, M. Shayegan, L. N. Pfeiffer
Summary: By improving sample quality and innovating materials and vacuum chamber design, researchers have achieved a breakthrough in GaAs quantum well systems with two-dimensional electrons, demonstrating high mobility and low residual impurities.
Article
Multidisciplinary Sciences
Xiaoyi Xu, Xinyu Wu, Kai Xu, Hong Xu, Hongzheng Chen, Ning Huang
Summary: Covalent organic frameworks (COFs) are highly tunable crystalline polymeric materials, but the development of ultramicroporous COFs is challenging. In this study, a pore partition strategy was developed to divide a mesopore into multiple ultramicroporous domains by inserting a rigid building block into a prebuilt framework. The resulting COF exhibited the smallest pore size among COFs and showed high efficiency in separating hexane isomers. This strategy is an important advancement in the functional exploitation of COFs.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jing Li, Peng Song, Jinpei Zhao, Kristina Vaklinova, Xiaoxu Zhao, Zejun Li, Zhizhan Qiu, Zihao Wang, Li Lin, Meng Zhao, Tun Seng Herng, Yuxin Zuo, Win Jonhson, Wei Yu, Xiao Hai, Pin Lyu, Haomin Xu, Huimin Yang, Cheng Chen, Stephen J. Pennycook, Jun Ding, Jinghua Teng, A. H. Castro Neto, Kostya S. Novoselov, Jiong Lu
Summary: A mild electrochemical exfoliation method has been developed to synthesize large-size, high crystallinity two-dimensional superconductor monolayers, enabling the fabrication of twisted van der Waals heterostructures and printed films. This method yields 2DSC monolayers with unconventional Ising pair superconductivity and enhanced upper critical field, with NbSe2 achieving a high yield of large single-crystal monolayers up to 300 μm. The resulting twisted NbSe2 vdWHs exhibit high stability, good interfacial properties, and modulation of critical current by magnetic field interaction.
Article
Physics, Fluids & Plasmas
Mario Merino, Judit Nuez, Eduardo Ahedo
Summary: In this study, a kinetic-electron, fluid-ion model is used to investigate 2D plasma expansion in an axisymmetric magnetic nozzle, showing the subdivision of electrons into different sub-populations. The impact of different electron sub-populations, as well as ions, on the magnetic thrust generation is analyzed for various upstream conditions. Additionally, the use of equivalent polytropic models with the same total potential fall is shown to result in a slower expansion rate and underprediction of thrust.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Applied
J. Pereles-Diaz, A. Dominguez-Vazquez, P. Fajardo, E. Ahedo, F. Faraji, M. Reza, T. Andreussi
Summary: Numerical simulations of a magnetically shielded Hall effect thruster with a centrally mounted cathode are described and discussed, focusing on the impact of magnetic configuration and central cathode on plasma behavior. Magnetic shielding significantly reduces energy fluxes, decreases heat loads, and minimizes wall erosion. Injection of neutrals at the central cathode facilitates electron drift and magnetic topology efficiently channels electron current away from lateral walls.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
J. Zhou, A. Dominguez-Vazquez, P. Fajardo, E. Ahedo
Summary: This paper introduces an axisymmetric fluid model to simulate electrodeless plasma thrusters. Numerical simulations are conducted to study plasma transport and discuss particle and energy fluxes of electrons. The results indicate that wall losses greatly affect the thrust efficiency of these thrusters, and a sensitivity analysis shows that the performance is underestimated due to incomplete electron expansion in finite plumes.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
Davide Maddaloni, Adrian Dominguez-Vazquez, Filippo Terragni, Mario Merino
Summary: This study presents a data-driven modal analysis of plasma oscillations in a stationary plasma thruster-100-like Hall thruster. The results show that higher order dynamic mode decomposition (HODMD) can successfully uncouple the different dynamics of the oscillations, allowing for separate reconstruction of the breathing and ion transit time modes. It is also found that each plasma variable behaves differently in the different oscillation modes.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
Pedro Jimenez, Mario Merino, Eduardo Ahedo
Summary: A two-dimensional, full-wave, frequency domain, cold plasma model is used to study electromagnetic power propagation and absorption in a helicon plasma thruster. Results show that a fraction of power is absorbed in the plume region and that the power deposition in the source is essentially unperturbed by the simulation domain size, the presence of metallic obstacles, or the plasma density in the environment.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Applied
I Adamovich, S. Agarwal, E. Ahedo, L. L. Alves, S. Baalrud, N. Babaeva, A. Bogaerts, A. Bourdon, P. J. Bruggeman, C. Canal, E. H. Choi, S. Coulombe, Z. Donko, D. B. Graves, S. Hamaguchi, D. Hegemann, M. Hori, H-H Kim, G. M. W. Kroesen, M. J. Kushner, A. Laricchiuta, X. Li, T. E. Magin, S. Mededovic Thagard, V Miller, A. B. Murphy, G. S. Oehrlein, N. Puac, R. M. Sankaran, S. Samukawa, M. Shiratani, M. Simek, N. Tarasenko, K. Terashima, E. Thomas, J. Trieschmann, S. Tsikata, M. M. Turner, I. J. van der Walt, M. C. M. van de Sanden, T. von Woedtke
Summary: The 2022 Roadmap is a publication that aims to identify important challenges in the field of low-temperature plasma (LTP) physics and technology. It includes visions from 41 leading experts representing 21 countries and five continents, with a focus on new topics and areas of interest in the field. The roadmap is expected to contribute to the continued development of LTP science and technology in the next 5-10 years.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Alberto Marin-Cebrian, Adrian Dominguez-Vazquez, Pablo Fajardo, Eduardo Ahedo
Summary: A one-dimensional particle-in-cell model was used to study the effect of a curved magnetic topology on the discharge plasma response and fluxes in a Hall thruster. The results showed that both positive and negative curvatures led to significant tail replenishment and isotropization of the temperature distribution. The radial magnetic force was found to either confine or expand electrons depending on the curvature, which greatly modified the radial electric and pressure forces. These changes in turn affected the plasma density near the wall and the degree of radial ion defocusing.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
Alvaro Sanchez-Villar, Federico Boni, Victor Desangles, Julien Jarrige, Denis Packan, Eduardo Ahedo, Mario Merino
Summary: This study compares the experimental and numerical behaviors of a plasma thruster and finds that the average relative errors are small in terms of ion current density and plasma density profiles, as well as thruster performance parameters. The comparison suggests the presence of enhanced cross-field diffusion in the plasma. Differences in electron temperature behavior indicate areas where the model could be improved.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
M. R. Inchingolo, M. Merino, J. Navarro-Cavalle
Summary: The research characterizes a circular waveguide electron cyclotron resonance plasma thruster prototype driven by microwaves at 5.8 GHz. The magnetic field is generated by a combination of Sm-CoYXG32 magnets and an electromagnet, which allows for tuning of the resonance position and magnetic nozzle shape. The main plasma plume properties and the propulsive performance of the device are analyzed by varying the mass flow rate (Xenon), microwave power, electromagnet current, and propellant injector design. Utilization efficiency of up to 70% and electron temperatures of up to 16 eV have been measured, while it was found that a single radial injector hole is not sufficient for a symmetric ion current profile and that magnetic nozzle shape and strength tuning can significantly affect the divergence angle and thruster floating potential.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Mario Merino, Diego Garcia-Lahuerta, Eduardo Ahedo
Summary: When two magnetic nozzles with opposite polarity are placed side by side, a 'magnetic arch' is formed, connecting the field lines of each nozzle into a closed-line configuration. This magnetic topology is important for electrodeless plasma thrusters and non-cylindrical thruster architectures. A model is introduced to analyze the plasma expansion and properties in this magnetic arch. It is shown that the ions from the nozzles form a single beam that propagates beyond the applied magnetic field, generating magnetic thrust.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Pedro Jimenez, Jiewei Zhou, Jaume Navarro, Pablo Fajardo, Mario Merino, Eduardo Ahedo
Summary: In this study, experiments and simulations were conducted to analyze a compact helicon plasma thruster. The results showed a consistency between the experimental and numerical findings, revealing that the cusp plays a central role in determining plasma losses and electron temperature distribution, thus limiting device performance.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)