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Simulations of electron zebra stripes in the inner radiation belt using a composite empirical electric field model

Science China Earth Sciences 2025年第1期68卷 27-38页

作者： Ziyang WANG Ying LIU Qiugang ZONG Hong ZOU Yuguang YE Xuzhi ZHOU Chao YUE Shan WANG Institute of Space Physics and Applied Technology Peking UniversityBeijing100871China State Key Laboratory of Lunar and Planetary Science Macao University of Science and TechnologyMacao999078China

The phenomenon termed“zebra stripes”manifests as regular patterns in the energy-space(L shell)spectrum of energetic electrons(ranging from tens to hundreds ke V)within the inner radiation *** structures exhibit drift-periodic behavior and commonly arise from large-scale electric field perturbations near the substorm *** this study,we introduce a composite electric field model and replicate the formation,structure,and evolution of zebra stripes using a bounce-averaged test particle code under this electric field ***-resolution measurements of energetic electrons obtained from the Van Allen Probes and the recently launched Macao Science Satellites-1 are used as initial conditions and served to validate our test particle *** analyses between observed data and simulations demonstrate our test particle method's efficacy in capturing zebra stripes'general ***,the composite model proves capable of reproducing realistic variations in the electric field within the inner radiation belt to a certain ***,subtle differences emerge in the flux strength and the positions of *** disparities primarily stem from limitations inherent in the electric field model and the initial conditions of the *** that the model represents an average case,it is conceivable that real-world scenarios may deviate from the average,thereby introducing variations in the observed phenomena.

关键词： Zebra stripes Inner radiation belt Large-scale electric fields Van Allen Probes Macao Science Satellite

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Multiplexed wavefront sensing using a grating array-based wavefront sensor

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Optics Express 2025年第3期33卷 4437-4445页

作者： Singh, Jaspal Pathak, Biswajit Narayanamurthy, C.S. Ganesan, A.R. Applied Optics Laboratory Department of Physics Indian Institute of Technology Madras Tamil Nadu Chennai600036 India Applied and Adaptive Optics Laboratory Department of Physics Indian Institute of Space Science and Technology Kerala Thiruvananthapuram695547 India

This paper addresses the ambiguity problem associated with a periodic array of spots in the Shack-Hartmann wavefront sensor (SHWS) when used for multiplexed wavefront sensing, corresponding to multiple isoplanatic patches. We overcome this issue by introducing a multiplexed wavefront sensing scheme, utilizing a grating array-based wavefront sensor that is a programmable version of SHWS. Three beams representing lights from three distinct guide stars are generated to validate the proposed scheme. Each beam passed through different regions of a pseudo-random phase plate, resulting in different random phases that mimic turbulence effects. We detected three wavefronts from a single frame of data by employing a binary phase grating array on a spatial light modulator at the pupil plane. The proposed sensing scheme is compatible with existing wavefront reconstruction algorithms. This study has potential applications in multi-conjugate adaptive optics, where multiple wavefront sensors are needed to detect various isoplanatic patches in order to expand the field of view in turbulent conditions. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Adaptive optics

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Radiation belt electron wisp inside South Atlantic Anomaly due to terrestrial VLF transmitter observed by MSS-1

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Science China Earth Sciences 2025年第2期68卷 538-548页

作者： Yixin SUN Ying LIU Qiugang ZONG Yixin HAO Hong ZOU Yuguang YE Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Lunar and Planetary Science Macao University of Science and TechnologyMacao 999078China Max Planck Institute for Solar System Research Goettingen 37077Germany

The South Atlantic Anomaly represents a region within near-Earth space characterized by a significantly weaker geomagnetic field and a higher flux of energetic particles compared to other areas. It is a space weather hazards to Low-EarthOrbit satellites. There has been evidence that the Very Low Frequency(VLF) waves from the powerful ground VLF radio transmitter in Australia, known as NWC, have the capacity to scatter energetic electrons' pitch angle in the inner radiation *** scattering directs electrons into the drift loss cone, forms a “wisp”, characterized by its peak intensity outside the South Atlantic Anomaly(SAA), and a “rift” exhibiting minimal intensity within SAA. Our findings mark the initial observation of a“wisp” precipitation, an unusual occurrence with peak intensity detected inside the SAA, observed via the Macao Science Satellite-1. Enabled by the Medium-energy Electron Spectrometer onboard Macao Science Satellite-1, we were able to comprehensively measure the full pitch angle distribution at Low-Earth-Orbit. This allowed us to attribute the “wisp” within the anomaly to a specific pitch angle range just outside the drift loss cone, a measurement unattainable by previous satellites. This“wisp” occurrence aligns with previous model predictions, despite being overlooked. Moreover, we distinguished between the trapped and precipitating electron populations. Directly derived from the ratio of these populations, our analysis revealed that approximately 2%-5% of trapped electrons will be lost in this specific wisp due to the influence of the ground VLF *** results not only complement existing evidence of energetic electron pitch angle scattering facilitated by the ground VLF transmitter but also offer a quantitative estimation of its impact.

关键词： South Atlantic Anomaly Radiation belts Electrons precipitation VLF transmitter Wave-particle interaction

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First observation results of Macao Science Satellite-1 on lightning-induced electron precipitation

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Science China Earth Sciences 2025年第1期68卷 1-10页

作者： Yongping WANG Yixin SUN Qiugang ZONG Gaopeng LU Xudong GU Ze-Jun HU Bin LI Key Laboratory for Polar Science Ministry of Natural ResourcesPolar Research Institute of ChinaShanghai 200136China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Lunar and Planetary Science Macao University of Science and TechnologyMacao 999078China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Electronic Information Wuhan UniversityWuhan 430072China

The Medium-energy Electron Spectrometers(MES)is a space-borne instrument onboard Macao Science Satellite-1(MSS-1)dedicated to monitoring the typical charged particle radiation characteristics in the satellite orbit and the process of their occurrence and development,including short bursts of lightning-induced electron precipitation(LEP).This paper presents the first results of the LEP measurements by the MSS-1.47 LEP events are identified with the routine operation for 3 months since satellite launch,all within the range of 1.5

关键词： Lightning-induced electron precipitation Inner radiation belts Energetic electrons Macao Science Satellite-1

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Latitudinal distribution and propagation of lightning-generated whistler:A statistical study by Van Allen Probes observation and ray-tracing simulation

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Science China Earth Sciences 2025年第4期68卷 1291-1297页

作者： Zhaoguo HE Jiang YU Xiangling DING Zuzheng CHEN Nigang LIU Yuguang YE Jun CUI Qiugang ZONG State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao999078China CNSA Macao Center for Space Exploration and Science Macao999078China Zhuhai MUST Science and Technology Research Institute Macao University of Science and TechnologyZhuhai519000China Planetary Environmental and Astrobiological Research Laboratory(PEARL) School of Atmospheric SciencesSun Yat-sen UniversityZhuhai519000China Institute of Space Physics and Applied Technology Peking UniversityBeijing100871China

Lightning-generated whistler(LGW)is an important electromagnetic wave in the magnetosphere,causing energetic electron *** we analyze the LGW distribution and propagation using Van Allen Probes data and ray-tracing *** statistics show that LGW occurs more frequently at L<2.5 with higher amplitudes in the northern *** Poynting flux demonstrates that LGW originates from both hemispheres within L~2.5,and propagates into the space as the wave power *** wave normal angle distributions indicate that LGW propagates quasi-parallel to the field line near its source and becomes oblique as the magnetic latitude ***,we use the ray-tracing model to simulate the LGW propagation,and statistically analyze the propagation characteristics of LGW,which are consistent with the observational *** paper presents the latitudinal distribution and propagation properties of LGW based on statistics for the first time,providing new insights into the LGW generation and evolution in the magnetosphere.

关键词： Lightning-generated whistler Ray-tracing model Magnetosphere Wave distribution Wave propagation

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Thermospheric neutral wind studies over the equatorial region:A review

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Earth and Planetary physics 2025年第1期9卷 81-100页

作者： Siti Syazwani Nasuha Idahwati Sarudin Nurul Shazana Abdul Hamid Ahmad Fairuz Omar School of Physics Universiti Sains Malaysia11800 USMPulau PinangMalaysia Department of Applied Physics Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia Space Science Centre(ANGKASA) Institute of Climate ChangesUniversiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia

Thermospheric neutral winds(TNWs)refer to the neutral gases in the thermosphere circulating as tides,which play a crucial role in the dynamics of the thermosphere-ionosphere system(TIS).Global geospace neutral winds,particularly over the magnetic equator,have been a subject of study for several ***,despite the known importance of neutral winds,a comprehensive understanding and characterization of the winds is still *** ground-based and satellite missions have provided valuable information on the contribution of neutral winds to the global atmospheric ***,efforts in the global monitoring of neutral winds are still lacking,and the drivers behind the behavior of TNWs as well as their influence on the TIS remain *** address these knowledge gaps in the global circulation of TNWs,it is crucial to develop a deep understanding of the neutral wind characteristics over different *** low-latitude equatorial region in particular has been observed to exert complex influences on TNWs because of the unique effects of the Earth’s magnetic field at the dip *** neutral winds over this region will provide valuable insights into the unique dynamics and processes that occur in this region,thereby enhancing our understanding of their role in the overall dynamics of the ***,through empirical observations,an improved ability to accurately model and predict the behavior of this region can be *** review article addresses challenges in understanding equatorial winds by reviewing historical measurements,current missions,and the interactions of ionospheric and thermospheric phenomena,emphasizing the need for comprehensive measurements to improve global atmospheric dynamics and weather forecasting.

关键词： thermospheric neutral wind thermosphere-ionosphere system dip equator equatorial region

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Suppression of microcracks in femtosecond laser grooving of aluminum using a flame environment

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Optics Letters 2025年第9期50卷 2836-2839页

作者： Guo, Sijia Jiang, Yuanfei Han, Jianhui Chen, Anmin Jin, Mingxing Institute of Atomic and Molecular Physics Jilin University Changchun130012 China Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy Jilin University Changchun130012 China State Key Laboratory of Advanced Space Propulsion Department of Aerospace Science and Technology Space Engineering University Beijing101416 China

Femtosecond laser machining of aluminum often suffers from microcrack formation and edge irregularities, affecting processing quality. This study explores the impact of a flame environment on groove characteristics. Results show that in ambient air, high-energy laser pulses induce microcracks, especially at high scanning speeds, while the flame environment suppresses microcracks and improves edge uniformity. The flame preheats the material, reduces thermal shock, and enhances material removal, leading to deeper and more consistent grooves. These findings provide insights for optimizing laser processing parameters to improve machining stability and surface quality. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Laser materials processing

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Advancements in Astronomy and space Sciences in Jordan: Contributions from Experts and Astrophysical Institutions 14th

Advancements in Astronomy and Space Sciences in Jordan: Cont...

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14th Arabic Conference of the Arab Union for Astronomy and space Sciences, AUASS-CONF 2023

作者： Abushattal, A.A. Azzam, Ala’a A. A. Al-Wardat, Mashhoor A. Widyan, Hatem Mardini, Mohammad Taani, Ali Talafha, Mohammed Department of Physics Al-Hussein Bin Talal University P.O. Box 20 Ma’an71111 Jordan Department of Physics The University of Jordan Queen Rania Street Amman Jordan Research Department AstroJo Institute Wasfi Al-Tal Street Amman Jordan Department of Applied Physics and Astronomy College of Sciences and Sharjah Academy for Astronomy Space Sciences and Technology University of Sharjah Sharjah27272 United Arab Emirates Department of Physics Al al-Bayt University Mafraq25113 Jordan Department of Physics Zarqa University Zarqa13110 Jordan Physics Department Faculty of Science Al Balqa Applied University Salt19117 Jordan Department of Space Physics and Space Technology Wigner Research Centre for Physics Budapest Hungary

ISBN: (纸本)9789819632756

Humanity has always been fascinated by astronomy and space sciences. Two distinct groups of Jordanians show interest in this subject: specialists and amateurs. Experts, often academicians and researchers, immerse themselves in the scientific mysteries of the universe, contributing to global knowledge. Their tools, telescopes, and methodologies are advanced, and they often collaborate with international institutions and agencies. Meanwhile, amateurs contribute significantly to popularising astronomy by driving passion and curiosity. Sometimes they make significant discoveries while stargazing, tracking meteors, or performing basic observational activities. The enthusiasm and grassroots approach of these individuals are essential for fostering a love for the cosmos and disseminating knowledge among the younger generation, even without the advanced tools of specialists. This synergy has led to a vibrant astronomical community in Jordan, where both groups complement each other’s efforts to understand and appreciate the universe’s vastness. Through specialized lenses such as research focuses and published academic studies, this seminal study explores the evolution of astronomy in Jordan. space science and astronomy experts from both within and outside the country are examined in this work. Furthermore, this study highlights the key role played in various facets of this development, including observational procedures, recreational astronomical endeavors, community involvement in these activities, and a critical discussion of the challenges facing astronomy in Jordan. © The Author(s) 2025.

关键词： Miocene

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Integrated input system for partially coherent light control in optical neural networks for remote sensing

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Optics and Laser technology 2025年 189卷

作者： Li, Hongmin Liu, Xun Xu, Haonan Peng, Zhenxing Zhou, Xu Li, Wei Lu, Yao Wu, Qiang Xu, Jingjun Key Laboratory of Weak-Light Nonlinear Photonics Ministry of Education TEDA Institute of Applied Physics and School of Physics Nankai University Tianjin300457 China Beijing Institute of Space Mechanics and Electricity China Academy of Space Technology Beijing100094 China

Laser-based all-optical neural networks (ONNs) offer remarkable advantages in processing speed, interference resistance, and energy efficiency, making them highly applicable for fields such as machine vision and image classification recognition. However, in practical scenarios, laser coherence can degrade due to transmission interference, posing a significant challenge to the performance and reliability of ONNs. Against this backdrop, the exploration of neural network technologies based on partially coherent light (PCL) becomes crucial, underscoring the urgent need for efficient and convenient methods to generate, calibrate, and precisely control PCL. Herein, we propose an integrated ONNs input system incorporating the functions of generation, calibration, precise control, and image reconstruction of PCL. The system not only enables the precise conversion and calibration from lasers to specific coherence levels but also achieves high-repetition-rate, high-quality image reconstruction. Consequently, it rapidly provides abundant high-quality samples support for the input layer of ONNs, significantly enhancing training efficiency. The system focuses on the future recognition and analysis of large, high-resolution images by ONNs, demonstrating robust scalability and further emphasizing the advantages of ONNs as highly efficient parallel systems. Our research effectively addresses the challenges posed by laser coherence degradation, offering new insights into the development and practical implementation of ONNs. Furthermore, it paves the way for their seamless integration into fields such as aerospace remote sensing and image classification recognition. © 2025

关键词： Laser pulses

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Ground Testing of spacecraft Attitude Dynamics during In-space Assembly and Manufacturing

Ground Testing of Spacecraft Attitude Dynamics during In-Spa...

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AIAA Science and technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Bhundiya, Harsh G. Cordero, Zachary C. Marshall, Michael A. Sternberg, David Lo, Kevin Mohan, Swati Department of Aeronautics and Astronautics Massachusetts Institute of Technology CambridgeMA United States Guidance and Control Analyst Space Exploration Sector The Johns Hopkins University Applied Physics Laboratory LaurelMD United States Payload/Instrument Pointing Control Systems Engineering Group Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States GNC Hardware and Testbed Development Group Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

The on-orbit construction of structures, i.e., in-space assembly and manufacturing (ISAM), is a promising approach for increasing mission flexibility and achieving structures optimized for the space environment. Although many construction processes have been proposed, a critical aspect that needs further investigation is the spacecraft attitude dynamics during ISAM given the large changes in mass properties of the spacecraft and the long timescales of fabrication. This work investigates the ground testing of spacecraft attitude dynamics during Bend-Forming, a candidate process for the on-orbit construction of truss structures via plastic deformation of metallic feedstock. Specifically, we conduct experiments on a planar air bearing platform and develop rigid body dynamics models to understand the platform motion during Bend-Forming. The experimental results reveal 1) the effect of metal spring back on the attitude dynamics, and 2) the possibility of control-structure interaction during fabrication with closed-loop, thruster-based position and attitude control. Overall, this study highlights how artifacts of the manufacturing process like spring back affect attitude dynamics and results in important guidelines for the ground testing of spacecraft attitude dynamics during ISAM. © 2025, American institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Trusses

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