London, UK – From September 14th to 20th, 2025, a delegation of twelve graduate students from the Beihang Electric Propulsion Research Team, led by Postdoctoral Researchers Dr. Guangchuan Zhang and Dr. Zhiyuan Chen, successfully completed their visit to London, UK, for the 39th International Electric Propulsion Conference (IEPC). During the conference, the student delegation engaged in numerous academic exchanges and presentations, gained insights into the latest developments in international electric propulsion technology, and shared advanced concepts and research experience with foreign counterparts. This trip significantly broadened their international perspective and boosted Beihang University’s reputation and influence in the electric propulsion field.
JLPP and ASPEL Delegation Group Photo at the Conference
I . Conference Overview
The International Electric Propulsion Conference (IEPC) is a premier academic event in the global electric propulsion community. Since its inception, the IEPC has played a crucial role in advancing electric propulsion technology, serving as a vital platform for experts, scholars, engineers, and students from around the world to showcase the latest research findings and technical progress. Through various formats, including invited talks, product demonstrations, and paper presentations, the conference fosters global exchange and cooperation in the electric propulsion sector, providing valuable support and momentum for the development of spacecraft propulsion technology. Each IEPC attracts a large number of participants who share their achievements, discuss technical challenges, and collectively drive innovation in electric propulsion.
The theme of the 39th IEPC was: “Electric Propulsion, a Gateway to the Cosmos.” The conference brought together over 690 scholars from around the globe, featuring 563 oral and poster presentations across 15 technical areas, including Hall Thrusters, Air-Breathing Electric Propulsion, Electromagnetic and Electrodeless Propulsion, and EP Diagnostics and Simulation. These sessions facilitated in-depth discussions on the current status and future trends of electric propulsion technology.
II . Beihang Delegation’s Participation
Leveraging their solid academic foundation and sharp research acumen, the Beihang representatives delivered several high-quality academic presentations during the conference. Their research covered cutting-edge topics in electric propulsion, such as magnetic nozzle optimization, advanced spectroscopic/LIF diagnostic techniques, high-efficiency MHD/PIC simulation methods, and high-frequency discharge instability in Hall thrusters.
Following their reports, the student presenters confidently answered questions from foreign scholars and engaged in discussions on related technological advancements. These presentations not only highlighted Beihang’s deep expertise and innovative capabilities in the electric propulsion domain but also earned unanimous recognition from international peers through detailed analysis, unique insights, and engaging delivery. Their excellent work enhanced foreign scholars’ awareness and understanding of Beihang’s research efforts.
- Dr. Guangchuan Zhang, Postdoctoral Researcher: Presentation Summary
Title: Design and initial verification of a dual-magnetic-mirror magnetic nozzle for MPDT
Magnetic nozzles, which utilize magnetic fields instead of physical walls to confine and accelerate plasma, remain a hot topic in electric propulsion research. While traditional magnetic nozzles employ an expanding magnetic field generated by coils, this study focused on a dual-magnetic-mirror magnetic nozzle, which features a unique coil-permanent magnet hybrid configuration and a “expanding-contracting-re-expanding” three-stage magnetic topology. This design significantly enhances plasma confinement.
After validating the dual-magnetic-mirror nozzle’s ability to modulate internal plasma distribution, the research investigated the plasma expansion behavior within this configuration. Using a first-principles-based 2D axisymmetric Particle-in-Cell (PIC) model, the plasma expansion processes in traditional and dual-magnetic-mirror nozzles were compared. The analysis delved into the plasma expansion mechanism and electromagnetic interactions within the dual-magnetic-mirror design. The results showed that, under the same reference magnetic field strength, the dual-magnetic-mirror magnetic nozzle achieved significant improvements in both thrust performance and energy conversion efficiency compared to the traditional design. This achievement offers new ideas and methods for the design and optimization of magnetic nozzles, laying a solid foundation for the development of future high-performance electric propulsion systems, potentially playing a vital role in space exploration.
Furthermore, Dr. Guangchuan Zhang served as the Chair of the Hall Thruster Developments session, contributing Beihang’s strength to the successful running of the IEPC.
Postdoctoral Researcher Dr. Guangchuan Zhang presenting at a session
- Dr. Zhiyuan Chen, Postdoctoral Researcher: Presentation Summary
Title: Particle Detachment Processes in the Magnetic Nozzle
Plasma magnetic detachment within the magnetic nozzle is a frontier issue in international electric propulsion, given the nozzle’s critical role in high-efficiency electric thrusters. Based on a fully kinetic 2D axisymmetric Particle-in-Cell (PIC) method, this study defined the electron detachment ratio and systematically analyzed the distinct detachment characteristics of electrons upstream and downstream of the magnetic nozzle. The research indicated that electron detachment in the upstream region is primarily governed by inertial effects, while the downstream region exhibits a dual mechanism dominated by both inertia and gyro-viscosity, with the gyro-viscous effect being particularly pronounced in weak magnetic fields. Further calculations revealed that electron detachment significantly influences the plasma flow structure and propulsion efficiency. This work not only clarified the roles of electron inertia and gyro-viscosity in magnetic nozzle detachment but also provided new theoretical support for optimizing electric thruster design and deepening the understanding of energy conversion mechanisms.
Postdoctoral Researcher Dr. Zhiyuan Chen presenting at a session
- Yuzhe Sun, PhD Candidate: Presentation Summary
Title: The Effect of Magnetic Field Divergence on Electromagnetic Force Distribution in an Applied-Field Magnetoplasmadynamic Thruster
The Applied-Field Magnetoplasmadynamic Thruster (AF-MPDT) relies on the Lorentz force for high-power electric propulsion, yet the influence of magnetic field configuration on the electromagnetic force distribution remains unclear. This study investigated two magnetic field configurations with different divergence angles under the same operating conditions. The results demonstrated that magnetic field divergence significantly alters the Lorentz force distribution: radially diverging fields change the force generation location, while converging fields extend the Lorentz force downstream. This effect is attributed to the coupling between the current generated by electron pressure and electric field gradients, and the magnetic field topology, which influences the distribution of plasma parameters. These findings provide new insights for AF-MPDT magnetic field optimization, suggesting that controlling magnetic divergence can effectively modulate plasma distribution and improve thruster performance.
PhD Candidate Yuzhe Sun presenting at a session
- Kun Feng, PhD Candidate: Presentation Summary
Title: Color diagnostics of xenon, argon, and krypton electric propulsion plasma plumes
Electric propulsion systems often use inert gases as propellants. While Xenon is widely used for its superior performance, Krypton and Argon are gaining attention across different power levels due to cost and supply constraints. The specific color of plasma plumes under different gases stems from local plasma parameters and the type of gas used. Building on previous Xenon research, this study extended the Collisional-Radiative Model (CRM) color diagnostic method to Argon and Krypton plasmas. A complete CRM, including atomic and ionic emission, was constructed for Argon, and an atomic model was established for Krypton. The results showed that the atomic emission of all three inert gases (Xenon, Krypton, and Argon) exhibits a transition tendency from blue to magenta, while the ionic emission color remains relatively stable and varies depending on the gas type. The research ultimately developed a comparative color map for the three inert gases and revealed the link between plume color and plasma parameters.
Additionally, Kun Feng served as the Chair of the Gridded Ion Engine Developments session, contributing Beihang’s effort to the smooth running of the IEPC.
PhD Candidate Kun Feng presenting at a session
- Renfan Mao, PhD Candidate: Presentation Summary
Title: Kinetic Simulation of Plasma Asymmetry in Hall Thruster with Side-placement Hollow Cathode
The side placement of the cathode introduces three-dimensional asymmetry into the otherwise near-axisymmetric Hall thruster plasma distribution. Although supported by experimental evidence, this phenomenon is not fully understood, particularly lacking in simulation studies. This research developed a GPU-accelerated 3D Particle-in-Cell (PIC) model to simulate the plasma dynamics of an SPT-100 type Hall thruster, from the discharge channel to the near-plume region. The study found that while the near-plume region exhibits significant asymmetry due to the cathode position, the discharge channel itself does not show a corresponding asymmetric mode and has very low angular non-uniformity near the channel exit. By constructing a simplified angular electron transport model, a self-homogenization mechanism was proposed, which causes the non-uniformity to significantly diminish from the near-plume area toward the channel exit. These findings provide theoretical support for a deeper understanding of the 3D effects of side-placement cathodes in Hall thrusters.
PhD Candidate Renfan Mao presenting at a session
- Xu Wu, PhD Candidate: Presentation Summary
Title: Experimental Study on Plasma Flow Velocity in an Applied-Field Magnetoplasmadynamic Thruster
Ion velocity distribution is a critical parameter for understanding the acceleration mechanism of the Applied-Field Magnetoplasmadynamic Thruster (AF-MPDT). This study employed Laser-Induced Fluorescence (LIF) spectroscopy to conduct two-dimensional measurements of the ion velocity distribution in the AF-MPDT beam. Ion velocity vectors and their spatial characteristics were obtained under different magnetic field strengths. The results showed that as the magnetic field strength increased from 50 mT to 75 mT, the average ion velocity in the high-speed core region increased from 13,000 m/s to 14,000 m/s, and the core region extended 100 mm downstream. Concurrently, the angle of the velocity vector within the central 10mm beam region remained below 2∘ for both magnetic fields. These findings indicate that the applied magnetic field effectively enhances ion acceleration, suppresses radial diffusion, and improves beam collimation.
PhD Candidate Xu Wu presenting at a session
- Chen Wang , PhD Candidate: Presentation Summary
Title: Numerical Simulation of Outflow Current in AF-MPDT
Achieving high-stability numerical simulations for the Applied-Field Magnetoplasmadynamic Thruster (AF-MPDT) remains a significant challenge. Explicit numerical methods require resolving the smallest characteristic time scales, leading to low computational efficiency and easy divergence. In contrast, fully implicit numerical schemes can effectively ensure computational stability by implicitly integrating all physical fields over time. This research developed a fully implicit numerical simulation framework based on the Jacobian-Free Newton-Krylov (JFNK) method. This model can solve for single-fluid, multi-component, thermochemical non-equilibrium plasma and calculate related physical field distributions using relatively large time steps, significantly enhancing the overall stability of the simulation.
PhD Candidate Chen Wang presenting at a session
- Wudi Luo, PhD Candidate: Presentation Summary
Title: A Fully Kinetic Study on the Plasma Swirling Flow in the Magnetic Nozzle of Applied-Field MagnetoPlasma Dynamic Thruster
This study utilized a first-principles Particle-in-Cell (PIC) simulation method to investigate the generation mechanism of plasma swirling flow and its impact on thrust in the magnetic nozzle of the Applied-Field Magnetoplasmadynamic Thruster (AF-MPDT). The simulation results showed good agreement with experimental data, providing deep insights into the complex interactions governing thruster performance. Our findings suggest that a low-divergence magnetic field without a throat is more favorable for thrust generation. Furthermore, the analysis indicated that higher anode voltage and shorter anode protrusion length contribute to higher thrust by enhancing the electron leakage current in the anode plume. These results reveal crucial design principles for optimizing the AF-MPDT and may aid in the future development of thrust prediction models.
PhD Candidate Wudi Luo presenting at a session
The IEPC 2025 journey offered the student delegation not only valuable knowledge but also significant growth experiences. By participating in official events such as the IEPC 2025 Opening Ceremony and the Awards Dinner, the students gained an invaluable platform for deep interaction with the international academic community. These events greatly broadened their international academic horizons, sparked research inspiration, and showcased the confident and vibrant spirit of Beihang students.
Attending the IEPC 2025 Opening Ceremony
Attending the IEPC 2025 Dinner
III. Conclusion and Outlook
The 39th IEPC trip was another successful showcase of the Beihang Electric Propulsion Research Team on the international stage. We both displayed our expertise and gained valuable experience. The journey is long, and our steps are unwavering. Building upon the bridges established and the inspiration sparked by this conference, the Beihang Electric Propulsion Research Team will proceed with greater determination, continuously deepening exchanges and mutual learning with top teams worldwide. We are committed to fostering innovation and breakthroughs in electric propulsion technology, contributing an indispensable force to humanity’s dream of space exploration.
Article: Wudi Luo
Layout/Edited by: Lehui Cao