Jiwon Lee
Komurasaki & Koizumi Laboratory · JSPS Research Fellow (DC1)
I'm a Ph.D. student and JSPS Research Fellow (DC1) at the University of Tokyo (Komurasaki & Koizumi Lab), working on argon Hall thrusters. I combine in-house DSMC simulation with thruster experiments to improve argon Hall thrusters, with broad interest in rarefied gas dynamics and air-breathing electric propulsion (ABEP).
📄 Download CV (PDF · WIP)Research Interest
I study the performance enhancement of electric thrusters through the control of rarefied gas flow. Using an in-house Direct Simulation Monte Carlo (DSMC) code, I characterized how the neutral-particle behavior inside an argon Hall thruster changes with the propellant injection method, and demonstrated that a sawtooth hollow anode increases the reverse flow to raise the neutral density within the discharge channel. Both studies were validated experimentally on the RAIJIN-66 Hall thruster. I am currently writing a paper on gas–surface interaction modeling for design optimization, and I am extending my research toward Particle-In-Cell (PIC) simulations to analyze how the neutral density and magnetic-field design affect the ionization efficiency. (to be updated)
- Electric Propulsion: Neutral flow dynamics in Hall thrusters, Alternative propellants (Argon, etc.)
- Numerical Simulation: Developing Direct Simulation Monte Carlo (DSMC) codes
Keywords
Experimental Facilities of Our Group
RAIJIN-66 Argon Hall Thruster
The group's main anode-layer-type (TAL) Hall thruster and the primary testbed for our experiments, now operated with argon. It was designed by Hamada et al. as a 70%-scaled version of the 5 kW RAIJIN94 thruster (66 mm channel outer diameter).
Building on this platform, Dibyesh Satpathy has modified RAIJIN-66 to experiment with a swirl injector and a sawtooth anode.
Reference: doi:10.1016/j.vacuum.2020.110040
RAIJIN-30 High-Density Hall Thruster
A newly developed argon Hall thruster designed for higher-density operation, currently being tested in our laboratory. It was designed by Nadine Barth as a scaled-down variant of RAIJIN-66, based on a Hall-MHD analysis. Its anode cross-sectional area is about 2.7 times smaller, which raises the propellant mass-flow density and, with it, the neutral and plasma density in the ionization region. The higher density improves argon's relatively low propellant-utilization efficiency.
In laboratory testing, RAIJIN-30 has reached an anode efficiency of 30% at an anode mass flow rate of 2.72 mg/s, and has produced 45 mN of thrust at 70 sccm with a discharge power of Pw = 1500 W.
2D Dual-Pendulum Thrust Stand for Hall Thrusters (1–100 mN class)
A high-precision two-dimensional dual-pendulum thrust stand for direct thrust measurement of Hall thrusters in the 1–100 mN range. It combines inner and outer pendulums, a J × B calibration/control system, temperature-uniform plates to suppress thermal drift, and a dedicated sensor system. Currently used to characterize the RAIJIN-66 argon Hall thruster.
Reference: doi:10.1063/1.2815336
Probe Measurement System
A motorized plasma-diagnostic system for mapping the thruster plume. An emissive probe mounted on a probe holder is traversed in the radial (r) and axial (z) directions by step motors and a fast linear motor, enabling spatially-resolved plasma-potential measurements.
Space Chamber
Vacuum facilities of the Department of Aeronautics and Astronautics, The University of Tokyo, used for electric propulsion as well as a wide range of space-environment experiments. The RAIJIN-66 and RAIJIN-30 Hall thrusters are currently under test here.
- ø2000 × L3000; 2 rotary pumps, booster pump, diffusion pump (3,275 + 37,000 L/s). Facility page →
Academic Work
Publications (Peer-Reviewed)
- D. Satpathy, N. Barth, M. Matsukura, J. Lee, et al., "Effects of peak magnetic flux density position on the characteristics of an argon propellant Hall thruster", Vacuum, Under Review
- N. Barth, K. Komurasaki, D. Satpathy, J. Lee, et al., "Magnetohydrodynamic Analysis of Acceleration Length and Magnetic Field Optimization in an Argon Hall Thruster", Journal of Applied Physics, Accepted
- D. Satpathy, K. Komurasaki, J. Lee, et al., “Impact of reverse flow induced by a sawtooth anode on the performance of an argon Hall thruster”, Journal of Applied Physics, American Institute of Physics Publishing, 2026, doi:10.1063/5.0307266
- J. Lee, et al., “Numerical Analysis of Rarefied Gas Flow Dominated by Wall Reflection in a Straight Channel”, Vacuum, 2026, doi:10.1016/j.vacuum.2025.114930
- D. Satpathy, H. Sekine, J. Lee, et al., "Influence of propellant injection directionality on the performance of an argon Hall thruster", Journal of Applied Physics, American Institute of Physics Publishing, 2024, doi:10.1063/5.0241386
International Conferences (Oral 4 · Poster 1 · · Total 11)
- D. Satpathy, H. Sekine, J. Lee, et al., "Enhancement of neutral particle density by propellant reversal through a sawtooth hollow anode", 39th International Electric Propulsion Conference, London, UK, Sep. 2025. Oral
- D. Satpathy, H. Sekine, J. Lee, et al., "Difference in plasma potential profiles between xenon and argon propellants in RAIJIN-66", 39th International Electric Propulsion Conference, London, UK, Sep. 2025. Oral
- N. Barth, D. Satpathy, J. Lee, et al., "Magnetohydrodynamic Analysis of High-Density Plasma Hall Thruster Operation", 39th International Electric Propulsion Conference, London, UK, Sep. 2025. Oral
- D. Satpathy, H. Sekine, J. Lee, et al., "An argon Hall thruster using a hollow anode with corrugated surface", 35th International Symposium on Space Technology and Science, Tokushima, Japan, Jul. 2025. Oral
- N. Barth, T. Suehiro, D. Satpathy, J. Lee, et al., "Magnetohydrodynamic Analysis of High Mass Flow Rate-Induced High-Density Plasma Hall Thruster Operation", 12th Asian Joint Propulsion Conference, Xi'an, China, Mar. 2025. Oral
- D. Satpathy, H. Sekine, J. Lee, et al., "Propellant Utilization Efficiency of an Argon Hall Thruster with Swirl Injection", 38th International Electric Propulsion Conference, Toulouse, France, Jun. 2024. Oral
Domestic Conferences (Oral 6 · Poster 1 · · Total 10)
- N. Barth, D. Satpathy, K. Komurasaki, J. Lee, et al., "The Role of the Hall Parameter in Magnetohydrodynamic Scaling of Hall Thrusters", 令和7年度 宇宙輸送シンポジウム, Kanagawa, Japan, Jan. 2026. Oral
- D. Satpathy, J. Lee, et al., "Impact of active anode cooling on argon Hall thruster performance", 第63回航空原動機・宇宙推進講演会, Sapporo, Japan, Mar. 2024. Oral
- D. Satpathy, H. Sekine, J. Lee, et al., "Ionization length estimation of RAIJIN-66 determined from performance measurements during its thermal transient operation", 令和5年度 宇宙輸送シンポジウム, Kanagawa, Japan, Jan. 2024. Oral
Experience
CFD Engineer
- Specializing in computational modeling of gas-liquid two-phase flows in industrial tanks.
Research Internship
Complex Micro-Fluids Lab, KIST (Korea Institute of Science and Technology), Republic of Korea
- Measurement of fluorescent particle velocity in microchannels through Particle Streak Velocimetry.
Education
Ph.D. in Aeronautics and Astronautics
The University of Tokyo, Japan
Department of Aeronautics and Astronautics, Graduate School of Engineering
Advisor: Kimiya Komurasaki, Ph.D.
M.S. in Aeronautics and Astronautics
The University of Tokyo, Japan
Department of Aeronautics and Astronautics, Graduate School of Engineering
Advisor: Kimiya Komurasaki, Ph.D.
Thesis: “Anode Design Optimization of Argon Hall Thrusters Based on DSMC Analysis of Neutral Particle Behavior”
Research Student in Aeronautics and Astronautics
The University of Tokyo, Japan
Department of Aeronautics and Astronautics, Graduate School of Engineering
Advisor: Kimiya Komurasaki, Ph.D.
B.S. in Mechanical Engineering
Hanyang University, Republic of Korea
School of Mechanical Engineering
Advisor: Rhokyun Kwak, Ph.D.
Thesis: “Electroconvective instability on liquid metal electrodes”
Honors & Awards
Most prestigious fellowship for Ph.D. students in Japan with an acceptance rate of approx. 9% (3/33 in the division), providing a three-year monthly stipend and research grant.
Grant number: 26KJ0944
Selected as the top student of the Fall 2024 cohort and honored as the representative award recipient.
Awarded the Grand Prize in the 'Future Tech' theme, ranking among the Top 3 out of 126 teams.
Awarded to the top 10% of graduation theses.
Skills
Programming
- Python
- C, C++
- Fortran
- MATLAB
Numerical Simulation
- DSMC
- PIC
- CFD
- Molecular Dynamics (MD)
Simulation & Visualization Tools
- OpenFOAM
- Ansys
- ParaView
- VMD
CAD & Instrumentation
- Autodesk Inventor
- LabVIEW
Languages
- Korean (Native)
- English (Fluent)
- Japanese (Fluent, JLPT N1)
Activities & Others
Memberships
- Member, The Japan Society for Aeronautical and Space Sciences (JSASS, 日本航空宇宙学会)
- Member, Space Solar Power Systems Society (SSPS, 宇宙太陽発電学会)
- Member, Aerospace Division, The Korean Scientists and Engineers Association in Japan (KSEAJ, 在日韓国科学技術者協会)
Activities
- The 54th President, Korean Student Association, The University of Tokyo, Apr. 2026 - Mar. 2027
- Completed Deep Space Exploration Education Program, The University of Tokyo, Mar. 2025
- Completed Computational Science Alliance Program, The University of Tokyo, Mar. 2025
- Military Service in Army Aviation Command, R.O.K. Army, Jul. 2020 - Jan. 2022
Served as a Medium Utility Helicopter mechanic. - Student Council President, Pungmu High School, Mar. 2016 - Feb. 2017
Contact
Feel free to contact me for any inquiries or collaboration opportunities.
Komurasaki & Koizumi Lab
Graduate School of Engineering
Department of Aeronautics and Astronautics
The University of Tokyo
7-3-1, Hongo, Bunkyo, Tokyo Japan, 113-8656
TEL & FAX: +81-3-5841-6559
🎓 Google Scholar: Google Scholar Profile
🆔 ORCID: orcid.org/0009-0005-8982-1239
🔗 LinkedIn: linkedin.com/in/jiwon-lee
📧 Email: l.jiwon [at] al.t.u-tokyo.ac.jp