We will continue with our Seminar Series on Tues. 21 February 2023
On site: Room 3.S1.08 (Building -“Rey Pastor” Library)
For the next event in the Aerospace PhD Seminar Series, we will have the pleasure of hosting Prof. Wonho Choe from the Korea Advanced Institute of Science and Technology (KAIST).
The event will take place in the Room 3.S1.08 (Building -“Rey Pastor” Library) on Tuesday 21 February.
Prof. Wonho Choe will begin his lecture at 11.45 a.m. with a presentation on the Korea Advanced Institute of Science and Technology (KAIST), after which the seminar will take place at 12.00 p.m.
Wonho Choe is a professor in the Department of Nuclear and Quantum Engineering of the Korea Advanced Institute of Science and Technology (KAIST). He is also working as a joint professor in the Department of Physics and also Department of Aerospace Engineering at KAIST. He pioneered electric propulsion research in Korea with a particular focus on Hall thruster plasma science. Over the past two decades, his group has developed more than 25 different laboratory-model low power Hall thrusters, and some of them became the basis for thrusters commercialized by satellite industry. From 2021, his group, together with the Korea Aerospace Research Institute, has been leading the industry-led development of 200 mN Hall thrusters. His research interests also include physics and applications of low temperature weakly-ionized plasmas, and the development of advanced imaging plasma diagnostics such as plasma tomography. He received the KAIST Technology Revolution Excellence Award, the Academic Award from the Korean Vacuum Society, the Prime Minister’s Achievement Award, and the Minister of Education, Science and Technology Achievement Award. His recent work on Stabilization of liquid instabilities with ionized gas jets, published in Nature, was selected by the Korean government as the Best Achievement Research among 2022 Top 100 National R&D Outstanding Achievements.
He is currently the Vice Chair of the Association of Asia Pacific Physical Societies – Division of Plasma Physics (AAPPS-DPP), the Vice President of Korea Accelerator and Plasma Research Association (KAPRA), a member of the Science and Technology Advisory Committee of ITER International Organization, and a member of the International Union of Pure and Applied Physics (IUPAP) C16 Commission. From 2009 to 2021, he served as the Director of the Impurity and Edge plasma Research Center supported by the Korean National Research Foundation.
He obtained his PhD degree from Princeton University and has co-authored 190 SCI(E) papers in various journals including Nature and Nature Communications.
“Unique physical features of cylindrical Hall thruster plasmas”
The Hall thruster is an efficient space electric propulsion system that utilizes ExB plasma to accelerate ions to high speeds (~15 km/s) and provides a high thrust-to-power ratio (~60 mN/kW). For miniaturization of Hall thrusters for low power operation, cylindrical Hall thrusters are considered advantageous because larger plasma volume-to-surface ratios are provided by the removal of magnetic components and channel wallssurrounding the thruster axis. In a cylindrical Hall thruster, the magnetic field is axially dominant near the thruster axis, and a plasma is formed in a hollow cylindrical discharge channel. Therefore, the axial as well as the radial components of the magnetic field play an important role in electron confinement and transport. Compared with conventional annular Hall thrusters, many interesting and unique physical features have been reported, such as high propellant utilization, a significant fraction of multiply-charged ions, and the presence of high energy ions. In addition, different electric potential profiles due to different magnetic field configurations and ion acceleration regions extending beyond several centimeters outside the discharge cavity have also been reported. Magnetic field tailoring, a magnetic field parallel to the thruster channel wall, has been attempted in a cylindrical Hall thruster. It resulted in higher thrust, higher propellant efficiency, and less erosion of the channel walls, suggesting that magnetic field tailored cylindrical Hall thrusters could be advantageous for space missions with limited propellant. The details of all these interesting physics of cylindrical Hall thruster plasmas will be discussed in the presentation.
The seminars will begin at 11:45 a.m. and will take place in the Room 3.S1.08 (Building –“Rey Pastor” Library) campus of Leganés.
No previous registration is required.