Kentaro Hara
Assistant Professor of Aeronautics and Astronautics
Web page: https://pdml.stanford.edu/
Bio
Ken Hara is an Assistant Professor of Aeronautics and Astronautics at Stanford University. He received a Ph.D. in Aerospace Engineering and a Graduate Certificate in Plasma Science and Engineering from the University of Michigan, and B.S. and M.S. in Aeronautics and Astronautics from the University of Tokyo. He was a Visiting Research Physicist at Princeton Plasma Physics Laboratory as a Japan Society for the Promotion of Science Postdoctoral Fellow. Professor Hara’s research interests include electric propulsion, low temperature plasmas, plasma physics (plasma-wall interactions, plasma-wave interactions), data-driven modeling, rarefied gas flows, and computational fluid and plasma dynamics. He is a recipient of the Air Force Young Investigator Program Award, the Department of Energy Early Career Award, and the Office of Naval Research Young Investigator Program Award.
Honors & Awards
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Associate Fellow, American Institute of Aeronautics and Astronautics (2024)
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NPSS Early Achievement Award, IEEE Nuclear and Plasma Sciences Society (2023)
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Noah Hershkowitz Early Career Award, Plasma Sources Science and Technology, IOP Publishing (2023)
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Young Investigator Program (YIP) Award, Office of Naval Research (2021)
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Kuriki Award for Young Professionals, Electric Rocket Propulsion Society (2019)
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Early Career Research Program Award, Department of Energy (2018)
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JPL Summer Faculty Research Program, Jet Propulsion Laboratory, Caltech (2017)
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Young Investigator Research Program (YIP) Award, Air Force Office of Scientific Research (2017)
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Postdoctoral Fellowship, Japan Society for the Promotion of Science (2015-2016)
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Nuclear and Plasma Sciences Society Graduate Scholarship Award, IEEE (2015)
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Outstanding Student Paper Award, 41st IEEE International Conference on Plasma Science (2014)
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Richard F. and Eleanor A. Towner Prize for Distinguished Academic Achievement, College of Engineering, University of Michigan (2013)
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Best Student Award, 41st Annual Meeting of Japan Society for Aeronautical and Space Sciences (2010)
Boards, Advisory Committees, Professional Organizations
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Plasma Science and Applications Committee, Nuclear and Plasma Sciences Society, IEEE (2020 - 2023)
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Editorial Board, Plasma Sources Science and Technology, IOP Publishing (2023 - Present)
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Electric Propulsion Technical Committee, American Institute of Aeronautics and Astronautics (2018 - Present)
Professional Education
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PhD, University of Michigan, Aerospace Engineering (2015)
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MS, University of Tokyo, Aeronautics and Astronautics (2010)
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BS, University of Tokyo, Aeronautics and Astronautics (2008)
2024-25 Courses
- Fundamentals of Compressible Flow
AA 210A (Aut) - Plasma Science and Technology Seminar
AA 296, ME 350 (Win) - Rarefied and Ionized Gases
AA 205 (Spr) - Spacecraft Electric Propulsion
AA 204 (Win) -
Independent Studies (4)
- Directed Research and Writing in Aero/Astro
AA 190 (Aut, Win, Spr, Sum) - Independent Study in Aero/Astro
AA 199 (Aut, Win, Spr, Sum) - Practical Training
AA 291 (Aut, Win, Spr, Sum) - Problems in Aero/Astro
AA 290 (Aut, Win, Spr)
- Directed Research and Writing in Aero/Astro
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Prior Year Courses
2023-24 Courses
- Fundamentals of Compressible Flow
AA 210A (Win) - Plasma Science and Technology Seminar
AA 296, ME 350 (Win) - Spacecraft Electric Propulsion
AA 204 (Spr)
2022-23 Courses
- Advanced Plasma Physics and Engineering
AA 244B (Spr) - Aircraft and Rocket Propulsion
AA 283 (Win) - Fundamentals of Compressible Flow
AA 210A (Aut)
2021-22 Courses
- Fundamentals of Compressible Flow
AA 210A (Aut) - Introduction to Aeronautics and Astronautics
AA 100 (Win) - Spacecraft Electric Propulsion
AA 204 (Spr)
- Fundamentals of Compressible Flow
Stanford Advisees
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Doctoral Dissertation Reader (AC)
Trevor Hedges, Adura Jibodu, Raymond Lau, Ashwyn Sam -
Postdoctoral Faculty Sponsor
Anubhav Dwivedi, Luca Vialetto, Yusuke Yamashita -
Doctoral Dissertation Advisor (AC)
Andy Castillo, Andrew Denig, Derek Kuldinow, Adnan Mansour, Eva Marinopoulou, Vedanth Sharma, Shigemitsu Suzuki, Daniel Troyetsky -
Orals Evaluator
Adnan Mansour -
Master's Program Advisor
Allan Attia, Aliza Fisher, Nathan Fournier, Jerry Liu, Damian Meza, Pierre-Louis Monteil, Jasmine Narine, Jack Oswald, Timmy Robertson -
Doctoral Dissertation Co-Advisor (AC)
James Hansen, Konstantinos Kotsarinis, Alka Panda, Tal Schwartz
All Publications
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Effects of the chirp rate on single-shot coherent Rayleigh-Brillouin scattering
PHYSICAL REVIEW A
2024; 110 (3)
View details for DOI 10.1103/PhysRevA.110.033519
View details for Web of Science ID 001318353000007
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Case study in machine learning for predicting moderate pressure plasma behavior
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
2024; 42 (4)
View details for DOI 10.1116/6.0003434
View details for Web of Science ID 001222229600001
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Hysteresis between gas breakdown and plasma discharge
PHYSICS OF PLASMAS
2024; 31 (7)
View details for DOI 10.1063/5.0198151
View details for Web of Science ID 001272562600006
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Ten-moment fluid model with heat flux closure for gasdynamic flows
JOURNAL OF COMPUTATIONAL PHYSICS
2024; 508
View details for DOI 10.1016/j.jcp.2024.113030
View details for Web of Science ID 001233447200001
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Effects of multi-dimensionality and energy exchange on electrostatic current-driven plasma instabilities and turbulence
JOURNAL OF PLASMA PHYSICS
2024; 90 (2)
View details for DOI 10.1017/S0022377824000230
View details for Web of Science ID 001191253500001
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Loss cone effects and monotonic sheath conditions of a partially magnetized plasma sheath
PHYSICS OF PLASMAS
2024; 31 (3)
View details for DOI 10.1063/5.0187972
View details for Web of Science ID 001180029000005
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State estimation of the dynamic behavior of plasma properties in a Hall effect thruster discharge
JOURNAL OF PHYSICS D-APPLIED PHYSICS
2023; 56 (44)
View details for DOI 10.1088/1361-6463/ace7da
View details for Web of Science ID 001043714400001
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Inertial and anisotropic pressure effects on cross-field electron transport in low-temperature magnetized plasmas
JOURNAL OF PHYSICS D-APPLIED PHYSICS
2023; 56 (38)
View details for DOI 10.1088/1361-6463/acdb83
View details for Web of Science ID 001011405800001
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Dynamics of electrified liquid metal surface using shallow water model
PHYSICS OF FLUIDS
2023; 35 (4)
View details for DOI 10.1063/5.0145930
View details for Web of Science ID 000969142200041
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Three-dimensional coupling of electron cyclotron drift instability and ion-ion two stream instability
PHYSICS OF PLASMAS
2023; 30 (3)
View details for DOI 10.1063/5.0122293
View details for Web of Science ID 000956989800001
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Effects of macroparticle weighting in axisymmetric particle-in-cell Monte Carlo collision simulations
PLASMA SOURCES SCIENCE & TECHNOLOGY
2023; 32 (1)
View details for DOI 10.1088/1361-6595/acb28b
View details for Web of Science ID 000918556700001
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Effects of the Wavelength of the Plasma Waves on Cross-Field Electron Transport in Partially Magnetized Plasmas
IEEE TRANSACTIONS ON PLASMA SCIENCE
2022
View details for DOI 10.1109/TPS.2022.3202194
View details for Web of Science ID 000862335600001
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Theory of gradient drift instabilities in low-temperature, partially magnetised plasmas
JOURNAL OF PLASMA PHYSICS
2022; 88 (4)
View details for DOI 10.1017/S002237782200068X
View details for Web of Science ID 000840421400001
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Estimation of plasma properties using an extended Kalman filter with plasma global models
JOURNAL OF PHYSICS D-APPLIED PHYSICS
2022; 55 (25)
View details for DOI 10.1088/1361-6463/ac5c1c
View details for Web of Science ID 000773688700001
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Full fluid moment modeling of rotating spokes in Penning-type configuration
PLASMA SOURCES SCIENCE & TECHNOLOGY
2022; 31 (5)
View details for DOI 10.1088/1361-6595/ac6a73
View details for Web of Science ID 000802918800001
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Mutually guided light and particle beam propagation.
Scientific reports
2022; 12 (1): 4810
Abstract
The polarizability of atoms and molecules gives rise to optical forces that trap particles and a refractive index that guides light beams, potentially leading to a self-guided laser and particle beam propagation. In this paper, the mutual interactions between an expanding particle beam and a diffracting light beam are investigated using an axisymmetric particle-light coupled simulation. The nonlinear coupling between particles and photons is dependent on the particle beam radius, particle density, particle velocity and temperature, polarizability, light beam waist, light frequency (with respect to the resonance frequency), and light intensity. The computational results show that the maximum propagation distance is achieved when the waveguiding effect is optimized to single-mode operation. The application of the coupled beam propagation as a space propulsion system is discussed.
View details for DOI 10.1038/s41598-022-08802-z
View details for PubMedID 35314753
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Characterization of hollow cathode plasma turbulence using coherent Thomson scattering
JOURNAL OF APPLIED PHYSICS
2021; 130 (24)
View details for DOI 10.1063/5.0071650
View details for Web of Science ID 000739055500001
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Effects of multiply charged ions on microturbulence-driven electron transport in partially magnetized plasmas
JOURNAL OF APPLIED PHYSICS
2021; 130 (17)
View details for DOI 10.1063/5.0067305
View details for Web of Science ID 000716462300004
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Real-time state estimation of low-frequency plasma oscillations in Hall effect thrusters
PHYSICS OF PLASMAS
2021; 28 (9)
View details for DOI 10.1063/5.0057751
View details for Web of Science ID 000747761200002
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2D radial-azimuthal particle-in-cell benchmark for E x B discharges
PLASMA SOURCES SCIENCE & TECHNOLOGY
2021; 30 (7)
View details for DOI 10.1088/1361-6595/ac0a4a
View details for Web of Science ID 000668701000001
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Application of State Estimation Methods to Low-Temperature Plasma Dynamics
IEEE. 2021: 1-5
View details for DOI 10.1109/CDC45484.2021.9682995
View details for Web of Science ID 000781990300001
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Nonlinear dynamics of coupled light and particle beam propagation
Physical Review A
2021; 103 (04)
View details for DOI 10.1103/PhysRevA.103.043502
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Physics of ExB discharges relevant to plasma propulsion and similar technologies
PHYSICS OF PLASMAS
2020; 27 (12)
View details for DOI 10.1063/5.0010135
View details for Web of Science ID 000600206100001
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Full fluid moment model for low temperature magnetized plasmas
PHYSICS OF PLASMAS
2020; 27 (11)
View details for DOI 10.1063/5.0021474
View details for Web of Science ID 000590777500001
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Non-monotonic double layers and electron two-stream instabilities resulting from intermittent ion acoustic wave growth
PHYSICS OF PLASMAS
2020; 27 (11)
View details for DOI 10.1063/5.0019729
View details for Web of Science ID 000595631700001
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Cross-field electron diffusion due to the coupling of drift-driven microinstabilities
PHYSICAL REVIEW E
2020; 102 (2)
View details for DOI 10.1103/PhysRevE.102.023202
View details for Web of Science ID 000555843100009
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Cross-field electron diffusion due to the coupling of drift-driven microinstabilities.
Physical review. E
2020; 102 (2-1): 023202
Abstract
In this paper, the nonlinear interaction between kinetic instabilities driven by multiple ion beams and magnetized electrons is investigated. Electron diffusion across magnetic field lines is enhanced by the coupling of plasma instabilities. A two-dimensional collisionless particle-in-cell simulation is performed accounting for singly and doubly charged ions in a cross-field configuration. Consistent with prior linear kinetic theory analysis and observations from coherent Thomson scattering experiments, the present simulations identify an ion-ion two-stream instability due to multiply charged ions (flowing in the direction parallel to the applied electric field) which coexists with the electron cyclotron drift instability (propagating perpendicular to the applied electric field and parallel to the E×B drift). Small-scale fluctuations due to the coupling of these naturally driven kinetic modes are found to be a mechanism that can enhance cross-field electron transport and contribute to the broadening of the ion velocity distribution functions.
View details for DOI 10.1103/PhysRevE.102.023202
View details for PubMedID 32942351
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Self-organized standing waves generated by AC-driven electron cyclotron drift instabilities
APPLIED PHYSICS LETTERS
2019; 115 (23)
View details for DOI 10.1063/1.5131019
View details for Web of Science ID 000504304400030
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Two-dimensional hybrid-direct kinetic simulation of a Hall thruster discharge plasma
PHYSICS OF PLASMAS
2019; 26 (12)
View details for DOI 10.1063/1.5122290
View details for Web of Science ID 000505578200008
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2D axial-azimuthal particle-in-cell benchmark for low-temperature partially magnetized plasmas
PLASMA SOURCES SCIENCE & TECHNOLOGY
2019; 28 (10)
View details for DOI 10.1088/1361-6595/ab46c5
View details for Web of Science ID 000503203700010
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A data-driven approach to model calibration for nonlinear dynamical systems
JOURNAL OF APPLIED PHYSICS
2019; 125 (24)
View details for DOI 10.1063/1.5085780
View details for Web of Science ID 000474439600008
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Ion kinetics and nonlinear saturation of current-driven instabilities relevant to hollow cathode plasmas
PLASMA SOURCES SCIENCE & TECHNOLOGY
2019; 28 (5)
View details for DOI 10.1088/1361-6595/ab18e4
View details for Web of Science ID 000468882200003
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An overview of discharge plasma modeling for Hall effect thrusters
PLASMA SOURCES SCIENCE & TECHNOLOGY
2019; 28 (4)
View details for DOI 10.1088/1361-6595/ab0f70
View details for Web of Science ID 000464043800001
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Spatiotemporal data fusion and manifold reconstruction in Hall thrusters
PLASMA SOURCES SCIENCE & TECHNOLOGY
2019; 28 (4)
View details for DOI 10.1088/1361-6595/ab0b1f
View details for Web of Science ID 000463548800004
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Multispecies plasma fluid simulation for carbon arc discharge
JOURNAL OF PHYSICS D-APPLIED PHYSICS
2019; 52 (10)
View details for DOI 10.1088/1361-6463/aaf945
View details for Web of Science ID 000455359600003
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Non-oscillatory quasineutral fluid model of cross-field discharge plasmas
PHYSICS OF PLASMAS
2018; 25 (12)
View details for DOI 10.1063/1.5055750
View details for Web of Science ID 000454905100069
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Test cases for grid-based direct kinetic modeling of plasma flows
PLASMA SOURCES SCIENCE & TECHNOLOGY
2018; 27 (6)
View details for DOI 10.1088/1361-6595/aac6b9
View details for Web of Science ID 000435580100001
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Amplification due to two-stream instability of self-electric and magnetic fields of an ion beam propagating in background plasma
AMER INST PHYSICS. 2018
View details for DOI 10.1063/1.5038878
View details for Web of Science ID 000433961800024
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Numerical analysis of azimuthal rotating spokes in a crossed-field discharge plasma
PLASMA SOURCES SCIENCE & TECHNOLOGY
2018; 27 (3)
View details for DOI 10.1088/1361-6595/aab39c
View details for Web of Science ID 000428498700001
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On limitations of laser-induced fluorescence diagnostics for xenon ion velocity distribution function measurements in Hall thrusters
PHYSICS OF PLASMAS
2018; 25 (3)
View details for DOI 10.1063/1.5020749
View details for Web of Science ID 000428987800077
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Generation of forerunner electron beam during interaction of ion beam pulse with plasma
AMER INST PHYSICS. 2018
View details for DOI 10.1063/1.5002688
View details for Web of Science ID 000424021700015
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Kinetic simulations of ladder climbing by electron plasma waves
PHYSICAL REVIEW E
2017; 95 (5): 053212
Abstract
The energy of plasma waves can be moved up and down the spectrum using chirped modulations of plasma parameters, which can be driven by external fields. Depending on whether the wave spectrum is discrete (bounded plasma) or continuous (boundless plasma), this phenomenon is called ladder climbing (LC) or autoresonant acceleration of plasmons. It was first proposed by Barth et al. [Phys. Rev. Lett. 115, 075001 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.075001] based on a linear fluid model. In this paper, LC of electron plasma waves is investigated using fully nonlinear Vlasov-Poisson simulations of collisionless bounded plasma. It is shown that, in agreement with the basic theory, plasmons survive substantial transformations of the spectrum and are destroyed only when their wave numbers become large enough to trigger Landau damping. Since nonlinear effects decrease the damping rate, LC is even more efficient when practiced on structures like quasiperiodic Bernstein-Greene-Kruskal (BGK) waves rather than on Langmuir waves per se.
View details for DOI 10.1103/PhysRevE.95.053212
View details for Web of Science ID 000402019600015
View details for PubMedID 28618641
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Detailed modeling of electron emission for transpiration cooling of hypersonic vehicles
JOURNAL OF APPLIED PHYSICS
2017; 121 (5)
View details for DOI 10.1063/1.4974961
View details for Web of Science ID 000394345700008
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AMPLIFICATION DUE TO THE TWO-STREAM INSTABILITY OF SELF-ELECTRIC AND MAGNETIC FIELDS OF AN ION OR ELECTRON BEAM PROPAGATING IN BACKGROUND PLASMA
IEEE. 2017
View details for Web of Science ID 000450253400221
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ADVANCED MAGNETO-GAS-KINETIC SCHEME FOR MHD: ANALYSIS AND COMPARISON TO EXISTING MODELS
IEEE. 2017
View details for Web of Science ID 000450253400063
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NUMERICAL MODELING OF ROTATING SPOKES IN HALL THRUSTER DISCHARGE PLASMA
IEEE. 2017
View details for Web of Science ID 000450253400168
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Electron acceleration due to the interaction between a neutralized ion beam and background plasma
IEEE. 2017
View details for Web of Science ID 000450253400342
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Quantitative study of the trapped particle bunching instability in Langmuir waves
PHYSICS OF PLASMAS
2015; 22 (2)
View details for DOI 10.1063/1.4906884
View details for Web of Science ID 000350552000021
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Perturbation analysis of ionization oscillations in Hall effect thrusters
PHYSICS OF PLASMAS
2014; 21 (12)
View details for DOI 10.1063/1.4903843
View details for Web of Science ID 000347162700007
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Mode transition of a Hall thruster discharge plasma
JOURNAL OF APPLIED PHYSICS
2014; 115 (20)
View details for DOI 10.1063/1.4879896
View details for Web of Science ID 000337143500016
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One-dimensional hybrid-direct kinetic simulation of the discharge plasma in a Hall thruster
PHYSICS OF PLASMAS
2012; 19 (11)
View details for DOI 10.1063/1.4768430
View details for Web of Science ID 000312033700072