Hantao Ji's Homepage

Plasma Physics Laboratory Forrestal Campus, C-Site, Room L222 Princeton University PO Box 451, Princeton, NJ 08543 Tel: (609) 243-2162 Email: hji@pppl.gov Typically on Mon. and Tue.		Department of Astrophysical Sciences Peyton Hall, Room 207 Princeton University 4 Ivy Lane, Princeton, NJ 08544 Tel: (609) 258-9969 Email: hji@princeton.edu Typically on Wed., Thur., and Fri.
	Hantao Ji

I am a Professor at Department of Astrophysical Sciences and a Distinguished Research Fellow at Princeton Plasma Physics Laboratory (PPPL) (try here and here also), Princeton University.

News: A manuscript by Sayak Bose has been submitted to a refereed journal reporting first experimental detection of Alfven wave reflection relevant to solar corona heating!

News: A new review paper titled, “Laboratory study of collisionless magnetic reconnection”, has been published in Space Science Reviews (here is its pdf). It concisely summaries the progress made in the past two decades from the laboratory on collisionless magnetic reconnection in direct relation with space measurements. Highlights include spatial structures of electromagnetic fields in diffusion regions, energy conversion and partitioning from magnetic field to ions and electrons, kinetic plasma waves, and plamoid-mediated multiscale reconnection. The latter topic offers immediate and long-term future research opportunities. This review is part of International Space Science Institute book titled "Magnetic Reconnection: Explosive Energy Conversion in Space Plasmas"

News: A pair of papers have been published in Nature Physics in 2023 to report experimental results using a newly developed laboratory platform to study magnetic reconnection at low plasma beta using capacitor coils powered by lasers. The first paper is titled "Non-thermal electron acceleration from magnetically driven reconnection in a laboratory plasma" and the second paper is titled "Ion and Electron Acoustic Bursts during Anti-Parallel Reconnection Driving by Lasers". There is a News & Views story by Giovanni Lapenta on Nature Physics. Click here for a news story by Princeton Plasma Physics Laboratory and click here for a news story by phys.org. Also, here is a news story by Lawrence Livermore National Laboratory, and another news story by Laboratory of Laser Energetics, University of Rochester. These results were highlighted at Press Release at the American Physical Society Division of Plasma Physics meeting in Denver, October 30 to November 3, 2023.

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Current Course: AST552 (General Plasma Physics II: Magnetohydrodynamics)

Main Research Activities

Study of angular momentum transport including Magnetorotational Instability (MRI) in experimental devices at PPPL. Selected publications:
- A. Secunda, P. Donnel, H. Ji, and J. Goodman, "Magnetorotational instability in a swirling partially ionized gas", Mon. Not. R. Astron. Soc. 526, 4093 (2023). (link)
- H. Ji and J. Goodman, “Taylor-Couette flow for astrophysical purposes”, Phil. Trans. R. Soc. A. 381, 20220119 (2023). (pdf)
- Y. Wang, E. Gilson, F. Ebrahimi, J. Goodman, and H. Ji, “Observation of Axisymmetric Standard Magnetorotational Instability in the Laboratory,” Physical Review Letters 129, 115001 (2022). (link) (news story)
- Y. Wang, E. Gilson, F. Ebrahimi, J. Goodman, K. Caspary, H. Winarto, and H. Ji, “Identification of a non-axisymmetric mode in laboratory experiments searching for standard magnetorotational instability,” Nature Communications 13, 4679 (2022). (link)
- A. Barekat, M.J. Kapyla, P.J. Kapyla, E.P. Gilson, and H. Ji, “Generation of mean flows in rotating anisotropic turbulence: The case of solar near-surface shear layer,” Astron. Astrophys. 655, A79 (2021). (pdf)
- F. Pucci, K. Tomida, J. Stone, S. Takasao, H. Ji, and S. Okamura, “Transition Region from Turbulent to Dead Zone in Protoplanetary Disks: Local Shearing Box Simulations,” Astrophys. J. 907, 13 (2021). (pdf)
- H. Winarto, H. Ji, J. Goodman, F. Ebrahimi, E. Gilson, and Y. Wang, "Parameter space mapping of the Princeton magnetorotational instability experiment", Phys. Rev. E 102, 023113 (2020). (pdf)
- D. Choi, F. Ebrahimi, K. Caspary, E. Gilson, J. Goodman, and H. Ji, "Nonaxisymmetric simulations of the Princeton magnetorotational instability experiment with insulating and conducting axial boundaries", Phys. Rev. E 100, 033116 (2019). (pdf)
- M. Burin, K. Caspary, E. Edlund, R. Ezeta, E. Gilson, H. Ji, M. McNulty, J. Squire, and G. Tynan, “Turbulence and jet-driven zonal flows: Secondary circulation in rotating liquids due to asymmetric forcing”, Phys. Rev. E 99, 023108 (2019). (pdf)
- D. Hung, E. Blackman, K. Caspary, E. Gilson, and H. Ji, "Experimental Confirmation of the Standard Magnetorotational Instability Mechanism with a Spring-Mass Analogue", Communication Physics 2, 9 (2019). (pdf)
- K. Caspary, D. Choi, F. Ebrahimi, E. Gilson, J. Goodman, and H. Ji, "Effects of axial boundary conductivity on a free Stewartson-Shercliff layer", Phys. Rev. E 97, 063110 (2018). (pdf)
- X. Wei, H. Ji, J. Goodman, F. Ebrahimi, E. Gilson, F. Jenko, and K. Lackner, "Numerical simulations of the Princeton magnetorotational instability experiment with conducting axial boundaries", Phys. Rev. E 94, 063107 (2016). (pdf)
- E. Edlund and H. Ji, “Reynolds number scaling of the influence of boundary layers on the global behavior of laboratory quasi-Keplerian flows”, Phys. Rev. E 92, 043005 (2015). (pdf)
- E. Edlund and H. Ji, “Nonlinear stability of laboratory quasi-Keplerian flows”, Phys. Rev. E 89, 021004 (2014). (pdf)
- H. Ji and S. Balbus, “Angular Momentum Transport in Astrophysics and in the Lab”, Physics Today 66, 27 (2013). (pdf)
- C. Gissinger, J. Goodman, and H. Ji, "The role of boundaries in the magnetorotational instability", Phys. Fluids 24, 074109 (2012). (pdf)
- E. Schartman, H. Ji, M. Burin, and J. Goodman, "Stability of quasi-Keplerian shear flow in a laboratory experiment", Astron. Astrophys. 543, A94 (2012). (pdf)
- E. Spence, A. Roach, E. Edlund, P. Sloboda, and H. Ji, "Free magnetohydrodynamic shear layers in the presence of rotation and magnetic field", Phys. Plasmas 19, 056502 (2012). (pdf)
- A. Roach, E. Spence, C. Gissinger, E. Edlund, P. Sloboda, J. Goodman and H. Ji, "Observation of a Free-Shercliff-Layer Instability in Cylinderical Geometry", Phys. Rev. Lett. 108, 154502 (2012). (pdf)
- C. Gissinger, H. Ji, and J. Goodman, "Instabilities in magnetized spherical Couette flow", Phys. Rev. E 84, 026308 (2011). (pdf)
- M. Nornberg, H. Ji, E. Schartman, A. Roach, and J. Goodman, "Observation of Magnetocoriolis Waves in a Liquid Metal Taylor Couette Experiment", Phys. Rev. Lett. 104, 074501 (2010). (pdf)
- M. Burin, E. Schartman and H. Ji, "Local measurements of turbulent angular momentum transport in circular Couette ﬂow", Exp. Fluids 48, 763 (2010). (pdf)
- E. Schartman, H. Ji and M. Burin, "Development of a Couette–Taylor flow device with active minimization of secondary circulation ", Rev. Sci. Instrum. 80, 024501 (2009). (pdf)
- H. Ji, P. Kronberg, S. Prager, and D. Uzdensky, "Mini-conference on angular momentum transport in laboratory and nature", Phys. Plasmas 15, 058302 (2008). (pdf)
- W. Liu, J. Goodman, and H. Ji, "Traveling waves in magnetized Taylor-Couette flow", Phys. Rev. E 76, 016310 (2007). (pdf)
- W. Liu, J. Goodman, I. Herron, and H. Ji, "Helical magnetorotational instability in magnetized Taylor-Couette flow", Phys. Rev. E 74, 056302 (2006). (pdf)
- H. Ji, M. Burin, E. Schartman, and J. Goodman, "Hydrodynamic turbulence cannot transport angular momentum effectively in astrophysical disks", Nature 444, 343 (2006). (pdf, introduction by S. Balbus)
- W. Liu, J. Goodman, and H. Ji, "Simulation of Magnetorotational Instability in a Magnetized Couette Flow", Astrophys. J. 643, 306 (2006). (pdf)
- M. Burin, E. Schartman, H. Ji, R. Cutler, P. Heitzenroeder, W. Liu, L. Morris, and S. Raftopolous, "Reduction of Ekman Circulation within Circular Couette Flow", Exp. Fluids 40, 962 (2006). (pdf)
- A. Kageyama, H. Ji, J. Goodman, F. Chen, and E. Shoshan, "Numerical and Experimental Investigation of Circulation in Short Cylinders", J. Phys. Soc. Jpn. 73, 2434 (2004). (Abstract) (pdf file)
- J. Goodman and H. Ji, "Magnetorotational Instability of Dissipative Couette Flow", J. Fluid Mech. 462, 365 (2002). (Abstract) (pdf file)
- H. Ji, J. Goodman, and A. Kageyama, "Magnetorotational Instability in a Rotating Liquid Metal Annulus", Monthly Notices of Royal Astronomical Society 325, L1 (2001). (Abstract) (pdf file)

Study of magnetic reconnection, especially in the Magnetic Reconnection Experiment (MRX) and Facility for Laboratory Reconnection Experiments (FLARE) at PPPL. Selected publications:
- B. Na, A. Robbins, J. Yoo, and H. Ji, “Double-Sided Electron Energy Analyzer for Measurement of Non-Maxwellian Electron Energy Distributions”, Rev. Sci. Instrum. 94, 123509 (2023). (pdf)
- H. Ji, J. Yoo, W. Fox, M. Yamada, M. Argall, J. Egedal, Y.-H. Liu, R. Wilder, S. Eriksson, W. Daughton, K. Bergstedt, S. Bose, J. Burch, R. Torbert, J. Ng, and L.-J. Chen, “Laboratory study of collisionless magnetic reconnection”, Space Sci. Rev. 219, 76 (2023). (pdf) (part of ISSI book "Magnetic Reconnection: Explosive Energy Conversion in Space Plasmas")
- A. Goodman, H. Ji, S. Bose, J. Yoo, and A. Alt, “Measurement of ion temperature and toroidal flow during magnetic reconnection with a large guide field”, Phys. Plasmas 30, 112104 (2023). (pdf)
- A. Alt, H. Ji, J. Yoo, S. Bose, A. Goodman, and M. Yamada, “Laboratory study of the failed torus mechanism in arched, line-tied, magnetic flux ropes”, Phys. Plasmas 30, 042901 (2023). (pdf)
- S. Majeski and H. Ji, “Super-Fermi acceleration in multiscale MHD reconnection”, Phys. Plasmas 30, 042106 (2023). (pdf)
- J. Ng, J. Yoo, L.-J. Chen, N. Bessho, and H. Ji, “3D simulations of lower-hybrid drift waves in strong guide field asymmetric reconnection in laboratory experiments”, Phys. Plasmas 30, 042101 (2023). (pdf)
- H. Ji and W. Daughton, “Preface for frontiers of magnetic reconnection research in heliophysical, astrophysical, and laboratory plasmas”, Phys. Plasmas 29, 070401 (2022). (pdf)
- H. Ji, W. Daughton, J. Jara-Almonte, A. Le, A. Stanier, and J. Yoo, "Magnetic reconnection in the era of exascale computing and multiscale experiments," Nature Reviews Physics 4, 263 (2022) (pdf).
- J. Yoo, Y.-B. Hu, J.-Y. Ji, H. Ji, M. Yamada, A. Goodman, K. Bergstedt, W. Fox, and A. Alt, “Effects of Coulomb collisions on lower hybrid drift waves inside a laboratory reconnection current sheet”, Phys. Plasmas 29, 022109 (2022). (pdf)
- S. Majeski, H. Ji, J. Jara-Almonte, and J. Yoo, “Guide Field Effects on the Distribution of Plasmoids in Multiple Scale Reconnection”, Phys. Plasmas 28, 092106 (2021). (pdf)
- J. Jara-Almonte and H. Ji, “Thermodynamic Phase Transition in Magnetic Reconnection”, Phys. Rev. Lett. 127, 055102 (2021). (pdf)
- A. Goodman, J. Yoo, J. Jara-Almonte, and H. Ji, “Ion temperature measurements from tomographic reconstruction of Doppler spectra in the presence of multi-component flow in two dimensions”, Rev. Sci. Instrum. 92, 063508 (2021). (pdf)
- J. Jara-Almonte, N. Murphy, and H. Ji, “Multi-Fluid and Kinetic Models of Partially Ionized Magnetic Reconnection”, Phys. Plasmas 28, 042108 (2021). (pdf)
- Y. Hu, J. Yoo, H. Ji, A. Goodman, and X. Wu, “Probe measurements of electric field and electron density fluctuations at megahertz frequencies using in-shaft miniature circuits”, Rev. Sci. Instrum. 92, 033534 (2021). (pdf)
- A. Alt, C.E. Myers, H. Ji, J. Jara-Almonte, J. Yoo, S. Bose, A. Goodman, M. Yamada, B. Kliem, and A. Savcheva, “Laboratory study of the torus instability threshold in solar-relevant, line-tied magnetic flux ropes”, Astrophys. J. 908, 41 (2021). (pdf)
- F. Pucci, M. Velli, C. Shi, K. Singh, A. Tenerani, F. Alladio, F. Ambrosino, P. Buratti, W. Fox, J. Jara-Almonte, H. Ji, M. Yamada, J. Yoo, S. Okamura, R. Ergun, S. Hoilijoki, and S. Schwarz, "Onset of fast magnetic reconnection and particle energization in laboratory and space plasmas", J. Plasma Phys. 86, 53586061 (2020). (pdf)
- J. Yoo, J.-Y. Ji, M. Ambat, S. Wang, H. Ji, J. Lo, B. Li, Y. Ren, J. Jara-Almonte, L.-J. Chen, W. Fox, M. Yamada, A. Alt, and A. Goodman, "Lower Hybrid Drift Waves During Guide Field Reconnection", Geophys. Res. Lett 47, e2020GL087192 (2020). (pdf)
- K. Bergstedt, H. Ji, J. Jara-Almonte, J. Yoo, R. Ergun, and L.-J. Chen, "Statistical Properties of Magnetic Structures and Energy Dissipation during Turbulent Reconnection in the Earth's Magnetotail", Geophys. Res. Lett 47, e2020GL088540 (2020). (pdf)
- L. Ni, H. Ji, N. Murphy, and J. Jara-Almonte, "Magnetic reconnection in partially ionized plasmas", Proc. R. Soc. A 476, 20190867 (2020). (pdf)
- R.E. Ergun, S. Hoilijoki, N. Ahmadi, S.J. Schwartz, F.D. Wilder, J.F. Drake, M. Hesse, M.A. Shay, H. Ji, M. Yamada, D.B. Graham, P.A. Cassak, M. Swisdak, J.L. Burch, R.B. Torbert, J.C. Holmes, J.E. Stawarz, K.A. Goodrich, S. Eriksson, R.J. Strangeway, and O. LeContel, "Magnetic Reconnection in Three Dimensions: Modeling and Analysis of Electromagnetic Drift Waves in the Adjacent Current Sheet", J. Geophys. Res. 124, 10085 (2019). (pdf)
- J. Yoo, S. Wang, E. Yerger, J. Jara-Almonte, H. Ji, M. Yamada, L.-J. Chen, W. Fox, A. Goodman, and A. Alt, "Whistler wave generation by electron temperature anisotropy during magnetic reconnection at the magnetopause", Phys. Plasmas 26, 052903 (2019). (pdf)
- J. Jara-Almonte, H. Ji, J. Yoo, M. Yamada, W. Fox, and W. Daughton, “Kinetic simulations of magnetic reconnection in partially ionized plasmas”, Phys. Rev. Lett. 122, 015101 (2019). (pdf)
- F. Pucci, S. Usami, H. Ji, X. Guo, R. Horiuchi, S. Okamura, W. Fox, J. Jara-Almonte, M. Yamada, and J. Yoo, “Energy transfer and electron energization in collisionless magnetic reconnection for different guide-field intensities”, Phys. Plasmas 25, 122111 (2018). (pdf)
- W. Fox, F.D. Wilder, S. Eriksson, J. Jara-Almonte, F. Pucci, J. Yoo, A. von Stechow, H. Ji, M. Yamada, R.E. Ergun, M. Oieroset, and T.D. Phan, “Energy conversion by parallel electric fields in reconnection diffusion regions in scaled laboratory and space experiments”, Geophys. Res. Lett. 45, 12677 (2018). (pdf)
- M. Yamada, L.-J. Chen, J. Yoo, S. Wang, A. Le, W. Daughton, W. Fox, J. Jara-Almonte, H. Ji, J. Burch, B. Giles, M. Hesse, T. Moore, R. Torbert, "The two-fluid dynamics and energetics of the asymmetric magnetic reconnection in laboratory and space plasmas", Nature Communications 9, 5223 (2018). (pdf)
- J. Yoo, J. Jara-Almonte, E. Yerger, S. Wang, T. Qian, A. Le, H. Ji, M. Yamada, W. Fox, E.-H. Kim, L.-J. Chen, and D. Gershman, "Whistler Wave Generation by Anisotropic Tail Electrons During Asymmetric Magnetic Reconnection in Space and Laboratory", Geophys. Res. Lett. 45, 8054 (2018). (pdf)
- J. Jing, C. Liu, J. Lee, H. Ji, N. Liu, Y. Xu, and H. Wang, "Statistical Analysis of Torus and Kink Instabilities in Solar Eruptions", Astrophys. J. 864, 138 (2018). (pdf)
- A. von Stechow, W. Fox, J. Jara-Almonte, J. Yoo, H. Ji, and M. Yamada, "Electromagnetic fluctuations during guide field reconnection in a laboratory plasma", Phys. Plasmas 25, 052120 (2018). (pdf)
- J. Yoo, B. Na, J. Jara-Almonte, M. Yamada, H. Ji, V. Roytershteyn, M. Argall, W. Fox, and L.-J. Chen, "Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma", J. Geophys. Res. 122, 9264 (2017). (pdf)
- W. Fox, F. Sciortino, A. von Stechow, J. Jara-Almonte, J. Yoo, H. Ji, and M. Yamada, "Experimental Verification of the Role of Electron Pressure in Fast Magnetic Reconnection with a Guide Field", Phys. Rev. Lett. 118, 125002 (2017). (pdf)
- C. Myers, M. Yamada, H. Ji, J. Yoo, J. Jara-Almonte, and W. Fox, "Quasi-static and dynamic magnetic tension forces in arched, line-tied magnetic flux ropes", Plasma Phys. Control. Fusion 59, 014048 (2016). (pdf)
- C. Myers, M. Yamada, H. Ji, J. Yoo, J. Jara-Almonte, and W. Fox, "Laboratory study of low-b forces in arched, line-tied magnetic flux ropes", Phys. Plasmas 23, 112102 (2016). (pdf)
- J. Jara-Almonte, H. Ji, M. Yamada, J. Yoo, and W. Fox, "Laboratory Observation of Resistive Electron Tearing in a Two-Fluid, Reconnecting Current Sheet", Phys. Rev. Lett. 117, 095001 (2016). (pdf) (click here for a news story)
- C. Myers, M. Yamada, H. Ji, J. Yoo, W. Fox, J. Jara-Almonte, A. Savcheva, and E. DeLuca, "A dynamic magnetic tension force as the cause of failed solar eruptions", Nature 528, 526 (2015). (pdf)
- Y. Chen, K. Fujimoto, C. Xiao, and H. Ji, "Plasma waves around separatrix in collisionless magnetic reconnection with weak guide field", J. Geophys. Res. 120, 6309 (2015) (pdf).
- M. Yamada, J. Yoo, J. Jara-Almonte, W. Daughton, H. Ji, R. Kulsrud, and C. Myers, "Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma", Phys. Plasmas 22, 056501 (2015). (pdf)
- H. Ji and E. Zweibel, "Understanding Particle Acceleration in Astrophysical Plasmas", Science 347, 944 (2015). (pdf)
- M. Yamada, J. Yoo, J. Jara-Almonte, H. Ji, R. Kulsrud, C. Myers, "Conversion of magnetic energy in the magnetic reconnection layer of a laboratory plasma", Nature Communications 5, 4774 (2014). (pdf)
- J. Yoo, M. Yamada, H. Ji, J. Jara-Almonte, C. Myers, L.-J. Chen, "Laboratory study of magnetic reconnection with a density asymmetry across the current sheet", Phys. Rev. Lett. 113, 095002 (2014). (pdf)
- J. Yoo, M. Yamada, H. Ji, J. Jara-Almonte, C. Myers, "Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasma", Phys. Plasmas 21, 055706 (2014). (pdf)
- J. Jara-Almonte, W. Daughton, and H. Ji, "Debye scale turbulence within the electron diffusion layer during magnetic reconnection", Phys. Plasmas 21, 032114 (2014). (pdf)
- S. Dorfman, H. Ji, M. Yamada, J. Yoo, E. Lawrence, C. Myers, and T. Tharp, “Experimental observation of 3-D, implusive reconnection events in a Laboratory Plasma”, Phys. Plasmas 21, 012109 (2014). (pdf)
- N. Jain, J. Buechner, S. Dorfman, H. Ji and A. Sharma, “Current disruption and its spreading in collisionless magnetic reconnection”, Phys. Plasmas 20, 112101 (2013). (pdf)
- J. Yoo, M. Yamada, H. Ji, and C. Myers, “Observation of ion acceleration and heating during collisionless magnetic reconnection in a laboratory plasma”, Phys. Rev. Lett. 110, 215007 (2013). (pdf)
- T.D. Tharp, M. Yamada, H. Ji, E. Lawrence, S. Dorfman, C. Myers, Y.-M. Huang, A. Bhattacharjee, “Study of the Effects of Guide Field on Hall Reconnection”, Phys. Plasmas 20, 055705 (2013). (pdf)
- V. Roytershteyn, S. Dorfman, W. Daughton, H. Ji, M. Yamada, and H. Karimabadi, “Electromagnetic instability of thin reconnection layers: comparison of 3D simulations with MRX observations”, Phys. Plasmas 20, 061212 (2013). (pdf)
- S. Dorfman, H. Ji, M. Yamada, J. Yoo, T. Tharp, E. Lawrence, and C. Myers, “Three-dimensional, Impulsive Magnetic Reconnection in a Laboratory Plasma”, Geophys. Phys. Lett. 40, 233 (2013). (pdf)
- E. Lawrence, H. Ji, M. Yamada, and J. Yoo, “Laboratory Study of Hall Reconnection in Partially Ionized Plasmas”, Phys. Rev. Lett. 110, 015001 (2013). (pdf)
- T. Tharp, M. Yamada, H. Ji, E. Lawrence, S. Dorfman, C. Myers, and J. Yoo, “Quantitative Study of Guide Field Effects on Hall Reconnection in a Laboratory Plasma”, Phys. Rev. Lett. 109, 165002 (2012) (pdf)
- H. Ji and W. Daughton, "Phase diagram for magnetic reconnection in heliophysical, astrophysical, and laboratory plasmas," Phys. Plasmas 18, 111207 (2011) (pdf)
- E. Zweibel, E. Lawrence, J. Yoo, H. Ji, M. Yamada, and L. Malyshkin, "Magnetic reconnection in partially ionized plasmas", Phys. Plasmas 18, 111211 (2011) (pdf)
- E. Oz, C. Myers, M. Yamada, H. Ji, R. Kulsrud, and J. Xie, "Experimental verification of the Kruskal-Shafranov stability limit in line-tied partial-toroidal plasmas", Phys. Plasmas 18, 102107 (2011) (pdf)
- V. Roytershteyn, W. Daughton, S. Dorfman, Y. Ren, H. Ji, M. Yamada, H. Karimabadi, L. Yin, B.J. Albright, and K.J. Bowers, "Driven magnetic reconnection near the Dreicer limit", Physics of Plasmas 17, 055706 (2010). (pdf)
- M. Yamada, R. Kulsrud, and H. Ji, "Magnetic Reconnection", Reviews of Modern Physics 82, 603 (2010). (pdf)
- Y. Wang, R. Kulsrud, and H. Ji, "An analytic study of the perpendicularly propagating electromagnetic drift instabilities in the Magnetic Reconnection Experiment", Physics of Plasmas 15, 122105 (2008). (pdf)
- S. Dorfman, W. Daughton, V. Roytershteyn, H. Ji, Y. Ren, M. Yamada, "Two-dimensional fully kinetic simulations of driven magnetic reconnection with boundary conditions relevant to the Magnetic Reconnection Experiment", Physics of Plasmas 15, 102107 (2008). (pdf)
- Y. Ren, M. Yamada, H. Ji, S. Dorfman, S. Gerhardt, R. Kulsrud, "Experimental study of the Hall effect and electron diffusion region during magnetic reconnection in a laboratory plasma", Physics of Plasmas 15, 082113 (2008). (pdf)
- Y. Ren, M. Yamada, H, Ji, S. Gerhardt, R. Kulsrud, "Identification of the electron-diffusion region during magnetic reconnection in a laboratory plasma", Physical Review Letters 101, 085003 (2008). (pdf)
- H. Ji, Y. Ren, M. Yamada, S. Dorfman, W. Daughton, S. Gerhardt, "New insights into dissipation in the electron layer during magnetic reconnection", Geophysical Research Letters 35, L13106 (2008). (pdf)
- A. Kuritsyn, H. Ji, S. Gerhardt, Y. Ren, M. Yamada, "Effects of global boundary and local collisionality on magnetic reconnection in a laboratory plasma", Geophysical Research Letters 34, L16106 (2007). (pdf)
- M. Inomoto, S. Gerhardt, M. Yamada, H. Ji, E. Belova, A. Kuritsyn, and Y. Ren, "Coupling between Global Geometry and the Local Hall Effect Leading to Reconnection-Layer Symmetry Breaking", Physical Review Letters 97, 135002 (2006). (pdf)
- M. Yamada, Y. Ren, H. Ji, J. Breslau, S. Gerhardt, R. Kulsrud, and A. Kuritsyn, "Experimental study of two-fluid effects on magnetic reconnection in a laboratory plasma with variable collisionality", Physics of Plasmas 13, 052119 (2006). (pdf)
- A. Kuritsyn, M. Yamada, S. Gerhardt, H. Ji, R. Kulsrud, and Y. Ren, "Measurements of the parallel and transverse Spitzer resistivities during collisional magnetic reconnection", Physics of Plasmas 13, 055703 (2006). (pdf)
- Y. Ren, M. Yamada, S. Gerhardt, H. Ji, R. Kulsrud, and A.Kuritsyn, "Experimental Verification of the Hall Effect during Magnetic Reconnection in a Laboratory Plasma", Phys. Rev. Lett. 95, 055003 (2005). (Abstract) (pdf)
- R. Kulsrud, H. Ji, W. Fox, and M. Yamada, "An electromagnetic drift instability in the magnetic reconnection experiment and its importance for magnetic reconnection", Phys. Plasmas 12, 082301 (2005). (Abstract) (pdf)
- H. Ji, R. Kulsrud, W. Fox, and M. Yamada, "An obliquely propagating electromagnetic drift instability in the lower hybrid frequency range", J. Geophys. Res. 110, A08212 (2005). (Abstract) (pdf)
- H. Ji, S. Terry, M. Yamada, R. Kulsrud, A. Kuritsyn, and Y. Ren, "Electromagnetic Fluctuations during Fast Reconnection in a Laboratory Plasma", Phys. Rev. Lett. 92, 115001(2004). (Abstract) (pdf)
- F. Trintchouk, M. Yamada, H. Ji, R. M. Kulsrud, and T. A. Carter "Measurement of the transverse Spitzer resistivity during collisional magnetic reconnection", Phys. Plasmas 10, 319(2003). (Abstract) (pdf)
- T. Carter, M. Yamada, H. Ji, R. Kulsrud, and F. Trintchouk "Experimental study of lower-hybrid drift turbulence in a reconnecting current sheet", Phys. Plasmas 9, 3272(2002). (Abstract) (pdf)
- T. Carter, H. Ji, F. Trintchouk, M. Yamada, and R. Kulsrud, "Measurement of Lower-Hybrid Drift Turbulence in a Reconnecting Current Sheet", Phys. Rev. Lett. 88, 015001(2002). (Abstract) (pdf)
- Hantao Ji, Troy Carter, Scott Hsu, and Masaaki Yamada, "Study of Local Reconnection Physics in a Laboratory Plasma", Earth Planets Space 53, 539(2001). (Abstract) (pdf)
- S. Hsu, T. Carter, G. Fiksel, H. Ji, R. Kulsrud, and M. Yamada "Experimental Study of Ion Heating and Acceleration during Magnetic Reconnection", Phys. Plasmas 8, 1916(2001). (Abstract) (pdf)
- S. Hsu, G. Fiksel, T. Carter, H. Ji, R. Kulsrud, and M. Yamada, "Local Measurement of Nonclassical Ion Heating during Magnetic Reconnection", Phys. Rev. Lett. 84, 3859(2000). (Abstract) (pdf)
- M. Yamada, H. Ji et al., "Experimental investigation of the neutral sheet profile during magnetic reconnection", Phys. Plasmas 7, 1781(2000). (Abstract) (pdf)
- H. Ji, "Helicity, Reconnection, and Dynamo Effects", AGU monograph "Magnetic Helicity in Space and Laboratory Plasmas", p.167 (1999). (Abstract) (pdf)
- H. Ji, M. Yamada et al., "Magnetic Reconnection with Sweet-Parker Characteristics in Two-dimensional Laboratory Plasmas", Phys. Plasmas 6, 1743(1999). (Abstract) (pdf)
- T.-H. Watanabe, T. Hayashi, T. Sato, M. Yamada, and H. Ji, "Modeling of magnetic island formation in magnetic reconnection experiment", Phys. Plasmas 6, 1253 (1999) (pdf)
- H. Ji, M. Yamada et al., "Experimental Test of the Sweet-Parker Model of Magnetic Reconnection", Phys. Rev. Lett. 80, 3256(1998). (Abstract) (pdf)
- M. Yamada, H. Ji et al., "Identification of Y-Shaped and O-Shaped Diffusion Regions during Magnetic Reconnection in a Laboratory Plasma", Phys. Rev. Lett. 78, 3117(1997). (Abstract) (pdf)
- M. Yamada, H. Ji et al., "Study of Driven Magnetic Reconnection in a Laboratory Plasma", Phys. Plasmas 4, 1936(1997). (Abstract) (pdf)
Study of magnetic field effects in high-energy-density (HED) plasmas, including magnetic reconnection. Selected publications:

S. Zhang, A. Chien, L. Gao, H. Ji, E. Blackman, R. Follett, D. Froula, J. Katz, C. Li, A. Birkel, R. Petrasso, J. Moody, and H. Chen, “Ion and Electron Acoustic Bursts during Anti-Parallel Reconnection Driving by Lasers,” Nature Physics 19, 909 (2023). (pdf)
A. Chien, L. Gao, S. Zhang, H. Ji, E. Blackman, W. Daughton, A. Stanier, A. Le, F. Guo, R. Follett, H. Chen, G. Fiksel, G. Bleotu, R. Cauble, S. Chen, A. Fazzini, K. Flippo, O. French, D. Froula, J. Fuchs, S. Fujioka, K. Hill, S. Klein, C. Kuranz, P. Nilson, A. Rasmus, R. Takizawa, “Non-thermal electron acceleration from magnetically driven reconnection in a laboratory plasma,” Nature Physics 19, 254 (2023). (pdf)
P. Gourdain, M. Evans, P. Efthimion, R. Ellis, W. Fox, H.R. Hasson, H. Ji, R. Shapovalov, J.R. Young, and I. West-Abdallah, “Coreless Fast Pulsed-Power Drivers”, IEEE Transactions on Plasma Science 49, 2161 (2021). (pdf)
A. Chien, L. Gao, S. Zhang, H. Ji, E. Blackman, H. Chen, G. Fiksel, K. Hill, and P. Nilson, “Pulse width dependence of magnetic field generation using laser-powered capacitor coils”, Phys. Plasmas 28, 052105 (2021). (pdf)
K. Huang, Q.-M. Lu, A. Chien, L. Gao, H. Ji, X. Wang, and S. Wang, "Particle-in-cell simulations of asymmetric reconnection driven by laser-powered capacitor coils", Plasma Phys. Control. Fusion 63, 015010 (2021) (link)
A. Chien, L. Gao, H. Ji, X. Yuan, E. Blackman, H. Chen, P. Efthimion, G. Fiksel, D. Froula, K. Hill, K. Huang, Q.-M. Lu, J. Moody, P. Nilson, "Study of a magnetically driven reconnection platform using ultrafast proton radiography", Phys. Plasmas 26, 062113 (2019) (pdf)
L. Gao, E. Liang, Y. Lu, R. Follett, H. Sio, P. Tzeferacos, D. Froula, A. Birkel, C. Li, D. Lamb, R. Petrasso, W. Fu, M. Wei, and H. Ji, “Mega-Gauss Plasma Jet Creation Using a Ring of Laser Beams”, Astrophys. J. Lett. 873, L11 (2019) (pdf)
Y. Lu, P. Tzeferacos, E. Liang, R. Follett, L. Gao, A. Birkel, D. Froula, W. Fu, H. Ji, D. Lamb, C.K. Li, H. Sio, R. Petrasso, and M. Wei, “Numerical simulation of magnetized jet creation using a hollow ring of laser beams”, Phys. Plasms 26, 022902 (2019) (pdf)
K. Huang, Q. Lu, L. Gao, H. Ji, X. Wang, and F. Fan, "Particle-in-cell simulations of magnetically driven reconnection using laser-powered capacitor coils", Phys. Plasmas 25, 052104 (2018). (pdf)
G. Fiksel, W. Fox, L. Gao, and H. Ji, "A simple model for estimating a magnetic field in laser-driven coils", Appl. Phys. Lett. 109, 134103 (2016). (pdf)
L. Gao, H. Ji, G. Fiksel, W. Fox, M. Evans, and N. Alfonso, "Ultrafast Proton Radiography of the Magnetic Fields Generated by Laser-Driven Coil Currents", Phys. Plasmas 23, 043106 (2016). (pdf)

Study of plasma-facing components (PFC) and plasma-material interactions (PMI) including free-surface liquid metal flow for heat removal. Selected publications:

K. Kusumi, T. Kunugi, T. Tokomine, Z. Kawara, S. Nakamura, E. Kolemen, and H. Ji, "Thermal mixing enhancement of liquid metal MHD free-surface flow by optimizing vortex generator arrays", Fusion Eng. Design 136, 223 (2018). (link)
T. Huang, C. Jin, Y. Yang, X. Wu, L. Zhuge, Q. Wang, and H. Ji, "Control of Ion Species and Energy in High-Flux Helicon-Wave Excited Plasma Using Ar/N2 Gas Mixtures", IEEE Trans. Plasma Sci. 46, 895 (2018). (pdf)
G. Zhang, T. Huang, C. Jin, X. Wu, L. Zhuge, and H. Ji, "Development of a helicon-wave excited plasma facility with high magnetic field for plasma-wall interactions studies", Plasma Sci. Tech. 20, 085603 (2018). (pdf)
M. Hvasta, E. Kolemen, A. Fisher, and H. Ji, "Demonstrating electromagnetic control of free-surface, liquid-metal flows relevant to fusion reactors", Nucl. Fusion 58, 016022 (2018). (link)
K. Kusumi, T. Kunugi, T. Yokomine, Z. Kawara, E. Kolemen, H. Ji, and E. Gilson, "Study of Thermal Mixing of MHD Liquid Metal Free-Surface Film Flow", Fusion Sci. Tech. 72, 796 (2017). (pdf)
K. Kusumi, T. Tokomine, Z. Kawara, T. Kunugi, J. Hinojosa, E. Kolemen, H. Ji, and E. Gilson, "Study on thermal mixing of liquid-metal free-surface flow by obstacles installed at the bottom of a channel", Fusion Eng. Design 109-111, 1193 (2016). (link)
J. Rhoads, E. Edlund, and H. Ji, "Effects of magnetic field on the turbulent wake of a cylinder in free-surface magnetohydrodynamic channel flow", J. Fluid Mech. 742, 446 (2014) (pdf, movie)
C. Jin, T. Yu, Y. Zhao, Y. Bo, C. Ye, J. Hu, L. Zhuge, S. Ge, X. Wu, H. Ji, and J. Li, "Helicon Plasma Discharge in a Toroidal Magnetic Field of the Tokamak", IEEE Trans. Plasma Sci. 39, 3103 (2011). (pdf)
M. Nornberg, H. Ji, J.L. Peterson, and J.R. Rhoads, "A liquid metal flume for free surface magnetohydrodynamic experiments", Rev. Sci. Instru. 79, 094501 (2008). (pdf)
H. Ji, W. Fox, D. Pace, and H. Rappaport, "Study of Magnetohydrodynamic Surface Waves in Liquid Gallium", Phys. Plasmas 12, 012102 (2005). (Abstract) (pdf)

Dynamo EMF measurements, magnetic helicity conservation, fluctuation driven transport, confinement improvement in the Madison Symmetric Torus (MST), a medium-sized, toroidal reversed field pinch (RFP) device in the Department of Physics at the University of Wisconsin-Madison. Selected publications:
- K. Kemel, A. Brandenburg, and H. Ji, "Model of driven and decarying magnetic turbulence in a cylinder", Phys. Rev. E 84, 056407 (2011) (pdf)
- E. Blackman and H. Ji, "Laboratory plasma dynamos, astrophysical dynamos and magnetic helicity evolution", Monthly Notices of Royal Astronomical Society 369, 1837(2006). (pdf)
- H. Ji and S.C. Prager, "The Alpha Dynamo Effects in Laboratory Plasmas", Magnetohydrodynamics 18, 191(2002). (Abstract) (pdf)
- H. Ji, "Turbulent Dynamos and Magnetic Helicity", Phys. Rev. Lett. 83, 3198(1999). (Abstract) (pdf)
- H. Ji, A.F.Almagri, S.C.Prager, and J.S.Sarff, "Time-resolved Observation of Discrete and Continuous MHD Dynamo in the Reversed-Field Pinch Edge", Phys. Rev. Lett. 73, 668 (1994). (Abstract) (pdf)
- H. Ji et al., "Effect of Collisionality and Diamagnetism on the Plasma Dynamo", Phys. Rev. Lett. 75, 1086 (1995). (Abstract) (pdf)
- H. Ji et al., "Measurement of the dynamo effect in a plasma", Phys. Plasmas 3, 1935 (1996). (Abstract) (pdf)
- H. Ji, S.C.Prager, and J.S.Sarff, "Conservation of Magnetic Helicity during Plasma Relaxation", Phys. Rev. Lett. 74, 2945 (1995). (Abstract) (pdf)
- M.R. Stoneking et al., "Particle Transport due to Magnetic Fluctuations", Phys. Rev. Lett. 73, 549 (1994). (pdf)
- J.S. Sarff, S.A. Hokin, H. Ji, S.C.Prager, and C.R. Sovinec, "Fluctuation and Transport Reduction in a Reversed Field Pinch by Inductive Poloidal Current Drive", Phys. Rev. Lett. 72, 3670 (1994). (pdf)
Concept innovation for magnetically confined fusion plasmas in the proposed SPIRIT (Self-organized Plasmas with Induction, Reconnection, and Injection Techniques): Field Reversed Configuration (FRC) plasmas formed by counter-helicity merging of spheromaks and low-aspect-ratio Reversed Field Pinch (RFP) plasmas formed by co-helicity merging of spheromaks. Selected Publications:
- S. Gerhardt, E. Belova, M. Yamada, H. Ji, Y. Ren, B. McGeehan, M. Inomoto, "Field-reversed configuration formation scheme utilizing a spheromak and solenoid induction", Physics of Plasmas 15, 032503 (2008). (pdf)
- S. Gerhardt, E. Belova, M. Yamada, H. Ji, M. Inomoto, Y. Ren, B. McGeehan, "New method for inductively forming an oblate field reversed configuration from a spheromak". Nuclear Fusion 48, 032001 (2008). (pdf)
- S. Gerhardt, E. Belova, M. Yamada, H. Ji, M. Inomoto, C, Jacobson, R. Maqueda, B. McGeehan, Y. Ren, "Inductive sustainment of oblate field-reversed configurations with the assistance of magnetic diffusion, shaping, and finite-Larmor radius stabilization", Physics of Plasmas 15, 022503 (2008). (pdf)
- S. Gerhardt, E. Belova, M. Yamada, H. Ji, M. Inomoto, R. Ren, B. McGeehan, "Inductive Sustainment of a Field-Reversed Configuration Stabilized by Shaping, Magnetic Diffusion, and Finite-Larmor-Radius Effects", Physical Review Letters 99, 245003 (2007). (pdf)
- M. Yamada, H. Ji, S. Gerhardt, E. Belova, R. Davidson, D. Mikkelsen, "A Self-Organize Plasma with Induction, Reconnection, and Injection Techniques: the SPIRIT Concept for Field Reversed Configuration Research", Plasma Fusion Res. 2, 004 (2007). (pdf)
- S. P. Gerhardt, E. Belova, M. Inomoto, M. Yamada, H. Ji, Y. Ren, and A. Kuritsyn, "Equilibrium and stability studies of oblate field-reversed configurations in the Magnetic Reconnection Experiment", Phys. Plasmas 13, 112508 (2006) (pdf)
- H. Ji, E. Belova, S. P. Gerhardt, and M. Yamada, "Recent Advances in the SPIRIT (Self-organized Plasma with Induction, Reconnection, and Injection Techniques) Concept", J. Fusion Energy (2006) (pdf)
- Elena V. Belova, Ronald C. Davidson, Hantao Ji, and Masaaki Yamada, "Advances in the numerical modeling of field-reversed configurations", Phys. Plasmas 13, 056115 (2006).
- E.V. Belova, R.C. Davidson, H. Ji, M. Yamada, C.D. Cothran, M.R. Brown and M.J. Schaffer, "Numerical study of the formation, ion spin-up and nonlinear stability properties of field-reversed configurations", Nucl. Fusion 46, 162-170 (2006).
- E. Belova, R. Davidson, H. Ji, and M. Yamada, "Kinetic effects on the stability properties of field-reversed configurations. II. Nonlinear evolution", Phys. Plasmas 11, 2523(2004).
- E. Belova, R. Davidson, H. Ji, and M. Yamada, "Kinetic effects on the stability properties of field-reversed configurations. I. Linear stability", Phys. Plasmas 10, 2361(2003).
- E. Belova, S. Jardin, H. Ji, M. Yamada, and R. Kulsrud, "Numerical study of global stability of oblate field-reversed configurations", Phys. Plasmas 8, 1267(2001). (Abstract) (pdf)
- E. Belova, S. Jardin, H. Ji, M. Yamada, and R. Kulsrud, "Numerical study of tilt stability of prolate field-reversed configurations", Phys. Plasmas 7, 4996(2000). (Abstract) (pdf)
- A. B. Hassam, R. M. Kulsrud, R. J. Goldston, H. Ji, and M. Yamada, "Steady State Thermoelectric Field-Reversed Configurations", Phys. Rev. Lett. 83, 2969(1999). (Abstract) (pdf)
- H. Ji et al., "Studies of Global Stability of Field-reversed Configuration Plasmas Using a Rigid Body Model", Phys. Plasmas 5, 3685(1998). (Abstract) (pdf)
3D helical divertor design in the Large helical device (LHD), the world's largest stellarator being built at the National Institute for Fusion Science, Japan. Selected publications:
- N. Ohyabu, N. Noda, H. Ji et al., "Helical Divertor in the Large Helical Device", J. Nucl. Mater. 196-198, 276 (1992).
- O. Motojima et al., "Physics and Engineering Design Studies on the Large Helical Device", Fusion Eng. Design 20, 3 (1993).
- N. Ohyabu, T. Watanabe, H. Ji et al., "The Large Helical Device (LHD) Helical Divertor", Nucl. Fusion 34, 387 (1994).
Fluctuation driven transport, dynamo measurements, and anomalous ion heating in the Reversed Field Pinch University of Tokyo Experiment (REPUTE-1), a small-to-medium-sized, toroidal reversed field pinch (RFP) device at the University of Tokyo, Japan. Selected publications:
- H. Ji, H. Toyama, K. Miyamoto, S. Shinohara, and A. Fujisawa, "Fluctuation and Electron-Heat Transport in a Reversed-Field-Pinch Plasma", Phys. Rev. Lett. 67, 62 (1991). (Abstract) (pdf)
- H. Ji, H. Toyama, A. Fujisawa, S. Shinohara, and K. Miyamoto, "Fluctuation and Edge Current Sustainment in a Reversed-Field-Pinch", Phys. Rev. Lett. 69, 616 (1992). (Abstract) (pdf)
- H. Ji et al., "Probe measurements in the REPUTE-1 reversed field pinch", Rev. Sci. Instrum. 62, 2326 (1991). (pdf)
- A. Fujisawa, H. Ji et al., "Anomalous Ion Temperature and Plasma Resistance due to MHD Fluctuation in REPUTE-1 RFP Plasma", Nucl. Fusion 31, 1443 (1991). (pdf)