A5047581227- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Magnetic confinement fusion research
- Geomagnetism and Paleomagnetism Studies
- Plasma Diagnostics and Applications
- Magnetic Field Sensors Techniques
- Astro and Planetary Science
- Laser-induced spectroscopy and plasma
- Magnetic Properties and Applications
- Earthquake Detection and Analysis
- Magnetic Bearings and Levitation Dynamics
- Geophysics and Gravity Measurements
- Non-Destructive Testing Techniques
- Electron and X-Ray Spectroscopy Techniques
- Fusion materials and technologies
- Atomic and Subatomic Physics Research
- Magnetic Properties of Alloys
- Particle accelerators and beam dynamics
- Ion-surface interactions and analysis
- Magnetic properties of thin films
- Atomic and Molecular Physics
- Electrochemical Analysis and Applications
- Vacuum and Plasma Arcs
- Advanced MRI Techniques and Applications
- Geophysics and Sensor Technology
Princeton Plasma Physics Laboratory
2016-2025
Princeton University
2013-2023
Soochow University
2021-2022
Utah State University
2022
Pohang University of Science and Technology
2007
Korea Advanced Institute of Science and Technology
2003
The lower hybrid drift wave (LHDW) has been a candidate for anomalous resistivity and electron heating inside the diffusion region of magnetic reconnection. In laboratory reconnection layer with finite guide field, quasielectrostatic LHDW (ES-LHDW) propagating along direction nearly perpendicular to local field is excited in region. ES-LHDW generates large density fluctuations ($\ensuremath{\delta}{n}_{\mathrm{e}}$, about 25% mean density) that are correlated out-of-plane electric...
The ion dynamics in a collisionless magnetic reconnection layer are studied laboratory plasma. measured in-plane plasma potential profile, which is established by electrons accelerated around the electron diffusion region, shows saddle-shaped structure that wider and deeper towards outflow direction. This ballistically accelerates ions near separatrices toward Ions heated as they travel into high-pressure downstream region.
Magnetic reconnection is a fundamental process at work in laboratory, space, and astrophysical plasmas, which magnetic field lines change their topology convert energy to plasma particles by acceleration heating. One of the most important problems research has been understand why occurs so much faster than predicted magnetohydrodynamics theory. Following recent pedagogical review this subject [Yamada et al., Rev. Mod. Phys. 82, 603 (2010)], paper presents more discoveries findings fast...
Magnetic reconnection has been observed in the transition region of quasi-parallel shocks. In this work, particle-in-cell method is used to simulate three-dimensional a shock. The shock turbulent, leading formation reconnecting current sheets with various orientations. Two sites weak and strong guide fields are studied, it shown that fast transient. Reconnection characterized using diagnostics including electron flows magnetic flux transport. contrast two-dimensional simulations, field...
Use of a large-area liquid lithium limiter in the CDX-U tokamak produced largest relative increase (an enhancement factor 5–10) Ohmic confinement ever observed. The results from do not agree with existing scaling laws, and cannot easily be projected to new experiment (LTX). Numerical simulations low recycling discharges have now been performed ASTRA-ESC code special reference transport model suitable for diffusion-based regime, incorporating boundary conditions nonrecycling walls, fuelling...
Impulsive, local, 3‐D reconnection is identified for the first time in a laboratory current sheet. The events observed Magnetic Reconnection Experiment are characterized by large local gradients third direction and cannot be explained 2‐D models. Detailed measurements show that ejection of flux rope structures from sheet plays key role these events. By contrast, even though electromagnetic fluctuations lower hybrid frequency range also concurrently with impulsive behavior, they not physics...
Bulk ion acceleration and particle heating during magnetic reconnection are studied in the collisionless plasma of Magnetic Reconnection Experiment (MRX). The is two-fluid regime, where motion ions decoupled from that electrons within diffusion region. process here quasi-symmetric since parameters such as magnitude reconnecting field, density, temperature compatible on each side current sheet. Our experimental data show in-plane (Hall) electric field plays a key role acceleration....
The effects of a density asymmetry across the current sheet on anti-parallel magnetic reconnection are studied systematically in laboratory plasma. Despite significant ratio up to 10, in-plane field profile is not significantly changed. On other hand, out-of-plane Hall considerably modified; it almost bipolar structure with asymmetry, as compared quadrupolar symmetric configuration. Moreover, ion stagnation point shifted low-density side, and electrostatic potential also becomes asymmetric...
We report detailed laboratory observations of the structure a reconnection current sheet in two-fluid plasma regime with guide magnetic field. observe and quantitatively analyze quadrupolar electron pressure variation ion-diffusion region, as originally predicted by extended magnetohydrodynamics simulations. The projection gradient parallel to field contributes significantly balancing electric field, resulting cross-field jets layer are diamagnetic origin. These results demonstrate how...
While the most important feature of magnetic reconnection is that it energizes plasma particles by converting energy to particle energy, exact mechanisms which this happens are yet be determined despite a long history research. Recently, we have reported our results on conversion and partitioning in laboratory layer short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper detailed elaboration report together with an additional dataset different boundary sizes. Our...
The spontaneous formation of plasmoids via the resistive electron tearing a reconnecting current sheet is observed in laboratory. These experiments are performed during driven, antiparallel reconnection two-fluid regime within Magnetic Reconnection Experiment. It found that present even at very low Lundquist number, and number scales with both aspect ratio number. electric field increases when formed, leading to an enhanced rate.
The magnetic reconnection experiment has recently seen short wavelength ( k ρ e ∼ 1) lower-hybrid waves near the electron diffusion region in strong guide field reconnection. Based on plasma parameters from experiment, we perform a three-dimensional fully kinetic simulation order to investigate generation of and their effects process. We find that low-beta regions around site are unstable drift instability propagating outflow direction, driven by difference between ion outflows. modify...
We review the theory of magnetic reconnection in weakly ionized gases. The is relevant to interstellar medium, protostellar and protoplanetary disks, outer envelopes cool stars, a new laboratory experiment. In general, partial ionization introduces three effects beyond obvious one: increased resistivity due electron-neutral collisions. First, neutral sheets are steepened by plasma-neutral drift, setting up conditions for reconnection. Second, when ion-neutral friction strong, effective ion...
We present laboratory measurements showing the two-dimensional (2D) structure of energy conversion during magnetic reconnection with a guide field over electron and ion diffusion regions, resolving separate deposition on electrons ions. find that are energized by parallel electric at two locations, $X$ line around separatrices. On other hand, ions ballistically perpendicular in vicinity high-density An balance calculation evaluating terms Poynting theorem shows 40% is converted to particle...
Abstract We investigate properties of lower hybrid drift waves (LHDWs) near and inside the electron diffusion regions in 17 magnetopause 9 magnetotail reconnection events using Magnetospheric MultiScale (MMS) mission observations. Our analysis show that LHDW type depend on beta, as beta increases LHDWs become more electromagnetic nature. The energy transfer from fields to particles is higher electrostatic it largely parallel direction with respect local magnetic field. Linear dispersion...
The effect of guide field on magnetic reconnection is quantitatively studied by systematically varying an applied in the Magnetic Reconnection Experiment (MRX). quadrupole field, a signature two-fluid at zero altered finite field. It shown that rate significantly reduced with increasing and this dependence explained combination local global physics: locally, in-plane Hall currents are reduced, while globally compression produces increased pressure both within downstream region.
Magnetic reconnection is a fundamental process in magnetized plasma where magnetic energy converted to energy. Despite huge differences the physical size of layer, remarkably similar characteristics are observed both laboratory and magnetosphere plasmas. Here we present comparative study dynamics mechanisms governing conversion space context two-fluid physics, aided by numerical simulations. In strongly asymmetric layers with negligible guide field, deposition electrons found primarily occur...
Abstract Generation and propagation of lower hybrid drift wave (LHDW) near the electron diffusion region (EDR) during guide field reconnection at magnetopause is studied with data from Magnetospheric Multiscale mission a theoretical model. Inside current sheet, beta ( β e ) determines which type LHDW excited. EDR, where high ∼ 5 ), long‐wavelength electromagnetic observed propagating obliquely to local magnetic field. In contrast, short‐wavelength electrostatic LHDW, nearly perpendicular...
Abstract Whistler wave generation near the magnetospheric separatrix during reconnection at dayside magnetopause is studied with data from Magnetospheric Multiscale mission. The dispersion relation of whistler mode measured for first time region in space, which shows that waves propagate nearly parallel to magnetic field line. A linear analysis indicates are generated by temperature anisotropy electron tail population. This caused loss electrons a high velocity exhaust region. There positive...
The loss-of-equilibrium is a solar eruption mechanism whereby sudden breakdown of the magnetohydrodynamic force balance in Sun's corona ejects massive burst particles and energy into heliosphere. Predicting loss-of-equilibrium, which has more recently been formulated as torus instability, relies on detailed understanding various forces that hold pre-eruption magnetic flux rope equilibrium. Traditionally, idealized analytical expressions are used to derive simplified criteria can be compared...