A5058174941- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Plasma Diagnostics and Applications
- Fusion materials and technologies
- Laser-induced spectroscopy and plasma
- Magnetic Field Sensors Techniques
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Magnetic Properties of Alloys
- Metallic Glasses and Amorphous Alloys
- Superconducting Materials and Applications
- Magnetic Properties and Applications
- Earthquake Detection and Analysis
- Atomic and Molecular Physics
- Magnetic properties of thin films
- Nuclear Physics and Applications
- Dust and Plasma Wave Phenomena
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Ion-surface interactions and analysis
- Hydrogen embrittlement and corrosion behaviors in metals
- Vacuum and Plasma Arcs
Princeton Plasma Physics Laboratory
2016-2025
Tri Alpha Energy (United States)
2025
Tokyo University of Agriculture and Technology
2012-2024
Kanagawa University
2024
Hiroshima University
1983-2023
Princeton University
2010-2022
Soochow University
2022
Utah State University
2022
Japan Research Institute
2017
University of Wisconsin–Madison
1994-2016
The fundamental physics of magnetic reconnection in laboratory and space plasmas is reviewed by discussing results from theory, numerical simulations, observations satellites, recent plasma experiments. After a brief review the well-known early work, representative experimental theoretical works are discussed essence significant modern findings interpreted. In area local physics, many have been made with regard to two-fluid related cause fast reconnection. Profiles neutral sheet, Hall...
Magnetic reconnection is a topological rearrangement of magnetic field that converts energy to plasma energy. Astrophysical flares, from the Earth's magnetosphere γ-ray bursts and sawtooth crashes in laboratory plasmas, may all be powered by reconnection. Reconnection essential for dynamos large-scale restructuring known as self-organization. We review theory evidence it. emphasize recent developments two-fluid physics, experiments, observations, simulations verify effects. discuss novel...
The magnetic reconnection experiment has been constructed to investigate the fundamental physics of in a well-controlled laboratory setting. This device creates an environment satisfying criteria for magnetohydrodynamic plasma (S≫1, ρi≪L). boundary conditions can be controlled externally, and experiments with fully three-dimensional are now possible. In initial experiments, effects third vector component reconnecting fields have studied. Two distinctively different shapes neutral sheet...
Ion acceleration and direct ion heating in magnetic reconnection were experimentally observed during counterhelicity merging of two plasma toroids. Plasma ions are accelerated up to the order Alfv\'en speed through contraction reconnected field lines with three components. The significant (from 10 200 eV) is attributed conversion energy into thermal energy, agreement magnetohydrodynamic macroparticle simulations.
Experimental evidence for a positive correlation is established between the magnitude of electromagnetic fluctuations up to lower-hybrid frequency range and enhancement reconnection rates in well-controlled laboratory plasma. The belong right-hand polarized whistler wave branch, propagating obliquely reconnecting magnetic field, with phase velocity comparable relative drift electrons ions. measured short coherence lengths indicate their strongly nonlinear nature.
In this Letter we report a clear and unambiguous observation of the out-of-plane quadrupole magnetic field suggested by numerical simulations in reconnecting current sheet reconnection experiment. Measurements show that Hall effect is large collisionless regime becomes small as collisionality increases, indicating plays an important role reconnection.
Magnetic reconnection phenomena are investigated taking into account all three vector components of the magnetic field in a laboratory experiment. Two toroidal magnetized plasmas carrying identical currents and poloidal configurations made to collide, thereby inducing reconnection. The direction plays an important role merging process. It is found that antiparallel helicity merge much faster than those parallel helicity. also rate proportional initial relative velocity two plasma tori,...
This article describes the recent findings on two-fluid effects magnetic reconnection in plasmas with variable collisionality experiment (MRX) [M. Yamada et al., Phys. Plasmas 4, 1936 (1997)]. The MRX device has been upgraded to accommodate a variety of operation modes and high energy density experiments by increasing its capacitor bank extending discharge duration. As our experimental regime moved from collisional collision-free, have become more evident. It is observed that two-dimensional...
Experimental investigation of three-dimensional (3-D) effects magnetic reconnection dynamics has been extended by use axially colliding spheromaks [M. Yamada et al., Phys. Fluids B 3, 2379 (1991)]. The two toroidal shape spheromak plasmas with major radii 15–20 cm and parallel currents up to 30 kA collide merge in an external equilibrium field. It is important note that the present experimental setup allows one investigate comprehensively from both local global points view. Reconnection...
In this paper a laboratory investigation is made on magnetic reconnection in high-temperature Tokamak Fusion Test Reactor (TFTR) plasmas [Plasma Physics and Controlled Nuclear Research 1986 (International Atomic Energy Agency, Vienna, 1987), Vol. 1, p. 51]. The motional Stark effect (MSE) diagnostic employed to measure the pitch angle profile of field lines, hence q profile. An analytical expression that relates presented for toroidal plasma with circular cross section. During crash phase...
A novel method for creating the spheromak configuration has been proposed and verified experimentally. The scheme is based on a transfer of poloidal toroidal magnetic fluxes into plasma from "flux core." We present first experimental verification this quasistatic (${\ensuremath{\tau}}_{\mathrm{Alfv}\stackrel{\ifmmode\acute\else\textasciiacute\fi{}}{\mathrm{e}}\mathrm{n}}\ensuremath{\ll}{\ensuremath{\tau}}_{\mathrm{form}}<{\ensuremath{\tau}}_{\mathrm{diff}}$) formation scheme, which...
This paper reviews the progress in understanding fundamental physics of magnetic reconnection, focusing on significant results past decade from dedicated laboratory experiments, numerical simulations, and space astrophysical observations. Particularly area local reconnection physics, many important findings have been made with respect to two-fluid dynamics, profile neutral sheet, effects guide field, scaling laws collisionality. Notable global dynamics through detailed documentation...
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...
We present a detailed study of fluctuations in laboratory current sheet undergoing magnetic reconnection. The measurements reveal the presence lower-hybrid-frequency-range on edge sheets produced reconnection experiment (MRX). measured fluctuation characteristics are consistent with theoretical predictions for lower-hybrid drift instability (LHDI). Our observations suggest that LHDI turbulence alone cannot explain observed fast rate MRX.
Detailed comparisons are reported between laboratory observations of electron‐scale dissipation layers near a reconnecting X‐line and direct two‐dimensional full‐particle simulations. Many experimental features the electron layers, such as insensitivity to ion mass, reproduced by simulations; layer thickness, however, is about 3–5 times larger than predictions. Consequently, leading candidate 2D mechanism based on collisionless nongyrotropic pressure insufficient explain observed...
A lower-hybrid instability with ion cyclotron harmonics is observed to be resonantly driven by an beam injected obliquely the confining magnetic field, in agreement a linear, warm-plasma theory. Quasilinear velocity-space diffusion of observed.
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...
Two strikingly different shapes of diffusion regions are identified during magnetic reconnection in a magnetohydrodynamic laboratory plasma. The depend on the third vector component reconnecting fields. Without (antiparallel or null-helicity reconnection), thin double-Y--shaped region is identified. In this case, neutral sheet current profile accurately measured to be as narrow order ion gyro-radius. presence an appreciable (cohelicity O-shaped appears and grows into spheromak configuration.
During magnetic reconnection, a “neutral sheet” current is induced, heating the plasma. The resultant plasma thermal pressure forms stationary equilibrium with opposing fields. reconnection layer profile holds significant clues about physical mechanisms which control reconnection. In Magnetic Reconnection Experiment [M. Yamada et al., Phys. Plasmas 4, 1936 (1997)], quasi steady-state and axisymmetric neutral sheet has been measured precisely using probe array spatial resolution equal to one...