Related Experiment Video
Updated: Jul 13, 2026
10:29
Experimental Methodology for Estimation of Local Heat Fluxes and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames
Published on: June 1, 2016
Temperature gradients in fast collisionless magnetic reconnection.
Emiel V van der Plas1, Hugo J de Blank
1FOM-Institute for Plasma Physics Rijnhuizen, Association Euratom-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands.
Physical Review Letters
|August 7, 2007
Summary
Temperature gradients deform magnetic islands during fast collisionless reconnection. Kinetic electron models reveal how these gradients impact plasma dynamics and magnetic field behavior.
Area of Science:
- Plasma Physics
- Astrophysics
- Magnetic Reconnection
Background:
- Collisionless magnetic reconnection is a key process in space and laboratory plasmas.
- Electron inertia plays a crucial role in decoupling plasma motion from magnetic fields during fast reconnection.
- Temperature gradients can significantly influence plasma behavior and magnetic structures.
Purpose of the Study:
- To investigate the effect of temperature gradients on magnetic islands during collisionless reconnection.
- To model the collisionless processes involving kinetic electrons in regions with varying temperatures.
- To analyze the linear and nonlinear stages of reconnecting instability using a novel surface mode model.
Main Methods:
- Development of a kinetic electron model for collisionless reconnection.
- Analytical treatment of kinetic effects in both linear and nonlinear instability stages.
- Modeling the instability as a surface mode in a current-carrying low-beta plasma slab with a strong guide field.
Main Results:
- Temperature gradients are shown to deform and shift growing magnetic islands.
- The kinetic electron model accurately describes collisionless processes during reconnection.
- Analytical results provide insights into the instability dynamics under specific plasma conditions.
Conclusions:
- Temperature gradients are a critical factor in the dynamics of magnetic islands during fast collisionless reconnection.
- Kinetic electron effects, particularly electron inertia, are essential for understanding the decoupling of plasma and magnetic fields.
- The developed surface mode model offers a new framework for studying reconnecting instabilities.
Related Concept Videos
01:28Magnetostatic Boundary Conditions
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
01:28Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:21Carrier Transport
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
01:26Divergence and Curl of Magnetic Field
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
01:25Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:27Gradient Fields
A gradient field is a vector field derived from a scalar field. A scalar field assigns a single numerical value to every point in space, such as temperature, pressure, or electric potential. The gradient field describes how that value changes from point to point. It gives both the direction of the fastest increase and the rate of change in that direction.For a scalar field f(x, y), the gradient is written as\begin{equation*}\nabla f=\left\langle \jfrac{\partial f}{\partial x},\jfrac{\partial...