What is guiding center in plasma?
In physics, the motion of an electrically charged particle such as an electron or ion in a plasma in a magnetic field can be treated as the superposition of a relatively fast circular motion around a point called the guiding center and a relatively slow drift of this point.
What is E * B drift?
This is called E-cross-B drift, sometimes written ExB drift from the mathematical notation. To understand why this is, consider just the motion of the positive particle. Eventually, the curving of the path redirects the positive particle so it is moving in a direction opposite the electric field.
What is polarization drift?
This force gives rise to an inertial drift and to a corresponding drift current. An especially important case, in which acceleration results from a change in the rate of electrical drift, is caused by variations in the electric field. This particular case of inertial drift is therefore called the polarization drift.
What is curvature drift?
Curvature drift is a mode of motion of charged particles in a curved magnetic field. In contrast to the motion of charged particles in a uniform magnetic field, where the charged particles gyrate around the magnetic fields, in curvature drift the particles move mostly parallel to the magnetic field.
What is meant by cyclotron frequency?
The cyclotron frequency or gyrofrequency is the frequency of a charged particle moving perpendicular to the direction of a uniform magnetic field B (constant magnitude and direction). Since that motion is always circular, the cyclotron frequency is given by equality of centripetal force and magnetic Lorentz force.
What is B in F qvB?
The magnetic field B is defined from the Lorentz Force Law, and specifically from the magnetic force on a moving charge: The magnitude of the force is F = qvB sinθ where θ is the angle < 180 degrees between the velocity and the magnetic field.
What is particle drift?
Particle or droplet drift occurs during or soon after the application. ‘Particle’ means the active ingredient of a pesticide as a liquid (spray droplet), granule, pellet, dust, fumigant, etc. Small droplets are more likely to drift than larger droplets.
What is meant by radius of curvature?
In differential geometry, the radius of curvature, R, is the reciprocal of the curvature. For a curve, it equals the radius of the circular arc which best approximates the curve at that point. For surfaces, the radius of curvature is the radius of a circle that best fits a normal section or combinations thereof.
What is the use of cyclotron frequency?
The cyclotron frequency is also useful in non-uniform magnetic fields, in which (assuming slow variation of magnitude of the magnetic field) the movement is approximately helical – in the direction parallel to the magnetic field, the motion is uniform, whereas in the plane perpendicular to the magnetic field the …
How do you calculate cyclotron frequency?
The cyclotron frequency of this circular motion is ω c = q B / m and the cyclotron radius is r c = m v ⊥ / q B . Here v⊥ is the magnitude of the particle velocity perpendicular (⊥) to the magnetic field direction.
What will cause a magnetized nail to demagnetize?
To demagnetize a nail magnetized by prolonged contact or rubbing, banging the nail on a hard surface or dropping it to the floor shakes up the aligned atoms with sharp impact. For the electromagnet, simply detaching one end of the copper wire from its terminal kills the magnetic field.
Can a pressure gradient cause a guiding center drift?
Diamagnetic drift The diamagnetic drift is not actually a guiding center drift. A pressure gradient does not cause any single particle to drift. Nevertheless, the fluid velocity is defined by counting the particles moving through a reference area, and a pressure gradient results in more particles in one direction than in the other.
How is the magnetic mirror related to guiding center?
If the field has a parallel gradient, a particle with a finite Larmor radius will also experience a force in the direction away from the larger magnetic field. This effect is known as the magnetic mirror. While it is closely related to guiding center drifts in its physics and mathematics, it is nevertheless considered to be distinct from them.
How is guiding center related to magnetic drift?
While it is closely related to guiding center drifts in its physics and mathematics, it is nevertheless considered to be distinct from them. Generally speaking, when there is a force on the particles perpendicular to the magnetic field, then they drift in a direction perpendicular to both the force and the field. If v → f = 1 q F → × B → B 2 .
