Plasma Zoo: Gyroresonant Scattering

Representations of electromagnetic waves of different polarizations: Right circular polarization (upper/right); Linear polarization (middle); and Left circular polarization (lower/left). Yellow arrows are the electric field, green arrows are the magnetic field. Representation of a linearly polarized wave. Yellow arrows are the electric field, green arrows are the magnetic field. Representation of a left-circularly polarized electromagnetic wave. Yellow arrows are the electric field, green arrows are the magnetic field. Representation of a right-circularly polarized electromagnetic wave. Yellow arrows are the electric field, green arrows are the magnetic field. A huge amount of our remote sensing capability depends on the light, AKA electromagnetic radiation, which we receive from distant objects. In addition to the light's wavelength and frequency (which tell us the speed of the radiation - which can be slower than 'c' in some environments), the polarization of the waves can reveal more insights on the source of the light, and the region through which it has passed.The wave polarization is determined by the direction of the electric vector (represented by yellow arrows in these visualizations). We classify electromagnetic wave polarization as linearly polarized or circularly polarized, depending on whether the electric vector maintains a fixed direction in space (linear polarization) or rotates around the direction vector (red arrows) in the case of circular polarization. Circular polarization can be classified as left-circularly polarized or right-circularly polarized. There is also elliptical polarization which can be constructed as a combination of linear, left- and right-polarized waves.For these visualizations, we define left- and right-circular polarization based on the 'Right-hand rule' (Wikipedia), determined by the motion of the electric vector at a fixed position along the wave (see Wikipedia: Circular Polarization). There is some ambiguity in these conventions, so use caution when applying. Related pages

Visualization from two camera positions of simple 2-dimensional gyro-motion of charged particles in a magnetic field. Motions of charged particles in electromagnetic fields are important in understanding the behaviors of plasmas in space. In Plasma Zoo, we present visualizations of particle motions in simple electromagnetic field configurations.Consider a magnetic field which fills a region of space with uniform intensity and direction. Here we represent that magnetic field (designated with the letter 'B') as a cyan (light green) arrow, its direction representing the direction of the field vector. One of the more fundamental motions of charged particles in a magnetic field is gyro-motion, or cyclotron motion. If a charged particle is moving in a magnetic field, the particle experiences a force perpendicular to the direction of the charge motion and the field. This direction is determined by the Right-Hand Rule (Wikipedia). In the simplest case, this curves the particle path into a circle. The direction of the force also depends on the charge of the particle, with negative particles (labelled '-') being directed in circles in a sense opposite to positive particles (labelled '+'). If we view along the direction the magnetic field is pointing, we will see that the positive particles gyrate anti-clockwise while the negative particles gyrate clockwise.In this visualization, we have two charged particles, with the same mass and speed, one positive and one negative, moving in a plane. The magnetic field is uniform and directed perpendicular to the plane.Under these conditions, we see that the two charged particles, starting out in the same direction, have their trajectories bent into circles and traverse the circular path in opposite directions.Important Note: The example here shows particles with the same speed and mass. If the masses are different (for example, a positive proton has about 1836 times more mass than an electron), the radius of the gyromotion will be proportionally larger for the same speed. Related pages

Visualization from two camera positions of simple 3-dimensional gyro-motion of charged particles in a magnetic field. Motions of charged particles in electromagnetic fields are important in understanding the behaviors of plasmas in space. In Plasma Zoo, we present visualizations of particle motions in simple electromagnetic field configurations.Consider a magnetic field which fills a region of space with uniform intensity and direction. Here we represent that magnetic field (designated with the letter 'B') as a cyan (light green) arrow, its direction representing the direction of the field vector. One of the more fundamental motions of charged particles in a magnetic field is gyro-motion, or cyclotron motion. If a charged particle is moving in a magnetic field, the particle experiences a force perpendicular to the direction of the charge motion and the field. This direction is determined by the Right-Hand Rule (Wikipedia). In the simplest case, this curves the particle path into a circle. The direction of the force also depends on the charge of the particle, with negative particles (labelled '-') being directed in circles in a sense opposite to positive particles (labelled '+'). If we view along the direction the magnetic field is pointing, we will see that the positive particles gyrate anti-clockwise while the negative particles gyrate clockwise.In this visualization, we have two charged particles, with the same mass and speed, one positive and one negative, moving in a 3-dimensional space. Similar to the resuts we see in Plasma Zoo: Gyromotion in Two Dimensions, we see that the two charged particles, starting out in the same direction, have their trajectories bent into circles and traverse the circular path in opposite directions.The magnetic field is uniform and directed perpendicular to the plane. In this case, the circular path of the particle becomes a helical path.Important Note: The example here shows particles with the same speed and mass. If the masses are different (for example, a positive proton has about 1836 times more mass than an electron), the radius of the gyromotion will be proportionally larger for the same speed. Related pages