Plasma typically consists of neutral particles, positively charged atoms (ions) and negatively electrons. Negatively charged atoms (ions) are observed more rarely.
The forces between charged particles forms the basics of plasma physics.
When a charged particle (positive ion or negative electron) moves, it creates a circular magnetic field within a plane perpendicular to its direction of movement and an electrostatic field parallel to its direction of movement. Often the first step in analyzing a moving charged particle is to draw the magnetic field lines using the "right hand rule."
To perform the right hand rule, point your thumb in the direction of travel of a positively charged proton or other ion, curl your fingers in a circular direction around the proton particle. Your fingers should point in the direction of the magnetic field lines around the proton from north to south. For electronics, you would point your thumb in the direction of conventional current flow (opposite to electron flow) and curl your fingers around the wire/conductor. Your fingers would again point in the direction of the magnetic field lines from north to south magnetic poles. For a negatively charged electron or other particle, you would need to point your thumb in the OPPOSITE direction to its movement to find the direction of magnetic field lines.
As can be seen by the right hand rule, the flow of charged particles will therefore create a circular magnetic field around the particles. Conversely, a circular magnetic field around a particle will create movement of the charged particle. The force created by the magnetic field around a group of charged particles traveling in parallel or anti-parallel is called an electrostatic force.
Using the right hand rule, it can be easily discerned that a positively charged particle (proton) will produce magnetic field lines that would appear circular and clockwise when the proton travels away from an observer. An electron would produce a magnetic field that would appear circular and counter-clockwise when the electron travels away from an observer.
If particles of the same charge move in a parallel direction but are oriented perpendicular to each other, their magnetic field lines would be pointing in the same direction (both clockwise or both counter-clockwise) and would combine, causing an attractive force between them. Conversely, if the magnetic field lines are pointing in opposite directions, the forces would be repulsive between them.
Electrostatic fields and electrostatic forces are created by the sharing of the the energy in magnetic fields when particles are traveling along the same linear paths in a parallel or anti-parallel direction. This "sharing" of magnetic field energy causes the particles to resist a change in current flow (inductance). Although both magnetic forces and electrostatic forces are derived from the energy in the magnetic field, they behave differently and always labeled as different forces and fields.
The energy in a magnetic field is proportional to charge and velocity of the moving particles. The faster a charged particle moves and the higher its charge, the greater magnetic field strength. The momentum of higher mass particles (protons, positive ions) will better maintain their velocity and thus magnetic field strength compared to lower mass particles (electrons). Higher mass (usually positively charged) particles therefore play a much greater role in maintaining current flow. In a wire, the positive charged atoms are bound to the wire, so the movement and velocity of the electrons would be proportional to the magnetic field strength. In plasma in space, both electrons and protons are free to move and typically move in opposite directions along magnetically confined filaments when they share similarly oriented magnetic fields.
When a proton or positively charged particle accelerates, it will induce an acceleration of an electron in the opposite direction.
Conversely, if a positively charged atom or proton decelerates, it will cause the oppositely charged
electrons to decelerate.
In a positively charged rotating structure, the positively charged ions rotate in one direction and electrostatic forces will cause electrons to rotate in the opposite direction.
In a rotating cloud of gas or dust, magnetic forces hold the structure together and cause it to rotate more closely to a solid structure. The particles in the outer layers will have a higher velocity than particles in the inner layers. The higher velocity of particles in the outer layers creates a greater magnetic field there, causing electrons to be pulled to the outer layers. While electrostatic forces in a positively charged rotating body propel electrons in a circular direction, magnetic forces propel electrons radially outward.
Gas or dust in space will slowly coalesce due to gravity to form large clouds or nebula. There
will always be some rotational momentum imparted as fast-moving atoms race toward each other due mostly to gravitational attraction. Under gravitational attraction, vibration of gas particles will keep them separated at distances proportional to their temperature with cooler particles closer together.
The electric current generated by the rotating and positively charged cloud of gas and dust will cause magnetic fields that compress the gas/dust into a long cylinder shape. Rotation velocities and rotational axes of the gas/dust along the cylinder will not be uniform, causing momentum, magnetic and electrostatic forces that break the cylinder into rotating segments that are shaped like discs or pancakes. The central rotational axis of each disc-like structure will be positively charged and attract electrons.
When several disc-like structures form along a massive cloud of gas and dust, the larger structure often evolves into the "parent" galaxy and the smaller structures are typically called "quasars." The parent galaxy will have a strong positively charged central core, pulling in electrons and emitting positively charged ions.
As explained earlier, electrostatic forces on electrons in a rotating body cause them to be propelled in a circular direction, opposite of the movement of the positively charged particles. The magnetic forces push the electrons radially outward. The resultant direction of the combined magnetic and electrostatic forces is diagonal outward.
The diagonally directed outward movement of electrons creates a magnetic field that organizes material into spiral shaped arms.
A similar phenomenon of electron acceleration can be seen in a cyclotron where the electrons flow in a spiral pattern outward from the rotational axis and are ejected at the outward edge.
The electrons that are ejected from the spiral arms of a galaxy may continue traveling into space or take a looping path back toward the positively charged central core of the galaxy.
Parent galaxies with quasars can have a more complicated electron current flow since the larger parent galaxy's positively charged rotational axis will attract electrons from the quasars.
