Study Of Relativistic Two-stream Instability In Unmagnetized Plasma

The two-stream instability is an electrostatic instability of plasma, the energy which caused the instability comes from kinetic energy of the beam. When a beam of energetic electrons propagate into the plasma, it will produce a return stream to make the total current less than the Alfven critical current, if there are perturbations parallel to the beams velocity direction, it can feed the two-stream instability. As an important problem in the plasma physics, it has been investigated deeply. In this paper, we have study the relativistic two-stream instability in the unmagnetized plasma. The main question is formed as the following two parts:First, based on a set of the complete covariant relativistic electromagnetic fluid equations, we derived out the dispersion relation expression of the relativistic electrostatic two-stream instability caused by the cold electron beam, in the unmagnetized plasma. Using the numerical solution method, we obtained the relationship between the instability growth rate and various parameters and the existent region of the instability. These results may be a new mechanism for anomalous ion heating, also can good for explaining the cosmic rays and the intense release of electromagnetic radiation by gamma ray bursts, as well as the Earth bow shock.Second, the same as the preceding chapter, based on a set of the complete covariant relativistic electromagnetic fluid equations, we discussed the electrostatic two-stream instability when the relativistic hot beam transport in the unmagnetized plasma, then, obtained the analytical expression of the dispersion relation. By numerical calculation, we studied the relationship between the instability growth rate and the existent region of the instability and the parameters of beam thermal pressure、density、Lorenz factor. These results are useful for us to study the magnetic confinement fusion and the fast electron propagation in fast ignition physics, also be important for understanding the solar type III bursts in coronal region.