S.H. Kim

Bio: S.H. Kim is an academic researcher from Hanyang University. The author has contributed to research in topics: Magnetic field & Plasma modeling. The author has an hindex of 1, co-authored 1 publications receiving 6 citations.

Heating of and force acting on the electrons of the magnetic plasma by the electromagnetic wave

Abstract: The heating and force acting on the electrons of the magnetic plasma by the externally launched electromagnetic wave are considered. The quantum-mechanically extended Vlasov equation is first derived to include the collisionless inverse bremsstrahlung due to the turbulence induced by the electromagnetic field, and then a quasilinear equation is derived from this quantum-mechanically extended Vlasov equation to consider properly the electron velocity-space diffusion by the turbulence. The heating rate and the force acting on the electrons are explicitly expressed in the forms of hydrodynamic energy and momentum equations derived from the quasilinear equation. Both quantities are shown to be due to (i) the inverse bremsstrahlung and (ii) the Landau and cyclotron damping of the turbulence induced by the electromagnetic wave.

The Vlasov equation and the description of inverse bremsstrahlung

Abstract: It is shown that the Vlasov equation based on the Lorentz force equation does not describe inverse bremsstrahlung since the force by inverse bremsstrahlung is not included in the Lorentz force equation. It is also shown that quasilinear theory based on the classical Vlasov equation can adequately explain inverse bremsstrahlung.

The net force acting on relativistic electrons caused by net inverse bremsstrahlung in a plasma wave

Abstract: The net force acting on relativistic electrons in a laser-irradiated plasma is calculated by using both the pure classical electrodynamics and quantum mechanics. It is shown that the net force, averaged over the electron distribution, calculated by classical electrodynamics is zero, while that by quantum mechanics can exceed the oscillating Lorentz force of the laser wave when the electron energy is large and the momentum spread of the beam is properly controlled. We attribute it to the fact that inverse bremsstrahlung is not included in classical electrodynamics.

Electron cyclotron masing and the force due to net stimulated bremsstrahlung in an electron cyclotron maser using a dilute non-relativistic electron beam

Abstract: The amplification of an electromagnetic wave by net stimulated bremsstrahlung (the emission by stimulated bremsstrahlung minus the absorption by inverse bremsstrahlung) injected into a non-relativistic dilute electron beam travelling in a uniform magnetic field is considered. The d.c. ponderomotive force by net stimulated emission is calculated by using quantum kinetics. From the calculated ponderomotive force, the amplification of the intensity of the electromagnetic wave by the net stimulated bremsstrahlung is derived as a function of the relevant parameters of the electromagnetic wave and the electron beam. It is found that masing is possible when the perpendicular temperature of the electron beam is greater than its parallel temperature. It is shown that the efficiency of a practical gyrotron cannot be explained by the phase-bunching concept, and that simulated bremsstrahlung has nothing to do with any phase bunching.