WAVE SCATTERING AND RELATIVISTIC ELECTRON BEAM ACCELERATION AND HEATING INDUCED BY NONLINEAR LANDAU DAMPING

(1)从相对论Vlasov-Maxwell方程出发，从理论上研究了等离子体中三个或四个(十)强电磁波作用下相对论电子束通过级联非线性朗道阻尼器的加速和加热。三个或四个(十)电磁波相继发出两个或三个(九)非共振拍波驱动的相对论电子等离子体波，相速度接近于light[nu_p=c(1-gamma_P^&lt；-2&gt；)^&lt；1/2&gt；，伽马_p=omega/omega_&lt；pe&gt；]。三(九)个拍波与电子束的非线性相互作用，并将电子束加速到一个高度相对论能量的伽马_PM_EC^2，比通常的两个电磁波的非线性朗道阻尼更有效。(2)我们使用一个测试粒子研究了等离子体中两个电磁波的非线性朗道阻尼激发的拍波对电子的数值加速。这表明一些电子可以被加速到…的能量(3)从相对论Vlasov-Maxwell方程出发，导出了相对论磁化等离子体中电磁波和静电波共振波散射的动量空间扩散方程和动力学波动方程。给出了p相关扩散系数和非线性波波耦合系数的三阶张量形式，便于分析。通过动量-空间扩散方程的动量空间积分，得到了描述波与粒子之间能量和动量传递的输运方程，并用动力学波动方程中的非线性波波耦合系数表示。从动力学波动方程和输运方程出发，验证了波和粒子的总能量和动量密度守恒定律。这些方程对于理论分析输运现象或由拟线性和共振波散射引起的高能或相对论粒子的加速和产生是非常有用的。(4)从相对论Vlasov-Maxwell方程出发，从理论上研究了磁化等离子体中由低杂波的非线性朗道阻尼引起的相对论电子束的加速和加热。(5)通过对非线性波粒耦合系数的数值分析，从理论上研究了近乎垂直于磁场传播的非常波的非线性朗道衰减引起的康普顿散射对高能或相对论电子束的加速和加热。结果表明，当拍波的相速度超过电子束的速度，并且非常波的频率大于右手边截止频率时，就会产生有效的加速。(6)在电子束-等离子体系统中，我们从实验上观察到电子加热是通过朗道衰减发生的，并且产生了电子密度的径向中空分布以及径向和轴向电场。这是由静电波的准线性朗道衰减引起的等离子体电子加速引起的，被认为是聚变等离子体中观察到的反常输运现象。(7)从Valsov-Maxwell方程出发，从理论上研究了磁化等离子体中几乎垂直传播的静电波诱导的粒子沿磁场和穿过磁场的输运。这个理论能够解释托卡马克中锯齿形碰撞或边缘等离子体中的涨落引起的反常输运，托卡马克和空间等离子体中垂直离子的加速，以及在电子束-等离子体系统中观察到的电子反常输运。较少

(1) Acceleration and heating of a relativistic electron beam by cascading nonlinear Landau damping involving three or four (ten) intense electromagnetic waves in a plasma were studied theoretically based on kinetic wave equations derived from relativistic Vlasov-Maxwell equations. Three or four (ten) electromagnetic waves exite successively two or three (nine) nonresonant beat-wave-driven relativistic electron plasma waves with a phase velocity near the speed of light[nu_p=c(1-gamma_P^<-2>)^<1/2>, gamma_p=omega/omega_<pe>]. Three (nine) beat-waves interact nonlinearly with the electron beam and accelerate it to a highly relativistic energy gamma_pm_ec^2 more effectively than by the usual nonlinear Landau damping of two electromagnetic waves.(2) We used a test-particle to investigate numerically relativistic electron acceleration by the beat-wave excited by nonlinear Landau damping of two electromagnetic wave in plasma. It suggests that some electrons can be accelerated to the energy of … More -2gamma_pm_ec^2, as has been predicted theoretically.(3) The momentum-space diffusion equation and the kinetic wave equation for resonant wave-wave scattering of electromagnetic and electrostatic waves in relativistic magnetized plasma were derived from the relativistic Vlasov-Maxwell equations. The p-dependent diffusion coefficient and the nonlinear wave-wave coupling coefficient are given in terns of third-order tensors which are amenable to analysis. The transport equations describing energy and momentum transfer between waves and particles were obtained by momentum space integration of the momentum-space diffusion equation, and are expressed in terms of nonlinear wave-wave coupling coefficient in the kinetic wave equation. The conservation laws for total energy and momentum densities of waves and particles are verified from the kinetic wave equation and the transport equations. These equations are very usuful for the theoretical analysis of transport phenomena or the acceleration and generation of high-energy or relativistic particles caused by quasi-linear and resonant wave-wave scattering.(4) Acceleration and heating of a relativistic electron beam induced by nonlinear Landau damping of lower-hybrid waves in a magnetized plasma ware investigated theoretically based on kinetic wave equations and transport equations derived from relativistic Vlasov-Maxwell equations. It was proved that a relativistic electron beam can be efficiently by two lower-hybrid waves.(5) Acceleration and heating of a high-energy or relativistic electron beam due to Compton scattering induced by nonlinear Landau damping of extraordinary waves propagating almost perpendicularly to the magnetic field were investgated theoretically by numerical analysis of the nonlinear wave-particle coupling coefficients. It is verified that the efficient acceleration occurs when the phase velocity of the beat-wave exceeds the velocity of the electron beam and the frequency of the extraordinary wave is larger than the right-hand cutoff frequency. The same results were derived from the single-particle theory.(6) In an electron beam-plasma system, we observed experimentally that the electron heating occurs via Landau damping by electrostatic waves excited by nonlinear Landau damping and that the hollow radial profile of the electron density and the radial and axial electric field are produced. This is induced by the acceleration of plasma electrons due to quasilinear Landau damping of electrostatic waves and is thought to be phenomena of the anomalous transport which is observed in a fusion plasma.(7) Particle transport along and across a magnetic field and an electric field across a magnetic field which are induced by almost perpendicularly propagating electrostatic waves in a magnetized plasma have been investigated theoretically based on quasilinear transport equations derived from Valsov-Maxwell equations. This theory is capable of explaining the fluctuation-induced anomalous transport occuring in sawtooth crashes or edge plasmas in tokamaks and the perpendicular ion acceleration in tokamaks and space plasmas as well as the anomalous electron transport observed in an electron beam-plasma system. Less