Kinetic Alfvén waves in a deuterium-tritium fusion plasma with slowing-down distributed α-particles

The dispersion relation and damping rate of kinetic Alfvén waves (KAWs) in a deuterium-tritium fusion plasma with slowing-down distributed $\alpha$-particles are investigated using the kinetic theory. The variations of wave frequency and damping rate with respect to the $\alpha$ concentration (${n_{\alpha}/n_{\rm e}}$) and perpendicular wave number (${k_ \bot }$) are studied from a numerical way. The results show that the fluctuation of $\alpha$ concentration slightly affects the frequency and damping rate of KAWs at low ${n_{\alpha}/n_{\rm e}}$. In addition, the frequency and the damping rate increase as the ${k_ \bot}$ and the background temperature ${T_{\rm e}}$ increase. For comparison, the calculations are performed also in the case of $\alpha$-particles following an equivalent Maxwellian distribution. For a given ${k_ \bot }$, the value of the frequency obtained in the slowing-down distribution case is smaller than that obtained in the Maxwellian distribution case. Conversely, the value of the damping rate obtained in the slowing-down distribution case is slightly larger than that obtained in the Maxwellian distribution case.     

线性偏振激光在相对论等离子体中的调制不稳定性

 从相对论等离体中电磁波的非线性色散方程出发,利用Karpman方法获得了线性偏振波模所满足的非线性控制方程,在非线性色散方程和非线性控制方程的基础上对线性偏振激光在相对论等离体中传播的调制不稳定性进行分析,给出了调制不稳定的时间增长率与扰动态波数之间的函数关系。