相对论性冷电子束流静电双流不稳定性

Theoretical study of electrostatic two-stream instability on cold relativistic electron beams

激光核聚变的"快点火"过程中高能电子的产生会引起相对论性静电双流不稳定性,它对相对论性电子的传输和能量沉积有重要影响。从完全协变相对论性电磁流体力学方程出发,研究了相对论性冷电子束流激发的静电双流不稳定性。研究表明,快电子束流速度越大,对不稳定的增长率和不稳定区域的抑制性越强,即相对论性越强,越能抑制双流不稳定性的产生;而快电子束密度越大,越易于引发双流不稳定性;随着快电子束流速度以及束流密度的增大,不稳定性最大增长率都向小波数区域移动。

The relativistic electrostatic two-stream instability can take place in the fast ignition process of in- ertial confinement fusion, which has an important influence on the fast electron propagation and energy deposition. From the full covariant relativistic hydrodynamic equations of electromagnetism,the relativistic electrostatic two-stream instability has been investigated both （delete） analytically and numerically. The dispersion relation for cold relativistic electron beams was derived. The numerical results indicated that a- long with the fast-electron beam density increasing,the electron two-stream instability growth rate would become larger,while the unstable range would become smaller and shift to the smaller wave number re- gion. By contrast, as the speed of fast stream increases, the growth rate and unstable region decrease. In brief, the two-stream instability is restrained.