激光驻波场中电子运动与能量分析

Analysis of electron motion and energy in laser standing wave

采用相对论Lorentz方程,数值计算了高能电子在线极化激光驻波场中的运动过程。计算结果表明,电子能量存在一个临界值,能量超过临界值的入射电子在驻波场中振荡运动的稳定平衡位置由波节变成波腹。在波腹处平行于电场入射的高能电子在强电场作用下速度和能量快速振荡,其振幅包络近似为余弦函数。而在波节处垂直于磁场入射的电子仅在Lorentz力作用下快速振荡,在穿过驻波中心前获得能量,穿过中心后失去能量,电子出射后能量均保持不变。

The motion and energy of electron in linearly polarized laser standing wave field are calculated with the relativistic Lorentz equation. The results show that there is a critical electron energy, and the balancing position of electron oscillation chan- ges from nodes to antinodes at the incident electron energy in excess of the critical energy. At the incidence of antinode plane parallel to the electric field, the high energy electron is driven by the strong electric filed and the velocity and energy of the electron has a fast oscillation with the amplitude envelope as a cosine structure. The electron, however, is driven by the Lorentz field at the incidence of the node plane vertical to the magnetic field. The electron oscillates, gaining and losing energy in front and behind the standing wave center, but keeps the energy unchanged after passing through the standing wave field.