The role played by temporal asymmetry in a linearly polarized laser pulse on the acceleration of an electron in vacuum in the presence of an axial magnetic field has been investigated. The temporal shapes of the laser pulses considered here are Gaussian, positive skew (sharp rise and slow fall), and negative skew (slow rise and sharp fall). Since the pulse amplitude rises sharply in the case of positive skew, the electron experiences a strong intensity gradient during its interaction with the laser pulse, which strengthens the ponderomotive force. On the other hand, the electron experiences a gradual rise in pulse amplitude for a longer time duration in the case of negative skew. The electron energy is observed to be highest for a pulse with negative skew at low laser intensities and for a pulse with positive skew at high laser intensities. In the presence of an axial magnetic field, electron energy is observed to be highest for a pulse with positive skew at both low and high laser intensities.

中文翻译：

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存在轴向磁场的真空中激光脉冲不对称性在电子加速中的作用

已经研究了在轴向磁场存在的情况下，线偏振激光脉冲中的时间不对称性对真空中电子加速所起的作用。这里考虑的激光脉冲的时间形状是高斯、正偏斜（急剧上升和缓慢下降）和负偏斜（缓慢上升和急剧下降）。由于在正偏斜的情况下脉冲幅度急剧上升，电子在与激光脉冲相互作用过程中经历了强烈的强度梯度，从而增强了质动力。另一方面，在负偏斜的情况下，电子在较长的持续时间内经历脉冲幅度的逐渐上升。对于在低激光强度下具有负偏斜的脉冲和在高激光强度下具有正偏斜的脉冲，观察到电子能量最高。