The effect of beam waist radius on the radiation properties of electrons in the presence or absence of an applied magnetic field is comparatively investigated when Gaussian circularly polarized laser pulse drives electrons for relativistic nonlinear Thomson forward scattering. This effect will be investigated in terms of the electrodynamic properties of high-energy electrons, the full-angular distribution of radiated power and the spectral properties. We study the coupling effect of the crossover parameter, the applied magnetic field and the beam waist radius. Based on theoretical analyses and numerical calculations, we find that the various radiation properties at different beam waist radii are consistent. And there always exists an optimal beam waist radius, which makes the stimulated radiation of high-energy electrons high-power, highly-collimated, well-directed, wide-frequency-domain, and super-continuous, when Gaussian laser drives the electron oscillating. Moreover, we found that the radiation properties are significantly improved in all directions when an applied magnetic field is introduced. Accordingly, we select the optimal beam radius on the basis of the applied magnetic field. After numerical simulations, we developed a modulation method for \(X\)-rays with optimal radiation properties. The above study is a pioneering guide for modulation of \(X\)-rays in optical laboratories.

比较研究了高斯圆偏振激光脉冲驱动电子进行相对论性非线性汤姆逊前向散射时，在存在或不存在外加磁场的情况下束腰半径对电子辐射特性的影响。将从高能电子的电动力学特性、辐射功率的全角分布和光谱特性方面研究这种效应。我们研究了交叉参数、外加磁场和束腰半径的耦合效应。基于理论分析和数值计算，我们发现不同束腰半径下的各种辐射特性是一致的。并且总存在一个最佳束腰半径，使得高斯激光驱动电子振荡时，高能电子的受激辐射具有高功率、高准直、定向性好、宽频域、超连续的特点。 。此外，我们发现，当引入外加磁场时，各个方向的辐射性能均得到显着改善。因此，我们根据所施加的磁场选择最佳光束半径。经过数值模拟，我们开发了一种具有最佳辐射特性的X射线调制方法。上述研究为光学实验室中\(X\)射线的调制提供了开创性的指导。