Laser chirping in inverse Compton sources at high electron beam energies and high laser intensities
Laser chirping in inverse Compton sources at high electron beam energies and high laser intensities
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DOI：
10.1103/physrevaccelbeams.24.094401
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发表时间：
2021-09
影响因子：
1.7
通讯作者：
B. Terzić;J. McKaig;E. Johnson;T. Dharanikota;G. Krafft
中科院分区：
文献类型：
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作者：
B. Terzić;J. McKaig;E. Johnson;T. Dharanikota;G. Krafft
非线性效应的发生，如有质动力加宽，增加了辐射带宽，从而对逆康普顿源中使用的激光强度施加了严格的限制。最近，我们已经表明，一个明智的纵向激光频率调制（“啁啾”）可以完美地补偿这种有质动力加宽，并恢复散射辐射的窄带特性在汤姆逊制度，当电子反冲碰撞过程中与激光可以忽略不计。因此，使用QED，激光啁啾已被扩展到康普顿制度，其中电子反冲被适当占。在这里，我们提出了一个新的，半经典模型计算散射光谱的康普顿制度。我们还得到了一个全面推广的表达式啁啾处方线偏振激光脉冲在一维平面波近似与任意形状和任意散射角的康普顿制度。我们使用这些新的表达式表明，高的激光场和高的电子束能量（非线性康普顿制度）的源的高阶谐波将非线性红移相比，较低的光束能量（汤姆逊制度）。啁啾处方将用于校正非常高的谐波中的有质动力加宽。
The onset of nonlinear effects, such as ponderomotive broadening, increases the radiation bandwidth and thereby places a stringent limitation on the laser intensity used in inverse Compton sources. Recently, we have shown that a judicious longitudinal laser frequency modulation (“chirping”) can perfectly compensate for this ponderomotive broadening and restore the narrow band property of scattered radiation in the Thomson regime, when electron recoil during the collision with the laser can be neglected. Consequently, using QED, the laser chirping has been extended to the Compton regime, where electron recoil is properly accounted for. Here we present a new, semiclassical model for computation of scattered spectra in the Compton regime. We also derive a comprehensive generalization of the expressions for chirping prescription for linearly polarized laser pulses in 1D plane-wave approximation with arbitrary shapes and arbitrary scattering angle in the Compton regime. We use these new expressions to show that the higher-order harmonics in sources with high laser fields and high electron beam energies (nonlinear Compton regime) will be nonlinearly redshifted when compared to those with lower beam energies (Thomson regime). The chirping prescription will act to correct ponderomotive broadening in very high harmonics.