Ramsey D, Malaca B, Di Piazza A, Formanek M, Franke P, Froula D H, Pardal M, Simpson T T, Vieira J, Weichman K, Palastro J P
Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal.
Phys Rev E. 2022 Jun;105(6-2):065201. doi: 10.1103/PhysRevE.105.065201.
In nonlinear Thomson scattering, a relativistic electron reradiates the photons of a laser pulse, converting optical light to x rays or beyond. While this extreme frequency conversion offers a promising source for probing high-energy-density materials and driving uncharted regimes of nonlinear quantum electrodynamics, conventional nonlinear Thomson scattering has inherent trade-offs in its scaling with laser intensity. Here we discover that the ponderomotive control afforded by spatiotemporal pulse shaping enables regimes of nonlinear Thomson scattering that substantially enhance the scaling of the radiated power, emission angle, and frequency with laser intensity. By appropriately setting the velocity of the intensity peak, a spatiotemporally shaped pulse can increase the power radiated by orders of magnitude. The enhanced scaling with laser intensity allows for operation at significantly lower electron energies or intensities.
在非线性汤姆逊散射中，相对论电子重新辐射激光脉冲的光子，将光转换为X射线或更高频率的射线。虽然这种极端的频率转换为探测高能量密度材料和驱动非线性量子电动力学的未知领域提供了一个有前景的光源，但传统的非线性汤姆逊散射在与激光强度的比例关系上存在固有的权衡。在这里，我们发现时空脉冲整形所提供的有质动力控制能够实现非线性汤姆逊散射的模式，从而显著增强辐射功率、发射角和频率与激光强度的比例关系。通过适当地设置强度峰值的速度，一个时空整形的脉冲可以将辐射功率提高几个数量级。与激光强度增强的比例关系允许在显著更低的电子能量或强度下运行。
