Piovella N, Cola M M, Volpe L, Schiavi A, Bonifacio R
Dipartimento di Fisica, Università Degli Studi di Milano, via Celoria 16, I-20133 Milano, Italy.
Phys Rev Lett. 2008 Feb 1;100(4):044801. doi: 10.1103/PhysRevLett.100.044801. Epub 2008 Jan 29.
A free-electron laser (FEL) operating in the quantum regime can provide a compact and monochromatic x-ray source. Here we present the complete quantum model for a FEL with a laser wiggler in three spatial dimensions, based on a discrete Wigner-function formalism taking into account the longitudinal momentum quantization. The model describes the complete spatial and temporal evolution of the electron and radiation beams, including diffraction, propagation, laser wiggler profile and emittance effects. The transverse motion is described in a suitable classical limit, since the typical beam emittance values are much larger than the Compton wavelength quantum limit. In this approximation we derive an equation for the Wigner function which reduces to the three-dimensional Vlasov equation in the complete classical limit. Preliminary numerical results are presented together with parameters for a possible experiment.
工作在量子 regime 的自由电子激光器（FEL）能够提供一个紧凑且单色的 X 射线源。在此，我们基于离散维格纳函数形式主义并考虑纵向动量量子化，给出了一个在三维空间中带有激光摆动器的 FEL 的完整量子模型。该模型描述了电子束和辐射束完整的空间与时间演化，包括衍射、传播、激光摆动器轮廓和发射度效应。由于典型的束发射度值远大于康普顿波长量子极限，横向运动在一个合适的经典极限下进行描述。在这种近似下，我们推导了一个维格纳函数方程，该方程在完全经典极限下简化为三维弗拉索夫方程。给出了初步的数值结果以及一个可能实验的参数。
