简谐近似与晶体摆动场辐射的一般特征

晶体摆动场辐射的能量很高,是获得短波长激光的重要途径之一。关键问题是如何提高摆动场辐射强度,如何将摆动场辐射与沟道辐射分离,将摆动场辐射中的相干辐射与自发辐射分离。首先,在经典力学框架内和线性近似下,讨论了摆动场辐射的瞬时辐射强度和平均辐射强度;引入无量纲偏转角讨论了这两种辐射的强度比、频率比和相干性。结果表明,在无量纲偏转角大于大于1时,只需在束流方向上放置一个张角为Δθ≈γ-1的接受器就可以将相干的摆动场辐射成功收集,而这时两种辐射的频率比和强度比都很大。

Harmonic Approximation and General Characteristics for Crystalline Undulator Field Radiation

With high energy,the crystalline undulator field radiation is one of the important ways for obtaining short-wavelength laser.But the problems of how to improve the intensity of the radiation field,how to separate the undulator field radiation from the channeling radiation,and how to separate the coherent radiation from the spontaneous radiation in the undulator field radiation should be considered.In this paper,first,within the framework of classical mechanics and linear approximation,the instantaneous radiation intensity and average radiation intensity of undulator field radiation are discussed.Then by introducing the dimensionless deflection angle,the intensity ratio,frequency ratio and coherence of the both radiation are discussed.The results show that if the dimensionless deflection angle is,only by placing the receiver with the angle width of along the beam direction,the undulator field radiation can be successfully collected;meanwhile both the frequency ratio and the intensity ratio are larger.