晶体摆动场的辐射衰减与能量增益

由于晶体弯曲、电子多重散射和晶格热振动引起的粒子退道,辐射同原子相互作用引起的电离损失,以及系统非线性引起的全局分叉与混沌行为等,晶体摆动场辐射面临的问题比自由电子激光要复杂得多。首先,引入晶体摆动场自发辐射谱分布,并在简谐近似下讨论了运动方程、系统增益和能量衰减。结果表明:一般情况下辐射谱只有少数几条谱线,而在简谐近似下,谱线只有一条。其次,指出了辐射能量比较高时,衰减是主要的,选择的晶体长度必须小于衰减长度,且可选择正电子或质子作炮弹;当辐射能量比较低时,退道是主要的,选择的晶体长度必须小于退道长度,且可选择重离子作炮弹。

The Radiation Attenuation and Energy Gain for Crystallie Undulator Field

The problem included in the crystalline undulator field radiation is complex and more the free electron laser because of the dechanneling effect by the crystal bend,the electron multi-scattering and the thermal oscillation of the lattice, the ionization loss by an interaction between the radiation with an atom, the global bifurcation and the chaotic behaviours by the nonlinearity of the system,etc. Firstly, the introducing the spectral distribution of a spontaneous radiation for the crystalline undulator field based on the classical field theory, the particle motion equation,the gain factor and the radiation attenuation were discussed in a harmoric approximation. The results showed that there is few radiation lines in the general case; and there is only one line in a harmoric approximation. Secondly, it was pointed out that the radiation attenuation is major if energy is higher, then the crystal length must be selected smaller than the dechanneling length, and one may selects a positron or a proton as projectile; in addition, the dechanneling effect is major if energy is lower, then the crystal length must be selected smaller than the attenuation length, and one may select a heavy ion as projectile.