参数激励与晶体摆动场辐射的稳定性

Parametric excitation and stability of crystalline undulator radiation

寻找新光源,特别是短波长相干光源备受关注.本文讨论了晶体摆动场辐射作为短波长激光的可能性和必须满足的基本条件;指出了至今尚未获得可利用的短波长激光可能不只是技术原因,而且还有物理原因.利用参数激励方法对这个问题进行了分析.在经典力学框架内和偶极近似下,引入正弦平方势,把粒子运动方程化为具有阻尼项和参数激励项的摆方程.利用Melnikov方法讨论了系统的稳定性,并对系统的临界条件进行了分析.结果表明:系统的稳定性与其参数有关,只需适当调节这些参数,系统的稳定性就可以原则上得到保证.

Looking for a new light source, especially short-wavelength coherent light source has attracted much attention. A possibility and basic conditions are discussed by using crystalline undulator field radiation as a short-wavelength laser;it is pointed out that the short-wavelength laser has not yet been available so far which is due to not only technical reasons, but also physical reasons. In this paper, the physical problem is analyzed by using parametric excitation method. Introducing the sine-squared potential, the particle motion equation is reduced to a pendulum equation with a damping term and parameter excitation term in the framework of classical mechanics and the dipole approximation. A stability of the system is discussed using Melnikov method, and the critical condition of the system is also analyzed. The results show that the stability of the system relates to its parameters. By adjusting these parameters appropriately, the stability of the system can be ensured in principle.