在环型自由电子激光器中电子运动的混沌特性

本文分析了相对论性电子在环型摆动器磁场，轴向磁场和由非中性电子束产生的平衡自电场和自磁场中的运动。通过数值计算画出Ｐｏｉｎｃａｒｅ截面映射图，表明当自场足够强时，这种运动变成混沌的。虽然现实的环型摆动器场和自场一样使电子运动方程成为不可积的，但自场使运动产生混沌的作用要比摆动器场强。轴向磁场有抑制混沌发生的作用。     

平衡自场对有线性摆动器的自由电子激光器的自发辐射和受激辐射的影响

本文计算了在平衡自场、线性摆动器场和轴向磁场作用下的电子轨道,并由此求得有线性摆动器的自由电子激光器的自发辐射和受激辐射。结果表明自场有增强辐射的作用。     

有矩形波导和线性摆动器的自由电子激光器的特性研究

本文研究圆柱电子呸通过矩形波导和线性摆动器时产生相干辐射的特性，用线性化弗拉索夫－麦克斯韦方程分析了因对自洽的电子束平衡态引起扰动产生的不稳定性，导出了ＴＭｍｎ模的色散方程并数值计算了辐射和增长率与电子束能量、轴向磁场，摆动器强度和波长以及电子束半径的关系。     

等离子体波摆动器中电子运动的混沌特性

本文用Ｐｏｉｎｃａｒｅ截面及Ｌｙａｐｕｎｏｖ指数两种方法，研究了新型的等离子体波摆动器中电子运动的混沌特性，结果表明，当摆动器强度增大时电子从规则运动向混沌状态发展，这是提高自由电子激光输出功率时必须解决的一个重大课题。     

有矩形波导和线性摆动器的自由电子激光器的特性研究

本文研究圆柱电子束通过矩形波导和线性摆动器时产生相干辐射的特性。用线性化弗拉索夫-麦克斯韦方程分析了因对自洽的电子束平衡态引起扰动产生的不稳定性。导出了TMmn模的色散方程并数值计算了辐射频率和增长率与电子束能量、轴向磁场、摆动器强度和波长以及电子束半径的关系。     

有轴向磁场的平面摆动器自由电子激光

研究了电子在有同向磁场的平面摆动器中的自发辐射和谐波相干辐射，得到了一个较普遍的自发辐射谱表达式和谐波自由电子激光的增益。当电子的能量较高或者沿摆动器轴线观察时，辐射是椭圆极化的，适当附加轴向磁场，可以提高激光增益，对于较低次谐波，增益提高更明显。     

新型摆动器自由电子的自发辐射

Ｓ．Ｐｉｎｈａｓ于１９９０年提出一种新型摆动器－－磁场与纵向坐标无关摆动器。本文在Ｓ．Ｐｉｎｈａｓ工作的基础上，利用广义Ｂｅｓｓｅｌ函数计算了电子在这种摆动器中运动产生的自发辐射强度分布，得到了一筱较普遍的自发辐射谱表达式。结果表明：新型摆动顺自由电子的自发辐射谱与普通平面摆动器自由电子的自发辐射谱相似，谱线 形状由ｓｉｎｃ（η）函数决定。     

带有同轴摆动器的拉曼自由电子激光器

1　引言自由电子激光器 ( FEL)是连续可调谐的高功率相干电磁辐射源。这种辐射由相对论电子束通过摆动器磁场产生 ,这种磁场是沿电子束轴线方向 ,具有空间周期的静磁场。电子束通常由均匀的轴向磁场引导 ,对运行在亚毫米波和更长波长上的情况 ,则由波导周围的磁场引导。当以拉曼方式运转时 ,其物理机制可以用在电子束座标中传播着的电磁(抽运 )波 ,从空间电荷波上后向散射的受激拉曼效应来描述。普通自由电子激光器使用螺旋式对称的摇摆器 ,其磁场由双线缠绕的电流产生。最近 Jackson等人提议用同轴摆动器代替螺旋式摆动器 ,这样可带来一…     

两元摆动器自由电子激光器

提出一种两元摆动器,它的前一小段是空间周期磁场,后一段是空间均匀磁场。这种摆动器兼有空间均匀磁场摆动器那种结构简单、容易扩大尺寸的优点,而同时又因提高了电子横向运动速度,可望获得很高的激光增益和能量转换效率。     

电子在磁场与纵向坐标无关的摆动器中的辐射谱分布

应用Ｍａｄｅｙ定理计算了电子在ＳｈｏｌｍｏＰｉｎｈａｓ提出的一种磁场与纵向坐标无关的摆动器中自发辐射谱分布，并将所得到的结果与利用线性摆动器时产生的辐射谱进行了比较，发现它们有相同的形式。初步论证了利用该摆动器产生高次谐波相干辐射的可能性。     

CHAOTIC ELECTRON TRAJECTORIES IN A CIRCULAR FREE ELECTRON LASER

The motion of a relativistic electron is analyzed in the field configuration consisting of a circular wiggler magnetic field, an axial magnetic field, and the equilibrium self-electric and self-magnetic fields produced by the non-neutral electron ring. By generating Poincare surface-of-section maps, it is shown that when the equilibrium self-fields is strong enough, the electron motions become chaotic. Although the realistic circular wiggler magnetic field destroys the inte-grability of the electron motion as the equilibrium self-fields do, the role the latter plays to make the motions become chaotic is stronger than the former does. In addition, the axial magnetic field can restrain the occurrence of the chaoticity.     

Chaotic electron trajectories in a circular free electron laser

The motion of a relativistic electron is analyzed in the field configuration consisting of a circular wiggler magnetic field, an axial magnetic field, and the equilibrium self-electric and self-magnetic fields produced by the non-neutral electron ring. By generating Poincare surface-of-section maps, it is shown that when the equilibrium self-fields is strong enough, the electron motions become chaotic. Although the realistic circular wiggler magnetic field destroys the integrability of the electron motion as the equilibrium self-fields do, the role the latter plays to make the motions become chaotic is stronger than the former. In addition, the axial magnetic field can restrain the occurrence of the chaoticity.     

The influence of equilibrium self-fields on the spontaneous emission and stimulated emission of fel with a linearly polarized wiggler

The orbits of an electron in a linear wiggler and axial field under the influence of self-fields are calculated. Then the spontaneous emission coefficient and the growth rate of the stimulated scattering are obtained. The numerical results show under some condition the self-fields can enhance the radiation.     

纵向摇摆器磁场中的电子轨道

本文求解纵向摇摆器磁场加直流磁场中的电子运动方程,在直角坐标系中求得电子速度的严格解析解,并导出直角坐标和圆柱坐标中电子位置坐标的近似析解。同时用电子运动模拟计算进行了校验,指出近似解析解有较好的准确性。     

加反向导引场自由电子激光动力学理论

本文对加反向导引场自由电子激光加以描述，假定摇摆场是理想化的，分析电子的运动轨道，解得运动常数，求解符拉索夫方程得到扰动分布函数，从波方程可得色散关系，进而得增益公式，该公式近似适用于有导引场和无导引起的情况。     

Phase velocity of a transverse electric wave propagating in a magnetized electron beam

In this paper three-dimentional simulations are carried out to the phase velocity of a transverse electric wave which propagates in a relativistic electron beam magnetized by a wiggler field and an axial guide magnetic field. Results show that the phase velocities are quite different from each other as the axial guide magnetic field changes its direction.     

THE TRANSVERSAL GEOMETRIC EFFECTS IN A FREE ELECTRON LASER

The effects of a beam thickness and a conducting wall in a free electron laser with a linearlypolarized wiggler magnetic field and an axial magnetic field are investigated within the framework of fluid-Maxwell equations.The growth rate of free electron laser instability is obtained,in which the nonlinear bulkand surface current density are simultaneously considered.The numerical calculations indicate that the bulkcoupling is dominant.There is an optimum beam thickness and separation between the conducting walls forwhich the growth rate is maximum.     

电子在多层膜摇摆器中的辐射

提出了利用多层膜作自由电子激光器的摇摆器,利用虚光子和康普顿散射讨论了运动电子在多层膜摇摆器中的自发辐射。(Fe/Cr)N等铁磁-非磁层状材料的铁磁层之间存在反铁磁耦合,因此可以利用磁性多层膜制作自由电子激光器的摇摆器。考虑到静磁场的空间周期只有7.8nm,要精确计算电子在多层膜摇摆器中运动的自发辐射的波长和辐射功率就必须考虑电子的反冲。给出了运动电子在多层膜摇摆器中的自发辐射波长和辐射功率的精确计算表达式。结果发现,自发辐射波长和辐射功率表达式中都含有康普顿波长。     

CHARACTERISTIC STUDY OF A FREE ELECTRON LASER WITH LINEARLY POLARIZED WIGGLER AND RECTANGULAR WAVEGUIDE

The characteristics of coherent radiation produced by a cylindrical electron beam passing through a rectangular waveguide and linearly polarized wiggler are studied. The instability analysis is based on the linearized Vlasov-Maxwell equations for the perturbations about a self-consistent beam equilibrium. The dispersion equation of TMmn mode is deduced and by making use of numerical calculation the radiation frequency and growth rate as a function of electron beam energy and radius, axial magnetic field, wiggler field and wave length are presented and discussed.