共查询到18条相似文献,搜索用时 156 毫秒
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波荡器是基于自由电子激光的小型THz源关键器件,其可调节的周期性磁场结构与两端的光腔配合,使得穿越的电子束产生带增益的相干辐射,最终达到THz源所需要的功率.同纯永磁结构相比,混合型波荡器通过软铁材料调节由永磁块磁化方向性差异导致的磁场分布误差,同时可提供更高的场强.本文针对小型THz源需求,对混合型波荡器进行了相关物理设计.在解析方法分析的基础上,采用0PERA3/TOSCA有限元分析软件,对波荡器进行了三维磁场数值模拟和积分场优化.通过对波荡器端部结构的调整,优化后模型的一次场积分(导向误差)小于0.0lGs.m,电子轨迹偏移小于0.02mm. 相似文献
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波荡器是基于自由电子激光的小型THz源关键器件, 其可调节的周期性磁场结构与两端的光腔配合, 使得穿越的电子束产生带增益的相干辐射, 最终达到THz源所需要的功率. 同纯永磁结构相比, 混合型波荡器通过软铁材料调节由永磁块磁化方向性差异导致的磁场分布误差, 同时可提供更高的场强. 本文针对小型THz源需求, 对混合型波荡器进行了相关物理设计. 在解析方法分析的基础上, 采用OPERA3D/TOSCA有限元分析软件, 对波荡器进行了三维磁场数值模拟和积分场优化. 通过对波荡器端部结构的调整, 优化后模型的一次场积分(导向误差)小于0.01Gs﹒m, 电子轨迹偏移小于0.02mm. 相似文献
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纯永磁波荡器由多个磁块组成,磁块的剩磁离散性会引起波荡器磁场误差,从而影响储存环工作状态和自发辐射谱质量。在波荡器磁块安装之前,使用模拟退火法对磁块进行组合排序优化,可以使峰值场强误差降低到10
-4量级以下,磁场一次积分降低到10-6 T·m量级,二次积分降低到10
-6 T·m
2量级,优化结果不依赖于初始状态的选择。给出优化的详细过程,提出了根据磁块剩磁快速计算波荡器峰值场强误差和积分场的方法。 相似文献
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为了更有效地测量用于上海同步辐射光源波荡器的积分场误差,在已有的伸展线磁测系统的基础上研制了一套翻转线圈磁测系统,该系统的运动控制、数据采集和数据分析处理均可自动完成。在利用这套磁测系统测量3.4×10-6 T·m磁场积分时获得高于1×10-6 T·m的测量精度,初步的实验结果表明这套波荡器积分磁场测量系统具有测量精度好、速度快的特点,与已有的伸展线磁测系统、平移线圈磁测系统和霍尔点测系统相比,它更适合于测量波荡器的一、二次场积分和多极场分量。 相似文献
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波荡器位相误差及垫补计算 总被引:4,自引:2,他引:2
给出了波荡器位相误差的函数式, 可由磁场峰值分布直接计算波荡器位相均方根误差。给出了波荡器垫补修正场的简单解析计算式, 可根据垫片的位置、大小、厚度、磁极间隙等参数直接计算出对磁场及位相的修正 。 相似文献
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Ting-Yi Chung Cheng-Hsing Chang Cheng-Hsiang Chang Ching-Shiang Hwang 《Synchrotron Radiation News》2015,28(3):29-33
A spatially periodic magnetic field is essential to cause an electron beam to wiggle and to emit electromagnetic radiation in a synchrotron (SR) source of radiation, and to provide fully coherent light in free electron lasers (FEL). To create this field, permanent magnets (PM) or electromagnets are patterned in a device commonly called an insertion device for SR and a radiator or modulator for FEL. In reality, magnet blocks or iron poles are not identical, in terms of geometry and magnetic properties, even with progressive manufacture. Compensatory methods are thus desired to recover the magnetic field and also to decrease the duration of construction. Magnet sorting is a pre-process that aims to eliminate the effect of manufacturing error. Before assembly of an insertion device, data of each component, especially the magnetic properties of each magnet block and the gap variation of mechanical structure, are organized to optimize the performance of the magnetic field. After that process, there is sometimes an optimization to shim the magnetic field. An effective algorithm of both processes is significant, particularly for a long undulator and an elliptically polarized undulator (EPU). 相似文献
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There is an empirical formula describing the relationship between the peak magnetic field and the undulator structure parameters for a uniform-parameter hybrid undulator.In this paper, we investigate the relationship for a linearly tapered undulator through numerical calculation by using the code RADIA, and check it with the empirical formula.The results imply that this empirical formula is also effective for linearly tapered undulators at a big enough scope for the requirements of normal FEL experiments.Therefore, for a linearly tapered undulator,we can use the empirical formula to design the variation of the undulator gap.For the tapering rate demanded by normal FEL experiments, the gap of a linearly tapered undulator increases almost linearly, and the tapering rate will keep constant while adjusting the undulator gap with the same variation for each undulator period. 相似文献
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N. V. Smolyakov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2017,11(6):1246-1259
The motion of relativistic electrons in an ideal three-dimensional magnetic undulator field satisfying the stationary Maxwell equation is considered. The system of nonlinear differential equations of the electron motion is solved analytically using perturbation theory rather than the method for averaging fast oscillations of the electron trajectory (the focusing approximation), as was done in a series of previous studies. The obtained analytical expressions for the trajectories describe the behavior of particles in a three-dimensional magnetic undulator field much more accurately than the formulas obtained within the framework of the focusing approximation. The analysis of these expressions shows that the behavior of electrons in a three-dimensional undulator field is much more complicated than that described by equations obtained using the averaging method. In particular, it turns out that the electron trajectories in the undulator have a cross dependence; in this case, variations in the initial trajectory parameters in the vertical plane cause changes in the horizontal trajectory components, and vice versa. The results of calculations of the trajectories carried out using analytical expressions are close to those of numerical calculations using the Runge-Kutta method. 相似文献
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In this paper we consider the motion of relativistic electrons in an ideal three-dimensional magnetic field of an undulator. The ideality of the magnetic field means that, on the undulator axis, the field is directed strictly vertically upward and has a strictly sinusoidal shape. In the overwhelming majority of cases, only this leading component of the field is taken into account in calculating the electron trajectory. In this paper, in the equations of motion of an electron in the magnetic field of an undulator, all three components of the field are taken into account, so that the undulator field under consideration satisfies the stationary Maxwell equations. In this case, the differential equations of motion of the electron are solved analytically with the help of perturbation theory, and not by the method of averaging over fast oscillations of the electron, as was done in a number of previous papers. These analytic expressions for trajectories describe the behavior of particles in the focusing magnetic field of an undulator much more completely. An analysis of these expressions shows that the behavior of electrons in such a three-dimensional field of the undulator is much more complicated than what follows from the equations obtained by the averaging method. In particular, there is a cross effect when changes in the initial vertical parameters of the electron trajectory cause changes in the horizontal component of its trajectory and vice versa. A comparison of the solutions obtained analytically with the results of numerical calculations of electron trajectories using the Runge–Kutta method demonstrates their high accuracy. 相似文献
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G. N. Gestrin B. P. Yefimov 《International Journal of Infrared and Millimeter Waves》2003,24(10):1617-1647
In this paper the results of theoretical and experimental research of the motion and radiation of low-voltage electron beams in Motz undulator are given. Constant magnetic field of undulator ordinary magnet under some conditions can be substituted for field of magnet dipole. Such substitution allows us to accurately integrate the electron trajectory. We can with the high accuracy consider this field as chaotic and this fact allow us to use well-known Ginsburg theory for estimation of power of braking radiation. There are longitudinal and transversal components of magnetic fields of described structure. The longitudinal component can be gained by covering of external longitudinal constant magnetic field. In this connection certain resonance effects are observed. 相似文献
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在考虑平面型摆动器(Wiggler)场误差△B(z)的情况下,求解电子在磁场中运动的洛仑兹(Lotentz)方程,得到场误差对电子横向速度的改变,然后作傅里叶变换即为电子自发辐射谱的改变,并讨论了各种场误差对自由电子激光器自发辐射谱的影响,选择北京自由电子激光器(BFEL)参数,进行模拟,最后确定出各种场误差的可接受条件。 相似文献
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针对快焦比特大非球面度离轴非球面反射镜,设计了3片式Offner补偿器。为应对3片式补偿器对中心偏差及镜间隔严格的公差要求,设计了相应的补偿器镜筒结构。该结构使透镜中心倾斜及平移调整相分离,实现补偿器的高精度装调。根据中心偏差测量仪的测量结果,2片补偿镜之间倾斜误差4.4″,平移误差3.5 μm, 镜间隔误差3.8 μm;补偿镜组与场镜之间倾斜误差5.3″,平移误差4.2 μm, 镜间隔误差7.2 μm,满足检测使用要求。利用该补偿器及4D动态干涉仪对精抛光阶段的离轴非球面进行检测,面形结果PVq值达到0.135λ,RMS值达到0.019 5λ,优于设计要求。 相似文献
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G. Mishra Mona Gehlot Geetanjali Sharma Frederic Trillaud 《Journal of synchrotron radiation》2017,24(2):422-428
The magnetic design of a ten‐period (each period 14 mm) prototype superconducting undulator is reported using RADIA. The results of modelling the magnetic flux density are presented in an analytical formula. The dependence of the field integrals and phase error on the current density and undulator gap has been calculated, and temperature curves are determined for the models and are compared with earlier reported Moser–Rossmanith fits. 相似文献