共查询到20条相似文献,搜索用时 171 毫秒
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在一般的近代物理实验教材中,关于电子衍射实验采用的是晶体表面反射衍射或金属箔透射衍射。本文提出一套基于双缝衍射的、用于研究微观粒子波粒二象性的电子衍射实验方案,并且鉴于在一般的实验中不具备进行电子双缝衍射实验的条件,本实验方案是在电子双缝衍射计算机模拟的仿真环境下进行的。 相似文献
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利用Mathematica软件分别计算了单缝衍射及双缝衍射的光强分布,成功解决了菲涅耳衍射的计算这一较难问题,并得到了双缝衍射向杨氏双逢干涉过渡的具体条件,完成了实验室内难以完成的任务. 相似文献
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为了打破二维模拟回旋脉塞的一些局限性,研究了电子回旋受激辐射的基本原理,使用唯象的描述方法,以统计物理学为基础,在电子回旋中心坐标系中完成了三维Yee网格模型中对电子注平衡态物理模型的数值建模,并结合PIC方法和FDTD算法进行电子回旋脉塞的数值模拟.为了减少计算时间,在模拟中加入了MPI并行算法,加速比能提高到2.7以上.最后以一个94 GHz的回旋振荡管为例,对它的整体结构进行了模拟,并通过对频谱,功率,工作模式等方面验证了模拟的正确性.
关键词:
电子回旋脉塞
Yee网格模型
PIC方法
FDTD算法 相似文献
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以适合亚微米器件的流体动力学模型为基础,建立了1维数值模拟程序,程序中采用耦合牛顿法求解非线性方程组。应用该程序对亚微米1维弹道二极管进行了瞬态数值模拟,分析了外加低电压和高电压脉冲情况下的电场强度、载流子浓度、载流子温度等参数的变化情况。低电压脉冲下的结果与文献一致;对于文献中并未开展的高电压脉冲下的模拟,得到了器件处于非正常工作状态的各参数分布曲线,并尝试用二次击穿理论对结果进行分析。结果显示:随着外电压的升高,载流子的碰撞电离将导致少子空穴浓度急剧增大,并达到与电子浓度相同的量级,这时在器件分析中空穴方程已不能省略,并且载流子浓度将取代掺杂浓度控制电势分布,并进而影响电场及电流密度,涌极附近电场将增强,电流密度也将迅速增加。结论可为研究瞬态电磁脉冲对2维器件的损伤效应提供参考。 相似文献
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Zhifeng Zhang Huanghuang BaiGuishuan Yang Fengchun JiangYufen Ren Junfeng LiKun Yang Hongjun Yang 《Optik》2013
In this paper, we describe a novel computer simulation technique of generating Fraunhofer diffraction images from different patterns. The simulation can be performed in almost any PC using the software MATLAB. The patterns of five types of elements, including one slit, one rectangular aperture, two rectangular apertures, the grating and one circular aperture are discussed and simulated. Diffractions images can be generated for any wavelength of light and for any program are presented. Finally, the Fraunhofer diffraction optical intensity distribution is analyzed. Simulation results can improve the physics experimental teaching of Fraunhofer diffraction. The programs based on MATLAB have been used as the platform to real-time calculation and simulation and solve the optical problem. 相似文献
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I. N. Meshkov R. V. Pivin A. O. Sidorin A. V. Smirnov G. V. Trubnikov 《Physics of Particles and Nuclei Letters》2006,3(1):S50-S52
The BETACOOL program, developed by electron cooling group of the Joint Institute for Nuclear Research (JINR), is a set of algorithms based on common format of input and output files. The program is oriented toward simulation of the ion beam dynamics in a storage ring in the presence of cooling and heating effects. The version presented in this report includes three basic algorithms: simulation of root-mean-square (rms) parameters of the particle distribution function evolving in time, simulation of the distribution function evolution using the Monte Carlo method, and a tracking algorithm based on a molecular dynamics technique. The general processes investigated with the program are intrabeam scattering in the ion beam, electron cooling, and interaction with residual gas and an internal target. 相似文献
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A novel algorithm for the simulation of the X-ray diffraction profiles in multilayers is developed, which can be applied to any multilayered structure, with no limitations. The simulation program in the MATLAB format is based on the direct summation of waves scattered by individual atomic planes. It takes into account the strain and concentration-induced fluctuations of interplanar spacings, interface roughness and buried amorphous layers, and enables adding the diffuse scattering contributions of the Gaussian or Lorentzian types.The summation over individual layers can be done coherently or incoherently, depending on the interface structure. In order to visualize the steps of the fitting procedure, the contribution of each layer can be plotted separately.In this paper the simulation routine is described with a focus on handling asymmetric reflections. We stress that in this case, the effective thickness of the layers, participating in the formation of diffraction signals, can be very different for low or high X-ray incidence angles. We also show that in contrast to symmetric reflections, when treating the asymmetric ones, an additional phase shift depending on the distance between the sample and detector, should be taken into account. The simulation program is applied to fit experimental diffraction profiles, symmetric and asymmetric, taken from the MOVPE-grown heterostructures and superlattices of practical importance, based on the InGaAsP/InP materials system. 相似文献
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通过数值计算及粒子模拟程序, 分析了强流电子束阻抗、电压及电流特性对相对论速调管放大器(relativistic klystron amplifier, RKA)中束流调制、群聚特性的影响, 其中粒子模拟程序中采用 束发射方式以精确控制电子束的阻抗.结果表明, 低阻抗电子束有利于减小群聚距离, 缩短RKA器件的整体长度, 不利于注入微波对电子束的调制, 而高阻抗电子束情况正好相反.在电子束阻抗不变时, 增加电子束加速电压类似于增大电子束阻抗的情况.另外, 用粒子模拟方法确定了不同阻抗电子束对特定输入腔的电子负载电导, 从而可以得到不同阻抗的强流电子束对种子源 功率水平的需求以及对输入腔外观品质因数的要求.
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相对论速调管放大器
电子束阻抗
群聚距离
输入调制 相似文献
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In this paper, we describe a new computer simulation technique of generating Fresnel diffraction images from rectangular apertures of arbitrary dimensions by using Fresnel integrals instead of the more common fast Fourier transform methods. The simulation can be performed in almost any PC using the software MATLAB. Diffraction images can be generated for any wavelength of light and for any aperture–screen and aperture-source distances. Images for rectangular obstacles can also be simulated. Details of the algorithm and program are presented, as well as the interesting insights than can be gained from using the program. Finally, it is shown that the simulated images reduce to the simple Fraunhofer diffraction patterns for certain limiting situations. 相似文献
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相对论双流放大器是一种结构简单、高效率的高功率微波器件。其作用机理是沿同一方向传播的两束同心的环形电子束之间的双流不稳定性。这种双流不稳定性导致两个电子束之间的能量交换,最后由输出腔变成微波放大输出。相对论双流放大器成功的关键之一就是同一方向传播的两束同心的环形电子束的成形,利用MAGIC粒子模拟程序,对相对论双流放大器电子注的成形进行了粒子模拟。通过粒子模拟,证实了选择合适的参数来形成两束环形同心束是可行的。 相似文献
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Two advanced optical system applications are implemented in a Matlab™ based simulation engine. The applications are aligning a micro-optic fiber coupler and scanning an optical disk with a readout system having an effective numerical aperture of 1.8. Many phenomena, like scalar diffraction, vector diffraction, addition of aberrations, thin-film interactions, and Babinet decomposition are described in the examples. A powerful graphical user interface (GUI) is also described that allows users to define optical elements, program operations and control program flow. Users can also easily interface custom field operations to the simulation engine. 相似文献