共查询到20条相似文献,搜索用时 46 毫秒
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K. Ohkubo 《International Journal of Infrared and Millimeter Waves》2001,22(11):1709-1727
By using two scalar eigenfunctions, electric and magnetic fields in the rectangular (or square) corrugated waveguide are analyzed. In a rectangular corrugated waveguide, the boundary conditions on two corrugated and two smooth walls can be satisfied to excite the hybrid mode. In a highly oversized waveguide where the wavelength of dominant mode is close to that in vacuum, two smooth walls can be exchanged with the corrugated walls because the boundary condition at those walls is satisfied approximately. The replacement is possible due to almost no penetration of the electromagnetic fields into the gap of the replaced walls when the direction of main electric field is parallel to the gap of replaced walls. This characteristic enables us to rotate the polarization of the hybrid mode in the oversized square waveguide with all four corrugated walls and is applicable to the remote steering antenna for electron cyclotron heating in the ITER. 相似文献
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G.G. Denisov S.V. Kuzikov N. Kobayashi 《International Journal of Infrared and Millimeter Waves》2001,22(12):1735-1760
An application of remote RF beam steering concept, based on image multiplication phenomena in a corrugated square waveguide, to electron-cyclotron plasma heating and current drive for ITER has been considered. In the present paper high attention is paid to studies of reliability of the remote steering capability in realistic waveguide condition. Different factors, could limit efficiency (RF breakdown, random technological spread of parameters, and heating of system), are simulated. Polarization properties of the remote steering antenna, arising due to non-ideal corrugation, are investigated. It is suggested a new configuration of antenna to be not sensible to corrugation parameters. RF analysis of the system, supplemented by dog-legs and a vacuum window, is also presented. A new way to use beating wave transmission in the remote steering waveguide is suggested, in order to reduce losses caused by mitre bends. 相似文献
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ITER超导磁体线圈电磁分析 总被引:1,自引:0,他引:1
ITER装置CS线圈、PF线圈、TF线圈是ITER装置超导磁体系统的重要组成部分.电磁性能是超导磁体重要的方面,在研制时对各个线圈的电磁分析是十分重要的.文中通过PRO/E建立模型用Ansys软件,对ITER导体的线圈在其最大工作电流下进行有限元分析,分析的模型分别为:只有CS线圈与PF线圈二维模型;单独TF线圈三维模... 相似文献
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蒙特卡罗粒子输运计算自动建模程序MCAM在ITER核分析建模中的应用 总被引:2,自引:0,他引:2
国际热核试验堆(ITER)核分析的主要计算工具是三维蒙特卡罗输运程序MCNP。MCAM(MCNP Auto-Modeling system)作为MCNP自动建模与可视化软件,其主要功能是CAD模型与MCNP计算模型之间的数据交互。一方面MCAM可将通用格式的CAD模型转换成MCNP计算模型,另一方面作为一个可视化工具,它可以以CAD模型的方式显示MCNP计算模型中几何及材料等相关信息。主要介绍利用MCAM对ITER三维MCNP模型的改进,主要包括:包层模块的重建和内包层几何细化;模型环向角度从20°到40°的扩展。In order to conduct nuclear analyses on neutronics issues for ITER (International Thermonuclear Experimental Reactor), a standard three-dimensional model of the ITER reactor is being developed. The complex nuclearanalyses are conducted by MCNP/4C in three dimensions. MCAM (MCNP Auto-Modeling system) , as an implementation of the interface code between modern CAD system and MCNP, is a modeling and visualization tool which can convert a CAD model to neutronics model for MCNP and vice versa. This paper presents the application of MCAM to modify ITER 3-D neutronics model, which include blanket segmentation update, incorporation of fine structures of inboard blanket and the model extension from 20° to 40° in toroidal direction 相似文献
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用ANSYS软件对ITER聚变功率关闭系统(FPSS)的一种阀门箱的结构在ITER各种典型荷载组合下的应力和应变进行了有限元分析,并遵照ASME及ITER标准对分析结果进行了评判。结果表明这种阀门箱结构能够满足ITER的设计要求。 相似文献
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对ITER中子通量监测器(NFM)建立了简化模型并进行了计算分析。利用MCNP程序模拟计算了具有不同慢化剂材料/类型的NFM的探测效率能量响应和时间响应,通过对结果的分析确定了不同NFM上所使用的慢化剂种类及其用量,同时给出了对ITER NFM的初步物理认识。 相似文献
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Sound propagation through a waveguide is generally modeled by the Webster horn equation which assumes a planar pressure wavefront. However, most of the sources are non-planar in nature. In this work, a 1-D model is derived for sound propagation through a 2-D waveguide with circular wavefront. The model is derived from the 2-D Helmholtz equation using the weighted residual method. The model assumes a uniform pressure across the angular coordinate at a given radial distance. A 2-D finite element model is used to validate the results for different waveguide geometries and it shows good agreement. 相似文献
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Nuclear fusion has enormous potential to greatly affect global energy production. The next-generation tokamak ITER, which is aimed at demonstrating the feasibility of energy production from fusion on a commercial scale, is under construction. Wall erosion, material transport, and fuel retention are known factors that shorten the lifetime of ITER during tokamak operation and give rise to safety issues. These factors, which must be understood and solved early in the process of fusion reactor design and development, are among the most important concerns for the community of plasma–wall interaction researchers. To date, laser techniques are among the most promising methods that can solve these open ITER issues, and laser-induced breakdown spectroscopy (LIBS) is an ideal candidate for online monitoring of the walls of current and next-generation (such as ITER) fusion devices. LIBS is a widely used technique for various applications. It has been considered recently as a promising tool for analyzing plasma-facing components in fusion devices in situ. This article reviews the experiments that have been performed by many research groups to assess the feasibility of LIBS for this purpose. 相似文献
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针对新设计的ITER纵场重力支撑结构特点,用ANSYS有限元软件对它建立了有限元模型。采用Block Lanczos方法求出了ITER重力支撑的屈曲特征值。分析结果表明ITER重力支撑不会发生屈曲。为了确保新设计结构的可靠性,初步设计了全尺寸支撑的半原型件拟用来对支撑进行工程受力测试。 相似文献
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为保障ITER极向场(PF)电源系统的高实时性控制需求,根据其设备体积大、分布分散等特点,选取了支持多种设备连接拓扑的实时工业以太网现场总线EtherCAT作为ITER PF电源现场层监控系统的数据通讯协议.为研究ITER极向场电源现场层监控系统的实时性,分析了数据帧在几种适合ITER PF整流器单元现场层信号采集与控... 相似文献
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We introduce a mathematical model based on a concept of intrinsic mode in order to analyse and synthesise optical wave propagation and radiation occurring in a non-uniform optical waveguide used in integrated optics as optical coupler. The model is based on numerical evaluation of electromagnetic wave by applying an intrinsic field integral to evaluate the field behaviour inside the optical waveguide. To analyse the field distribution inside the non-uniform waveguide and predict the beam propagation of optical energy involved in the propagation process, it is necessary to track the motion of any observation point along the tapered waveguide itself. Physically, the rays of the spectrum undergo reflections on the waveguide boundaries until the cut-off occurs and the phenomena of radiation begin. The numerical results show good agreement with those obtained by classical methods of evaluation used bv other works. 相似文献
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A mathematical model of linear dynamic distortions of average signal power in a planar optical waveguide stemming from the intermodal coupling and dispersion of waveguide modes caused by macroscopic bends and irregularities of the optical waveguide surface has been developed on the basis of pulse intermodal scattering matrix. It is shown that the elements of this matrix are determined at a waveguide segment whose length greatly exceeds the correlation scale of the field of irregularities but is much smaller than the normalization length of waveguide modes and are described by rectangular functions with a duration proportional to the relative velocity of the corresponding modes. The dependences of the pulse intermodal scattering matrix on the intensities of absorption, Rayleigh scattering, and optical signal scattering from waveguide irregularities have been established. It is shown that, at waveguide lengths exceeding the normalization length, the optical signal shape becomes almost stable and can be expressed in terms of the pulse characteristic of an integrating circuit. It has been established that irregularities of the film in a bent optical waveguide lead not only to additional attenuation but also to enhancement of multimode distortion. A matrix method is proposed for taking into account these distortions, which is based on the effect of equalization (scrambling) of the signal energy over the spectrum of the bent waveguide modes. The model developed was used to process the experimental data on the dynamics of a signal in a weakly guiding multimode polymer optical fiber in order to estimate the parameters of attenuation and irregularities of the waveguide surface. 相似文献
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InvestigationofFarInfraredWaveguideFreeElectronLaserDrivenbyRFLinacHUSuxing;FUEnsheng(ShanghaiInstituteofOpticalandFineMechan... 相似文献
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Jost B.M. Scharer J.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(5):802-813
Theoretical and experimental investigations of the folded waveguide launcher as proposed for use in the ion-cyclotron range of frequencies (ICRF) heating of tokamak plasmas are presented. Theoretical results include an analysis of the folded waveguide using Ritz's method to obtain various field quantities. The cutoff wavenumbers from this analysis are within 10% of those calculated using an unfolded equivalent rectangular waveguide model. Measurements of cavity resonances for a scale-model ICRF-folded waveguide with a cutoff frequency of 2.4 GHz also agree closely with those calculated using an unfolded equivalent model. An unfolded equivalent waveguide model is used to evaluate the properties of an inductive strip placed in the folded waveguide. Applying variational analyses provides upper and lower bounds to the reflection magnitude |S 11| that are in good agreement with measured values. Polarizing plates (which have been proposed to increase the on-axis directivity of the radiated power) are modeled using an unfolded equivalent waveguide. A variational analysis is used to determine an upper-bound value of |S 11| in air due to a polarizing plate inside a matched folded waveguide. Measured values are found to be within 3% of the calculated values, with |S 11|>0.95 for frequencies between 2.5 and 4.5 GHz 相似文献
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Guofang Fan Yuan Li Bing Han Qi Wang Xinhou Liu Zhen Zhen 《Optics & Laser Technology》2012,44(6):1776-1779
A numerical design model is presented for the polymer waveguide in an electro-optic modulator. The effective index method is used to analyze the height of the core waveguide and rib waveguide, an improved Marcatili method is presented to design the rib waveguide width in order to keep the strong single mode operation and have a good match with the standard fiber. Also, the thickness of the upper cladding layer is discussed through calculating the effective index of the multilayer planar waveguide structure has been obtained by setting the optical loss due to the metallic absorption to an acceptable value (<0.1 dB/cm). As a consequence, we take the EO polymer waveguide structure of UV15:CLD/APC:UFC170 as an example, an optimized design is reported. 相似文献
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Uniform stable conformal convolutional perfectly matched layer for enlarged cell technique conformal finite-difference time-domain method 下载免费PDF全文
Based on conformal construction of physical model in a three-dimensional Cartesian grid,an integral-based conformal convolutional perfectly matched layer(CPML) is given for solving the truncation problem of the open port when the enlarged cell technique conformal finite-difference time-domain(ECT-CFDTD) method is used to simulate the wave propagation inside a perfect electric conductor(PEC) waveguide.The algorithm has the same numerical stability as the ECT-CFDTD method.For the long-time propagation problems of an evanescent wave in a waveguide,several numerical simulations are performed to analyze the reflection error by sweeping the constitutive parameters of the integral-based conformal CPML.Our numerical results show that the integral-based conformal CPML can be used to efficiently truncate the open port of the waveguide. 相似文献