100 MeV回旋加速器的磁铁设计和建造准备

由于高频谐振腔、对中线圈和束流诊断装置的安装需要,要求磁极的间隙增加约1cm,显然在中心区和加速区的磁场分布都将改变,因此,为满足加速器的束流动力学的需要,必须在改变励磁安匝数的同时,重新设计磁极的间隙、镶条、芯柱等磁铁参数。在2005年,除了设计确定磁铁的几何参数、磁场分布外,许多工程方面的工作得到了推进,其中包括机械结构设计和建造的前期准备工作。1磁铁的基本几何结构和磁场分布100MeV回旋加速器的主磁铁为紧凑型磁铁、有四个直边扇形磁极,主磁铁的直径为6.16m,高2.31m,磁极的半径为2.0m,主磁铁的主要尺寸见参考文献[1],二…     

100 MeV紧凑型回旋加速器主磁铁的三维磁场有限元分析技术

100 MeV紧凑型回旋加速器主磁铁的几何结构十分复杂,但为了形成加速器束流动力学所要求的磁场分布,本文对初步设计的磁铁进行必要的简化。综合采用各种适当的三维有限元网格剖分技术,对该磁铁的磁场进行数值分析,计算精度满足加速器物理设计的要求。     

230 MeV超导回旋加速器测磁线圈校准

正磁场测量与垫补系统是230 MeV超导质子回旋加速器主磁铁系统的子系统之一。目前,230 MeV超导质子回旋加速器主磁铁、线圈、配套电源均已完成加工,磁场测量工作即将展开。磁能量法是加速器中常用的磁场测量方法。磁能量法原理简单,但误差来源较丰富,需要对感应线圈探头的面积进行标定。利用回旋加速器研究设计中心临时厂房的标准C型二极铁提供高均匀度磁场,校准时利用NMR测量探头进行磁场标定。通过多次校准,经计算后取平均值可得到感应线圈的面积与厂家所     

智能化回旋加速器主磁铁CAE系统的研制及应用

阐述了一种回旋加速器主磁铁的CAE方法,基于该方法在VAX—11/780上所形成的CAE系统,具有可移植性好的特点,目前已成功地移植到PC—386微机上。智能化的CAD工作,在专家经验知识库的帮助下,使一般的设计者,也能得到高水平的磁铁结构;磁场分析基于多次考验过的磁场数值计算程序,束流动力计算经过实际考验;CAM工作是根据现有数控车床的具体要求,将设计结果转换成必要的加工数控数据,并能根据实际测磁结果,以形成等时性磁场为目标,计算出叶片修改量并输出数控数据,指导整个磁铁加工过程。应用该CAE系统设计的回旋加速器主磁铁,结构与目前国际上回旋加速器的结构十分接近,运行功耗有所下降。     

14 MeV医用小型回旋加速器磁场测量

<正>为满足恶性肿瘤、心脑血管等医疗行业重大疾病早期诊断的需求,回旋加速器研究设计中心正研制一台用于硼中子治疗(BNCT)的14 MeV医用回旋加速器。加速器主磁铁采用紧凑型结构,选择4叶片直边扇形磁极,引出束流强度为1mA,针对BNCT医用小型回旋加速器结构特点,采用一套全自动化的磁场测量系统对其进行磁场测量与垫补。     

CYCIAE-100主磁铁磁性能检测

2008年CYCIAE．100主磁铁的磁极毛坯件运抵中国原子能科学研究院，同时主磁铁上、下盖板和4个磁轭铸造完成。按照合同要求，磁极毛坯件的生产厂家（Industeel）提供了磁极毛坯件的化学性能和磁性能的检测结果，盖板和磁轭生产厂家（中信重机）提供了毛坯件的化学成分检测结果，为了复测磁极毛坯件的磁性能、检测盖板和磁轭的磁性能，分别对磁极、盖板和磁轭的本体样品进行了磁性能的检测。     

智能化回旋加速器主磁铁CAE系统的研制及应用

回旋加速器的主磁铁是加速器建造中最重要的部件,它代表了回旋加速器的特性。虽然有许多解磁场计算问题的程序,但结果却大不相同,取决于用户的水平和经验。为了帮助磁铁设计者们获得可接受的结果,开发了一个智能化的CYCLONE型回旋加速器主磁铁设计、分析与指导加工的CAE(计算机辅助工程)。由于程序中安装了专家知识库,即使设计者是一位初学者,也可得到合理的设计结果。     

智能化回旋加速器主磁铁CAE系统的研制及应用

回旋加速器的主磁铁是加速器建造中最重要的部件,它代表了回旋加速器的特性。虽然有许多解磁场计算问题的程序,但结果却大不相同,取决于用户的水平和经验。为了帮助磁铁设计者们获得可接受的结果,开发了一个智能化的CYCLONE型回旋加速器主磁铁设计、分析与指导加工的CAE(计算机辅助工程)。由于程序中安装了专家知识库,即使设计者是一位初学者,也可得到合理的设计结果。     

18 CYCIAE-100回旋加速器主磁铁电磁力和形变的数值模拟

在CYCIAE-100回旋加速器的整体设计中，满足各种束流动力学要求的磁场分布的实现是最为关键的环节之一。在紧凑型回旋加速器中，磁铁的形变将严重影响中心平面及其附近的磁场分布。导致磁铁变形的主要因素有磁铁自身的重力、电磁力和外界的大气压力。其中对于重力和电磁力引起的磁铁形变，如果变形足够小，可留待磁场测量和垫补阶段处理；如果变形较大，则需在设计阶段对气隙的结构尺寸加以补偿。而对于大气压力引起的磁铁变形，由于磁场测量是在非真空条件下进行，因此需详细分析这样的变形对磁场的影响，为大气下测磁数据的真空校正处理提供依据。总之，主磁铁的结构力学研究对于CYCIAE-100最终磁场达到高的精度有重要意义。     

基于台阶垫补的磁场优化算法研究

在回旋加速器磁铁设计过程中,磁场优化是非常重要的一个环节。由于加速器磁铁的磁场响应随着磁极台阶高度变化呈现非线性的特点,使得在优化复杂的磁场时,计算过程复杂、时间成本高且需要手动迭代。以1台圆形轴对称磁铁垫补为例,发展了磁场优化算法。利用三维电磁场仿真软件CST和数据分析软件MATLAB,研究了单个台阶垫补块对中心平面上不同半径处磁场幅值的影响,实现了一种自动优化磁场的算法,并以磁场降落指数为0.2的磁场为优化模拟实例,最终求得了对应的磁极台阶高度,证明了本算法的可行性和便捷性。     

中国先进研究堆安全棒驱动机构改进设计

分析了中国先进研究堆（CARR）在C阶段调试过程中发生的安全棒意外落棒事件,查找原因为：安全棒驱动机构回路中电磁阀因长时间工作引发烧损失效,为解决该安全隐患,对CARR安全棒驱动机构进行改进设计,提出“水力提升-水力磁力保持式”安全棒驱动机构设计方案,使用Ansoft公司的有限元分析软件Maxwell对水力提升-水力磁力保持式安全棒驱动机构磁路进行有限元分析,计算得到驱动机构的电磁场分布及电磁力的数值,计算结果表明,磁力保持装置产生电磁力可达到安全棒驱动线重量的2.12倍,具有一定的裕度。     

Electromagnetic Analyses of ITER Lower ELM Right Bottom Corner

ELM(edge localized mode) coils are key components of ITER that suppress the edge localized mode phenomenon. A giant electromagnetic force is generated during normal operations by the current flowing in the ELM coils interacting with the external background field. The Lorentz force will induce Tresca stress in the ELM coils. If the load goes beyond the allowable threshold, the coils can hardly satisfy the safety requirements. The right-hand bottom corner was chosen to perform our electromagnetic analyses. Based on the Maxwell equation, the detailed magnetic field and Lorentz force were calculated. By use of the finite element software ANSYS,the Tresca stress was extracted and evaluated based on our analytical design. The present analysis aims to verify the feasibility of the current design. It can also serve as guidance for fabrication and structural optimization.     

Method on Adjustment of Isochronous Field Change Caused by Temperature Increase for CYCIAE-100 and Experimental Study on Coil Insulation

In the compact cyclotron with small magnetic pole gap, it places high requirement for the isochronous filed, as is the case with the 100 MeV high intensity cyclotron under construction at CIAE. As the gap between the sectors is small, magnetic field in the gap is sensitive to the magnetic pole deformation caused by factors such as temperature increase and electromagnetic force while the machine is in operation. In this case, the isochronous filed should be maintained by compensating the field divergence caused by pole deformation on line to guarantee the normal accelerating of the particles.     

Characteristics of temporal evolution of particle density and electron temperature in helicon discharge

On the basis of considering electrochemical reactions and collision relations in detail,a direct numerical simulation model of a helicon plasma discharge with three-dimensional two-fluid equations was employed to study the characteristics of the temporal evolution of particle density and electron temperature.With the assumption of weak ionization,the Maxwell equations coupled with the plasma parameters were directly solved in the whole computational domain.All of the partial differential equations were solved by the finite element solver in COMSOL MultiphysicsTM with a fully coupled method.In this work,the numerical cases were calculated with an Ar working medium and a Shoji-type antenna.The numerical results indicate that there exist two distinct modes of temporal evolution of the electron and ground atom density,which can be explained by the ion pumping effect.The evolution of the electron temperature is controlled by two schemes:electromagnetic wave heating and particle collision cooling.The high RF power results in a high peak electron temperature while the high gas pressure leads to a low steady temperature.In addition,an OES experiment using nine Ar I lines was conducted using a modified CR model to verify the validity of the results by simulation,showing that the trends of temporal evolution of electron density and temperature are well consistent with the numerically simulated ones.     

Explicit structure-preserving geometric particle-in-cell algorithm in curvilinear orthogonal coordinate systems and its applications to whole-device 6D kinetic simulations of tokamak physics

Explicit structure-preserving geometric particle-in-cell(PIC) algorithm in curvilinear orthogonal coordinate systems is developed. The work reported represents a further development of the structure-preserving geometric PIC algorithm achieving the goal of practical applications in magnetic fusion research. The algorithm is constructed by discretizing the field theory for the system of charged particles and electromagnetic field using Whitney forms, discrete exterior calculus, and explicit non-canonical symplectic integration. In addition to the truncated infinitely dimensional symplectic structure, the algorithm preserves exactly many important physical symmetries and conservation laws, such as local energy conservation, gauge symmetry and the corresponding local charge conservation. As a result, the algorithm possesses the long-term accuracy and fidelity required for first-principles-based simulations of the multiscale tokamak physics. The algorithm has been implemented in the Sym PIC code, which is designed for highefficiency massively-parallel PIC simulations in modern clusters. The code has been applied to carry out whole-device 6 D kinetic simulation studies of tokamak physics. A self-consistent kinetic steady state for fusion plasma in the tokamak geometry is numerically found with a predominately diagonal and anisotropic pressure tensor. The state also admits a steady-state subsonic ion flow in the range of 10 km s~(-1), agreeing with experimental observations and analytical calculations Kinetic ballooning instability in the self-consistent kinetic steady state is simulated.It is shown that high-n ballooning modes have larger growth rates than low-n global modes, and in the nonlinear phase the modes saturate approximately in 5 ion transit times at the 2% level by the E × B flow generated by the instability. These results are consistent with early and recent electromagnetic gyrokinetic simulations.     

控制棒驱动机构运动过程的联合数值仿真研究

控制棒驱动机构运动过程是电磁场-流场-运动场相互耦合的复杂动态过程,无法通过静态方法或单项技术进行准确的计算。使用Magnet软件、Fluent软件和Adams软件进行了电磁仿真分析、流场分析和多体动力学分析的耦合计算。综合考虑了重力、电磁力、水阻力和弹簧力在控制棒驱动机构步跃过程中的作用,定量计算了电磁力、水阻力、运动件位移与速度等运动特性,以及步跃载荷。通过与试验值对比,计算得到的移动磁极吸合时间、临界吸合电流和步跃载荷值与试验值较为吻合,证明了控制棒驱动机构运动过程的联合仿真分析是一种有效的动态分析方法。      

Transmissivity of electromagnetic wave propagating in magnetized plasma sheath using variational method

A variational method is introduced to analyze the transmissivity of an electromagnetic wave propagating in the magnetized plasma sheath. The plasma density is modeled by two parabolic inhomogeneous regions separated by one homogeneous region. The Lagrangian density of the system is constructed based on the fluid energy density and the electromagnetic energy density.The total variation of the Lagrangian density is derived. The fluid and electromagnetic fields are numerically solved by expansion in piecewise polynomial function space. We investigate the effect of an external magnetic field on the transmissivity of the electromagnetic wave. It is found that the transmissivity is increased when an external magnetic field is applied. The dependence of transmissivity on the collision frequency between the electrons and the neutral particles has also been studied. We also show that the external magnetic field causes a shift in the critical frequency of the plasma sheath.     

Calculation and Optimization of ITER Upper VS Feeder Under an Electromagnetic Load

The upper vertical stability (VS) feeder is a part connected to the upper VS coil by a welding joint.The function of the feeder is to transfer current and coolant water to the VS coil.A giant electroma...     

设计S—N曲线的概率估计和ASME法的可靠性评价

基于ＬａｎｇｅｒＳ－Ｎ曲线,提出了设计Ｓ－Ｎ曲线的概率估计方法和ＡＳＭＥ法的可靠性评价方法。Ｐ－Ｓ－Ｎ曲线由文中提出的广义极大似然法估计。方法可应用于处理具有双随机性特征的Ｓ－Ｎ数据,并可推广应用于处理应力控制成组法疲劳试验和极大似然法试验得到的Ｓ－Ｎ数据。     

PRTHRUST-J1 code for calculation of blowdown thrust force and its experimental verification

This paper presents an outline of the PRTHRUST-J1 code for calculating blowdown thrust force and gives two numerical examples to show the effectiveness of this code. One numerical example is the problem of saturated steam blowdown. The blowdown thrust forces obtained from the PRTHRUST-J1 code were compared with those of the simplified method of Moody. Fairly good agreement was found between these two results. The other numerical example is the problem of jet discharging tests with stop valve performed in Japan Atomic Energy Research Institute. Analysis was carried out by varying the discharge coefficient. The analytical blowdown thrust force and pressure in the discharging nozzle were compared with experimental results. Qualitative agreement was found between the analytical and experimental results of the blowdown thrust force. Generally speaking, the blowdown thrust forces obtained from the experiment were between the analytical results for discharge coefficients of 1.0 and 0.6.