上海光源新型波荡器EPU200磁结构的机械设计及力学分析

跟据用户的实验要求,本项目为上海光源中产生低轴功率密度的同步辐射光设计了新型波荡器EPU200(Elliptically Polarized Undulator)。EPU200是首台拥有8排磁化块、可以产生椭圆极化辐射并降低轴功率密度的纯永磁波荡器。其8排磁排列安装在4根铝梁上,每个磁化块固定件上安装两块磁化块,其磁结构的机械结构和安装十分复杂。磁结构对波荡器的品质有很大影响,首先设计EPU200的磁结构的机械结构,根据磁化块的排列通过Radia程序计算出磁化块的最大受力,并通过ANSYS Workbench对磁结构进行力学分析,得出该结构中磁化块的位置变形量,从而验证该机械结构的可行性。     

可变椭圆极化波荡器EPU10.0的传动控制

可变椭圆极化波荡器EPU10.0是一种可产生多种极化模式相干太赫兹辐射的波荡器。EPU10.0的主要特点是波荡器内的磁块分上下各两排，上下气隙固定，一对对角线永磁块排列固定，另一对可独立做纵向移动，移动重复定位精度小于0.01mm。对该波荡器的磁测结果显示：在水平线极化和圆极化模式下，磁场的两个横向分量的一、二积分分别为0.012T•cm和0.7T•cm²，达到了设计指标。     

带周期性分布纵向涡发生器的矩形狭窄通道内传热流动的数值模拟

在换热表面上周期性地安装粗糙元,可以使流动区域产生漩涡从而增强换热.本文采用数值分析的方法,以水作为工作介质,以带有纵向涡发生器狭窄矩形通道为研究对象,研究不同排列方式纵向涡发生器的传热性能,分析不同的纵向涡发生器入射角度β、不同流向、不同纵向涡间距对换热和流动特性的影响.结果表明,纵向涡发生器能够强化换热,当入射角度β=50°时,换热效果最佳.     

波荡器磁场误差对其自发辐射的影响模拟研究

波荡器由多个单磁块组成,磁块不可避免的剩磁离散性和尺寸离散性是引起波荡器磁场误差的根本原因。波荡器磁场误差将影响波荡器自发辐射谱的质量。本文给出一种新的单磁块磁场、波荡器磁场及自发辐射的模拟方法,从单磁块磁场模拟人手,使用正态分布随机数发生器产生多组不同剩磁或者不同尺寸的单磁块,再由这种方式产生的单磁块组成波荡器,然后计算自发辐射,从而研究波荡器磁场误差对自发辐射的影响。     

单侧带有周期性分布纵向涡发生器的矩形窄通道内传热强化的实验研究

在换热表面上周期性地安装粗糙元可以使流动区域产生漩涡从而增强换热。对单侧带有周期性分布纵向涡发生器的矩形窄通道内的强化传热进行了实验研究,得出了Re在3×103～2×104的范围内不同流动方向(顺流、逆流)条件下纵向涡发生器对流动与换热特性的影响规律。结果表明:纵向涡发生器对换热有较好的强化作用,同时通道的阻力略有增加。在3种不同比较准则(相同泵功率、相同压降及相同流量)条件下,顺流强化效果均略好于逆流。     

非晶磁性材料与磁共振研究

非晶磁性材料是指原子排列无序而自旋(磁矩)排列有序的磁有序(序磁)材料。这类材料由于其基本磁性的许多特点和在磁、电、力学性质上的良好性能,而受到基础研究和实际应用上的重视。要深入了解和充分发挥这类材料的作用,就必须研究宏观性能、微观结构及其相互关系,而磁共振正是研究这类材料微观结构的重要方法之一。磁共振是指系统能谱在恒定磁场作用下产生Zeeman磁能级分裂,当外加高频电磁场的量子能量与磁能级裂距相等时发生的强烈量子跃迁现象。利用核磁矩系统基态磁能级间跃迁的核磁共振和基态与激发态磁     

直动电磁阀磁场特性分析

控制棒水压驱动技术是清华大学核能与新能源技术研究院具有自主知识产权的一项新型发明专利技术.组合阀属于该项技术的关键部件,组合阀是由三个直动电磁阀组成,电磁阀的性能直接影响组合阀的性能,从而影响控制棒水压驱动技术的运行性能.本文就控制棒水压驱动系统运行过程中所出现的异常工况,运用ANSYS电磁场分析软件,对其直动电磁阀的多种运行工况进行了电磁场特性分析.分析结果表明:导磁材料的不当使用形成磁路的改变,引起某些工况下磁力反向,使电磁阀在特定情况下出现故障,进而造成控制棒水压驱动系统异常;通过电磁场特性分析可以进一步优化直动电磁阀的设计.     

退磁场对穆斯堡尔谱形的影响

对于一些铁磁物质,原子磁矩的排列会使界面处产生未抵消的磁极,在其内部产生退磁场。当样品宏观未被磁化时,由于磁畴混乱取向,退磁场影响相互抵消。当外加磁场Hex时,磁畴按一定顺序排列,退磁场影响就比较明显。这时作用于穆斯堡尔原子核的有效磁场为     

区域剪切带的磁场模式

低空航磁测量和高程数据的详细数字分析揭示了约80m 宽的大区域剪切带的系统模式。通过使用数字图象分析,利用变向“照明”的“山地屏蔽”技术可获得最大分辨力(空间的和函数的)。原来识别的与断层有关的低磁氧化带是三维网络的一部分,这种网络包含有迁移的地壳岩石碎片,大小和形态不同的长条形透镜体。与近代活动断层比较,在前寒武地区,使原来未变形岩石产生变形的地     

伪双元合金Hf0.82Ta0.18Fe2温度诱导自旋重取向的穆斯堡尔研究

制备了伪双元合金Hf0.82Ta0.18Fe2.X射线衍射表明,合金为C14型Laves相结构,晶格常数为a=4.92133(3)(A),c=8.0488(1)(A).在温度20K～380K范围内测量了穆斯堡尔谱.表明合金随温度存在两个磁相变点,一个从顺磁态(PM)到反铁磁态(AFM),相变温度为330K,另一个从反铁磁(AFM)到铁磁态(FM),相变温度约为180K.在AFM-FM相变点,6h位Fe原子自旋方向发生翻转,从沿c方向转向ab平面.相应地,2a位的Fe原子,在AFM态为顺磁性,经过该相变后,相应地呈现铁磁性排列.     

Development and Investigation of a Dipole Magnet with a High-Temperature Superconductor Winding

The structure of a dipole magnet with an iron yoke, where the winding is made of a Bi-2223 high-temperature superconductor, has been developed and the magnet has been built at the Institute of High-Energy Physics. The magnet has also been tested. A magnetic field 0.9 T has been attained in the aperture at temperature 65 K and 1.9 T at 4.2 K. The special features of the magnet structure are described and the results of testing of the magnet in a submerged cryostat at different temperatures are presented.     

Design Studies of a Multicusp Ion Source with FEMLAB Simulation

Femlab simulations have been used to arrive at the first step in the design of an ion source. The goal is to optimize Magnetic multipole plasma confinement geometries, the increased area of constant magnetic field in the central region of the plasma volume and the increase in number of electrons which have stationary orbits within this region of the field. The confinement of electrons is essential for Multicusp ion source to produce intense beams of negative hydrogen ions (H⁻). A higher electron temperature and density given by a better plasma confinement leads to the higher efficiencies of the ionization and the production of highly charged ions. We have performed Femlab simulations of the magnetic flux density from permanent magnet used for a Multicusp ion source, plasma confinement and trapping of fast electrons by the magnetic field.     

钕铁硼低温永磁波荡器静态热负载研究

低温永磁波荡器(Cryogenic Permanent Magnet Undulator,CPMU)利用稀土永磁材料钕铁硼或镨铁硼在低温下的剩磁及内禀矫顽力大幅增大的特性,通过使磁体工作在50-150 K的低温环境,获得相比于常规真空内波荡器(In-vacuum Undulator,IVU)高30%-50%的磁场性能。在磁气隙一定的条件下,CPMU可以在较小的周期长度下获得较大的磁场强度,这对于提升同步辐射光的亮度具有重要意义。本文介绍了上海光源(Shanghai Synchrotron Radiation Facility,SSRF)钕铁硼CPMU磁体冷却技术的研究进展,对CPMU的静态热负载进行了详细的理论分析及实验研究。CPMU静态热负载的理论分析方法在CPMU样件低温冷却实验装置得到了验证,并在完整钕铁硼CPMU样机中得到了应用。     

全永磁ECR离子源研究进展

ECR(电子回旋共振)离子源是产生稳定的强流多电荷态离子束流最有效装置.全永磁ECR离子源因其独特的特点为很多中小型多电荷态离子束流实验平台与离子注入机等系统所采用,为后者产生重复性好、稳定性强的多电荷态离子束流.本文着重论述了中国科学院近代物理研究所研制的几台全永磁多电荷态ECR离子源及其特性与典型性能,如能产生强流高电荷态离子束流的高性能全永磁离子源LAPECR2,能产生强流中低电荷态离子束流的LAPECR1,能产生多电荷态重金属离子柬流的LAPECRl-M等.这些性能稳定的离子源为提高近代物理研究所相关试验平台的性能提供了关键的束流品质保障.     

尼尔逊离子源重离子束流的发射度

尼尔逊离子源已广泛地应用于重离子加速器、同位素分离器及研究用离子注入机。用于C-600离子注入机的尼尔逊离子源,目前已获得达100μA的三十余种重离子束,其中有近二十种固体元素。     

Estimation of Excitation Coefficient by Floating Wire Technique for Reflection Magnet of EAST NBI

The principle of floating wire technique is introduced. Wire trace and current are measured through a dipole magnet through 180° in the horizontal plane. Measurements are made for testing the reflection magnet performance of neutral beam injector of experimental advanced superconducting tokamak. The magnetic field intensity is estimated by wire current, wire tension and radius of wire orbit. The excitation coefficient of the reflection magnet is about 1.07, which is in agreement with requirement of engineering design. Using the excitation coefficient, the operation guide data of reflection magnet is given with ion energy, $ I = 40.99\sqrt E $ .     

中国散裂中子源快循环同步加速器注入系统水平涂抹凸轨磁铁样机的设计

阐述了中国散裂中子源（CSNS）快循环同步加速器（RCS）注入系统水平涂抹凸轨磁铁样机的设计。为满足设计要求和空间位置关系的需要,提出一种不对称窗框型铁芯结构,同时针对样机研制中存在的技术难题提出相应的解决方案。磁场模拟计算和试验的结果表明,该结构设计合理。     

EAST中性束注入器稳态偏转磁铁的参数设计与估算研究

中性束注入器偏转磁铁是剥离束流中剩余离子的关键设备,它与剩余离子吞食器等内部部件构成了中性束注入器的束偏转系统。束偏转系统的性能对中性束注入器束流的品质及其束传输效率发挥着重要作用。本文根据EAST(Experimental Advanced Superconducting Tokamak,EAST)中性束注入器对束偏转系统的要求,对其偏转磁铁各性能参数进行了估算。为中性束注入器设计了一台用以剩余离子180°偏转的偏转磁铁。该偏转磁铁采用H型二极电磁铁结构;其磁极端面设计为138cm×47cm的圆角矩形结构;其线圈设计为每侧2饼,每饼2层,每层8根的串联结构,导线选用外方内圆空心铜导体,以满足偏转磁铁稳态运行的需要。该设计的偏转磁铁在370 A励磁电流条件下,可提供80keV氘离子束偏转所需的磁场。实验测试结果显示:500 A励磁电流稳态运行条件下,偏转磁铁线圈冷却水温升约21.5℃,该设计结构的偏转磁铁满足EAST中性束注入器满参数稳态运行和未来运行参数逐步提高的需要。     

Energy compensation of an ISOLDE-type isotope separator

The placement of an electric dipole following the magnet in an ISOLDE-type isotope separator can compensate for the energy dispersion introduced by the magnet. This allows the injection into such a separator of ion beams with energy spreads of up to ±3% at mass A = 120, an order of magnitude larger than previously possible. Calculations are presented applying this technique to an IGISOL (ion guide isotope separator on-line) facility, where such energy spreads occur under the conditions where the highest yields are available.     

Magnet stage optimization of 5 kW multi-cusped field thruster

The multi-cusped field thruster is a unique electric thruster device, which has many advantages such as long lifetime, large-range thrust throttling ability, high thrust density, and low mass. The thruster employs several alternating polarity permanent magnets to create a periodic magnetic field with several cusps. Previous studies have indicated that the basic ionization and acceleration processes are directly related to the electron motion behavior, which mainly depends on the magnetic field characteristics. The magnet number and magnet stage length are two key magnetic field parameters that have important effects on the thruster performances. In this paper, both the magnet number and magnet stage length parameters are studied for the optimization of a 5 k W multi-cusped field thruster. The results indicate that the three-stage thruster has a better electron confinement than the two-stage thruster. It has lower ion energy loss at the wall, and shows a higher ionization rate. Therefore, the three-stage magnetic field is a superior magnetic field configuration. Besides, the three-stage magnetic field simulation results indicate that an optimal accelerating electric field distribution and ionization region distribution could be obtained when the magnet length ratio is 78:25:20.