多路温度监测系统研制

本论文主要讲述了一种服务于CSR磁场安全的多路(64路)磁铁温度测量系统.根据CSR工程的要求,该温度测量系统能对磁铁线圈中的数百个点进行测温,并达到±1℃的测温精度.文中详细阐述了以MSP430F149为主控芯片的系统软硬件的研究、设计和实现.     

旋转线圈测量法测量BEPCⅡ对撞区超导磁铁磁场

北京正负电子对撞机二期工程(BEPCⅡ)中的超导磁铁用来提高BEPCⅡ的对撞亮度,并对闭轨和耦合进行校正。超导磁铁要尽可能靠近对撞点(IP),并浸泡在1.0T的探测器BESⅢ螺线管磁场中。对撞点两侧各有1块超导磁铁,每块都包含有聚焦磁铁SCQ、水平偏转磁铁SCB/HDC、垂直校正子VDC、斜四极子SKQ及反螺线管AS等功能磁铁。利用旋转线圈的测量方法对SCQ、SCB/HDC、VDC、SKQ等进行测量,了解其积分场、高次谐波及沿束流运行方向的局部磁场。通过与BNL在垂直杜瓦中的测量结果进行的比较可知,高次谐波测量结果差别不大;与张力线的比较可知,SCQ及SCB的主极矩偏差小于3×10-3。表明提出的计算方法可进行磁场的绝对测量。     

上海同步辐射装置平移长线圈磁测机的研制

描述了上海同步辐射装置(SSRF)平移长线圈磁测机的设计和制造。磁测机包括的硬件主要有：测量线圈、直线运动平台、高精度数字积分仪、步进电机控制卡、高稳定度电源、直流电流传感器、6位半数字电压表、通用接口总线(GPIB)接口卡及高精度编码器等。磁场测量和数据分析程序采用LabVIEW编制。该磁测机已测量了SSRF储存环二极磁铁的样机，效果良好，能做到灵活、快速和自动化地测量积分场。     

BRIF—ISOL二极铁磁场三阶梯度指数修正研究

串列加速器升级工程在线同位素分离器（ISOL）要求质量分辨率20000，分析磁铁场均匀性要求好于0．001％。采用所谓的垫补线圈可以有效地在磁场径向产生各阶梯度场，对二极铁引起的高阶像差进行修正。使用垫补线圈的优点在于可以方便地改变磁场梯度，而不受磁铁主场强的影响，同时可以节省系统的空间。改变一阶、二阶以及三阶梯度场的垫补线圈分别叫α、β和修正线圈。     

超灵敏小型回旋加速器质谱计主体(磁铁)的机械工程设计与计算

介绍SMCAMS主体(磁铁)的机械工程设计依据、磁铁与线圈的结构特点、安装与测试结果,并简述主机其它部件的机械设计.     

极坐标自动测磁装置

为了测量批量生产具有不同曲率半径的弯转磁铁,我们设计一种极坐标自动测磁装置,该装置可利用线圈或霍尔元件,对磁铁进行绝对测量和相对测量,用霍尔元件作绝对测量时,精度好于3×10~(-4),用长线圈作相对测量时,精度好于1×10~(-4),以用于检查批量生产磁铁的生产工艺的稳定性。     

扫描质子微探针扫描系统优化与分辨率测量

介绍了中国科学院上海应用物理研究所扫描质子微探针(Scanning Proton Microprobe,SPM)扫描线圈的改进与系统扫描分辨率的测试,设计了匝数可调的空心马鞍形扫描线圈,通过以单片机为核心的遥控系统来实现线圈匝数的调节和线圈的过载保护;给出了改进后SPM的扫描图像分辨率的测量计算方法以及测量结果,并初步研究了四膜虫和单颗粒大气气溶胶的元素分布.     

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     

大功率辐照加速器磁场系统研制

针对10MeV大功率辐照加速器研制的需求,对其磁场系统进行研制,此磁场系统由聚焦系统和扫描系统组成。根据束流加速输运的磁场要求,进行了磁场设计、模拟计算。聚焦系统由6个聚焦线圈组成,每个线圈约束磁场的径向均匀区为4cm,为加速管聚束段提供横向约束磁场,实测磁场分布与束流要求计算曲线分布基本吻合。扫描磁铁采用分体结构,扫描宽度为±334mm,最大扫描频率为15s^-1,通过优化磁极结构,使扫描均匀度达到92%。磁场系统各项性能均满足10MeV电子直线辐照加速器的技术要求并稳定运行至今。     

旋转线圈测量系统信号采集设备的研制

研制了动态信号采集卡与具有特定功能的软件相结合的旋转线圈磁场测量系统。该测量系统的信号采集设备实现了PDI-5025积分器功能,且在采样率、量程、精度、灵活性等方面优于常规测量系统。本文对信号采集设备的研制方案、采集功能的实现及系统的可靠性和稳定性等进行了介绍。     

Calibration of Power Systems and Measurements of Discharge Currents Generated for Different Coils in the EGYPTOR Tokamak

The EGYPTOR tokamak is a small device of rectangular cross section 25 × 20 cm. Its major (R) and minor (A) radius are 30 and 10 cm, respectively. The aspect ratio is 3. The present work is devoted to measure the absolute values of the discharge currents and to calibrate the different power systems used to supply different coils in the tokamak. Two different methods are applied to measure the discharge currents from different capacitor banks. The first is the direct method employing a calibrated resistance R=0.008 Ω; this resistance was prepared and calibrated in the IPP of the Czech Academy of Sciences, Czech Republic. The second is the indirect method using a calibrated Rogowski coil, fabricated and calibrated also in Prague (Czech Rogowski coil). Both methods are applied simultaneously. Details of each power system presently used are reported. Sensitivity calibration of two different Rogowski coils is also done, and comparison with the calculated sensitivity shows good agreement.     

Finite Element Analyses and Instrumentation Layout for Single Coil Testing of TF Coils in HT-7U

The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian '. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.     

二极铁磁场一阶和二阶梯度指数修正

本文采用表面修正线圈对二极铁磁场一阶（α线圈）和二阶（β线圈）指数进行修正。当分别通电流I=3A时,α=0.052、β=0.27。实验结果与理论设计符合得很好,α值相差约1%,β值相差约2%。     

Absolute Measurements of the Magnetic Field Generated by Different Coils in the Center of EGYPTOR Tokamak

The present work is devoted to measure the absolute magnetic field produced by different coils in the EGYPTOR tokamak using a calibrated pickup coil. Scaling these measurements in different equations connected with the discharge currents from each supply system are performed. The pickup coil used in the present study is well calibrated with Helmholz coils at the IPP in Prague, Czech Republic. A 0.2% deviation has been found between an evaluation done in the present study and the calibration using Helmholz coils. Experimental measurements of the toroidal magnetic field are in good agreement with calculations to within 2%. Very low values of stray magnetic field components arising from TF and OH coils are recorded which proves that the compensation coils for these components are sufficient.     

Quench detection of fast plasma events for the JT-60SA central solenoid

The JT-60 is planned to be modified to a full-superconducting tokamak referred to as the JT-60 Super Advanced (JT-60SA). The maximum temperature of the magnet during its quench might reach the temperature of higher than several hundreds Kelvin that will damage the superconducting magnet itself. The high precision quench detection system, therefore, is one of the key technologies in the superconducting magnet protection system.The pick-up coil method, which is using voltage taps to detect the normal voltage, is used for the quench detection of the JT-60SA superconducting magnet system. The disk-shaped pick-up coils are inserted in the central solenoid (CS) module to compensate the inductive voltage. In the previous study, the quench detection system requires a large number of pick-up coils. The reliability of quench detection system would be higher by simplifying the detection system such as reducing the number of pick-up coils. Simplifying the quench detection system is also important to reduce the total cost of the protection system. Hence the design method is improved by increasing optimizing parameters. The improved design method can reduce the number of pick-up coils without reducing the sensitivity of detection; consequently the protection system can be designed with higher reliability and lower cost. The applicability of the disk-shaped pick-up coil for quench detection system is evaluated by the two dimensional analysis. In the previous study, however, the analysis model only took into account the CS, EF (equilibrium field) coils and plasma. Therefore, applicability of the disk-shaped pick-up coil for the quench detection system remains open question because the fast plasma events, such as disruption, mini collapse and ELM (edge localized mode), directly influences on the voltage of pick-up coil making the quench signal undetectable. Consequently, a new analysis model proposed in the present paper was designed to avoid this difficulty by introducing the passive coil series such as vacuum vessel and stabilizer. The influence of fast plasma events is absorbed by passive coil series like real system, and the evaluation of applicability can be examined in detail. The analysis results show that the disk-shaped pick-up coil is applicable whenever the standard operation, disruption, mini collapse and ELM.     

Revisiting the poloidal magnetic confinement

This note proposes a closed poloidal magnetic configuration with an in-vessel coil system held by shielded supports. A dipole field is bounded by external coils and constrained into a hollow torus aiming at uniform intensity. In the horizontal mid-plane region the external coils and the dipole outer coils are broken in four arcs and bridged by couple of straight branches. Arcs and straight branches build a set of four side coils. In the clearance between their straight branches four tunnels in the poloidal magnetic field are achieved, to pass the supports and the feeders of the in-vessel coil system.A poloidal machine with a plasma thick as those of present large experiments is outlined. The dipole radius is 5.4 m, the plasma about it has a constant poloidal cross-section about 40 m², a volume about 1300 m³ and a minimum thickness 1 m in the outboard. The magnetic field ranges from 1.4 to 1.8 T.     

Thermal analysis of the Mirnov coils of Wendelstein 7-X

Mirnov coils are used to measure fluctuations of the magnetic field which are in particular generated by magnetohydrodynamic (MHD) modes. The underlying plasma currents have a multipolar structure in a poloidal cross-section. Therefore the amplitude of the magnetic fluctuations decays quickly with increasing distance from the plasma edge. It is hence important to place the Mirnov coils as close to the plasma edge as possible where they are exposed to high thermal loads. Two types of Mirnov coils are proposed to be used in Wendelstein 7-X (W7-X). Type 1 (44 Mirnov coils) should be mounted on the plasma side of wall protection panels with a graphite cap to shield them from direct plasma exposure. Type 2 (137 Mirnov coils) will be located behind the tiles of the heat shields. An important issue concerning the design of these Mirnov coils is to verify their suitability for steady state operation from the thermal point of view. Both steady state and transient finite element thermal analyses were performed for the Mirnov coils under different conditions and with different designs. The paper presents detailed thermal analyses of the Mirnov coils.     

Mechanical Analysis and Optimization of ITER Upper ELM Coil & Feeder

International thermonuclear experimental reactor （ITER） edge localized mode （ELM） coils are used to mitigate or suppress ELMs. The location of the coils in the vacuum vessel and behind the blankets exposes them to high radiation levels and high temperatures. The feeders provide the power and cooling water for ELM coils. They are located in the chinmey ports and experience lower radiation and temperature levels. These coils and feeders work in a high magnetic field environment and are subjected to alternating electromagnetic force due to the interaction between high magnetic field and alternating current （AC） current in the coils. They are also subjected to thermal stresses due to thermal expansion. Using the ITER upper ELM coil and feeder as an example, mechanical analyses are performed to verify and optimize the updated design to enhance their structural performance. The results show that the conductor, jacket and bracket can meet the static, fatigue and crack threshold criteria. The optimization indicates that adding chamfers to the bracket can reduce the high stress of the bracket, and removing two rails can reduce the peak reaction force on the two rails arising from thermal expansion.     

Testing and qualification of Control & Safety Rod and its drive mechanism of Fast Breeder Reactor

Prototype Fast Breeder Reactor (PFBR) has two independent fast acting diverse shutdown systems. The absorber rod of the first system is called Control & Safety Rod (CSR). CSR and its Drive Mechanism (CSRDM) are used for reactor control and for safe shutdown of the reactor by scram action. In view of the safety role, the qualification of CSRDM is one of the important requirements.CSR & CSRDM were qualified in two stages by extensive testing. In the first stage, the critical subassemblies of the mechanism, such as scram release electromagnet, hydraulic dashpot & dynamic seals and CSR subassembly, were tested and qualified individually simulating the operating conditions of the reactor. Experiments were also carried out on sodium vapour deposition in the annular gaps between the stationary and mobile parts of the mechanism.In the second stage, full-scale CSRDM and CSR were subjected to all the integrated functional tests in air, hot argon and subsequently in sodium simulating the operating conditions of the reactor and finally subjected to endurance tests. Since the damage occurring in CSRDM & CSR is mainly due to fatigue cycles during scram actions, the number of test cycles was decided based on the guidelines given in ASME, Section III, Div. 1. The results show that the performance of CSRDM & CSR is satisfactory. Subsequent to the testing in sodium, the assemblies having contact with liquid sodium/sodium vapour were cleaned using CO₂ process and the total cleaning process has been established, so that the mechanism can be reused in sodium. The various stages of qualification programmes have raised the confidence level on the performance of the system as a whole for the intended and reliable operation in the reactor.     

A Systematic study of modular coil characteristics for 2-field periods quasi-axisymmetric stellarator QAS-LA

Modular coil characteristics of a 2-field periods quasi-axisymmetric stellarator QAS-LA configuration with an aspect ratio A_p = 3, magnetic pressure ∼4% and rotational transform ι ∼ 0.15 per field period supplied by its own shaping have been detailed studied. In addition, the characteristics of modular coils for QAS-LA were compared with those of an intermediate QA configuration QAS-LAx and a tokamak based on the same center magnet field B₀, aspect ratio and number of coils. As expected, the B_max/B₀, force F and overturning moment M, increase with the increased complexity of the coil shape. The relationships between the modular coils’ parameters (such as radius curvature ρ, distance from coil to coil Δ_c–c and the cross-section of coils) and the electromagnetic characteristics have been systematically summarized. The approximate formula for the maximum magnetic field in the coil body as functions of modular coil parameters (Δ_c–c, ρ) was derived for a simple two wire system which will be useful when optimizations of coil properties are called for.