基于DSP技术的长时间积分器

本文通过讨论积分器实现的形式和积分误差抑制的措施,介绍了一种先由模拟积分电路对输入信号进行交替积分,再用数字信号处理方式实现积分误差修正和积分结果拼接的长时间、低漂移积分器的设计方法,并给出了相关实验结果.     

HT-7中长时间低漂移模拟积分器的研制

电磁测量是托卡马克装置中最基本的诊断方法,通常利用磁感应原理来测量HT-7装置内部磁场和磁通,因此需要用积分器对磁测量的输出信号进行积分。讨论了单运放模拟积分器的特点,提出了利用实时积分漂移补偿的方法设计新型积分器,解决了积分过程中积分器本身的等效输入偏移量、温度漂移及地噪声等带来的积分误差。给出了系统原理和设计框图,并在HT-7超导托卡马克的实验中,验证了该积分器能够满足等离子体长时间放电对积分器在积分精度和噪声精度上的要求。     

长时间无零漂积分器中的单元积分电路

本文论述了应用在长时间无零漂积分器中的单元积分电路的原理与设计.该电路结合了零点补偿和基于斩波思想的分段积分两项技术,主要解决传统模拟积分器存在的积分零漂问题,使积分零漂减小到极低的水平,积分1000s绝对积分零漂典型值为16.7mV,同时也改善了由于积分泄漏引起的非线性误差.该电路的研制完成为进一步设计用于托卡马克装置上电磁测量的长时间积分器系统奠定了基础.     

HLS储存环注入系统冲击磁铁微秒脉冲磁场设计计算

介绍了合肥光源(HLS)新注入系统中铁氧体磁芯冲击磁铁的脉冲磁场形态的设计与计算。首先根据注入过程跟踪计算,给出了冲击磁铁脉冲磁场的设计要求。然后对脉冲磁场的产生进行了定性分析和数值计算,讨论了在不同条件下磁芯中产生的涡流对脉冲磁场均匀性的影响,最后根据物理设计要求确定了磁铁设计参数。     

微秒脉冲磁场自动测量系统及误差分析

简要介绍冲击磁铁在加速器在应用以及微秒脉冲磁场的测量原理，并对整个测量系统的误差加以分析说明。     

单次性脉冲磁场的测量原理及实现方法

单次性脉冲磁场在各种高能加速器中有着重要的应用。本文主要介绍单次性脉冲磁场波形、场型分布、磁场幅度绝对值的测量原理和实现方法。在场型分布测量中,着重介绍了误差的消除方法和利用微型计算机或单板机实现数字化测量。     

合肥光源储存环铁氧体冲击磁铁涡流模型与分析

铁氧体冲击磁铁是国家同步辐射实验室二期工程注入系统改造课题中关键注入部件之一 ,其主要功能是产生微秒量级均匀的脉冲磁场。文章介绍了铁氧体冲击磁铁设计过程中建立的涡流问题的数学模型及关于涡流问题分析。数值计算结果表明 :选择合理的铁氧体电导率和磁芯结构参数 ,可以基本消除磁芯中涡流对脉冲磁场分布的影响。冲击磁铁脉冲磁场测量结果表明 ,合肥光源储存环铁氧体冲击磁铁设计是合理的     

基于SOPC架构的脉冲磁场数据采集系统

提出了一种嵌入式高速高精度脉冲磁场数据采集系统的设计方案,基于先进SOPC技术,在FPGA中嵌入了32位Nios Ⅱ软核系统,实现脉冲磁场信号的采集、处理、存储、传输等功能.该系统具有设计灵活、数据处理速度快、精度高和扩展性好等优点.     

EAST托卡马克新型积分器系统控制器的研制

为了满足EAST托卡马克的实验需求,提升积分器系统的可维护性和可测试性,研制了新型积分器系统控制器。该控制器采用ARM微控制器和轻量级IP协议栈,实现了积分器系统的网络化控制。所提供的参数设置指令可远程设置和读取积分器板卡上放大器的放大倍数,而控制指令则提供了初始化、标准信号积分、脉冲积分、积分保持、标定和探针测试功能。经实验和EAST现场测试,该积分器系统控制器可满足EAST装置的实验要求。     

单次性脉冲磁场幅度跳动测量及其计算机测量系统

单次性脉冲磁场在各种高能加速器中有着重要的应用。其磁场波形、场型分布、磁场幅度绝对值的测量已经有过报导,本文继续介绍单次性脉冲磁场幅度跳动的测量及其计算机测量系统。在系统的工作原理部分,以软件硬件相结合的方式介绍了系统的工作原理,给出了测量结果。文章最后分析了测量误差,提出了减小误差,提高测量精度的方法,给出了系统精度。     

托卡马克程控积分器系统的研制

为满足J-TEXT托卡马克装置电磁诊断的需求,研制了程控积分器系统。积分器系统采用模块化方式设计,由积分器板卡、控制器板卡、线性电源板卡和BNC接口板卡组成,并由上位机控制程序进行网络化控制。一套积分器系统可提供32路积分器通道,所有积分器通道均具有4种可供程控选择的积分时间常数,同时提供3种积分器运行控制方式。实验室和J-TEXT现场测试结果为：每路积分器通道的输出电压范围为-10～10 V;输出噪声≤5 mV;在4种积分时间常数条件下,积分器累计积分100 s的输出漂移均小于5 mV。     

Measurement system for SSRF pulsed magnets

This paper describes the magnetic field measurement system for pulsed magnets in SSRF.The system consists of magnetic probes,analog active integrator,oscilloscope,stepper motor and a controller.An application pro- gram based on LabVIEW has been developed as main control unit.After the magnetic field mapping of a septum magnet prototype,it is verified that the test results accord with the results of theoretical calculation and computer simulation.     

Tunable biasing magnetic field design of ferrite tuner for ICRF heating system in EAST

Ion cyclotron range of frequency(ICRF) heating has been used in tokamaks as one of the most successful auxiliary heating tools and has been adopted in the EAST. However, the antenna load will fluctuate with the change of plasma parameters in the ICRF heating process. To ensure the steady operation of the ICRF heating system in the EAST, fast ferrite tuner(FFT) has been carried out to achieve real-time impedance matching. For the requirements of the FFT impedance matching system, the magnet system of the ferrite tuner(FT) was designed by numerical simulations and experimental analysis, where the biasing magnetic circuit and alternating magnetic circuit were the key researched parts of the ferrite magnet. The integral design goal of the FT magnetic circuit is that DC bias magnetic field is 2000 Gs and alternating magnetic field is±400 Gs. In the FTT, E-type magnetic circuit was adopted. Ferrite material is Nd Fe B with a thickness of 30 mm by setting the working point of Nd Fe B, and the ampere turn of excitation coil is 25 through the theoretical calculation and simulation analysis. The coil inductance to generate alternating magnetic field is about 7 m H. Eddy-current effect has been analyzed, while the magnetic field distribution has been measured by a Hall probe in the medium plane of the biasing magnet. Finally, the test results show the good performance of the biasing magnet satisfying the design and operating requirements of the FFT.     

多道时间幅度变换电路的设计

介绍了一个多道时间幅度转换器(TAC)电路.它主要由起-停型时间幅度变换电路、放大电路、采样保持电路、积分控制电路、采样保持控制电路、判断电路等组成.其特点是精度高,速度快,电路简单,多通道,易与计算机数据获取和处理系统配合使用.可以广泛应用于大型探测器阵列前端电子学系统.     

基于Labview的相关法测量钠流量系统设计

为满足中国实验快堆(CEFR)一回路主泵旁路钠流量计校准的需求,设计了1套基于Labview软件的相关钠流量测量系统。本文介绍了相关法的测量原理、设计的相关钠流量测量系统、对该系统的仿真试验和钠回路上的验证试验。试验结果表明,这套基于Labview的相关钠流量测量系统是可行的。本文还进行了该系统的测量误差分析,给出了减小误差的方法。该系统及其试验为CEFR一回路主泵旁路钠流量计在役校准装置的设计、调试和运行提供了依据。     

大功率脉冲磁场电源系统

描述了中国环流器2号A(HL-2A)装置磁场电源系统,介绍了电源的控制系统和实验结果。磁场电源总脉冲容量近250 MVA,一次放电脉冲释能1 300 MJ,其中单套电源的最高直流电压为3510 V,最大电流为45 kA,均以脉冲方式运行,脉冲时间5 s,重复周期10 min。电源主回路主要由飞轮脉冲发电机、晶闸管变流设备、硅整流器等组成。采用了硅整流器直接并联、电流平衡、恒角移相控制、整流器全关断检测、先进的监控和脉冲高压强流检测等技术措施。实验表明,磁场电源的性能指标能够满足装置实验的要求。     

Effects of pulsed magnetic field on density reduction of high flow velocity plasma sheath

A three-dimensional model is proposed in this paper to study the effect of the pulsed magnetic field on the density distribution of high flow velocity plasma sheath. Taking the typical parameters of plasma sheath at the height of 71 km as an example, the distribution characteristics and time evolution characteristics of plasma density in the flow field under the action of pulsed magnetic field, as well as the effect of self-electric field on the distribution of plasma density, are studied. The simulation results show that pulsed magnetic field can effectively reduce the density of plasma sheath. Meanwhile, the simulation results of three-dimensional plasma density distribution show that the size of the density reduction area is large enough to meet the communication requirements of the Global Position System(GPS) signal. Besides, the location of density reduction area provides a reference for the appropriate location of antenna. The time evolution of plasma density shows that the effective density reduction time can reach 62% of the pulse duration, and the maximum reduction of plasma density can reach 55%. Based on the simulation results, the mechanism of the interaction between pulsed magnetic field and plasma flow field is physically analyzed. Furthermore, the simulation results indicate that the density distributions of electrons and ions are consistent under the action of plasma self-electric field.However, the quasi neutral assumption of plasma in the flow field is not appropriate, because the self-electric field of plasma will weaken the effect of the pulsed magnetic field on the reduction of electron density, which cannot be ignored. The calculation results could provide useful information for the mitigation of communication blackout in hypersonic vehicles.     

A user configurable data acquisition and signal processing system for high-rate,high channel count applications

Real-time signal processing in plasma fusion experiments is required for control and for data reduction as plasma pulse times grow longer. The development time and cost for these high-rate, multichannel signal processing systems can be significant. This paper proposes a new digital signal processing (DSP) platform for the data acquisition system that will allow users to easily customize real-time signal processing systems to meet their individual requirements.The D-TACQ reconfigurable user in-line DSP (DRUID) system carries out the signal processing tasks in hardware co-processors (CPs) implemented in an FPGA, with an embedded microprocessor (μP) for control. In the fully developed platform, users will be able to choose co-processors from a library and configure programmable parameters through the μP to meet their requirements.The DRUID system is implemented on a Spartan 6 FPGA, on the new rear transition module (RTM-T), a field upgrade to existing D-TACQ digitizers.As proof of concept, a multiply-accumulate (MAC) co-processor has been developed, which can be configured as a digital chopper-integrator for long pulse magnetic fusion devices. The DRUID platform allows users to set options for the integrator, such as the number of masking samples. Results from the digital integrator are presented for a data acquisition system with 96 channels simultaneously acquiring data at 500 kSamples/s per channel.     

太阳X射线成像望远镜低噪声信号采集系统

太阳X射线成像望远镜是我国正在研制的第一台观测太阳10nm以下X射线活动的空间仪器,采用背照射式全耗尽型短波敏感CCD作为成像传感器,利用低噪声信号采集系统采集X射线CCD中的电荷信号,生成图像数据.文章在详细介绍X射线CCD输出结构的基础上,分析了CCD输出信号产生的过程,复位噪声产生原因和CCD输出信号的特点,引出了对信号采集系统性能指标和电路结构的要求.继而介绍了信号采集系统的各组成部分,包括前置放大电路,相关双采样电路,主放大器和AD转换电路,重点分析了相关双采样电路的原理,文中给出了各部分的设计参考和测试结果,最后总结了空间相机低噪声信号采集系统的设计原则.测试结果表明该系统成功抑制了噪声,满足太阳X射线观测的要求.     

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。