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。     

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。     

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。     

模拟有源积分器在脉冲磁场测量中的分析和应用

本文介绍了应用于脉冲磁场测量系统中的模拟有源积分器的研制.针对测量系统的需求和精度要求,设计了积分电路,并对实际有源积分电路的设计参数和器件参数做了误差分析,论证了电路的可行性和合理性,并给出了合理电路设计的有关参数和误差控制范围.电路实验和测试表明,脉冲磁场测量模拟有源积分器电路达到了设计要求,可满足磁测系统的需求.     

脉冲线测量波荡器磁场的研究

介绍脉冲线测量波荡器磁场一、二次积分分布的原理和一套较高精度的脉冲线测量系统的研制，分析了传感器、实验环境、线的张力和波的反射性等因素对测量精度的影响。该系统对5周期波荡器模型的磁场测量结果与高精度Hall探头测量值作了比较，结果满意。     

紧凑型脉冲磁场发生装置研制

研制并测试一套紧凑型脉冲强磁场发生系统,包括一套1mF/8kV高储能密度电容器电源、两台脉冲磁体和一套监控系统。系统分别在27mm和45mm的大孔径内产生最高为20T和10T的脉冲磁场。     

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     

脉冲磁体中电磁与温度场耦合的有限元分析

脉冲强磁体处于复杂的电磁、热、应力等多物理场共同作用下,设计中考虑的因素众多,物理关系复杂,分析过程繁琐。借助大型有限元软件分析工具ANSYS建立了70T脉冲强磁体中电磁、温度场耦合分析模型,实现了磁场与温度场的计算,并通过有限元方法实现了脉冲磁体性能的优化。实验结果表明,磁体样机达到70T磁场水平。     

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。     

脉冲强磁场高功率脉冲电源系统研制

本文介绍了用于脉冲强磁场大功率电源系统工作原理及研制工作。该系统由58台55心电容器提供1．0MJ储能，采用真空合闸开关作为主放电开关，由大功率二极管和电阻串联构成续流回路。整个脉冲电源系统可以输出最大脉冲宽度30ms，峰值30kA可调脉冲电流，以适应不同参数脉冲磁体实验需要。初步实验已达到30ms脉宽、35T脉冲磁场，该脉冲电源系统工作稳定可靠，具有抗干扰能力，达到设计参数要求，为今后更高参数脉冲强磁场科学实验装置研制提供了重要参考。     

基于嵌入式Linux的SPECT探头系统设计

设计了一套基于嵌入式Linux的单光子发射计算机断层成像(SPECT)探头系统。该系统硬件由探测器模块、数据采集模块、ARM微处理模块、网络接口模块和人机接口模块等几大模块组成。系统软件采用嵌入式Linux,并使用多线程技术。可以实现高速数据采集、实时数据校正和网络化数据通信,从而提高采集速率,减少系统死时间,提高系统的智能化和稳定性。     

A 7 T Pulsed Magnetic Field Generator for Magnetized Laser Plasma Experiments

A pulsed magnetic field generator was developed to study the effect of a magnetic field on the evolution of a laser-generated plasma.A 40 kV pulsed power system delivered a fast(~230 ns),55 kA current pulse into a single-turn coil surrounding the laser target,using a capacitor bank of 200 nF,a laser-triggered switch and a low-impedance strip transmission line.A one-dimensional uniform 7 T pulsed magnetic field was created using a Helmholtz coil pair with a 6 mm diameter.The pulsed magnetic field was controlled to take effect synchronously with a nanosecond heating laser beam,a femtosecond probing laser beam and an optical Intensified Charge Coupled Device(ICCD) detector.The preliminary experiments demonstrate bifurcation and focusing of plasma expansion in a transverse magnetic field.     

加速器磁场测量的霍尔多探头装置

描述了用于加速器磁场测量的霍尔多探头装置,它包括一个具有三只恒温盒(内有58只霍尔片)的测磁长臂,高精度磁场检定系统以及数据自动获取系统。分别叙述了霍尔片的定位、恒温、校准、数据采集、处理等内容。并提出了多探头装置测量中霍尔片稳定性的重要性。给出了在我们条件下的一些具体数据。本装置已应用在兰州重离子研究装置(HIRFL)的建造过程中,实践证明它能有效地高质量地满足加速器磁场测量的要求。     

The Power Supply System for HL-2A Tokamak＇s Magnetic Field

The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC output voltage and current are 3510 V and 45 kA, respectively. All the units are operated in a pulsed mode. The pulse duration is 5 s, and the cyclic period is 15 min. The power supply system consists mainly of pulsed flywheel motor generators, rectifying transformers, thyristor converters, diode rectifiers and switches. The system incorporates many key technologies-supply equalization with two generators and four diode bridges, constant-angle phase triggers with a wide frequency range, current equalization, a status detector for the high current 6-phase converter, and advanced monitoring based on a programmable logic computer and engineering parameter measurement. The experimental results show that the performance of the power supply system satisfies the requirements of HL-2A experiments very well.     

Efficiency of Removing Sulfur Dioxide in the Air by Non-Thermal Plasma Along with the Application of the Magnetic Field

1 IntroductionSO2 is one of the main hazards to human health, andit is the main component of the acidic oxides in the at-mosphere. The menace of the acidic pollution by SO2can be curtailed if it is removed from the air. In recenttime, researchers across the world have been concernedabout efficient removal of SO2.Several techniques have been applied to decompos-ing SO2 in the air in recent years. At present, themain technologies for removing sulfur dioxide include:the gas-phase reaction [1]…     

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.     

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.     

基于FPGA的数字核脉冲高速传输系统设计

针对高速数字核脉冲采集中的实时传输问题,提出了一种基于FPGA和USB的传输结构。该结构采用现场可编程逻辑阵列(FPGA)作为核心控制器,并通过乒乓操作原理对高速核脉冲进行采集,定义特定的简单可靠的传输帧结构。利用USB与PC机通信,既实现了高速数据的实时传输又真正实现了"即插即用",提高了整套系统的实用性。实验测试验证了该系统的高效性。     

Fabrication and absolute calibration of B-dot probe for magnetic field measurement on a high power laser facility

The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-II high power laser facility. Copper enameled silk with a cross section diameter of 0.1 mm is used to wind the one-turn coil with a 1 mm diameter. Two coils are paired and reversely linked to their respective circuits to form a differential B-dot probe that is sealed in and protected by a quartz shell. This B-dot probe is experimentally calibrated and then used to measure the pulsed magnetic field in laser targeting experiments at the Shenguang-II high power laser facility. Signals show a high performance of this B-dot probe. The common mode noise can be effectively canceled out by the differential pair. The magnetic field of over 300 T can be extrapolated at the location close to the target.