纵向多灯丝电子帘加速器的束流不均匀度

束流不均匀度是电子帘加速器束流性能的一重要指标。影响束流不均匀度的主要因素是加速器结构中各电极（阴极、反射极、栅极、阳极）的电位、形状及其相对位置。本工作针对1台纵向多灯丝电子帘加速器的实际结构参数,计算其束流不均匀度,通过分析和比较,讨论了进一步改善束流不均匀度的可能途径,为改进电子帘加速器的设计提供了参考。     

Design of Beam Control Magnet System for High Energy and High Power Electron Irradiation Accelerator

正The high energy and high power electron irradiation accelerator of 10MeV/20kW is mainly used in food preservation,sterilization and other fields.It has a wide range of applications.In order to ensure the system with high stability,high repeatability and continuous operation,the system uses beam control system.The beam control     

Harp, A Short Pulse, High Current Electron Beam Accelerator

A 3 MV, 800 kA, 24 ns electron beam accelerator is described and the results of initial switching experiments are discussed. The generator will provide a source for studying the physics of processes leading to electron beam driven, inertially confined fusion. The major components of the accelerator are two diodes with a common anode, twelve oildielectric Blumleins with low jitter (< 2 ns) multichannel switches, three intermediate storage capacitors, a trigger pulse generator and two Marx generators.     

A Simulation Model for the FX-75 Relativistic Electron Beam Accelerator

A one-dimensional, time-dependent coaxial transmission line model is presented for analysis of the voltage, v(z,t), and current, i(z,t), response to an electron beam load for the FX-75 accelerator. The model consists of finite segments of coaxial transmission lines separated by lumped equivalent circuits representing the various abrupt discontinuity points. Each line segment is divided into two one-dimensional grids with a 0.1 nanosecond transit time grid separation for the backward and forward TEM waves. Results from program FXPULSE utilizing a thirty-eight line-load representation of the FX-75 accelerator for a time-invariant, high-impedance diode load show close agreement.     

电子辐照加速器大功率工频高压电源

文章介绍目前两种用于烟气脱硫加速器的不同形式直流高压电源，分析了它们各自的特点。针对它们存在的不足之处，提出了一种全新的倍压型桥式整流线路，并对此线路进行了理论推导和计算机模拟仿真。     

Power Consumption in Positive Ion Beam Converter with Electrostatic Electron Suppressor

The power recovery characteristics of an in-line direct beam converter provided with electrostatic electron suppressor were studied numerically by tracing the orbits of fast primary ions and secondary charged particles generated along their beam path by collision with background gas molecules. It is shown that, in reference to the electrostatic field potential at the point of impact, the energy distribution of secondary ions impinging on the suppressor has two peaks—one corresponding to a zone of high positive potential surrounding the collector and the other to one of slightly negative potential around the electron suppressor. Secondary electron emission from the suppressor is ascribed mainly to the latter peak, associated with impingement of slower secondary ions. Far much power consumed in secondary particle acceleration is spent for emitting electrons from the suppressor than for secondary ions generated by beam-gas collision. The upper limit of background pressure is discussed on the basis of criteria prescribed for restricting the power consumed in this secondary particle acceleration, as for practical convenience of electrode cooling. Numerical examples are given of calculations based on particle trajectory analysis of both primary ions and secondary particles, for the case of a 100 keV-proton sheet beam 10 cm thick of 35mA/cm² current density.     

电子直线加速器串联谐振充电电源的设计与实现

电子直线加速器一般使用线型脉冲调制器作为脉冲电源。在脉冲调制器充电系统中,使用LC串联谐振充电技术为脉冲形成网络（PFN）充电可提高效率并减小体积,是大功率线型脉冲调制器的发展方向之一。本工作基于串联谐振充电技术的基本原理,设计并制造了1台脉冲调制器样机,结合实测波形和工程应用,提出了改善稳定度的方法。测量结果表明,脉冲调制器样机的设计方案正确,实现了设计指标。     

高能大功率电子辐照加速器270°偏转光路设计

为实现高能大功率电子辐照加速器的一机多用目的,需研制270°偏转光路支线。本文采用Trace3D程序对270°偏转光路进行了设计与模拟计算,设计了双135°偏转磁铁和整体270°偏转磁铁。对双135°和整体270°两种偏转磁铁元件进行二维和三维电磁场设计与模拟计算,计算结果表明,整体270°偏转磁铁的场分布与光路设计中所要求的物理参数差距较大。由于整体270°偏转磁铁的场分布调整较困难,使工程实施中的束流调试难度较大,因此采用双135°偏转磁铁的光路方案。     

盘荷波导行波电子直线加速结构功率效率的优化

盘荷波导行波结构(TWS)是电子加速器中重要的加速结构,在科学研究和工业生产中得到了较为广泛的应用。在对该加速结构进行设计时,加速结构的功率效率是一重要指标,对工程造价和商业运行的经济性具有重要影响。本文对TWS关键参数指标与功率效率的关系进行了研究,使设计优化TWS的工作快速有效,为TWS的优化设计提供了依据和方向。通过与相关实验结果对照,验证了分析结论的正确性,结果具有一定的工程指导意义。     

Measurement of the Beam Position in the Extraction System of the ILU-10 Linear Electron Accelerator

A system for measuring beam position for a ILU-10 pulsed linear electron accelerator is described. The accelerator generates an electron beam with energy up to 5 MeV. The rf generator operates at 115 MHz in the pulsed mode with pulse duration of about 500 sec and pulse repetition frequency up to 50 Hz. The average beam power can reach 60 kW. Two electrostatic sensors (pickups) are used to measure the position of the beam. The principle of operation of the measurement apparatus is based on homodyne detection of the signals from the pickups. The second harmonic of the frequency of the accelerating voltage of the accelerator power supply (230 MHz) is chosen as the working frequency. The detected signal is fed from each pickup plate into an integrator and then a ADC. The beam position is calculated on a computer. The resulting error in the beam coordinates is about 0.5 mm with a 110 mm in diameter position sensor.     

Electron Beam Transport Experimts with Short Duration Pulses

This paper describes experiments designed to extend the simulation of IEMP effects by fast pulse (<5 ns) electron-beam techniques, to larger areas (>700 cm2) and greater total currents (~9 kA) than heretofore. Both charge and current neutralization as a function of pressure from <10-2 mTorr to 700 mTorr were determined with an electron-beam facility that generated an injected pulse with rise time ~l.5 ns and a peak intensity of 12.5 A/cm2. The results indicate that for such large time rate of change of total currents, the necessary pressure to achieve space-charge barrier dissipation before the peak of the pulse will also lead to avalanche breakdown of the ambient gas, occurring at almost the same time and thus reducing the net transmitted current.     

用于加速器电源的一种矩阵变换器拓扑研究

本文提出了一种适用于加速器电源的磁耦合型矩阵整流拓扑,并在加速器电源上对该矩阵拓扑的基本整流原理进行了验证。研究了空间矢量调制（SVM）和反馈控制相结合的控制策略,该策略能较好地抑制网侧电流谐波,提高网侧功率因数,同时确保负载侧电流对指令电流较好地跟踪。仿真实验及原理样机测试结果表明,该拓扑和控制策略可实现直流输出,达到预期目标。因此,作为加速器电源变换器拓扑的一种可行性选择,矩阵整流器具有良好的研究前景。     

法拉第筒用于大面积电子束均匀性诊断

在电子束泵浦气体激光实验中,大面积均匀电子束是获得高效能激光输出的必要条件.本文介绍了利用SPG200脉冲功率源产生大面积均匀电子束实验中,利用法拉第筒进行大面积电子束均匀性诊断的研究工作.重点介绍了法拉第筒的测量原理、结构及标定,给出了大面积电子束发射均匀性曲线,并对实验结果进行了分析.     

Velocity Distributions in High Density Gadolinium Atomic Beam Produced with Axial Electron Beam Gun

The parallel and perpendicular velocity distributions of a gadolinium atomic beam produced with an axial electron beam gun have been measured by a Doppler-shift technique and a Doppler limited absorption spectroscopy, respectively. The atomic density of 10¹⁸~10¹⁹atoms/m³ at a laser irradiated zone was sufficient for the process, such as an atomic vapor laser isotope separation. The atomic beam velocity of 800 m/s was obtained by a free expansion near an evaporation surface. This velocity, however, was 100 m/s slower than that we had measured with a magnetic transverse electron beam gun in a previous experiment. The reasons for the slower velocity in this experiment than that in the previous one are discussed. In keeping with the deposition rate, the parallel translational temperature rapidly decreased to 200 K, while the perpendicular translational temperature gradually increased and approached to the parallel translational temperature. This result suggested that the collisional region where both translational temperatures are equal extended to the laser irradiated zone in high-rate evaporations.     

微波零相位法测量超导加速器ps级电子束纵向长度

本文基于微波零相位法,将中国工程物理研究院太赫兹自由电子激光(CTFEL)2×4-cell超导加速器的下游腔作为零相位腔,测量了上游腔增能后的电子束纵向长度,并通过束流动力学模拟证明,当两个超导腔正常工作时,上游腔出口处的电子束纵向长度与下游腔出口处的接近。实验结果表明,CTFEL 2×4-cell超导加速器能实现半高宽小于6.8 ps的电子束,满足装置出光要求。     

Development of Multi Energy Electron Linac with Double Beam Line

<正>An electron linac with energy of 7.5,10 and12 MeV has been developed.The X-ray generated by 7.5 MeV electron beam is used in the research of food irradiation technology,10 MeV electron beam is used in scientific research,and12 MeV electron beam is mainly used in the research of radiation modification of semiconductor materials.Its structure is shown as Fig.     

The Propagation Characteristics of the Electron Beam with Initial Modulation

The propagation characteristics of the beam under various initial conditions are investigated by means of PIC method. The influences of density modulation and velocity modulation on the propagation characteristics are discussed and compared. The results reveal that by changing the amplitude of the two kinds of modulations and the phase difference between them, the distribution property of the first harmonic of the current density can be adapted along the beam propagating path, which is a feasible method to enhance the beam-wave interaction efficiency in Cerenkov HPM devices.     

PIC-MC Code to Model Fast Electron Beam Transport Through Dense Matter

A PIC （particle-in-cell）-MC （Monte Carlo） code to model electron beam transport into dense matter is developed. The background target is treated as a cold, stationary fluid and the fast electrons as particles with the relativistic motions. The process is described by a particle-in-cell method with consideration of the influence of both the self-generated electric and magnetic fields as well as collisions between the fast electrons and the target. The collisional part of the code is solved by the Monte Carlo-type method. Furthermore by assuming that the background current balances with the fast electron current, the electric field is given by the Ohm＇s law and the magnetic field is calculated from the Faraday＇s law. Both are solved in a two-dimensional cylindrical geometry. The algorithms implemented in the code are demonstrated and the numerical experiments are performed for monoenergy homogeneous fast electron beam transport in an aluminum target when the fields, collision and angular scattering are switched on and off independently.