天光Ⅱ-B装置的诊断刻度

设计并制作了天光Ⅱ-B脉冲功率装置的电流电压诊断设备,根据天光Ⅱ-B脉冲功率装置的同轴传输线结构特点,在传输线末端设置了用于测量负载电压的电容分压器。利用金属膜连接传输线外筒与负载外筒构成回流来测量负载的电流,并利用电路模拟软件对此过程进行模拟,两个诊断探头采取直接标定的方法,测定电容分压器的分压比和回流器的灵敏度。实验结果表明,该探头性能稳定、时间响应快、功率负荷大,是测量脉冲电流与电压的一种理想工具。     

两种变截面的高压纳秒电阻分压器

文章介绍了一种具有完全横向电容补偿功能的特殊结构的电阻分压器——扇形分压器,以及另一种同时具有横向电容补偿和减小趋肤效应功能的锥形薄壁分压器,用于测量纳秒上升沿的脉冲高电压。简述了它们的补偿原理和结构。刻度表明,它们具有良好的响应特性,并给出了它们在脉冲加速器上测到的电压波形。     

250千伏双同轴电容分压器

本电容分压器是为了测量速调管电源——脉冲调制器的输出脉冲高压而设计的。该分压器是双同轴结构,它具有耐压高、体积小、输入阻抗高、波形畸变小、结构紧凑简单、加工和使用方便等特点。经长期使用,性能良好,满足了工作的需要。     

基于阻容低通反馈的电荷灵敏前置放大器的设计

传统电荷灵敏前置放大器以高阻值电阻作为低频反馈端,高阻值电阻所引入的热噪声为前置放大器噪声的主要来源。本文以N沟道结型场效应晶体管和阻容(Resistor-Capacitance,RC)电路构成低通网络代替传统高阻值反馈电阻完成了新型电荷灵敏前置放大器的研制。该电路以结型场效应晶体管和集成运算放大器构成放大电路,具有高输入阻抗及大开环增益的优点;以小容值电容构成高通回路,为电路提供高频反馈回路,同时实现核脉冲电流的积分;以RC低通网络构成直流反馈回路,为电路提供一个稳定的直流工作点,同时构成电压分压器使N沟道结型场效应管工作在正向偏置状态,实现对反馈电容中的电荷进行连续放电。相比于传统阻容反馈式电荷灵敏放大器,该电路能够有效克服大阻值反馈电阻引入的噪声,尤其适用于Si-PIN等半导体探测器。将该电荷灵敏前置放大器与BPX66型Si-PIN探测器连接,在室温下对241Am源进行测量,其能量分辨率可达到3.03%@59.5 keV。     

伽玛射线探测器(GRD)的PMT分压器研究

为了减小由大信号带来的死时间,满足GRB探测所需的高计数率,提高探测效率,设计了三极管分压器。仿真分析和实验结果表明:与传统的电阻电容分压器方案比较,三极管分压器方案下的恢复时间小一个数量级,具有更稳定的增益。     

一种用于大面积塑料闪烁体电子学电路的设计

介绍的电子学电路用于大面积塑料闪烁探测器,包括光电倍增管分压器电路、电荷前放、主放大器几部分,主放大器由放大、成形、甄别及符合电路组成.电路主要具有快速、动态范围宽、电荷灵敏度高等特点.     

高精度CMOS峰值保持电路设计

介绍了一种CMOS峰值保持电路.该电路具有精度高,输出摆幅大,驱动能力强等特点.电路具有两种工作状态:“读”状态和“写”状态.在“写”状态时,通过OTA追踪信号,将输入信号峰值存储到保持电容中.在“读”状态时,将OTA连接成单位增益放大器使用,将存储在保持电容上电压值读出.该工作过程可以有效消除放大器自身offset产...     

带有长测量电缆的电容分压器的传输特性

该文研究了z_3=z_0,z_4=∞情况下电容分压器测量系统的传输特性,得出了U_(in)(s)=G(s)~(-1)U_0(s)在时间域的解析解及其差分形式,此解正可用于进行波形重建。给出了波形畸变与分压器、电缆及被测波形参数间的定量关系。     

线缆X射线瞬态响应的电路模型计算

建立了同轴电缆和腔体内带保护层导线、裸导线X射线瞬态辐照响应的电路计算模型,该模型考虑了X射线辐照线缆时电子的运动规律及瞬态响应的产生机理,适用于瞬态响应的规律研究和工程预估。结合实例,介绍了计算模型中电流源、电容参数的物理意义及其计算方法,采用该模型计算了同轴屏蔽电缆的X射线瞬态响应,并与数值计算结果进行了比较。结果表明,电容的计算是采用电路模型计算响应的关键,采用衰减法计算的电子射程更适合计算电容。     

一种基于电流反馈芯片的电荷灵敏快前放设计

介绍了一种基于电流反馈运算放大器(CFOA)的快电荷灵敏放大电路。通过一个小电阻的引入避免了CFOA电路直接电容反馈所引起的电路不稳定问题,通过反馈电阻和反馈电容的适当取值降低了噪声。经过测试,其带宽可达200MHz,时间分辨率可达125ps。该前放具有高带宽、高性噪比、高时间分辨率等特点,已成功应用于兰州重离子加速器单粒子效应地面模拟实验TR5终端。     

HI—13串列加速器框架式电阻分压系统的改造

在HI－13串列加速器上的电阻分压系统中,以玻璃釉膜电阻替代原合成膜电阻,电阻阻值税定,而高压性能良好,提高了HI－13串列加速器的高压性能和运行效率。     

Design of High-power Microwave Waveguide Divider

1. IntroductionHigh-power divider plays an important part inmany fields, such as military affairs, civil affairs, scientific research. In a longpulse tokamak plasma dis-charge, Lower Hybrid Wave (LHW) is a very effectivemeans fOr current driving. According to the con-struction plan of tokamak HT-7U, a twcrowave sys-tem fOr Lower Hybrid Current Drive (LHCD) will bebuilt up, in which a power divider is required to splitthe 100 kW microwave power at a frequency of 2.45GHz into two equal …     

SRAM单粒子锁定效应电路级防护设计研究

高密度CMOS工艺SRAM对单粒子锁定极端敏感的特性使其在空间应用时必须采取相应的防护策略。对于抗辐照能力较弱的CTOS,电路级防护成为提高系统可靠性的一项重要内容。利用激光单粒子效应试验装置,对CYPRESS公司的CY62167DV30LL型SRAM开展了一系列单粒子锁定效应试验。通过对试验结果进行线性拟合,计算出该款SRAM维持电压为1?5?1?6 V,维持电流为9?9?11?2 mA。根据维持电流、维持电压、工作电流、工作电压,对能否采用电路级防护做出判断。提出了电源限流和分压电阻两种电路级防护方法,并定量计算出电源限流取值和分压电阻取值范围。以往文献中电阻只是作为锁定被触发后限流的一种手段,并不能阻止器件发生锁定,本研究发现在满足一定条件下分压电阻可达到退出锁定的目的。两种防护方法均通过脉冲激光试验进行了验证。     

Fitness for service evaluation of cracked divider plate bolt locking tabs for nuclear steam generators

This paper is to address the structural integrity issues related to continued service without repair or replacement for cracked locking tabs on divider plates of nuclear steam generators. Significantly high residual stress introduced by cold bending of locking tabs at installation was simulated by elastic–plastic finite element method and considered in the fitness for service evaluation. Significant work hardening resulted from the accumulation of large and inhomogeneous plastic deformation introduced by the in situ bending was quantified and considered. Failure and degradation mechanisms for crack stability and propagation were identified. Linear elastic fracture mechanics (LEFM) theory with crack tip plastic zone correction was adopted to establish critical crack sizes. Life of safe operation of the cracked locking tabs from inspected crack sizes to the critical crack sizes was then evaluated. Initial crack sizes at installation were also established through a highly contrived backward fitting evaluation procedure.     

Impedance matching for repetitive high voltage all-solid-state Marx generator and excimer DBD UV sources

The purpose of impedance matching for a Marx generator and DBD lamp is to limit the output current of the Marx generator,provide a large discharge current at ignition,and obtain fast voltage rising/falling edges and large overshoot.In this paper,different impedance matching circuits (series inductor,parallel capacitor,and series inductor combined with parallel capacitor) are analyzed.It demonstrates that a series inductor could limit the Marx current.However,the discharge current is also limited.A parallel capacitor could provide a large discharge current,but the Marx current is also enlarged.A series inductor combined with a parallel capacitor takes full advantage of the inductor and capacitor,and avoids their shortcomings.Therefore,it is a good solution.Experimental results match the theoretical analysis well and show that both the series inductor and parallel capacitor improve the performance of the system.However,the series inductor combined with the parallel capacitor has the best performance.Compared with driving the DBD lamp with a Marx generator directly,an increase of 97.3％ in radiant power and an increase of 59.3％ in system efficiency are achieved using this matching circuit.     

电容法测量气—液两相流截面含气率实验研究

本文介绍了一种用于测量气-液两相流载面含气率的新型结构的电容器,并在两种条件下进行标定。结果表明,电容法的主要影响因素——空泡分布对这种结构的电容器影响不大。     

A New Approach to Direct Current Integration

A new all-solid state direct-current integrator integrates currents as low as 10-11 ampere with an accuracy of 1%. The operating principle is similar to that of more conventional current integrators in that the voltage across a storage capacitor in the input circuit is monitored by an electrometer type operational amplifier, the output of which triggers a discriminator at a given voltage level. The discriminator generates a reset pulse which removes a fixed charge from the integrating capacitor. This is where the similarity ends. The diode pump circuit, which has long been recognized as an ideal circuit for removing precise quantities of charge from the integrating capacitor, has been replaced by complementary silicon planar transistors that operate in the inverted-mode and serve as current switches. These transistors normally have both their base-emitter and base-collector junctions reverse biased and look like open switches with leakage currents of about 10-13 ampere. Reset pulses switch these transistors from the reverse-biased state to the active state for a precise time during which a constant current flows to or from the integrating capacitor. Therefore, each reset pulse removes from the integrating capacitor a precise charge that is the product of the current and the period of the active state. By the employment of sufficient gain in the operational amplifier to maintain small voltage excursions at the input, the total effective leakage may be kept as low as 10-14 ampere.     

快中子飞行时间谱仪中光电倍增管的分压供电电路(ORTEC269)的改进

本文叙述了对使用在快中子飞行时间谱仪中的光电倍增管分压器电路(ORTEC269)管座的改进,改进后的时间探头的脉冲幅度、脉冲形状甄别和时间分辨的性能有了很大的改善。