数字化平均流强测量方法研究

平均流强测量可用DCCT或ICT探头,ICT探头有很强的抗电磁干扰能力,但测量精度不高.用高精度A/D转换器和等效采样测量算法使ICT探头组成的平均流强测量系统有较高的测量精度.本文主要介绍了基于ICT探头的平均流强测量系统、测量算法和实验室测试结果.     

可连续采样任意长数据采集板

介绍了利用无限长采样方法设计的多通道数据采集板，详细描述了其电路原理。     

新型γ射线成像位置能量信息获取系统研制

研发了一种探测器波形获取电路,实现了1GHz采样率,12 bit采样精度。基于该电路,研制了一套新型γ射线成像位置能量获取系统,用于H8500多阳极位置灵敏光电倍增管的前端位置信号读出与处理。采用信号发生器以及241Am放射源对系统的位置及能量分辨能力进行了测试。结果表明,该系统在对64路阳极信号准确定位的同时也能对γ射线的能量准确测量。     

一种高速、高精度全差分采样保持电路的ASIC设计

为了实现新型密集型阵列探测器信号的高速、高密度读出,必须采用专用集成电路技术,利用模数变换器将物理量变换为数字信号后进行串行输出.采样保持电路是模数变换器中的关键单元,决定了整个模数变换过程的性能.论文在国内高能物理领域,首次利用专用集成电路技术,设计实现了一种用于10位、3.3 Msps采样率的逐次逼近ADC的全差分采样保持电路并成功流片.实测结果表明,该设计分别实现了48 dB的SNDR和78 dB的SFDR,达到了预期的设计指标,实现了较高的性能.     

线性脉冲放大器

提出了一种微型成形放大器和门积分器和门积分,简要介绍了电路结构与电路设计,工作原理及技术指标。该电路主要用于半导体探测器,正比计数器,闪烁探测器等仪器输出信号的放大,成形和多道脉冲幅度分析器等仪器的采样,保持电路的分析与研究。     

基于交叉采样技术的多道脉冲幅度分析仪设计

为提高核脉冲信号幅度分析精度,本文设计的多道脉冲幅度分析仪采用多片AD7626交叉采样方式提高系统的实时采样率,弥补单片ADC芯片低采样率的不足;使用时钟分配芯片AD9522为时间交叉采样提供精确的转换时钟;FPGA上构建SOPC系统和各功能模块实现时间交叉采样的控制、数字信号读取重组以及脉冲幅度数字化分析处理。通过对设计的多道脉冲幅度分析仪进行谱线采集测试,结果表明其可应用于伽玛能谱测量领域。     

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.     

随机脉冲触发峰值采集电路的设计

射线检测装置的输出信号是随机离散的不等幅的高频信号,为形成能谱图,需对此信号进行峰值采样和计数。介绍的随机脉冲触发峰值采集电路,在脉冲到来时自动触发进行采样,使信号采样过程和信号到来时间实时配合,在计算机的控制下,提高了采样频率,又不因空脉冲而占据内存。     

采样示波卡的研制

采样示波卡的研制，采用了虚拟仪器的设计设计思想，该卡性能的设计指标为：最高采样率每通道３０Ｍｂ／ｓ，分辩率８位Ａ／Ｄ，通道数２；输入信号０－２０．０Ｖ存储深度每通道６４ＫＢ。硬件包括Ａ／Ｄ转换器，高速缓存，采样时钟控制电路，地址产生器电路及与微机的通讯电路等。     

核电站放射性环境调查的气溶胶采样方法

介绍了秦山核电站二三期放射性环境调查气溶胶采样的方法、滤膜的检查、采样体积的修正和质量保证措施,并对采样中经常存在和值得注意的问题展开了讨论,提出了一些解决的方法,为今后进一步做好气溶胶采样工作提供了有益的参考。     

积分型全景取样保持电路

本文简要描述了一种具有宽带响应特性的积分型取样保持电路,并对电路设计和测量结果作了介绍。     

基于压水堆核电机组等效热降法的改进算法

由于核电汽轮机抽汽状态点焓值及排汽焓难以准确确定,使得压水堆核电机组常规等效热降法计算结果存在偏差.针对这一问题,提出压水堆核电机组等效热降法的改进算法.对1000MW压水堆核电机组二回路热力系统进行实例计算,结果表明:用等效热降法的改进算法所得的汽轮机实际循环热效率与设计值相比较,误差在允许的范围内.等效热降法的改进...     

一种微机快电路分析程序

本文介绍一种快电路分析程序——FCAP,该程序具有直流分析、交流分析和瞬态分析三种分析功能。它的主要特点是不固定有源元件模型,用户可以根据条件任选一种等效电路。FCAP用FORTRAN77语言写成,运行于IDM PC及各种兼容机。FCAP可以作为快电路分析和设计的辅助工具。     

反应堆燃料元件破损当量诊断方法

破损当量是衡量反应堆燃料元件破损严重程度的重要指标,但破损当量无法直接测量,在决策应用中不具有可操作性,需要建立与破损当量对应的可监测指标。本文结合实践经验,分析确定了可用于燃料元件破损诊断的典型核素,建立了反应堆一回路冷却剂中裂变产物核素活度浓度与燃料元件破损当量之间的传递关系;给出了一回路冷却剂取样分析实验方法,并指出实验过程中应注意的问题;建立了采用监测一回路冷却剂中典型裂变产物核素活度浓度诊断破损当量的方法,并分析了诊断中不确定度的主要影响因素。本研究为反应堆燃料元件破损当量诊断提供了技术方法。     

Diagnostic of capacitively coupled radio frequency plasma from electrical discharge characteristics: comparison with optical emission spectroscopy and fluid model simulation

The capacitively coupled radio frequency(CCRF)plasma has been widely used in various fields.In some cases,it requires us to estimate the range of key plasma parameters simpler and quicker in order to understand the behavior in plasma.In this paper,a glass vacuum chamber and a pair of plate electrodes were designed and fabricated,using 13.56 MHz radio frequency(RF)discharge technology to ionize the working gas of Ar.This discharge was mathematically described with equivalent circuit model.The discharge voltage and current of the plasma were measured atdifferent pressures and different powers.Based on the capacitively coupled homogeneous discharge model,the equivalent circuit and the analytical formula were established.The plasma density and temperature were calculated by using the equivalent impedance principle and energy balance equation.The experimental results show that when RF discharge power is 50–300 W and pressure is 25–250 Pa,the average electron temperature is about 1.7–2.1 e V and the average electron density is about 0.5?×?10~(17)–3.6?×?10~(17)m~(-3).Agreement was found when the results were compared to those given by optical emission spectroscopy and COMSOL simulation.     

Charge-Control Equivalent Circuit for Predicting Transient Radiation Effects in Transistors

A charge-control equivalent circuit is developed in detail which can be used with a computer to predict the time-dependent response of any transistor to a pulse of ionizing radiation. Operation of the equivalent circuit during saturation is also provided. Measurement procedures are described for each of the necessary parameters in the circuit and comparison with experimental flash X-ray data is presented. Use of this transistor representation is demonstrated for predicting the response of a complete transistorized amplifier circuit.     

谐振腔加载波导系统的分析计算

提出了一种亲的分析计算谐振腔加载波导系统的精确等效电路法，同时还介绍了另一种国际上新近发展的分析该问题的Ｓｌａｔｅｒ相位调曲线模拟法，并通过简单算例说明了它们的范围和精度。     

Cellular neural networks (CNN) simulation for the TN approximation of the time dependent neutron transport equation in slab geometry

This paper describes the application of a multilayer cellular neural network (CNN) to model and solve the time dependent one-speed neutron transport equation in slab geometry. We use a neutron angular flux in terms of the Chebyshev polynomials (T_N) of the first kind and then we attempt to implement the equations in an equivalent electrical circuit. We apply this equivalent circuit to analyze the T_N moments equation in a uniform finite slab using Marshak type vacuum boundary condition. The validity of the CNN results is evaluated with numerical solution of the steady state T_N moments equations by MATLAB. Steady state, as well as transient simulations, shows a very good comparison between the two methods. We used our CNN model to simulate space–time response of total flux and its moments for various c (where c is the mean number of secondary neutrons per collision).     

压电变压器原理研究及特性测试

研究了一种可用于粒子加速器的压电变压器结构及工作原理，并采用等效电路和实验相结合的方法测试了压电变压器的若干工作特性。     

Electrical model and experimental analysis of a double spiral structure surface dielectric barrier discharge

A surface dielectric barrier discharge (SDBD) can discharge at atmospheric pressure and produce a large area of low-temperature plasma. An SDBD plasma reactor based on the double spiral structure is introduced in this paper. To study the discharge mechanism of SDBD, an equivalent circuit model was proposed based on the analysis of the micro-discharge process of SDBD. Matlab/Simulink is used to simulate and compare the voltage–current waves, Lissajous and discharge power with the experimental results. The consistency of the results verifies the validity of the SDBD equivalent circuit model. Maxwell software based on the finite elements method is used to analyze the electrostatic field distribution of the device, which can better explain the relationship between the discharge image and the electrostatic field distribution. The combination of equivalent circuit simulation and electrostatic field simulation can provide better guidance for optimizing a plasma generator. Finally, the device is used to treat PM2.5 and formaldehyde. The test results show that the degradation rate of PM2.5 can reach 78% after 24 min, and formaldehyde is about 31.5% after 10 min of plasma treatment.