可变积分时间常数的长时间积分器

采用可变积分时间常数和扣除积分漂移斜率相结合的方法,设计了一种新型长时间积分器。通过切换积分器积分电阻来改变积分时间常数,提高积分器的信噪比,防止积分输出饱和;利用DSP计算一段时间内积分器的积分漂移斜率,并利用该斜率对原始积分信号进行实时扣除,以达到减小积分漂移的目的。测试结果表明,该方案是一种有效消除积分漂移的长时间积分方法,并能消除改变积分时间常数后对积分漂移带来的不良影响,通过远程控制能方便地根据实验需要改变积分时间常数,且不再需要人工手动调节积分漂移,极大地提高了实验效率,适合于托卡马克装置放电实验中的电磁测量。     

一种束流强度监测电路设计

介绍了一种新型的电流频率(I-F)转换电路,该电路用于测量平行板气体电离室的电流信号,配合实现了中国科学院近代物理研究所重离子治癌中束流强度的监测.治癌终端的临床试验表明该束流强度监测电路具有较高的灵敏度,能很好地应用在束流强度监测系统中.该电路也可以用于条形电离室信号的读出.     

一种非积分式瞬态电流传感器设计

瞬态电流（IDDT）测试技术自20世纪90年代提出以来受到了人们越来越多的关注。文章提出了一种非积分式CMOS电路IDDT传感器,该传感器能够有效的抑制噪声、准确的提取IDDT信号并较好的反应出故障信息,工作频率可达700MHz。     

基于电流频率变换法的微弱电流测量电路

电离辐射探测中经常需要开展微弱电离电流测量.微弱电离电流的测量因待测信号极其微弱需要克服各类型干扰源的影响,同时需要达到较宽的测量范围,故具有较大挑战.为了完成辐射防护用电离室输出微弱电流信号的测量,设计了一款基于电流频率变换法的宽量程微弱电离电流测量电路,其有效量程为10?13～10?8 A.通过Keithley 6...     

高温环境下数字反应性仪微电流测控技术可靠性研究

数字反应性仪是核电厂用于测量反应性的专用设备,能够实现宽范围的微电流测量,采用高精度驱动电路控制电磁继电器实现电流范围自动量程切换是本设备的关键技术之一。在高温环境下,继电器会出现线圈阻值变化而导致驱动电压需求增大的现象,进而导致继电器可靠性降低。为提高高温环境下微电流测控技术可靠性,重点开展不同继电器驱动方式对高温环境下数字反应性仪微电流测控技术可靠性研究。研究发现,相对于低电平驱动模式,高电平驱动模式能够有效提高高温环境下反应性仪微电流测控电路可靠性。通过高温步进试验验证,该数字反应性仪在65℃环境下,达到热平衡后的30 min内,微电流测量稳定有效。     

电流-频率转化法放大电离室探测器微电流信号

首次提出了一种基于电流-频率转化的电离室探测器微电流信号放大技术,测试结果表明其性能指标满足甚至优于目前市场上同类技术。该技术具有广泛的应用前景。     

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。     

TFTR中的模转换加热和电流驱动实验

本文报导了在找卡马克等离子体中用弱场侧天线时，从快磁声波到离子Ｂｅｒｍｓｔｅｉｎ波的模转换能有效地加热电子和驱动电流的首次实验证明。在ＴＦＴＲ中，轴上和离轴的非感应驱动了直到１３０ｋＡ，的电流，并且测量了所造成的电流分布，。在加热实验中，用３．３ＭＷ射频加热功率产生了１０ｋｅＶ的峰值电子温度。     

EAST上快波电流驱动的数值模拟

针对EAST全超导托卡马克的参数,利用射线追踪法在离子回旋共振频段（ICRF）发射机的工作频段内进行快波电流驱动的数值模拟,找到了一组适合于快波电流驱动的参数。模拟结果表明,发射频率只要避开基频吸收和二次谐频吸收,电流驱动的效果就很明显。     

一种先进的电流-频率变换器

介绍一种先进的电流－频率变换器,对其原理,组成和特点等进行了讨论。这种变换器适用于在探测器的电路中使用。     

Actual and possible nuclear power long-time development lines

The current state of nuclear power engineering is described. It is shown that this industry is still at the initial stage in general industrial use in spite of experimental evidence accumulated for more than half a century. It has not even attained the stage of establishment, which would enable one to utilize all the power facilities concealed in it. The long-term future of nuclear power involves a closed fuel cycle including the recycling of fuel from extended breeding of fissile materials, which supports the safe treatment of radioactive wastes. Nuclear power has no alternatives over millennia, and any groups opposed to its extension and companies within the country that strive to delay its development by not providing facilities for the latter in essence have started on a road involving marked difficulty for our civilization. Bochvar All-Russia New Materials Research Institute, Russian Federation State Scientific Center. Translated from Atomnaya énergiya, Vol. 86, No. 2, pp. 83–94, February, 1999.     

瞬态波形数字化在飞行时间测量中的应用研究

探讨了将瞬态波形数字化技术应用于粒子飞行时间(TOF)测量中的可行性,并介绍了为了进行这一研究而设计的一个测试系统。经过测试,系统的采样率可达1．4Gsps,在10bit变换精度下,微分非线性小于0．5LSB,积分非线性小于8LSB。通过采用乒乓工作方式,系统在10K/s计数率时的事例丢失率约为1％。     

便携式多道能谱分析系统的研制

介绍了一种基于数字寻峰技术的多道能谱测量系统.利用可编程逻辑器件设计灵活方便的特点,借助VHDL硬件描述语言,设计了数字寻峰电路,利用单片机进行采集和管理数据,并通过USB口上传数据到主计算机.与传统的多道能谱测量系统相比,本系统具有结构简单,功耗小,操作方便,体积小等特点.     

GERO: a general SCA-based readout ASIC for micro-pattern gas detectors with configurable storage depth and on-chip digitizer

The paper presents GEneral Read Out(GERO), a general readout ASIC based on a switched capacitor array for micro-pattern gas detectors. It aims at providing general readout electronics for low-to-medium event-rate gas detectors with high sampling frequency, configurable storage depth, and data digitalization. The first prototype GERO chip integrates 16 channels and was fabricated using a 0.18-lm CMOS process. Each channel consists of a sampling array working in a ping-pong mode, a storage array with a 1024-cell depth, and 32 Wilkinson analog-todigital converters. The detailed design and test results are presented in the paper.     

Design and offline processing of an ultrafast digitizer based on internal cascaded DRS4

In this paper, we present an ultrafast digitizer utilizing the DRS4 switched capacitor array applicationspecific integrated circuit to achieve an ultrafast sampling speed of at most 5 GS/s. We cascaded all eight channels(sub-channels) of a single DRS4 chip for increased storage depth. The digitizer contains four DRS4 chips, a quadchannel analog-to-digital converter,a controlling fieldprogrammable gate array, a PXI interface, and an SFP+connector. Consequently, each DRS4 channel has a depth of 8192 points and a vertical resolution of 14 bits. The readout sequences should be broken into several segments and then reordered to obtain the correct sequential data sets, and this offline procedure varies in different readout modes. This paper describes the design and implementation of the hardware; in particular, the respective processing procedures are described in detail. Furthermore, the offset error is calibrated and corrected to improve the precision of the captured waveform in both single-channel and highresolution modes.     

Influence of the axial magnetic field on sheath development after current zero in a vacuum circuit breaker

After current zero,which is the moment when the vacuum circuit breaker interrupts a vacuum arc,sheath development is the first process in the dielectric recovery process.An axial magnetic field (AMF) is widely used in the vacuum circuit breaker when the high-current vacuum arc is interrupted.Therefore,it is very important to study the influence of different AMF amplitudes on the sheath development.The objective of this paper is to study the influence of different AMF amplitudes on the sheath development from a micro perspective.Thus,the particle in cell-Monte Carlo collisions (PIC-MCC) method was adopted to develop the sheath development model.We compared the simulation results with the experimental results and then validated the simulation.We also obtained the speed of the sheath development and the energy density of the ions under different AMF amplitudes.The results showed that the larger the AMF amplitudes are,the faster the sheath develops and the lower the ion energy density is,meaning the breakdown is correspondingly more difficult.     

The development of a cooling wave on a hot surface

The method of weighted residuals is applied to the time dependent rewetting of a hot surface. The solution holds for a relatively arbitrary heat flux distribution along the surface. The various parameters affecting the solution are investigated and discussed. It is shown that the width of the cooling wave and its speed approach steady state values. The transition time and distance are calculated for typical water reflooding experiments and cryogenic systems. The transition period is more important in cryogenic systems.     

新型数字BPM信号处理器研制进展

介绍了采用Arm微处理器技术、FPGA数字信号处理技术、高速带通欠采样技术的新型BPM信号处理器研制进展情况;对两类主要的原理样机进行了评估测试.信号处理算法评估样机基于商业评估板搭建,用于测试包含数字下变频、低通滤波、抽取降速等信号处理算法功能模块.自主开发的硬件评估样机用于测试不同硬件功能模块及整机集成后的硬件性能...