Measurement of Resolving Times with the Fast RCA C-70045 Photomultipliers

This work deals with tests of the RCA C-70045 photomultipliers in a delayed coincidence apparatus. Illuminating the photocathode of the photomultiplier with constant height light pulses, resolving time measurements are performed. Prompt resolution curves are then measured using two photomultipliers of this type associated with two plastic scintillators. A time resolution of 1.85×1O-10s (f.w. h.m.) was obtained with Co60.     

Evaluation of New Photomultipliers for Scintillation Counting

This paper presents a comprehensive evaluation of a new bi-alkaliphotocathode photomultiplier developed specifically for scintillation counting. This recently developed photomultiplier is compared to existing photomultiplier types, and data are presented showing photocathode quantum efficiency as a function of wavelength, pulse-height resolution for Cs137 and Fe55, dark-noise spectra at 25 C and -100 C, anode rise time and pulse shape, and pulse-height stability with respect to time and count rate. A method is described for measuring the spatial uniformity of photomultipliers, utilizing a dot-pattern-scanned cathode-ray-tube light source, a pulse-height analyzer, and a live cathode-ray-tube display.     

A Method Using Nuclear Emulsions for Measuring the Anisotropy of Fast Neutron Fluxes due to Arrangement of Fast Core Cell

Measurements using nuclear emulsions have been made on the neutron spectra and on the fine structure of neutron fluxes in the cell of the I-4 core of the fast critical assembly at the Japan Atomic Energy Research Institute. The I-4 core is a graphite-diluted fast core with 3:1 volume ratio of 20% enriched metallic uranium and graphite. The nuclear emulsions were irradiated in two typical patterns of arrangement of the cell (systems with graphite plates (a) bunched and (b) distributed among fuel plates).

For the distributed graphite plate system a marked discrepancy was found between the direct measurements and calculations based on the Monte Carlo method. This is attributed to anisotropy in the incident neutron flux due to the parallel plate arrangement of the simulated materials. It is concluded that Reines' formula requires correction to amount for such anisotropy, even when the emulsions are irradiated at the core center. A simple method for treating this anisotropy is proposed for use in fine structure analysis. The method utilizes, in part, the calculated results.     

木材微密度测量的微机接口和软件

本文介绍了一个测量木材薄片样品径向密度分布的微机系统.它基于低能X射线透射的衰减原理.系统扫描样品的最小步长为10μm,对射线活度能作定时或定计数测量,给出密度随径向距离变化的分布曲线.     

A MWPC Read-Out System with Novel Photon Identification Capabilities

A MWPC read-out system is described that determines the position of a photon interaction by calculating the center of gravity of the charge induced in sense wires. The width of the charge induction is determined to distinguish photon interactions from disturbing events that occur in the system. The position resolution is 0.3 mm FWHM at 6 keV. The energy range is 2 - 30 keV.     

On the Performance of Grid-Controlled Photomultipliers in the Nanosecond Region

Controlled photomultipliers may be used for analysing modulation frequencies and other time parameters of radiation, which lie beyond the bandwidth or the time parameters of secondary emission systems. On the basis of the electron-optical characteristics of a control system for photomultipliers with two control grids, the properties to be expected are investigated for quasi-stationary operation and under consideration of transit-time effects. Due to the electron-optical properties of the control system, disturbing residual pulses are nearly made ineffective. It is experimentally shown that when using two controlled photomultipliers of the Type SKP-1 as coincidence elements at a distance of 1.5 ns of the gating intervals, the pulse rate decreases to less than 0.1 % (Fig. 12) compared with the rate at a time coincidence of the gating intervals. These values do not only depend on the photomultiplier, but also on the length of the light pulses and the period of the control voltage. The half-width of the coincidence between a light pulse and an electrical control pulse is smaller than 0.5 ns.     

A Fast Pulsed Electron Gun System

A pulsed electron gun system has been developed for use with the Stanford superconducting accelerator and the free-electron laser. This report reviews the design and operating characteristics of the system and its components.     

人体下肢静脉血流测定系统的研究

文章叙述了测量人体下肢血流的意义和利用微机测量人体下肢血流系统的结构，测量方法及临床意义。     

用于裂变研究的多参数测量系统

介绍了一种用于理解变研究的多参数测量系统。描述了裂变源、微型裂变室、中子探测器、实验安排以及降低测量本底的措施。系统适用于精确测量自发裂变中子能谱和裂变碎片特性,也可用于其他类型的测量。     

Studying of Laser Plasma Physics Related With Fast Ignition of ICF

Fast ignition(FI) concept of ICF is one of the most attractive application of high intensity ultrashort laser. The UV light has some advantages for applying to fast ignition, the first, as the I λ2 scaling law of hot electron temperature, at the FI required intensity(1020 W/cm2), the long wavelength light will generate >10 MeV electron that can not deposit energy efficiently in the fuel region. Meanwhile the UV light can just generate the electron with the required energy of 1 MeV.     

基于DSP技术的高速反馈系统

本文介绍一个用于加速器束流轨道校正的实时反馈系统，该系统采用高速浮点ＤＳＰ和高性能ＶＭＥ实时工作站、具有的响应速度、高度的灵活性和长期稳定性。文中介绍了其基本原理和结构以及对该系统的测试原理及测试结果。     

CSNS电源磁测时序控制系统

电源磁测时序控制系统能够提供磁铁在运行过程中电源控制设备和磁铁测量设备所需要的时序触发信号和同步时钟信号,该系统的准确性和稳定性对于整个磁测显得极为重要。论文介绍了基于Xilinx系列FPGA硬件电路设计、电光-光电转换电路的设计、串口通信驱动模块和LabVIEW-EP-ICS人机控制界面的实现。通过联机测试结果表明,该系统满足了电源磁测对时序控制系统的要求。     

System for Measuring the Beam Position in a Racetrack Microtron-Recuperator

The system described is intended for studying the positions (at 29 points) of the beam trajectory where electrostatic pickups are placed as sensors. The frequency of particle injection into the microtron-recuperator can vary from 20 kHz to 22.5 MHz with 1-nsec bunches. The system makes it possible to measure the position of the accelerated and delayed beams which are both present in the resonator gap. The measurement method is based on simultaneous measurement of the amplitudes of the pulsed signals from four pickup plates using a fast ADC.     

A Digital Waveform Analysis System with a Fast Digitizer and VXIbus System

A radiation digital waveform processing system has been studied using a fast signal digitizer on the VXIbus system. The proposed system is able to measure pulse signals at the maximum counting rate of over 160 waveforms per second. When applying to an n-γ pulse shape discrimination for an NE213 scintillation detector, more refined pulse shape discrimination can be easily accomplished by adjusting the discrimination parameter on the basis of energy of each incident radiation.     

Fermilab Fast Parallel Readout System for Data Acquisition

Three modules have recently been developed at Fermilab to provide high speed parallel readout of data for high energy physics experiments. This paper describes how these modules provide a fast and efficient method for transferring CAMAC event data into VME-based or FASTBUS-based memories, thus enhancing and extending the usefulness of experiments' large investments in CAMAC hardware. Using these modules can decrease the dead time of an experiment by up to a factor of 10. This paper includes a discussion of the experiment topologies In which these modules are being used.     

EAST速调管快速保护系统的研制

介绍了EAST速调管快速保护系统的研制.EAST速调管快速保护系统的功能是对磁场电流,主回路电流,管体电流和打火保护信号进行监测.当这些信号超过设定的阈值,快速保护系统立即给后面的控制系统发出过阈报警信号,从而快速保护速调管.     

Data-Acquisition System for the Fast Criticals ZPR-6 and ZPR-9

This system is used for experimental data acquisition and processing for the ZPR-6 and ZPR-9 fast critical assemblies. It replaces a setup based on a Systems SEL-840 computer that had been in use for almost a decade. It is noteworthy for a number of departures from standard Harris hardware and software. These were made to minimize expense and to facilitate this changeover as well as future changeovers.     

Pneumatically-Driven Fast Closing Valve System for Synchrotron Radiation Sources

A fast closing valve (FCV) system has been built to protect the vacuum of the electron storage ring against sudden vacuum failures during synchrotron radiation experiments. An electronic control detects the failure, and closes a 140 × 17 mm aperture within 32 ms with a guillotine blade driven by pneumatic pressure. This pressure is gated by a magnetic valve which is operated by an explosive charge from a capacitor bank. The design of the FCV itself is very simple; it is operated directly by a single pneumatic piston. The FCV system has a long operating lifetime and the blade can be readily rearmed in 0.5 s.     

钠冷快堆系统程序FR-Sdaso开发

为解决600 MW示范快堆（CFR600）事故分析和工况设计中的实际问题,自主开发了钠冷快堆系统程序FR-Sdaso,其建模范围包括堆芯、一回路、二回路、三回路、四回路和事故余热排出系统,主要物理模型包括点堆模型、单通道堆芯热工模型、多区钠池模型、四区蒸汽发生器模型等核岛设备或部件分析模型,汽轮机、凝汽器、给水加热器、除氧器等常规岛设备采用集总参数模型,泵、阀门、管道及控制体等采用通用模型。对程序进行了初步验证,结果表明,FR-Sdaso程序可用于分析全厂瞬态工况及超功率、失流、失热阱等典型事故过程。目前,FR-Sdaso程序已用于CFR600的设计和安全分析。