A scintillation strip detector for detection of thermal neutrons

A scintillation strip detector designed for precise experiments on the reflectometry of thermal neutrons is described. Test results obtained on the beam of a time-of-flight spectrometer have shown that the detector has a detection efficiency for thermal neutrons close to 100%, a lowered sensitivity to the neutron background, and a low level of intrinsic noise. The coordinate resolution of the detector can be varied in the range 1.5–0.1 mm. The strip is manufactured from a mixture of a ZnS(Ag) scintillator and a ⁶LiF neutron converter.     

Circular one-dimensional position-sensitive time-of-flight microchannel plate detector using resistive anode for space plasma measurements

We have developed circular one-dimensional position-sensitive time-of-flight microchannel plate (MCP) detector for space plasma measurements. The MCP detector is equipped with a 354.375 degrees resistive anode and a grid anode for obtaining position and timing signals simultaneously from one start event. The resistive anode provides high-resolution and continuous position sensing with two electronic channels alone. The grid anode generates start signals with pulse width of 1 ns for time-of-flight measurements. The resistive anode is formed on an alumina substrate which is installed behind the output side of the MCP plates. The grid anode is installed between the MCP plates and the resistive anode for the simultaneous detection of position and start signals. Stop signals are obtained from stop events by a center anode formed on the alumina substrate behind the MCP plates. On the basis of the test experiments, we have evaluated that the MCP detector functionally deals with the position and timing signals.     

A distributed fiber-optic position-sensitive detector of an electric arc

A distributed fiber-optic position-sensitive detector for detecting an electric arc by optical radiation at an illuminance of ∼10⁵ lx, a fiber length of 25 m, and an arc location error of 1 m is described. Original Russian Text ? Yu.P. Kazachkov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 145–147.     

A gas mixture regeneration system for a position-sensitive thermal neutron detector with a 3He-based gas converter

A gas mixture regeneration system is designed for a two-dimensional position-sensitive thermal neutron detector based on a multiwire proportional chamber with a ³He-based converter. The basic characteristics of the system are given, and processing steps aimed at decreasing the gas liberation from the detector structure are described. The influence of the electronegative impurity accumulation on the detector characteristics and operation of the gas regeneration system are studied. The system is designed on request of the Laboratory of Neutron Physics, JINR (Dubna), for modernizing the ДH-2 diffractometer operating on beams of the ИБP-2 reactor.     

A new position-sensitive silicon pixel detector based on bipolar transistors

A new type of detector of ionizing particles and radiations is described. The sensitive region of the detector, which is an array of bipolar transistors, is the collectors of these transistors, in which the primary signal of an ionizing particle is also preamplified. Using circuits of multiemitter transistors, it is very easy to branch the initial signal directly at the detector to several readout buses with equal signal levels in each bus. This possibility allows, in particular, the development of two-coordinate detectors with readout only on one side or detectors with an outputted readout triggering signal (self-triggering systems). Since 2005, several prototypes of such detectors have been produced in Russia. This paper presents their designs, some important elements of the manufacturing process, and the test results.     

一种MCP光子计数位置灵敏探测器图像采集系统

光子计数位置灵敏探测器在光子、粒子成像领域应用广泛,而图像采集系统是其重要组成部分。在介绍光子计数位置灵敏探测器的工作原理的基础上,分析了实现计数成像功能的软硬件需求,并设计了一套满足该需求的软硬件平台;依据该设计搭建了图像采集系统的硬件平台并采用LabVIEW编写了图像采集软件;最后进行成像实验验证了该套图像采集系统的性能。实验结果显示,基于该图像采集系统光子计数位置灵敏探测器能够将空间频率为7.14lp/mm的目标分开,表明该图像采集系统实现了其预期功能。     

Linear position-sensitive x-ray detector incorporating a self-scanning photodiode array

A linear position-sensitive x-ray detector for x-ray spectroscopy and diffraction applications has been tested which can provide excellent spatial resolution, wide dynamic range and good sensitivity. The heart of the system is a self-scanning, photosensitive silicon diode array. It is interfaced via fiber optics to a thin layer of ZnS which fluoresces visible light upon absorption of x-radiation. The conversion to visible light and optical coupling provide several-fold gain in the efficiency of detection as compared to the direct detection of x-ray by the diode array. Equally important is that the array is protected from irreversible damage by high energy radiation, a limitation which previously hindered this application of silicon diode technology.     

基于位置敏感探测器的六自由度精密位姿测量系统

位置敏感探测器(Position Sensitive Detector,PSD)是一种高精度的二维位移测量传感器,利用三片二维PSD的组合实现空间六自由度相对运动的位移和角度测量。测量系统主要包括三片PSD传感器(包括PSD光敏面和发光管)、低噪声的信号调理和AD采集电路,采用三片PSD正交布局方案,通过PSD光敏面的光点位置计算相对运动的位移和角度。设计了六自由度的PSD标定测试系统,用于PSD测量系统中心偏移和发光管安装误差的标定测试。测试结果表明,PSD测量系统的测量范围优于位移±10mm、角度±2.5°,标定后PSD测量系统的噪声误差为位移0.1mm、角度0.02°,测量系统的绝对位移误差小于0.5mm、角度误差小于0.14°,满足系统0.5mm和0.5°的指标要求。此外,对PSD传感器的环境适应性进行了评估。PSD测量系统具有量程宽、精度高、线性度好的优点,成功应用于天舟1号货运飞船微重力主动隔振装置的相对运动测量中。     

Data acquisition system for an advanced x-ray imaging crystal spectrometer using a segmented position-sensitive detector

A versatile time-to-digital converter based data acquisition system for a segmented position-sensitive detector has been developed. This data acquisition system was successfully demonstrated to a two-segment position-sensitive detector. The data acquisition system will be developed further to support multisegmented position-sensitive detector to improve the photon count rate capability of the advanced x-ray imaging crystal spectrometer system.     

A thermal neutron detector based on single-crystalline silicon

It is shown that a change in the specific electrical conductivity (SEC) in silicon single crystals after irradiation and radiation defect annealing is directly proportional to the thermal neutron fluence. This fact is used as a basis of a method for measuring the neutron flux. In this case, the proportionality factor is dependent on the neutron spectrum, being independent of the initial SEC, which significantly simplifies detector calibration. In measurements of the thermal neutron fluence in terms of relative and absolute units, the rms was 4 and 8%, respectively.     

A LED-based thermal detector of hidden corrosion flaws

Results of using powerful LED matrices to inspect metal articles for hidden corrosion by active thermal-wave method are described. The effect of the color of paint-and-lacquer coating on the efficiency of heating with LED and halogen emitters is analyzed. The possibility of using powerful LED panels as thermal stimulation sources in portable flaw detectors is described.     

A fiber-optic thermal detector of unconfined alpha particles

A prototype thermal detector intended for measuring spectra and profiles of energetic particles and based on a multifoil thermal detector was tested. Three types of absorbing films were tested: nickel foil, diamond-like carbon (DLC) film, and epitaxial CVD diamond film. A fiber-optic infrared bolometer was used as a sensing element.     

A silicon position-sensitive detector of charged particles and radiations on the basis of functionally integrated structures with nano-micron active regions

A novel pixel array two-coordinate detector with internal amplification is described. Linear amplification of the primary ionization current is attained by using functionally integrated structures of a p-i-n diode and a bipolar transistor in the detector pixel. It is shown that a 16-fold decrease (from 0.64 to 0.04 μm²) in the emitter area of the functionally integrated structures allows the current gain of pixel bipolar structures to be increased from 10 to 80 at a pixel collector current of ∼1 nA. As a result, it is possible to obtain spectra of radiations weakly interacting with the silicon (e.g., γ rays) and to reduce the response time of the position-sensitive detectors by an order of magnitude, down to 100 ns and less. It is demonstrated that the detector can be used in fast position-sensitive detection of particles with time, coordinate, and energy resolutions of ≤100 ns, ≤25 μm, and ≤12%, respectively.     

单片机控制的气相色谱热导检测器研究

针对气相色谱热导检测器的弱信号失真问题,研究与设计热导检测器的弱信号测量电路及其单片机控制系统,进一步提高气相色谱热导检测系统的灵敏度和可靠性。     

GC-14A气相色谱仪热导检测器三种故障的处理方法

热导检测器 (ＴＣＤ)是ＧＣ - 14Ａ气相色谱仪常用检测器之一。但ＴＣＤ故障往往不易准确判断 ,处理不当还会扩大故障部位。本文在排除电路和气路方面的原因外 ,分析了ＴＣＤ常见的三种故障现象 ,提出了相应的处理方法。(1)开机后基线不稳 ,噪声大或基线严重漂移。故障分析 :可能是ＴＣＤ被污染 ,从ＴＣＤ工作时间长短可粗略推断ＴＣＤ受污染的程度。处理方法 :对于轻微污染 ,可将ＴＣＤ的气路进口和出口拆下 ,用 5 0ｍＬ注射器依次将丙酮、无水乙醇和蒸馏水从进气口反复注入 5～ 10次 ,用吹气球从进气口处缓慢吹气 ,吹出杂质和残余液体 ,然…     

Low-distortion resistive anodes for two-dimensional position-sensitive MCP systems

Microchannel plates (MCPs) are frequently employed with resistive anodes to detect charged particles or photons and yield analog signals from which event positions can be decoded. We discuss an anode geometry devised by C.W. Gear that offers theoretically distortionless encoding of Cartesian event positions into pulse charge ratios. Electron beam images taken with such an anode are shown, and confirm the usefulness of the approach.     

First results of use of a scintillating-fiber position-sensitive detector for recording the target image in a 14-MeV neuron beam at the ISKRA-5 facility

The design of the scintillating-fiber detector is described, and the first results obtained in recording the target image in a 14-MeV neutron beam at the ISKRA-5 facility are presented. The scintillating-fiber position-sensitive detector has been designed for diagnosing laser fusion processes by recording the spatial distribution of thermonuclear neutrons escaping from the target. Position-sensitive detection is effected by conversion of neutron radiation into light in a scintillating fiber array. Discrimination of neutrons from γ rays by their time of flight and image intensification are performed with the aid of a frame camera. Images are recorded by a CCD camera. A technique for recording penumbra images is used for imaging at low neutron yields (3 × 10⁸−10¹¹).     

气相色谱热导检测器的信号测量与电源电路研究

在气相色谱仪中,采用热导检测器检测物质成分的浓度变化,具有构造简单、测定范围广、稳定性好、线性范围宽等优点。针对气相色谱热导检测器的弱信号失真和电源不稳定问题,研究与设计热导检测器的弱信号测量电路、信号放大电路以及电源电路。实践表明,该方法有效提高气相色谱热导检测系统的可靠性。     

A measuring complex for time-of-flight spectrometry of fast neutrons

A measuring complex for solving problems of fast neutron spectrometry using the time-of-flight method has been developed on the basis of an ЗГП-15 electrostatic tandem accelerator operating in a pulsed mode. The pulse repetition rate of the accelerator is 2.5 MHz, and the pulse duration is τ ≤ 1 ns. The accelerator components, some features of their performance, and their main parameters are described. The complex has been used to investigate the differential neutron emission cross sections for different constructional materials. A method providing the stable performance of its measuring channels has been proposed and tested.