Electrostatic-lenses position-sensitive TOF MCP detector for beam diagnostics and new scheme for mass measurements at HIAF

A foil–microchannel plate(MCP)detector,which uses electrostatic lenses and possesses both good position and timing resolutions,has been designed and simulated for beam diagnostics and mass measurements at the next-generation heavy-ion-beam facility HIAF in China.Characterized by low energy loss and good performances of timing and position measurements,it would be located at focal planes in fragment separator HFRS for position monitoring,beam turning,Bq measurement,and trajectory reconstruction.Moreover,it will benefit the building-up of a magnetic-rigidity–energy-loss–time-offlight(BqDETOF)method at HFRS for high-precision in-flight particle identification of radioactive isotope beams on an event-by-event basis.Most importantly,the detector can be utilized for in-ring TOF and position measurements,beam-line TOF measurements at two achromatic foci,and position measurements at a dispersive focus of HFRS,thus making it possible to use two complementary mass measurement methods[isochronous mass spectrometry at the storage ring SRing and magnetic-rigidity–time-of-flight(BqTOF)at the beam-line HFRS]in one single experimental run.

Preliminary results of a Compton camera based on a single 3D position-sensitive CZT detector

A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source.The angular resolution of the 662 keV line is 36° FWHM for the simple back-projection method and 9.6° FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.

Application of 2-D Position Sensitive Detector in Spatial Straightness Measurement of Guide Rails

A laser collimating system based on 2-D position sensitive detector (PSD) is presented in this paper. The working principle of PSD is depicted in detail. A calibration device was developed to check the nonlinearity errors of PSD and a multilayer feedforward neural network based on error back-propagation algorithm was used to compensate errors. With the aid of computer-based data acquisition system, an automatic dynamic measuring process was realized. A series of experiments, including comparison tests with laser interferometer, were done to evaluate the performance of the measuring system. The experimental results show that the spatial straightness errors of guide rails can be measured with high accuracy. The maximum differences between the device and laser interferometer are 0.027 mm in Y direction, and 0.053 mm in X direction in the measuring distance of 6 m.

Response Characteristics of Position Sensitive Detector under Oblique Incidence Condition

Based on Lucovsky equation,the response solution of 1-D position sensitive detector(PSD) is given under the condition of parallel light oblique incidence and Gaussian beam oblique incidence,and the response characteristics are analyzed by numerical calculation. The relation between oblique incident angle and output current is introduced and illustrated.

Technique of Position Sensitive Detector with Alternating Light Source

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In-situ fabrication of on-chip 1T'-MoTe_(2)/Ge Schottky junction photodetector for self-powered broadband infrared imaging and position sensing

High-sensitivity room-temperature multi-dimensional infrared(IR)detection is crucial for military and civilian purposes.Recently,the gapless electronic structures and unique optoelectrical properties have made the two-dimensional(2D)topological semimetals promising candidates for the realization of multifunctional optoelectronic devices.Here,we demonstrated the in-situ construction of high-performance 1T’-MoTe_(2)/Ge Schottky junction device by inserting an ultrathin AlOx passivation layer.The good detection performance with an ultra-broadband detection wavelength range of up to 10.6 micron,an ultrafast response time of~160 ns,and a large specific detectivity of over 109 Jones in mid-infrared(MIR)range surpasses that of most 2D materials-based IR sensors,approaching the performance of commercial IR photodiodes.The on-chip integrated device arrays with 64 functional detectors feature high-resolution imaging capability at room temperature.All these outstanding detection features have enabled the demonstration of position-sensitive detection applications.It demonstrates an exceptional position sensitivity of 14.9 mV/mm,an outstanding nonlinearity of 6.44%,and commendable trajectory tracking and optoelectronic demodulation capabilities.This study not only offers a promising route towards room-temperature MIR optoelectronic applications,but also demonstrates a great potential for application in optical sensing systems.

Development of a PSD-based photon beam position measurement system

As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam position monitor based on position-sensitive detector (PSD) has been developed to measure the photon beam position in vertical and horizontal directions at the same time at HLS (Hefei Light Source). The new PBPM based on the PSD has fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, and then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. As the results shown, the resolution of the system is better than 3 mm.

基于透镜阵列多元聚焦的连续晶体三维位置灵敏探测器设计和仿真

连续晶体闪烁体探测器可以实现γ射线作用点的三维位置定位。本文提出一种新的探测器结构,引入透镜阵列实现作用点定位。探测器采集多元聚焦图像,从而改变对连续晶体闪烁光分布探测的需求。文中建立连续晶体、透镜阵列和光子计数器阵列的模型进行模拟研究,建立多元聚焦的光路反演重建算法定位γ射线作用点的三维位置。通过重建结果分析评估基于透镜阵列的连续晶体探测器性能,这种结构具有较好的定位能力和位置分辨。对于尺寸为48 mm×48 mm×45 mm的硅酸钇镥(LYSO)闪烁晶体,实现了xy平面位置分辨优于1.54 mm,z方向位置分辨优于3.13 mm。基于连续晶体和透镜阵列结构的探测器还可对多作用点的情形进行重建,分析三组选定位置的重建结果,该结构对双作用点定位具有可行性。

一维光学位置传感器融合的非接触多自由度位姿测量系统

为实现机器人末端位姿多自由度实时测量反馈,融合一维光学位置传感器(Position Sensitive Detector,PSD)建立了平面3自由度非接触测量系统,对其测量原理,信号处理电路,环境光干扰去除和非线性标定算法等进行研究。根据PSD传感器测量特性和平面3自由度测量要求设计了4-PSD测量系统,并建立测量系统数学模型。研究了PSD传感器的信号处理电路,通过运放和除法器实现了单个PSD的信号处理,结合单片机与A/DC采样电路,实现了上位机的高频率信号采集。对4-PSD测量系统进行预实验,为消除环境光干扰,通过激光调制和数字滤波等方法进行验证。最后,通过激光位移传感器标定4-PSD测量系统,介绍了4-PSD的标定步骤(原点、转角、长度和二阶非线性标定),测定了系统标定后的误差分布。该测量系统具有较高的测量频率(50 Hz)。标定实验结果表明:标定后的4-PSD测量系统在70 mm×70 mm内,测量精度平均为0.49 mm,比标定前降低了90%的误差,能满足大部分高速、高精度机器人末端的非接触式实时测量反馈需求。

An improved method of angle measurement with a position sensitive detector

An improved method of angle measurement is proposed based on a parallel plate interferometer. A position detection system is incorporated into a parallel plate interferometer in order to realize large deflection angle measurement. A reflecting mirror is introduced for increasing the measurement resolution. In experiments, a deflection angle of a measured target was measured within ～3° with high accuracy. And as a phase modulating interferometer, it was used to measure a small angular displacement with a repeatability of 5.5 × 10^-8 rad.

感应读出延时线阳极光子计数探测器研究

针对空间天文、生物荧光、光谱测量等领域对高灵敏、大面阵探测器的应用需求,研制出基于感应读出方式的延迟线阳极光子计数成像探测器。该探测器由微通道板、延时线阳极以及读出电路组成,其中延时线阳极的性能直接影响探测器的成像质量。作为一种电荷感应读出延时线阳极,该阳极利用信号到达的时间差解码入射光子的位置,可获得高的探测灵敏度和大的成像面积,同时简化了工艺难度并提升了可靠性。设计了感应读出延时线阳极,理论分析了探测器不同设计参数及材料对感应电荷量的影响,提出了解决异层电极间感应电荷量难以平衡的方法。据此研制出了收集面积为40 mm×40 mm的位敏阳极。测试结果表明该阳极信号传输衰减小于10%,极间串扰小于3%。利用该阳极进行了光子计数成像实验,获得了优于150μm的空间分辨率,为研制可应用于天文紫外光谱测量的大面阵、高灵敏探测器提供了理论依据及实验指导。

基于双PSD的三维测角传感器精度分析

在机载光电转台、多自由度摇摆台等系统中,对于一些运动体与基座间没有确定的回转轴的柔性支撑、并联支撑平台,需要考虑非接触三轴角度测量方法,目前大部分的光电非接触三轴角度测量方案系统复杂,占用空间大,无法适用于如机载、星载等载荷对体积、质量敏感的场景。为此,文中提出了基于双位置敏感探测器(PSD)的非接触三轴角度测量方案,使用准直镜头汇聚、双面反射光楔反射,将光源在两片PSD上汇聚成像,利用PSD上的光斑位置坐标反解出三轴角度。描述了其工作原理以及传感器构成,分析了因两片PSD的相对位置偏移产生的误差,提出了对应补偿方法以减少焊装产生的PSD位置偏移对测量精度的影响。主要对采集的PSD模拟信号值的抖动噪声进行FIR滤波处理,分析了滤波器的相频响应特性,并在MCU中测量相位滞后时间以及滤波器的响应带宽,验证了该数字滤波器在系统内拥有较好的实时传输特性。自准直测量单元总质量为230 g,尺寸为50 mm×50 mm×50 mm。实验结果表明,34阶FIR滤波器将角度测量的误差减小至60%,在±2°测量范围内单轴测量时,方位角、俯仰角、横滚角的误差均方根分别为0.003°、0.007°、0.017°,组合测量时分别为0.006°、0.009°、0.021°,文中所提出的三维测角传感器精度较高,满足机载等场景的使用要求。

位置探测器与加速度计结合的测振方法

非接触式的振动测量方法具有非侵入和易布置的优点,在实际的工业生产和科研实验中有广泛的应用,但目前的非接触测量方式对测量装置自身受环境冲击振动产生的影响考虑较少。文中提出了一种振动自补偿的低成本的测振方法,采用位置探测器测量振动信号,并利用MEMS加速度计测量测振系统自身振动用于补偿。搭建实验系统对该方法进行了验证。实验结果表明:基于位置探测器的方法能够测量待测物体与测振系统间的振动,而MEMS加速度计能够测量环境引起的测振系统自身振动。经补偿后,环境振动冲击对使用位置探测器方法得到的振动测量结果的影响显著减弱。

基于PSD的六自由度位移测量解耦方法研究

基于位置敏感探测器(Position Sensitive Detector,PSD)的六自由度(6 Degree of Freedom,6DOF)位移测量对紧凑空间内精密位移台初始位置和姿态的精密测量具有重要作用。精密位移台位移与PSD上光斑位移之间非线性关系的解耦是实现精密位移台亚微米及微弧度位移测量精度的关键。根据PSD与6DOF精密位移台上角锥棱镜之间的位置关系,构建了6DOF位移测量方案,建立了6DOF位移台位移与PSD上光斑位移之间的精确对应关系模型,采用数值计算法对该模型进行解耦求解,并与小角度近似法进行了对比分析。结果表明,当6DOF位移台单自由度位移范围为±10 mm和±10 mrad时,数值计算法引入的解算误差最大值为10^(-17)mm和10^(-15)~10^(-16)mrad量级,而小角度近似法引入的解算误差最大值为5.39μm和35.5μrad;在此基础上,采用蒙特卡洛法以随机均匀分布方式产生10000组六自由度位移进行分析,表明数值计算法引入的解算误差平均值为10^(-17)mm和10^(-17)mrad量级,而小角度近似法引入的解算误差平均值为10^(-3)~10^(-6)mm和10^(-5)mrad量级,其中z方向解算误差达到4.4μm,R_(x)和R_(y)方向解算误差达到28μrad,故小角度近似法无法满足上述位移测量精度要求。所提出的基于数值计算法的解耦方法对实现6DOF位移台的高精度位移测量具有重要意义。

基于信号幅度的^(3)He管中子探测器刻度算法优化研究

本研究针对中国散裂中子源下的高压中子衍射谱仪中核心组件——位置灵敏型^(3)He管中子探测器的刻度问题进行了深入探究。通过实验验证和理论分析,揭示了传统刻度方法中未考虑到的中子信号幅度对刻度参数的影响,以及由此产生的位置分布畸变和空间分辨率降低的问题。为解决这些问题,本研究提出了一种改进的刻度算法,该算法能够有效地考虑中子信号幅度的变化,从而显著改善了探测器系统的空间分辨能力。经过实验结果分析显示,新的刻度算法不仅消除了位置分布的拖尾现象,而且提高了不同位置处的空间分辨率,与理论预期相符。本研究的成果为高压中子衍射谱仪在极端条件下的应用提供了重要的技术支持,并为进一步优化中子探测器的刻度方法和提高中子衍射技术的应用精度奠定了基础。

First large scale application of novel Si stripixel detector in real large experiment: Si VTX in PHENIX upgrade at RHIC

2D position sensitive, single-sided Si stripixel detector was selected as the one of the two main components of the Si vertex tracker (Si SVX) in the upgraded PHENIX detector at RHIC (relativistic heavy ion collider) in Brookhaven National Laboratory (BNL). This is the first large scale application of the novel Si stripixel detector in a real large experiment after many years of research and development at BNL. The first and second prototype fabrication runs of the SVX stripixel detectors were carried out successfully in BNL’s Si detector development and processing Lab. The processing of these stripixel detectors is similar to that for the standard single-sided strip detectors: one-sided processing, single implant for the pixel (strip) electrodes, etc. The only additional processing step is the double metal process, a technology that is simple and well matured by many Si detector processing industries and labs, including BNL. The laser and beam tests on those prototype detectors show the 2D position sensitivity and good position resolution in both X and U coordinates (about 25 μm for 80 μm pitch). For the mass production of 400 sensors needed for the Si SVX, the processing technology has been successfully transferred to the industrial: Hamamatsu Photonics (HPK). HPK has produced a pre-production run of stripixel sensors with the full PHENIX SVX specification on 150 mm diameter wafers. The laser tests on these pre-production wafers show good signal to noise ratio (about 20∶1).

基于PSD的风力发电机主轴监测系统研究

为实现风力发电机主轴轴向窜动的实时监测,基于位置敏感探测器(PSD)利用斜射式激光三角法搭建了非接触式光电主轴轴向位移测量系统。根据测量精度及使用环境要求,设计了STM32单片机与AD7606结合的数据采集模块,lwip协议栈与Usb-Host模块结合的数据传输与存储模块,满足测量数据准确性及远距离实时传输的要求。结合设计结果,在实验室利用直线位移台及角位移台搭建模拟监测系统,进行位移曲线标定及稳定性测试,并利用BP神经网络算法对系统非线性误差进行校正。实验结果表明,静态位置误差小于0.03 mm,动态位置误差小于0.1 mm,最大位置误差小于1 mm,满足系统研制要求。

基于PSD的汽轮机转子轴振动传感器

针对汽轮机转子轴振动的测量需求,文章研制一款基于位置敏感器件(position sensitive detector,PSD)的振动传感器。建立传感器的灵敏度模型,根据模型得出传感器的最优结构参数,并设计低噪声的信号处理电路;通过实验对该传感器进行标定和测试,并与商用电涡流传感器进行对比测试。结果表明:振动传感器的灵敏度为0.33 V/mm,测量范围为2 mm,振幅分辨率为4μm,频率响应范围为10~325 Hz,重复实验标准差优于3μm;与商用电涡流传感器的测量结果具有良好一致性,可用于汽轮机转子轴振动的检测。

中国先进研究堆中子织构谱仪二维位置灵敏探测器数据分析与处理方法

中子织构谱仪在航空航天、交通、核工业等领域关键材料的织构研究中具有独特的优势。为了提升探测效率,中国先进研究堆中子织构谱仪在2020—2021年进行了升级改造,将探测系统从单个3He计数管升级为大尺寸二维位置灵敏探测器。本研究针对中国先进研究堆中子织构谱仪升级后的实验测量数据,提出了从二维位置灵敏探测器获得的衍射中子计数到织构极图转换的数据处理与分析方法,并基于该方法使用Python语言开发了中子织构数据处理和分析软件系统,对实际测量数据的应用验证了该软件系统的可靠性。该系统实现了二维位置灵敏探测器数据到极图数据的转换和极图绘制,满足了中子织构谱仪升级后的功能需求。

低能电子穿越绝缘体微孔膜动力学过程研究

采用二维位置灵敏的微通道板探测器对能量为1500 eV的低能电子束穿过孔径为400 nm、未经照射过的的聚对苯二甲酸乙二醇酯(PET)微孔膜后的全角分布以及时间演化进行了测量,同时采用自制的积分式能谱测量装置测量了穿透电子的能量分布。实验结果表明:在充电阶段,当入射电子束束流较弱时,透射电子强度随充电时间逐渐上升;充电过程中,透射电子的角分布宽度由小变大,但是角分布中心基本不随膜的倾角移动。对出射电子达到平衡态时的电子能谱的测量表明,穿透电子的能量保持着入射时的能量。对于理解电子在绝缘体微孔中的传输给出了新的实验证据,给出了可能形成“导向效应”的微孔内部电场的条件。