基于SOPC架构的脉冲磁场数据采集系统

提出了一种嵌入式高速高精度脉冲磁场数据采集系统的设计方案,基于先进SOPC技术,在FPGA中嵌入了32位Nios Ⅱ软核系统,实现脉冲磁场信号的采集、处理、存储、传输等功能.该系统具有设计灵活、数据处理速度快、精度高和扩展性好等优点.     

A dual-port FASTBUS memory to test the L3 data acquisition system

A dual-port 0.25-Mbytes (64 K×32 bits) FASTBUS memory module is described which implements a large set of functions on the Crate Port, while the Cable Port is mainly used for data transfers. Both linear and circular FIFO-like modes are software-selectable. Two pointers are available for write and read operations, respectively. The memory, successfully used to test the L3 event builders, exhibits features of an interesting, general purpose, FASTBUS module for event buffering in large data acquisition systems     

ITER Fast Plant System Controller prototype based on PXIe platform

The ITER Fast Plant System Controller (FPSC) is based on embedded technologies. The FPSC will be devoted to both data acquisition tasks (sampling rates higher than 1 kHz) and control purposes (feedback loop actuators). Some of the essential requirements of these systems are: (a) data acquisition and data preprocessing; (b) interfacing with different networks and high speed links (Plant Operation Network, timing network based on IEEE1588, synchronous data transference and streaming/archiving networks); and (c) system setup and operation using EPICS (Experimental Physics and Industrial Control System) process variables.CIEMAT and UPM have implemented a prototype of FPSC using a PXIe (PCI eXtension for Instrumentation) form factor in a R&D project developed in two phases. The paper presents the main features of the two prototypes developed that have been named alpha and beta. The former was implemented using LabVIEW development tools as it was focused on modeling the FPSC software modules, using the graphical features of LabVIEW applications, and measuring the basic performance in the system. The alpha version prototype implements data acquisition with time-stamping, EPICS monitoring using waveform process variables (PVs), and archiving. The beta version prototype is a complete IOC implemented using EPICS with different software functional blocks. These functional blocks are integrated and managed using an ASYN driver solution and provide the basic functionalities required by ITER FPSC such as data acquisition, data archiving, data pre-processing (using both CPU and GPU) and streaming.     

Test bed for real-time image acquisition and processing systems based on FlexRIO,CameraLink, and EPICS

Image diagnostics are becoming standard ones in nuclear fusion. At present, images are typically analyzed off-line. However, real-time processing is occasionally required (for instance, hot-spot detection or pattern recognition tasks), which will be the objective for the next generation of fusion devices. In this paper, a test bed for image generation, acquisition, and real-time processing is presented. The proposed solution is built using a Camera Link simulator, a Camera Link frame-grabber, a PXIe chassis, and offers software interface with EPICS. The Camera Link simulator (PCIe card PCIe8 DVa C-Link from Engineering Design Team) generates simulated image data (for example, from video-movies stored in fusion databases) using a Camera Link interface to mimic the frame sequences produced with diagnostic cameras. The Camera Link frame-grabber (FlexRIO Solution from National Instruments) includes a field programmable gate array (FPGA) for image acquisition using a Camera Link interface; the FPGA allows for the codification of ad-hoc image processing algorithms using LabVIEW/FPGA software. The frame grabber is integrated in a PXIe chassis with system architecture similar to that of the ITER Fast Controllers, and the frame grabber provides a software interface with EPICS to program all of its functionalities, capture the images, and perform the required image processing. The use of these four elements allows for the implementation of a test bed system that permits the development and validation of real-time image processing techniques in an architecture that is fully compatible with that of the ITER Fast Controllers. This paper provides a specific example of a pattern search in a movie, its real-time implementation, and a performance analysis of the entire platform.     

基于波带片纳米聚焦装置的快速扫描X射线荧光成像实验系统

在上海光源硬X射线微聚焦光束线站BL15U1,为提高波带片纳米聚焦装置的X射线荧光成像实验效率,设计实现了一种快速扫描荧光成像实验装置。该装置包括运动控制系统、样品荧光探测系统和实验数据同步获取系统。运动控制系统设计了闭环反馈控制、样品台电机运动控制和扫描轨迹,实现了快速扫描过程中样品的准确定位。样品荧光探测系统和实验数据同步获取系统实现了硬件同步触发计数器获取荧光计数,保证了荧光成像的准确性。实验结果表明,运动控制系统三角波形跟踪误差小于20 nm,满足光斑在样品处的重复定位精度小于光斑尺寸1/10的要求。用该系统获取了标准铜网的元素分布图像,图像获取时间是“走停”扫描模式的1/5,验证了实验系统的可行性和高效性。     

基于AFE0064和FPGA的千兆网X射线图像采集系统

X射线实时检测系统应用于多个行业。针对目前快递物流、输送带、集装箱、乘用车等检测中,对高性能X射线图像采集系统的需求,基于光电二极管阵列(含闪烁体)和高速电流输入模拟前端,采用高速串行ADC、千兆以太网控制器MAC、千兆以太网PHY,结合FPGA主控制器,设计了高速度、高性能、双能量线阵列X射线图像采集系统,像素尺寸为5.0、2.5、1.6、0.8、0.4 mm、50μm,采集速度最高可达6 m/s,经调试后样机可以正常运行,图像清晰,性能稳定,完全满足上述需求。     

Imaging with Photons: A Unified Picture Evolves

The square root of the density of exposure quanta at the image plane is a popular measure of image quality for photon images. This is in fact only an upper limit which is rarely realized in the image. It is the density of noise equivalent quanta (NEQ) deduced from image measurements which is relevant to real imagery. In general NEQ is a non-trivial function of spatial frequency. Examples are taken from screen/ film mammography, electrostatic mammography, and computed tomography. The signal-to-noise ratios computed from these NEQ values characterize the performance of an ideal observer confronted with the image and a detection task. This sets goals for real observer performance, i. e., image processing and display for human acquisition.     

一台便携式伽玛相机的数据采集系统设计

介绍了一套用于便携式小型伽玛相机成像的高性能数据采集系统.为满足其便携式移动方便的要求,该数据采集系统的设计基于通用的USB接口,采用模块化的设计与系统集成.选用多通道数据同时采集的高速USB-ADC卡(DT9836)与LabVIEW软件开发平台,实现了高分辨小型伽玛相机多通道数据的同时采集、处理、图像显示与存储等功能...     

跨临界时二氧化碳体系微观结构特征的分子动力学模拟

应用分子动力学模拟方法研究了跨越临界点时二氧化碳体系微观结构特性。径向分布函数的分析表明,临界点前后体系内短程序结构变化很小,主要受分子间极强的近邻相互作用的强化效果影响,第一近邻配位数的分析进一步显示近程结构的变化以配对分子数量的变化为主;气态条件下的二氧化碳体系仍呈“近程有序且长程无序”状态;静态结构因子的分析表明,拟临界区体系中存在中远程有序结构;定义了无序距离,该参数的突增表明了临界点附近分子间相互作用距离剧烈增大。      

Improvements to conventional X-ray tube-based cone-beam computed tomography system

Conventional X-ray tube-based cone-beam computed tomography(CX-CBCT) systems have great potential in industrial applications. Such systems can rapidly obtain a three-dimensional(3D) image of an object.Conventional X-ray tubes fulfill the requirements for industrial applications, because of their high tube voltage and power. Continuous improvements have been made to CX-CBCT systems, such as imaging time shortening,acquisition strategy optimization, and imaging software development, etc. In this study, a CX-CBCT system is developed. Additionally, some improvements to the CX-CBCT system are proposed based on the hardware conditions of the X-ray tube and detector. A near-detector(ND)geometry condition is employed to obtain a sharper image and larger detection area. An improved acquisition strategy is proposed to simplify operations and reduce total imaging time. In the ND geometry condition, a simplified method called FBP slice stacking(SS-FBP) is proposed, which can be applied to 3D image reconstruction. SS-FBP is timesaving relative to traditional methods. Furthermore, imaging software for the CX-CBCT system is developed in the MATLAB environment. Several imaging experiments were performed. The results suggest that the CX-CBCT system works properly, and that the above improvements are feasible and practical.     

大型集装箱检测系统管理站的任务需求分析与结构规划

由加速器周期性产生的Ｘ射线经前准直器成形为扇形脉冲束流，透过集装箱后再经过后准直器进入阵列探测器，再由前置放大器放大成形为电压信号送入采样保持电路，经多路选择器送去变换成为一组数字量，再经过一系列的预处理就可形成一列象素。由于集装箱是载于拖动装置上的，随着拖动装置的运动，这一列列的象素就可组成一幅完整的集装箱透视图，这样的一个完整过程由中心管理站统一控制和同步。本文介绍实时扫描数据获取与处理，并给     

Effect of lens-to-sample distance on spatial uniformity and emission spectrum of flat-top laser-induced plasma

The optimal spectral excitation and acquisition scheme is explored by studying the effect of the lens-to-sample distance (LTSD) on the spatial homogeneity and emission spectra of flat-top laser converging spot induced plasma. The energy distribution characteristics before and after the convergence of the laser beam with quasi flat-top intensity profile used in this study are theoretically simulated and experimentally measured. For an aspheric converging mirror with a focal length of 100 mm, the LTSD (106 mm ≥ LTSD ≥ 96 mm) was changed by raising the stainless-steel sample height. The plasma images acquired by ICCD show that there is air breakdown when the sample is below the focal point, and a ring-like plasma is produced when the sample is above the focal point. When the sample is located near the focal point, the plasma shape resembles a hemisphere. Since the spectral acquisition region is confined to the plasma core and the image contains all the optical information of the plasma, it has a lower relative standard deviation (RSD) than the spectral lines. When the sample surface is slightly higher than the focal plane of the lens, the converging spot has a quasi flat-top distribution, the spatial distribution of the plasma is more uniform, and the spectral signal is more stable. Simultaneously, there is little difference between the RSD of the plasma image and the laser energy. In order to further improve the stability of the spectral signal, it is necessary to expand the spectral acquisition area.     

A TDC-Based System for X-Ray Imaging Detectors

An image acquisition system is presented for use with position sensitive detectors (PSD). The system is based on a high-resolution time-to-digital converter (TDC) and a field programmable gate array (FPGA). The detectors use gas as absorbing medium and two delay lines to identify the coordinates of each detected particle. The TDC translates the time information coming from the delay lines into digital words, from which the particle position coordinates are encoded. The FPGA is responsible for processing each event, controlling the data acquisition and communicating with a personal computer. 256 pixels$times$256 pixels images are stored into an on-board memory. This resolution is increased to 512 pixels$times$512 pixels by using a time multiplexing technique. The maximum data acquisition rate is 1.2 million events per second. X-ray images obtained with the system are shown, which illustrate the overall performance.     

微焦点X射线成像系统扫描参数测量及投影图像校正研究

微焦点X射线成像系统由于被重新安装以及初始化,导致系统参数读数与实际值之间存在偏量。给出了测量这些偏量值的基本原理和方法,并通过实验求出偏量值。由于图像增强器与图像获取装置本身固有特点以及非线性获取成像,投影图像存在几何畸变。讨论了图像几何畸变校正的基本原理,并给出具体步骤以及校正后的图像.     

PIP软件平台的评估与开发

ＰＩＰ软件包是一套集采集流程控制与图像自理于一体的核医学图像处理软件平台。本文介绍了ＰＩＰ的基本功能开发环境，并重点介绍如何在ＰＩＰ平台上开发心脏和肾脏临床处理程序。     

基于WEB的BES数据存储系统模型

讨论了基于WEB的数据存储系统模型的系统结构和基本方法。从BES数据结构分析、数据处理过程、系统结构设计、实验方案选择、关键技术以及图像处理等方面详细介绍了系统模型的实现过程，守成了从系统实验软硬件平台的建立到数据装入、数据库建立、数据存取、数据远程处理以及数据图形处理等功能。     

Software for fast cameras and image handling on MAST

The rapid progress in fast imaging gives new opportunities for fusion research. The data obtained by fast cameras play an important and ever-increasing role in analysis and understanding of plasma phenomena. The fast cameras produce a huge amount of data which creates considerable problems for acquisition, analysis, and storage.

We use a number of fast cameras on the Mega-Amp Spherical Tokamak (MAST). They cover several spectral ranges: broadband visible, infra-red and narrow band filtered for spectroscopic studies. These cameras are controlled by programs developed in-house. The programs provide full camera configuration and image acquisition in the MAST shot cycle.

Despite the great variety of image sources, all images should be stored in a single format. This simplifies development of data handling tools and hence the data analysis. A universal file format has been developed for MAST images which supports storage in both raw and compressed forms, using either lossless or lossy compression. A number of access and conversion routines have been developed for all languages used on MAST. Two movie-style display tools have been developed—Windows native and Qt based for Linux.

The camera control programs run as autonomous data acquisition units with full camera configuration set and stored locally. This allows easy porting of the code to other data acquisition systems. The software developed for MAST fast cameras has been adapted for several other tokamaks where it is in regular use.     

A mobile tomographic gamma camera system for acute studies

A mobile tomographic gamma camera system, called Cardiotom Mark 1, has been developed for imaging the myocardium and other small organs. The Cardiotom system is based on a tomographic technique, ectomography, which is a limited view angle method using a rotating slant hole collimator (RSHC) and a stationary detector to produce projection images. This enables the ectomographic system to be implemented as a mobile system. With the system developed, almost 200 perfusion studies have been performed. The system is based on a second-hand detector and a 30° RSHC. By segmenting the collimator, total system efficiency is increased and acquisition time can be reduced by a factor equal to the number of segments. The system developed is PC-based and totally self-contained with data acquisition, reconstruction, and image presentation. The mobility of the system and the fact that the examination requires no patient cooperation enable acute studies of myocardial perfusion in the critically ill patient, either in the intensive care unit or the emergency room. A mobile system with three-dimensional imaging can offer new possibilities in cardiological research and diagnosis     

Advanced thermal-hydraulic analysis of the ITER TF magnets performed with VENECIA code for 15 MA reference scenario

Normal operation of the ITER TF coils at 15 MA reference scenario is simulated with the use of the VENECIA code. The developed numerical model adopts a full scale quasi 3D approach for thermal hydraulic and thermal diffusion analysis of TF coils at the reference scenario with greatly variable heat loads from nuclear heating and Eddy/AC losses. The model implements latest heat load specifications and corrective changes in design of TFWP, TF case and their cryogenic circuits. For the first time the primary auxiliary cryogenic boxes (ACBs) are included in a common model to provide for the forced-flow cooling of the TF winding, TF case together with CS/OIS structures and PF supports.     

轮型代码自动识别系统图像处理算法改进研究

详细介绍了轮型代码自动识别系统的工作原理和图像处理算法,系统通过图像获取、图像预处理、阈值分割、边缘检测和模板匹配来识别不同型号的轮毂。通过改进轮毂图像边缘特征提取算法来提高轮型代码的识别速度,增强系统识别的正确率。