Recent Developments in Insertion Devices at the ESRF: Working Toward Diffraction-Limited Storage Rings

The development of permanent-magnet insertion devices (IDs) is a feature of third-generation light sources (3GLS). Since the early 1990s, an important research and engineering effort has been carried out on various types of undulators at the ESRF, as in many other 3GLS facilities. We are presently at the forefront of an interesting migration toward new storage ring lattices with ultra-low horizontal emittance [1 M. Erikson, Journal of Synchrotron Radiation, 21(5), 837–842 (2014).[Crossref], [PubMed], [Web of Science ®] , [Google Scholar], 2 M. Borland, Synchrotron Radiation News, 27(6), 2–31 (2014).[Taylor &; Francis Online] , [Google Scholar]]. The upgrade of the ESRF accelerator will take place before 2020. A new magnet lattice comprising seven bending magnets per cell will replace the existing DBA structure, leading to a dramatic reduction of the horizontal emittance from 4 nm to about 130 pm. Because the new ring will be operated at the same energy as the current ring, the majority of existing IDs will be used in the upgraded ring, at least as a starting point. From the present state of the art in ID technology, one can obviously identify the development of very short-period, small-gap undulators as potential major X-ray sources in such new storage rings. Technically, various methods in magnetic field processing and correction need to be revisited and possibly updated.     

ESRF 11th users' meeting and workshops

More than 90 participants from Europe, the US and Japan gathered from April 27 to 29, 2005, in Zeuthen, near Berlin, to hold a lively international meeting on time-resolved soft X-ray science. The meeting continued the series of preceding workshops held in 2002 in Napa (California, USA) and in 2003 in Montreux (Switzerland). It was organized by the three synchrotron radiation sources BESSY (Berlin, Germany), the Swiss Light Source SLS (Villigen) and the French synchrotron radiation source SOLEIL (Orsay).

The aim of the workshop was to bring together the existing ultrafast laser community and the emerging ultrafast X-ray community in order to discuss recent scientific highlights from both fields and to outline new directions for the application of ultrafast X-rays.     

Jefferson Lab Mass Storage and File Replication Services

Jefferson Lab has implemented a scalable,distributed,high performance mass storage system-JASMine.The system is entirely implemented in Java,provides access to robotic tape storage and includes disk cache and stage manager components.The disk manager subsystem may be used independently to manage stand-alone disk pools.The system includes a scheduler to provide policy-based access to the storage systems.Security is provided by pluggable authentication modules and is implemented at the network socket level.The tape and disk cache systems have well defined interfaces in order to provids integration with grid-based services.The system is in production and being used to archive 1 TB per day from the experiments.and currently moves over 2 TB per day total.This paper will describe the architecture of JASMine;discuss the rationale for building the system,and present a transparent 3^rd party file replication service to move data to collab-orating institutes using JASMine,XML,and servlet technology interfacing to grid-based file transfer mechanisms.     

dCache,a Distributed Storage Data Cahing System

This article is about a piece of middle ware,allowing to convert a dump tape based Tertiary Storage System into a multi petabyte random access device with thousands of channels.Using typical caching mechanisms,the software optimizes the access to the underlying Storage System and makes better use of possibly expensive drives and robots or allows to integrate cheap and slow devices without introducing unacceptable performance degadation.In addition,using the standard NFS2 protocol,the dCache provides a unique view into the storage repository,hiding the physical location of the file data,cached or tape only.Bulk data transfer is supported through the kerberized FTP protocol and a C-API,providing the posix file access semantics,Dataset staging and disk space management is performed invisibly to the data clients.The project is a DESY,Fermilab joint effort to overcome limitations in the usage of tertiary storage resources common to many HEP labs.The distributed cache nodes may range from high performance SGI machines to commodity CERN Linux-IDE like file server models.Different cache nodes are assumed to have different affinities to particular storage groups or file sets.Affinities may be defined manually or are calculated by the dCache based on topology considerations.Cache nodes may have different disk space management policies to match the large variety of applications from raw data to user analysis data pools.     

Scanning Probe Instruments and Synchrotron Light at the ESRF

In 2004, the aim of the X-Tip European Project was to pursue the integration of scanning probe microscopy techniques into synchrotron radiation beamlines to provide new opportunities to both fields of microscopy and spectroscopy. Given the limited X-ray focusing capabilities at that time and the difficulty of alignment, the first emphasis was given to the possibility of exploring the morphology of the sample surface within the area illuminated by the X-rays, selecting an area of interest and, using the scanning tip, aligning it into the X-ray beam and extract by total electron yield spectroscopic information, with lateral resolutions ideally defined by tip dimensions.     

全息光盘存储器的数据存取与像素匹配

全息光盘存储(HDS)技术作为一种非常具有潜力的新型信息存储技术, 是下一代光盘发展的目标。在全息光盘存储系统中, 为了实现数据精确快速地写入和读出, 降低误码率, 需要在整个高分辨率页面上实现空间光调制器(SLM)与光电阵列耦合器(CCD)之间1∶1像素匹配。在体全息存储理论和光学设计理论基础上, 研究实现SLM和CCD像素1∶1匹配的方法, 提出了实现像素匹配的要求和条件, 并且按照此要求完成该全息光盘存储器的光学系统。实验中, 分别使用随机数据掩膜版和SLM实现了对CCD的512×512精确像素匹配, 在光学系统中引入存储介质条件下, 图像质量良好, 掩膜版和SLM原始误码率分别为2.5×10-4和1.5×10-4。     

State of the Art and Perspectives of Biomedical Imaging at the ESRF

Over the last decade, synchrotron radiation sources have seen a significant increase in brilliance, and the advent of free electron lasers has made entire new research fields accessible to investigations with X-rays. These advances in light source capabilities have resulted not only in a host of scientific advances and discoveries, but also in a need for a new generation of X-ray imaging detectors that can match the sources' capabilities in terms of frame rate and image dynamic range while recording image information with fine granularity over a large – preferably uninterrupted – (multi)megapixel area with single-photon sensitivity. Developing such next-generation imagers is both costly and time-consuming, and the requirements at many photon science facilities are similar enough to invite a collaborative effort. The Percival (“Pixellated Energy Resolving CMOS Imager, Versatile And Large”) imager is being developed by a collaboration of DESY, Rutherford Appleton Laboratory (RAL), Elettra, and Diamond Light Source (DLS) to answer this need for the soft X-ray regime.     

高速CCD图像数据存储技术

介绍了一种高速CCD图像数据的实时存储方法利用FIFO缓存器使CCD输出的高速数据流和低速存储介质二者的速度匹配,将多路高速大容量图像数据实时记录到了存储介质中,为后期的图像恢复和图像处理提供了原始数据该图像数据存储的方法对各种数据采集以及存储系统的设计具有很好的参考意义.     

A Model of BES Data Storage Management System

In this article we will introduce the system structure of a model built for BES data management and storage as well as the basic methods on how to establish the system.Additionally the analysis of the data structure,the data process,the selection of experimental program,the image manipulation and the key techniques will be discussed in detail,The model implements the setup of the system environment and all those functions from data loading,database cresting,data accessing,remote data process to data figuring.     

体全息存储中二维交错编码技术的研究及实现

为了克服和纠正体全息存储系统中大量的随机错误和突发错误,数据在按"页面"为单位存入系统时,通常采用纠错编码、交错和调制相结合的编码方式来进行信息组页.文中提出了一种二维交错技术用于克服数据"页面"存在的突发错误,以提高纠错编码的纠错能力,并通过FPGA实现了块交错RS(255,223)编码码字在数据"页面"中的均匀分布.     

绿光光存储实验研究

在光存储技术中,采用短激光波长激光器和大数值孔径物镜是提高光存储密度的两种有效途径.本文采用532 nm波长激光, 0.65数值孔径物镜,建立了绿光存储实验装置.并采用该实验装置在CD-RW相变光盘上进行了存储实验研究,实现了线宽约为500 nm的实验结果.     

恶劣环境下高速数据存储的研究与实现

针对强震动、强冲击等恶劣环境的要求,应用FLASH固态存储器,开发了一种基于单片机控制的接口简单、重量轻、体积小的大容量数据存储系统在机载CCD相机的高速图像数据存储设计中,得到了很好的应用.     

一类高效的数据库系统安全存储策略研究

针对云存储环境下多副本方案存储效率低下的问题,设计了一种高效的数据安全存储策略。该策略采用了并行思想,设计了高效的数据同步存储算法。该算法将用户的存储请求同时转发给多个工作者,由这多个工作者同时向每个副本服务器写入数据。该策略将云端设计为整体协调、并行处理模式,即多个工作者由管理者统一分配调度,各个工作者独立地服务于对应的副本存储服务器,由管理者与用户进行交互处理,并且这多个工作者对用户来说是透明的,该设计模式并没有增加用户使用云存储的复杂度。实验结果表明,本文设计的数据安全存储策略在保证副本冗余的情况下可以有效地降低额外的时间损耗,保证用户读写云端数据的效率不低于单副本情况下的效率。该方案用于云存储环境下高效的数据安全存储是可行的、有效的。     

水泥生产线数据采集与存储系统的设计与实现

为了实现水泥厂生产线设备运行状态大量实时数据的存储,考虑到成本,选择关系数据库进行实时数据的存储,提出了中间缓冲和相同数据放弃存储等技术。首先对水泥厂实时数据采集方案设计的过程进行认知和分解,指出关系数据库存储大量实时数据是设计过程中的难点。综上设计了总体模型,采用opc协议与采集服务器进行通信,通过在水泥厂现场部署数据采集客户端运行,效果良好,验证了该设计的有效性。     

Fluorescent Aluminum Oxide Crystals for Volumetric Optical Data Storage and Imaging Applications

New fluorescent aluminum oxide crystals (Al₂O₃:C,Mg) for volumetric optical data storage and imaging applications were investigated. Magnesium impurity and double oxygen vacancy aggregate defects are responsible for the main optical properties of the new material. Spectroscopic investigation of these defects in different charge states was performed. Optical absorption, excitation-emission spectra and fluorescent lifetime of the new fluorescent medium were studied. Quantum yield of fluorescence from Al₂O₃:C,Mg crystals was measured in comparison with standard laser dyes.     

等曝光量时间递增双光子三维光存储

为提高双光子三维光存储的深层存储信息的读出信号强度和存储容量,根据Torok的光在多层介质中传播理论,模拟了折射率失配情况下(介质折射率为1.48,数值孔径为NA=0.65)双光子写入光束在不同存储深度处会聚点的强度分布,分析得到了会聚点处最大光强平方与存储深度的关系;根据原子的光吸收基本理论,分析得到了等曝光量写入光强不变情况下曝光时间随存储深度增加的递增关系;根据上述结果和利用自制的双光子三维光存储系统在光致变色存储材料中实现了连续八层的信息存储对比实验,实验结果表明等曝光量时间递增存储方法可有效提高存储容量和深层存储信息的读出信号强度.