PSI数字化电源控制器在上海光源大功率电源上的应用及创新

本文介绍了国外使用PSI数字化控制器在大功率电源上的控制方式,进而阐明了上海光源（SSRF）大功率开关电源的控制方式,及PSI数字化控制器在SSRF大功率开关电源上的创新应用。     

SSRF高性能数字化电源检测系统

设计了上海光源(SSRF)高性能数字化电源检测系统的硬件,并采用LabVIEW开发了RS-232/以太网通信的系统检测软件,实现了仪器与数字化电源控制和24 h的数据采集、显示与保存功能.用户可通过局域网方便地通过此系统获取数据,并用Excel格式存储数据为SSRF数字化电源系统性能分析和建立数字化电源性能指标数据库提供依据.     

基于现场可编程门阵列的数字调节器设计

根据磁铁稳流电源闭环控制的基本原理，将模拟调节器及相关的外围控制电路采用全数字化控制技术，并通过嵌入数字信号处理模块的现场可编程门阵列（FPGA）来实现，设计了数字调节器（DRL）。通过样机试验证明，该数字调节器可实现对电源的全数字化调节和控制，满足多数加速器对静态磁铁稳流电源的控制需求。     

SSRF数字化电源巡检系统的设计

开发了SSRF数字电源巡检系统,实现远程巡检与本地巡检两种模式,采用LabVIEW软件开发平台设计了简单美观的用户界面,两种硬件结构在数字化电源巡检用户软件界面上不需修改.远程巡检用于模拟数字化电源与中央控制室间远程监控通讯的调试,及时排查远程通讯或电源的故障;本地巡检可同时检测18台数字化电源,长期(24 h)进行故障状态监视,并通过Excel或text记录与保存,进行电源性能指标验收.两种巡检模式已用于SSRF的数字化电源巡检.     

SSRF磁铁数据库系统的开发

上海同步辐射装置(SSRF)磁铁数据库系统的开发过程包括数据库的设计、数据库的实现和功能。SSRF磁铁数据库由一系列的用于存储磁铁物理设计参数、磁场测量数据、准直测量数据和电源数据等的数据表组成。它对于确保磁铁质量、分析磁场误差和准直偏差对装置性能的影响、帮助磁铁的安装准直以及装置的调试和运行等具有十分重要的作用。     

加速器磁铁电源数字化逻辑控制电路的设计

加速器磁铁电源的逻辑保护和控制一般通过可编程逻辑控制器PLC实现.随着现代加速器技术的发展,电源的控制趋于全数字化,电源的逻辑控制可以综合至其数字控制芯片中得以实现,例如现场可编程门阵列FPGA.文章介绍了两种加速器磁铁电源数字化逻辑控制电路的设计方法,以FP-GA作为控制器件,实现电源的逻辑保护和控制功能.     

BEPCⅡ磁铁电源快速检测系统的实现

为使北京正负电子对撞机（BEPCⅡ）在运行时能快速找到磁铁电源引起的加速器束流不稳定或丢束的原因,研制了磁铁电源快速检测系统。该检测系统主要采用PXI系统,其8 h稳定度达0.005%,最快可在0.33 ms内采集一遍近500套磁铁电源电流值,所有历史数据均通过TCP/IP传输并实时写入远程MySQL数据库,从而可通过数据库的数据分析比对迅速排查电源电流稳定度问题。     

基于EPICS的磁铁电源控制系统

本文介绍了在EPICS软件环境下实现的磁铁电源控制系统,详细分析了基于DeviceNet现场总线的磁铁电源控制器原理、硬件结构及软硬件系统的集成。测试结果表明该系统的精度、分辨率和稳定度均已达到设计指标,目前已成功地应用在100MeV电子直线加速器的磁铁电源控制中。     

基于EPICS的注入凸轨脉冲电源控制样机研制

中国散裂中子源（CSNS）快循环同步加速器（RCS）是一台高束流功率质子加速器,凸轨磁铁脉冲（BUMP）电源是CSNS注入系统的重要设备。根据CSNS工程建设的要求,需在预研阶段研制一套凸轨电源控制样机,用于研究和解决控制系统建造中的一些关键技术。注入凸轨电源样机通过横河公司生产的WE7000测量系统实现对脉冲电源的控制,根据物理设计需要可完成对电源的任意波形给定输出并实现对电源输出波形的回采显示。本文主要介绍了基于EPICS系统的WE7000设备驱动的开发,以及在此基础上研制的注入凸轨脉冲电源控制样机的应用。通过联机测试的结果表明,该样机满足对注入凸轨脉冲电源的控制要求,达到了预研目的。     

新型PID校正技术在2Hz动态开关电源中的运用

上海光源(SSRF)中的增强器磁铁电源要求输出2Hz的偏置正弦波,对参考曲线的跟踪误差小于0.1%.通常情况下,该电源的补偿回路会采用双闭环调节电路.本文结合仿真分析和理论计算,采用了独创的PID校正技术,并在一台100A/100V的电源上实现,电路简单,效果明显.     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Interaction between uranium and humic acid (Ⅰ): Adsorption behaviors of U(Ⅵ) in soil humic acids

The adsorption behaviors of uranium on three soil humic acids (HAs), which were extracted from soils of different depths at the same site, were investigated under various experimental conditions. The adsorption results showed that U(Ⅵ) in solutions can be adsorbed by the three soil HAs, with the order of FHA (HA from 5 m depth of soil) ＞SHA (HA from the surface) ＞THA (HA from 10 m depth of soil) for adsorption efficiency in each desirable condition, and the adsorption reached equilibrium in about 240 min. Although the maximum adsorption efficiency was adsorption could be described with Langmiur isotherm or Freundlich isotherm equation. The L/S (liquid/solid, mL/g)ratio and pH were important factors influencing the adsorption in our adsorption system besides uranium concentration. The adsorption efficiency decreased with the increase of the L/S ratio and pH at the pH range of 2.0-3.0 for SHA and THA or 2.5 - 6.0 for FHA. However, no significant difference in adsorption of U(Ⅵ) was observed at the experimental temperature. All the results implied that humic substances have different characteristics in samples even collected at the same site.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

Information for authors

<正>1.NUCLEAR SCIENCE AND TECHNIQUES(NST),a bimonthly journal,is devoted to all aspects of nuclear science and technology,theoretical or experimental.Its special interest lies in the subjects of synchrotron radiation science and technology;low energy accelerators,radiation technology and applications;radiochemistry,radiopharmaceuticals and nuclear medicine;nuclear electronics and instrumen-     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.