HI-13 Tandem Accelerator in 2005

直线加速器网络监控系统旨在通过网络远程监视、控制电子直线加速器，从而使管理人员能在不同的地点通过网络监控加速器，及时了解加速器的运行情况并操作加速器。目前已通过开发软件ASR.NET实现了对直线加速器的网络远程监视。     

滑雪式磁偏转系统

滑雪式磁偏转系统是根据医用电子直线加速器对偏转系统的要求，采取一种计算机方法自动确定系统参数．该系统具有良好的消色散特性和聚焦特性，在垂直方向所占空间小，特别适用于医用电子直线加速器。     

直线加速器粒子运动包络线方程

在文献[12]里已经根据各自的情况,用不同的方法独立导出了电子直线加速器圆对称系统考虑加速过程的粒子横向运动包络线方程。这对于解决象强流短脉冲电子直线加速器、电子直线感应加速器之类的横向运动问题是很有意义的。但是,在某些情况下,象质子直线加速器,螺旋波导直线加速器,中、高能电子直线     

9MeV探伤加速器爆炸物检测系统数字成像

电子直线加速器扫描系统是辐照加速器的重要组成部分，扫描系统的磁场及其相关参数的计算关系到加速器的均匀度和扫描宽度等重要性能指标。     

BEPCII直线加速器定时系统

北京正负电子对撞机升级改造工程BEPCII的重要组成部分--直线加速器于2006年7月通过了所内预验收,其中定时系统是全新建造的基于EVG/EVR的事件定时系统[1],于2006年3月起投入运行,为直线加速器的电子枪、微波激励源、能量倍增器、正电子源、调制器、BPM等设备提供精确的时序触发信号.本文介绍直线加速器定时系统的研制、安装调试、运行和改进等工作情况.     

120 MeV电子直线加速器在线自动老练系统研制

为保证电子直线加速器的性能和稳定运行，需对高功率微波加速结构进行老练。针对微波系统老练效率低、时间长和实验人员工作强度大等问题，研制了基于EPICS和SNL的在线自动老练系统，系统基于现有控制系统结构开发，提高了老练效率，缩短了约25%的老练时间，同时减少了工作人员操作设备的工作强度，为后续加速器顺利出束并达到设计指标打下良好的基础。     

麦克风效应对CiADS超导腔稳定性影响的仿真分析

加速器驱动嬗变研究装置(CiADS)对质子超导直线加速器提出了高稳定性要求，在工程设计阶段需对直线加速器的各种不稳定因素，特别是对超导腔的麦克风效应的影响进行评估。基于谐振系统的冲击响应模型，发展了一种离散化的电压迭代求解方法，并利用该方法构建了高频系统仿真程序，用于分析麦克风效应作用下超导腔的时变状态。通过仿真，研究了麦克风效应对腔体幅相稳定性的影响及与超导腔的谐振频率、Q值和带宽等参数的关系。结果表明，麦克风效应主要影响超导腔的相位稳定，其影响程度取决于麦克风振荡频率与腔的谐振频率、频率偏移量与腔体半带宽的比值。给出了满足CiADS直线加速器超导腔幅相稳定性指标(0.1%和0.1°)的麦克风振荡强度限值。     

2MeV行波电子直线加速器自动频率控制系统

在电子直线加速器中,微波功率源输出频率的稳定性非常重要,它直接影响到加速器整机的物理性能指标。由于微波功率源磁控管的输出频率会随外部工作环境变化而发生漂移,所以必需在电子直线加速器中采用自动频率控制(AFC)系统。讨论了2MeV小型行波电子直线加速器AFC系统的设计要素,分析了微波信号的鉴频原理及鉴频模块的测试结果。结合实际的工作环境,测试了信号处理单元主要功能模块的输出,并对测量结果的精度进行了分析。     

上海光源150MeV直线加速器传输波导相长度测量与调整

上海光源直线加速器加速器主体由电子枪、次谐波束聚器、基波聚束器及四台加速管组成,其功能是通过低能输运线向增强器注入150 MeV能量的电子束.直线加速器2006年12月开始安装,2007年5月出束,10月完成束流调试,向增强器供束,束流指标达到设计目标.传输波导相长度的测量与调整是微波系统及加速器建设安装过程中的的关键环节,调试结果直接关系到直线加速器的升能效果,影响到束流其它相关参数.本文阐述了上海光源直线加速器波导相长度测量与调整过程,给出了加速器束流调试的相关指标结果.     

CSNS漂移管直线加速器水冷联锁系统设计

为了保证中国散裂中子源漂移管直线加速器安全、稳定、可靠地运行,利用横河FA-M3 PLC搭建了基于实验物理及工业控制系统软件框架的水冷联锁系统。该系统监测漂移管直线加速器冷却水系统流量开关、流量计和温度传感器的状态,并进行逻辑运算,为磁铁电源和射频系统提供联锁保护信号。目前,该系统已完成现场安装和调试,并已正式投入运行。     

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.     

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.     

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。     

The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

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.     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.     

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

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Radioactivity levels in soil of salt field area,Kelambakkam,Tamilnadu,India

Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ~(232)Th,~(238)U and ~(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ~(232)Th in the present study is 1.19 times higher than world median value while the activity of ~(238)U and ~(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ~(232)Th,~(238)U and ~(40)K in soil samples is 36.99 nGy·h~(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.