通用粉末衍射谱仪安全联锁系统的设计与实现

通用粉末衍射仪是中国散裂中子源一期工程三条谱仪中的一条。它在运行的过程中会有辐射的产生,因此我们设计了人身安全联锁系统来保护工作人员的安全。本文阐述了GPPD人身安全联锁系统的设计原则、控制区划分、系统架构。对联锁PLC系统、联锁钥匙系统、联锁门禁系统进行详细的介绍。详细描述控制区进出及清场流程。最后,对调试及运行情况进行了总结。     

光束线3W1A实验站辐射安全联锁系统的设计与建造

本文扼要地介绍了光束线3W1A及其实验站辐射安全联锁系统的设计、系统的构成、系统功能作用和操作规则。此外，还为两个实验大厅研制并安装了同步辐射运行状态实时显示装置和电子注入自动报警与语音提示装置。这种自动报警装置和辐射安全联锁系统为实验人员和其他工作人员的人身安全提供了可靠的保证。     

FELiChEM联锁系统的设计

联锁系统是加速器装置的重要组成部分,用于保护设备和人员的安全。本文基于EPICS设计FELiChEM联锁系统,该系统由硬件联锁系统和软件联锁系统两部分组成,硬件联锁系统又分为机器保护系统(MPS)和人身安全保护系统(PPS)。硬件联锁系统的架构分为IOC层、Profinet IO控制层和Profinet IO设备层。每层均可进行冗余配置,而各层之间相互独立。原型样机的测试显示,硬件联锁系统的响应时间为2.144ms,远好于100ms的设计需求。软件联锁系统的设计采用联锁程序与配置文件分离的方式。测试表明,软件联锁逻辑完全由配置文件确定,具有非常好的灵活性。     

电子加速器辐照装置清场巡检联锁的优化设计

电子加速器运行期间,辐照室和主机室会产生多种辐照源,人员误入辐照室或主机室会受到辐射危害,为此我们必须建立性能齐全且稳定可靠的辐射安全联锁系统。清场巡检联锁是辐射安全联锁系统的重要组成部分,本文介绍清场巡检联锁的优化设计方案,将清场巡检与控制门联锁、与防人误入信号联锁、与声光报警联锁,实现了开门必须清场巡检、巡检警示和巡检过程中防人员跟随等功能,进一步完善了清场巡检,更好地保护人员的人身安全。     

BESⅢ安全联锁慢控制系统方案设计与可靠性研究

新一代北京谱仪BESⅢ安全联锁系统完成北京谱仪内部装置以及与加速器中央控制室间的协同工作,保证系统运行时的重要设备与人身安全。文章从设计需求入手,主要介绍了安全联锁系统的硬件和软件设计,提出了基于PLC的状态机软件实现方法以及提高系统可靠性的研究。     

小型粒子加速器人身安全联锁系统设计与实现

20世纪30年代以来,世界上运行中的粒子加速器已超过3万台,其中用于科研的大型粒子加速器有200台左右。粒子加速器在运行过程中会产生对人体有害的电离辐射,为保障工作人员在联锁控制区内的人身辐射安全,避免出现辐照事故,需建立一套人身安全联锁系统。本文利用全硬件、模块化的设计思想,基于PLC、置换型机械联锁钥匙、自主研制的急停/巡更装置及摄像监控等一系列硬件设备,专门为小型粒子加速器研制了人身安全联锁系统。该系统在加速器驱动的次临界系统（ADS）注入器Ⅰ和中国科学院高能物理研究所（IHEP）加速器电子标定束线装置两个项目中至今运行稳定可靠,并可推广应用于工业辐照装置。     

小型粒子加速器人身安全联锁系统设计与实现

20世纪30年代以来,世界上运行中的粒子加速器已超过3万台,其中用于科研的大型粒子加速器有200台左右。粒子加速器在运行过程中会产生对人体有害的电离辐射,为保障工作人员在联锁控制区内的人身辐射安全,避免出现辐照事故,需建立一套人身安全联锁系统。本文利用全硬件、模块化的设计思想,基于PLC、置换型机械联锁钥匙、自主研制的急停/巡更装置及摄像监控等一系列硬件设备,专门为小型粒子加速器研制了人身安全联锁系统。该系统在加速器驱动的次临界系统(ADS)注入器Ⅰ和中国科学院高能物理研究所(IHEP)加速器电子标定束线装置两个项目中至今运行稳定可靠,并可推广应用于工业辐照装置。     

BEPCⅡ数字化辐射防护平台研究及应用

平台在BEPCⅡ(北京正负电子对撞机二期工程)的人身及设备防护安全需求上根据粒子加速器辐射防护最新发展理念,结合计算机控制技术、可编程序控制器技术、门禁控制技术、多媒体视听技术、网络技术等建立起来。它集成了人身安全联锁PLC系统、人身安全联锁门禁系统、剂量监测系统、急停按钮警示系统等,各子系统均有独立的上位机。平台采用分布式控制系统,将从各子系统采集到的信息进行集中处理后可对加速器辐射安全做出评估。     

上海光源Canted光束线安全联锁系统设计

上海光源(Shanghai Synchrotron Radiation Facility,SSRF)光束线站安全联锁系统的目的是在光束线站运行期间,一旦出现紧急情况,安全联锁系统会及时关闭活动光子挡光器或通知储存环控制系统剔除电子束流,以保障实验人员的人身安全及光束线站的设备安全。在SSRF第一条Canted光束线安全联锁系统设计过程中,通过分析Canted光束线与常规插入件光束线在布局与安全联锁要求方面的区别,实现了Canted前端的设备联锁控制要求,并提出了利用束线仲裁信号实现两条光束线和谐相处的设计方法,最终完成了两条光束线的安全联锁系统的安装调试及其验收。Canted光束线安全联锁系统自2013年7月投入试运行以来运行正常,为光束线和实验站的正常调试提供了保障。     

合肥先进光源光束线站辐射安全联锁系统设计

合肥先进光源(HALF)是基于衍射极限储存环的第四代同步辐射光。同步辐射光通过管道进入光束线站,可能会对人体健康产生危害,为此,需要建立线站辐射安全联锁系统。线站辐射安全联锁系统是确保工作人员人身安全的重要保障。基于EPICS和冗余PLC技术,设计了HALF光束线站辐射安全联锁系统,并完成了系统IOC与OPI等软件的开发。最后在研制的原型样机上,进行了冗余PLC主备CPU的切换时间的测试,验证了冗余PLC的性能,满足设计要求。     

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。     

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.     

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.     

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%。     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

Linear accelerators equipped with multileaf collimators （MLC） are becoming more common and are widely used in the intensity-modulated radiotherapy （IMRT）. There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance （QA） and quality control （QC）. This paper is aimed to investigate the role of AGFA high-energy CR （Computed Radiography） in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.