60Co大型客体辐射成像系统γ检测射线束研究

应用MCNP程序研究了^60Co大型客体辐射成像系统中的检测射线束．本计算模拟实际钻源大小获得了面源条件下距泊不同位置处的射线剂量分布曲线,对近检测面处射线束的强度和分布形状给出详细的计算结果．并由此得出成像系统对被检客体的单次检测剂量。从结果分析,采用该计算模型得到的射线束具有良好的准直效果并满足实际检测的要求。     

33 重离子微束辐照装置

采用针孔准直技术，在HI-13串列加速器上建立了微电子器件单粒子效应重离子微束辐照装置。该装置主要由5个主要部分组成：产生微束装置、定位装置、样品运动控制装置、束流注量检测装置和单粒子效应测量装置组成。图1为装置的平面布局图。     

用蒙特卡罗方法对60Co数字辐射成像系统检测射线束的准直研究

应用蒙特卡罗方法模拟了^60Co辐射成像系统检测射线束的准直过程。通过分析MCNP程序给出的计算数据，讨论了源室、准直器和侧屏蔽体在射线准直过程中的不同作用，对实现成像系统射线的准直具有参考价值。     

Study on the Preparation of Target by Electrodeposition

350keV、21kW高压倍加器是一台高压型辐照加速器，用于塑料薄膜的辐照。经加速管加速的电子束，在扫描盒内由扫描磁铁扫描后，通过钛窗引出对塑料薄膜进行辐照。     

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     

窄束X射线半价层测量法标定电子直线加速器的能量

X射线半价层测量法是一种常用的低能电子直线加速器能量标定方法，本文对窄束X射线半价层的测量方法进行了讨论。利用Monte-Carlo程序MCNP4B对窄束X射线半价层进行了计算和分析，并与实测数据进行了比较，测量数据与MCNP4B计算结果符合得很好。此外，还讨论了准直锥的长度和材料、准直缝的尺寸、靶的厚度和材料等因素对半价层的影响。     

重离子微束辐照装置

采用针孔准直技术,在HI-13串列加速器上建立了微电子器件单粒子效应重离子微束辐照装置。该装置主要由5个主要部分组成:产生微束装置、定位装置、样品运动控制装置、束流注量检测装置和单粒子效应测量装置组成。图1为装置的平面布局图。装置建立后,使用能量为48MeV的32S束流,经     

HI—13串列加速器重离子扫描辐照装置

介绍了ＨＩ－１３串列加速器重离子扫描辐照装置的研制结果。其技术和工艺有如下特点：（１）能对１００—２００ＭｅＶ能区的重离子进行扫描；（２）采用二维（ｘ，ｙ）扫描方式；（３）小巧紧凑的扫描磁铁；（４）特制的磁极内陶瓷束流管道；（５）使用了三角波扫描磁场电源；（６）紧凑精密的扫描靶室和辐照传动靶室。该装置可满足核孔膜高级滤材、大功率快速电子器件改性以及生物样品等重离子均匀辐照的需要。     

60Co射线集装箱检测系统数据传输设计与实现

＾６０Ｃｏ射线集装箱检测系统是国际首创的以＾６０Ｃｏ为射性源对大型集装箱进行了不开箱检测的高技术设备。该系统的数据传输了系统通过设计合理的数据传输流程,并采用先进的Ｗｉｎｄｏｗｓ Ｓｏｃｋｅｔ技术,实现了数据在各工作站点之间的可靠传输、集装箱扫描图像与对应集装箱信息的正确关联和关联图像在各图像检查站之间的合理分配。介绍了系统的数据传输设计的这一子系统。     

高能X或γ辐射成像阵列探测装置的研制与应用

介绍了高能Ｘ或γ辐射成像阵列探测装置的概况和高压阵列电离室的设计特征、结构与工艺，阐明了用９ＭｅＶ电子直线加速器Ｘ射线测量高压阵列电离得到的各项技术指标及其在大型集装箱和工业零部件无损检测系统中的应用。     

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.     

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.     

Gamma radiation levels in the ambient environment of the QNPP Base

Monitoring results of gamma dose rate level in 1992～2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84～113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.