75MeV／u^16O离子在辐照生物实验区产生的中子角分布

应用Ａｌ为阈探测器对７５ＭｅＶ／ｕ＾１６Ｏ离子在辐照生物研究区产生的Ｅｎ〉６ＭｅＶ中子的角分布进行了实验测量，以了解辐照生物实验区的中子分布情况，为进一步开展的重离子冶癌研究提供辐射防护的实验数据。实验结果表明实验区产生的中子具有明显的前冲分布。     

7MeV／u~（16）O~（6＋）离子在CR－39固体径迹探测器中投影射程的确定

采用与生物样品等效的ＣＲ－３９作为固体径迹探测器来测定７ＭｅＶ／ｕ１６Ｏ６＋离子注入该种材料中的投影射程，利用实验观测到的数据，采用蚀刻速率比和剩余射程统计分布规律的方法，分析和讨论了这种重离子在ＣＲ－３９中的投影射程（即离子注入深度）．两者符合较好，分别为３２．５±６．２μｍ和３０．５±６μｍ。本工作为重离子注入生物样品定点定位诱变研究提供数据。     

重离子加速器实验靶区的中子剂量当量率

用阈探测器中子活化法测量了５０ＭｅＶ／ｕ＾１８Ｏ离子轰击Ｂｅ、Ｃｕ、Ａｕ厚靶出射中子的注量率分布,并利用中子注量率对剂量当量率的转移因子,得到了重离子实验靶区的中子剂量当量率分布。     

外延硅dE／dX探测器的研制

本文介绍了厚度为５．２－６．０、１０－１３、１９μｍ，有效面积为２８－１５４ｍｍ＾２的外延硅ｄＥ／ｄＸ探测器的研制工艺，主要用途，测试结果（对９．８７ＭｅＶ α粒子的能损△Ｅ的分辨率为５６－１２８ｋｅＶ）和在核物理实验中的应用。     

14MeV中子在φ600mm贫化铀球中造钚率测量

使用中子活化技术对２３８Ｕ（ｎ，γ）２３９Ｕ反应产物２３９Ｕ衰变后的２３９Ｎｐ子体的２７８ｋｅＶγ射线的绝对测量，获得了１４ＭｅＶ中子在６００ｍｍ贫化铀球中的造钚率。其实验测量值为２．４６±０．０９。２７８ｋｅＶγ射线用高纯锗探测器测量，探测器的有效计数效率用２４３Ａｍ源刻度。６００ｍｍ贫化铀球由７层贫化铀球壳组成，球心有一８０ｍｍ源腔，总重约２．１ｔ。     

5.0MeV和9.5MeV快中子辐照在GaAs中产生的辐射损伤的正电子湮没研究

采用正电子湮没寿命测量方法研究了５．０ＭｅＶ和９．５ＭｅＶ快中子辐照在ＧａＡｓ中产生的辐射损伤，实验结果表明１０＾１１－１０＾１２ｎ／ｃｍ＾２注量的中子辐照只产生单空位缺陷１０＾１３ｎ／ｃｍ＾３注量的中子辐照产生单空位和双空位缺陷，１０＾１２ｎ／ｃｍ＾２注量的９．５ＭｅＶ中子辐照的ＧａＡｓ经４５０－６２０℃退火产生三空位缺陷，产生的缺陷浓度随中子能量和注量的增大而增大，但缺陷产生率对中子注量更灵敏     

轻粒子焦面探测器系统基本特性在束检验

利用中国原子能科学研究院的ＨＩ－１３串列加速器提供的质子和α束流轰击＾１９７Ａｕ，＾１２Ｃ，＾５６Ｆｅ，Ｃ３Ｈ６Ｎ６等靶核的反应产物对配合Ｑ３Ｄ磁谱仪使用的轻粒子焦面探测器系统基本特性进行了在束检验，测量的平均本征位置分辨为１．３６±０．０７ｍｍ；积分非线性度好于７．５×１０＾－３。由△Ｅ－Ｅ组成的粒子鉴别望远镜可明显区分不同类型的轻粒子群。     

70MeV质子加速器产生的白光中子源强度和能谱的计算

用７０ＭｅＶ质子束轰击厚靶可产生白光中子源。选用金属钨作厚靶材料，应用适用于几十ＭｅＶ能区的核反应模型程序计算了中子能谱和角分布。结果表明：７０ｍｅＶ质子束在钨厚靶中终止前有４．６％的质子发生了反应，２００μＡ的７０ＭｅＶ质子束流产生的中子总强度为１．０１×１０１４Ｓ－１，中子平均能量为４．２ＭｅＶ，１０ＭｅＶ以上的中子强度为１．１５×１０１３Ｓ－１，高能中子主要在朝前的小角度区发射。     

用阈探测器活化法测量50MeV／u重离子实验靶区的中子注量率,…

用阈探测器中子活化法测定了５０ＭｅＶ／ｕ＾１２Ｃ离子实验靶区的次级中子平均注量率、角分布、粗略能谱，并估算了重离子反应的中子产额。     

用CR—39固体径迹探测器测定重带电粒子的Bragg峰位

采用ＣＲ－３９固体径迹探测器，根据辐射损伤密度沿粒子的径迹分布规律，测定了经３、４ｃｍ空气降能和φ１ｍｍ孔准直的α粒子（５．１５ＭｅＶ）的Ｂｒａｇｇ峰位。对于通过３ｃｍ空气后能量降至～１．２ＭｅＶ的α粒子，在ＣＲ－３９中的Ｂｒａｇｇ峰位大约在７μｍ深度处，理论计算值在６．１４μｍ，实验值与理论值符合得较好。     

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.