中国液态锂铅包层材料研究进展

液态锂铅包层是国际上普遍关注和最有发展潜力的聚变堆包层概念设计之一,而包层材料是液态锂铅包层的核心问题之一.目前,液态锂铅包层普遍选用低活化铁素体/马氏体钢(RAFM钢)作为结构材料,液态锂铅作为中子倍增剂及氚增殖剂.另外,部分设计采用了耐高温、电绝缘流道插件作为功能材料,以降低磁流体动力学效应及提高冷却剂出口温度(高于700℃).为适应液态包层的发展需求,中国科学院等离子体物理研究所FDS团队联合国内外相关研究单位,进行了具有中国自主知识产权的中国低活化马氏体钢(CLAM钢)及液态锂铅包层功能材料研发,并开展了锂铅热对流及强迫对流回路的设计、研制及腐蚀实验研究,以研究液态金属锂铅的流动特性及其与结构和功能材料的相容性.同时建立了聚变堆材料数据库平台,为促进中国聚变堆液态包层及材料技术的研究和发展提供数据支持.     

CLAM钢基体上大气等离子体喷涂制备氧化铝涂层工艺研究

液态金属锂铅包层是目前国际上聚变堆包层设计研究的主流方案之一,但其仍面临高氚渗透率、液态锂铅对包层结构材料的腐蚀以及锂铅流动引起的磁流体动力学MHD效应等问题,而包层结构材料表面加覆涂层是解决上述问题的关键技术之一。本实验尝试利用大气等离子体喷涂(APS)工艺在中国低活化马氏体CLAM钢上制备多功能氧化铝涂层,试验结果表明:涂层与基底具有较好的结合强度,平均值为31.7 MPa;涂层电阻率为5.26×109~1.54×1010Ω.m;并呈现较高的显微硬度和致密度。本工作可为未来聚变堆液态锂铅包层涂层制备提供理论依据和技术储备。     

聚变堆液态金属锂铅包层多功能涂层研发

液态金属锂铅包层是目前国际上聚变堆包层设计研究的主要方案之一,结构材料表面制备涂层是降低锂铅包层中的氚渗透率、液态锂铅腐蚀及磁流体动力学(MHD)效应的重要技术之一.本文主要从涂层材料及其制备工艺两个方面重点介绍了国内外在液态锂铅包层涂层材料研发方面的进展概况,并对涂层技术发展进行了展望,最后提出了中国发展液态锂铅包层涂层的规划建议.     

中国液态金属锂铅实验回路DRAGON-Ⅳ MHD实验段设计与分析

锂铅实验回路是研究液态金属锂铅包层关键技术问题的必备装置,MHD(Magneto Hydro Dynamic)实验是探究液态金属在聚变强磁场环境下流动特性的重要环节.本文结合聚变堆锂铅包层设计特点和实际的工程可行性,设计了中国高温多功能液态金属锂铅实验回路DRAGON-Ⅳ中的MHD实验段.初步结果表明MHD实验段设计方案的合理性,能够满足回路的设计原则和要求.     

中国系列液态锂铅实验回路设计与研发进展

锂铅实验回路是聚变堆液态锂铅包层关键技术研究必备实验平台之一.结合液态金属锂铅包层技术发展战略建议,FDS团队多年来不断开展液态锂铅实验回路技术研究,设计并建造了具有自主知识产权和具有不同功能参数的DRAGON系列锂铅实验回路.本文阐述了中国锂铅实验回路的发展路线建议,系统介绍了目前各实验回路的设计原则、结构特点、功能和相关实验研究进展等情况.     

液态金属回路DRAGON-Ⅱ锂铅合金流动与传热三维数值模拟

高温热对流实验回路DARGON-Ⅱ实验时液态金属锂铅流动的详细流场难以精确测量,利用CFD软件FLUENT对锂铅流动与传热特性进行三维数值模拟,给出了实验工况时实验样品区的详细流场包括温度分布、速度分布与压力分布等,验证了理论分析和实验测量结果,为不同流速、温度时液态锂铅流动对聚变堆候选结构材料低活化钢的腐蚀特性、相容性实验参数的确定提供理论依据和数据参考。     

中国低活化马氏体钢CLAM研究进展

低活化铁素体/马氏体钢(RAFM钢)被普遍认为是未来聚变示范堆和聚变动力堆的首选结构材料。国际上给予了高度重视,许多国家都在研发其特有的RAFM钢。中科院等离子体物理研究所在与国内外多家单位的合作下发展了中国低活化马氏体钢———CLAM。本文总结了CLAM钢研制发展的主要进展,包括其成分优化设计、冶炼加工制备工艺、物理性能、机械性能、辐照性能及与液态LiPb的相容性等测试与研究以及各种焊接工艺研究等,并对今后的发展方向进行了展望。     

液态铅铋回路设计研制与材料腐蚀实验初步研究

铅铋合金共晶体是加速器驱动次临界系统(ADS)重要的散裂靶材料和冷却剂候选材料,也是先进快中子堆的重要冷却剂材料,液态铅铋回路是开展液态铅铋合金相关技术研究的必备实验平台。FDS团队正在设计研制KYLIN系列铅铋实验回路,本文基于中国首座热对流铅铋回路KYLIN-Ⅰ开展了马氏体钢T92、CLAM和奥氏体钢316L在480℃下,流速为0.14 m/s的饱和氧浓度铅铋中的腐蚀实验研究。初步实验结果显示,三种实验材料均发生氧化腐蚀。     

ITER中国液态锂铅实验包层模块设计研究与实验策略

在广泛调研和深入分析国际聚变堆包层发展状况的基础上,根据液态锂铅包层一般特点和中国发展的系列液态锂铅包层概念设计,提出了一个具有演示氦气单冷却剂和氦气/锂铅双冷却剂包层技术的双功能包层模块实验系统方案,对其性能进行了分析研究,作为中国向ITER实验包层工作组(TBWG)提交的液态包层实验模块最终设计描述文件的内容框架。总结了该工作主要内容,包括基本设计思想和方案描述、性能分析概况、对辅助系统的要求和实验策略与关键技术等。     

中国液态锂铅热对流实验回路DRAGON-Ⅰ温度场和速度场数值模拟分析

锂铅实验回路是研究聚变堆液态金属锂铅包层关键科学技术问题的必备装置,其锂铅温度场和速度场分布对分析相关实验结果是必需的。DRAGON-I是中国第一座热对流锂铅实验回路,采用FLU-ENT软件对该回路中液态锂铅的温度场和速度场进行了二维和三维模拟分析。结果表明:回路内锂铅温度场分布符合回路设计时的温度变化要求,并在回路管径截面上变化很小;锂铅速度除了在回路上端两个直拐角处波动较大外,其余管道直段波动非常小,平均速度约0.14 m/s。     

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.     

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.     

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.