EAST中性束注入器稳态偏转磁铁的参数设计与估算研究

中性束注入器偏转磁铁是剥离束流中剩余离子的关键设备,它与剩余离子吞食器等内部部件构成了中性束注入器的束偏转系统。束偏转系统的性能对中性束注入器束流的品质及其束传输效率发挥着重要作用。本文根据EAST(Experimental Advanced Superconducting Tokamak,EAST)中性束注入器对束偏转系统的要求,对其偏转磁铁各性能参数进行了估算。为中性束注入器设计了一台用以剩余离子180°偏转的偏转磁铁。该偏转磁铁采用H型二极电磁铁结构;其磁极端面设计为138cm×47cm的圆角矩形结构;其线圈设计为每侧2饼,每饼2层,每层8根的串联结构,导线选用外方内圆空心铜导体,以满足偏转磁铁稳态运行的需要。该设计的偏转磁铁在370 A励磁电流条件下,可提供80keV氘离子束偏转所需的磁场。实验测试结果显示:500 A励磁电流稳态运行条件下,偏转磁铁线圈冷却水温升约21.5℃,该设计结构的偏转磁铁满足EAST中性束注入器满参数稳态运行和未来运行参数逐步提高的需要。     

半球形偏转电子能量分析器的设计和应用

本文较详细地介绍了静电半球偏转电子能量分析器的原理，设计和实际制作，并说明半球分析器作为单色器和分析器在中能电子能量损失谱仪的成功使用。     

加速器-电镜联机的离子光路及其调整方案

离子辐照引起的材料微结构变化是一个复杂的过程,用加速器-电镜联机装置可原位观察载能离子束辐照引起的材料微结构演变.武汉大学加速器-电镜联机装置由1台2×1.7 MV串列加速器、1台200 kV离子注入机和1台200 kV透射电镜组成,通过自行设计的传输系统实现联机.本文介绍联机装置的光路布局,给出了静电加速器离子动力学计算程序LEADS(linear and electrostatic accelerator dynamics simulation)优化计算的结果,提出了两种改进方案,并用LEADS对改造后的加速器-电镜联机中离子运动进行了计算.结果显示,调整现光路二单元四极透镜的同时,在200 kV注入机90°偏转磁铁至电镜之间增加1个二单元静电四极透镜,将提高该系统中离子束传输效率.     

北京HI-13串列加速器注入器的升级改造

本文简单介绍了北京HI-13串列加速器注入器升级改造的情况,注入器台架电压由原来的150kV提高到300kV,并成功封接一根300kV、1．2m长的加速管。另增加一套AMS专用注入线,由静电分析器与磁分析器构成能量消色散系统,质量分辨率可达到380以上。     

用于2.5MeV质子静电加速器ns脉冲装置的晶体管移相倍频器

本文介绍一个幅-相和相-幅特性均优良、能跟随加速器长期稳定运行的晶体管移相倍频器。它用于我所2.5MeV质子静电加速器ns脉冲装置的电子线路中。调节该器输出电压幅值和相位,能有效地控制频率为2MHz、宽度为10—20ns的脉冲束沿中心轨道横向偏转的张角大小和对称性。     

可变能量回旋加速器静电偏转板的物理设计

本文描述了静电偏转孔道入口间隙及其位置等有关物理参数的确定原则。以单粒子运动理论为基础对静电偏转系统进行设计。最后,还讨论了粒子束在该孔道内相空间的变化。     

聚变堆中性束注入系统的电偏转器概念设计

中性束注入是磁约束核聚变研究重要的辅助加热和电流驱动手段.由于负离子源中性束注入系统束能量高、束斑大,电偏转已经成为剩余离子剥离的首选方案,其剩余离子剥离设备被称为电偏转器.电偏转器作为实现束流中性化的核心设备,其性能决定了中性束注入系统的工作效率.本文提出了聚变堆主机关键系统研究中负离子源中性束注入系统电偏转器的概念...     

复旦大学单粒子微束研制进展

建设了一基于复旦大学2×3 MV串列加速器的单粒子微束装置。离子束经分析磁铁30°水平偏转传输后再经90°偏转磁铁竖直上行至辐照终端,以内径1.5 μm的毛细玻璃管微准直器获取离子微束。采用薄膜闪烁体结合光电倍增管的探测结构对微束离子进行精确探测和计数,并以高压静电偏转开关快速关断束流以实现对离子数目的精确控制。目前实验已获得在质子能量为3 MeV时,能散（能量分布曲线中半高宽FWHM）<60 keV、束分辨<2.2 μm、定量照射精度>95%的质子微束。本文对复旦大学单粒子微束的束流管道设计、微束获取、束开关及单粒子探测等核心环节的研制进展进行介绍。     

利用质子静电加速器加速H_2~ 和H_3~

为满足物理实验需要,我们将质子静电加速器分析磁铁真空盒加以保护,成功地加速了H_2~ 和H_5~ 离子。束流经分析磁铁偏转聚焦后进入实验管道,通过如图1所示的装置轰击到靶上。加速H_2~ 、H_3~ 离子束时,分析磁铁出口60cm处石英屏上束流强度分别可达10μA、3.2μA,靶上流强一般被限制在几nA左右,束流能散度0.07％。     

EAST-NBI偏转磁体线圈水冷能力分析与测试研究

偏转磁体是中性束注入器的关键部件之一,它安装在中性束注入器真空室内部。为适应核聚变研究装置对中性束注入器高能量、长脉冲、稳态运行的要求,对其偏转磁体原先励磁线圈的水冷系统进行了分析,提出增加水冷抽头的方法完成了改进设计,并对改进前后线圈的冷却能力进行了实验测试。测试结果显示,当中性束注入器长脉冲稳态运行时,改进后的水冷结构能及时带走偏转磁体励磁线圈产生的热量;冷却水的进出口水温差约21 oC;偏转磁体线圈导体表面的温度约45 oC;改进设计水冷系统性能得到优化,满足了EAST-NBI高参数、稳态运行的要求。     

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.     

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.