改进型PSII―IM全方位离子注入工业样机(英文)

报告了核工业西南物理研究院最近研制成功的改进型PSII―IM全方位离子注入工业样机。该机的真空室由不锈钢制成,其直径为1000 mm,长 1070 mm,采用多极会切磁场约束产生的等离子体。该机抽气系统由低温泵、扩散泵和机械泵组成。本底真空度小于 2×10- Pa。真空室内的气体等离子体可由热灯丝或射频放电产生, 4另外还配置了 4 个金属等离子体源、两套磁控溅射靶和冷却靶台。所以该机可以实现全方位离子注入或增强沉积薄膜。该机的负高压脉冲幅值为 10～90 kV, 重复频率为 50～500 Hz, 脉冲上升沿小于2 μs。一般情况下等离子体密度为 108～1010 cm- , 膜沉积速率为 30.1～1.0 nm/s。并给出了一些实验结果。     

全方位离子注入与沉积技术及其工业机的研制

全方位离子注入与沉积（Plasma immersion ion implantation and deposition,PIIID）技术发展到现在,已经逐步走向工业化应用。本文介绍了全方位离子注入与沉积技术的原理,探讨了全方位离子注入与沉积工业机应该具备的功能,介绍了研制成功的全方位离子注入与沉积设备的结构和实施效果,其脉冲阴极弧等离子体源沉积速率达到2．9A／s,IGBT固体开关调制器输出电压达到10kv,能够一次处理多个工业零件。     

核工业西南物理研究院的等离子体源离子注入技术研究(英文)

介绍了等离子体源离子注入装置PSⅡ-EX原型机和PSⅡ—IM工业样机,并对其功能、主要技术指标及特点作了简述。等离子体源离子注入处理后,一些材料表面机械性能(如显微硬度、耐磨性、摩擦因数及生物相容性等)的改善情况、改性层的微观分析及计算机模拟结果、工艺开发及初步的等离子体源离子注入增强沉积实验也作了介绍。最后提出了拟开展的有关PSⅡ工作。     

等离子体浸没离子注入圆筒内表面的时空尺度

等离子体浸没离子注入与工件外表面的注入不同 ,存在空间和时间上的尺度。研究结果表明 ,由于内腔 ,如内筒的有限尺寸 ,使注入电压的利用率降低 ,同时使内部等离子体快速耗尽 ,对于特定的内筒 ,利用提高注入电压从而提高注入能量只能在一定的电压范围内实现。在典型的外表面注入工艺条件下 ,内表面离子的耗尽速度是惊人的。如在对于直径 2 0cm的圆筒在 30kV、2× 10 15ions/cm3的条件下 ,等离子体耗尽时间仅为 0 .5 5 μs ,这个时间甚至小于多数脉冲电源的上升沿时间。结果表明 ,内部等离子体源的硬件结构可能是一种有效的解决方法。     

中心螺线圈式大面积均匀金属等离子体形成方法

传统的磁过滤阴极真空弧系统的金属等离子体输出面积较小且出口处的密度呈高斯分布,阻碍了等离子体浸没离子注入与沉积(PⅢ&D)技术的工业化应用,使得大面积均匀金属等离子体的产生成为了业内研究的热点.本文提出了一种基于多阴极脉冲真空弧源对称配置的中心螺线圈式大面积均匀金属等离子体形成方法,可输出直径约为600mm的金属等离子体.沉积探针结果表明:载流螺线圈对沉积均匀性有较大的影响.单源X方向的沉积均匀性优于Y方向的沉积均匀性;四弧源的离子流密度约为单源的5.5倍,沉积均匀性最高可达83.8%.     

300Cm~2平行板α屏栅电离室的研制

本文介绍了阴极面积为300cm~2的流气式平行板α屏栅电离室的结构和性能。电离室工作气体为 P-10(90%Ar+10%CH_4)气体,充气压约1.8×10~5Pa。在流气量小于25mL/min 时可连续工作48h。该装置的主要性能是:能量分辨率为36keV(对φ<10mm的~(239)Pu 电沉积源),4—6MeV 能区本底为12.6cph,最小可探测活度为2×10~(-4)Bq(按本底计数率标准差的3倍及27小时测量时间估计),探测效率为44%(对φ=190mm 大面积~(232)Th 源)。     

钼离子注入对锆-4合金耐腐蚀性的影响

观察钼离子注入对锆-4合金在硫酸水溶液中耐腐蚀性的影响。使用MEVVA(Metalvaporvacuumarc)源对锆-4合金表面注入1×1016—1×1017cm-2剂量的钼离子,用X射线光电子能谱(XPS)分析其表面元素价态;用三次极化扫描评价其在1mol·L–1硫酸水溶液中的耐腐蚀性;并对三次极化后的样品进行扫描电镜(SEM)观察。实验表明,当钼离子注入剂量小于5×1016cm-2时,注入样品的耐腐蚀性显著增强。当钼离子注入剂量为1×1017cm-2时,注入样品的耐腐蚀性反而比未注入时差。讨论了钼离子注入锆-4合金后耐腐蚀性改变的原因。     

北京慢正电子强束流性能研究

采用电子束流以及脉冲慢正电子束流对系统进行了调试,对束流系统的性能参数进行了测定和研究。实验结果表明,系统对于模拟电子的传输效率高于98%,电子束斑直径小于5mm。在目前加速器短脉冲的运行模式下,脉冲慢正电子束流的强度达到了105/s以上,IP成像板束流沉积形貌直径小于15mm,脉冲慢正电子束流微分能谱半高宽(FWHM)约为10eV;;在高于3×10?Pa的超高真空中,慢正电子在直流化管道内7存贮40ms后,束流强度减弱到原来的50%。系统各项性能运行参数达到了设计要求。     

恒比定时单道分析器

本文介绍对具有成形网络的核放大器输出的宽脉冲有良好定时性能的恒比定时单道分析器。用时间常数为0.4μs的CR—(RC)~4成形脉冲,幅度从10V变到1V,定时移动小于±1ns。     

大平面型高纯锗探测器

一般制备平面型探测器的工艺是一面扩散锂制n~ ,另一面蒸钯作p~ 接触,国外有报道用离子注入结作p~ 接触。我们在p~ 接触方面用离子注入硼、蒸钯和蒸金等方法作了实验,并对比了用这些方法制探测器后得到的结果。 一、制备 探测器使用的原材料是比利时Hoboken公司和美国LBL实验室制造的高纯锗单晶,其技术指标为:净杂质浓度小于3×10~(10)cm~(13),77K时迁移率大于4×10~4cm~2/(V·s)位错密度小于5×10~3cm~(-3),并且均布。     

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.