离子注入与离子束混合两用机

早在1979年,为了解决应用于高温高真空环境下的轴承的自润滑问题,我们就着手采用     

Electron beam ion traps and their applications

A brief introduction to the historical background and current status of electron beam ion traps (EBITs) is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally, EBITs as a potential tool in hot-plasma diagnostics and in studying frontier problems of highly charged ion physics are discussed.     

Proton beam micromachining: electron emission from SU-8 resist during ion beam irradiation

Proton beam micromachining (PBM) is a direct write lithographic technique that uses a focused beam of MeV protons to pattern a resist material. The most common resist material used in the PBM process is SU-8 which is usually spin coated onto various substrates. The method used to ensure that the correct dose is delivered to the sample during irradiation is Rutherford backscattering spectrometry (RBS). There are however limitations to using the RBS signal for normalizing the dose in highly sensitive resist materials such as SU-8. The limited number of backscatter events means that normalizing the dose for every pixel is not possible. The secondary electron yield for SU-8 is at least an order of magnitude higher than that for backscattered ions. With an appropriate detector these signals can be essentially used for ion detection and thus used to accurately monitor ion dose. In this paper we investigate the secondary electron yield from SU-8 polymer resist layers of varying thickness on silicon. It is shown that the signals produced during MeV ion irradiation can be directly related to the ion dose and used for dose normalization during PBM.     

The effects of beam line pressure on the beam quality of an electron cyclotron resonance ion source

The results of a series of measurements studying the possibility to use neutral gas feeding into the beam line as a way to improve the quality of the heavy ion beams produced with an electron cyclotron resonance ion source (ECRIS) are presented. Significant reduction of the beam spot size and emittance can be achieved with this method. The observed effects are presumably due to increased space charge compensation degree of the ion beam in the beam line section between the ion source and the analyzing magnet. This is the region where the neutral gas was injected. It is shown that the effects are independent of the ion source tuning. Transmission measurements through the beam line and K-130 cyclotron have been carried out to study the effects of improved ion beam quality to the transmission efficiency.     

水溶液中氯代苯酚的电子束辐射降解研究

利用电子束辐射降解水中的2-氯苯酚(2-CP),4-氯苯酚(4-CP)和2,4-2氯苯酚(2,4-DCP),研究了辐照剂量对初始浓度各为200mg/L的三种氯代苯酚以及浓度各为50mg/L的三种混合物辐射降解、去除有机氯及溶液pH值的影响。用HPLC测定了辐照溶液中2-CP、4-CP和2,4-DCP的含量,测试结果表明,随着辐照剂量的增加氯代苯酚的降解增加,溶液中的氯离子增加,pH值减小。浓度为200mg/L的三种溶液,在同样的辐射剂量率下,其辐射降解速度和氯离子产率的顺序为2,4-DCP>4-CP>2-CP;对浓度各为50mg/L氯代苯酚的混合物溶液,2,4-DCP的辐射降解速度最大,4-CP和2-CP的降解速度几乎相同。在辐照剂量为21kGy时,对浓度为200mg/L的三种溶液,其辐射降解率分别为93.0%(2-CP)、98.5%(4-CP)和99.4%(2,4-DCP),氯离子产率为55.4%、71.3%和69.0%,降解率为90%所需剂量(D90)分别为18.0kGy(2-CP)、11.4kGy(4-CP)和6.1kGy(2,4-DCP)。浓度各为50mg/L混合体系中的D90值分别为16.1kGy(2-CP)、15.6kGy(4-CP)和12.8kGy(2,4-DCP)。     

Preparation of cobalt nanoparticles by electron beam irradiation

and laser mattering particle size distribution analysis. Average size of the nanoparticles was about 32 nm with a narrow size distribution. Melting point of the nanoparticles was about 451.3 ℃.     

氧化锡气体传感器的电子束辐照效应

There are many traditional ways to improve sensitivity and selectivity of semiconductor gas sensors, such as metal ions adulteration and surface modification. In this paper 1.75 MeV electron beam was used to modify surface structure of tin dioxide gas sensors, and the gas sensing characteristics were studied. Results showed that the sensitivity and selectivity of SnO2 sensors were improved after the electron beam irradiation.     

离子束混合对锆氧化行为影响的研究

锆及其合金是核反应堆工程常用的结构材料。在高温空气或氧气环境中,锆材表面会生成以ZrO_2为主要成分的氧化膜。同时氧在膜下锆基体中大量溶解。前者导致锆材耗蚀,引起作为燃料元件包壳的锆材加速氧化的“自催化效应”;后者会对锆材力学性质产生不利影响。因此研究锆氧化的机理和抑制方法是一个具有理论和实际意义的课题。     

62Zn放射性核束的产生

介绍了利用串列加速器作为驱动加速器在线产生62Zn放射性核束的方法,包括靶的制备和束流调试方法,在线产生了能量为25 keV、强度大于106/s的62Zn放射性核束.也评估了实验产生放射性核束的效率,实际测量了实验结束后的放射性剂量.     

电子束处理前后C—SiC涂层的微观分析

在不锈钢材料表面，用射频磁控溅射沉积Ｃ－ＳｉＣ，利用ＸＲＤ、ＸＰＳ对电子束处理前后的Ｃ－ＳｉＣ涂层进行了微观分析。     

B-Ni、B-Fe系离子束混合实验研究

近年来,常用离子束混合法来研究二元金属系统的合金化问题。但是,在用离子束混合法研究类金属-金属二元系统结构变化方面,除掉Si与Pt、Pd等金属的单层膜反冲混合外,迄今还未见有研究资料发表。然而,类金属元素在金属的离子束表面改性中,以及在用其它方法形成非晶态等的研究中,是常用的元素。因此,研究类金属-金属在离子束作用下的结构变化具有现实意义。     

Hydrodynamic response of converter target impacted by high-current relativistic electron beam

The typical response of the X-ray converter material impacted by an intense relativistic electron beam is vaporization and rapid expansion. For the Dragon-I accelerator (2.5 kA, 20 MeV, 60 ns), the slab target is replaced by a multi-foil target in order to reduce the unwanted debris ejected from the target. Comparisons of the output X-ray performance and the hydrodynamic response between the slab target and the multi-foil target are calculated by numerical methods. We found that vaporization and melt ejection dominate the hydrodynamic response in the multi-foil target while the mechanical effect plays an important role in the slab target. We also report the single-pulse experiments which measure the surface density decrease of the converter material after a specified delay. The experimental results show good agreement with the numerical prediction. Hydrodynamic response of the multi-foil target impacted by three successive pulses in 1 μs is also studied by simulation. The results indicate that although the surface density of the material decreases rapidly during the inter-pulse time scale, the X-ray dose produced by the second and the third pulse will nearly maintain the same as the first one.     

Treatment of municipal sewage sludge by electron beam irradiation

Irradiation treatment of sewage sludge was carried out using an electron beam accelerator.The effects of irradiation dose,sludge water content and sludge thickness on the breakdown of sludge flocs,thus the formulation of soluble chemical oxygen demand (SCOD) and soluble total nitrogen (STN),and the reduction of MLSS and endogenous OUR,and so on,were investigated.It was observed that,with increased doses,the SCOD,STN and UV absorption intensity of the sludge supernatant increased rapidly with similar trends,and MLSS considerably decreased,all indicating that a large amount of the cell contents of sewage sludge were released by electron beam irradiation.The results of endogenous OUR also showed that a large number of microorganisms in sewage sludge were killed or deactivated.Zeta potential sludge became more positive with increased doses,implying that the dewatering performance of sewage sludge was not adversely affected.It was also found that the thickness of sludge was an operation parameter of great importance in the electron beam treatment of sewage sludge due to the relatively short penetration depth in water/sludge of the high-energy electrons.     

离子束混合提高耐热钢抗高温氧化性能研究

耐热钢4Cr9Si2试样上溅射沉积60nm左右的Si_3N_4或Si薄层,然后用120keV的N_2~+或Ar~+束轰击。氧化动力学曲线测量及扫描电镜观察表明,离子束混合使耐热钢的抗高温氧化性能有明显的提高。离子束混合同时也延长了汽车车灯玻璃耐热钢成型模具的使用寿命。并用TEM,AES,XPS及Monte-Carlo模拟法进行了分析。     

电子束辐照对冷却猪肉杀菌保鲜效果的研究

利用电子束辐照技术对冷却猪肉的杀菌和保鲜效果进行了研究,为电子束辐照技术应用于肉类加工业提供应用依据。以束流能量（X1）和辐照吸收剂量（X2）为试验因子,以菌落总数（Y）为指标,通过响应面分析法（RSM）研究了电子束辐照杀菌的效果及对货架期的影响。电子束辐照对冷却猪肉杀菌效果的二次多项数学模型为：Y=3．78—0．24X1-0．13X2-0．16X1X2—0．18X1^2＋0．15X2^2（R^2=0．9755）。辐照吸收剂量与束流能量之间存在协同增效作用,试验因子的显著性顺序为：剂量〉交互作用〉束流能量。使冷却肉初始菌数下降2个对数单位的辐照参数范围为3．23-4．0kGy,2．3～3．8MeV。经电子束辐照的冷却猪肉样品在4℃条件下贮藏,货架期比对照样品延长12d左右;在7～10℃条件下保存,货架期比对照延长9d左右。研究结果表明,电子束辐照对冷却猪肉具有杀菌保鲜作用,该研究对电子束辐照技术应用于冷却猪肉的生产实践具有指导意义。     

Material dependence of total electron emission yields following slow highly charged ion impact

The total electron emission yields following the interaction of “Slow (2 keV/a.u.) Highly Charged Ions” (SHCI) (O³⁺⁷⁺, Xe¹²⁺⁵²⁺, Au⁵⁴⁺⁶⁹⁺) with different target surfaces (highly-oriented pyrolytic graphite (HOPG), Au and SiO2) have been measured. The emission yields increase with charge state, and is found to be highest for carbon, the HOPG target, and lowest for the SiO₂ target. An empirical formula for the electron emission is including recent results from investigations of plasmon excitation following SHCI impact are used to interpret the results.     

Ni/Si体系离子束混合及相变研究

注入参量变化引起不同的混合结果,在宽温区中得到Ni_2Si、NiSi、NiSi_2多种化合物相,进而探讨了Xe离子诱导的Ni/Si体系界面原子混合机理及诱发相变的动力学过程。     

重离子束辐照细胞研究的文献计量学分析

应用文献计量学方法和相应的应用软件,借助Web of Science平台对重离子束辐照细胞这一研究主题的相关文献、作者、期刊、机构以及关键词进行定量和系统考察。结果显示,重离子束辐照细胞研究在1990年之后日益活跃并深入;不同品质的重离子束辐照诱导不同类型细胞会产生不同的生物学效应、旁观者效应及其机制、重离子束辐照细胞生物学效应评估模型、重离子束治疗癌症过程中辐照品质选择与控制模型以及相应的计算机程序是该研究主题的重要内容;引入特定指数推测所得该研究主题重要学术期刊与Nature,Proceedings of the National Academy of Sciences of the United States of America,Cancer Research等期刊之间有较高的共被引频次,表明更多科学前沿的突破性成果和思路应用于该主题研究中;此外,该研究主要集中于少数国家、少数机构、少数作者,并且合作相对较少。     

Production of radioactive 9C ion beam and its optimization

1IntroductionCarbonionbeamhasattractedgrowinginterestintumortreatmentinthepastdecade.Thisisattrib-utedtoexcellentphysicalcharacteristicsofcarbonbeamlikedoselocalizationintheBraggpeakandhighrelativebiologicaleffectivenessoverthepeak.Toenhancetheefficacyofheavyionbeamsintreatingtumors,wehaveevenproposedanovelideausingdelayedβ-particledecaybeamssuchas9Cand8Bfortumortreatment.Theseradioactiveionscanisotropi-callyemitlowenergyα-particlesand/orprotonsaftertheir+β-decay.Besideslocalizingionsinbo…     

对束流均匀化扫描装置的性能改进方法

介绍了对束流均匀化扫描装置三角波电流功率源性能的改进,通过对设备电路改进和设备结构的改造,在重离子对作物种子的诱变育种,生物效应研究以及用重离子束注入处理金属,塑料等使其表面变性的实验中,取得了很好的效果。