静态随机存储器单粒子效应的角度影响研究

利用兰州重离子加速器加速的高能离子研究了入射角度对IDT71256的单粒子翻转截面和多位翻转比例的影响.研究表明：在大角度掠射轰击下单粒子翻转截面的增大包括了多位翻转的贡献；离子在器件敏感层中沉积的能量及其横向分布是影响多位翻转的两个重要参数，IDT71256发生三位以上多位翻转的比例随着离子入射角度的增大而增加. 关键词： 静态存储器 单粒子翻转 多位翻转 沉积能量 横向分布     

Effects of oxygen concentration and irradiation defects on the oxidation corrosion of body-centered-cubic iron surfaces: A first-principles study

Oxidation corrosion of steels usually occurs in contact with the oxygen-contained environment, which is accelerated by high oxygen concentration and irradiation. The oxidation mechanism of steels is investigated by the adsorption/solution of oxygen atoms on/under body-centered-cubic (bcc) iron surfaces, and diffusion of oxygen atoms on the surface and in the near-surface region. Energetic results indicate that oxygen atoms prefer to adsorb at hollow and long-bridge positions on the Fe(100) and (110) surfaces, respectively. As the coverage of oxygen atoms increases, oxygen atoms would repel each other and gradually dissolve in the near-surface and bulk region. As vacancies exist, oxygen atoms are attracted by vacancies, especially in the near-surface and bulk region. Dynamic results indicate that the diffusion of O atoms on surfaces is easier than that into near-surface, which is affected by oxygen coverage and vacancies. Moreover, the effects of oxygen concentration and irradiation on oxygen density in the near-surface and bulk region are estimated by the McLean's model with a simple hypothesis.     

基于HIRFL 的高温应力材料载能离子辐照实验装置

针对未来先进核能装置候选结构材料在高温和应力等条件下抗辐照性能的评价与快速筛选的需求,基于兰州重离子研究装置( HIRFL ) 可提供的离子束流条件,设计制作了国内第一套高温应力材料载能离子辐照装置。该装置由束流扫描及探测系统、高温系统、应力系统、真空冷却系统和远程控制系统等5 部分组成,可以同时提供高温和拉/ 压应力下材料的离子束均匀辐照件,温区覆盖了室温至1 200 °C范围,拉/ 压应力范围为0 ~1176 N,x-y 方向均匀扫描面积可大于40 mmx40 mm。利用该装置,已经成功进行了多次高温和应力条件下载能离子辐照先进核能装置候选材料的实验研究,并取得了初步成果。In order to expedite the evaluation of properties of irradiated materials and the selection of candidate materials for future nuclear energy systems, we developed a specific ion irradiation equipment installed on the Heavy Ion Research Facility of Lanzhou ( HIRFL ) for materials under high temperature and stress. This equipment consists of ion beam scanning and detector system, high temperature load system, stress load system, water cooling system as well as telecommunication and control system. It can supply a wide range of temperature (from room temperature to 1 200 °C ) and stress ( pull / push from 0 to 1 176 N) simultaneously for materials under ion irradiation. The x-y scanning area with high uniformity is larger than 40 mm40 mm. This is the first suit of ion irradiation equipment made in China that can be used to study co-operating effects of high temperature and stress in an irradiated material. It has been successfully used several times for materials irradiations under high temperatures and stress, which proved that the new equipment has very good performances in experiments.     

加速器驱动次临界系统中堆外中子注量率监测方法（英文）

在加速器驱动的次临界（ADS）系统中,次临界反应堆的功率控制是通过控制束流强度来实现。监测堆外中子注量率,不仅提供了反应堆功率指示,也为反应堆保护系统在启动和运行阶段提供了重要的监测信息,因此,堆外中子注量率的监测在ADS系统的控制与保护中起着非常重要的作用。采用3套裂变室和3套非补偿电离室来监测ADS堆外中子注量率。由于裂变室有脉冲、电流和均方电压3种操作模式,1套裂变室可以监测源量程、中间量程和功率量程等宽范围的反应堆功率。所以,使用的监测方法有3个优点,即:增加了监测通道的冗余度,提高了保护系统的可靠性,以及能提供更多的轴向功率分布信息。由于这些中子探测器对中子能谱很敏感,提出了一种有效的校准方法,即先用一个标准的中子源校准这些中子探测器,然后再将中子注量率除以一个修正因素。基于Geant4仿真结果显示,所提取的裂变室和非补偿电离室的修正因素分别为5和42。In an accelerator driven sub-critical (ADS) system, power control in sub-critical reactor is achieved through the control of the beam current. Excore neutron flux monitoring in an ADS system, not only provides indication of reactor power, but also provides important inputs to reactor protection system during startup and power operation, and thus plays a very important role in the control and protection of ADS system. This paper presents the excore neutron flux monitoring method which uses three fission chambers (FCs) and three uncompensated ion chambers (UICs). With three operation modes, pulse mode, current mode, and mean square voltage mode, an FC can monitor reactor power over a wide range from the source range to the intermediate and power ranges. The proposed monitoring method increases the redundancy of independent monitoring channels, improves the reliability of the protection system, and provides more information on axial power distribution. Since these neutron detectors are sensitive to the neutron energy spectrum, we propose an effective calibration method to provide the exact value of neutron flux, i.e., these neutron detectors are calibrated with a standardized neutron source, and then, a correction factor is added in the calibration by comparing the neutron energy spectrum of the neutron source with that in ADS system. Based on Geant4 simulation, the correction factors of 5 and 42 are extracted for FCs and UICs, respectively.     

中能重离子微束辐照装置的研制

微束辐照装置是将辐照样品的束斑缩小到微米量级, 能够对辐照粒子进行准确定位和精确计数的实验平台, 是开展辐照材料学、辐照生物学、辐照生物医学以及微加工的有力工具. 中国科学院近代物理研究所(IMP)正在研制中能重离子微束辐照装置. 该装置以兰州重离子加速器(HIRFL)系统提供的中能和低能重离子束流为基础, 采用磁聚焦方式形成微米束. 束运线上两台铅垂方向的偏转磁铁辅以四极磁铁构成对称消色差系统, 将束流导向地下室, 再用高梯度的三组合四极透镜强聚焦形成微米束斑, 在真空中或大气中辐照样品. 它将成为国内首台能够提供从低能(10MeV/u)到中能(100MeV/u)的重离子微束的公共实验平台, 用于定位、定量照射靶物质(生物细胞、组织或其它非生物材料等), 有助于深入揭示重离子与物质相互作用的本质, 也为探索重离子辐照效应的应用提供新的手段.     

粒子探针简介

粒子探针,国外文章中称为NucIearmicroprebe,我们这样称呼它,是为了对称于电子探针(electron microprobe),区别于离子探针(Ion microprobe)。它是将加速器提供的兆电子伏数量级的粒子束(质子、α粒子或者其它重离子)进一步准直和聚焦到微米数量级。当前世界上聚焦最好的可使束斑达0.5微米,下一步的目标是0.1微米。     

金属材料中高能重离子辐照效应的理论描述

简要介绍了高能重离子在金属材料中引起辐照效应的主要理论 ,特别是与电子能损引起的缺陷产生与演化、离子潜径迹形成、辐照相变以及各向异性塑性形变等效应相应的理论描述.Experimental results showed that, for high energy heavy ion irradiations, electronic energy loss could play a dominant role in damage process in solid materials. In order to explain the experimental phenomena and results, a series of theoretical models based on Coulomb explosion or thermal spike mechanisms have been proposed. In the present paper, more attention was paid to theoretical expressions of high energy heavy ion irradiation induced effects in metallic materials ...     

C-N化合物合成研究

用能量 50 - 1 1 0 ke V的 N离子在低于 80°C温度下注入 CVD法合成的金刚石薄膜后 ,分别用 X射线光电子谱、红外谱和拉曼谱检测注入后的薄膜中是否形成了 C- N化合物 .结果表明注入后的薄膜中存在有 3种化学键态的 C- N化合物 ,且低能离子注入更有利于 C- N化合物的形成 .由于在注入区内形成了大量的 C- N单键 ,这有利于β- C3N4 的合成 .对 C- N化合物薄膜的场发射特性也做了研究.Diamond films were implanted with 50-110 keV N ions to the dosage of 1×10 17 ions/cm 2 at the temperature below 80 °C . The possibility of the formation of C N compounds in diamond films was investigated by means of X ray photoelectron spectroscopy (XPS), X ray diffraction analysis (XRD), Fourier transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy. New evidence has been presented that plenty of C-N single bonds which are necessary ...     

快重离子在固体材料中的强电子激发效应

简要介绍了快重离子在固体材料中强电子激发效应的基本特点、研究现状和在HIRFL上获得的部分实验结果,并对今后的研究工作进行了展望。In this paper the outline of intense electronic excitation effects in solid materials induced by swift heavy ions and international research status were briefly reviewed. Few examples of experimental results obtained on HIRFL were presented. And also the developing tendency in the field was looked into the future.     

高能质子引起器件单粒子效应的研究方法

简略介绍了高能质子在半导体芯片中引起单粒子效应的实验测量和理论分析方法,包括核反应分析方法、半经验方法,介绍了质子和重离子翻转截面间的关系,并用重离子实验数据预测器件在质子环境下的翻转率. This article introduces briefly the experimental and theoretical methods that have been used to study high energy proton induced single event effect in semiconductor devices. The theoretical methods including nuclear reaction analysis method and semi empirical method are presented. The relationship of upset cross section between proton and heavy ions is described. Finally, on orbit proton upset rates are predicted by using the heavy ion test data.