离子束分析进展

1983年在美国亚里桑那州州立大学召开了第六届国际离子束分析会议。这次会议的侧重方向是低能离子散射。近年来,由于超高真空技术、高速计算机、飞行时间方法、离子源等技术的发展和应用,散射截面、射程、阻止本领等各种基本参数的精确化,促进了低能离子散射技术的发展,使它成为表面结构分析中的重要手段。必须指出,上述多方面技术的进步所产生的影响,不仅仅局限于低能离子散射,而是遍及离子束分析的整个领域。     

离子束分析进展——介绍第六届国际离子束分析会议

第六届国际离子束分析会议于1983年5月23日至27日在美国凤凰城附近的亚里桑那州州立大学召开,由该校物理系主办。主办单位必须提出一个“这次会议的主导方向”或“侧重方向”。 这次会议的主办单位提出的侧重方向是:低能离子散射。必须指出,在离子束分析领域中的“低能、中能、高能”与原子核物理或粒子物理中相应的概念大不相同。在这里,低能是指离子的能量低于约10keV,中能是指10～1000keV,高能则是指MeV量级的离子束。     

离子束分析技术在抗核加固研究中的应用

本文介绍了核辐射使电子元器件失效的机制以及离子束分析技术在抗核加固研究中的若干应用。     

离子束生物技术及其在玉米育种中的应用

离子束作为一种新兴诱变源,已广泛应用于各种农作物的诱变育种。离子束生物技术为玉米品种的改良和种质资源的创新开辟了一条新的道路,推动了玉米育种事业的长足发展。本文阐述了离子束的特点、诱变机理以及在玉米育种中的应用。     

中国科学院物理研究所的离子束分析及离子注入改性研究

介绍了中国科学院物理研究所离子束研究室的主要设备、分析方法、离子注入材料改性研究以及近年来在半导体材料、高Ｔｃ超导材料、环保等领域中的研究工作。     

固体核径迹探测器在地质学和考古学中的应用

本文介绍了裂变径迹年龄测定方法及其在地质年代学、考古学、古人类学、第四纪地质     

双等源强流离子束分析

目前所使用的各种离子源,还不能产生具有完全单一荷质比的离子,所以,离子源所提供的离子束是包含多种离子组态的混合束。因此,要把离子加速到高能,就涉及到一个多动量离子束加速系统。在由电磁场(电磁组件)构成的强流带电粒子加速系统中,多动量离子束的加速和聚焦会产生许多缺陷与困难。在强流加速器中,提高所需离子的加速效率,减轻加速器的总负荷,是一个很重要的     

离子束材料改性应用中的新进展

着重分析了离子注入提高离子束加工效益的途径，离子束工业生产发展现状和未来离子束技术在国民经济中的重要作用。     

组合离子束技术在硅基材料芯片中的应用

将组合技术和离子束技术结合起来,用于硅基发光材料的研究用组合离子束技术在硅基材料上制备了64个直径为2mm的单元--材料芯片,并对硅基材料芯片各单元进行了卢瑟辐背散射质子弹性散射和扫描阴极射线发光特性分析     

Applications of ion beam analysis in archaeology and the arts

Ion beam techniques are widely used for the nondestructive analysis of objects of art and archaeology. With simple, fast, and direct procedures practically all chemical elements present in the object can be identified, and determined quantitatively with good sensitivity, accuracy and precision. The external beam technique gives the possibility of examining all articles of any size and shape without sampling. Thus, valuable information can be obtained for the composition of the objects, for the fabrication techniques, the origin of materials, etc. This information may be used for purposes of historical interest, for restoration procedures, for identification of forgeries, and many other aspects. Examples are described briefly for dating by fluorine determination, for studies on coins ceramic surfaces, old paintings, etc.     

Ion beam methods to determine trace heavy metals concentrations and sources in urban airsheds

Unique data for Australia on the concentration of selected metals in fine particle ambient air pollution is presented for urban, industrial and rural sites along 300 km section of the eastern coast line of Australia around Sydney. IBA techniques were used to determine over 25 different chemical species in the air including, H, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Se and Pb. This included many trace metals at concentrations around 1 ng/m³ of air sampled.     

茯苓聚糖的氚离子束标记及其在小鼠体内的药物动力学研究

本文采用氚离子束标记法,对茯苓聚糖进行了标记,放射性比活性达1.81—2.07TBq/mmol。药物动力学研究证明~3H-茯苓聚糖尿素液口服灌喂小白鼠,按一定时间在尾部静脉取血样作放射性分析。得到的药-时曲线适合于双定模型。     

Ion beam characterization of advanced luminescent materials for application in radiation effects microscopy

The ion photon emission microscope (IPEM) is a technique developed at Sandia National Laboratories (SNL) to study radiation effects in integrated circuits with high energy, heavy ions, such as those produced by the 88” cyclotron at Lawrence Berkeley National Laboratory (LBNL). In this method, an ion-luminescent film is used to produce photons from the point of ion impact. The photons emitted due to an ion impact are imaged on a position-sensitive detector to determine the location of a single event effect (SEE). Due to stringent resolution, intensity, wavelength, decay time, and radiation tolerance demands, an engineered material with very specific properties is required to act as the luminescent film. The requirements for this material are extensive. It must produce a high enough induced luminescent intensity so at least one photon is detected per ion hit. The emission wavelength must match the sensitivity of the detector used, and the luminescent decay time must be short enough to limit accidental coincidences. In addition, the material must be easy to handle and its luminescent properties must be tolerant to radiation damage. Materials studied for this application include plastic scintillators, GaN and GaN/InGaN quantum well structures, and lanthanide-activated ceramic phosphors. Results from characterization studies on these materials will be presented; including photoluminescence, cathodoluminescence, ion beam induced luminescence, luminescent decay times, and radiation damage. Results indicate that the ceramic phosphors are currently proving to be the ideal material for IPEM investigations.     

Ion beam induced formation of nanocrystalline silicon in pulsed laser deposited SiOX thin films

Synthesis and structural studies of nanocrystalline silicon grown in pulsed laser deposited SiO_X films is reported. The effect of high energy heavy ion beam irradiation on these films is studied using 100 MeV Ag ions. The structural studies were carried out using micro Raman spectroscopy, GAXRD, FTIR, TEM, HRTEM, SAED and EDX. The occurrence of phase separation in non-stoichiometric silicon oxide by means of ion beam irradiation leading to the formation of silicon nanocrystals in the films is confirmed by the results. HRTEM results reveal the structure of silicon phase formed after ion beam treatment and the particle size can be controlled up to 2-3 nm. A detailed analysis by micro Raman and HRTEM studies suggest the presence of crystallite size distribution. The results of GAXRD and SAED confirm the formation of cubic phase of silicon with two different lattice parameters. The studies conclude that the size of the nanocrystals can be controlled by varying deposition and ion irradiation parameters.     

Ion beam propagation and focusing

Inertial confinement fusion with ion beams requires the efficient delivery of high energy (1 MJ), high power (100 TW) ion beams to a small fusion target. The propagation and focusing of such beams is the subject of this paper. Fundamental constraints on ion beam propagation and focusing are discussed, and ion beam propagation modes are categorized. For light ion fusion (LIF), large currents (2–33 MA) of moderate energy (3–50 MeV) ions of low atomic number (1A12) must be directed to a target of radius 1 cm. The development of pulsed power ion diodes for LIF is discussed, and the necessity for virtually complete charge neutralization during transport and focusing is emphasized. Fornear-term LIF experiments, the goal is to produce pellet ignition without the standoff needed for the ultimate reactor application. Ion diodes for use on Sandia National Laboratories Particle Beam Fusion Accelerators PBFA-I (2–4 MV, 1 MJ, 30 TW, operational) and PBFA-II (2–16 MV, 3.5 MJ, 100 TW, scheduled for operation in 1985) are discussed. Ion beam transport from these diodes to the pellet is examined in reference to the power brightness . While values of =2–5 TW/cm²/sr have been achieved to date, a value of 100 TW/cm²/sr is needed for breakeven. Research is now directed toward increasing , and means already exist (e.g., scaling to higher voltages, enhanced ion diode current densities, and bunching), which indicate that the required goal should be attainable. Forfar-term LIF applications, the goal is to produce net energy gain with standoff suitable for a reactor. This may be achieved by ion beam transport in preformed, current-carrying plasma channels. Channel transport research is discussed, including experiments with wire-initiated, wall-initiated, and laser-initiated discharge channels, all of which have demonstrated transport with high efficiency (50–100%). Alternate approaches to LIF are also discussed, including comoving electron beam schemes and a neutralized beam scheme. For heavy ion fusion (HIF), moderate currents (10 kA) of high energy (10 GeV) ions of high atomic number (A200) must be directed to a target of radius 0.3 cm. Conventional accelerator drivers for HIF are noted. For a baseline HIF reactor system, the optimum transport mode for low charge state beams is ballistic transport in near vacuum (10^–4–10^–3 Torr lithium), although a host of other possibilities exists. Development of transport modes suitable for higher charge state HIF beams may ultimately result in more economical HIF accelerator schemes. Alternate approaches to HIF are also discussed which involve collective effects accelerators. The status of the various ion beam transport and focusing modes for LIF and HIF are summarized, and the directions of future research are indicated.     

Ion beam irradiation of nanostructures - A 3D Monte Carlo simulation code

A computer code for the simulation of ion beam irradiation of nanostructures has been developed. The code simulates the transport of energetic ions through matter by means of a Monte Carlo algorithm, similar to the often-used TRIM code (Ziegler et al. (1985) [1]). New effects occur compared to bulk, when irradiating nanostructures, which are of the same size as the ion range or the damage cascade. To account for these effects, the target in our code does not consist of layers like in TRIM but can be defined as an arbitrary 3-dimensional structure. This allows to obtain more accurate 3D distributions of implanted ions and implantation damage for nanostructures, which cannot be described by a stack of layers. We demonstrate the functionality of the code by comparing simulations with ion beam implantation into nanowires.     

Computer simulation of ion beam analysis: Possibilities and limitations

Quantitative application of ion beam analysis methods, such as Rutherford backscattering, elastic recoil detection analysis, and nuclear reaction analysis, requires the use of computer simulation codes. The different types of available codes are presented, and their advantages and weaknesses with respect to underlying physics and computing time requirements are discussed. Differences between different codes of the same type are smaller by about one order of magnitude than the uncertainty of basic input data, especially stopping power and cross section data. Even very complex sample structures with elemental concentration variations with depth or laterally varying structures can be simulated quantitatively. Laterally inhomogeneous samples generally result in an ambiguity with depth profiles. The optimization of ion beam analysis measurements is discussed, and available tools are presented.