多种离子束分析技术在大气气溶胶研究中的应用

介绍了使用质子弹性散射测定大气气溶胶样品中的氢，使用质子透射能量损失测定样品的总质量和使用质子X荧光测定采在不同滤膜上的气溶胶样品化学成分的分析方法。结果表明，多种离子束分析技术的组合使用，为大气气溶胶研究提供了十分重要和有用的工具。     

气溶胶样品氢含量的质子弹性散射分析

利用单个标准样品比较法质子弹性散射分析（PESA）对一组采集在核孔膜上的气溶胶样品的氢含量进行定量分析。在质子束能量为2.5MeV、散射角为40°时，PESA测量10μm厚核孔膜上气溶胶中H含量的探测限为0.36μg/cm²。几个样品H含量的测量结果在3.2~37.5μg/cm²之间，显著高于探测限。质子能量在1.0~2.5MeV范围内，3.5μmMylar膜的束流归一化H峰面积随入射质子能量的变化在±3%以内。所以，不同厚度的气溶胶样品可采用同一个标准样品来进行PESA测量。     

质子非卢瑟福背散射测量气溶胶样品中氢、碳、氮和氧的含量

气溶胶样品中Z＞12以上元素含量的质子荧光(PIXE)分析是北京师范大学GIC4117串列加速器的主要应用领域之一。为弥补PIXE无法分析H、C、N和O等轻元素之不足，在PIXE靶室160°散射角安装金硅面垒探测器，用质子非卢瑟福背散射分析（PNBS）方法对核孔膜采集的气溶胶样品中H、C、N和O等轻元素的含量进行测量。测量得到的气溶胶样品中H和Si元素含量与质子前角散射（PESA）和PIXE的分析结果相近，表明PNBS可用于核孔膜采集的气溶胶样品的分析。     

一个PIXE-RBS离子束分析系统的刻度

四川大学原子核科学技术研究所依托2.5 MeV范德格拉夫静电加速器搭建了质子诱发X射线荧光分析(Proton Induced X-ray Emission,PIXE)与卢瑟福背散射分析(Rutherford Backscattering Spectrometry,RBS)相结合的离子束分析系统,描述了该分析系统和刻度过程。通过10个金属单质的PIXE-RBS测量,刻度得到的仪器常数H值是一条随能量变化的曲线,然后采用最小二乘法拟合确定了X射线探测器前的Mylar膜有效厚度、选择性滤膜的有效厚度和中心小孔大小,从而得到H值。为了对刻度H值进行检验,在相同实验条件下测量了标准粘土样品元素成分,测量数据与证书数据符合得较好。刻度结果将用于以后的PIXE-RBS分析。     

轻元素深度剖面的离子束分析方法

轻元素深度剖面分析有着许多实际的应用,如:聚变堆第一壁的辐射损伤;结构材料的氢脆;氧化、贮氢材料、超导材料、太阳能材料中氢的分布等。本文介绍用于轻元素深度剖面分析的核反应法、质子弹性散射法、前散射符合法和弹性反冲探测法,并简单介绍这些方法的应用。     

氢和其它轻元素的同时分析

准确测定材料中的成分及杂质的含量和其深度分布在新材料的研制中有重要作用。近年来，在新材料的研制和改性中经常用各种方法加入不同量的氢成分来改变材料的各种性能。由于卢瑟福背散射(RBS)不能测量H，人们通常用RBS测其它元素，再用α束弹性反冲法测H。两次测量存在截面归一和样品两次受照带来的辐射损伤问题。     

As离子束混合形成硅化钨的卢瑟福背散射分析

本工作用卢瑟福背散射研究了离子束混合方法形成硅化钨的条件。通过对热烧结和离子束混合法的比较,结合X射线衍射分析相结构的结果,指出离子束混合法可降低形成二硅化钨所需的退火温度。观察到氧杂质对形成条件的影响,简单讨论了离子束混合形成硅化物的机理。     

质子在天然硼上的非卢瑟福弹性背散射截面测量

采用相对测量法对能量为0.15-2.00MeV的质子在天然硼上的非卢瑟福弹性背散射截面(160     

用质子弹散符合测量方法分析薄膜中氢分布的蒙特卡罗研究

本文从离子与物质相互作用的基本原理出发,用蒙特卡罗方法模拟了用质子弹性散射符合分析方法分析表面含氢的几组不同厚度的金属薄膜样品的实验,详细介绍了模拟过程中影响深度分辨率的多种因素,如束流能量、能损歧离、角度歧离等。本文基于2×1.7MV串列静电加速器可以提供的质子束能量范围,通过模拟计算得到用能量为1.5 Me V的质子束分析厚度为1~3微米的铝膜,深度分辨可以达到0.2微米。本文还给出了内部含氢的多层铝膜的模拟结果,表明此方法可以很好地分析薄膜内部氢元素的深度分布。     

一种用于SPM分析的大气气溶胶单颗粒样品的制备方法

介绍了一种用于扫描质子微探针分析的大气气溶胶单颗粒样品的制备方法。通过实验摸索出一种适合于支撑颗粒物的材料聚乙烯醇缩丁醛(PVB)。大气颗粒物被直接采集在PVB薄膜上从而制成样品,保持了颗粒物的原始信息。用显微镜观察了采集的颗粒物,颗粒物之间完全分开,颗粒物间距合适。样品的扫描质子微探针试验结果表明,所制成的单颗粒样品能经受住质子束的长久轰击。对PVB薄膜的本底测试表明,这种膜的本底很小,不会对被测颗粒物的元素产生干扰。     

Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps.The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.     

Instrumentation and application of the ion beam analysis line of the in situ ion beam system

An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The system was tested by performing qualitative and quantitative analysis of Si, Ni/Si, Bi Fe O3:La/Si,Mo C/Mo/Si and Ti BN/Si samples. RBS of a Bi Fe O3:La film was used as system calibration. Tested by ion beam channeling, a Si(100) is of good crystallinity(χmin= 3.01%). For thin film samples, the measured thickness agrees well with simulation results by SIMNRA. In particular, composition of a Mo C/Mo/Si and Ti BN film samples were analyzed by RBS and non-Rutherford elastic backscattering.     

Infrared analysis of ion beam irradiated polymers

Irradiation with heavy ions can produce several modifications in the chain structure of polymers. These modifications can be related to scissioning and cross-linking of chemical bonds, which depend on the ion fluence and the density of energy deposited in the material. Stacked thin film Makrofol-KG^® samples were irradiated with 350 MeV Au²⁶⁺ ions and FTIR absorption spectroscopy was used to determine the bond changes in the samples. Data on the absorption bands as a function of the fluence indicated a higher probability for simple-bonds scissioning than for double-bonds scissioning and no dependence on the number of double bonds breaking with ion fluence. Since sample irradiation was done in a non-track-overlapping regime, a novel process for double bonds formation is suggested: the excitation of a site in the material by only one incident ion followed by a double bond formation during the de-excitation process.     

Study of individual atmospheric aerosol particles at the Debrecen ion microprobe

Aerosol samples collected in outside and indoor environments with a 9-stage PI cascade impactor were analysed using PIXE, STIM (on and off-axis) and RBS ion beam analytical techniques at the Debrecen ion microprobe. Elemental composition, size and morphology of single aerosol particles were determined.Since the quantitative determination of light element concentrations requires a support material with small or no light element content, impactor surfaces made of different materials were tested in order to optimize the sampling and analysis. Thin polymer and Al foils were found to be possibly adequate substrate materials.     

Control of temperature in thin samples during ion beam analysis

The ability of ion beam analytical techniques such as proton induced X-ray emission (PIXE) to determine elemental content without damaging fragile objects is a key factor in their increasing use in the analysis of art and archaeological objects In this paper, we calculate the expected temperature rise in thin, planar samples with and without radiative, conductive and convective cooling The results show that the primary emphasis must be placed on minimizing energy input to the sample, and that forced convective cooling is by far the most effective method of energy removal in materials such as paper, parchment, and fabrics     

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.     

Proton beam writing of microstructures at the ion nanoprobe LIPSION

Proton beam writing (PBW) is a direct writing technique which allows the creation of three-dimensional structures with a high aspect ratio in the micrometer and nanometer range in photoresist materials without the use of templates. At the high-energy ion nanoprobe LIPSION of the University of Leipzig this technique was established recently. In this article the latest results concerning this topic are presented. PBW was successfully performed with the positive resist polymethyl methacrylate (PMMA) which is now used at LIPSION in addition to the negative resist SU-8. With the new data acquisition system MICRODAS being commissioned, a new scan program was developed and tested which is dedicated to the creation of arbitrarily shaped structures. Squares with dimensions down to 1.2 μm were created in SU-8 at LIPSION. Furthermore, Ni grids were produced by electroplating, using templates written in PMMA resist. In addition, first structures for studying the growing behavior of Bragg reflectors and the optical characterisation of ZnO nanowhiskers were produced by PBW.     

Quantification of sodium in ancient Roman glasses with ion beam analysis

Concentrations of light elements (Na, Al, Si) in glass have been profiled by comparing the PIGE yields as a function of beam energy to those of a glass standard in combination with PIXE measurements which are used to determine the specific energy loss of protons in the unknown glasses. The technique has been tested on a known sample and applied to a few Roman natron glasses giving results compatible with the morphology of the archaeological samples, as deduced from microscopy. The results have suggested some considerations on the systematic use of the PIGE technique in the determination of bulk sodium concentration in ancient materials.