The high-energy ion nanoprobe LIPSION at the University of Leipzig has been operational since October 1998. The ultrastable single ended 3.5 MV SINLETRONTM accelerator supplies the H+ or He+ ion beam. A magnetic scanning system moves the focused beam across the sample. At present, a resolution of 150 nm in the low current mode and 300 nm at 5 pA could be achieved.

Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores (<10μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation.

In order to identify the sources of individual aerosol particles, we developed an identification system based on the combination of the micro-PIXE (particle-induced X-ray emission) technique with the pattern recognition (PR) technique. It uses the micro-PIXE spectrum of an individual aerosol particle as its fingerprint to identify the origin of the particles. A total of 294 micro-PIXE spectra of individual aerosol particles, collected at Shanghai City in China, were applied to test the PR system. These particles were collected from several pollution sources and a local environment monitor site. Most of the environment particles were identified, and the most probable sources were assigned by the PR system. It was found that cement factories and vehicle exhaust are the major contributors. About 14% of the particles from the environment monitor site could not be identified by their spectra. They might have come from some other sources we have not yet investigated. The validity and the efficiency of the system are evaluated and discussed. It is demonstrated that the combination of micro-PIXE with the pattern recognition technique offers a new, powerful tool for the source identification of individual aerosol particles.

A new method for direct assessment of air pollution is developed by using nuclear microprobe techniques to analyse single aerosol particles (SAP). Every particle is characterized by its PIXE spectrum which can be considered to be its fingerprint. The strategy for fingerprint classification and identification is used to trace a measured aerosol particle to its original source. Most of the particles have a size of up to 3μm. The particles are separately attached to a clean thin foil. The Leipzig Nanoprobe, LIPSION, is used for this study. There are two steps in the new method. First, collect samples from different sources, measure them and compile their characteristic spectra into a library. Then, assess the environmental samples by comparing their spectra with those in the library. An artificial neural network (ANN) package is used for spectrum comparison.

A new method combining the pattern recognition (PR) technique with micro-PIXE spectrum was used for direct assessment of lead pollution in the atmosphere of Shanghai City. Single aerosol particles (SAP) of PM10 (<10 mu m) were analyzed using the nuclear microprobe. Every particle is characterized with its micro-PIXE spectrum, which can be considered its fingerprint. The PR technique was applied to trace a lead contaminated aerosol particle back to its source. The discrimination of different pollutant sources was enhanced with investigating the individual aerosol particles. The results showed that the lead contamination from automobile exhaust should not be neglected. The lead concentration with low level was detected in most unleaded gasoline particles; however, the highest lead level of 1500 ppm was found in one of them. Furthermore, four other main pollutant sources contributing to the lead contamination in the Shanghai atmosphere were clearly identified by this method. They are the cement industry, the coal combustion, the oil combustion, and the metallurgic industry. Some other unidentified particles suggested that some more lead emitters might also exist in Shanghai.

The high-energy ion nanoprobe LIPSION at the University of Leipzig has been operational since October 1998. Its magnetic quadrupole lens system, arranged as a separated Russian quadruplet, has been developed by the Microanalytical Research Centre (MARC), Melbourne. The ultrastable single-ended 3.5 MV SINGLETRON™ accelerator (High Voltage Engineering Europa) supplies H+ and He+ ion beams with a beam brightness in the range of 10–20 Arad−2m−2eV−1 [D.J.W. Mous, R.G. Haitsma, T. Butz, R.-H. Flagmeyer, D. Lehmann, J. Vogt, Nucl. Instr. and Meth. B 130 (1997) 31]. Due to this high brightness, the excellent optical properties of the focusing system of the nanoprobe and the suppression of mechanical vibrations, lateral resolutions of 100 nm for the low current mode (STIM) and 340 nm at a current of 10 pA (PIXE, RBS, SEI modes) were achieved. Further improvements are expected.

The channeling technique is an interesting and powerful tool for the determination of impurity lattice sites in single crystals, Since the investigation of light impurities in heavy matrices using the Rutherford backscattering spectrometry/channeling technique is often very difficult or impossible, the combination of particle induced x-ray emission (PIXE) with the channeling effect is an important alternative, Experimental results for various impurities in cubic and non-cubic crystals are presented to show the feasibility of the method, In order to permit the quantitative analysis of such PIXE/channeling data, the computer code CASSIS was developed and successfully applied, Copyright (C) 1999 John Wiley & Sons, Ltd.

The influence of the dry etching process parameters on the ion induced damage profile was investigated by nitrogen ion beam etching (IBE) of AlGaAs at two different ion energies by spatial resolved confocal photoluminescence (PL) measurements on specially prepared beveled sections of Al 0.35 Ga 0.65 As/GaAs MQW structures. The results reveal that the extension of the defect profile is not proportional to the energy of the nitrogen ions, i.e. the lower ion energy leads to a higher defect profile deep in the materal. The difference in both defect profiles can be explained by the different etching rates and defect diffusion coefficients. The high-energy etching leads to a higher defect concentration at the surface measured by RBS/channeling and in accordance with a simple model calculation.

This paper describes investigations using the Particle Induced X-ray Emission method (PIXE) to evaluate the concentration of Ca together with that of other elements (S, Cl, and K) across the articular cartilage of domestic pigs in order to verify a putative influence of calcium on the structural changes in early arthrotic stage, derived from NMR microscopic imaging. The measurements were carried out with focused ion beams of a lateral resolution down to 20 μm. The main matrix components (C, N, O) were evaluated from proton backscattering spectra.

At the Rossendorf nuclear microprobe facility, a beam of protons with MeV energy was used to analyse ancient human bones of the Merowingian period (6-8th century AD), Emitted X-rays were detected to determine the elemental composition of the bones and to estimate the influence of the burial environment on the elemental content of the skeletons, In cross sections of human femora, a different behaviour of the radial distributions of the main and trace elements like P, Ca, Mn, Fe, Zn, Br, and Sr was observed using lateral-resolved mu PIXE. This result indicates post mortem mineral exchange processes and diagenetic alteration during burial of bone tissue in soil. (C) 1998 Elsevier Science B.V.

In order to study the intercalation process of Hg into the layered crystal TiS2 we performed Rutherford Backscattering (RBS) and channeling experiments on TiS2 and on the intercalation compound HgxTiS2 with variable Hg uptake. After the intercalation of Hg in TiS2 we observed a clear Hg-signal in the RBS-spectrum, increasing with reaction time and temperature. The variation of the Hg RBS-signal depending on the lateral position of the analysing beam cannot be explained by vertical reaction fronts or by a spatially homogenous intercalation process. We conclude from these measurements that the intercalation process proceeds parallel to the TiS2 layers in concave reaction fronts. The empty TiS2 crystal exhibits a good channeling effect (χmin ≈ 20%). Owing to Hg uptake, however, the ion channeling effect in the “misfit compound” HgxTiS2 vanishes. We attribute this to the incommensurability of the Hg and TiS2 sublattices as well as to a bending of the crystal induced by the intercalation process.

Confocal photoluminescence (PL) spectroscopy on an Al0.35Ga0.65As/GaAs multiple quantum well (MQW) structure has been utilized to study the damage depth profile induced by the ion beam etching (IBE) with argon and nitrogen. A high depth resolution of almost 2 nm has been achieved with this method using a MQW structure with monolayer thickness, a beveled sectioning technique with small inclination angles in the range of 1×10−3 deg. resulting in a high stretching of the material depth along the beveled surface and spatially resolved confocal PL measurement. It is shown that the nitrogen IBE process causes significantly less loss on QW PL yield, and thus a lower defect concentration profile compared to the argon etching process. A model including diffusion effects was used to interpret the experimental results and yields a value for the defect diffusion coefficient of ∼4×10−15 cm2/s and ∼12.3×10−15 cm2/s for nitrogen- and argon-etched samples, respectively. For the determination of the near surface amorphization we carried out RBS/Channeling measurements.

Proton backscattering spectrometry, Rutherford backscattering spectrometry, proton induced X-ray emission, and proton induced Gamma-ray emission as well as X-ray fluorescence analysis were applied to analyse major and trace elements of bones of two Merowingian populations (8(th) century AD). Hereof, together with quantitative digital radiography which gives the bone mineral density, we expect to obtain more information about our ancestors. As a region of special interest the femur neck (Collum femoris) was investigated to determine the bone mineral content and the Ca/P-ratio. In order to estimate the influence of the burial environment radial distributions of element concentrations of cross sections of the femur shaft (Corpus femoris) were recorded by lateral-resolved PIXE and PIGE.

Recently, HVEE has completed a novel 3.5 MV single ended accelerator (Singletron™) for the University of Leipzig, Germany. For one of the main applications, the system will be connected to a nanobeamline to achieve submicron resolution. Because the energy stability and ripple of the beam, and beam brightness are of vital importance for the performance of a nanoprobe, special care has been taken in optimizing these parameters. The system consists of an RF source which is directly mounted on the accelerator tube, a switching magnet to bend the beam into a chamber for standard analysis purposes and an analysis magnet that directs the beam into the nanoprobe. The stability of the beam energy was measured at a terminal voltage of 1.881 MV. These measurements were taken during factory acceptance with large production equipment operational, which negatively influenced the stability of the mains. The measured stability was found to be approx. ±50 eV over 5 h, but it is anticipated that this figure will be as good as ±20 eV (i.e. ∼ 10−5) under normal laboratory conditions. The terminal voltage ripple was measured at 2.25 MV to be 25 Vpp (i.e. ∼ 1.1 × 10−5). Finally, the beam brightness of a 2.25 MeV hydrogen beam was measured by the use of two micrometer slit systems. A brightness of approx. 18 Amps · rad−2 m−2 eV−1 was obtained. In this article we will describe the considerations which have led to the layout of the present system.

In this contribution the compilation of data on high energy ( > 1 MeV) ion microprobes (lateral resolution < 50 mu m) prepared for ECAART-4, 1995, is analyzed statistically in order to provide an overview over existing installations, technical details, and research activities, possibly indicating future trends.

Quantitative digital radiography, ion beam methods, and Xray fluorescence analysis are combined for the determination of bone mineral density and the analysis of major and trace elements of two Merowingian populations. Radial distributions of element concentrations are recorded to estimate post-mortem mineral exchange processes.

Zn ions with energies of 1.2 and 2.5 MeV were implanted into InP with the intention of producing p-conducting buried layers. In order to minimize the implantation-induced damage a priori an elevated sample temperature of 200 degrees C was chosen. The implanted samples were annealed using Rapid Thermal Annealing (RTA) at 750 degrees C. Because often a diffusion of implanted accepters into the bulk occurs during thermal treatment, the Zn profiles were studied for different annealing times using SNMS. Fur annealing times greater than 40 s a strong broadening of the Zn profile was observed. For a better understanding of these transport phenomena, the lattice sites occupied by the Zn atoms after implantation and after annealing were investigated, It is demonstrated that the combined use of SNMS, pIXE/RBS/channelling, and Hall effect measurement results in more quantitative information about the incorporation of Zn into InP. From the comparison of calculated with experimental PIXE channelling yields it is shown hat, after implantation, nearly all Zn atoms occupy substitutional In sites. As a result of RTA. the substitutional Zn fraction decreases and Zn atoms appear partly on tetrahedral and partly on randomly distributed interstitial sites. Differential Hall effect measurements pave hints that the remaining substitutional Zn is completely electrically active.

A new dedicated high energy ion nanoprobe will be installed at Leipzig University, Germany. We describe the concept and layout.

Zinc implantations in the MeV energy regime at temperatures of about 200°C within the dose range of 5 × 1014–1 × 1016 cm−2 were carried out. The investigations included RBS and PIXE measurements combined with ion channeling in the major crystallographic axes and additionally SNMS and XTEM. The implantation-induced damage is characterized by mobile point defects at the elevated implantation temperature. This results in damaged layers containing point-like defects, but far from amorphization. During rapid thermal annealing the surface up to about 0.6Rp recovered channeling-perfect, while in a depth of (1–2)Rp a band of extrinsic dislocation loops was formed. Comparing the experimental with the calculated PIXE minimum yields, conclusions about the zinc positions were drawn: Due to the low ZnK aligned yield nearly all zinc atoms occupy substitutional lattice sites in the as-implanted samples. After annealing a remarkable diffusion of zinc combined with lattice site changes is observed.

The high-energy Zn+ ion implantation of InP is a promising method for the formation of buried p-type conducting layers. Defect properties and inclusion mechanism of zinc implanted samples with energies of 1.2 and 2.5 MeV to doses of 5 × 1014−5 × 1015 cm−2 at a temperature of 200°C were investigated with ion beam methods, XTEM and SNMS to some extent. Also the influence of rapid thermal annealing on the structural properties was studied. After implantation we found no evidence for amorphization or extended defects but point-like defects. During annealing the surface region recovered nearly completely while in depth the point-like defects agglomerated in dislocation loops. Further we observed a remarkable redistribution of the Zn atoms due to annealing.