Aim of this project is to (i) proof and (ii) quantify the thickness of possible oxide layers on Cu and CuAl systems. The experiments are planned within a large scale micromechanical investigation on dislocation nucleation at coherent twin boundaries, performed at the Max-Planck-Institut für Eisenforschung. So far, using nanoindentation, we have shown that grain boundaries might act as frequent sources of dislocations. However, to ultimately proof this we need to proof the absence of surface oxides.

We investigate bacterial iron acquisition, the role of siderophores, and the role of ionophores.

Funded by: Deutsche Forschungsgemeinschaft

Our research group is expert in Hybrid Quantum Devices where spins in solids are coupled to superconducting quantum circuits. We use these devices for quantum computing applications; in particular we develop spin-based quantum memories for microwave photons. For this application, we need implantation of Bismuth atoms in a silicon substrate. The Bismuth atoms when cooled at low temperature form donors, whose electron spin has a very long coherence time. Therefore, in this project, we will provide silicon substrates (isotopically enriched in the nuclear-spin-free Si28 isotope), and we request implantation of bismuth ions from Rubion.

A burried graphite layer to serve as a gate for a FET should be produced by the implantation of carbon in diamond with an energy of 100 keV to open the possibility to stabilize and manipulate single NV centres.

We aim to study the catalytic release of different fluorescent dyes in B. subtitles bacteria. The bacterial cells shall be incubated with different dyes, which are non-fluorescent as they are in a protected state. Upon addition of a Ruthenium compound as catalyst the fluorescent dye will be released. Fluorescent intensity is to be determined over a time course of 24 h. In order to apply different concentrations and different dyes, the plate reader from Prof. Bandow's group will be used. Potentially, these studies will also be carried out in life cells under a fluorescent microscope.

Funded by: None / internal funds from RUB

ATPases are integral membrane proteins that play a pivotal role in cell homeostasis by pumping substrates as diverse as ions and lipids. Although several members of this group are well-studied, many molecular details involved in their working mechanism and regulation on the molecular level still remain unsolved. In combination with transporter mutants we expect to gain a molecular understanding of how ATP, pH, the ion concentration, and the lipid environment regulate these transporters.

The chemistry of organic, functional coatings will quantitatively be analyzed. This concerns coatings prepared by grafting from as well as by grafting to approaches. Also polymer coatings with different crosslinking mechanisms will be investigated by element sensitive chemical analysis. The coatings are at a later stage tested in our research group regarding their low-fouling properties and the results from surface analysis will be correlated to protein attachment and biofouling assays.

The properties of transition metal nitrides (TM-N) strongly depend on their chemical composition (e.g. TM/N ratio) and density. Both, density and composition are affected by synthesis parameters (e.g. temperature, plasma properties). Transition metal nitrides were synthesized by magnetron sputtering using sets of different process parameters. Mechanical properties like Young’s modulus and hardness are determined by nano indentation and residual stress is evaluated by curvature method. The aim of the project is to identify relationships between synthesis parameters, composition and density and mechanical properties. The project is part of the collaborative research center SFB-TR 87.

14C-labelled substrates or nutrients and combinations will be added to the moist soil samples after a 10-day pre-incubation period. The incubation will be conducted in a CarbO2Bot® instrument which allows temperature control and records CO2 evolution from the samples through changes in electric conductivity in an alkaline solution. After certain time intervals, the solution is replaced by a fresh one and the evolved 14CO2 is determined in a scintillation counter (Perkin Elmer Tri-Carb 2800 TR). In this way, the substrate-borne CO2 can be differentiated from the SOC-borne CO2 and priming effects are calculated by subtracting the CO2 evolved from an unsupplemented control sample (Hamer and Marschner 2005). Enzyme activities will be determined in soil suspensions to which fluorogenic substrates (MUF, AMC) are added in a 96 well microplate assay as described by Marx et al. (2001).

The transport of H in glasses at relatively low temperatures (below 200 °C) is relevant for a number of applications such as obisidian dating of archaeological artefacts, palaeoclimate studies, storage of high level nuclear waste and many more. We have developed several new experimental aspects, and in particular (a) the ability to produce H-bearing amorphous thin films to act as a source of H without the presence of free H2O, and (b) the ability to measure low concentrations of H, independent of the speciation, with a high spatial resolution on the nanometer scale. In this project it is intended to use these developments to explore the diffusion of H-bearing species at conditions that have been inaccessible so far. A specific goal is to characterize the compositional dependence of H-diffusion at these conditions and understand the change of diffusion mechanism that leads to a different behaviour from those observed at higher temperatures.

Funded by: DFG, DFG

The generation of NV centers in diamond is an essential task of quantum technology. NV centers can be used as qubits in quantum computers. For this task it is necessary to address single NVs and to generate them deterministically. The latter is not yet possible and should be the subject of this investigation. It should be clarified whether near-surface nitrogen diffuses. For this purpose, high-purity diamonds are irradiated with 15N, annealed at high temperature and investigated at the University of Munich with ERDA. A complimentary investigation with protons 15N(p,gamma) in Bochum would also be very helpful.

The continuous improvement of analytical techniques led to the finding that minerals, which were once thought to be water-free (nominally anhydrous minerals), can indeed incorporate substantial amounts of water in their atomic structure. This observation changed fundamental aspects of our geodynamic models. The detection of water in minerals that are part of mantle xenoliths is one example. This information is interpreted to be evidence for a "wet mantle". To better understand the entity of the geologic water cycle in our earth it is necessary to quantify the transport rates of hydrogen in various phases in dependence of intensive variable (e.g. temperature). In this project we study the diffusion of hydrogen in minerals specifically at low temperatures using hydrogen implantation and NRRA.

For many accelerator applications, precise knowledge of the ion beam energy is required. For the tandem accelerator at RUBION, this applies in particular to the methods of ion beam analysis and modification of materials. There are currently indications that there are deviations from the actual ion energy. The energy E of the ions from the accelerator is determined and controlled via the magnetic field B of the analysing magnet. The magnetic constant for the relationship between E and B was last determined in 1995. The aim of the project is to redetermine the magnetic constant as part of a new energy calibration. For this purpose, measurements of the reaction yields of resonant reactions are used, which result in each case in an assignment of the B field with the known resonance energy. Various reactions will be selected to cover a broad spectrum of the B field. Measurements are thus carried out with various ion beams and targets. A wide variety of measuring setups and detection systems are used.

The surface of asteroids and planets, with no atmosphere and a strong magnetic field, in the Solar System (e.g. Moon, Mercury) is impacted by energetic (~1 keV/nucleon) solar wind ions. The solar wind consists of 95% protons, 2-4% He++, and the rest heavy ions. The interaction of ions with minerals, present on the surface of planets and asteroids, changes the structure and chemical composition of the upper few nanometers of the mineral surface and this leads to changes in the optical properties (UV, VNIR) of the material. Since optical spectroscopy is generally used to characterize the surface composition of solar system bodies, it is important to understand the mechanism and products of interaction between ions and minerals. Here, I propose to experimentally implant 40-60 keV Ar++ ions (Fluence: 1e16-1e18 ions/cm2) into thin slices of minerals (e.g. olivine, pyroxene) crystals and pressed powder pellets. After irradiation the samples will be studied using FIB and TEM.

Single group-IV defects in diamond are attractive spin qubits with outstanding optical properties, which make them unique for the realization of efficient long-distance entanglement protocols. Particularly, silicon-vacancy (SiV) and germanium-vacancy (GeV) defects are spectrally stable and possess a high Debye-Waller factor (~70%). However, SiV and GeV have a short spin coherence time at 2 K and require cooling to a few tens of millikelvin to prolong it. On the other hand, group-IV defects based on heavier elements Sn and Pb are expected to have long spin coherence time already at 2 K, preserving nearly ideal optical properties. Therefore, engineering these defects is a highly desirable task. In this project, we plan to fabricate the PbV defects in diamond using the implantation of lead ions at different energies and investigate their optical and electron spin properties.

Pyroxenes are common minerals in a wide range of magmatic rocks. Diffusion chronometry using major and trace element zoning in pyroxenes is being increasingly used in the last decade but this approach is hampered by the incomplete availability of diffusion data. New experimental and analytical developments for sample investigations on the nanoscale now allow the urgently needed diffusion data for diffusion chronometry to be precisely measured. In our novel experimental approach we will combine pulsed laser deposition for the preparation of thin-film diffusion couples and samples will be investigated using various analytical methods on the nm-scale. RBS will be used to measure the Fe diffusion profile. This research project is a sub-project of a research unit of the DFG (FOR2881).

Funded by: Deutsche Forschungsgemeinschaft

The project addresses the focused ion beam implantation of metal ions from the rare earth group into semiconductor nanostructures. In particular, we focus on the incorporation of erbium ions (Er3+) into gallium arsenide (GaAs). The optical transitions of the erbium should lead to an emission of electro-magnetic radiation at a wavelength of 1.54 µm. To better quantify the optical investigation of this emission, it is crucial to qualitatively and quantitatively verify the incorporation of the erbium into GaAs after implantation. For this purpose, highly sensitive analytical methods will be used at RUBION. Among other methods, elemental analyses will be carried out with the help of PIXE. Other research in this field has shown that the luminescence of erbium can be increased by additional implantation of further elements. For this purpose, oxygen is implanted over the surface of the GaAs:Er samples and the luminescence is then investigated.

Nanodiamonds are biocompatible nanoparticles, which can be functionalized by manifold surface modifications. Therefore, they are an excellent candidate for biomedical and even therapeutic applications. Here we aim at developing nanodiamonds labeled by different lattice modifications, such that they are detectable by various techniques, from microscopy and radiography to magnet resonance imaging. Modifying the nanodiamond lattice instead of its surface ensures that the nanoparticle and its label do not dissolve in physiologic environment. Additionally, it does not alter its interactions with the environment and hence the biocompatibility of the nanoparticle is preserved. A nanoparticle that is not detectable due to surface but to lattice modifications for the first time allows comparable investigations from the subcellular to organism level, eventually leading to the development of nanodiamond based tools for biomedical and therapeutic applications.

Funded by: VolkswagenStiftung

For experiments at the superconducting cyclotron at the Laboratory Nazionali del Sud of the INFN in Catania He4 targets are prepared by He implantation into thin aluminum foils. The goal is to have a high He concentration in foils as thin as possible. The foils will be characterized by RBS with protons.

In order to produce group IV elements based colour centres in diamond, samples are prepared using high implantation energies. The aim is to have these centres situated deeply (>50nm) in the diamond to minimize the impact of charge fluctuations at the surface. The characterization afterwards is performed optically by looking at the homogeneity of different emitters emission wavelength and coherence properties.

Molybdenum Compunds, MoS2 and Mo(2)C are promising new catalysts for electrochemical applications, e.g. water electrolysers. It is planned to study several aspects of hydrogen dynamics in these materials using neutron scattering (ILL Grenoble), electrochemical spectroscopy (WH Recklinghausen) and nuclear reaction analysis (present proposal): hydrogen sorption, fast hydrogen diffusion under reaction conditions, hydrogen modes and substrate phonons as well as ortho-para-conversion of hydrogen on cold catalyst surfaces. Model systems of bulk materials, pure powder samples and electrochemical electrodes will be used. The expected results of these studies are diffusion parameters (binding sites, pathways, activation energies), and key parameters of structure and dynamics of the active surface. Since hydrogen sorption and the motion of several hydrogen species are involved, hydrogen concentrations profiles are required for the full interpretation of the neutron scattering results.

Funded by: Institut Laue-Langevin, Doktorandenstipendium

In this project we would like to implant Ni into ultrapure as well as p-doped synthetic diamonds to create a class of inversion-symmetric Ni defects, the nickel vacancy center (NiV), which so far hasn't been studied in great detail. Theoretical investigations and preliminary experiments suggest that the NiV could offer electronic properties excelling those of the known color centers such as NV and SiV and the defects might therefore be of great interest for quantum technologies. We will use the samples fabricated at RUBION to perform optical spectrocopy experiments at high-resolution to validate the theoretically predicted electronic structure of the defect on an ensemble and single-defect level.

Space weathering involves solar wind implantation of elements, such as hydrogen, in planetary materials. Thus, it is crucial to study this process in order to evaluate its impact on the hydrogen budget of planetary bodies. We implant different amounts of hydrogen (fluences) in olivine at different energies to study at which fluence hydrogen saturation in this mineral is attained. This project is a collaboration with Shun-ichiro Karato, Jiang Zhenting, and Qinting Jiang of the Yale University.

Interactions between microbial activities and hierarchical aggregation in soil carbon and nutrient retention: analysis of organic fertilization practices for sustainable production of vegetable crops in West-Africa I intend to carry out a 18-week incubation experiment with 220 bulk/aggregate soil samples using a temperature controlled respirometer which automatically records carbondioxide evolution from the samples through changes in electrical conductivity in an alkaline solution.

The work includes material development and structural Layering of perovskite for electroluminescence and laser applications. Different layer formation procedures such as pure liquid phase processes, pure vacuum deposition, as well as hybrid deposition processes are demonstrated. The work aims to study and optimize luminescence quantum efficiency and optical amplification and to understand the relationship between composition / structure and optical amplification. And then, selected materials are integrated into electroluminescent devices.

One major nuclear-physics uncertainty for the prediction of branching points in the γ-process reaction network is the α+nucleus optical model potential at sub-Coulomb energies. To improve the scarce experimental database of α-induced reaction cross sections, our group is interested in measuring the (α,γ) cross sections on ruthenium isotopes via the 4π-summing method at RUBION. We plan to measure the cross section at alpha energies from 12 MeV down to ca. 7 MeV.

With the tandem accelerator at RUBION, samples are examined for their hydrogen concentrations using the 15N(p,αγ)12C method. Concentrations in the range of a few 100 at. ppm can be determined with a certain amount of effort. The limiting factor when measuring materials of low concentrations, such as NAMs (normal anhydrous minerals), is the signal-to-background ratio in the measured gamma-ray spectra. Within the framework of this project, in a first step investigations should be carried out that provide quantitative information on the different proportions of the background. The aim of the next step is a reduction of background proportions. Finally, measurements of samples with different low concentrations should quantify the detection limit for the determination of hydrogen concentrations using the 15N(p,αγ)12C at RUBION.

MnSb is a promising candidate for efficient spin injection into GaAs structures, which has a high Curie temperature and is compatible with the III-V lattice structure. The influence of different growth parameters on the formation of nanoclusters and their properties such as size, shape, density and magnetic behavior will be investigated. The aim of the project is to use RBS to investigate the influence of growth parameters on the chemical composition of nanostructures.

This practical lab course is part of the Master studies of Biochemistry and iSTEM.

Fourier Transform Infrared (FTIR) Spectroscopy is a frequently used technique for measuring water species in geological materials. However, the method has to be calibrated for each type of mineral or glass. We use the "standard-free" NRRA technique to analyse hydrogen depth profiles, which can then be used to calibrate methods such as FTIR or SIMS. This project is a collaboration with Prof. Jörg Hermann and Julien Reynes of the Geological Department of the University Bern.

Advanced practical experiments at the accelerators for students from the Ruhr University Bochum and Paderborn University.

In the course of this project cell cultures will be obtained from postnatal rats. These cultures primarily composed of neurons and astrocytes will be treated with growth factors or other proteins and factors that are capable of modulating neuronal excitability. Our aim is to test the hypothesis that an increased excitability in neurons also leads to an upregulated expression of Na+/K+-ATPase. We use Tritium-labeled ouabain which selectively binds to the Na+/K+-ATPase to determine the density of this enzyme in the cell membrane.

We are currently investigating the deposition of metal oxide thin films by chemical vapor deposition processes (CVD) using partially fluorinated metal acetylacetonate complexes. We are particularly interested in the relationship between the degree of fluorination of the precursor complex and the degree of F-doping of the resulting metal oxide filmt (CoO and Co3O4). A correlation was already confirmed by TOF-SIMS but couldn't be quantifized. For quantification of the F-doping as well as the metal-to-oxygen relation and to further investigate the degree of N-doping from the precursor awe are intersted in RBS and DNRA measurements.

In vitro transcription with radioactive labeling

As a part of the advanced module "Gen, Cell, Organism" students practise the characterization of intracellular steroid hormone receptors in tissue samples of vertebrates.

Using radiolabeled precursors in incorporation experiments, we analyze the antibacterial mechanism of action.

Funded by: BMBF, NIH

The amount of Ti incorporated in quartz (SiO2) is dependent on the temperature of formation. Therefore, Ti in quartz from natural rocks can be used as a geothermometer. Electron microprobe analysis can be used to quantify the amount of Ti in quartz, but as a low accuracy of such measurements would result in erroneous temperature estimates, secondary quartz standards with known Ti contents are needed. Such standards do not yet exist. This project is aimed at producing six standards with defined Ti content (10 μg g-1, 50 μg g-1, 100 μg g-1, 250 μg g-1, 500 μg g-1, and 1000 μg g-1) by means of ion implantation. Rutherford Backscattering Spectrometry should be used for chemical depth profiling before homogenizing the newly produced materials by heating. Finally, these secondary standard materials will be used for data verification during microprobe measurements of high-temperature metamorphic rocks.

A 12C Target for Nuclear Astrophysics purposes will be produced by implantation with energies between 30 and 50 keV at the 100 keV implanter

We use pulse-labeling to investigate the proteins newly synthesized in response to stress, e.g. antibiotic treatment.

Funded by: BMBF, Deutsche Forschungsgemeinschaft, National Institutes of Health, EFRE, Investing in your future, NRW, DAAD

PANI/Au atomic metal clusters are prepared by the method of Jonke et al. [1]. It was shown before that these structures exhibit the odd/even effects characteristic of atomic Au clusters in the range of one to six Au atoms. In order to understand the formation mechanism, extensive characterization by RBS is required. [1] Jonke et al 2012 J. Electrochem. Soc. 159 P40

VO2 is of interest due to its Semiconductor-to-Metal phase transition. Elmental addition can modulate the transition properties of VO2. To systematically study the effect of elemental doping, V-M-O thin film libraries with continuous composition spread are fabricated by magnetron reactive co-sputtering. The concentration of dopant (M) will be determined by Rutherford backscattering spectrometry (RBS). In addition, it has been reported that the stoichiometry of VOx, e.g., the ratio of oxygen to the metals, can also influence the transition properties. To estimate the amount of oxygen, Nuclear reaction analysis (NRA) will be performed on the libraries.

Funded by: DFG, DFG

At the Tandem Accelerator Laboratory of the University of Cologne experiments ar performed in the fields of Nuclear Structure and Nuclear Astrophysics. For the data analysis it is mandatory to know the exact composition and thickness of the targets. From previous measurements we know that the RBS setup ab RUBION is ideally suited for such studies.

Funded by: DFG

The project aims at the realization of single photon sources in the telecom wavelength regime, based on single rare-earth ions (like erbium or ytterbium) precisely doped into optical crystals by means of ion implantation (up to 200nm below the surface). The main advantage of the proposed single photon sources are their true single photon emission, their fourier-limited linewidth and the ability to store emitted photons directly in a medium based on rare-earth ions (straight forward interfacing). The typically low fluorescent signal of single erbium/ytterbium ions can be boosted by orders of magnitude through coupling them to optical resonators (fabricated from thin film lithium niobate) with high Q factors. The single photon source behaviour will be assessed by the indistinguishability of the emitted photons in a Hong-Ou-Mandel experiment.

Funded by: European Commission

In order to investigate, whether cryopreservation invokes changes in the membrane of neural cells, roughness measurements using scanning ion conductance microscopy are performed.

The genus Penicillium represents a large number of important fungal species, which have significance for applied microbiology. However, little is known about their developmental features related to sexual reproduction. Furthermore, the observation that the regulatory function of mating-type locus (MAT)-encoded transcription factors (TFs) extends far beyond the control of sexual processes points to their particular biotechnological relevance. Therefore, the analysis of MAT-controlled cellular and developmental functions represents a promising research approach. Beyond the characterization of MAT TFs, gene regulatory networks controlled by MAT proteins in different Penicillium species are of interest. We intend to gain insight into the functional and mechanistic properties of MAT-TFs in order to understand their cooperative interaction with DNA and other proteins. Therefore, we will address the following questions: a.) What factors do MAT-TFs interact with at the protein level? and b.) What is the X-ray structu

Spatio-temporal analyses of soil properties are important for more profound insights into soil processes. Up to now, non-invasive approaches analyzing physical and biological soil properties and dynamics at the microscale are not available due to methodological, instrumental, and analytical challenges. In this study, we evaluate the use of active and passive infrared thermography (IRT), a non-invasive and non-contact technique, for the detection of surface temperature-based parameters on soil surfaces. The potential and possibilities of IRT were analyzed with a focus on the detection and calibration of soil moisture using active IRT and the determination of microbial activity using passive IRT. A pool of 51 soil samples was used to cover a wide range of chemical, physical, and biological soil properties. The samples were rewetted to 16 different moisture contents, filled into vessels, and placed in an air-proof glove box with an adjusted relative humidity of about 92% to reduce soil drying. Immediately after

Thin film refractory metamaterials for high-temperature application are prepared by magnetron sputtering and characterized by non-ambient x-ray diffraction. An interesting candidate is a multilayered structure of metallic tungsten and dielectric hafnia. During annealing we observed structural changes of the obtained phases which require a confirmation with further methods. It is planned to carry out RBS and XPS measurements of three different sub-units (3-layer-stacks: as prepared and after two different annealing temperatures).

The biogenesis of photosynthetic protein complexes of the chloroplast thylakoid membrane requires highly specific protein sorting, integration and assembly mechanisms of nucleus as well as plastid encoded subunits. Central steps in the biogenesis of photosystem II (PS II) are the cotranslational insertion of the plastid encoded D1 protein into the thylakoid membrane and its subsequent assembly into functional PS II. We recently established a technique to partially reconstitute the cotranslational insertion of [35S]-D1 using a homologous in vitro translation system derived from pea chloroplasts. The aims of this proposal are (I) to identify novel components involved in cotranslational protein insertion in thylakoid membranes, (II) to dissect the protein contacts of the nascent D1 chain during translation and insertion and (III) to get insight into the mechanisms underlying targeting and attachment of ribosome-nascent chain complexes to the thylakoid membrane.

Funded by: Deutsche Forschungsgemeinschaft

We will quantify uptake rates of radioisotopes of various mineral nutrients and/or their toxic analogues into roots of Arabidopsis or into plant gene-expressing cells. We will measure the incorporation of radiolabelled organic and inorganic substrates into endogenous metabolites and/or macromolecules of plant cells, organs and/or cells of heterologous expression systems. We will localize various elements of interest in sections of plant tissues by imaging using Particle Induced X-Ray Emission (PIXE) combined with Rutherford Backscattering Spectrometry (RBS) comparatively between wild type and mutant/transgenic plants. We will conduct live cell imaging of plant cells expressing suitably marker proteins using the Olympus IX 81 live cell imaging microscope with the goal of determining protein localization and its dynamics. It is possible that it might be necessary to apply STED super-resolution fluorescence imaging to answer our research questions.

This "project" covers a conglomerate of activities that entail the use of infrastructure of the Bandow lab that is located at RUBION, but does not entail work with unstable isotopes.

II-VI compound forms predominantly cubic crystallographic structures. Ternary compound with a different atomic ration of magnesium, manganese and beryllium gives us the opportunity to change compound bandgap and lattice constant. Sets of (Zn,Mg)Se (Mg at.% ~5%) and (Zn,Mn,Be)Se (Mn at.% ~5%, Be at.% ~5%) crystals grown by modified Bridgman-Stockbarger method can be implanted with transition metals (TM) elements to check the influence of the crystal field of host material to energy levels of d-electrons. Additionally, optical constants (refractive index, extinction coefficient) can be modified selectively when implanted with TM due to split in spectroscopic terms. Chemical composition of obtained samples can be checked with XPS and PIXE methods. Host damage caused by ions implantation and electrical properties of implanted II-VI crystals are also important concerns.