Publikationen Rasterionenmikroskopie (Materialanalytik)

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2018

Physics at the Munich Tandem Accelerator Laboratory
G. Dollinger and T. Faestermann; Nuclear Physics News 28 (1) (2018) 5-12.
Abstract: The Tandem accelerator situated in Garching, just 20 km north of Munich, is of the “Emperor” (MP) series manufactured by High Voltage Engineering Corporation (HVEC). It delivered the first beams for experiments in 1970 and came close to its design voltage of 10 MV. In 1991 the tubes were exchanged to the extended version of HVEC. Routine operation at a terminal voltage of 14 MV was then possible.
BibTeX:
	@article{Dollinger2018,
	  author = {Günther Dollinger and Thomas Faestermann},
	  title = {Physics at the Munich Tandem Accelerator Laboratory},
	  journal = {Nuclear Physics News},
	  publisher = {Taylor & Francis},
	  year = {2018},
	  volume = {28},
	  number = {1},
	  pages = {5-12},
	  url = {https://www.tandfonline.com/doi/full/10.1080/10619127.2018.1427405},
	  doi = {https://doi.org/10.1080/10619127.2018.1427405}
	}
	
Physics at the Munich Tandem Accelerator Laboratory
G. Dollinger and T. Faestermann; ArXiv (v2) (2018) .
Abstract: This review reports on the science performed in various fields at the Munich tandem accelerator during the past decade. It covers nuclear structure studies, also with respect to astro- and particle physics as well as for the understanding of fundamental symmetries, the extremely sensitive detection of long-lived radionuclides from Supernova or r-process production with accelerator mass spectrometry and studies of the elemental composition of thin films with extreme depth resolution and sensitivity by elastic recoil detection (ERD). The ion microbeam is used for 3D hydrogen microscopy as well as in radiobiology to study the response of living cells on well-defined irradiations. In medical research new therapeutic methods of tumour irradiation are tested using proton minibeams as well as the determination of ion ranges in tissue with iono-acoustics. Primary and secondary beams from the accelerator are also used for development and testing of detector components in large setups, e.g. at the LHC, and for testing new kinds of fuel materials of high uranium density to use them as medium enriched fuels at the Munich research reactor FRM II in the future.
BibTeX:
	@openaccess{Dollinger2018a,
	  author = {Günther Dollinger and Thomas Faestermann},
	  title = {Physics at the Munich Tandem Accelerator Laboratory},
	  journal = {ArXiv},
	  type = {OpenAccess},
	  year = {2018},
	  number = {v2},
	  url = {https://arxiv.org/abs/1802.07057}
	}
	
Hydrogen concentration analysis in clinopyroxene using proton--proton scattering analysis
F.A. Weis, L. Ros, P. Reichart, H. Skogby, P. Kristiansson and G. Dollinger; Physics and Chemistry of Minerals 45 (2018) 669-678.
Abstract: Traditional methods to measure water in nominally anhydrous minerals (NAMs) are, for example, Fourier transformed infrared (FTIR) spectroscopy or secondary ion mass spectrometry (SIMS). Both well-established methods provide a low detection limit as well as high spatial resolution yet may require elaborate sample orientation or destructive sample preparation. Here we analyze the water content in erupted volcanic clinopyroxene phenocrysts by proton--proton scattering and reproduce water contents measured by FTIR spectroscopy. We show that this technique provides significant advantages over other methods as it can provide a three-dimensional distribution of hydrogen within a crystal, making the identification of potential inclusions possible as well as elimination of surface contamination. The sample analysis is also independent of crystal structure and orientation and independent of matrix effects other than sample density. The results are used to validate the accuracy of wavenumber-dependent vs. mineral-specific molar absorption coefficients in FTIR spectroscopy. In addition, we present a new method for the sample preparation of very thin crystals suitable for proton--proton scattering analysis using relatively low accelerator potentials.
BibTeX:
	@article{Weis2018,
	  author = {Weis, Franz A. and Ros, Linus and Reichart, Patrick and Skogby, Henrik and Kristiansson, Per and Dollinger, Günther},
	  title = {Hydrogen concentration analysis in clinopyroxene using proton--proton scattering analysis},
	  journal = {Physics and Chemistry of Minerals},
	  year = {2018},
	  volume = {45},
	  pages = {669-678},
	  url = {https://link.springer.com/article/10.1007%2Fs00269-018-0953-2},
	  doi = {https://doi.org/10.1007/s00269-018-0953-2}
	}
	

2017

3D Hydrogen Microscopy at the Munich Proton Microprobe SNAKE
Marcus Moser; Dissertation, Universität der Bundeswehr München, 2017.
Abstract: The coincidence analysis of proton-proton (pp) scattering events from a MeV proton microprobe is an unique method for 3D hydrogen microscopy, where sub-ppm atomic sensitivity is achieved in light materials with μm depth and lateral resolution using 17 MeV protons. Up to 25 MeV protons can be used with a new detector system at the Munich microprobe SNAKE. Hence, the analysis of unsupported samples with high mass density or large thickness up to e.g. 50 μm tungsten, 150 μm silicon or 250 μm plastics becomes possible. At these energies, new challenges arise and are solved in this thesis for the dedicated setup at the Munich Tandem accelerator: (1) The optimum beam brightness and stability is required in particular for μm lateral resolution in large depth as well as for meeting reasonable measurement times. Therefore, a new multicusp ion source has been installed at the 14-MV Tandem accelerator with the brightness of up to B = 27 μAmm-2mrad-2MeV-1 at the space charge limit of 30 kV extraction potential. Beam transport calculations are performed and reveal the limits due to the Tandem accelerator stripper foil in conjunction with the intrinsic astigmatism and possible parasitic in uences on Bmax = 23.5 μAmm-2mrad-2MeV-1. It brings up the injection parameters and improvements for a future injection system to get an optimized phase space volume for an optimum brightness Bexp at the experiment. With the existing system, even Bexp = 2μAmm-2mrad-2MeV-1 has been achieved. This is 20 times more than with the previously used proton source and equals the originally suggested design value for the microprobe SNAKE. Additionally, it was required to construct and install a new water-cooled beam micro slit system as an object aperture for SNAKE. It includes a possibility of tandem stability control as well as combined heating and cooling pipe system that minimizes vibrations and temperature dilatation to less than 1 μm even up to 250 W blockedbeam power. (2) At the data analysis, the efficiency of the angular and coincidence filtering has been calibrated using a special Monte-Carlo simulation code. This enables an accuracy better than 5% for the quantification of the hydrogen content independent of the thickness of the sample, the atomic number/composition or density. The simulation has been verified on multilayered sandwich targets, demonstrating a depth calibrating from the energy signal of the protons with an accuracy of better than 1% of the sample thickness. As a basic requirement, the energy dependent scattering cross section data have been evaluated with a precision of 0.2%. Furthermore, detectors energy resolution of better than 30 keV for 17 MeV protons has been achieved with a new calibration method using elastic and inelastic scattering signals of thin foils. This allows correction of energy loss effects in the pixels of the detector and finally optimizes the sensitivity to the sub-ppm level. The system has been successfully applied for measuring the hydrogen content in buckled niobium hydrogen films showing enrichment in the buckels and confirming theory of hydrogen release with relevance to hydrogen storage devices.
BibTeX:
	@phdthesis{Moser2017diss,
	  author = {Marcus Moser},
	  title = {3D Hydrogen Microscopy at the Munich Proton Microprobe SNAKE},
	  school = {Universität der Bundeswehr München},
	  year = {2017},
	  url = {https://athene-forschung.rz.unibw-muenchen.de/node?id=121394}
	}
	

2016

Hydrogen analysis depth calibration by CORTEO Monte-Carlo simulation
M. Moser, P. Reichart, A. Bergmaier, C. Greubel, F. Schiettekatte and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 371 (2016) 161-166.
Abstract: Abstract Hydrogen imaging with sub-μm lateral resolution and sub-ppm sensitivity has become possible with coincident proton-proton (pp) scattering analysis (Reichart et al., 2004). Depth information is evaluated from the energy sum signal with respect to energy loss of both protons on their path through the sample. In first order, there is no angular dependence due to elastic scattering. In second order, a path length effect due to different energy loss on the paths of the protons causes an angular dependence of the energy sum. Therefore, the energy sum signal has to be de-convoluted depending on the matrix composition, i.e. mainly the atomic number Z, in order to get a depth calibrated hydrogen profile. Although the path effect can be calculated analytically in first order, multiple scattering effects lead to significant deviations in the depth profile. Hence, in our new approach, we use the CORTEO Monte-Carlo code (Schiettekatte, 2008) in order to calculate the depth of a coincidence event depending on the scattering angle. The code takes individual detector geometry into account. In this paper we show, that the code correctly reproduces measured pp-scattering energy spectra with roughness effects considered. With more than 100 μm thick Mylar-sandwich targets (Si, Fe, Ge) we demonstrate the deconvolution of the energy spectra on our current multistrip detector at the microprobe SNAKE at the Munich tandem accelerator lab. As a result, hydrogen profiles can be evaluated with an accuracy in depth of about 1% of the sample thickness.
BibTeX:
	@article{Moser2016,
	  author = {Moser, M. and Reichart, P. and Bergmaier, A. and Greubel, C. and Schiettekatte, F. and Dollinger, G.},
	  title = {Hydrogen analysis depth calibration by CORTEO Monte-Carlo simulation},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	  year = {2016},
	  volume = {371},
	  pages = {161-166},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X15009428},
	  doi = {https://doi.org/10.1016/j.nimb.2015.09.069}
	}
	
Deuterium microscopy using 17 MeV deuteron-deuteron scattering
P. Reichart, M. Moser, C. Greubel, K. Peeper and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 371 (2016) 178-184.
Abstract: Abstract Using 17 MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron-deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5 sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150 ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25 MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering ( 100 mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron-proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel.
BibTeX:
	@article{Reichart2016,
	  author = {Reichart, Patrick and Moser, Marcus and Greubel, Christoph and Peeper, Katrin and Dollinger, Günther},
	  title = {Deuterium microscopy using 17 MeV deuteron-deuteron scattering},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	  year = {2016},
	  volume = {371},
	  pages = {178-184},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X15009489},
	  doi = {https://doi.org/10.1016/j.nimb.2015.09.075}
	}
	

2015

Transport of a high brightness proton beam through the Munich tandem accelerator
M. Moser, C. Greubel, W. Carli, K. Peeper, P. Reichart, B. Urban, T. Vallentin and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 348 (0) (2015) 34-42.
Abstract: Basic requirement for ion microprobes with sub-μm beam focus is a high brightness beam to fill the small phase space usually accepted by the ion microprobe with enough ion current for the desired application. We performed beam transport simulations to optimize beam brightness transported through the Munich tandem accelerator. This was done under the constraint of a maximum ion current of 10 μA that is allowed to be injected due to radiation safety regulations and beam power constrains. The main influence of the stripper foil in conjunction with intrinsic astigmatism in the beam transport on beam brightness is discussed. The calculations show possibilities for brightness enhancement by using astigmatism corrections and asymmetric filling of the phase space volume in the x- and y-direction.
BibTeX:
	@article{Moser2015,
	  author = {Moser, M. and Greubel, C. and Carli, W. and Peeper, K. and Reichart, P. and Urban, B. and Vallentin, T. and Dollinger, G.},
	  title = {Transport of a high brightness proton beam through the Munich tandem accelerator},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	  year = {2015},
	  volume = {348},
	  number = {0},
	  pages = {34--42},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X14009495},
	  doi = {https://doi.org/10.1016/j.nimb.2014.11.068}
	}
	
Quantification of water in hydrous ringwoodite
S.-M. Thomas, S.D. Jacobsen, C.R. Bina, P. Reichart, M. Moser, E.H. Hauri, M. Koch-Müller, J.R. Smyth and G. Dollinger; Frontiers in Earth Science 2 (2015) 38/1-10.
Abstract: Ringwoodite, γ-(Mg,Fe)2SiO4, in the lower 150 km of Earth's mantle transition zone (410–660 km depth) can incorporate up to 1.5–2 wt% H2O as hydroxyl defects. We present a mineral-specific IR calibration for the absolute water content in hydrous ringwoodite by combining results from Raman spectroscopy, secondary ion mass spectrometry (SIMS) and proton-proton (pp)-scattering on a suite of synthetic Mg- and Fe-bearing hydrous ringwoodites. H2O concentrations in the crystals studied here range from 0.46 to 1.7 wt% H2O (absolute methods), with the maximum H2O in the same sample giving 2.5 wt% by SIMS calibration. Anchoring our spectroscopic results to absolute H-atom concentrations from pp-scattering measurements, we report frequency-dependent integrated IR-absorption coefficients for water in ringwoodite ranging from 78,180 to 158,880 Lmol−1cm−2, depending upon frequency of the OH absorption. We further report a linear wavenumber IR calibration for H2O quantification in hydrous ringwoodite across the Mg2SiO4-Fe2SiO4 solid solution, which will lead to more accurate estimations of the water content in both laboratory-grown and naturally occurring ringwoodites. Re-evaluation of the IR spectrum for a natural hydrous ringwoodite inclusion in diamond from the study of Pearson et al. (2014) indicates the crystal contains 1.43 ± 0.27 wt% H2O, thus confirming near-maximum amounts of H2O for this sample from the transition zone.
BibTeX:
	@article{Thomas2015,
	  author = {Thomas, Sylvia-Monique and Jacobsen, Steven D. and Bina, Craig R. and Reichart, Patrick and Moser, Marcus and Hauri, Erik H. and Koch-Müller, Monika and Smyth, Joseph R. and Dollinger, Günther},
	  title = {Quantification of water in hydrous ringwoodite},
	  journal = {Frontiers in Earth Science},
	  year = {2015},
	  volume = {2},
	  pages = {38/1-10},
	  url = {http://www.frontiersin.org/earth_and_planetary_materials/10.3389/feart.2014.00038/abstract},
	  doi = {https://doi.org/10.3389/feart.2014.00038}
	}
	
A microbeam slit system for high beam currents
T. Vallentin, M. Moser, S. Eschbaumer, C. Greubel, T. Haase, P. Reichart, T. Rösch and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 348 (0) (2015) 43-47.
Abstract: A new microbeam slit system for high beam currents of 10 μA was built up to improve the brightness transport of a proton beam with a kinetic energy of up to 25 MeV into the microprobe SNAKE. The new slit system features a position accuracy of less than 1 μm under normal operating conditions and less than 2 μm if the beam is switched on and off. The thermal management with a powerful watercooling and potential-free thermocouple feedback controlled heating cables is optimized for constant slit aperture at thermal power input of up to 250 W. The transparent zone is optimized to 0.7 μm due to the use of tungsten formed to a cylindrical surface with a radius r = 100 mm and mechanically lapped surface to minimize small angle scattering effects and to minimize the number of ions passing the slits with low energy loss. Electrical isolation of the slit tip enables slit current monitoring, e.g. for tandem accelerator feedback control. With the ability to transport up to 10 μA of protons with the new microslit system, the brightness B_exp transported into the microprobe was increased by a factor of 2 compared to low current injection using the old slit system.
BibTeX:
	@article{Vallentin2015,
	  author = {Vallentin, T. and Moser, M. and Eschbaumer, S. and Greubel, C. and Haase, T. and Reichart, P. and Rösch, T. and Dollinger, G.},
	  title = {A microbeam slit system for high beam currents},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	  year = {2015},
	  volume = {348},
	  number = {0},
	  pages = {43--47},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X14010313},
	  doi = {https://doi.org/10.1016/j.nimb.2014.12.015}
	}
	

2014

Three-dimensional microscopy of deuterium in tungsten
K. Peeper, M. Moser, P. Reichart, E. Markina, S. Elgeti (Lindig), M. Balden, T. Schwarz-Selinger, M. Mayer and G. Dollinger; Physica Scripta T159 (2014) 014070.
Abstract: The hydrogen isotope retention in tungsten is an important issue for fusion devices. In this paper we study the possibility of using a μ m-focused deuterium beam in order to quantify deuterium distributions in microscopic dimensions. Due to the lack of cross-section data for deuteron-deuteron-scattering (dd-scattering) a validated reference sample is needed. For this purpose we used a15 μ m thick aluminum foil covered by a-C:D-layers that have been deposited in a CD 4 plasma discharge from both sides. At the SNAKE facility of the Munich tandem accelerator we already established a three-dimensional microscopy of hydrogen using protons within an energy range between 17 and 25 MeV. Now, we have tested the possibility for deuteron microscopy. As a first application we analyzed a25 μ m foil implanted with 2.0 × 10 20 atom cm −2 deuterons.
BibTeX:
	@article{Peeper2014,
	  author = {Peeper, K. and Moser, M. and Reichart, P. and Markina, E. and Elgeti (Lindig), S. and Balden, M. and Schwarz-Selinger, Th. and Mayer, M. and Dollinger, G.},
	  title = {Three-dimensional microscopy of deuterium in tungsten},
	  journal = {Physica Scripta},
	  year = {2014},
	  volume = {T159},
	  pages = {014070},
	  url = {http://stacks.iop.org/1402-4896/2014/i=T159/a=014070},
	  doi = {https://doi.org/10.1088/0031-8949/2014/T159/014070}
	}
	

2013

3D-microscopy of hydrogen in tungsten
K. Peeper, M. Moser, P. Reichart, E. Markina, M. Mayer, S. Lindig, M. Balden and G. Dollinger; Journal of Nuclear Materials 438, Supplement (0) (2013) S887-S890.
Abstract: The mapping of hydrogen distributions in 3 dimensions and its correlation with structural features allow further insight into mechanisms of hydrogen trapping in tungsten. We studied hydrogen distributions in 25 μm thick polycrystalline tungsten foils by 3D hydrogen microscopy using a proton-proton-scattering method. Two types of tungsten samples were prepared: (i) at 1200 K annealed foils and using 1.8 MeV implantation energy (ii) at 2000 K annealed foils using 200 eV implantation energy. It has been found that large variations of surface hydrogen contamination occur within different samples. Nevertheless, a statistically significant variation of the hydrogen content across grain boundaries has been observed.
BibTeX:
	@article{Peeper2013,
	  author = {Peeper, K. and Moser, M. and Reichart, P. and Markina, E. and Mayer, M. and Lindig, S. and Balden, M. and Dollinger, G.},
	  title = {3D-microscopy of hydrogen in tungsten},
	  booktitle = {Proceedings of the 20th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices},
	  journal = {Journal of Nuclear Materials},
	  year = {2013},
	  volume = {438, Supplement},
	  number = {0},
	  pages = {S887--S890},
	  url = {http://www.sciencedirect.com/science/article/pii/S0022311513002006},
	  doi = {https://doi.org/10.1016/j.jnucmat.2013.01.192}
	}
	
Hydrogen microscopy - Distribution of hydrogen in buckled niobium hydrogen thin films
S. Wagner, M. Moser, C. Greubel, K. Peeper, P. Reichart, A. Pundt and G. Dollinger; International Journal of Hydrogen Energy 38 (31) (2013) 13822-13830.
Abstract: Hydrogen absorption in thin metal films clamped to rigid substrates results in mechanical stress that changes the hydrogen's chemical potential by ΔμH(σ) = −1.124σ kJ/molH for σ measured in [GPa]. In this paper we show that local stress relaxation by the detachment of niobium hydrogen thin films from the substrate affects the chemical potential on the local scale: using coincident proton-proton scattering at a proton microprobe, the hydrogen concentration is determined with μm resolution, revealing that hydrogen is not homogenously distributed in the film. The local hydrogen solubility of the film changes with its local stress state, mapping the buckled film fraction. In niobium hydrogen thin films loaded up to nominal concentrations in the two-phase coexistence region, the clamped film fraction remains in the solid solution phase, while the buckles represent the hydride phase. These results are compared to a simple model taking the stress impact on the chemical potential into account.
BibTeX:
	@article{Wagner2013,
	  author = {Wagner, Stefan and Moser, Marcus and Greubel, Christoph and Peeper, Katrin and Reichart, Patrick and Pundt, Astrid and Dollinger, Günther},
	  title = {Hydrogen microscopy - Distribution of hydrogen in buckled niobium hydrogen thin films},
	  journal = {International Journal of Hydrogen Energy},
	  year = {2013},
	  volume = {38},
	  number = {31},
	  pages = {13822--13830},
	  url = {http://www.sciencedirect.com/science/article/pii/S0360319913019137},
	  doi = {https://doi.org/10.1016/j.ijhydene.2013.08.006}
	}
	

2012

High brilliance multicusp ion source for hydrogen microscopy at SNAKE
M. Moser, P. Reichart, W. Carli, C. Greubel, K. Peeper, P. Hartung and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 273 (2012) 226-230.
Abstract: In order to improve the lateral resolution of the 3D hydrogen microscopy by proton-proton scattering at the Munich microprobe SNAKE, we have installed a new multicusp ion source for negative hydrogen ions manufactured by HVEE at the Munich 14 MV tandem accelerator that boosts the proton beam brilliance with the potential to reduce the beam diameter at the focal plane of SNAKE. We measured a beam brilliance B = 27 A m -2 rad -2 eV -1 directly behind the ion source that is at the space charge limit for conventional ion sources. After preacceleration to in total 180 keV beam energy we measure a slightly reduced beam brilliance of B = 10 μA mm -2 mrad -2 MeV -1. For injection into the tandem accelerator, the extracted H --current of the multicusp source of 1 mA is reduced to about 10 μA because of radiation safety regulations and heating problems at the object slits of SNAKE. Due to beam oscillations and influences of the terminal stripper of the tandem we measured a reduced beam brilliance of 0.8 μA mm -2 mrad -2 MeV -1 in front of SNAKE at 25 MeV but still being nearly 10 times larger than measured with any other ion source.
BibTeX:
	@article{Moser2012,
	  author = {Moser, M. and Reichart, P. and Carli, W. and Greubel, C. and Peeper, K. and Hartung, P. and Dollinger, G.},
	  title = {High brilliance multicusp ion source for hydrogen microscopy at SNAKE},
	  booktitle = {20th International Conference on Ion Beam Analysis},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2012},
	  volume = {273},
	  pages = {226--230},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X11007257},
	  doi = {https://doi.org/10.1016/j.nimb.2011.07.081}
	}
	
Non-Rutherford backscattering microscopy using 25 MeV protons
K. Peeper, M. Moser, P. Reichart and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 273 (2012) 254-257.
Abstract: Protons at energies between 10 and 25 MeV are a very sensitive probe for hydrogen using coincident proton-proton scattering with the possibility for depth profiling samples up to several 100 μm thickness. At the Munich microprobe SNAKE we have developed this method for sensitive 3D hydrogen microscopy [1]. In parallel to sensitive 3D hydrogen microscopy by proton-proton scattering we introduce a non-Rutherford backscattering analysis utilizing 25 MeV protons in order to obtain 3D depth profiles of all major elements. We present energy spectra of backscattered protons at various thin and thick film samples of pure elements which we use as fingerprints to analyse more complex materials like minerals or metals. It is due to the low stopping power of the high energy protons that the depth profiles of several elements do not or do only partially overlap when analysing freestanding samples with thicknesses in the 100 μm range. The merit of our method is that signals of the light elements may not be affected by heavier matrix elements. Analysing thin films smaller than 5 μm we have achieved a mass resolution of ΔA/A≤1/28 for non-overlapping mass signals utilizing a 5 mm thick Si(Li)-detector.
BibTeX:
	@article{Peeper2012,
	  author = {Peeper, K. and Moser, M. and Reichart, P. and Dollinger, G.},
	  title = {Non-Rutherford backscattering microscopy using 25 MeV protons},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2012},
	  volume = {273},
	  pages = {254--257},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X11007324},
	  doi = {https://doi.org/10.1016/j.nimb.2011.07.088}
	}
	

2011

Differential proton-proton scattering cross section for energies between 1.9 MeV and 50 MeV
M. Moser, P. Reichart, C. Greubel and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 269 (20) (2011) 2217-2228.
Abstract: We present a phase shift analysis of differential elastic proton-proton scattering cross sections (dσ/dΩ) pp in the energy range from 1.9 MeV to 50 MeV and laboratory scattering angles θlab= 15-75°. That results in an accurate representation of the experimental data by an analytical function (χred2=1.95). The average statistical error of the resulting data fit is 0.2%. The evaluation is representing the experimental data better than the evaluated cross section by the framework of the R-matrix theory as available from the ENDF database (χred2=6.98). For a fast evaluation we extract an E,θ-matrix for (dσ/dΩ) pp with a negligible interpolation error. These data may be used for data evaluation when using proton-proton scattering for hydrogen detection in material analysis.
BibTeX:
	@article{Moser2011,
	  author = {Moser, M. and Reichart, P. and Greubel, C. and Dollinger, G.},
	  title = {Differential proton-proton scattering cross section for energies between 1.9 MeV and 50 MeV},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2011},
	  volume = {269},
	  number = {20},
	  pages = {2217--2228},
	  note = {12th International Conference on Nuclear Microprobe Technology and Applications},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X1100200X},
	  doi = {https://doi.org/10.1016/j.nimb.2011.02.017}
	}
	

2009

Hydrogen Analysis by Proton-Proton Scattering
P. Reichart and G. Dollinger; In: Y. Wang and M. Nastasi (Eds.), Handbook of Modern Ion Beam Materials Analysis (2nd Ed.) , Chapter 9 , p. 187-206 , Materials Research Society , 2009.
BibTeX:
	@incollection{Reichart2009,
	  author = {Reichart, P. and Dollinger, G.},
	  title = {Hydrogen Analysis by Proton-Proton Scattering},
	  booktitle = {Handbook of Modern Ion Beam Materials Analysis (2nd Ed.)},
	  publisher = {Materials Research Society},
	  year = {2009},
	  pages = {187--206},
	  edition = {2nd},
	  editor = {Y. Wang and M. Nastasi},
	  url = {http://www.mrs.org/ibh2}
	}
	
Proton–Proton Scattering Cross Sections
P. Reichart and G. Dollinger; In: Y. Wang and M. Nastasi (Eds.), Handbook of Modern Ion Beam Materials Analysis (2nd Ed.) Appendices , Chapter 14 , p. 229-254 , Materials Research Society , 2009.
BibTeX:
	@incollection{Reichart2009a,
	  author = {Reichart, P. and Dollinger, G.},
	  title = {Proton–Proton Scattering Cross Sections},
	  booktitle = {Handbook of Modern Ion Beam Materials Analysis (2nd Ed.) Appendices},
	  publisher = {Materials Research Society},
	  year = {2009},
	  pages = {229--254},
	  edition = {2nd},
	  editor = {Y. Wang and M. Nastasi},
	  url = {http://www.mrs.org/ibh2}
	}
	
IR calibrations for water determination in olivine, r-GeO2, and SiO2 polymorphs
S.-M. Thomas, M. Koch-Müller, P. Reichart, D. Rhede, R. Thomas, R. Wirth and S. Matsyuk; Physics and Chemistry of Minerals 36 (2009) 489-509.
Abstract: Mineral-specific IR absorption coefficients were calculated for natural and synthetic olivine, SiO2 polymorphs, and GeO2 with specific isolated OH point defects using quantitative data from independent techniques such as proton–proton scattering, confocal Raman spectroscopy, and secondary ion mass spectrometry. Moreover, we present a routine to detect OH traces in anisotropic minerals using Raman spectroscopy combined with the ‘‘Comparator Technique’’. In case of olivine and the SiO2 system, it turns out that the magnitude of e for one structure is independent of the type of OH point defect and therewith the peak position (quartz e = 89,000 ± 15,000 l mol^-1_H2O cm^-2), but it varies as a function of structure (coesite e = 214,000 ± 14,000 l mol-1 H2O cm-2; stishovite e = 485,000 ± 109,000 l mol-1 H2O cm-2). Evaluation of data from this study confirms that not using mineral-specific IR calibrations for the OH quantification in nominally anhydrous minerals leads to inaccurate estimations of OH concentrations, which constitute the basis for modeling the Earth’s deep water cycle.
BibTeX:
	@article{Thomas2009,
	  author = {Thomas, Sylvia-Monique and Koch-Müller, Monika and Reichart, Patrick and Rhede, Dieter and Thomas, Rainer and Wirth, Richard and Matsyuk, Stanislav},
	  title = {IR calibrations for water determination in olivine, r-GeO2, and SiO2 polymorphs},
	  journal = {Physics and Chemistry of Minerals},
	  year = {2009},
	  volume = {36},
	  pages = {489--509},
	  url = {http://link.springer.com/article/10.1007%2Fs00269-009-0295-1},
	  doi = {https://doi.org/10.1007/s00269-009-0295-1}
	}
	

2008

Water in natural olivine—determined by proton-proton scattering analysis
J. Gose, P. Reichart, G. Dollinger and E. Schmädicke; American Mineralogist 93 (10) (2008) 1613-1619.
Abstract: Here we present water concentration data for olivine from different host rocks, measured with a nuclear technique using proton-proton scattering. This method, which is used here for the first time on olivine, is very powerful for determining trace amounts of water. The studied olivine specimens differ in their H2O contents, ranging from 4 to 51 wt ppm (=10–117 atom ppm H). The lowest concentrations are found in olivine from spinel peridotite xenoliths, the highest concentrations in olivine from alpine-type peridotite; the contents of an ophiolitic and a hydrothermal olivine are intermediate. Infrared spectroscopy was applied to ensure that the measured water contents stem solely from hydroxyl defects in the mineral structure. The infrared spectra differ from sample to sample. Five of six olivine specimens show absorption bands typical of hydroxyl groups associated with Ti defects. These olivines differ in their Ti contents by two orders of magnitude. However, a correlation of water and Ti content was not observed.
BibTeX:
	@article{Gose2008,
	  author = {Gose, Jürgen and Reichart, Patrick and Dollinger, Günther and Schmädicke, Esther},
	  title = {Water in natural olivine—determined by proton-proton scattering analysis},
	  journal = {American Mineralogist},
	  year = {2008},
	  volume = {93},
	  number = {10},
	  pages = {1613-1619},
	  url = {http://ammin.geoscienceworld.org/content/93/10/1613.abstract},
	  doi = {https://doi.org/10.2138/am.2008.2835}
	}
	
Application of Raman spectroscopy to quantify trace water concentrations in glasses and garnets
S.-M. Thomas, R. Thomas, P. Davidson, P. Reichart, M. Koch-Müller and G. Dollinger; American Mineralogist 93 (10) (2008) 1550-1557.
Abstract: We present a new technique for the quantification of water in glasses down to the parts per million level, using confocal microRaman spectroscopy with the recently developed “Comparator Technique.” To test this method, we used a suite of glasses and gemstone-quality garnets with varying chemical compositions. Water contents were independently determined with proton-proton (pp) scattering and infrared (IR) spectroscopy. Moreover, water concentrations obtained for the garnets were compared to data from a study by Maldener et al. (2003) using nuclear reaction analysis (NRA). For each sample, we recorded Raman spectra in the frequency range from 3100 to 3750 cm−1 and standardized them using an independently well-characterized glass. In this paper, we demonstrate the usefulness of this technique for quantifying water concentrations in natural and synthetic glass samples and garnets, and verify its adaptability for concentrations from 40 wt ppm up to 40 wt% H2O. However, in the case of absorbing material (e.g., Fe-bearing samples), the suggested method needs to be modified to overcome problems due to heating and melting of those phases. Furthermore, we propose an integrated molar absorption coefficient for water in quartz glass, εitot = 72 000 ± 12 000 Lmol−1H2Ocm−2, for quantitative IR spectroscopy that is higher than a previously reported value of Paterson (1982) or that predicted by the general calibration trend determined by Libowitzky and Rossman (1997).
BibTeX:
	@article{Thomas2008,
	  author = {Thomas, Sylvia-Monique and Thomas, Rainer and Davidson, Paul and Reichart, Patrick and Koch-Müller, Monika and Dollinger, Günther},
	  title = {Application of Raman spectroscopy to quantify trace water concentrations in glasses and garnets},
	  journal = {American Mineralogist},
	  year = {2008},
	  volume = {93},
	  number = {10},
	  pages = {1550-1557},
	  url = {http://ammin.geoscienceworld.org/content/93/10/1550.abstract},
	  doi = {https://doi.org/10.2138/am.2008.2834}
	}
	

2006

3D-Hydrogen analysis of ferromagnetic microstructures in proton irradiated graphite
P. Reichart, D. Spemann, A. Hauptner, A. Bergmaier, V. Hable, R. Hertenberger, C. Greubel, A. Setzer, G. Dollinger, D. Jamieson, T. Butz and P. Esquinazi; Nuclear Instruments and Methods in Physics Research Section B 249 (1-2) (2006) 286-291.
Abstract: Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced by proton broad- and microbeam irradiation was discovered. Theoretical models propose that hydrogen could play a major role in the magnetism mechanism. We analysed the hydrogen distribution of pristine as well as irradiated HOPG samples, which were implanted to μm-sized spots as well as extended areas with various doses of 2.25 MeV protons at the Leipzig microprobe LIPSION. For this we used the sensitive 3D hydrogen microscopy system at the Munich microprobe SNAKE. The background hydrogen level in pristine HOPG is determined to be less than 0.3 at-ppm. About 4.8 × 1015 H-atoms/cm2 are observed in the near-surface region (4 μm depth resolution). The depth profiles of the implants show hydrogen located within a confined peak at the end of range, in agreement with SRIM Monte Carlo simulations, and no evidence of diffusion broadening along the c-axis. At the sample with microspots, up to 40 at.% of the implanted hydrogen is not detected, providing support for lateral hydrogen diffusion.
BibTeX:
	@article{Reichart2006,
	  author = {Reichart, P. and Spemann, D. and Hauptner, A. and Bergmaier, A. and Hable, V. and Hertenberger, R. and Greubel, C. and Setzer, A. and Dollinger, G. and Jamieson, D.N. and Butz, T. and Esquinazi, P.},
	  title = {3D-Hydrogen analysis of ferromagnetic microstructures in proton irradiated graphite},
	  booktitle = {Proceedings of the Seventeenth International Conference on Ion Beam Analysis},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2006},
	  volume = {249},
	  number = {1-2},
	  pages = {286--291},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X06004605},
	  doi = {https://doi.org/10.1016/j.nimb.2006.04.014}
	}
	

2005

Three dimensional hydrogen microscopy in diamond
G. Dollinger, P. Reichart, A. Bergmaier, A. Hauptner and C. Wild; In: , S. Ashok, J. Chevallier, B.L. Sopori, M. Tabe and P. Kiesel (Ed.), Materials Research Society Symposium Proceedings 864 (2005) 541-547 , MRS, Warrendale, PA, United States.
Abstract: We introduce proton-proton scattering at a microprobe of 17 MeV protons to quantitatively image three dimensional hydrogen distributions in polycrystalline diamond at a lateral resolution better than 1 μm and high sensitivity. The images show that most of the hydrogen of a 〈110〉-textured undoped polycrystalline diamond film is located at grain boundaries. The average amount of hydrogen is (8.1±1.5)·10 14 atoms/cm 2 along the grain boundaries which corresponds to about a third of a monolayer. The content within the grain is below the detection limit of 1.4-10 16 atoms/cm 2 (0.08 at-ppm).
BibTeX:
	@inproceedings{Dollinger2005a,
	  author = {Dollinger, G. and Reichart, P. and Bergmaier, A. and Hauptner, A. and Wild, C.},
	  title = {Three dimensional hydrogen microscopy in diamond},
	  booktitle = {Materials Research Society Symposium Proceedings},
	  publisher = {MRS, Warrendale, PA, United States},
	  year = {2005},
	  volume = {864},
	  pages = {541--547},
	  editor = {Ashok S., Chevallier J., Sopori B.L., Tabe M., Kiesel P.},
	  note = {cited By (since 1996)0},
	  url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-30544438196&partnerID=40&md5=4d513ce20703288ffbfba125377daf31}
	}
	

2004

Three-Dimensional Hydrogen Microscopy in Diamond
P. Reichart, G. Datzmann, A. Hauptner, R. Hertenberger, C. Wild and G. Dollinger; Science 306 (5701) (2004) 1537-1540.
Abstract: A microprobe of protons with an energy of 17 million electron volts is used to quantitatively image three-dimensional hydrogen distributions at a lateral resolution better than 1 micrometer with high sensitivity. Hydrogen images of a <110>-textured undoped polycrystalline diamond film show that most of the hydrogen is located at grain boundaries. The average amount of hydrogen atoms along the grain boundaries is (8.1 ± 1.5) × 1014 per square centimeter, corresponding to about a third of a monolayer. The hydrogen content within the grain is below the experimental sensitivity of 1.4 × 1016 atoms per cubic centimeter (0.08 atomic parts per million). The data prove a low hydrogen content within chemical vapor deposition–grown diamond and the importance of hydrogen at grain boundaries, for example, with respect to electronic properties of polycrystalline diamond.
BibTeX:
	@article{Reichart2004,
	  author = {Reichart, P. and Datzmann, G. and Hauptner, A. and Hertenberger, R. and Wild, C. and Dollinger, G.},
	  title = {Three-Dimensional Hydrogen Microscopy in Diamond},
	  journal = {Science},
	  year = {2004},
	  volume = {306},
	  number = {5701},
	  pages = {1537-1540},
	  url = {http://www.sciencemag.org/content/306/5701/1537.abstract},
	  doi = {https://doi.org/10.1126/science.1102910}
	}
	
3D hydrogen microscopy with sub-ppm detection limit
P. Reichart, G. Dollinger, A. Bergmaier, G. Datzmann, A. Hauptner, H.-J. Körner and R. Krücken; Nuclear Instruments and Methods in Physics Research Section B 219-220 (1-4) (2004) 980-987.
Abstract: Coincident elastic proton-proton scattering at a 17 MeV microprobe is used to investigate hydrogen distributions on microscopic scale inside freestanding samples up to some 100 μm thickness. Hydrogen imaging at atomic ppm level needs a total count rate of about 100 kHz of scattered protons in order to get sufficient statistics from the small fraction of coincident hydrogen signals. It is obtained using a highly segmented silicon strip detector of 2.3 sr for proton currents of less than 100 pA impinging on films thicker 10 μm. A five level filter almost completely suppresses accidental coincidences. The sensitivity of this kind of 3D hydrogen microscopy is demonstrated by the analysis of a 55 μm thick synthetic diamond layer showing a detection limit of 0.08 at-ppm hydrogen. In addition, the proposed depth resolution of 3-6 μm is experimentally confirmed and a lateral resolution of 0.6 μm full width half maximum is obtained at a significant hydrogen enhancement inside the layer.
BibTeX:
	@article{Reichart2004a,
	  author = {Reichart, P. and Dollinger, G. and Bergmaier, A. and Datzmann, G. and Hauptner, A. and Körner, H.-J. and Krücken, R.},
	  title = {3D hydrogen microscopy with sub-ppm detection limit},
	  booktitle = {Proceedings of the Sixteenth International Conference on Ion Beam Analysis},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2004},
	  volume = {219-220},
	  number = {1-4},
	  pages = {980--987},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X04002502},
	  doi = {https://doi.org/10.1016/j.nimb.2004.01.200}
	}
	
Dreidimensionale Wasserstoffmikroskopie mittels Proton-Proton-Streuung
Patrick Reichart; Dissertation, Technische Universität München, 2004.
Abstract: Mit der Methode der Proton-Proton-Streuung zum Wasserstoffnachweis wurde ein Verfahren entwickelt, um unter Einsatz eines fokussierten 17 MeV Protonenstrahls Wasserstoffverteilungen auf mikroskopischer Skala quantitativ mit einer sub-ppm Nachweisgrenze dreidimensional abzubilden. Die Realisierung am Rasterionenmikroskop SNAKE am Münchener 14 MV Tandembeschleuniger mit einem großen ringförmigen, segmentierten Detektor und einem komplexen Analysesystem ermöglicht eine Nachweisgrenze von 0.08 at-ppm bei einer lateralen Auflösung von 0.6 μm und einer Tiefenauflösung besser als 5 μm. Mit den hohen Protonenenergien können Proben bis einige 100 μm untersucht werden. Damit konnte erstmals nachgewiesen werden, dass in künstlich hergestellten polykristallinen Diamantschichten der Wasserstoff hauptsächlich an den Korngrenzen lokalisiert ist. In weiteren Experimenten wird das Potential für zukünftige Anwendungen zur Untersuchung organischer Materialien oder innerer Grenzflächen demonstriert.
BibTeX:
	@phdthesis{Reichart2004diss,
	  author = {Reichart, Patrick},
	  title = {Dreidimensionale Wasserstoffmikroskopie mittels Proton-Proton-Streuung},
	  school = {Technische Universität München},
	  year = {2004},
	  url = {http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:91-diss2004030314833}
	}
	

2003

Three-dimensional hydrogen microscopy using a high-energy proton probe
G. Dollinger, P. Reichart, G. Datzmann, A. Hauptner and H.-J. Körner; Applied Physics Letters 82 (1) (2003) 148-150.
Abstract: It is a challenge to measure two-dimensional or three-dimensional (3D) hydrogen profiles on a micrometer scale. Quantitative hydrogen analyses of micrometer resolution are demonstrated utilizing proton–proton scattering at a high-energy proton microprobe. It has more than an-order-of-magnitude better position resolution and in addition higher sensitivity than any other technique for 3D hydrogen analyses. This type of hydrogen imaging opens plenty room to characterize microstructured materials, and semiconductor devices or objects in microbiology. The first hydrogen image obtained with a 10 MeV proton microprobe shows the hydrogen distribution of the microcapillary system being present in the wing of a mayfly and demonstrates the potential of the method.
BibTeX:
	@article{Dollinger2003a,
	  author = {Dollinger, G. and Reichart, P. and Datzmann, G. and Hauptner, A. and Körner, H.-J},
	  title = {Three-dimensional hydrogen microscopy using a high-energy proton probe},
	  journal = {Applied Physics Letters},
	  year = {2003},
	  volume = {82},
	  number = {1},
	  pages = {148--150},
	  url = {http://apl.aip.org/resource/1/applab/v82/i1/p148_s1},
	  doi = {https://doi.org/10.1063/1.1533111}
	}
	
Sensitive 3D hydrogen microscopy using high energy protons at SNAKE
P. Reichart, G. Dollinger, G. Datzmann, A. Hauptner, R. Hertenberger and H.J. Körner; Nuclear Instruments and Methods in Physics Research Section B 210 (2003) 135-141.
Abstract: The new ion microprobe SNAKE (Superconducting Nanoscope for Applied nuclear (Kern-) physics Experiments) is a tool to focus, beside heavy ions, 4-28 MeV protons to submicron beam spot size. This facility establishes a sensitive 3D microscopy of hydrogen distributions by elastic proton proton scattering. The high proton energy enables analysis at a target thickness up to some 100 μm without significant reduction of the micrometer lateral resolution. The scattered projectile and recoiled target protons are detected in coincidence using an annular silicon strip detector. It covers scattering angles from 29° to 61° and a 2.3 sr solid angle of detection. The readout electronics with a 50 ns coincidence window allows an efficient reduction of accidental coincidence events even at some 10 kHz count rates. 3D hydrogen microscopy using 17 MeV proton proton scattering is tested successfully providing a ppm detection limit in a 55 μm thick diamond plate. First measurements on CVD grown diamond show the possibility to investigate such low hydrogen content of the bulk region with micrometer lateral resolution.
BibTeX:
	@article{Reichart2003,
	  author = {Reichart, P. and Dollinger, G. and Datzmann, G. and Hauptner, A. and Hertenberger, R. and Körner, H. - J.},
	  title = {Sensitive 3D hydrogen microscopy using high energy protons at SNAKE},
	  booktitle = {8th International Conference of Nuclear Microprobe Technology and Applications},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2003},
	  volume = {210},
	  pages = {135--141},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X0301084X},
	  doi = {https://doi.org/10.1016/S0168-583X(03)01084-X}
	}
	

2002

Sensitive 3D hydrogen microscopy by proton proton scattering
P. Reichart, G. Dollinger, A. Bergmaier, G. Datzmann, A. Hauptner and H.-J. Körner; Nuclear Instruments and Methods in Physics Research Section B 197 (1-2) (2002) 134-149.
Abstract: Elastic proton proton scattering is a sensitive and fast method for hydrogen analysis. Utilising a nuclear microprobe it is actually the only technique for the absolute quantification of hydrogen distributions with micrometer or even better lateral resolution. High proton energies, e.g. 20 MeV, allow a wide field of applications since even materials, some 100 μm thick, can be analysed. Irradiation damage is reduced to a minimum compared to all other known ion beam analysis techniques, because a large solid angle of detection of some stradian can be used and the nuclear scattering cross section for protons at these energies is enhanced nearly three orders of magnitudes compared to Coulomb scattering. As a consequence, a sensitivity in the ppm range for hydrogen microscopy is possible. However, the large solid angle of detection induces geometrical effects in the energy analysis which are kept within a physical limit by an angular resolution of 10 mrad e.g. by utilising an annular silicon strip detector of 2.3 sr solid angle of detection. Therefore, the third dimension is provided with a depth resolution better 10 μm using the energy information of the scattered protons.
BibTeX:
	@article{Reichart2002,
	  author = {Reichart, P. and Dollinger, G. and Bergmaier, A. and Datzmann, G. and Hauptner, A. and Körner, H.-J.},
	  title = {Sensitive 3D hydrogen microscopy by proton proton scattering},
	  journal = {Nuclear Instruments and Methods in Physics Research Section B},
	  year = {2002},
	  volume = {197},
	  number = {1-2},
	  pages = {134--149},
	  url = {http://www.sciencedirect.com/science/article/pii/S0168583X02014799},
	  doi = {https://doi.org/10.1016/S0168-583X(02)01479-9}
	}