Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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40439 Publications

Proton-Proton Correlations in Central Collisions of Ni+Ni at 1.93 A GeV and the Space-Time Extent of the Emission Source

Kotte, R.; Biegansky, J.; Mösner, J.; Neubert, W.; Plettner, C.; Wohlfarth, D.; Alard, J. P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belyaev, I.; Berek, G.; Best, D.; Buta, A.; Caplar, R.; Cindro, N.; Coffin, J. P.; Crochet, P.; Dona, R.; Dupieux, P.; Dzelalija, M.; Eskef, M.; Fintz, P.; Fodor, Z.; Fraysse, L.; Genoux-Lubain, A.; Göbels, G.; Gobbi, A.; Guillaume, G.; Häfele, E.; Herrmann, N.; Hildenbrand, K. D.; Hölbling, S.; Hong, B.; Jundt, F.; Kecskemeti, J.; Kirejczyk, M.; Korolija, M.; Kuhn, C.; Lebedev, A.; Legrand, I.; Leifels, Y.; Maazouzi, C.; Manko, V.; Merlitz, H.; Mohren, S.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Pras, P.; Rami, F.; Reisdorf, W.; Ritman, J. L.; Roy, C.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczynska, K.; Sodan, U.; Somov, A.; Tizniti, L.; Trzaska, M.; Vasiliev, M. A.; Wagner, P.; Wang, G. S.; Wienold, T.; Yatsunenko, Y.; Zhilin, A.


Small-angle correlations of Proton pairs produced in central Ni+Ni collisions at a beam energy of 1.93 AGeV are investigated with the FOPI detector System at GSI Darmstadt. A well-defined emission source is selected by triggering on central events which comprise about 8% of the total cross section. Simultaneous comparison of longitudinal and transverse correlation functions with the predictions of the Koonin model allows to unravel the space-time ambiguity of the emission process. Taking into account the strong collactive expansion of the participant zone, which introduces a reduction of the extracted source radius of more than 30% r.m.s. radius and emission time parameters of Rrms = ( 4.2 ± 1.2) fm and trms = (11+7 -5) fm/c are extracted, respectively. In contrast, the analysis of the angle-integrated correlation function gives an upper limit Rrms = (7.0 ± 1.4) fm of the source radius.

  • Zeitschrift für Physik A 359, (1997) 47-54
  • Open Access Logo Forschungszentrum Rossendorf; FZR-164 Preprint
    ISSN: 1436-3976


Publ.-Id: 818

The Binary and Ternary Decay of Hot Heavy Nuclei Produced in the Reaction 14N (34 AMeV) + 197Au

Wagner, W.; Herbach, C.-M.; Ortlepp, H.-G.; Aleksandrov, A. A.; Aleksandrova, I. A.; Dietterle, L.; Doronin, V. N.; Dshemuchadse, S.; Gippner, P.; Kamanin, D. V.; Matthies, A.; Pausch, G.; Penionzhkevich, Y. E.; Renz, G.; Schilling, K.-D.; Shishkin, D. I.; Strekalovsky, O. V.; Tichtchenko, V. G.; Tsurin, I. P.; Umlauf, C.; Vakatov, D. V.; Vasko, V. M.; Wilpert, M.; Zuchko, V. E.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-163 Preprint
    ISSN: 1436-3976


Publ.-Id: 817

Wear mechanisms in titanium implanted silicon nitride ceramics

Brenscheidt, F.; Oswald, S.; Mücklich, A.; Wieser, E.; Möller, W.

The wear of silicon nitride ceramics is reduced by titanium
implantation albeit the friction coefficient is slightly increased. X-ray
excited photoelectron spectroscopy indicates that silicon oxide is formed
in the wear track while possible lubricating titanium oxides are not found.
Therefore we attribute the observed wear reduction to the amorphization
of the surface as proved by transmission electron microscopy.

  • Nuclear Instruments and Methods in Physics Research B 129 (1997) 483-486

Publ.-Id: 815

In-situ Investigation of Ion Driff Processes in Glass ...

Schmidt, B.

  • Lecture (Conference)
    EUROSENSORS XI, Warshaw, 21.-24.9.1997

Publ.-Id: 814

Two-phonon J=1 states in even-mass Te isotopes with A=122-130* Account No.: 0076898

Schwengner, R.; Winter, G.; Schauer, W.; Grinberg, M.; Becker, F.; von Brentano, P.; Eberth, J.; Enders, J.; von Egidy, T.; Herzberg, R.-D.; Huxel, N.; Käubler, L.; von Neumann-Cosel, P.; Nicolay, N.; Ott, J.; Pietralla, N.; Prade, H.; Raman, S.; Reif, J.; Richter, A.; Schlegel, C.; Schnare, H.; Servene, T.; Skoda, S.; Steinhardt, T.; Stoyanov, C.; Thomas, H. G.; Wiedenhöver, I.; Zilges, A.

Excited states of the nuclei 122, 126, 130Te were populated
via the (gamma, gamma') reaction at endpoint energies of the bremsstrahlung
between 4.5 and 5.5 MeV. Gamma rays were detected with a EUROBALL CLUSTER
detector and a single HPGe detector. In all investigated nuclei two or
three prominent dipole transitions were identified at Egammaca.
3 MeV. The corresponding low-lying J=1 states are interpreted as two-phonon
excitations. Quasiparticle-phonon-model calculations predict at about 3
MeV on 1- state arising from coupling of the first quadrupole
and the first octupole phonon, and one 1+ state arising from
the coupling of the first and the second quadrupole phonon, where the latter
has isovector character. Such an excitation mode can be considered as an
analogue of the scissors mode in vibrational nuclei. The calculated transition
strengths are compatible with experimental ones within a factor of about

  • Nuclear Physics A 620 (1997) 277-295

Publ.-Id: 813

Dichtemessung mit Positronenstrahlung

Hensel, F.

Ein berührungsloses Dichtemeßverfahren für Medien geringer Dichte wird vorgestellt, das auf der Abhängigkeit der Reichweite von Positronenstrahlung von der Dichte des Meßmediums beruht. Die Positronen werden von einem Radionuklid in einer festen Quelle erzeugt und in das zu untersuchende Volumen emittiert. Seitlich angeordnete Detektoren registrieren die bei der Annihilation der Positronen entstehenden Gammaquanten. Das Verfahren wurde in einem Dichtebereich von 15 kg/m3 bis 38 kg/m3 getestet, eine Erweiterung des Meßbereichs von 5 kg/m3 bis 300 kg/m3 ist möglich.

Einsatzfelder sind mehrphasige Strömungen mit hohem Massenstromanteil der gasförmigen Phase (Schäume und Dämpfe) sowie unter Druck stehende Gase. Der Vorteil des Verfahrens besteht in einer Kombination der hohen Dichtesensitivität der Betastrahlung mit der geringen Absorption der bei der Annihilation entstehenden Gammastrahlung in Rohr- bzw. Behälterwänden.

  • Lecture (Conference)
    ACHEMA 97: Int. Treffen für chem. Technik, Umweltschutz und Biotechnologie, 25. Ausstellungstagung, 9.-14. Juni 1997, Frankfurt/Main

Publ.-Id: 812

Studies of Bubble Flows by Positron Emitting Radiotracers

Hensel, F.; Prasser, H.-M.

Positron Emission Tomography was used in a series of experiments in the field of two-phase flow systems. The main goal was to observe mixing and flow phenomena in efficient spatial and time resolution [1].

Liquid positron emitting tracers were used for monitoring the mixing of a tracer distribution in a bubbly flow. At the beginning of the experiment an aqueous solution of Sodium Fluorine (NaF), labelled with 18F is injected into the two-phase mixture at a certain local position. This tracer starts to disperse caused by turbulence. The radiation originating from the annihilation of the positrons is detected by two opposite detector arrays, a double head spherical PET-scanner [2]. From the recorded event rates, a spatial intensity distribution of the annihilation events is calculated, which corresponds to the local concentration of the tracer.

For the experiments two setups were used. The fist consists of a flat rectangular water tank. Here the bubbly flow was generated by air injection near the tank bottom and by catalytic H2O2 decomposition, respectively. In the other setup, a vertical pipe was used. The bubbles were generated along a rod centred in the pipe, using catalytic H2O2 decomposition. In another experiment, the liquid drainage in a cellular foam was monitored.

The quantity of the active nuclide was restricted to several MBq, due to radiation protection requirements. Despite of this limitation, a good imaging is possible if the evaluation of event data can be restricted to two dimensions. For that case, a simple and time sparing midplane backprojection of the annihilation events can be applied. For the tracer, 18F was used in solution.

Using this technique, time sequences of images of the tracer concentration distribution with a time resolution of 0.5s were obtained and will be presented in the paper. This time base provides an appropriate statistical accuracy for the determination of the dispersion coefficients, too, which were determined for the bubbly flow and in the foam zone of the vertical pipe.

Transport processes in bubbly flows and foams seem to be interesting topics for investigation using a PET technique. The main advantage of PET tracers is the fact that many organic substances can be labelled with positron emitting isotopes which is important for the component sensitive investigation of many industrial processes, an objective of the further work.

  • Lecture (Conference)
    Frontiers in industrial Process Tomography, Delft, April 9-12, 1997
  • Contribution to proceedings
    Proceedings of the Conference Frontiers in Industrial Process Tomography II Delft, The Nederlands, April 9 - 12, 1997, pp. 47 - 51

Publ.-Id: 811

Stand der Projektvorhaben BMFT 02 S 7442 2 und Ziele des Neuantrages

Nebelung, C.; Nitsche, H.; Hübener, S.; Bernhard, G.

  • Lecture (Conference)
    5. Sitzg. Arbeitskreis "Freimessg. v. Anlageteilen u. Bauschutt aus dem Abbau kerntechn. Anlagen des Brennstoffkreislaufes" TU München, 15.3.96

Publ.-Id: 809

Direktmessung alpha-aktiver Nuklide

Nebelung, C.; Nitsche, H.

  • Lecture (Conference)
    6. Sitzg. Arbeitskreis "Freimessg. v. Anlageteilen u. Bauschutt aus dem Abbau kerntechn. Anlagen des Brennstoffkreislaufes" Rossendorf, 6.11.96

Publ.-Id: 808

Untersuchungen der Erwärmungsprozesse in Lagertanks mit gefährdenden Flüssigkeiten bei äußerer Brandeinwirkung

Aszodi, A.; Liewers, P.; Krepper, E.; Prasser, H.-M.

Wenn ein zylindrischer Lagertank durch ein externes Feuer von der Seite intensiver Wärmeeinwirkung ausgesetzt ist, so setzt der Massenverlust infolge von Dampffreisetzung viel eher ein, als im Fall einer Wärmezuführung vom Behälterboden. Mittels eines vereinfachten Modells konnten die Details des Erwärmungsprozesses und die Ursachen für das unterschiedliche Verhalten in Abhängigkeit von der Art und Weise der Wärmezufuhr erklärt werden. Die ZUfuhr vom Boden führt zu einer irregulären thermischen Konvektion und damit einer guten Durchmischung des Fluids, so daß die Sättigungstemperatur an allen Punkten im Behälter nahezu gleichzeitig erreicht wird. Die maximale Enthalpie im Behälter verbleibt während der gesamten Zeit nahe dem Mittelwert. Wird der Behälter von der Seite beheizt, so bildet sich eine stabile horizontale Temperaturschichtung heraus. Die Bildung von Dampf erfolgt bereits lange bevor die mittlere Temperatur den Siedepunkt erreicht hat. Passive konstruktive Maßnahmen, wie der Einbau von Prallplatten, können die Schichtung stören, das verstärkte Aufheizen an der Oberfläche vermeiden und die Freisetzung von Dampf verzögern. Eine durchgreifende Vermischung des flüssigen Inhalts konnte jedoch nicht erreicht werden. Die genaue Gestalt und die Wirkung dieser Prallplatten hängt von der konkreten Behältergeometrie ab und läßt sich weiter optimieren.

  • Technische Überwachung 38 (1997) 4, pp. 22-25

Publ.-Id: 807

Dynamic instabilities in electromagnetic levitation

Priede, J.; Gerbeth, G.

  • Contribution to proceedings
    3rd Int. Conference Transfer Phenomena in Magnetohydrodynamic & Electroconducting Flows, Aussois, France, September, 22-26, 1997, Vol. 2, pp. 377 - 384

Publ.-Id: 806

Velocity profile optimization for the Riga dynamo experiment

Stefani, F.; Gerbeth, G.; Gailitis, A.

  • Contribution to proceedings
    3rd Int. Conference Transfer Phenomena in Magnetohydrodynamic & Electroconducting Flows,Aussois, France, September, 22-26, 1997, Vol. 1, pp. 27 - 32

Publ.-Id: 805

Two- and three-dimensional instabilities of the cylinder wake in an aligned magnetic field

Mutschke, G.; Gerbeth, G.; Shatrov, V.; Tomboulides, A.

  • Physics of Fluids, Vol. 9, No.11, 1997, pp.3114-3116

Publ.-Id: 804

Technetium Coordination Ability of Cysteine-containing Peptides: X-ray Absorption Spectroscopy of a 99 Tc Labelled Endothelin Derivative

Johannsen, B.; Jankowsky, R.; Noll, B.; Spies, H.; Reich, T.; Nitsche, H.; Dinkelborg, L.; Hilger, C. S.; Semmler, W.

  • Applied Radiation and Isotopes Vol. 48, No. 8, pp. 1045-1050, 1997

Publ.-Id: 803

Synthesis and Molecular Structure of a Rhenium Complex derived from 6-Methyl-8 Alpha-amino-ergoline

Spies, H.; Noll, B.; Noll, S.; Findeisen, A.; Leibnitz, P.; Schulze, P. E.; Johannsen, B.

  • Chemische Berichte, Recueil 1997, 130, 839-841

Publ.-Id: 802

Das sächsische Windenergiepotential und seine Wirtschaftlichkeit

Rindelhardt, U.; Hirsch, W.

Auf der Basis der Ergebnisse eines speziellen Windmeßprogramms und unter Nutzung des Windatlasprogramms WASP wurde das sächsische Windenergiepotential zu 6000 GWh/Jahr ermittelt. Das Erwartungspotential liegt bei 1700 GWh/Jahr (entsprechend 10% der derzeitigen Elektroenergiebedarfes). Bei einem jährlichen Ertrag einer Windenergieanlage von 2000 Vollbenutzungsstunden kann diese unter den derzeitigen Rahmenbedingungen wirtschaftlich betrieben werden. Die bisher vorliegenden Betriebsergebnisse unterstreichen die Notwendigkeit qualifizierter Standortgutachten.

  • Lecture (Conference)
    Energie und Umwelt '97, Chemnitz, 19./20.3.97, Tagungsband S. 159
  • Contribution to proceedings
    Energie und Umwelt '97, Chemnitz, 19./20.3.1997, Tagungsband S. 159

Publ.-Id: 801

2-D and 3-D instabilities of the cylinder wake in external magnetic fields

Mutschke, G.; Gerbeth, G.; Shatrov, V.

  • Contribution to external collection
    APS/DFD '96, Syracuse, USA, Nov. 1996
  • Bulletin of the American Physical Society 41 (1996) 9, pp. 1715

Publ.-Id: 800

Separation Control of the cylinder wake using surface localized electromagnetic forces

Weier, T.; Gerbeth, G.; Mutschke, G.; Lielausis, O.; Platacis, E.

  • Contribution to external collection
    APS/DFD '96, Syracuse, USA, 25. Nov. 1996
  • Bulletin of the American Physical Society 41 (1996) 9, pp. 1750

Publ.-Id: 799

Hydrothermal Wave Instability of Thermocapillary-Driven Convection in a Coplanar Magnetic Field

Priede, J.; Gerbeth, G.

  • Journal Fluid Mechanics 11 (1996) pp. 1-000

Publ.-Id: 798

Experiments on cylinder wake stabilization in an electrolyte solution by means of electromagnetic forces localized on the cylinder surface

Weier, T.; Gerbeth, G.; Mutschke, G.; Platacis, E.; Lielausis, O.

Electromagnetic body forces, i.e. Lorentz forces, have been used to modify the boundary layer around a circular cylinder in cross flow. Depending on the polarity of the applied electric field different effects on the flow can be obtained. Lorentz forces directed with the mean flow are able to prevent the boundary layer from separation. Therefore flow separation as well as the von Karman vortex trail can be suppressed. When the momentum gain produced by the Lorentz forces in the boundary layer is high enough, thrust is produced, what results in a jet flow originated from the cylinders back side. If the Lorentz forces are directed opposite to the mean flow, the separation points are shifted towards the front stagnation point, the recirculation region broadens and the von Karman vortex trail is modified. The described technique gives a variety of opportunities to control the flow around the cylinder and the flow structure of the cylinder wake. Results from flow visualizations and numerical calculations are presented.

  • Lecture (Conference)
    Flow Control - Workshop, Cargese, July 1996
  • Experimental Thermal and Fluid Science, Vol.16, 1998, pp.84-91, Elsevier Science

Publ.-Id: 797

On some instabilities of electromagnetically levitated spherical bodies

Priede, J.; Galindo, V.; Gerbeth, G.

  • Contribution to proceedings
    Proceedings of the Int. Congress "Electromagnetic Processing of Materials", Paris, May 27 - 29, 1997, Vol. 2, pp. 419 - 424

Publ.-Id: 795

Influence of thermal boundary conditions on the stability of thermocapillary driven convection low-Prandtl-numbers convection

Priede, J.; Gerbeth, G.

  • Physics of Fluids, Vol. 9, 1997, pp. 1621 - 1634

Publ.-Id: 794

Modelling of the Isothermal Melt Flow due to Rotating Magnetic Fields in Crystal Growth

Barz, R.-U.; Gerbeth, G.; Wunderwald, U.; Buhrig, E.; Gelfgat, Y. M.

  • Journal of Crystal Growth, Vol. 180, 1997, pp. 410-421
  • Poster
    Int. Workshop on Modelling in Crystal Growth, Durbuy , Oct. '96

Publ.-Id: 793

Untersuchungen zur Spezitation von f-Elementen mittels laserinduzierter photoakustischer Spektroskopie

Geipel, G.; Bernhard, G.; Brachmann, A.; Brendler, E.; Nitsche, H.

  • Poster
    Anakon '97, Konstanz, 06.-08. 1997

Publ.-Id: 792

Light-scattering spectroscopy of a liquid gallium surface

Kolevzon, V.; Gerbeth, G.

  • Journal of Physics D: Applied Physics 29 (1996) pp. 2071-2081

Publ.-Id: 789

Light scattering study of the mercury liquid-vapor interface

Kolevzon, V.; Gerbeth, G.; Pozdniakov, G.

  • Physical Review E Volume 55, Number 3, March 1997, pp. 3134 - 3142
  • Lecture (Conference)
    Int. Workshop on Hydrodynamic Aspects of Electron Beam Technologies, Dresden, March 16 - 18, 1997

Publ.-Id: 788

Advances in technetium chemistry towards 99m Tc receptor imaging agents

Johannsen, B.; Spies, H.

  • Transition Metal Chemistry, 22. 318-320 (1997)

Publ.-Id: 787

Measurements of random and channeling stopping powers and charge state distributions in silicon for 0.2 - 1.2 MeV/u heavy ions

Jiang, W.; Grötzschel, R.; Pilz, W.; Schmidt, B.; Möller, W.

  • Physical Review B Volume 59, Number 1, 1 January 1999, pp. 226-234

Publ.-Id: 786

The Kinetics of the Ion-Beam-Induced Interfacial Amorphization in Silicon, Seite 5360, Manuskript-Nr.: 015721 JAP

Henkel, T.; Heera, V.; Kögler, R.; Skorupa, W.; Seibt, M.

  • Journal of Applied Physics, 82 (11), 1 December 1997, S. 5360-5373

Publ.-Id: 785

Synthesis of 17 Alpha-Substituted Mercaptoalkynyl Derivatives of 3,17 Beta-Estradiol

Wüst, F.; Spies, H.; Johannsen, B.

  • Tetrahedron Letters 38 (1997) 17 pp. 2931-2932

Publ.-Id: 784

Comparison of Uranyl Complexation Behavior with Natural and Model Humic Acids

Pompe, S.; Brachmann, A.; Bubner, M.; Heise, K.-H.; Geipel, G.; Nitsche, H.

  • Poster
    Migration '97, 26.-31.10.1997

Publ.-Id: 783

Sorption of Uranium(VI) on Rock Material of a Mine Tailing Pile: Solution Speciation by Fluorescence Spectroscopy

Geipel, G.; Bernhard, G.; Brendler, V.; Nitsche, H.

  • Radiochimica Acta 74 (1996) pp. 235-238
  • Poster
    Migration '95

Publ.-Id: 782

Methodenentwicklung zur Freimessung von Bauschutt auf alpha-aktive Nuklide (Th, U, Np, Pu, Am)

Nebelung, C.; Hübener, S.; Bernhard, G.

  • Other report
    zum Fördervorhaben BMBF 02 S 7442 2 (Schlußbericht)

Publ.-Id: 780

Light scattering study of viscoelastic properties of a liquid Gallium surface

Kolevzon, V.

  • The journal of chemical physics 106 (14), 8 April 1997

Publ.-Id: 779

Determination of relative arsenite and arsenate Concentrations in aqueous mixtures by XANES

Denecke, M. A.; Friedrich, H.; Reich, T.; Bernhard, G.; Knieß, T.; Rettig, D.; Zorn, T.; Nitsche, H.

  • Other report
    HASYLAB - Annual Report 1996 I, 751(1997)
  • Lecture (Conference)
    HASYLAB Nutzertreffen, Hamburg, Germany, 31.01.1997

Publ.-Id: 777

Structural Analysis of Uranium(VI) Complexes by X-ray Absorption Spectroscopy

Reich, T.; Hudson, E. A.; Denecke, M. A.; Allen, P. G.; Nitsche, H.

  • Contribution to external collection
    Poverkhnost (Moskau) 4-5, 149 (1997)
  • Surface Investigations 13, 557 (1998)

Publ.-Id: 776

EXAFS Investigations on the Interaction of Uranium(VI) with Natural and Synthetic Humic Acids

Denecke, M. A.; Pompe, S.; Reich, T.; Moll, H.; Bubner, M.; Heise, K.-H.; Nicolai, R.; Nitsche, H.

  • Radiochimica Acta 79 (1997), 151-159

Publ.-Id: 772

Corrosion Behavior and Microstructure of Titanium implanted with alpha and beta stabilizing elements

Pham, T.; Zyganow, V.; Matz, W.; Reuther, H.; Oswald, S.; Richter, E.; Wieser, E.

  • Thin Solid Films 310 (1997) 251-259

Publ.-Id: 771

Blue photoluminescence from high-dose Si+ - and Ge+ - implanted silicon dioxide layers

Rebohle, L.; Tyschenko, I. E.; Fröb, H.; Leo, K.; Yankov, R. A.; von Borany, J.; Skorupa, W.

  • Microelectronic Engineering 36 (1997) 107
  • Lecture (Conference)
    10th Biennial Conf. on Insulating Films on Semiconductors, Stenungsund, Sweden, June 11 - 14, 1997

Publ.-Id: 769

Impurity gettering effects in SIMOX wafers: what getters what, where and how

Yankov, R. A.; Kaschny, J.; Fichtner, P.; Mücklich, A.; Kreißig, U.; Skorupa, W.

  • Microelectronic Engineering 36 (1997) 129

Publ.-Id: 768

Relativistic Description of Exclusive Deuteron Break-up Reactions

Kaptari, L. P.; Kämpfer, B.; Dorkin, S. M.; Semikh, S. S.

The exclusive deuteron break-up reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Relativistic effects in the cross section, tensor analyzing power and polarization transfer are investigated in explicit form. Results of numerical calculations are presented for kinematical conditions in forthcoming p + D reactions at COSY.

  • Physics Letters B 404(1997)8-14
  • Open Access Logo Forschungszentrum Rossendorf; FZR-161 Preprint
    ISSN: 1436-3976


Publ.-Id: 767

Self-organization Kinetics in Finite Precipitate Ensembles During Coarsening

Borodin, V.; Heinig, K.-H.; Reiß, S.

A rate equation approach is applied for the description of the self-organization (layering) phenomenon predicted in recent computer experiments. This layering was observed in finite precipitate systems during annealing and is caused by Ostwald ripening. We demonstrate that the layering is triggered by local inhomogenities in the spatial distribution of precipitate sizes and should not be treated in terms of the frequently considered "spinodal
decomposition" approach. The change of the spatial profile of precipitate size starts from the boundary of the system and occurs within a "reaction shell" having a thickness of the order of the diffusional screening
length. During annealing this "reaction shell" shifts progressively into the system, leaving behind layers of precipitates. The layering is shown to occur only in sufficiently large systems with characteristic dimensions of at least several diffusional screening lengths. The reason for the weak sensitivity of interlayer distance to variations of system parameters is elucidated.

  • Phys. Rev. B56 (1997) 5332

Publ.-Id: 766

Influence of Input Neutron Spectrum Covariances on Results of Pressure Vessel Neutron Spectrum Adjustments

Böhmer, B.; Manturov, G.

One of the most critical problems in practical applications of spectrum adjustment in pressure vessel dosimetry is the insufficient knowledge of the input spectrum covariance matrix. Usually very crude approximations for this covariance matrix are used in adjustment procedures and, moreover, it is not clear to which extent these approximations influence the final results. Therefore it appeared useful to calculate this matrix as carefully as possible for a typical system and in positions for which a sufficient amount of activation measurements and precise transport calculations was available. The paper presents and discusses results of such calculations for a VVER-1000 type reactor. They base on the one hand on sensitivity coefficients estimated in transport calculations by means of the ANISN code and on the other hand on cross section covariance data taken from the Obninsk ABBN-93 data library. The results of spectrum adjustments based on the estimated covariance matrix are compared with results based on formerly used matrices. The obtained differences are discussed.

  • Poster
    9th International Symposium on Reactor Dosimetry, Sept. 2-6, 1996, Prague Eds H. Ait Abderrahim, P. D'hondt, B. Osmera, World Scientific Publishing, Singapore (1998) ISBN 981-02-3346-9, pp 294-301
  • Contribution to proceedings
    9th International Symposium on Reactor Dosimetry, Sept. 2-6, 1996, Prague Eds H. Ait Abderrahim, P. D'hondt, B. Osmera, World Scientific Publishing, Singapore (1998) ISBN 981-02-3346-9, pp 294-301

Publ.-Id: 765

Rossendorfer Intranet-Bibliotheks-Informationssystem

Rücker, C.; Koch, R.

  • Merkmale des Internets
  • Was ist ein Intranet?
  • Entwicklungen im Internet/Intranet
  • Integrierbarkeit lokaler Bibliothekssysteme
  • Vorarbeiten zum Rossendorfer Intranet
  • Probleme mit File-Server-Datenbanken (z. B. MS-ACCESS und dBASE)
  • Ziele und Arbeitsprogramm
  • Weitere Informationsdienste im Rossendorfer Intranet-Bibliotheks-Informationssystem
  • Oracle als Basis des Informationssystems
  • Zum Oracle WebServer
  • Lecture (others)
    Nutzung naturwissenschaftlich-technischer Datenbanken durch Forschungseinrichtungen in den neuen Bundesländern (NDF), 1996

Publ.-Id: 764

Natural circulation experiments at the ISB-VVER integral test facility and calculations using the code athlet

Krepper, E.

In 1995 at the integral test facility ISB-VVER in Elektrogorsk near Moscow natural circulation experiments were performed, which were scientifically accompanied by the Forschungszentrum Rossendorf. These experiments were the first of this kind at a test facility, which models VVER-1000 thermalhydraulics. Using the code ATHLET which is being developed by "Gesellschaft für Anlagen- und Reaktorsicherheit", pre- and posttest calculations were done to determine the thermalhydraulic events to be expected and to define and tune the boundary conditions of the test. The conditions found for natural circulation instabilities and cold leg loop seal clearing could be confirmed by the tests. Besides the thermalhydraulic standard measuring system, the facility was equipped with needle shaped conductivity probes for measuring the local void fractions.

  • Lecture (Conference)
    Jahrestagung Kerntechnik Aachen 1997
  • Contribution to proceedings
    Jahrestagung Kerntechnik Aachen 1997, Proceedings pp. 85-88

Publ.-Id: 763

Simulation der einphasigen Naturkonvektion auf der Sekundärseite der NOKO Anlage mit dem CFD-Code CFX 4

Aszodi, A.

  • Lecture (Conference)
    Jahrestagung Kerntechnik 1997

Publ.-Id: 762

Eine Methodik zur Bestimmung der Neutronenbelastung von Reaktordruckbehältern und deren Anwendung auf WWER

Barz, H.-U.; Böhmer, B.; Stephan, I.

  • Lecture (Conference)
    Jahrestagung Kerntechnik 1997 (KT6)
  • Contribution to proceedings
    Jahrestagung Kerntechnik 97, Aachen, 13.-15. Mai 1997, Tagungsbericht S. 37-40

Publ.-Id: 761

Determination of Pressure Vessel Neutron Fluence Spectra for a Low Leakage Rovno-3 Reactor Core Using Three Dimensional Monte Carlo Neutron Transport Calculations and Ex-vessel Neutron Activation Data

Barz, H.-U.; Böhmer, B.; Konheiser, J.; Stephan, I.; Borodkin, G.

Three dimensional Monte Carlo calculations considering all known geometrical and composition details were used for the determination not only of fluence integrals but also of fluence spectra with good statistical accuracy. This was possible by the application of own specially developed codes (TRAMO) and successfully modifying variance reduction on the basis of the weight window method (TRAWEI). Modern multigroup data sets were applied. For the real representation of fission sources the burn up and power history also for the fuel rods within the fuel assemblies was considered.
The investigation was accomplished for the irradiation period seven with a special low leakage loading of the reactor. During this period Russian and German detectors were irradiated in the ex-vessel cavity and analysed by advanced gamma spectrometric methods.
The reaction rates obtained with the calculated fluence spectra were compared with activation reaction rates measured in the ex-vessel cavity. Furthermore the calculated spectra were adjusted to the experimental reaction rates taking into account the variances and correlations of calculated input spectra, detector sensitivities and measurements. Using the adjustment code COSA2 based on the maximum likelihood method best estimate fluence spectra and fluence integrals could be provided.

  • Lecture (Conference)
    9th International Symposium on Reactor Dosimetry, Sept. 2-6, 1996, Prague
  • Contribution to proceedings
    in H.A. Abderrahim, P. D'hondt and B. Osmera (Ed.), Proceedings of the 9th International Symposium on Reactor Dosimetry, Prag (pp.58-66)

Publ.-Id: 760

Alpha-ERDA analysis of the energy distribution of oxygen ions implanted into silicon with plasma immersion ion implantation

Barradas, N.; Maas, A. J. H.; Mändl, S.; Günzel, R.

Plasma immersion ion implantation was used to implant
oxygen ions into silicon with applied voltage pulses of -40 kV and 2.5
ms lenght. Positive ions, O2+ and O+, with a continuous energy distribution
between 0 and 40 keV were implanted. Between 3x104 and 3x105 pulses, corresponding
to nominal doses from 2x1016 to 2x1017/cm2 were used. The resulting oxygen
depth profiles were measured with elastic recoil detection analysis (ERDA)
using 13.4 MeV a particles. Rutherford backscattering was used to determine
possible co-implanted contaminations. The obtained depth profiles were
simulated using a linear supersposition of calculated single-energy profiles.
The results obtained for the energy distribution of the incident ions are
compared with calculations obtained from a theoretical model, and the agreement
is very good. The incident flux is found to be composed of 34(5)% O2+ and
66(5)% O+ ions with an Fe contamination of ca. 0.5%.

  • Journal of Applied Physics 81 (10), 15 Mai 1997

Publ.-Id: 759

The Rossendorfer Beamline at the ESRF (Project ROBL)

Matz, W.; Prokert, F.; Schlenk, R.; Claußner, J.; Schell, N.; Eichhorn, F.; Bernhard, G.

In this final design report the general layout and the optics of the beamline ROBL is described. The beamline is buildt by the Research Center Rossendorf at the bending magnet source BM20 of the European Synchrotron Radiation Facility (ESRF), Grenoble. The design criteria for the beamline optics and the adopted solutions are reported in detail. Some performance data of the beamline as resolution, focussing and intensity are modelled by the ray-tracing code SHADOW. Furthermore tha layout of the vacuum system is described.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-158
    ISSN: 1436-3976


Publ.-Id: 758

Bericht der Herbsttagung der Studiengruppe für Elektronische Instrumentierung vom 30. September bis 2. Oktober 1996 in Zeuthen

Gabriel, F.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-160
    ISSN: 1436-3976


Publ.-Id: 755

Decay Study of Hot Nuclei Below the Multifragmentation Threshold with the FOBOS Detector at Dubna

Herbach, C.-M.; Ortlepp, H.-G.; Gippner, P.; Kamanin, D. V.; Penionzhkevich, Y. E.; Renz, G.; Schilling, K.-D.; Strekalovsky, O. V.; Tichtchenko, V. G.; Wagner, W.; u. a.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-159 Preprint
    ISSN: 1436-3976
  • Contribution to proceedings
    Int. Research Workshop, Poiana Brusov, Romania, Oct. 7 - 14, 1996


Publ.-Id: 754

Conductive Tungsten-Based Layers Synthesized by Ion Implantation into 6H-Silicon Carbide

Weishart, H.; Schöneich, J.; Voelskow, M.; Renkewitz, S.; Skorupa, W.

We studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2×10(17) W(+)cm(-2) at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.

  • Materials Research Society symposium proceeding 438 (1997) pp. 283-288 (MRS 1996 Fall Mtg)

Publ.-Id: 753

Resonant photon scattering on the semi-magic nucleus 89Y up to 7 MeV* Account Nr.: 00269871

Reif, J.; von Brentano, P.; Eberth, J.; Enders, J.; Herzberg, R.-D.; Huxel, N.; Käubler, L.; von Neumann-Cosel, P.; Nicolay, N.; Pietralla, N.; Prade, H.; Richter, A.; Schlegel, C.; Schnare, H.; Schwengner, R.; Servene, T.; Skoda, S.; Thomas, H. G.; Wiedenhöver, I.; Winter, G.; Zilges, A.

The semi-magic nucleus 89Y has been investigated in a (gamma,gamma')
experiment at an endpoint energy of the bremsstrahlung of E0=
7 MeV. The scattered photons have been detected with a EUROBALL Cluster
detector. The observed excitations are discussed in the framework of the
shell model and a coupling of the unpaired proton to milti-phonon structures
in the doubly even neighbours. Transitions above 4.7 MeV are considered
to have E1 character. Around 6.3 MeV an unusually large concentration of
E1 strength is found. Its origin is likely to correspond to similar structures
in the 88Sr and 90Zr isotones which can be interpreted
to result from the constructive interference of strong two-phonon amplitudes
with weak admixtures from the low-energy tail of the giant dipole resonance.

  • Nuclear Physics A 620 (1997) 1-15

Publ.-Id: 752

A Simple and Effecient Synthesis of a Derivatized Pseudotripeptide containing a Methylene Thioether Isoster and its Use for the Design of Bifunctional Rhenium and Technetium Chelating Agents

Scheunemann, M.; Johannsen, B.

  • Tetrahedron Letters 38 (1997) 1371-1372

Publ.-Id: 751

Synthesis and Molecular Structure of a Rhenium Complex Derived from 8-alpha-Amino-6-methyl-ergoline

Spies, H.; Noll, B.; Noll, S.; Findeisen, M.; Leibnitz, P.; Schulze, P.; Johannsen, B.

  • Chemische Berichte, Recueil 1997, 130, 839-841

Publ.-Id: 750

Institute of Safety Research, Annual Report 1995

Weiß, F.-P.; Rindelhardt, U.; (Editors)

The report gives an overview on the scientific work of the Institute of Safety Research in 1995.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-152 September 1996
    ISSN: 1436-3976


Publ.-Id: 748

Quantitative AMS depth profiling of the hydrogen isotopes collected in Graphite Divertor and Wall Tiles of the Tokamak ASDEX - Upgrade

Sun, G.; Friedrich, M.; Grötzschel, R.; Bürger, W.; Behrisch, R.; Garcia-Rosales, C.

The accelerator mass spectrometry (AMS) facility at the
3 MV Tandetron in Rossendorf has been applied for quantitative depth profiling
of deuterium and tritium in samples cut from the vessels walls of the fusion
experiment ASDEX-Upgrade in Garching. The tritium originates from D(d,p)T
fusion reaction in the plasma and it is implanted in the vessel walls together
with deuterium atoms and ion from the plasma. The high deuterium concentrations
in the samples were measured by a conventional SIMS mode. The concentrations
in the surface layers down to the analysing depth of about 25 mm are for
deuterium in the range of up to 3x1018 to 8x1021 atoms/cm3, corresponding
to a deuterium retention of 2.5x1016 to 2.5x1018 atoms/cm2 in a surface
layer £ 25 mm, and for tritium in the range form 1011 to 5x1015 atoms/cm3,
corresponding to a tritium retention of 3.0x1010 to 3.5x1012 atoms/cm2
in a surface layer £25 mm. The estimated total amount of tritium
in the vessel walls is in agreement with the total number of neutrons produced
in D(d,n)3He reaction.

  • Journal of Nuclear Materials 246 (1997) 9-16

Publ.-Id: 747

Study of the ion-acoustic effect using focused ion beams

Teichert, J.; Bischoff, L.; Köhler, B.

Acoustic waves induced by an intensity-modulated focused
ion beam (FIB) have been measured. The experiments were performed with
Ga+ ions of 35 keV at a current of 3 nA and variable chopping frequency
up to 10 MHz. The acoustic signals were detected by means of a piezoelectric
sensor with integrated pre-amplifier. A dependence on the sample material
was found. The results suggest that the ion-acoustic effect can be utilized
for imaging and material characterization of surface and subsurface structures
in FIB systems.

  • Lecture (Conference)
    Proc. bei MRS Fall Meeting, Boston, Dez. 1996
  • MRS Symp. Proc. 438 (1997) 453

Publ.-Id: 746

Entwicklung einer einfachen Alpha-Meßmethode

Nebelung, C.; Nitsche, H.

  • Lecture (Conference)
    Seminar "Freigabemessung" 19.11.1995, Stuttgart

Publ.-Id: 745

Reaction Gas Chromatography of Oxide and Hydroxide Species of Molybdenum - Simulation and Experiment

Vahle, A.; Hübener, S.; Dressler, R.; Eichler, B.; Türler, A.

  • Radiochimica Acta 78, 53-57 (1997)

Publ.-Id: 744

Thermochromatography of Heavy Actinoides - Determination of the Sublimation Enthalpy of Es

Taut, S.; Hübener, S.; Eichler, B.; Gäggeler, H. W.; Schädel, M.; Zvara, I.

  • Radiochimica Acta 78, 33-38 (1997)

Publ.-Id: 743

Evidence for acoustic waves induced by focused ion beams

Teichert, J.; Bischoff, L.; Köhler, B.

Acoustic waves induced by an intensity modulated focused ion beam (FIB) have been measured. The experiments were performed with Ga+ ions of 35 keV at a current of 3 nA and variable chopping frequency up to 10 MHz. The acoustic signals were detected by means of a piezoelectric sensor with integrated pre-amplifier. Frequency and position sensitivity of the sensor has been measured by laser excitation. Ion acoustic measurements have been carried out at the resonance frequencies of the sensor. A dependence on the sample material was found. The results show that the ion-acoustic effect can be utilized for imaging and material analysis in FIB systems.

  • Applied Physics Letters 69 (1996) 11, pp. 1544-46

Publ.-Id: 742

Structure, properties and applications of thin Fe-Al layers

Reuther, H.

Fe-Al show interesting physical properties and offer some
special industrial applications. There are phase transitions combined with
changes in the magnetic behaviour. Another interesting fact is the excellent
oxidation and corrosion resistance of iron aluminides even at high temperatures.
Thin Fe-Al layers can be produced in different ways. Ion beam methods enable
to produce surface layers on bulk material modifying the initial properties
completely. The properties depend strongly on the phase structure induced
by the preparation process. 57-Fe Mössbauer spectroscopy, and in the
case of surface layers conversion electron Mössbauer spectroscopy
is very suitable to identify this phase structure. In the present work,
it is described for Al implanted Fe layers. Depending on implantation dose
and energy both magnetic and non-magnetic phases can be produced. Due to
the inhomogeneous distribution of Al in the Fe target a layer structure
of different phases can be created. Moreover, due to double implantation
an Fe-Si-Al alloy can be prepared

  • Hyperfine Interactions 111 (1998) 135-140
  • Lecture (Conference)
    ISIAME '96

Publ.-Id: 741

Heating of Nuclei with Energetic Antiprotons

Goldenbaum, F.; u. a.; Eades, J.; von Egidy, T.; u. a.; Galin, J.; u. a.; Golubeva, Y. S.; Gulda, K.; u. a.; Pausch, G.; Proschitzki, S.

  • Physical Review Letters 77 (1996) 7 pp. 1230-33

Publ.-Id: 740

Interfering Doorway States and Giant Resonances II: Transition strengths Manuskript-Nr.: CC6302

Sokolov, V. V.; Rotter, I.; Savin, D. V.; Müller, M.

The mixing of the doorway components of a giant resonance due to the interaction via the common decay channels influences significantly the distribution of the multipole strength and the energy spectrum of the decay products of the giant resonance. The photoemission turns out to be most sensitive to the overlapping of the doorway states. At high excitation energies, the interference between the doorway states leads to a restructuring towards lower energies and apparent quenching of the dipole strength.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-154 Preprint
    ISSN: 1436-3976
  • Physical Review C, Volume 56, Number 2, 1044-1056


Publ.-Id: 738

Interfering Doorway States and Giant Resonances I: Resonance Spectrum and Multipole Strengths

Sokolov, V. V.; Rotter, I.; Savin, D. V.; Müller, M.

Using a phenomenological schematic model of multipole giant resonances we consider the effects of overlapping of their doorway components. The conccpt of the partial widths of a giant resonance becomes ambiguous when the escape widths get comparable with the spacings between the components. In such a case, the partial widths determined in terms of the K- and S-matrices differ from each othcr. The mixing of the doorway components due to the interaction via the common decay channels influences significantly their multipole strengths, widths and positions in energy.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-153 Preprint
    ISSN: 1436-3976
  • Physical Review C, Volume 56, Number 2, S.1031-1043


Publ.-Id: 737

Tilted Rotation of Triaxial Nuclei

Frauendorf, S.; Meng, J.

The Tilted Axis Crankiug theory is applied to the model of two particles coupled to a triaxial rotor. Cornparirig with the exact quantal solutions, the interpretation and quality of the mean field approximations studied. Conditions are discussed when the axis of rotation lies inside or outside of the principal planes of the triaxial density distribution. The planar solutions represent ∆ I = 1 bands, whereas the aplanar solutions represent pairs of identical ∆ I = 1 bands with the same parity. The two bands differ by the chirality of the principal axes with respect to the angular momentum vector. The transition from planar to chiral solutions is evident in both the quantal and the mean field calculations. Its physical origin is discussed.

  • Open Access Logo Forschungszentrum Rossendorf; FZR-156 Preprint
    ISSN: 1436-3976
  • Nuclear Physics A 617(1997), 131-147


Publ.-Id: 736

Composition analysis of Nd x Fe y B thin films by RBS and heavy ion ERDA

Grötzschel, R.; Mäder, M.; Kreißig, U.; Grigull, S.; Assmann, W.; Parhofer, S.

  • Nuclear Instruments and Methods in Physics Research B 118 (1996) pp. 139-143

Publ.-Id: 735

Depth resolved ion beam analysis of objects of art

Neelmeijer, C.; Wagner, W.; Schramm, H.-P.

  • Nuclear Instruments and Methods in Physics Research B 118 (1996) pp. 338-345

Publ.-Id: 734

Tribological properties of chromium implanted silicon nitride ceramics with respect to microstructure

Brenscheidt, F.; Wieser, E.; Matz, W.; Mücklich, A.; Möller, W.

The tribological and microstructural properties of gas-pressure
sintered Si3N4 ceramics after chromium implantation have been investigated
in dependence on implantation energy. The fluence was kept constant at
1017 ions/cm2. The wear of the modified material is reduced for a load
of 2 N independent of ion energy. This behaviour is accompanied by a slight
incerase of the friction coefficient. At higher loads only high energy
implantations result in an improved wear behaviour. The microstructural
investigations show that no new phase are formed due to implantation. For
all energies a part of the surface becomes amorphous. For smaller energies
this amorphous layer reaches up to the surface whereas at higher energies
it is covered by still crystalline but damaged material. The amorphization
of the surface is accompanied by a large surface swelling which incerases
with implantation energy. We discuss the relationship between the microstructural
features and the observed wear behaviour.

  • Applied Physics A 65, 281-286 (1997)

Publ.-Id: 733

Limitations of the Pulse-Shape Technique for Particle Discrimination in Planar Si Detectors

Pausch, G.; Moszynski, M.; Cederkäll, J.; Grawe, H.; Klamra, W.; Lampert, M.-O.; Rohr, P.; Schubart, R.; Seidel, W.; Wolski, D.

Limitations of the pulse-shape discrimination (PSD) technique - a promising method to identify the charged particIes stopped in planar Si-detectors - have been investigated. The particle resolution turned out to be basically determined by resistivity fluctuations in the buk silicon which cause the charge-collection time to depend on the point of impact. Detector maps showing these fluctuations have been measured and are discussed. Furthermore we present a simple method to test the performance of detectors with respect to PSD. Another limitation of the PSD technique is the finite energy threshold for particle identification. This threshold is caused by an unexpected decrease of the total charge-collection time for ions with a short range, in spite of the fact that the particle tracks are located in a region of very low electric field.

  • Contribution to proceedings
    IEEE Nuclear Science Symposium (NSS'96) Anaheim, California, November 2 - 9, 1996
  • IEEE Transactions on Nuclear Science, Vol. 44, No. 3, June 1997, p 1040-1045
  • Open Access Logo Forschungszentrum Rossendorf; FZR-157 Preprint
    ISSN: 1436-3976


Publ.-Id: 732

The fractal dimension of young colonies of macrophomina phaseolina produced from microsclerotia

Mihail, J. D.; Obert, M.; Taylor, S. J.; Bruhn, J. N.

  • Mycologia 86 (1994) pp. 350


Publ.-Id: 731

Studies of radiometal uptake by cultured normal and tumor cells

Kampf, G.; Knop, G.; Wenzel, U.; Wunderlich, G.; Bergmann, R.; Franke, W.-G.

  • European Journal of Nuclear Medicine 21 (1994) pp. 874

Publ.-Id: 730

Beziehungen zwischen der 169Yb-Aufnahme in Normal- und Tumorzellen und deren metabolischer Aktivität in Abhängigkeit von der Ligandspezies

Kampf, G.; Knop, G.; Matys, S.; Kunz, G.; Wenzel, U.; Bergmann, R.; Franke, W.-G.

  • Nuklearmedizin 33 (1994) A 82

Publ.-Id: 729

Characterization of serotonin uptake sites on the blood brain barrier

Brust, P.; Bergmann, R.

  • Journal of Neurochemistry 63 (1994) (Suppl. 1) S13C

Publ.-Id: 728

ß-Casomorphins - chemical signals of intestinal transport systems

Brandsch, M.; Brust, P.; Neubert, K.; Ermisch, A.

  • Book (Authorship)
    ß-Casomorphins and Related Peptides: Recent Developments (Brantl V. and Teschemacher H., eds.) VCH, Weinheim, 1994, pp. 207-219

Publ.-Id: 727

Compartmental analysis of blood brain transfer and protein incorporation of L-[75Se]seleno methionine in rat brain

Bergmann, R.; Brust, P.; Coenen, H. H.; Stöcklin, G.

  • Journal of Neurochemistry 63 (1994) (Suppl. 1) S78C

Publ.-Id: 726

Differentiating between Monodentate and Bidentate Carboxylate Ligands Coordinated to Uranyl Ions using EXAFS

Denecke, M. A.; Reich, T.; Pompe, S.; Bubner, M.; Heise, K.-H.; Nitsche, H.; Allen, P. G.; Bucher, J. J.; Edelstein, N. M.; Shuh, D. K.

  • Contribution to external collection
    J. Phys. IV France 7, C2-637 (1997)

Publ.-Id: 725

Shears bands in 193Pb

Baldsiefen, G.; u. a.; Stoyer, M. A.; u. a.; Cederwall, B.; u. a.; Vo, D. T.; Frauendorf, S.

  • Physical Review C 54 (1996) 3 pp. 1106-1116

Publ.-Id: 724

Investigation of Fe-Mg alloys produced by ion implantation

Reuther, H.; Betzl, K.; Richter, E.

Iron and magnesium are insoluble elements with each other
and there is no phase diagram. However, it is possible to produce artificial
alloys by ion implantation, in this study by iron implantation into magnesium.
Samples are investigated by conversion electron Mössbauer spectroscopy,
Auger electron spectroscopy and x-ray diffraction. While at low doses gaussian
shaped iron profiles and paramagnetic doublets as Mössbauer spectra
are obtained, the iron concentration reaches at the highest dose 90 at.-%
in maximum and the Mössbauer spectrum shows a dominant ferromagnetic
fraction. The x-ray diffraction pattern let conclude that a dilated a-iron
lattice is formed. Microhardness of all samples is clearly increased due
to the implantation.

  • Hyperfine Interactions 112(1998) 165-168

Publ.-Id: 723

Microdisperse iron silicide structures produced by implantation of iron ions in silicon

Dobler, M.; Reuther, H.; Möller, W.

Iron implanted and subsequently annealed n-type Si(111) was
studied by conversion electron Mössbauer spectroscopy for phase analysis
and Auger electron spectroscopy for sputter depth profiling and element mapping.
During implantation (200 keV, 3 x 1017 cm-2, 350 °C) a mixture of ß-
and a-FeSi2 and after the subsequent annealing (900 °C for 18 h and
1150 °C for 1 h) a complete transition to the ß- and a-phase can
be detected. The as-implanted profile has Gaussian shape which becomes broad
during annealing at 900 °C to a plateau-like profile and shows only
a slight broadening and depth depending fluctuations of the iron concentration
after the 1150 °C annealing. With scanning Auger electron spectroscopy
the lateral iron and silicon distribution were investigated show for the
sample annealed at 900 °C large separated ß-FeSi2 precipitates
which grow due to the process of Ostwald ripening. At 1150 °C additionally
coalescence of the precipitates occur and a wide extended penetration a-FeSi2
network structure is formed.

  • Hyperfine Interactions 112 (1998) 185-188
  • Lecture (Conference)
    ISI AME '96, Südafrika

Publ.-Id: 722

Intruder bands in 114Te: Smooth band termination

Thorslund, I.; Fossan, D. B.; Lafosse, D. R.; Schnare, H.; Hauschild, K.; Hibbert, I. M.; Mullins, S. M.; Paul, E. S.; Ragnarsson, I.; Sears, J. M.; Vaska, P.; Wadsworth, R.

  • Physical Review C 52 (1995) 6 pp. R2839-R2843

Publ.-Id: 721

Band structure of the odd-even 125La, 127La nuclei

Starosta, K.; u. a.; Fossan, D. B.; Lafosse, D. R.; Schnare, H.; u. a.; Satula, W.; Rohozinski, S. G.; Wyss, R.; Hibbert, I. M.; u. a.; Beausang, C. W.; u. a.

  • Physical Review C 53 (1996) 1 pp. 137-150

Publ.-Id: 720

Smooth band termination in 108Sn

Wadsworth, R.; Hauschild, K.; Beausang, C. W.; Cromaz, M.; Schnare, H.; Fossan, D. B.; Flibotte, S.; Galindo-Uribarri, A.; Ragnarsson, I.

Publ.-Id: 719

Triaxial bands in 133Ce

Hauschild, K.; Wadsworth, R.; u. a.; Fallon, P.; Macchiavelli, A. O.; Fossan, D. B.; Schnare, H.; u. a.; Nolan, P. J.

  • Physical Review C 54(1996) 2 pp. 613-619

Publ.-Id: 718

Solubility and Speciation of (UO2)2SiO4 2H2O in Aqueous Systems

Moll, H.; Geipel, G.; Matz, W.; Bernhard, G.; Nitsche, H.

  • Radiochimica Acta 74 (1996) pp. 3-7
  • Poster
    Migration '95

Publ.-Id: 717

A Comparison of Natural Humic Acids with Synthetic Humic Acid Model Substances: Characterization and Interaction with Uranium (VI)

Pompe, S.; Bubner, M.; Denecke, M. A.; Reich, T.; Brachmann, A.; Geipel, G.; Nicolai, R.; Heise, K.-H.; Nitsche, H.

  • Radiochimica Acta 74 (1996) pp. 135-140

Publ.-Id: 716

Identification of Light Charged Particles and Heavy Ions in Silicon Detectors by Means of Pulse-Shape Discrimination

Pausch, G.; Ortlepp, H.-G.; Bohne, W.; Grawe, H.; Hilscher, D.; Moszynski, M.; Wolski, D.; Schubart, R.; de Angelis, G.; de Poli, M.

  • IEEE Transactions on Nuclear Science 43 (1996) 3 pp. 1097-1101

Publ.-Id: 715

K+ -meson production in pBe interactions at Tp = 2.9 GeV

Büscher, M.; Eßer, R.; Franzen, A.; u. a.; Müller, H.; Prietzschtk, B.; Rimarzig, B.; u. a.; Akindinov, A.; Chumakov, M.; Demechin, V.; u. a.; Sibirtsev, A.; Kruglov, V.; Petrus, A.; Koptev, V.; Mikirtychyants, S.

The production of K+ and π+ mesons and protons in pBe collisions at T p =2.9 GeV has been studied at the ITEP proton synchrotron. Ejectiles with a momentum of p=545 MeV/c were observed under an emission angle theta=17°. The detectors which have been developed for the identification of kaons out of a six orders of magnitude more intense background of pions and protons are described. A cross-section ration d2σK+ /dωdp: d2σπ+ /dωdp: d2σ p + /dωdp of (1±0.34):(85±1):(31±1) has been measured. Normalization with existing pion data yields an invariant differential cross section E∙d3σK+ /d3 p=(3.1±1.2) mb GeV-2c3sr-1 and a total cross section of σtot(pBe) =(3.7±1.5) mb. These cross sections are compared with existing data and theoretical predictions. The A dependence of K+ production in the few-GeV range is analyzed.

  • Zeitschrift für Physik A 355 (1996) pp. 93-100

Publ.-Id: 714

The gamma-decay of particle-hole states in 208Pb using the Euroball Cluster detector

Radermacher, E.; Wilhelm, M.; Albers, S.; Eberth, J.; Nicolay, N.; Thomas, H. G.; von Brentano, P.; Schwengner, R.; Skoda, S.; Winter, G.; Maier, K. H.

Neutron particle-hole states in the doubly magic nucleus 208Pb
were investigated using a Euroball Cluster detector and five usual HPGe
detectors at the Osiris cube spectrometer in Cologne. 126 gamma-ray transitions
with energies up to 7.2 MeV could be detected, 14 of those for the first
time. The states were excited with the 208Pb (p,p'gamma)208Pb
reaction via isobaric analogue resonances in 209Bi at Ep=16.5,
17, 17.45, 17.5 and 18.5 MeV and through the subcoulomb 207Pb(d,pgamma)208Pb
reaction at Ed=10 MeV. For most of the excited states assignments
for the particle and/or the hole component of the configuration could be
made, 22 of these are new.

  • Nuclear Physics A 597 (1996) pp. 408-426

Publ.-Id: 713

Formation of ternary (Fe1-xCox)Si2 structures by ion beam assisted deposition and ion implantation

Wieser, E.; Panknin, D.; Barradas, N. P.; Betzl, M.; Reuther, H.; Henrion, W.; Lange, H.

  • Nuclear Instruments and Methods in Physics Research B 124 (1997) 533-541

Publ.-Id: 712

Potential-Energy Surfaces of Sodium Clusters with Quadrupole, Hexadecapole, and Triaxial Deformations

Reimann, S. M.; Frauendorf, S.

  • Surface Review and Letters 3 (1996) 1 pp. 25-29

Publ.-Id: 711

Shapes and Free Energies of Molten Sodium Clusters

Frauendorf, S.; Pashkevich, V. V.

  • Surface Review and Letters 3 (1996) 1 pp. 241-245

Publ.-Id: 710

Magnetic Properties of Sodium Clusters

Frauendorf, S.; Pashkevich, V. V.; Reimann, S. M.

  • Surface Review and Letters 3 (1996) 1 pp. 441-445

Publ.-Id: 709

Thermodynamics and Decay of Liquid Alkali Clusters

Frauendorf, S.; Pashkevich, V. V.

  • Contribution to external collection
    T. P. Martin: Large Clusters of Atoms and Molecules, Dordrecht, Netherlands: Kluwer Academic Publishers, 1996, 201-220

Publ.-Id: 708

Charakterisierung der Submicron-Partikel in einem umweltrelevanten Wasser: Stauwasser in einer Kommunalmülldeponie über einem Schlammteich (Tailing) der Uranerzaufbereitung in Freital/Sachsen

Zänker, H.; Richter, W.; Hüttig, G.; Nitsche, H.; Wiesener, W.; Mende, A.

Characterization of Submicron Particles in an Environmentally-Relevant Water: Backwater From a Sanitary Landfill on a Uranium Mine Tailing at Freital, Saxony. A strategy for characterizing submicron particles in environmental waters based on filtration, centrifugation and photon correlation spectroscopy (PCS) is proposed. Filtration and centrifugation are not used here as methods for particle characterization but serve merely as techniques of a rough separation of the sample. They are applied as cautiously and non-invasively as possible and are only aimed at separating the sample sufficiently for measurements by primarily PCS. The separation should unmask small particles
that scatter little light and divide the sample into populations of particles that have monomodal or bimodal size distributions. In this way, the strategy optimizes subsequent particle-size determinations by PCS and minimizes the influence of sample preparation on the samples. A further essential feature of this strategy is the parallel application of complementary methods for both sample preparation and particle characterization (filtration/centrifugation, PCS/SEM, gravimetry/ICP-MS etc.). This facilitates the validation of results and increases the probability for recognizing artifacts. Based on our experimental experience, a guideline for PCS measurements on low-concentration colloids with the BI 90/Correlator BI 9000 AT system from Brookhaven Instruments Corp. was developed. This guideline is aimed at obtaining autocorrelation functions of sufficiently good photon counting statistics which is crucial in PCS on colloidal solutions poor in particles. A measuring campaign on an environmentally-relevant water (backwater from a sanitary landfill on a uranium mine tailing at Freital, Saxony) showed the presence of about 1 to 2 mg/l of submicron particles having a particle size of 30 to 300 nm and of about 5 mg/l of suspended matter (>1000 nm).

  • Open Access Logo Forschungszentrum Rossendorf; FZR-155
    ISSN: 1436-3976


Publ.-Id: 707

Windpotentialmodellierung in komplexem Gelände

Heinemann, D.; Müller, R.; Waldl, H. P.; Hirsch, W.; Rindelhardt, U.

Das Windenergiepotential wird für komplexes Gelände im Binnenland mit zwie rechzeitökonomischen Modellen simuliert. Hierzu wird das in schwach gegliedertem Gelände Mitteleuropas erprobte und bewährte Programmpaket WAsP, sowie ein einfaches mesoskaliges Strömungsmodell (AIOLOS) verwendet. Die Ergebnisse der Simulation werden für ausgewählte Standorte verglichen und diskutiert. Die mit dem Modell WAsP berechnete Leistungsdichte, welche im Rahmen einer Windpotentialstudie für Zentralsachsen ermittelt wurde, wird dargestellt.

  • Lecture (Conference)
    DEWEK 96, Wilhelmshaven, 23.-25.10.96, Tagungsband S. 334
  • Contribution to proceedings
    DEWEK 96, Wilhelmshaven, 23.-25.10.1996, Tagungsband S. 334

Publ.-Id: 706

Overpressurised bubbles versus voids in helium implanted and annealed silicon

Fichtner, P.; Kaschny, J.; Yankov, R. A.; Mücklich, A.; Kreißig, U.; Skorupa, W.

  • Applied Physics Letters 70 (1997) 732

Publ.-Id: 705

Application of Highly Focused Ion Beams

Bischoff, L.; Teichert, J.

The impressive development of focused ion beam (FIB) systems
from the laboratory level to high performance industrial machines during
the last twenty years is briefly reported. The design and the functional
principle of a liquid metal ion source as well as a FIB column are described.
The main application fields of the FIB technology are discussed. More in
detail the Rossendorf FIB activities, like writing Co+ FIB implantation
in silicon to fabricate CoSi2 microstructures by ion beam synthesis and
the writing Ga+ FIB implantation to create a patterned etch stop during
a following anisotropic etching for micromechanical 3D structure fabrication
are presented.

  • Lecture (Conference)
    14th Int. Conf. Applic. of Accelerators in Research and Industry, Denton, 6.-9.11.96
  • Mat. Sci. Forum 248-249 (1997) 445
  • Contribution to external collection
    CP392, Application of Accelerators in Research and Industry, edited by J. L. Duggan and I. L. Morgan, AIP Press, New York 1997, 1175-1178

Publ.-Id: 704

Pages: [1.] [2.] [3.] [4.] [5.] [6.] [7.] [8.] [9.] [10.] [11.] [12.] [13.] [14.] [15.] [16.] [17.] [18.] [19.] [20.] [21.] [22.] [23.] [24.] [25.] [26.] [27.] [28.] [29.] [30.] [31.] [32.] [33.] [34.] [35.] [36.] [37.] [38.] [39.] [40.] [41.] [42.] [43.] [44.] [45.] [46.] [47.] [48.] [49.] [50.] [51.] [52.] [53.] [54.] [55.] [56.] [57.] [58.] [59.] [60.] [61.] [62.] [63.] [64.] [65.] [66.] [67.] [68.] [69.] [70.] [71.] [72.] [73.] [74.] [75.] [76.] [77.] [78.] [79.] [80.] [81.] [82.] [83.] [84.] [85.] [86.] [87.] [88.] [89.] [90.] [91.] [92.] [93.] [94.] [95.] [96.] [97.] [98.] [99.] [100.] [101.] [102.] [103.] [104.] [105.] [106.] [107.] [108.] [109.] [110.] [111.] [112.] [113.] [114.] [115.] [116.] [117.] [118.] [119.] [120.] [121.] [122.] [123.] [124.] [125.] [126.] [127.] [128.] [129.] [130.] [131.] [132.] [133.] [134.] [135.] [136.] [137.] [138.] [139.] [140.] [141.] [142.] [143.] [144.] [145.] [146.] [147.] [148.] [149.] [150.] [151.] [152.] [153.] [154.] [155.] [156.] [157.] [158.] [159.] [160.] [161.] [162.] [163.] [164.] [165.] [166.] [167.] [168.] [169.] [170.] [171.] [172.] [173.] [174.] [175.] [176.] [177.] [178.] [179.] [180.] [181.] [182.] [183.] [184.] [185.] [186.] [187.] [188.] [189.] [190.] [191.] [192.] [193.] [194.] [195.] [196.] [197.] [198.] [199.] [200.] [201.] [202.] [203.] [204.] [205.] [206.] [207.] [208.] [209.] [210.] [211.] [212.] [213.] [214.] [215.] [216.] [217.] [218.] [219.] [220.] [221.] [222.] [223.] [224.] [225.] [226.] [227.] [228.] [229.] [230.] [231.] [232.] [233.] [234.] [235.] [236.] [237.] [238.] [239.] [240.] [241.] [242.] [243.] [244.] [245.] [246.] [247.] [248.] [249.] [250.] [251.] [252.] [253.] [254.] [255.] [256.] [257.] [258.] [259.] [260.] [261.] [262.] [263.] [264.] [265.] [266.] [267.] [268.] [269.] [270.] [271.] [272.] [273.] [274.] [275.] [276.] [277.] [278.] [279.] [280.] [281.] [282.] [283.] [284.] [285.] [286.] [287.] [288.] [289.] [290.] [291.] [292.] [293.] [294.] [295.] [296.] [297.] [298.] [299.] [300.] [301.] [302.] [303.] [304.] [305.] [306.] [307.] [308.] [309.] [310.] [311.] [312.] [313.] [314.] [315.] [316.] [317.] [318.] [319.] [320.] [321.] [322.] [323.] [324.] [325.] [326.] [327.] [328.] [329.] [330.] [331.] [332.] [333.] [334.] [335.] [336.] [337.] [338.] [339.] [340.] [341.]