Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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32208 Publications
Aufbau eines technischen Systems zur Verbesserung der betrieblichen Überwachung der KKW durch die staatlichen Aufsichtsbehörden (Saporoshje)
Beyer, M.; Carl, H.; Langer, L.; Schumann, P.; Seidel, A.; Zschau, J.; Nowak, K.; Tolksdorf, P.;
Es wird ein techisches System zur Verbesserung der betrieblichen Überwachung eines WWER-1000-Reaktorblockes im KKW Saporoshje vorgestellt, das die Aufsichtsbehörde in die Lage versetzen soll, diesen Block unabhängig vom Betreiber zu beaufsichtigen, seinen Sicherheitszustand zu beurteilen und durch Auflagen zu beeinflussen. Das System gestattet auf Grund moderner Ausrüstung eine frühzeitige Meldung von Störungen aller Art und der damit verbundenen Aktivitätsfreisetzungen. Es stellt eine Grundlage für die Frühwarnung der Öffentlichkeit in Gefahrensituationen sowie für eine effektive Einleitung von Notfallschutzmaßnahmen dar. Dazu werden 49 betriebliche Parameter vom Reaktorblock, 18 block- und analgenspezifische radiologische und 6 meteorologische Meßgrößen überwacht. Die geschätzten Kosten für die Realisierung einer Minimalvariante (ohne Baumaßnahmen und Installationsaufwand) belaufen sich auf ca. 1,3 Mio. DM, zuzüglich 650 TDM für notwendige Ertüchtigungen der Meßtechnik. Der Anschluß eines weiteren WWER-1000-Blockes verursacht entsprechende Kosten von etwa 200 TDM.
  • Open Access LogoForschungszentrum Rossendorf; FZR-44: Kurzfassung (nicht zur Veröffentl. freigeg.)
  • Open Access LogoForschungszentrum Rossendorf; FZR-45: Anlage A: Textteil (nicht zur Veröffentl. freigeg.)

Publ.-Id: 198 - Permalink


Unified description of quasi-free and resonant processes of hypernuclear production and decay
Wünsch, R.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-92-03, March 1992

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Publ.-Id: 197 - Permalink


Description of an open quantum mechanical system
Rotter, I.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-42 Preprint

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Publ.-Id: 196 - Permalink


Writing implantation with a high current Focused Ion Beam to form CoSi2 - Microstructures
Bischoff, L.; Teichert, J.; Hesse, E.; Panknin, D.; Skorupa, W.;
  • Lecture (Conference)
    EIPB '94, New Orleans, 31.5.-3.6.1994

Publ.-Id: 195 - Permalink


ASAXS and SANS investigations of the chemical composition of irradiation-induced precipitates in nuclear pressure vessel steels
Große, M.; Böhmert, J.; Eichhorn, F.; Brauer, G.; Haubold, H.-G.; Goerigk, G.;
  • Poster
    1st European Conference on Synchrotron Radiation in Material Science, Chester UK, 2.-8.7.1994

Publ.-Id: 194 - Permalink


Recherche zu Gruppendatenbibliotheken für die Anwendung des Programmes DYN3D auf Reaktoren vom Typ WWER
Mittag, S.;
Für die Berechnung des Reaktorverhaltens mit Kernmodellen (wie DYN3D) werden sog. Weniggruppen-Neutronendaten benötigt. Es wird eine Übersicht zu entsprechenden Datenbibliotheken für die Spaltzonen von russischen WWER-Reaktoren aufgestellt. Die Informationen über verwendete Primärdaten und die Genauigkeit der Zellcodes für die Gruppendatengenerierung werden im wesentlichen in Tabellenform gegeben. Zur Beurteilung der Qualität der Daten werden Vergleiche zwischen gemessenen und berechneten Reaktorparametern zusammengestellt. Die verfügbaren Informationen ergeben keine signifikanten Qualitätsunterschiede zwischen den einzelnen Datenbibliotheken.
  • Open Access LogoForschungszentrum Rossendorf; FZR-46

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Publ.-Id: 193 - Permalink


Thermocapillary bubble migration in a drop tower experiment
Treuner, M.; Langbein, D.; Galindo, V.; Gerbeth, G.;
  • Lecture (Conference)
    und Proceedings: 45th IAF Congress, Jerusalem, 9.-14.10.1994

Publ.-Id: 192 - Permalink


Synthesis and molecular structure of chlore(3-thiapentane-1.5-dithiolato)oxorhenium(V)
Fietz, T.; Spies, H.; Pietzsch, H.-J.; Leibnitz, P.;
  • Inorganica Chimica Acta 231 (1995) pp. 233-236

Publ.-Id: 191 - Permalink


Buried (fe 2-x Co x) Si2 layers with variable band gap formed in silicon by ion beam synthesis (IBS)
Panknin, D.; Wieser, E.; Skorupa, W.; Henrion, W.; Lange, H.;
  • Journal of Applied Physics A 62 (1996), 155

Publ.-Id: 190 - Permalink


Ermittlung dynamischer Rißeinleitungszähigkeiten mit dem instrumentierten Kerbschlagbiegeversuch bei elastisch-plastischem Werkstoffverhalten
Richter, H.; Viehrig, H.-W.; Winkler, S.;
Rißwiderstandskurven sind zum unentbehrlichen Instrumentarium zur Beschreibung des Versagens rißbehafteter Komponenten bei elastisch-plastischem Werkstoffverhalten geworden. Die Abhängigkeit der R-Kurve von der Dicke der jeweiligen Proben gestattet aber nur bedingt die Übertragung der Versuchsergebnisse auf das Bauteilverhalten. In der Literatur wird gezeigt, daß der Beginn der stabilen Rißeinleitung einen echten, geometrieunabhängigen Werkstoffkennwert darstellt. Als anerkannte Methode zur Bestimmung kritischer Rißeinleitungsparameter wird die Messung der Stretchzonenbreite vor der Rißspitze (SZW) verwendet. In quasistatischen Einproben (EPT)- oder in Mehrprobentechniken (MPT) lassen sich mit Hilfe von kritschen SZW gültige Rißeinleitungszähigkeiten auf J-Integralbasis bestimmen.
Noch ungelöst ist das Problem der Ermittlung von dynamischen Rißeinleitungszähigkeiten in EPT mit Hilfe des instrumentierten Kerbschlagbiegeversuches. Hierfür muß durch Messung physikalischer Größen, die mit dem Rißeinleitungsprozeß in Verbindung stehen, der Zeitpunkt der Rißeinleitung detektiert werden. Derartige physikalische Detektionsverfahren sind beispielsweise akustische Emission, elektrische und magnetische Emission. Man erkennt, daß alle drei Verfahren nur indirekt auf Rißbildungsprozesse reagieren. Erste Experimente mit einer Instrumentierung des Kerbschlagbiegeversuchs werden vorgestellt, wobei neben der Schlagkraft gleichzeitig akustische, magnetische und elektrische Emission erfaßt werden.
Durch die simultane Erfassung der Signale verschiedener Methoden in Zusammenhang mit hochauflösender Meßtechnik und mathematisch-numerischen Verfahren der Signalauswertung kann erwartet werden, daß die charakteristischen Zeitpunkte für Rißeinleitung und stabilen Rißfortschritt zuverlässig detektiert werden können.
  • Contribution to proceedings
    Tagungsband der 26. Vortragsveranstaltung des DVM-AK "Bruchvorgänge", Magdeburg, 22. - 23. Februar 1994, S. 373 - 383

Publ.-Id: 189 - Permalink


Effects of flow on intermediate mass fragments in central gold on gold collisions
Heide, B.; Barz, H.-W.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-41 Preprint
  • Physics Letters B 337 (1994) pp. 53
  • Physics Letters B 340 (1994) pp. 267 (Erratum)

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Publ.-Id: 188 - Permalink


Institute of Nuclear and Hadron Physics; Annual Report 1993
Dönau, F.; Prade, H.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-35

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Publ.-Id: 187 - Permalink


Institute of Bioinorganic and Radiopharmaceutical Chemistry; Annual Report 1993
Johannsen, B.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-32

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Publ.-Id: 186 - Permalink


N.C.A. 11C-labelling of aromatic compounds in the ring-position: synthesis of nitro-[1-11C]benzene and [1-11C]aniline
Steinbach, J.; Mäding, P.; Füchtner, F.; Johannsen, B.;
  • Journal of Labelled Compounds and Radiopharmaceuticals 36 (1994) 1 pp. 33

Publ.-Id: 185 - Permalink


High Specific Activity 17alpha-Cyanomethyl-17ß-hydroky-[14alpha, 15alpha-3H]estra-4,9-dien-3-one
Droescher, P.; Römer, J.;
  • Journal of Labelled Compounds and Radiopharmaceuticals 36 (1995) 2, pp. 111-119

Publ.-Id: 184 - Permalink


Radial pattern of nuclear decay processes
Iskra, W.; Müller, M.; Rotter, I.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-39 Preprint
  • Physical Review C 51 (1995) pp. 1842

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Publ.-Id: 182 - Permalink


Photovoltaik - Beispielhafte Anlagen in Sachsen
Rindelhardt, U.;
Aufgrund verschiedener Förderprogramme des Bundes bzw. des Freistaates Sachsen wurden bis Mai 1994 in Sachsen netzgekoppelte Photovoltaikanlagen mit einer Leistung von insgesamt 400 kWp errichtet. Im Vortrag wird hauptsächlich auf die Ergebnisse der Anlagen eingegangen, die im Rahmen des Bund-Länder-1000-Dächer-Photovoltaik-Programmes errichtet wurden. Weiterhin werden die 40-kWp-Anlage zur Versorgung der Kirnitzschtalbahn (Sächsische Schweiz) und die mit amorphen Si-Modulen ausgerüstete 7,5-kWp-Anlage im SOS-Kinderdorf Zwickau vorgestellt.
  • Lecture (Conference)
    Konferenz "Erneuerbare Energien in Sachsen" des Forums für Zukunftsenergien, Chemnitz, 1.6.1994

Publ.-Id: 181 - Permalink


Kaon Polarization in Nuclear Matter
Kolomeitsev, E. E.; Voskresensky, D. N.; Kämpfer, B.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-40 Preprint
  • Nuclear Physics A 588 (1995) pp. 889

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Publ.-Id: 180 - Permalink


Solar betriebene netzunabhängige Meßstation - Energiebilanzen eines einjährigen Betriebes
Futterschneider, H.; Rindelhardt, U.; Morgenstern, H.;
Für die dosimetrische Umgebungsüberwachung des Forschungsstandortes Rossendorf wurden zwei solar betriebene netzunabhängige Meßsysteme konzipiert und in einem einjährigen Meßzyklus erprobt. Eine wesentliche Forderung bestand in der Gewährleistung einer 100%igen Versorgungssicherheit der Meßsonden.
Die energetisch relevanten Ergebnisse dieser Langzeiterprobung werden diskutiert. Zur Analyse der Energiebilanzen wurden die 10-Minuten-Mittelwerte von Mudolstrom ,und -spannung, Batteriestrom und -spannung, der jeweilige Laststrom und die solare Einstrahlung gemessen. Beide Systeme liefen auch im sehr einstrah- lungsarmen Winter 1993/94 ohne Ausfall. Die vollständige Jahresbilanz des Systems 1 ergab einen reinen Solarbetrieb während 3022 h, einen Batteriebetrieb während 4686 h und in der restlichen Zeit einen Mischbetrieb.
Die gewählte Dimensionierung der beiden photovoltaischen Energieversorgungssysteme erwies sich als ausreichend für einen sicheren Betrieb, die der Auslegung zugrunde liegenden Parameter (spezifische Modulgröße 33 - 41 Wp/W, spezifische Batteriegröße 33 d) können für Systeme mit beliebig großen Lasten verallgemeinert werden.
  • Lecture (Conference)
    9. Internationales Sonnenforum, Stuttgart, 28.6.-1.7.1994, Tagungsbaricht S. 1243 - 1250
  • Contribution to proceedings
    9. Internationales Sonnenforum, Stuttgart, 28.6.-1.7.1994, Tagungsbaricht S. 1243 - 1250

Publ.-Id: 179 - Permalink


ZERO-POINT Energy Corrected Solitonic Configurations of the Semibosonized NAMBU & JONA-LASINIO Model
Wünsch, R.; Schleif, M.;
  • Lecture (Conference)
    Int. Conf. on "Mesons and Nuclei", Dubna, May 1994, World Scientific Publishing Co

Publ.-Id: 178 - Permalink


Double-grid avalanche counters with large dynamic range
Seidel, W.; u. a.;
  • Book (Authorship)
    Fa. ALTIUM, USA, Buch über P-CAD

Publ.-Id: 177 - Permalink


Solare Brauchwasserbereitung und Einspeisung solarer Überschüsse in den Fernwärmerücklauf
Brünig, D.; Naehring, F.; Rindelhardt, U.;
In der Stadt Freital wird ein Modellvorhaben zur Integration solarer Warmwasserbereitung in ein neu geschaffenes Fernwärmesystem auf Erdgasbasis realisiert. Das Projekt beinhaltet den Bau einer solarthermischen Anlage mit einer Kollektorfläche von 100 m² auf einer Schule und deren Einbindung in die im Keller der Schule errichtete Heizzentrale für das umliegende Wohngebiet. Mittels eines umfangreichen Meßprogramms werden die Ergebnisse erfaßt und analysiert.
  • Poster
    Viertes Symposium Thermische Solarenergie, Staffelstein, 9.-10.6.1994, Tagungsband S. 241
  • Contribution to proceedings
    Viertes Symposium Thermische Solarenergie, Staffelstein, 9.-10.6.1994, Tagungsband S. 241

Publ.-Id: 176 - Permalink


Particle identification in a wide dynamic range based on pulse-shape analysis with solid-state detectors
Pausch, G.; Bohne, W.; Hilscher, D.; Ortlepp, H.-G.; Polster, D.;
  • Nuclear Instruments and Methods in Physics Research A 349 (1994) 2/3 pp. 281-284
  • Open Access LogoForschungszentrum Rossendorf; FZR-38

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Publ.-Id: 175 - Permalink


General Axial Shapes of Sodium Clusters
Frauendorf, S.; Pashkevich, V. V.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-37 Preprint
  • Annals of Physics 5 (1996) pp. 34-56

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Publ.-Id: 174 - Permalink


Institute of Ion Beam Physics and Materials Research; Annual Report 1993
Möller, W.; Wieser, E.; Kirch, S.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-36

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Publ.-Id: 173 - Permalink


Detailed Monitoring Results and Operating Experiences from 200 Grid Connected Photovoltaic Systems in Germany
Jahn, U.; Grochowski, J.; Decker, B.; Rindelhardt, U.; Teichmann, G.;
The German 1000 Roofs Programme includes more than 2000 grid connected photovoltaic (PV) plants, which are being supported by the Federal Ministry for Research and Technology and the governments of the Federal States. Monitoring data, which are continuously produced from the installed PV plants, are now availabe. This paper presents some recent monitored performance data from 250 installed PV systems in Saxony and Lower Saxony together with operating experiences gathered from technical inspections of the projects.
  • Lecture (Conference)
    Proceedings of the 12th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 11-15 April, 1994, Volume I, p. 919 - 922
  • Contribution to proceedings
    Proceedings of the 12th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 11-15 April, 1994, Volume I, p. 919 - 922

Publ.-Id: 171 - Permalink


Dielectron production in pp and pd collisions at 1-5 GeV
Titov, A. I.; Kämpfer, B.; Bratkovskaya, E. L.;
  • Physical Review C 51 (1995) pp. 227
  • Open Access LogoForschungszentrum Rossendorf; FZR-34 Preprint

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Publ.-Id: 169 - Permalink


Relaxation of Radiation Damages
Schmidt, B.; Eremin, V.; Ivanov, A.; Strokan, N.; Verbitskaya, E.; Li, Z.;
The behavior of radiation-induced carbon-related defects in high-resistivity silicon detectors has been investigated. The defects were introduced by alpha-praticle irradiation and investigated by deep-level transient spectroscopy. An unusual defect behavior consists in low-temperature anealing, including self-annealing at room temperatur, of the interstitial carbon Ci with a simultaneous increase of the Ci-Oi-complex concentration. The kinetic parameters of the process have been determined from the increase of the Ci-center concentration versus time. Two annealing velocities have been observed, which arise from different heat treatments during the detector fabrication process.
  • Journal of Applied Physics 76 (7),1994, 4072-4076

Publ.-Id: 168 - Permalink


Electromagnetic detection of nonconducting inclusions in a liquid metal flow
Gerbeth, G.; Block, F. R.; Dittmer, R.;
The paper describes a first experimental test of a new electromagnetically based bubble detection method in an electrically conducting fluid. A reliable and contin-uous bubble detection method is important for a lot of liquid metal flows, in particular, flows of reactive liquid metals like sodium or lithium. Moreover, the method is suitable for the detection of any inhomogeneity having different electrical conductivity compared to the bulk flow.
The experimental approach for the detection of inhomogeneities was developed at RWTH Aachen for an early slag detection in steel production. The method is based on the fact that a primary electromagnetic field is changed by the motion of an electrically conducting fluid. This change is very sensitive to any inhomogeneities in the flow which have a different electrical conductivity compared to that of the fluid. The signals of suitably arranged secondary coils are evaluated in order to separate the influence of the inhomogeneity. In the experiments performed at the sodium facility of RCR we were able to detect single bubbles which were of diameters in the range 0.5 - 2 mm.
Compared to usual, mainly acoustically based detection methods the following advantages of the electromagnetic approach are obvious:
- No time delay between bubble occurence in the coil region and the signal.
- High sensitivity up to single bubble detection.
- Contactless method. No need to install sensors at hot walls, even a thermal isolation between the coils and the channel is possible.
- Every flowing bubble is detected whereas acoustic methods are able to detect acoustically active bubbles only.
The results of our experiment show convincingly the efficiency of such an electromagnetic detection method.
  • Lecture (Conference)
    "Electromagnetic Proceeding of Materials", Okt. 94, Nagoya, Japan und als Publ. bei ISIJ Japan

Publ.-Id: 167 - Permalink


Theoretical Aspects of Thermocapillary Convection in Liquid Metals under Magnetic Fields Influence
Priede, J.; Gerbeth, G.; Thess, A.;
Magnetic fields provide the possibility to influence the convective flow pattern in an predefined contactless way, in particular, to suppress and control oscillatory instabilities. Therefore, there is increasing interest now in the use of magnetic fields in a variety of materials processing technologies like crystal growth from the melt or directional solidification.
Available knowledge is very limited on the influence of a steady magnetic field (described by the Hartmann number Ha) on convective motions, described by the Grashoff number Gr (buoyancy), and by the Marangoni number Ma (thermocapillarity at free surfaces) in low Prandtl number fluids like liquid metals. Therefore, in the present paper we present theoretical results on the prototype problem of an infinitely extended fluid layer heated either from the side or from the bottom, and exposed to a steady external magnetic field.
In the first part we consider the stability of a unidirectional thermocapillary flow set up by a temperature gradient parallel to the free surface. The magnetic field is supposed to be parallel to the free surface. In this case the magnetic field has no influence on the basic flow, the stability of which is well known without magnetic field. The restriction to disturbances propagating in the same direction as the magnetic field allows to obtain an analytical solution of the stability problem and an explicit expression for the dispersion relation. The hydrothermal wave instability is suppressed by the magnetic field, the critical Marangoni number grows proportionally to Ha. The most unstable wave pattern is stretched along the field lines. The wave number of the most unstable mode decreases as Ha-4/5 for Ha >> 1.
The second part of this communication is devoted to the analysis of the thermocapillary instability in a layer with both temperature gradient and magnetic field being perpendicular to the free surface. Although this problem has been extensively treated in the past, the ...
  • Lecture (Conference)
    "Electromagnetic Processing of Materials", Okt. 94, Nagoya, Japan und als Publ. bei ISIJ Japan

Publ.-Id: 166 - Permalink


Hydrothermal Wave Instability of Thermocapillary Driven Convection in a Plane Layer Subjected to a Uniform Magnetic Field
Priede, J.; Gerbeth, G.;
Thermocapillary driven motion is considered in a horizontal electrically conducting fluid layer heated from the side and exposed to a magnetic field coplanar to the layer. The hydrothermal wave instability and its control by the magnetic field is studied by a linear stability analysis. The special assumption of disturbances traveling crosswise the basic flow allows an analytical solution of the problem. For a particular class of perturbations considered here, the critical Marangoni number and the wavelength of the most unstable mode increase directly with the strength of the applied magnetic field.
  • Advances in Space Research, Vol. 16, No. 7, pp. 55 - 58, Pergamon Press, 1995
  • Lecture (Conference)
    "30th COSPAR Scientific Assembly", Juli 94, Hamburg

Publ.-Id: 165 - Permalink


Anisotropic transport in MHD turbulence: Experimental results using small gas bubbles as local tracers
Eckert, S.; Gerbeth, G.; Witke, W.; Langenbrunner, H.;
It is well known now that in a liquid metal duct flow exposed to a strong transverse magnetic field turbulent fluctuations can persist even when the mean flow can be regarded as laminar with respect to the overall pressure drop. It was also found, that these fluctuations can even be increased under distinct conditions. This effect is in line with the model of two-dimensional MHD turbulence. While 3D turbulence elements are effectively damped by the magnetic field, 2D eddies with axes in the direction of the B-field are not influenced by this damping mechanism. The use of this 2D turbulence allows an enhancement of the heat/mass transport perpendicular to the flow direction without a significant influence on the overall pressure drop.
There is an ongoing research in the FZR MHD group on local transport phenomena in a turbulent LM duct flow exposed to a transverse magnetic field. Measurements were performed at the FZR sodium facility. The advantage of sodium is that high MHD parameters (Ha = 3000, N = 800) can be reached with moderate values of the magnetic field (B = 0.5 T). On the other hand the properties of sodium cause considerable difficulties with respect to any local measurements in such a flow (velocity, fluctuation intensities). Thus the idea was created to use small gas bubbles (argon) as local tracers for the investigation of local transport mechanisms. In the case of our experimental conditions a volumetric gas flow ratio lower than 0.09 clearly indicates a pure bubbly flow regime. The bubbles are injected by means of a single injector in the center of the channel cross section or in the vicinity of a channel wall. The injector was located in the region where the flow enters into the magnetic field. A traversing mechanism allows to move the B-field-region. Single wire resistivity probes are used for measuring the local void fraction and the number of bubbles.
The measured local dispersion of bubbles shows a significant anisotropy which clearly corre ...
  • Lecture (Conference)
    Proceedings of the Second International Conference on ENERGY TRANSFER IN MAGNETOHYDRODYNAMIC FLOWS, Aussois, France, September 26-30, 1994, pp. 787 - 799
  • Contribution to proceedings
    Proceedings of the Second International Conference on ENERGY TRANSFER IN MAGNETOHYDRODYNAMIC FLOWS, Aussois, France, September 26-30, 1994, pp. 787 - 799

Publ.-Id: 164 - Permalink


Thermocapillary Instabilities in Liquid Metals: Hartmann Number Versus Prandtl-Number
Priede, J.; Gerbeth, G.; Thess, A.;
The technical need for instability postponement, turbulence suppression and flow control in material processing as well as the seek for low-cost alternatives to space-technologies for crystal growth are currently leading to an increased interest in the interaction between thermocapillary flows in electrically conducting fluids and magnetic fields. While the interplay between isothermal flows and magnetic fields is well understood, our physical understanding of the influence of magnetic fields on thermocapillary flow phenomena, i.e. flows driven by surface tension gradients, leaves still much to be desired.
The goal of the püresent communication is to demonstrate that a magnetic field acting on the thermocapillary flow of a low Prandtl number fluid causes the fluid to behave like a high Prandtl number fluid. This important feature is exemplified by considering the linear stability of a unidirectional thermocapillary flow set up by a temperature gradient parallel to the free surface of an unbounded planar fluid layer. The magnetic field is supposed to be normal to the free surface. Our problem is the magnetic counterpart to the work of Smith & Davis. We report results of a comprehensive study of the critical Marangoni number for the onset of hydrothermal waves as a function of the Hartmann number and of the Prandtl number. For weak magnetic field the instability mechanism in liquid metals is found to be the same as in the nonmagnetic case for low Prandtl numbers. For sufficiently strong magnetic field the basic flow and the most unstable perturbation are confined to a thin Hartmann boundary layer below the free surface which leads to a decrease of the effective viscous diffusion time-scale as Ha-2. Our Computations reveal that at a certain value of the Hartmann number, when the effective viscous time equals the thermal diffusion time, the character of the instability changes discontinously. The new type of instability is reminiscent of the instability mechanism w ...
  • Magnetohydrodynamics, Proc. Energy Transfer in MHD Flows, Conference, Aussois, France, Sept. 1994, pp. 571 - 580
  • Lecture (Conference)
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 571 - 580
  • Contribution to external collection
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 571 - 580

Publ.-Id: 163 - Permalink


Numerical simulation of the two-dimensional MHD flow around a circular cylinder
Shatrov, V.; Mutschke, G.; Gerbeth, G.;
In the present paper the time-dependent, two-dimensional, incompressible MHD flow around a circular cylinder is investigated numerically using a finite difference method in stream function-vorticity formulation. The calculations are restricted to the typical situation of liquid metal flows under laboratory conditions where the magnetic Reynolds number is small. The flow is investigated in the parameter range of Re < 10000 and magnetic interaction parameter N < 20 (N = Ha²/Re).
To validate the numerical method, a comparison with the few published numerical results (MOCHIMARU, TSINOBER) is performed, and a good agreement is found. Furthermore, the influence of different outer boundary conditions is tested.
The two cases of a magnetic field aligned to the flow as well as perpendicular to it are investigated in detail. The influence of the magnetic forces on the flow is shown in stream function and vorticity isoline plots for different Reynolds numbers and interaction parameters. The vorticity and pressure distribution at the cylinder surface and the induced magnetic field are calculated and compared with experimental results. The occurrence of a large, but slow recirculation eddy behind the cylinder for a strong aligned magnetic field is discussed. The motion of the fluid becomes more and more stagnant in that region for increasing magnetic fields.
The downstream wake is characterized by the velocity profiles, and the farfield of the vorticity is discussed.
As expected, the influence of the magnetic field on the flow in general is a stabilizing one. In particular, the suppression of an instationary wake flow can be achieved by the magnetic forces. A stability line in the (Re,N)-plane is extracted from the numerical simulations. This result will be compared with a linear stability analysis based on a Galerkin approach.
  • Magnitnaya gidrodinamika 1997 Vol. 33, No. 1, p. 3-13 (in Russian)
  • Lecture (Conference)
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 745 - 756
  • Contribution to external collection
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 745 - 756

Publ.-Id: 162 - Permalink


Influence of external magnetic fields on slip ratio in LMMHD two-phase flow
Eckert, S.; Gerbeth, G.; Mihalache, G.; Thibault, J.-P.;
LMMHD two-phase flow modelling strongly depends on the accuracy of the constitutive equations and the corresponding closure laws. Several questions rise from various attempts to model these flows. They are mainly connected with the modification of two-phase flow (interfacial dragging, wall friction, apparent elec- trical conductivity, etc.) due to the electromagnetic forces.
The present paper presents a comprehensive survey of the LMMHD two-phase investigations performed in our two laboratories using different liquid systems, mercury-air (LEGI-IMG) and sodium-argon (FZR), with quite different properties. The remarkable difference in the material properties allow us to reach a wide range of nondimensional parameters.
For theoretical predictions a two fluid model (LEGI-IMG) and a bubbly flow model (FZR) have been developed in order to meet the requirements of the corresponding facilities.
The experiments have been realized in rectangular vertical test sections immersed into a transverse magnetic field. The gas is injected in the entrance region of the magnetic field. The distribution of the local void fraction across the channel cross section was measured by means of single wire resistivity probes. The electrical boundary conditions of the test sections are rather different. While the FZR test section consists of a simple stainless steel channel (thickness of the walls: 5 mm), the LEGI-IMG configuration, which includes segmented copper electrodes and an external load resistance, is more similar to a MHD generator. In the FZR experiment a volumetric quality in the range of 0.06 - 0.09 leads to a pure bubbly flow regime. In contrast to this the LEGI-IMG facility usually work with considerable higher gas flow rates.
We present experimental results showing the dependence of the mean values of the void fraction, the slip ratio and the gas velocity on the magnetic field strength as well as on the mean sodium velocity. These results will be compared with the theoreti ...
  • Poster
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 607 - 616
  • Contribution to external collection
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich, pp. 607 - 616

Publ.-Id: 161 - Permalink


On Stability of MHD flow around a cylinder in an aligned magnetic fields
Weier, T.; Mutschke, G.; Gerbeth, G.; Alemany, A.; Pilaud, A.;
The hydromagnetic stability of the flow of an incompressible conducting fluid around a circular cyliner in a uniform magnetic field parallel to the mean flow is investigated with different approaches:
Experiments for 1000 < Re < 9000
a simple analytical model
numerical simulation for Re < 1000.
Main goal of the investigations is to find the stability curce inthe (Re, N)-plane, and to distinguish between 2D and 3D instabilities.
Experimental results will be presented based on hot-wire measurements in the down-stream cylinder wake. The suppression of the vortex street by increasing magnetic fields is clearly identified.
Parallel to the disappearance of the typical Kármán frequency an increase of low frequency fluctuations is observed in the spectrum. This will be discussed in therms of theoretical predictions for long-wave MHD instabilities.
More physical insight into the stability behaviour is obtained by a simple Kolmogorov flow modelling of the cylinder wake and the corresponding stability analysis. Theoretical results will be presented for the 2D case: critical Reynolds number, wave number and Strouhal number as function of the magnetic field.
The critical wave number jumbs form the region of the typical Kármán value to very low values at a distinct magnetic field strength. The simple model is extended to include 3D instabilities in the flow. Limitations of the model and the comparison to experiments will be discussed.
Finally the 2D case for Re < 1000 will be compared with results of a full numerical simulation.
  • Magnitnaya gidrodinamika 1997 Vol. 33, No. 1, p. 14-22 (in Russian)
  • Lecture (Conference)
    "Energy Transfer in MHD Flows", Sept. 1994, Aussois, Frankreich

Publ.-Id: 160 - Permalink


Unsteady Thermocapillary Drop Migration in a Uniform Temperature Gradient
Galindo, V.; Gerbeth, G.; Langbein, D.; Treuner, M.;
A theoretical analysis of liquid drop unsteady migration under microgravity conditions is presented, if an interfracial tension gradient is generated on the drop surface by a uniform temperature gradient in the surrounding liquid. The effect of buoyancy due to a residual gravity vector aligned parallel to the temperature gradient is included. The relevant equations are solved in the creeping flow limit where in the convective transport of momentum as well as that of the energy is neglected, i.e. at low Reynolds and Marangoni numbers. The flow and the temperature field within and around the drop are obtained after transforming the results from the Laplace transform domain, in which they are derived, to the time domain. The time transient behaviour of the Migration speed depends strongly on the choice of the initial flow and temperature fields. The comparison with other initial conditions from the literature is performed.
  • Lecture (Conference)
    "Drop Tower Days 94", Bremen, Juli 1994
  • Contribution to external collection
    Proc. "Drop Tower Days 94", Bremen, Juli 1994, pp. 90 - 94

Publ.-Id: 159 - Permalink


Some proposals for Marangoni experiments with a pre-prepared temperature gradient
Gerbeth, G.;
A serious disadvantage of a lot of microgravity experiments on Marangoni convection is often times the fact that most of the valuable time under microgravity is lost for preparing the necessary temperature gradient. Therefore, the paper will discuss two possibilities of short-term marangoni experiments where the temperature gradient over a plane fluid layer can be prepared in advance, but keeps the fluid motionless.
At first, a convective motion will be started simply by switching off gravity which can result in long-wave surface capillary waves. Such a motion due to surface deformations is suppressed under earth conditions.
Second, various types of Marangoni motions will be discussed for liquid metals exposed to an external magnetic field. Instability thresholds are increased by the magnetic field, i.e. the liquid can be kept motionless by means of the magnetic field under a given temperature gradient.
The paper will discuss the feasibility of such investigations in drop tower experiments.
  • Lecture (Conference)
    "Drop Tower Days 94", Bremen, Juli 1994

Publ.-Id: 158 - Permalink


Transportreaktionen der Elemente der 6. Gruppe im O2-H2O(g)/SiO2(s)-System
Roß, A.; Hübener, S.; Eichler, B.;
  • Lecture (Conference)
    Vortragstagung Fachgruppe Nuklearchemie der GDCh, 5.-7.9.1994

Publ.-Id: 156 - Permalink


Modellexperimente zur physikochemischen Charakterisierung des Elements 106 als Oxid
Hübener, S.; Roß, A.; Funke, H.;
  • Poster
    Vortragstagung der Fachgruppe Nuklearchemie der GDCh

Publ.-Id: 155 - Permalink


Zur Bestimmung von Actiniden in Bauschutt
Hübener, S.; Nebelung, C.; Bernhard, G.;
  • Poster
    Vortragstagung der GDCh-Fachgruppe Nuklearchemie 05.09.-07.09.1994, Berlin

Publ.-Id: 154 - Permalink


Dekontaminationsuntersuchungen an Bauteilen der Anlage "AMOR-I"
Friedrich, H.; Bernhard, G.; Boeßert, W.;
  • Poster
    Vortragstagung der GDCh-Fachgruppe Nuklearchemie

Publ.-Id: 153 - Permalink


Elektroanalytische IN-SITU-Verfolgung von Schwermetallretentions- und Auslaugungsprozessen an Gesteinsmaterial
Thieme, M.; Geipel, G.; Bernhard, G.; Nitsche, H.;
  • Poster
    Analytica Conference 1994, 4/94

Publ.-Id: 152 - Permalink


Isotopic ratios of intermediate mass fragments produced in p + A reactions at 1 GeV
Neubert, W.; Andronenko, L. N.; Andronenko, M. N.; Kotov, A. A.; Seliverstov, D. M.; Strakovsky, I. I.; Vaishnene, L. A.;
  • Zeitschrift für Physik A 350 (1994) 1

Publ.-Id: 151 - Permalink


Beiträge des FZ Rossendorf zur Sicherheit von WWER-Reaktoren
Weiß, F.-P.;
  • Lecture (Conference)
    WTZ-Statusseminar, Moskau, 8./9. Februar 1994

Publ.-Id: 150 - Permalink


Structural Reasons of the Trough-Thickness Variation of Mechanical Properties in Large Forgings of Nuclear Reactor Pressure Vessel Steel
Große, M.; Böhmert, J.; Viehrig, H.-W.;
The ductile-brittle transition temperature is the usual reference parameter for the safety assessment of the reactor pressure vessel. In large forgings this parameter can change with the distance from the surface. Thus, the safety assessment must consider the effect. To evaluate the significance for the VVER 440-type pressure vessel the relationship among mechanical properties, through-the-thickness position and microstructure was investigated at a forging of 15Kh2MFA steel. The change of the mechanical properties (hardness, strength, transition temperature) are relatively low. The surface-near position is harder and tougher than the deeper range. Both ranges differ in the content of preeutectoid ferrite and in the arrangement, but not in the content of carbides. The Orowan model of the mechanism of precipitation hardening can describe quantitatively the dependence of the yield strength and the number of M23C7 carbides per unit area of section plane found experimentally on the trough-the-thickness position.
  • Poster
    und Proceedings EUROMAT 1994

Publ.-Id: 149 - Permalink


Characterisation of Nanoscale Precipitates in Reactor Pressure Vessel Steel 15Kh2MFA by Small Angle Scattering Experiments
Große, M.; Böhmert, J.; Eichhorn, F.; Haubold, H.-G.; Goerigk, G.; Brauer, G.;
The deterioration of the mechanical properties of reactor pressure vessel (RPV) steels during their irradiation in a nuclear power plant is known as neutron embrittlement. The microscopic mechanisms of the neutron embrittlement of low alloy RPV steel are not fully understood.
These mechanisms were investigated at the RPV steel of Russian and Czech type 15Kh2MFA. This steel differs from ASTM type A503 or A533 steels mainly in its contents of the carbide forming elements Cr and V. Neutron small angle scattering (SANS) using the SANS-2 facility at the FRG-1 reactor in Geesthacht and anomalous X-ray small angle scattering (ASAXS) using the JUSIFA facility at the HASYLAB in Hamburg were employed.
The difference between the scattering intensities from irradiated and unirradiated specimens give the small angle scattering effect of the radiation damages. Irradiation induced precipitates were found with a mean diameter of = 1...2 nm. The defect volume fraction is depending from the neutron fluence.
From the magnetic scattering contrast (SANS) and the anomalous scattering contrast (ASAXS) information about the chemical composition were got. This results are compared with the idea that the irradiation induced precipitates in 15Kh2MFA steel are carbides.
  • Lecture (Conference)
    und Proceeding EUROMAT 94, Balatonszeplak, Hungaria, 30. Mai bis 01. Juni 1994, p. 448

Publ.-Id: 148 - Permalink


Entwicklung eines TDC mit extrem kleiner Totzeit für schnelle Triggerprozesse
Gabriel, F.; Michel, P.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-30

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Publ.-Id: 147 - Permalink


Anwendung des feinfokussierten Ionenstrahles zur Fertigung mikromechanischer Bauelemente
Bischoff, L.; Teichert, J.; Hesse, E.; Geßner, T.; Löbner, B.; Breng, U.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-31

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Publ.-Id: 146 - Permalink


The Observation of Phonons in TSCC by Pulsed Neutron Diffraction
Prokert, F.; Savenko, B. N.; Balagurov, A. M.;
  • Poster
    ECM-15, Dresden 28.8.-2.9.1994, Book of Abstracts, 15. European Crystollographic Meeting
  • Contribution to proceedings
    ECM-15, Dresden 28.8.-2.9.1994, Book of Abstracts, 15. European Crystollographic Meeting

Publ.-Id: 145 - Permalink


Messung der Volumenströme von Gas und Flüssigkeit in einer Zweikomponentenströmung mit Ultraschall und Mustererkennung
Prasser, H.-M.; Hensel, F.; Schütz, P.;
The state-of art of ultrasonic two-phase flow measurements is characterised by a number of different approaches commonly based on the identification and characterisation of individual voids (bubbles, plugs etc.) applying the techniques of ultrasonic testing. The recorded individual events are integrated to extract parameters as void fraction or volume flow rates. The main limitation of these methods arises from the complicated structure of two-phase flow at higher void fractions which leads to multiple diffractions of the sound beam. The measurement is therefore limited to low void fractions or an easy flow structure.
The main idea of the present work was to overcome these limitations by means of pattern recognition. An ultrasonic beam crossing the two-phase flow is modulated by the changing structure of the voids passing by and therefore the through-transmission signal must contain information about the parameters of the two-phase flow even if information about individual flow effects cannot be derived. Therefore it was supposed that a pattern recognition algorithm trained with signals obtained at known conditions is able to identify the set of the flow parameters (flow rates, void fraction etc.) in an unknown situation.
  • Lecture (Conference)
    ACHEMA '94, Internationales Treffen für Chemische Technik und Biotechnologie, Frankfurt am Main, 5.-11.06.1994

Publ.-Id: 144 - Permalink


Fluidik-ISFET-Mikrosystem
Pham, T.; Howitz, S.;
  • Lecture (Conference)
    "Sensoren-Technologie und Anwendungen", Bad Nauheim, März 1994

Publ.-Id: 143 - Permalink


Erfahrungen und Ergebnisse des 1000-Dächer-Photovoltaik-Programms in Sachsen
Rindelhardt, U.; Teichmann, G.;
Die Ergebnisse aus dem einjährigen Betrieb von 43 netzgekoppelten PV-Anlagen in Sachsen werden dargestellt. Schwerpunkte bilden die architektonische Einbindung der Generatoren in die Gebäude, die mögliche Synchronisation zwischen solarer Stromerzeugung und dem Verbrauch von Elektroenergie sowie Erfahrungen bei der Installation und dem Betrieb von netzgekoppelten PV-Anlagen.
Hervorhebenswert sind die Ergebnisse zum möglichen Eigenverbrauch des solar erzeugten Stromes. Es konnte gezeigt werden, daß gerade energiesparende Haushalte stark auf die "Zwischenspeicherung" im öffentlichen Netz angewiesen sind (Eigenverbrauch 20 %). Maximal wird ein Eigenverbrauch von ca. 50 % erreicht.
Die erreichten jährlichen Energieerträge betragen im Mittel 680 kWh/kWp, wobei große Unterschiede zwischen den einzelnen Anlagen gefunden wurden. Als Hauptursache für die unterschiedlichen energetischen Ergebnisse werden Abweichungen der Modulparameter von den Datenblattangaben der Hersteller vermutet.
  • Lecture (Conference)
    9. Nationales Symposium Photovoltaische Solarenergie, Staffelstein, 16.-18.3.1994, Tagungsband S. 149
  • Contribution to proceedings
    9. Nationales Symposium Photovoltaische Solarenergie, Staffelstein, 16.-18.3.1994, Tagungsband S. 149

Publ.-Id: 142 - Permalink


The reaction Au + Au at 150 AMeV simulated by the Copenhagen Statistical Multifragmentation Model
Neubert, W.; Mösner, J.; Kotte, R.; Wohlfarth, D.; Barz, H.-W.;
  • Contribution to proceedings
    XXXII International Winter Meeting on Nuclear Physics, Bormio, Italy, 24.-29.1.1994

Publ.-Id: 141 - Permalink


Thermal Diffuse Scattering in Time-of-Flight Neutron Diffraction Studied on SBN and TSCC Single Crystals
Prokert, F.; Savenko, B. N.; Balagurov, A. M.;
  • Acta Crystallographica Section A 51 (1995) pp. 124-129

Publ.-Id: 140 - Permalink


Developmental changes of enzymes involved in peptide degradation in isolated rat brain microvessels
Brust, P.; Bech, A.; Kretzschmar, R.; Bergmann, R.;
  • Peptides 15 (1994) 6 pp. 1085-1088

Publ.-Id: 139 - Permalink


The Neutronphysical Development of the IBR-2 Reflektor
Noack, K.;
  • Kerntechnik 59 (1994) 6

Publ.-Id: 138 - Permalink


Gas Chromatographie Studies of Molybdenum in Humid Oxygen
Roß, A.; Hübener, S.; u. a.;
  • Other report
    Annual Report 1993 im Paul Scherrer Institut

Publ.-Id: 137 - Permalink


ROSY (2. Fassung)
Einfeld, D.; Matz, W.;
Der Projektvorschlag für eine kompakte Synchrotronstrahlungsquelle der 3. Generation ROSY wird beschrieben. Die Quelle sol1 für die Materialforschung dediziert sein, die für die Forschung im regionalen Umfeld von Rossendorf prägend ist.
Bei einer Speicherringenergie von 3 GeV wird Synchrotronstrahlung im harten Röntgenbereich mit einer kritischen Energie des Spektrums von Ec = 8,4 keV (hc=0,14 nm) emittiert. Mit einer naturlichen Emittanz von 28 n nm rad wird eine sehr brillante Strahlung zur Verfügung gestellt. Neben der Strahlung aus Ablenkmagneten kann Strahlung aus Wigglern und Undulatoren genutzt werden. Für diese insertion devices sind 8 Einbaumöglichkeiten vorhanden, von denen 4 in nichtdispersionsfreien geraden Strecken liegen. Der Speicherring hat eine vierfache Symmmetrie, einen Umfang von 148 m und ist als modifizierte FODO-Struktur konzipiert. Ein nachträglicher Einbau von supraleitenden Ablenkmagneten zur Erzeugung eines harteren Spektrums und damit zur Ausweitung des Anwendungsbereiches ist möglich.
Der Teil I enthält die wissenschaftliche Begründung fur ROSY und eine Darstellung der Nutzungsmöglichkeiten. Im Teil II werden das Speicherringkonzept und die technischen Details der einzelnen Komponenten beschrieben.
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-27 (2. Auflage) 1993

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Publ.-Id: 136 - Permalink


Correlation between volume fraction of radiation-induced precipitates and toughness of VVER pressure vessel steel 15Kh2MFA
Große, M.; Böhmert, J.; Viehrig, H.-W.;
The deterioration of mechanical properties of reactor pressure vessel (RPV) steel during its irradiation in a nuclear power plant is known as neutron embrittlement. It is for instance manifested as a shift of the ductile - brittle transition temperature toward higher values. The microscopic mechnisms of neutron embrittlement of low alloy RPV steel are not yet fully understood. It is known that dislocation loops, vacancy clusters (voids) and precipitates are formed during irradiation.
The dimensions of radiation induced precipitates are less than 5 nm, in RPV steel 15Kh2MFA they are about 1 - 3 nm. One of the objectives of present research in this field is to throw light on the nature of these precipitates.
In this article the correlation between the results of small angle neutron scattering (SANS) and the ductile - brittle transition temperature are studied and possible mechanisms of neutron embrittlement are discussed.
  • Journal of Nuclear Materials 211 (1994), pp. 177 - 180

Publ.-Id: 135 - Permalink


Photon production in an expanding and chemically equilibrating gluon-enriched plasma
Kämpfer, B.; Pavlenko, O. P.;
Abstract Photon production in a longitudinally and transversely expanding gluon plasma with initially little quark admixture is considered. Chemical equilibration of quarks and gluons is followed by rate equations. The yields of hard photons withE2 GeV are insensitive to chemical equilibration and depend mainly on the initial thermalized state. Medium-energy photons withE1 GeV are more frequently produced in case of faster equilibration, despite of faster cooling. For an assumed fast equilibration we follow the evolution of matter through mixed and hadron phases. The transverse momentum kick, due to transverse expansion, of photons from hadron matter is shown to be reduced for an equation of state with reduced latent heat. The photon yield in the regionE>1 GeV from deconfined matter dominates for conditions, estimated to be achieved at RHIC, in case of a weakly first-order confinement transition.
  • Zeitschrift für Physik C 62 (1994) 491

Publ.-Id: 134 - Permalink


Quasi-particle description of a strongly interacting pion gas
Bunatian, G. G.; Kämpfer, B.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-28 Preprint

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Publ.-Id: 133 - Permalink


Resonante Röntgenkleinwinkelstreuung zur Untersuchung bestrahlungsinduzierter Ausscheidungen im Stahl 15Ch2MFA
Große, M.; Böhmert, J.; Eichhorn, F.; Haubold, H.-G.; Goerik, G.;
  • Contribution to external collection
    Jahresbericht 1993 des HASYLAB

Publ.-Id: 132 - Permalink


Trigonal-bipyramidale Technetium- und Rhenium-Komplexe mit vierzähnigen tripodalen NS3-Liganden
Spies, H.; Glaser, M.; Pietzsch, H.-J.; Hahn, F. E.; Kintzel, O.; Lügger, T.;
  • Angewandte Chemie 106 (1994) 13 pp. 1416-1419

Publ.-Id: 131 - Permalink


Technetium Complexes with Thioether Ligands
Pietzsch, H.-J.; Spies, H.; Leibnitz, P.; Reck, G.; Johannsen, B.;
  • Radiochimica Acta 63 (1993) pp. 163-166

Publ.-Id: 129 - Permalink


Occurence and Nature of Different Tc(V) and Re(V) Complexes with Mercapto/Amide Ligands
Johannsen, B.; Noll, B.; Leibnitz, P.; Reck, G.; Noll, S.; Spies, H.;
  • Radiochimica Acta 63 (1993) pp. 133-137

Publ.-Id: 128 - Permalink


Achromatic two-stage E x B mass filter for a focused ion beam column with collimated beam
Teichert, J.; Tiunov, M. A.;
A two-stage achromatic E x B mass seperator has been desinged for a high-current focused ion beam column with collimated beam. The seperator consists of two homogeneous field E x B filters, a stigmator and the seperation aperture. The second-order geometrical and chromatic aberration coefficients are derived and their dependence on magnetic pole piece and electrode geometry are investigated in performing electric and magnetic field calculations. The influence of the mass seperator on the spatial resolution of the column is discussed.
  • Measurement Science and Technology 4 (1993) pp. 754-763 (nur bis 1991 im Bestand)

Publ.-Id: 127 - Permalink


Cosmic phase transitions
Kämpfer, B.; Lukacs, B.; Paal, G.;
  • Book (Authorship)
    beim Verlag: Teubner, Stuttgart-Leipzig (1994), TEUBNER-TEXTE zur Physik, Band 29 (1994)

Publ.-Id: 126 - Permalink


Dilepton production as probe for nuclear exotic states and nuclear interactions
Bratkovskaya, E. L.; Kämpfer, B.; Titov, A. I.;
  • Contribution to external collection
    World Scientific, Signapore, Hadrons and Nuclei from QCD, K. Fuji et al. (Eds.), 123

Publ.-Id: 125 - Permalink


Dilepton radiation from pre-equilibrium parton matter
Kämpfer, B.; Pavlenko, O. P.;
  • Contribution to proceedings
    Int. Workshop on Nuclei + Nuclear Excitations, Hirschegg 1993

Publ.-Id: 124 - Permalink


Estimates of dielectron production in pp and pd reactions at 1 - 2 GeV
Kämpfer, B.; Titov, A. I.; Bratkovskaya, E. L.;
  • Physics Letters B 301 (1993) 123
  • Open Access LogoForschungszentrum Rossendorf; FZR 92-04 1992

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Publ.-Id: 123 - Permalink


Nuclear structure funktion F2A:Moments Mn(F2A) and kinematics beyond x=1
Kaptari, L. P.; Umnikov, A. Y.; Kämpfer, B.;
  • Physical Review D 47 (1993) 3804
  • Open Access LogoForschungszentrum Rossendorf; FZR 92-7 Preprint

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Publ.-Id: 122 - Permalink


Velocity correlations of intermediate mass fragments produced in central collisions of Au + Au at E = 150 A MeV
Kämpfer, B.; Kotte, R.; Mösner, J.; Neubert, W.; Wohlfarth, D.; Alard, J. P.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Blaich, T.; Buta, A.; Caplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Dupieux, P.; Erö, J.; Fan, Z. G.; Fintz, P.; Fodor, Z.; Freifelder, R.; Fraysse, L.; Frolov, S.; Gobbi, A.; Grigorian, Y.; Guillaume, G.; Herrmann, N.; Hildenbrand, K. D.; Hölbling, S.; Houari, A.; Jeong, S. C.; Jorio, M.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Krämer, M.; Kuhn, C.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Matulewicz, T.; Mgebrishvili, G.; Moisa, D.; Montaru, G.; Montbel, I.; Morel, P.; Pelte, D.; Petrovici, M.; Rami, F.; Reisdorf, W.; Sadchikov, A.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Teh, K.; Tezkratt, R.; Trzaska, M.; Vasiliev, M. A.; Wagner, P.; Wessels, J. P.; Wienold, T.; Wilhelmi, Z.; Zhilin, A. L.;
  • Physical Review C, 48, (1993) pp. R955-R959
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-14 Preprint

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Publ.-Id: 121 - Permalink


Photon production in a expanding and chemically equilibrating gluon-enriched plasma
Kämpfer, B.; Pavlenko, O. P.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-29 Preprint Dezember 1993

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Publ.-Id: 118 - Permalink


Institute of Bioinorganic and Radiopharmaceutical Chemistry; Annual Report 1992
Johannsen, B.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-12

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Publ.-Id: 117 - Permalink


Institute of Radiochemistry; Annual Report 1992
Bernhard, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-15

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Publ.-Id: 115 - Permalink


Institute of Safety Research; Annual Report 1992
Weiß, F.-P.; Böhmert, J.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-25

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Publ.-Id: 113 - Permalink


Electrical and optical properties of Co alloyed ß-FeSi2 formed by ion beam synthesis
Panknin, D.; Henrion, W.; Wieser, E.; Voelskow, M.; Skorupa, W.; Vöhse, H.;
  • Contribution to proceedings
    MRS Fall Meeting 1993, Boston

Publ.-Id: 110 - Permalink


Ion Beam Induced Epitaxial Crystallization of Single Crystalline 6H-SiC
Heera, V.; Kögler, R.; Skorupa, W.; Glaser, E.;
  • Contribution to proceedings
    MRS Fall Meeting 1993, Boston

Publ.-Id: 109 - Permalink


Untersuchungen zur Windenergienutzung in Sachsen
Hirsch, W.; Lischke, R.; Matthäi, J.; Rindelhardt, U.;
Im Rahmen eines umfangreichen Programmes wurden Untersuchungen zur Anwendbarkeit der Windatlas-Methode (WASP) zur Ermittlung des Windenergiepotentials in Sachsen durchgeführt. Das Ziel der Untersuchungen bestand darin, die erwarteten Grenzen bei der Nutzung von WASP in orografisch gegliedertem Gelände genauer zu ermitteln. Grundlage der Berechnungen waren Messungen von vier Stationen des sächsischen Windmeßprogrammes. Es konnte gezeigt werden, daß in großen Gebieten der Oberlausitz die Windatlas-Methode genutzt werden kann. In den Kammregionen des Erzgebirges wurden widersprüchliche Ergebnisse gefunden, so daß eine Nutzung hier praktisch nur in sehr kleinen Repräsentationsgebieten in der Umgebung einer Meßstation möglich ist.
  • Lecture (Conference)
    Kongreß "TERRATEC" 9.-12.3.1994, Leipzig, Tagungsband S. 144
  • Contribution to proceedings
    Kongreß "TERRATEC" 9.-12.3.1994, Leipzig, Tagungsband S. 144

Publ.-Id: 108 - Permalink


ION-BEAM ANALYSIS INVESTIGATIONS ON MULTILAYER DEVICES FOR VISIBLE OPTICS
Wagner, W.; Rauch, F.; Jescakowski, U.; Bawge, K.;
  • Contribution to external collection
    TATF 1994 PROCEEDINGS

Publ.-Id: 107 - Permalink


Formation of CoSi2 wires by maskless implantation with the focused ion beam
Teichert, J.; Bischoff, L.; Hesse, E.; Panknin, D.; Skorupa, W.;
The maskless ion implatation with the focused ion beam as as a new method for ion beam synthesis of cobalt silicide wires is presented. In order to perform the implantation a special achromatic mass seperator was implemented into the ion column, liquid alloy ion sources for cobalt ions were 30 keV Co+ and 60 keV Co++ ions. The dose dependence for room temperature implantation and the influence of the substrate temperature were investigated.
  • Lecture (Conference)
    und Proceedings MRS Fall Meeting, Boston, 29.11.-3.12.1993
  • Materials Research Society, Symposium Proceedings; Materials Synthesis and Processing Using Ion Beams; Vol. 316 (1994) pp. 741-746
  • Materials Research Society, Symposium Proceedings; Silicides, Germanides, and Their Interfaces; Vol. 320 (1994) pp. 153-158

Publ.-Id: 106 - Permalink


Two-phase flow behaviour during a medium size cold leg test on PMK-II (SPE-4)
Prasser, H.-M.; Zippe, W.; Baldauf, D.; Szabados, L.; Ézsöl, G.; Baranyai, G.; Nagy, I.;
The Hungarian integral test rig PMK of the KFKI Atomic Energy Research Institute was used as a source of experimental data for the IAEA Standard Problem Exercise SPE-4, a Medium size cold leg Loca with a secondary Bleed-and-feed procedure. The needle shaped conductivity probes developed by the Research Center Rossendorf have been applied in order to obtain information about the void fraction and the structure of the two-phase flow. The primary circuit of the PMK-II test facility was practically fully equipped with probes (with exception of the core simulator and the downcomer). An overview of the signals of all probes and the general chronology of characteristic events are discussed. As a main result the mechanism of the hot leg loop-seal clearing was clarified in detail.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994, Stuttgart, 17.-19.5.1994
  • Contribution to proceedings
    Jahrestagung Kerntechnik 1994, 17.-19. Mai 1994, Stuttgart, Tagungsbericht, ISSN 0720-9207, S. 77-80

Publ.-Id: 105 - Permalink


Bestimmung der Neutronenflüsse in der drehbaren Bestrahlungseinrichtung im BER-II des HMI Berlin
Stephan, I.; Gawlik, D.; Gatschke, W.; Matthes, M.;
Zur Aktualisierung der Neutronenparameter in der drehbaren Bestrahlungseinrichtung des rekonstruierten BER-II wurde der im Forschungszentrum Rossendorf entwickelte Mehrkomponentenaktivierungsdetektor eingesetzt.
Durch das umfangreiche Datenmaterial sind axiale und radiale Neutronenflußverläufe bestimmt und es gelingt ein eindeutiger Bezug von Meßwert zur Bestrahlungsprobe.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994
  • Open Access LogoForschungszentrum Rossendorf; FZR-33
  • Contribution to proceedings
    Jahrestagung Kerntechnik 1994, Stuttgart, p. 519

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Publ.-Id: 104 - Permalink


Komponentenschwingungen an WWER-Reaktoren "Diagnose und Modellierung"
Altstadt, E.; Scheffler, M.; Schumann, P.; Weiß, F.-P.; Liewers, P.;
Seit Anfang der 70er Jahre sind an WWER-440-Reaktoren mehrfach anomale Schwingungen von Einbauten des RDB beobachtet worden, die teilweise zu Komponentenschäden führten.
Daher wurden speziell für den WWER-Typ zugeschnittene Diagnoseverfahren entwickelt, die auf der Korrelationsanalyse von Schwankungsanteilen des Neutronenflusses (incore und excore) und von nichtnuklearen Signalen wie Körperschall, Druckfluktuation und Beschleunigungen beruhen.
Um eine wirklich sensitive Fehlerfrüherkennung zu erreichen, wird ein theoretisches Schwingungsmodell auf der Basis Finiter Elemente (FE) entwickelt. Dieses Modell gestattet die Interpretation von gemessenen Schwingungssignalen in dem Sinne, daß die gemessenen Resonanzpeaks den Eigenschwingungen des gekoppelten mechanischen Systems zugeordnet werden können.
Darüber hinaus werden Sensitivitätsstudien durchgeführt, die die Veränderungen des Schwingungsverhaltens bei mechanischen Komponentenschäden verdeutlichen.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994

Publ.-Id: 103 - Permalink


Analytical and Experimental Investigations for Modelling the Fluid-Structure-Interaction in Annular Gaps
Grunwald, G.; Altstadt, E.;
Modelling the mechanical vibrations of pressurized water reactor internals the fluid-structure-interaction is to be taken into account. Especially at VVER-440 reactors there is a strong influence of the fluid due to the specific geometry. The intention of the presentation is to provide a solution of the continuity and the Navier-Stokes equations for the special case of a narrow annular gap geometry considering the fluid friction.
To obtain an analytical solution for these coupled 3D partial differential equations further assumptions and simplifications must be made:
- the width of the annular gap is small compared with the diameter,
- displacements of the mechanical structure are small compared with the gap width
- the fluid flow velocity components are independent on the radius.
Keeping these assumptions in mind one can reduce the dimension of the continuity equation from 3D to 2D by averaging over the gap width.
Two elementary types of motion of the cylinder are considered: parallel displacement and pendular motion. By superimposing these elementary types even more general motions can be described.
In practice the application could be meaningful for core barrel motion at LWRs in general and for flow induced vibrations of control elements at VVER-440 reactors.
The analytical results are compared with experimental ones from a cylindrical pendulum setup. The criteria of comparison are the eigenfrequency and the damping of the pendulum in the static and flowing fluid. There is a good agreement between analytical and experimental results. Especially the strong influence of the chosen boundary condition upon the pressure equations can be shown.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994
  • Other report
    Arbeitsbericht: FWSM - 1/1993

Publ.-Id: 102 - Permalink


Rechnungen zum Naturumlaufexperiment ISP-33 an der Anlage Pactel mit dem Code ATHLET
Krepper, E.;
Due to the low geodetic height differences and the presence of loop seals in VVER-reactors, the behaviour of natural circulation is an important safety feature. The experiment to the OECD/NEA/CSNI International Standard Problem No. 33 was dedicated to the investigation of this phenomenon. During the test, defined quantities of primary coolant waere drained, while the facility was operated at 10% of nominal power and without pumps. The test was stopped with increasing temperatures of the fuel rod simulator.
In RC Rossendorf pre- and posttest calculations were performed by the code ATHLET, which was developed by the "Gesellschaft für Anlagen- und Reaktorsicherheit".
The main events of the experiment could be predicted, shown and explained by the ATHLET calculations:
- After draining of about 20% of the primary inventory, the mass flow in the loops stagnates. Simultaneously, the primary pressure increases and the pressurizer is partly refilled.
- In later periods the mass flow through the three loops is nonequally distributed, which could be reproduced by the ATHLET calculations at least qualitatively.
  • Contribution to proceedings
    und Vortrag: Jahrestagung Kerntechnik Stuttgart 1994, Proceedings pp. 93-96

Publ.-Id: 101 - Permalink


Natural Circulation Instabilities During a Loca of VVER-Type Reactors
Krepper, E.; Rohde, U.;
In the Research Centre Rossendorf pre- and posttest calculations to the OECD/NEA/CSNI International Standard Problem No. 33 were carried out with the GRS code ATHLET. This Problem was a natural circulation experiment with stepwise reduced primary coolant inventory. In the ATHLET calculations after a drainage of about 50% of the primary inventory cyclic oscillations of the mass flows and the void fractions were observed. These are found in the experimental results also. A simple analytical model was developed to distinguish physically caused oscillations from numerically caused ones. The oscillations observed could be interpreted as density wave instability in the local recirculation loop core- bypass.
  • Lecture (Conference)
    und Proceedings: International Conference New Trends in Nuclear System Thermohydraulics, Pisa, 30.5.-2.6.1994, pp. 793 - 797

Publ.-Id: 100 - Permalink


3-Dimensional Analysis of a Baron Dilution Accident by Using the Code DYN3D/M2
Grundmann, U.; Rohde, U.;
An incorrect startup of a pump in an isolated loop containing a plug of diluted absorber can initiate a reactivity accident in a VVER-440. It is assumed that the main gate valve is opened after starting the main coolant pump. When the plug enters the core, it gives rise to a positive reactivity. An asymmetric distribution of diluted water in the core is expected which requires a 3-dimensional analysis for a more correct description of this accident.
The code DYN3D/M2 developed for investigations of reactivity initiated accidents in thermal reactors with hexagonal fuel elements is used for analysis. A model describing the mixing of water from the different loops in the lower plenum of a VVER-440 reactor gives the boron concentration at the inlet of each fuel element. The two limiting cases, ideal mixing and no mixing, are investigated for comparisons.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994

Publ.-Id: 99 - Permalink


Bestrahlungsexperimente im Rheinsberger WWER-2-Reaktor zum Nachweis der neutroneninduzierten Versprödungssuszeptibilität von russischen Druckbehälterstählen
Böhmert, J.; Viehrig, H.-W.;
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994

Publ.-Id: 98 - Permalink


Rotationsbanden mit geneigter Spinorientierung in geraden Xe- und Ba-Kernen
Dönau, F.; Frauendorf, S.; Vogel, O.; Gelberg, A.; von Brentano, P.;
  • Contribution to external collection
    Verhandlungen der DPG (VI) 29 (1994) s. 1941

Publ.-Id: 94 - Permalink


Vibrations versus collisions and the iterative structure of two-body dynamics
Pfitzner, A.; Cassing, W.; Peter, A.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-26
  • Nuclear Physics A 577 (1994) pp. 753

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Publ.-Id: 92 - Permalink


Neutron Fluence Calculations and Spectrum Adjustments for the Rheinsberg Pressure Vessel Steel Irradiation Program
Barz, H.-U.; Böhmer, B.; Konheiser, J.;
The starting point of these investigations is the performed irradiation program for the Rheinsberg reactor for 3 different reactor periods during 1984 to 1988. In this program a great number of steel specimens were irradiated at different positions. Additionally a certain number of activation monitors were installed. For the planned mechanical proof of these specimens information of the irradiation condition of all specimens are needed. Therefore we have to calculate the neutron fluences at the different irradiation points for all relevant reactor periods. A spectrum adjustment is used to proof and correct calculational results taking into account measurement results.
  • Lecture (Conference)
    Jahrestagung Kerntechnik 1994 vom 17.-19.5.1994
  • Contribution to proceedings
    Jahrestagung Kerntechnik 1994 vom 17.-19.5.1994, Tagungsbericht S. 19

Publ.-Id: 91 - Permalink


PET for treatment plan verification and beam monitoring in light ion tumour therapy.
Hasch, B.-G.; Manfraß, P.; Pawelke, J.; Sobiella, M.; Enghardt, W.; Blochberger, P.; Friedrich, A.; Geißel, H.; Irnich, H.; Kraft, G.; Magel, A.; Meufels, W.; Münzenberg, G.; Nickel, F.; Poppensieker, K.; Schall, I.; Schardt, D.; Scheidenberger, C.; Voss, B.; Ziegler, C.;
  • Lecture (Conference)
    Proceedings of the XIth International Conference on Computers in Radiation Therapy, 20-24 March 1994, Manchester, 364-365
  • Contribution to proceedings
    Proceedings of the XIth International Conference on Computers in Radiation Therapy, 20-24 March 1994, Manchester, 364-365

Publ.-Id: 89 - Permalink


Development of a cobalt liquid alloy ion source
Hesse, E.; Bischoff, L.; Teichert, J.;
A cobalt-neodymium liquid alloy ion source for applications in focused ion beam devices was developed and investigated. The performance and the main parameters of the ion source are presented.
  • Journal of Physics D: Applied Physics (Rapid Communication) 27 (1994) pp. 427-428

Publ.-Id: 88 - Permalink


Determination of Inorganic Species in Seepage Water of Uranium-Mining Rockpiles and in Related Media
Geipel, G.; Thieme, M.;
  • Journal of Radioanalytical and Nuclear Chemistry, Articles and Letters 183 (1994) 1 pp. 139-145

Publ.-Id: 87 - Permalink


Excited states built on the 6- isomer in ...
Winter, G.; Schwengner, R.; Reif, J.; Prade, H.; Döring, J.; Wirowski, R.; Nicolay, N.; von Brentano, P.; Grawe, H.; Schubart, R.;
  • Physical Review C 49 (1994) pp. 2427

Publ.-Id: 86 - Permalink


Transport treatment of an expanding pion gas in ultrarelativistic heavy ion collisions
Barz, H.-W.; Bertsch, G.; Danielewicz, P.; Schulz, H.; Welke, G. M.;
  • Book (Authorship)
    "HOT AND DENSE NUCLEAR MATTER" Plenum Press (Konferenzbericht - Buch) New York, 1994, pp. 687

Publ.-Id: 85 - Permalink


Photovoltaik-Experimentierfeld im Forschungszentrum Rossendorf
Rindelhardt, U.; Teichmann, G.; Schubert, D.;
Im Institut für Sicherheitsforschung des Forschungszentrums Rossendorf wurde ein Photovoltaik-Experimentierfeld in Betrieb genommen. Die Anlage, die der Durchführung von wissenschaftlichen Begleituntersuchungen zum Bund-Länder-1000-Dächer-Programm dient, besteht aus 3 Teilfeldern. Ein Strahlungsmeßfeld dient der Erfassung meteorologischer Parameter und der Bestimmung der Energieproduktion unterschiedlich geneigter und ausgerichteter Module. Eine netzgekoppelte Referenzanlage erlaubt die Untersuchung der Energieflüsse und Verlustquellen. Im Modulfeld werden der effektive Wirkungsgrad bzw. die Energieproduktion von derzeit 13 unterschiedlichen Modulen in Abhängigkeit von Einstrahlung und Temperatur gemessen. Zur Durchführung der Messungen und Datenauswertung wurden spezielle Hard- und Softwarelösungen entwickelt.
  • ELEKTRIE 48 (1994), S.31

Publ.-Id: 84 - Permalink


Transverse momentum dependence of dileptons from parton matter produced in ultrarelativistic heavy-ion collisions
Kämpfer, B.; Pavlenko, O. P.;
  • Open Access LogoForschungszentrum Rossendorf; FZR 93-23 Preprint
  • Physical Review C 49 (1994) pp. 2716

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Publ.-Id: 83 - Permalink


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