Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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32216 Publications
Gettering of iron and oxygen at cavities formed by helium ion implantation in Czochralski and float-zone silicon
Kaschny, J. R.; Fichtner, P. F. P.; Yankov, R. A.; Fukarek, W.; Mücklich, A.; Kreißig, U.; Peeva, A.; Danilin, A. B.; Skorupa, W.;
  • Lecture (Conference)
    E-MRS´98, Strasbourg, June 16-19, 1998

Publ.-Id: 2561 - Permalink


Stabilizing the direct melt extraction of intermetallic fibres by magnetic fields
Cramer, A.; Gerbeth, G.; Bojarevics, A.; Gelfgat, Y.;
In the direct melt extraction process a quickly rotating wheel draws fibres out of a liquid metal pool which may contain any pure metal or alloy. One common application of such fibres is the production of highly porous metallic substrates, which, in the case of Ni-Al is ideally suited to serve as a highly heat- and corrosion-resistant catalyst carrier. But this demands the fibres to have diameters in the range of 50 to 100 microns and a small width distribution of their cross section. The main limitations of this process are due to turbulence within the melt and a wavy motion on the surface which both inhibit to fulfil these requirements.
Many patents are concerned with the stabilisation of the melt pool or at least of the contact region between metal surface and the extraction wheel. They propose submersing mechanical parts directly into, or placing them at least in close vicinity to the melt to avoid the non-stationary conditions produced by the turbulence within the liquid metal pool. Even made of heat resistant ceramics they suffer from corrosion or cracks and do not work reliable at all. The present work describes a non invasive control mechanism by means of magnetic fields of different strength and orientation. They can be applied either globally to damp the flow within the whole melt volume or locally to the meniscus region where the fibre is formed, to reach higher Lorentz forces in this very sensitive region. Model experiments (In-Ga-Sn, liquid at room temperature; no extraction) with global stabilisation were carried out to study the calm down of the turbulent surface of an inductively stirred melt. In a second setup the influence of this globally applied field on the fibres have been investigated (low melting Sn-Pb). Though the otherwise wavy surface was damped down to a nearly mirror-like plane the goal of significant smaller fibre cross-section was not reached by the global stabilisation alone. The clearly observable positive tendency towards smaller fibres is presently investigated with two series of model experiments with local stabilisation. The smaller volume which needs to be magnetised allows for a 5 times stronger field which can be achieved either by rare earth permanent magnets or a concentration of the globally applied field with magnetic field guides.
  • Lecture (Conference)
    The 3rd International Symposium on Electromagnetic Processing of Materials (EPM2000) April 3-6 / Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp 147-152
  • Contribution to proceedings
    The 3rd International Symposium on Electromagnetic Processing of Materials (EPM2000) April 3-6 / Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp 147-152

Publ.-Id: 2560 - Permalink


Characterization of vacancy-type defects in Al+ and N+ co-implanted SiC by slow positron implantation spectroscopy (SPIS)
Anwand, W.; Brauer, G.; Coleman, P. G.; Yankov, R. A.; Skorupa, W.;
  • Lecture (Conference)
    30th Polish Seminar on Positron Annihilation, Jarnoltowek, Sept. 17-21, 1998
  • Lecture (Conference)
    8th Int. Workshop on Slow Positron Beam Techniques for Solids and Surfaces (SLOPOS-8), Cape Town, Sept 6 - 12, 1998
  • Applied Surface Science 149 (1999) 140-143

Publ.-Id: 2559 - Permalink


Instabilities of electromagnetically levitated bodies and its prevention
Priede, J.; Gerbeth, G.; Mikelsons, A.; Gelfgat, Y.;
Electromagnetic levitation is a well-known technique for containerless processing of metals and alloys both in the solid and in the molten state. In experiments the levitated bodies often times show different types of instabilities resulting in a rotating and oscillating motion of the sample. In the paper we analyze the physical reasons for such spontaneous instabilities, and conclude on possible measures against it. The first type of instability considered is that due to possible coupling between the electric current passing through the magnetic system and the variation of position of the levitated body. It is shown that oscillatory motion of the body may be unstable if the electric power supply regime permits the electric current passing through the magnetic system to vary depending on its effective inductance. Another type of instabilities may occur because of the coupling between the motion of the body and the electric currents induced in the body itself. This effect may cause a spontaneous spin-up of the spherical body, occuring if the magnetic field frequency exceeds a certain critical threshold depending on the configuration of the field. It is shown that this type of linear instability may be completely suppressed by imposing a steady magnetic field of a strength comparable to that of the oscillating one. As a third type of instability we consider small vibrations of the spherical body occuring due to the finite diffusion time of the magnetic field into the body resulting in a delay of the induced currents with respect to the body position. Again, such vibrations may occur if the non-dimensional field frequency exceeds some specific threshold. This threshold and the
underlaying mechanism will be explained. The theoretical predictions are verified by model experiments using solid Al or Mg spheres. These instabilities can obviously be avoided by system parameters below the corresponding non-dimensional reshold. If this is not possible in reality, an active damping method using DC magnetic fields has been developed, too. The DC field can either be produced by permanent magnets or by an electromagnetic superposition to the levitation coils. Experiments will be shown demonstrating the stabilization effect due to the DC magnetic fields.
  • Lecture (Conference)
    The 3rd International Symposium on Electromagnetic Processing of Materials (EPM2000) April 3-6 / Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp 352-357
  • Contribution to proceedings
    The 3rd International Symposium on Electromagnetic Processing of Materials (EPM2000) April 3-6 / Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp 352-357

Publ.-Id: 2558 - Permalink


A New Criterion for the Bubble Slug Transition in Vertical Tubes
Krüssenberg, A.-K.; Prasser, H.-M.; Schaffrath, A.;
Vertical two-phase flow is normally classified into the four basic flow regimes bubble, slug, churn and annular flow. The transition between the different flow regimes does not occur suddenly and many extensions of this classification can be found in literature. For the prediction of flow patterns empirical and theoretical flow pattern maps have been developed.
A new criterion is presented for the transition between bubble and slug flow which is based on local instantaneous conductivity measurements with a wire mesh sensor (1 kHz that means 1000 frames per second, 242 measuring points in a tube cross section area). The high resolution allows the calculation of particle size distributions.
The transition from homogeneous bubble flow to heterogeneous bubble flow is indicated by the appearance of a bimodal bubble size distribution. If the equivalent bubble diameter exceeds the tube diameter the transition from bubble to slug flow occurs. The new criterion is compared with different empirical (Govier & Aziz, Weisman & Kang) and theoretical flow maps (Taitel, Bornea & Dukler, Ishii & Mishima) and shows a good agreement.

Keywords: Bubble Size Distribution, Bubble Slug Flow Transition Criteria
  • Kerntechnik 65/1 (2000) 7-13
  • Contribution to external collection
    NURETH-9, San Francisco, California, USA, October 3-8, 1999

Publ.-Id: 2557 - Permalink


Numerical Simulation of the Emergency Condenser of the SWR1000
Krepper, E.; Schaffrath, A.; Aszódi, A.;
The SWR1000 is a new innovative boiling water reactor concept, which is developed by Siemens AG. This concept is characterized in particular by passive safety systems (e.g. four emergency condensers, four building condensers, eight passive pressure pulse transmitters, six gravity-driven core flooding lines). In the framework of BWR Physics and Thermohydraulic Complementary Action (BWR-CA) to the EU BWR R&D Cluster emergency condenser tests were performed by Forschungszentrum Jülich at the NOKO test facility. In this paper post test calculations with ATHLET are presented, which aim at the determination of the removable power of the emergency condenser and its operation mode. The 1D thermal-hydraulic code ATHLET was extended by the module KONWAR for the calculation of the heat transfer coefficient during condensation in horizontal tubes. In addition, results of CFD-calculations using the code CFX-4 are presented, which investigate the natural convection during the heat up process at the secondary side of the NOKO test facility.
Keywords: BWR, emergency condenser, condensation inside horizontal tubes, natural convection, CFD
  • Kerntechnik 64 (1999) 5-6, p. 243-252

Publ.-Id: 2556 - Permalink


ROBL (German Beamline) on BM20: Structural and radiochemical investigations
Matz, W.; Schell, N.; Funke, H.; Bernhard, G.;
  • ESRF- Newsletter 30 (1998) 45

Publ.-Id: 2554 - Permalink


Rossendorfer Beamline an der ESRF
Matz, W.;
  • Phys. Bl. 54 (1998) Nr. 9, 785

Publ.-Id: 2553 - Permalink


Investigation of liquid metal two phase flow characteristics by means of local resistivity probes and X-ray screening technique
Eckert, S.; Gerbeth, G.; Guttek, B.; Stechemesser, H.; Lielausis, O.;
In many technologies such as the refinement of metallic melts the injection of gas bubbles is used to drive some liquid motion, enhance transport processes or to control the rate of chemical reactions. The resulting flow structure strongly depends on two phase flow parameters such as bubble size, bubble distribution or the local void fraction. Magnetic fields can be used to control the characteristics of a liquid metal bubbly flow.
We present experimental investigations of the bubble formation in heavy liquid metals as well as the influence of external magnetic fields on the turbulent dispersion of gas bubbles and the slip ratio in liquid metal bubbly flows, respectively.

a) Bubble formation
If gas bubbles are injected into a liquid metal characterised by a large surface tension one should be care to get a good wetting between the fluid and the surface of the gas injector. Otherwise, the gas would try to spread out along this interface to form gas layers. A control of the bubble size and formation rate becomes difficult. The comparison between experiment and theoretical models describing bubble formation processes requires an ideal wetted gas injector.
The bubble formation in mercury and the eutectic alloy InGaSn has been studied by means of several methods of gas injection, for instance through single orifices or injectors made from sintered metals with a mean porosity of a few microns. X-ray measurements have been used to directly observe the resulting gas bubbles rising in the liquid metal. In the case of an single orifce the influence of electromagnetic forces on the bubble frequency has been demonstrated.

b) Turbulent bubble dispersion, slip ratio
The transport properties of small argon bubbles have been studied in turbulent upwards channel flows of sodium and mercury. The bubbles were injected by a single orifice located in the centre of the channel cross section. After a distinct distance the local void fraction and the bubble velocity has been measured by means of electrical resistivity probes. The flow has been exposed to external magnetic fields directed transverse or longitudinal to the mean flow direction.
We will present and discuss measuring results showing the effect of the magnetic field strength and direction on the horizontal gas distribution and the ratio between gas and liquid velocity.
Keywords: two-phase flow, bubbly regime, liquid metals, void fraction measurements, electric resistivity probe, X-ray imaging
  • Lecture (Conference)
    International Workshop on Measuring Techniques for Liquid Metal Flows (MTLM), Dresden, October 11-13, 1999

Publ.-Id: 2552 - Permalink


Local velocity measurements in high temperature liquid metals by means of mechano-optical probes
Eckert, S.; Witke, W.; Pisseloup, L.; Gerbeth, G.;
Model experiments are an important tool to understand the details of the flow structure and the transport properties of
flows occurring in real-scale metallurgical facilities as well as to validate the multitude of numerical codes for flow
simulation. Generally, water experiments are often performed to characterise the flow. Nevertheless, due to the large
differences of material properties like density, heat conductivity, surface tension or electrical conductivity the use of liquid
metals has clearly to be preferred if heat transfer phenomena, two-phase flows or the influence of electromagnetic fields
on the flow should be investigated. The application of suitable alloys with low melting points, for instance PbBi (Tm = 125
°C) or InGaSn (Tm = 5...10 °C), makes such kind of experiments very flexible and offers the ability to measure the
essential flow quantities like velocity, pressure or void fraction.

In this lecture we want to discuss a novel sensor which has been developed by the Rossendorf group to measure the local
velocities in opaque liquid flows. The measuring principle is based on the separation of a direct mechanical interaction
between flow and sensor tip and the optical acquisition and processing of the signal. In principle, this fact allows the
extension of the range of applicability to higher temperatures. Furthermore, the insensitivity of the system to electrical
noise and external magnetic fields can be considered as an important advantage. Until now, the sensor has been tested in
metallic melts up to temperatures of about 350 °C . In principle, an extension of the range of application up to
temperatures of about 1100 °C should be possible by the utilisation of quartz glass as material for the sensitive sensor tips.
The first sensors have been manufactured and tested with low temperature melts.

We present measurements of the local velocity obtained in an eutectic InGaSn melt driven by a rotating magnetic field.
The interest is focussed on geometry and parameters relevant for crystal growth technologies and mixing processes in
metallurgical applications, respectively. Measured profiles of the azimuthal velocity have been obtained at different
frequencies and field amplitudes.
Keywords: flow measurement technique, fluid velocity, mechano-optical principle, local sensor, liquid metals, rotating magnetic field
  • Lecture (Conference)
    International Workshop on Measuring Techniques for Liquid Metal Flows (MTLM) , Dresden, October 11-13, 1999

Publ.-Id: 2551 - Permalink


Reaktorsicherheitsforschung im Institut für Sicherheitsforschung des Forschungszentrums Rossendorf
Weiß, F.-P.; Rohde, U.; Prasser, H.-M.; Altstadt, E.; Böhmert, J.; Böhmer, B.; Carl, H.;
Das Institut für Sicherheitsforschung ist eines von fünf wissenschaftlichen Instituten des Forschungszentrums Rossendorf e. V. (FZR). Die Rossendorfer Sicherheitsforschung baut auf langjährige Erfahrungen zur Analyse von Druckwasserreaktoren des russischen WWER-Types auf. WWER-Reaktoren nehmen bis heute einen wichtigen Platz im Spektrum des Institutes ein. So unterstützt das Institut im Rahmen eines Programmes des Bundesministeriums für Umwelt, Naturschutz, und Reaktorsicherheit die ukrainische Atomaufsichtsbehörde beim Aufbau einer modernen KKW-Überwachung. Inzwischen hat das Institut ebenso Kompetenz zur Sicherheitsforschung für westliche Leichtwasserreaktoren aufgebaut und kooperiert mit deutschen, europäischen und amerikanischen Forschungseinrichtungen und der Industrie.
Die Schwerpunkte der Sicherheitsforschung in Rossendorf liegen auf der Modellierung thermohydraulischer Phänomene bei unterstellten Störfallabläufen, der Reaktorphysik und dem Strahlungstransport und dem Verhalten von Komponenten und Materialien.
Der erste Teil des Forschungsberichtes beschäftigt sich ausschließlich mit den thermohydraulischen Arbeiten des Institutes wie den Vermischungsvorgängen im Primärkreis bei Borverdünnungs- und Kaltwassertransienten sowie der Modellentwicklung für transiente Zweiphasenströmungen. Für die thermohydraulischen Arbeiten hat das Institut ein 1:5 Modell eines deutschen DWR aufgebaut, die Experimente werden mit CFD-Codes (Computational Fluid Dynamics) nachgerechnet.
  • atw 44. Jg. (1999) Heft 6 - Juni, S. 348

Publ.-Id: 2550 - Permalink


Measuring techniques for model experiments in liquid metal alloys
Eckert, S.; Witke, W.; Gerbeth, G.;
Model experiments are an important tool to understand the details of the flow structure and the transport properties of flows occurring in real-scale metallurgical facilities as well as to validate the multitude of numerical codes for flow simulation. The application of suitable alloys with low melting points, for instance PbBi (T = 125 °C) or InGaSn (T = 5...10 °C), guarantees realistic flow parameters and also offers the ability to measure essential flow quantities like velocity, pressure or void fraction. Two approaches will be discussed to measure the local velocities in opaque liquid flows such as liquid metals: a mechano-optical sensor and the ultrasonic Doppler method, respectively. Today, with respect to problems like high temperatures or material compatibility both techniques reveal severe limitations considering velocity measurements in liquid steel or aluminium, however, their reliability at moderate temperatures has been demonstrated. Here, we present velocity measurements obtained by means of both methods for the case of a cylinder filled with an eutectic InGaSn melt driven by a rotating magnetic field.
Keywords: flow measurement technique, fluid velocity, mechano-optical principle, ultrasonic Doppler method, liquid metals, rotating magnetic field
  • Lecture (Conference)
    EPM2000, The 3rd International Symposium on Electromagnetic Processing of materials, April 3-6, Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp. 43-48
  • Contribution to proceedings
    EPM2000, The 3rd International Symposium on Electromagnetic Processing of materials, April 3-6, Nagoya, Japan, Published by: The Iron and Steel Institute of Japan, pp. 43-48

Publ.-Id: 2549 - Permalink


Comparative Study of Methods to Estimate Elastic-Plastic Dynamic Fracture Initiation Toughness
Richter, H.;
There has not yet been generally accepted single specimen technique in order to obtain dynamic fracture mechanical parameters. A potential candidate could be the measurement of the acoustic emission (AE). Previous investigations showed that characteristic AE signals appears in the vicinity of crack initiation for the first time. With a specially developed measuring arrangement the method could be compared with simultaneously measuring additional physical parameters at specimens of strongly different levels of toughness and strength. Furthermore the results could be verified by the results of multiple specimens technique. With this technique the dynamic crack resistance curve was determined and the physical crack initiation toughness was deduced by measurement of the stretch zone width. To realize the idea the inverted impact pendulum developed and installed by VTT Espoo/Finland was modified with an AE transducer and a magnetic emission (ME) probe. The inverted impact pendulum design reduces the inertia and oscillation effects in the recorded load curve and allows to measure the crack opening (COD) by a laser scattering light method. In this way, at the same specimen crack opening displacement (COD), AE, and ME could be measured.
Neither of the three single specimen methods can directly detect crack initiation. Except the lower shelf region, were only a tiny amount of ductile crack growth occurs before cleavage, the stable crack initiation could be proven by AE and COD. Good agreement between initiation parameters based on SZW and AE was found for all toughness levels. In some cases a strong scattering of toughness parameters was, however, observed and the ranking did not correspond. COD indicates crack initiation after an amount of macroscopic stable crack growth, which is small but cannot be ignored. The correlation to the SZW is not independent of the toughness; for steels with high toughness the correlation is unsatisfied. Eventually, ME does not reflect stable crack initiation and growth.
Obviously, the physical connection between crack initiation and AE cannot be revealed. The AE method has been proved as very sensible for microscopically active processes, which coincide spatially and chronologically with ductile crack initiation. Thus, it is appropriate to estimate the dynamic fracture mechanical parameter "crack initiation toughness" better than other recently applied methods.
  • Lecture (Conference)
    Beitrag zu European Conference Junior Euromat‘98, 7.-11.9.1998, Lausanne, Switzerland, p. 333
  • Contribution to proceedings
    Beitrag zu European Conference Junior Euromat‘98, 7.-11.9.1998, Lausanne, Switzerland, p. 333

Publ.-Id: 2548 - Permalink


TRIDYN-Computersimulationen zur Schicht-Deposition von BN und zur Hochdosisimplantation in Si
Schwieger, T.;
  • Other report
    Friedrich-Schiller-Universität Jena, April 1997

Publ.-Id: 2547 - Permalink


Synthese schwermetallionensensitiver Membranen für ISFETs mittels Ionenimplantation
Möller, D.;
  • Other report
    TU Dresden, July 1997

Publ.-Id: 2546 - Permalink


Crystal-GRID: Eine neue nukleare Sonde zur Untersuchung atomarer Bewegung im Festkörper
Jentschel, M.;
  • Other report
    TU Dresden, April 1997

Publ.-Id: 2545 - Permalink


Defect engineering and prevention of imurity gettering in ion implanted silicon
Kögler, R.; Peeva, A.; Skorupa, W.; Kaschny, J.; Hutter, H.;
Additional self-interstitials were introduced into the vacancy-rich depth range around half of the projected ion range of high energy ion implanted silicon in order to balance radiation induced excess vacancies. The trapping of Cu atoms was found to be not effected by this procedure. Additional interstitial loops were formed during annealing if the concentration of self-interstitials exceeded a certain threshold. These dislocation loops did not act as gettering centres for Cu atoms. The results obtained are not in agreement with the assumption that excess vacancies are the gettering centres for metal impurities like Cu. Instead, it may be assumed that small clusters of self-interstitials act as gettering centres.
Keywords: silicon, ion implantation, point defects, gettering, impurities
  • Solid State Phenom. 82-84, 399 (2001)
  • Lecture (Conference)
    Int. Autum Meeting Gettering an Defect Engineering in Semiconductor Technology, GADEST 2001, St. Tecla, Sept. 30- Oct. 3., 2001

Publ.-Id: 2544 - Permalink


Transport und Strukturmodifikation bei der Stickstoffimplantation in amorphen Kohlenstoff
Grigull, S.;
  • Other report
    TU Dresden, July 1997

Publ.-Id: 2543 - Permalink


Morphologie, chemische Heterogenität und Lumineszenz von Zirkonen und ihre Bedeutung für petrogenetische Typologie und Genchronologie
Wolf, D.; Oberhänsli, R.; Grambole, D.; Gruner, T.;
  • Other report
    DFG-Abschlußbericht zur Sachbeihilfe Wo 489/2 - 2

Publ.-Id: 2542 - Permalink


Entwicklung eines Permeable Base Transistors mit Kobaltdisilizid-Gate auf der Basis maskenloser Implantation mit feinfokussiertem Ionenstrahl
Teichert, J.; Hausmann, S.;
  • Other report
    DFG-Te 250/1-1, Zwischenbericht, 12/97

Publ.-Id: 2541 - Permalink


Hochstromionenquelle für Dünnschichttechnologien
Siemroth, P.; Richter, E.; Schülke, T.; Witke, T.; Brückner, J.; Brutscher, J.;
  • Other report
    SMWK 4-7541.83-IWS/504

Publ.-Id: 2540 - Permalink


Schlußbericht: Anwendungsgerechte Systemintegration und Zuverlässigkeit für die intelligente mikro-mechanische Sensorik (AN-SYS), Teilvorhaben: Silizium-Glas- und Silizium-Silizium-Bonden
Schmidt, B.; Lange, K.; Harz, M.; Nitsche, P.;
  • Other report
    BMBF-Verbundprojekt, Förderkennzeichen 13 MV 0266, Mai 1997

Publ.-Id: 2539 - Permalink


Fluorine profiles in antarctic meteorites by nuclear reaction analysis
Noll, K.; Döbeli, M.; Tobler, L.; Grambole, D.; Krähenbühl, U.;
  • Contribution to external collection
    Annual Report 1996, Labor f. Radio- u. Umweltchemie der Univ. Bern u. des PSI

Publ.-Id: 2538 - Permalink


Dotierte und undotierte Diamantfilme
Fontaine, F.; von Borany, J.; Heera, V.;
  • Other report
    SMWK: 4-7531.50-03-IFW/602, Zwischenberichte 25.6.1997, 11.12.1997

Publ.-Id: 2537 - Permalink


Abschlußbericht zum Verbundprojekt "Strukturelle Ursachen und Mechanismen der bestrahlungsinduzierten Versprödung in Reaktordruckbehälterstählen"
Böhmert, J.; Brauer, G.;
  • Other report
    Verbundprojekt Forschungsförderung SMWK 1994, 4-7541.83 - FZR/403 Berichtsdatum: 15.01.1997

Publ.-Id: 2536 - Permalink


Impurity gettering effects in separation-by-implanted-oxygen (SIMOX) structures: what getters what, where and how
Yankov, R. A.;
  • Lecture (others)
    Bell Labs, Lucent Technologies, Murray Hill, NJ, USA, Dec. 8, 1997

Publ.-Id: 2535 - Permalink


A neural network approach for acoustic leak monitoring in the VVER440 pressure vessel head
Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.;
A neural network approach has been developed for localizing leakages and estimating the leak rate in the VVER-440 pressure vessel head. Results are presented from experiments with simulated leaks. Three-layer perceptron networks were found to be best suited for leak localization and for the estimation of leak rates. However, the estimation of leak rates required an additional neural network because a different normalization procedure was necessary for extracting features from RMS values of the acoustic emission sensors. Perceptron networks with continuously valued outputs corresponding to the coordinates of the leak positions were useful for indentifying even leak positions which had not been offered during training.
Keywords: Leak; monitoring; neural networks; pressurized water reactors; VVER reactors
  • Progress in Nuclear Energy, Vol. 34, No. 3, pp. 173 - 183, 1999

Publ.-Id: 2534 - Permalink


Interaction of high-energy ion beams with silicon: buried layers, gettering and defect engineering
Yankov, R. A.;
  • Lecture (others)
    VARIAN Company, Gloucester, MA, USA, Dec. 4, 1997

Publ.-Id: 2533 - Permalink


Proximity gettering of transition-metal impurities in separation-by-implanted-oxygen (SIMOX) structures using buried carbon- and helium-implanted layers
Yankov, R. A.;
  • Lecture (others)
    Naval Res. Lab, Electronics Division, Washington D.C., USA, Nov. 26, 1997

Publ.-Id: 2532 - Permalink


Effekte bei der Implantationsdotierung von Bor und Aluminium in 6H-SiC
Wirth, H.;
  • Lecture (others)
    Daimler-Benz-AG, FZ Frankfurt/M., Oct. 29, 1997

Publ.-Id: 2531 - Permalink


Verfahren zur Minimierung des Einflusses von Resonanzfluktuationen auf das Meßsignal bei Ultraschall-Durchschallungsuntersuchungen
Prasser, H.-M.; Hensel, F.; Schütz, P.;
Das Patent beschreibt ein Verfahren zur Minimierung des Einflusses von Resonanzfluktuationen des Meßmediums bei Ultraschall-Durchschallungsuntersuchungen an in Rohrleitungen geführten Zwei- und Mehrphasenströmungen durch eine schnelle Variation der Arbeitsfrequenz des Senders der Meßeinrichtung.
Keywords: ultrasonic transmission measurement, wobbling, Wobbeln, Ultraschall-Transmissionsmessung
  • Patent
    DE 4333645 A1
  • Patent
    EP 0721572 B1

Downloads:

Publ.-Id: 2530 - Permalink


Using ANSYS/FLOTRAN® and CFX-4® for the solution of a mixed convection flow benchmark
Krepper, E.; Willschütz, H.-G.; Altstadt, E.; Weiß, F.-P.;
For the design, optimisation and safety analysis of nuclear plants, the use of 1D system codes is state of the art. However, for the modelling of passive equipment the range of validity of the 1D-codes is exceeded, because in these structures 3D-flow phenomena are often dominating. The fast progress of the computer technique and of Computational-Fluid-Dynamics (CFD-) codes gives the opportunity, to apply CFD-codes to the assessment of the efficiency of those components. Most of these codes are based either on the finite-volume or the finite-element method.
Integrated simulation of thermo-hydraulic phenomena and the resulting thermo-mechanical loadings for the surrounding structures (e. g. the reactor pressure vessel) can be achieved using a finite-element-code like ANSYS/Multiphysics®. The finite volume code CFX® has been proven to be an appropriate tool for modelling of 3D single phase fluid phenomena.
The governing mechanism in passive components for decay heat removal is natural convection and heat transfer with internal heating. To assess the capability of both codes describing a mixed convection flow, post test calculations of an IAHR (International Association for Hydraulic Research) benchmark exercise were performed (Kamide et. al, 1991). The working fluid was water in the temperature range of 15 to 50°C at atmospheric pressures.
This paper presents a discussion of the problems and capabilities of each code to calculate complex flow regimes and temperature fields.
Keywords: buoyancy driven fluid flow, CFD post-test analysis, ANSYS/FLOTRAN, CFX-4, heat transfer, natural convection
  • Lecture (Conference)
    17. CAD-FEM Users´ Meeting, 6.-8. Oktober 1999, Sonthofen, Germany, Proceedings Paper No. I 2.4
  • Contribution to proceedings
    17. CAD-FEM Users´ Meeting, 6.-8. Oktober 1999, Sonthofen, Germany, Proceedings Paper No. I 2.4

Publ.-Id: 2529 - Permalink


Subthreshold Production of Kaons and Antikaons in Nucleus-Nucleus Collisions at Equivalent Beam Energies
Barth, R.; Senger, P.; Ahner, W.; Beckerle, P.; Bormann, C.; Brill, D.; Cieslak, M.; Debowski, M.; Grosse, E.; Koczon, P.; Kohlmeyer, B.; Miskowiec, D.; Müntz, C.; Oeschler, H.; Pühlhofer, F.; Schwab, E.; Schicker, R.; Shin, Y.; Speer, J.; Ströbele, H.; Sturm, C.; Völkel, K.; Wagner, A.; Walus, W.;
  • Physical Review Letters, Volume 78, Number 21, 26 May 1997, 4007-4010

Publ.-Id: 2528 - Permalink


Enhanced Out-of-Plane Emission of K+ Mesons Observed in Au + Au Collisions at 1 A GeV
Shin, Y.; Ahner, W.; Barth, R.; Beckerle, P.; Brill, D.; Cieslak, M.; Debowski, M.; Grosse, E.; Koczon, P.; Kohlmeyer, B.; Mang, M.; Miskowiec, D.; Müntz, C.; Oeschler, H.; Pühlhofer, F.; Schwab, E.; Schicker, R.; Senger, P.; Speer, J.; Ströbele, H.; Sturm, C.; Völkel, K.; Wagner, A.; Walus, W.;
  • Physical Review Letters, Volume 81, Number 8, 24 August 1998, 1576-1579

Publ.-Id: 2527 - Permalink


Ionenimplantation in 6H-SiC; Elektrische Untersuchungen und Sublimation
Wirth, H.;
  • Lecture (others)
    Daimler-Benz-AG, FZ Frankfurt/M., Jan. 8, 1997

Publ.-Id: 2526 - Permalink


Bestimmung von Ni-Tiefenprofilen in Al und Aufklärung der Phasenbildung bei Ionenimplantation in Al
Wieser, E.;
  • Lecture (others)
    Seminar des Sonderforschungsbereiches "Strukturbildung und Eigenschaften in Grenzschichten", Dresden, Nov. 20, 1997

Publ.-Id: 2525 - Permalink


Flüssigmetall-Ionenquellen und ihre Anwendung in Ionenfeinstrahlanlagen
Teichert, J.;
  • Lecture (Conference)
    Univ. Magdeburg, Inst. f. experimentelle Physik, Nov. 27, 1997

Publ.-Id: 2524 - Permalink


Monte-Carlo and rate-equation simulations describing the evolution of nanoclusters in high-dose ion implantation
Strobel, M.;
  • Lecture (others)
    Solid State Division, Oak Ridge National Laboratory, Oak Ridge, USA, Oct. 23, 1997

Publ.-Id: 2523 - Permalink


Medium Effects in Kaon and Antikaon Production in Nuclear Collisions at Subthreshold Beam Energies
Laue, F.; Sturm, C.; Böttcher, I.; Debowski, M.; Förster, A.; Grosse, E.; Koczon, P.; Kohlmeyer, B.; Mang, M.; Naumann, L.; Oeschler, H.; Pühlhofer, F.; Schwab, E.; Senger, P.; Shin, Y.; Speer, J.; Ströbele, H.; Surowka, G.; Uhlig, F.; Wagner, A.; Walus, W.;
  • Physical Review Letters Volume 82, Number 8, 22 February 1999, 1640-1643

Publ.-Id: 2522 - Permalink


High energy implantation into silicon: Gettering and Defect Engineering
Skorupa, W.;
  • Lecture (others)
    Bell Labs, Lucent Technologies, Murray Hill, NJ, USA, Dec. 8, 1997

Publ.-Id: 2521 - Permalink


Ion beam processing of Semiconductors: Research activities at the Forschungszentrum Rossendorf
Skorupa, W.;
  • Lecture (others)
    VARIAN Company, Gloucester, MA, USA, Dec. 4, 1997

Publ.-Id: 2520 - Permalink


Blaue Lumineszenz hoher Intensität aus implantierten SiO2-Schichten: Nanocluster oder ....?
Skorupa, W.;
  • Lecture (others)
    Innovationskolleg "Methoden und Materialsysteme für den Nanometerbereich", Institut für Physik, TU Chemnitz, Oct. 24, 1997

Publ.-Id: 2519 - Permalink


Strong blue photo-and electroluminescence from ion beam synthesized Ge-rich SiO2-layers
Skorupa, W.;
  • Lecture (others)
    Dept. de Fisica Aplicada i Electronica, Univ.Barcelona, Spain, Nov. 11, 1997
  • Lecture (others)
    Naval Res. Lab, Electronics Division, Washington, D.C., USA, Nov. 26, 1997

Publ.-Id: 2518 - Permalink


Defectengineering and gettering by high energy implantation into Silicon
Skorupa, W.;
  • Lecture (others)
    Center for Analysis of Substances, Moscow, Russia, May 26, 1997

Publ.-Id: 2517 - Permalink


Hochenergieimplantation in Silicium: Defekt-Engineering und Gettern
Skorupa, W.;
  • Lecture (others)
    Institut für Physik, FSU Jena, May 16, 1997

Publ.-Id: 2516 - Permalink


Ionenstrahlmodifizierung von Halbleitermaterialien: Forschungsaktivitäten am Institut für Ionenstrahlphysik und Materialforschung
Skorupa, W.;
  • Lecture (others)
    Vortrag zur Evaluierung durch den Wissenschaftlichen Beirat des FZR, Rossendorf, Apr. 29, 1997
  • Lecture (others)
    Treffen der Dresdener Forschungsinstitute mit der Sächsischen Industrie, Dresden, June 27, 1997

Publ.-Id: 2515 - Permalink


Verschleißschutz von Alumnium- und Magnesiumlegierungen durch Ionenimplantation
Richter, E.; Chudoba, T.; Wieser, E.;
  • Lecture (others)
    Innovative Verfahren der Oberflächenvergütung von Leichtmetallen, Essen, June 5, 1997

Publ.-Id: 2514 - Permalink


Strong blue and violet light emission from silicon- and germanium-implanted silicon dioxide
Rebohle, L.;
  • Lecture (others)
    Bell Labs, Lucent Technologies, Murray Hill, NJ, USA, Dec. 8, 1997

Publ.-Id: 2513 - Permalink


Erzeugung blauer Lumineszenz-Zentren in SiO2 durch Ionenstrahlsynthese
Rebohle, L.;
  • Lecture (others)
    Vortrag zur Evaluierung durch den Wissenschaftlichen Beirat des FZR, Rossendorf, Apr. 4, 1997

Publ.-Id: 2512 - Permalink


Theoretische Beschreibung von Implantationsprozessen: Grundlagen, Methoden, Anwendungen
Posselt, M.;
  • Lecture (Conference)
    Sommerschule "Nukleare Sonden und Ionen", Bad Blankenburg, Germany, Sept. 1-5, 1997

Publ.-Id: 2511 - Permalink


Recent positron annihilation studies of the CuMn-system
Nicht, E.-M.;
  • Lecture (others)
    Lehrstuhl für Tieftemperaturphysik, Univ. Prag, Oct. 30, 1997

Publ.-Id: 2509 - Permalink


Ionenstrahlen in Forschung und Technik
Möller, W.;
  • Lecture (others)
    Physikalisches Kolloquium des Inst. für Physikalische Hochtechnologie, Jena, June 4, 1997

Publ.-Id: 2508 - Permalink


Ion beam analysis in Europe and Germany
Möller, W.;
  • Lecture (others)
    Univ. of Surrey, Dept. Electrica Engineering, Guildford, U.K., Feb. 4, 1997

Publ.-Id: 2507 - Permalink


Das Rossendorfer Strahlrohr ROBL an der ESRF
Matz, W.;
  • Lecture (others)
    Zentrumsseminar FZR, Dec. 4, 1997

Publ.-Id: 2506 - Permalink


Synchrotronstrahlung: Eigenschaften, Quellen, Anwendungen
Matz, W.;
  • Lecture (others)
    Zentrumsseminar FZR, Nov. 20, 1997

Publ.-Id: 2505 - Permalink


Der Materialforschungsmeßplatz der Rossendorfer Beamline an der Europäischen Synchrotronstrahlungs-quelle in Grenoble
Matz, W.;
  • Lecture (others)
    TU Dresden, Institut für Kristallographie und Festkörperphysik, Nov. 11, 1997

Publ.-Id: 2504 - Permalink


Experimente der Materialforschung an ROBL
Matz, W.; Prokert, F.; Eichhorn, F.; Schell, N.; Betzl, M.;
  • Lecture (others)
    Nutzertreffen ROBL, FZR, Rossendorf, June 19, 1997

Publ.-Id: 2503 - Permalink


ROBL: Strahlrohr und Experimentierausrüstung
Matz, W.;
  • Lecture (others)
    Nutzertreffen ROBL, FZR, Rossendorf, June 19, 1997

Publ.-Id: 2502 - Permalink


Basics and applications of plasma immersion ion implantation
Mändl, S.;
  • Lecture (others)
    University of Augsburg, Nov. 20, 1997

Publ.-Id: 2501 - Permalink


Plasma immersion ion implantation
Mändl, S.;
  • Lecture (others)
    City University of Hongkong, Oct. 13, 1997

Publ.-Id: 2500 - Permalink


Defective zones in Si detected by means of metal gettering
Kögler, R.;
  • Lecture (others)
    Univ. Barcelona, Dept. Fisica Aplicada i Electronica, Barcelona, Spain, Nov. 10, 1997

Publ.-Id: 2499 - Permalink


Detektion von Defektzonen in ionenimplantiertem Si
Kögler, R.;
  • Lecture (others)
    MLU Halle-Wittenberg, FB Physik, Halle (Saale), Apr. 10, 1997

Publ.-Id: 2498 - Permalink


Theoretische Grundlagen der Ionenstrahlsynthese: Computersimulationen auf atomarer Ebene
Heinig, K.-H.;
  • Lecture (others)
    Seminar an der TU Chemnitz, Chemnitz, Germany, May 13, 1997

Publ.-Id: 2497 - Permalink


Theoretische Grundlagen der Ionenstrahlsynthese: Beschreibungen basierend auf Ratengleichungen
Heinig, K.-H.;
  • Lecture (others)
    Seminar an der TU Chemnitz, Chemnitz, Germany, May 6, 1997

Publ.-Id: 2496 - Permalink


Grundlagen der Synthese von Nanoclustern und dünnen Schichten mit Ionenstrahlen
Heinig, K.-H.;
  • Lecture (others)
    Seminar am ISI des Forschungszentrum Jülich, Jülich, Germany, February 27, 1997

Publ.-Id: 2495 - Permalink


Implantations- und Ausheileffekte in SiC
Heera, V.;
  • Lecture (others)
    Institutsseminar FWI-FZR, Rossendorf, June 5, 1997

Publ.-Id: 2494 - Permalink


Verschleißfester Edelstahl – ein Erfolg der Ionenstrahltechnik
Günzel, R.; Richter, E.;
  • Lecture (others)
    Workshop "Werkstoffe innovativ", Hannovermesse 1997

Publ.-Id: 2493 - Permalink


Plasma source ion implantation in the Forschungszentrum Rossendorf: state of the art and recent developments
Günzel, R.;
  • Lecture (others)
    IPR, Ghandinagar, March 18, 1997

Publ.-Id: 2492 - Permalink


Recent developments of in situ ion beam analysis at Rossendorf
Grötzschel, R.;
  • Lecture (others)
    Faure, South Africa, Nov. 19, 1997

Publ.-Id: 2491 - Permalink


Grundlagen der Ionenstrahlanalytik
Grötzschel, R.;
  • Lecture (others)
    TU Chemnitz, Graduiertenkolleg, Jan./Feb., 1997

Publ.-Id: 2490 - Permalink


Möglichkeiten der Oberflächenanalytik mit Ionenstrahlverfahren im Forschungszentrum Rossendorf
Grambole, D.;
  • Lecture (others)
    TU Dresden, Inst. f. Werkstoffwissenschaften, Aug. 13, 1997

Publ.-Id: 2489 - Permalink


Ellipsometry as a diagnostic tool for thin film processing
Fukarek, W.;
  • Lecture (others)
    Institute of Polymer Physics, Charles University Prague, Nov. 27, 1997

Publ.-Id: 2488 - Permalink


The Rossendorf electrostatic accelerator
Friedrich, M.;
  • Lecture (others)
    SINR Shanghai, Dept. of Physics, P. R. China, April 17, 1997

Publ.-Id: 2487 - Permalink


Progress in the study of vacancy-type defects in ion implanted SiC by slow positron implantation spectroscopies
Brauer, G.;
  • Lecture (others)
    Univ. of East Anglia (School of Physics), Norwich, Nov. 7, 1997

Publ.-Id: 2486 - Permalink


Positron studies of defects in ion-implanted and annealed SiC
Brauer, G.;
  • Lecture (others)
    Lawrence Livermore National Lab, Physics and Space Technology, Livermore, USA, May 22, 1997

Publ.-Id: 2485 - Permalink


Ionenstrahlsynthese von Nanoclustern für elektrooptische Anwendungen
von Borany, J.;
  • Lecture (others)
    1. Materialwissenschaftliche Tagung der WGL, Berlin, Oct. 14, 1997

Publ.-Id: 2484 - Permalink


Ionenstrahlphysik und Technik im Forschungszentrum Rossendorf
von Borany, J.;
  • Lecture (others)
    FernUniversität Hagen, FB Elektrotechnik, Jan. 31, 1997

Publ.-Id: 2483 - Permalink


Zusammenarbeit mit industriellen Einrichtungen (Industriekooperation)
von Borany, J.;
  • Lecture (others)
    Vortrag zur Evaluierung durch den Wissenschaftlichen Beirat des FZR, Rossendorf, Apr. 29, 1997

Publ.-Id: 2482 - Permalink


Neutronenstreuung am RFR
Betzl, M.;
  • Lecture (others)
    Vortrag auf Kolloquium des VKTA - 40 Jahre Rossendorfer Forschungsreaktor RFR, Rossendorf, Dec. 16, 1997

Publ.-Id: 2481 - Permalink


Impurity gettering effects in separation-by-implanted-oxygen (SIMOX) structures - what getters what, where and how
Yankov, R. A.; Kaschny, J. R.; Fichtner, P. L. F.; Mücklich, A.; Kreißig, U.; Skorupa, W.;
  • Lecture (Conference)
    10th Biennial Conf. on Insulating Films on Semiconductors, Stenungsund, Sweden, June 11 - 14, 1997

Publ.-Id: 2480 - Permalink


Ionenimplantation aus Vakuumbogenplasmen
Witke, W.; Siemroth, P.; Brückner, J.; Brutscher, J.; Richter, E.;
  • Lecture (Conference)
    8. Bundesdeutsche Fachtagung Plasmatechnologie, Dresden, Sept. 14 - 17, 1997

Publ.-Id: 2479 - Permalink


Kristallgitter-Einbau implantierter Ionen in 6H-SiC
Wirth, H.; Voelskow, M.; Panknin, D.; Skorupa, W.;
  • Lecture (Conference)
    DPG-Frühjahrstagung, Münster, March 17 - 21, 1997

Publ.-Id: 2478 - Permalink


Investigation of ion-implantation induced damage in 6H-SiC by RBS/C and Positron Annihilation Spectroscopy
Wirth, H.; Anwand, W.; Brauer, G.; Voelskow, M.; Panknin, D.; Skorupa, W.; Coleman, P. G.;
  • Lecture (Conference)
    Int. Conf. on Silicon Carbide, III-Nitrides and Related Materials, Stockholm, Sweden, Aug. 31 - Sept. 5, 1997

Publ.-Id: 2477 - Permalink


Synchrotron X-ray studies of AlGaAs/GaAs epitaxial layers implanted with Se ions
Wieteska, K.; Wierzchowski, W.; Turos, A.; Grötzschel, R.;
  • Lecture (Conference)
    4th Symp. on Synchrotron Radiation, Krakow, PL, 1997

Publ.-Id: 2476 - Permalink


Teilchenbeschleuniger - Grundlagen
Guratzsch, H.;
Ausgehend von der Wirkung elektischer und magnetischer Felder auf elektrisch geladene Teilchen, wie Elektronen und Ionen, wird die Funktion der Teilchenbeschleuniger erläutert. Auf die Analogie zwischen Lichtoptik und Elektronen- bzw. Ionenoptik wird bei der Betrachtung der Strahlführung hingewiesen. Wichtig für das Funktionieren eines Beschleunigers ist die korrekte Berücksichtigung der kinematischen Beziehungen zwischen Energie, Masse und Geschwindigkeit. Mit Hilfe von schematischen Darstellungen werden verschiedene Beschleunigertypen vorgestellt. Die Emission von Synchrotronstrahlung begrenzt bei Elektronen-Kreisbeschleunigern die praktisch erreichbare Energie. Der LEP-Ring im CERN erreicht mit 27 km Umfang eine Energie von 50 GeV. Für noch höhere Energien müssen Linearbeschleuniger gebaut werden. Am TESLA-Projekt für einen 33 km langen Elektronen-Positronen-Collider mit einer Energie im Wechselwirkungspunkt von 500 GeV wird im DESY Hamburg gearbeitet. Auf der Basis der supraleitenden TESLA-Beschleunigungsstrukturen wird derzeit im Forschungszentrum Rossendorf ein 40-MeV-Linearbeschleuniger für Elektronen aufgebaut. In Zukunft werden mit diesem Beschleuniger kern- und strahlungsphysikalische Forschungsarbeiten durchgeführt sowie kohärente Infrarotstrahlung (Freier-Elektronen-Laser) für materialwissenschaftliche Untersuchungen erzeugt.
Keywords: Beschleuniger, Elektronen, Ionen
  • Lecture (others)
    Lehrerfortbildung 1999 im Forschungszentrum Rossendorf, 26. August 1999

Publ.-Id: 2475 - Permalink


Blue photoluminescence from high-dose Si+- and Ge+-implanted silicon-dioxide layers
Tyschenko, I. E.; Kachurin, G. A.; Zhuravlev, K. S.; Pazdnikov, N. A.; Volodin, V. A.; Gutakovsky, A. K.; Leier, A. F.; Fröb, H.; Leo, K.; Böhme, T.; Rebohle, L.; Yankov, R. A.; Skorupa, W.;
  • Lecture (Conference)
    Int. Workshop des Innovationskollegs der TU Chemnitz "Methoden und Materialsysteme für den Nanometerbereich", Schöneck/Vogtl., March 3 - 5, 1997

Publ.-Id: 2474 - Permalink


A computational model of the formation of (SiC)1-x(AlN)x structures by hot, high-dose N+ and Al+ coimplants in 6H-SiC
Trushin, Y. V.; Yankov, R. A.; Kharlamov, V. S.; Kulikov, D. V.; Tsigankov, D. N.; Kreißig, U.; Voelskow, M.; Pezoldt, J.; Skorupa, W.;
  • Lecture (Conference)
    Int. Conf. on Silicon Carbide, III-Nitrides and Related Materials, Stockholm, Sweden, Aug. 31 - Sept. 5, 1997

Publ.-Id: 2473 - Permalink


Formation and self-organization of nanoclusters by ion beam synthesis: a combined atomistic and continuum description
Strobel, M.; Heinig, K.-H.; Möller, W.;
  • Lecture (Conference)
    MRS Fall Meeting, Boston, USA, Dec. 1-5, 1997

Publ.-Id: 2472 - Permalink


Computersimulationen zur Evolution von Nanoclustern
Strobel, M.; Heinig, K.-H.; Möller, W.;
  • Lecture (Conference)
    Frühjahrstagung der DPG, Münster, Germany, March 17-21, 1997

Publ.-Id: 2471 - Permalink


A comparative study of ERDA, EELS and XPS for structural analysis of amorphous carbon nitride films
Späth, C.; Kühn, M.; Richter, F.; Falke, U.; Hietschold, M.; Kilper, R.; Kreißig, U.;
  • Lecture (Conference)
    Int. Conf. Diamond '97

Publ.-Id: 2470 - Permalink


MeV-Implantation in Silicium
Skorupa, W.;
  • Lecture (Conference)
    20. Dt. Nutzertreffen Ionenimplantation, SIMEC-Werk der Siemens AG, Dresden, Oct. 29 -30, 1997

Publ.-Id: 2469 - Permalink


Composition, structural and hardeness change of aluminium implanted with carbon
Segrouchni, Z.; Betzl, M.; Richter, E.;
  • Lecture (Conference)
    SMMIB 97, Gatlinburg, TE, USA, Sept. 1997

Publ.-Id: 2468 - Permalink


Abscheidung von Si/SiO2-Cluster-Schichten durch reaktives Magnetron-Sputtern
Seifarth, H.; Grötzschel, R.; Markwitz, A.; Matz, W.; Nitsche, P.; Rebohle, L.;
  • Lecture (Conference)
    8. Bundesdeutsche Fachtagung Plasmatechnologie, Dresden, Sept. 14 - 17, 1997

Publ.-Id: 2467 - Permalink


Atomistic modeling of ion implantation within a 2d process simulator
Schmidt, B.; Posselt, M.; Strecker, N.; Feudel, T.;
  • Lecture (Conference)
    MRS Fall Meeting, Boston, USA, Dec. 1 - 5, 1997
  • Contribution to external collection
    Mat. Res. Soc. Symp. Proc. 490 (1998) 21

Publ.-Id: 2466 - Permalink


Applying ANSYS/Multiphysics to In-Vessel and Ex-Vessel Core Melt Phenomena
Willschütz, H.-G.;
For future nuclear power plants it is demanded that there are no consequences for the environment and the population even in the closest vicinity of the plant during and after every possible accident scenario. This includes the hypothetical scenario of a severe accident with subsequent core meltdown, corium relocation and formation of a melt pool with internal heat sources in the reactor pressure vessel (RPV) lower head (LH). Some reactor concepts have the aim to arrest the melt in the lower head removing the decay heat by external water flooding. In other concepts a dry reactor pit is designed and after the vessel failure a core catcher shall assure the long term stabilization of the corium within the containment.

For both strategies investigations on the transient behaviour of the RPV or of the core catcher are necessary. Two kinds of vessel failure can be distinguished: thermal and structural failure. Thermal failure means that the heat flux through the vessel wall becomes so high that the steel solidus temperature at any position of the vessel outside is exceeded. Structural failure means that a combination of thermal and mechanical loads causes the failure, e. g. the wall thickness of the vessel is reduced by thermal ablation and at the same time the internal pressure and the gravitational forces induce creeping with subsequent creep failure.

Different melt configurations can be assumed. They can be distinguished by the melt masses released into the LH, the melt composition, the segregation behaviour of the oxidic and the metallic component, and the density and the distribution of the internal heat sources. One of the most dangerous accident scenarios for a pressurized water reactor (PWR) assumes the relocation of a melt mass in the range of 200 Mg or more which is segregated into some 150 Mg of the heavier oxidic component at the bottom and some 50 Mg of a metallic melt above. The oxidic melt is surrounded by an oxidic crust due to the high solidification temperature of the oxide. The internal heat sources are mainly in the oxidic component, but due to the geometric configuration and the different fluid properties the highest heat fluxes and the major thermal ablation is expected between the metallic layer and the vessel wall. This phenomenon is called focussing effect.

An in-vessel-scenario of a PWR has been assumed and modelled with ANSYS/ Multiphysics. Using this Finite Element (FE) code package it is possible to simulate the velocity and temperature field for a fluid region and the corresponding temperature field within the surrounding solid structures. This thermo-fluiddynamic calculation can be coupled with a mechanical FE-model of the solid structures to analyse the stress and possible creeping forced by the mechanical and thermal loads. In this presentation, the recent modelling approach and the results obtained with the code ANSYS/Multiphysics are discussed. An outlook on the further development is given.

Keywords: Severe Accident, Core Meltdown, In-Vessel-Retention, Core Catcher, Finite Element Code, Transient Calculation, Computational Fluid Dynamics, Coupled Solid Structures, Thermal Failure, Structural or Creep Failure
  • Lecture (others)
    Seminar held at the Division of Nuclear Power Safety at the Royal Institute of Technology, Stockholm, Sweden, August 2nd, 1999.

Publ.-Id: 2465 - Permalink


Dünnschichtsysteme für die Photo- und Elektrolumineszenz
Schmidt, B.; von Borany, J.; Grötzschel, R.; Heinig, K.-H.; Markwitz, A.; Matz, W.; Nitzsche, P.; Rebohle, L.; Seifarth, H.; Strobel, M.; Skorupa, W.;
  • Lecture (Conference)
    Photonik-Symposium, Würzburg, Oct. 8 - 10, 1997

Publ.-Id: 2460 - Permalink


Influence of the substrate structure (SIMOX, bulk Si) on the SiC synthesis by high dose carbon implantation
Romano-Rodriguez, A.; Kögler, R.; Bachrouri, A.; Perez-Rodriguez, A.; Serre, C.; Reuther, H.; Voelskow, M.; Skorupa, W.; Calvo-Barrio, L.; Morante, J. R.;
  • Lecture (Conference)
    7th Int. Conf. on Gettering and Defect Engineering in Semiconductor Technology, GADEST'97, Spa, Belgium, Oct. 5-10, 1997

Publ.-Id: 2459 - Permalink


Nitrierung austenitischer Edelstähle mittels Plasma-Immersions-Ionenimplantation
Richter, E.;
  • Lecture (Conference)
    OWT-97, Chemnitz, June 16-18, 1997

Publ.-Id: 2458 - Permalink


The influence of heat treatment during the implantation of oxygen into magnesium
Richter, E.; Reuther, H.; Kreißig, U.;
  • Lecture (Conference)
    SMMIB 97, Gatlinburg, TE, USA, Sept. 1997

Publ.-Id: 2457 - Permalink


Investigation of Fe-Mg-alloys produced by ion implantation
Reuther, H.; Betzl, M.; Matz, W.; Richter, E.;
  • Lecture (Conference)
    10th Int. Conf. Surface Modification of Metals by Ion Beams, Gatlinburg, USA, Sept. 21 - 26, 1997

Publ.-Id: 2456 - Permalink


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