Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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32470 Publications
First Observation of the Scissors Mode in a Gamma-Soft Nucleus: The Case of 196Pt
von Brentano, P.; Eberth, J.; Enders, J.; Esser, L.; Herzberg, R.-D.; Huxel, N.; Meise, H.; von Neumann-Cosel, P.; Nicolay, N.; Pietralla, N.; Prade, H.; Reif, J.; Richter, A.; Schlegel, C.; Schwengner, R.; Skoda, S.; Thomas, H. G.; Wiedenhöver, I.; Winter, G.; Zilges, A.;
A nuclear resonance fluorescence experiment with one of the newly developed
highly efficient EUROBALL cluster detectors has been performed on the gamma-soft
nucleus 196Pt. Magnetic dipole excitations were observed between
2 and 3.5 MeV excitation energiy. They are interpreted as the main fragments
of the scissors mode based on the measured excitation strengths and branching
ratios. A strong gamma decay, which we believe to be an E2 decay of the
scissors mode to the 21+ state, is observed. It allows
an extraction of the effective boson quadrupole charges in the interacting
boson model.
  • Physical Review Letters 76 (1996) 12 pp. 2029-32

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Permalink: https://www.hzdr.de/publications/Publ-595
Publ.-Id: 595


Bericht der Frühjahrstagung der Studiengruppe für Elektronische Instrumentierung vom 25. bis 27. März 1996 in Karlsruhe
Gabriel, F.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-141

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Permalink: https://www.hzdr.de/publications/Publ-594
Publ.-Id: 594


Plasma source ion implantation of oxygen and nitrogen in aluminum
Günzel, R.; Wieser, E.; Richter, E.; Steffen, H. J.;
  • Journal of Vacuum Science and Technology Part B 12 (1994) 2

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Permalink: https://www.hzdr.de/publications/Publ-593
Publ.-Id: 593


Added Stiffness Relating to Small Motions of Two Concentric Cylinders Submitted to Axial Annular Incompressible Flow
Zoller, J.;
Abstract
Axial incompressible, viscous flow is considered in an annular gap between two rigid cylinders. If the cylinders are displaced from their concentric positions in a certain manner, the displacement will cause reaction forces exerted by the fluid pressure. In this investigation the pressure fluctuations caused by the displacement of the structures are approximated by analytical means. Pressure fluctuations in phase with acceleration and velocity of the structure are not calculated here. Stationary flow is considered, because structural displacements are assumed to be small.
  • Open Access LogoForschungszentrum Rossendorf; FZR-146 August 1996

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Permalink: https://www.hzdr.de/publications/Publ-592
Publ.-Id: 592


Schwankungen des Massenstroms bei Druckentlastungsvorgängen
Lucas, D.; Prasser, H.-M.;
Bei der linearen Stabilitätsanalyse des Abblaseprozesses aus Druckbehältern mit zweiphasigem, aufwallendem Medium wurden Instabilitätsbereiche mit starken Massenstrompulsationen in der Abblaseleitung gefunden. Entscheidender Mechanismus ist die Rückkopplung zwischen Gemischspiegelschwankung, kritischer Ausströmrate und Druckabfallgeschwindigkeit. Für die Stabilitätsanalyse wurden analytische Modelle zur Beschreibung des šbertragungsverhaltens aufgestellt. Es wurden Nyquist-Diagramme für verschiedene Parameterkombinationen untersucht und so die Instabilitätsbereiche identifiziert. Die Schwingneigung wird durch hohe Gasgehalte an der Entlastungsarmatur, eine große Verzögerungszeit (Länge der Abblaseleitung) und geringe Höhen der Schaumzone befördert.
  • Lecture (Conference)
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996
  • Contribution to proceedings
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Preprints, S. 233-240

Permalink: https://www.hzdr.de/publications/Publ-591
Publ.-Id: 591


Investigations of an externally heated storage vessel
Aszodi, A.; Liewers, P.; Krepper, E.; Prasser, H.-M.;
Storage tanks for fluids are widely used industrial facilities. As a consequence of an external fire, the heat-up of the inventory may lead to the evaporation of the liquid and to release of significant quantities of dangerous gases into the environment. Experimental investigations performed in FZ-Rossendorf have shown that the liquid inventory behaves very differently depending on the mode of heating. Bottom heating leads to an irregular thermoconvective motion of the liquid, which causes good mixing, so that saturation is reached at all places inside the tank approximately at the same time. The maximum enthalpy of the liquid always remains close to the average value. If the vessel is heated from the side, a stable temperature stratification is observed leading to large temperature gradients. Evaporation can start much earlier than the average temperature reaches saturation.
In order to clarify the physical nature of the details of the heating-up and the evaporation process in simple geometrical boundary conditions a two-dimensional mathematical model was developed, which includes also evaporation and two-phase flow. The aim of the simulations was, to understand the basic phenomena observed during the experiment.
To avoid fast temperature increase at the fluid surface in the case of side wall heating, the insertion of baffle plates inside the vessel was investigated by additional calculations using the CFD-code CFX-4.
  • Poster
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Tagungsband S.251 - 258
  • Contribution to proceedings
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Tagungsband S.251 - 258

Permalink: https://www.hzdr.de/publications/Publ-590
Publ.-Id: 590


Anwendung neuronaler Netze zur Identifizierung gefährlicher Betriebszustände in Chemieanlagen
Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.;
  • Other report
    Preprint - GVC / VDI Fachtagung in Köthen, 7. - 8. November 1996, S. 141-147

Permalink: https://www.hzdr.de/publications/Publ-589
Publ.-Id: 589


Thermal dilepton and open charm signals versus hard initial yields in heavy-ion collisions at RHIC and LHC energies
Kämpfer, B.; Pavlenko, O. P.;
Abstract
The hard initial production of open charm and dileptons is compared with possible thermal signals in heavy-ion collisions at RHIC and LHC energies. Our approach is based on the perturbative QCD mini-jet mechanism of quark-gluon matter formation. The thermal dilepton signal is found to rise much stronger as compared to the hard Drell - Yan background with increasing collider energy and clearly dominates at LHC energy. Oppositely, open charm stems from initial hard production. A possible rnanifestation of gluon shadowing at RHIC and LHC energies is discussed.
  • Open Access LogoForschungszentrum Rossendorf; FZR-144 Preprint
  • Physics Letters B 391 (1997) pp. 185-190

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Permalink: https://www.hzdr.de/publications/Publ-588
Publ.-Id: 588


Retropane - a new Rhenium-Complex as a potential Ligand to label the Dopamin-Transporter
Hoepping, A.; Spies, H.; Johannsen, B.;
  • Bioorganic and Medicinal Chemistry Letters 6 (1996) 23 pp. 2871-2874

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Permalink: https://www.hzdr.de/publications/Publ-587
Publ.-Id: 587


Technetium and Rhenium Complexes with Thioether Ligands, 5 Synthesis and Structural Characterization of Neutral Oxorhenium (V) Complexes with Tridentate Dithioethers
Pietzsch, H.-J.; Reisgys, M.; Spies, H.; Leibnitz, P.; Johannsen, B.;
  • Chemische Berichte, Recueil 1997, 130, 357-361

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Permalink: https://www.hzdr.de/publications/Publ-586
Publ.-Id: 586


Comparison of measured and calculated dose for plasma source ion implantation into 3-D objects
Mändl, S.; Barradas, N.; Brutscher, J.; Günzel, R.; Möller, W.;
  • Nuclear Instruments and Methods in Physics Research B 127/128 (1997) 996-999

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Permalink: https://www.hzdr.de/publications/Publ-585
Publ.-Id: 585


Pulsationen bei der Druckentlastung von Reaktoren
Lucas, D.;
During two-phase blowdown from pressure vessels considerable pulsations of the discharged mass flow rate were found. Regions of instability were predicted by a linear stability analysis. The oscillations are caused by the following feedback circuit: boil up - level movement - void fraction of the discharging mixture - critical discharge rate - velocity of pressure decrease - boil up.
  • Lecture (Conference)
    ACHEMA '97, Frankfurt/M., 9.-14.6.1997

Permalink: https://www.hzdr.de/publications/Publ-583
Publ.-Id: 583


Messung der Volumenströme Gas und Flüssigkeit in einer Zweiphasenströmung mit Ultraschall und Mustererkennung
Kossok, N.; Prasser, H.-M.; Schütz, P.;
  • Lecture (Conference)
    Kraftwerkstechn. Kolloquium 1996, Dresden, 29.-30.10.96
  • Contribution to proceedings
    Kraftwerkstechnisches Kolloquium, Dresden, 29. -30. Oktober 1996, Tagungsband S. 121

Permalink: https://www.hzdr.de/publications/Publ-582
Publ.-Id: 582


Verhalten von Lagertanks bei externem Feuer
Krepper, E.; Aszodi, A.;
Wenn ein zylindrischer Lagertank durch ein externes Feuer von der Seite intensiver Wärmeeinwirkung ausgesetzt ist, so setzt der Massenverlust infolge von Dampffreisetzung viel eher ein, als im Fall einer Wärmezuführung vom Behälterboden. Mittels eines vereinfachten Modells konnten die Details des Erwärmungsprozesses und die Ursachen für das unterschiedliche Verhalten in Abhängigkeit von der Art und Weise der Wärmezufuhr erklärt werden. Die ZUfuhr vom Boden führt zu einer irregulären thermischen Konvektion und damit einer guten Durchmischung des Fluids, so daß die Sättigungstemperatur an allen Punkten im Behälter nahezu gleichzeitig erreicht wird. Die maximale Enthalpie im Behälter verbleibt während der gesamten Zeit nahe dem Mittelwert. Wird der Behälter von der Seite beheizt, so bildet sich eine stabile horizontale Temperaturschichtung heraus. Die Bildung von Dampf erfolgt bereits lange bevor die mittlere Temperatur den Siedepunkt erreicht hat. Passive konstruktive Maßnahmen, wie der Einbau von Prallplatten, können die Schichtung stören, das verstärkte Aufheizen an der Oberfläche vermeiden und die Freisetzung von Dampf verzögern. Eine durchgreifende Vermischung des flüssigen Inhalts konnte jedoch nicht erreicht werden. Die genaue Gestalt und die Wirkung dieser Prallplatten hängt von der konkreten Behältergeometrie ab und läßt sich weiter optimieren.
  • Lecture (Conference)
    ACHEMA '97, Frankfurt/M., 9.-14.6.1997

Permalink: https://www.hzdr.de/publications/Publ-581
Publ.-Id: 581


Untersuchung von Zweiphasenströmungen gasförmig / flüssig mit Positronenemittern
Hensel, F.;

Die Methode der Positronen-Emissions-Tomographie (PET, Positron Emission Tomography) wird zur Untersuchung von Zweiphasenströmungen flüssig / gasförmig angewandt. PET ist ein bildgebendes Verfahren, das für die Nuklearmedizin entwickelt wurde. Im medizinischen Bereich wird diese Technik hauptsächlich als nichtinvasives Untersuchungsverfahren für die quantitative Erfassung von Stoffwechselvorgängen in-vivo genutzt. Die hier vorgestellten Untersuchungen zur Methodik der Anwendung von Radiotracern für Strömungsuntersuchungen wurden 1994 begonnen. Das Ziel der Arbeiten war die örtlich und zeitlich aufgelöste Erfassung von Vermischungs- und Transportprozessen sowie die Messung der Dichte von zweiphasigen Medien. Zur Dichtemessung wurde die Abhängigkeit der Positronenreichweite von der Dichte des Materials ausgenutzt. Bei den entsprechenden Experimenten kam eine örtlich fixierte Positronenquelle (45Ti) zum Einsatz. Desweiteren wurden Messungen zum Stofftransport in Blasenströmungen durchgeführt, hier wurden flüssige Tracer mit dem Nuklid 18F eingesetzt.

  • Lecture (Conference)
    XXVIII. Kraftwerkstechnisches Kolloquium und 6. Kolloquium Meßtechnik für Energieanlagen 1996, Dresden, 29.-30.10.96
  • Contribution to proceedings
    in Kaiser, E.; Nöther, K. (Hrsg): Meßtechnik zur Untersuchung von Vorgängen in thermischen Energieanlagen. Tagung Dresden, 29./30. Oktober 1996. Beitragsmanuskripte Bd. 1 S. 101. ISBN 3-86005-168-7
  • Poster
    XXVIII. Kraftwerkstechnisches Kolloquium und 6. Kolloquium Meßtechnik für Energieanlagen 1996, Dresden, 29.-30.10.96

Permalink: https://www.hzdr.de/publications/Publ-580
Publ.-Id: 580


Determination of Crack-Initiation Toughness by Impact and Dynamic Testing
Richter, H.; Böhmert, J.; Viehrig, H.-W.;
The critical J-integral (Jid) can be useful as toughness parameter at initiation of stable crack growth. Under the condition of the impact bending test the critical step for evaluating of Jid is the detection of the crack initiation point on the impact load displacement curve. In this paper the crack initiation is determined by using emission of acoustic waves (AE). The experimental techniques used to evaluate Jid include both instrumented impact testing based on 300 J pendulum impact tester with a piezoelectric broadband AE sensor within the impact tup and dynamic 3 point bending loading with a servohydraulic test machine and additional AE sensors on the specimen.
Different kind of pulses of the AE signals can be observed. One of them corresponds with crack initiation. The evidence of initiation at this point was confirmed by single and multiple specimen methods.
  • Lecture (Conference)
    Proc. of the 11th European Conference on Fracture - ECF 11, Poitiers-Futurscope, France, Sept. 1996, Vol. III, pp. 2001 - 2006
  • Contribution to proceedings
    Proc. of the 11th European Conference on Fracture - ECF 11, Poitiers-Futurscope, France, Sept. 1996, Vol. III, pp. 2001 - 2006

Permalink: https://www.hzdr.de/publications/Publ-579
Publ.-Id: 579


DYN3D - A 3-DIMENSIONAL CORE MODEL FOR STEADY STATE AND TRANSIENT ANALYSIS IN THERMAL REACTOR
Grundmann, U.; Rohde, U.;
The 3D core model DYN3D developed firstly for analyses of transients in thermal reactors with hexagonal fuel assemblies was extended by a new version DYN3D/R for reactors with quadratic fuel elements. The method used in Cartesian geometry is described. Numerical results for benchmarks as the NEACRP rod ejection benchmarks are compared with the reference solutions. Results of uncontrolled withdrawal of control rod bank are shown. The efficiency of steady-state neutronic calculation by using multiprocessor workstation is presented.

  • Lecture (Conference)
    Int. Conf. on Physics of Reactors, 16.-20.9.1996, Mito, Japan, Proceedings pp. J-70 - J-79
  • Contribution to external collection
    Int. Conf. on Physics of Reactors, 16.-20.9.1996, Mito, Japan, Proceedings pp. J-70 - J-79

Permalink: https://www.hzdr.de/publications/Publ-578
Publ.-Id: 578


Preparation and Characterization of Novel Mixed-Ligand Complexes Bearing up to Four Ester Groups
Seifert, S.; Hoepping, A.; Klostermann, K.; Spies, H.; Johannsen, B.;
  • Applied Radiation and Isotopes, 48 (1997) 943-948

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Permalink: https://www.hzdr.de/publications/Publ-577
Publ.-Id: 577


Diphoton rates from thermalized matter resulting in ultra-relativistic heavy-ion collisions
Hentschel, M.; Kämpfer, B.; Pavlenko, O. P.; Redlich, K.; Soff, G.;
Abstract
Diphoton radiation off strongly interacting matter resulting from ultrarelativistic heavy-ion collisions is estimated for SPS and RHIC conditions. At SPS emrgies tha thermal diphoton signal competes strongly with the Drell - Yan like background. For given charged-particle rapidity density a scenario with deconfinement transition predicts a larger diphoton yield than a scenario without phase transition. For RHIC energies we find that radiation from initially undersaturated (but gluon-rich) deconfined matter overwhelms the hadron gas and the Drell - Yan like diphotons in the invariant mass window 1 < M < 2.5 GeW. Due to this the so-called M1 scaling is approximately obtained and can serve as additional tsol for discriminating radiation from quark-gluon matter.
  • Open Access LogoForschungszentrum Rossendorf; FZR-142 Preprint
  • Other report
    GSI-Preprint-96-37, August 1996
  • Z. Phys. C 75, 333-339 (1997)

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Permalink: https://www.hzdr.de/publications/Publ-576
Publ.-Id: 576


Can hexadecapole deformation lead to Delta I = 2 staggering in superdeformed bands?
Dönau, F.; Frauendorf, S.; Meng, J.;
  • Physics Letters B 387(1996) pp. 667-672

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Permalink: https://www.hzdr.de/publications/Publ-574
Publ.-Id: 574


Abbau Polychlorierter Biphenyle (PCB) in Pflanzen und bei Kompostierungsprozessen - Untersuchungen mit [14C]PCB Nr. 77
Bubner, M.; Bock, C.; Kolb, M.; van Raaij, E.; Bruhn, G.; Heise, K.-H.; Nitsche, H.; Harms, H.; Förster, U.;
  • Poster
    Gesellschaft Deutscher Chemiker, 7.-10.10.1996, Ulm

Permalink: https://www.hzdr.de/publications/Publ-573
Publ.-Id: 573


Interaction of Uranium (VI) with Silicon Species in aqueous Solutions
Moll, H.; Geipel, G.; Reich, T.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Poster
    NRC4-Konferenz in St. Malo (Frankreich) 8.-13.9.1996

Permalink: https://www.hzdr.de/publications/Publ-572
Publ.-Id: 572


Radium Sorption on Sandy and Clayey Sediments of the Upper Saxon Elbe River Valley
Baraniak, L.; Thieme, M.; Funke, H.; Bernhard, G.; Nindel, K.; Schreyer, J.; Nitsche, H.;
The interaction of radium with characteristic sediments of the upper Saxon Elbe river valley was investigated with a two-fold aim: to provide key data for transport modelling within the framework of mining site restoration and to study the influence of barium-radium-sulfate coprecipitation on the radium adsorption behaviour. For this purpose sorption measurements were carried out on site-specific sediments (different kinds of sandstone, claystone and lime marl) using (1) original low-mineralized groundwater of this area, (2) typical acidic mine water coming from sulfuric acid residues of a former in-situ leaching process (~3 g/L SO42-, pH _ 2.5) and (3) groundwater which was contaminated by 2% mine water. The distribution ratios (Rd) were determined by batch experiments using an 8 weeks' equilibration at aquifer temperature (14C).

Radium sorption from pure and slightly contaminated groundwater onto limonite-rich turonian sandstone is characterized by relatively low distribution ratios (60-180 mL/g). When contacted with mine water, the sorption was enhanced by more than 20-fold compared to the pure and contaminated groundwaters. For the typical lime marl, the strongest sorption occured from the groundwater (390-520 mL/g) and a slightly reduced sorption took place from the acidic mine water.

In addition, the radium sorption was studied as a function of the Ba2+ and SO42- concentration. The results were discussed in terms of the ion product and the solubility product. Conclusions were drawn regarding the predominant sorption mechanisms: coprecipitation, surface complexation and ion exchange.

The long-term migration behaviour in the aquifers of the south-east Saxon Elbe basin was calculated on the basis of Hadermanns' equation, considering convection, dispersion, retardation and radioactive decay.

  • Lecture (Conference)
    4 th International Conference on Nuclear and Radiochemistry, Saint Malo, France, Sept.8-13, 1996

Permalink: https://www.hzdr.de/publications/Publ-571
Publ.-Id: 571


Uranium (VI) Sulfate Complexation studied by Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS)
Geipel, G.; Brachmann, A.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Radiochimica Acta 75, 199-204 (1996)

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Permalink: https://www.hzdr.de/publications/Publ-570
Publ.-Id: 570


Nanometre-sized Silver Halides Entrapped in SiO2 Matrices
Matz, W.; Pham, T.; Mücklich, A.;
The formation of nanocrystals after implantation of silver
alone as well as together with the halogen ions Cl, Br, and I into a SiO2
layer of about 100 nm was studied by X-ray diffraction and transmission
electron microscopy. The co-implantation of Ag and Cl/Br results in the
formation of cubic AgX-crystals which are stable in size under annealing.
The co-implantation of Ag and I as well as single Ag implantation result
in Ag crystallites, which grow under annealing. The annealing procedure
causes a redistribution of the particles within the layer.
  • Journal of Materials Science 33 (1998) 155-159

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Permalink: https://www.hzdr.de/publications/Publ-569
Publ.-Id: 569


Positronen-Emissions-Tomographie bei der Schwerionentherapie. Ein Verfahren zur in-situ Kontrolle der Tumorbehandlung mit Strahlen schwerer Ionen
Enghardt, W.;
  • Physikalische Blätter 52 (1996) 9 pp. 874-875

Permalink: https://www.hzdr.de/publications/Publ-568
Publ.-Id: 568


Radiation damage and annealing behaviour of Ge+ -implanted SiC
Pacaud, Y.; Stoemenos, J.; Brauer, G.; Yankov, R. A.; Heera, V.; Voelskow, M.; Kögler, R.; Skorupa, W.;
In recent years, single crystal SiC has become an important electronic material due to its excellent physical and chemical properties. The present paper reports a study of the defect reduction and recrystallization during annealing of Ge+-implanted 6H-SiC. Implants have been performed at 200 keV with doses of 1x1014 and 1x1015 cm-2. Furnace annealing has been carried out at temperatures of 500 °C, 950 °C and 1500 °C. Three analytical techniques including Rutherford backscattering spectrometry in conjunction with channelling (RBS/C), positron annihilation spectroscopy (PAS) and cross-sectional transmission electron microscopy (XTEM) have been employed for sample characterization. It has been shown that damage removal is more complicated than in ion-implanted Si. The recrystallization of amorphized SiC layers has been found to be unsatisfactory for temperatures up to 1500 °C. The use of ionbeam-induced epitaxial crystallization (IBIEC) has been more successfull as lattice regrowth, altough still imperfect, has been observed to occur at a temperature as low as 500 °C.
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 177-180

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Permalink: https://www.hzdr.de/publications/Publ-567
Publ.-Id: 567


Proximity gettering of copper in separation-by-implanted-oxygen structures
Yankov, R. A.; Hatzopoulos, N.; Skorupa, W.; Danilin, A.;
  • Lecture (Conference)
    E-MRS, Spring Meeting, Strasbourg, France, 4-7 June 1996
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 60

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Permalink: https://www.hzdr.de/publications/Publ-566
Publ.-Id: 566


A study of the blue photoluminescence emission from thermally-grown, Si+ -implanted SiO2 films after short-time annealing
Skorupa, W.; Yankov, R. A.; Rebohle, L.; Fröb, H.; Böhme, T.; Leo, K.; Tyschenko, I. E.; Kachurin, G. A.;
Thermal SiO2 films have been implanted with Si+ ions using double-energy implants (200 + 100 keV) at a substrate temperature of about -20 °C to total doses in the range 1.6 x 1016 - 1.6 x 1017 cm-2 followed by short-time thermal processing, in order to form a Si nanostructure capable of yielding blue photoluminescence (PL). The intensity and the peak position of the PL band have been investigated as a function of ion dose, manner of heat treatment, anneal time and anneal temperature. For the formation
of blue PL emitting centres, optimum processing conditions in terms of excess Si concentration and overall thermal budget are mandatory. The nature of the observed blue emission is discussed.
  • Lecture (Conference)
    E-MRS, Spring Meeting, Strasbourg, France, June 4-7, 1996
  • Nuclear Instruments and Methods in Physics Research B 120 (1996)106

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Permalink: https://www.hzdr.de/publications/Publ-565
Publ.-Id: 565


Damage behaviour and annealing of germanium implanted 6H-SiC
Pacaud, Y.; Heera, V.; Yankov, R. A.; Kögler, R.; Brauer, G.; Voelskow, M.; Skorupa, W.; Stoemenos, J.; Perez-Rodriguez, A.; Calro-Barrio, L.; Serre, C.; Morante, J.; Barklie, R.; Collins, M.; Holm, B.;
The present paper reports a study of the defect reduction
and recrystallization during annealing of Ge+-implanted 6H-SiC. Implants
have been performed at 200 keV with doses of 1x1014 and 1x1015 cm-2. Furnace
annealing has been carried out at temperatures of 500°, 900° and
1500 °C. Several analytical techniques including Rutherford backscattering
spectrometry in conjunction with channeling (RBS/C), cross-sectional transmission
electron microscopy (XTEM), positron annihilation spectroscopy (PAS), Raman
scattering (RS), and electron paramagnetic resonance (EPR) measurements
have been employed for sample characterization. It has been shown that
damage removal is more complicated than in ion-implanted Si. Using PAS
deeply diffusion vacancy-like defects were found far below the region defined
by TRIM as containing the maximum amount of nuclear energy deposition.
The amorphized SiC is characterized by carbon dangling bonds as revealed
by EPR. The recrystallization of amorphized SiC layers has been found to
be unsatisfactory for temperatures up to 1500 °C. The use of ion-beam-induced
epitaxial crystallization (IBIEC) has been more successful as lattice regrowth,
altough still imperfect, has been observed to occur at a temperature
as low as 500 °C.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 713

Permalink: https://www.hzdr.de/publications/Publ-564
Publ.-Id: 564


Proximity gettering of Fe in SIMOX structures
Skorupa, W.; Yankov, R. A.; Hatzopoulos, N.; Danilin, A.;
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 737

Permalink: https://www.hzdr.de/publications/Publ-563
Publ.-Id: 563


Ion Beam Synthesis of SiC in Silicon-on-Insulator
Kögler, R.; Reuther, H.; Voelskow, M.; Skorupa, W.; Romano-Rodriguez, A.; Perez-Rodriguez, A.; Serre, C.; Calvo-Barrio, L.; Morante, J. R.;
Ion beam synthesis of ß-SiC in the top-Si-layer of a SIMOX (Separation by Implantation of OXygen) substrate is reported.
All the implanted C is captured inside the 200 nm top-Si-layer and is accumulated preferentially at the Si/SiO2-interface during annealing. A Si/SiC/SiO2-structure is obtained by C implantation at high temperature (T>500 °C) and subsequent annealing treatment (T=1250 °C). It consists of a crystalline Si overlayer, a Si layer with a high density of perfectly aligned ß-SiC grains and a buried oxide layer. Implantation at elevated temperatures is crucial for the quality of the SiC layer. However, the use of such implantation temperatures is limited by the dissolution of the buried oxide layer.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 709

Permalink: https://www.hzdr.de/publications/Publ-562
Publ.-Id: 562


Impurity gettering in damaged regions of Si produced by high energy ion implantation
Kögler, R.; Panknin, D.; Skorupa, W.; Werner, P.; Danilin, A.;
Point defects and defect agglomerates are created by high
energy ion implantation into Si and subsequent annealing. These defects
are investigated by gettering of metal atoms and analysing the metal concentration
distribution. Beside a gettering layer at the projected ion range (Rp)
where the implant is deposited also a gettering layer is also found at
the Rp/2-position. This Rp/2-layer is related to implantation defects -
not to the implant atoms. It is thermally stable up to a temperature of
more than 1000 °C.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Engineers, Piscataway, USA, 1997, p. 679

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Publ.-Id: 561


Laser and X-ray spectroscopic studies of uranium-calcite interface phenomena
Geipel, G.; Reich, T.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Lecture (Conference)
    Workshop JAERT, Japan
  • Journal of Nuclear Materials 248 (1997) 408-411

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Publ.-Id: 560


Investigation of the Development of Irradiation - Induced Precipitates in VVER-440-Type Reactor Pressure Vessel Steels and Weld Metals During Irradiation and Annealing
Große, M.; Nitzsche, P.; Böhmert, J.; Brauer, G.;
The development of irradiation-induced precipitates in VVER-440 type reactor pressure vessel steels 15Kh2MFA and weld metals SV-10KhMFT during irradiation and post-irradiation annealing is studied by small angle neutron and X-ray scattering. The kinetic conditions for the precipitation of particles, which already exist in the unirradiated state, seem to be improved at temperatures of about 270 °C due to the irradiation. The size distribution of the irradiation-induced precipitates depends on the copper content and differs between weld and base metal. A strong correlation between the formation of irradiation-induced precipitates and the irradiation hardening is found. The hardness nearly linearly depends on the number of these precipitates.
  • Lecture (Conference)
    18th International Symposium "Effects of Radiation in Materials", Hyannis (USA), June 25 - 27, 1996, ASTM STP 1325

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Publ.-Id: 559


Interpretation and Quality of the Tilted Axis Cranking Approximation
Frauendorf, S.; Meng, J.;
Comparing with the exact solutions of the model system of one and two particles coupled to an axial rotor, the quality of the semi classical tilted axis cranking approximation is investigated. Extensive comparisons of the energies and M1 and E2 transition probabilities are carried out for the lowest bands. Very good agreement is found, except near band crossings. Various recipes to take into account finite K within the frame of the usual principal axis cranking are included into the comparison. A set of rules is suggested that permits to construct the excited bands from the cranking configurations, avoiding spurious states.
  • Zeitschrift für Physik A 356 (3): 263-279 DEC 1996
  • Open Access LogoForschungszentrum Rossendorf; FZR-140 Preprint

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Publ.-Id: 558


Implantation and growth of large ß-FeSi2 precipitates and a-FeSi2 network structures in silicon
Reuther, H.; Dobler, M.;
Iron implanted and subsequently annealed n-type Si(111) was
studied by conversion electron Mössbauer spectroscopy and Auger electron
spectroskopy. Phase analysis performed with Mössbauer spectroscopy indicates
the formation of a mixture of ß- and a-FeSi2 due to the implantation
(200 keV, 3 x 1017 cm-2, 350 °C) and a complete transition of the mixture
to the ß-and the a-phase after annealing at 900 °C for 18 h and
1150 °C for 1 h, respectively. The iron concentration profiles were
determined with Auger electron sputter depth profiling. The profile of the
as-implanted sample is Gaussian shaped and boradened after annealing at 900
°C to a pleateau-like profile. For the sample annealed at 1150 °C
only a slight broadening occurs and depth depending fluctuations of the iron
concentration can be observed. Investigations with scanning Auger electron
spectroscopy show in the case of the as-implanted sample only slight fluctuations
of the iron distribution in the center of the profile. After annealing at
900 °C large separated ß-FeSi2 precipitates grow due to the process
of Ostwald ripening. At 1150 °C Ostwald ripening and coalescence of
the precipitates occur and a wide extended penetration a-FeSi2 network structure
is formed. It is the first time that such large iron disilicide structures
could be proved by scanning Auger electron spectroscopy.
  • Applied Physics Letters 69 (1996) 3176 - 3178

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Publ.-Id: 557


Tritium Depth Profiling in Carbon by Accelerator Mass Spectrometry
Friedrich, M.; Sun, G.; Grötzschel, R.; Behrisch, R.; Garcia-Rosales, C.; Roberts, M. L.;
  • Nuclear Instruments and Methods in Physics Research B 123 (1997) pp. 410-413

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Publ.-Id: 556


Ion Beam Processing of SiC
Skorupa, W.; Heera, V.; Pacaud, Y.; Weishart, H.;
A short review is presented concerning problems of ion beam processing of single crystalline silicon carbide. Emphasis is given
to recent results on point defect, extended defects, amorphization and recrystallization, electrical activation of dopant atoms, and metallization.
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 114-120

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Publ.-Id: 553


Speciation of Uranium in Natural Waters of an Uranium Mining Area
Geipel, G.; Bernhard, G.; Brendler, V.; Brachmann, A.; Nitsche, H.;
  • Lecture (Conference)
    NRC 4, St. Malo, Sept. 1996

Permalink: https://www.hzdr.de/publications/Publ-551
Publ.-Id: 551


Investigation of the ion acoustic effect during focused ion beam irradiation
Teichert, J.; Bischoff, L.; Köhler, B.;
  • Lecture (Conference)
    E-MRS, Strasbourg, 4.-7.6.1996

Permalink: https://www.hzdr.de/publications/Publ-550
Publ.-Id: 550


The use of plasma source ion implantation for wear protection
Günzel, R.; Brutscher, J.; Mändl, S.; Möller, W.;
Plasma source ion implantation (PSII) has been developed
as an alternative technique to circumvent the limitations of conventional
ion implantation, like the requirements of a complicated target handling
and beam raster system for a uniform ion implantation of 3-dimensional
samples. In this method, a plasma sheath conformably surrounds the target.
By applying negative high voltage pulses, positively charged ions are accelerated
from the plasma trough the sheath and implanted into the target. Critical
parameters for the further development of this implantation process are
the ion implantation current and the sheath expansion characteristics.
  • Lecture (Conference)
    NATO-ARW, Portimao, Portugal, 30.5.-5.6.1996
  • Book (Authorship)
    Y. Pauleau and P. B. Barna (eds), Protective Coatings and Thin Films, pp. 635-647, c 1997 Kluwer Academic Publishers, Printed in the Netherlands

Permalink: https://www.hzdr.de/publications/Publ-547
Publ.-Id: 547


Consideration of Added Stiffness Resulting from Edging Out of an Axial Annular Flow by Motions of the Pressure Vessel and the Core Barrel
Zoller, J.; Altstadt, E.; Grunwald, G.; Zimmermann, W.;
  • Lecture (Conference)
    IMORN '26, Piestany, May 27 - 29, 1996

Permalink: https://www.hzdr.de/publications/Publ-546
Publ.-Id: 546


Charge pickup of 238U at relativistic energies
Seidel, W.; Möhlenkamp, T.; Rubehn, T.; u. a.; Bassini, R.; u. a.; Blaich, T.; Immé, G.; u. a.; Moretto, L. G.; Schüttauf, A.; Trzcinski, A.; u. a.;
  • Physical Review C 53 (1996) pp. 993-996

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Publ.-Id: 543


Theoretical study of boron nitride modifications at hydrostatic pressures
Albe, K.;
This paper presents a detailed study of boron nitrides
at hydrostatic pressures. Cohesive properties of zincblende (c-BN), wurtzite
(w-BN), hexagonal (h-BN), rhombohedral (r-BN) and rocksalt structure are
calculated by systematic optimization of unit cell parameters using total-energy
DFT techniques. With focus on the very rarely discussed layered modifications
the p - V equation of states are derived. It is confirmed taht the isothermal
bulk modulus of the sp2 bonded phases is more than ten times smaller in
comparison to the dense phases. Additionally the equilibrium line of c-BN
and h-BN in the phase p, T diagram is estimated. According to recent experimental
reports c-BN is predicted as stable modification at standard conditions.
  • Physical Review B 55 (1997) 10 pp. 6203-6210

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Publ.-Id: 542


Aufnahme und Verteilung von Trichloressigsäure in Trieben Norwegischer Fichte
Uhlirova, H.; Matucha, M.; Kretzschmar, M.; Bubner, M.;
  • Umweltwissenschaften und Schadstoff-Forschung: Zeitschrift für Umweltchemie und Ökotoxikologie 8 (1996) 3 pp. 138-142

Permalink: https://www.hzdr.de/publications/Publ-541
Publ.-Id: 541


Decay rates of resonance states at high level density
Persson, E.; Gorin, T.; Rotter, I.;
Abstract
The time dependent Schrödinger equation of an open quantum mechanical system is solved by using the stationary bi-orthogonal eigenfunctions of the non-Hermitean time independent Hamilton operator. We calculate the decay rates at low and high level density in two different formalism. The rates are, generally, time dependent and oscillate around an average value due to the non-orthogonality of the wavefunctions. The decay law is studied disregarding the oscillations. In the one-channel case, it is proportional to t-b with b ≈ 3/2 in all cases considered, including the critical region of overlapping where the non-orthogonality of the wavefunctions is large. Starting from the shell model, we get b ≈ 2 for 2 and 4 Open decay channels and all coupling strengths to the continuum. When the closed system is described by a random matrix, b ≈ 1 + K/2 for K = 2 and 4 channels. This law holds in a limited time interval. The distribution of the widths is different in the two models when more than one channel are open. This leads to the different exponents b in the power law. Our calculations are performed with 190 and 130 states, respectively, most of them in the critical region. The theoretical results should be proven experimentally by measuring the time behaviour of de-excitation of a realistic quantum system.
  • Open Access LogoForschungszentrum Rossendorf; FZR-139 Preprint
  • Physical Review E 54 (1996) 4, pp. 3339-51

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Publ.-Id: 540


Saxon Wind Energy Ressources: Comparison of WASP and KAMM Results
Hirsch, W.; Rindelhardt, U.; Tetzlaff, G.;
The wind energy ressources of a selected saxon area ( 64 km x 48 km ) has been investigated in detail. The region can be characterized by a mean height of 200 m a.s.l. with complex surface profil. Based on measuring data of three stations WASP calculations with a grid step of 0.25 km has been performed for the whole region. The data are compared with calculation results of the mesoscale KAMM model. These calculations based on the geostrophic wind data of the Czech station Prague and used a 1.0 km and a 2.5 km grid ( coresponding 60 and 120 wind clusters ). The ressource maps ( mean wind velocity and power density ) calculated by both methods show corresponding high wind potential in the investigated area. Differences in the absolute values are explained by the features of the used programmes.
  • Lecture (Conference)
    Proceedings of the 1996 European Union Wind Energy Conference and Exhibition, Göteborg (Sweden), 20.-24.5.1996, pp. 604-607

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Publ.-Id: 539


Solare Warmwasserbereitung und Fernwärmeeinspeisung -Waldblickschule Freital-
Brünig, D.; Rindelhardt, U.;
In ein mit Erdgas betriebenes konventionelles Fernwärmesystem (Anschlußleistung 2,1 MW) wurde eine Solarkollektoranlage mit einer Bruttofläche von 100 m² integriert. Die Kollektoranlage diente vorrangig der Erzeugung von Brauchwarmwasser für eine Schule, solare Überschüsse wurden in den Rücklauf des Fernwärmesystems eingespeist. Ein umfangreiches Meßprogramm ermöglichte Effizienzuntersuchungen des Systems.
Der jährliche Nettoertrag des Solarsystems lag bei 280 kWh/m² bei einem Systemnutzungsgrad von 26%. Beide Kennziffern wurden durch hohe Rücklauftemperaturen (58°C) im Nahwärmenetz negativ beeinflußt. Weitere Untersuchungen galten dem Betrieb der eingesetzten Schichtspeicher (Reihenschaltung). Bei Ausschöpfung der in dem Vorhaben deutlich gewordenen Optimierungspotentiale können in künftigen Anlagen Nettoerträge von 350 kWh/m² und solare Wärmegestehungskosten unter 30 Pf./kWh erreicht werden.
  • Open Access LogoForschungszentrum Rossendorf; FZR-137, April 1996

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Publ.-Id: 537


Electromagnetic signals from deconfined matter resulting from ultrarelativistic heavy-ion collisions
Kämpfer, B.; Peshier, A.; Hentschel, M.; Soff, G.; Pavlenko, O. P.;
  • Contribution to external collection
    World Scientific, Singapore: Structure of Vacuum and Elementary Matter, World Scientific 1997, New Jersy, London, Hongkong, (Eds.) H. Stoecker, A. Gallmann, J. H. Hamilton, p. 483
  • Open Access LogoForschungszentrum Rossendorf; FZR-136

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Publ.-Id: 536


Elektroenergieerzeugung einer kombinierten Wind-Photovoltaik-Anlage in Ottendorf-Okrilla (Sachsen)
Futterschneider, H.; Hirsch, W.; Rindelhardt, U.; Teichmann, G.;
Vom Zentrallager der Plus-Warenhandelsgesellschaft in Ottendorf-Okrilla (Sachsen) wird seit 1992 eine hybride Wind-Photovoltaik-Anlage zur Erzeugung von Elektroenergie betrieben. Die Anlage besteht aus einer 60-kW-Windkraftanlage des Typs TW 60 und einer Phtovoltaikanlage mit einer Spitzenleistung von 3,18 kW. Letztere zeichnet sich durch einige Besonderheiten (Orientierung des Generators, Master-Slave-Betieb der Wechselrichter) aus. Das Betriebsverhalten der Anlagen wurde über einen längeren Zeitraum untersucht.

Im Jahr 1995 erreichte die Photovoltaikanlage mit 689 Vollastbetriebsstunden etwa die Ergebnisse anderer Photovoltaikanlagen in Sachsen. Mögliche höhere Erträge werden durch die gewählte Orientierung des Generators verhindert. Die Master-Slave-Schaltung der Wechselrichter arbeitete ohne Probleme. Ihre Effektivität wurde durch die nicht optimale Abstimmung von Generator- und Wechselrichterleistung beeinträchtigt.
  • Open Access LogoForschungszentrum Rossendorf; FZR-138 April 1996

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Publ.-Id: 535


A Neural-Network Approach for Acoustic Leak Monitoring in Pressurized Plants with Complicated Topologies
Hessel, G.; Schmitt, W.; Weiß, F.-P.;
A neural-network approach has been developed for localizing leakages and estimating the leak rate in pressurized plants with complicated three-dimensional structures. Results are presented from experiments with simulated leaks at a VVER-440 reactor vessel head. As features for characterizing the occurrence and the location of a leak, RMS values of acoustic emission sensors and coherence values and power spectra of microphone signals were used. Three-layer perceptron networks were found to be best suited for leak localization and for 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 the RMS values of the acoustic emission sensors. Perceptron networks with continuously valued outputs corresponding to the coordinates of the leak positions were useful for classifying even positions which had not been offered during training.
  • Control Engineering Practice, Vol. 4, No. 9, pp. 1271-1276, 1996, pp. 1271 - 1276

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Publ.-Id: 534


Institute of Nuclear and Hadron Physics; Annual Report 1995
Dönau, F.; Prade, H.; Enghardt, W.; Möller, K.; Mösner, J.; Winter, G.; Wünsch, R.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-130

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Publ.-Id: 533


Institute of Ion Beam Physics and Materials Research; Annual Report 1995
Möller, W.; Wieser, E.; von Borany, J.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-129

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Publ.-Id: 532


Lieferung von Investitionsgütern zur Erhöhung der Betriebssicherheit des Kernkraftwerkes Saporoshje - Betriebliche Überwachung, 2. Realisierungsstufe -
Beyer, M.; Carl, H.; Schikora, B.; Schumann, P.; Seidel, A.; Zschau, J.;
Im Rahmen eines Programms des Bundesministeriums für Umwelt, Naturschutz und Reaktorsicherheit zur Zusammenarbeit mit den MOE-Staaten und der GUS auf dem Gebiet der kerntechnischen Sicherheit hat das Forschungszentrum Rossendorf, Institut für Sicherheitsforschung, im Verbund mit dem technischen Überwachungsverein TÜV Rheinland, Institut für Kerntechnik und Strahlenschutz, die einvernehmlich spezifizierten "technischen Mittel für ein System zur verbesserten betrieblichen Überwachung" an das Kernkraftwerk Saporoshje, Ukraine, geliefert und in Betrieb genommen. Im vorliegenden Bericht (Textteil) werden die Lieferungen und Leistungen nach Art und Umfang (Beschaffenheit, Abnahmeprüfung, Übergabe und Inbetriebnahme der technischen Mittel und die für das ukrainische Fachpersonal durchgeführten Schulungsmaßnahmen) bis zur Aufnahme des Probebetriebes am 30. November 1995 beschrieben. Dem Bericht ist ein Anhang A mit Vorschlägen zur Gestaltung der automatisch arbeitenden Überwachungssoftware und ein Anhang B mit wissenschaftsorganisatorischen Details beigefügt.
  • Open Access LogoForschungszentrum Rossendorf; FZR-135 April 1996

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Publ.-Id: 531


The binary decay of hot heavy nuclei: fission, evaporation, and also flow?
Wagner, W.; Ortlepp, H.-G.; Gippner, P.; Herbach, C.-M.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-133 Preprint

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Publ.-Id: 530


Bethe-Salpeter amplitudes and static properties of the deuteron
Kaptari, L. P.; Umnikov, A. Y.; Bondarenko, S. G.; Kazakov, K. Y.; Khanna, F. C.; Kämpfer, B.;
Abstract
Extended calculations of the deuteron's static properties, based on the numerical solution of the Bethe-Salpeter equation,.are presented. A formalism is developed, which provides a comparative analysis of the covariant amplitudes in various representations and nonrelativistic wave functions. The magnetic and quadrupole moments of the deuteron are calculated in the Bethe-Salpeter formalism and tlie role of relativistic corrections is discussed.
  • Physical Review C 54 (1996) 3 pp. 986-1005
  • Open Access LogoForschungszentrum Rossendorf; FZR-134 Preprint

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Publ.-Id: 529


Unexpected formation of the new oxorhenium (V) complex [ReO(NH(CH2CH2S)2)(SC6H5)] obtained by N-C cleavage of the tripodal ligand N(CH2CH2SH)3
Glaser, M.; Spies, H.; Berger, R.; Hahn, F. E.; Lügger, T.; Johannsen, B.;
  • Inorganica Chimica Acta 257 (1997) 143-147

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Publ.-Id: 528


Inertial Mass of the Chiral Quark-Loop Soliton in the Nambu & Jona-Lasinio Model at Finite Temperature and Density
Schleif, M.; Wünsch, R.;
Abstract
We consider the mass of the one-loop hedgehog soliton of the bosonized SU(2) Nambu & Jona-Lasinio model embedded in hot nuclear matter mimiced by a gas of constituent quarks. We prove that the proper-time regularized and self-consistently determined soliton in a heat bath obeys Poincare's invariance up order V2. At ifinite temperature and chemical potential, we show that the inertial mass obtained in the perturbative pushing approach coincides with the total internal energy of the soliton.
  • Open Access LogoForschungszentrum Rossendorf; FZR-132 Preprint

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Publ.-Id: 527


Output Maximization of a 7.25 GHz ECR Ion Source
Henke, D.; Tyrroff, H.; Wirth, H.; Zschornack, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-131 Preprint

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Publ.-Id: 526


Synthesis and reactions of trigonal-bipyramidal rhenium and technetium complexes with a tripodal, tetradentate NS3 ligand*
Spies, H.; Glaser, M.; Pietzsch, H.-J.; Hahn, F. E.; Lügger, T.;
  • Inorganica Chimica Acta 240 (1995) pp. 465-478

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Publ.-Id: 525


Are missing-mass measurements the key for understanding subthreshold particle production
Müller, H.;
By measuring the fast particles emerging from a proton-nucleus interaction the number of participants can be determined. This might be the key quantity for understanding subthreshold particle production.
  • Zeitschrift für Physik A 355 (1996) pp. 223-224

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Publ.-Id: 524


Comment on "Evidence of enhanced epitaxial crystallization at ion temperature by inelastic electronic scattering of mega-electronvolt heavy-ion-beam irradiation"
Heera, V.;
The results on epitaxial crystallization of Si by mega-electron-volt heavy-ion-beam irradiation recently published by Nakata can be understood in the framework of the "point defect diffusion model". It is not necessary to consider inelastic electronic scattering effects in order to explain the decrease in the normalized crystallization rate with increasing nuclear deposited energy.
  • Journal of Applied Physics (short communication) 80 (1996) 4235

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Publ.-Id: 523


A Neutron Double-Crystal Diffractometer with a Position Sensitive Detector for Small-Angle Scattering Studies
Hempel, A.; Eichhorn, F.; Reichel, P.; Boede, W.;
A neutron double-crystal diffractometer (DCD) with a position sensitive detector for a simultaneous measurement of the whole scattering range was realized. In this arrangement the angular dependence of the intensity distribution is transformed into a positional one by an elastically bent perfect analyzer (second) crystal set in a completely asymmetric diffraction geometry. The DCD may be used for the study of neutron beams scattered, diffracted, refracted or reflected in small angles. By tuning the curvature of the analyzer in the momentum transfer a range from 2x10-1 nm-1 is available. At present this DCD is used for small-angle neutron scattering investigations as well as for experiments with neutron optical components.
  • Nuclear Instruments and Methods in Physics Research A 381 (1996) pp. 466-471

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Publ.-Id: 521


SAXS Investigation of Structural Changes in the Plastic Zone Ahead of the Crack Tip in Ductile Metals
Große, M.; Böhmert, J.; Hempel, A.; Riekel, C.; Engstroem, P.;
  • Poster
    ESRF-User-Meeting 1995, Grenoble 20.-21.11.1995

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Publ.-Id: 520


Einfluß bestrahlungsindizierter Ausscheidungen auf die Zähigkeit von Cr-Mo-V-legierten Reaktordruckbehälterstählen
Böhmert, J.; Große, M.; Viehrig, H.-W.;
  • Contribution to proceedings
    28. Tagung DVM-Arbeitskreises Bruchvorgänge, Bremen, 26. - 27. Februar 1996, DVM-Bericht 228, S. 173 - 182

Permalink: https://www.hzdr.de/publications/Publ-519
Publ.-Id: 519


Institute of Safety Research, Annual Report 1994
Weiß, F.-P.; Rindelhardt, U.; (Editors)
The report gives an overview on the scientific work of the Institute of Safety Research in 1994.
  • Open Access LogoForschungszentrum Rossendorf; FZR-126 Juni 1995

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Publ.-Id: 517


The Temperature Dependence of the Ion Beam Induced Interfacial Amorphization in Silicon
Henkel, T.; Heera, V.; Kögler, R.; Skorupa, W.; Seibt, M.;
The temperature dependence of the ion beam induced interfacial amorphization process (IBIIA) in silicon has been investigated at temperatures above 80 K using Rutherford Backscattering Spectroscopy/Channeling (RBS/C) and Cross-Sectional Transmission Electron Microscopy (XTEM). Three regimes are observed. Above temperatures of about 320 K there is strong temperature dependence of the IBIIA rate (thermal regime). At lower temperatures the rate moves towards a saturation value (transition regime). Below approximately 150 K IBIIA is nearly temperature independent (ballistic regime). This low temperataure regime can be explained by an athermal transport of point defects like in ballistic mixing processes.
  • Applied Physics Letters 68 (1996) 24 pp. 34253427

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Publ.-Id: 513


Herstellung, Charakterisierung und Ionenstrahlmodofizierung amopher Kohlenstoffschichten
Kolitsch, A.; Ullmann, J.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-127

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Publ.-Id: 512


Institute of Radiochemistry; Annual Report 1995
Nitsche, H.; Engelmann, H.-J.; Bernhard, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-123

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Publ.-Id: 511


Parallele Erfassung und Übertragung nicht synchronisierter Datenströme aus mehreren Echtzeitrechnern
Schikora, B.; Zschau, J.;
  • Lecture (Conference)
    bei der Firma PEP Modular Computers GmbH, Dresden, 27.06.1996

Permalink: https://www.hzdr.de/publications/Publ-510
Publ.-Id: 510


Estimates of Electromagnetic Signals from Deconfined Matter Produced in Ultrarelativistic Heavy-Ion Collisions
Kämpfer, B.; Pavlenko, O. P.; Peshier, A.; Hentschel, M.; Soff, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-128
  • Book (Authorship)
    Advances in Nuclear Dynamics 2, Edited by Bauer and Westfall, Plenum Press, New York, 1996, p. 285

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Publ.-Id: 509


Surface Light Scattering Spectroscopy of the Gallium Liquid-Vapor Interface
Kolevzon, V.;
Surface Light Scattering Spectroscopy of the Gallium Liquid-Vapor Interface
Vladimir Kolevzon
Abstract
High frequency capillary waves at liquid Ga surface have been studied by means of quasielastic light scattering spectroscopy. The observed frequencies and damping constants of waves differed greatly from classical theoretical treatment of liquid Ga surface as that of a simple liquid. This effect was explained due to the presence of the surface layer, possessing visco-elastic properties extracted, for the first time, from the fit of experimental spectra with an appropriate theoretical form. Negative value of the surface dilational viscosity has been derived for all wavenumbers studied. At high wavenumbers q the wave dispersion behavior is best likely linked to the weak coupling between dilational and capillary modes, while at low and moderate q the experimental data resemble to the mixed oscillations. This behavior is consistent with an influence of diffusion and adsorption on the waves propagation.
  • Open Access LogoForschungszentrum Rossendorf; FZR-124

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Permalink: https://www.hzdr.de/publications/Publ-508
Publ.-Id: 508


Institute of Bioinorganic and Radiopharmaceutical Chemistry; Annual Report 1995
Johannsen, B.; Seifert, S.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-122

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Permalink: https://www.hzdr.de/publications/Publ-507
Publ.-Id: 507


A Neural Network Approach for Acoustic Leak Monitoring at Pressurized Plants with Complicated Topology
Hessel, G.; Schmitt, W.; Weiß, F.-P.;
  • Contribution to proceedings
    Preprints of the IFAC Workshop on On-line Fault Detection and Supervision in the Chemical Process Industries, Newcastle (England), June 12 - 13th 1995, pp. 98 - 102

Permalink: https://www.hzdr.de/publications/Publ-505
Publ.-Id: 505


OS/9-Anwendungen zur parallelen Erfassung nichtsynchronisierter Datenströme aus mehreren Echtzeitrechnern
Schikora, B.; Zschau, J.; Wiedemann, H.;
  • Lecture (Conference)
    OS/9-Konferenz, 20.-22.9.1996 in Emmetten/Schwiz

Permalink: https://www.hzdr.de/publications/Publ-504
Publ.-Id: 504


Phase identification of boron nitride thin films by polarized infrared reflection spectroscopy
Plass, M.; Fukarek, W.; Mändl, S.; Möller, W.;
Six different types of boron nitride films were investigated by polarized infrared reflection spectroscopy. Films with a highly cubic, mixed cubic and non-cubic, and exclusively non-cubic phase composition were synthesized using ion beam assisted deposition. Additionally, post-deposition argon ion irradiated cubic and non-cubic boron nitride films as well as nitrogen implanted boron sample were analyzed. Using this technique, besides the cubic phase, two different non-cubic modifications, layered anisotropic and amorphous, could be distinguished. A preferentional orientation of the normal axis of the sp2-bonded basal planes parallel to the substrate surface was observed.
  • Applied Physics Letters 69 (1996) 1 pp. 46-48

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Publ.-Id: 503


Technetium and rhenium complexes of mercaptoacetyl glycine ligands 2. Formation and molecular structure of Re(V) complexes with mercaptoacetyl glycine and mercaptoacetyl glycine ethylester
Noll, B.; Noll, S.; Leibnitz, P.; Spies, H.; Schulze, P. E.; Semmler, W.; Johannsen, B.;
  • Inorganica Chimica Acta 255 (1997) 399-403

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Publ.-Id: 502


Nodales Modell zur Berechnung des Neutronenflußrausches infolge zufälliger Regelelementschwingungen in WWER-440 Reaktoren
Hollstein, F.;
  • Lecture (Conference)
    und Proceedings zur Jahrestagung "Kerntechnik '96", Mannheim, 21.-23.5.1996

Permalink: https://www.hzdr.de/publications/Publ-501
Publ.-Id: 501


40-kWp-Potovoltaikanlage Kirnitzschtalbahn
Brockmann, R.; Henkel, R.; Rindelhardt, U.;
Die 40-kWp-Photovoltaikanlage ist die größte netzgekoppelte PV-Anlage in Sachsen. Trotz nichtoptimaler Lage (Abschattungen im Winter) erreichte die Anlage im Jahr 1995 einen Ertrag von fast 700 kWh/kWp und liegt damit im Durchschnitt der Erträge anderer sächsischer Anlagen. Bewährt hat sich die Master-Slave-Schaltung der Wechselrichter. Der Strombedarf der Kirntzschtalbahn wird durch die Anlage zu knapp 30% gedeckt.
  • Lecture (Conference)
    11. Symposium Photovolterische Solarenergie, 13.-15.3.1996, Staffelstein, Tagungsband S. 289-293
  • Contribution to proceedings
    11. Symposium Photovolterische Solarenergie, 13.-15.3.1996, Staffelstein, Tagungsband S. 289-293

Permalink: https://www.hzdr.de/publications/Publ-500
Publ.-Id: 500


Betriebsverhalten von netzgekoppelten Photovoltaikanlagen aus dem 1000-Dächer-Programm
Ihle, T.; Rindelhardt, U.; Teichmann, G.;
Durch das FZR werden an 50 PV-Anlagen in Sachsen mehrjährige Untersuchungen zum Betriebsverhalten durchgeführt. Das Untersuchungsprogramm umfaßt die technische Überprüfung des Anlagenzustandes und die Messung der Kennlinien des PV-Generators und der eingesetzten Wechselrichter. Ferner erfolgt eine monatliche Analyse der erreichten Energieerträge. Die ersten Ergebnisse dieser Untersuchungen sind im Beitrag zusammengefaßt.
  • Lecture (Conference)
    11. Symposium Photovolterische Solarenergie, 13.-15.3.1996, Staffelstein, Tagungsband S. 294-298
  • Contribution to proceedings
    11. Symposium Photovolterische Solarenergie, 13.-15.3.1996, Staffelstein, Tagungsband S. 294-298

Permalink: https://www.hzdr.de/publications/Publ-499
Publ.-Id: 499


A Fast and Precise Generating Voltmeter
Bürger, W.;
  • Contribution to external collection
    9th Int. Symp. on High Voltage Engineering, Graz, 1995

Permalink: https://www.hzdr.de/publications/Publ-497
Publ.-Id: 497


Investigations of ion implanted iron silicide layers after annealing and irradiation
Dobler, M.; Reuther, H.; Betzl, M.; Mäder, M.; Möller, W.;
  • Nuclear Instruments and Methods in Physics Research B 117 (1996) pp.117-122

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Permalink: https://www.hzdr.de/publications/Publ-496
Publ.-Id: 496


Aufbau und Optimierung einer Hochfrequenzübertragungsstrecke mittels Glasfaserkabel zur phasenstarren Synchronisierung verschiedener 1,3GHz-HF-Systeme eines Beschleunigers
Scheurer, S.;
  • Other report
    Diplomarbeit, Hochschule für Technik und Wirtschaft (FH) Dresden/Sa.

Permalink: https://www.hzdr.de/publications/Publ-495
Publ.-Id: 495


Ein technisches Informationssystem zur verbesserten betrieblichen Überwachung des Kernkraftwerkes Saporoshje/Ukraine
Beyer, M.; Carl, H.; Schikora, B.; Schumann, P.; Seidel, A.; Weiß, F.-P.; Zschau, J.; Nowak, K.; Tolksdorf, P.;
In order to improve the operational surveillance of a VVER-1000 unit of the Ukrainian nuclear power plant Zaporosh´ye a technical monitoring system has been specified. The system will enable the state regulatory and supervisory bodies to survey the unit operation independently of operators to assess its safety status, and to impose appropriate conditions. Due to its up-to-date configuration the system provides early indication of any operational incident and emission of radioactive materials connected. Based on the system an immediate warning in mergency situations is possible as well as an effective emergency management. For this purpose 49 different operational parameters of the unit, 18 radiological parameters of the unit and the plant site and 6 meteorological parameters are monitored.
The monitoring concept and its technical realization are described.
  • Lecture (Conference)
    Postervortrag zum 4. Kolloquium Technische Diagnostik, TU Dresden, 14./15. März 1996
  • Open Access LogoForschungszentrum Rossendorf; FZR-171 März 1997

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Permalink: https://www.hzdr.de/publications/Publ-494
Publ.-Id: 494


Simulation of a Small Cold Leg Break Experiment on PMK-2 Test Facility using the codes RELAP5 and ATHLET
Prasser, H.-M.; Schäfer, F.; Krepper, E.; Ézsöl, G.; Guba, A.; Perneczky, L.;
Results of a small break loss of coolant accident experiment, conducted on the PMK-2 integral type test facility are presented. The experiment simulated a 1% break in the cold leg of a VVER-440-type reactor. The main phenomena of the experiment are discussed and in case of selected events a more detailed interpretation with the help of measured void fraction, obtained by a special measurement device is given. Two thermohydraulic computer codes, RELAP5 and ATHLET, are used for post test calculations. The aim of the presented calculations is to investigate the code capability for modeling natural circulation phenomena in VVER-440-type reactors. Therefore the results of the experiment and both calculations are compared. Both codes predict most of the transient events well, with the exception that RELAP5 fails to predict the dry-out-period in the core. In the experiment the hot and cold leg loop seal clearing is accompanied by natural circulation instabilities, which can be explained by means of the ATHLET calculation.
  • Nuclear Technology Vol. 118, May 1997, pp. 162-174

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Publ.-Id: 493


Ultrasonic Time-of-Flight Diffraction Method for Monitoring Stable Crack Growth
Bergmann, U.; Bergner, F.; Langenberg, K. J.; Hofmann, C.;
  • Lecture (Conference)
    14th World Conference on Nondestructive Testing, Neu Delhi, December 8 - 13, 1996, Beitrag zu Sammelwerken: Proc. of the 14th World Conference on NDT, New Delhi, 1996, pp. 2325
  • Contribution to proceedings
    14th World Conference on Nondestructive Testing, Neu Delhi, December 8 - 13, 1996, Beitrag zu Sammelwerken: Proc. of the 14th World Conference on NDT, New Delhi, 1996, pp. 2325

Permalink: https://www.hzdr.de/publications/Publ-492
Publ.-Id: 492


Application of the Guiding Centre Approximation to the Transport of Injected Fast Ions in a Mirror Based Plasma Neutron Source
Kumpf, H.; Noack, K.;
Abstract
The guiding centre appraximation for the motion of charged particles in axially symmetric magnetic and electric fields is formulated and stopping as well as small angle scattering on a multicompenent plasma are included. The developed code has been applied to the design of a 14-MeV neutron source according to the concept of the Budker Institute Novosibirsk. It is demonstrated that the self-interaction of injected D and T ions by stopping, scattering and induced internal Fields has to be taken into account, if the injected power exceeds a few megawatt.
  • Open Access LogoForschungszentrum Rossendorf; FZR-121 1996

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Publ.-Id: 491


A 100 kV 10 A high-voltage pulse generator for plasma immersion ion implantation
Brutscher, J.;
The design of a high voltage pulsing system for a plasma immersion ion implantation (PIII) facility is presented. A list of requirements, which have to be fulfilled by a high voltage pulse generator to get best results and a optimum operation of the PIII system, is given. A simple electrical model of the plasma is presented which describes the plasma as a capacitive-resistive load. The model parameters are determined to fit experimental results. The requirements for the pulse generator can be fulfilled well using a pulse generator design which employs a hard tube switch. A pulse generator design is presented which is especially optimized for PIII systems. Especially the hard tube control is optimized for obtaining voltage rise times as short as possible.

Comments or further questions to: brutscher@fz-rossendorf.de

  • Review of Scientific Instruments 67 (1996) 7 pp. 2621-2625

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Permalink: https://www.hzdr.de/publications/Publ-490
Publ.-Id: 490


Influence of the depth position on the neutron embrittlement of the VVER reactor pressure vessel steel 15Cr2MoV(A) Consequences for the assessment of reactor safety
Böhmert, J.; Gosse, H.-W.; Viehrig, H.-W.; Bergner, F.;
The dependence of the mechanical properties on the depth position in the unirradiated state and after irradiation up to neutron fluences of approximately 5x1018 and 70x1018 cm-2 (E > 0.5 MeV) is tested on a forging made out of VVER 440 reactor pressure vessel (RPV) steel 15CrMoV. The near-surface position shows a higher strength and a lower transition temperature than the positions greater than 1/4 wall thickness. Irradiation does not change these differences in a significant manner. The testing of specimens from the 1/4 depth position withi the surveillance programme, as normally laid down in the legal rules relating to nuclear power plants, results in a conservative safety assessment against brittle failure up to the EOL fluence. On taking into account fluence attenuation, the flux effect, etc., the toughness gradually increases from the inside to the outside of the wall after longer RPV operating times.
  • Nuclear Engineering and Design 159 (1995) pp. 131-141

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Publ.-Id: 489


Sources of radiochemical impurities in the ...
Noll, B.; Johannsen, B.; Spies, H.;
  • Nuclear Medicine and Biology 22 (1995) 8 pp. 1057-1062

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Fernüberwachung ukrainischer Kernkraftwerke
Beyer, M.; Carl, H.; Schikora, B.; Schumann, P.; Zschau, J.; Nowak, K.; Tolksdorf, P.;
Zur Verbesserung der betrieblichen Überwachung eines WWER-1000-Reaktors im ukrainischen Kernkraftwerk Saporoshje wurde ein technisches Informationssystem entworfen. Dieses System soll die Staatliche Aufsichtsbehörde in die Lage versetzen, den Reaktorbetrieb unabhängig vom Betreiber zu beobachten, den Sicherheitszustand der Anlage zu erfassen und nötigenfalls Auflagen zu erteilen. Durch eine moderne Ausrüstung soll das System eine Früherkennung von betrieblichen Störungen und Unfällen sowie der damit verbundenen Emission radioaktiver Substanzen ermöglichen. Auf dieser Grundlage soll sowohl eine rechtzeitige Warnung als auch ein effektives Störfall-Management möglich werden. Zu diesem Zweck werden 49 betriebliche Parameter, 18 radiologische Parameter und 6 meteorologische Parameter kontinuierlich überwacht. Das Überwachungskonzept und die technische Realisierung werden vorgestellt.

  • Contribution to proceedings
    Jahrestagung Kerntechnik '96, Mannheim, 21. - 23. Mai 1996, Tagungsbericht S. 476 - 479

Permalink: https://www.hzdr.de/publications/Publ-486
Publ.-Id: 486


Methodische Untersuchungen und Testmessungen für das pp-Bremsstrahlungsexperiment am COSY-TOF-Spektrometer
Schülke, A.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-120

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Permalink: https://www.hzdr.de/publications/Publ-483
Publ.-Id: 483


An explanation of trap-limited self-interstitial diffusion and enhanced boron clustering in boron doped silicon superlattices
Jäger, H.-U.;
Boron doped crystalline superlattices grown by low-temperature molecular beam epitaxy have been used by Stolk et al. to study the diffusion of self-interstitials I in Si. After 40 keV Si+ ion implantation and subsequent annealing, stationary interstitial profiles are found at 670 °C for periods t ~1 h, demonstrating that the penetration depth of interstitials is limited by trapping at hitherto unidentified impurities. In addition, the high
interstitial supersaturation causes B de-activation in the near-surface region. We show that both these effects, the trap-limited interstitial diffusion and the enhanced B clustering, can be explained, if the transient de-activation of boron is modeled by the first-order reaction I + B_s ->B_i. Boron atomic and electrical profiles as well as self-interstitial profiles are computed which are in good agreement with the experimental results.
  • Lecture (Conference)
    Proceedings of the Fourth International Symposium on Process Physics and Modeling in Semiconductor Technology, edited by G. R. Srinivasan, C. S. Murthy and S. T. Dunham, pp. 210-215
  • Contribution to proceedings
    Proceedings of the Fourth International Symposium on Process Physics and Modeling in Semiconductor Technology, edited by G. R. Srinivasan, C. S. Murthy and S. T. Dunham, pp. 210-215

Permalink: https://www.hzdr.de/publications/Publ-482
Publ.-Id: 482


CEMS and AES Investigations on Iron Silicides
Reuther, H.; Dobler, M.;
  • Surface and Interface Analysis 24 (1996) pp. 411-415

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Permalink: https://www.hzdr.de/publications/Publ-481
Publ.-Id: 481


Berücksichtigung der Zusatzsteifigkeit aus der Verdrängung einer axialen Ringspaltströmung bei Kernbehälter- und Kernmantelschwingungen
Altstadt, E.; Grunwald, G.; Zimmermann, W.; Zoller, J.;
  • Lecture (Conference)
    Jahrestagung Kerntechnik '96
  • Contribution to proceedings
    Jahrestagung Kerntechnik 1996

Permalink: https://www.hzdr.de/publications/Publ-479
Publ.-Id: 479


Resonance phenomena near thresholds
Persson, E.; Müller, M.; Rotter, I.;
Abstract
The trapping effect is investigated close to the elastic threshold. The nucleus is described as an Open quantum mechanical many-body system embedded in the continuum of decay channels. An ensemble of compound nucleus states with both discrete and resonance states is investigated in an energy-dependent formalism. It is shown that the discrete states can trap the resonance ones and also that the discrete states can directly influence the scattering cross section.
  • Physical Review C 53, (1996), 3002-3008
  • Open Access LogoForschungszentrum Rossendorf; FZR-119 Preprint

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Publ.-Id: 478


The reaction NN -> NNgamma in the 1 GeV region within an effective one-boson exchange model
Titov, A. I.; Kämpfer, B.; Reznik, B. L.; Shklyar, V.;
Abstract
Within an effective one- boson exchange parametrization of the T matrix of NN interactions we calculate cross sections for the reactions pp → ppγ and pn → pnγ for proton incidence energies in the order of 1 GeV. Besides bremsstrahlung processes we consider photons from ∆ decays and contributions from the η → γγ process, where the η is excited via the N1535 resonance. At beam energies above 700 MeV the ∆ decay channiel dsminates for large photon energies, while above the η threshold the η decay photons ähsw up only in a narrow window. The low energy photons stem frorn pure bremsstrahlunig processes.
  • Physics Letters B 372 (1996) pp. 15-19
  • Open Access LogoForschungszentrum Rossendorf; FZR-118 Preprint

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Permalink: https://www.hzdr.de/publications/Publ-477
Publ.-Id: 477


Contribution of the massive photon decay channel to the neutrino cooling of neutron stars
Voskresensky, D. N.; Kolomeitsev, E. E.; Kämpfer, B.;
Abstract

The role of the massive photon decay via intermediate states of electron-electron-holes and proton-proton-holes into neutrino-anti-neutrino pairs in the course of neutron star cooling is investigated. These reactions may ba operative in hot neutron stars in the region of proton pairing. The corresponding contribution to the neutrino emissivity is calculated. It varies with the temperature as T3/2e−mγ/T for T < m γ, where mγ is an effective photon mass in superconducting matter. Estimates show that this process appears as strong cooling channel of neutron stars at temperatures T ≈ ( 109 - 1010) K.
  • J. Exp. Theor. Phys. 87 (1998), 211
  • Open Access LogoForschungszentrum Rossendorf; FZR-117 Preprint

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Publ.-Id: 476


Langzeitmeßprogramm "1000-Dächer-Programm"
Rindelhardt, U.; Teichmann, G.;
Die technische Überprüfung von bisher 30 netzgekoppelten Anlagen ergab keine gravierenden Mängel. Einzelne technische Schwächen von eingesetzten Komponenten wurden identifiziert. Zur energetischen Bewertung der Anlagen wurde ein PC-gestützter PV-Anlagen-Analysator entwickelt und erprobt. Ein optimales Verfahren zur Umrechnung gemessener PV-Generator-Kennlinie auf STC-Bedingungen existiert noch nicht.
  • Lecture (Conference)
    BMBF-Statusseminar "Photovoltaik", Bad Breisig, 23.-25. April 1996, Berichtsband, Beitrag Nr. 73
  • Contribution to proceedings
    BMBF-Statusseminar "Photovoltaik", Bad Breisig, 23.-25. April 1996, Berichtsband, Beitrag Nr. 73

Permalink: https://www.hzdr.de/publications/Publ-475
Publ.-Id: 475


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