Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

"Online First" included
Without submitted and only approved publications
Only approved publications

33168 Publications

High resolution Runge-Kutta tracking for kaon reconstruction

Sadovski, A.;
  • Lecture (Conference)
    DPG Tagung, 04.03.2005, Berlin, Dtl.

Permalink: https://www.hzdr.de/publications/Publ-9950
Publ.-Id: 9950


Mensch und Strahlung

Pawelke, J.;
  • Lecture (others)
    Lange Nacht der Wissenschaften, 01.07.2005, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9949
Publ.-Id: 9949


Design and construction of a prototype TRD for the CBM experiment at GSI

Naumann, L.;
  • Invited lecture (Conferences)
    GSI Darmstadt, 08.-09.12.2005, Darmstadt, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9948
Publ.-Id: 9948


Testing RPC timing at the Rossendorf electron Linac ELBE

Kotte, R.;
  • Lecture (Conference)
    CBM-RPC-Hadron-ID workshop, 14.12.2005, Darmstadt, Dtl.

Permalink: https://www.hzdr.de/publications/Publ-9947
Publ.-Id: 9947


FOPI plastic wall status (S279, S297)

Kotte, R.;
  • Lecture (Conference)
    FOPI collaboration meeting, 12.-13.12.2005, Darmstadt, Dtl.

Permalink: https://www.hzdr.de/publications/Publ-9946
Publ.-Id: 9946


RPC timing tests at ELBE

Kotte, R.;
  • Lecture (Conference)
    FOPI collaboration meeting, 12.-13.12.2005, Darmstadt, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9945
Publ.-Id: 9945


Seeking sub-100ps timing without fast reference detector at the Rossendorf Electron Linac ELBE

Kotte, R.;
  • Lecture (Conference)
    FOPI collaboration meeting, 26.-28.05.2005, Split, Croatia

Permalink: https://www.hzdr.de/publications/Publ-9944
Publ.-Id: 9944


Development of a Neutron Time-of-Flight Source at ELBE Accelerator

Klug, J.;
  • Lecture (Conference)
    Int. Conf. on New Trends in Physics Applications and Technology, 09.09.2005, Pavia, Italy

Permalink: https://www.hzdr.de/publications/Publ-9943
Publ.-Id: 9943


Flash lamp processing for Group IV semiconductors

Skorupa, W.;
The flash lamp processing for Group IV semiconductors is discussed.
Keywords: flash lamp processing, semiconductors
  • Lecture (others)
    Lecture, Department of Engineering, University of Cambridge, 02.12.2004, Cambridge, UK

Permalink: https://www.hzdr.de/publications/Publ-9942
Publ.-Id: 9942


Blitzlampen-Temperung im msec-Bereich für die SiC-Si-Heteroepitaxie

Skorupa, W.;
Das Verfahren zur Blitzlampen-Temperung im msec-Bereich für die SiC-Si-Heteroepitaxie wird vorgestellt.
Keywords: flash lamp annealing, silicon, silicon carbide, heteroepitaxy
  • Lecture (others)
    Vortrag, Institut für Angewandte Physik, Universität Erlangen-Nürnberg, 11.11.2004, Erlangen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9941
Publ.-Id: 9941


Silizium-basierte Lichtemission und Blitzlampen-Temperung: Innovationen bei FWI

Skorupa, W.;
Es wird ein Überblick über Innovationen im Institut FWI bei der Silizium-basierten Lichtemission und der Blitzlampen-Temperung gegeben.
Keywords: light emission, silicon, ion implantation, flash lamp annealing
  • Lecture (others)
    Vortrag, Senioren-Club des FZR,, 04.11.2004, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9940
Publ.-Id: 9940


Silicon-based light emission from ion-implanted materials

Skorupa, W.;
An overview about silicon-based light emission from ion-implanted materials is given.
Keywords: light emission, silicon, ion implantation
  • Lecture (others)
    Lecture, Department of Physics, Oslo University, 12.08.2004, Oslo, Norway

Permalink: https://www.hzdr.de/publications/Publ-9939
Publ.-Id: 9939


EPOS – ELBE positron source: positron annihilation multifacility project in Dresden

Krause-Rehberg, R.; Bondarenko, V.; Brauer, G.;
The EPOS – ELBE positron source, a positron annihilation multifacility project in Dresden, is presented.
Keywords: positron source
  • Lecture (others)
    MATERIALICA, Neue Messe München, 21.-23.09.2004, München, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9938
Publ.-Id: 9938


Fabrication and evaluation of efficient light emitters comprising nanocluster-rich SiO2 layers

Yankov, R. A.; Gebel, T.; Rebohle, L.; Trautmann, T.; Skorupa, W.; Gauglitz, G.; Frank, R.;
Fabrication and evaluation of efficient light emitters comprising nanocluster-rich SiO2 layers
Keywords: efficient light emitters, nanocluster, silicon dioxide
  • Contribution to external collection
    Photonic Crystal Materials and Nanostructures: Fabrication and evaluation of efficient light emitters comprising nanocluster-rich SiO2 layers, SPIE vol. 5450, Bellingham, WA, USA: SPIE, 2004, 578-585

Permalink: https://www.hzdr.de/publications/Publ-9937
Publ.-Id: 9937


Enhancement of the photoluminescence of silicon nanocrystals under the influence of electric field

Vandyshev, E. N.; Zhuravlev, K. S.; Gilinsky, A. M.; Skorupa, W.;
The effect of electric field generated by the application of surface acoustic waves on photoluminescence (PL) of silicon nanocrystals embedded in SiO2 films is studied. It is shown that the application of electric field results in an increase in the intensity of nanocrystal PL, the increase amounting to 10% at a field amplitude of 6 kV cm(-1). The results are discussed within the frame of the self-trapped exciton model.
Keywords: photoluminescence, silicon dioxide, ion implantation, nanocrystals
  • Physica E 21(2004)2-4, 304-307

Permalink: https://www.hzdr.de/publications/Publ-9936
Publ.-Id: 9936


Ion Beam Processing for Silicon - Based Light Emission

Skorupa, W.; Dekorsy, T.; Gebel, T.; Helm, M.; Lysenko, V. S.; Nazarov, A. N.; Osiyuk, I. N.; Rebohle, L.; Schmidt, B.; Sun, J. M.;
In this talk an overview will be presented regarding the influence of ion irradiation effects and treatments on the formation of silicon-based light emission structures and devices. After a short overview to the complete field-as to my knowledge- we will concentrate on two activities performed at the FZR during the last years, (i) Blue-violet (400 nm) light emitters basing on Metal-Oxide-Silicon capacitors, and, (ii) Infrared (~1µm) light emitters basing on pn-junctions. Both approaches use ion beam processing as a key doping technique of advanced semiconductor technologies. For the first case we employed implantation of group IV ions (C, Si, Ge, Sn) into thermally silicon dioxide layers followed by an appropriate annealing step leading to electroluminescence effects with a power efficiency/external quantum efficiency of ~0.5/10 %. This preparation leads to the formation of semiconductor nanoclusters in the oxide matrix; the luminescence itself is related to defects. Comparing to other oxide production techniques like sputtering or evaporation it is shown that such high electroluminescence values are only possible on the base of ion beam processing, i.e. the combination of nanocluster synthesis and beam-induced energy deposition. For the second case we will demonstrate that appropriate boron implantation and annealing steps can lead to pn-junctions with two electroluminescence bands from bound excitons at 1.065 eV and around 0.95 eV. This effect needs local oversaturation of boron –which, of course, is only possible by ion implantation- leading to nanoclusters which produce the necessary doping and strain induced disturbances to the band structure.
Keywords: ion beam processing, silicon, light emission
  • Contribution to proceedings
    Materials Research Society Fall Meeting, 01.-05.12.2003, Boston, USA
    Materials Research Society Fall Meeting, vol. 792 (2004), R 11.1.1

Permalink: https://www.hzdr.de/publications/Publ-9935
Publ.-Id: 9935


Nanocluster-rich silicon dioxide layers: electroluminescence and charge trapping

Gebel, T.; Rebohle, L.; Yankov, R. A.; Nazarov, A. N.; Skorupa, W.; Keywords: Nanocluster, silicon dioxide layers, electroluminescence, charge trapping
  • Contribution to external collection
    Pistora, Jaromir (u.a.): Microwave and Optical Technology 2003, Proceedings of the SPIE, Volume 5445, Bellingham, WA, USA: SPIE Int. Soc. Opt. Eng., 2004, 284-289

Permalink: https://www.hzdr.de/publications/Publ-9934
Publ.-Id: 9934


Comparative evaluation of coolant mixing experiments at the ROCOM, Vattenfall, and Gidropress test facilities

Kliem, S.; Hemström, B.; Bezrukov, Y.; Höhne, T.; Rohde, U.;
Coolant mixing is an important mitigative mechanism against reactivity accidents caused by local boron dilution. Experiments on coolant mixing were carried out at three different test facilities representing three different reactor types. These are the ROCOM test facility modelling a German KONVOI-type reactor, the Vattenfall test facility being a model of a Westinghouse three-loop PWR and the Gidropress test facility modelling a VVER-1000 PWR. The scenario of the start-up of the first main coolant pump was investigated in all three facilities.
The experiments were accompanied by velocity measurements in the downcomer for the same scenario in the ROCOM and the Vattenfall test facilities. A similar flow structure was found in these measurements in both cases. A maximum of the velocity is measured at the opposite side in regard to the position of the loop with the starting-up pump whilst a recirculation area was found just below this inlet nozzle in both facilities.
The analysis of the slug mixing experiments showed also comparable flow behaviour. In accordance with the velocity measurements, the first part of the deboration is also found on the opposite side. In this region, the maximum deboration is measured in all three cases. These maximum values are in the same order of magnitude for nearly identical initial slug volumes.
  • Open Access Logo Science and Technology of Nuclear Installations 2007(2007), 25950
    DOI: doi:10.1155/2007/25950
  • Lecture (Conference)
    Annual Meeting of the AER Working Group D, 08.-09.05.2007, Paris, France

Downloads:

  • available with HZDR-Login

Permalink: https://www.hzdr.de/publications/Publ-9933
Publ.-Id: 9933


Deep level defects in He-implanted n-6H-SiC studied by deep level transient spectroscopy

Chen, X. D.; Ling, C. C.; Fung, S.; Beling, C. D.; Wu, H. S.; Brauer, G.; Anwand, W.; Skorupa, W.;
Deep level defects in He-implanted n-6H-SiC studied by deep level transient spectroscopy
Keywords: He-implantion, n-6H-SiC,deep level transient spectroscopy
  • Contribution to proceedings
    Materials Research Society Spring Meeting 2004, 12.-16.04.2004, San Francisco, USA
    Silicon carbide – materials, processing, and devices 815 (2004), J5.5, New York: Taylor & Francis

Permalink: https://www.hzdr.de/publications/Publ-9932
Publ.-Id: 9932


Slow positron implantation spectroscopy – a tool to characterize vacancy-type damage in ion-implanted 6H-SiC

Brauer, G.; Anwand, W.; Coleman, P. G.; Skorupa, W.;
A lecture is given about slow positron implantation spectroscopy as a tool to characterize vacancy-type damage in ion-implanted 6H-SiC
Keywords: positron beam, SiC, defects
  • Lecture (others)
    Lecture, Department of Physics, University of Texas at Austin, 19.10.2004, Austin/TX, USA
  • Lecture (others)
    Lecture, Physics Department, University of Texas at Arlington, 21.10.2004, Arlington/TX, USA
  • Lecture (others)
    Lecture, Department of Physics, Texas Christian University, 22.10.2004, Ft. Worth/TX, USA

Permalink: https://www.hzdr.de/publications/Publ-9931
Publ.-Id: 9931


Epitaxial 3C-SiC formation at the SiO2/Si interface by C+ Implantation into SiO2 and subsequent annealing

Voelskow, M.; Panknin, D.; Polychroniadis, E. K.; Ferro, G.; Monteil, Y.; Godignion, P.; Mestres, N.; Skorupa, W.; Stoemenos, J.;
The epitaxial 3C-SiC formation at the SiO2/Si interface by C+ Implantation into SiO2 and subsequent annealing is studied.
Keywords: SiC formation, carbon implantation, SiO2
  • Lecture (Conference)
    5th European Conference Silicon Carbide and Related Materials, 31.08.-04.09.2004, Bologna, Italy

Permalink: https://www.hzdr.de/publications/Publ-9930
Publ.-Id: 9930


Efficient silicon light emitting diodes by boron implantation: the mechanism

Sun, J. M.; Dekorsy, T.; Skorupa, W.; Schmidt, B.; Mücklich, A.; Helm, M.;
The mechanism of efficient light emission in boron implanted silicon diodes is discussed.
Keywords: silicon, light emission, boron implantation
  • Lecture (Conference)
    European Materials Research Society Spring Meeting, 24.-28.05.2004, Strasbourg, France

Permalink: https://www.hzdr.de/publications/Publ-9929
Publ.-Id: 9929


Temperature dependence of efficient silicon light-emitting diodes prepared by ion implantation

Sun, J. M.; Dekorsy, T.; Skorupa, W.; Schmidt, B.; Helm, M.;
The temperature dependence of efficient silicon light-emitting diodes prepared by ion implantation is investigated.
Keywords: silicon, light emitting diodes, ion implantation
  • Lecture (Conference)
    DPG Tagung, 08.-12.03.2004, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9928
Publ.-Id: 9928


Physik fernab vom Gleichgewicht: Nanostrukturierung mit Ionenstrahlen

Heinig, K.-H.; Keywords: Nanostruktur, Ionenstrahl
  • Lecture (others)
    Universität Jena, Physikalisches Kolloquium, 01.11.2004, Jena, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9927
Publ.-Id: 9927


CFD-modelling of mineral wool in the containment sump

Krepper, E.; Cartland-Glover, G.; Grahn, A.; Weiß, F.-P.; Alt, S.; Hampel, R.; Kästner, W.; Seeliger, A.;
The investigation of insulation debris generation, transport and sedimentation becomes more important with regard to reactor safety research for PWR and BWR, when considering the long-term behavior of emergency core coolant systems during all types of loss of coolant accidents (LOCA). The insulation debris released near the break during a LOCA incident consists of a mixture of disparate particle population that varies with size, shape, consistency and other properties. Some fractions of the released insulation debris can be transported into the reactor sump, where it may perturb/impinge on the emergency core cooling systems.
Open questions of generic interest are for example the particle load on strainers and corresponding pressure drop, the sedimentation of the insulation debris in a water pool, its possible re-suspension and transport in the sump water flow. A joint research project on such questions is being performed in cooperation with Institute of Process Technology, Process Automation and Measuring Technology (IPM) Zittau. The project deals with the experimental investigation and the development of CFD models for the description of particle transport phenomena in coolant flow. While the experiments are performed at the IPM-Zittau, the theoretical work is concentrated at Forschungszentrum Dresden-Rossendorf.
In the paper the basic concepts for CFD modeling are described and feasibility studies including the conceptual design of the experiments are presented.
Keywords: CFD, two-fluid approach, fiber flows
  • Lecture (Conference)
    Annual Meeting on Nuclear Technology 2007, 22.-24.05.2007, Karlsruhe, Germany
  • Contribution to proceedings
    Annual Meeting on Nuclear Technology 2007, 22.-24.05.2007, Karlsruhe, Germany

Permalink: https://www.hzdr.de/publications/Publ-9926
Publ.-Id: 9926


Thermal model for flashlamp annealing of 3C-SiC/Si multilayer systems (i-FLASiC)

Smith, M.; Mcmahon, R. A.; Voelskow, M.; Skorupa, W.; Stoemenos, J.;
A thermal model for flash lamp annealing of 3C-SiC/Si multilayer systems is developed.
Keywords: thermal model, SiC, flash lamp annealing
  • Lecture (Conference)
    5th European Conference Silicon Carbide and Related Materials, 31.08.-04.09.2004, Bologna, Italy

Permalink: https://www.hzdr.de/publications/Publ-9925
Publ.-Id: 9925


Nanostructure formation with ion beams

Heinig, K.-H.;
An abstract is not available, please contact the author.
Keywords: ion beam, nanostructure
  • Lecture (others)
    Lecture at University of Aarhus, 07.10.2004, Aarhus, Danmark

Permalink: https://www.hzdr.de/publications/Publ-9924
Publ.-Id: 9924


Ultra-shallow junctions produced by plasma doping and flash lamp annealing

Skorupa, W.; Yankov, R. A.; Anwand, W.; Voelskow, M.; Gebel, T.; Downey, D. F.; Arevalo, E. A.;
The way how to fabricate ultra-shallow junctions by plasma doping and flash lamp annealing is demonstrated.
Keywords: ultra-shallow junctions, plasma doping, flash lamp annealing
  • Lecture (Conference)
    European Materials Research Society Spring Meeting, 24.-28.05.2004, Strasbourg, France

Permalink: https://www.hzdr.de/publications/Publ-9923
Publ.-Id: 9923


Advanced Thermal Processing of Semiconducting Materials Using Flash Lamp Annealing

Skorupa, W.; Panknin, D.; Voelskow, M.; Anwand, W.; Gebel, T.; Yankov, R. A.;
Advanced Thermal Processing of Semiconducting Materials using Flash Lamp Annealing is Discussed.
Keywords: thermal processing, flash lamp annealing, semiconductors
  • Lecture (Conference)
    Materials Research Society Spring Meeting, 13.-16.04.2004, San Francisco, USA

Permalink: https://www.hzdr.de/publications/Publ-9922
Publ.-Id: 9922


Manipulation of 2D arrays of Si nanocrystals by ultra-low-energy ion beam-synthesis for nonvolatile memories applications

Bonafos, C.; Cherkashin, N.; Carrada, M.; Coffin, H.; Ben Assayag, G.; Schamm, S.; Dimitrakis, P.; Normand, P.; Perego, M.; Fanciulli, M.; Mueller, T.; Heinig, K.-H.; Argawal, A.; Claverie, A.;
An abstract is not available, please contact the authors.
Keywords: Si, nanocrystals, nonvolatile memory
  • Lecture (Conference)
    2004 MRS Fall Meeting, 29.11.-03.12.2004, Boston, USA

Permalink: https://www.hzdr.de/publications/Publ-9921
Publ.-Id: 9921


Tailoring magnetic nanostructures by ion irradiation

Bernas, H.; Chappert, C.; Devolder, T.; Ravelosona, D.; Mathet, V.; Ferre, J.; Jamet, J. P.; Mougin, A.; Bauer, M.; Repain, V.; Samson, Y.; Marty, A.; Halley, D.; Attane, J.; Heinig, K.-H.; Stamps, R.; Chen, Y.; Suzuki, Y.; Kaitasov, O.; Ruault, M.-O.; Gautrot, S.;
An abstract is not available, please contact the authors.
Keywords: magnetic nanostructures, ion irradiation
  • Lecture (Conference)
    14th International Conference on Ion Beam Modification of Materials (IBMM 2004), 05.-10.09.2004, Monterey, USA

Permalink: https://www.hzdr.de/publications/Publ-9919
Publ.-Id: 9919


Optical and microstructural properties of doubly implanted SiO2 layers using combined Ge-Si implantation

Prucnal, S.; Cheng, X. Q.; Sun, J. M.; Kögler, R.; Zuk, J.; Skorupa, W.;
The optical and microstructural properties of doubly implanted SiO2 layers fabicated combined Ge-Si implantation are investigated.
Keywords: optical properties, defects, microstucture, SiO2, implantation
  • Lecture (Conference)
    5th Int. Conf. on Ion Implantation and other Applications of Ions and Electrons (ION2004), 14.-17.06.2004, Kazimierz Dolny, Poland

Permalink: https://www.hzdr.de/publications/Publ-9918
Publ.-Id: 9918


2D-arrays of Si nanocrystals embedded in thin SiO2 layers for new memory devices

Perego, M.; Ferrari, S.; Fanciulli, M.; Soncini, V.; Mathiot, D.; Heinig, K.-H.; Müller, T.; Schmidt, B.; Normand, P.; Dimitrakis, P.; Kapetanakis, E.; Ben Assayag, G.; Bonafos, C.; Carrada, M.; Claverie, A.;
An abstract is not available, please contact the authors.
Keywords: Si, nanostructures
  • Lecture (Conference)
    INFM-Workshop, 10.-15.06.2004, Genova, Italy

Permalink: https://www.hzdr.de/publications/Publ-9917
Publ.-Id: 9917


Nucleation control in FLASiC assisted short time liquid phase epitaxy by melt modification

Pezoldt, J.; Polychroniadis, E. K.; Stauden, T.; Ecke, G.; Chassagne, T.; Vennegues, P.; Leycuras, A.; Panknin, D.; Stoemenos, J.; Skorupa, W.;
The nucleation control in FLASiC assisted short time liquid phase epitaxy by melt modification is studied.
Keywords: nucleation, liquid phase epitaxy, flash lamp processing
  • Lecture (Conference)
    5th European Conference Silicon Carbide and Related Materials, 31.08.-04.09.2004, Bologna, Italy

Permalink: https://www.hzdr.de/publications/Publ-9916
Publ.-Id: 9916


Ion beam assisted Ge nanocrystallization in Ta2O5 films

Peeva, A.; Kalitzova, M.; Zollo, G.; Beshkov, G.; Vitali, G.; Skorupa, W.;
The ion beam assisted formation of Ge nanocrystals in Ta2O5 films is studied.
Keywords: ion beam assisted naocrystallization
  • Lecture (Conference)
    13th Int. School on Condensed Matter Physics, 30.08.-03.09.2004, Varna, Bulgaria

Permalink: https://www.hzdr.de/publications/Publ-9915
Publ.-Id: 9915


Detailed profiling of ion implantation induced excess vacancies in silicon

Peeva, A.;
Profiles of excess vacancies in silicon produced by ion implantation are studied by TEM.
Keywords: excess vacancies, Si, ion implantation
  • Lecture (others)
    Arbeitstreffen “Punktdefekte” TU Dresden, 01.-02.04.2004, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9914
Publ.-Id: 9914


E1/E2 an Z1/Z2 deep level defects in n-type 6H silicon carbide induced by electron irradiation and He implantation

Ling, C. C.; Cheng, X. D.; Fung, S.; Beling, C. D.; Brauer, G.; Anwand, W.; Skorupa, W.;
E1/E2 an Z1/Z2 deep level defects in n-type 6H silicon carbide induced by electron irradiation and He implantation are studied.
Keywords: deep levels, SiC, electron irradiation, He implantation
  • Lecture (Conference)
    27th International Conference on the Physics of Semiconductors (ICPS-27), 26.-30.07.2004, Flagstaff, USA

Permalink: https://www.hzdr.de/publications/Publ-9913
Publ.-Id: 9913


EPOS – an intense positron beam project at the Research Center Rossendorf

Krause-Rehberg, R.; Brauer, G.; Sachert, S.; Bondarenko, V.; Rogov, A.; Noack, K.;
EPOS – an intense positron beam project at the Research Center Rossendorf is presented
Keywords: intense positron Beam
  • Lecture (Conference)
    International Symposium on Positron Beam and its Application, 29.-30.10.2004, Wuhan, China

Permalink: https://www.hzdr.de/publications/Publ-9912
Publ.-Id: 9912


Design of a mono-energetic positron source for positron lifetime measurements at the radiation source ELBE

Krause-Rehberg, R.; Sachert, S.; Brauer, G.; Rogov, A.; Noack, K.; Michel, P.;
The design of a mono-energetic positron source for positron lifetime measurements at the radiation source ELBE is presented.
Keywords: mono-energetic positron source
  • Lecture (Conference)
    18th International conference on the application of accelerators in research and industry (CAARI2004), 10.-15.10.2004, Ft. Worth/TX, USA

Permalink: https://www.hzdr.de/publications/Publ-9911
Publ.-Id: 9911


Investigation of gettering effects in CZ-type Silicon with SIMS

Krecar, D.; Fuchs, M.; Kögler, R.; Hutter, H.;
Gettering effects in CZ-type Silicon are investigated with SIMS
Keywords: gettering, SIMS, Si, defects
  • Lecture (Conference)
    13th Arbeitstagung Angewandte Oberflächenanalytik (AOFA), 14.-17.10.2004, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9910
Publ.-Id: 9910


Effects of ion beam induced excess vacancies in silicon: analysis, modelling, application

Kögler, R.; Eichhorn, F.; Mücklich, A.; Skorupa, W.; Serre, C.; Perez-Rodriguez, A.;
Effects of ion beam induced excess vacancies in silicon are discussed.
Keywords: vacancies, silicon, defect engineering
  • Lecture (Conference)
    5th Int. Conf. on Ion Implantation and other Applications of Ions and Electrons (ION2004), 14.-17.06.2004, Kazimierz Dolny, Poland

Permalink: https://www.hzdr.de/publications/Publ-9909
Publ.-Id: 9909


Investigation of defects induced by ion implantation of noble gases in yttria-stabilized zirconia

Grynszpan, R. I.; Fradin, J.; Saude, S.; Thome, L.; Anwand, W.; Brauer, G.;
Investigation of defects induced by ion implantation of noble gases in yttria-stabilized zirconia
Keywords: defects, ion implantation, zirconia, PAS
  • Lecture (Conference)
    18th International conference on the application of accelerators in research and industry (CAARI2004), 10.-15.10.2004, Ft. Worth/TX, USA

Permalink: https://www.hzdr.de/publications/Publ-9908
Publ.-Id: 9908


Microarrays of miniaturized silicon-based light sources: fabrication and use

Gebel, T.; Rebohle, L.; Yankov, R. A.; Skorupa, W.; Gauglitz, G.; Frank, R.;
Microarrays of miniaturized silicon-based light sources: fabrication and use
Keywords: silicon, light emission, LED
  • Lecture (others)
    Statusseminar “Chiptechnologien, Mikroarrays, Hygiene und Gesundheit”, DECHEMA, Frankfurt/M., 26.-27.01.2004, Frankfurt/M., Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9907
Publ.-Id: 9907


Microstructural characterization of 3C-SiC thin films epitaxially formed by the flash lamp process (FLASIC)

Ferro, G.; Panknin, P.; Polychroniadis, E. K.; Monteil, Y.; Skorupa, W.; Stoemenos, J.;
Microstructural characterization of 3C-SiC thin films epitaxially formed by the flash lamp process (FLASIC)
Keywords: flash lamp, annealing, SiC
  • Lecture (Conference)
    5th Europ. Conf. Silicon Carbide and Related Materials, 31.08.-04.09.2004, Bologna, Italy

Permalink: https://www.hzdr.de/publications/Publ-9906
Publ.-Id: 9906


Positron annihilation spectroscopy of ultra fine-grained metals prepared by severe plastic deformation

Cizek, J.; Prochazka, I.; Kuzel, R.; Matej, Z.; Cherkaska, V.; Cieslar, M.; Smola, B.; Stulikova, I.; Brauer, G.; Anwand, W.; Islamgaliev, R. K.; Kulyasova, O.;
In the present work, positron annihilation spectroscopy (PAS) is employed for microstructure investigations of various ultra fine grained (UFG) metals (Cu, Ni, Fe) prepared by severe plastic deformation (SPD), namely high-pressure torsion (HPT) and equal channel angular pressing (ECAP): Generally, UFG metals prepared using both the techniques exhibit two kinds of defects introduced by SPD: dislocations and small microvoids. The size of the microvoids is determined from the PAS data. Significantly larger microvoids are found in HPT deformed Fe and Ni compared to HPT deformed Cu. The microstructure of UFG Cu prepared by HPT and ECAP is compared and the spatial distribution of defects in UFG Cu samples is characterized. In addition, the mircrostructure of a pure UFG Cu prepared by HPT and HPT deformed Cu+Al2O3 nanocomposite (GlidCop) is compared.
Keywords: PAS
  • Lecture (Conference)
    35th Polish Seminar on Positron Annihilation, 20.-24.09.2004, Turawa, Poland

Permalink: https://www.hzdr.de/publications/Publ-9905
Publ.-Id: 9905


-Hydrogen-induced defects in niobium studied by positron annihilation spectroscopy

Cizek, J.; Prochazka, I.; Kuzel, R.; Becvar, F.; Cieslar, M.; Brauer, G.; Anwand, W.; Kirchheim, R.; Pundt, A.;
Our aim in the present work was to investigate changes of the defect structure of bulk niobium induced by hydrogen loading. The evolution of the microstructure with increasing hydrogen concentration was studied by x-ray diffraction and two complementary techniques of positron annihilation spectroscopies (PAS), namely positron lifetime spectroscopy and slow positron implantation spectroscopy with the measurement of the Doppler broadening, in defect-free Nb (99.9%) and Nb containing a remarkable number of dislocations. These samples were electrochemically loaded with hydrogen up to xH=0.06 [H/Nb], i.e. in the alpha-phase region, and it was found that the defect density increases with hydrogen concentration in both Nb samples. This means that hydrogen-induced defects are created in the Nb samples. A comparison of PAS results with theoretical calculations revealed that vacancy-hydrogen complexes are introduced into the samples due to hydrogen loading. Most probably these are vacancies surrounded by 4 hydrogen atoms.
Keywords: PAS
  • Lecture (Conference)
    The International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications – MH2004, 05.-10.09.2004, Cracow, Poland

Permalink: https://www.hzdr.de/publications/Publ-9904
Publ.-Id: 9904


-Positron annihilation studies of microstructure of ultra fine grained metals prepared by severe plastic deformation

Cizek, J.; Prochazka, I.; Smola, B.; Stulikova, I.; Kuzel, R.; Cieslar, M.; Matej, Z.; Cherkaska, V.; Brauer, G.; Anwand, W.; Islamgaliev, R. K.; Kulyasova, O.;
In the present work, positron annihilation spectroscopy (PAS) is employed for microstructure investigations of various ultra fine grained (UFG) metals (Cu, Ni, Fe) prepared by severe plastic deformation (SPD), namely high-pressure torsion (HPT) and equal channel angular pressing (ECAP): Generally, UFG metals prepared using both the techniques exhibit two kinds of defects introduced by SPD: dislocations and small microvoids. The size of the microvoids is determined from the PAS data. Significantly larger microvoids are found in HPT deformed Fe and Ni compared to HPT deformed Cu. The microstructure of UFG Cu prepared by HPT and ECAP is compared and the spatial distribution of defects in UFG Cu samples is characterized. In addition, the mircrostructure of a pure UFG Cu prepared by HPT and HPT deformed Cu+Al2O3 nanocomposite (GlidCop) is compared.
Keywords: PAS
  • Lecture (Conference)
    Fourth International Conference on Materials Structure and Micromechanics of Fracture (MSMF-4), 23.-25.06.2004, Bro, CZ

Permalink: https://www.hzdr.de/publications/Publ-9903
Publ.-Id: 9903


Photoluminescence of Er doped SiO2 films embedded Si nanoclusters using dual implantation chamber and annealing

Cheng, X. Q.; Sun, J. M.; Kögler, R.; Skorupa, W.; Möller, W.; Prucnal, S.; Zuk, J.;
The photoluminescence of Er doped SiO2 films embedded Si nanoclusters is investigated. These clusters are fabricated by dual ion implantation and annealing.
Keywords: Er doped Si nanoclusters, photoluminescence, dual ion implantation
  • Lecture (Conference)
    5th Int. Conf. on Ion Implantation and other Applications of Ions and Electrons (ION2004), 14.-17.06.2004, Kazimierz Dolny, Poland

Permalink: https://www.hzdr.de/publications/Publ-9902
Publ.-Id: 9902


Potential energy retention of slow highly charged Ar-ions in chemical clean silicon surfaces

Kost, D.; Facsko, S.;
A UHV device with a base pressure of p<10^-9 mbar was connected to the ECR ion source of the Forschungszentrum Rossendorf for improved calorimetric measurements of the retention of the potential energy of highly charged ions. The chemical state of the target surface is controlled by AES using LEED optics. With a clean silicon and gold surface prepared by sputtering using Ar-ions, the retained energy of Ar^q+ (q = 1 up to 9) ions was determined at kinetic energies between q*60 eV and q*200 eV . By extrapolation to zero kinetic energy, the retained fraction of the potential energy is obtained, which is related to the full potential energy given by the ionization potentials. The potential energy retention coefficient results as (0.8 up to 0.9) +- 0.2 and decreases weakly with increasing charge state. This is about three times larger than earlier results with contaminated copper surfaces.
Keywords: highly charged ions, potential energy retention
  • Lecture (Conference)
    DPG-Frühjahrstagung, 08.-12.03.2004, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9901
Publ.-Id: 9901


Deep level defects in He-implanted n-6H-SiC studied by deep level transient spectroscopy

Chen, X. D.; Ling, C. C.; Fung, S.; Beling, C. D.; Wu, H. S.; Brauer, G.; Anwand, W.; Skorupa, W.;
Deep level defects in He-implanted n-6H-SiC are studied by deep level transient spectroscopy.
Keywords: deep levels, SiC, defects, DLTS, ion implantation
  • Lecture (Conference)
    Materials Research Society (MRS), 2004 Spring Meeting, 12.-16.04.2004, San Francisco/ CA, USA

Permalink: https://www.hzdr.de/publications/Publ-9900
Publ.-Id: 9900


Structures of actinide complexes: combining DFT calculations, EXAFS spectroscopy, and thermodynamic speciation

Tsushima, S.; Hennig, C.; Ikeda, A.; Rossberg, A.; Scheinost, A.;
Density functional theory (DFT) calculations in combination with the polarizable continuum model (PCM) are a very useful method for obtaining the structure of actinide complexes in aqueous solution. The accuracy in energy, however, is often not sufficient to find a definite answer on whether ligands are coordinated in monodentate or bidentate fashion [1], pinpointing the limitations of working solely with theoretical calculations. Extended X-ray absorption fine structure (EXAFS) spectroscopy is a powerful experimental method for the determination of structures of aqueous complexes; the limitation is, however, a relatively poor distal resolution and often no information on the spatial orientation, making the resolution of co-existing species difficult. Finally, thermodynamic calculations also do not always provide accurate information.
Therefore, we combined all three methods, DFT, EXAFS, and thermodynamic speciation, to study the speciation and structure of actinide complexes in aqueous solution. We will show examples of uranyl(VI) ligation towards water, carbonate, and sulfate. We will also address the formation of polymeric complexes.
  • Invited lecture (Conferences)
    American Chemical Society 234th National Meeting, Symposium: Computational Actinide and Transactinide Chemistry: Progress and Perspectives, 19.-23.08.2007, Boston, United States

Permalink: https://www.hzdr.de/publications/Publ-9899
Publ.-Id: 9899


Uranium redox chemistry and its importance in nuclear waste disposal

Tsushima, S.; Hennig, C.; Ikeda, A.; Scheinost, A.;
For the safety assessment of geological disposal of spent nuclear fuels, to predict and prevent migration of uranium in the geo-sphere is very important. Uranium can take oxidation states IV, V, and VI in aqueous solution. Its solubility differ several orders of magnitude depending on its oxidation state, but also depends strongly on pH and Eh of the solution and concentrations of co-existing organic/inorganic ligands. In this study, quantum chemical methods (MP2, CASPT2) were used to estimate the redox potential of the U(VI)/U(V) couple and the result was compared with experimental data. Similarly, An(VI)/An(V) redox potentials were also calculated for An = Np, Pu, and Am, and the importance of multi-configurational calculations and the role of spin-orbit effect were discussed.
Uranium may coordinate with various organic/inorganic ligands, and this is also a determining factor of the redox potential. We studied the complexation of uranium(VI) with several inorganic ligands (sulfate, carbonate, etc.) by DFT calculations and also by electrochemistry experiments. The structures of uranium complexes were characterized using EXAFS (extended X-ray absorption fine structure) spectroscopy at the Rossendorf Beamline, European Synchrotron Radiation Facility, in Grenoble, France. DFT and EXAFS were found to provide complementary structural information.
  • Invited lecture (Conferences)
    American Chemical Society 234th National Meeting, Symposium: Computational Electrochemistry for New Energy, 19.-23.08.2007, Boston, United States

Permalink: https://www.hzdr.de/publications/Publ-9898
Publ.-Id: 9898


RBS with high depth resolution using a small magnetic spectrometer

Grötzschel, R.; Klein, C.; Mäder, M.;
Rutherford Backscattering Spectrometry ( RBS) and Elastic Recoil Detection Analysis (ERDA) are well established techniques for quantitative thin film and surface analysis. The advantage of these methods consists in the simple physics they are basing on, namely the stopping of energetic ions in matter and the binary scattering of at the Coulomb potential of atomic nuclei.
In particular RBS with He ions is widely used at many small accelerators utilizing standard surface barrier or implanted silicon detectors with typical depth resolution values of 12 keV, which provides a depth resolution in the order of 10 nm.
The increasing importance of ultra-thin layers for novel technologies demands quantitative analysis techniques with a depth resolution of atomic monolayers, which can be obtained for RBS and ERDA by magnetic spectrometers only.
We operate at the 3 MV Tandetron accelerator a magnetic spectrometer consisting of an UHV scattering chamber and a simple magnet with circular field boundaries (Browne-Buechner spectrometer). Since in many cases of high resolution IBA the samples must be prepared in situ in UHV, the chamber with a base vacuum of 4x10-10 mbar is equipped with an Ar ion sputter gun and two OMICRON EFM3 low rate e-beam evaporators for in situ layer deposition.
A RHEED system is used to check the surface reconstruction and monitor the layer growth. Samples are transferred, together with a BN heater, to the precision 5-axes channelling goniometer . The magnet with a mean radius of 0.65 m is mounted vertically and can be positioned either at 35.5° or 144.5°. The backward position offers the advantage of a high mass resolution, but the Rutherford cross sections are a factor of about 100 lower than at the forward angle, which is the preferred position if kinematically possible.
Using a two-dimensional position sensitive focal plane detector the transversal position provides the possibility for kinematical corrections since the transversal focusing of the magnet is small. A multiple-pad PSD with a pitch of 4 mm is adequate.
This spectrometer is described, recent applications are discussed and as well as he influence of charge state transitions of ions on the obtainable depth resolution will be demonstrated.
  • Invited lecture (Conferences)
    14th Hellenic Symposium on Nuclear Physics, 21.-23.05.2004, Athens, Greece

Permalink: https://www.hzdr.de/publications/Publ-9897
Publ.-Id: 9897


Depth profiling of defects using a slow positron beam

Brauer, G.;
The fundamentals of and recent results on depth profiling of defects in materials by means of a slow positron beam are reported.
Keywords: depth profiling, defects, positron beam, PAS
  • Lecture (Conference)
    35th Polish Seminar on Positron Annihilation, 20.-24.09.2004, Turawa, Polska

Permalink: https://www.hzdr.de/publications/Publ-9896
Publ.-Id: 9896


AFM characterization of 6H-SiC surfaces after ion implantation and annealing

Brauer, G.; Brandstetter, S.; Teichert, C.; Anwand, W.; Skorupa, W.;
6H-SiC surfaces after ion implantation and annealing are characterized by AFM.
Keywords: AFM, SiC surface, ion implantation, annealing
  • Lecture (Conference)
    18th International conference on the application of accelerators in research and industry (CAARI2004), 10.-15.10.2004, Ft. Worth/TX, USA

Permalink: https://www.hzdr.de/publications/Publ-9895
Publ.-Id: 9895


The prototype of the new flash lamp apparatus: experiences, results, comparison old and new equipment

Anwand, W.;
The prototype of the new flash lamp apparatus is discussed and compared with the old equipment. First experiences and results are reported.
Keywords: flash lamp annealing, semiconductor processing
  • Lecture (others)
    EU-Projekttreffen FLASiC, 15.10.2004, Ilmenau, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9894
Publ.-Id: 9894


Chiral Condensate and Open Charm

Kämpfer, B.;
  • Invited lecture (Conferences)
    CBM-Meeting, 15.-16.12.2005, Darmstadt, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9893
Publ.-Id: 9893


Primordiale Nukleosynthese

Kämpfer, B.;
  • Lecture (Conference)
    IKTP, 10.11.2005, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9892
Publ.-Id: 9892


QCD matter within quasi-particle model and the critical end point

Kämpfer, B.;
  • Lecture (Conference)
    Quark Matter 2005, 04.-09.08.2005, Budapest, Hungary

Permalink: https://www.hzdr.de/publications/Publ-9891
Publ.-Id: 9891


Konzeption und prototypische Realisierung einer Datenbankanwendung für die Verwaltung von Betriebsparametern von Ionenstrahlbeschleunigern

Kunze, P.;
Es wird beschrieben, wie eine Datenbank für Betriebswerte eines Teilchenbeschleunigers aufgebaut wurde. Der Schwerpunkt der Betrachtungen liegt dabei auf der Theorie zum Aufbau einer solchen Datenbank.
  • Other report
    Dresden: HTW Dresden, Diplomarbeit, 2005
    50 Seiten

Permalink: https://www.hzdr.de/publications/Publ-9890
Publ.-Id: 9890


Open charm and leptons at RHIC

Kämpfer, B.;
  • Lecture (Conference)
    ECT* - Electromagnetic probes of hot and dense matter, 03.-11.06.2005, Trento, Italy

Permalink: https://www.hzdr.de/publications/Publ-9889
Publ.-Id: 9889


Quasi-particle description of QCD matter

Kämpfer, B.;
  • Lecture (Conference)
    Probing QCD with High Energy Nuclear Collisions, 16.01.2005, Hirschegg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9888
Publ.-Id: 9888


Digitalisierung der Signalverarbeitung eines Rotorvoltmeters

Arnold, S.;
Das Ziel der Diplomarbeit war, auf Basis eines 32-Bit Mikrocontrollers wesentliche Teile der Signalverarbeitung eines Rotorvoltmeters von analoger Schaltungstechnik in eine digitale Verarbeitung zu überführen. Mit diesem Schritt kann das am Institut für Ionenstrahlphysik und Materialforschung des FZR eingesetzte Rotorvoltmeter eines Van-de-Graaff-Ionenbeschleunigers in seiner Anwendung wesentlich verbessert werden. Erwartet werden neben der einfacheren Parametrierung und der erhöhten Flexibilität des Gerätes vor allem auch eine Erhöhung der Stabilität im Betrieb durch den Wegfall von Drifterscheinungen analoger Schaltungstechnik.
  • Other report
    Chemnitz: TU Chemnitz, Diplomarbeit, 2006
    50 Seiten

Permalink: https://www.hzdr.de/publications/Publ-9887
Publ.-Id: 9887


Digitalisierung der Funktion eines Meßgerätes zur Bestimmung der Beschleunigungsspannung von Van-de-Graaff-Ionenbeschleunigern

Voigtländer, G.;
Das Ziel der Diplomarbeit war, auf Basis eines 32-Bit Mikrocontrollers wesentliche Teile der Signalverarbeitung eines Rotorvoltmeters von analoger Schaltungstechnik in eine digitale Verarbeitung zu überführen. Mit diesem Schritt kann das am Institut für Ionenstrahlphysik und Materialforschung des FZR eingesetzte Rotorvoltmeter eines Van-de-Graaff-Ionenbeschleunigers in seiner Anwendung wesentlich verbessert werden. Erwartet werden neben der einfacheren Parametrierung und der erhöhten Flexibilität des Gerätes vor allem auch eine Erhöhung der Stabilität im Betrieb durch den Wegfall von Drifterscheinungen analoger Schaltungstechnik.
  • Other report
    Dresden: HTW Dresden, Diplomarbeit, 2004
    50 Seiten

Permalink: https://www.hzdr.de/publications/Publ-9886
Publ.-Id: 9886


Low-energy tail of the giant dipole resonance in 98Mo and 100Mo deduced from photon-scattering experiments

Rusev, G.; Schwengner, R.; Dönau, F.; Erhard, M.; Grosse, E.; Junghans, A. R.; Kosev, K.; Schilling, K. D.; Wagner, A.; Becvar, F.; Krticka, M.;
Dipole-strength distributions in the nuclides 98Mo and 100Mo up to the neutron-separation energies have been studied in photon-scattering experiments at the superconducting electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf. In order to determine the dipole-strength distribution up to the neutron emission threshold statistical methods were developed for the analysis of the measured spectra. The measured spectra of scattered photons were corrected for detector response and atomic background by simulations using the code GEANT3. Simulations of gamma-ray cascades were performed in order to correct the intensities of ground-state transitions for feeding from high-lying levels and to determine their branching ratios. The photoabsorption cross sections obtained for 98Mo and 100Mo from the present (gamma,gamma) experiments are combined with (gamma,n) data from literature resulting in a photoabsorption cross section covering the full range from 4 to about 15 MeV of interest for nuclear astrophysics network calculations. Novel information about the low-energy tail of the Giant Dipole Resonance and the energy spreading of its strength is derived. The photoabsorption cross sections deduced from the present photon-scattering experiments are compared with existing data from neutron capture and 3He induced reactions.
Keywords: Photon scattering, nuclear structure, giant dipole resonance, dipole strength, photoabsorption cross section

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Permalink: https://www.hzdr.de/publications/Publ-9885
Publ.-Id: 9885


Defect profiling with positrons – recent results on ion implanted 6H-SiC

Anwand, W.; Brauer, G.; Skorupa, W.;
Positron annihilation spectroscopy is used to analyse implantation defects in 6H-SiC.
Keywords: Positron annihilation Spectroscopy, SiC, defects
  • Lecture (Conference)
    Frühjahrstagung des Arbeitskreises “Herstellung und Charakterisierung von massiven GaAs-, InP- und SiC-Kristallen” der Deutschen Gesellschaft für Kristallwachstum und Kristallzüchtung (DGKK),, 31.03.-01.04.2004, Halle (Saale), Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9884
Publ.-Id: 9884


Ionenstrahlmodifikationen magnetischer Schichten

Fassbender, J.ORC
In dem Vortrag werden die neuen Ergebnisse auf dem Gebiet der Cr- bzw. Ni-Implantation in Permalloy vorgestellt. Darüber hinaus wird über erste Ergebnisse der Bestrahlung von FeAl-Legierungen berichtet.
Keywords: ion irradiation, ion implantation, magnetism, permalloy, FeAl
  • Lecture (Conference)
    Workshop zur "Ionenstrahlphysik und Nanotechnologie", 10.-11.05.2007, Bochum, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9883
Publ.-Id: 9883


Early stage of ripple formation on Ge(001) surfaces under near-normal ion beam sputtering

Carbone, D.; Alejandro, A.; Raul, G.; Facsko, S.; Plantevin, O.; Metzger, T. H.;
We present a study of the early stage of ripple formation on Ge(001) surfaces irradiated by a 1 keV Xe+ ion beam at room temperature and near-normal incidence. A combination of a grazing incidence x-ray scattering technique and atomic force microscopy allowed us to observe a variation of the symmetry of the surface nanopattern upon increase of the ion fluence. The isotropic dot pattern formed during the first minutes of sputtering evolves into an anisotropic ripple pattern for longer sputtering time. These results provide a new basis for further steps in the theoretical description of the morphology evolution during ion beam sputtering.
Keywords: ion beam sputtering, nanostructures

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Permalink: https://www.hzdr.de/publications/Publ-9882
Publ.-Id: 9882


Polymorphism in Liquid Crystals from Star-shaped Mesogens

Gemming, S.; Popov, I.; Lehmann, M.;
Star-shaped molecules based on a phloroglucinol core with three oligobenzoate arms are powerful mesogens, that can be combined to columnar liquid crystalline materials and to soft organic crystals. The structural properties of such modern materials exhibit polymorphism at two different length scales. On the molecular level, the mesogens are highly flexible molecules with a large variety of almost isoenergetic conformers of different propensity towards a regular stacking in the bulk phase. On the supramolecular level, polymorphic structures occur, which comprise different liquid crystalline phases with anisotropic columnar order and soft crystals with a more isotropic three-dimensional ordering. For the smallest mesogen the present experimental structure data and computational results give evidence that the two forms of polymorphism are linked. Columnar liquid crystals form from a low-symmetry, folded conformer, which already accounts for the nano-segregation of the planar aromatic centre and the flexible aliphatic chain parts of the mesogen, whereas the soft, more isotropic crystals are grown from the C3-symmetric, star-shaped conformer. Molecular dynamics simulations confirm the stability of each structure at room temperature.
Keywords: liquid crystals, polymorphism, computer modelling, density-functonal methods

Permalink: https://www.hzdr.de/publications/Publ-9881
Publ.-Id: 9881


Comparison of different buncher cavity designs for the 4GLS ERLP

Wooldridge, E.; Beard, C. D.; Gerth, C.; Büchner, A.;
A DC photocathode gun is part of the injector of the Energy Recovery Linac Prototype (ERLP) presently being built at Daresbury Laboratory. A buncher is required for the ERLP downstream of the photocathode gun to decrease the relatively long bunches (20-30ps) from the GaAs cathode. Three different single-cell cavity designs were investigated: the Cornell buncher, the ELBE buncher and an EU cavity without Higher Order Mode (HOM) dampers. The properties of these cavities were studied with the computer codes CSTs Microwave Studio and ASTRA. The fundamental frequency and field pattern of each buncher was investigated in Microwave Studio. The EU cavity was scaled from 500MHz to the required frequency for the buncher of 1.3GHz. As the anticipated kinetic energy of the electron beam after the gun is about 350keV a particle tracking code including the space charge forces is mandatory to study the effect of the different buncher cavity designs on the beam dynamics. The particle tracking code ASTRA was used to study the performance of the bunchers for a variety of beam parameters. From these investigations it was found that the three bunchers produce very similar effects on the particle bunch.
Keywords: ELBE; RF; Buncher; Injector
  • Poster
    EPAC 2004, 05.-09.07.2004, Luzern, Schweiz
  • Contribution to proceedings
    EPAC 2004, 05.-09.07.2004, Luzern, Schweiz
    Proceedings of EPAC 2004: European Physical Society Accelerator Group, 92-9083-232-0, 467-469

Permalink: https://www.hzdr.de/publications/Publ-9880
Publ.-Id: 9880


FIB induced growth of antimony nanowires

Schoendorfer, C.; Lugstein, A.; Bischoff, L.; Hyun, Y. J.; Pongratz, P.; Bertagnolli, E.;
The impact of high energy Ga ion beams focused to diameters below 100 nm on antimony (Sb) substrates offers a new approach for the formation of pure Sb nanowires. In contrast to several well-known processes for bottom–up fabrication of one-dimensional nanostructures, for this process neither additional temperature treatment nor any additional material component is needed. Initially, the resulting nanostructures are completely amorphous and show very homogeneous diameters in the range of 20 nm. Lengths up to several microns can be achieved. Annealing at temperatures around 150 °C leads to re-crystallization of these nanowires.
Keywords: Nanowires; Nanofibers; Quantum wires; Antimony; Sb; Focused ion beam; FIB
  • Microelectronic Engineering 84(2007)5-8, 1440-1442

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Permalink: https://www.hzdr.de/publications/Publ-9879
Publ.-Id: 9879


Nuclear astrophysics measurements with photo-neutrons and bremsstrahlung at ELBE

Junghans, A. R.;
  • Lecture (others)
    Physikalisch-Technische Bundesanstalt Dep. 6.4, 01.09.2005, Braunschweig, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9876
Publ.-Id: 9876


Search for pygmy strength in Molybdenum isotopes close to particle separation energies

Grosse, E.;
  • Lecture (Conference)
    Nuclear Physics in Astrophysics-II, 16.-20.05.2005, Debrecen, Hungary

Permalink: https://www.hzdr.de/publications/Publ-9875
Publ.-Id: 9875


Sterne und Kerne - Die Entstehung der chemischen Elemente durch nukleare Prozesse in Urknall, Sternen und Supernovae

Grosse, E.;
  • Lecture (others)
    Tag der offenen Tür, 30.04.2005, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9874
Publ.-Id: 9874


Energie aus der Kernfusion und aus der Kernspaltung

Grosse, E.;
  • Lecture (others)
    Jugendzentrum Pi, 03.03.2005, Freiberg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9873
Publ.-Id: 9873


Isovector Proton-Neutron Pairing

Frauendorf, S.;
  • Lecture (Conference)
    INT Program 05-3: Nuclear Structure Near the Limits of Stability, 14.11.2005, Seattle, USA

Permalink: https://www.hzdr.de/publications/Publ-9872
Publ.-Id: 9872


New Symmetries of rotating nuclei

Frauendorf, S.;
  • Lecture (Conference)
    Colloquium, Physics Division, 15.-16.12.2005, Argonne, USA

Permalink: https://www.hzdr.de/publications/Publ-9871
Publ.-Id: 9871


Infrarotspektroskopie an Proteinen: Fluoreszenz-IR-Kreuzkorrelation

Fahmy, K.;
  • Lecture (Conference)
    Anwendertreffen Bruker Ettlingen, 28.11.2005, Ettlingen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9870
Publ.-Id: 9870


Structure and pH sensitivity of transmembrane helix 3 of rhodopsin

Fahmy, K.;
  • Lecture (Conference)
    European Conference on the Spectroscopy of Biological Molecules, 06.09.2005, Aschaffenburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9869
Publ.-Id: 9869


Coupling of helix 8 of rhodopsin to the retinal Schiff base studied by infrared and fluorescence cross-correlation spectroscopy

Fahmy, K.;
  • Lecture (Conference)
    Sektionstagung Deutsche Gesellschaft für Biophysik, 05.05.2005, Münster, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9868
Publ.-Id: 9868


Infrared and fluorescence spectroscopic studies on molecular switching by G protein.coupled receptors

Fahmy, K.;
  • Lecture (others)
    Deutsche Universität in Kairo, 22.03.2005, Kairo, Egypt

Permalink: https://www.hzdr.de/publications/Publ-9867
Publ.-Id: 9867


Molecular switching by GPCRs

Fahmy, K.;
  • Lecture (others)
    Université Strasbourg, 21.02.2005, Strasbourg, France
  • Lecture (others)
    Universität Osnabrück, 19.04.2005, Osnabrück, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9866
Publ.-Id: 9866


High resolution grazing incidence diffraction on lateral nanostructures created by focused ion beam implantation on semiconductor surfaces

Grenzer, J.; Bischoff, L.; Posselt, M.; Pietsch, U.;
  • Lecture (Conference)
    Deutsche Tagung für Forschung mit Synchrotronstrahlung, Neutronen und Ionenstrahlen an Grossgeräten (SNI-2006), 04.-06.10.2006, Hamburg, Germany

Permalink: https://www.hzdr.de/publications/Publ-9865
Publ.-Id: 9865


X-ray studies of semiconductor surfaces modified by focused ion beam implantation

Grenzer, J.; Bischoff, L.; Posselt, M.; Pietsch, U.;
  • Lecture (Conference)
    8th Biennial Conference on High Resolution X-ray Diffraction and Imaging, 19.-22.09.2006, Karlsruhe, Germany
  • Lecture (Conference)
    Deutsche Tagung für Forschung mit Synchrotronstrahlung, Neutronen und Ionenstrahlen an Grossgeräten (SNI-2006), 04.-06.10.2006, Hamburg, Germany

Permalink: https://www.hzdr.de/publications/Publ-9864
Publ.-Id: 9864


Influence of energetic ions on the L10 ordering of FePt films fabricated by magnetron sputtering

Cantelli, V.; von Borany, J.; Grenzer, J.; Fassbender, J.ORC
Due to the high uniaxial anisotropy L10-ordered FePt is currently the most favored candidate for future high density storage applications. With respect to a feasible fabrication technology, it is necessary (i) to produce such films on amorphous substrates, and (ii) to enable a low processing temperature (T<400°C). FePt films deposited at RT only exhibit the face-centered cubic A1-phase. Thus, either deposition or a post-deposition heat treatment at temperatures above typically 500°C is required, in order to achieve the L10-phase. We report on the L10 ordering of stoichiometric FePt thin films fabricated on SiO2/Si substrates by magnetron sputtering at various temperatures (RT - 400°C). Using a low deposition rate of about 0.6 Å/s and an Ar pressure of 0.3 Pa the ion/atom-ratio during deposition is » 1 where the ions exhibit energies of about 20 eV. In addition, FePt films have been irradiated subsequently with He ions of 50 keV and fluencies between 1x1015 and 3x1016 cm−2 for comparison. The kinetics of A1-L10 transition and ordering have been investigated with in-situ X-ray diffraction at the Synchrotron-beamline ROBL at ESRF. L10 ordered FePt films with an ordering parameter S=0.8 have been achieved already for an overall process temperature below 350°C. The results are discussed in terms of ion-assisted activation and segregation which supports the atomic relocation during L10 ordering.
Keywords: FePt, L10 transition, magnetron sputtering, ion irradiation
  • Lecture (Conference)
    15th Intn Conf. on Ion Beam Modification of Materials, 18.-22.09.2006, Taormina, Italy

Permalink: https://www.hzdr.de/publications/Publ-9863
Publ.-Id: 9863


Structural studies of ion beam synthesized nanocrystals: diamond in SiC and SiC in diamond

Eichhorn, F.; Heera, V.; Weishart, H.; Schell, N.;
  • Lecture (Conference)
    13th ESRF User Meeting, 12.02.2003, Grenoble, France

Permalink: https://www.hzdr.de/publications/Publ-9862
Publ.-Id: 9862


The Rossendorf CRG Beamline ROBL for radiochemistry and materials research

Schell, N.;
  • Lecture (others)
    Institute of Physics of the Academy of Sciences, 11.09.2003, Warsaw, Poland

Permalink: https://www.hzdr.de/publications/Publ-9861
Publ.-Id: 9861


Melt stirring during directional solidification using modulated magnetic fields

Willers, B.; Räbiger, D.; Dong, J.; Eckert, S.; Nikrityuk, P. A.; Eckert, K.;
The imposition of an RMF on a solidifying metal column causes problems like the occurrence of typical segregation pattern or a deflection of the upper free surface leading to surface defects or the entrainment of gas. The RMF application provides a permanent radial inward flow along the solidification front. Such flow is responsible for the transport of solute to the axis of the ingot resulting in typical freckle segregation pattern in form of vertical channels filled with alloy of eutectic composition. In this paper we present a new innovative method of electromagnetic stirring using a modulated RMF which offers a considerable potential for a well-aimed modification of casting properties Solidification experiments as well as numerical simulations were carried out considering the directional solidification of Pb Sn alloys from a water cooled copper chill. A modulated rotating magnetic field (RMF) was applied for melt agitation. Thermocouples were used to measure the temperature field during solidification. The velocity field in the liquid phase was determined by means of Ultrasound Doppler velocimetry (UDV). Our numerical model is based on the classical mixture formulation. The comparison between numerical simulations and solidification experiments delivered a good agreement. Our results demonstrate the modulation magnetic field enables an effective control of the flow field and the structure of the solidified samples. Modifications of the grain structure and macrosegregation effects are discussed with respect to the details of the flow field.
Keywords: solidification, Pb-Sn alloys, convection, rotating magnetic field, Ultrasound Doppler Velocimetry
  • Lecture (Conference)
    EUROMAT2007 - European Congress on Advanced Materials and Processes, 10.-13.09.2007, Nürnberg, Germany

Permalink: https://www.hzdr.de/publications/Publ-9860
Publ.-Id: 9860


Materials research with synchrotron radiation at the Rossendorf Beamline ROBL at ESRF

Schell, N.;
  • Lecture (others)
    University of Sao Paulo, 20.03.2003, Sao Paulo, Brazil
  • Lecture (others)
    CENIMAT F.C.T./Universidade Nova de Lisboa, 04.04.2003, Lisbon, Portugal

Permalink: https://www.hzdr.de/publications/Publ-9859
Publ.-Id: 9859


PET-guided Radiotherapy - Fact or Fiction

Enghardt, W.;
  • Invited lecture (Conferences)
    Workshop of the Belgian Foundation against Cancer Emerging Hadron Therapy Projects in Europe, 13.11.2005, Brüssel, Belgium

Permalink: https://www.hzdr.de/publications/Publ-9858
Publ.-Id: 9858


Heavy Ion Tumour Therapy and In-Beam Position Emission Tomography

Enghardt, W.;
  • Lecture (others)
    TU Dresden, 06.06.2005, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9857
Publ.-Id: 9857


Data Processing for In-Beam Position Emission Tomography

Enghardt, W.;
  • Invited lecture (Conferences)
    Real Time Conf. 2005, 08.06.2005, Stockholm, Sweden

Permalink: https://www.hzdr.de/publications/Publ-9856
Publ.-Id: 9856


Zentrum für Innovationskompetenz für Medizinische Strahlenforschung in der Onkologie Dresden

Enghardt, W.;
  • Lecture (others)
    Berufsakademie Riesa, 31.05.2005, Riesa, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9855
Publ.-Id: 9855


In-beam PET bei der Krebstherapie mit Ionenstrahlen

Enghardt, W.;
  • Invited lecture (Conferences)
    Atominst. der österreichischen Univ., 13.04.2005, Wien, Austria

Permalink: https://www.hzdr.de/publications/Publ-9854
Publ.-Id: 9854


PET-geführte Strahlentherapie - Vision oder Realität

Enghardt, W.;
  • Lecture (others)
    Medizinische Fakultät, 17.01.2005, Dresden, Deutschland
  • Lecture (Conference)
    GDC Jahrestagung 2005, Fachgruppe Nuklearchemie, 12.09.2005, Düsseldorf, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9853
Publ.-Id: 9853


RPC detectors at ELBE

Dohrmann, F.;
  • Lecture (Conference)
    CBM Collab. Meeting, 10.09.2005, Piaski, Poland

Permalink: https://www.hzdr.de/publications/Publ-9852
Publ.-Id: 9852


Testing RPC detectors at ELBE

Dohrmann, F.;
  • Lecture (Conference)
    HADES Collab. Meeting, 10.06.2005, Dubna, Russia

Permalink: https://www.hzdr.de/publications/Publ-9851
Publ.-Id: 9851


Tests of RPC detectors at ELBE: Status report

Dohrmann, F.;
  • Lecture (Conference)
    CBM Collab. Meeting, 10.03.2005, Darmstadt, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9850
Publ.-Id: 9850


Quasiparticle Model of QCD Matter and the QCD Critical End Point

Bluhm, M.;
  • Lecture (others)
    Universität Bielefeld, 20.09.2005, Bielefeld, Deutschland
  • Lecture (Conference)
    VI Workshop, 07.10.2005, Prerow, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-9849
Publ.-Id: 9849


Strongly Interaction Matter within a Quasiparticle Perspective with Critical End Point Effects

Bluhm, M.;
  • Lecture (Conference)
    Extreme QCD, 04.08.2005, Swansea, England

Permalink: https://www.hzdr.de/publications/Publ-9848
Publ.-Id: 9848


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