Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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34106 Publications

Ergebnisse der Streukorrektur für PET bei der Schwerionentherapie

Pönisch, F.; Enghardt, W.

no abstract

  • Poster
    Verhandlungen der Deutschen Physikalischen Gesellschaft Spring Meeting Münster 2002 Nuclear Physics, S. 44

Permalink: https://www.hzdr.de/publications/Publ-5533
Publ.-Id: 5533


Attenuation and Scatter Correction in Fully 3D Limited Angle PET

Pönisch, F.; Enghardt, W.; Lauckner, K.

The in-beam dual head positron camera BASTEI (Beta+ Activity meaSurements at the Therapy with Energetic Ions) is used to monitor and control the applied dose distributions simultaneously to tumor irradiations with carbon ion beams at the experimental heavy ion therapy facility at GSI Darmstadt. Therefore, the PET system has been mounted directly at the treatment site. A fully 3D reconstruction algorithm based on the Maximum Likelihood Expectation Maximization algorithm has been developed and adapted to a spatially varying imaging situation. The scatter and attenuation correction is applied to the measured list mode data before each iterative step. This requires an attenuation map containing the information on the tissue composition and densities. This information is derived from the X-ray computed tomograms (CT) of the patient and the patient fixation system including the head rest. The scatter correction is included into the forward projection step of the Maximum Likelihood image reconstruction. The normalization of scattered events relative to the unscattered events is done by a global scatter fraction factor. The results are presented.

  • Poster
    Proc. IEEE Nuclear Science Symposium and Medical Imaging Conference, San Diego, USA (2001) M13B-23
  • Contribution to proceedings
    Proc. IEEE Nuclear Science Symposium and Medical Imaging Conference, San Diego, USA (2001) M13B-23

Permalink: https://www.hzdr.de/publications/Publ-5532
Publ.-Id: 5532


A Fully 3D Maximum Likelihood Estimator Algorithm with Attenuation and Scatter Correction Adapted to a Limited Angle Positron Camera

Pönisch, F.; Enghardt, W.

The in beam dual head positron camera BASTEI (Beta+ Activity meaSurements at the Therapy with Energetic Ions) is used to monitor and control the applied dose distributions simultaneously to the irradiation of the therapeutic carbon ion beam at the experimental heavy ion therapy facility at GSI Darmstadt. Therefore, the PET system is mounted directly at the treatment site. A fully 3D reconstruction algorithm based on the Maximum Likelihood Estimator algorithm has been developed and adapted to a strongly spatially-varying imaging situation. A scatter and attenuation correction is applied to the measured listmode data prior to the image reconstruction. The scatter correction method uses the subtraction of scattered data from measured data.
In this particular PET-application the fluence of registered events at the detector surface is in the order of 10 to 102 cm-2 compared with about 102 to 103 cm-2 in conventional PET in nuclear medicine. The emission data are acquired in a 3D list mode. Since less than 100,000 out of approximately 4 millions coincidence channels typically contribute to the reconstruction all detected events have to be utilized. In addition, they cannot be sorted into sinograms because the necessary interpolation procedures would generate additional noise. Therefore the reconstruction algorithm takes the original emission data as input. The non-zero elements of the 3D transition matrix are calculated at run-time using a Monte-Carlo code that models the individual crystal responses along each coincidence channel. Results of the performance studies as well as examples of use are presented.

  • Poster
    Proc. F3D-2001 The Sixth International Meeting on Fully Three-Dimensional Image reconstruction in Radiology and Nuclear Medicine, Pacific Groove, USA (2001)
  • Contribution to proceedings
    Proc. F3D-2001 The Sixth International Meeting on Fully Three-Dimensional Image reconstruction in Radiology and Nuclear Medicine, Pacific Groove, USA (2001)

Permalink: https://www.hzdr.de/publications/Publ-5531
Publ.-Id: 5531


Proposal for a dedicated ion beam facility for cancer therapy.

Debus, J.; Wannenmacher, M.; Ertner, D.; Fuss, M.; Heeg, P.; Wenz, F.; Zur Hausen, H.; Bendel, R.; Bortfeld, T.; Hartmann, G.; Jäkel, O.; Karger, C.-P.; Kriessbach, A.; Lappe, C.; Massimino, M.; Ölfke, U.; Schlegel, W.; Specht, H.-J.; Angert, N.; Badura, E.; Becher, W.; Böhne, D.; Brand, H.; Brusasco, C.; Dolinskij, A.; Eickhoff, H.; Essel, H.-G.; Franzcak, B.; Geiss, O.; Haberer, T.; Hoffmann, J.; Krämer, M.; Kraft, G.; Kraft-Weyrather, W.; Krause, U.; Kurz, N.; Langenbeck, B.; Ott, W.; Pavlovic, M.; Poppensieker, K.; Richter, M.; Schardt, D.; Schempp, A.; Schlitt, B.; Scholz, M.; Spiller, P.; Steiner, R.; Stelzer, H.; Voss, B.; Weber, U.; Pobell, F.; Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pawelke, J.; Sobiella, M.

The Radiologische Universitätsklinik Heidelberg, the Deutsche Krebsforschungszentrum Heidelberg (DKFZ) and the Gesellschaft für Schwerionenforschung Darmstadt (GSI) in cooperation with the Forschungszentrum Rossendorf jointly propose to build a hospital-based ion beam facility for tumour therapy in Heidelberg, Germany. Compared to conventional photon radiation, the use of ion beams in cancer therapy has a number of principal advantages which allow the effective tumour dose to be raised while the surrounding healthy tissue can be spared. The proposed facility is capable of treating some 1,000 patients per year. It centers around a synchrotron of 20 meters in diameter which will provide beams of protons, helium, carbon and oxygen ions with energies between 50 and 430 MeV per nucleon. Three therapy rooms will be available, two equipped with gantry systems for multifield irradiation and one with a fixed horizontal beam. The facility will make use of major innovations made in particle therapy during recent years, amongst them: the intensity-controlled rasterscan technique for a 3D tumour-conformal dose delivery, the in-situ verification of the beam position by positron emission tomography (PET), and the realisation of a biologically optimised treatment planning.
All these new developments were successfully realised and tested within a pilot project for ion beam therapy at the accelerator complex of GSI. Already the first patient treatments performed at the pilot facility demonstrated the realibility and clinical applicability of the newly developed techniques. The proposed facility is thus the next step on the path to establish clinical ion beam therapy in Germany and Europe, including techniques which are presently unique on a world-wide scale.

  • Other report
    K.D. Groß, M. Pavlovic (Eds.), D.O.G. Digital-Offsetdruck Gass, Darmstadt (September 1998)

Permalink: https://www.hzdr.de/publications/Publ-5530
Publ.-Id: 5530


Ionenstrahlen werden sichtbar: Tumortherapie-Kontrolle mit PET - vom Kohlenstoff zu den Protonen.

Enghardt, W.; Parodi, K.; Pawelke, J.; Pönisch, F.

no abstract

  • Contribution to HZDR-Annual report
    Wissenschaftlich-Technische Berichte / Helmholtz-Zentrum Dresden-Rossendorf; FZR-349 Januar 2003, 47-52
    ISSN: 1437-322X

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-5529
Publ.-Id: 5529


Positronen-Emissions-Tomographie für die Qualitätssicherung bei der Schwerionen-Tumortherapie.

Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pawelke, J.; Sobiella, M.

Bei der Gesellschaft für Schwerionenforschung in Darmstadt ist in den vergangenen Jahren eine experimentelle Anlage für die Krebstherapie mit Strahlen schwerer Ionen errichtet worden. Im Herbst 1997 sollen dort die ersten Tumorpatienten mit 12C Strahlen behandelt werden. Bei der Installation der Anlage und ihrem künftigen Betrieb kooperieren die Gesellschaft für Schwerionenforschung Darmstadt (GSI), das Deutsche Krebsforschungszentrum in Heidelberg (DKFZ), die Radiologischen Kliniken der Universitäten Heidelberg und Magdeburg sowie das Forschungszentrum Rossendorf. Der Rossendorfer Beitrag zur Therapieanlage besteht in der Entwicklung und Realisierung von Verfahren, welche die Positronen-Emissions-Tomographie (PET) für die Kontrolle der Schwerionen-Tumortherapie anwenden. Mit der Installation des in Rossendorf gebauten Positronen-Emissions-Tomographen am Therapieplatz in Darmstadt im Januar 1996 konnten die methodischen Vorarbeiten zum Einsatz von PET für die Tumortherapie mit schweren Ionen beginnen.

  • Other report
    H. Grünberg, W. Wendler (Eds.), Forschungszentrum Rossendorf Jahresbericht 1996, Initial Satz & Grafik Studio Rossendorf (1997) 29-35

Permalink: https://www.hzdr.de/publications/Publ-5528
Publ.-Id: 5528


PET bei der Krebstherapie mit 12C-Strahlen: Resultate der ersten klinischen Anwendungen.

Pönisch, F.; Debus, J.; Enghardt, W.; Haberer, T.; Hasch, B.-G.; Hinz, R.; Jäkel, O.; Krämer, M.; Lauckner, K.; Pawelke, J.; Poppensieker, K.

no abstract

  • Lecture (Conference)
    Frühjahrstagung des Fachverbandes Physik der Hadronen und Kerne der Deutschen Physikalischen Gesellschaft, Freiburg, 22-26 Mar, 1999
    Verhandl. DPG, Vol. 34, No. VI (1999) 114
  • Contribution to proceedings
    Frühjahrstagung des Fachverbandes Physik der Hadronen und Kerne der Deutschen Physikalischen Gesellschaft, Freiburg, 22-26 Mar, 1999
    Verhandl. DPG, Vol. 34, No. VI (1999) 114

Permalink: https://www.hzdr.de/publications/Publ-5527
Publ.-Id: 5527


Comparison between the in-beam and the out-of-beam methods for PET control of carbon ion therapy.

Pawelke, J.; Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Yoshikawa, K.; Tomitani, T.; Kanazawa, M.; Kanai, T.; Tsujii, H.

no abstract

  • Lecture (Conference)
    Fifth Biennial ESTRO Meeting on Physics for Clinical Radiotherapy, Göttingen, 6-11 Apr, 1999
    Radiother. Oncol., Vol. 51, Suppl. 1 (1999) S7
  • Contribution to proceedings
    Fifth Biennial ESTRO Meeting on Physics for Clinical Radiotherapy, Göttingen, 6-11 Apr, 1999
    Radiother. Oncol., Vol. 51, Suppl. 1 (1999) S7

Permalink: https://www.hzdr.de/publications/Publ-5526
Publ.-Id: 5526


Quasi-monochromatic X-rays from the ELBE radiation source.

Enghardt, W.; Lehnert, U.; Naumann, B.; Neubert, W.; Pawelke, J.; Prade, H.; Wagner, W.

no abstract

  • Poster
    18th International Conference on X-Ray and Inner-Shell Processes, Chicago, USA, 23-27 Aug, 1999
    Book of Abstracts (1999) 330
  • Contribution to proceedings
    18th International Conference on X-Ray and Inner-Shell Processes, Chicago, USA, 23-27 Aug, 1999
    Book of Abstracts (1999) 330

Permalink: https://www.hzdr.de/publications/Publ-5525
Publ.-Id: 5525


Simultaneous monitoring of heavy-ion therapy by positron emission tomography.

Hinz, R.; Enghardt, W.; Hasch, B.-G.; Lauckner, K.; Pawelke, J.; Pönisch, F.; Sobiella, M.

no abstract

  • Lecture (Conference)
    Sixth International Conference on Medical Physics, Patras, Hellas, 1-4 Sep, 1999
    Physica Medica, Vol. XV, No. 3 (1999) 157
  • Contribution to proceedings
    Sixth International Conference on Medical Physics, Patras, Hellas, 1-4 Sep, 1999
    Physica Medica, Vol. XV, No. 3 (1999) 157

Permalink: https://www.hzdr.de/publications/Publ-5524
Publ.-Id: 5524


Positronen-Emissions-Tomographie zur retrospektiven Dosislokalisation bei der Schwerionen-Tumortherapie.

Enghardt, W.; Hinz, R.; Lauckner, K.; Pawelke, J.; Pönisch, F.

no abstract

  • Lecture (Conference)
    Wiss. Konferenz der WGL über Naturwissenschaftlich-Technische Beiträge zur modernen Entwicklung der Medizin, München, 13 Okt, 1999
    Zusammenfassung der Beiträge, Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz, Bonn (1999) 32
  • Contribution to proceedings
    Wiss. Konferenz der WGL über Naturwissenschaftlich-Technische Beiträge zur modernen Entwicklung der Medizin, München, 13 Okt, 1999
    Zusammenfassung der Beiträge, Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz, Bonn (1999) 32

Permalink: https://www.hzdr.de/publications/Publ-5523
Publ.-Id: 5523


PET zur Qualitätskontrolle der Schwerionen-Tumortherapie.

Pönisch, F.; Debus, J.; Enghardt, W.; Haberer, T.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pawelke, J.

no abstract

  • Lecture (Conference)
    5. Deutscher Kongreß für Radioonkologie, Strahlenbiologie und Medizinische Physik, Karlsruhe, 6-9 Nov, 1999
    Strahlenther. Onkol., Band 175, Sondernr. 1 (1999) 143
  • Contribution to external collection
    5. Deutscher Kongreß für Radioonkologie, Strahlenbiologie und Medizinische Physik, Karlsruhe, 6-9 Nov, 1999
    Strahlenther. Onkol., Band 175, Sondernr. 1 (1999) 143

Permalink: https://www.hzdr.de/publications/Publ-5522
Publ.-Id: 5522


A project for radiobiological studies with channeling radiation.

Panteleeva, A.; Enghardt, W.; Lehnert, U.; Pawelke, J.; Prade, H.; Dörr, W.; Dörschel, B.

no abstract

  • Lecture (Conference)
    3. Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Dresden, 29-01 Sep/Okt, 1999
    W. Dörr (Ed.), Book of Abstracts (ISBN 3-00-004964-9) (1999) 25
  • Contribution to proceedings
    3. Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Dresden, 29-01 Sep/Okt, 1999
    W. Dörr (Ed.), Book of Abstracts (ISBN 3-00-004964-9) (1999) 25

Permalink: https://www.hzdr.de/publications/Publ-5521
Publ.-Id: 5521


In-situ Kontrolle der Strahlentherapie mit Schwerionen durch Positronen-Emissions-Tomographie.

Pawelke, J.; Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pönisch, F.; Sobiella, M.

no abstract

  • Lecture (Conference)
    3. Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Dresden, 29-01 Sep/Okt, 1999
    W. Dörr (Ed.), Book of Abstracts (ISBN 3-00-004964-9) (1999) 32
  • Contribution to proceedings
    3. Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Dresden, 29-01 Sep/Okt, 1999
    W. Dörr (Ed.), Book of Abstracts (ISBN 3-00-004964-9) (1999) 32

Permalink: https://www.hzdr.de/publications/Publ-5520
Publ.-Id: 5520


The potential of in-beam PET for proton therapy monitoring: first experimental investigation

Parodi, K.; Enghardt, W.; Haberer, T.

  • Lecture (Conference)
    Verhandl. Fruejahrstagung der DPG, Physik der Hadronen und Kerne, Muenster, Maerz 11-15, 2002
  • Contribution to proceedings
    Verhandl. Fruejahrstagung der DPG, Physik der Hadronen und Kerne, Muenster, Maerz 11-15, 2002

Permalink: https://www.hzdr.de/publications/Publ-5519
Publ.-Id: 5519


Potential capabilities of positron emission tomography for quality assurance of proton therapy

Parodi, K.; Enghardt, W.

  • Lecture (Conference)
    XXXIII PTCOG -Meeting, Berlin, Sept. 25-27, 2000
    Book of Abstract
  • Contribution to proceedings
    XXXIII PTCOG -Meeting, Berlin, Sept. 25-27, 2000
    Book of Abstract

Permalink: https://www.hzdr.de/publications/Publ-5518
Publ.-Id: 5518


Cell survival studies after X-ray irradiation.

Panteleeva, A.; Enghardt, W.; Lehnert, U.; Pawelke, J.; Prade, H.; Dörr, W.; Dörschel, B.

no abstract

  • Lecture (Conference)
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)
  • Contribution to proceedings
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)

Permalink: https://www.hzdr.de/publications/Publ-5517
Publ.-Id: 5517


A device for cell irradiation with low energy quasi-monochromatic photons at ELBE.

Pawelke, J.; Enghardt, W.; Lehnert, U.; Naumann, B.; Neubert, W.; Panteleeva, A.; Prade, H.; Wagner, W.

no abstract

  • Lecture (Conference)
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)
  • Contribution to proceedings
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)

Permalink: https://www.hzdr.de/publications/Publ-5516
Publ.-Id: 5516


The potential of positron emission tomography for the monitoring of proton therapy

Parodi, K.; Crespo, P.; Enghardt, W.; Hinz, R.; Lauckner, K.; Pawelke, J.; Pönisch, F.

  • Poster
    7th Workshop on Heavy Charged Particles in Biology and Medicine, Darmstadt , Sept. 28-30, 2000
    GSI Report 2000-4

Permalink: https://www.hzdr.de/publications/Publ-5515
Publ.-Id: 5515


Quasi-monochromatic X-rays from ELBE.

Wagner, W.; Enghardt, W.; Lehnert, U.; Naumann, B.; Neubert, W.; Panteleeva, A.; Pawelke, J.; Prade, H.

no abstract

  • Lecture (Conference)
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)
  • Contribution to proceedings
    Workshop on X-rays from electron beams, Dresden, 24-26 Feb, 2000
    H. Prade (Ed.), Wissenschaftlich-Technische Berichte, Forschungszentrum Rossendorf, FZR-287 (ISSN 1437-322X) (2000)

Permalink: https://www.hzdr.de/publications/Publ-5514
Publ.-Id: 5514


Schwächungs- und Streukorrektur für die Positronen-Emissions-Tomografie (PET) bei der Schwerionentherapie.

Lauckner, K.; Enghardt, W.; Hinz, R.; Pawelke, J.; Pönisch, F.

no abstract

  • Lecture (Conference)
    Frühjahrstagung des Fachverbandes Physik der Hadronen und Kerne der Deutschen Physikalischen Gesellschaft, Dresden, 20-24 Mar, 2000
    Verhandl. DPG, Vol. 35, No. VI (2000) 212
  • Contribution to proceedings
    Frühjahrstagung des Fachverbandes Physik der Hadronen und Kerne der Deutschen Physikalischen Gesellschaft, Dresden, 20-24 Mar, 2000
    Verhandl. DPG, Vol. 35, No. VI (2000) 212

Permalink: https://www.hzdr.de/publications/Publ-5513
Publ.-Id: 5513


Improvements of the FLUKA simulation code for radiobiological applications

Parodi, K.; Squarcia, S.

  • Poster
    Fruehjahrstagung der DPG Physik der Hadronen und Kerne, Dresden, 20-24 Maerz 2000
    Verhandl. DPG (VI) 35 (2000) 218

Permalink: https://www.hzdr.de/publications/Publ-5512
Publ.-Id: 5512


Radiobiological studies with soft X-rays.

Panteleeva, A.; Enghardt, W.; Lehnert, U.; Pawelke, J.; Prade, H.; Dörr, W.; Dörschel, B.; Brankovic, K.; Slonina, D.

no abstract

  • Poster
    30th Annual Meeting of the European Society for Radiation Biology, Waszawa, Poland, 27-31 Aug, 2000
    Book of Abstracts (2000) 55
  • Contribution to proceedings
    30th Annual Meeting of the European Society for Radiation Biology, Waszawa, Poland, 27-31 Aug, 2000
    Book of Abstracts (2000) 55

Permalink: https://www.hzdr.de/publications/Publ-5511
Publ.-Id: 5511


An Ultrafast Time-Resolved Fluorescence Spectroscopy System for Metal Ion Complexation Studies with Organic Ligands

Geipel, G.; Acker, M.; Vulpius, D.; Bernhard, G.; Nitsche, H.; Fanghänel, T.

Abstract wir von Dr. Geipel nachgereicht

  • Spectrochimica Acta Part A 60(2004)1-2, 417-424

Permalink: https://www.hzdr.de/publications/Publ-5509
Publ.-Id: 5509


Multifragmentation and Flow: peripheral vs. central collisions

Pochodzalla, J.; Aiello, S.; Begemann-Blaich, M.; Bowman, D. R.; Charity, R. J.; Cosmo, A.; Ferrero, A.; Gelbke, C. K.; Hsi, W. C.; Hubele, J.; Imme, G.; Iori, I.; Kempter, J.; Kreutz, P.; Kunde, G. J.; Kunze, W. D.; Lindenstruth, V.; Lisa, M. A.; Lynch, W. G.; Lynen, U.; Mang, M.; Moretto, L. G.; Moroni, A.; Müller, W. F. J.; Neumann, M.; Ocker, B.; Ogilvie, C. A.; Pappalardo, V.; Peaslee, G. F.; Raciti, G.; Rosenberger, F.; Rubehn, T.; Sann, H.; Scardaoni, R.; Schüttauf, A.; Seidel, W.; Serfling, V.; Sobotka, L. G.; Stroth, J.; Stuttge, L.; Trautmann, W.; Tsang, M. B.; Tucholski, A.; Williams, C. W.; Wörner, A.; Zude, E.; Zwieglinski, B.; Blaich, T.

  • Nuclear Physics A583(1995) 553-560

Permalink: https://www.hzdr.de/publications/Publ-5507
Publ.-Id: 5507


Probing the Nuclear Liquid-Gas Phase Transition

Pochodzalla, J.; Möhlenkamp, T.; Rubehn, T.; Schüttauf, A.; Wörner, A.; Zude, E.; Begemann-Blaich, M.; Blaich, T.; Gross, C.; Emling, H.; Ferrero, A.; Imme, G.; Iori, I.; Kunde, G. J.; Kunze, W. D.; Lindenstruth, V.; Lynen, U.; Moroni, A.; Müller, W. F. J.; Ocker, B.; Raciti, G.; Saun, H.; Schwarz, C.; Seidel, W.; Serfling, V.; Stroth, J.; Trzcinski, A.; Trautmann, W.; Tuchalski, A.; Verde, G.; Zwieglinski, B.

  • GSI Preprint, GSI 95 - 13, Feb. 1995 und Phys. Rev. Lett. 75(1995)1040-1043

Permalink: https://www.hzdr.de/publications/Publ-5506
Publ.-Id: 5506


Squeeze-out of nuclear matter in Au+Au collisions

Tsang, M. B.; Danielewicz, P.; Hsi, W. C.; Huang, M.; Lynch, W. G.; Bowman, D. R.; Gelbke, K. C.; Lisa, M. A.; Peaslee, G. F.; Charity, R. J.; Sobotka, L. G.; Begemann-Blaich, M.; Cosmo, F.; Ferrero, A.; Hubele, J.; Imme, G.; Iori, I.; Kempter, J.; Kreutz, P.; Kunde, G. J.; Kunze, W. D.; Lindenstruth, V.; Lynen, U.; Mang, M.; Morroni, A.; Müller, W. F. J.; Neumann, M.; Ocker, B.; Ogilvie, C. A.; Pochodzalla, J.; Raciti, G.; Rosenberger, F.; Rubehn, T.; Saun, H.; Scardavnic, R.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Trautmann, W.; Tucholski, A.; Wörner, A.; Zwieglinski, B.

  • MSU Preprint, MSUCL-983, Nov. 1995 Phys. Rev. C53(1996)1959

Permalink: https://www.hzdr.de/publications/Publ-5505
Publ.-Id: 5505


Speciation of Actinides (Environmental, Food, Clinical, Occupational, Health) (The contribution will follow then the arrangement of the actinides in the periodic table.)

Geipel, G.

Outline
Actinides are the fourteen elements, which follow the element actinium in the periodic table of elements. The first three actinides uranium, protactinium and thorium can be found in the nature, the other elements are artificial elements. Most speciation studies are carried with actinides from thorium to curium. The elements uranium, neptunium and plutonium show a wide variety of oxidation states. In tetravalent oxidation state the solubility is very low. In this oxidation state the hydrolysis is the most important reaction.

All these elements are radioactive. Therefore special laboratories to handle these elements are necessary. The concentration range for speciation studies with actinides is below 1 x 10-5 M. Therefore several speciation techniques, mostly basing on laser induced methods, are developed. A short overview in these methods will be given.

For thorium and protactinium only few data are available. Thorium does only exist in tetravalent oxidation state. Hydrolysis and phosphate speciation will be described. Protactinium exists in the pentavalent oxidation state and forms a dioxy-cation.

Most data are available for uranium speciation. Uranium exists in four oxidation states. Uranium-(III) is only stable in non-aqueous environments and plays therefore no role in speciation studies. Under reducing conditions uranium-(IV) is formed. Speciation examples for hydrolysis, sulfate, phosphate and arsenate will be given. In aqueous solutions uranium?(V) disproportionates into uranium-(IV) and uranium-(VI). Hexavalent uranium exists only as dioxy-cation.
In a next section environmental aspects of the uranium-(VI) speciation will be described. Uranium is found in more or less high concentrations in anywhere in the environment. Speciation examples from mining and milling will be described.
Uranium speciation in plants (as example for the food chain) will be described.
Neptunium forms oxidation states from +3 to + 7. Np(III) is slightly oxidized to Np(IV). The most stable oxidation states are Np(IV) and Np(V), the latter also forms a dioxy-cation. As example for environmental speciation the speciation of Np(V) with humic substances will be quoted.
Plutonium has oxidation states from + 3 to + 6. The redox potentials between these oxidation states are close together, so one can often find several oxidation states existing together. Examples for speciation in environment (here as specials case the Oklo mine in Gabun and results of bomb tests will be included) are shown, clinical and health aspects should be discussed (Pu is one of the most toxic elements).
Americium and Curium form trivalent ions in solution. These elements are important in waste repositories. Speciation in concentrated salt solutions and in mineral (calcite) phases are important examples for speciation in natural environments.
Actinides higher than Curium show at least short half-life. The long living isotopes are Berkelium 247 (1400 y), Californium 251 (900 y) and Einsteinium 252 (1.24 y). Fermium, Mendelevium, Nobelium and Lawrencium as well as the transactinide elements have half-life less than 1 y. Due to the very low production rates most of these elements are less relevant in speciation chemistry. Berkelium is found to have two oxidation states (III and V). Only few data on chloride and sulfate speciation are available.

  • Contribution to external collection
    in: Handbook of Elemental Speciation II (Eds.R. Cornelis), London: Wiley Verlag, 2005, 509-563

Permalink: https://www.hzdr.de/publications/Publ-5504
Publ.-Id: 5504


A positron emission tomograph for the on-line control of heavy ion tumour therapy.

Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pawelke, J.; Sobiella, M.; Byars, L.

no abstract

  • GSI-Nachrichten, Gesellschaft für Schwerionenforschung, Darmstadt, 07-95 (1995) 16-17

Permalink: https://www.hzdr.de/publications/Publ-5503
Publ.-Id: 5503


Application of secondary beams to treatment planning.

Tomitani, T.; Kanazawa, M.; Yoshikawa, K.; Pawelke, J.; Kanai, T.; Murakami, T.; Noda, K.; Torikoshi, M.; Kitagawa, A.; Kouda, S.; Muramatsu, M.; Suda, M.; Fukumura, A.; Wada, Y.; Shinoda, I.

A secondary beam facility had been built at the end of last fiscal year and commenced the operation since the second term of HIMAC machine time. Optimum momentum spread was sought so as to compromise two contradictory factors, the blurring of sharp Bragg peak and broadening of the 11C end-point distribution. Three types of irradiation, namely, focused beam irradiation, line irradiation and curved surface irradiation, were tested to see the uniformity of the irradiation field. The field uniformity turned out competent with the assessment of beam end-point in all cases, since it only affects the statistical noise in PET images that degrades indirectly the assessment of end-point. Preliminary irradiation tests were performed on rabbits to see biological half-life of 11C in the thigh muscle of the rear leg.

  • Other report
    Report National Institute of Radiological Sciences, Chiba, Japan, 1999

Permalink: https://www.hzdr.de/publications/Publ-5502
Publ.-Id: 5502


Medical application of secondary beams.

Tomitani, T.; Kanazawa, M.; Yoshikawa, K.; Pawelke, J.; Futami, Y.; Kitagawa, A.; Kanai, T.; Kouda, S.; Suda, M.; Fukumura, A.; Matsuura, H.; Takizawa, S.

In the application of positron emitting secondary beams to the verification of heavy ion treatment planning, the implanted radioactive isotopes undergo metabolism. Experiments on rabbit thigh muscle were performed using 11C secondary beams from HIMAC. PET allows us three-dimensional imaging of the implanted 11C, however, the early phase cannot be measured. The positron camera allows us in-situ measurement. By focusing the beam to narrow region, time-activity analysis of the volume of interest revealed the existence of faster metabolic component.

  • Other report
    National Institute of Radiological Sciences, Chiba, Japan, NIRS-M-139/HIMAC-026 (2000) 207-208

Permalink: https://www.hzdr.de/publications/Publ-5501
Publ.-Id: 5501


Can the autoactivation of a stable light ion beam be employed for dose control in light ion tumour therapy?

Enghardt, W.; Fromm, W.-D.; Manfraß, P.; Pawelke, J.; Sobiella, M.; Schardt, D.; Geissel, H.; Keller, H.; Kraft, G.; Magel, A.; Münzenberg, G.; Nickel, F.; Scheidenberger, C.

no abstract

  • Particles Newsletter (Harvard University, Boston, USA), Number 11 (January 1993) 13-14

Permalink: https://www.hzdr.de/publications/Publ-5500
Publ.-Id: 5500


Electromagnetic Fission of 238U at 600 and 1000 MeV per Nucleon

Rubehn, T.; Müller, W. F. J.; Bassini, R.; Begemann-Blaich, M.; Blaich, T.; Ferrero, A.; Gross, C.; Imme, G.; Iori, I.; Kunde, G. J.; Kunze, W. D.; Lindenstruht, V.; Lynen, U.; Möhlenkamp, T.; Moretto, L. G.; Ocker, B.; Pochodzalla, J.; Raciti, G.; Reito, S.; Sann, H.; Schüttauf, A.; Seidel, W.; Serfling, V.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Zude, E.; Zwieglinski, B.

  • GSI Preprint, GSI 95-28, Mai 1995 und Zeitschrift für Physik A 353(1995) 197-204

Permalink: https://www.hzdr.de/publications/Publ-5499
Publ.-Id: 5499


The FOBOS* 4Pi-Detector of charged particles at the FLNR of the JINR Dubna

Andrassy, M.; Aleksandrov, A. A.; Aleksandrova, I. A.; Budzanowski, A.; Danziger, M.; Dietterle, L.; Doronin, V. N.; Dshemuchadse, S.; Fomichew, A. S.; Gippner, P.; Gebhardt, M.; Heidel, K.; Heinitz, S.; Herbach, C.-M.; Hilscher, D.; Holik, J.; Homeyer, H.; Ivanenko, A. I.; Ivanovski, S. A.; Janczur, W.; Kamanin, D. V.; Kolesov, I. V.; Matthies, A.; May, D.; Merzlyakov, S. I.; von Oertzen, W.; Oganessian, Y. T.; Ortlepp, H. G.; Penionzhkevich, Y. E.; Pausch, G.; Pokrovsky, V. N.; Pyatkov, Y. V.; Radnev, S. V.; Renz, G.; Rubinskaya, L. A.; Sandrev, I. D.; Schilling, K. D.; Seidel, W.; Shishkin, D. I.; Sodan, H.; Strekalovsky, O. V.; Trofimov, V. V.; Tsurin, I. P.; Umlauf, C.; Vakatov, D. V.; Vasko, V. M.; Wagner, W.; Zhuchko, V. E.; Ziem, P.; Zrodkowski, L.

  • Dubna, E7 - 95 - 148, March 1995

Permalink: https://www.hzdr.de/publications/Publ-5498
Publ.-Id: 5498


Nuclear Caloric Curve

Raciti, G.; Bassini, R.; Begemann-Blaich, M.; Fritz, S.; Gaff, S. J.; Groß, C.; Imme, G.; Iori, I.; Kleinevoß, U.; Kunde, G. J.; Kunze, W. D.; Lynen, U.; Mahi, M.; Moroni, A.; Möhlenkamp, T.; Müller, W. F. J.; Ocker, B.; Odeh, T.; Petruzelli, F.; Pochodzalla, J.; Riccobene, G.; Romano, F. P.; Rubehn, T.; Sajia, A.; Schnittker, M.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Sfienti, C.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Xi, H.; Zude, E.; Zwieglinski, B.

  • Contribution to proceedings
    Proceedings of the 3rd INFN-RIKEN Meeting on Perspectives in Heavy Ions Physics, October 13-15, 1997, Padova, Italy, 11pp.

Permalink: https://www.hzdr.de/publications/Publ-5497
Publ.-Id: 5497


Breakup Temperature of Target Spectators in 197 AU + 197 AU Collisions at E/A = 1000 MeV

Hongfei, X.; Odeh, T.; Bassini, R.; Begemann-Blaich, M.; Botvina, A. S.; Fritz, S.; Gaff, S. J.; Groß, C.; Imme, G.; Iori, I.; Kleinevoß, U.; Kunde, G. J.; Kunze, W. D.; Lynen, U.; Maddalena, V.; Mahi, M.; Möhlenkamp, T.; Nociforo, C.; Ocker, B.; Petruzelli, F.; Pochodzalla, J.; Raciti, G.; Riccobene, G.; Romano, F. P.; Rubehn, T.; Saija, A.; Schnittker, M.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Sfienti, C.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Zwieglinski, B.; Müller, W. F. J.; Moroni, A.

  • GSI- Preprint 97-20, März 1997 und Zeitschrift für Physik A 359 (1997) 379-406

Permalink: https://www.hzdr.de/publications/Publ-5496
Publ.-Id: 5496


Interview with a foreign researcher.

Pawelke, J.

no abstract

  • Radiological Sciences (ISSN 0441-2540), Vol. 41, No. 12 (1998) 524-525

Permalink: https://www.hzdr.de/publications/Publ-5494
Publ.-Id: 5494


Metabolic studies of 11C in rabbit thigh muscle implanted by secondary beam of HIMAC.

Tomitani, T.; Pawelke, J.; Kanazawa, M.; Yoshikawa, K.; Yoshida, K.; Sato, M.; Takami, A.; Koga, M.; Futami, Y.; Kitagawa, A.; Urakabe, E.; Suda, M.; Kanai, T.; Matsuura, H.; Shinoda, I.; Takizawa, S.

no abstract

  • Lecture (Conference)
    2nd Japan-Korean Joint Meeting on Medical Physics, Chiba, Japan, 5-6 Nov, 1999
  • Japanese Journal of Medical Physics, Vol. 19, No. 61 (1999) 192-195
  • Contribution to proceedings
    2nd Japan-Korean Joint Meeting on Medical Physics, Chiba, Japan, 5-6 Nov, 1999

Permalink: https://www.hzdr.de/publications/Publ-5493
Publ.-Id: 5493


Electrochemical behaviour of bimetallic Ni-Ti surface generated by ion implantation

Pham, M. T.; Maitz, M.; Reuther, H.; Richter, E.; Matz, W.; Muecklich, A.; Prokert, F.

Thin films NiTi (< 100 nm) having surface Ni content below 5 at. % were prepared by ion implanting Ni into Ti surfaces. The Ni containing phase exposed or buried within the Ti matrix was amorphous. Following an anodic oxidation in NaOH the material was shown to be redox active and promote the electrocatalytic oxidation of glucose depending on the surface NiTi composition. Compared to the NiTi bulk alloy (55.9:44.08) the Ni implanted Ti displayed a more efficient catalytic activity and improved corrosion resistance.

Keywords: Ionenimplantation; Katalyse; NiTi-Legierung

  • Journal of Materials Research 19(2004), 439-446

Permalink: https://www.hzdr.de/publications/Publ-5492
Publ.-Id: 5492


Experimental and Numerical Studies of Flow in Rectangular Bubble Columns

Reddy, V. B. N.; Krepper, E.; Prasser, H.-M.; Zaruba, A.; Lopez De Bertodano, M. A.

Bubbly flow is encountered in a wide variety of industrial applications ranging from flows in nuclear reactors to process flows in chemical reactors. The presence of a second phase, re-circulating flow, instabilities of the gas plume and turbulence, complicate the hydrodynamics of bubble column reactors. This paper describes preliminary experimental and numerical results obtained in a rectangular bubble column with a cross-sectional area of 20 cm2. Images obtained from a high speed camera have been processed to calculate bubble velocities, bubble turbulence parameters and bubble size distributions. Gas disengagement technique was used to obtain the volume averaged gas fraction over a range of superficial gas velocities. Numerical calculations were performed with an Eulerian-Eulerian two–fluid model approach using the commercial code CFX-4.4. In this paper, the image processing algorithms and numerical modeling are discussed and an analysis of the preliminary results presented.

Keywords: Bubble column; bubble plume; image processing; CFD; re-circulating flow

  • Lecture (Conference)
    The 10th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003
  • Lecture (Conference)
    Multiphase Flows in Industrial Applications CFX-Germany, FZ-Rossendorf 28.-30.04.03
  • Contribution to proceedings
    The 10th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003

Permalink: https://www.hzdr.de/publications/Publ-5491
Publ.-Id: 5491


Breakup density in spectator fragmentation

Fritz, S.; Schwarz, C.; Bassini, R.; Begemann-Blaich, M.; Gaff-Ejakov, S. J.; Gourio, D.; Groß, C.; Imme, G.; Iori, I.; Kleinevoß, U.

Proton-proton correlations of protons, deuterons and tritons with alpha particles from spectator decays following 197Au+197Au collisions at 1000 MeV per nucleon have been measured with two highly efficient detector sodoscopes. The constructed correlation functions, interpreted within the approximation of a simultaneous volume decay, dedicate a moderate expansion and low breakup densities, similar to assumptions made in statistical multifragmentation models.

  • Phys. Letters B 461(1999) 315-321

Permalink: https://www.hzdr.de/publications/Publ-5489
Publ.-Id: 5489


First patients' treatment at GSI using heavy-ion beams.

Kraft, G.; Badura, E.; Becher, W.; Böhne, D.; Brand, H.; Brusasco, C.; Eickhoff, H.; Essel, H.-G.; Franzcak, B.; Geiß, O.; Haberer, T.; Hoffmann, J.; Kainsberger, P.; Krämer, M.; Krause, K.; Kurz, N.; Langenbeck, B.; Ott, W.; Poppensieker, K.; Richter, M.; von Rüden, W.; Schardt, D.; Scholz, M.; Spiller, P.; Steiner, R.; Stelzer, H.; Voss, B.; Weber, U.; Debus, J.; Ertner, D.; Russ, N.; Heeg, P.; Wannenmacher, M.; Wenz, F.; Enghardt, W.; Hasch, B.-G.; Hinz, R.; Lauckner, K.; Pawelke, J.; Sobiella, M.; Hartmann, G.; Jäkel, O.; Karger, C.-P.; Krießbach, A.; Lappe, C.; Massimino, M.

Beams of heavy-charged particles of high energy like carbon ions are superior to any other type of radiation conventionally used in external radiotherapy. In contrast to photons and neutrons, the dose for the ions increases with penetration depth and culminates in a sharp maximum at the end of range. Due to the microscopic track structure this region of high energy deposition has an increased biological efficiency. In addition, a small amount of positron emitting isotopes is produced by the projectile and makes it possible to trace the beam inside the patient's body by PET techniques. At GSI an experimental heavy-ion therapy started with patient treatment. It is based on a totally active beam delivery and a biology-oriented treatment planning system in order to exploit the favourable particle properties to a maximum extent.

  • Lecture (Conference)
    6th European Particle Accelerator Conference, Stockholm, 22-26 Jun, 1998
    S. Myers, L. Liljeby, C. Petit-Jean-Genaz, J. Poole, K.G. Rensfelt (Eds.): Proceedings, Institute of Physics Publishing, Bristol and Philadelphia, Vol. 1 (1998) 212-216
  • Contribution to proceedings
    6th European Particle Accelerator Conference, Stockholm, 22-26 Jun, 1998
    S. Myers, L. Liljeby, C. Petit-Jean-Genaz, J. Poole, K.G. Rensfelt (Eds.): Proceedings, Institute of Physics Publishing, Bristol and Philadelphia, Vol. 1 (1998) 212-216

Permalink: https://www.hzdr.de/publications/Publ-5487
Publ.-Id: 5487


Fragment Kinetic Energies and Modes of Fragment Formation

Odeh, T.; Bassini, R.; Begemann-Blaich, M.; Fritz, S.; Gaff-Ejakov, S. J.; Gourio, D.; Groß, C.; Imme, G.; Iori, I.; Kleinevoß, U.; Kunde, G. J.; Kunze, W. D.; Lynen, U.; Maddalena, V.; Mahi, M.; Möhlenkamp, T.; Moroni, A.; Müller, W. F. J.; Nociforo, C.; Ocker, B.; Petruzzelli, F.; Pochodzalla, J.; Raciti, G.; Riccobene, G.; Romano, F. P.; Saija, A.; Schnittker, M.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Sfienti, C.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Hongfei, X.; Zwieglinski, B.

Kinetic energies of light fragments (A ? 10) from the decay of target spectators in 197Au + 197Au collisions at 1000 MeV per nucleon have been measured with high-resolution telescopes at backward angles. Except for protons and apart from the observed evaporation components, the kinetic-energy spectra exhibit slope temperatures of about 17 MeV, independent of the particle species, but not corresponding to the thermal or chemical degrees of freedom at breakup. It is suggested that these slope temperatures may reflect the intrinsic Fermi motion and thus the buld density of the spectator system at the instant of becoming unstable.

  • Phys. Rev. Letter 84 (2000)4557 and GSI - Preprint 2000-10/ März 2000

Permalink: https://www.hzdr.de/publications/Publ-5486
Publ.-Id: 5486


The spatial distribution of positron-emitting nuclei generated by relativistic light ion beams in organic matter.

Enghardt, W.; Fromm, W.-D.; Geissel, H.; Keller, H.; Kraft, G.; Magel, A.; Manfraß, P.; Münzenberg, G.; Nickel, F.; Pawelke, J.; Schardt, D.; Scheidenberger, C.; Sobiella, M.

no abstract

  • Phys. Med. Biol., Vol. 37, No. 11 (1992) 2127-2131

Permalink: https://www.hzdr.de/publications/Publ-5485
Publ.-Id: 5485


Projects for Two-Color Pump-Probe Studies at the Radiation Source ELBE

Seidel, W.; Büchner, A.; Enghardt, W.; Evtushenko, P.; Gabriel, F.; Gippner, P.; Grosse, E.; Kalionka, D.; Lehnert, U.; Michel, P.; Schamlott, A.; Wagner, W.; Wohlfahrt, D.; Wolf, A.; Wünsch, R.

  • Poster
    22nd International Conference on Free Electron Lasers, 2000, Durkham, USA
  • Open Access Logo Contribution to proceedings
    22nd International Conference on Free Electron Lasers (FEL 2000), 13.-18.08.2000, Durkham, USA, Amsterdam, 11-53-54

Permalink: https://www.hzdr.de/publications/Publ-5484
Publ.-Id: 5484


The ELBE-Project at Dresden-Rossendorf

Büchner, A.; Gabriel, F.; Grosse, E.; Michel, P.; Seidel, W.; Voigtlaender, J.

  • Poster
    EPAC 2000, 26.-30.07. 2000, Wien, Österreich
  • Contribution to proceedings
    EPAC 2000, 26.-30.07.2000, Wien, Österreich
    Proceedings of EPAC 2000

Permalink: https://www.hzdr.de/publications/Publ-5483
Publ.-Id: 5483


An improved numerical study of the wall effect on hot-wire measurements

Shi, J.-M.; Breuer, M.; Durst, F.; Schaefer, M.

Numerical investigations of the heat transfer from hot wires in near-wall measurements were carried out. Special attention was paid to the effect of the wall thickness, the flow conditions below the wall and the shear velocity connected to different wall
materials. Compared with previous studies, an improved physical model taking into account the flow region below the wall
in the computational domain was applied. The results obtained agree well with experimental data in the literature for walls consisting of both highly and poorly conducting materials. The investigation showed that the shear velocity $U_\tau$ has a significant influence on hot-wire measurements in the vicinity of a wall. Nevertheless, discernible effects of the wall thickness and the flow condition below the wall were found only in the case of a poorly conducting wall. In addition, the results also suggest a weak effect of the overheat ratio for a wire with an infinitely large aspect ratio.

Keywords: Hot wire; Heat Transfer; Near-wall measurement; Shear velocity; Overheat ratio; Wall material; Wall thickness; Numerical simulation; Convection boundary condition

  • ASME, J. Heat Transfer, 125:595-603, 2003

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-5482
Publ.-Id: 5482


MR perfusion measurements in contrast uptaking lesions: Comparison of three correction levels

Hietschold, V.; Kittner, T.; Appold, S.; Abolmaali, N.; Parodi, K.; Laniado, M.

Susceptibilitys contrast based MR perfusion measurement in contrast uptaking tissues are complicated by the contribution of the interstitially deposited contrast medium (CM) to the shortening of both T1 and T2. Applying double echo sequences, both contributions can be corrected for. In this paper, the consequences of different degrees of correction on perfusion parameters are investigated.

  • Poster
    19th Annual Meeting of the European Society for Magnetic Resonance in Medicine and Biology, Cannes,August 22-25,2002

Permalink: https://www.hzdr.de/publications/Publ-5481
Publ.-Id: 5481


Positron emission tomography for quality assurance of cancer therapy with light ion beams.

Enghardt, W.; Debus, J.; Haberer, T.; Hasch, B.-G.; Hinz, R.; Jäkel, O.; Krämer, M.; Lauckner, K.; Pawelke, J.; Pönisch, F.

Positron emission tomography (PET) offers the possibility of in-situ monitoring the tumour treatment with light ion beams by means of imaging the spatial distribution of positron-activity that is produced as a byproduct of the therapeutic irradiation via nuclear fragmentation reactions between the projectiles and the atomic nuclei of the tissue within the target volume. The implementation of this PET technique at the experimental tumour therapy facility at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt and first results of its clinical application are presented.

  • Nuclear Physics A, Vol. 654 (1999)1047c-1050c

Permalink: https://www.hzdr.de/publications/Publ-5480
Publ.-Id: 5480


Analysis of heat transfer from single wires close to walls

Shi, J.-M.; Gerlach, D.; Breuer, M.; Durst, F.; Lange, C. F.

Two-dimensional numerical investigations of the forced heat convection from a microcylinder in laminar cross-flow, both in free stream and in near-wall flow, were carried out aiming at a better understanding of the physics behind the wall effects on hot-wire near-wall measurements. In the physical model, an infinitely thin plate with the same properties as the fluid (air) was used as an
artificial wall. The conjugate heat transfer between the flow regions on both sides of the plate was taken into account. The effect of the conjugate thermal conditions (temperature distribution and diffusive heat flux) at the interface of the two flow regions on the heat transfer from the wire was investigated by varying the flow conditions on the side opposite to the wire location. Careful energy balance analysis was performed for both the free-stream case and the near-wall case. This enabled the authors to verify their own understanding of the physical mechanism responsible for the wall effect on hot-wire measurements and to examine other mechanisms proposed in the literature. The numerical results showed that the heat diffusion from the wire is significantly enhanced in the case of small wire-to-wall distances (Y+ < 3). This is mainly caused by modifications of the thermal boundary condition (diffusive effect) at the fluid-wall interface. In contrast, the flow distortion (enhanced convection) was shown not to be the most important influencing factor for the heat transfer of a hot wire. Although the present model study was performed for a laminar
flow, the results obtained are applicable to hot-wire measurements in turbulent flows, as stated in the literature.

Keywords: Hot wire; Heat tranasfer; Near-wall measurement; Numerical simulation

  • Phys. Fluids, 15 (2003) 908-921

Permalink: https://www.hzdr.de/publications/Publ-5479
Publ.-Id: 5479


A combined analytical-numerical method for treating corner singularities in viscous flow predictions

Shi, J.-M.; Breuer, M.; Durst, F.

A combined analytical-numerical method based on a matching asymptotic algorithm is proposed for treating angular (sharp corner or wedge) singularities in the numerical solution of the Navier-Stokes equations. We adopt an asymptotic solution for the local flow around the angular points based on the Stokes flow approximation and a numerical solution for the global flow outside the singular regions using a finite-volume method. The coefficients involved in the analytical solution are iteratively updated by matching both solutions in a small region where the Stokes flow approximation holds. Moreover, an error analysis is derived for this method, which serves as a guideline for the practical implementation. The present method is applied to treat the leading-edge singularity of a semi-infinite plate. The effect of various influencing factors related to the implementation are evaluated with the help of numerical experiments. The investigation showed that the accuracy of the numerical solution for the flow around the leading edge can be significantly improved with the present method. The results of the numerical experiments support the error analysis and show the desired properties of the new algorithm, i.e., accuracy, robustness and efficiency. Based on the numerical results for the leading-edge singularity, the validity of various classical approximate models for the flow, such as the Stokes approximation, the inviscid flow model and the boundary layer theory of varying orders are examined.

Keywords: Numerical method; numerical accuracy; angular singularity; Navier-Stokes equations; boundary layer; leading edge

  • International Journal for Numerical Methods in Fluids 45(2004), 659-688
    DOI: 10.1002/fld.722

Permalink: https://www.hzdr.de/publications/Publ-5478
Publ.-Id: 5478


Luminescence studies of blood phagocyte oxygenation activities in patients with antiphospholipid syndrome

Kopprasch, S.; Roch, B.; Pietzsch, J.; Kuhlisch, E.; Gräßler, J.

  • Book (Authorship)
    In: Stanley PE, Kricka LJ. (Hrsg.) Bioluminescence and Chemiluminescence 2002: Progress and Current Applications. World Scientific Publishing Company, New Jersey. S. 265-268

Permalink: https://www.hzdr.de/publications/Publ-5477
Publ.-Id: 5477


Chemiluminescence as a tool to assess hyperglycemia-induced systemic oxidative stress in different insulin-resistant states

Kopprasch, S.; Pietzsch, J.; Kuhlisch, E.; Gräßler, J.

  • Book (Authorship)
    In: Stanley PE, Kricka LJ. (Hrsg.) Bioluminescence and Chemiluminescence 2002: Progress and Current Applications. World Scientific Publishing Company, New Jersey. S. 261-264

Permalink: https://www.hzdr.de/publications/Publ-5476
Publ.-Id: 5476


Untersuchungen zur in vivo-Kinetik humaner Lipoproteine mittels stabiler Isotope: Störungen des Lipoproteinstoffwechsels bei Diabetesvorstadien

Pietzsch, J.

  • Lecture (others)
    Lebensmittelchemisches Kolloquium der Universität Stuttgart-Hohenheim, 30.01.2003

Permalink: https://www.hzdr.de/publications/Publ-5475
Publ.-Id: 5475


FTIR- and Fluorescence-Spectroscopic Analyses of Receptor G-Protein Coupling in Photoreception Curr. Org. Chem. 2002, 6, 1259-1284.

Fahmy, K.

G protein-coupled receptors (GPCRs) are heptahelical transmembrane proteins. They transduce a large variety of extracellular signals, allowing perception of taste, odor, hormones, and light. Binding of an extracellular ligand induces structural changes in the cytosolic domain of a GPCR which, thereby, catalyzes nucleotide exchange in a G protein. Rhodopsins, the visual pigments, are prototypical GPCRs that are activated by photoisomerization of covalently bound 11-cis retinal. Unlike other GPCRs, bovine rhodopsin and transducin, its cognate G protein, can be prepared from cow eyes in large quantities for spectroscopic and biochemical investigations. Rhodopsin is the best studied GPCR and the only one for which an X-ray structure has been solved. Structural information together with the wealth of biophysical data on native and recombinant rhodopsins allows to determine structure function relationships that are relevant to GPCR-dependent signaling in general. Here, results from Fourier-transform-infrared (FTIR) spectrocopic studies of rhodopsin and measurements of nucleotide-dependent transducin fluorescence are reviewed. Intra- and intermolecular processes during signaling by the photoreceptor have thus been identified and analyzed kinetically. Recent applications of these techniques concern rhodopsin transducin coupling in synthetic lipidic matrices and analysis of drug action at the receptor G protein interface.The data are discussed in the context of the crystal structure of rhodopsin and additional biochemical information if required for the understanding of the spectroscopic results.

  • Curr. Org. Chem. 2002, 6, 1259-1284.

Permalink: https://www.hzdr.de/publications/Publ-5474
Publ.-Id: 5474


Investigation of deep implanted fluorine channeling profiles in silicon using resonant NRA

Kokkoris, M.; Perdikakis, G.; Vlastou, R.; Papadopoulos, C. T.; Aslanoglou, X. A.; Posselt, M.; Grötzschel, R.; Harrissopulos, S.; Kossionides, S.

Si (100) and (111) crystals were irradiated in the random as well as in the channeling direction, using 5 MeV 19F+ ions, to a maximum dose of approximately 1×1017 particles/cm2. The occurring deep implanted profiles were subsequently investigated using the Resonant Nuclear Reaction Analysis technique in the energy range Ep=950-1200 keV. The reaction 19F(p, αγ)16O reaction exhibits a strong resonant behavior in the above mentioned energy range, thus providing an excellent tool for the depth profiling of fluorine, yielding minimum detection limits of the order of a few ppm. The occurring profiles are analyzed with SRIM and c-TRIM and an attempt is made to explain the peculiarities of the experimental spectra, as well as to compare with results already existing in literature

Keywords: High-energy implantation; Channeling; Nuclear resonance; Fluorine profiling; Resonant NRA; c-TRIM

Permalink: https://www.hzdr.de/publications/Publ-5473
Publ.-Id: 5473


Nuclear Transparency with the gamma n to pi- p Process in 4He

Dutta, D.; Xiong, F.; Zhu, L. Y.; Arrington, J.; Averett, T.; Beise, E.; Calarco, J.; Chang, T.; Chen, J. P.; Chudakov, E.; Coman, M.; Clasie, B.; Crawford, C.; Dieterich, S.; Dohrmann, F.; Fissum, K.; Frullani, S.; Gao, H.; Gilman, R.; Glashauser, C.; Gomez, J.; Hafidi, K.; Hansen, O.; Higinbotham, D. W.; Holt, R. J.; Dejager, C. W.; Jiang, X.; Kinney, E.; Kramer, K.; Kumbartzki, G.; Lerose, J.; Liyanage, N.; Mack, D.; Markowitz, P.; Mccormick, K.; Meziani, Z.-E.; Michaels, R.; Mitchell, J.; Nanda, S.; Potterveld, D.; Ransome, R.; Reimer, P. E.; Reitz, B.; Saha, A.; Schulte, E. C.; Seely, J.; Sirca, S.; Strauch, S.; Sulkosky, V.; Vlahovic, B.; Weinstein, L. B.; Wijesooriya, K.; Williamson, C.; Wojtsekhowski, B.; Xiang, H.; Xu, W.; Zeng, J.; Zheng, X.

We have measured the nuclear transparency of the fundamental process gamma n to pi- p in 4He. These measurements were performed at Jefferson Lab in the photon energy range of 1.6 to 4.5 GeV and at thetacmSUP>pi = 70 and 90 . These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. the transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations which include the quantum chromodynamics phenomenon of color transparency.

Keywords: nuclear transparency; color transpareny; photon scattering

  • Phys.Rev.C68:021001,2003 e-Print Archive: nucl-ex/0305005

Permalink: https://www.hzdr.de/publications/Publ-5472
Publ.-Id: 5472


Subthreshold K+ production in deuteron and alpha induced nuclear reactions

Debowski, M.; Senger, P.; Boivin, M.; Le Bornec, Y.; Courtat, P.; Gacougnolle, R.; Grosse, E.; Kabana, S.; Kirchner, T.; Koczon, P.; Mang, M.; Schwab, E.; Tatischeff, B.; Wagner, A.; Walus, W.; Willis, N.; Wolf, G.; Wurzinger, R.; Yonnet, J.

Double differential cross sections d2?/dpd? have been measured for ?+ and K+ emitted around midrapidity in d+A and ?+A collisions at a beam kinetic energy of 1.15 GeV/nucleon. The total ?+ yield increases by a factor of about 2 when using an alpha projectile instead of of a deuteron whereas the K+ yield increases by a factor of about 4. According to transport calculations, the K+ enhancement depends both on the number of hadron-hadron collisions: their center-of-mass energy increases with increasing number of projectile nucleons.

  • Phys. Lett. B 413(1997)8

Permalink: https://www.hzdr.de/publications/Publ-5471
Publ.-Id: 5471


Alloy liquid metal ion sources and their application in mass separated focused ion beams

Bischoff, L.

During the last decades, the focused ion beam (FIB) became a very useful and versatile tool in the microelectronics industry, as well as in the field of research and development. For special purposes like writing ion implantation or ion mixing in the µm- or sub-µm range ion species other than gallium are needed. Therefore alloy liquid metal ion sources (LMIS) were developed. The energy distribution of the ions from an alloy LMIS is one of the determining factors for the performance of an FIB column. Different source materials like Au73Ge27, Au82Si18, Au77Ge14Si9, Co36Nd64, Er69Ni31, and Er70Fe22Ni5Cr3 were investigated with respect to the energy spread of the different ion species as a function of emission current I, ion mass m and emitter temperature T. For singly charged ions a predicted dependence of the energy spread, DE µ I2/3 m1/3 T1/2 found for Ga could be reasonable confirmed. The alloy LMIS`s discussed above have been used in the Rossendorf FIB system IMSA-100 especially for writing implantation to fabricate sub-µm pattern without any lithographic steps. A Co-FIB obtained from a Co36Nd64 alloy LMIS was applied for the ion beam synthesis of CoSi2 micro-structures down to 60 nm. Additionally, the possibility of varying the current density of the FIB by changing the pixel dwell-time was used for investigations of radiation induced damage and its dynamic annealing in Si and SiC at elevated implantation temperatures. Furthermore, a broad spectrum of ions was employed to study the sputtering process depending on temperature, angle of incidence and ion mass on a couple of target materials using the volume loss method. Especially this direct patterning 3D technique was used for the fabrication of various kinds of micro-tools.
All these examples underline the importance of FIBs in modern research and the new possibilities opened up by a mass separated system applying a broad spectrum of ion species.

Keywords: focused ion beam; alloy liquid metal ion sources; applications

  • Lecture (Conference)
    The 9th Frontiers of Electron Microscopy in Materials Sience Conference, FEMMS 2003, Claremont Resort and Spa in Berceley, Ca., USA, 05.-10. Oct. 2003

Permalink: https://www.hzdr.de/publications/Publ-5470
Publ.-Id: 5470


Experimental and Theoretical Background of Multi-component Cluster Formation in Reactor Pressure Vessel Steels due to Neutron Irradiation

Gokhman, A.; Böhmert, J.; Ulbricht, A.

Sophisticated microstructural analysis methods like small angle neutron scattering and atom probe field ion microscopy have proven the presence of so-called multicomponent clusters due to neutron irradiation in ferritic reactor pressure vessel steels. The formation of such clusters is surprising from the thermodynamic point of view. The cluster formation from the solid solution was modelled as phase transformation of the first kind that corresponds to the negative minimum of the so-called thermodynamic force under consideration of six components. The essential parameter is the sum of interaction energy between all pairs of atoms in the system. The approach result in stable multicomponent cluster if the clusters exhibit a high content of vacancies and a core-shell structure with very high vacancy content within the shell. The kinetics background of the suggested model was investigated using the cluster dynamic approach generalized for multiple components. The computed results are consistent with the experimental findings.

  • Lecture (others)
    Paper on VII. Research Workshop Nucleation Theory and Applications, Dubna, Russia, April 2003

Permalink: https://www.hzdr.de/publications/Publ-5469
Publ.-Id: 5469


Increased cholesteryl ester transfer protein (CETP) activity in impaired glucose tolerance: relationship to high density lipoprotein metabolism

Pietzsch, J.; Fücker, K.

Aim. To investigate the mechanisms and dynamics of cholesteryl ester (neutral lipid) transfer protein activity in subjects with impaired glucose tolerance. Methods. Eighty six Caucasian subjects were recruited by advertisement from the local population between January 1998 and December 1999. The activity of cholesteryl ester transfer protein in 44 non-obese subjects with impaired glucose tolerance (plasma triglycerides 1.56-/+0.64 mmol/L; high density lipoprotein (HDL) cholesterol 0.96-/+0.25 mmol/L; and plasma insulin 78-/+8 pmol/L) and in 42 normoglycemic controls (plasma triglycerides 0.88-/+0.41 mmol/L; HDL cholesterol 1.48-/+0.29 mmol/L; and plasma insulin 38-/+14 pmol/L) was measured with a new fluorometric assay. Results. Cholesteryl ester transfer protein activity was increased in subjects with impaired glucose tolerance by 47% (39.5-/+7.8 vs 26.8-/+6.8 nmol/mL x h-1; t-test, p<0.05). Linear regression analysis showed that cholesteryl ester transfer protein activity in subjects with impaired glucose tolerance significantly correlated with the following parameters: plasma triglycerides (r=0.614, p<0.05), HDL-triglycerides (r=0.595, p<0.05), percentage of HDL-triglyceride (r=0.667, p<0.05), percentage of HDL cholesterol ester (r=-0.751, p<0.01), percentage of HDL phospholipid (r=0.648, p<0.05), 2-h-insulin (r=0.668, p<0.05), and 2-h-proinsulin (r=0.658, p<0.01). In a subgroup of 13 subjects with impaired glucose tolerance, cholesteryl ester transfer protein activity correlated with HDL apoA-I fractional catabolic rate (r=0.701, p<0.01). In normoglycemic subjects, significant correlations were found only between cholesteryl ester transfer protein activity and percentage of HDL-triglycerides (r=0.541, p<0.05), percentage of HDL cholesteryl ester (r=-0.639, p<0.01), 2-h-proinsulin (r=0.642, p<0.05), and HDL apoA-I fractional catabolic rate (n=10, r=0.587, p<0.05). Conclusion. Cholesteryl ester transfer is important for HDL composition and HDL catabolism both in normoglycemic subjects and subjects with impaired glucose tolerance. Under insulin resistant conditions, increased cholesteryl ester transfer protein activity modulates HDL metabolism more drastically than in normoglycemic conditions. This modulation may be explained by increased availability of triglyceride-rich lipoproteins for neutral lipid exchange in subjects with impaired glucose tolerance.

  • Croatian Medical Journal 44 (2): 171-177, 2003

Permalink: https://www.hzdr.de/publications/Publ-5468
Publ.-Id: 5468


Lack of association between serum paraoxonase (PON1) activities and increased oxidized LDL levels in impaired glucose tolerance and newly diagnosed diabetes mellitus

Kopprasch, S.; Pietzsch, J.; Kuhlisch, E.; Gräßler, J.

Several in vitro investigations showed that serum paraoxonase 1 (PON1) that is located on high-density lipoprotein reduces or prevents low-density lipoprotein (LDL) oxidation and therefore retards atherosclerosis. Accordingly, the well documented loss of PON1 activity in patients with overt diabetes mellitus was causally related to the development of micro- and macroangiopathy in the disease course. Because vascular complications start already in prediabetic states, e.g. impaired glucose tolerance (IGT), we investigated serum PON1 activities and circulating levels of oxidized LDL (oxLDL) in 125 IGT subjects, 75 patients with newly diagnosed diabetes mellitus type 2, and 403 individuals with normal glucose tolerance. Using three different substrates (paraoxon, phenylacetate, p-nitrophenylacetate) we found that PON1 activity is not significantly altered in IGT and diabetes mellitus subjects, respectively, when compared with normoglycemic controls. Both IGT subjects and diabetes mellitus patients had significantly increased levels of oxLDL in the circulation. However, serum PON1 activity variations and glutamine/arginine phenotype were not related to the levels of oxLDL. The data suggest that 1) PON1 activity loss is an event occurring later in the course of diabetes mellitus; and 2) PON1 does not affect oxidation of circulating LDL, at least in early diabetes mellitus.

  • Journal of Clinical Endocrinology & Metabolism 2003; 88: 1711-1716

Permalink: https://www.hzdr.de/publications/Publ-5467
Publ.-Id: 5467


Analysis of 3-chlorotyrosine as a specific marker of protein oxidation: The use of N(O,S)-ethoxycarbonyl trifluoroethyl ester derivatives and gas chromatography/mass spectrometry

Pietzsch, J.; Kopprasch, S.; Bergmann, R.

N(O,S)-Ethoxycarbonyltrifluoroethyl amino acid esters are formed by the reaction of amino acids with ethylchloroformate plus trifluoroethanol plus pyridine. The use of these derivatives for a rapid and sensitive determination of 3-chlorotyrosine, a highly specific marker of myeloperoxidase-catalyzed protein oxidation, by using standard gas chromatography/electron impact mass spectrometry, is discussed.

  • Rapid Commun. Mass Spectrom 17 (2003):767-770

Permalink: https://www.hzdr.de/publications/Publ-5466
Publ.-Id: 5466


Intraindividual comparison of two extracorporeal LDL apheresis methods: lipidfiltration and HELP

Julius, U.; Metzler, W.; Pietzsch, J.; Fassbender, T.; Klingel, R.

Low density lipoprotein (LDL) apheresis is an effective treatment option for patients with severe hypercholesterolemia not adequately responding to diet and drug therapy. Membrane differential filtration (MDF), synonymous with double filtration plasmapheresis (DFPP), here named Lipidfiltration, and heparin-induced extracorporeal LDL-precipitation (HELP) are two of the five methods available for extracorporeal LDL apheresis. In this prospective investigation 6 patients with severe LDL-hypercholesterolemia and CAD were treated in a cross-over design with Lipidfiltration at two stages of technical development and HELP to compare the efficacy of these two LDL apheresis methods with respect to lowering and modifying plasma lipids and rheologically relevant plasma proteins, especially fibrinogen. In total, 44 LDL apheresis sessions were investigated. In weekly intervals, patients were treated with consecutive LDL apheresis sessions with either Lipidfiltration and HELP, treating identical plasma volumes. In one part of the investigation Lipidfiltration was performed with the novel Lipidfilter EC-50, combined with a newly developed blood and plasma therapy machine allowing optimized plasma heating. The results showed that the reduction rates of LDL-cholesterol, lipoprotein(a) and triglycerides were essentially identical for both methods. Also pretreatment levels of total cholesterol, triglycerides, LDL-cholesterol and HDL-cholesterol were not significantly different in both treatment groups. Both methods lead to a significant reduction of serum lipoproteins, especially for LDL-cholesterol, which was decreased by 61.4% with Lipidfiltration (treated plasma volume: 2998 ml) and 61.3% with HELP (treated plasma volume: 3013 ml). With respect to Lipidfiltration LDL-cholesterol reduction was more efficient with the novel Lipidfilter EC-50. Mean pretreatment HDL cholesterol concentrations remained unchanged. Comparing Cascadeflo AC-1770 with the novel Lipidfilter EC-50 reduction rates of HDL-cholesterol (17.4% versus 6.4%) and total protein (17.9% versus 7.8%) were significantly reduced. Lipidfiltration and HELP both resulted in a reduction of plasma viscosity and hemorheologically relevant plasma proteins, like fibrinogen.

  • Int J Artif Organs 25 (2002): 1180-1188

Permalink: https://www.hzdr.de/publications/Publ-5465
Publ.-Id: 5465


An LSO-based scanner for in-beam PET: A feasibility study.

Lauckner, K.; Crespo, P.; Enghardt, W.; Pawelke, J.; Kraft, G.

Over the last 3 years in-beam PET has proven its capability of quality assurance in carbon ion tumour therapy at the pilot project of cancer therapy at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. In this paper we investigate the possibility of using LSO as the scintillation material for the next generation of in-beam PET cameras. We address the issue of background coincidences arising from the natural radioactivity of LSO. Because the true count rate measured with a BGO-based dual-head positron camera (total sensitive area of each head 21 x 42 cm2) during the cancer treatment averages at only 100 coincidences/s we studied the influence of the LSO backround on realistic in-beam PET-images.

  • Lecture (Conference)
    IEEE Nuclear Science Symposium and Medical Imaging Conference, Lyon, France 15-20 Oct, 2000
    Book of Abstracts(2000)164
    Conference Record M14(2001)14-51--14-54
  • Contribution to proceedings
    IEEE Nuclear Science Symposium and Medical Imaging Conference, Lyon, France 15-20 Oct, 2000
    Book of Abstracts(2000)164
    Conference Record M14(2001)14-51--14-54

Permalink: https://www.hzdr.de/publications/Publ-5464
Publ.-Id: 5464


Die relative biologische Wirksamkeit von weicher Röntgenstrahlung.

Pawelke, J.; Brankovic, K.; Dörr, W.; Dörschel, B.; Enghardt, W.; Lehnert, U.; Panteleeva, A.; Prade, H.; Slonina, D.

no abstract

  • Lecture (Conference)
    4.Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Bad Kissingen, 4-6 Oct, 2000
    F. Eckardt-Schupp, F. Ahne, M. Kistler (Hrsg.): Proceedings (ISBN 3-00-996800-7)(2000)52
  • Contribution to proceedings
    4.Jahrestagung der Gesellschaft für Biologische Strahlenforschung, Bad Kissingen, 4-6 Oct, 2000
    F. Eckardt-Schupp, F. Ahne, M. Kistler (Hrsg.): Proceedings (ISBN 3-00-996800-7)(2000)52

Permalink: https://www.hzdr.de/publications/Publ-5463
Publ.-Id: 5463


First experimental results of measurements on air/water flow in a vertical pipe with an inner diameter of 194 mm

Lucas, D.; Prasser, H.-M.

The new TOPFLOW facility of the Forschungszentrum Rossendorf allows investigations of two-phase flow phenomena in vertical pipes with an inner diameter up to 194 mm (DN200) and a length up to 8.5 m. The maximum water mass flow of 50 kg/s equals to a superficial velocity of 1.7 m/s in such a pipe, while the maximum air flow rate of 900 m3/h corresponds to a superficial velocity of 8 m/s. For the measurements presented here, a wire-mesh sensor with 64*64 measuring points was installed. It corresponds to a lateral resolution of 3 mm. The senor delivers instantaneous void fraction distributions over the entire cross section with a time resolution of 2500 frames per second, which can be used for fast flow visualisation as well as to obtain averaged void fraction profiles and bubble size distributions. Earlier, similar experiments were carried out at a 51.2 mm pipe. In this case, sensors with 16x16 and 24x24 points were applied. A comparison of the data obtained for the two diameters allows to identify the effects of scaling on void fraction profiles, bubbles size distributions and the flow patterns. In the small pipe, the increase of the air flow rate leads to a transition from bubbly to slug flow. In the bubble size distributions a second peak corresponding to the class of large Taylor bubbles respectively gas plugs was found in the slug flow region. In the large pipe at identical superficial velocities a similar behaviour was found, though the large bubble fraction has a significantly bigger mean diameter, the peak is less high but wider. This reflects the fact that large bubbles move more freely than in the small pipe. The transition from a mono-modal to a bimodal bubble size distribution starts in both pipes, if bubbles with an equivalent diameter larger 1/3 of the pipe diameter occur. Due to the less pronounced confining action of the pipe walls, the bubbles show much more deformations. Their shape can be complicated and far from an ideal Taylor bubble. The small bubble fraction can also develop more freely in the large pipe. This is reflected by a wider bubble size distribution in the small bubble region. Small bubbles that surround the large bubbles obstruct the view and lead to the empirical impression of a direct transition from bubbly to churn turbulent flow.

Keywords: Two phase flow; large pipe; bubble flow

  • Lecture (Conference)
    41st European Two-Phase Flow Group meeting, Norway, May 12-13, 2003
  • Contribution to proceedings
    41st European Two-Phase Flow Group meeting, Norway, May 12-13, 2003

Permalink: https://www.hzdr.de/publications/Publ-5462
Publ.-Id: 5462


Radioactive beam project at HIMAC.

Kitagawa, A.; Endo, M.; Hosaka, M.; Kanai, T.; Kanazawa, M.; Koda, K.; Minohara, S.; Murakami, T.; Noda, K.; Suda, M.; Tomitani, T.; Torikoshi, M.; Urakabe, E.; Yamada, S.; Yoshikawa, K.; Mizuno, H.; Nishio, T.; Shinbo, M.; Futami, Y.; Pawelke, J.; Hanawa, K.; Iseki, Y.; Sato, K.; Mizota, M.; Hirata, M.; Komiyama, A.

Heavy-ion radiotherapy gives a good localized dose distribution just on a cancer tumor. In order to emphasize this advantage, the verification system of a particle range and an irradiated area in a human body has been developed for the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS). The idea comes from the fact that the stopping position of a short-lived positron emitting nuclei, such as 11C, 15O or 19Ne, can be precisely detected by measuring annihilation gamma-rays.

  • Lecture (Conference)
    Proceedings of the Second Asian Particle Accelerator Conference, Beijing, China, 17-21 Sep (2001) 800-802
  • Other report
    Report, National Institute of Radiological Sciences, Chiba, Japan, HIMAC-044 (Dec 2001) 26-28
  • Contribution to proceedings
    Proceedings of the Second Asian Particle Accelerator Conference, Beijing, China, 17-21 Sep (2001) 800-802

Permalink: https://www.hzdr.de/publications/Publ-5461
Publ.-Id: 5461


Therapie mit Radionukliden

Wiegrebe, W.; Johannsen, B.

  • Pharm. Ztg. 148, 2003, 1610-1611

Permalink: https://www.hzdr.de/publications/Publ-5458
Publ.-Id: 5458


Nanopatterning of Si Surfaces by low-energy ion sputtering

Gago, R.

In this seminar the production of nanopatterning by ion beam sputtering (IBS) is presented, namely ripple and dot morphologies. The work is focused on the irradiation of Si surfaces but a general view of this research field is also discussed. Finally, the search of potential applications for these nanostructures is addresed.

Keywords: Ion sputtering; nanopatterning; ripples; nanodots

  • Lecture (others)
    05.05.2003 Forschungsseminar Micro- und Nano-Elektronik, Institut Für Materialwissenschaften Bergische Universität, Wuppertal (gez. Prof. Dr. Clivia SOTOMAYOR-TORRES)

Permalink: https://www.hzdr.de/publications/Publ-5457
Publ.-Id: 5457


Influence of plasma parameters on properties of ITO films produced by reactive pulsed dual magnetron deposition

Rogozin, A.; Vinnichenko, M.; Shevchenko, N.; Kolitsch, A.; Moeller, W.

Middle frequency dual reactive magnetron sputter deposition was used in order to prepare the Indium tin oxide (ITO) films with an optimum of resistance and transmittance. The films were deposited on Si covered with 500 nm SiO2 and soda lime glass substrates. The plasma ions and neutrals flow parameters have been studied during the deposition process by the Langmuir probe, HIDEN analyzer, and optical emission spectroscopy. Complex characterization of the ITO films have been carried out in order to relate their properties with pulsed magnetron operation parameters. The optical constants and the thickness of these films were determined by means of spectroscopic ellipsometry (SE) operating within the wavelength range l=300-1700 nm. The optical transmittance was measured for l=350-2000 nm. Four probe technique was used to determine the film specific resistance. The dependence of the ITO film properties on the O2/Ar partial pressure relation was obtained similarly to known researches. The influence of the pulse duration and base pressure level on the film characteristics was detected. The decrease of the magnetron pulse on-time to the values of about 50 micro seconds, leads to strong increase of the films resistance at their high transmittance. The AFM data for these samples demonstrated five-times increase of the film grain sizes compared to those obtained at the on-time values 100 micro seconds. The observed decrease of optical transmittance in the near IR spectral range corresponds to the decrease of the film resistance. High optical transmittance at low resistance is found only at certain relation between the free electron plasma and relaxation frequency. The grading of optical constants was revealed by SE while the other techniques did not show depth grading of the film properties. Annealing of the ITO films in air atmosphere reduces the film resistance.

Keywords: reactive dual magnetron sputtering; tin doped indium oxide; plasma assisted deposition

  • Lecture (Conference)
    The International Conference on Metallurgical Coatings and Thin Films, San Diego, California, USA, April 26 - May 2, 2003

Permalink: https://www.hzdr.de/publications/Publ-5456
Publ.-Id: 5456


Optimierung der Positronen-Emissions-Tomographie bei der Schwerionentherapie auf der Basis von Röntgentomogrammen

Pönisch, F.

Die Positronen-Emissions-Tomographie (PET) bei der Schwerionentherapie ist eine wichtige Methode zur Qualitätskontrolle in der Tumortherapie mit Kohlenstoffionen. Die vorliegende Arbeit beschreibt die Verbesserungen des PET-Verfahrens, wodurch sich in der Folge präzisere Aussagen zur Dosisapplikation treffen lassen. Aufbauend auf den Grundlagen (Kap. 2) werden die Neuentwicklungen in den drei darauf folgenden Abschnitten (Modellierung des Abbildungsprozesses bei der PET, Streukorrektur für PET bei der Schwerionentherapie, Verarbeitung der rekonstruierten PET-Daten) beschrieben. Die PET-Methode bei der Schwerionentherapie basiert auf dem Vergleich zwischen den gemessenen und vorausberechneten Aktivitätsverteilungen. Die verwendeten Modelle in der Simulation (Erzeugung der Positronenemitter, deren Ausbreitung, der Transport und der Nachweis der Annihilationsquanten) sollten so präzise wie möglich sein, damit ein aussagekräftiger Vergleich möglich wird. Die Genauigkeit der Beschreibung der physikalischen Prozesse wurde verbessert und zeiteffiziente Algorithmen angewendet, die zu einer erheblichen Verkürzung der Rechenzeit führen. Die erwarteten bzw. die gemessenen räumlichen Radioaktivitätsverteilungen werden mit einem iterativen Verfahren rekonstruiert [Lau99]. Die gemessenen Daten müssen hinsichtlich der im Messobjekt auftretenden Comptonstreuung der Annihilationsphotonen korrigiert werden. Es wird ein geeignetes Verfahren zur Streukorrektur für die Therapieüberwachung vorgeschlagen und dessen Realisierung beschrieben. Zur Einschätzung der Güte der Behandlung wird die gemessene und die simulierte Aktivitätsverteilung verglichen. Dazu wurde im Rahmen der vorliegenden Arbeit eine Software entwickelt, das die rekonstruierten PET-Daten visualisiert und die anatomischen Informationen des Röntgentomogramms mit einbezieht. Nur durch dieses Auswerteverfahren war es möglich, Fehler im physikalischen Strahlmodell aufzudecken und somit die Bestrahlungsplanung zu verbessern.

Keywords: PET Schwerionentherapie Streukorrektur MLEM Rekonstruktion

  • Open Access Logo Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-378, Mai 2003
    ISSN: 1437-322X

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-5455
Publ.-Id: 5455


Study of the reaction pp to ppπ0 within 10 MeV above the threshold

Abdel Samad, S.; Bilger, R.; Böhm, A.; Brinkmann, K.-T.; Clement, H.; Dshemuchadse, S.; Eyrich, W.; Filges, D.; Freiesleben, H.; Fritsch, M.; Geyer, R.; Hesselbarth, D.; Jakob, B.; Kilian, K.; Koch, H.; Karsch, L.; Kress, J.; Kuhlmann, E.; Marwinski, S.; Michel, P.; Möller, K.; Morsch, H. P.; Naumann, L.; Richter, M.; Roderburg, E.; Rogge, M.; Schamlott, A.; Schmitz, M.; Schönmeier, P.; Schroeder, M.; Schulte-Wissermann, M.; Sun, G. Y.; Steinke, M.; Stinzing, F.; Wagner, G. J.; Wagner, M.; Wilms, A.; Wirth, S.

Kinematographically complete measurement of the pp to ppc0;0 reaction were performed for beam energies in the range 292 - 298 MeV. By detecting both protons in coincidence with the large acceptance COSY-TOF spectrometer set up at an external beam line of the proton synchrotron COSY-Jülich, total and differential cross sections and energy distributions were obtained. A strong enhancement is observed in the Dalitz plots resulting from the final state interaction between the outgoing proton pair; the data are well reproduced by Monte Carlo simulations with standard parameters for scattering lengths a0 = 7.83 fm and effective range r0 = 2.8 fm. The total cross section exceed the ones measured recently in internal target experiments at IUCF and CELSIUS by roughly 50%. Arguments are presented which link this discrepancy with the effect of the final state interaction pushing yield into the very small-angle region and the near-impossibility of an internal target experiment to cover just this range.

Permalink: https://www.hzdr.de/publications/Publ-5453
Publ.-Id: 5453


Radiopharmazie - Herausforderung und Chance für Apotheker

Wiegrebe, W.; Johannsen, B.

  • Pharm. Ztg. 148, 2003, 1526-1530

Permalink: https://www.hzdr.de/publications/Publ-5452
Publ.-Id: 5452


Measurement of the η production in proton-proton collisions with the COSY time-of-flight spectrometer

Abdel-Bary, M.; Abdel-Samad, S.; Bilger, R.; Brinkmann, K.-T.; Clement, H.; Dshemuchadse, S.; Dorochkevitch, E.; Dutz, H.; Eyrich, W.; Erhardt, A.; Filges, D.; Filippi, A.; Freiesleben, H.; Fritsch, M.; Geyer, R.; Gillitzer, A.; Hesselbarth, D.; Jakob, B.; Karsch, L.; Kilian, K.; Koch, H.; Kreß, J.; Kuhlmann, E.; Marcello, S.; Marwinski, S.; Mauro, S.; Meyer, W.; Michel, P.; Möller, K.; Morsch, H. P.; Naumann, L.; Paul, N.; Richter, M.; Roderburg, E.; Rogge, M.; Schamlott, A.; Schmitz, M.; Schönmeier, P.; Schulte-Wissermann, M.; Schroeder, W.; Sefzik, T.; Stinzing, F.; Sun, G. Y.; Wagner, G. J.; Wagner, M.; Wilms, A.; Wintz, P.; Wirth, S.; Zupranski, P.

The reaction pp to pp η was measured at excess energies of 15 and 41 MeV at an external target of the Jülich Cooler Synchrotron COSY with the time-of-flight spectrometer. About 25000 events were measured for the excess energy of 15 MeV and about 8000 for 41 MeV. Both protons of the process pp η were detected with an acceptance of nearly 100 % and the η was reconstructed by the missing-mass technique. For both excess energies the angular distributions are found to be nearly isotropic. In the invariant-mass distributions strong derivations from the pure phase space distributions are seen.

Permalink: https://www.hzdr.de/publications/Publ-5451
Publ.-Id: 5451


Investigation of flashing-induced instabilities at the CIRCUS test facility using the code ATHLET

Schäfer, F.; Manera, A.

The CIRCUS test facility (Circulation during startup) has been built to study the start-up phase of a natural-circulation BWR. During the start-up so called flashing-induced instabilities can arise. These instabilities are induced by flashing, due to steam production in the long adiabatic riser section, which is placed above the core to enhance the flow rate. Flashing occurring in the riser causes an unbalance between driving force and pressure losses in the natural-circulation loop, giving rise to flow oscillations.

Within the European-Union 5th Framework Programme, a project, NACUSP, has been started in December 2000, having as one of its main aims the understanding of the physics of the phenomena involved during the start-up phase of natural-circulation-cooled BWRs, providing a large experimental database and validating state-of-the-art thermalhydraulic codes in the low-pressure, low-power operational region of these reactors.

One part of this project deals with the modeling of selected CIRCUS tests using the thermo-hydraulic code ATHLET. This paper gives an overview about experimental results and the physics of the instabilities. ATHLET is used to investigate the dynamic behavior of the CIRCUS test facility and the results of the calculations are compared with the experimental data.

Keywords: Natural Circulation; Flow Instabilities; ATHLET; CIRCUS Test Facility

  • Lecture (Conference)
    The 10 th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003
  • Contribution to proceedings
    The 10 th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003

Permalink: https://www.hzdr.de/publications/Publ-5450
Publ.-Id: 5450


Mössbauer-effect study of metastable c-FeSi synthesized by molecular beam epitaxy (MBE) and by ion implantation

Walterfang, M.; Keune, W.; Reuther, H.

Mössbauer-effect study of metastable c-FeSi synthesized by molecular beam epitaxy (MBE) and by ion implantation

  • Phase Transitions 76 (2003) 437-444

Permalink: https://www.hzdr.de/publications/Publ-5449
Publ.-Id: 5449


Mikronukeus-Induktion in Keratinocyten und Fibroblasten durch Bestrahlung mit weichen Röntgenstrahlen.

Spekl, K.; Slonina, D.; Brankovic, K.; Hoinkis, C.; Panteleeva, A.; Pawelke, J.; Dörr, W.

no abstract

  • Experimentelle Strahlentherapie und Klinische Strahlenbiologie, Vol. 11 (2002) 135-139

Permalink: https://www.hzdr.de/publications/Publ-5448
Publ.-Id: 5448


Determination of RBE of X-rays by a novel quasi-monochromatic X-ray source.

Pawelke, J.; Brankovic, K.; Dörr, W.; Dörschel, B.; Enghardt, W.; Lehnert, U.; Neubert, W.; Panteleeva, A.; Prade, H.; Slonina, D.

In the last years, there were several reports about the enhanced risk from irradiation with soft X-rays (below 50 keV). This energy range is relevant for diagnostic radiology, such as mammography, radiotherapy, and for the application of novel radiotherapy approaches such as use of miniature X-ray devices. In order to study this phenomenon, the relative biological effectiveness (RBE) of the X-rays in this energy range has to be determined more precisely. Experiments for determination of biological response after conventional X-ray tube irradiation were performed at TU Dresden. Cell survival for NIH/3T3 mouse fibroblasts was measured for soft X-rays (25 kV) and reference X-rays (200 kV). RBE value of 1.28 ± 0.5 was determined from the linear-quadratic model fit at 10% survival level. Further endpoint to be studied is the formation of micronuclei. At present, experiments are performed on human keratinocytes and chinese hamster fibroblasts. However, the precise determination of the energy dependence of RBE has to be performed by means of irradiation with a monochromatic source. One of the applications of the superconducting electron linear accelerator ELBE, at present under construction at Forschungscentrum Rossendorf, will be to provide such X-rays. The first cell irradiation will be performed with X-rays in the range 10 - 50 keV generated by channeling radiation from relativistic electrons in a diamond crystal. The properties of the electron beam (picosecond structure) as well as the intrinsic energy and intensity distribution of the channeling radiation require consideration of precise dose delivery and monitoring, the results of which will be also presented.

  • Contribution to external collection
    K. Mück, A. Hefner, N. Vana (Hrsg.), Proceedings, TÜV-Verlag GmbH, Köln, ISBN 3-8249-0661-9 (2001) 13-16
  • Lecture (Conference)
    Gemeinsame Tagung des Österreichischen Verbandes für Strahlenschutz und des Fachverbandes für Strahlenschutz e.V. und 33. Jahrestagung des FS "Strahlenschutz für Mensch und Gesellschaft im Europa von morgen", Gmunden, Österreich, 17.-21.09.2001

Permalink: https://www.hzdr.de/publications/Publ-5447
Publ.-Id: 5447


Chromosomal damage and survival of keratinocytes and fibroblasts after irradiation with 200 kV or 25 kV X-rays.

Slonina, D.; Brankovic, K.; Panteleeva, A.; Dörr, W.

no abstract

  • Lecture (Conference)
    5th Conference under the auspices of the Polish Society of Radiation Oncology, "Advances in Radiation Oncology", Poznan, Poland, 19-21 Apr, 2001
    Reports of Practical Oncology and Radiotherapy, Vol. 6 (No. 1) (2001) 39 (ISSN 1507-1367)
  • Contribution to proceedings
    5th Conference under the auspices of the Polish Society of Radiation Oncology, "Advances in Radiation Oncology", Poznan, Poland, 19-21 Apr, 2001
    Reports of Practical Oncology and Radiotherapy, Vol. 6 (No. 1) (2001) 39 (ISSN 1507-1367)

Permalink: https://www.hzdr.de/publications/Publ-5446
Publ.-Id: 5446


Chromosomal damage and survival of keratinocytes and fibroblasts after irradiation with 200 kV or 25 kV X-rays.

Slonina, D.; Spekl, K.; Brankovic, K.; Panteleeva, A.; Dörr, W.

no abstract

  • Poster
    11th European Cancer Conference, Lisbon, Portugal, 21-25 Oct, 2001
    European Journal of Cancer, Vol. 37 (Suppl. 6) (2001) S207 (Abstract No. 758)
  • Contribution to proceedings
    11th European Cancer Conference, Lisbon, Portugal, 21-25 Oct, 2001
    European Journal of Cancer, Vol. 37 (Suppl. 6) (2001) S207 (Abstract No. 758)

Permalink: https://www.hzdr.de/publications/Publ-5445
Publ.-Id: 5445


The estimation of the absorbed dose in the cell.

Panteleeva, A.

no abstract

  • Lecture (Conference)
    Workshop Dosimetrie von Teilchenstrahlung und weicher Röntgenstrahlung, FZ Rossendorf, 10.11.2000
    Proceedings, Institut für Strahlenschutz der Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Köln, Bestell-Nr. IfS 8 (2000) 43-47
  • Contribution to proceedings
    Workshop Dosimetrie von Teilchenstrahlung und weicher Röntgenstrahlung, FZ Rossendorf, 10.11.2000
    Proceedings, Institut für Strahlenschutz der Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Köln, Bestell-Nr. IfS 8 (2000) 43-47

Permalink: https://www.hzdr.de/publications/Publ-5444
Publ.-Id: 5444


Klonogenes Zellüberleben von Keratinozyten und Fibroblasten nach Bestrahlung mit 25 kV und 200 kV Röntgenstrahlen.

Brankovic, K.; Slonina, D.; Panteleeva, A.; Dörr, W.

no abstract

  • Lecture (Conference)
    Gemeinsamer Jahreskongress der Deutschen Gesellschaft für Radioonkologie, Strahlenbiologie und Medizinische Physik, der ÖGRO und der DGMP, München, 06-09 Okt, 2000
    Strahlentherapie und Onkologie, Vol. 176, Sondernr. 1 (2000) 110
  • Contribution to proceedings
    Gemeinsamer Jahreskongress der Deutschen Gesellschaft für Radioonkologie, Strahlenbiologie und Medizinische Physik, der ÖGRO und der DGMP, München, 06-09 Okt, 2000
    Strahlentherapie und Onkologie, Vol. 176, Sondernr. 1 (2000) 110

Permalink: https://www.hzdr.de/publications/Publ-5443
Publ.-Id: 5443


Preparation of RBE measurements of soft X-rays at ELBE.

Panteleeva, A.; Enghardt, W.; Lehnert, U.; Neubert, W.; Pawelke, J.; Prade, H.; Brankovic, K.; Dörr, W.; Dörschel, B.; Slonina, D.

no abstract

  • Poster
    7th Workshop on Heavy Charged Particles in Biology and Medicine, Darmstadt, 28-30 Sep, 2000
    G. Kraft, K. Langbein (Eds.): Book of Abstracts, GSI Report 2000-04, GSI Darmstadt (2000) attachment
  • Contribution to proceedings
    7th Workshop on Heavy Charged Particles in Biology and Medicine, Darmstadt, 28-30 Sep, 2000
    G. Kraft, K. Langbein (Eds.): Book of Abstracts, GSI Report 2000-04, GSI Darmstadt (2000) attachment

Permalink: https://www.hzdr.de/publications/Publ-5442
Publ.-Id: 5442


Radiobiological studies with soft X-rays.

Panteleeva, A.; Enghardt, W.; Lehnert, U.; Pawelke, J.; Prade, H.; Dörr, W.; Dörschel, B.; Brankovic, K.; Slonina, D.

no abstract

  • Contribution to external collection
    V.L. Korogodina, N.A. Zyuzikov (Eds.): Book of Abstracts, Joint Institute for Nuclear Research, Dubna, ISBN 5-85165-572-0 (2000) 142
  • Poster
    Int. Conf. on Modern Problems of Radiobiology, Radioecology and Evolution (Timofeeff-Ressovsky Centennial Conference), Dubna, Russia, 06.-09.09.2000.

Permalink: https://www.hzdr.de/publications/Publ-5441
Publ.-Id: 5441


Skutecznosc bilologiczna niskoenergetycznego promieniowania X (25 kV) oceniana na ludzkich fibroblastach i keratynocytach.

Slonina, D.; Brankovic, K.; Spekl, K.; Panteleeva, A.; Dörr, W.

no abstract

  • Lecture (Conference)
    12th Meeting of Polish Radiation Research (materialy XII Zjazdu Polskiego Towarzystwa Badan Radiacyjnych), Krakow, Poland, 10-12 Sep, 2001
    Proceedings, Instytut Fizyki Jadrowej, Krakow, ISBN 83-908998-3-3 (2001) 74
  • Contribution to proceedings
    12th Meeting of Polish Radiation Research (materialy XII Zjazdu Polskiego Towarzystwa Badan Radiacyjnych), Krakow, Poland, 10-12 Sep, 2001
    Proceedings, Instytut Fizyki Jadrowej, Krakow, ISBN 83-908998-3-3 (2001) 74

Permalink: https://www.hzdr.de/publications/Publ-5440
Publ.-Id: 5440


CFD modelling of subcooled boiling

Krepper, E.

Heat transfer and boiling are key phenomena for power generation facilities. Whereas for 1D thermalhydraulic system codes modeling of boiling was state aof the art from the beginning of their development, the 3D modelling of boiling has not yet reached this maturity. In the paper the boiling model implemented in the CFD-code CFX-4 was applied, to analyse lots of experiments, their results were published in the literature. The validity of the implemented correlations is examined. In many cases the model yields a good agreement to experiments. Especially in the low pressure region, the steam volume fraction is calculated too low. The used models are critical reviewed and compared to alternative solutions. The sensitivity of the calculated results on different influences are compared. Needs for improvements of the model and for further experiments are derived. Main attention should be focused on measuring and modelling of the correct size of the generated steam bubbles.

Keywords: Boiling; CFD; multiphase flow simulations; two fluid model

  • Lecture (Conference)
    The 10th International Topic Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5 - 9, 2003
  • Contribution to proceedings
    The 10th International Topic Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5 - 9, 2003

Permalink: https://www.hzdr.de/publications/Publ-5438
Publ.-Id: 5438


Determination of hydrogen in GaMnN and GaMnMgN by nuclear reaction analysis

Podsiadlo, S.; Szyszko, T.; Grzegorz, W.; Turos, A.; Ratajczak, R.; Kowalczyk, A.; Gebicki, W.; Strzalkowski, I.; Grambole, D.; Herrmann, F.

Gallium nitride is a novel material for short wavelength (blue) optoelectronics. Our previous investigation showed that Mn doped GaN has paramagnetic or antiferromagnetic properties opening new possible applications. The high concentration of magnetic ions possibly allows for the use of such a material in magnetooptic and spintronic devices. GaMnN and GaMnMgN powders were prepared by heating mixtures of gallium and manganese powder or powders of gallium nitride and manganese in a stream of ammonia at the temperature up to 1250°C. The powders have a grain size about 1-10 µm and they contain more than 2% of manganese by weight. Powders of doped GaN were prepared in a series of technological processes at various temperatures, ammonia flow rates and concentration of dopants in initial mixtures. Since hydrogen largely attributes to the passivation of p-dopants it plays an essential role in determination of electrical properties of these materials. Hydrogen content analysis was performed by the NRA method using the 1H(15Na,alpha gamma)12C reaction. This reaction has a sharp resonance of the cross-section at 6.385 MeV. Therefore it is possible by changing the incident 15N beam energy to measure depth distribution of hydrogen. It was found out that hydrogen concentration in our materials was below 1.5at%.

Keywords: Gallium nitride; Doping; Manganese: Magnesium; Ion beam analysis

  • Vacuum 70 (2003) 207-213
  • Poster
    4th Internat. Symposium on Ion Implantation and other Application of Ions and Electrons, ION 2002, 10.-13.06.2002, Kazimierz Dolny, Poland

Permalink: https://www.hzdr.de/publications/Publ-5437
Publ.-Id: 5437


Modelling of bubble flow in vertical pipes

Lucas, D.; Krepper, E.; Prasser, H.-M.

To qualify CFD codes for two-phase flows, they have to be equipped with constitutive models standing for the interaction between the gaseous and the liquid phases. In case of bubble flow this particularly concerns the forces acting on the bubbles and bubble coalescence and break-up. Information on the local structure of the flow is also required by 1D thermal-hydraulic codes. Gas-liquid flow in vertical pipes is a very good object for studying the corresponding phenomena. Here, the bubbles move under clear boundary conditions, resulting in a shear field of nearly constant structure where the bubbles rise for a comparatively long time. The evolution of the flow within the pipe depends on a very complex interaction between bubble forces and bubble coalescence and break-up. E.g. the Lift-force, which strongly influences the radial distribution of the bubbles, changes its sign depending on the bubble diameter. Basing on extensive experimental data with a high resolution in space and time the applicability and the limits for the simulation of bubble flow with current CFX-codes are demonstrated, using the simulation of vertical pipe flow with CFX-4 as an example. Using a simplified model, parametric studies can be conducted. They give an indication for necessary improvements of the codes. Finally a possible way for the improvement of the CFD-codes is shown.

Keywords: two phase flow; bubble flow; bubble size; vertical pipe flow; CFD

  • Lecture (Conference)
    The 10 th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003, Paper A00301
  • Contribution to proceedings
    The 10 th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9, 2003, Paper A00301

Permalink: https://www.hzdr.de/publications/Publ-5436
Publ.-Id: 5436


Phase changes in steels irradiated with intense pulsed plasma beams

Sartowska, B.; Piekoszewski, J.; Walis, L.; Kopcewicz, M.; Werner, Z.; Stanislawski, J.; Kalinowska, J.; Prokert, F.

It is known that transformation of martensite into austenite (alpha'--> gamma) can take place in the surface layers of steels treated with sufficiently intense pulses of laser, ion or plasma beams. Our present work focuses on the phase transformations in the near-surface layer of various types of steel irradiated with short(µs range) intense (5-6 xE-4 J/m2) argon and nitrogen plasma pulses. The results of CEMS measurements, the pin-on-disc wear tests and SEM observations are presented.

Keywords: Intense pulsed plasma beams; Carbon steels; Paramagnetic phases; SEM; CEMS; Wear tests

  • Vacuum 70 (2003) 285-291

Permalink: https://www.hzdr.de/publications/Publ-5435
Publ.-Id: 5435


Alkyl-Substituted 2,6-Dioxadiazolylpyridines as Selective Extractants for Trivalent Actinides

Weigl, M.; Müllich, U.; Geist, A.; Gompper, K.; Zevaco, T.; Stephan, H.

2,6-di(3-alkyl-1,2,4-oxadiazol-5-yl)pyridines, 2,6-di(5-alkyl-1,3,4-oxadiazol-2-yl)pyridines, and 2,6-di(5-alkyl-1,2,4-oxadiazol-3-yl)pyridines were synthesized and tested for their americium(III)-europium(III) selectivity by liquid-liquid extraction. 0.02 M solutions of the compounds extract americium(III) 2-bromohexanoates as monosolvates, AmA3B, from solutions of pH = 2, with an americium(III)-europium(III) separation factor of up to 23. Decreasing the alkyl chain length (butyl < ethyl < methyl) or the polarity of the diluent (chlorobenzene < toluene < tert.-butyl benzene) increased both americium(III) distribution ratio and americium(III)-europium(III) separation factor.

  • Journal of Radioanalytical and Nuclear Chemistry, 256/3 (2003) 403-412

Permalink: https://www.hzdr.de/publications/Publ-5434
Publ.-Id: 5434


Where the anion extraction is going?

Gloe, K.; Stephan, H.; Grotjahn, M.

Reactive extraction processes represent efficient and smart technologies for separation and concentration of metal ions in solution, which are frequently used in industry. Despite the importance of anions in biology, medicine, environment and industry, practical examples of anion extraction are relatively limited compared to metal ion separation. Anion extraction processes are mainly based on the non-specific ion pair formation with hydrophobic ammonium cations. In this case the phase transfer of anions is dominated by their lipophilicity. The reasons for this situation are closely connected with the specific features of anions in contrast to cations. Novel approaches for specific binding and selective transport of anionic components are based both on the better understanding of the biological role of anions and on the possibilities of supramolecular chemistry to build up receptor architectures with complementary binding modes for anions. In the given review the authors discuss present research tendencies and application possibilities of new extractant types for separation and concentration of anionic species in solution.

  • Chem. Eng. Technol. 26 (2003) 1107-1117

Permalink: https://www.hzdr.de/publications/Publ-5433
Publ.-Id: 5433


Towards promising oxoanion extractants: azacages and open-chain counterparts

Farrell, D.; Gloe, K.; Gloe, K.; Goretzki, G.; Mckee, V.; Nelson, J.; Nieuwenhuyzen, M.; Pál, I.; Stephan, H.; Town, R. M.; Wichmann, K.

The efficiency of a series of amino-azacryptands for encapsulation and etraction of the oxoanions pertechnetate and perrhenate from aqueous solution is investigated and compared with that of their open-chain counterparts. The aqueous formation constants for oxoanion association with the cryptands were determined by pH potentiometry and/or NMR, and X-ray analysis of single crystals provides evidence for encapsulation. The extractabilities could not be explained solely on the basis of ligand lipophilicity; the level of protonation also plays an important role.

  • J. Chem. Soc., Dalton Trans. (2003) 1961-1968
  • Lecture (Conference)
    Dalton Discussion 5 "Ligand Design for Functional Complexes", Noordwijkerhout, The Netherlands, 10.-12.04.2003

Permalink: https://www.hzdr.de/publications/Publ-5432
Publ.-Id: 5432


Binding and Extraction of Pertechnetate and Perrhenate by Azacages

Stephan, H.; Gloe, K.; Kraus, W.; Spies, H.; Johannsen, B.; Wichmann, K.; Chand, D. K.; Bharadwag, P. K.; Müller, U.; Müller, W. M.; Vögtle, F.

The design and synthesis of anion receptors of technical and biochemical significance is receiving more and more attention.1-8 Currently, effective binding and selective phase transfer of the oxoanions pertechnetate and perrhenate is of considerable interest from different point of view. Due to its long half-life and environmental mobility, the radioactive pertechnetate is one of the most hazardous contaminants. In this context, effective and selective separation processes are of utmost importance.9-12 On the other hand, there are some emerging possibilities for the application of the radiochemically active oxoanions pertechnetate and perrhenate in nuclear medicine.13,14 The most commonly used isotope in diagnostic nuclear medicine 99mTc is readily available from a 99Mo/99mTc generator system.15-19 Likewise, the b-emitting 188Re – discussed as one of the most interesting radionuclides for specific therapeutic applications – is conveniently produced by a 188W/188Re generator.20-22 In both cases the radionuclides are available as oxoanions in isotonic solution, and it appears highly desirable to directly complex 99mTcO4- and 188ReO4- as they exist in the generator eluate itself. But, the binding of such large, lowly charged anions is a difficult venture. The enthalpic contribution for complexation is rather small. Hence, host compounds being capable to encapsulate these oxoanions are of great interest.
For both directions discussed above, some different requirements have to be fulfilled for the design of ligands. The essential properties of ligands serving as extractants and imaging/therapeutic agents are summarized in Table 1.

  • Contribution to external collection
    B. A. Moyer, R. P. Singh (Eds.): Fundamentals and Applications of Anion Separation, New York: Kluwer Academic/Plenum Publishers, 2004, 151-168

Permalink: https://www.hzdr.de/publications/Publ-5431
Publ.-Id: 5431


Proceedings of the 6th International Conference on Computer Simulation of Radiation Effects in Solids, Dresden, Germany June 23 - 27, 2002

Möller, W.; Posselt, M.; Jäger, H.-U.; (Editors)

no abstract

  • Book (Authorship)
    Nuclear Instruments and Methods B 202 (2003) 1- 322

Permalink: https://www.hzdr.de/publications/Publ-5430
Publ.-Id: 5430


Effect of deposition parameters on properties of ITO films prepared by reactive MF pulsed dual magnetron sputtering

Rogozin, A. I.; Vinnichenko, M. V.; Kolitsch, A.; Möller, W.

ITO layers with low resistivity and high visible transmittance were produced by means of middle frequency reactive dual magnetron sputtering. The influence of base pressure, Ar/O2 ratio and magnetron pulse duration on the film composition, structure, electrical and optical properties has been investigated. The deposition rate is proportional to the magnetron operation power at changing pulse duration and constant Ar and O2 flows. At enhanced O2 flows an onset of the magnetron target oxidation is discussed as a reason for the decrease of the deposition rate. The presence of water vapor in the residual gas is determined to be a reason for deterioration of resistivity and optical transmittance observed for ITO films produced at base pressures higher than 5×10-4 Pa. It is demonstrated that spectroscopic ellipsometry can be used as a non contact tool to monitor the resistivity of ITO films.

Keywords: middle frequency reactive dual magnetron sputtering; indium tin oxide; resistivity; optical properties; spectroscopic ellipsometry

  • Journal of Vacuum Science and Technology A 22(2004), 349-355
    DOI: 10.1116/1.1647595

Permalink: https://www.hzdr.de/publications/Publ-5429
Publ.-Id: 5429


Strangeness Saturation: Dependence on System-Size, Centrality, and Energy

Kämpfer, B.; Cleymans, J.; Wheaton, S.; Steinberg, P.

The dependence of the strangeness saturation factor on the system size, centrality and energy is studied in relativistic
heavy-ion collisions.

Keywords: relativistic heavy-ion collisions; statistical hadronization; strangeness

  • Contribution to external collection
    Proc. Nuclear Dynamics 19 (2003) 103-108
  • Acta Physica Hungarica A 21(2004)2-4, 207-213

Permalink: https://www.hzdr.de/publications/Publ-5428
Publ.-Id: 5428


Kaons in dense matter: results from KaoS

Koczon, P.; Laue, F.; Schwab, E.; Senger, P.; Förster, A.; Oeschler, H.; Sturm, C.; Uhlig, F.; Shin, Y.; Ströbele, H.; Böttcher, I.; Kohlmeyer, B.; Menzel, M.; Pühlhofer, F.; Debowski, M.; Surowka, G.; Walus, W.; Dohrmann, F.; Grosse, E.; Naumann, L.; Scheinast, W.; Wagner, A.

The production of kaons and antikaons in nucleus-nucleus collisions has been studied with the kaon spectrometer at SIS/GSI. The K-/K+ ration was measured in C+C, Ni+Ni, Au+Au collisions at 1.5 AGeV and was found to be almost independent of the system size. In Ni+Ni collisions at 1.93 AGeV we measured the phase-space distributions of K- and K+ mesons. Within the framework of transport models, the measured K+ and K- yields can only be explained if in-medium modifications of the K meson masses are assumed.
In Au-Au collisions at 1 AGeV, we observe non-vanishing elliptic flow near mid-rapidity and in-plane flow at target rapidity for K+ mesons. This effect can be explained by transport models when a repulsive in-medium K+ N potential is taken into account. The ratio of the K+ meson excitation functions for Au+Au and C+C collisions increases with decreasing beam energies. This effect is expected for a soft nuclear equation of state.

  • J.Phys. G: Nucl. Part. Phys. 27 (2001) 275-281

Permalink: https://www.hzdr.de/publications/Publ-5427
Publ.-Id: 5427


Improved 3C-SiC films epitaxially grown on Si by flash lamp processing

Stoemenos, J.; Panknin, D.; Eickhoff, M.; Heera, V.; Skorupa, W.; (Editors)


For the realization of good quality 3C-SiC films, epitaxially grown on Si, the perfection of the film during the early stage of growth is substantial. In this work the beneficial role of Flash Lamp Process (FLP) for defect elimination and strain reduction in the 3C-SiC films is discussed. FLP is a highly transient process with a flash duration of a few milliseconds (ms), preferentially occurring at the SiC/Si interface where the irradiated flux has its maximum absorption. If the energy density is sufficiently high, the temperature at the interface increases above the melting point of silicon. As a result, Si at the interface melts and subsequently dissolves the 3C-SiC in the vicinity of the interface, while the non-melted part of the film is annealed. During the re-solidification phase separation occurs and that part of the SiC film which is already dissolved into silicon is epitaxially deposited on the annealed uppermost part, which acts as the seed layer. The process resembles liquid phase epitaxy (LPE) resulting in substantial improvement of the SiC film. This process also eliminates the cavities and the stress at the 3C-SiC/Si interface. The irradiated 3C-SiC films were characterized by Transmission Electron Microscopy.

Keywords: 3C-SiC interface; flash lamp processing; TEM

  • Journal of the Electrochemical Society 151(2004)2, G136-G143

Permalink: https://www.hzdr.de/publications/Publ-5426
Publ.-Id: 5426


First Measurement of Antikaon Phase-Space Distributions in Nucleus-Nucleus Collisions at Subthreshold Beam Energies

Menzel, M.; Böttcher, I.; Debowski, M.; Dohrmann, F.; Förster, A.; Grosse, E.; Koczon, P.; Kohlmeyer, B.; Laue, F.; Naumann, L.; Oeschler, H.; Pülhofer, F.; Schwab, E.; Senger, P.; Shin, Y.; Ströbele, H.; Sturm, C.; Surowka, G.; Uhlig, F.; Wagner, A.; Walus, W.

Differential production cross sections of K- and K+ mesons have been measured as function of the polar emission angle in Ni+Ni collisions at a beam energy of 1.93 AGeV. In near-central collisions, the spectral shapes and the widths of the rapidity distributions of K- and K+ mesons are in agreement with the assumption of isotropic emission. In non-central collisions, the K- and K+ rapidity distributions are broader than expected for a single thermal source. In this case, the polar angle distributions are strongly forward-backward peaked and the nonisotropic contribution to the total yield is about one third both for K+ and K- mesons. The K-K+ ratio is found to be about 0.03 independent of the centrality of the reaction. This value is significantly larger than predicted by microscopic transport calculations if in-medium modifications of K mesons are neglected.

  • Physics Letters B, 495 (2000) 26-32

Permalink: https://www.hzdr.de/publications/Publ-5425
Publ.-Id: 5425


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