TY - GEN A1 - Hahn, Oliver A1 - Bartoll, Jens A1 - Wolff, Timo A1 - Schade, U. T1 - Analysis of binding media in cross sections using synchrotron infrared radiation KW - Synchrotron infrared radiation KW - FTIR KW - Organic materials KW - Archaeometry KW - Cultural heritage PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=357 SN - 0179-4159 SP - 357 EP - 358 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hahn, Oliver A1 - Bartoll, Jens A1 - Schade, U. T1 - Analysis of binding media in cross sections using synchrotron infrared radiation KW - Synchrotron based FTIR KW - Archaeometry PY - 2006 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2005.pdf#page=383 SN - 0179-4159 SP - 381 EP - 382 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-12411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Masic, Admir A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Schade, U. A1 - Ortolani, M. A1 - Lee, J. A1 - Schmidt, M. A1 - Coluccia, T1 - Dead sea Scrolls: materials characterisation by means of synchrotron based µ-FTIR spectroscopy T2 - III° Convegno internazionale: "Scienza e patrimonio culturale nel mediterrano", Diagnostica e conservazione:esperienze e proposte per una Carta del Rischio CY - Palermo, Italy DA - 2007-10-17 PY - 2007 AN - OPUS4-15028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Oliver A1 - Rabin, Ira A1 - Wolff, Timo A1 - Kanngießer, B. A1 - Malzer, W. A1 - Mantouvalou, I. A1 - Schade, U. A1 - Masic, Admir A1 - Weinberg, G. T1 - Non-destructive investigation of the dead sea scrolls N2 - The Dead Sea Scrolls belong to the most important cultural assets of mankind. Their long term preservation and study is a challenge that demands an interdisciplinary approach. As early as the 1950s natural scientists assisted the scholars in studying the scrolls. It was at this time that the first extensive study of the scroll material took place. It was found that most fragments were written not on leather but on parchment. In addition, a method for determining the age of the parchment was developed which is still of value today. In the 1990s the AMS-C14 method confirmed the palaeographic determination of the age of the manuscripts. The use of carbon ink throughout the scrolls is also consistent with the known scribal practices of that time. There are, however, manuscripts, and among them the famous Genesis Apocryphon Scroll, which exhibit ink corrosion, normally associated with iron-gall inks. Today, 60 years after their discovery, a community of scientists from the Jewish National and University Library (JNUL), the Technical University of Berlin (TU Berlin), the Federal Institute for Materials Research and Testing (BAM) and Fritz-Haber-Institute of the MPG (FHI) set out to scientifically investigate the finds of Qumran using the most modern methods. The results of the study will be used to determine the provenance of the texts as well as to contribute to their long-term preservation. A considerable part of the non-destructive investigation is taking place in the Berlin State Library and at the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung , BESSY II. Preliminary investigations, performed at the BAM on some fragments, were used to evaluate the extent to which X-ray analytical methods can provide information regarding the geographical origin of the fragments and match the individual pieces. The interpretation of the measurement results is made more difficult by age and storage of the objects. It is believed that ageing processes as well as conservation methods have altered the samples in addition to the changes caused by environmental influences. In collaboration with the TU Berlin, the samples from the parchments found in the caves near Qumran were tested by means of three-dimensional synchrotron based X-ray fluorescence analysis (3D-SyXRF). The aim of this non-destructive investigation was the identification of the inorganic material used in the manufacture of the parchments. The XRF experiments are supported by the non-destructive analysis by means of synchrotron based infrared spectroscopy (SyFTIR) in collaboration with BESSY II as well as optical and electron microscopy in collaboration with Fritz-Haber-Institute (FHI). T2 - Art 2008, 9th International Conference CY - Jerusalem, Israel DA - 2008-05-25 KW - Cultural heritage KW - Archaeometry KW - Micro-XRF KW - Quantification KW - Parchment KW - DSS PY - 2008 IS - CD-ROM SP - 1 EP - 7 PB - ISAS International Seminars CY - Jerusalem, Israel AN - OPUS4-17547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartoll, Jens A1 - Hahn, Oliver A1 - Schade, U. T1 - Application of synchrotron infrared radiation in the study of organic coatings in cross-sections KW - Cultural heritage KW - FTIR KW - Synchrotron radiation KW - Non-destructive testing KW - Organic material PY - 2008 SN - 0039-3630 SN - 0370-9124 VL - 53 IS - 1 SP - 1 EP - 8 PB - International Institute for Conservation of Historic and Artistic Works CY - London AN - OPUS4-17709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Chrzanowski, Lars A1 - Beckmann, Jörg A1 - Marchetti, Barbara A1 - Ewert, Uwe A1 - Schade, U. T1 - Capability of terahertz-wave instrumentation for non destructive testing of liquids T2 - 10th European conference on non-destructive testing CY - Moscow, Russia DA - 2010-06-07 KW - Terahertz PY - 2010 UR - http://www.ndt.net/article/ecndt2010/reports/1_05_16.pdf IS - Paper 4.02.18 SP - 1 EP - 8 AN - OPUS4-21685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Wolff, Timo A1 - Kindzorra, Emanuel A1 - Masic, A. A1 - Schade, U. A1 - Weinberg, G. ED - Dik, J. ED - Gunneweg, J. ED - Adriaens, A. T1 - Characterization of the writing media of the Dead Sea scrolls KW - Dead Sea scrolls KW - Parchment KW - Carbon ink KW - XRF KW - FTIR KW - SEM PY - 2010 SN - 978 90 04 18152 6 SN - 0169-9962 IS - Chapter 9 SP - 123 EP - 134 PB - Brill CY - Leiden, The Netherlands AN - OPUS4-21238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - von Chrzanowski, Lars A1 - Beckmann, Jörg A1 - Marchetti, Barbara A1 - Ewert, Uwe A1 - Schade, U. T1 - Terahertz time domain spectroscopy for non-destructive testing of hazardous liquids N2 - Flüssige Gefahr- und Brennstoffe sowie explosive Flüssigkeiten werden mittels zeitaufgelöster Terahertz-Spektroskopie (THZ-TDS) in Analogie zu den in der zerstörungsfreien Werkstoffprüfung verwendeten Strategien untersucht. Verschiedene polare Flüssigkeiten (Alkohole, Aceton, Wasserstoffperoxid, Nitromethan), unpolare Flugzeug- und Kraftfahrzeugkraftstoffe sowie organische Lösungsmittel werden in der praxisrelevanten Reflexionsgeometrie berührungs- und zerstörungsfrei im Zeitbereich charakterisiert. Die Absorptions- und Brechungsindizes einer repräsentativen Auswahl von Flüssigkeiten wurden im Frequenzbereich zwischen 0.1 THz und 1.1 THz unter Verwendung der Transmissionsanordnung spektral ermittelt. Die Messkonfiguration wird für stark und schwach absorbierende Flüssigkeiten jeweils angepasst. KW - Zeitaufgelöste Terahertz-Spektroskopie (THZ-TDS) KW - Flüssige Gefahr und Brennstoffe KW - Time domain spectroscopy PY - 2012 SN - 0025-5300 VL - 54 IS - 6 SP - 444 EP - 450 PB - Hanser CY - München AN - OPUS4-26057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Puskar, L. A1 - Ritter, E. A1 - Schade, U. T1 - Novel Technique for On-Line Monitoring of the Curing Process of Fiber Reinforced Polymer Composites N2 - A specially developed experimental set up has been integrated into a commercially available FT IR Spectrometer to study the curing of Epoxy Systems. MIR and FIR spectra measured during the curing process at different temperatures of an epoxy system will be presented in dependency of the curing time. The experiments and the selected set up are discussed to demonstrate its potential for future monitoring and ageing control applications during a manufacturing process of polymer composites. T2 - 45. International conference on infrared, millimeter, and terahertz waves CY - Online meeting DA - 08.11.2020 KW - Far-infrared spectroscopy KW - Online Curing Monitoring PY - 2021 SN - 978-1-7281-6620-9 U6 - https://doi.org/10.1109/irmmw-thz46771.2020.9370646 SP - 1 PB - IEEE AN - OPUS4-53059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beckmann, Jörg A1 - Marchetti, B. A1 - von Chrzanowski, Lars S. A1 - Ritter, E. A1 - Puskar, L. A1 - Aziz, E. F. A1 - Schade, U. T1 - Optical constants of harmful and highly energetic liquids for application to THz screening systems N2 - The far-infrared (IR) optical constants of a set of hazardous and flammable liquids have been obtained by means of spectroscopic ellipsometry in attenuated total reflection configuration over a broad spectral range. Such liquids recently became of considerable concern for transportation security measures worldwide. Their optical identification at check-in gates can only become possible if the characteristic spectra are already known. The refractive indices and the extinction coefficients reported here contribute to a spectroscopic data base in the far-IR and terahertz (THz) spectral regions and may support modeling the performance of THz screening systems on liquids for airports and other security sensitive areas. Examples of several container material/liquid systems are discussed. From the measured optical constants typical THz waveforms are calculated and discussed. KW - liquids material characterization KW - Ellipsometry KW - FT-IR spectroscopy KW - THz time-domain spectroscopy (THz-TDS) PY - 2016 U6 - https://doi.org/10.1109/TTHZ.2016.2547319 SN - 2156-342X VL - 2016 / Vol. PP IS - 99 SP - 1 EP - 12 PB - IEEE - Inst. Electrical Electronics Engineers Inc CY - New York, NY, USA AN - OPUS4-36366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Ritter, E. A1 - Puskar, L. A1 - Aziz, E. F. A1 - Beckmann, Jörg T1 - Estimation of THz waveforms for material characterization of stratified objects N2 - The poster discusses theoretically and exemplarily the influence of the materials and experimentally selected situation on the shape and size deformation of a detected pulse signal previously reflected on a three layer sheet. T2 - 41st International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2016) CY - Copenhagen, Denmark DA - 25.09.2016 KW - THz spectroscopy KW - Pulse reflection KW - Pulse shape analysis KW - Optical layer model PY - 2016 AN - OPUS4-37639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Schade, U. A1 - Aziz, E. F. A1 - Wolff, Dietmar T1 - Fourier-spektroskopische Untersuchungen im mittleren- und fernen Infrarotbereich an Co-60 bestrahlten und thermisch belasteten ultrahochmolekularen Polyethylen-Proben N2 - Fourier-Spektroskopische Untersuchungen von hochmolekularem Polyethylen (HMW-PE) und ultrahochmolekularem Polyethylen (UHMW-PE) im Mittleren - und Fernen Infrarotbereich können Veränderungen der molekularen Strukturen nachweisen, die durch Co60 γ-Strahlung und Rekristallisationsprozesse initiiert werden. UHMW-PE und HMW-PE sind im gewählten IR-Bereich unterscheidbar. Die integrale Absorption der B1u – Gitterschwingungen im Fernen Infrarotbereich (THz-Bereich) ermöglichen die quantitative Beschreibung des Kristallinitätsgrades und dessen Abbau. Die Bildung ungesättigter Vinylengruppen und der Abbau ungesättigter Methylengruppen können im Mittleren Infrarotbereich nachgewiesen werden. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 KW - Infrared and far-infrared spectroscopy KW - Polyethylene KW - Co-60 irradiation PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-313317 SN - 978-3-940283-61-0 VL - 148 SP - 1 EP - 7 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-31331 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Ritter, E. A1 - Bawagan, A.D.O. A1 - Aziz, E. F. A1 - Beckmann, Jörg T1 - Far-Infrared Absorption Measurements on Thin Polymer Films T2 - 39th Int. Conf. on Infrared, Millimeter, and THz Waves CY - The University of Arizona, Tucson, AZ, USA DA - 2014-09-14 PY - 2014 AN - OPUS4-31903 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Aziz, E. F. T1 - THz and Mid IR Fourier Transform Spectroscopy on Polyethylene Irradiated with Gamma- Co60 Radiation T2 - 39th Int. Conf. on Infrared, Millimeter, and THz Waves CY - The University of Arizona, Tucson, AZ, USA DA - 2014-09-14 PY - 2014 AN - OPUS4-31904 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marchetti, Barbara A1 - von Chrzanowski, Lars A1 - Beckmann, Jörg A1 - Röseler, A. A1 - Schade, U. T1 - THz Spectroscopy to derive the optical constants of liquids N2 - THz stand-off detection of explosives and other hazardous liquids in public areas becomes more and more relevant and with it the knowledge of their optical properties. We present here both the results of THz transmission spectroscopy measurements and spectroscopic ellipsometry measurements on liquids and their mixtures. T2 - IRMMW-THz 2010 - 35th International conference on infrared, millimeter, and terahertz waves CY - Rome, Italy DA - 2010-09-05 KW - THz Spectroscopy KW - Optical constants KW - Liquids PY - 2010 SN - 978-1-4244-6656-6 U6 - https://doi.org/10.1109/ICIMW.2010.5612487 SP - 1 EP - 2 AN - OPUS4-22045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Chrzanowski, Lars A1 - Beckmann, Jörg A1 - Marchetti, Barbara A1 - Ewert, Uwe A1 - Schade, U. T1 - Terahertz-Strahlung - Möglichkeiten für die zerstörungsfreie Prüfung von Flüssigkeiten N2 - Elektromagnetische Wellen von 0.3 bis 6 Terahertz (THz) werden als THz-Strahlung bezeichnet. Im elektromagnetischen Spektrum sind sie zwischen Mikro-/Millimeterwellen und Infrarot angesiedelt. Der nicht ionisierende Charakter und die Möglichkeit, Verpackungsmaterialen sowie Kleidung zu durchstrahlen, machen die THz-Strahlung für bildgebende- und spektroskopische Anwendungen sehr interessant. Besondere Aufmerksamkeit gilt der Zeitaufgelösten Terahertz- Spektroskopie (THz-TDS) im Sicherheitssektor. Feste Spreng- und Gefahrenstoffe sind vielfach bezüglich ihrer Transmissions- und Reflexionseigenschaften untersucht worden, um sie anhand ihrer ‚Fingerprints’ zu identifizieren. Moderne mit Glasfaser ausgerüstete THz-TD-Spektrometer zeichnen sich im Vergleich zu konventionellen Freistrahlgeräten durch höhere Flexibilität aus. In Zukunft werden diese auch als ‚Handheld’-Geräte entwickelt, um eine Nutzung außerhalb des Laboratoriums zu ermöglichen. Das glasfasergekoppelte Picometrix T-ray 2000 System der BAM wurde in ein Zwei-Kreis Goniometer integriert. Probe und Detektor können unabhängig voneinander bewegt werden. Eine schnelle Überführung der Transmissionsin die Reflexionsanordnung und umgekehrt, ist möglich. Seit der Verwendung flüssiger Brand- und Gefahrstoffe bei terroristischen Anschlägen ist das Interesse an der Identifizierung im Sicherheitsbereich zunehmend gewachsen. Um zu überprüfen, ob die THz-TDS für die spektrale Charakterisierung von Flüssigkeiten eingesetzt werden kann, wurden Transmissions- und Reflexionseigenschaften repräsentativer Flüssigkeiten und Flüssigkeitsgemische bestimmt. Polare Flüssigkeiten sind starke Absorber im THz-Bereich. Ab einer Flüssigkeitsschichtdicke von ca. 1mm ist mit dem THz-Spektrometer T-ray 2000 kein Signal stark polarer Flüssigkeiten mehr detektierbar. Der Einsatz einer Messzelle mit variabler Schichtdicke (50 - 1000 .m) war für die Bestimmung der Transmissionseigenschaften polarer Flüssigkeiten notwendig. Anhand von Transmissions- und Reflexionsuntersuchungen an polaren sowie unpolaren Flüssigkeiten werden die Möglichkeiten der THz-TDS zur berührungslosen Identifizierung von Flüssigkeiten aufgezeigt. T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Deutschland DA - 2010-05-10 PY - 2010 UR - http://www.ndt.net/article/dgzfp2010/Inhalt/di3b2.pdf SN - 978-3-940283-26-9 IS - DGZfP-BB 122 (Di.3.B.2) SP - 1 EP - 10 CY - Berlin AN - OPUS4-21932 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Schade, U. A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Aziz, E. F. T1 - THz and Mid IR Fourier transform spectroscopy on polyethylene irradiated with Gamma- Co60 radiation N2 - THz and mid IR spectroscopy of high molecular PE (HMW) and ultra high molecular PE (UHMW) reveals modifications of the molecular structure induced by γ-Co60 radiation. UHMW-PE and HMW-PE can be distinguished. The integral absorption in the B1u THz-region can quantitatively describe the amorphization of crystallinity. The formation of trans vinylene unsaturations and the decay of vinyl can be followed by mid IR spectroscopy T2 - IRMMW-THz 2014 - 39th International conference on infrared, millimeter, and terahertz waves CY - Tucson, Arizona, USA DA - 14.09.2014 KW - Thz and Mid IR Fourier transform spectroscopy KW - Polyethylene KW - Gamma-Co-60 radiation KW - Fourier transform spectroscopy KW - Infrared spectroscopy KW - Light absorption KW - Molecular electronic states KW - Polymers KW - MidIR Fourier transform spectroscopy KW - Terahertz spectroscopy KW - THz spectroscopy KW - γ-Co60radiation KW - HMW KW - High molecular PE KW - Ultrahigh molecular PE KW - Molecular structure modifications KW - UHMW-PE KW - HMW-PE KW - Integral absorption KW - B1uTHz-region KW - Crystallinity amorphization KW - Transvinylene unsaturation formation KW - Vinyl decay KW - Absorption KW - Radiation effects KW - Temperature measurement KW - Spectroscopy PY - 2014 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6956355&isnumber=6955975 SN - 978-1-4799-3877-3 U6 - https://doi.org/10.1109/IRMMW-THz.2014.6956355 IS - IEEE Catalog No.: CFP14IMM-ART SP - 1 EP - 2 AN - OPUS4-32699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Ritter, E. A1 - Bawagan, A.D.O. A1 - Beckmann, Jörg A1 - Aziz, E. F. T1 - Far-infrared absorption measurements on thin polymer films N2 - Interference fringes in the far-infrared spectra of thin films are the result of the coherent adding up of waves and can influence the spectral interpretation by concealing smaller features. A number of methods have been developed in order to eliminate such oscillating features from the transmittance spectrum. The paper critically evaluates the total transmission-reflection technique and applies the method to quantify the spectra of different polymer films. T2 - IRMMW-THz 2014 - 39th International conference on infrared, millimeter, and terahertz waves CY - Tucson, Arizona, USA DA - 14.09.2014 KW - Far-infrared spectra KW - Thin films KW - Total transmission reflection technique KW - Infrared spectroscopy KW - Light absorption KW - Light reflection KW - Polymer films KW - Far-infrared absorption measurements KW - Thin polymer films KW - Interference fringes KW - Spectral interpretation KW - Transmittance spectrum KW - Oscillating features KW - Total transmission-reflection technique KW - Interference KW - Absorption KW - Finite impulse response filters KW - Optical films KW - Optical reflection PY - 2014 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6956145&isnumber=6955975 SN - 978-1-4799-3877-3 U6 - https://doi.org/10.1109/IRMMW-THz.2014.6956145 IS - IEEE Catalog No.: CFP14IMM-ART SP - 1 EP - 2 AN - OPUS4-32700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schade, U. A1 - Dawei, C. A1 - Puskar, L. A1 - Ritter, E. A1 - Beckmann, Jörg T1 - Removal of Etalon Features in the Far-Infrared–Terahertz Transmittance Spectra of Thin Polymer Films N2 - Etalon features in infrared spectra of stratified samples, their influence on the interpretation and methods to circumvent their presence in infrared spectra have been in discussion for decades. This paper focuses on the application of a method originally developed to remove interference fringes in the mid-infrared spectra for far-infrared Fourier transform spectroscopy on thin polymer films. We show that the total transmittance-reflectance technique, commonly used for mid-infrared, also works successfully in the far infrared spectral range where other approaches fail. Experimental spectra obtained by such technique are supported by model calculations and reveal the possibility and limits to obtain almost undisturbed far-infrared spectra which are suitable to determine low energy vibrations of ionomer salts under certain sample conditions. KW - Far-infrared spectroscopy KW - Absorption KW - Etalon feature KW - Total transmittance reflectance PY - 2020 U6 - https://doi.org/10.1177/0003702820922295 VL - 74 IS - 12 SP - 1530 EP - 1539 PB - Sage journals AN - OPUS4-51367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Pulskar, L. A1 - Ritter, E. A1 - Beckmann, Jörg T1 - Etalon Effects in THz Film Measurements N2 - Etalon effects in THz transmittance spectra, either taken in time-domain or frequency-domain, often hamper or even hinder the interpretation of film properties. In this paper we discuss the transferability and applicability of spectroscopic methods usually employed in the near and mid infrared spectral range and exemplarily present the application field. T2 - 45. International Confercene on infrared, milimeter and terahertz waves CY - Online meeting DA - 08.11.2020 KW - Far-infrared spectroscopy KW - Etalon Effects PY - 2020 UR - https://live-irmmwthz.pantheonsite.io/technical-program AN - OPUS4-51652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Chatzigiannakis, E. A1 - Beckmann, Jörg A1 - Wachtendorf, Volker A1 - von der Ehe, Kerstin A1 - Braun, Ulrike A1 - Jaunich, Matthias A1 - Schade, U. A1 - Wolff, Dietmar T1 - Discoloration Effects of High-Dose gamma-Irradiation and Long-Term Thermal Aging of (U) HMW-PE N2 - Two polyethylene types with ultra-high (UHMWPE) and high molecular weight (HMW-PE) used as neutron radiation shielding materials in casks for radioactive waste were irradiated with doses up to 600 kGy using a 60Co gammasource. Subsequently, thermal aging at 125∘C was applied for up to one year. Degradation effects in the materials were characterized using colorimetry, UV-Visspectroscopy, IR spectroscopy, and DSC. Both materials exhibited a yellowing upon irradiation.The discoloration of UHMW-PE disappeared again after thermal aging.Therefore, the yellowing is assumed to originate fromannealable color centers in the formof free radicals that are trapped in the crystalline regions of the polymer and recombine at elevated temperatures. For the antioxidantcontaining HMWPE, yellowing was observed after both irradiation and thermal aging. The color change was correlated mainly to decomposition products of the antioxidant in addition to trapped radicals as in UHMW-PE. Additionally, black spots appeared after thermal aging of HMW-PE. KW - Irradiation KW - UHMWPE KW - Colour center KW - Yellowness index PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-423992 SN - 1687-9422 VL - 2017 IS - Article ID 1362491 SP - 1 EP - 10 PB - Hindawi AN - OPUS4-42399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Ritter, E. A1 - Aziz, E. F. A1 - Puskar, L. A1 - Beckmann, Jörg T1 - Spectroscopic ellipsometry on liquids in the far infrared N2 - The far infrared refractive indices and the extinction coefficients of liquids can be obtained by means of spectroscopic ellipsometry in attenuated total reflection configuration. Such optical constants will contribute to a spectroscopic data base in the far infrared and terahertz spectral regions. The experimental implementation and the calibration procedure of the method are described in detail. The temperature dependency of the optical constants for water over a broad spectral range is exemplarily presented. T2 - 42nd International Conference on Infrared, Millimeter and THz Waves CY - Cancun, Mexico DA - 27.08.2017 KW - Ellipsometry KW - Far Infrared KW - ATR KW - Attenuated total reflection KW - Calibration KW - Extinction coefficients KW - Refractive index measurement KW - Spectroscopic ellipsometry KW - Far infrared refractive index KW - Terahertz spectral region KW - Optical constant KW - Attenuated total reflection configuration KW - Liquid extinction coefficient KW - Optical refraction KW - Optical variables control KW - Optical reflection KW - Liquids KW - Optical films KW - Optical polarization KW - Optical variables measurement PY - 2017 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8066931&isnumber=8066832 U6 - https://doi.org/10.1109/IRMMW-THz.2017.8066931 SN - 2162-2035 SP - MD.1.5-1 EP - MD.1.5-2 PB - IEEE CY - Danvers AN - OPUS4-42028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Puskar, L. A1 - Ritter, E. A1 - Beckmann, Jörg T1 - Etalon effects in THz film measurements N2 - Etalon effects in THz transmittance spectra, either taken in time- domain or frequency-domain, often hamper or even hinder the interpretation of film properties. In this paper we discuss the transferability and applicability of spectroscopic methods typically employed in the near and mid infrared spectral range to eliminate the fringes in the transmittance spectra in the THz spectral range. T2 - 2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) CY - Buffalo, NY, USA DA - 08.11.2020 KW - THz radiation KW - Total transmittance reflection technique KW - Etalon effects PY - 2020 SN - 978-1-7281-6620-9 U6 - https://doi.org/10.1109/IRMMW-THz46771.2020.9370451 SN - 2162-2035 SN - 2162-2027 SP - 1 PB - IEEE CY - Buffalo, NY AN - OPUS4-56943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Puskar, L. A1 - Ritter, E. A1 - Beckmann, Jörg T1 - Etalon effects in THz film measurements N2 - Etalon features in transmittance spectra of films arise due to the coherent superposition of waves caused by reflections multiple times at the inner film boundaries. The fringe maxima occur at i𝜆 = 2nd cos 𝜑 with i - being an integer, 𝜆 - the wavelength, d - the film thickness, 𝜑 - the angle of incidence in respect to the film normal and n - the refractive index of the film. It is obvious that such features can hinder the interpretation of absorption bands when fringe amplitude and period are in the same range as the expected bands. This poster discusses the suitability of two optical methods for the THz spectral range applied to Fourier Transform Spectroscopy. T2 - 2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) CY - Buffalo, NY, USA DA - 08.11.2020 KW - THz radiation KW - Total transmittance reflection technique PY - 2020 AN - OPUS4-56945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Puskar, L. A1 - Golnak, R. A1 - Veber, A. A1 - Beckmann, Jörg T1 - Infrared Attenuate Total Reflection Cell with a Functionalized Surface N2 - ATR cell utilizing chips from silicon wafers is discussed. The cell can be used for wet-chemical analysis on functionalized surfaces. Here, silicon chips are exemplarily "functionalized" by silica layers to provide a hydrophilic or hydrophobic ATR surface in-situ. T2 - 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) CY - Montreal, Quebec, Canada DA - 17.09.2023 KW - THz radiation KW - ATR KW - FTIR PY - 2023 U6 - https://doi.org/10.1109/IRMMW-THz57677.2023.10298918 SP - 1 PB - IEEE CY - New York, NY AN - OPUS4-59326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -