TY - JOUR A1 - Fleischhaker, Robert A1 - Krauß, Nico A1 - Schättiger, Farina A1 - Dekorsy, Thomas T1 - Consistent characterization of semiconductor saturable absorber mirrors with singe-pulse and pump-probe spectroscopy JF - Optics Express Y1 - 2013 U6 - https://doi.org/10.1364/OE.21.006764 SN - 1094-4087 VL - 21 IS - 6 SP - 6764 EP - 6776 PB - Optica CY - Washington, DC ER - TY - JOUR A1 - Fleischhaker, Robert A1 - Evers, Jörg T1 - A Maxwell–Schrödinger solver for quantum optical few-level systems JF - Computer Physics Communications N2 - The msprop program presented in this work is capable of solving the Maxwell–Schrödinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax–Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax–Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown. Y1 - 2011 U6 - https://doi.org/10.1016/j.cpc.2010.10.018 SN - 0010-4655 VL - 182 IS - 3 SP - 739 EP - 747 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Fleischhaker, Robert A1 - Evers, Jörg A1 - Dey, Tarak N. T1 - Phase modulation induced by cooperative effects in electromagnetically induced transparency JF - Physical Review A - Atomic, molecular, and optical physics N2 - We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium. Y1 - 2010 U6 - https://doi.org/10.1103/PhysRevA.82.013815 SN - 1050-2947 VL - 82 IS - 1 PB - AIP Publishing CY - Melville, NY ER - TY - JOUR A1 - Fleischhaker, Robert A1 - Evers, Jörg T1 - Nonlinear effects in pulse propagation through Doppler-broadened closed-loop atomic media JF - Physical Review A - Atomic, molecular, and optical physics Y1 - 2008 U6 - https://doi.org/10.1103/PhysRevA.77.043805 SN - 1050-2947 VL - 77 IS - 4 SP - 043805 ER - TY - JOUR A1 - Fleischhaker, Robert A1 - Evers, Jörg T1 - Four-wave mixing enhanced white-light cavity JF - Physical Review A - Atomic, molecular, and optical physics Y1 - 2008 SN - 0556-2791 VL - 78 IS - 5 SP - 051802(R) ER - TY - THES A1 - Fleischhaker, Robert T1 - Light propagation in dense and chiral media Y1 - 2009 N1 - Heidelberg, Univ., Diss., 2009 ER - TY - CHAP A1 - Evers, Jörg A1 - Fleischhaker, Robert A1 - Pálffy, A. A1 - Keitel, C. T1 - Light propagation : From atomic to nuclear quantum optics T2 - Modern optics and photonics: atoms and structured media Y1 - 2010 SN - 978-981431327-8 U6 - https://doi.org/10.1142/9789814313278_0001 SP - 3 EP - 15 PB - World Scientific Publishing Co. ER - TY - BOOK A1 - Pieper, Martin T1 - Quantenmechanik : Einführung in die mathematische Formulierung Y1 - 2019 SN - 978-3-658-28329-2 U6 - https://doi.org/10.1007/978-3-658-28329-2 N1 - auch gedruckt in der Bereichbibliothek Jülich unter der Signatur 61 UHH 41 PB - Springer Spektrum CY - Wiesbaden ER - TY - JOUR A1 - Henriques, A. A1 - Jurado, B. A1 - Grieser, M. A1 - Denis-Petit, D. A1 - Chiron, T. A1 - Gaudefroy, L. A1 - Glorius, J. A1 - Langer, Christoph A1 - Litvinov, Yu. A. A1 - Mathieu, L. A1 - Meot, V. A1 - Perez-Sanchez, R. A1 - Pibernat, J. A1 - Reifarth, R. A1 - Roig, O. A1 - Thomas, B. A1 - Thomas, B. A. A1 - Thomas, J. C. A1 - Tsekhanovich, I. T1 - Indirect measurements of neutron cross-secti at heavy-ion storage rings JF - Journal of Physics: Conference Series N2 - Cross sections for neutron-induced reactions of short-lived nuclei are essential for nuclear astrophysics since these reactions in the stars are responsible for the production of most heavy elements in the universe. These reactions are also key in applied domains like energy production and medicine. Nevertheless, neutron-induced cross-section measurements can be extremely challenging or even impossible to perform due to the radioactivity of the targets involved. Indirect measurements through the surrogate-reaction method can help to overcome these difficulties. The surrogate-reaction method relies on the use of an alternative reaction that will lead to the formation of the same excited nucleus as in the neutron-induced reaction of interest. The decay probabilities (for fission, neutron and gamma-ray emission) of the nucleus produced via the surrogate reaction allow one to constrain models and the prediction of the desired neutron cross sections. We propose to perform surrogate reaction measurements in inverse kinematics at heavy-ion storage rings, in particular at the CRYRING@ESR of the GSI/FAIR facility. We present the conceptual idea of the most promising setup to measure for the first time simultaneously the fission, neutron and gamma-ray emission probabilities. The results of the first simulations considering the 238U(d,d') reaction are shown, as well as new technical developments that are being carried out towards this set-up. Y1 - 2020 U6 - https://doi.org/10.1088/1742-6596/1668/1/012019 VL - 1668 IS - Art. 012019 PB - IOP CY - Bristol ER - TY - JOUR A1 - Varga, Laszlo A1 - Davinson, Thomas A1 - Glorius, Jan A1 - Jurado, Beatrix A1 - Langer, Christoph A1 - Lederer-Woods, Claudia A1 - Litvinov, Yuri A. A1 - Reifarth, Rene A1 - Slavkovska, Zuzana A1 - Stöhlker, Thomas A1 - Woods, Phil J. A1 - Xing, Yuan Ming T1 - Towards background-free studies of capture reaction in a heavy-ion storage ring JF - Journal of Physics: Conference Series N2 - Stored and cooled, highly-charged ions offer unprecedented capabilities for precision studies in the realm of atomic, nuclear structure and astrophysics[1]. After the successful investigation of the 96Ru(p,7)97Rh reaction cross section in 2009[2], the first measurement of the 124Xe(p,7)125Cs reaction cross section has been performed with decelerated, fully-ionized 124Xe ions in 2016 at the Experimental Storage Ring (ESR) of GSI[3]. Using a Double Sided Silicon Strip Detector, introduced directly into the ultra-high vacuum environment of a storage ring, the 125Cs proton-capture products have been successfully detected. The cross section has been measured at 5 different energies between 5.5AMeV and 8AMeV, on the high energy tail of the Gamow-window for hot, explosive scenarios such as supernovae and X-ray binaries. The elastic scattering on the H2 gas jet target is the major source of background to count the (p,7) events. Monte Carlo simulations show that an additional slit system in the ESR in combination with the energy information of the Si detector will enable background free measurements of the proton-capture products. The corresponding hardware is being prepared and will increase the sensitivity of the method tremendously. Y1 - 2020 VL - 1668 IS - Art 012046 PB - IOP CY - Bristol ER - TY - BOOK A1 - Pieper, Martin T1 - Quantenmechanik: Einführung in die mathematische Formulierung Y1 - 2019 SN - 978-3-658-28328-5 U6 - https://doi.org/10.1007/978-3-658-28329-2 PB - Springer Spektrum CY - Wiesbaden ER - TY - GEN A1 - Nobisrath, Ulrich A1 - Zündorf, Albert A1 - George, Tobias A1 - Ruben, Jubeh A1 - Kraft, Bodo T1 - Software Stories Guide N2 - Software Stories are a simple graphical notation for requirements analysis and design in agile software projects. Software Stories are based on example scenarios. Example scenarios facilitate the communication between lay people or domain experts and software experts. Y1 - 2017 ER - TY - BOOK A1 - Pieper, Martin T1 - Mathematische Optimierung: Eine Einführung in die kontinuierliche Optimierung mit Beispielen Y1 - 2017 SN - 978-3-658-16975-6 U6 - https://doi.org/10.1007/978-3-658-16975-6 PB - Springer Fachmedien CY - Wiesbaden ER - TY - JOUR A1 - Rieke, Christian A1 - Stollenwerk, Dominik A1 - Dahmen, Markus A1 - Pieper, Martin T1 - Modeling and optimization of a biogas plant for a demand-driven energy supply JF - Energy N2 - Due to the Renewable Energy Act, in Germany it is planned to increase the amount of renewable energy carriers up to 60%. One of the main problems is the fluctuating supply of wind and solar energy. Here biogas plants provide a solution, because a demand-driven supply is possible. Before running such a plant, it is necessary to simulate and optimize the process. This paper provides a new model of a biogas plant, which is as accurate as the standard ADM1 model. The advantage compared to ADM1 is that it is based on only four parameters compared to 28. Applying this model, an optimization was installed, which allows a demand-driven supply by biogas plants. Finally the results are confirmed by several experiments and measurements with a real test plant. Y1 - 2018 U6 - https://doi.org/10.1016/j.energy.2017.12.073 SN - 0360-5442 VL - 145 SP - 657 EP - 664 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dotzauer, Martin A1 - Pfeiffer, Diana A1 - Lauer, Markus A1 - Pohl, Marcel A1 - Mauky, Eric A1 - Bär, Katharina A1 - Sonnleitner, Matthias A1 - Zörner, Wilfried A1 - Hudde, Jessica A1 - Schwarz, Björn A1 - Faßauer, Burkhardt A1 - Dahmen, Markus A1 - Rieke, Christian A1 - Herbert, Johannes A1 - Thrän, Daniela T1 - How to measure flexibility – Performance indicators for demand driven power generation from biogas plants JF - Renewable Energy Y1 - 2019 U6 - https://doi.org/10.1016/j.renene.2018.10.021 SN - 0960-1481 SP - 135 EP - 146 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Borchert, Jörg A1 - Tenbrake, Andre T1 - Bewirtschaftung von Flexibilität über Microservices eines Plattformanbieters T2 - Realisierung Utility 4.0 Band 1 N2 - Die Energiewirtschaft befindet sich in einem starken Wandel, der v. a. durch die Energiewende und Digitalisierung Druck auf sämtliche Marktteilnehmer ausübt. Das klassische Geschäftsmodell des Energieversorgungsunternehmens verändert sich dabei grundlegend. Der kontinuierlich ansteigende Einsatz dezentraler und volatiler Erzeugungsanlagen macht die Identifikation von Flexibilitätspotenzialen notwendig, um weiterhin eine hohe Versorgungssicherheit zu gewährleisten. Dieser Schritt ist nur mit einem hohen Digitalisierungsgrad möglich. Eine funktionale Plattform mit Microservices, die zu Geschäftsprozessen verbunden werden können, wird als Möglichkeit zur Aktivierung der Flexibilität und Digitalisierung der Energieversorgungsunternehmen im Folgenden vorgestellt. Y1 - 2020 SN - 978-3-658-25332-5 U6 - https://doi.org/10.1007/978-3-658-25332-5_37 SP - 615 EP - 626 PB - Springer Vieweg CY - Wiesbaden ER - TY - BOOK A1 - Bröder, Alois A1 - Bauschke, Stefan M. T1 - Strom-Messwandler: Informationen für Anwender Y1 - 2019 SN - 978-3-8440-6233-5 N1 - gedruckt in der Bereichsbibliothek Jülich unter der Signatur 61 XXA 10 PB - Shaker CY - Düren ER - TY - CHAP A1 - Kern, Alexander A1 - Imani Vashiani, Anahita A1 - Timmermanns, Tobias T1 - Threat for human beings due to touch voltages and body currents caused by direct lightning strikes in case of non-isolated lightning protection systems using natural components T2 - 35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA) N2 - For typical cases of non-isolated lightning protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal façades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS. As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal façade is used the threat for human beings touching is usually very low, if the façade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp. KW - Lightning protection system KW - down-conductor KW - steel columns KW - metal façade KW - touch voltage Y1 - 2021 SN - 978-1-6654-2346-5 U6 - https://doi.org/10.1109/ICLPandSIPDA54065.2021.9627465 N1 - 35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA), 20-26 Sept. 2021, Colombo, Sri Lanka PB - IEEE CY - New York, NY ER - TY - BOOK A1 - Pieper, Martin T1 - Quantum mechanics: Introduction to mathematical formulation N2 - Anyone who has always wanted to understand the hieroglyphs on Sheldon's blackboard in the TV series The Big Bang Theory or who wanted to know exactly what the fate of Schrödinger's cat is all about will find a short, descriptive introduction to the world of quantum mechanics in this essential. The text particularly focuses on the mathematical description in the Hilbert space. The content goes beyond popular scientific presentations, but is nevertheless suitable for readers without special prior knowledge thanks to the clear examples. KW - Quantenmechanik KW - Hilbert Room KW - Postulates KW - Schrödingers cat KW - Operators Y1 - 2021 SN - 978-3-658-32644-9 SN - 978-3-658-32645-6 U6 - https://doi.org/10.1007/978-3-658-32645-6 PB - Springer CY - Wiesbaden ER - TY - CHAP A1 - Jordan, Frank A1 - Katz, Christiane A1 - Pieper, Martin T1 - Online-Kollaboration in der Mathematik: Ein Design-Based-Research-Projekt T2 - Forschungsimpulse für hybrides Lehren und Lernen an Hochschulen N2 - Die Studie erörtert anhand eines Fallbeispiels aus der Mathematik für Ingenieur*innen, wie didaktische Gestaltungsprinzipien für Soziale Präsenz, Kollaboration und das Lösen von praxisnahen Problemen mit mathematischem Denken in einer Online-Umgebung aussehen können. Hierfür zieht der Beitrag den forschungsmethodologischen Rahmen Design-Based Research (DBR) hinzu und berichtet über Zwischenergebnisse. DBR wird an dieser Stelle als eine systematische Herangehensweise an kurzfristige Lehrveränderungen und als Chance auf dem Weg zu einer neuen Hochschullehre nach der COVID-19-Pandemie dargestellt, die theoretische und empirische Erkenntnisse mit Praxisverknüpfung und -relevanz vereint. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-cos4-9465 SP - 245 EP - 261 PB - TH Köln CY - Köln ER -