@article{FleischhakerEversDey2010, author = {Fleischhaker, Robert and Evers, J{\"o}rg and Dey, Tarak N.}, title = {Phase modulation induced by cooperative effects in electromagnetically induced transparency}, series = {Physical Review A - Atomic, molecular, and optical physics}, volume = {82}, journal = {Physical Review A - Atomic, molecular, and optical physics}, number = {1}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {1050-2947}, doi = {10.1103/PhysRevA.82.013815}, pages = {013815}, year = {2010}, abstract = {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.}, language = {en} } @article{FleischhakerEvers2008, author = {Fleischhaker, Robert and Evers, J{\"o}rg}, title = {Nonlinear effects in pulse propagation through Doppler-broadened closed-loop atomic media}, series = {Physical Review A - Atomic, molecular, and optical physics}, volume = {77}, journal = {Physical Review A - Atomic, molecular, and optical physics}, number = {4}, issn = {1050-2947}, doi = {10.1103/PhysRevA.77.043805}, pages = {043805}, year = {2008}, language = {en} } @article{FleischhakerEvers2008, author = {Fleischhaker, Robert and Evers, J{\"o}rg}, title = {Four-wave mixing enhanced white-light cavity}, series = {Physical Review A - Atomic, molecular, and optical physics}, volume = {78}, journal = {Physical Review A - Atomic, molecular, and optical physics}, number = {5}, issn = {0556-2791}, pages = {051802(R)}, year = {2008}, language = {en} } @article{HenriquesJuradoGrieseretal.2020, author = {Henriques, A. and Jurado, B. and Grieser, M. and Denis-Petit, D. and Chiron, T. and Gaudefroy, L. and Glorius, J. and Langer, Christoph and Litvinov, Yu. A. and Mathieu, L. and Meot, V. and Perez-Sanchez, R. and Pibernat, J. and Reifarth, R. and Roig, O. and Thomas, B. and Thomas, B. A. and Thomas, J. C. and Tsekhanovich, I.}, title = {Indirect measurements of neutron cross-secti at heavy-ion storage rings}, series = {Journal of Physics: Conference Series}, volume = {1668}, journal = {Journal of Physics: Conference Series}, number = {Art. 012019}, publisher = {IOP}, address = {Bristol}, doi = {10.1088/1742-6596/1668/1/012019}, year = {2020}, abstract = {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.}, language = {en} } @article{VargaDavinsonGloriusetal.2020, author = {Varga, Laszlo and Davinson, Thomas and Glorius, Jan and Jurado, Beatrix and Langer, Christoph and Lederer-Woods, Claudia and Litvinov, Yuri A. and Reifarth, Rene and Slavkovska, Zuzana and St{\"o}hlker, Thomas and Woods, Phil J. and Xing, Yuan Ming}, title = {Towards background-free studies of capture reaction in a heavy-ion storage ring}, series = {Journal of Physics: Conference Series}, volume = {1668}, journal = {Journal of Physics: Conference Series}, number = {Art 012046}, publisher = {IOP}, address = {Bristol}, year = {2020}, abstract = {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.}, language = {en} } @article{RiekeStollenwerkDahmenetal.2018, author = {Rieke, Christian and Stollenwerk, Dominik and Dahmen, Markus and Pieper, Martin}, title = {Modeling and optimization of a biogas plant for a demand-driven energy supply}, series = {Energy}, volume = {145}, journal = {Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0360-5442}, doi = {10.1016/j.energy.2017.12.073}, pages = {657 -- 664}, year = {2018}, abstract = {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.}, language = {en} } @article{DotzauerPfeifferLaueretal.2019, author = {Dotzauer, Martin and Pfeiffer, Diana and Lauer, Markus and Pohl, Marcel and Mauky, Eric and B{\"a}r, Katharina and Sonnleitner, Matthias and Z{\"o}rner, Wilfried and Hudde, Jessica and Schwarz, Bj{\"o}rn and Faßauer, Burkhardt and Dahmen, Markus and Rieke, Christian and Herbert, Johannes and Thr{\"a}n, Daniela}, title = {How to measure flexibility - Performance indicators for demand driven power generation from biogas plants}, series = {Renewable Energy}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2018.10.021}, pages = {135 -- 146}, year = {2019}, language = {en} } @article{SrivastavaChaharSharmaetal.2017, author = {Srivastava, A. and Chahar, V. and Sharma, V. and Sun, Y. and Bol, R. and Knolle, F. and Schnug, E. and Hoyler, Friedrich and Naskar, N. and Lahiri, S. and Patnaik, R.}, title = {Study of uranium toxicity using low-background gamma-ray spectrometry}, series = {Journal of Radioanalytical and Nuclear Chemistry}, journal = {Journal of Radioanalytical and Nuclear Chemistry}, number = {Online first}, publisher = {Springer}, address = {Berlin}, issn = {1588-2780}, doi = {10.1007/s10967-017-5466-9}, pages = {1 -- 7}, year = {2017}, language = {en} } @article{BirklDiendorferKernetal.2018, author = {Birkl, Josef and Diendorfer, Gerhard and Kern, Alexander and Thern, Stephan}, title = {Extrem hohe Blitzstr{\"o}me}, series = {Elektropraktiker}, volume = {72}, journal = {Elektropraktiker}, number = {3}, publisher = {Huss Medien}, address = {Berlin}, pages = {217 -- 225}, year = {2018}, abstract = {Blitze sind nach wie vor eine enorme Schadensquelle f{\"u}r Personensch{\"a}den, Br{\"a}nde, mechanische Zerst{\"o}rungen und insbesondere auch {\"U}berspannungen. Das zeigen nicht zuletzt aktuelle Statistiken der Schadensversicherer. Immer wieder gibt es Meldungen {\"u}ber extrem hohe Blitzstr{\"o}me, die nat{\"u}rlich auch zu großen Sch{\"a}den und Zerst{\"o}rungen f{\"u}hren k{\"o}nnen. Dabei werden Scheitelwerte von teilweise deutlich {\"u}ber 300 kA genannt. Dies wirft Fragen auf, da die „klassische" Blitzstatistik (z. B. nach CIGRE und IEC [8][10]) bisher solche Werte nicht kennt. Diese extremen Blitzstr{\"o}me werden meist aus den Daten von Blitzortungssystemen ermittelt.}, language = {de} } @article{KellerRathBruckmannetal.2020, author = {Keller, Johannes and Rath, Volker and Bruckmann, Johanna and Mottaghy, Darius and Clauser, Christoph and Wolf, Andreas and Seidler, Ralf and B{\"u}cker, H. Martin and Klitzsch, Norbert}, title = {SHEMAT-Suite: An open-source code for simulating flow, heat and species transport in porous media}, series = {SoftwareX}, volume = {12}, journal = {SoftwareX}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-7110}, doi = {10.1016/j.softx.2020.100533}, pages = {9}, year = {2020}, abstract = {SHEMAT-Suite is a finite-difference open-source code for simulating coupled flow, heat and species transport in porous media. The code, written in Fortran-95, originates from geoscientific research in the fields of geothermics and hydrogeology. It comprises: (1) a versatile handling of input and output, (2) a modular framework for subsurface parameter modeling, (3) a multi-level OpenMP parallelization, (4) parameter estimation and data assimilation by stochastic approaches (Monte Carlo, Ensemble Kalman filter) and by deterministic Bayesian approaches based on automatic differentiation for calculating exact (truncation error-free) derivatives of the forward code.}, language = {en} }