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
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  - 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  - 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  - JOUR
A1  - Schüller-Ruhl, Aaron
A1  - Dinstühler, Leonard
A1  - Senger, Thorsten
A1  - Bergfeld, Stefan
A1  - Ingenhag, Christian
A1  - Fleischhaker, Robert
ED  - Mackenzie, Jacob
T1  - Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications
JF  - Applied Physics B
N2  - We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg–Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10−3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements.
Y1  - 2022
U6  - https://doi.org/10.1007/s00340-022-07928-2
SN  - 1432-0649 (Online)
SN  - 0946-2171 (Print)
N1  - Corresponding author: Robert Fleischhaker
VL  - 128
IS  - Article number: 208
SP  - 1
EP  - 11
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Srivastava, A.
A1  - Chahar, V.
A1  - Sharma, V.
A1  - Sun, Y.
A1  - Bol, R.
A1  - Knolle, F.
A1  - Schnug, E.
A1  - Hoyler, Friedrich
A1  - Naskar, N.
A1  - Lahiri, S.
A1  - Patnaik, R.
T1  - Study of uranium toxicity using low-background gamma-ray spectrometry
JF  - Journal of Radioanalytical and Nuclear Chemistry
Y1  - 2017
U6  - https://doi.org/10.1007/s10967-017-5466-9
SN  - 1588-2780
IS  - Online first
SP  - 1
EP  - 7
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Keller, Johannes
A1  - Rath, Volker
A1  - Bruckmann, Johanna
A1  - Mottaghy, Darius
A1  - Clauser, Christoph
A1  - Wolf, Andreas
A1  - Seidler, Ralf
A1  - Bücker, H. Martin
A1  - Klitzsch, Norbert
T1  - SHEMAT-Suite: An open-source code for simulating flow, heat and species transport in porous media
JF  - SoftwareX
N2  - 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.
Y1  - 2020
U6  - https://doi.org/10.1016/j.softx.2020.100533
SN  - 2352-7110
VL  - 12
PB  - Elsevier
CY  - Amsterdam
ER  -