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5,321 results on '"Fuchs, M"'

1. Nonlinear microrheology with time-dependent forces -- Application to recoils in viscoelastic fluids

Author

Ditz, Nikolas, Puertas, Antonio M., and Fuchs, M.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

This work presents a theoretical analysis of the motion of a tracer colloid driven by a time-dependent force through a viscoelastic fluid. The recoil of the colloid after application of a strong force is determined. It provides insights into the elastic forces stored locally in the fluid and their weakening by plastic processes. We generalize the mode coupling theory of microrheology to include time-dependent forces. After deriving the equations of motion for the tracer correlator and simplifying to a schematic model we apply the theory to a switch-off force protocol that features the recoiling of the tracer after cessation of the driving. We also include Langevin dynamics simulations to compare to the results of the theory. A non-monotonic trend of the recoil amplitude is found in the theory and confirmed in the simulations. The linear-response approximation is also verified in the small-force regime. While the overall agreement between simulation and theory is good, simulation shows that the theory predicts a too strong non-monotonous dependence of the recoil distance on the applied force., Comment: 17 pages, 12 figures

Published
2024

2. ZynqMP-based board-management mezzanines for Serenity ATCA-blades

Author

Mehner, T., Ardila-Perez, L. E., Balzer, M. N., Sander, O., Tcherniakhovski, D., Schleicher, M., Fuchs, M., Fedi, G., Gimas, G., Iles, G. M., Pesaresi, M., Rose, A. W., and Schuh, T.

Subjects
Physics - Instrumentation and Detectors
Abstract

In the context of the CMS Phase-2 tracker back-end processing system, two mezzanines based on the Zynq Ultrascale+ Multi-Processor System-on-Chip (MPSoC) device have been developed to serve as centralized slow control and board management solution for the Serenity-family \textcolor{black}{Advanced Telecommunications Computing Architecture (ATCA)} blades. This paper presents the developments of the MPSoC mezzanines to execute the Intelligent Platform Management Controller (IPMC) software in the real-time capable processors of the MPSoC. In coordination with the Shelf Manager, once full-power is enabled, a CentOS-based Linux distribution is executed in the application processors of the MPSoC, on which EMPButler and the Serenity Management Shell (SMASH) are running., Comment: 6 pages, 3 figures

Published
2024
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5. Lessons learned while developing the Serenity-S1 ATCA card

Author

Mehner, T., Ardila-Perez, L. E., Balzer, M., Fedi, G., Fuchs, M., Howard, A., Iles, G., Loutit, M., Mansbridge, S., Palla, F., Parker, D., Pesaresi, M., Rose, A., Saleh, M., Sander, O., Schleicher, M., Strohman, C., Tcherniakhovski, D., Williams, T., and Zhao, J.

Subjects
Physics - Instrumentation and Detectors
Abstract

The Serenity-S1 is a Xilinx Virtex Ultrascale+ based Advanced Telecommunications Computing Architecture (ATCA) processing blade that has been optimised for production. It incorporates many developments from the Serenity-A and Serenity-Z prototype cards and, where possible, adopts solutions being used across CERN. It also uses many new parts because commonly used parts have disappeared from the market during the semiconductor crisis, with only some returning. Improvements to simplify manufacture, the performance of new components, some of the more difficult aspects of procurement, the performance of production-grade Samtec 25\,Gb/s optical firefly parts, and issues with the rack cooling infrastructure are discussed., Comment: 5 pages, 4 figures, TWEPP 2023

Published
2023

6. Plasma-based particle sources

Author

Fuchs, M, Andonian, G, Apsimon, O, Büscher, M, Downer, MC, Filippetto, D, Lehrach, A, Schroeder, CB, Shadwick, BA, Thomas, AGR, Vafaei-Najafabadi, N, and Xia, G

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Affordable and Clean Energy, Engineering, Nuclear & Particles Physics, Physical sciences
Abstract

Abstract High-brightness particle beams generated by advanced accelerator concepts have the potential to become an essential part of future accelerator technology. In particular, high-gradient accelerators can generate and rapidly accelerate particle beams to relativistic energies. The rapid acceleration and strong confining fields can minimize irreversible detrimental effects to the beam brightness that occur at low beam energies, such as emittance growth or pulse elongation caused by space charge forces. Due to the high accelerating gradients, these novel accelerators are also significantly more compact than conventional technology. Advanced accelerators can be extremely variable and are capable of generating particle beams with vastly different properties using the same driver and setup with only modest changes to the interaction parameters. So far, efforts have mainly been focused on the generation of electron beams, but there are concepts to extend the sources to generate spin-polarized electron beams or positron beams. The beam parameters of these particle sources are largely determined by the injection and subsequent acceleration processes. Although, over the last decade there has been significant progress, the sources are still lacking a sufficiently high 6-dimensional (D) phase-space density that includes small transverse emittance, small energy spread and high charge, and operation at high repetition rate. This is required for future particle colliders with a sufficiently high luminosity or for more near-term applications, such as enabling the operation of free-electron lasers (FELs) in the X-ray regime. Major research and development efforts are required to address these limitations in order to realize these approaches for a front-end injector for a future collider or next-generation light sources. In particular, this includes methods to control and manipulate the phase-space and spin degrees-of-freedom of ultrashort plasma-based electron bunches with high accuracy, and methods that increase efficiency and repetition rate. These efforts also include the development of high-resolution diagnostics, such as full 6D phase-space measurements, beam polarimetry and high-fidelity simulation tools. A further increase in beam luminosity can be achieve through emittance damping. Emittance cooling via the emission of synchrotron radiation using current technology requires kilometer-scale damping rings. For future colliders, the damping rings might be replaced by a substantially more compact plasma-based approach. Here, plasma wigglers with significantly stronger magnetic fields are used instead of permanent-magnet based wigglers to achieve similar damping performance but over a two orders of magnitude reduced length.

Published
2024

7. Snowmass Whitepaper AF6: Plasma-Based Particle Sources

Author

Fuchs, M., Shadwick, B. A., Vafaei-Najafabadi, N., Thomas, A. G. R., Andonian, G., Büscher, M., Lehrach, A., Apsimon, O., Xia, G., Filippetto, D., Schroeder, C. B., and Downer, M. C.

Subjects
Physics - Accelerator Physics, Physics - Plasma Physics
Abstract

High-brightness beams generated by particle sources based on advanced accelerator concepts have the potential to become an essential part of future accelerator technology. High-gradient accelerators can generate and rapidly accelerate particle beams to relativistic energies while minimizing irreversible detrimental effects to the beam brightness that occur at low beam energies. Due to the high accelerating gradients, these novel accelerators are also significantly more compact than conventional technology. The beam parameters of these particle sources are largely determined by the injection and subsequent acceleration processes. While there has been significant progress crucial parameters that are required for a future collider or more near-term applications, including X-ray free-electron lasers (XFELs), such as a sufficiently small energy spread and small emittance for bunches with a high charge and at high pulse repetition rate. Major research and development efforts are required to realize these approaches for a front-end injector for a future collider in order to address these limitations. In particular, this includes methods to control and manipulate the phase-space and spin degrees-of-freedom of ultrashort LWFA electron bunches with high accuracy, methods that increase the laser-to-electron beam efficiency and increased repetition rate. This also includes the development of high-resolution diagnostics, such as full 6D phase-space measurements, beam polarimetry and high-fidelity simulation tools. A further increase in beam luminosity can be achieve through emittance damping. For future colliders, the damping rings might be replaced by a substantially more compact plasma-based approach. Here, plasma wigglers are used to achieve similar damping performance but over a two orders of magnitude reduced length., Comment: contribution to Snowmass 2021

Published
2022

8. Linear colliders based on laser-plasma accelerators

Author

Benedetti, C., Bulanov, S. S., Esarey, E., Geddes, C. G. R., Gonsalves, A. J., Huebl, A., Lehe, R., Nakamura, K., Schroeder, C. B., Terzani, D., van Tilborg, J., Turner, M., Vay, J. -L., Zhou, T., Albert, F., Bromage, J., Campbell, E. M., Froula, D. H., Palastro, J. P., Zuegel, J., Bruhwiler, D., Cook, N. M., Cros, B., Downer, M. C., Fuchs, M., Shadwick, B. A., Gessner, S. J., Hogan, M. J., Hooker, S. M., Jing, C., Krushelnick, K., Thomas, A. G. R., Leemans, W. P., Maier, A. R., Osterhoff, J., Poder, K., Thevenet, M., Joshi, C., Mori, W. B., Milchberg, H. M., Palmer, M., Power, J. G., and Vafaei-Najafabadi, N.

Subjects
Physics - Accelerator Physics
Abstract

White paper to the Proceedings of the U.S. Particle Physics Community Planning Exercise (Snowmass 2021): Linear colliders based on laser-plasma accelerators, Comment: Contribution to Snowmass 2021, Accelerator Frontier

Published
2022

10. Impact of individualized treatment on recovery from fatigue and return to work in survivors of advanced-stage Hodgkin’s lymphoma: results from the randomized international GHSG HD18 trial

Author

Ferdinandus, J., Müller, H., Damaschin, C., Jacob, A.S., Meissner, J., Krasniqi, F., Mey, U., Schöndube, D., Thiemer, J., Mathas, S., Zijlstra, J., Greil, R., Feuring-Buske, M., Markova, J., Rüffer, J.U., Kobe, C., Eich, H.-T., Baues, C., Fuchs, M., Borchmann, P., and Behringer, K.

Published
2024
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11. The direct correlation function of a crystalline solid

Author

Lin, S. -C., Oettel, M., Hring, J. M., Haussmann, R., Fuchs, M., and Kahl, G.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

Direct correlation functions (DCFs), linked to the second functional derivative of the free energy with respect to the one-particle density, play a fundamental role in a statistical mechanics description of matter. This holds in particular for the ordered phases: DCFs contain information about the local structure including defects and encode the thermodynamic properties of crystalline solids; they open a route to the elastic constants beyond low temperature expansions. Via a numerical tour de force we have explicitly calculated for the first time the DCF of a solid: based on the fundamental measure concept we provide results for the DCF of a hard sphere crystal. We demonstrate that this function differs at coexistence significantly from its liquid counterpart - both in shape as well as in its order of magnitude - because it is dominated by vacancies. We provide evidence that the traditional use of liquid DCFs in functional Taylor expansions of the free energy is conceptually wrong and show that the emergent elastic constants are in good agreement with simulation-based results.

Published
2021
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12. Cratering of Soil by Impinging Jets of Gas, with Application to Landing Rockets on Planetary Surfaces

Author

Metzger, Philip T., Vu, Bruce T., Taylor, D. E., Kromann, M. J., Fuchs, M., Yutko, B., Dokos, Adam, Immer, Christopher D., Lane, John E., Dunkel, M. B., Donahue, Carly M., and Latta III, Robert C.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Condensed Matter - Statistical Mechanics, Physics - Fluid Dynamics
Abstract

Several physical mechanisms are involved in excavating granular materials beneath a vertical jet of gas. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. A series of experiments and simulations have been performed to provide a detailed view of the complex gas/soil interactions. Measurements have also been taken from the Apollo lunar landing videos and from photographs of the resulting terrain, and these help to demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a fundamental level to support the on-going design of higher-fidelity numerical simulations and larger-scale experiments. These are needed to enable future lunar exploration wherein multiple hardware assets will be placed on the Moon within short distances of one another. The high-velocity spray of soil from landing spacecraft must be accurately predicted and controlled lest it erosively damage the surrounding hardware., Comment: 6 pages, 5 figures

Published
2021

13. GEMAS: Chemical weathering of silicate parent materials revealed by agricultural soil of Europe

Author

Albanese, S., Andersson, M., Baritz, R., Batista, M.J., Bel-lan, A., Cicchella, D., De Vivo, B., De Vos, W., Dinelli, E., Ďuriš, M., Dusza-Dobek, A., Eklund, M., Ernstsen, V., Filzmoser, P., Flem, B., Flight, D.M.A., Forrester, S., Fuchs, M., Fügedi, U., Gilucis, A., Gosar, M., Gregorauskiene, V., De Groot, W., Gulan, A., Halamić, J., Haslinger, E., Hayoz, P., Hoffmann, R., Hoogewerff, J., Hrvatovic, H., Husnjak, S., Janik, L., Jordan, G., Kaminari, M., Kirby, J., Kivisilla, J., Klos, V., Krone, F., Kwećko, P., Kuti, L., Lima, A., Locutura, J., Lucivjansky, D.P., Mann, A., Mackovych, D., Matschullat, J., McLaughlin, M., Malyuk, B.I., Maquil, R., Meuli, R.G., Mol, G., O'Connor, P., Oorts, R.K., Ottesen, R.T., Pasieczna, A., Petersell, W., Pfleiderer, S., Poňavič, M., Pramuka, S., Prazeres, C., Rauch, U., Radusinović, S., Salpeteur, I., Scanlon, R., Schedl, A., Scheib, A.J., Schoeters, I., Šefčik, P., Sellersjö, E., Skopljak, F., Slaninka, I., Šorša, A., Srvkota, R., Stafilov, T., Tarvainen, T., Trendavilov, V., Valera, P., Verougstraete, V., Vidojević, D., Zissimos, A., Zomeni, Z., Négrel, Philippe, Ladenberger, Anna, Reimann, Clemens, Demetriades, Alecos, Birke, Manfred, and Sadeghi, Martiya

Published
2023
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15. Multiple Fourier Component Analysis of X-ray Second Harmonic Generation in Diamond

Author

Chakraborti, P., Senfftleben, B., Kettle, B., Teitelbaum, S. W., Bucksbaum, P. H., Ghimire, S., Hastings, J. B., Liu, H., Nelson, S., Sato, T., Shwartz, S., Sun, Y., Weninger, C., Zhu, D., Reis, D. A., and Fuchs, M.

Subjects
Physics - Optics
Abstract

The unprecedented brilliance of X-ray free-electron lasers (XFELs) [1, 2] has enabled first studies of nonlinear interactions in the hard X-ray range. In particular, X-ray-optical mixing [3], X-ray second harmonic generation (XSHG) [4] and nonlinear Compton scattering (NLCS) [5] have been recently observed for the first time using XFELs. The former two experiments as well as X-ray parametric downconversion (XPDC)[6, 7] are well explained by nonlinearities in the impulse approximation[8], where electrons in a solid target are assumed to be quasi free for X-ray interactions far from atomic resonances. However, the energy of the photons generated in NLCS at intensities reaching up to 4 x 1020 W/cm2 exhibit an anomalous red-shift that is in violation with the free-electron model. Here we investigate the underlying physics of X-ray nonlinear interactions at intensities on order of 1016 W/cm2. Specifically, we perform a systematic study of XSHG in diamond. While one phase-matching geometry has been measured in Shwartz et al.[4], we extend these studies to multiple Fourier components and with significantly higher statistics, which allows us to determine the second order nonlinear structure factor. We measure the efficiency, angular dependence, and contributions from different source terms of the process. We find good agreement of our measurements with the quasi-free electron model.

Published
2019

17. Active and passive microrheology with large tracers in hard colloids.

Author

Orts, F., Maier, M., Fuchs, M., Ortega, G., Garzón, E. M., and Puertas, A. M.

Subjects
NEWTONIAN fluids, PARTICLE dynamics, MOLECULAR force constants, COLLOIDS, DIFFUSION coefficients
Abstract

The dynamics of a tracer particle in a bath of quasi-hard colloidal spheres is studied by Langevin dynamics simulations and mode coupling theory (MCT); the tracer radius is varied from equal to up to seven times larger than the bath particles radius. In the simulations, two cases are considered: freely diffusing tracer (passive microrheology) and tracer pulled with a constant force (active microrheology). Both cases are connected by linear response theory for all tracer sizes. It links both the stationary and transient regimes of the pulled tracer (for low forces) with the equilibrium correlation functions; the velocity of the pulled tracer and its displacement are obtained from the velocity auto-correlation function and the mean squared displacement, respectively. The MCT calculations give insight into the physical mechanisms: At short times, the tracer rattles in its cage of neighbours, with the frequency increasing linearly with the tracer radius asymptotically. The long-time tracer diffusion coefficient from passive microrheology, which agrees with the inverse friction coefficient from the active case, arises from the transport of transverse momentum around the tracer. It can be described with the Brinkman equation for the transverse flow field obtained in extension of MCT, but cannot be recovered from the MCT kernel coupling to densities only. The dynamics of the bath particles is also studied; for the unforced tracer the dynamics is unaffected. When the tracer is pulled, the velocity field in the bath follows the prediction of the Brinkman model, but different from the case of a Newtonian fluid. [ABSTRACT FROM AUTHOR]

Published
2023
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18. Prognostic and predictive value of CA 19-9 in locally advanced pancreatic cancer treated with multiagent induction chemotherapy: results from a prospective, multicenter phase II trial (NEOLAP-AIO-PAK-0113)

Author

Hartlapp, I., Valta-Seufzer, D., Siveke, J.T., Algül, H., Goekkurt, E., Siegler, G., Martens, U.M., Waldschmidt, D., Pelzer, U., Fuchs, M., Kullmann, F., Boeck, S., Ettrich, T.J., Held, S., Keller, R., Anger, F., Germer, C.T., Stang, A., Kimmel, B., Heinemann, V., and Kunzmann, V.

Published
2022
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20. Study protocol of the FIRE-8 (AIO-KRK/YMO-0519) trial: a prospective, randomized, open-label, multicenter phase II trial investigating the efficacy of trifluridine/tipiracil plus panitumumab versus trifluridine/tipiracil plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer

Author

Sommerhäuser, G., Kurreck, A., Stintzing, S., Heinemann, V., von Weikersthal, L. Fischer, Dechow, T., Kaiser, F., Karthaus, M., Schwaner, I., Fuchs, M., König, A., Roderburg, C., Hoyer, I., Quante, M., Kiani, A., Fruehauf, S., Müller, L., Reinacher-Schick, A., Ettrich, T. J., Stahler, A., and Modest, D. P.

Published
2022
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22. Nonlinear rheological behavior of glass-forming colloidal suspensions under oscillatory shear: Experiment and relation to mode coupling theory predictions.

Author

Fischer, L., Maier, M., Dingenouts, N., Hirschberg, V., Wittemann, A., Fuchs, M., and Wilhelm, M.

Subjects
MODE-coupling theory (Phase transformations), STRAINS & stresses (Mechanics), AMORPHOUS substances, PREDICTION theory, ANHARMONIC motion
Abstract

Glass-forming colloids consisting of soft core-shell particles were investigated experimentally under medium and large amplitude oscillatory shear (MAOS and LAOS) using Fourier transform rheology to decompose the stress signal into a series of higher harmonics. The anharmonicity of the stress response under MAOS and LAOS is quantified by the intensity of the third harmonic normalized to the fundamental (I 3 / 1 = I 3 / I 1) and within the intrinsic nonlinearity framework of the Q-parameter (Q 0 = lim γ 0 → 0 ⁡ (I 3 / 1 / γ 0 2)). Furthermore, the results of the strain amplitude dependence were compared to the literature showing the mechanical anharmonic behavior of the core-shell system being close to the behavior of ultrasoft systems. In the glassy state, I 3 / 1 shows an unusual scaling of I 3 / 1 ∝ γ 0 4 at low frequencies, similar to amorphous polymeric materials when they undergo plastic deformation. For investigating the frequency dependence of the anharmonicity in a specially designed binary mixture to test for critical behavior close to the glass transition as predicted by mode coupling theory (MCT) and extend the measurements to the glassy state, we used the frequency sweep MAOS methodology. Using this time-efficient method, the frequency dependence of a wide range of volume fractions and frequencies was investigated, finding the anharmonicity parameter Q 0 to be maximal in the region of the α -relaxation for colloidal liquids. The colloidal glasses do not exhibit a maximum in Q 0 , but an increase in Q 0 with decreasing frequency over the investigated region, as the α -relaxation slows down significantly in colloidal glasses. Predictions from MCT from the literature show agreement with the experimentally determined scaling laws. [ABSTRACT FROM AUTHOR]

Published
2024
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24. Impact of Optimized Trailing Edge Shapes on Noise Generation

Author

Kramer, F., Fuchs, M., Knacke, T., Mockett, C., Özkaya, E., Gauger, N., Thiele, F., Cavas-Martínez, Francisco, Series Editor, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Series Editor, Ivanov, Vitalii, Series Editor, Kwon, Young W., Series Editor, Trojanowska, Justyna, Series Editor, Braza, Marianna, editor, Hoarau, Yannick, editor, Zhou, Yu, editor, Lucey, Anthony D., editor, Huang, Lixi, editor, and Stavroulakis, Georgios E., editor

Published
2021
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27. Roadmap of ultrafast x-ray atomic and molecular physics

Author

Young, L, Ueda, K, Gühr, M, Bucksbaum, PH, Simon, M, Mukamel, S, Rohringer, N, Prince, KC, Masciovecchio, C, Meyer, M, Rudenko, A, Rolles, D, Bostedt, C, Fuchs, M, Reis, DA, Santra, R, Kapteyn, H, Murnane, M, Ibrahim, H, Légaré, F, Vrakking, M, Isinger, M, Kroon, D, Gisselbrecht, M, L'Huillier, A, Wörner, HJ, and Leone, SR

Subjects
ultrafast molecular dynamics, x-ray spectroscopies and phenomena, table-top sources, x-ray free-electron lasers, attosecond phenomena, General Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Optical Physics, Theoretical and Computational Chemistry, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (1020 W cm-2) of x-rays at wavelengths down to ∼1 Ångstrom, and HHG provides unprecedented time resolution (∼50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths. For context, timescales can be referenced to the Bohr orbital period in hydrogen atom of 150 attoseconds and the hydrogen-molecule vibrational period of 8 femtoseconds; wavelength scales can be referenced to the chemically significant carbon K-edge at a photon energy of ∼280 eV (44 Ångstroms) and the bond length in methane of ∼1 Ångstrom. With these modern x-ray sources one now has the ability to focus on individual atoms, even when embedded in a complex molecule, and view electronic and nuclear motion on their intrinsic scales (attoseconds and Ångstroms). These sources have enabled coherent diffractive imaging, where one can image non-crystalline objects in three dimensions on ultrafast timescales, potentially with atomic resolution. The unprecedented intensity available with XFELs has opened new fields of multiphoton and nonlinear x-ray physics where behavior of matter under extreme conditions can be explored. The unprecedented time resolution and pulse synchronization provided by HHG sources has kindled fundamental investigations of time delays in photoionization, charge migration in molecules, and dynamics near conical intersections that are foundational to AMO physics and chemistry. This roadmap coincides with the year when three new XFEL facilities, operating at Ångstrom wavelengths, opened for users (European XFEL, Swiss-FEL and PAL-FEL in Korea) almost doubling the present worldwide number of XFELs, and documents the remarkable progress in HHG capabilities since its discovery roughly 30 years ago, showcasing experiments in AMO physics and other applications. Here we capture the perspectives of 17 leading groups and organize the contributions into four categories: ultrafast molecular dynamics, multidimensional x-ray spectroscopies; high-intensity x-ray phenomena; attosecond x-ray science.

Published
2018

28. Bidirectional low temperature district energy systems with agent-based control: Performance comparison and operation optimization

Author

Bünning, F, Wetter, M, Fuchs, M, and Müller, D

Subjects
Low temperature network, District heating, Urban energy systems, Operation optimization, Modelica, Agent-based control, Energy, Engineering, Economics
Abstract

Bidirectional low temperature networks are a novel concept that promises more efficient heating and cooling of buildings. Early research shows theoretical benefits in terms of exergy efficiency over other technologies. Pilot projects indicate that the concept delivers good performance if heating and cooling demands are diverse. However, the operation of these networks is not yet optimized and there is no quantification of the benefits over other technologies in various scenarios. Moreover, there is a lack of understanding of how to integrate and control multiple distributed heat and cold sources in such networks. Therefore, this paper develops a control concept based on a temperature set point optimization and agent-based control which allows the modular integration of an arbitrary number of sources and consumers. Afterwards, the concept is applied to two scenarios representing neighborhoods in San Francisco and Cologne with different heating and cooling demands and boundary conditions. The performance of the system is then compared to other state-of-the-art heating and cooling solutions using dynamic simulations with Modelica. The results show that bidirectional low temperature networks without optimization produce 26% less emissions in the San Francisco scenario and 63% in the Cologne scenario in comparison to the other heating and cooling solutions. Savings of energy costs are 46% and 27%, and reductions of primary energy consumption 52% and 72%, respectively. The presented operation optimization leads to electricity use reductions of 13% and 41% when compared to networks with free-floating temperature control and the results indicate further potential for improvement. The study demonstrates the advantage of low temperature networks in different situations and introduces a control concept that is extendable for real implementation.

Published
2018

31. Industrial Prediction of Jet-Flap Interaction Noise with Advanced Hybrid RANS-LES Methods

Author

Mockett, C., Fuchs, M., Knacke, T., Kramer, F., Michel, U., Steger, M., Thiele, F., Hirschel, Ernst Heinrich, Founding Editor, Schröder, Wolfgang, Series Editor, Boersma, Bendiks Jan, Series Editor, Fujii, Kozo, Series Editor, Haase, Werner, Series Editor, Leschziner, Michael A., Series Editor, Periaux, Jacques, Series Editor, Pirozzoli, Sergio, Series Editor, Rizzi, Arthur, Series Editor, Roux, Bernard, Series Editor, Shokin, Yurii I., Series Editor, Hoarau, Yannick, editor, Peng, Shia-Hui, editor, Schwamborn, Dieter, editor, Revell, Alistair, editor, and Mockett, Charles, editor

Published
2020
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36. Dynamic equation-based thermo-hydraulic pipe model for district heating and cooling systems

Author

van der Heijde, B, Fuchs, M, Ribas Tugores, C, Schweiger, G, Sartor, K, Basciotti, D, Müller, D, Nytsch-Geusen, C, Wetter, M, and Helsen, L

Subjects
District heating and cooling, Heat loss, Dynamic thermo-hydraulic model, Modelica, District energy systems, Simulation, Thermal network, Energy, Electrical and Electronic Engineering, Mechanical Engineering
Abstract

Simulation and optimisation of district heating and cooling networks requires efficient and realistic models of the individual network elements in order to correctly represent heat losses or gains, temperature propagation and pressure drops. Due to more recent thermal networks incorporating meshing decentralised heat and cold sources, the system often has to deal with variable temperatures and mass flow rates, with flow reversal occurring more frequently. This paper presents the mathematical derivation and software implementation in Modelica of a thermo-hydraulic model for thermal networks that meets the above requirements and compares it to both experimental data and a commonly used model. Good correspondence between experimental data from a controlled test set-up and simulations using the presented model was found. Compared to measurement data from a real district heating network, the simulation results led to a larger error than in the controlled test set-up, but the general trend is still approximated closely and the model yields results similar to a pipe model from the Modelica Standard Library. However, the presented model simulates 1.7 (for low number of volumes) to 68 (for highly discretized pipes) times faster than a conventional model for a realistic test case. A working implementation of the presented model is made openly available within the IBPSA Modelica Library. The model is robust in the sense that grid size and time step do not need to be adapted to the flow rate, as is the case in finite volume models.

Published
2017

38. GEMAS: Geochemical distribution of Mg in agricultural soil of Europe

Author

Albanese, S., Andersson, M., Baritz, R., Batista, M.J., Bel-lan, A., Cicchella, D., De Vivo, B., De Vos, W., Dinelli, E., Ďuriš, M., Dusza-Dobek, A., Eklund, M., Ernstsen, V., Filzmoser, P., Flem, B., Flight, D.M.A., Forrester, S., Fuchs, M., Fügedi, U., Gilucis, A., Gosar, M., Gregorauskiene, V., De Groot, W., Gulan, A., Halamić, J., Haslinger, E., Hayoz, P., Hoffmann, R., Hoogewerff, J., Hrvatovic, H., Husnjak, S., Janik, L., Jordan, G., Kaminari, M., Kirby, J., Kivisilla, J., Klos, V., Krone, F., Kwećko, P., Kuti, L., Lima, A., Locutura, J., Lucivjansky, D.P., Mann, A., Mackovych, D., Matschullat, J., McLaughlin, M., Malyuk, B.I., Maquil, R., Meuli, R.G., Mol, G., O'Connor, P., Oorts, R.K., Ottesen, R.T., Pasieczna, A., Petersell, W., Pfleiderer, S., Poňavič, M., Pramuka, S., Prazeres, C., Rauch, U., Radusinović, S., Salpeteur, I., Scanlon, R., Schedl, A., Scheib, A.J., Schoeters, I., Šefčik, P., Sellersjö, E., Skopljak, F., Slaninka, I., Šorša, A., Srvkota, R., Stafilov, T., Tarvainen, T., Trendavilov, V., Valera, P., Verougstraete, V., Vidojević, D., Zissimos, A., Zomeni, Z., Négrel, Philippe, Ladenberger, Anna, Reimann, Clemens, Birke, Manfred, Demetriades, Alecos, and Sadeghi, Martiya

Published
2021
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39. Klinische Profile des Leipziger Sprachinstrumentariums Jugend: Fallbeispiele der Auditiven Verarbeitungs- und Wahrnehmungsstörung im Jugendalter

Author

Pino, D, Wagner, S, Schütz, V, Kessler, R, Krause, CD, Scheithauer, B, Iagudin, M, Oelze, V, Glück, CW, Fuchs, M, Meuret, S, Pino, D, Wagner, S, Schütz, V, Kessler, R, Krause, CD, Scheithauer, B, Iagudin, M, Oelze, V, Glück, CW, Fuchs, M, and Meuret, S

Abstract

Hintergrund: Das Leipziger Sprach-Instrumentarium (LSI.J) ermöglicht die Tablet-basierte Überprüfung des Hör-/Sprachverstehens von Jugendlichen (Normen für den Altersbereich 14-22 Jahre, n=456) in den Bereichen frühe Lautverarbeitung, Lexikon, Syntax, pragmatisch-kommunikative Fähigkeiten sowie visuelle und auditive Aufmerksamkeit. Im Projekt DINKO wird LSI.J mit verschiedenen klinischen Populationen erprobt, u.a. mit Kindern und Jugendlichen, die eine klinisch gesicherte Diagnose "Auditive Verarbeitungs- und Wahrnehmungsstörung (AVWS)" haben.Material und Methoden: Jugendliche mit einer fachärztlich gesicherten AVWS-Diagnose wurden in einer Leipziger Schule mit dem Förderschwerpunkt Hören rekrutiert. Sie absolvierten neben den LSI.J-Tests auch die CELF-V-Sprachtests und eine IQ-Testung mit den IDS-2. In der Sektion Phoniatrie und Audiologie des Universitätsklinikums Leipzigs wurden Reinton- und Sprachaudiogramm, BERA, das Hören im Störgeräusch (OLKISA) und das dichotische Hören (Feldmann) überprüft.Ergebnisse: Hier werden 3 Einzelprofile aus der Untersuchungsgruppe vorgestellt. Die 3 Jugendlichen (TP1-TP3) zeigten keine Einschränkungen des peripheren Hörens. TP1 erreichte einen IQ-Wert im durchschnittlichen Bereich, die Werte von TP2 und TP3 lagen 2-3 SD unterhalb des Mittelwertes. Alle 3 Jugendlichen waren im dichotischen Hören sowohl im LSI.J als auch im Feldmann auffällig und zeigten auffällige Leistungen im Nachsprechen und im lexikalischen Entscheiden. Einschränkungen beim Hören im Störgeräusch zeigte nur TP1. Bei TP2 und TP3 erwies sich hingegen bereits die Verarbeitung von Wortbedeutungen als auffällig.Diskussion: In den Einzelprofilen zeigt sich die Vielfältigkeit sprachlicher und kognitiver Leistungsprofile bei AVWS. Die Tests liefern Hinweise auf sprachliche und kognitive Leistungsbereiche, die bei einer AVWS häufig gemeinsam betroffen sind.Fazit: Mit der LSI.J liegt ein Verfahren vor, das aufgrund seiner Test-Zusammenstellung die Differenzial-Diagnostik b

Published
2024

40. Kann künstliche Intelligenz bei der Unterscheidung zwischen physiologischen und pathologischen Stimmklängen unterstützen?

Author

Gänzle, M, Keller, J, Schneider, D, Engel, C, Fuchs, M, Gänzle, M, Keller, J, Schneider, D, Engel, C, and Fuchs, M

Abstract

Hintergrund: Diese Studie untersucht, inwieweit künstliche Intelligenz mittels maschinellen Lernens in der klinischen Diagnostik bei der Zuordnung gesunder und pathologischer Stimmschallsignale unterstützen kann. Ziel war es, durch automatische Mustererkennung im Stimmschallsignal Messgrößen zur Unterscheidung und Stratifizierung von gesunden und pathologischen Stimmschallsignalen zu gewinnen.Material und Methoden: Als Untersuchungsmaterial dienten Stimmschallsignale der Sprechstimme mit mehrsilbigen Zahlwörtern in verschiedenen Steigerungsstufen von 2.000 Personen (ab 18. Lbj., normalverteilte Bevölkerungskohorte) aus der LIFE-Studie und 216 Patient:innen (19-101 Jahre, Median 61; 108:108 m:w) mit Dysphonien zehn verschiedener Genesen. Alle Zahlwörter wurden in Mel-Frequenz-Cepstrum-Koeffizienten umgewandelt. Anschließend war es Aufgabe der KI, zwischen gesunden und pathologischen Stimmschallsignalen zu unterscheiden. Es wurden zwei unabhängige Methoden untersucht. In Methode 1 rekonstruierte ein unüberwachtes Modell (Autoencoder) gesunde Stimmschallaufnahmen über einen Informationsengpass. Der Rekonstruktionsfehler ermöglichte eine Einteilung nach ihrem Abweichungsgrad von gesunden Stimmschallsignalen. In Methode 2 lernte ein überwachtes Modell (Morse-Netz) im Kreuzvalidierungsverfahren eine Transformation der Stimmschallaufnahmen auf ein vorher definiertes Intervall und so die Unterscheidung verschiedener Krankheitsbilder. Mittels Bestimmung der AUROC wurde die Diskriminierungsfähigkeit bestimmt und gezeigt, wie gut das Modell zwischen positiven und negativen Fällen unterscheiden kann.Ergebnisse: Methode 1 erreichte eine AUROC von 0,98 und Methode 2 eine AUROC von 0,99. Damit wurde eine sehr hohe Diskriminierungsfähigkeit der KI gezeigt. Die Ordnung verschiedener Krankheitsbilder auf der Messskala von Methode 2 korrelierte stark mit der vorher trainierten Diagnose.Diskussion: Bisherige Studien konnten mittels KI den Schweregrad einer bekannten Dysphonie richtig e

Published
2024

41. Kontinuierliche Altersnormen im Leipziger Sprach-Instrumentarium Jugend

Author

Kessler, R, Krause, CD, Schütz, V, Glück, CW, Oelze, V, Fuchs, M, Meuret, S, Wagner, S, Kessler, R, Krause, CD, Schütz, V, Glück, CW, Oelze, V, Fuchs, M, Meuret, S, and Wagner, S

Abstract

Hintergrund: Das Leipziger Sprach-Instrumentarium Jugend (LSI.J) ist ein Tablet-basiertes Diagnostik-Instrumentarium zur Überprüfung des Hör-/Sprachverstehens bei Jugendlichen und jungen Erwachsenen. Mit 10 Tests überprüft es 5 Kernbereiche des Sprachverstehens: frühe Lautverarbeitung, Lexikon, Syntax, pragmatisch-kommunikative Fähigkeiten sowie visuelle und auditive Aufmerksamkeit. Das Verfahren zielt auf eine Verbesserung der Diagnostik für Jugendliche und Erwachsene mit persistierenden Entwicklungsstörungen wie AVWS und Sprachentwicklungsstörungen. Die Tests sind so konstruiert, dass sie vor allem im unteren Leistungsbereich gut differenzieren.Für die Normierung wurde ein Verfahren gesucht, das einheitlich für alle Tests verwendet werden kann, normalverteilte, aber auch schiefe Rohwert-Verteilungen verarbeiten kann und keine Altersstufen-Sprünge in den Normwerten erzeugt. Die über das Alter kontinuierliche, nicht-parametrische Normierung nach Lenhard und Kolleg*innen wurde als Möglichkeit identifiziert, diese Anforderungen abzudecken.Material und Methoden: An der Normierung nahmen 446 Jugendliche im Alter von 14 bis 22 Jahren teil, 263 weiblich, 182 männlich. Die Jugendlichen hatten entweder Deutsch als Muttersprache oder besuchten seit mindestens 7 Jahren eine deutsche Kita/Schule. Für 3 Tests wurden keine Normen erstellt, sondern entweder ein Cut-Off-Wert festgelegt oder qualitative Auswertungen erstellt. Für alle anderen Tests wurden die Rohwerte als kontinuierliche Funktion über das Alter mit dem R-Paket cNORM modelliert.Ergebnisse: Die Verteilung der Rohwerte für die einzelnen Tests fiel erwartungsgemäß heterogen aus. Es gab normal- und schief verteilte Rohwerte. Die berechneten Norm-Modelle wiesen für alle einbezogenen Tests eine hohe Anpassungsgüte auf (R2-Wert zwischen 96,2 und 99,5%). Ebenfalls erwartbar für 14- bis 22-Jährige zeigten sich keine oder nur geringe Alterseffekte.Diskussion: Die Verwendung kontinuierlicher Normen erwies sich für LSI.J-Sprach

Published
2024

42. Circular economy in tourism and hospitality: A micro-meso-macro framework for inter-disciplinary research

Author

Tomassini, L, Baggio, R, Cavagnaro, E, Farsari, Ioanna, Fuchs, M, Sørensen, F, Tomassini, L, Baggio, R, Cavagnaro, E, Farsari, Ioanna, Fuchs, M, and Sørensen, F

Abstract

This contribution elaborates on the theoretical and practical implications of the circular economy in tourism and hospitality through an inter-disciplinary approach advancing novel possibilities for future research. Acknowledging the literature gap on circular economy in tourism and hospitality as an under-researched and under-theorised area of research, this contribution identifies a set of theoretical lenses that can help to elaborate the notion of circular economy and unpack it through an inter-disciplinary approach for future research. It does so by discussing the notion of circular economy through a micro-meso-macro framework combining practice theory, network theory, complexity theory, and the spatial and mobilities turn in social sciences. The originality of this work lies in its inter-disciplinary approach based on a micro-meso-macro theoretical framework offering novel opportunities to discuss, envision, and operationalize circular regenerative processes in tourism futures in terms of multidimensional, networked, complex, practice-based, and localised processes and operations.

Published
2024
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43. Spectral Characterization of Battery Components from Li-Ion Battery Recycling Processes

Author

Richter, J., (0000-0001-8464-2331) Lorenz, S., Kaas, A., (0000-0001-7210-1132) Fuchs, M., Röder, C., Peuker, U. A., Heitmann, J., (0000-0002-4383-473X) Gloaguen, R., Richter, J., (0000-0001-8464-2331) Lorenz, S., Kaas, A., (0000-0001-7210-1132) Fuchs, M., Röder, C., Peuker, U. A., Heitmann, J., and (0000-0002-4383-473X) Gloaguen, R.

Abstract

Considering the increasing demand for Li-ion batteries, there is a need for sophisticated recycling strategies with both high recovery rates and low costs. Applying optical sensors for automating component detection is a very promising approach because of the non-contact, real-time process monitoring and the potential for complete digitization of mechanical sorting processes. In this work, mm-scale particles from shredded end-of-life Li-ion batteries are investigated by five different reflectance sensors, and a range from the visible to long-wave infrared is covered to determine the ideal detection window for major component identification as relevant input signals to sorting technologies. Based on the characterization, a spectral library including Al, Cu, separator foil, inlay foil, and plastic splinters was created, and the visible to near-infrared range (400–1000 nm) was identified as the most suitable spectral range to reliably discriminate between Al, Cu, and other battery components in the recycling material stream of interest. The evaluation of the different sensor types outlines that only imaging sensors meet the requirements of recycling stream monitoring and can deliver sufficient signal quality for subsequent mechanical sorting controls. Requirements for the setup parameters were discussed leading to the setup recommendation of a fast snapshot camera with a sufficiently high spectral resolution and signal-to-noise ratio.

Published
2024

44. Data publication: The fate of fluvially-deposited organic carbon during transient floodplain storage

Author

S. Scheingross, J., N. Repasch, M., Hovius, N., (0000-0001-7210-1132) Fuchs, M., S. Scheingross, J., N. Repasch, M., Hovius, N., and (0000-0001-7210-1132) Fuchs, M.

Abstract

The data set contains all relevant luminescence measurement data used in the corresponding article: Scheingross et al. 2021. The fate of fluvially-deposited organic carbon during transient floodplain storage. EPSL 561, 116822, doi: 10.1016/j.epsl.2021.116822.

Published
2024

45. PCB-Vision: A Multiscene RGB-Hyperspectral Benchmark Dataset of Printed Circuit Boards

Author

Arbash, E., (0000-0001-7210-1132) Fuchs, M., Rasti, B., (0000-0001-8464-2331) Lorenz, S., (0000-0003-1203-741X) Ghamisi, P., (0000-0002-4383-473X) Gloaguen, R., Arbash, E., (0000-0001-7210-1132) Fuchs, M., Rasti, B., (0000-0001-8464-2331) Lorenz, S., (0000-0003-1203-741X) Ghamisi, P., and (0000-0002-4383-473X) Gloaguen, R.

Abstract

PCB-Vision Dataset Description: The PCB-Vision dataset is a multiscene RGB-Hyperspectral benchmark dataset comprising 53 Printed Circuit Boards (PCBs). The RGB images are collected using a Teledyne Dalsa C4020 camera on a conveyor belt, while hyperspectral images (HSI) are acquired with a Specim FX10 spectrometer. The HSI data contains 224 bands in the VNIR range [400 - 1000]nm. Data Format RGB Images: .png files PCB Masks: .jpg files HSI Data: Each hyperspectral data cube is accompanied by a data file and a .hdr file. Folder Organization PCBVision HSI/ 53 subfolders (one for each PCB) 'General_masks' folder for 'General' segmentation ground truth 'Monoseg_masks' folder for 'Monoseg' segmentation ground truth 'PCB_Masks' folder for masks of the 53 PCBs in the hyperspectral cube RGB/ 53 .jpg images 'General' folder for RGB images 'General' segmentation ground truth 'Monoseg_masks' folder for RGB images 'Monoseg' segmentation ground truth Data Classes in Masks Masks (both 'General' and 'Monoseg') contain 1 to 4 segmentation classes: 0: "Others" 1: "IC" 2: "Capacitors" 3: "Connectors" Code Repository To facilitate reading and working with the data, Python codes are available on the GitHub repository: https://github.com/hifexplo/PCBVision Citation If you use this dataset, please cite the following article: Word: Arbash, Elias, Fuchs, Margret, Rasti, Behnood, Lorenz, Sandra, Ghamisi, Pedram, & Gl

Published
2024

46. Multi-Sensor Characterization for an Improved Identification of Polymers in WEEE Recycling

Author

(0000-0003-0096-3627) Lima Ribeiro, A., (0000-0001-7210-1132) Fuchs, M., (0000-0001-8464-2331) Lorenz, S., Röder, C., Heitmann, J., (0000-0002-4383-473X) Gloaguen, R., (0000-0003-0096-3627) Lima Ribeiro, A., (0000-0001-7210-1132) Fuchs, M., (0000-0001-8464-2331) Lorenz, S., Röder, C., Heitmann, J., and (0000-0002-4383-473X) Gloaguen, R.

Abstract

Polymers represent around 25% of total waste from electronic and electric equipment. Any successful recycling process must ensure that polymer-specific functionalities are preserved, to avoid downcycling. This requires a precise characterization of particle compounds moving at high speeds on conveyor belts in processing plants. We present an investigation using imaging and point measurement spectral sensors on 23 polymers including ABS, PS, PC, PE-types, PP, PVC, PET-types, PMMA, and PTFE to assess their potential to perform under the operational conditions found in recycling facilities. The techniques applied include hyperspectral imaging sensors (HSI) to map reflectance in the visible to near infrared (VNIR), short-wave (SWIR) and mid-wave infrared (MWIR) as well as point Raman, FTIR and spectroradiometer instruments. We show that none of the sensors alone can identify all the compounds while meeting the industry operational requirements. HSI sensors successfully acquired simultaneous spatial and spectral information for certain polymer types. HSI, particularly the range between (1600–1900) nm, is suitable for specific identification of transparent and light-coloured (non-black) PC, PE-types, PP, PVC and PET-types plastics; HSI in the MWIR is able to resolve specific spectral features for certain PE-types, including black HDPE, and light-coloured ABS. Fast-acquisition Raman spectroscopy (down to 500 ms) enabled the identification of all polymers regardless their composition and presence of black pigments, however, it exhibited limited capacities in mapping applications. We therefore suggest a combination of both imaging and point measurements in a sequential design for enhanced robustness on industrial polymer identification.

Published
2024

47. Photoproduction of {\omega} Mesons off the Proton

Author

Wilson, A., Crede, V., Anisovich, A. V., Bacelar, J. C. S., Bantes, B., Bartholomy, O., Bayadilov, D., Beck, R., Beloglazov, Y. A., Brinkmann, K. T., Castelijns, R., Dutz, H., Elsner, D., Ewald, R., Frommberger, F., Fuchs, M., Funke, Chr., Gregor, R., Gridnev, A., Gutz, E., Hannappel, J., Hillert, W., Hoffmeister, P., Horn, I., Jaegle, I., Jude, T., Junkersfeld, J., Kalinowsky, H., Kleber, V., Klein, Frank, Klein, Friedrich, Klempt, E., Kotulla, M., Krusche, B., Lang, M., Löhner, H., Lopatin, I. V., Lugert, S., Mertens, T., Messchendorp, J. G., Metag, V., Nanova, M., Nikonov, V. A., Novinski, D., Novotny, R., Ostrick, M., Pant, L. M., van Pee, H., Pfeiffer, M., Roy, A., Sarantsev, A. V., Schmidt, C., Schmieden, H., Shende, S., Sokhoyan, V., Sparks, N., Süle, A., Sumachev, V. V., Szczepanek, T., Thoma, U., Trnka, D., Varma, R., Walther, D., Wendel, Ch., and Wiedner, U.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The differential cross sections and unpolarized spin-density matrix elements for the reaction $\gamma p\to p\omega$ were measured using the CBELSA/TAPS experiment for initial photon energies ranging from the reaction threshold to 2.5 GeV. These observables were measured from the radiative decay of the $\omega$ meson, $\omega\to\pi^0\gamma$. The cross sections cover the full angular range and show the full extent of the $t$-channel forward rise. The overall shape of the angular distributions in the differential cross sections and unpolarized spin-density matrix elements are in fair agreement with previous data. In addition, for the first time, a beam of linearly-polarized tagged photons in the energy range from 1150 MeV to 1650 MeV was used to extract polarized spin-density matrix elements. These data were included in the Bonn-Gatchina partial wave analysis (PWA). The dominant contribution to $\omega$ photoproduction near threshold was found to be the $3/2^+$ partial wave, which is primarily due to the sub-threshold $N(1720)\,3/2^+$ resonance. At higher energies, pomeron-exchange was found to dominate whereas $\pi$-exchange remained small. These $t$-channel contributions as well as further contributions from nucleon resonances were necessary to describe the entire dataset: the $1/2^-$, $3/2^-$, and $5/2^+$ partial waves were also found to contribute significantly., Comment: 8 pages, 5 figures, accepted for publication in Physics Letters B

Published
2015
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48. High statistics study of the reaction $\gamma p\to p\;2\pi^0$

Author

Sokhoyan, V., Gutz, E., Crede, V., van Pee, H., Anisovich, A. V., Bacelar, J. C. S., Bantes, B., Bartholomy, O., Bayadilov, D., Beck, R., Beloglazov, Y. A., Castelijns, R., Dutz, H., Elsner, D., Ewald, R., Frommberger, F., Fuchs, M., Funke, Ch., Gregor, R., Gridnev, A. B., Hillert, W., Hoffmeister, Ph., Horn, I., Jaegle, I., Junkersfeld, J., Kalinowsky, H., Kammer, S., Kleber, V., Klein, Frank, Klein, Friedrich, Klempt, E., Kotulla, M., Krusche, B., Lang, M., Löhner, H., Lopatin, I. V., Lugert, S., Mertens, T., Messchendorp, J. G., Metag, V., Metsch, B., Nanova, M., Nikonov, V. A., Novinsky, D., Novotny, R., Ostrick, M., Pant, L., Pfeiffer, M., Piontek, D., Roy, A., Sarantsev, A. V., Schmidt, Ch., Schmieden, H., Seifen, T., Shende, S., Süle, A., Sumachev, V. V., Szczepanek, T., Thiel, A., Thoma, U., Trnka, D., Varma, R., Walther, D., Wendel, Ch., and Wilson, A.

Subjects
Nuclear Experiment
Abstract

The photoproduction of 2$\pi^0$ mesons off protons was studied with the Crystal Barrel/TAPS experiment at the electron accelerator ELSA in Bonn. The energy of photons produced in a radiator was tagged in the energy range from 600\,MeV to 2.5\,GeV. Differential and total cross sections and $p\pi^0\pi^0$ Dalitz plots are presented. Part of the data was taken with a diamond radiator producing linearly polarized photons, and beam asymmetries were derived. Properties of nucleon and $\Delta$ resonances contributing to the $p\pi^0\pi^0$ final state were determined within the BnGa partial wave analysis. The data presented here allow us to determine branching ratios of nucleon and $\Delta$ resonances for their decays into $p\pi^0\pi^0$ via several intermediate states. Most prominent are decays proceeding via $\Delta(1232)\pi$, $N(1440)1/2^+\pi$, $N(1520)3/2^-\pi$, $N(1680)5/2^+\pi$, but also $pf_0(500)$, $pf_0(980)$, and $pf_2(1270)$ contribute to the reaction., Comment: 28 pages, 17 figures, 7 tables

Published
2015
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