1. |
- Alberdi, Antxon, et al.
(author)
-
The jet of the Low Luminosity AGN of M81. Evidence of Precession
- 2013
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 61
-
Conference paper (peer-reviewed)abstract
- In this contribution, we summarize our main results of a big campaign of global VLBI observations of the AGN in M81 (M81*) phase-referenced to the radio supernova SN 1993J. Thanks to the precise multi-epoch and multi-frequency astrometry, we have determined the normalized core-shift of the relativistic jet of M81* and estimated both the magnetic field and the particle density at the jet base. We have also found evidence of jet precession in M81* coming from the systematic time evolution of the jet orientation correlated with changes in the overall flux density.
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2. |
- Audouin, L., et al.
(author)
-
High-precision measurement of isotopic fission yields of 236 U
- 2018
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 193
-
Conference paper (peer-reviewed)abstract
- We report on the second SOFIA experiment, dedicated to the fission yields of 236U∗, analog to 235U(n,f). The measurement is based on the inverse kinematics method, using a relativistic, secondary beam of 236U. Both fission fragments are identified in mass and charge in the SOFIA recoil spectrometer. The obtained isotopic yields are compared with existing spectroscopy measurements and the elemental yields are used to discuss the treatment of the even-odd effect with energy in nuclear data libraries.
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3. |
- Babaahmadi, Arezou, 1985, et al.
(author)
-
Electrochemical migration technique to accelerate ageing of cementitious materials
- 2013
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759810468 ; 56
-
Conference paper (peer-reviewed)abstract
- Durability assessment of concrete structures for constructions in nuclear waste repositories requires long term service life predictions. As deposition of low and intermediate level radioactive waste (LILW) takes up to 100 000 years, it is necessary to analyze the service life of cementitious materials in this time perspective. Using acceleration methods producing aged specimens would decrease the need of extrapolating short term data sets. Laboratory methods are therefore, needed for accelerating the ageing process without making any influencing distortion in the properties of the materials. This paper presents an electro-chemical migration method to increase the rate of calcium leaching from cementitious specimens. This method is developed based on the fact that major long term deterioration process of hardened cement paste in concrete structures for deposition of LILW is due to slow diffusion of calcium ions. In this method the cementitious specimen is placed in an electrochemical cell as a porous path way through which ions can migrate at a rate far higher than diffusion process. The electrical field is applied to the cell in a way to accelerate the ion migration without making destructions in the specimen's micro and macroscopic properties. The anolyte and catholyte solutions are designed favoring dissolution of calcium hydroxide and compensating for the leached calcium ions with another ion like lithium.
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4. |
- Bensby, Thomas, et al.
(author)
-
Chemical constraints on the formation of the Galactic thick disk
- 2012
-
In: Assembling the Puzzle of the Milky Way. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 19
-
Conference paper (peer-reviewed)abstract
- We highlight some results from our detailed abundance analysis study of 703 kinematically selected F and G dwarf stars in the solar neighbourhood. The analysis is based on spectra of high-resolution (R = 45 000 to 110 000) and high signal-to-noise (S/N approximate to 150 to 300). The main findings include: (1) at a given metallicity, the thick disk abundance trends are more alpha-enhanced than those of the thin disk; (2) the metal-rich limit of the thick disk reaches at least solar metallicities; (3) the metal-poor limit of the thin disk is around [Fe/H] approximate to -0.8; (4) the thick disk shows an age-metallicity gradient; (5) the thin disk does not show an age-metallicity gradient; (6) the most metal-rich thick disk stars at [Fe/H] approximate to 0 are significantly older than the most metal-poor thin disk stars at [Fe/H] approximate to -0.7; (7) based on our elemental abundances we find that kinematical criteria produce thin and thick disk stellar samples that are biased in the sense that stars from the low-velocity tail of the thick disk are classified as thin disk stars, and stars from the high-velocity tail of the thin disk are classified as thick disk stars; (8) age criteria appears to produce thin and thick disk stellar samples with less contamination.
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5. |
- Bijnens, Johan
(author)
-
ChPT loops for the lattice : Pion mass and decay constant, HVP at finite volume and nn̄ -oscillations
- 2018
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 175
-
Journal article (peer-reviewed)abstract
- I present higher loop order results for several calculations in Chiral perturbation Theory. 1) Two-loop results at finite volume for hadronic vacuum polarization. 2) A three-loop calculation of the pion mass and decay constant in two-flavour ChPT. For the pion mass all needed auxiliary parameters can be determined from lattice calculations of ππ-scattering. 3) Chiral corrections to neutron-anti-neutron oscillations.
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6. |
- Bijnens, Johan
(author)
-
On the Hadronic light-by-light contribution to the muon g-2
- 2018
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 179
-
Journal article (peer-reviewed)abstract
- This talk is about the hadronic light-by-light contribution to the muon anomalous magnetic moment, mainly our old work but including some newer results as well. It concentrates on the model calculations. Most attention is paid to pseudo-scalar exchange and the pion loop contribution. Scalar, a1-exchange and other contributions are shortly discussed as well. For the π0-exchange a possible large cancellation between connected and disconnected diagrams is expected.
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7. |
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8. |
- Bouzid, Mehdi, et al.
(author)
-
Non-local rheology of dense granular flows
- 2017
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 140
-
Journal article (peer-reviewed)abstract
- The rheology of dense granular flows is studied numerically in a shear cell controlled at constant pressure and shear stress, confined between two granular shear flows. We show that a liquid state can be achieved even far below the yield stress, whose flow can be described with the same rheology as above the yield stress. A non-local constitutive relation is derived from dimensional analysis through a gradient expansion and calibrated using the spatial relaxation of velocity profiles observed under homogeneous stresses. Both for frictional and frictionless grains, the relaxation length is found to diverge as the inverse square root of the distance to the yield point, on both sides of that point. We also make use of a micro-rheometer to determine the influence of a distant shear band on the local rheological behaviour. Finally, we compare various approaches based on different non-local constitutive relations and choices for the fluidity parameter. We emphasise that, to discriminate between the different approaches proposed in the literature, one has to go beyond the predictions derived from linearisation around a uniform stress profile, such as that obtained in a simple shear cell. We argue that future tests can be based on the nature of the chosen fluidity parameter, and the related boundary conditions, as well as the hypothesis made to derive the models and the dynamical mechanisms underlying their dynamics.
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9. |
- Bovo, Mirko, 1979, et al.
(author)
-
Measurements of a single pulse impinging jet. A CFD reference
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9788026053750 ; 67
-
Conference paper (peer-reviewed)abstract
- This paper reports three sets of measurements of a single pulse impinging jet. The purpose is to serve as a reference for CFD validation. A gas injector generates a single pulse jet at Re ~90000. The jet impinges on a temperature controlled flat target at different angles (0̈, 30̈, 45̈ and 60̈). The jet velocity field is measured with PIV. The evolution of the jet velocity profile in time is reported at two different locations (suitable as CFD inlet conditions). At the same locations also turbulence quantities are reported. The impingement wall temperature is measured with fast responding thermocouples and infrared camera. These give high time and space resolution respectively. Results are reported in a format suitable for comparison with CFD simulations. The results show that the heat transfer effects are highest for the jet impinging normally on the target. Target inclination has remarkable effects on the jet penetration rate and repeatability. Even small target inclinations result creates a preferential direction for the jet flow and cause a shift in the position of the stagnation region.
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10. |
- Broeg, C., et al.
(author)
-
CHEOPS: A transit photometry mission for ESA's small mission programme
- 2013
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759809851 ; 47
-
Conference paper (peer-reviewed)abstract
- Ground based radial velocity (RV) searches continue to discover exoplanets below Neptune mass down to Earth mass. Furthermore, ground based transit searches now reach milli-mag photometric precision and can discover Neptune size planets around bright stars. These searches will find exoplanets around bright stars anywhere on the sky, their discoveries representing prime science targets for further study due to the proximity and brightness of their host stars. A mission for transit follow-up measurements of these prime targets is currently lacking. The first ESA S-class mission CHEOPS (CHaracterizing ExoPlanet Satellite) will fill this gap. It will perform ultra-high precision photometric monitoring of selected bright target stars almost anywhere on the sky with sufficient precision to detect Earth sized transits. It will be able to detect transits of RV-planets by photometric monitoring if the geometric configuration results in a transit. For Hot Neptunes discovered from the ground, CHEOPS will be able to improve the transit light curve so that the radius can be determined precisely. Because of the host stars' brightness, high precision RV measurements will be possible for all targets. All planets observed in transit by CHEOPS will be validated and their masses will be known. This will provide valuable data for constraining the mass-radius relation of exoplanets, especially in the Neptune-mass regime. During the planned 3.5 year mission, about 500 targets will be observed. There will be 20% of open time available for the community to develop new science programmes.
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11. |
- Brydegaard, Mikkel, et al.
(author)
-
Short-Wave infrared atmospheric scheimpflug lidar
- 2018
-
In: EPJ Web of Conferences. - : EDP Sciences. ; 176
-
Conference paper (peer-reviewed)abstract
- Atmospheric dual-band Scheimpflug lidar is demonstrated at 980 and 1550 nm. Signals are compared during three weather conditions, and the spatio-temporal resolution of the atmospheric structure is considered. The potential for aerosol classification is evaluated, and future directions are discussed.
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12. |
- Chakraborty, S., et al.
(author)
-
Ground-state configuration of neutron-rich Aluminum isotopes through Coulomb breakup
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
-
Conference paper (peer-reviewed)abstract
- Neutron-rich 34,35Al isotopes have been studied through Coulomb excitation using LAND-FRS setup at GSI, Darmstadt. The method of invariant mass analysis has been used to reconstruct the excitation energy of the nucleus prior to decay. Comparison of experimental CD cross-section with direct breakup model calculation with neutron in p3/2 orbital favours 34Al(g.s) - νp3/2 as ground state configuration of 35Al. But ground state configuration of 34Al is complicated as evident from γ-ray spectra of 33Al after Coulomb breakup of 34Al. © Owned by the authors, published by EDP Sciences, 2014.
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13. |
- Chatillon, A., et al.
(author)
-
Accurate measurements of fission-fragment yields in U-234,U-235,U-236,U-238(gamma,f) with the SOFIA set-up
- 2016
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759819706 ; 111
-
Conference paper (peer-reviewed)abstract
- SOFIA (Studies On Fission with Aladin) is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (gamma,f) electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in U-234,U-235,U-236,U-238(gamma,f) reactions.
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14. |
- Cubero, M., et al.
(author)
-
Scattering of 9Li on 208Pb at energies around the Coulomb barrier
- 2011
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759806935 ; 17, s. Art. no. 16002-
-
Conference paper (peer-reviewed)abstract
- In order to study the dynamics of 11Li and 9Li beams in a strong electric field at energies around the Coulomb barrier, we measured at the ISACII-TRIUMF Facility the angular distribution of elastic and inelastic scattering of 11Li+208Pb at 24.2 and 29.7 MeV and 9Li+208Pb at 24, 29.5 and 33 MeV laboratory energies. We present here the first determination of the angular distribution of the cross section of 9Li+208Pb. The results are compared with theoretical calculations using the double-folding São Paulo Potential (SPP) for the real part and a for the imaginary part a Woods-Saxon potential. A good overall agreement is obtained.
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15. |
- Deen, Pascale, et al.
(author)
-
A design study of VOR: A versatile optimal resolution chopper spectrometer for the ESS
- 2015
-
In: QENS/WINS 2014 - 11th International Conference on Quasielastic Neutron Scattering and 6th International Workshopon Inelastic Neutron Spectrometers. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 83, s. 03002-03002
-
Conference paper (peer-reviewed)abstract
- VOR, the versatile optimal resolution chopper spectrometer, is designed to probe dynamic phenomena that are currently inaccessible for inelastic neutron scattering due to flux limitations. VOR is a short instrument by the standards of the European Spallation Source (ESS), 30.2m moderator to sample, and provides instantaneous access to a broad dynamic range, 1-120 meV within each ESS period. The short instrument length combined with the long ESS pulse width enables a quadratic flux increase, even at longer wavelengths, by relaxing energy resolution from Delta E/E = 1% up to Delta E/E = 7%. This is impossible both on a long chopper spectrometer at the ESS and with instruments at short pulsed sources. In comparison to current day chopper spectrometers, VOR can offer an order of magnitude improvement in flux for equivalent energy resolutions, Delta E/E = 1-3%. Further relaxing the energy resolution enables VOR to gain an extra order of magnitude in flux. In addition, VOR has been optimised for repetition rate multiplication (RRM) and is therefore able to measure, in a single ESS period, 6-14 incident wavelengths, across a wavelength band of 9 angstrom with a novel chopper configuration that transmits all incident wavelengths with equivalent counting statistics. The characteristics of VOR make it a unique instrument with capabilities to access small, limited-lifetime samples and transient phenomena with inelastic neutron scattering.
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16. |
- del Rio, J. S., et al.
(author)
-
CEPA: A LaBr 3 (Ce)/LaCl 3 (Ce) phoswich array for simultaneous detection of protons and gamma radiation emitted in reactions at relativistic energies
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
-
Conference paper (peer-reviewed)abstract
- A prototype CEPA4, made of four optically isolated phoswich-crystals of LaBr3(Ce)+LaCl3(Ce) packed together in one can of Al, was tested with high energy protons (70-230 MeV) at the cyclotron of Krakow. Further, the response to different gamma radiation standard sources and cosmic muons was determined. Shape analysis of the pulses derived from the four individually coupled PM-tubes was performed and were used as input functions for Monte Carlo simulations in order to simulate the efficiencies and resolutions of a final detector design consisting of 750 such phoswich crystals arranged in a cylindrical disc. © Owned by the authors, published by EDP Sciences, 2014.
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17. |
- Dostal, Jakub, et al.
(author)
-
Fast Exciton Dynamics and Coherent Oscillations Revealed by Coherent 2D Spectroscopy in Chlorosomes
- 2013
-
In: XVIIITH International Conference on Ultrafast Phenomena. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 41
-
Conference paper (peer-reviewed)abstract
- In this study ultrafast energy transfer dynamics in chlorosomes from sulphur bacterium Chlorobaculum tepidum were explored by means of coherent electronic two-dimensional spectroscopy. Observed sub-100 fs dynamics were attributed to incoherent downhill excitation diffusion between disordered domains within chlorosomes. At the same time vibrational coherent oscillations were investigated on the longer timescales.
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18. |
- Ehlers, G., et al.
(author)
-
Neutron xyz - polarization analysis at a time-of-flight instrument
- 2015
-
In: QENS/WINS 2014 - 11th International Conference on Quasielastic Neutron Scattering and 6th International Workshopon Inelastic Neutron Spectrometers. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 83, s. 03004-03004
-
Conference paper (peer-reviewed)abstract
- When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.
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19. |
- El-Alti, Mohammad, 1981, et al.
(author)
-
Experimental and computational studies of active flow control on a model truck-trailer
- 2012
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 25:01012, s. pp 16-
-
Conference paper (peer-reviewed)abstract
- Active flow control is probably the most challenging research area in vehicle aerodynamics. Being able to manipulate a flow field in order to achieve desired results beneficial to engineering is the only way to meet today’s demands for competitive and efficient solutions in the automotive industry. The current work studies the flow control on a semi detailed model truck by using detached-eddy simulations and wind tunnel experiments aiming at reducing the aerodynamic drag. This study combines both passive and active flow control applied on the rear end of the trailer. An indigenous fluidic actuator (loudspeaker in cavity with slots) is used as a synthetic jet in the experiment. Both experiments and computations demonstrate that the active flow control works successfully and results in flow reattachment to the flaps. The numerical simulations show that the drag coefficient, CD decreased by 3.9% when AFC was activated compared to the baseline case without flaps. The corresponding decrease when AFC was deactivated (with flaps) was only 0.7%. The experimental results show a decrease of CD by 3.1% for the case with activated AFC compared to the baseline case. When AFC was deactivated the corresponding decrease in CD was 1.8%. A detailed flow analysis made in computations and experiments is used to explain these results.
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20. |
- Elter, Zsolt, 1987, et al.
(author)
-
Energy Correlation of Prompt Fission Neutrons
- 2016
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759819706 ; 111, s. Art no 05003-
-
Conference paper (peer-reviewed)abstract
- In all cases where neutron fluctuations in a branching process (such as in multiplicity measurements) are treated in an energy dependent description, the energy correlations of the branching itself (energy correlations of the fission neutrons) need to be known. To date, these are not known from experiments. Such correlations can be theoretically and numerically derived by modelling the details of the fission process. It was suggested earlier that the fact that the prompt neutrons are emitted from the moving fission targets, will influence their energy and angular distributions in the lab system, which possibly induces correlations. In this paper the influence of the neutron emission process from the moving targets on the energy correlations is investigated analytically and via numerical simulations. It is shown that the correlations are generated by the random energy and direction distributions of the fission fragments. Analytical formulas are derived for the two-point energy distributions, and quantitative results are obtained by Monte-Carlo simulations. The results lend insight into the character of the two-point distributions, and give quantitative estimates of the energy correlations, which are generally small.
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21. |
- Feltzing, Sofia, et al.
(author)
-
The chemical evolution of the Galactic Bulge seen through micro-lensing events
- 2012
-
In: Assembling the Puzzle of the Milky Way. - : EDP Sciences. - 2100-014X .- 2101-6275. ; 19
-
Conference paper (peer-reviewed)abstract
- Galactic bulges are central to understanding galaxy formation and evolution. Here we report on recent studies using micro-lensing events to obtain spectra of high resolution and moderately high signal-to-noise ratios of dwarf stars in the Galactic bulge. Normally this is not feasible for the faint turn-off stars in the Galactic bulge, but micro-lensing offers this possibility. Elemental abundance trends in the Galactic bulge as traced by dwarf stars are very similar to those seen for dwarf stars in the solar neighbourhood. We discuss the implications of the ages and metallicity distribution function derived for the micro-lensed dwarf stars in the Galactic bulge.
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22. |
- Fernandez-Garcia, J. P., et al.
(author)
-
Li-11 structural information from inclusive break-up measurements
- 2015
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 88
-
Conference paper (peer-reviewed)abstract
- Structure information of Li-11 halo nucleus has been obtained from the inclusive break-up measurements of the Li-11+Pb-208 reactions at energies around the Coulomb barrier (E-lab = 24.3 and 29.8 MeV). The effective break-up energy and the slope of B(E1) distribution close to the threshold have been extracted from the experimental data.
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23. |
- Floderus, Anders
(author)
-
Searches for direct supersymmetric gaugino and slepton pair production in final states with leptons with the ATLAS detector
- 2013
-
In: HCP 2012 - Hadron Collider Physics Symposium 2012. - : EDP Sciences. - 2100-014X .- 2101-6275. ; 49, s. 15008-15008
-
Conference paper (peer-reviewed)abstract
- A search for direct production of supersymmetric gauginos and sleptons in final states with two and three leptons is presented. The two lepton analysis uses 4.7 fb(-1) of proton-proton collision data at root s = 7 TeV, while the three lepton analysis uses 13 fb(-1) at root s = 8 TeV. All data were recorded by the ATLAS detector at the Large Hadron Collider. The results are interpreted in the phenomenological minimal supersymmetric Standard Model, as well as simplified models. No significant excess above the Standard Model expectation is observed. Limits on the particle masses are placed at the 95% confidence level. In simplified models, chargino masses are excluded up to 580 GeV.
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24. |
- Fomichev, A. S., et al.
(author)
-
Recent results related to excited states of 6Be and 10He
- 2012
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 38, s. Art. no. 15002-
-
Conference paper (peer-reviewed)abstract
- The 1H(6Li,6Be)n charge-exchange reaction and the 3H(8He, p)10He two-neutron transfer reaction were recently carried out at the ACCULINNA fragment separator (FLNR, Dubna) to populate the ground and excited states of 6Be and 10He nuclei, respectively. The 6Be ET spectrum (ET is the 6Be energy above its 4He+p+p decay threshold) was obtained with high statistics and described by the well-known 0+ ground state of 6Be at ET = 1.37 MeV, the 2+ state at ET = 3.05 MeV and a broad structure extending from 4 to 16 MeV which could be interpreted as the isovector soft dipole mode associated with the 6Li ground state. In the 10He case the 0+ ground state was found at about 2.1(2) MeV (T ∼ 2 MeV) above the 8He+n+n breakup threshold. Angular correlations observed for 10He decay products show prominent interference patterns allowing to draw conclusions about the structure of low-energy excited states: 1- (E T ∼ 5 MeV) and 2+ (ET > 6 MeV).
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25. |
- Forsberg, Ulrika, et al.
(author)
-
Spectroscopic Tools Applied to Element Z = 115 Decay Chains
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X .- 2101-6275. - 9782759811755 - 9782759811762 ; 66, s. 02036-02036
-
Conference paper (peer-reviewed)abstract
- Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.
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26. |
- Goncalves, V. P.
(author)
-
Searching saturation effects in inclusive and exclusive eA processes
- 2016
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 112
-
Journal article (peer-reviewed)abstract
- The searching of saturation effects in inclusive and exclusive eA collisions is reviewed. In particular, we present a comparison between the linear and non-linear predictions for the nuclear structure functions as well as for the Deep Virtual Compton Scattering and vector meson production in future eA colliders.
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27. |
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28. |
- Grente, L., et al.
(author)
-
The SOFIA experiment: Measurement of 236U fission fragment yields in inverse kinematics
- 2016
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 122:01006
-
Conference paper (peer-reviewed)abstract
- The SOFIA (Studies On FIssion with Aladin) experiment aims at measuring fission-fragments isotopic yields with high accuracy using inverse kinematics at relativistic energies. This experimental technique allows to fully identify the fission fragments in nuclear charge and mass number, thus providing very accurate isotopic yields for low energy fission of a large variety of fissioning systems. This report focuses on the latest results obtained with this set-up concerning electromagnetic-induced fission of 236U.
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29. |
- Gustafson, Gösta
(author)
-
Effects of diffraction in pp and pA collisions
- 2017
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 141
-
Journal article (peer-reviewed)abstract
- Diffractive excitation is a large fraction of the pp cross section, also at high energies. Diffraction has been described by multi-Regge diagrams, or in the Good-Walker formalism as a result of fluctuations. The two formalisms are, however, just different sides of the same phenomenon. The dipole cascade formalism in impact parameter space is well suited to describe diffractive excitation including effects of saturation. Diffractive excitation is also an important effect in pA scattering, where the Glauber formalism has been used to estimate the number of NN subcollisions and of "wounded" nucleons. Diffractive excitation has here been either neglected or included in a simplified way, not including excitation of target nucleons. In this talk we discuss how these effects can be included with the help of the dipole cascade model DIPSY.
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30. |
- Gustafson, Gösta
(author)
-
Minireview on diffraction
- 2015
-
In: Xliv International Symposium on Multiparticle Dynamics (Ismd 2014). - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 90, s. 06002-06002
-
Conference paper (peer-reviewed)abstract
- A short review is presented on diffractive excitation in high energy collisions. [GRAPHICS] .
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31. |
- Hennig, A., et al.
(author)
-
Mixed-symmetry octupole and hexadecapole excitations in N=52 isotones
- 2015
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759817948 ; 93
-
Conference paper (peer-reviewed)abstract
- In addition to the well-established quadrupole mixed-symmetry states, octupole and hexadecapole excitations with mixed-symmetry character have been recently proposed for the N = 52 isotones 92Zr and 94Mo. We performed two inelastic proton-scattering experiments to study this kind of excitations in the heaviest stable N = 52 isotone 96Ru. From the combined experimental data of both experiments absolute transition strengths were extracted.
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32. |
- Henning, G., et al.
(author)
-
Exploring the stability of super heavy elements: First measurement of the fission barrier of 254No
- 2014
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
-
Conference paper (peer-reviewed)abstract
- The gamma-ray multiplicity and total energy emitted by the heavy nucleus 254No have been measured at 2 different beam energies. From these measurements, the initial distributions of spin I and excitation energy E * of 254No were constructed. The distributions display a saturation in excitation energy, which allows a direct determination of the fission barrier. 254No is the heaviest shell-stabilized nucleus with a measured fission barrier. © Owned by the authors, published by EDP Sciences, 2014.
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33. |
- Hurley, Ryan C., et al.
(author)
-
Force measurements in stiff, 3D, opaque granular materials
- 2017
-
In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 140
-
Journal article (peer-reviewed)abstract
- We present results from two experiments that provide the first quantification of inter-particle force networks in stiff, 3D, opaque granular materials. Force vectors between all grains were determined using a mathematical optimization technique that seeks to satisfy grain equilibrium and strain measurements. Quantities needed in the optimization - the spatial location of the inter-particle contact network and tensor grain strains - were found using 3D X-ray diffraction and X-ray computed tomography. The statistics of the force networks are consistent with those found in past simulations and 2D experiments. In particular, we observe an exponential decay of normal forces above the mean and a partition of forces into strong and weak networks. In the first experiment, involving 77 single-crystal quartz grains, we also report on the temporal correlation of the force network across two sequential load cycles. In the second experiment, involving 1099 single-crystal ruby grains, we characterize force network statistics at low levels of compression.
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34. |
- Jurado, B., et al.
(author)
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Investigation of the surrogate-reaction method via the simultaneous measurement of gamma-emission and fission probabilities
- 2017
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 146
-
Conference paper (peer-reviewed)abstract
- We present the results of two experiments where we have measured for the first time simultaneously the fission and gamma-decay probabilities induced by different surrogate reactions. In particular, we have investigated the 238 U(d,p), 238 U( 3 He,t) and 238 U( 3 He, 4 He) reactions as surrogates for the neutron-induced n + 238 U, n + 237 Np and n + 236 U reactions, respectively. In the region where gamma emission, neutron emission and fission compete, our results for the fission probabilities agree fairly well with the neutron-induced data, whereas our gamma-decay probabilities are significantly higher than the neutron-induced data. The interpretation of these results is not obvious and is discussed within the framework of the statistical model with preliminary results for calculated spin-parity distributions populated in surrogate reactions. We also present future plans for surrogate-reaction studies in inverse kinematics with radioactive-ion beams at storage rings.
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35. |
- Kern, Ralph, et al.
(author)
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Search for Isovector Valence-Shell Excitations in 140Nd and 142Sm via Coulomb excitation reactions of radioactive ion beams
- 2018
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In: International Conference on Nuclear Structure and Related Topics (NSRT18). - : EDP Sciences. - 2101-6275. ; 194
-
Conference paper (peer-reviewed)abstract
- Projectile Coulomb excitation experiments were performed at HIE-ISOLDE at CERN with the radioactive ion beams of 140Nd and 142Sm. Ions with an energy of 4:62 MeV/A were impinging on a 1.45 mg/cm2 thick 208Pb target. The γ-rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL and scattered particles were detected by a double-sided silicon strip detector. Experimental intensities were used for the determination of electromagnetic transition matrix elements. A preliminary result of the B(M1; 2+ 3 → 2+ 1) of 140Nd and an upper limit for the case of 142Sm are revealing the main fragments of the proton-neutron mixed-symmetry 2+ 1;ms states.
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36. |
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37. |
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38. |
- Krupko, S. A., et al.
(author)
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The status of new fragment separator ACCULINNA-2 project and the first day experiments
- 2014
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
-
Conference paper (peer-reviewed)abstract
- The new facility fragment separator ACCULINNA-2 will be put into operation at the beginning of 2015 in FLNR JINR. The new separator is destined to add considerably to the studies of drip-line nuclei performed with the use of variety of direct reactions known to be distinctive to the 15 - 50 MeV/amu exotic secondary RIBs. Intense beams provided by the U-400M cyclotron will ensure the achievement of this objective. In addition to the RIB separation accomplished by means of the dipole-wedge-dipole selection, the addition of a zero-degree dipole magnet setup is foreseen. A long (13 m) straight section will provide precise time-of-flight measurements. © Owned by the authors, published by EDP Sciences, 2014.
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39. |
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40. |
- Lalovic, Natasa, et al.
(author)
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Analysis of the Response of AGATA Detectors at GSI
- 2015
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759817948 ; 93, s. 07007-07007
-
Conference paper (peer-reviewed)abstract
- In 2012 and 2014 the γ-ray tracking spectrometer AGATA was operated at the SIS/FRS facility at GSI in Darmstadt, Germany. The performance of the array is discussed, outlining some important aspects of the offline data processing and analysis. Relying on the data obtained from measurements with standard γ-ray sources, a first estimate of the photopeak efficiency and peak-to-total (P/T) is presented.
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41. |
- Lebois, M., et al.
(author)
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Studies for γ-ray emission in the fission process with LICORNE
- 2016
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 122:01010
-
Conference paper (peer-reviewed)abstract
- The LICORNE neutron source is a new device at the ALTO facility. Its use of inverse kinematics makes the production of naturally focused neutron beams possible with an energy range of 0.5 to 4 MeV. This is perfect for any studies concerning fast neutron induced reaction based on detection setup that require to be placed in a compact geometry - such as Ge based ? detection setup. In this paper, neutron production with LICORNE is described. The development of a gascell target and the extension of the energy range up to 7 MeV with the p(11B,n)11C are presented. An overview of the major research fields studied with LICORNE is given and two types of experiment are presented. The first one dedicated to prompt fission ?-ray emission in fission, as a function of incident neutron energy, is described. Some preliminary results are shown. The second, in the context of the MINORCA campaign, is detailed. The most recent outcomes in the data analysis process are also presented.
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42. |
- Lenngren, Nils, et al.
(author)
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Multiexciton Absorption Cross Sections of CdSe Nanocrystals at Band-Edge Energy
- 2013
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In: XVIIIth International Conference On Ultrafast Phenomena. - : EDP Sciences. - 2100-014X .- 2101-6275. ; 41
-
Conference paper (peer-reviewed)abstract
- Picosecond transient absorption signals of two kinds of cadmium selenide quantum dots were measured at various excitation intensities. The average number of excitons per quantum dot was calculated from a Poisson model, which together with kinetic parameters was used to determine exciton population kinetics. Exciton and multiexciton absorption cross sections were determined and analyzed in terms of the electronic states of the quantum dots.
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43. |
- Lopez-Martens, A., et al.
(author)
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Stability and synthesis of superheavy elements: Fighting the battle against fission - example of No-254
- 2016
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759890118 ; 131
-
Conference paper (peer-reviewed)abstract
- Superheavy nuclei exist solely due to quantum shell effects, which create a pocket in the potential-energy surface of the nucleus, thus providing a barrier against spontaneous fission. Determining the height of the fission barrier and its angular-momentum dependence is important to quantify the role that microscopic shell corrections play in enhancing and extending the limits of nuclear stability. In this talk, the first measurement of a fission barrier in the very heavy nucleus No-254 will be presented.
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44. |
- Lubenchenko, Alexander, 1966, et al.
(author)
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An XPS method for layer profiling of NbN thin films
- 2017
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 132, s. Art no 03053-
-
Conference paper (peer-reviewed)abstract
- Layer chemical and phase profiling of niobium nitride thin films on a silicon substrate oxidized on air was performed with the help of a method designed by us. The method includes: a new method of background subtraction of multiple inelastically scattered photoelectrons considering depth inhomogeneity of electron inelastic scattering; a new method of photoelectron line decomposition into component peaks considering physical nature of different decomposition parameters; joint solution of the background subtraction and photoelectron line decomposition problems; control of line decomposition accuracy with the help of a suggested performance criterion; calculation of layer thicknesses for a multilayer target using a simple formula.
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45. |
- Malmqvist, Elin, et al.
(author)
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CW Laser radar for combustion diagnostics
- 2018
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 176
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Journal article (peer-reviewed)abstract
- A CW-laser radar system developed for combustion diagnostics is described. The system is based on triangulation to attain range information. A portable system has been constructed and here we show some result from measurements in various flames, for example Rayleigh scattering thermometry and monitoring of particle distributions with high temporal and spatial resolution. The concept can equally well be based on pulsed lasers, allowing suppression of background emission through gated detection.
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46. |
- Martins, Murillo L., et al.
(author)
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Encapsulation of paclitaxel into a bio-nanocomposite. A study combining inelastic neutron scattering to thermal analysis and infrared spectroscopy
- 2015
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 83
-
Conference paper (peer-reviewed)abstract
- The anticancer drug paclitaxel was encapsulated into a bio-nanocomposite formed by magnetic nanoparticles, chitosan and apatite. The aim of this drug carrier is to provide a new perspective against breast cancer. The dynamics of the pure and encapsulated drug were investigated in order to verify possible molecular changes caused by the encapsulation, as well as to follow which interactions may occur between paclitaxel and the composite. Fourier transformed infrared spectroscopy, thermal analysis, inelastic and quasi-elastic neutron scattering experiments were performed. These very preliminary results suggest the successful encapsulation of the drug.
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47. |
- Merdasa, Aboma, et al.
(author)
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Non-radiative processes in metal halide perovskite semiconductors probed by photoluminescence microscopy
- 2018
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In: XIII International Conference on Hole Burning, Single Molecule, and Related Spectroscopies: Science and Applications (HBSM-2018). - : EDP Sciences. - 2101-6275. ; 190
-
Conference paper (peer-reviewed)abstract
- Organo metal halide perovskites are solution processed semiconductors that recently attracted a great attention. They possess a rather "soft" and (photo) chemically active solid structure allowing for ion migration and other mass diffusion processes. This is a likely reason why non-radiative recombination centres in these materials are activated and deactivated on relatively slow time-scales. This dynamics reveals as photoluminescence (PL) fluctuations (blinking) of individual microcrystals and local areas of films and allows for application of a broad range of single molecule spectroscopy methods including optical super-resolution. Studying PL blinking resolves properties of individual non-radiative centres and helps to unravel their chemical nature.
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48. |
- Nagy, Lajos, 1991, et al.
(author)
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Measurements and simulations to investigate the feasibility of neutron multiplicity counting in the current mode of fission chambers
- 2020
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 225
-
Conference paper (peer-reviewed)abstract
- In two earlier papers [1], [2] we investigated the possibility of extracting traditional multiplicity count rates from the cumulants of fission chamber signals in current mode. It was shown that if all neutrons emitted from the sample simultaneously are also detected simultaneously, the multiplicity rates can be retrieved from the first three cumulants of the currents of up to three detectors, but the method breaks down if the detections of neutrons of common origin take place with a time delay spread wider than the pulse shape. To remedy these shortcomings, in this work we extended the theory to two- and three-point distributions (correlations). It was found thatthe integrals of suitably chosen two- and three-point moments with respect to the time differences become independent of the probability density of the time delays of detections. With this procedure, the multiplicity rates can be retrieved from the detector currents for arbitrary time delay distributions. To demonstrate the practical applicability of the proposed method, a measurement setup was designed and built. The statistics (shape and amplitude distribution) of the detector pulse were investigated as important parameters of the theoretical model. Simulations were performed to estimate the expected value of the multiplicity rates in the built setup. Measurements were performed and two types of moments (the mean and the covariance function) of the recorded detector signals were calculated. Values of singles rates were successfully recovered.
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49. |
- Niebles Atencio, Bercelay, 1979, et al.
(author)
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An experimental study on laminar-turbulent transition at high free-stream turbulence in boundary layers with pressure gradients
- 2012
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In: The European Physical Journal Conferences. - : EDP Sciences. ; 25, s. Art. no. 01012-
-
Conference paper (peer-reviewed)abstract
- We report here the results of a study on measurements and prediction of laminar-turbulenttransition at high free-stream turbulence in boundary layers of the airfoil-like geometries with presence of the external pressure gradient changeover. The experiments are performed for a number of flow cases with different flow Reynolds number, turbulence intensity and pressure gradient distributions. The results were then compared to numerical calculations for same geometries and flow conditions. The experiments and computations are performed for the flow parameters which are typical for turbomachinery applications and the major idea of the current study is the validation of the turbulencemodel which can be used for such engineering applications.
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50. |
- Oberstedt, S., et al.
(author)
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Prompt fission γ -rays from the reactions 252Cf(SF) and 235U(nth, f) - New data
- 2013
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 62, s. Art. no. 02003-
-
Conference paper (peer-reviewed)abstract
- We present new spectral data of prompt γ-ray emission from the spontaneous fission of 252Cf. This work was performed in direct response to an OECD/NEA high priority data request. We discuss the impact of our new data on evaluated nuclear data tables not only for this nuclide, but also for 238U and 241Pu, which are always produced in a reactor. Furthermore, we will show results from our investigation of prompt γ-ray emission from the reaction 235 U(nth, f), measured in at the Centre for Energy Research of the Hungarian Academy of Sciences in Budapest, Hungary. Spectral data obtained with three different detectors are consistent and led to an uncertainty on total energy and multiplicity considerably smaller than requested by the OECD/NEA.
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