bluuebunny/crossref_metadata_2025 huggingface dataset:
A general phenomenological relation for the subdiffusive exponent of anomalous diffusion in disordered media
Authors: Alcázar-Cano Nerea , Delgado-Buscalioni Rafael
Published: November 2018

Distinction between mobile and trapped tracers in disordered media reveals a simple phenomenological law for the subdiffusive exponent which reproduces the behaviour observed in a wide range of obstacles structures.
Two-time correlations for probing the aging dynamics of glassy colloids
Authors: Robe Dominic , Boettcher Stefan
Published: November 2018

We present results for the aging dynamics of a dense 2D colloidal system obtained with molecular dynamics simulations.
Facile synthesis of monodisperse bulk boron- and nitrogen-doped carbon nano/microspheres
Authors: Zhao Jianming , Luque Rafael , Gilani Muhammad Rehan Hasan Shah , Lai Jianping , Nsabimana Anaclet , Xu Guobao
Published: November 2018

Monodisperse bulk boron- and nitrogen-doped carbon nano/microspheres were prepared by pyrolysis of novel boron- and nitrogen-doped resin nano/microspheres and show nice supercapacitor performance.
Ternary non-fullerene polymer solar cells with a high crystallinity n-type organic semiconductor as the second acceptor
Authors: Zhong Lian , Bin Haijun , Li Yongxi , Zhang Ming , Xu Jianqiu , Li Xiaojun , Huang He , Hu Qin , Jiang Zuo-Quan , Wang Jing , Zhang Chunfeng , Liu Feng , Russell Thomas P. , Zhang Zhanjun , Li Yongfang
Published: November 2018

Ternary blend is an effective way to realize high photovoltaic performance of polymer solar cells (PSCs). A highly crystalline n-type organic semiconductor (n-OS) IDIC was introduced into a low crystalline blend of conjugated polymer donor J61 and n-OS acceptor BT-IC.
Interlayer coupling to enhance the energy storage performance of Na0.5Bi0.5TiO3–SrTiO3 multilayer films with the electric field amplifying effect
Authors: Zhang Yulei , Li Weili , Xu Shichong , Wang Zhenyu , Zhao Yu , Li Ji , Fei Weidong
Published: November 2018

High energy storage density and good thermal stability are simultaneously achieved in a new lead-free relaxor ferroelectric 0.7Na0.5Bi0.5TiO3–0.3SrTiO3/0.6SrTiO3–0.4Na0.5Bi0.5TiO3 multilayer film.
Correction: A high temperature stable piezoelectric strain of KNN-based ceramics
Authors: Cen Zhenyong , Huan Yu , Feng Wei , Yu Yan , Zhao Peiyao , Chen Lingling , Zhu Chaoqiong , Li Longtu , Wang Xiaohui
Published: November 2018

Correction for ‘A high temperature stable piezoelectric strain of KNN-based ceramics’ by Zhenyong Cen et al., J. Mater. Chem. A, 2018, 6, 19967–19973.
Pyridine boronic acid-polyoxometalate based porous hybrid for efficient depletion of high abundant glycoproteins in plasma
Authors: Hu Xue , Chen Qing , Zhang Dan-Dan , Chen Xu-Wei , Wang Jian-Hua
Published: November 2018

A porous hybrid, namely PW12@TiO2–Si(Et)Si/Pba, is fabricated by the modification of PW12@TiO2–Si(Et)Si with pyridine boronic acid and used for glycoprotein depletion.
Genome size evolution in the Archaea
Authors: Kellner Siri , Spang Anja , Offre Pierre , Szöllősi Gergely J. , Petitjean Celine , Williams Tom A.
Published: November 2018

What determines variation in genome size, gene content and genetic diversity at the broadest scales across the tree of life? Much of the existing work contrasts eukaryotes with prokaryotes, the latter represented mainly by Bacteria. But any general theory of genome evolution must also account for the Archaea, a diverse and ecologically important group of prokaryotes that represent one of the primary domains of cellular life. Here, we survey the extant diversity of Bacteria and Archaea, and ask whether the general principles of genome evolution deduced from the study of Bacteria and eukaryotes also apply to the archaeal domain. Although Bacteria and Archaea share a common prokaryotic genome architecture, the extant diversity of Bacteria appears to be much higher than that of Archaea. Compared with Archaea, Bacteria also show much greater genome-level specialisation to specific ecological niches, including parasitism and endosymbiosis. The reasons for these differences in long-term diversification rates are unclear, but might be related to fundamental differences in informational processing machineries and cell biological features that may favour archaeal diversification in harsher or more energy-limited environments. Finally, phylogenomic analyses suggest that the first Archaea were anaerobic autotrophs that evolved on the early Earth.
Cooperative vehicle localisation method based on the fusion of GPS, inter‐vehicle distance, and bearing angle measurements
Authors: Song Xiaolin , Ling Yifei , Cao Haotian , Huang Zhi
Published: November 2018

A new cooperative localisation method based on the Bayesian framework is proposed to obtain accurate and reliable vehicle localisation in intelligent transportation system applications. The new position estimation is achieved by the fusion of the filtered global positioning system (GPS) data, the inter‐vehicle distance, and bearing angle. The simulation results indicate that the accuracy of vehicle localisation is effectively improved with the consideration of bearing angle, when compared with the fusion of GPS and inter‐vehicle distance. A simulated scenario with multi‐target dynamic environment is designed to discuss an appropriate number of nearby vehicles for cooperative localisation. The simulation results show that four nearby vehicles around the host vehicle for localisation is the most appropriate while balancing the accuracy and computing burden. Moreover, the proposed localisation method has also been proved to provide a well‐robustness performance as well as localisation accuracy.
Non‐linear fixed and multi‐level random effects of origin–destination specific attributes on route choice behaviour
Authors: Li Dawei , Miwa Tomio , Xu Chengcheng , Li Zhibin
Published: November 2018

This study explores the effects of origin–destination (O–D) attributes on route choice with long‐term GPS data collected by private vehicles in Toyota city, Japan. The non‐linear fixed effects are captured by the piecewise specified structural tastes on costs in the utility functions. The multi‐level random effects are captured by the multi‐level random terms. This empirical analysis demonstrates that the incorporation of O–D attributes can enhance the route choice models significantly. The effects of both O–D distance and drivers’ familiarity with the O–D on route utilities are proved to be non‐linear and non‐monotonic. Besides the fixed effects, the multi‐level random effects of OD attributes are also confirmed to be significant.
Randomised scheduling algorithm for virtual output queuing switch at the presence of non‐uniform traffic
Authors: Jamali Majid , Ghiasian Ali
Published: November 2018

Virtual Output Queuing (VOQ) is a well‐known queuing discipline in data switch architecture that eliminates Head of Line (HOL) blocking issue. In VOQ scheme, for each output port, a separate FIFO is maintained by each input port. Consequently, a scheduling algorithm is required to determine the order of service to virtual queues at each time slot. Maximum Weight Matching (MWM) is a well‐known scheduling algorithm that achieves the entire throughput region. Despite of outstanding attainable throughput, high complexity of MWM makes it an impractical algorithm for implementation in high‐speed switches. To overcome this challenge, a number of randomised algorithms have been proposed in the literature. They commonly perform poorly when input traffic does not uniformly select output ports. Here, the authors propose two randomised algorithms that outperform the well‐known formerly proposed solutions. They exploit a method to keep a parametric number of heavy edges from the last time matching and mix it by randomly generated matching to produce a new schedule. Simulation results confirm the superior performance of the proposed algorithms.
Searching for the most powerful thermonuclear X-ray bursts with the Neil Gehrels Swift Observatory
Authors: in ’t Zand J. J. M. , Kries M. J. W. , Palmer D. M. , Degenaar N.
Published: November 2018

We searched for thermonuclear X-ray bursts from Galactic neutron stars in all event mode data of the Neil Gehrels Swift Observatory collected until March 31, 2018. In particular, we are interested in the intermediate-duration bursts (shell flashes fueled by thick helium piles) with the ill-understood phenomenon of strong flux fluctuations. Nine such bursts have been discussed in the literature to date. Swift is particularly suitable for finding additional examples. We find and list a total of 134 X-ray bursts; 44 are detected with BAT only, 41 with XRT only, and 49 with both. Twenty-eight bursts involve automatic slews. We find 12 intermediate-duration bursts, all detected in observations involving automatic slews. Five show remarkably long Eddington-limited phases in excess of 200 s. Five show fluctuations during the decay phase; four of which are first discussed in the present study. We discuss the general properties of the fluctuations, considering also 7 additional literature cases. In general two types of fluctuations are observed: fast ones, with a typical timescale of 1 s and up and downward fluctuations of up to 70%, and slow ones, with a typical timescale of 1 min and only downward fluctuations of up to 90%. The latter look like partial eclipses because the burst decay remains visible in the residual emission. We revisit the interpretation of this phenomenon in the context of the new data set and find that it has not changed fundamentally despite the expanded data set. It is thought to be due to a disturbance of the accretion disk by outflowing matter and photons, causing obscuration and reflection due to Thompson scattering in an orbiting highly ionized cloud or structure above or below the disk. We discuss in detail the most pronounced burster SAX J1712.6–3739. One of the bursts from this source is unusual in that it lasts longer than 5600 s, but does not appear to be a superburst.
A role of an Enterprise Identification Card in a building process of water tourist investments
Authors: Miszewska Emilia , Bolt Adam , Apollo Magdalena
Published: November 2018

An essential element of a building process for water tourist investments in Poland is a document called the Enterprise Identification Card. It is required for the investments, which are classified according to the Regulation [1] as the ones that could potentially impact the environment. It is assumed that KIP is there to protect the environment against the excessive human interference and it just provides the guidelines regarding the enterprise completion for an applicant. TOWS-SWOT analysis has been used in order to conduct an accurate evaluation of a role of the Enterprise Identification Card in a building process of water tourist investments. It is one of the modifications of the basic method of strategic analysis SWOT.
Analysis and design improvement of high class roads’ arched sections in Poland
Authors: Żukowska Joanna , Słomiński Paweł
Published: November 2018

Although Polish road network standards, in particular higher classes of roads are improving dynamically the number of fatalities on the network is still higher that EU’s average. Ensuring road safety and high maintaining standards is a complex issue and one that poses a major challenge for all road authorities. Road accidents at high speed roads characterize specially serious material and social consequences, thus research into road safety is of a special interest and numerous analyses and debates are being conducted worldwide as well as in Poland. In this paper the authors provide the results and recommendations coming from the analysis of accidents which happened on high speed roads during the heavy rainfall. The analysis of incidents which happened on sections with changing vertical alignment shows that a properly designed road geometry does not eliminate road accidents or conflicts.
Terrestial laser scaning in forest invetory based on OptD optimization method
Authors: Janicka Joanna , Błaszczak-Bąk Wioleta , Pawłowski Krystian
Published: November 2018

Nowadays the time of acquiring spatial data is one of the most important parameters during measurements. Laser scanning technology makes it possible to record a huge number of measurement data in a relatively short time. Thus it is possible to acquire and update spatial data on large surface areas in a significantly shorter time compared to classical measurement methods. Terrestrial laser scanning can be used in forest inventory because measurements can acquire millimeter-level of detail. Thus measurement are performed quickly, automatically and provides periodical estimates of many important forest inventory attributes.
Standard deviation as the optimization criterion in the OptD method and its influence on the generated DTM
Authors: Błaszczak-Bąk Wioleta , Sobieraj-Żłobińska Anna
Published: November 2018

Reduction of the measurement dataset is one of the current issues related to constantly developing technologies that provide large datasets, e.g. laser scanning. It could seems that presence and evolution of processors computer, increase of hard drive capacity etc. is the solution for development of such large datasets. And in fact it is, however, the “lighter” datasets are easier to work with. Additionally, reduced datasets can be exchange/transfer/download faster via internet or cloud stored. Therefore the issue of data reduction algorithms/methods is continuously relevant. In this paper authors presented the results of the study whether the standard deviation of measurement data can be used as optimization criterion in the process of dataset reduction conducted by means of the OptD method. The OptD is based on the cartographic generalization methods. In iterative process irrelevant points are being removed and those that characteristic are being preserved, what in results means more points in complex fragments of scanned object/surface and less in flat/uncomplicated area. Obtained reduced datasets were then the basis for DTMs generation. For DTMs assessment RMSE was calculated.
Flood Hazard Zone Modeling for Cadastral Plots in Ojców National Park in Poland
Authors: Piech Izabela , Bacior Stanisław , Mika Monika
Published: November 2018

The paper presents the stages of development of DTM for fragment of ONP (Ojcow National Park). Model was created in order to illustrate potential flood zones of river Pradnik. In subsequent stages of the development are shown: Basic concepts of subjects taken in the publication, characteristics of research object, methodology of DSM implementation, elements of flood zones and assessment of flooded plots devastation impact on their cadastral and landscape values. The advantage of the method is a low cost and short time of DTM creation based on aerial photographs. Created model has also a relatively high accuracy of elaboration. It is noteworthy that for the area being elaborated independent survey were performed using classical and modern technology methods. The work results will provide a base for further analysis in order to determine the flood zones for mountain rivers. Described problem will be the subject of subsequent papers by the authors.
Evaluation of the quality of cadastral data
Authors: Taszakowski Jarosław , Litwin Urszula , Doroż Arkadiusz , Misiak Karolina
Published: November 2018

The purpose of the work is to determine the possibility of assessing the quality of cadastral data basing on the system of land and building registry. The study of discrepancies between the descriptive and graphical parts of the of the land and buildings registry was accepted as the scope of research in the field of marking plots and their areas, checking the level of: supplementing registry data with PESEL numbers for private entities and REGON numbers for public entities, completeness of addresses data, verification of documents defining the legal status of real estates and data on border points. The research objects were 14 precincts, including 11 rural ones in the commune of Dąbrowa Tarnowska and 3 in the urban commune of Dąbrowa Tarnowska, located in the Dąbrowski district in the Małopolskie voivodship.
Confinement, Monopoles and Gauge Invariance
Authors: Di Giacomo Adriano
Published: November 2018

The status is reviewed of the lattice studies of confinement by dual superconductivity of QCD vacuum. Progress is made by proving that the existence and the creation of a monopole are gauge invariant concepts. This proof fully legitimates an existing order parameter, and with it the evidence it provides of monopole condensation in the confining vacuum.
Diffractive patterns in deep-inelastic scattering and parton genealogy
Authors: Munier Stéphane
Published: November 2018

We report on our recent observation that the occurrence of diffractive patterns in the scattering of electrons off nuclei obeys the same law as the fluctuations of the height of genealogical trees in branching diffusion processes.
Two loop four dimensional formulation of dimensionally regularized amplitudes in quantum chromodynamics
Authors: Fazio Angelo Raffaele
Published: November 2018

We propose a pure four-dimensional formulation (FDF) of the ddimensional regularization of one and two loop scattering amplitudes in quantum chromodynamics. In our formulation particles propagating inside the loops are represented by massive internal states regulating the divergences. The equivalence between the FDF and the Four Dimensional Helicity scheme is discussed. We present explicit representations of the polarization and helicity states of the four-dimensional particles propagating in the loops. They allow for a complete, four-dimensional, unitarity-based construction of d-dimensional amplitudes. Generalized unitarity within the FDF does not require any higherdimensional extension of the Cli↵ord and the spinor algebra.
Open heavy-flavour measurements with ALICE at the LHC
Authors: Colamaria Fabio
Published: November 2018

Heavy quarks are produced in the early stages of ultra-relativistic heavy-ion collisions, and their number is preserved throughout the subsequent evolution of the system. Therefore, they constitute ideal probes for characterising the Quark-Gluon Plasma (QGP) medium and for the study of its transport properties. In particular, heavy quarks interact with the partonic constituents of the plasma, losing energy, and are expected to be sensitive to the medium collective motion induced by its hydrodynamical evolution. In pp collisions, the measurement of heavy-flavour hadron production provides a reference for heavyion studies, and allows also testing perturbative QCD calculations in a wide range of collision energies. Similar studies in p-Pb collisions help in disentangling cold nuclear matter effects from modifications induced by the presence of a QGP medium, and are also useful to investigate the possible existence of collective phenomena also in this system. The ALICE detector provides excellent performances in terms of particle identification and vertexing capabilities. Hence, it is fully suited for the reconstruction of charmed mesons and baryons and of electrons from heavy-flavour hadron decays at central rapidity. Furthermore, the ALICE muon spectrometer allows reconstructing heavy-flavour decay muons at forward rapidity. A review of the main ALICE results on open heavy flavour production in pp, p-Pb and Pb-Pb collisions is presented. Recent, more differential measurements are also shown, including azimuthal correlations of heavy-flavour particles with charged hadrons in p-Pb collisions, and D-meson tagged-jet production in p-Pb and Pb-Pb collisions.
Prospects for Higgs Boson Measurements and Beyond Standard Model Physics at the High-Luminosity LHC with CMS
Authors: Venditti Rosamaria
Published: November 2018

The High-Luminosity Large Hadron Collider (HL-LHC) is a major upgrade of the LHC, expected to deliver an integrated luminosity of up to 3000/fb over one decade. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (pileup) superimposed to each event of interest, therefore providing extremely challenging experimental conditions. The scientific goals of the HL-LHC physics program include precise measurement of the properties of the recently discovered standard model Higgs boson and searches for beyond the standard model physics (heavy vector bosons, SUSY, dark matter and exotic long-lived signatures, to name a few). In this contribution we will present the strategy of the CMS experiment to investigate the feasibility of such search and quantify the increase of sensitivity in the HL-LHC scenario.
Simplified Bethe-Salpeter Description of Basic Pseudoscalar-Meson Features
Authors: Lucha Wolfgang
Published: November 2018

We assess a description of pseudoscalar mesons as pseudo-Goldstone bosons by its compatibility with some Gell-Mann-Oakes-Renner-type relation.
Strong Isospin Breaking in Heavy-Meson Decay Constants: Employing Borelized QCD Sum Rules in Local-Duality Limit
Authors: Lucha Wolfgang , Melikhov Dmitri , Simula Silvano
Published: November 2018

Applying the QCD sum-rule machinery in the so-called local-duality shape to heavy-light mesons reveals that, as a consequence of the non-zero mass gap between up and down quarks, the leptonic decay constants of the neutral and charged versions of the D, D*, B and B* mesons differ by approximately 1 MeV.
Dynamical picture for the exotic XYZ states
Authors: Ivanov Mikhail
Published: November 2018

We present a dynamical approach for description of the multi-quark states that is based on an effective interaction Lagrangian describing the coupling of hadrons to their constituent quarks. First, we explore the consequences of treating the X(3872) meson as a tetraquark bound state. We calculate the decay widths of the observed channels and conclude that for reasonable values of the size parameter of the X(3872) one finds consistency with the available experimental data. Then we have critically checked the tetraquark picture for the Zc(3900) state by analyzing its strong decays. We found that Zc(3900) has a much more stronger coupling to DD* than to J/Ψπ that is in discord with experiment. As an alternative we have employed a molecular-type four-quark current to describe the decays of the Zc(3900) state as the charged particle in the isotriplet. We found that a molecular-type current gives the values of the above decays in accordance with the experimental observation. By using moleculartype four-quark currents for the recently observed resonances Zb(10610) and Zb(10650), we have calculated their two-body decay rates into a bottomonium state plus a light meson as well as into B-meson pairs.
Shells, Anti-Shells and Modes in nuclear Fission
Authors: Gönnenwein Friedrich
Published: November 2018

Fission phenomena are surveyed where fragment properties are catching the eye. Beyond the Liquid Drop the relevant properties of fragments are shell effects and nuclear pairing. Shell effects influence on mass, charge, stability and deformability of fragments. Most often only the stabilizing effects of shells are discussed and the equally frequent destabilizing effects are not mentioned. For the present purpose the terms shells and anti-shells are used in case of stabilizing and destabilizing effects, respectively. Fragment shells and anti-shells lead to fission modes with characteristic properties. A special issue is where in the course of fission these modes assume their characteristic features. Surprisingly fragment angular distributions in above- and sub-barrier fission help elucidating this question. The discussion is focussed on fission in the standard actinides.
Neutron anisotropic evaporation and scission emission in fission
Authors: Stuttgé L. , Chietera A. , Gönnenwein F. , Kopatch Yu. , Mutterer M. , Gagarski A. , Guseva I. , Chernysheva E. , Hambsch F.-J. , Hanappe F. , Mezentseva Z. , Telezhnikov S.
Published: November 2018

Experimental neutron distributions have been investigated in the spontaneous fission of 252Cf at IPHC in Strasbourg. The CORA experiment associating the CODIS twin ionisation chamber and the neutron multi-detector DEMON aimed to solve an long-standing problem in fission: the possible emission of scission neutrons and/or the presence of a dynamical anisotropy in the neutron evaporation by the moving fission fragments. A new method allowing to establish the dynamical anisotropy in an independent way is presented. The results obtained from a comparison with simulations based on GEANT4 are shown.
First Results on 238U(n,f) Prompt Fission Neutron Spectra from 1 to 200 MeV incident neutron energy
Authors: Marini Paola , Laurent Benoit , Belier Gilbert , Bonnet Thomas , Chatillon Audrey , Taieb Julien , Etasse David , Devlin Matthew , Haight Robert
Published: November 2018

A new 238U(n,f) prompt fission neutron spectra (PFNS) measurement has been recently performed at the WNR facility of the Los Alamos National Laboratory. The measurement allows one to explore the dependence of the prompt fission neutron energy spectra on the incident neutron energy. The experimental setup couples the Chi-Nu scintillator array to a newly developed fission chamber, characterized by an improved alphafission discrimination and time resolution, a reduced amount of matter in the neutron beam and a higher actinide mass. The dedicated setup and the high statistics collected allow us to obtain a good precision on the measured fission neutron energy, as well as to explore the low energy region, down to 650keV, and the high energy region, above 5 MeV, of the emitted neutron spectrum. These are indeed the regions where discrepancies in the evaluated PFNS data are found. We present here the first preliminary results of the experiment.
Measurements of the Prompt Fission Neutron Spectrum at LANSCE: The Chi-Nu Experiment
Authors: Kelly Keegan J. , Devlin Matthew , Gomez Jaime A. , O’Donnell John M. , Taddeucci Terry N. , Haight Robert C. , Lee Hye Young , Mosby Shea M. , Fotiades Nikolaos , Neudecker Denise , Talou Patrick , Rising Michael E. , White Morgan C. , Solomon Clell J. , Wu Ching-Yen , Bucher Brian , Buckner Matthew Q. , Henderson Roger A.
Published: November 2018

The goal of the Chi-Nu experiment at the Los Alamos Neutron Science Center is to measure the prompt fission neutron spectra from major actinides using a double time-of-flight method with a pulsed, white incoming neutron source. Fission events are detected with a parallel-plate avalanche counter and outgoing neutrons are detected with either a 6Li-glass or liquid scintillator detector array for low- or high-energy neutrons, respectively. A detector response matrix for the interaction of neutrons with the experimental environment for neutrons measured with the Chi-Nu 6Li-glass detector array has been calculated to obtain a full understanding of the measured Chi-Nu data and also to allow for nearly instantaneous production of simulated Chi-Nu data spectra. Prompt fission neutron spectra corresponding to 19 incoming neutron energy ranges from 0.7-20 MeV have been extracted using the ratio-of-ratios method with Chi-Nu 6Li-glass data on the neutron-induced fission of 235U.
Prompt fission gamma rays and their angular distributions
Authors: Oberstedt Andreas , Billnert Robert , Gatera Angélique , Göök Alf , Oberstedt Stephan
Published: November 2018

In a recent measurement of prompt γ rays from the spontaneous fission of 252Cf an experimental setup was chosen that allowed the study of angular correlations between γ rays and the nuclei from which they were emitted. The observed angular distribution of the prompt fission γ rays was then analyzed to estimate the relative contributions from radiation of different multipolarity. From that we hope to obtain more detailed information about the early stage of the de-excitation process of fission fragments, right after prompt neutron emission. First preliminary results are presented below.
Use of active scintillating targets in nuclear physics experiments - Measurement of spontaneous fission
Authors: Bélier G. , Aupiais J. , Sibbens G. , Moens A. , Vanleeuw D.
Published: November 2018

A novel detector has been used, in order to perform measurements of spontaneous fission to α-decay ratios for 240Pu, 242Pu and 252Cf isotopes. The detectors are based on the well-known technique of liquid scintillating counting. The principle and advantages of the use of such detectors in nuclear physics is discussed. The application to the characterization of spontaneous fission is described and it is demonstrated that highly precise measurements are possible, and that the main limit is due to the isotopic content knowledge of the measured samples.
Recent developments of the FALSTAFF experimental setup
Authors: Chietera A. , Thulliez L. , Berthoumieux E. , Doré D. , Letourneau A. , Legou P. , Kebbiri M. , Piret Y. , Mols J.P. , Combet M. , Riallot M. , Marcel A. , Pancin J. , Frégeau M. O. , Ledoux X. , Lecolley F. R. , Perronnel J. , Goupillere D.
Published: November 2018

The study of nuclear fission is encountering renewed interest with the development of GEN-IV reactor concepts, mostly working in the neutron fast energy domain. To support the fast reactor technologies, new high quality nuclear data are needed. New facilities are being constructed to produce high intensity neutron beams from hundreds of keV to few tens of MeV (Licorne, NFS, nELBE, ...). They will open new opportunities to provide nuclear data. In this framework the development of an experimental setup called FALSTAFF for a characterisation of actinide fission fragments has been undertaken. Fission fragment yields and associated neutron multiplicities will be measured as a function of the neutron energy. Based on time-of-flight and residual energy technique, the setup will allow the simultaneous measurement of the complementary fragment velocity and energy. The FALSTAFF setup and the upgrade of the first arm prototype with the new ionisation chamber CALIBER will be presented. The performances of the experimental apparatus is discussed.
Measuring neutron capture rates on ILL-produced unstable isotopes (147Pm, 171Tm and 204Tl, and plans for 79Se and 163Ho) for nucleosynthesis studies
Authors: Lerendegui-Marco J. , Guerrero C. , Domingo-Pardo C. , Casanovas A. , Dressler R. , Halfon S. , Heinitz S. , Kivel N. , Köster U. , Paul M. , Schumann D. , Tessler M. ,   and The n_TOF Collaboration
Published: November 2018

Neutron capture cross sections are among the main inputs for nucleosynthesis network calculations. Although well known for the majority of the stable isotopes, this quantity is still unknown for most of the unstable isotopes of interest. A recent collaboration between ILL, PSI, U. Sevilla and IFIC aims at producing the isotopes of interest at ILL, preparing suitable targets at PSI, and measuring their capture cross sections at facilities such as n_TOF/CERN, LiLiT and the Budapest Research Reactor (BRR). This work is focused on the description of the different beams and techniques and shows some highlights of the preliminary results of the capture measurements on 171Tm, 147Pm and 204Tl, along with the future plans for 79Se and 163Ho.
The nuclear symmetry energy and the breaking of the isospin symmetry: how do they reconcile with each other?
Authors: Roca-Maza X. , Colò G. , Sagawa H.
Published: November 2018

Our current knowledge of the Equation of State of asymmetric nuclear matter around saturation density and of the energy of the Isobaric Analog State in a heavy nucleus such as 208Pb seem to be in contradiction. In Ref. [1], the problem has been highlighted and a solution has been proposed. In the present contribution, we overview the aforementioned work by giving some new details not previously published.
Bohr Hamiltonian with a potential having spherical and deformed minima at the same depth
Authors: Buganu Petrica , Budaca Radu , Budaca Andreea-Ioana
Published: November 2018

A solution for the Bohr-Mottelson Hamiltonian with an anharmonic oscillator potential of sixth order, obtained through a diagonalization in a basis of Bessel functions, is presented. The potential is consid- ered to have simultaneously spherical and deformed minima of the same depth separated by a barrier (a local maximum). This particular choice is appropriate to describe the critical point of the nuclear phase transition from a spherical vibrator to an axial rotor. Up to a scale factor, which can be cancelled by a corresponding normalization, the energy spectra and the electromagnetic E2 transition probabilities depend only on a single free parameter related to the height of the barrier. Investigations of the numerical data revealed that the model represents a good tool to describe this critical point.
Skyrme-RPA study of charged-current neutrino opacity in hot and dense supernova matter
Authors: Dzhioev Alan A. , Martínez-Pinedo Gabriel
Published: November 2018

Neutrino emission and their transport of energy to the supernova shock region are sensitive to the physics of hot and dense nuclear matter, which is a complex problem due to the strong correlations induced by nuclear forces. We derive charged-current opacities for electron neutrinos and antineutrinos in supernova matter using a self-consistent approach based on the Skyrme effective interaction. We include a mean field energy shift due to nuclear interaction and corrections due to RPA correlations. A complete treatment of the full Skyrme interaction, including a spin-orbit term, is given. To test the effect of RPA corrections, neutrino and antineutrino opacities are computed using different Skyrme parameterisations consistent with a number of infinite matter constraints.
Search for Isovector Valence-Shell Excitations in 140Nd and 142Sm via Coulomb excitation reactions of radioactive ion beams
Authors: Kern Ralph , Stegmann Robert , Pietralla Norbert , Rainovski Georgi , Gaffney Liam Paul , Blazhev Andrey , Boukhari Amar , Cederkäll Joakim , Cubiss James , Djongolov Martin , Fransen Christoph , Gladnishki Kalin , Giannopoulos Efstathios , Hess Herbert , Jolie Jan , Karayonchev Vasil , Kaya Levent , Keatings James , Kocheva Diana , Kröll Thorsten , Möller Oliver , O'Neill George , Pakarinen Janne , Reiter Peter , Rosiak Dawid , Scheck Marcus , Snall Jacob , Söderström Pär-Anders , Spagnoletti Pietro , Stoyanova Milena , Thiel Stefan , Vogt Andreas , Warr Nigel , Welker Andree , Werner Volker , Wiederhold Johannes , De Witte Hilde , Zidarova Radostina
Published: November 2018

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.
Individual low-energy E1 toroidal and compression states in light nuclei: deformation effect, spectroscopy and interpretation
Authors: Nesterenko Valentin , Kvasil Jan , Repko Anton , Reinhard Paul-Gerhard
Published: November 2018

The existence of individual low-energy E1 toroidal and compression states (TS and CS) in24Mg was predicted recently in the framework of quasiparticle random phase approximation (QRPA) model with Skyrme forces. It was shown that the strong axial deformation of24Mg is crucial to downshift the toroidal strength to the low-energy region and thus make the TS the lowest E1(K=1) dipole state. In this study, we explain this result by simple mean-field arguments. Comparing TS in two strongly axial nuclei,24Mg and20Ne, we show that the lowest TS is not a universal phenomenon but rather a peculiarity of24Mg. The spectroscopy of TS and CS is analyzed and some additional interpretation of these states is suggested.
Some new chapters of the long history of SU(3)
Authors: Cseh József
Published: November 2018

The SU(3) symmetry of nuclear structure has its 60’th birthday this year. In this contribution we recall some of its historical aspects, including several generalizations, furthermore, we discuss a few new features of this symmetry.
U(6) dynamical and quasi-dynamical symmetry in strongly deformed heavy nuclei
Authors: Ganev H.G.
Published: November 2018

The low-lying collective states of the ground, β and γ bands in154Sm and238U are investigated within the framework of the microscopic proton-neutron symplectic model (PNSM). For this purpose, the model Hamiltonian is diagonalized in a U(6)-coupled basis, restricted to the symplectic state space spanned by the fully symmetric U(6) vectors. A good description of the energy levels of the three bands under consideration, as well as the intraband B(E2) transition strengths between the states of the ground band is obtained for the two nuclei without the use of an effective charge. The calculations show that when the collective quadrupole dynamics is covered already by the symplectic bandhead structure, as in the case of154Sm, the results show the presence of a very good U(6) dynamical symmetry. In the case of238U, when we have an observed enhancement of the intraband B(E2) transition strengths, then the results show small admixtures from the higher major shells and a highly coherent mixing of different irreps which is manifested by the presence of a good U(6) quasi-dynamical symmetry in the microscopic structure of the collective states under consideration.
Dinuclear system model in spontaneous fission process
Authors: Rogov Ivan , Adamian Gurgen , Antonenko Nikolai
Published: November 2018

The application of the dinuclear system model is discussed to describe the spontaneous fission process. Cluster decay widths and spontaneous fission of 234U are calculated within the same approach. The model describes well the experimental data on half-lives.
Elastic scattering and breakup reactions with light proton- and neutron-rich exotic nuclei
Authors: Gaidarov M.K. , Lukyanov V.K. , Kadrev D.N. , Zemlyanaya E.V. , Antonov A.N. , Lukyanov K.V. , Spasova K.
Published: November 2018

A microscopic analysis of the optical potentials (OPs) and cross sections of elastic scattering of 8B on 12C, 58Ni, and 208Pb targets at energies 20 < E < 170 MeV and 12,14Be on 12C at 56 MeV/nucleon is carried out. The real part of the OP is calculated by a folding procedure and the imaginary part is obtained on the base of the high-energy approximation (HEA). The density distributions of 8B evaluated within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the potentials. The 14Be densities obtained in the framework of the the generator coordinate method (GCM) are used to calculate the optical potentials, while for the same purpose both the VMC model and GCM densities of 12Be are used. In the hybrid model developed and explored in our previous works, the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the experimental data. The use of HEA to estimate the imaginary OP at energies just above the Coulomb barrier is discussed. In addition, cluster model, in which 8B consists of a p-halo and the 7Be core, is applied to calculate the breakup cross sections of 8B nucleus on 9Be, 12C, and 197Au targets, as well as momentum distributions of 7Be fragments. A good agreement of the theoretical results with the available experimental data is obtained. It is concluded that the reaction studies performed in this work may provide supplemental information on the internal spatial structure of the proton- and neutron-halo nuclei.
ARIADNE – a program estimating covariances in detail for neutron experiments
Authors: Neudecker Denise
Published: November 2018

The python program ARIADNE is a tool developed for evaluators to estimate detailed uncertainties and covariances for experimental data in a consistent and efficient manner. Currently, it is designed to aid in the uncertainty quantification of prompt fission neutron spectra, and was employed to estimate experimental covariances for CIELO and ENDF/B-VIII.0 evaluations. It provides a streamlined way to estimate detailed covariances by (1) implementing uncertainty quantification algorithms specific to the observables, (2) defining input quantities for typically encountered uncertainty sources and correlation shapes, and (3) automatically generating plots of data, uncertainties and correlations, GND formatted XML and plain text output files. Covariances of the same and between different datasets can be estimated, and tools are provided to assemble a database of experimental data and covariances for an evaluation based on ARIADNE outputs. The underlying IPython notebook files can be easily stored, including all assumptions on uncertainties, leading to more reproducible inputs for nuclear data evaluations. Here, the key inputs and outputs are shown along with a representative example for the current version of ARIADNE to illustrate its usability and to open a discussion on how it could address further needs of the nuclear data evaluation community.
Innovative experiments for reduction of nuclear data uncertainty
Authors: Danon Yaron
Published: November 2018

Due to the complexity of nuclear reaction models, current nuclear data evaluations must rely on experimental observations to constrain models and provide the accuracy needed for applications. For criticality applications, the accuracy of nuclear data needed is higher than what is currently possible from differential experiments alone, and integral measurements are often used for data adjustment within the uncertainties of differential experiments. This approach does not necessarily result in physically correct cross sections or other adjusted quantities because compensation between different materials is hard to avoid. One of the objectives of the recent CIELO project [M. Chadwick et al., Nucl. Data Sheets 118, 1 (2014)] was simultaneous evaluation of important materials in an attempt to minimize the effects of compensation. Improvement to the evaluation process depends on obtaining new experimental data with high accuracy and lower uncertainty that will help constrain the evaluations for certain important reactions. Improved experiments are accomplished by careful design with the objective of achieving high accuracy and lower uncertainty, and by designing new innovative experiments. New and unconventional experiments do not necessarily provide differential data but instead nuclear data that evaluators will find useful to constrain the evaluation and reduce the uncertainty. This also means that closer information exchange and collaboration between experimentalists and evaluators is important. For conventional experiments such as neutron transmission or capture measurements, it is important to understand the sources of uncertainty and address them in the experiment design. Such a process can also lead to the design of innovative methods. For example, the filtered beam method minimizes uncertainties due to background, and the Quasi-Differential Neutron Scattering method simplifies the experiment and data analysis and results in lower experimental uncertainty. A review of the sources of uncertainty in various experiments and examples of experimental techniques that help reduce experimental and evaluation uncertainty and increase accuracy will be discussed.
Sensitivity and uncertainty analysis of βeff for MYRRHA using a Monte Carlo technique
Authors: Iwamoto Hiroki , Stakovskiy Alexey , Fiorito Luca , Van den Eynde Gert
Published: November 2018

This paper presents a nuclear data sensitivity and uncertainty analysis of the effective delayed neutron fraction βeff for critical and subcritical cores of the MYRRHA reactor using the continuous-energy Monte Carlo N-Particle transport code MCNP. The βeff sensitivities are calculated by the modified k-ratio method proposed by Chiba. Comparing the βeff sensitivities obtained with different scaling factors a introduced by Chiba shows that a value of a = 20 is the most suitable for the uncertainty quantification of βeff. Using the calculated βeff sensitivities and the JENDL-4.0u covariance data, the βeff uncertainties for the critical and subcritical cores are determined to be 2.2 ± 0.2% and 2.0 ± 0.2%, respectively, which are dominated by delayed neutron yield of 239Pu and 238U.
Generation of the1H in H2O neutron thermal scattering law covariance matrix of the CAB model
Authors: Scotta Juan Pablo , Noguère Gilles , Marquez Damian Jose Ignacio
Published: November 2018

The thermal scattering law (TSL) of1H in H2O describes the interaction of the neutron with the hydrogen bound to light water. No recommended procedure exists for computing covariances of TSLs available in the international evaluated nuclear data libraries. This work presents an analytic methodology to produce such a covariance matrix-associated to the water model developed at the Atomic Center of Bariloche (Centro Atomico Bariloche, CAB, Argentina). This model is called as CAB model, it calculates the TSL of hydrogen bound to light water from molecular dynamic simulations. The performance of the obtained covariance matrix has been quantified on integral calculations at “cold” reactor conditions between 20 and 80∘ C. For UOX fuel, the uncertainty on the calculated reactivity ranges from ±71 to ±155 pcm. For MOX fuel, it ranges from ±110 to ±203 pcm.
Template for estimating uncertainties of measured neutron-induced fission cross-sections
Authors: Neudecker Denise , Hejnal Brooke , Tovesson Fredrik , White Morgan C. , Smith Donald L. , Vaughan Diane , Capote R.
Published: November 2018

A template for estimating uncertainties (unc.) of measured neutron-induced fission, (n,f), cross-sections (cs) is presented. This preliminary template not only lists all expected unc. sources but also supplies ranges of unc., estimates for correlations between unc. of the same and different experiments which can be used if the information is nonexistent. If this template is applied systematically when estimating experimental covariances for an evaluation, it may help in pinpointing missing unc. for individual datasets, identifying unreasonably low unc., and estimating correlations between different experimental datasets. Thus, a detailed unc. estimate – usually, a time-intensive procedure – can be undertaken more consistently and efficiently. As an example, it is shown that unc. and correlations of 239Pu(n,f) by Merla et al. [Proceedings of the Conference on Nuclear Data for Science and Technology 1991 Jülich (Springer-Verlag, Berlin, 1992) pp. 510–513], which are questionably low in the GMA database underlying the neutron cs standards evaluations, are distinctly larger at 14.7 MeV and more strongly correlated if this template is used for reestimating the associated covariances.