Angle-correlated cross sections in the framework of the continuum shell model

International Nuclear Information System (INIS)

Moerschel, K.P.

1984-01-01

In the present thesis in the framework of the continuum shell modell a concept for the treatment of angle-correlated cross sections was developed by which coincidence experiments on electron scattering on nuclei are described. For this the existing Darmstadt continuum-shell-model code had to be extended to the calculation of the correlation coefficients in which nuclear dynamics enter and which determine completely the angle-correlated cross sections. Under inclusion of the kinematics a method for the integration over the scattered electron was presented and used for the comparison with corresponding experiments. As application correlation coefficients for the proton channel in 12 C with 1 - and 2 + excitations were studied. By means of these coefficients finally cross sections for the reaction 12 C (e,p) 11 B could be calculated and compared with the experiment whereby the developed methods were proved as suitable to predict correctly both the slope and the quantity of the experimental cross sections. (orig.) [de

Charged-current inclusive neutrino cross sections in the SuperScaling model

Energy Technology Data Exchange (ETDEWEB)

Ivanov, M. V., E-mail: martin.inrne@gmail.com [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid E-28040 (Spain); Megias, G. D.; Caballero, J. A. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); González-Jiménez, R. [Department of Physics and Astronomy, Ghent University, Proeftuinstraat 86, B-9000 Gent (Belgium); Moreno, O.; Donnelly, T. W. [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Barbaro, M. B. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, 10125 Torino (Italy); Antonov, A. N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Moya de Guerra, E.; Udías, J. M. [Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid E-28040 (Spain)

2016-03-25

SuperScaling model (SuSA) predictions to neutrino-induced charged-current π{sup +} production in the Δ-resonance region are explored under MiniBooNE experimental conditions. The SuSA charged-current π{sup +} results are in good agreement with data on neutrino flux-averaged double-differential cross sections. The SuSA model for quasielastic scattering and its extension to the pion production region are used for predictions of charged-current inclusive neutrino-nucleus cross sections. Results are also compared with the T2K experimental data for inclusive scattering.

Cross-Sectional Analysis of Longitudinal Mediation Processes.

Science.gov (United States)

O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

2018-01-01

Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

Optical and statistical model calculation of the americium 242m capture cross section

International Nuclear Information System (INIS)

Tellier, Henry.

1981-04-01

The capture cross sections of Am 242m can be deduced from resonances analysis at low energy and computed with theoretical models at high energy. In this work, a coherent set of cross sections which reproduced the experimental values of the fission cross sections is computed. These calculations were performed for an energy of the incoming neutron between 1 keV and 1 MeV

Measurements of the effective thermal neutron absorption cross-section in multi-grain models

International Nuclear Information System (INIS)

Drozdowicz, K.; Gabanska, B.; Igielski, A.; Krynicka, E.; Schneider, K.; Woznicka, U.

2005-01-01

The effective macroscopic absorption cross-section Σ a eff of thermal neutrons in a grained medium differs from the corresponding cross-section Σ a hom in the homogeneous medium consisting of the same components, contributing in the same amounts. The ratio of these cross-sections defines the grain parameter, G, which is a measure of heterogeneity of the system for neutron absorption. Heterogeneous models have been built as two- or three-component systems (Ag, Cu and Co 3 O 4 grains distributed in a regular grid in Plexiglas, in various proportions between them). The effective absorption cross-section has been measured and the experimental grain parameter has been found for each model. The obtained values are in the interval 0.34 < G < 0.58, while G = 1 means the homogeneous material. (author)

Program POD; A computer code to calculate nuclear elastic scattering cross sections with the optical model and neutron inelastic scattering cross sections by the distorted-wave born approximation

International Nuclear Information System (INIS)

Ichihara, Akira; Kunieda, Satoshi; Chiba, Satoshi; Iwamoto, Osamu; Shibata, Keiichi; Nakagawa, Tsuneo; Fukahori, Tokio; Katakura, Jun-ichi

2005-07-01

The computer code, POD, was developed to calculate angle-differential cross sections and analyzing powers for shape-elastic scattering for collisions of neutron or light ions with target nucleus. The cross sections are computed with the optical model. Angle-differential cross sections for neutron inelastic scattering can also be calculated with the distorted-wave Born approximation. The optical model potential parameters are the most essential inputs for those model computations. In this program, the cross sections and analyzing powers are obtained by using the existing local or global parameters. The parameters can also be inputted by users. In this report, the theoretical formulas, the computational methods, and the input parameters are explained. The sample inputs and outputs are also presented. (author)

Simple kinetic theory model of reactive collisions. IV. Laboratory fixed orientational cross sections

International Nuclear Information System (INIS)

Evans, G.T.

1987-01-01

The differential orientational cross section, obtainable from molecular beam experiments on aligned molecules, is calculated using the line-of-normals model for reactive collisions involving hard convex bodies. By means of kinetic theory methods, the dependence of the cross section on the angle of attack γ 0 is expressed in a Legendre function expansion. Each of the Legendre expansion coefficients is given by an integral over the molecule-fixed cross section and functions of the orientation dependent threshold energy

Photoproduction within the two-component Dual Parton Model: amplitudes and cross sections

International Nuclear Information System (INIS)

Engel, R.; Siegen Univ.

1995-01-01

In the framework of the Dual Parton Model an approximation scheme to describe high energy photoproduction processes is presented. Based on the distinction between direct, resolved soft, and resolved hard interaction processes we construct effective impact parameter amplitudes. In order to treat low mass diffraction within the eikonal formalism in a consistent way a phenomenological ansatz is proposed. The free parameters of the model are determined by fits to high energy hadro- and photoproduction cross sections. We calculate the partial photoproduction cross sections and discuss predictions of the model at HERA energies. Using hadro- and photoproduction data together, the uncertainties of the model predictions are strongly reduced. (orig.)

cmpXLatt: Westinghouse automated testing tool for nodal cross section models

International Nuclear Information System (INIS)

Guimaraes, Petri Forslund; Rönnberg, Kristian

2011-01-01

The procedure for evaluating the merits of different nodal cross section representation models is normally both cumbersome and time consuming, and includes many manual steps when preparing appropriate benchmark problems. Therefore, a computer tool called cmpXLatt has been developed at Westinghouse in order to facilitate the process of performing comparisons between nodal diffusion theory results and corresponding transport theory results on a single node basis. Due to the large number of state points that can be evaluated by cmpXLatt, a systematic and comprehensive way of performing verification and validation of nodal cross section models is provided. This paper presents the main features of cmpXLatt and demonstrates the benefits of using cmpXLatt in a real life application. (author)

Challenging fission cross section simulation with long standing macro-microscopic model of nucleus potential energy surface

International Nuclear Information System (INIS)

Tamagno, Pierre

2015-01-01

The work presented here aims to improve models used in the fission cross section evaluation. The results give insights for a significant breakthrough in this field and yielded large extensions of the evaluation code CONRAD. Partial cross sections are inherently strongly correlated together as of the competition of the related reactions must yield the total cross section. Therefore improving fission cross section benefits to all partial cross sections. A sound framework for the simulation of competitive reactions had to be settled in order to further investigate on the fission reaction; this was implemented using the TALYS reference code as guideline. After ensuring consistency and consistency of the framework, focus was made on fission. Perspective resulting from the use of macroscopic-microscopic models such as the FRDM and FRLDM were analyzed; these models have been implemented and validated on experimental data and benchmarks. To comply with evaluation requirements in terms of computation time, several specific numerical methods have been used and parts of the program were written to run on GPU. These macroscopic-microscopic models yield potential energy surfaces that can be used to extract a one-dimensional fission barrier. This latter can then be used to obtained fission transmission coefficients that can be used in a Hauser-Feshbach model. This method has been finally tested for the calculation of the average fission cross section for 239 Pu(n,f). (author) [fr

α -induced reactions on 115In: Cross section measurements and statistical model analysis

Science.gov (United States)

Kiss, G. G.; Szücs, T.; Mohr, P.; Török, Zs.; Huszánk, R.; Gyürky, Gy.; Fülöp, Zs.

2018-05-01

Background: α -nucleus optical potentials are basic ingredients of statistical model calculations used in nucleosynthesis simulations. While the nucleon+nucleus optical potential is fairly well known, for the α +nucleus optical potential several different parameter sets exist and large deviations, reaching sometimes even an order of magnitude, are found between the cross section predictions calculated using different parameter sets. Purpose: A measurement of the radiative α -capture and the α -induced reaction cross sections on the nucleus 115In at low energies allows a stringent test of statistical model predictions. Since experimental data are scarce in this mass region, this measurement can be an important input to test the global applicability of α +nucleus optical model potentials and further ingredients of the statistical model. Methods: The reaction cross sections were measured by means of the activation method. The produced activities were determined by off-line detection of the γ rays and characteristic x rays emitted during the electron capture decay of the produced Sb isotopes. The 115In(α ,γ )119Sb and 115In(α ,n )Sb118m reaction cross sections were measured between Ec .m .=8.83 and 15.58 MeV, and the 115In(α ,n )Sb118g reaction was studied between Ec .m .=11.10 and 15.58 MeV. The theoretical analysis was performed within the statistical model. Results: The simultaneous measurement of the (α ,γ ) and (α ,n ) cross sections allowed us to determine a best-fit combination of all parameters for the statistical model. The α +nucleus optical potential is identified as the most important input for the statistical model. The best fit is obtained for the new Atomki-V1 potential, and good reproduction of the experimental data is also achieved for the first version of the Demetriou potentials and the simple McFadden-Satchler potential. The nucleon optical potential, the γ -ray strength function, and the level density parametrization are also

Cross-section crushing behaviour of hat-sections (Part II: Analytical modelling)

NARCIS (Netherlands)

Hofmeyer, H.

2005-01-01

Hat-sections are often used to experimentally investigate building sheeting subject to a concentrated load and bending. In car doors, hat-sections are used for side-impact protection. Their crushing behaviour can partly be explained by only observing their cross-sectional behaviour [1]. This

Homogenization of linearly anisotropic scattering cross sections in a consistent B1 heterogeneous leakage model

International Nuclear Information System (INIS)

Marleau, G.; Debos, E.

1998-01-01

One of the main problems encountered in cell calculations is that of spatial homogenization where one associates to an heterogeneous cell an homogeneous set of cross sections. The homogenization process is in fact trivial when a totally reflected cell without leakage is fully homogenized since it involved only a flux-volume weighting of the isotropic cross sections. When anisotropic leakages models are considered, in addition to homogenizing isotropic cross sections, the anisotropic scattering cross section must also be considered. The simple option, which consists of using the same homogenization procedure for both the isotropic and anisotropic components of the scattering cross section, leads to inconsistencies between the homogeneous and homogenized transport equation. Here we will present a method for homogenizing the anisotropic scattering cross sections that will resolve these inconsistencies. (author)

Josephson cross-sectional model experiment

International Nuclear Information System (INIS)

Ketchen, M.B.; Herrell, D.J.; Anderson, C.J.

1985-01-01

This paper describes the electrical design and evaluation of the Josephson cross-sectional model (CSM) experiment. The experiment served as a test vehicle to verify the operation at liquid-helium temperatures of Josephson circuits integrated in a package environment suitable for high-performance digital applications. The CSM consisted of four circuit chips assembled on two cards in a three-dimensional card-on-board package. The chips (package) were fabricated in a 2.5-μm (5-μm) minimum linewidth Pb-alloy technology. A hierarchy of solder and pluggable connectors was used to attach the parts together and to provide electrical interconnections between parts. A data path which simulated a jump control sequence and a cache access in each machine cycle was successfully operated with cycle times down to 3.7 ns. The CSM incorporated the key components of the logic, power, and package of a prototype Josephson signal processor and demonstrated the feasibility of making such a processor with a sub-4-ns cycle time

Testing Cross-Sectional Correlation in Large Panel Data Models with Serial Correlation

Directory of Open Access Journals (Sweden)

Badi H. Baltagi

2016-11-01

Full Text Available This paper considers the problem of testing cross-sectional correlation in large panel data models with serially-correlated errors. It finds that existing tests for cross-sectional correlation encounter size distortions with serial correlation in the errors. To control the size, this paper proposes a modification of Pesaran’s Cross-sectional Dependence (CD test to account for serial correlation of an unknown form in the error term. We derive the limiting distribution of this test as N , T → ∞ . The test is distribution free and allows for unknown forms of serial correlation in the errors. Monte Carlo simulations show that the test has good size and power for large panels when serial correlation in the errors is present.

Evaluation of fusion-evaporation cross-section calculations

Science.gov (United States)

Blank, B.; Canchel, G.; Seis, F.; Delahaye, P.

2018-02-01

Calculated fusion-evaporation cross sections from five different codes are compared to experimental data. The present comparison extents over a large range of nuclei and isotopic chains to investigate the evolution of experimental and calculated cross sections. All models more or less overestimate the experimental cross sections. We found reasonable agreement by using the geometrical average of the five model calculations and dividing the average by a factor of 11.2. More refined analyses are made for example for the 100Sn region.

Design and Implementation of Radar Cross-Section Models on a Virtex-6 FPGA

Directory of Open Access Journals (Sweden)

B. U. V. Prashanth

2014-01-01

Full Text Available The simulation of radar cross-section (RCS models in FPGA is illustrated. The models adopted are the Swerling ones. Radar cross-section (RCS which is also termed as echo area gives the amount of scattered power from a target towards the radar. This paper elucidates the simulation of RCS to represent the specified targets under different conditions, namely, aspect angle and frequency. This model is used for the performance evaluation of radar. RCS models have been developed for various targets like simple objects to complex objects like aircrafts, missiles, tanks, and so forth. First, the model was developed in MATLAB real time simulation environment and after successful verification, the same was implemented in FPGA. Xilinx ISE software was used for VHDL coding. This simulation model was used for the testing of a radar system. The results were compared with MATLAB simulations and FPGA based timing diagrams and RTL synthesis. The paper illustrates the simulation of various target radar cross-section (RCS models. These models are simulated in MATLAB and in FPGA, with the aim of implementing them efficiently on a radar system. This method can be generalized to apply to objects of arbitrary geometry for the two configurations of transmitter and receiver in the same as well as different locations.

Total cross sections of hadron interactions at high energies in low constituents number model

International Nuclear Information System (INIS)

Abramovskij, V.A.; Radchenko, N.V.

2009-01-01

We consider QCD hadrons interaction model in which gluons density is low in initial state wave function in rapidity space and real hadrons are produced from color strings decay. In this model behavior of total cross sections of pp, pp bar, π ± p, K ± p, γp, and γγ interactions is well described. The value of proton-proton total cross section at LHC energy is predicted

Validation of elastic cross section models for space radiation applications

Energy Technology Data Exchange (ETDEWEB)

Werneth, C.M., E-mail: charles.m.werneth@nasa.gov [NASA Langley Research Center (United States); Xu, X. [National Institute of Aerospace (United States); Norman, R.B. [NASA Langley Research Center (United States); Ford, W.P. [The University of Tennessee (United States); Maung, K.M. [The University of Southern Mississippi (United States)

2017-02-01

The space radiation field is composed of energetic particles that pose both acute and long-term risks for astronauts in low earth orbit and beyond. In order to estimate radiation risk to crew members, the fluence of particles and biological response to the radiation must be known at tissue sites. Given that the spectral fluence at the boundary of the shielding material is characterized, radiation transport algorithms may be used to find the fluence of particles inside the shield and body, and the radio-biological response is estimated from experiments and models. The fidelity of the radiation spectrum inside the shield and body depends on radiation transport algorithms and the accuracy of the nuclear cross sections. In a recent study, self-consistent nuclear models based on multiple scattering theory that include the option to study relativistic kinematics were developed for the prediction of nuclear cross sections for space radiation applications. The aim of the current work is to use uncertainty quantification to ascertain the validity of the models as compared to a nuclear reaction database and to identify components of the models that can be improved in future efforts.

Modelling of N21P emission rates in aurora using various cross sections for excitation

Directory of Open Access Journals (Sweden)

O. Jokiaho

2009-06-01

Full Text Available Measurements of N21P auroral emissions from the (4,1 and (5,2 bands have been made at high temporal and spatial resolution in the region of the magnetic zenith. The instrument used was the auroral imager ASK, situated at Ramfjordmoen, Norway (69.6 N, 19.2 E on 22 October 2006. Measurements from the European Incoherent Scatter Radar (EISCAT have been combined with the optical measurements, and incorporated into an ionospheric model to obtain height profiles of electron density and emission rates of the N21P bands. The radar data provide essential verification that the energy flux used in the model is correct. One of the most important inputs to the model is the cross section for excitation to the B3Πg electronic state, as well as the cross sections to higher states from which cascading into the B state occurs. The balance equations for production and loss of the populations of all levels in each state are solved in order to find the cascade contributions. Several sets of cross sections have been considered, and selected cross sections have been used to construct "emission" cross sections for the observed bands. The resulting brightnesses are compared with those measured by ASK. The importance of specific contributions from cascading is found, with more than 50% of the total brightness resulting from cascading. The cross sections used are found to produce a range of brightnesses well within the uncertainty of both the modelled and measured values.

Fast-neutron total and scattering cross sections of sup 58 Ni and nuclear models

Energy Technology Data Exchange (ETDEWEB)

Smith, A.B.; Guenther, P.T.; Whalen, J.F. (Argonne National Lab., IL (United States)); Chiba, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

1991-07-01

The neutron total cross sections of {sup 58}Ni were measured from {approx} 1 to > 10 MeV using white-source techniques. Differential neutron elastic-scattering cross sections were measured from {approx} 4.5 to 10 MeV at {approx} 0.5 MeV intervals with {ge} 75 differential values per distribution. Differential neutron inelastic-scattering cross sections were measured, corresponding to fourteen levels with excitations up to 4.8 MeV. The measured results, combined with relevant values available in the literature, were interpreted in terms of optical-statistical and coupled-channels model using both vibrational and rotational coupling schemes. The physical implications of the experimental results nd their interpretation are discussed in the contexts of optical-statistical, dispersive-optical, and coupled-channels models. 61 refs.

Perturbation analysis for Monte Carlo continuous cross section models

International Nuclear Information System (INIS)

Kennedy, Chris B.; Abdel-Khalik, Hany S.

2011-01-01

Sensitivity analysis, including both its forward and adjoint applications, collectively referred to hereinafter as Perturbation Analysis (PA), is an essential tool to complete Uncertainty Quantification (UQ) and Data Assimilation (DA). PA-assisted UQ and DA have traditionally been carried out for reactor analysis problems using deterministic as opposed to stochastic models for radiation transport. This is because PA requires many model executions to quantify how variations in input data, primarily cross sections, affect variations in model's responses, e.g. detectors readings, flux distribution, multiplication factor, etc. Although stochastic models are often sought for their higher accuracy, their repeated execution is at best computationally expensive and in reality intractable for typical reactor analysis problems involving many input data and output responses. Deterministic methods however achieve computational efficiency needed to carry out the PA analysis by reducing problem dimensionality via various spatial and energy homogenization assumptions. This however introduces modeling error components into the PA results which propagate to the following UQ and DA analyses. The introduced errors are problem specific and therefore are expected to limit the applicability of UQ and DA analyses to reactor systems that satisfy the introduced assumptions. This manuscript introduces a new method to complete PA employing a continuous cross section stochastic model and performed in a computationally efficient manner. If successful, the modeling error components introduced by deterministic methods could be eliminated, thereby allowing for wider applicability of DA and UQ results. Two MCNP models demonstrate the application of the new method - a Critical Pu Sphere (Jezebel), a Pu Fast Metal Array (Russian BR-1). The PA is completed for reaction rate densities, reaction rate ratios, and the multiplication factor. (author)

Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

Energy Technology Data Exchange (ETDEWEB)

Ridolfi, E.; Napolitano, F., E-mail: francesco.napolitano@uniroma1.it [Sapienza Università di Roma, Dipartimento di Ingegneria Civile, Edile e Ambientale (Italy); Alfonso, L. [Hydroinformatics Chair Group, UNESCO-IHE, Delft (Netherlands); Di Baldassarre, G. [Department of Earth Sciences, Program for Air, Water and Landscape Sciences, Uppsala University (Sweden)

2016-06-08

The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.

Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

International Nuclear Information System (INIS)

Ridolfi, E.; Napolitano, F.; Alfonso, L.; Di Baldassarre, G.

2016-01-01

The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers’ cross-sectional spacing.

Preliminary assessment of Geant4 HP models and cross section libraries by reactor criticality benchmark calculations

DEFF Research Database (Denmark)

Cai, Xiao-Xiao; Llamas-Jansa, Isabel; Mullet, Steven

2013-01-01

Geant4 is an open source general purpose simulation toolkit for particle transportation in matter. Since the extension of the thermal scattering model in Geant4.9.5 and the availability of the IAEA HP model cross section libraries, it is now possible to extend the application area of Geant4......, U and O in uranium dioxide, Al metal, Be metal, and Fe metal. The native HP cross section library G4NDL does not include data for elements with atomic number larger than 92. Therefore, transuranic elements, which have impacts for a realistic reactor, can not be simulated by the combination of the HP...... models and the G4NDL library. However, cross sections of those missing isotopes were made available recently through the IAEA project “new evaluated neutron cross section libraries for Geant4”....

The Total Cross Section at the LHC: Models and Experimental Consequences

CERN Document Server

Cudell, J R

2010-01-01

I review the predictions of the total cross section for many models, and point out that some of them lead to the conclusion that the standard experimental analysis may lead to systematic errors much larger than expected.

On the model-dependence of the relation between minimum-bias and inelastic proton-proton cross sections

International Nuclear Information System (INIS)

Ostapchenko, S.

2011-01-01

The model-dependence of the relation between the inelastic and various minimum-bias proton-proton cross sections is analyzed, paying a special attention to the sensitivity of minimum-bias triggers to diffractive collisions. Concentrating on the trigger selections of the ATLAS experiment, the measured cross sections are compared to predictions of a number of hadronic Monte Carlo models used in the cosmic ray field. It is demonstrated that the ATLAS results are able to discriminate between different models and between certain theoretical approaches for soft multi-particle production. On the other hand, the strong model-dependence of the selection efficiency of the minimum-bias triggers prevents one from inferring high mass diffraction rate from the discussed data. Moreover, the measured cross sections prove to be insensitive to the production of low mass diffractive states in proton-proton collisions. Consequently, a reliable determination of the total inelastic cross section requires forward proton tracking by a dedicated experiment.

How to Use Benchmark and Cross-section Studies to Improve Data Libraries and Models

Science.gov (United States)

Wagner, V.; Suchopár, M.; Vrzalová, J.; Chudoba, P.; Svoboda, O.; Tichý, P.; Krása, A.; Majerle, M.; Kugler, A.; Adam, J.; Baldin, A.; Furman, W.; Kadykov, M.; Solnyshkin, A.; Tsoupko-Sitnikov, S.; Tyutyunikov, S.; Vladimirovna, N.; Závorka, L.

2016-06-01

Improvements of the Monte Carlo transport codes and cross-section libraries are very important steps towards usage of the accelerator-driven transmutation systems. We have conducted a lot of benchmark experiments with different set-ups consisting of lead, natural uranium and moderator irradiated by relativistic protons and deuterons within framework of the collaboration “Energy and Transmutation of Radioactive Waste”. Unfortunately, the knowledge of the total or partial cross-sections of important reactions is insufficient. Due to this reason we have started extensive studies of different reaction cross-sections. We measure cross-sections of important neutron reactions by means of the quasi-monoenergetic neutron sources based on the cyclotrons at Nuclear Physics Institute in Řež and at The Svedberg Laboratory in Uppsala. Measurements of partial cross-sections of relativistic deuteron reactions were the second direction of our studies. The new results obtained during last years will be shown. Possible use of these data for improvement of libraries, models and benchmark studies will be discussed.

Neutron-capture Cross Sections from Indirect Measurements

Energy Technology Data Exchange (ETDEWEB)

Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

2011-10-18

Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

Mean multiplicity in the Regge models with rising cross sections

International Nuclear Information System (INIS)

Chikovani, Z.E.; Kobylisky, N.A.; Martynov, E.S.

1979-01-01

Behaviour of the mean multiplicity and the total cross section σsub(t) of hadron-hadron interactions is considered in the framework of the Regge models at high energies. Generating function was plotted for models of dipole and froissaron, and the mean multiplicity and multiplicity moments were calculated. It is shown that approximately ln 2 S (energy square) in the dipole model, which is in good agreement with the experiment. It is also found that in various Regge models approximately σsub(t)lnS

Electron-impact ionization cross section of rubidium

International Nuclear Information System (INIS)

Kim, Y.; Migdalek, J.; Siegel, W.; Bieron, J.

1998-01-01

A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter endash dipole (BED) model, combines a modified Mott cross section with the high-energy behavior of Born cross sections. To obtain the continuum dipole oscillator strength df/dE of the 5s electron required in the BED model, we used Dirac-Fock continuum wave functions with a core polarization potential that reproduced the known position of the Cooper minimum in the photoionization cross section. For inner-shell ionization, we used a simpler version of df/dE, which retained the hydrogenic shape. The contributions of the 4p→4d, 5s, and 5p autoionizing excitations were estimated using the plane-wave Born approximation. As a by-product, we also present the dipole oscillator strengths for the 5s→np 1/2 and 5s→np 3/2 transitions for high principal quantum numbers n near the ionization threshold obtained from the Dirac-Fock wave functions with the same core polarization potential as that used for the continuum wave functions. copyright 1998 The American Physical Society

Developing Scientific Reasoning Through Drawing Cross-Sections

Science.gov (United States)

Hannula, K. A.

2012-12-01

Cross-sections and 3D models of subsurface geology are typically based on incomplete information (whether surface geologic mapping, well logs, or geophysical data). Creating and evaluating those models requires spatial and quantitative thinking skills (including penetrative thinking, understanding of horizontality, mental rotation and animation, and scaling). However, evaluating the reasonableness of a cross-section or 3D structural model also requires consideration of multiple possible geometries and geologic histories. Teaching students to create good models requires application of the scientific methods of the geosciences (such as evaluation of multiple hypotheses and combining evidence from multiple techniques). Teaching these critical thinking skills, especially combined with teaching spatial thinking skills, is challenging. My Structural Geology and Advanced Structural Geology courses have taken two different approaches to developing both the abilities to visualize and to test multiple models. In the final project in Structural Geology (a 3rd year course with a pre-requisite sophomore mapping course), students create a viable cross-section across part of the Wyoming thrust belt by hand, based on a published 1:62,500 geologic map. The cross-section must meet a number of geometric criteria (such as the template constraint), but is not required to balance. Each student tries many potential geometries while trying to find a viable solution. In most cases, the students don't visualize the implications of the geometries that they try, but have to draw them and then erase their work if it does not meet the criteria for validity. The Advanced Structural Geology course used Midland Valley's Move suite to test the cross-sections that they made in Structural Geology, mostly using the flexural slip unfolding algorithm and testing whether the resulting line lengths balanced. In both exercises, students seemed more confident in the quality of their cross-sections when the

Neutron-capture cross sections from indirect measurements

Directory of Open Access Journals (Sweden)

Scielzo N.D.

2012-02-01

Full Text Available Cross sections for compound-nuclear reactions reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f reactions, but need to be improved upon for applications to capture reactions.

Statistical Model Analysis of (n, α Cross Sections for 4.0-6.5 MeV Neutrons

Directory of Open Access Journals (Sweden)

Khuukhenkhuu G.

2016-01-01

Full Text Available The statistical model based on the Weisskopf-Ewing theory and constant nuclear temperature approximation is used for systematical analysis of the 4.0-6.5 MeV neutron induced (n, α reaction cross sections. The α-clusterization effect was considered in the (n, α cross sections. A certain dependence of the (n, α cross sections on the relative neutron excess parameter of the target nuclei was observed. The systematic regularity of the (n, α cross sections behaviour is useful to estimate the same reaction cross sections for unstable isotopes. The results of our analysis can be used for nuclear astrophysical calculations such as helium burning and possible branching in the s-process.

Effects of cross-section on mechanical properties of Au nanowire

Energy Technology Data Exchange (ETDEWEB)

Vazinishayan, Ali; Yang, Shuming, E-mail: shuming.yang@mail.xjtu.edu.cn; Duongthipthewa, Anchalee; Wang, Yiming [State Key Laboratory for manufacturing system engineering, Xi’an Jiaotong University, Xi’an, 710049 (China)

2016-02-15

The aim of this paper is study of the effects of multiple cross-section of Au nanowire on mechanical properties. Different cross-section models of Au nanowires including circular, hexagonal, pentagonal and rectangular were simulated by finite element modeling using ABAQUS. In this study, the bending technique was applied so that both ends of the model were clamped with mid-span under loading condition. The cross-sections had the length of 400 nm and the diameter of 40 nm, except the circular cross-section while the rest of the cross-sections had an equivalent diameter. Von Misses stresses distribution were used to define the stress distribution in the cross-section under loading condition, and elastic deformation was analyzed by the beam theory. The results disclosed that the circular and the rectangular models had highest and lowest strengths against plastic deformation, respectively.

Cross section data for ionization of important cyanides

International Nuclear Information System (INIS)

Kaur, Jaspreet; Antony, Bobby

2015-01-01

Highlights: • Multi centre spherical complex optical potential formalism used to find the CS. • Effective method (CSP-ic) to derive ionization contribution from inelastic CS. • Result shows excellent accord with previous results and consistent behaviour. • Maiden attempt to find CS for many cyanide molecules. • Strong correlation observed between peak of ionization with target properties. - Abstract: This article presents cross section calculations for interactions of important cyanides with electrons possessing energies beginning from ionization threshold of the target molecule to 5 keV. These data are pursued to meet the ever increasing demand for cross sections by the relevant atomic and molecular community for modelling astrophysical, atmospheric and technological domains. The calculations have been executed using an amalgam of multi centre spherical complex optical potential (MSCOP) formalism and complex scattering potential-ionization contribution (CSP-ic) method. Cross sections are compared with experimental and theoretical data wherever available. Strong correlations are observed for the cross sections which affirms consistent and reliable cross sections. Isomeric effect has been interpreted using variation of cross section with structure and target properties. Our cross sections will be tabulated in atomic collision database for use in modelling various statistical and dynamical quantities.

Cross section data for ionization of important cyanides

Energy Technology Data Exchange (ETDEWEB)

Kaur, Jaspreet; Antony, Bobby, E-mail: bka.ism@gmail.com

2015-11-15

Highlights: • Multi centre spherical complex optical potential formalism used to find the CS. • Effective method (CSP-ic) to derive ionization contribution from inelastic CS. • Result shows excellent accord with previous results and consistent behaviour. • Maiden attempt to find CS for many cyanide molecules. • Strong correlation observed between peak of ionization with target properties. - Abstract: This article presents cross section calculations for interactions of important cyanides with electrons possessing energies beginning from ionization threshold of the target molecule to 5 keV. These data are pursued to meet the ever increasing demand for cross sections by the relevant atomic and molecular community for modelling astrophysical, atmospheric and technological domains. The calculations have been executed using an amalgam of multi centre spherical complex optical potential (MSCOP) formalism and complex scattering potential-ionization contribution (CSP-ic) method. Cross sections are compared with experimental and theoretical data wherever available. Strong correlations are observed for the cross sections which affirms consistent and reliable cross sections. Isomeric effect has been interpreted using variation of cross section with structure and target properties. Our cross sections will be tabulated in atomic collision database for use in modelling various statistical and dynamical quantities.

Target dependence of K+-nucleus total cross sections

International Nuclear Information System (INIS)

Jiang, M.F.; Ernst, D.J.; Chen, C.M.

1995-01-01

We investigate the total cross section and its target dependence for K + -nucleus scattering using a relativistic momentum-space optical potential model which incorporates relativistically normalized wave functions, invariant two-body amplitudes, covariant kinematics, and an exact full-Fermi averaging integral. The definition of the total cross section in the presence of a Coulomb interaction is reviewed and the total cross section is calculated in a way that is consistent with what is extracted from experiment. In addition, the total cross sections for a nucleus and for the deuteron are calculated utilizing the same theory. This minimizes the dependence of the ratio of these cross sections on the details of the theory. The model dependence of the first-order optical potential calculations is investigated. The theoretical results are found to be systematically below all existing data

Capture cross sections on unstable nuclei

Science.gov (United States)

Tonchev, A. P.; Escher, J. E.; Scielzo, N.; Bedrossian, P.; Ilieva, R. S.; Humby, P.; Cooper, N.; Goddard, P. M.; Werner, V.; Tornow, W.; Rusev, G.; Kelley, J. H.; Pietralla, N.; Scheck, M.; Savran, D.; Löher, B.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Tsoneva, N.; Goriely, S.

2017-09-01

Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Capture cross sections on unstable nuclei

Directory of Open Access Journals (Sweden)

Tonchev A.P.

2017-01-01

Full Text Available Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

Modelisation of the fission cross section

International Nuclear Information System (INIS)

Morariu, Claudia

2013-03-01

The neutron cross sections of four nuclear systems (n+ 235 U, n+ 233 U, n+ 241 Am and n+ 237 Np) are studied in the present document. The target nuclei of the first case, like 235 U and 239 Pu, have a large fission cross section after the absorption of thermal neutrons. These nuclei are called 'fissile' nuclei. The other type of nuclei, like 237 Np and 241 Am, fission mostly with fast neutrons, which exceed the fission threshold energy. These types of nuclei are called 'fertile'. The compound nuclei of the fertile nuclei have a binding energy higher than the fission barrier, while for the fissile nuclei the binding energy is lower than the fission barrier. In this work, the neutron induced cross sections for both types of nuclei are evaluated in the fast energy range. The total, reaction and shape-elastic cross sections are calculated by the coupled channel method of the optical model code ECIS, while the compound nucleus mechanism are treated by the statistical models implemented in the codes STATIS, GNASH and TALYS. The STATIS code includes a refined model of the fission process. Results from the theoretical calculations are compared with data retrieved from the experimental data base EXFOR. (author) [fr

Shell-model computed cross sections for charged-current scattering of astrophysical neutrinos off 40Ar

Science.gov (United States)

Kostensalo, Joel; Suhonen, Jouni; Zuber, K.

2018-03-01

Charged-current (anti)neutrino-40Ar cross sections for astrophysical neutrinos have been calculated. The initial and final nuclear states were calculated using the nuclear shell model. The folded solar-neutrino scattering cross section was found to be 1.78 (23 ) ×10-42cm2 , which is higher than what the previous papers have reported. The contributions from the 1- and 2- multipoles were found to be significant at supernova-neutrino energies, confirming the random-phase approximation (RPA) result of a previous study. The effects of neutrino flavor conversions in dense stellar matter (matter oscillations) were found to enhance the neutrino-scattering cross sections significantly for both the normal and inverted mass hierarchies. For the antineutrino scattering, only a small difference between the nonoscillating and inverted-hierarchy cross sections was found, while the normal-hierarchy cross section was 2-3 times larger than that of the nonoscillating cross section, depending on the adopted parametrization of the Fermi-Dirac distribution. This property of the supernova-antineutrino signal could probably be used to distinguish between the two hierarchies in megaton LAr detectors.

Scattering cross section for various potential systems

Directory of Open Access Journals (Sweden)

Myagmarjav Odsuren

2017-08-01

Full Text Available We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the α–α system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the α–α and α–n systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

Scattering cross section for various potential systems

Energy Technology Data Exchange (ETDEWEB)

Odsuren, Myagmarjav; Khuukhenkhuu, Gonchigdorj; Davaa, Suren [Nuclear Research Center, School of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar (Mongolia); Kato, Kiyoshi [Nuclear Reaction Data Centre, Faculty of Science, Hokkaido University, Sapporo (Japan)

2017-08-15

We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the α–α system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the α–α and α–n systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

The LXCat project: Electron scattering cross sections and swarm parameters for low temperature plasma modeling

International Nuclear Information System (INIS)

Pancheshnyi, S.; Biagi, S.; Bordage, M.C.; Hagelaar, G.J.M.; Morgan, W.L.; Phelps, A.V.; Pitchford, L.C.

2012-01-01

Graphical abstract: LXCat is an open-access website containing data needed for low temperature plasma modeling as well as on-line tools useful for their manipulation. Highlights: ► LXCat: an open-access website with data for low temperature plasma modeling. ► Contains compilations of electron scattering cross sections and transport data. ► Data from different contributors for many neutral, ground-state species. ► On-line tools for browsing, plotting, up/downloading data. ► On-line Boltzmann solver for calculating electron swarm parameters. - Abstract: LXCat is a dynamic, open-access, website for collecting, displaying, and downloading ELECtron SCATtering cross sections and swarm parameters (mobility, diffusion coefficient, reaction rates, etc.) required for modeling low temperature, non-equilibrium plasmas. Contributors set up individual databases, and the available databases, indicated by the contributor’s chosen title, include mainly complete sets of electron-neutral scattering cross sections, although the option for introducing partial sets of cross sections exists. A database for measured swarm parameters is also part of LXCat, and this is a growing activity. On-line tools include options for browsing, plotting, and downloading cross section data. The electron energy distribution functions (edfs) in low temperature plasmas are in general non-Maxwellian, and LXCat provides an option for execution of an on-line Boltzmann equation solver to calculate the edf in homogeneous electric fields. Thus, the user can obtain electron transport and rate coefficients (averages over the edfs) in pure gases or gas mixtures over a range of values of the reduced electric fields strength, E/N, the ratio of the electric field strength to the neutral density, using cross sections from the available databases. New contributors are welcome and anyone wishing to create a database and upload data can request a username and password. LXCat is part of a larger, community

Microscopic cross sections: An utopia?

Energy Technology Data Exchange (ETDEWEB)

Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

2010-07-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Microscopic cross sections: An utopia?

International Nuclear Information System (INIS)

Hilaire, S.; Koning, A.J.; Goriely, S.

2010-01-01

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

Inelastic cross-sections for electron transport in liquid water: a comparison of dielectric models

International Nuclear Information System (INIS)

Emfietzoglou, D.

2003-01-01

Various methodologies for constructing inelastic cross-sections for low-energy (<10 keV) electron transport in liquid water are presented and compared. They are all based on an optical-data model which provides the dependence on energy loss, and a dispersion algorithm which incorporates the momentum-transfer dependence. A Drude dielectric model was used to analytically represent the optical data. Various dispersion schemes were examined: the Bethe approximation, the δ-oscillator models of Ashley and Liljequist, and two forms of Ritchie's extended-Drude model. They all have been used in Monte-Carlo (MC) codes for analog electron transport in the condensed phase. Results in the form of differential and total inelastic cross-sections are presented. Where possible, comparisons with results of other studies are made. It was found that, despite the application of general constraints (e.g. sum rules), the optical model has a notable influence on the single-collision energy loss spectrum. In addition, both the shape and peak position of the total and differential cross-section distributions depend strongly on the dispersion model adopted. The work is particularly relevant to the development of event-by-event MC transport codes for liquid water, as well as, to the calculations of stopping-powers below the range of applicability of Bethe's formula

Advanced modeling of reaction cross sections for light nuclei

International Nuclear Information System (INIS)

Resler, D.A.

1991-01-01

The shell model/R-matrix technique of calculating nuclear reaction cross sections for light projectiles incident on light nuclei is discussed, particularly in the application of the technique to thermonuclear reactions. Details are presented on the computational methods for the shell model which display how easily the calculations can be performed. Results of the shell model/R-matrix technique are discussed as are some of the problems encountered in picking an appropriate nucleon-nucleon interaction for the large model spaces which must be used for current problems. The status of our work on developing an effective nucleon-nucleon interaction for use in large-basis shell model calculations is presented. This new interaction is based on a combination of global constraints and microscopic nuclear data. 23 refs., 6 figs., 2 tabs

MODELING AND ANALYSIS OF COUPLED FLEXURAL-TORSIONAL SPINNING BEAMS WITH UNSYMMETRICAL CROSS SECTIONS

OpenAIRE

Wang, Jie; Li, Dongxu; Jiang, Jianping

2017-01-01

The structural modeling and dynamic properties of a spinning beam with an unsymmetrical cross section are studied. Due to the eccentricity and spinning, transverse deflections along the two principal directions and the torsional motion about the longitudinal axis are coupled. The structural model of the beam is established based on the Hamilton principle and by incorporating the torsional inertia. Moreover, because of its significant influence on characteristics for the non-circular cross-sec...

Low Energy Neutrino Cross Sections

International Nuclear Information System (INIS)

Zeller, G.P.

2004-01-01

Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ∼ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies.Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy

Fission cross-section calculations and the multi-modal fission model

International Nuclear Information System (INIS)

Hambsch, F.J.

2004-01-01

New, self consistent, neutron-induced reaction cross section calculations for 235,238 U, 237 Np have been performed. The statistical model code STATIS was improved to take into account the multimodality of the fission process. The three most dominant fission modes, the two asymmetric standards I (S1) and standard II (S2) modes and the symmetric superlong (SL) mode have been taken into account. De-convoluted fission cross sections for those modes for 235,238 U(n,f) and 237 Np(n,f) based on experimental branching ratios, were calculated for the first time up to the second chance fission threshold. For 235 U(n,f), the calculations being made up to 28 MeV incident neutron energy, higher fission chances have been considered. This implied the need for additional calculations for the neighbouring isotopes. As a side product also mass yield distributions could be calculated at energies hitherto not accessible by experiment. Experimental validation of the predictions is being envisaged

Revisiting the T2K data using different models for the neutrino-nucleus cross sections

Energy Technology Data Exchange (ETDEWEB)

Meloni, D., E-mail: meloni@fis.uniroma3.it [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma (Italy); Martini, M., E-mail: mmartini@ulb.ac.be [Institut d' Astronomie et d' Astrophysique, CP-226, Universite Libre de Bruxelles, 1050 Brussels (Belgium)

2012-09-17

We present a three-flavor fit to the recent {nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {mu}} T2K oscillation data with different models for the neutrino-nucleus cross section. We show that, even for a limited statistics, the allowed regions and best fit points in the ({theta}{sub 13},{delta}{sub CP}) and ({theta}{sub 23},{Delta}m{sub atm}{sup 2}) planes are affected if, instead of using the Fermi gas model to describe the quasielastic cross section, we employ a model including the multinucleon emission channel.

Discussion of electron cross sections for transport calculations

International Nuclear Information System (INIS)

Berger, M.J.

1983-01-01

This paper deals with selected aspects of the cross sections needed as input for transport calculations and for the modeling of radiation effects in biological materials. Attention is centered mainly on the cross sections for inelastic interactions between electrons and water molecules and the use of these cross sections for the calculation of energy degradation spectra and of ionization and excitation yields. 40 references, 3 figures, 1 table

Applications of the BEam Cross section Analysis Software (BECAS)

DEFF Research Database (Denmark)

Blasques, José Pedro Albergaria Amaral; Bitsche, Robert; Fedorov, Vladimir

2013-01-01

A newly developed framework is presented for structural design and analysis of long slender beam-like structures, e.g., wind turbine blades. The framework is based on the BEam Cross section Analysis Software – BECAS – a finite element based cross section analysis tool. BECAS is used for the gener......A newly developed framework is presented for structural design and analysis of long slender beam-like structures, e.g., wind turbine blades. The framework is based on the BEam Cross section Analysis Software – BECAS – a finite element based cross section analysis tool. BECAS is used...... for the generation of beam finite element models which correctly account for effects stemming from material anisotropy and inhomogeneity in cross sections of arbitrary geometry. These type of modelling approach allows for an accurate yet computationally inexpensive representation of a general class of three...

Introduction to the physics of the total cross section at LHC. A review of data and models

Energy Technology Data Exchange (ETDEWEB)

Pancheri, Giulia [INFN Frascati National Laboratory, Frascati (Italy); Massachusetts Institute of Technology, Center for Theoretical Physics, Cambridge, MA (United States); Srivastava, Yogendra N. [University of Perugia, Physics Department, Perugia (Italy); Northeastern University, Physics Department, Boston, MA (United States)

2017-03-15

This review describes the development of the physics of hadronic cross sections up to recent LHC results and cosmic ray experiments. We present here a comprehensive review - written with a historical perspective - about total cross sections from medium to the highest energies explored experimentally and studied through a variety of methods and theoretical models for over 60 years. We begin by recalling the analytic properties of the elastic amplitude and the theorems about the asymptotic behavior of the total cross section. A discussion of how proton-proton cross sections are extracted from cosmic rays at higher than accelerator energies and help the study of these asymptotic limits, is presented. This is followed by a description of the advent of particle colliders, through which high energies and unmatched experimental precisions have been attained. Thus the measured hadronic elastic and total cross sections have become crucial instruments to probe the so called soft part of QCD physics, where quarks and gluons are confined, and have led to test and refine Regge behavior and a number of diffractive models. As the c.m. energy increases, the total cross section also probes the transition into hard scattering describable with perturbative QCD, the so-called mini-jet region. Further tests are provided by cross section measurements of γp, γ*p and γ*γ* for models based on vector meson dominance, scaling limits of virtual photons at high Q{sup 2} and the BFKL formalism. Models interpolating from virtual to real photons are also tested. It seems to us to be a necessary task to explore bit-by-bit the rigorous consequences of analyticity, unitarity and crossing. Who knows if someday one will not be able to reassemble the pieces of the puzzle. - A. Martin and F. Cheung, based on 1967 A.M. Lectures at Brandeis Summer School and Lectures at SUNY and Stony Brook (Martin and Cheung in Analyticity properties and bounds of the scattering amplitudes. Gordon and Breach Science

Cross-section parameterization of the pebble bed modular reactor using the dimension-wise expansion model

International Nuclear Information System (INIS)

Zivanovic, Rastko; Bokov, Pavel M.

2010-01-01

This paper discusses the use of the dimension-wise expansion model for cross-section parameterization. The components of the model were approximated with tensor products of orthogonal polynomials. As we demonstrate, the model for a specific cross-section can be built in a systematic way directly from data without any a priori knowledge of its structure. The methodology is able to construct a finite basis of orthogonal polynomials that is required to approximate a cross-section with pre-specified accuracy. The methodology includes a global sensitivity analysis that indicates irrelevant state parameters which can be excluded from the model without compromising the accuracy of the approximation and without repetition of the fitting process. To fit the dimension-wise expansion model, Randomised Quasi-Monte-Carlo Integration and Sparse Grid Integration methods were used. To test the parameterization methods with different integrations embedded we have used the OECD PBMR 400 MW benchmark problem. It has been shown in this paper that the Sparse Grid Integration achieves pre-specified accuracy with a significantly (up to 1-2 orders of magnitude) smaller number of samples compared to Randomised Quasi-Monte-Carlo Integration.

A Non-Linear Finite Element Model for the LHC Main Dipole Coil Cross-Section

CERN Document Server

Pojer, M; Scandale, Walter

2006-01-01

The production of the dipole magnets for the Large Hadron Collider is at its final stage. Nevertheless, some mechanical instabilities are still observed for which no clear explanation has been found yet. A FE modelization of the dipole cold mass cross-section had already been developed at CERN, mainly for magnetic analysis, taking into account conductor blocks and a frictionless behavior. This paper describes a new ANSYS® model of the dipole coil cross-section, featuring individual turns inside conductor blocks, and implementing friction and the mechanical non-linear behavior of insulated cables. Preliminary results, comparison with measurements performed in industry and ongoing developments are discussed.

EDDIX--a database of ionisation double differential cross sections.

Science.gov (United States)

MacGibbon, J H; Emerson, S; Liamsuwan, T; Nikjoo, H

2011-02-01

The use of Monte Carlo track structure is a choice method in biophysical modelling and calculations. To precisely model 3D and 4D tracks, the cross section for the ionisation by an incoming ion, double differential in the outgoing electron energy and angle, is required. However, the double differential cross section cannot be theoretically modelled over the full range of parameters. To address this issue, a database of all available experimental data has been constructed. Currently, the database of Experimental Double Differential Ionisation Cross sections (EDDIX) contains over 1200 digitalised experimentally measured datasets from the 1960s to present date, covering all available ion species (hydrogen to uranium) and all available target species. Double differential cross sections are also presented with the aid of an eight parameter functions fitted to the cross sections. The parameters include projectile species and charge, target nuclear charge and atomic mass, projectile atomic mass and energy, electron energy and deflection angle. It is planned to freely distribute EDDIX and make it available to the radiation research community for use in the analytical and numerical modelling of track structure.

STAX-2, Neutron Scattering Cross-Sections by Optical Model and Moldauer Theory with Hauser-Feshbach

International Nuclear Information System (INIS)

Tomita, Y.

1972-01-01

1 - Nature of physical problem solved: The program calculates neutron scattering cross sections by means of the optical model and Moldauer's theory, and can search for potential parameters which reproduce measured cross sections. The Hauser-Feshbach calculation is also possible. 2 - Restrictions on the complexity of the problem: The maximum number of levels is 25. The largest value of the orbital angular momentum is 10

Reaction cross section calculation of some alkaline earth elements

Science.gov (United States)

Tel, Eyyup; Kavun, Yusuf; Sarpün, Ismail Hakki

2017-09-01

Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

Modeling and Analysis of a Piezoelectric Energy Harvester with Varying Cross-Sectional Area

Directory of Open Access Journals (Sweden)

Maiara Rosa

2014-01-01

Full Text Available This paper reports on the modeling and on the experimental verification of electromechanically coupled beams with varying cross-sectional area for piezoelectric energy harvesting. The governing equations are formulated using the Rayleigh-Ritz method and Euler-Bernoulli assumptions. A load resistance is considered in the electrical domain for the estimate of the electric power output of each geometric configuration. The model is first verified against the analytical results for a rectangular bimorph with tip mass reported in the literature. The experimental verification of the model is also reported for a tapered bimorph cantilever with tip mass. The effects of varying cross-sectional area and tip mass on the electromechanical behavior of piezoelectric energy harvesters are also discussed. An issue related to the estimation of the optimal load resistance (that gives the maximum power output on beam shape optimization problems is also discussed.

Standard cross-section data

International Nuclear Information System (INIS)

Carlson, A.D.

1984-01-01

The accuracy of neutron cross-section measurement is limited by the uncertainty in the standard cross-section and the errors associated with using it. Any improvement in the standard immediately improves all cross-section measurements which have been made relative to that standard. Light element, capture and fission standards are discussed. (U.K.)

ENDF/B-5 fission product cross section evaluations

International Nuclear Information System (INIS)

Schenter, R.E.; England, T.R.

1979-12-01

Cross section evaluations were made for the 196 fission product nuclides on the ENDF/B-5 data files. Most of the evaluations involve updating the capture cross sections of the important absorbers for fast and thermal reactor systems. This included updating thermal values, resonance integrals, resonance parameter sets, and fast capture cross sections. For the fast capture results generalized least-squares calculations were made with the computer code FERRET. Input for these cross section adjustments included nuclear models calculations and both integral and differential experimental data results. The differential cross sections and their uncertainties were obtained from the CSIRS library. Integral measurement results came from CFRMF and STEK Assemblies 500, 1000, 2000, 3000, 4000. Comparisons of these evaluations with recent capture measurements are shown. 15 figures, 10 tables

Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 132,134}Ba

Energy Technology Data Exchange (ETDEWEB)

Luo, Junhua [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering; Hexi Univ., Zhangye (China). Inst. of New Energy; Wu, Chunlei; Jiang, Li [Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry; Li, Suyuan [Hexi Univ., Zhangye (China). Inst. of New Energy

2017-07-01

Cross sections of the {sup 132}Ba(n,2n){sup 131m,g}Ba and {sup 134}Ba(n,2n){sup 133m,g}Ba reactions and their isomeric cross section ratios σ{sub m}/σ{sub g} have been measured by means of the activation technique at three neutron energies in the range 13-15 MeV. BaCO{sub 3} samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The quasimonoenergetic neutrons beam were produced via the {sup 3}H(d,n){sup 4}He reaction at the Pd-300 Neutron Generator of the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ ray spectroscopy. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. Cross sections were also evaluated theoretically using the numerical nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Failure of Stadard Optical Models to Reproduce Neutron Total Cross Section Difference in the W Isotopes

Energy Technology Data Exchange (ETDEWEB)

Anderson, J D; Bauer, R W; Dietrich, F S; Grimes, S M; Finlay, R W; Abfalterer, W P; Bateman, F B; Haight, R C; Morgan, G L; Bauge, E; Delaroche, J P; Romain, P

2001-11-01

Recently cross section differences among the isotopes{sup 182,184,186}W have been measured as part of a study of total cross sections in the 5-560 MeV energy range. These measurements show oscillations up to 150 mb between 5 and 100 MeV. Spherical and deformed phenomenological optical potentials with typical radial and isospin dependences show very small oscillations, in disagreement with the data. In a simple Ramsauer model, this discrepancy can be traced to a cancellation between radial and isospin effects. Understanding this problem requires a more detailed model that incorporates a realistic description of the neutron and proton density distributions. This has been done with results of Hartree-Fock-Bogolyubov calculations using the Gogny force, together with a microscopic folding model employing a modification of the JLM potential as an effective interaction. This treatment yields a satisfactory interpretation of the observed total cross section differences.

Light stops emerging in WW cross section measurements?

International Nuclear Information System (INIS)

Rolbiecki, Krzysztof

2013-03-01

Recent ATLAS and CMS measurements show a slight excess in the WW cross section measurement. While still consistent with the Standard Model within 1-2σ, the excess could be also a first hint of physics beyond the Standard Model. We argue that this effect could be attributed to the production of scalar top quarks within supersymmetric models. The stops of m t 1 ∝200 GeV has the right cross section and under some assumptions can significantly contribute to the final state of two leptons and missing energy. We scan this region of parameter space to find particle masses preferred by the WW cross section measurements. Taking one sample benchmark point we show that it can be consistent with low energy observables and Higgs sector measurements and propose a method to distinguish supersymmetric signal from the Standard Model contribution.

Double-differential heavy-ion production cross sections

International Nuclear Information System (INIS)

Miller, T. M.; Townsend, L. W.

2004-01-01

Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production. (authors)

Prospects for Precision Neutrino Cross Section Measurements

Energy Technology Data Exchange (ETDEWEB)

Harris, Deborah A. [Fermilab

2016-01-28

The need for precision cross section measurements is more urgent now than ever before, given the central role neutrino oscillation measurements play in the field of particle physics. The definition of precision is something worth considering, however. In order to build the best model for an oscillation experiment, cross section measurements should span a broad range of energies, neutrino interaction channels, and target nuclei. Precision might better be defined not in the final uncertainty associated with any one measurement but rather with the breadth of measurements that are available to constrain models. Current experience shows that models are better constrained by 10 measurements across different processes and energies with 10% uncertainties than by one measurement of one process on one nucleus with a 1% uncertainty. This article describes the current status of and future prospects for the field of precision cross section measurements considering the metric of how many processes, energies, and nuclei have been studied.

Electron-Impact Excitation Cross Sections for Modeling Non-Equilibrium Gas

Science.gov (United States)

Huo, Winifred M.; Liu, Yen; Panesi, Marco; Munafo, Alessandro; Wray, Alan; Carbon, Duane F.

2015-01-01

In order to provide a database for modeling hypersonic entry in a partially ionized gas under non-equilibrium, the electron-impact excitation cross sections of atoms have been calculated using perturbation theory. The energy levels covered in the calculation are retrieved from the level list in the HyperRad code. The downstream flow-field is determined by solving a set of continuity equations for each component. The individual structure of each energy level is included. These equations are then complemented by the Euler system of equations. Finally, the radiation field is modeled by solving the radiative transfer equation.

Colour intransparency and the cross sections for colour-singlet and colour-octet hadrons in the Low-Nussinov model

International Nuclear Information System (INIS)

Dolejsi, J.; Huefner, J.

1992-01-01

The dependence of cross sections on the colour state of the colliding hadrons is investigated within the Low-Nussinov model of two-gluon exchange. The total cross sections for colour-octet hadrons are practically constant as functions of the hadronic radii, while they tend to zero when the radii of the colour-singlet hadrons approach zero. The slope parameter of the differential elastic cross sections for small momentum transfers is rather insensitive to the colour structure of the colliding hadrons. The integrated colour exchange cross section is calculated. (orig.)

An integrative modeling approach for the efficient estimation of cross sectional tibial stresses during locomotion.

Science.gov (United States)

Derrick, Timothy R; Edwards, W Brent; Fellin, Rebecca E; Seay, Joseph F

2016-02-08

The purpose of this research was to utilize a series of models to estimate the stress in a cross section of the tibia, located 62% from the proximal end, during walking. Twenty-eight male, active duty soldiers walked on an instrumented treadmill while external force data and kinematics were recorded. A rigid body model was used to estimate joint moments and reaction forces. A musculoskeletal model was used to gather muscle length, muscle velocity, moment arm and orientation information. Optimization procedures were used to estimate muscle forces and finally internal bone forces and moments were applied to an inhomogeneous, subject specific bone model obtained from CT scans to estimate stress in the bone cross section. Validity was assessed by comparison to stresses calculated from strain gage data in the literature and sensitivity was investigated using two simplified versions of the bone model-a homogeneous model and an ellipse approximation. Peak compressive stress occurred on the posterior aspect of the cross section (-47.5 ± 14.9 MPa). Peak tensile stress occurred on the anterior aspect (27.0 ± 11.7 MPa) while the location of peak shear was variable between subjects (7.2 ± 2.4 MPa). Peak compressive, tensile and shear stresses were within 0.52 MPa, 0.36 MPa and 3.02 MPa respectively of those calculated from the converted strain gage data. Peak values from a inhomogeneous model of the bone correlated well with homogeneous model (normal: 0.99; shear: 0.94) as did the normal ellipse model (r=0.89-0.96). However, the relationship between shear stress in the inhomogeneous model and ellipse model was less accurate (r=0.64). The procedures detailed in this paper provide a non-invasive and relatively quick method of estimating cross sectional stress that holds promise for assessing injury and osteogenic stimulus in bone during normal physical activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Calculation of the intermediate energy activation cross section

Energy Technology Data Exchange (ETDEWEB)

Furihata, Shiori; Yoshizawa, Nobuaki [Mitsubishi Research Inst., Inc., Tokyo (Japan)

1997-03-01

We discussed the activation cross section in order to predict accurately the activation of soil around an accelerator with high energy and strong intensity beam. For the assessment of the accuracy of activation cross sections estimated by a numerical model, we compared the calculated cross section with various experimental data, for Si(p,x){sup 22}Na, Al(p,x){sup 22}Na, Fe(p,x){sup 22}Na, Si(p,x){sup 7}Be, O(p,x){sup 3}H, Al(p,x){sup 3}H and Si(p,x){sup 3}H reactions. We used three computational codes, i.e., quantum molecular dynamics (QMD) plus statistical decay model (SDM), HETC-3STEP and the semiempirical method developed by Silberberg et.al. It is observed that the codes are accurate above 1GeV, except for {sup 7}Be production. We also discussed the difference between the activation cross sections of proton- and neutron-induced reaction. For the incident energy at 40MeV, it is found that {sup 3}H production cross sections of neutron-induced reaction are ten times as large as those of proton-induced reaction. It is also observed that the choice of the activation cross sections seriously affects to the estimate of saturated radioactivity, if the maximum energy of neutron flux is below 100MeV. (author)

Reaction cross section calculation of some alkaline earth elements

Directory of Open Access Journals (Sweden)

Tel Eyyup

2017-01-01

Full Text Available Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

Handbook of LHC Higgs Cross Sections: 3. Higgs Properties Report of the LHC Higgs Cross Section Working Group

CERN Document Server

Heinemeyer, S; Passarino, G; Tanaka, R; Andersen, J R; Artoisenet, P; Bagnaschi, E A; Banfi, A; Becher, T; Bernlochner, F U; Bolognesi, S; Bolzoni, P; Boughezal, R; Buarque, D; Campbell, J; Caola, F; Carena, M; Cascioli, F; Chanon, N; Cheng, T; Choi, S Y; David, A; de Aquino, P; Degrassi, G; Del Re, D; Denner, A; van Deurzen, H; Diglio, S; Di Micco, B; Di Nardo, R; Dittmaier, S; Dührssen, M; Ellis, R K; Ferrera, G; Fidanza, N; Flechl, M; de Florian, D; Forte, S; Frederix, R; Frixione, S; Gangal, S; Gao, Y; Garzelli, M V; Gillberg, D; Govoni, P; Grazzini, M; Greiner, N; Griffiths, J; Gritsan, A V; Grojean, C; Hall, D C; Hays, C; Harlander, R; Hernandez-Pinto, R; Höche, S; Huston, J; Jubb, T; Kadastik, M; Kallweit, S; Kardos, A; Kashif, L; Kauer, N; Kim, H; Klees, R; Krämer, M; Krauss, F; Laureys, A; Laurila, S; Lehti, S; Li, Q; Liebler, S; Liu, X; Logan, E; Luisoni, G; Malberti, M; Maltoni, F; Mawatari, K; Maierhoefer, F; Mantler, H; Martin, S; Mastrolia, P; Mattelaer, O; Mazzitelli, J; Mellado, B; Melnikov, K; Meridiani, P; Miller, D J; Mirabella, E; Moch, S O; Monni, P; Moretti, N; Mück, A; Mühlleitner, M; Musella, P; Nason, P; Neu, C; Neubert, M; Oleari, C; Olsen, J; Ossola, G; Peraro, T; Peters, K; Petriello, F; Piacquadio, G; Potter, C T; Pozzorini, S; Prokofiev, K; Puljak, I; Rauch, M; Rebuzzi, D; Reina, L; Rietkerk, R; Rizzi, A; Rotstein-Habarnau, Y; Salam, G P; Sborlini, G; Schissler, F; Schönherr, M; Schulze, M; Schumacher, M; Siegert, F; Slavich, P; Smillie, J M; Stål, O; von Soden-Fraunhofen, J F; Spira, M; Stewart, I W; Tackmann, F J; Taylor, P T E; Tommasini, D; Thompson, J; Thorne, R S; Torrielli, P; Tramontano, F; Tran, N V; Trócsányi, Z; Ubiali, M; Vazquez Acosta, M; Vickey, T; Vicini, A; Waalewijn, W J; Wackeroth, D; Wagner, C; Walsh, J R; Wang, J; Weiglein, G; Whitbeck, A; Williams, C; Yu, J; Zanderighi, G; Zanetti, M; Zaro, M; Zerwas, P M; Zhang, C; Zirke, T J E; Zuberi, S

2013-01-01

This Report summarizes the results of the activities in 2012 and the first half of 2013 of the LHC Higgs Cross Section Working Group. The main goal of the working group was to present the state of the art of Higgs Physics at the LHC, integrating all new results that have appeared in the last few years. This report follows the first working group report Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002) and the second working group report Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002). After the discovery of a Higgs boson at the LHC in mid-2012 this report focuses on refined prediction of Standard Model (SM) Higgs phenomenology around the experimentally observed value of 125-126 GeV, refined predictions for heavy SM-like Higgs bosons as well as predictions in the Minimal Supersymmetric Standard Model and first steps to go beyond these models. The other main focus is on the extraction of the characteristics and properties of the newly discovered p...

Nonelastic-scattering cross sections of elemental nickel

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1980-06-01

Neutron total cross sections of elemental nickel were measured from 1.3 to 4.5 MeV, at intervals of approx. 50 keV, with resolutions of 30 to 50 keV and to accuracies of 1 to 2.5%. Neutron differential-elastic-scattering cross sections were measured from 1.45 to 3.8 MeV, at intervals and with resolutions comparable to those of the total cross sections, and to accuracies of 3 to 5%. The nonelastic-scattering cross section is derived from the measured values to accuracies of greater than or equal to 6%. The experimental results are compared with previously reported values as represented by ENDF/B-V, and areas of consistency and discrepancy, noted. The measured results are shown to be in good agreement with the predictions of a model previously reported by the authors. 4 figures, 1 table

A global reference for caesarean section rates (C-Model): a multicountry cross-sectional study.

Science.gov (United States)

Souza, J P; Betran, A P; Dumont, A; de Mucio, B; Gibbs Pickens, C M; Deneux-Tharaux, C; Ortiz-Panozo, E; Sullivan, E; Ota, E; Togoobaatar, G; Carroli, G; Knight, H; Zhang, J; Cecatti, J G; Vogel, J P; Jayaratne, K; Leal, M C; Gissler, M; Morisaki, N; Lack, N; Oladapo, O T; Tunçalp, Ö; Lumbiganon, P; Mori, R; Quintana, S; Costa Passos, A D; Marcolin, A C; Zongo, A; Blondel, B; Hernández, B; Hogue, C J; Prunet, C; Landman, C; Ochir, C; Cuesta, C; Pileggi-Castro, C; Walker, D; Alves, D; Abalos, E; Moises, Ecd; Vieira, E M; Duarte, G; Perdona, G; Gurol-Urganci, I; Takahiko, K; Moscovici, L; Campodonico, L; Oliveira-Ciabati, L; Laopaiboon, M; Danansuriya, M; Nakamura-Pereira, M; Costa, M L; Torloni, M R; Kramer, M R; Borges, P; Olkhanud, P B; Pérez-Cuevas, R; Agampodi, S B; Mittal, S; Serruya, S; Bataglia, V; Li, Z; Temmerman, M; Gülmezoglu, A M

2016-02-01

To generate a global reference for caesarean section (CS) rates at health facilities. Cross-sectional study. Health facilities from 43 countries. Thirty eight thousand three hundred and twenty-four women giving birth from 22 countries for model building and 10,045,875 women giving birth from 43 countries for model testing. We hypothesised that mathematical models could determine the relationship between clinical-obstetric characteristics and CS. These models generated probabilities of CS that could be compared with the observed CS rates. We devised a three-step approach to generate the global benchmark of CS rates at health facilities: creation of a multi-country reference population, building mathematical models, and testing these models. Area under the ROC curves, diagnostic odds ratio, expected CS rate, observed CS rate. According to the different versions of the model, areas under the ROC curves suggested a good discriminatory capacity of C-Model, with summary estimates ranging from 0.832 to 0.844. The C-Model was able to generate expected CS rates adjusted for the case-mix of the obstetric population. We have also prepared an e-calculator to facilitate use of C-Model (www.who.int/reproductivehealth/publications/maternal_perinatal_health/c-model/en/). This article describes the development of a global reference for CS rates. Based on maternal characteristics, this tool was able to generate an individualised expected CS rate for health facilities or groups of health facilities. With C-Model, obstetric teams, health system managers, health facilities, health insurance companies, and governments can produce a customised reference CS rate for assessing use (and overuse) of CS. The C-Model provides a customized benchmark for caesarean section rates in health facilities and systems. © 2015 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

The gross theory model for neutrino-nucleus cross-section

International Nuclear Information System (INIS)

Samana, A R; Barbero, C A; Krmpotic, F; Duarte, S B; Dimarco, A J

2008-01-01

The nuclear gross theory, originally formulated by Takahashi and Yamada (1969 Prog. Theor. Phys. 41 1470) for the β-decay, is applied to the electronic-neutrino nucleus reactions, employing a more realistic description of the energetics of the Gamow-Teller resonances. The model parameters are gauged from the most recent experimental data, both for β - -decay and electron capture, separately for even-even, even-odd, odd-odd and odd-even nuclei. The numerical estimates for neutrino-nucleus cross-sections agree fairly well with previous evaluations done within the framework of microscopic models. The formalism presented here can be extended to the heavy nuclei mass region, where weak processes are quite relevant, which is of astrophysical interest because of its applications in supernova explosive nucleosynthesis

Simultaneous Feedback Models with Macro-Comparative Cross-Sectional Data

Directory of Open Access Journals (Sweden)

Nate Breznau

2018-06-01

Full Text Available Social scientists often work with theories of reciprocal causality. Sometimes theories suggest that reciprocal causes work simultaneously, or work on a time-scale small enough to make them appear simultaneous. Researchers may employ simultaneous feedback models to investigate such theories, although the practice is rare in cross-sectional survey research. This paper discusses the certain conditions that make these models possible if not desirable using such data. This methodological excursus covers the construction of simultaneous feedback models using a structural equation modeling perspective. This allows the researcher to test if a simultaneous feedback theory fits survey data, test competing hypotheses and engage in macro-comparisons. This paper presents methods in a manner and language amenable to the practicing social scientist who is not a statistician or matrix mathematician. It demonstrates how to run models using three popular software programs (MPlus, Stata and R, and an empirical example using International Social Survey Program data.

Workshop on electronic and ionic collision cross sections needed in the modeling of radiation interactions with matter: proceedings

International Nuclear Information System (INIS)

1984-05-01

The term modeling in the Workship title refers to the mathematical analysis of the consequences of many collision processes for characterizing the physical stage of radiation actions. It requires as input some knowledge of collision cross sections. Traditionally, work on cross sections and work on the modeling are conducted by separate groups of scientists. It was the purpose of the Workshop to bring these two groups together in a forum that would promote effective communication. Cross-section workers described the status of their work and told what data were available or trustworthy. Modeling workers told what kind of data were needed or were most important. Twenty-two items from the workshop were prepared separately for the data base

Workshop on electronic and ionic collision cross sections needed in the modeling of radiation interactions with matter: proceedings

Energy Technology Data Exchange (ETDEWEB)

1984-05-01

The term modeling in the Workship title refers to the mathematical analysis of the consequences of many collision processes for characterizing the physical stage of radiation actions. It requires as input some knowledge of collision cross sections. Traditionally, work on cross sections and work on the modeling are conducted by separate groups of scientists. It was the purpose of the Workshop to bring these two groups together in a forum that would promote effective communication. Cross-section workers described the status of their work and told what data were available or trustworthy. Modeling workers told what kind of data were needed or were most important. Twenty-two items from the workshop were prepared separately for the data base.

Light stops emerging in WW cross section measurements?

Energy Technology Data Exchange (ETDEWEB)

Rolbiecki, Krzysztof [IFT-UAM/CSIC, Madrid (Spain). Inst. de Fisica Teorica; Sakurai, Kazuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2013-03-15

Recent ATLAS and CMS measurements show a slight excess in the WW cross section measurement. While still consistent with the Standard Model within 1-2{sigma}, the excess could be also a first hint of physics beyond the Standard Model. We argue that this effect could be attributed to the production of scalar top quarks within supersymmetric models. The stops of m{sub t{sub 1}}{proportional_to}200 GeV has the right cross section and under some assumptions can significantly contribute to the final state of two leptons and missing energy. We scan this region of parameter space to find particle masses preferred by the WW cross section measurements. Taking one sample benchmark point we show that it can be consistent with low energy observables and Higgs sector measurements and propose a method to distinguish supersymmetric signal from the Standard Model contribution.

Hardon cross sections at ultra high energies

International Nuclear Information System (INIS)

Yodh, G.B.

1987-01-01

A review of results on total hadronic cross sections at ultra high energies obtained from a study of longitudinal development of cosmic ray air showers is given. The experimental observations show that proton-air inelastic cross section increases from 275 mb to over 500 mb as the collision energy in the center of mass increases from 20 GeV to 20 TeV. The proton-air inelastic cross section, obtained from cosmic ray data at √s = 30 TeV, is compared with calculations using various different models for the energy variation of the parameters of the elementary proton-proton interaction. Three conclusions are derived

Photoneutron and Photonuclear Cross Sections According to Packed cluster Model

International Nuclear Information System (INIS)

El-Mekkawi, L.S.; El-Bakty, O.M.

1998-01-01

Photonuclear gross sections have been estimated for 232 Th, 237 Np, 239 Pu, 233 U, 234 U, 235 U, 238 U in the energy range from threshold up to 20 MeV, by perturbation balance in Packed Cluster. The Packed Cluster (gamma, f) and (gamma, n) cross sections require complete absence of any (gamma,2n) or (gamma,nf) cross sections for 233 U and 234 U as in experiment. It also explains the early (gamma,n) and gamma,nf) reactions in 235 U

Total Cross Sections at High Energies An update

CERN Document Server

Fazal-e-Aleem, M; Alam, Saeed; Qadee-Afzal, M

2002-01-01

Current and Future measurements for the total cross sections at E-811, PP2PP, CSM, FELIX and TOTEM have been analyzed using various models. In the light of this study an attempt has been made to focus on the behavior of total cross section at very high energies.

Cross sections for atmospheric corrections

International Nuclear Information System (INIS)

Meyer, J.P.; Casse, M.; Westergaard, N.

1975-01-01

A set of cross sections for spallation of relativistic nuclei is proposed based on (i) the best available proton cross sections, (ii) an extrapolation to heavier nuclei of the dependence on the number of nucleons lost of the 'target factor' observed for C 12 and O 16 by Lindstrom et al. (1975), in analogy with Rudstam's formalism, and (iii) on a normalization of all cross sections to the total cross sections for production of fragments with Asub(f) >= 6. The obtained cross sections for peripheral interactions are not inconsistent with simple geometrical considerations. (orig.) [de

LHCb cross-section measurements with heavy flavour jets

CERN Multimedia

Michielin, Emanuele

2017-01-01

Cross-section measurements of jets originating from the hadronization of beauty ($b$) and charm ($c$) quarks at LHCb give the unique opportunity to probe Parton Distribution Functions (PDFs) at low and large momentum fraction and to test the Standard Model in the forward region. In this poster the production of $t\\bar{t}$ pairs in the forward region, the measurement of the $W+b\\bar{b}$ and $W+c\\bar{c}$ cross-section and the measurement of the $Z\\rightarrow b\\bar{b}$ cross-section are presented.

A survey of cross-section sensitivity analysis as applied to radiation shielding

International Nuclear Information System (INIS)

Goldstein, H.

1977-01-01

Cross section sensitivity studies revolve around finding the change in the value of an integral quantity, e.g. transmitted dose, for a given change in one of the cross sections. A review is given of the principal methodologies for obtaining the sensitivity profiles-principally direct calculations with altered cross sections, and linear perturbation theory. Some of the varied applications of cross section sensitivity analysis are described, including the practice, of questionable value, of adjusting input cross section data sets so as to provide agreement with integral experiments. Finally, a plea is made for using cross section sensitivity analysis as a powerful tool for analysing the transport mechanisms of particles in radiation shields and for constructing models of how cross section phenomena affect the transport. Cross section sensitivities in the shielding area have proved to be highly problem-dependent. Without the understanding afforded by such models, it is impossible to extrapolate the conclusions of cross section sensitivity analysis beyond the narrow limits of the specific situations examined in detail. Some of the elements that might be of use in developing the qualitative models are presented. (orig.) [de

Intubation simulation with a cross-sectional visual guidance.

Science.gov (United States)

Rhee, Chi-Hyoung; Kang, Chul Won; Lee, Chang Ha

2013-01-01

We present an intubation simulation with deformable objects and a cross-sectional visual guidance using a general haptic device. Our method deforms the tube model when it collides with the human model. Mass-Spring model with the Euler integration is used for the tube deformation. For the trainee's more effective understanding of the intubation process, we provide a cross-sectional view of the oral cavity and the tube. Our system also applies a stereoscopic rendering to improve the depth perception and the reality of the simulation.

Asymptotic behaviour of pion-pion total cross-sections

Energy Technology Data Exchange (ETDEWEB)

Greynat, David [Dipartimento di Scienze Fisiche, Universita di Napoli “Federico II”,Via Cintia, 80126 Napoli (Italy); Rafael, Eduardo de [Aix-Marseille Université, CNRS,CPT, UMR 7332, 13288 Marseille (France); Université de Toulon, CNRS,CPT, UMR 7332, 83957 La Garde (France); Vulvert, Grégory [Departament de Física Teórica, IFIC,CSIC - Universitat de València, Apt. Correus 22085, E-46071 València (Spain)

2014-03-24

We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the ππ total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log{sup 2} s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for π{sup +}π{sup −}, π{sup ±}π{sup 0} and π{sup 0}π{sup 0} scattering within the framework of the constituent chiral quark model (CχQM) in the limit of a large number of colours N{sub c} and discuss their asymptotic behaviours. The same ππ cross sections are also discussed within the general framework of Large-N{sub c} QCD and we show that it is possible to make an Ansatz for the isospin I=1 and I=0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N{sub c} counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the σ{sub π{sup ±}π{sup 0total}}(s) cross section predicted by the CχQM with the high energy behaviour predicted by the Large-N{sub c} Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp-bar scattering total cross sections.

Asymptotic behaviour of pion-pion total cross-sections

International Nuclear Information System (INIS)

Greynat, David; Rafael, Eduardo de; Vulvert, Grégory

2014-01-01

We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the ππ total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log 2  s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for π + π − , π ± π 0 and π 0 π 0 scattering within the framework of the constituent chiral quark model (CχQM) in the limit of a large number of colours N c and discuss their asymptotic behaviours. The same ππ cross sections are also discussed within the general framework of Large-N c QCD and we show that it is possible to make an Ansatz for the isospin I=1 and I=0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large-N c counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the σ π ± π 0 total (s) cross section predicted by the CχQM with the high energy behaviour predicted by the Large-N c Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and pp-bar scattering total cross sections

Computer calculation of neutron cross sections with Hauser-Feshbach code STAPRE incorporating the hybrid pre-compound emission model

International Nuclear Information System (INIS)

Ivascu, M.

1983-10-01

Computer codes incorporating advanced nuclear models (optical, statistical and pre-equilibrium decay nuclear reaction models) were used to calculate neutron cross sections needed for fusion reactor technology. The elastic and inelastic scattering (n,2n), (n,p), (n,n'p), (n,d) and (n,γ) cross sections for stable molybdenum isotopes Mosup(92,94,95,96,97,98,100) and incident neutron energy from about 100 keV or a threshold to 20 MeV were calculated using the consistent set of input parameters. The hydrogen production cross section which determined the radiation damage in structural materials of fusion reactors can be simply deduced from the presented results. The more elaborated microscopic models of nuclear level density are required for high accuracy calculations

Neutron total scattering cross sections of elemental antimony

Energy Technology Data Exchange (ETDEWEB)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-11-01

Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V.

Neutron total scattering cross sections of elemental antimony

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-11-01

Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V

Study of p-4He Total Reaction cross section using Glauber and Modified Glauber Models

International Nuclear Information System (INIS)

Tag El Din, I.M.A.; Taha, M.M.; Hassan, S.S.A.

2012-01-01

The total nuclear reaction cross-section for p - 4 He in the energy range from 25 to 1000 MeV is calculated within Glauber and modified Glauber models. The modified Glauber model is introduced via both Coulomb trajectory of the projectile and calculation of the effective radius of interaction. The effects of density dependent total cross-section and phase variation of nucleon-nucleon scattering amplitude are studied. It is pointed out that the phase variation of the nucleon-nucleon amplitude plays a significant role in describing σR at E p 2 at e = e0 = 0 and γ=2fm 2 at e = e0 = 0.17fm -3 .

Shape dependency of the extinction and absorption cross sections of dust aerosols modeled as randomly oriented spheroids

Directory of Open Access Journals (Sweden)

R. Wagner

2011-09-01

Full Text Available We present computational results on the shape dependency of the extinction and absorption cross sections of dustlike aerosol particles that were modeled as randomly oriented spheroids. Shape dependent variations in the extinction cross sections are largest in the size regime that is governed by the interference structure. Elongated spheroids best fitted measured extinction spectra of re-dispersed Saharan dust samples. For dust particles smaller than 1.5 μm in diameter and low absorption potential, shape effects on the absorption cross sections are very small.

Temperature-dependent absorption cross sections for hydrogen peroxide vapor

Science.gov (United States)

Nicovich, J. M.; Wine, P. H.

1988-01-01

Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

Proton-air and proton-proton cross sections

Directory of Open Access Journals (Sweden)

Ulrich Ralf

2013-06-01

Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

Threshold law for ionization cross sections in the Temkin-Poet model

International Nuclear Information System (INIS)

Macek, J.H.; Ihra, W.

1997-01-01

An integral representation of wave functions for the Temkin-Poet model of electron impact on atomic hydrogen is given. Approximate wave functions are evaluated analytically for large hyperradius to extract the ionization S-matrix element. An ionization cross section of the form exp[-aE -1/6 +bE 1/6 ], where a and b are positive constants, is derived. The exponential suppression of ionization for small E appears to be the quantum counterpart of the delayed onset of ionization in the classical theory for this model. copyright 1997 The American Physical Society

Cross sections for hadron and lepton production processes

International Nuclear Information System (INIS)

Bhattacharya, R.

1976-01-01

Charged heavy lepton production in proton-proton collisions is studied. Motivated by recent experimental results from the Stanford Linear Accelerator Center a parton model analysis is given of the reaction p + p → L + + L - + x → μ +- + e/ -+ / + neutrinos + x. Results are presented for the total cross section and the differential cross sections with respect to the invariant mass squared of the final charged leptons and the transverse momenta of each one of them. The two-photon mechanism for pair production in colliding beam exeriments is considered. Through the use of mapped invariant integration variables, a reliable exact numerical calculation of the cross section for the production of muon and pion pairs by the two-photon mechanism is provided. Results are given for the exact total cross sections and also the differential cross sections with respect to the invariant mass squared of the pair. These are compared to the results obtained from the equivalent photon approximation method

Multitrajectory eikonal cross sections

International Nuclear Information System (INIS)

Turner, R.E.

1983-01-01

With the use of reference and distorted transition operators, a time-correlation-function representation of the inelastic differential cross section has recently been used to obtain distorted eikonal cross sections. These cross sections involve straight-line and reference classical translational trajectories that are unaffected by any internal-state changes which have occurred during the collision. This distorted eikonal theory is now extended to include effects of internal-state changes on the translational motion. In particular, a different classical trajectory is associated with each pair of internal states. Expressions for these inelastic cross sections are obtained in terms of time-ordered cosine and sine memory functions using the Zwanzig-Feshbach projection-operator method. Explicit formulas are obtained in the time-disordered perturbation approximation

Evaluation of covariance for 238U cross sections

International Nuclear Information System (INIS)

Kawano, Toshihiko; Nakamura, Masahiro; Matsuda, Nobuyuki; Kanda, Yukinori

1995-01-01

Covariances of 238 U are generated using analytic functions for representation of the cross sections. The covariances of the (n,2n) and (n,3n) reactions are derived with a spline function, while the covariances of the total and the inelastic scattering cross section are estimated with a linearized nuclear model calculation. (author)

FEMA DFIRM Cross Sections

Data.gov (United States)

Minnesota Department of Natural Resources — FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally...

Terahertz radar cross section measurements

DEFF Research Database (Denmark)

Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

2010-01-01

We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar...

Collisional-radiative model for neutral helium in plasma. Excitation cross section and singlet-triplet wavefunction mixing

Energy Technology Data Exchange (ETDEWEB)

Goto, Motoshi [National Inst. for Fusion Science, Toki, Gifu (Japan); Fujimoto, Takashi

1997-10-01

We have revised the collisional-radiative (CR) model code of neutral helium (T. Fujimoto, JQSRT 21, 1979). The spin-orbit interaction gives rise to mixing of the wavefunctions of the singlet and triplet states. The degree of the mixing depends on the magnetic field, and at the field strength of the level-anticrossings complete mixing, or complete breakdown of the L-S coupling scheme, occurs. We have approximately incorporated this effect into the code. We have reviewed the excitation cross section data for electron impacts. For transitions starting from the ground state, the recent assessment by the group led by Dr. de Heer is judged satisfactory. For transitions from the metastable levels the assessment by the same group appears rather conservative; there remains a question about the cross section values near the threshold. For transitions between different-l levels within the same multiplicity and same n, a semi-empirical formula based on the Born cross section gives a good agreement with experiment. Proton impacts are also considered for these transitions. We compare the new cross sections with those used in the original version. These cross sections for transitions starting from the metastable levels are fitted by analytical formulas and the parameter values are given. We also give parameter values for the excitation rate coefficient for these transitions as well as for transitions starting from the ground state. With all the above revisions incorporated into the CR model code, we have calculated the energy loss rates and the line intensity ratios for the purpose of plasma diagnostics, where the effect of a magnetic field is noted. The calculated population distribution over excited levels are compared with experiment, and a tentative conclusion is drawn concerning the excitation cross section from the metastable level. (author)

A randomised crossover study to compare the cross-sectional and longitudinal approaches to ultrasound-guided peripheral venepuncture in a model.

Science.gov (United States)

Griffiths, James; Carnegie, Amadeus; Kendall, Richard; Madan, Rajeev

2017-12-01

Ultrasound-guided peripheral intravenous access may present an alternative to central or intraosseous access in patients with difficult peripheral veins. Using venepuncture of a phantom model as a proxy, we investigated whether novice ultrasound users should adopt a cross-sectional or longitudinal approach when learning to access peripheral veins under ultrasound guidance. This result would inform the development of a structured training method for this procedure. We conducted a randomised controlled trial of 30 medical students. Subjects received 35 min of training, then attempted to aspirate 1 ml of synthetic blood from a deep vein in a training model under ultrasound guidance. Subjects attempted both the cross-sectional and longitudinal approaches. Group 1 used cross-sectional first, followed by longitudinal. Group 2 used longitudinal first, then cross-sectional. We measured the time from first puncture of the model's skin to aspiration of fluid, and the number of attempts required. Subjects also reported difficulty ratings for each approach. Paired sample t-tests were used for statistical analysis. The mean number of attempts was 1.13 using the cross-sectional approach, compared with 1.30 using the longitudinal approach (p = 0.17). Mean time to aspiration of fluid was 45.1 s using the cross-sectional approach and 52.8 s using the longitudinal approach (p = 0.43). The mean difficulty score out of 10 was 3.97 for the cross-sectional approach and 3.93 for the longitudinal approach (p = 0.95). We found no significant difference in effectiveness between the cross-sectional and longitudinal approaches to ultrasound-guided venepuncture when performed on a model. We believe that both approaches should be included when teaching ultrasound-guided peripheral vascular access. To confirm which approach would be best in clinical practice, we advocate future testing of both approaches on patients.

Coincidence cross sections within the quasi free break-up model for elastic projectile break-up

International Nuclear Information System (INIS)

Corcalciuc, V.; Jelitto, H.

1991-11-01

Scrutinizing the basic break-up model of Serber we show that it is possible to derive the triple differential cross sections for particle-particle coincidences in analytical form. An alternative interpretation within the opaque version of the model suggests to assign these cross sections to the elastic nonresonant projectile break-up due to the nuclear interaction. Distortion effects by the Coulomb field of the target are included in analogy to the Serber model. Beside the well known single maximum in the break-up spectra double and triple peak structures appear for certain combinations of the observation angles. The model yields reasonable agreement to the given experimental data, concerning the multiple peak structure as well as the order of magnitude for the absolute normalisation. Its application comprises the region of forward emission angles, especially the angular range of the classical Coulomb deflection. (orig.) [de

Measurement of np→dπ0 cross sections very near threshold

International Nuclear Information System (INIS)

Hutcheon, D.A.; Abegg, R.; Greeniaus, L.G.; Miller, C.A.; Korkmaz, E.; Moss, G.A.; Edwards, G.W.R.; Mack, D.; Olsen, W.C.; Ye, Y.

1989-06-01

We have measured np→dπ 0 cross sections at ten beam energies within 16 MeV of threshold. Total cross sections followed closely the relationship σ tot (np→dπ 0 ) = (1/2)[(184±5)η 3 ]μb, where η is the c.m. pion momentum in units of m π c. The differential cross sections are anisotropic at only 1 MeV (c.m.) above threshold. These results are predicted by Faddeev model calculations and by a perturbative model. Our cross sections are in fair agreement with previous π + d→pp data. (Author) 12 refs., tab., 4 figs

Fission cross sections in the intermediate energy region

International Nuclear Information System (INIS)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for 235 U and 238 U compared to intranuclear cascade and statistical model predictions

Fission cross sections in the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. (Los Alamos National Lab., NM (USA)); Carlson, A.D.; Wasson, O.A. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Hill, N.W. (Oak Ridge National Lab., TN (USA))

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

Study of fission cross sections induced by nucleons and pions using the cascade-exciton model CEM95

International Nuclear Information System (INIS)

Yasin, Z.; Shahzad, M. I.

2007-01-01

Nucleon and pion-induced fission cross sections at intermediate and at higher energies are important in current nuclear applications, such as accelerator driven-systems (ADS), in medicine, for effects on electronics etc. In the present work, microscopic fission cross sections induced by nucleons and pions are calculated using the cascade-exciton model code CEM95 for different projectile-target combinations; at various energies and the computed cross sections are compared with the experimental data found in literature. A new approach is used to compute the fission cross sections in which a change of the ratio of the level density parameter in fission to neutron emission channels was taken into account with the change in the incident energy of the projectile. We are unable to describe well the fission cross sections without using this new approach. Proton induced fission cross sections are calculated for targets 1 97Au, 2 08Pb, 2 09Bi, 2 38U and 2 39Pu in the energy range from 20 MeV to 2000 MeV. Neutron induced fission cross sections are computed for 2 38U and 2 39Pu in the energy range from 20 MeV to 200 MeV. Negative pion induced cross sections for fission are calculated for targets 1 97Au and 2 08Pb from 50 MeV to 2500 MeV energy range. The calculated cross sections are essential to build a data library file for accelerator driven systems just like was built for conventional nuclear reactors. The computed values exhibited reasonable agreement with the experimental values found in the literature across a wide range of beam energies

Quantifying and predicting interpretational uncertainty in cross-sections

Science.gov (United States)

Randle, Charles; Bond, Clare; Monaghan, Alison; Lark, Murray

2015-04-01

Cross-sections are often constructed from data to create a visual impression of the geologist's interpretation of the sub-surface geology. However as with all interpretations, this vision of the sub-surface geology is uncertain. We have designed and carried out an experiment with the aim of quantifying the uncertainty in geological cross-sections created by experts interpreting borehole data. By analysing different attributes of the data and interpretations we reflect on the main controls on uncertainty. A group of ten expert modellers at the British Geological Survey were asked to interpret an 11.4 km long cross-section from south-east Glasgow, UK. The data provided consisted of map and borehole data of the superficial deposits and shallow bedrock. Each modeller had a unique set of 11 boreholes removed from their dataset, to which their interpretations of the top of the bedrock were compared. This methodology allowed quantification of how far from the 'correct answer' each interpretation is at 11 points along each interpreted cross-section line; through comparison of the interpreted and actual bedrock elevations in the boreholes. This resulted in the collection of 110 measurements of the error to use in further analysis. To determine the potential control on uncertainty various attributes relating to the modeller, the interpretation and the data were recorded. Modellers were asked to fill out a questionnaire asking for information; such as how much 3D modelling experience they had, and how long it took them to complete the interpretation. They were also asked to record their confidence in their interpretations graphically, in the form of a confidence level drawn onto the cross-section. Initial analysis showed the majority of the experts' interpreted bedrock elevations within 5 metres of those recorded in the withheld boreholes. Their distribution is peaked and symmetrical about a mean of zero, indicating that there was no tendency for the experts to either under

Comparison of integral cross section values of several cross section libraries in the SAND-II format

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.

1976-09-01

A comparison of some integral cross-section values for several cross-section libraries in the SAND-II format is presented. The integral cross-section values are calculated with the aid of the spectrum functions for a Watt fission spectrum, a 1/E spectrum and a Maxwellian spectrum. The libraries which are considered here are CCC-112B, ENDF/B-IV, DETAN74, LAPENAS and CESNEF. These 5 cross-section libraries used have all the SAND-II format. Discrepancies between cross-sections in the different libraries are indicated but not discussed

Habit, Production, and the Cross-Section of Stock Returns

OpenAIRE

Chen, Andrew Y.

2014-01-01

Solutions to the equity premium puzzle should inform us about the cross-section of stock returns. An external habit model with heterogeneous firms reproduces numerous stylized facts about both the equity premium and the value premium. The equity premium is large, time-varying, and linked with consumption volatility. The cross-section of expected returns is log-linear in B/M, and the slope matches the data. The explanation for the value premium lies in the interaction between the cross-section...

Neutron capture cross sections of Kr

Directory of Open Access Journals (Sweden)

Fiebiger Stefan

2017-01-01

Full Text Available Neutron capture and β− -decay are competing branches of the s-process nucleosynthesis path at 85Kr [1], which makes it an important branching point. The knowledge of its neutron capture cross section is therefore essential to constrain stellar models of nucleosynthesis. Despite its importance for different fields, no direct measurement of the cross section of 85Kr in the keV-regime has been performed. The currently reported uncertainties are still in the order of 50% [2, 3]. Neutron capture cross section measurements on a 4% enriched 85Kr gas enclosed in a stainless steel cylinder were performed at Los Alamos National Laboratory (LANL using the Detector for Advanced Neutron Capture Experiments (DANCE. 85Kr is radioactive isotope with a half life of 10.8 years. As this was a low-enrichment sample, the main contaminants, the stable krypton isotopes 83Kr and 86Kr, were also investigated. The material was highly enriched and contained in pressurized stainless steel spheres.

Cross Sections for Inner-Shell Ionization by Electron Impact

Energy Technology Data Exchange (ETDEWEB)

Llovet, Xavier, E-mail: xavier@ccit.ub.edu [Centres Científics i Tecnològics, Universitat de Barcelona, Lluís Solé i Sabarís 1-3, 08028 Barcelona (Spain); Powell, Cedric J. [Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8370 (United States); Salvat, Francesc [Facultat de Física (ECM and ICC), Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Jablonski, Aleksander [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw (Poland)

2014-03-15

An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

Cross sectional moments and portfolio returns: Evidence for select emerging markets

Directory of Open Access Journals (Sweden)

Sanjay Sehgal

2016-09-01

Full Text Available Research does not indicate a consensus on the relationship between idiosyncratic volatility and asset returns. Moreover, the role of cross sectional higher order moments in predicting market returns is relatively unexplored. We show that the cross sectional volatility measure suggested by Garcia et al. is highly correlated with alternative measures of idiosyncratic volatility constructed as variance of errors from the capital asset pricing model and the Fama French model. We find that cross sectional moments help in predicting aggregate market returns in some sample countries and also provide information for portfolio formation, which is more consistent for portfolios sorted on sensitivity to cross sectional skewness.

Evaluation of cross sections for neutron-induced reactions in sodium

International Nuclear Information System (INIS)

Larson, D.C.

1980-09-01

An evaluation of the neutron-induced cross sections of 23 Na has been done for the energy range from 10 -5 eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V, and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables

Relativistic photon-Maxwellian electron cross sections

International Nuclear Information System (INIS)

Wienke, B.R.; Lathrop, B.L.; Devaney, J.J.

1986-01-01

Temperature corrected cross sections, complementing the Klein-Nishina set, are developed for astrophysical, plasma, and transport applications. The set is obtained from a nonlinear least squares fit to the exact photon-Maxwellian electron cross sections, using the static formula as the asymptotic basis. Two parameters are sufficient (two decimal places) to fit the exact cross sections over a range of 0-100 keV in electron temperature, and 0-1 MeV in incident photon energy. The fit is made to the total cross sections, yet the parameters predict both total and differential scattering cross sections well. Corresponding differential energy cross sections are less accurate. An extended fit to (just) the total cross sections, over the temperature and energy range 0-5 MeV, is also described. (author)

Application of an enhanced cross-section interpolation model for highly poisoned LWR core calculations

International Nuclear Information System (INIS)

Palau, J.M.; Cathalau, S.; Hudelot, J.P.; Barran, F.; Bellanger, V.; Magnaud, C.; Moreau, F.

2011-01-01

Burnable poisons are extensively used by Light Water Reactor designers in order to preserve the fuel reactivity potential and increase the cycle length (without increasing the uranium enrichment). In the industrial two-steps (assembly 2D transport-core 3D diffusion) calculation schemes these heterogeneities yield to strong flux and cross-sections perturbations that have to be taken into account in the final 3D burn-up calculations. This paper presents the application of an enhanced cross-section interpolation model (implemented in the French CRONOS2 code) to LWR (highly poisoned) depleted core calculations. The principle is to use the absorbers (or actinide) concentrations as the new interpolation parameters instead of the standard local burnup/fluence parameters. It is shown by comparing the standard (burnup/fluence) and new (concentration) interpolation models and using the lattice transport code APOLLO2 as a numerical reference that reactivity and local reaction rate prediction of a 2x2 LWR assembly configuration (slab geometry) is significantly improved with the concentration interpolation model. Gains on reactivity and local power predictions (resp. more than 1000 pcm and 20 % discrepancy reduction compared to the reference APOLLO2 scheme) are obtained by using this model. In particular, when epithermal absorbers are inserted close to thermal poison the 'shadowing' ('screening') spectral effects occurring during control operations are much more correctly modeled by concentration parameters. Through this outstanding example it is highlighted that attention has to be paid to the choice of cross-section interpolation parameters (burnup 'indicator') in core calculations with few energy groups and variable geometries all along the irradiation cycle. Actually, this new model could be advantageously applied to steady-state and transient LWR heterogeneous core computational analysis dealing with strong spectral-history variations under

Neutrino-nucleus cross sections for oscillation experiments

Science.gov (United States)

Katori, Teppei; Martini, Marco

2018-01-01

Neutrino oscillations physics is entering an era of high precision. In this context, accelerator-based neutrino experiments need a reduction in systematic errors to the level of a few percent. Today, one of the most important sources of systematic errors are neutrino-nucleus cross sections which, in the energy region of hundreds of MeV to a few GeV, are known to a precision not exceeding 20%. In this article we review the present experimental and theoretical knowledge of neutrino-nucleus interaction physics. After introducing neutrino-oscillation physics and accelerator-based neutrino experiments, we give an overview of general aspects of neutrino-nucleus cross sections, from both the theoretical and experimental point of view. Then, we focus on these cross sections in different reaction channels. We start with the quasi-elastic and quasi-elastic-like cross section, placing a special emphasis on the multinucleon emission channel, which has attracted a lot of attention in the last few years. We review the main aspects of the different microscopic models for this channel by discussing analogies and the differences among them. The discussion is always driven by a comparison with the experimental data. We then consider the one-pion production channel where agreement between data and theory remains highly unsatisfactory. We describe how to interpret pion data, and then analyze, in particular, the puzzle related to the difficulty of theoretical models and Monte Carlo to simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive cross sections are also discussed, as well as the comparison between the {ν }μ and {ν }e cross sections, relevant for the charge-conjugation-parity violation experiments. The impact of nuclear effects on the reconstruction of neutrino energy and on the determination of the neutrino-oscillation parameters is also reviewed. Finally, we look to the future by discussing projects and efforts in relation to future detectors, beams

Some sources of the underestimation of evaluated cross section uncertainties

International Nuclear Information System (INIS)

Badikov, S.A.; Gai, E.V.

2003-01-01

The problem of the underestimation of evaluated cross-section uncertainties is addressed. Two basic sources of the underestimation of evaluated cross-section uncertainties - a) inconsistency between declared and observable experimental uncertainties and b) inadequacy between applied statistical models and processed experimental data - are considered. Both the sources of the underestimation are mainly a consequence of existence of the uncertainties unrecognized by experimenters. A model of a 'constant shift' is proposed for taking unrecognised experimental uncertainties into account. The model is applied for statistical analysis of the 238 U(n,f)/ 235 U(n,f) reaction cross-section ratio measurements. It is demonstrated that multiplication by sqrt(χ 2 ) as instrument for correction of underestimated evaluated cross-section uncertainties fails in case of correlated measurements. It is shown that arbitrary assignment of uncertainties and correlation in a simple least squares fit of two correlated measurements of unknown mean leads to physically incorrect evaluated results. (author)

A Pebble Bed Reactor cross section methodology

International Nuclear Information System (INIS)

Hudson, Nathanael H.; Ougouag, Abderrafi M.; Rahnema, Farzad; Gougar, Hans

2009-01-01

A method is presented for the evaluation of microscopic cross sections for the Pebble Bed Reactor (PBR) neutron diffusion computational models during convergence to an equilibrium (asymptotic) fuel cycle. This method considers the isotopics within a core spectral zone and the leakages from such a zone as they arise during reactor operation. The randomness of the spatial distribution of fuel grains within the fuel pebbles and that of the fuel and moderator pebbles within the core, the double heterogeneity of the fuel, and the indeterminate burnup of the spectral zones all pose a unique challenge for the computation of the local microscopic cross sections. As prior knowledge of the equilibrium composition and leakage is not available, it is necessary to repeatedly re-compute the group constants with updated zone information. A method is presented to account for local spectral zone composition and leakage effects without resorting to frequent spectrum code calls. Fine group data are pre-computed for a range of isotopic states. Microscopic cross sections and zone nuclide number densities are used to construct fine group macroscopic cross sections, which, together with fission spectra, flux modulation factors, and zone buckling, are used in the solution of the slowing down balance to generate a new or updated spectrum. The microscopic cross-sections are then re-collapsed with the new spectrum for the local spectral zone. This technique is named the Spectral History Correction (SHC) method. It is found that this method accurately recalculates local broad group microscopic cross sections. Significant improvement in the core eigenvalue, flux, and power peaking factor is observed when the local cross sections are corrected for the effects of the spectral zone composition and leakage in two-dimensional PBR test problems.

Geodesic acoustic modes in noncircular cross section tokamaks

Energy Technology Data Exchange (ETDEWEB)

Sorokina, E. A., E-mail: sorokina.ekaterina@gmail.com; Lakhin, V. P. [National Research Center “Kurchatov Institute,” (Russian Federation); Konovaltseva, L. V. [People’s Friendship University of Russia (Russian Federation); Ilgisonis, V. I. [National Research Center “Kurchatov Institute,” (Russian Federation)

2017-03-15

The influence of the shape of the plasma cross section on the continuous spectrum of geodesic acoustic modes (GAMs) in a tokamak is analyzed in the framework of the MHD model. An expression for the frequency of a local GAM for a model noncircular cross section plasma equilibrium is derived. Amendments to the oscillation frequency due to the plasma elongation and triangularity and finite tokamak aspect ratio are calculated. It is shown that the main factor affecting the GAM spectrum is the plasma elongation, resulting in a significant decrease in the mode frequency.

Dynamic radar cross section measurements of a full-scale aircraft for RCS modelling validation

CSIR Research Space (South Africa)

Van Schalkwyk, Richard F

2017-10-01

Full Text Available In this paper the process followed in generating a high fidelity reference data set for radar cross section (RCS) modelling validation for a full-scale aircraft, is presented. An overview of two dynamic RCS measurement campaigns, involving both...

Electron-collision cross sections for iodine

International Nuclear Information System (INIS)

Zatsarinny, O.; Bartschat, K.; Garcia, G.; Blanco, F.; Hargreaves, L.R.; Jones, D.B.; Murrie, R.; Brunton, J.R.; Brunger, M.J.; Hoshino, M.; Buckman, S.J.

2011-01-01

We present results from a joint experimental and theoretical study of elastic electron scattering from atomic iodine. The experimental results were obtained by subtracting known cross sections from the measured data obtained with a pyrolyzed mixed beam containing a variety of atomic and molecular species. The calculations were performed using both a fully relativistic Dirac B-spline R-matrix (close-coupling) method and an optical model potential approach. Given the difficulty of the problem, the agreement between the two sets of theoretical predictions and the experimental data for the angle-differential and the angle-integrated elastic cross sections at 40 eV and 50 eV is satisfactory.

Integral nucleus-nucleus cross sections

International Nuclear Information System (INIS)

Barashenkov, V.S.; Kumawat, H.

2003-01-01

Expressions approximating the experimental integral cross sections for elastic and inelastic interactions of light and heavy nuclei at the energies up to several GeV/nucleon are presented. The calculated cross sections are inside the corridor of experimental errors or very close to it. Described in detail FORTRAN code and a numerical example of the cross section approximation are also presented

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

Science.gov (United States)

Couture, A.; Casten, R. F.; Cakirli, R. B.

2017-12-01

Background: Neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40 % , and has limited predictive power, with predictions from different models rapidly differing by an order of magnitude a few nucleons from the last measurement. Purpose: To develop a new approach to predicting neutron capture cross sections over broad ranges of nuclei that accounts for their values where known and which has reliable predictive power with small uncertainties for many nuclei where they are unknown. Methods: Experimental neutron capture cross sections were compared to empirical mass observables in regions of similar structure. Results: We present an extremely simple method, based solely on empirical mass observables, that correlates neutron capture cross sections in the critical energy range from a few keV to a couple hundred keV. We show that regional cross sections are compactly correlated in medium and heavy mass nuclei with the two-neutron separation energy. These correlations are easily amenable to predict unknown cross sections, often converting the usual extrapolations to more reliable interpolations. It almost always reproduces existing data to within 25 % and estimated uncertainties are below about 40 % up to 10 nucleons beyond known data. Conclusions: Neutron capture cross sections display a surprisingly strong connection to the two-neutron separation energy, a nuclear structure property. The simple, empirical correlations uncovered provide model-independent predictions of

Evaluation of the (n,xn) and (n,xnf) cross sections for heavy nuclei with the statistical model

International Nuclear Information System (INIS)

Jary, J.

1975-01-01

A method was presented to calculate the (n,xn) and (n,xnf) cross sections for the heavy nuclei having mass numbers of 232 1) without fission, according to the law of conventional statistical models, in the (n,xn) process. Fission can also compete with the emission of neutrons and γ-ray for the nuclei and the excitation energy considered. The fission cross sections of 235 U and 238 U recently evaluated by Sowerby and the fission cross section of 236 U have been used to determine the other parameters needed in the calculation. The fission widths of 239 U and 238 U have been obtained by fitting the first-chance and second-chance fission plateaus of the 238 U cross section. For the fission width of 238 U, good agreement was observed between the authors' results and Landrum and others' experimental data. (Iwase, T.)

Photon-splitting cross sections

International Nuclear Information System (INIS)

Johannessen, A.M.; Mork, K.J.; Overbo, I.

1980-01-01

The differential cross section for photon splitting (scattering of one photon into two photons) in a Coulomb field, obtained earlier by Shima, has been integrated numerically to yield various differential cross sections. Energy spectra differential with respect to the energy of one of the outgoing photons are presented for several values of the primary photon energy. Selected examples of recoil momentum distributions and some interesting doubly or multiply differential cross sections are also given. Values for the total cross section are obtained essentially for all energies. The screening effect caused by atomic electrons is also taken into account, and is found to be important for high energies, as in e + e - pair production. Comparisons with various approximate results obtained by previous authors mostly show fair agreement. We also discuss the possibilities for experimental detection and find the most promising candidate to be a measurement of both photons, and their energies, at a moderately high energy

Total Cross Sections and Event Properties from Real to Virtual Photons

International Nuclear Information System (INIS)

Friberg, Christer; Sjoestrand, Torbjoern

2000-01-01

A model for total cross sections with virtual photons is presented. In particular gamma*-p and gamma*-gamma* cross sections are considered. Our approach extends on a model for photoproduction, where the total cross section is subdivided into three distinct event classes: direct, VMD and anomalous. With increasing photon virtuality, the latter two decrease in importance. Instead Deep Inelastic Scattering dominates, with the direct class being the O(alpha s ) correction thereof. Hence, the model provides a smooth transition between the two regions. By the breakdown into different event classes, one may aim for a complete picture of all event properties. (author)

Mixed Legendre moments and discrete scattering cross sections for anisotropy representation

International Nuclear Information System (INIS)

Calloo, A.; Vidal, J. F.; Le Tellier, R.; Rimpault, G.

2012-01-01

This paper deals with the resolution of the integro-differential form of the Boltzmann transport equation for neutron transport in nuclear reactors. In multigroup theory, deterministic codes use transfer cross sections which are expanded on Legendre polynomials. This modelling leads to negative values of the transfer cross section for certain scattering angles, and hence, the multigroup scattering source term is wrongly computed. The first part compares the convergence of 'Legendre-expanded' cross sections with respect to the order used with the method of characteristics (MOC) for Pressurised Water Reactor (PWR) type cells. Furthermore, the cross section is developed using piecewise-constant functions, which better models the multigroup transfer cross section and prevents the occurrence of any negative value for it. The second part focuses on the method of solving the transport equation with the above-mentioned piecewise-constant cross sections for lattice calculations for PWR cells. This expansion thereby constitutes a 'reference' method to compare the conventional Legendre expansion to, and to determine its pertinence when applied to reactor physics calculations. (authors)

Large Psub(tr) and quark-quark cross section in the dynamical model of factorizing quarks

International Nuclear Information System (INIS)

Kapshay, V.N.; Sidorov, A.V.; Skachkov, N.B.

1978-01-01

Dynamical model of factorizing quarks containing the quark mass as free model parameter was described. Model calculations were compared with the experimental data on the cross section of the inclusive πsup(o) meson production in the proton-proton interaction. It is shown that the results of the paper are in good agreement with experiments

Relativistic three-dimensional Lippmann-Schwinger cross sections for space radiation applications

Science.gov (United States)

Werneth, C. M.; Xu, X.; Norman, R. B.; Maung, K. M.

2017-12-01

Radiation transport codes require accurate nuclear cross sections to compute particle fluences inside shielding materials. The Tripathi semi-empirical reaction cross section, which includes over 60 parameters tuned to nucleon-nucleus (NA) and nucleus-nucleus (AA) data, has been used in many of the world's best-known transport codes. Although this parameterization fits well to reaction cross section data, the predictive capability of any parameterization is questionable when it is used beyond the range of the data to which it was tuned. Using uncertainty analysis, it is shown that a relativistic three-dimensional Lippmann-Schwinger (LS3D) equation model based on Multiple Scattering Theory (MST) that uses 5 parameterizations-3 fundamental parameterizations to nucleon-nucleon (NN) data and 2 nuclear charge density parameterizations-predicts NA and AA reaction cross sections as well as the Tripathi cross section parameterization for reactions in which the kinetic energy of the projectile in the laboratory frame (TLab) is greater than 220 MeV/n. The relativistic LS3D model has the additional advantage of being able to predict highly accurate total and elastic cross sections. Consequently, it is recommended that the relativistic LS3D model be used for space radiation applications in which TLab > 220MeV /n .

Low energy total cross section of 36Ar

International Nuclear Information System (INIS)

Mughabghab, S.F.; Magurno, B.A.

1975-01-01

To compare the predictions of the valence model with measured partial radiative widths of 36 Ar an accurate knowledge of the bound-level parameters is required. This is achieved by carrying out a Breit-Wigner parameter fit to the total cross section of 36 Ar measured by Chrien et al and renormalized to the recommended values of the thermal capture and scattering cross sections. (1 figure, 1 table) (U.S.)

Comparison of integral cross section values of several cross section libraries in the SAND-II format

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.

1978-01-01

A comparison of some integral cross section values for several cross section libraries in the SAND-II format is presented. The integral cross section values are calculated with aid of the spectrum functions for a Watt fission spectrum, a 1/E spectrum and a Maxwellian spectrum. The libraries which are considered here are CCC-112B, ENDF/B-IV, DETAN74, LAPENAS and CESNEF. These 5 cross section libraries used have all the SAND-II format. (author)

Positron induced scattering cross sections for hydrocarbons relevant to plasma

Science.gov (United States)

Singh, Suvam; Antony, Bobby

2018-05-01

This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

single-top quark production cross section using the ATLAS detector

CERN Document Server

Feng, Cunfeng; The ATLAS collaboration

2014-01-01

Measurements of single top-quark production cross section in proton proton collisions at 7 and 8 TeV are presented. In the leading order process, a W boson is exchanged in the t-channel. For this process, for the first time a fiducial cross section measured within the detector acceptance is presented and the modelling uncertainty when extrapolating to the total inclusive cross section is assessed with a large number of different Monte Carlo generators. The result is in good agreement with the most up-to-date theory predictions. Furthermore, the single top-quark and anti-top total production cross sections, their ratio, as well as a measurement of the inclusive production cross section is presented. Differential cross sections are measured as a function of the transverse momentum and the absolute value of the rapidity of top and anti-top quarks. In addition, a measurement of the production cross section of a single top quark in association with a W boson is presented. The s-channel production is explored and l...

Jet inclusive cross sections

International Nuclear Information System (INIS)

Del Duca, V.

1992-11-01

Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons

Optical model calculation of neutron-nucleus scattering cross sections

International Nuclear Information System (INIS)

Smith, M.E.; Camarda, H.S.

1980-01-01

A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs

Electron collision cross sections of mercury

International Nuclear Information System (INIS)

Suzuki, Susumu; Kuzuma, Kiyotaka; Itoh, Haruo

2006-01-01

In this paper, we propose a new collision cross section set for mercury which revises the original set summarized by Hayashi in 1989. Hanne reported three excitation collision cross sections (6 3 P 0 , 6 3 P 1 , 6 3 P 2 ) determined from an electron beam experiment in 1988. As a matter for regret, no attentive consideration was given to combining these three excitation cross sections with the cross section set of Hayashi. Therefore we propose a new set where these three excitation cross sections are included. In this study, other two excitation cross sections (6 1 P 1 , 6 3 D 3 ) except for the three excitation collision cross sections (6 3 P 0 , 6 3 P 1 , 6 3 P 2 ) are taken from the original set of Hayashi. The momentum transfer cross section and the ionization collision cross section are also taken from Hayashi. A Monte Carlo Simulation (MCS) technique is applied for evaluating our new cross section set. The present results of the electron drift velocity and the ionization coefficient are compared to experimental values. Agreement is secured in relation to the electron drift velocity for 1.5 Td 2 ) is the reduced electric field, E (V/cm) is the electric field, N (1/cm 3 ) is the number density of mercury atoms at 0degC, 1 Torr, E/N is also equal to 2.828 x 10 -17 E/p 0 from the relation of the ideal gas equation, p 0 (Torr) is gas pressure at 0degC, 1 Torr=1.33322 x 10 -2 N/cm -2 and 10 -17 V/cm 2 is called 1 Td. Thus it is ensured that our new cross section set is reasonable enough to be used up to 100 eV when considering with the electron drift velocity and the ionization coefficient. (author)

Background-cross-section-dependent subgroup parameters

International Nuclear Information System (INIS)

Yamamoto, Toshihisa

2003-01-01

A new set of subgroup parameters was derived that can reproduce the self-shielded cross section against a wide range of background cross sections. The subgroup parameters are expressed with a rational equation which numerator and denominator are expressed as the expansion series of background cross section, so that the background cross section dependence is exactly taken into account in the parameters. The advantage of the new subgroup parameters is that they can reproduce the self-shielded effect not only by group basis but also by subgroup basis. Then an adaptive method is also proposed which uses fitting procedure to evaluate the background-cross-section-dependence of the parameters. One of the simple fitting formula was able to reproduce the self-shielded subgroup cross section by less than 1% error from the precise evaluation. (author)

Cross-section methodology in SIMMER

International Nuclear Information System (INIS)

Soran, P.D.

1975-11-01

The cross-section methodology incorporated in the SIMMER code is described. Data base for all cross sections is the ENDF/B system with various progressing computer codes to group collapse and modify the group constants which are used in SIMMER. Either infinitely dilute cross sections or the Bondarenko formalism can be used in SIMMER. Presently only a microscopic treatment is considered, but preliminary macroscopic algorithms have been investigated

Cross-section methodology in SIMMER

International Nuclear Information System (INIS)

Soran, P.D.

1976-05-01

The cross-section methodology incorporated in the SIMMER code is described. Data base for all cross sections is the ENDF/B system with various progressing computer codes to group collapse and modify the group constants which are used in SIMMER. Either infinitely dilute cross sections or the Bondarenko formalism can be used in SIMMER. Presently only a microscopic treatment is considered, but preliminary macroscopic algorithms have been investigated

A simplified unified Hauser-Feshbach/Pre-Equilibrium model for calculating double differential cross sections

International Nuclear Information System (INIS)

Fu, C.Y.

1988-01-01

A unified Hauser-Feshbach/Pre-Equilibrium model is extended and simplified. The extension involves the addition of correlations among states of different total quantum numbers (J and J') and the introduction of consistent level density formulas for the H-F and the P-E parts of the calculation. The simplification, aimed at reducing the computational cost, is achieved mainly by keeping only the off-diagonal terms that involve strongly correlated 2p-1h states. A correlation coefficient is introduced to fit the experimental data. The model has been incorporated into the multistep H-F model code TNG. Calculated double differential (n,xn) cross sections at 14 and 25.7 MeV for iron, niobium, and bismuth are in good agreement with experiments. In use at ORNL and JAERI, the TNG code in various stages of development has been applied with success to the evaluation of double differential (n,xn) cross sections from 1 to 20 MeV for the dominant isotopes of chromium, manganese, iron, nickel, copper, and lead. 11 refs., 2 figs

HADES. A computer code for fast neutron cross section from the Optical Model

International Nuclear Information System (INIS)

Guasp, J.; Navarro, C.

1973-01-01

A FORTRAN V computer code for UNIVAC 1108/6 using a local Optical Model with spin-orbit interaction is described. The code calculates fast neutron cross sections, angular distribution, and Legendre moments for heavy and intermediate spherical nuclei. It allows for the possibility of automatic variation of potential parameters for experimental data fitting. (Author) 55 refs

A new modelling of the multigroup scattering cross section in deterministic codes for neutron transport

International Nuclear Information System (INIS)

Calloo, A.A.

2012-01-01

In reactor physics, calculation schemes with deterministic codes are validated with respect to a reference Monte Carlo code. The remaining biases are attributed to the approximations and models induced by the multigroup theory (self-shielding models and expansion of the scattering law using Legendre polynomials) to represent physical phenomena (resonant absorption and scattering anisotropy respectively). This work focuses on the relevance of a polynomial expansion to model the scattering law. Since the outset of reactor physics, the latter has been expanded on a truncated Legendre polynomial basis. However, the transfer cross sections are highly anisotropic, with non-zero values for a very small range of the cosine of the scattering angle. Besides, the finer the energy mesh and the lighter the scattering nucleus, the more exacerbated is the peaked shape of this cross section. As such, the Legendre expansion is less suited to represent the scattering law. Furthermore, this model induces negative values which are non-physical. In this work, various scattering laws are briefly described and the limitations of the existing model are pointed out. Hence, piecewise-constant functions have been used to represent the multigroup scattering cross section. This representation requires a different model for the diffusion source. The discrete ordinates method which is widely employed to solve the transport equation has been adapted. Thus, the finite volume method for angular discretization has been developed and implemented in Paris environment which hosts the S n solver, Snatch. The angular finite volume method has been compared to the collocation method with Legendre moments to ensure its proper performance. Moreover, unlike the latter, this method is adapted for both the Legendre moments and the piecewise-constant functions representations of the scattering cross section. This hybrid-source method has been validated for different cases: fuel cell in infinite lattice

Analysis of proton-induced fragment production cross sections by the Quantum Molecular Dynamics plus Statistical Decay Model

Energy Technology Data Exchange (ETDEWEB)

Chiba, Satoshi; Iwamoto, Osamu; Fukahori, Tokio; Niita, Koji; Maruyama, Toshiki; Maruyama, Tomoyuki; Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-03-01

The production cross sections of various fragments from proton-induced reactions on {sup 56}Fe and {sup 27}Al have been analyzed by the Quantum Molecular Dynamics (QMD) plus Statistical Decay Model (SDM). It was found that the mass and charge distributions calculated with and without the statistical decay have very different shapes. These results also depend strongly on the impact parameter, showing an importance of the dynamical treatment as realized by the QMD approach. The calculated results were compared with experimental data in the energy region from 50 MeV to 5 GeV. The QMD+SDM calculation could reproduce the production cross sections of the light clusters and intermediate-mass to heavy fragments in a good accuracy. The production cross section of {sup 7}Be was, however, underpredicted by approximately 2 orders of magnitude, showing the necessity of another reaction mechanism not taken into account in the present model. (author)

Simplified polynomial representation of cross sections for reactor calculation

International Nuclear Information System (INIS)

Dias, A.M.; Sakai, M.

1985-01-01

It is shown a simplified representation of a cross section library generated by transport theory using the cell model of Wigner-Seitz for typical PWR fuel elements. The effect of burnup evolution through tables of reference cross sections and the effect of the variation of the reactor operation parameters considered by adjusted polynomials are presented. (M.C.K.) [pt

Development of a cross-section methodology and a real-time core model for VVER-1000 simulator application

Energy Technology Data Exchange (ETDEWEB)

Georgieva, Emiliya Lyudmilova

2016-06-06

The novel academic contributions are summarized as follows. A) A cross-section modelling methodology and a cycle-specific cross-section update procedure are developed to meet fidelity requirements applicable to a cycle-specific reactor core simulation, as well as particular customer needs and practices supporting VVER-1000 operation and safety. B) A real-time version of the Nodal Expansion Method code is developed and implemented into Kozloduy 6 full-scope replica control room simulator.

Electron-impact cross sections of Ne

International Nuclear Information System (INIS)

Tsurubuchi, S.; Arakawa, K.; Kinokuni, S.; Motohashi, K.

2000-01-01

Electron-impact absolute emission cross sections were measured for the 3p→3s transitions of Ne. Excitation functions of the 3s→2p first resonance lines were measured in the energy range from the threshold to 1000 eV by a polarization-free optical method and relative cross sections were normalized to the absolute values, (41.0±5.4)x10 -19 cm 2 for the 73.6 nm line and (7.1±1.0)x10 -19 cm 2 for the 74.4 nm line, which were determined at 500 eV. The integrated level-excitation cross sections of Suzuki et al for the 1s 2 and 1s 4 levels were combined with the corresponding 3p→3s cascade cross sections obtained in this paper to give absolute emission cross sections for the resonance lines. The level-excitation cross sections of the 1s 2 and 1s 4 states in Paschen notation were determined from the threshold to 1000 eV by subtracting 3p→3s cascade cross sections from the corresponding 3s→2p emission cross sections of the resonance lines. A large cascade contribution is found in the emission cross section of the resonance lines. It is 28.5% for the 73.6 nm line and 49.6% for the 74.4 nm line at 40 eV, and 17.0 and 61.8%, respectively, at 300 eV. (author)

Measurement of the Standard Model W+W- production cross-section using the ATLAS experiment on the LHC

International Nuclear Information System (INIS)

Zeman, Martin

2014-01-01

Measurements of di-boson production cross-sections are an important part of the physics programme at the CERN Large Hadron Collider. These physics analyses provide the opportunity to probe the electroweak sector of the Standard Model at the TeV scale and could also indicate the existence of new particles or probe beyond the Standard Model physics. The excellent performance of the LHC through years 2011 and 2012 allowed for very competitive measurements. This thesis provides a comprehensive overview of the experimental considerations and methods used in the measurement of the W + W - production cross-section in proton-proton collisions at √s = 7 TeV and 8 TeV. The treatise covers the material in great detail, starting with the introduction of the theoretical framework of the Standard Model and follows with an extensive discussion of the methods implemented in recording and reconstructing physics events in an experiment of this magnitude. The associated online and offline software tools are included in the discussion. The relevant experiments are covered, including a very detailed section about the ATLAS detector. The final chapter of this thesis contains a detailed description of the analysis of the W-pair production in the leptonic decay channels using the datasets recorded by the ATLAS experiment during 2011 and 2012 (Run I). The analyses use 4.60 fb -1 recorded at √s = 7 TeV and 20.28 fb -1 recorded at 8 TeV. The experimentally measured cross section for the production of W bosons at the ATLAS experiment is consistently enhanced compared to the predictions of the Standard Model at centre-of-mass energies of 7 TeV and 8 TeV. The thesis concludes with the presentation of differential cross-section measurement results. (author) [fr

Coherent production on nuclei and measurements of total cross sections for unstable particles

International Nuclear Information System (INIS)

Czyz, W.; Zielinski, M.

1980-01-01

The Koelbig-Margolis Formula is fitted to some explicity nonperturbative models of diffractive production. It is shown that, in spite of the fact that the standard procedure of fitting the integrated cross sections may give acceptable fits, thus obtained ''cross sections of unstable particles'', grossly disagree with the ''true'' cross sections known exactly from the models. (author)

Radar cross section measurements using terahertz waves

DEFF Research Database (Denmark)

Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

2010-01-01

Radar cross sections at terahertz frequencies are measured on scale models of aircrafts. A time domain broadband THz system generates freely propagating THz pulses measured with sub-picosecond time resolution. The THz radiation is generated using fs laser pulses by optical rectification...... in order to measure realistic radar cross sections. RCS polar and azimuthal angle plots of F-16 and F-35 are presented....... in a lithium niobate crystal with application of the tilted wave front method, resulting in high electric field THz pulses with a broad band spectrum from 100 GHz up to 4 THz. The corresponding wave lengths are two orders of magnitude smaller than normal radars and we therefore use scale models of size 5-10 cm...

Neutron cross sections: Book of curves

International Nuclear Information System (INIS)

McLane, V.; Dunford, C.L.; Rose, P.F.

1988-01-01

Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs

Measurement of 76Se and 78Se (γ, n) cross sections

International Nuclear Information System (INIS)

Kitatani, Fumito; Harada, Hideo; Goko, Shinji; Utsunomiya, Hiroaki; Akimune, Hidetoshi; Toyokawa, Hiroyuki; Yamada, Kawakatsu

2011-01-01

The (γ, n) cross sections of Se isotopes ( 76 Se, 78 Se) were measured to supply fundamental data for estimating the inverse reaction cross section, i.e., the 79 Se(n, γ) 80 Se cross section. The enriched samples and a reference 197 Au sample were irradiated with laser-Compton scattering (LCS) γ-rays. The excitation function of each (γ, n) cross section was determined for the energy range from each near neutron separation energy to the threshold energy of (γ, 2n) reaction. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS γ-rays. Systematic (γ, n) cross sections for Se isotopes including 80 Se were compared with those calculated by using a statistical model calculation code TALYS. (author)

Evaluated cross section libraries

International Nuclear Information System (INIS)

Maqurno, B.A.

1976-01-01

The dosimetry tape (ENDF/B-IV tape 412) was issued in a general CSEWG distribution, August 1974. The pointwise cross section data file was tested with specified reference spectra. A group averaged cross section data file (620 groups based on tape 412) was tested with the above spectra and the results are presented in this report

Photoproton cross section for /sup 19/F

Energy Technology Data Exchange (ETDEWEB)

Tsubota, H [Tohoku Univ., Sendai (Japan). Coll. of General Education; Kawamura, N; Oikawa, S; Uegaki, J I

1975-02-01

Proton energy spectra have been measured at 90/sup 0/ for the /sup 19/F(e,e'p)/sup 18/O reaction in the giant resonance region. The (..gamma..,p/sub 0/) and (..gamma..,p/sub 1/) differential cross sections are extracted from the proton energy spectra by using virtual-photon spectra. The integrated differential cross section of the (..gamma..,p/sub 0/) and (..gamma..,p/sub 1/) reactions are 1.80+-0.27 and 0.50+-0.45 MeV-mb/sr, respectively. The results are discussed with the shell model theory by comparing with the (..gamma..,p/sub 0/) cross section of the neighboring 4n-nucleus /sup 20/Ne. A significant increase of the proton yield leaving the non-ground states is found at 25 MeV of the incident electron energy. This is discussed in terms of the core excitation effect.

Total cross section for chloroflouromethanes and CClx radicals by electron impact

International Nuclear Information System (INIS)

Gupta, Dhanoj; Antony, Bobby

2013-01-01

Highlights: ► A model to find total CS for freons and CCl x by e − impact is employed. ► Complex optical potential formalism is used to find total inelastic and elastic CS. ► Result shows very good agreement with previous data wherever available. ► Maiden attempt to find cross section for the CCl x radicals. -- Abstract: We report here the total cross section for chloroflouromethanes namely CCl 3 F (Freon 11), CCl 2 F 2 (Freon 12), CClF 3 (Freon 13), CCl 4 and CCl x (x = 1–3), radicals by electron impact 50 to 5000 eV. The total inelastic and elastic cross sections are obtained employing a complex optical potential formalism and solving the Schrödinger equation through partial wave analysis. The total cross section is obtained as the sum of total inelastic and elastic cross sections. The results obtained are compared with the existing experimental and theoretical data, wherever available. The present result shows reasonable agreement with previous data. For the CCl x radicals, we have predicted the total cross sections for the first time. The data reported here has immense interest to atmospheric and technological plasma modelling

Measurement cross sections for radioisotopes production

International Nuclear Information System (INIS)

Garrido, E.

2011-01-01

New radioactive isotopes for nuclear medicine can be produced using particle accelerators. This is one goal of Arronax, a high energy - 70 MeV - high intensity - 2*350 μA - cyclotron set up in Nantes. A priority list was established containing β - - 47 Sc, 67 Cu - β + - 44 Sc, 64 Cu, 82 Sr/ 82 Rb, 68 Ge/ 68 Ga - and α emitters - 211 At. Among these radioisotopes, the Scandium 47 and the Copper 67 have a strong interest in targeted therapy. The optimization of their productions required a good knowledge of their cross-sections but also of all the contaminants created during irradiation. We launched on Arronax a program to measure these production cross-sections using the Stacked-Foils' technique. It consists in irradiating several groups of foils - target, monitor and degrader foils - and in measuring the produced isotopes by γ-spectrometry. The monitor - nat Cu or nat Ni - is used to correct beam loss whereas degrader foils are used to lower beam energy. We chose to study the nat Ti(p,X) 47 Sc and 68 Zn(p,2p) 67 Cu reactions. Targets are respectively natural Titanium foil - bought from Goodfellow - and enriched Zinc 68 deposited on Silver. In the latter case, Zn targets were prepared in-house - electroplating of 68 Zn - and a chemical separation between Copper and Gallium isotopes has to be made before γ counting. Cross-section values for more than 40 different reactions cross-sections have been obtained from 18 MeV to 68 MeV. A comparison with the Talys code is systematically done. Several parameters of theoretical models have been studied and we found that is not possible to reproduce faithfully all the cross-sections with a given set of parameters. (author)

Handbook of LHC Higgs Cross Sections: 2. Differential Distributions

CERN Document Server

Dittmaier, S; Passarino, G; Tanaka, R; Alekhin, S; Alwall, J; Bagnaschi, E A; Banfi, A; Blumlein, J; Bolognesi, S; Chanon, N; Cheng, T; Cieri, L; Cooper-Sarkar, A M; Cutajar, M; Dawson, S; Davies, G; De Filippis, N; Degrassi, G; Denner, A; D'Enterria, D; Diglio, S; Di Micco, B; Di Nardo, R; Ellis, R K; Farilla, A; Farrington, S; Felcini, M; Ferrera, G; Flechl, M; de Florian, D; Forte, S; Ganjour, S; Garzelli, M V; Gascon-Shotkin, S; Glazov, S; Goria, S; Grazzini, M; Guillet, J -Ph; Hackstein, C; Hamilton, K; Harlander, R; Hauru, M; Heinemeyer, S; Hoche, S; Huston, J; Jackson, C; Jimenez-Delgado, P; Jorgensen, M D; Kado, M; Kallweit, S; Kardos, A; Kauer, N; Kim, H; Kovac, M; Kramer, M; Krauss, F; Kuo, C -M; Lehti, S; Li, Q; Lorenzo, N; Maltoni, F; Mellado, B; Moch, S O; Muck, A; Muhlleitner, M; Nadolsky, P; Nason, P; Neu, C; Nikitenko, A; Oleari, C; Olsen, J; Palmer, S; Paganis, S; Papadopoulos, C G; Petersen, T C; Petriello, F; Petrucci, F; Piacquadio, G; Pilon, E; Potter, C T; Price, J; Puljak, I; Quayle, W; Radescu, V; Rebuzzi, D; Reina, L; Rojo, J; Rosco, D; Salam, G P; Sapronov, A; Schaarschmidt, J; Schonherr, M; Schumacher, M; Siegert, F; Slavich, P; Spira, M; Stewart, I W; Stirling, W J; Stockli, F; Sturm, C; Tackmann, F J; Thorne, R S; Tommasini, D; Torrielli, P; Tramontano, F; Trocsanyi, Z; Ubiali, M; Uccirati, S; Acosta, M Vazquez; Vickey, T; Vicini, A; Waalewijn, W J; Wackeroth, D; Warsinsky, M; Weber, M; Wiesemann, M; Weiglein, G; Yu, J; Zanderighi, G

2012-01-01

This Report summarises the results of the second year's activities of the LHC Higgs Cross Section Working Group. The main goal of the working group was to present the state of the art of Higgs Physics at the LHC, integrating all new results that have appeared in the last few years. The first working group report Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002) focuses on predictions (central values and errors) for total Higgs production cross sections and Higgs branching ratios in the Standard Model and its minimal supersymmetric extension, covering also related issues such as Monte Carlo generators, parton distribution functions, and pseudo-observables. This second Report represents the next natural step towards realistic predictions upon providing results on cross sections with benchmark cuts, differential distributions, details of specific decay channels, and further recent developments.

Nuclear Forensics and Radiochemistry: Cross Sections

Energy Technology Data Exchange (ETDEWEB)

Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-08

The neutron activation of components in a nuclear device can provide useful signatures of weapon design or sophistication. This lecture will cover some of the basics of neutron reaction cross sections. Nuclear reactor cross sections will also be presented to illustrate the complexity of convolving neutron energy spectra with nuclear excitation functions to calculate useful effective reactor cross sections. Deficiencies in the nuclear database will be discussed along with tools available at Los Alamos to provide new neutron cross section data.

Top pair cross section measurements and event modelling with the CMS detector

CERN Document Server

Keaveney, James Michael

2016-01-01

Precision measurements are presented of the top-quark pair inclusive production cross section in proton-proton collisions at the LHC at centre-of-mass energies of 7, 8 and 13 TeV. The data are collected with the CMS experiment during the years 2011, 2012, and 2015. The analyses profit from different top quark final states and make use of events with two, one or no reconstructed charged leptons. In most analyses b-jet identification is used to increase the purity of the selection. The backgrounds are determined using data-driven techniques. The results are combined with each other and compared with theory predictions. Indirect constraints on both the top quark mass and alpha_s are obtained through their relation to the inclusive cross section.Differential top quark pair production cross sections are measured in proton-proton collisions at the LHC at centre-of-mass energies of 7, 8, and 13 TeV, using data collected by the CMS experiment in the years 2011, 2012, and 2015. The differential cross sections are meas...

Differential Top Cross-section Measurements

CERN Document Server

Fenton, Michael James; The ATLAS collaboration

2017-01-01

The top quark is the heaviest known fundamental particle. The measurement of the differential top-quark pair production cross-section provides a stringent test of advanced perturbative QCD calculations. The ATLAS collaboration has performed detailed measurements of those differential cross sections at a centre-of-mass energy of 13 TeV. This talk focuses on differential cross-section measurements in the lepton+jets final state, including using boosted top quarks to probe our understanding of top quark production in the TeV regime.

Neutron cross sections for fusion

International Nuclear Information System (INIS)

Haight, R.C.

1979-10-01

First generation fusion reactors will most likely be based on the 3 H(d,n) 4 He reaction, which produces 14-MeV neutrons. In these reactors, both the number of neutrons and the average neutron energy will be significantly higher than for fission reactors of the same power. Accurate neutron cross section data are therefore of great importance. They are needed in present conceptual designs to calculate neutron transport, energy deposition, nuclear transmutation including tritium breeding and activation, and radiation damage. They are also needed for the interpretation of radiation damage experiments, some of which use neutrons up to 40 MeV. In addition, certain diagnostic measurements of plasma experiments require nuclear cross sections. The quality of currently available data for these applications will be reviewed and current experimental programs will be outlined. The utility of nuclear models to provide these data also will be discussed. 65 references

Gamma-ray production cross sections for MeV neutrons

International Nuclear Information System (INIS)

Kitazawa, Hideo; Harima, Yoshiko; Yamakoshi, Hisao; Sano, Yuji; Kobayashi, Tsuguyuki.

1979-01-01

Gamma-ray production cross section and spectra for 1- to 20-MeV neutrons were theoretically obtained, which were requested for heating calculations, for shielding design calculations, and for material damage estimates. Calculations were carried out for Al, Si, Ca, Fe, Ni, Cu, Nb, Ta, Au, and Pb, using a spin-dependent evaporation model without the parity conservation and including the dipole and quardupole gamma-ray transitions. The results were compared with the experimental data measured in ORNL to confirm the availability of this model in applications. In addition, the effects on the gamma-ray production cross section of the optical potential, level density, yrast level, and radiation width were investigated in detail. The conclusions are: 1) the use of the optical potential which gives the correct total reaction cross section is essential to gamma-ray production calculations, 2) the gamma-ray production cross section is not so sensitive to the choice of level density parameters, 3) the inclusion of yrast levels is necessary in dealing with the competition of the neutron and gamma-ray emissions from highly excited states, and 4) the Brink-Axel type's radiation width is unsuitable to be applied to radiative capture processes. (author)

Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

Directory of Open Access Journals (Sweden)

Meigo Shin-ichiro

2017-01-01

Full Text Available To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x7Be, Al(p,x22Na-22 and Al(p,x24Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data.

Dynamics of Longitudinal Impact in the Variable Cross-Section Rods

Science.gov (United States)

Stepanov, R.; Romenskyi, D.; Tsarenko, S.

2018-03-01

Dynamics of longitudinal impact in rods of variable cross-section is considered. Rods of various configurations are used as elements of power pulse systems. There is no single method to the construction of a mathematical model of longitudinal impact on rods. The creation of a general method for constructing a mathematical model of longitudinal impact for rods of variable cross-section is the goal of the article. An elastic rod is considered with a cross-sectional area varying in powers of law from the longitudinal coordinate. The solution of the wave equation is obtained using the Fourier method. Special functions are introduced on the basis of recurrence relations for Bessel functions for solving boundary value problems. The expression for the square of the norm is obtained taking into account the orthogonality property of the eigen functions with weight. For example, the impact of an inelastic mass along the wide end of a conical rod is considered. The expressions for the displacements, forces and stresses of the rod sections are obtained for the cases of sudden velocity communication and the application of force. The proposed mathematical model makes it possible to carry out investigations of the stress-strain state in rods of variable and constant cross-section for various conditions of dynamic effects.

Total Cross Sections at current/Future Colliders, conventional models and QCD

CERN Document Server

Fazal-e-Aleem, M

1999-01-01

Rise in total cross sections for elastic scattering generated immense interest both for experimental measurements and theoretical investigations. How will total cross section behave at LHC and Cosmic Ray energies is therefore in the limelight of our future measurements. Theoretical studies become even more interesting when we take into consideration the ratio of real and imaginary parts of the scattering amplitudes. We will briefly undertake the current results and future prospects in the light of conventional as well as QCD-based phenomenology.

Activation cross section data file, (1)

International Nuclear Information System (INIS)

Yamamuro, Nobuhiro; Iijima, Shungo.

1989-09-01

To evaluate the radioisotope productions due to the neutron irradiation in fission of fusion reactors, the data for the activation cross sections ought to be provided. It is planning to file more than 2000 activation cross sections at final. In the current year, the neutron cross sections for 14 elements from Ni to W have been calculated and evaluated in the energy range 10 -5 to 20 MeV. The calculations with a simplified-input nuclear cross section calculation system SINCROS were described, and another method of evaluation which is consistent with the JENDL-3 were also mentioned. The results of cross section calculation are in good agreement with experimental data and they were stored in the file 8, 9 and 10 of ENDF/B format. (author)

Self-scattering cross-section of molecules in a beam

International Nuclear Information System (INIS)

Lou, Y.S.

1974-01-01

Molecular collision cross-section has always been measured by the beam scattering method, or by the measurements of thermal conductivity and/or viscosity coefficient, etc. The cross-section thus obtained has been found to be different, qualitatively, from that of the self-scattering of the molecules moving within a molecular beam. By perturbing the zeroth order solution of the Boltzmann equation with a B-G-K kinetic model for the gas upstream to the orifice, and performing particle scattering calculation for molecules within the beam downstream to the orifice, such self-scattering collision cross-section can be determined from the experimental data of velocity distribution functions of molecules in the beam

Limit Theory for Panel Data Models with Cross Sectional Dependence and Sequential Exogeneity.

Science.gov (United States)

Kuersteiner, Guido M; Prucha, Ingmar R

2013-06-01

The paper derives a general Central Limit Theorem (CLT) and asymptotic distributions for sample moments related to panel data models with large n . The results allow for the data to be cross sectionally dependent, while at the same time allowing the regressors to be only sequentially rather than strictly exogenous. The setup is sufficiently general to accommodate situations where cross sectional dependence stems from spatial interactions and/or from the presence of common factors. The latter leads to the need for random norming. The limit theorem for sample moments is derived by showing that the moment conditions can be recast such that a martingale difference array central limit theorem can be applied. We prove such a central limit theorem by first extending results for stable convergence in Hall and Hedye (1980) to non-nested martingale arrays relevant for our applications. We illustrate our result by establishing a generalized estimation theory for GMM estimators of a fixed effect panel model without imposing i.i.d. or strict exogeneity conditions. We also discuss a class of Maximum Likelihood (ML) estimators that can be analyzed using our CLT.

Unobserved Heterogeneity in the Binary Logit Model with Cross-Sectional Data and Short Panels

DEFF Research Database (Denmark)

Holm, Anders; Jæger, Mads Meier; Pedersen, Morten

This paper proposes a new approach to dealing with unobserved heterogeneity in applied research using the binary logit model with cross-sectional data and short panels. Unobserved heterogeneity is particularly important in non-linear regression models such as the binary logit model because, unlike...... in linear regression models, estimates of the effects of observed independent variables are biased even when omitted independent variables are uncorrelated with the observed independent variables. We propose an extension of the binary logit model based on a finite mixture approach in which we conceptualize...

Fault-related-folding structure and reflection seismic sections. Construction of earth model using balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 1. Balanced cross section wo mochiita chika model no kochiku

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, T; Tamagawa, T [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

1997-05-27

Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. The viscous matter flows and deforms for the formation of an anticline on the ramp. Such enables the reproduction of a fault-bend fold formation process, and helpful discussion may be furthered on the dynamic aspect of this simulation. 5 refs., 4 figs.

Porosity effects in the neutron total cross section of graphite

International Nuclear Information System (INIS)

Santisteban, J. R; Dawidowski, J; Petriw, S. N

2009-01-01

Graphite has been used in nuclear reactors since the birth of the nuclear industry due to its good performance as a neutron moderator material. Graphite is still an option as moderator for generation IV reactors due to its good mechanical and thermal properties at high operation temperatures. So, there has been renewed interest in a revision of the computer libraries used to describe the neutron cross section of graphite. For sub-thermal neutron energies, polycrystalline graphite shows a larger total cross section (between 4 and 8 barns) than predicted by existing theoretical models (0.2 barns). In order to investigate the origin of this discrepancy we measured the total cross section of graphite samples of three different origins, in the energy range from 0.001 eV to 10 eV. Different experimental arrangements and sample treatments were explored, to identify the effect of various experimental parameters on the total cross section measurement. The experiments showed that the increase in total cross section is due to neutrons scattered around the forward direction. We associate these small-angle scattered neutrons (SANS) to the porous structure of graphite, and formulate a very simple model to compute its contribution to the total cross section of the material. This results in an analytic expression that explicitly depends on the density and mean size of the pores, which can be easily incorporated in nuclear library codes. [es

Determination of Ultimate Torque for Multiply Connected Cross Section Rod

Directory of Open Access Journals (Sweden)

V. L. Danilov

2015-01-01

Full Text Available The aim of this work is to determine load-carrying capability of the multiply cross-section rod. This calculation is based on the model of the ideal plasticity of the material, so that the desired ultimate torque is a torque at which the entire cross section goes into a plastic state.The article discusses the cylindrical multiply cross-section rod. To satisfy the equilibrium equation and the condition of plasticity simultaneously, two stress function Ф and φ are introduced. By mathematical transformations it has been proved that Ф is constant along the path, and a formula to find its values on the contours has been obtained. The paper also presents the rationale of the line of stress discontinuity and obtained relationships, which allow us to derive the equations break lines for simple interaction of neighboring circuits, such as two lines, straight lines and circles, circles and a different sign of the curvature.After substitution into the boundary condition at the end of the stress function Ф and mathematical transformations a formula is obtained to determine the ultimate torque for the multiply cross-section rod.Using the doubly connected cross-section and three-connected cross-section rods as an example the application of the formula of ultimate torque is studied.For doubly connected cross-section rod, the paper offers a formula of the torque versus the radius of the rod, the aperture radius and the distance between their centers. It also clearly demonstrates the torque dependence both on the ratio of the radii and on the displacement of hole. It is shown that the value of the torque is more influenced by the displacement of hole, rather than by the ratio of the radii.For the three-connected cross-section rod the paper shows the integration feature that consists in selection of a coordinate system. As an example, the ultimate torque is found by two methods: analytical one and 3D modeling. The method of 3D modeling is based on the Nadai�

Improvements on burnup chain model and group cross section library in the SRAC system

International Nuclear Information System (INIS)

Akie, Hiroshi; Okumura, Keisuke; Takano, Hideki; Ishiguro, Yukio; Kaneko, Kunio.

1992-01-01

Data and functions of the cell burnup calculation of the SRAC system were revised to improve mainly the accuracy of the burnup calculation of high conversion light water reactors (HCLWRs). New burnup chain models were developed in order to treat fission products (FPs) and actinide nuclides in detail. Group cross section library, SRACLIB-JENDL2, was generated based on JENDL-2 nuclear data file. In generating this library, emphasis was placed on FPs and actinides. Also revised were the data such as the average energy release per fission for various actinides. These improved data were verified by performing the burnup analysis of PWR spent fuels. Some new functions were added to the SRAC system for the convenience to yield macroscopic cross sections used in the core burnup process. (author)

Utilization of cross-section covariance data in FBR core nuclear design and cross-section adjustment

International Nuclear Information System (INIS)

Ishikawa, Makoto

1994-01-01

In the core design of large fast breeder reactors (FBRs), it is essentially important to improve the prediction accuracy of nuclear characteristics from the viewpoint of both reducing cost and insuring reliability of the plant. The cross-section errors, that is, covariance data are one of the most dominant sources for the prediction uncertainty of the core parameters, therefore, quantitative evaluation of covariance data is indispensable for FBR core design. The first objective of the present paper is to introduce how the cross-section covariance data are utilized in the FBR core nuclear design works. The second is to delineate the cross-section adjustment study and its application to an FBR design, because this improved design method markedly enhances the needs and importance of the cross-section covariance data. (author)

Validation of cross sections for Monte Carlo simulation of the photoelectric effect

CERN Document Server

Han, Min Cheol; Pia, Maria Grazia; Basaglia, Tullio; Batic, Matej; Hoff, Gabriela; Kim, Chan Hyeong; Saracco, Paolo

2016-01-01

Several total and partial photoionization cross section calculations, based on both theoretical and empirical approaches, are quantitatively evaluated with statistical analyses using a large collection of experimental data retrieved from the literature to identify the state of the art for modeling the photoelectric effect in Monte Carlo particle transport. Some of the examined cross section models are available in general purpose Monte Carlo systems, while others have been implemented and subjected to validation tests for the first time to estimate whether they could improve the accuracy of particle transport codes. The validation process identifies Scofield's 1973 non-relativistic calculations, tabulated in the Evaluated Photon Data Library(EPDL), as the one best reproducing experimental measurements of total cross sections. Specialized total cross section models, some of which derive from more recent calculations, do not provide significant improvements. Scofield's non-relativistic calculations are not surp...

Is the quasielastic pion cross section really bigger than the pion-nucleus reaction cross section

International Nuclear Information System (INIS)

Silbar, R.R.

1979-01-01

It is shown that soft pion charge exchanges may increase the inclusive (π + ,π 0 ') cross section, relative to the total quasielastic (π + ,π + ') cross section, by as much as a factor of two. 4 references

From ZZ to ZH: How Low Can These Cross Sections Go or Everybody, Let's Cross Section Limbo

International Nuclear Information System (INIS)

Strauss, Emanuel Alexandre

2009-01-01

We report on two searches performed at the D0 detector at the Fermi National Laboratory. The first is a search for Z di-boson production with a theoretical cross section of 1.4 pb. The search was performed on 2.6 fb -1 of data and contributed to the first observation of ZZ production at a hadron collider. The second is a search for a low mass Standard Model Higgs in 4.2 fb -1 of data. The Higgs boson is produced in association with a Z boson where the Higgs decays hadronically and the Z decays to two leptons. The ZZ search was performed in both the di-electron and di-muon channels. For the ZH search, we will focus on the muonic decays where we expanded the traditional coverage by considering events in which one of the two muons fails the selection requirement, and is instead reconstructed as an isolated track. We consider Higgs masses between 100 and 150 GeV, with theoretical cross sections ranging from 0.17 to 0.042 pb, and set upper limits on the ZH production cross-section at 95% confidence level

JENDL gas-production cross section file

International Nuclear Information System (INIS)

Nakagawa, Tsuneo; Narita, Tsutomu

1992-05-01

The JENDL gas-production cross section file was compiled by taking cross-section data from JENDL-3 and by using the ENDF-5 format. The data were given to 23 nuclei or elements in light nuclei and structural materials. Graphs of the cross sections and brief description on their evaluation methods are given in this report. (author)

Differential cross sections for neutrino scattering on 12C

International Nuclear Information System (INIS)

Kolbe, E.

1996-01-01

Differential cross sections for neutrino scattering on 12 C are calculated within the (continuum) random phase approximation model. The charged current (ν e ,e - ) and (ν μ ,μ - ) capture reactions on 12 C are measured by the LSND Collaboration at LAMPF. We investigate and discuss the merits of such studies, especially the information that can be extracted from data for differential neutrino scattering cross sections. copyright 1996 The American Physical Society

Development of a cross-section based stream package for MODFLOW

Science.gov (United States)

Ou, G.; Chen, X.; Irmak, A.

2012-12-01

Accurate simulation of stream-aquifer interactions for wide rivers using the streamflow routing package in MODFLOW is very challenging. To better represent a wide river spanning over multiple model grid cells, a Cross-Section based streamflow Routing (CSR) package is developed and incorporated into MODFLOW to simulate the interaction between streams and aquifers. In the CSR package, a stream segment is represented as a four-point polygon instead of a polyline which is traditionally used in streamflow routing simulation. Each stream segment is composed of upstream and downstream cross-sections. A cross-section consists of a number of streambed points possessing coordinates, streambed thicknesses and streambed hydraulic conductivities to describe the streambed geometry and hydraulic properties. The left and right end points are used to determine the locations of the stream segments. According to the cross-section geometry and hydraulic properties, CSR calculates the new stream stage at the cross-section using the Brent's method to solve the Manning's Equation. A module is developed to automatically compute the area of the stream segment polygon on each intersected MODFLOW grid cell as the upstream and downstream stages change. The stream stage and streambed hydraulic properties of model grids are interpolated based on the streambed points. Streambed leakage is computed as a function of streambed conductance and difference between the groundwater level and stream stage. The Muskingum-Cunge flow routing scheme with variable parameters is used to simulate the streamflow as the groundwater (discharge or recharge) contributes as lateral flows. An example is used to illustrate the capabilities of the CSR package. The result shows that the CSR is applicable to describing the spatial and temporal variation in the interaction between streams and aquifers. The input data become simple due to that the internal program automatically interpolates the cross-section data to each

Doppler broadening of cross sections

International Nuclear Information System (INIS)

Buckler, P.A.C.; Pull, I.C.

1962-12-01

Expressions for temperature dependent cross-sections in terms of resonance parameters are obtained, involving generalisations of the conventional Doppler functions, ψ and φ. Descriptions of Fortran sub-routines, which calculate broadened cross-sections in accordance with the derived formulae, are included. (author)

Computational models for interpretation of wave function imaging in cross-sectional STM of quantum dots

NARCIS (Netherlands)

Maksym, P.A.; Roy, M.; Wijnheijmer, A.P.; Koenraad, P.M.

2008-01-01

Computational models are used to investigate the role of electron-electron interactions in cross-sectional STM of cleaved quantum dots. If correlation effects are weak, the tunnelling current reflects the nodal structure of the non-interacting dot states. If correlation is strong, peaks in the

A dissociative electron attachment cross-section estimator

International Nuclear Information System (INIS)

Munro, James J; Harrison, Stephen; Fujimoto, Milton M; Tennyson, Jonathan

2012-01-01

Dissociative electron attachment (DEA) is the major process where molecules are destroyed in low-energy plasmas. DEA cross sections are therefore important for a whole variety of applications but are both hard to measure or compute accurately. A method for estimating DEA cross sections based a simple resonance plus survival model is presented. Test results are presented for DEA of molecular oxygen and molecular chlorine, for which experimental measurements are available for comparison, and SiBr and SiBr 2 , for which no previous data is available. The estimator has been implemented as part of Quantemol-N expert system which uses the R-matrix method to predict resonance positions and widths.

Total Cross Section in $\\gamma\\gamma$ Collisions at LEP

CERN Document Server

Acciarri, M.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Ambrosi, G.; Anderhub, H.; Andreev, Valery P.; Angelescu, T.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, L.; Balandras, A.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Bhattacharya, S.; Biasini, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Buffini, A.; Buijs, A.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.M.; Casaus, J.; Castellini, G.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Cesaroni, F.; Chamizo, M.; Chang, Y.H.; Chaturvedi, U.K.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Civinini, C.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; Cotorobai, F.; de la Cruz, B.; Csilling, A.; Cucciarelli, S.; Dai, T.S.; van Dalen, J.A.; D'Alessandro, R.; de Asmundis, R.; Deglon, P.; Degre, A.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; van Dierendonck, D.; Dionisi, C.; Dittmar, M.; Dominguez, A.; Doria, A.; Dova, M.T.; Duchesneau, D.; Dufournaud, D.; Duinker, P.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Erne, F.C.; Ewers, A.; Extermann, P.; Fabre, M.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gau, S.S.; Gentile, S.; Gheordanescu, N.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hasan, A.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hidas, P.; Hirschfelder, J.; Hofer, H.; Holzner, G.; Hoorani, H.; Hou, S.R.; Hu, Y.; Iashvili, I.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Khan, R.A.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, D.; Kim, J.K.; Kirkby, Jasper; Kiss, D.; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Kopp, A.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Krenz, W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, H.J.; Le Goff, J.M.; Leiste, R.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Lubelsmeyer, K.; Luci, C.; Luckey, David; Lugnier, L.; Luminari, L.; Lustermann, W.; Ma, W.G.; Maity, M.; Malgeri, L.; Malinin, A.; Mana, C.; Mangeol, D.; Mans, J.; Marian, G.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; von der Mey, M.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Moulik, T.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nisati, A.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Oulianov, A.; Palomares, C.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Paramatti, R.; Park, H.K.; Park, I.H.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Pothier, J.; Prokofev, D.O.; Prokofiev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M.A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Raven, G.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Rodin, J.; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Roux, B.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Sanders, M.P.; Schafer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schopper, H.; Schotanus, D.J.; Schwering, G.; Sciacca, C.; Seganti, A.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Smith, B.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stone, A.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Sztaricskai, T.; Tang, X.W.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Uchida, Y.; Ulbricht, J.; Valente, E.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobov, A.A.; Vorvolakos, A.; Wadhwa, M.; Wallraff, W.; Wang, M.; Wang, X.L.; Wang, Z.M.; Weber, A.; Weber, M.; Wienemann, P.; Wilkens, H.; Wu, S.X.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Ye, J.B.; Yeh, S.C.; Zalite, A.; Zalite, Yu.; Zhang, Z.P.; Zhu, G.Y.; Zhu, R.Y.; Zichichi, A.; Zilizi, G.; Zimmermann, B.; Zoller, M.

2001-01-01

The reaction e+e- -> e+e- gamma* gamma* -> e+e- hadrons for quasi-real photons is studied using data from root(s) = 183 GeV up to 202 GeV. Results on the total cross sections sigma(e+e- -> e+e- hadrons) and sigma(+e- gamma* gamma* -> e+e- hadrons) are given for the two-photon centre-of-mass energies 5 GeV < Wgammagamma < 185 GeV. The total cross section of two real photons is described by a Regge parametrisation. We observe a steeper rise with the two-photon centre-of-mass energy as compared to the hadron-hadron and the photon-proton cross sections. The data are also compared to the expectations of different theoretical models.

Improvement of Axial Reflector Cross Section Generation Model for PWR Core Analysis

Energy Technology Data Exchange (ETDEWEB)

Shim, Cheon Bo; Lee, Kyung Hoon; Cho, Jin Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

This paper covers the study for improvement of axial reflector XS generation model. In the next section, the improved 1D core model is represented in detail. Reflector XS generated by the improved model is compared to that of the conventional model in the third section. Nuclear design parameters generated by these two XS sets are also covered in that section. Significant of this study is discussed in the last section. Two-step procedure has been regarded as the most practical approach for reactor core designs because it offers core design parameters quite rapidly within acceptable range. Thus this approach is adopted for SMART (System-integrated Modular Advanced Reac- Tor) core design in KAERI with the DeCART2D1.1/ MASTER4.0 (hereafter noted as DeCART2D/ MASTER) code system. Within the framework of the two-step procedure based SMART core design, various researches have been studied to improve the core design reliability and efficiency. One of them is improvement of reflector cross section (XS) generation models. While the conventional FA/reflector two-node model used for most core designs to generate reflector XS cannot consider the actual configuration of fuel rods that intersect at right angles to axial reflectors, the revised model reflects the axial fuel configuration by introducing the radially simplified core model. The significance of the model revision is evaluated by observing HGC generated by DeCART2D, reflector XS, and core design parameters generated by adopting the two models. And it is verified that about 30 ppm CBC error can be reduced and maximum Fq error decreases from about 6 % to 2.5 % by applying the revised model. Error of AO and axial power shapes are also reduced significantly. Therefore it can be concluded that the simplified 1D core model improves the accuracy of the axial reflector XS and leads to the two-step procedure reliability enhancement. Since it is hard for core designs to be free from the two-step approach, it is necessary to find

Elastic and inelastic vibrational cross sections for positron scattering by carbon monoxide

Energy Technology Data Exchange (ETDEWEB)

Tenfen, W. [Departamento de Física, Universidade Federal da Fronteira Sul, 85770-000, Realeza, Paraná (Brazil); Arretche, F., E-mail: fartch@gmail.com [Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina (Brazil); Michelin, S.E.; Mazon, K.T. [Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina (Brazil)

2015-11-01

The vibrational cross sections of the CO molecule induced by positron impact is the focus of this work. The positron–molecule interaction is represented by the static potential plus a model potential designed to take into account the positron–target correlations. To calculate the vibrational cross sections, we applied the multichannel version of the continued fractions method in the close-coupling scheme. We present vibrational excitation cross sections and elastic ones, for the ground and excited vibrational states. The results are interpreted in terms of the vibrational coupling-scheme used in the scattering model.

Cox proportional hazards models have more statistical power than logistic regression models in cross-sectional genetic association studies

NARCIS (Netherlands)

van der Net, Jeroen B.; Janssens, A. Cecile J. W.; Eijkemans, Marinus J. C.; Kastelein, John J. P.; Sijbrands, Eric J. G.; Steyerberg, Ewout W.

2008-01-01

Cross-sectional genetic association studies can be analyzed using Cox proportional hazards models with age as time scale, if age at onset of disease is known for the cases and age at data collection is known for the controls. We assessed to what degree and under what conditions Cox proportional

Evaluation of the neutron and gamma-ray production cross-sections for 55Mn

International Nuclear Information System (INIS)

Takahashi, H.

1974-11-01

The evaluation of neutron and gamma production cross sections for manganese-55 from 1.0 (10) -5 eV to 20.0 MeV for ENDF/ B-IV is summarized. Included are resonance parameters, neutron cross sections, angular and energy distribution of secondary neutrons, gamma multiplicities and transition probability array, gamma angular and energy distributions, nuclear model calculations, uncertainty estimates of cross sections, and evaluated cross sections. (U.S.)

Aquelarre. A computer code for fast neutron cross sections from the statistical model

International Nuclear Information System (INIS)

Guasp, J.

1974-01-01

A Fortran V computer code for Univac 1108/6 using the partial statistical (or compound nucleus) model is described. The code calculates fast neutron cross sections for the (n, n'), (n, p), (n, d) and (n, α reactions and the angular distributions and Legendre moments.for the (n, n) and (n, n') processes in heavy and intermediate spherical nuclei. A local Optical Model with spin-orbit interaction for each level is employed, allowing for the width fluctuation and Moldauer corrections, as well as the inclusion of discrete and continuous levels. (Author) 67 refs

Cross-sectional anatomy for computed tomography

International Nuclear Information System (INIS)

Farkas, M.L.

1988-01-01

This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations

Electron transport in silicon nanowires having different cross-sections

Directory of Open Access Journals (Sweden)

Muscato Orazio

2016-06-01

Full Text Available Transport phenomena in silicon nanowires with different cross-section are investigated using an Extended Hydrodynamic model, coupled to the Schrödinger-Poisson system. The model has been formulated by closing the moment system derived from the Boltzmann equation on the basis of the maximum entropy principle of Extended Thermodynamics, obtaining explicit closure relations for the high-order fluxes and the production terms. Scattering of electrons with acoustic and non polar optical phonons have been taken into account. The bulk mobility is evaluated for square and equilateral triangle cross-sections of the wire.

Density-dependent expressions for photoionization cross-sections

International Nuclear Information System (INIS)

Sun Weiguo; Ma Xiaoguang; Cheng Yansong

2004-01-01

Alternative expressions for photoionization cross-sections and dielectric influence functions are suggested to study the photoionization cross-sections of atoms in solid system. The basic picture is that the photoionization cross-section of atoms in a real system can be described as the coupling between quantum quantity (QQ) and classical quantity (CQ) parts. The QQ part represents the photoionization cross-sections of an isolated particle, while the CQ part may represent most of the important influence of the macroscopic effects (e.g., the interactions of all surrounding polarized particles, and the dielectric property, etc.) on the photoionization cross-sections. The applications to the barium system show that the number-density-dependent new photoionization formula not only obtains the same cross-sections as those from the first order approximation for ideal gas, but also can generate the cross-sections for solid barium by transforming those of ideal gas of the same species using the dielectric influence function

Density-dependent expressions for photoionization cross-sections

Energy Technology Data Exchange (ETDEWEB)

Sun Weiguo; Ma Xiaoguang; Cheng Yansong

2004-06-07

Alternative expressions for photoionization cross-sections and dielectric influence functions are suggested to study the photoionization cross-sections of atoms in solid system. The basic picture is that the photoionization cross-section of atoms in a real system can be described as the coupling between quantum quantity (QQ) and classical quantity (CQ) parts. The QQ part represents the photoionization cross-sections of an isolated particle, while the CQ part may represent most of the important influence of the macroscopic effects (e.g., the interactions of all surrounding polarized particles, and the dielectric property, etc.) on the photoionization cross-sections. The applications to the barium system show that the number-density-dependent new photoionization formula not only obtains the same cross-sections as those from the first order approximation for ideal gas, but also can generate the cross-sections for solid barium by transforming those of ideal gas of the same species using the dielectric influence function.

Measured and evaluated neutron cross sections of elemental bismuth

International Nuclear Information System (INIS)

Smith, A.; Guenther, P.; Smith, D.; Whalen, J.; Howerton, R.

1980-04-01

Neutron total cross sections of elemental bismuth are measured with broad resolution from 1.2 to 4.5 MeV to accuracies of approx. = 1%. Neutron-differential-elastic-scattering cross sections of bismuth are measured from 1.5 to 4.0 MeV at incident neutron energy intervals of approx.< 0.2 MeV over the scattered-neutron angular range approx. = 20 to 160 deg. Differential neutron cross sections for the excitation of observed states in bismuth at 895 +- 12, 1606 +- 14, 2590 +- 15, 2762 +- 29, 3022 +- 21, and 3144 +- 15 keV are determined at incident neutron energies up to 4.0 MeV. An optical-statistical model is deduced from the measured values. This model, the present experimental results, and information available elsewhere in the literature are used to construct a comprehensive evaluated nuclear data file for elemental bismuth in the ENDF format. The evaluated file is particularly suited to the neutronic needs of the fusion-fission hybrid designer. 87 references, 10 figures, 6 tables

Fast-neutron scattering cross sections of elemental zirconium

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.

1982-12-01

Differential neturon-elastic-scattering cross sections of elemental zirconium are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV. Inelastic-neutron-scattering cross sections corresponding to the excitation of levels at observed energies of: 914 +- 25, 1476 +- 37, 1787 +- 23, 2101 +- 26, 2221 +- 17, 2363 +- 14, 2791 +- 15 and 3101 +- 25 keV are determined. The experimental results are interpreted in terms of the optical-statistical model and are compared with corresponding quantities given in ENDF/B-V

Recent progress in fast neutron activation cross section data

International Nuclear Information System (INIS)

Michaelis, W.

A brief review is given of some significant investigations performed during the past few years in the area of fast neutron activation cross sections that may be relevant for the use of nuclear techniques in the exploration of mineral resources, in process and quality control in industry as well as for general analytical purposes. Differential capture cross sections are considered for the natural elements or isotopes of Fe, Cu, Se, Y, Nb, Cd, In, Gd, W, Os and Au. Some of the data are compared with statistical model calculations. Experimental and evaluated average cross sections for capture and threshold reactions in the spontaneous fission neutron field of 252 Cf are reviewed taking into account the elements or isotopes of Mg, Al, Si, S, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Cd, In, Ba, Ta and Au. A summary of recent studies of differential cross sections for threshold reactions comprises data on Al, Si, S, Ti, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ta, W and Au. Besides experimental investigations, evaluations and theoretical model calculations are considered. Cross sections at 14 MeV and in the region around this energy are reviewed for Na, Mg, Al, Cl, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Zr, Nb, In, Er, Yb, Ta, W, Os, Ir, Au and Pb. Particular emphasis is laid on (n,p), (n,2n) and (n,α) reactions. (n,n') reactions are allowed for if the half-life of the metastable state excited permits elemental analyses by common experimental techniques. (orig.)

Tropical and Subtropical Cloud Transitions in Weather and Climate Prediction Models: The GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)

Science.gov (United States)

Teixeira, J.; Cardoso, S.; Bonazzola, M.; Cole, J.; DeGenio, A.; DeMott, C.; Franklin, C.; Hannay, C.; Jakob, C.; Jiao, Y.;

Total neutron cross section of lead

International Nuclear Information System (INIS)

Kanda, K.; Aizawa, O.

1976-01-01

The total thermal-neutron cross section of natural lead under various physical conditions was measured by the transmission method. It became clear that the total cross section at room temperature previously reported is lower than the present data. The total cross section at 400, 500, and 600 0 C, above the melting point of lead, 327 0 C, was also measured, and the changes in the cross section as a function of temperature were examined, especially near and below the melting point. The data obtained for the randomly oriented polycrystalline state at room temperature were in reasonable agreement with the theoretical values calculated by the THRUSH and UNCLE-TOM codes

EMPIRE-II 2.18, Comprehensive Nuclear Model Code, Nucleons, Ions Induced Cross-Sections

International Nuclear Information System (INIS)

Herman, Michal Wladyslaw; Panini, Gian Carlo

2003-01-01

1 - Description of program or function: EMPIRE-II is a flexible code for calculation of nuclear reactions in the frame of combined optical, Multi-step Direct (TUL), Multi-step Compound (NVWY) and statistical (Hauser-Feshbach) models. Incident particle can be a nucleon or any nucleus(Heavy Ion). Isomer ratios, residue production cross sections and emission spectra for neutrons, protons, alpha-particles, gamma-rays, and one type of Light Ion can be calculated. The energy range starts just above the resonance region for neutron induced reactions and extends up to several hundreds of MeV for the Heavy Ion induced reactions. IAEA1169/06: This version corrects an error in the Absoft compile procedure. 2 - Method of solution: For projectiles with A<5 EMPIRE calculates fusion cross section using spherical optical model transmission coefficients. In the case of Heavy Ion induced reactions the fusion cross section can be determined using various approaches including simplified coupled channels method (code CCFUS). Pre-equilibrium emission is treated in terms of quantum-mechanical theories (TUL-MSD and NVWY-MSC). MSC contribution to the gamma emission is taken into account. These calculations are followed by statistical decay with arbitrary number of subsequent particle emissions. Gamma-ray competition is considered in detail for every decaying compound nucleus. Different options for level densities are available including dynamical approach with collective effects taken into account. EMPIRE contains following third party codes converted into subroutines: - SCAT2 by O. Bersillon, - ORION and TRISTAN by H. Lenske and H. Wolter, - CCFUS by C.H. Dasso and S. Landowne, - BARMOM by A. Sierk. 3 - Restrictions on the complexity of the problem: The code can be easily adjusted to the problem by changing dimensions in the dimensions.h file. The actual limits are set by the available memory. In the current formulation up to 4 ejectiles plus gamma are allowed. This limit can be relaxed

Total cross section of furfural by electron impact: Experiment and theory

Science.gov (United States)

Traoré Dubuis, A.; Verkhovtsev, A.; Ellis-Gibbings, L.; Krupa, K.; Blanco, F.; Jones, D. B.; Brunger, M. J.; García, G.

2017-08-01

We present experimental total cross sections for electron scattering from furfural in the energy range from 10 to 1000 eV, as measured using a double electrostatic analyzer gas cell electron transmission experiment. These results are compared to theoretical data for furfural, as well as to experimental and theoretical values for the structurally similar molecules furan and tetrahydrofuran. The measured total cross section is in agreement with the theoretical results obtained by means of the independent-atom model with screening corrected additivity rule including interference method. In the region of higher electron energies, from 500 eV to 10 keV, the total electron scattering cross section is also estimated using a semi-empirical model based on the number of electrons and dipole polarizabilities of the molecular targets. Together with the recently measured differential and integral cross sections, and the furfural energy-loss spectra, the present total cross section data nearly complete the data set that is required for numerical simulation of low-energy electron processes in furfural, covering the range of projectile energies from a few electron volts up to 10 keV.

Total cross section of furfural by electron impact: Experiment and theory.

Science.gov (United States)

Traoré Dubuis, A; Verkhovtsev, A; Ellis-Gibbings, L; Krupa, K; Blanco, F; Jones, D B; Brunger, M J; García, G

2017-08-07

We present experimental total cross sections for electron scattering from furfural in the energy range from 10 to 1000 eV, as measured using a double electrostatic analyzer gas cell electron transmission experiment. These results are compared to theoretical data for furfural, as well as to experimental and theoretical values for the structurally similar molecules furan and tetrahydrofuran. The measured total cross section is in agreement with the theoretical results obtained by means of the independent-atom model with screening corrected additivity rule including interference method. In the region of higher electron energies, from 500 eV to 10 keV, the total electron scattering cross section is also estimated using a semi-empirical model based on the number of electrons and dipole polarizabilities of the molecular targets. Together with the recently measured differential and integral cross sections, and the furfural energy-loss spectra, the present total cross section data nearly complete the data set that is required for numerical simulation of low-energy electron processes in furfural, covering the range of projectile energies from a few electron volts up to 10 keV.

Ranking and validation of spallation models for isotopic production cross sections of heavy residua

Science.gov (United States)

Sharma, Sushil K.; Kamys, Bogusław; Goldenbaum, Frank; Filges, Detlef

2017-07-01

The production cross sections of isotopically identified residual nuclei of spallation reactions induced by 136Xe projectiles at 500AMeV on hydrogen target were analyzed in a two-step model. The first stage of the reaction was described by the INCL4.6 model of an intranuclear cascade of nucleon-nucleon and pion-nucleon collisions whereas the second stage was analyzed by means of four different models; ABLA07, GEM2, GEMINI++ and SMM. The quality of the data description was judged quantitatively using two statistical deviation factors; the H-factor and the M-factor. It was found that the present analysis leads to a different ranking of models as compared to that obtained from the qualitative inspection of the data reproduction. The disagreement was caused by sensitivity of the deviation factors to large statistical errors present in some of the data. A new deviation factor, the A factor, was proposed, that is not sensitive to the statistical errors of the cross sections. The quantitative ranking of models performed using the A-factor agreed well with the qualitative analysis of the data. It was concluded that using the deviation factors weighted by statistical errors may lead to erroneous conclusions in the case when the data cover a large range of values. The quality of data reproduction by the theoretical models is discussed. Some systematic deviations of the theoretical predictions from the experimental results are observed.

Ranking and validation of spallation models for isotopic production cross sections of heavy residua

Energy Technology Data Exchange (ETDEWEB)

Sharma, Sushil K.; Kamys, Boguslaw [Jagiellonian University, The Marian Smoluchowski Institute of Physics, Krakow (Poland); Goldenbaum, Frank; Filges, Detlef [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany)

2017-07-15

The production cross sections of isotopically identified residual nuclei of spallation reactions induced by {sup 136}Xe projectiles at 500 AMeV on hydrogen target were analyzed in a two-step model. The first stage of the reaction was described by the INCL4.6 model of an intranuclear cascade of nucleon-nucleon and pion-nucleon collisions whereas the second stage was analyzed by means of four different models; ABLA07, GEM2, GEMINI++ and SMM. The quality of the data description was judged quantitatively using two statistical deviation factors; the H-factor and the M-factor. It was found that the present analysis leads to a different ranking of models as compared to that obtained from the qualitative inspection of the data reproduction. The disagreement was caused by sensitivity of the deviation factors to large statistical errors present in some of the data. A new deviation factor, the A factor, was proposed, that is not sensitive to the statistical errors of the cross sections. The quantitative ranking of models performed using the A-factor agreed well with the qualitative analysis of the data. It was concluded that using the deviation factors weighted by statistical errors may lead to erroneous conclusions in the case when the data cover a large range of values. The quality of data reproduction by the theoretical models is discussed. Some systematic deviations of the theoretical predictions from the experimental results are observed. (orig.)

Re/Os cosmochronometer: measurement of neutron cross sections

International Nuclear Information System (INIS)

Mosconi, M.

2007-01-01

This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of 187 Re (t 1/2 =41.2 Gyr) into 187 Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the 187 Re/ 187 Os pair, provide the possibility to identify the radiogenic fraction of 187 Os exclusively by nuclear physics considerations. Apart from its radiogenic component, 187 Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, 187 Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of 187 Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of 187 Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of 186 Os, 187 Os and 188 Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for 186 Os, 187 Os, and 188 Os, respectively. Since, the first excited state in 187 Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, γ) experiments and by an improved measurements of the inelastic scattering cross section for

Cross sections for electron-impact excitation of argon by fourier transform spectroscopy

International Nuclear Information System (INIS)

Chilton, J.E.; Boffard, J.B.; Chun C.L.

1996-01-01

The authors report absolute measurements of electron-impact excitation cross sections out of the ground level to the ten levels in the 3p 5 4p configuration of argon. The apparent excitation cross sections are determined by measuring the optical cross sections for the emission lines in the 3p 5 4p → 3p 5 4s manifold. For cascade corrections the authors measured the optical cross sections for the various 3p 5 5s → 3p 5 4p and 3p 5 4p infrared lines using a Fourier transform weak emission spectrometer to obtain the direct excitation cross sections from the optical data. Although the optical cross sections vary with pressure in the regime of 0.1 to 6 mTorr, the direct cross sections remain invariant. These pressure effects are understood within the framework of a radiation-reabsorption model. The excitation functions for the different transitions are also found to show considerable variation in shape

Prediction of fission mass-yield distributions based on cross section calculations

International Nuclear Information System (INIS)

Hambsch, F.-J.; G.Vladuca; Tudora, Anabella; Oberstedt, S.; Ruskov, I.

2005-01-01

For the first time, fission mass-yield distributions have been predicted based on an extended statistical model for fission cross section calculations. In this model, the concept of the multi-modality of the fission process has been incorporated. The three most dominant fission modes, the two asymmetric standard I (S1) and standard II (S2) modes and the symmetric superlong (SL) mode are taken into account. De-convoluted fission cross sections for S1, S2 and SL modes for 235,238 U(n, f) and 237 Np(n, f), based on experimental branching ratios, were calculated for the first time in the incident neutron energy range from 0.01 to 5.5 MeV providing good agreement with the experimental fission cross section data. The branching ratios obtained from the modal fission cross section calculations have been used to deduce the corresponding fission yield distributions, including mean values also for incident neutron energies hitherto not accessible to experiment

Absolute total cross sections for noble gas systems

International Nuclear Information System (INIS)

Kam, P. van der.

1981-01-01

This thesis deals with experiments on the elastic scattering of Ar, Kr and Xe, using the molecular beam technique. The aim of this work was the measurement of the absolute value of the total cross section and the behaviour of the total cross section, Q, as function of the relative velocity g of the scattering partners. The author gives an extensive analysis of the glory structure in the total cross section and parametrizes the experimental results using a semiclassical model function. This allows a detailed comparison of the phase and amplitude of the predicted and measured glory undulations. He indicates how the depth and position of the potential well should be changed in order to come to an optimum description of the glory structure. With this model function he has also been able to separate the glory and attractive contribution to Q, and using the results from the extrapolation measurements he has obtained absolute values for Qsub(a). From these absolute values he has calculated the parameter C 6 that determines the strength of the attractive region of the potential. In two of the four investigated gas combinations the obtained values lie outside the theoretical bounds. (Auth.)

Hadronic cross-sections in two photon processes at a future linear collider

International Nuclear Information System (INIS)

Godbole, Rohini M.; Roeck, Albert de; Grau, Agnes; Pancheri, Giulia

2003-01-01

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear e + e - collider. We extend, to higher energy, our previous estimates of the accuracy with which the γ γ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the e + e - option a measurement of the hadron production cross-section via γ γ processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy e + e - collider CLIC. (author)

Top quark production cross-section measurements

CERN Document Server

Chen, Ye; The ATLAS collaboration

2017-01-01

Measurements of the inclusive and differential cross-sections for top-quark pair and single top production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented at center-of-mass energies of 8 TeV and 13 TeV. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. These measurements, including results using boosted tops, probe our understanding of top-pair production in the TeV regime. The results are compared to Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. For the t-channel single top measurement, the single top-quark and anti-top-quark total production cross-sections, their ratio, as well as differential cross sections are also presented. A measurement of the production cross-section of a single top quark in association with a W boson, the second largest single-top production mode, is also presented. Finally, measurements of ...

Calculation of neutron cross sections on iron up to 40 MeV

International Nuclear Information System (INIS)

Arthur, E.D.; Young, P.G.

1980-01-01

The development of high energy d + Li neutron sources for fusion materials radiation damage studies will require neutron cross sections up to 40 MeV. Experimental data above 15 MeV are generally sparse or nonexistent, and reliance must be placed upon nuclear-model calculations to produce the needed cross sections. To satisfy such requirements for the Fusion Materials Irradiation Test Facility (FMIT), neutron cross sections have been calculated for 54 56 Fe between 3 and 40 MeV. These results were joined to the existing ENDF/B-V evaluation below 3 MeV. In this energy range, most neutron reactions can be described using the Hauser-Feshbach statistical model with corrections for preequilibrium and direct-reaction effects. To properly use these models to obtain realistic cross sections, emphasis must be placed upon the determination of suitable input parameters (optical model sets, gamma-ray strength functions, level densities) valid over the energy range of the calculation. To do this, several types of independent data were used to arrive at consistent parameter sets as described

Optical model neutron cross sections calculations for Cu63, Cu65 and natural Cu in the energy range 1-15 Mev

International Nuclear Information System (INIS)

Iliescu, N.

1975-01-01

The theory of optical model and cross sections is developing. The neutron reactions considered in the high energy rate (0,1-15 MeV) were: total, elastic, elastic angular distributions, nonelastic, inelastic for resolved levels. This region was subdivided in two parts: in the first one, ranging from 0,1 to 1 MeV, the evaluation was mainly based on empirical fits of the experimental data, whereas in the second part the fits were carried out with theoretical models: optical and statistical. The potential parameters were obtained fitting the total, elastic, inelastic cross sections and elastic angular distributions. Using Hauser-Feshbach theory, angular distribution and cross sections for compound elastic scattering and inelastic scattering are calculated

Total neutron cross sections at energies around 20 MeV

International Nuclear Information System (INIS)

Morales, J.R.; Romero, J.L.; Martens, P.

1990-09-01

The results for measurements of total cross sections on C, Al, Mg, Cu, Ge and Pb at 17.6 and 19.8 MeV are reported. A detailed comparison is presented with previous data and with the global optical model by the Ohio group. We also discuss plans for total non elastic cross section measurements. 31 refs, 12 figs, 2 tabs

Automated Cross-Sectional Measurement Method of Intracranial Dural Venous Sinuses.

Science.gov (United States)

Lublinsky, S; Friedman, A; Kesler, A; Zur, D; Anconina, R; Shelef, I

2016-03-01

MRV is an important blood vessel imaging and diagnostic tool for the evaluation of stenosis, occlusions, or aneurysms. However, an accurate image-processing tool for vessel comparison is unavailable. The purpose of this study was to develop and test an automated technique for vessel cross-sectional analysis. An algorithm for vessel cross-sectional analysis was developed that included 7 main steps: 1) image registration, 2) masking, 3) segmentation, 4) skeletonization, 5) cross-sectional planes, 6) clustering, and 7) cross-sectional analysis. Phantom models were used to validate the technique. The method was also tested on a control subject and a patient with idiopathic intracranial hypertension (4 large sinuses tested: right and left transverse sinuses, superior sagittal sinus, and straight sinus). The cross-sectional area and shape measurements were evaluated before and after lumbar puncture in patients with idiopathic intracranial hypertension. The vessel-analysis algorithm had a high degree of stability with <3% of cross-sections manually corrected. All investigated principal cranial blood sinuses had a significant cross-sectional area increase after lumbar puncture (P ≤ .05). The average triangularity of the transverse sinuses was increased, and the mean circularity of the sinuses was decreased by 6% ± 12% after lumbar puncture. Comparison of phantom and real data showed that all computed errors were <1 voxel unit, which confirmed that the method provided a very accurate solution. In this article, we present a novel automated imaging method for cross-sectional vessels analysis. The method can provide an efficient quantitative detection of abnormalities in the dural sinuses. © 2016 by American Journal of Neuroradiology.

Pion photoproduction cross section at large momentum transfer

Energy Technology Data Exchange (ETDEWEB)

Sjoegren, Johan [Univ. of Glasgow, Scotland, United Kingdom

2015-02-27

The Real Compton Scattering experiment was performed in Hall A at the Thomas Jefferson National Accelerator Facility. It was designed to measure, for Compton scattering and π⁰-photoproduction, the differential cross section over a range of kinematic points and the polarisation transfer to the proton at a single kinematic point. The full range of the experiment in Mandelstam variables t and s was 1.6-6.46 GeV² and 4.82-10.92 GeV² respectively with beam energies of 2-6 GeV. The motivation for the experiment is to test the cross section and polarisation transfer predictions of perturbative QCD versus that of predictions from Generalised Parton Distribution models. This thesis will give an overview of the pertinent theory, experimental setup in Hall A and the extracting of the π⁰-photoproduction cross section.

Differences between LASL- and ANL-processed cross sections

International Nuclear Information System (INIS)

Kidman, R.B.; MacFarlane, R.E.; Becker, M.

1978-03-01

As part of the Los Alamos Scientific Laboratory (LASL) cross-section processing development, LASL cross sections and results from MINX/1DX system are compared to the Argonne National Laboratory cross sections and results from the ETOE-2/MC 2 -2 system for a simple reactor problem. Exact perturbation theory is used to establish the eigenvalue effect of every isotope group cross-section difference. Cross sections, cross-section differences, and their eigenvalue effects are clearly and conveniently displayed and compared on a group-by-group basis

Handbook of LHC Higgs Cross Sections: 3. Higgs Properties

Energy Technology Data Exchange (ETDEWEB)

Heinemeyer, S; et al.

2013-01-01

This Report summarizes the results of the activities in 2012 and the first half of 2013 of the LHC Higgs Cross Section Working Group. The main goal of the working group was to present the state of the art of Higgs Physics at the LHC, integrating all new results that have appeared in the last few years. This report follows the first working group report Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002) and the second working group report Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002). After the discovery of a Higgs boson at the LHC in mid-2012 this report focuses on refined prediction of Standard Model (SM) Higgs phenomenology around the experimentally observed value of 125-126 GeV, refined predictions for heavy SM-like Higgs bosons as well as predictions in the Minimal Supersymmetric Standard Model and first steps to go beyond these models. The other main focus is on the extraction of the characteristics and properties of the newly discovered particle such as couplings to SM particles, spin and CP-quantum numbers etc.

(n,{alpha}) cross section measurement of gaseous sample using gridded ionization chamber. Cross section determination

Energy Technology Data Exchange (ETDEWEB)

Sanami, Toshiya; Baba, Mamoru; Saito, Keiichiro; Ibara, Yasutaka; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering

1997-03-01

We are developing a method of (n,{alpha}) cross section measurement using gaseous samples in a gridded ionization chamber (GIC). This method enables cross section measurements in large solid angle without the distortion by the energy loss in a sample, but requires a method to estimate the detection efficiency. We solve this problem by using GIC signals and a tight neutron collimation. The validity of this method was confirmed through the {sup 12}C(n,{alpha}{sub 0}){sup 9}Be measurement. We applied this method to the {sup 16}O(n,{alpha}){sup 13}C cross section around 14.1 MeV. (author)

Measurement of the cross-section of Zγ and limits on ADD models at ...

Indian Academy of Sciences (India)

The measurement of the inclusive cross-section for Z production at LHC with 7 TeV proton–proton collision is presented. The electron and muon decay modes are used to reconstruct the boson. The total cross-section is measured for photon transverse energy greater than 10 GeV and with photon and charged lepton ...

Ecological Panel Inference from Repeated Cross Sections

NARCIS (Netherlands)

Pelzer, Ben; Eisinga, Rob; Franses, Philip Hans

2004-01-01

This chapter presents a Markov chain model for the estimation of individual-level binary transitions from a time series of independent repeated cross-sectional (RCS) samples. Although RCS samples lack direct information on individual turnover, it is demonstrated here that it is possible with these

Improved surface-roughness scattering and mobility models for multi-gate FETs with arbitrary cross-section and biasing scheme

Science.gov (United States)

Lizzit, D.; Badami, O.; Specogna, R.; Esseni, D.

2017-06-01

We present a new model for surface roughness (SR) scattering in n-type multi-gate FETs (MuGFETs) and gate-all-around nanowire FETs with fairly arbitrary cross-sections, its implementation in a complete device simulator, and the validation against experimental electron mobility data. The model describes the SR scattering matrix elements as non-linear transformations of interface fluctuations, which strongly influences the root mean square value of the roughness required to reproduce experimental mobility data. Mobility simulations are performed via the deterministic solution of the Boltzmann transport equation for a 1D-electron gas and including the most relevant scattering mechanisms for electronic transport, such as acoustic, polar, and non-polar optical phonon scattering, Coulomb scattering, and SR scattering. Simulation results show the importance of accounting for arbitrary cross-sections and biasing conditions when compared to experimental data. We also discuss how mobility is affected by the shape of the cross-section as well as by its area in gate-all-around and tri-gate MuGFETs.

Multiphysical model of heterogenous flow moving along а channel of variable cross-section

Directory of Open Access Journals (Sweden)

М. А. Васильева

2017-10-01

Full Text Available The article deals with the problem aimed at solving the fundamental problems of developing effective methods and tools for designing, controlling and managing the stream of fluid flowing in variable-section pipelines intended for the production of pumping equipment, medical devices and used in such areas of industry as mining, chemical, food production, etc. Execution of simulation modelling of flow motion according to the scheme of twisted paddle static mixer allows to estimate the efficiency of mixing by calculating the trajectory and velocities of the suspended particles going through the mixer, and also to estimate the pressure drop on the hydraulic flow resistance. The model examines the mixing of solids dissolved in a liquid at room temperature. To visualize the process of distributing the mixture particles over the cross-section and analyzing the mixing efficiency, the Poincaréplot module of the COMSOL Multiphysics software environment was used. For the first time, a multi-physical stream of heterogeneous flow model has been developed that describes in detail the physical state of the fluid at all points of the considered section at the initial time, takes into account the design parameters of the channel (orientation, dimensions, material, etc., specifies the laws of variation of the parameters at the boundaries of the calculated section in conditions of the wave change in the internal section of the working chamber-channel of the inductive peristaltic pumping unit under the influence of the energy of the magnetic field.

INC Model interpretation of the proton induced residual nuclide production cross sections below 2 GeV

International Nuclear Information System (INIS)

Divadeenam, M.; Ward, T.E.; Spergel, M.S.; Lakatos, S.; Manche, E.P.

1991-01-01

For the purposes of interpreting the abundances of various isotopes in meteorites or on lunar and planetary surfaces exposed to fragmentation by cosmic rays, Webber et al. recently reported the measured total elemental and isotopic cross sections with heavy ions as projectiles on H, He, and C targets with beam energies of 0.33 - 1.7 GeV/nucleon. We employ the INC model to predict the fragmentation of the heavy ions in a hydrogen target with the inverse reaction process: proton bombardment of a heavy-ion nucleus leading to spallation products. Charge-changing and mass-changing cross sections are calculated for proton bombardment of an 56 Fe target with beam energies ranging from 0.33 to 1.88 GeV. Total Z-changing and A-changing cross sections in the energy range 0.6 to 1.88 GeV are in excellent agreement with the corresponding experimental data of Webber et al. and Westfall at al., while the agreement below 0.6 GeV proton energy is not as good. The general trend of the Z-changing cross sections are reproduced by the model calculations at each proton incident energy. The interaction of 200-MeV protons with synthetic Stony Meteorite samples was undertaken to explain radionuclide production in a cosmic-ray environment. The BNL Linac 200-MeV-proton beam was used to irradiate synthetic Stony Meteorites to simulate cosmic-ray exposures corresponding to 6.4 and 16.4 million years. Each irradiated sample was analyzed with the help of a high-resolution gamma-ray spectrometer for long-lived radioisotopes. The intranuclear cascade code HETC was employed to simulate the 200-MeV proton bombardment on the meteorite samples to predict the radionuclides 7 Be, 22 Na, 46 Mn, and 56 Co produced in the experimental investigation

Heavy Ion SEU Cross Section Calculation Based on Proton Experimental Data, and Vice Versa

CERN Document Server

Wrobel, F; Pouget, V; Dilillo, L; Ecoffet, R; Lorfèvre, E; Bezerra, F; Brugger, M; Saigné, F

2014-01-01

The aim of this work is to provide a method to calculate single event upset (SEU) cross sections by using experimental data. Valuable tools such as PROFIT and SIMPA already focus on the calculation of the proton cross section by using heavy ions cross-section experiments. However, there is no available tool that calculates heavy ion cross sections based on measured proton cross sections with no knowledge of the technology. We based our approach on the diffusion-collection model with the aim of analyzing the characteristics of transient currents that trigger SEUs. We show that experimental cross sections could be used to characterize the pulses that trigger an SEU. Experimental results allow yet defining an empirical rule to identify the transient current that are responsible for an SEU. Then, the SEU cross section can be calculated for any kind of particle and any energy with no need to know the Spice model of the cell. We applied our method to some technologies (250 nm, 90 nm and 65 nm bulk SRAMs) and we sho...

Theoretical Studies on Expressions of Condensed-Phase Photoionization Cross Section

International Nuclear Information System (INIS)

Ma Xiaoguang; Wang Meishan; Wang Dehua; Qu Zhaojun

2006-01-01

A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell's equations and the Beer-Lambert's law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti (virtual cavity) model and the Glauber-Lewenstein (real cavity) model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.

Photoionization cross section of atomic and molecular oxygen

International Nuclear Information System (INIS)

Pareek, P.N.

1983-01-01

Photoionization cross sections of atomic oxygen and dissociative photoionization cross sections of molecular oxygen were measured from their respective thresholds to 120 angstrom by use of a photoionization mass spectrometer in conjunction with a spark light source. The photoionization cross sections O 2 + parent ion and O + fragment ion from neutral O 2 were obtained by a technique that eliminated the serious problem of identifying the true abundances of O + ions. These ions are generally formed with considerable kinetic energy and, because most mass spectrometers discriminate against energetic ions, true O + abundances are difficult to obtain. In the present work the relative cross sections for producing O + ions are obtained and normalized against the total cross sections in a spectral region where dissociative ionization is not possible. The fragmentation cross sections for O + were then obtained by subtraction of O 2 + cross sections from the known total photoionization cross sections. The results are compared with the previously published measurements. The absolute photoionization cross section of atomic oxygen sigma 8 /sub +/ was measured at 304 A. The actual number density of oxygen atoms within the ionization region was obtained by measuring the fraction of 0 2 molecules dissociated. This sigma/sub +/ at 304 angstrom was used to convert the relative photoinization cross sections, measured as a function of wavelength using a calibrated photodiode, to absolute cross sections. The results are compared with previous measurements and calculated cross sections. angstrom Rydberg series converging to the OII 4 P state was observed

Measurements of neutron capture cross sections

International Nuclear Information System (INIS)

Nakajima, Yutaka

1984-01-01

A review of measurement techniques for the neutron capture cross sections is presented. Sell transmission method, activation method, and prompt gamma-ray detection method are described using examples of capture cross section measurements. The capture cross section of 238 U measured by three different prompt gamma-ray detection methods (large liquid scintillator, Moxon-Rae detector, and pulse height weighting method) are compared and their discrepancies are resolved. A method how to derive the covariance is described. (author)

XCOM: Photon Cross Sections Database

Science.gov (United States)

SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

Fault-related-folding structures and reflection seismic sections. Study by seismic modeling and balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 2. Seismic modeling oyobi balanced cross section ni yoru study

Energy Technology Data Exchange (ETDEWEB)

Tamagawa, T; Matsuoka, T [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

1997-05-27

It occasionally happens that there exists a part where reflection near the thrust is not clearly observed in a thrust zone seismic survey cross section. For the effective interpretation of such an occurrence, the use of geological structures as well as the reflected pattern is effective. When the velocity structures for a fold structure having a listric fault caused anticline (unidirectionally inclined with a backlimb, without a forelimb) and for a fault propagation fold are involved, a wrong interpretation may be made since they look alike in reflection wave pattern despite their difference in geological structure. In the concept of balanced cross section, a check is performed, when the stratum after deformation is recovered to the time of deposition, as to whether the geologic stratum area is conserved without excess or shortage. An excess or shortage occurs if there is an error in the model, and this shows that the fault surface or fold structure is not correctly reflected. Positive application of geological knowledge is required in the processing and interpreting of data from a seismic survey. 6 refs., 6 figs.

Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Soran, P.D.; Seamon, R.E.

1980-05-01

Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ν, the average number of neutrons per fission, are also given

Cross-sectional dependence in panel data analysis

NARCIS (Netherlands)

Sarafidis, V.; Wansbeek, T.J.

2012-01-01

This article provides an overview of the existing literature on panel data models with error cross-sectional dependence (CSD). We distinguish between weak and strong CSD and link these concepts to the spatial and factor structure approaches. We consider estimation under strong and weak exogeneity of

Elastic scattering and total cross section at very high energies

International Nuclear Information System (INIS)

Castaldi, R.; Sanguinetti, G.

1985-01-01

The aim of this review is to summarize the recent progress in the field of elastic scattering and total cross section in this new energy domain. In Section 2 a survey of the experimental situation is outlined. The most significant data are presented, with emphasis on the interpretation, not the specific details or technicalities. This section is therefore intended to give a self-contained look at the field, especially for the nonspecialist. In Section 3, hadron scattering at high energy is described in an impact parameter picture, which provides a model-independent intuitive geometrical representation. The diffractive character of elastic scattering, seen as the shadow of inelastic absorption, is presented as a consequence of unitarity in the s-channel. Spins are neglected throughout this review, inasmuch as the asymptotic behavior in the very high-energy limit is the main concern here. In Section 4 some relevant theorems are recalled on the limiting behavior of hadron-scattering amplitudes at infinite energy. There is also a brief discussion on how asymptotically rising total cross sections imply scaling properties in the elastic differential cross sections. A quick survey of eikonal models is presented and their predictions are compared with ISR and SPS Collider data

The Underlying Event and the Total Cross Section from Tevatron to the LHC

CERN Document Server

Bähr, Manuel; Seymour, Michael H

2009-01-01

Multiple partonic interactions are widely used to simulate the hadronic final state in high energy hadronic collisions, and successfully describe many features of the data. It is important to make maximum use of the available physical constraints on such models, particularly given the large extrapolation from current high energy data to LHC energies. In eikonal models, the rate of multiparton interactions is coupled to the energy dependence of the total cross section. Using a Monte Carlo implementation of such a model, we study the connection between the total cross section, the jet cross section, and the underlying event. By imposing internal consistency on the model, we derive constraints on its parameters at the LHC.

Density dependence of stopping cross sections measured in liquid ethane

International Nuclear Information System (INIS)

Both, G.; Krotz, R.; Lohmer, K.; Neuwirth, W.

1983-01-01

Electronic stopping cross sections for 7 Li projectiles (840--175 keV) have been measured with the inverted Doppler-shift attenuation method in liquid ethane (C 2 H 6 ) at two different densities. The density of the target has been varied by changing the temperature, and measurements have been performed at 0.525 g/cm 3 (199 K) and 0.362 g/cm 3 (287 K). At the higher density the stopping cross section is about 2% smaller. This result agrees with a calculation of the stopping cross section of liquid ethane, applying Lindhard's theory in the local-density approximation using a simple model of the liquid. It is also in agreement with various observations of the so-called physical-state effect, which show that the stopping cross section of the same substance is smaller in a condensed phase than in the gaseous one

Re/Os cosmochronometer: measurement of neutron cross sections

Energy Technology Data Exchange (ETDEWEB)

Mosconi, M.

2007-12-21

This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of {sup 187}Re (t{sub 1/2}=41.2 Gyr) into {sup 187}Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the {sup 187}Re/{sup 187}Os pair, provide the possibility to identify the radiogenic fraction of {sup 187}Os exclusively by nuclear physics considerations. Apart from its radiogenic component, {sup 187}Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, {sup 187}Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of {sup 187}Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of {sup 187}Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of {sup 186}Os, {sup 187}Os and {sup 188}Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for {sup 186}Os, {sup 187}Os, and {sup 188}Os, respectively. Since, the first excited state in {sup 187}Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, {gamma

Improvement of one-nucleon removal and total reaction cross sections in the Liège intranuclear-cascade model using Hartree-Fock-Bogoliubov calculations

Science.gov (United States)

Rodríguez-Sánchez, Jose Luis; David, Jean-Christophe; Mancusi, Davide; Boudard, Alain; Cugnon, Joseph; Leray, Sylvie

2017-11-01

The prediction of one-nucleon-removal cross sections by the Liège intranuclear-cascade model has been improved using a refined description of the matter and energy densities in the nuclear surface. Hartree-Fock-Bogoliubov calculations with the Skyrme interaction are used to obtain a more realistic description of the radial-density distributions of protons and neutrons, as well as the excitation-energy uncorrelation at the nuclear surface due to quantum effects and short-range correlations. The results are compared with experimental data covering a large range of nuclei, from carbon to uranium, and projectile kinetic energies. We find that the new approach is in good agreement with experimental data of one-nucleon-removal cross sections covering a broad range in nuclei and energies. The new ingredients also improve the description of total reaction cross sections induced by protons at low energies, the production cross sections of heaviest residues close to the projectile, and the triple-differential cross sections for one-proton removal. However, other observables such as quadruple-differential cross sections of coincident protons do not present any sizable sensitivity to the new approach. Finally, the model is also tested for light-ion-induced reactions. It is shown that the new parameters can give a reasonable description of the nucleus-nucleus total reaction cross sections at high energies.

NNLO jet cross sections by subtraction

International Nuclear Information System (INIS)

Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.

2010-06-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Bolzoni, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Trocsanyi, Z. [CERN, Geneva (Switzerland)

2010-06-15

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

CERN Document Server

Somogyi, Gabor; Trocsanyi, Zoltan

2010-01-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of [1-4], over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Differential cross sections and cross-section ratios for the electron-impact excitation of the neon 2p53s configuration

International Nuclear Information System (INIS)

Khakoo, M. A.; Wrkich, J.; Larsen, M.; Kleiban, G.; Kanik, I.; Trajmar, S.; Brunger, M.J.; Teubner, P.J.O.; Crowe, A.; Fontes, C.J.; Clark, R.E.H.; Zeman, V.; Bartschat, K.; Madison, D.H.; Srivastava, R.; Stauffer, A.D.

2002-01-01

Electron-impact differential cross-section measurements for the excitation of the 2p 5 3s configuration of Ne are reported. The Ne cross sections are obtained using experimental differential cross sections for the electron-impact excitation of the n=2 levels of atomic hydrogen [Khakoo et al., Phys. Rev. A 61, 012701-1 (1999)], and existing experimental helium differential cross-section measurements, as calibration standards. These calibration measurements were made using the method of gas mixtures (Ne and H followed by Ne and He), in which the gas beam profiles of the mixed gases are found to be the same within our experimental errors. We also present results from calculations of these differential cross sections using the R-matrix and unitarized first-order many-body theory, the distorted-wave Born approximation, and relativistic distorted-wave methods. Comparison with available experimental differential cross sections and differential cross-section ratios is also presented

Elliptical cross section fuel rod study II

International Nuclear Information System (INIS)

Taboada, H.; Marajofsky, A.

1996-01-01

In this paper it is continued the behavior analysis and comparison between cylindrical fuel rods of circular and elliptical cross sections. Taking into account the accepted models in the literature, the fission gas swelling and release were studied. An analytical comparison between both kinds of rod reveals a sensible gas release reduction in the elliptical case, a 50% swelling reduction due to intragranular bubble coalescence mechanism and an important swelling increase due to migration bubble mechanism. From the safety operation point of view, for the same linear power, an elliptical cross section rod is favored by lower central temperatures, lower gas release rates, greater gas store in ceramic matrix and lower stored energy rates. (author). 6 refs., 8 figs., 1 tab

Methods and procedures for evaluation of neutron-induced activation cross sections

International Nuclear Information System (INIS)

Gardner, M.A.

1981-09-01

One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed

Methods and procedures for evaluation of neutron-induced activation cross sections

Energy Technology Data Exchange (ETDEWEB)

Gardner, M.A.

1981-09-01

One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed.

Status of neutron dosimetry cross sections

International Nuclear Information System (INIS)

Griffin, P.J.; Kelly, J.G.

1992-01-01

Several new cross section libraries, such as ENDF/B-VI(release 2), IRDF-90,JEF-2.2, and JENDL-3 Dosimetry, have recently been made available to the dosimetry community. the Sandia National Laboratories (SNL) Radiation Metrology Laboratory (RML) has worked with these libraries since pre-release versions were available. this paper summarizes the results of the intercomparison and testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available libraries for use within the SNL RML. this library, referred to as the SNLRML Library, contains 66 general dosimetry sensors and 3 special dosimeters unique to the RML sensor inventory. The SNLRML cross sections have been put into a format compatible with commonly used spectrum determination codes

Using the mean approach in pooling cross-section and time series data for regression modelling

International Nuclear Information System (INIS)

Nuamah, N.N.N.N.

1989-12-01

The mean approach is one of the methods for pooling cross section and time series data for mathematical-statistical modelling. Though a simple approach, its results are sometimes paradoxical in nature. However, researchers still continue using it for its simplicity. Here, the paper investigates the nature and source of such unwanted phenomena. (author). 7 refs

Graphs of the cross sections in the Alternate Monte Carlo Cross Section library at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Seamon, R.E.; Soran, P.D.

1980-06-01

Graphs of all neutron cross sections and photon production cross sections on the Alternate Monte Carlo Cross Section (AMCCS) library have been plotted along with local neutron heating numbers. The values of ν-bar, the average number of neutrons per fission, are also plotted for appropriate isotopes

Brief note on the statistical calculation of final continuum reaction cross sections of light nuclides

International Nuclear Information System (INIS)

Murata, Toru

2003-01-01

The level density parameters are determined to reproduce level structure and/or resonance level spacing of the nucleus. In the statistical compound nucleus model, cross sections to discrete levels decrease abruptly, and continuum level cross section increase strongly above the energy point where the continuum levels switched on. In the present study, for the nucleus which level scheme were well determined up to higher excitation energy more than 10 MeV, discrete level cross sections were calculated and summed up and compared with the cross section to the assumed continuum level corresponding to the discrete levels above several MeV excitation energy. Calculation of the (n, n') cross sections were made with CASTHY code of Moldauer model option using level density parameters determined with former method. It is shown that the assumed continuum cross section is fairly large compared with the summed up cross section. Origins of the discrepancy were discussed. (J.P.N.)

A Computer Model for the Hydraulic Analysis of Open Channel Cross Sections

Directory of Open Access Journals (Sweden)

W. H. Shayya

1996-01-01

Full Text Available Irrigation and hydraulic engineers are often faced with the difficulty of tedious trial solutions of the Manning equation to determine the various geometric elements of open channels. This paper addresses the development of a computer model for the design of the most commonly used channel-sections. The developed model is intended as an educational tool. It may be applied to the hydraulic design of trapezoidal , rectangular, triangular, parabolic, round-concered rectangular, and circular cross sections. Two procedures were utilized for the solution of the encountered implicit equations; the Newton-Raphson and the Regula-Falsi methods.  In order to initiate the solution process , these methods require one and two initial guesses, respectively. Tge result revealed that the Regula-Flasi method required more iterations to coverage to the solution compared to the Newton-Raphson method, irrespective of the nearness of the initial guess to the actual solution. The average number of iterations for the Regula-Falsi method was approximately three times that of the Newton-Raphson method.

Atlas of photoneutron cross sections obtained with monoenergetic photons

International Nuclear Information System (INIS)

Dietrich, S.S.; Berman, B.L.

1988-01-01

Photoneutron cross-section and integrated cross-section data obtained with monoenergetic photons are presented in a uniform format. All of the measured partial photoneutron cross sections, the total photoneutron cross section, and the photoneutron yield cross section are plotted as functions of the incident photon energy, as are the integrated photoneutron cross sections and their first and second moments. The values of the integrated cross sections and the moments of the integrated total cross section up to the highest photon energy for which they were measured are tabulated, as are the parameters of Lorentz curves fitted to the total photoneutron cross-section data for medium and heavy nuclei (A>50). This compilation is current as of June 1987. copyright 1988 Academic Press, Inc

(n, Xn) cross sections measurements at 96 MeV

International Nuclear Information System (INIS)

Sagrado Garcia, Inmaculada C.

2006-01-01

Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n, Xn) reactions in this energy range. Neutron double differential cross sections measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL laboratory, in Uppsala (Sweden). The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 deg.-98 deg.). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100 MeV). The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparisons between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its original treatment of nucleon-nucleus reactions. (author) [fr

Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector

Energy Technology Data Exchange (ETDEWEB)

de Florian, D. [National Univ. of San Martin, Buenos Aires (Argentina); et al.

2016-10-25

This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.

Model of homogeneous nucleus. Total and inelastic cross sections of nucleon-nucleus scattering

International Nuclear Information System (INIS)

Ponomarev, L.A.; Smorodinskaya, N.Ya.

1985-01-01

It is shown that the nucleon-nuckleus scattering amplitude at high energy can be easily calculated by generalization of the nucleon-nucleon scattering amplitude and satisfies a simple factorization relation. As distinct from the Glauber model, the suggested approach makes no use of the nucleonic structure of the nucleus and the hadron-nucleus scattering amplitude is not expressed in terms of hadron-nucleon scattering amplitudes. The energy dependence of total and inelastic cross sections is successfully described for a number of nuclei

Parametric equations for calculation of macroscopic cross sections

International Nuclear Information System (INIS)

Botelho, Mario Hugo; Carvalho, Fernando

2015-01-01

Neutronic calculations of the core of a nuclear reactor is one thing necessary and important for the design and management of a nuclear reactor in order to prevent accidents and control the reactor efficiently as possible. To perform these calculations a library of nuclear data, including cross sections is required. Currently, to obtain a cross section computer codes are used, which require a large amount of processing time and computer memory. This paper proposes the calculation of macroscopic cross section through the development of parametric equations. The paper illustrates the proposal for the case of macroscopic cross sections of absorption (Σa), which was chosen due to its greater complexity among other cross sections. Parametric equations created enable, quick and dynamic way, the determination of absorption cross sections, enabling the use of them in calculations of reactors. The results show efficient when compared with the absorption cross sections obtained by the ALPHA 8.8.1 code. The differences between the cross sections are less than 2% for group 2 and less than 0.60% for group 1. (author)

Constraints on the standard model by measuring cross sections and asymmetries for Z → ff-bar with Aleph detector at LEP

International Nuclear Information System (INIS)

Lucotte, A.

1996-01-01

This work is devoted to the precision tests of the electro-week sector of the standard model via the determination of the Z-lineshape parameters M Z , Γ Z , σ had 0 and R had extracted from the fermionic cross-sections measured on 89 to 94 data in Aleph. The first section reminds the formalism and the observables used to describe the Z-resonance physics. In a second step, the LEP collider is presented with the procedures used to determine the beam energy, this parameter being the main source of uncertainty in M Z and Γ Z determination. In the following part, the Aleph experimental context is described, together with the measurement of the luminosity from Bhabha counting. Then the hadronic cross section measurements are presented, emphasizing on the improvement performed on the systematic bias evaluation to the hadrons selection. This leads to a precision at the per mille level in cross-sections. Leptonic cross-sections measured in Aleph are also reported. The Z-resonance parameters are then derived. A great agreement is observed with the prediction of the standard model of the EW interactions. The interpretation of such measurements within this model leads to the determination of the number of light neutrinos species and to the constraints on the top quark mass, compatible with direct measurements from Fermilab. (author)

A dependence of quasielastic charged-current neutrino-nucleus cross sections

Science.gov (United States)

Van Dessel, N.; Jachowicz, N.; González-Jiménez, R.; Pandey, V.; Van Cuyck, T.

2018-04-01

Background: 12C has been and is still widely used in neutrino-nucleus scattering and oscillation experiments. More recently, 40Ar has emerged as an important nuclear target for current and future experiments. Liquid argon time projection chambers (LArTPCs) possess various advantages in measuring electroweak neutrino-nucleus cross sections. Concurrent theoretical research is an evident necessity. Purpose: 40Ar is larger than 12C , and one expects nuclear effects to play a bigger role in reactions. We present inclusive differential and total cross section results for charged-current neutrino scattering on 40Ar and perform a comparison with 12C , 16O , and 56Fe targets, to find out about the A -dependent behavior of model predictions. Method: Our model starts off with a Hartree-Fock description of the nucleus, with the nucleons interacting through a mean field generated by an effective Skyrme force. Long-range correlations are introduced by means of a continuum random phase approximation approach. Further methods to improve the accuracy of model predictions are also incorporated in the calculations. Results: We present calculations for 12C , 16O , 40Ar , and 56Fe , showcasing differential cross sections over a broad range of kinematic values in the quasielastic regime. We furthermore show flux-folded results for 40Ar and we discuss the differences between nuclear responses. Conclusions: At low incoming energies and forward scattering we identify an enhancement in the 40Ar cross section compared to 12C , as well as in the high ω (low Tμ) region across the entire studied Eν range. The contribution to the folded cross section of the reaction strength at values of ω lower than 50 MeV for forward scattering is sizable.

The underlying event and the total cross section from Tevatron to the LHC

International Nuclear Information System (INIS)

Baehr, Manuel; Butterworth, Jonathan M.; Seymour, Michael H.

2009-01-01

Multiple partonic interactions are widely used to simulate the hadronic final state in high energy hadronic collisions, and successfully describe many features of the data. It is important to make maximum use of the available physical constraints on such models, particularly given the large extrapolation from current high energy data to LHC energies. In eikonal models, the rate of multiparton interactions is coupled to the energy dependence of the total cross section. Using a Monte Carlo implementation of such a model, we study the connection between the total cross section, the jet cross section, and the underlying event. By imposing internal consistency on the model and comparing to current data we constrain the allowed range of its parameters. We show that measurements of the total proton-proton cross-section at the LHC are likely to break this internal consistency, and thus to require an extension of the model. Likely such extensions are that hard scatters probe a denser matter distribution inside the proton in impact parameter space than soft scatters, a conclusion also supported by Tevatron data on double-parton scattering, and/or that the basic parameters of the model are energy dependent.

From ZZ to ZH : How Low Can These Cross Sections Go or Everybody, Let's Cross Section Limbo!

Energy Technology Data Exchange (ETDEWEB)

Strauss, Emanuel Alexandre [Stony Brook Univ., NY (United States)

2009-08-01

We report on two searches performed at the D0 detector at the Fermi National Laboratory. The first is a search for Z di-boson production with a theoretical cross section of 1.4 pb. The search was performed on 2.6 fb^-1 of data and contributed to the first observation of ZZ production at a hadron collider. The second is a search for a low mass Standard Model Higgs in 4.2 fb^-1 of data. The Higgs boson is produced in association with a Z boson where the Higgs decays hadronically and the Z decays to two leptons. The ZZ search was performed in both the di-electron and di-muon channels. For the ZH search, we will focus on the muonic decays where we expanded the traditional coverage by considering events in which one of the two muons fails the selection requirement, and is instead reconstructed as an isolated track. We consider Higgs masses between 100 and 150 GeV, with theoretical cross sections ranging from 0.17 to 0.042 pb, and set upper limits on the ZH production cross-section at 95% confidence level.

Multiple cell upset cross-section modeling: A possible interpretation for the role of the ion energy-loss straggling and Auger recombination

Energy Technology Data Exchange (ETDEWEB)

Zebrev, G.I., E-mail: gizebrev@mephi.ru; Zemtsov, K.S.

2016-08-11

We found that the energy deposition fluctuations in the sensitive volumes may cause the multiple cell upset (MCU) multiplicity scatter in the nanoscale (with feature sizes less than 100 nm) memories. A microdosimetric model of the MCU cross-section dependence on LET is proposed. It was shown that ideally a staircase-shaped cross-section vs LET curve spreads due to the energy-loss straggling impact into a quasi-linear dependence with a slope depending on the memory cell area, the cell critical energy and efficiency of charge collection. This paper also presents a new model of the Auger recombination as a limiting process of the electron–hole charge yield, especially at the high-LET ion impact. A modified form of the MCU cross-section vs LET data interpolation is proposed, discussed and validated.

Multiple cell upset cross-section modeling: A possible interpretation for the role of the ion energy-loss straggling and Auger recombination

International Nuclear Information System (INIS)

Zebrev, G.I.; Zemtsov, K.S.

2016-01-01

We found that the energy deposition fluctuations in the sensitive volumes may cause the multiple cell upset (MCU) multiplicity scatter in the nanoscale (with feature sizes less than 100 nm) memories. A microdosimetric model of the MCU cross-section dependence on LET is proposed. It was shown that ideally a staircase-shaped cross-section vs LET curve spreads due to the energy-loss straggling impact into a quasi-linear dependence with a slope depending on the memory cell area, the cell critical energy and efficiency of charge collection. This paper also presents a new model of the Auger recombination as a limiting process of the electron–hole charge yield, especially at the high-LET ion impact. A modified form of the MCU cross-section vs LET data interpolation is proposed, discussed and validated.

Theoretical Predictions of Cross-Sections of the Super-Heavy Elements

Science.gov (United States)

Bouriquet, B.; Kosenko, G.; Abe, Y.

The evaluation of the residue cross-sections of reactionssynthesising superheavy elements has been achieved by the combination of the two-step model for fusion and the evaporation code (KEWPIE) for survival probability. The theoretical scheme of those calculations is presented, and some encouraging results are given, together with some difficulties. With this approach, the measured excitation functions of the 1n reactions producing elements with Z=108, 110, 111 and 112 are well reproduced. Thus, the model has been used to predict the cross-sections of the reactions leading to the formation of the elements with Z=113 and Z=114.

Theoretical predictions of cross-sections of the super-heavy elements

International Nuclear Information System (INIS)

Bouriquet, B.; Abe, Y.; Kosenko, G.

2004-01-01

The evaluation of the residue cross-sections of reactions synthesising superheavy elements has been achieved by the combination of the two-step model for fusion and the evaporation code (KEWPIE) for survival probability. The theoretical scheme of those calculations is presented, and some encouraging results are given, together with some difficulties. With this approach, the measured excitation functions of the 1n reactions producing elements with Z = 108, 110, 111 and 112 are well reproduced. Thus, the model has been used to predict the cross-sections of the reactions leading to the formation of the elements with Z = 113 and Z = 114. (author)

Photoionization cross-section for atomic orbitals with random and fixed spatial orientation

International Nuclear Information System (INIS)

Goldberg, S.M.; Fadley, C.S.; Kono, S.

1981-01-01

Atomic photoionization subshell cross-sections and asymmetry parameters necessary for determining the differential cross-sections of randomly-oriented atoms have been calculated within the one-electron, central-potential model and the dipole approximation for all subshells of C, O, Al, Si, S, Ni, Cu, Ga, Ge, As, Se, In, Sb, Cs, Ba, Ce, Ta, W, Pt, Au, and Pb for a photon energy range from 20 to 1500 eV, and the relevant Cooper minima located to within 10 eV. These values are tabulated for general use, together with the associated radial matrix elements and phase shifts. Differential photoionization cross-sections for fixed-orientation s-, p- and d-orbitals have also been derived within the same model for a completely general experimental geometry, and closed-form expressions depending on radial matrix elements and phase shifts are given. For the special geometry of a polarized excitation source with polarization parallel to the electron emission direction, it is further shown that such oriented-atom cross-sections are exactly proportional to the probability distribution of the initial orbital, a result equivalent to that derived by using a plane-wave final-state approximation. However, detailed numerical calculations of cross-sections for oriented Cu 3d and O 2p orbitals in various general geometries and at various energies exhibit significant differences in comparison to plane-wave cross-sections. By contrast, certain prior angular-resolved X-ray photoemission studies of single-crystal valence bands are found to have been carried out in an experimental geometry that fortuitously gave cross-sections close to the plane-wave predictions. (orig.)

Fast-neutron total and scattering cross sections of niobium

Energy Technology Data Exchange (ETDEWEB)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-07-01

Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V.

Fast-neutron total and scattering cross sections of niobium

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.; Whalen, J.F.

1982-07-01

Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V

Fast-neutron total and scattering cross sections of 58Ni

International Nuclear Information System (INIS)

Jorgensen, C.B.; Guenther, P.T.; Smith, A.B.; Whalen, J.F.

1981-09-01

Neutron total cross sections of 58 Ni were measured at 25 keV intervals from 0.9 to 4.5 MeV with 50 to 100 keV resolutions. Attention was given to self-shielding corrections to the observed total cross sections. Differential elastic- and inelastic-scattering cross sections were measured at 50 keV intervals from 1.35 to 4.0 MeV with 50 to 100 keV resolutions. Inelastic excitation of levels at 1.458 +- 0.009, 2.462 +- 0.010, 2.791 +- 0.015, 2.927 +- 0.012 and 3.059 +- 0.025 MeV was observed. The experimental results were interpreted in terms of optical-statistical and coupled-channels models. A spherical optical-statistical model was found generally descriptive of an energy-average of the experimental results. However, detailed considerations suggested significant contributions from direct-vibrational interactions, particularly associated with the excitation of the first 2+ level

Multiple Coulomb excitation effects in heavy ion compound and fusion cross sections

International Nuclear Information System (INIS)

Carlson, B.V.; Hussein, M.S.

1981-11-01

A simple model for the average S-matrix that describes heavy ion direct processes in the presence of absorption due to compound nucleus formation is developed. The fluctuation cross section and the fusion cross section are then calculated for deformed heavy ion systems where multiple Coulomb excitation is important. A simple expression for the fusion cross section valid for above-barrier energies is then obtained. The formula clearly displays the modification, due to Coulomb excitation, in the usual geometrical expression. (Author) [pt

Group cross-section processing method and common nuclear group cross-section library based on JENDL-3 nuclear data file

International Nuclear Information System (INIS)

Hasegawa, Akira

1991-01-01

A common group cross-section library has been developed in JAERI. This system is called 'JSSTDL-295n-104γ (neutron:295 gamma:104) group constants library system', which is composed of a common 295n-104γ group cross-section library based on JENDL-3 nuclear data file and its utility codes. This system is applicable to fast and fusion reactors. In this paper, firstly outline of group cross-section processing adopted in Prof. GROUCH-G/B system is described in detail which is a common step for all group cross-section library generation. Next available group cross-section libraries developed in Japan based on JENDL-3 are briefly reviewed. Lastly newly developed JSSTDL library system is presented with some special attention to the JENDL-3 data. (author)

Curves and tables of neutron cross sections

International Nuclear Information System (INIS)

Nakagawa, Tsuneo; Asami, Tetsuo; Yoshida, Tadashi

1990-07-01

Neutron cross-section curves from the Japanese Evaluated Nuclear Data Library version 3, JENDL-3, are presented in both graphical and tabular form for users in a wide range of application areas in the nuclear energy field. The contents cover cross sections for all the main reactions induced by neutrons with an energy below 20 MeV including; total, elastic scattering, capture, and fission, (n,n'), (n,2n), (n,3n), (n,α), (n,p) reactions. The 2200 m/s cross-section values, resonance integrals, and Maxwellian- and fission-spectrum averaged cross sections are also tabulated. (author)

To the calculation of differential and total cross sections of γπ interactions

International Nuclear Information System (INIS)

Duplij, S.A.

1980-01-01

The differential and total cross sections of different charge channels of the γπ→ππ process are calculated. At the threshold energies the vector dominance model predicts twice as large values of the total cross sections than the current algebra. In resonance the total cross section of photoproduction on a neutral pion is 10-50 μb, on a charged pion - 5-10μb, at near-threshold energies (Esub(γ)=300-600 MeV) both cross sections are of the 20-40 nb order. For the γπ→ππ process the differential cross sections according to the invariant mass of two pions are obtained for different charge channels. At the threshold energies the total cross sections of the γπ→ππ process is of the 0.1-1 nb order

Single Top quark production cross section using the ATLAS detector at the LHC

CERN Document Server

Hirschbuehl, D; The ATLAS collaboration

2014-01-01

Measurements of single top-quark production cross section in proton proton collisions at 7 and 8 TeV are presented. In the leading order process, a W boson is exchanged in the t-channel. For this process for the first time a fiducial cross section measured within the detector acceptance is presented and the modelling uncertainty when extrapolating to the total inclusive cross section is assessed with a large number of different Monte Carlo generators. The result is in good agreement with the most up-to-date theory predictions. Furthermore, the single top-quark and anti-top total production cross sections, their ratio, as well as a measurement of the inclusive production cross section is presented. Differential cross sections are measured as a function of the transverse momentum and the absolute value of the rapidity of top and anti-top quarks.

Displacement cross sections and PKA spectra: tables and applications

International Nuclear Information System (INIS)

Doran, D.G.; Graves, N.J.

1976-12-01

Damage energy cross sections to 20 MeV are given for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, niobium, molybdenum, tantalum, tungsten, lead, and 18Cr10Ni stainless steel. They are based on ENDF/B-IV nuclear data and the Lindhard energy partition model. Primary knockon atom (PKA) spectra are given for aluminum, iron, niobium, tantalum, and lead for neutron energies up to 15 MeV at approximately one-quarter lethargy intervals. The contributions of various reactions to both the displacement cross sections (taken to be proportional to the damage energy cross sections) and the PKA spectra are presented graphically. Spectral-averaged values of the displacement cross sections are given for several spectra, including approximate maps for the Experimental Breeder Reactor-II (EBR-II) and several positions in the Fast Test Reactor (FTR). Flux values are included to permit estimation of displacement rates. Graphs show integral PKA spectra for the five metals listed above for neutron spectra corresponding to locations in the EBR-II, the High Flux Isotope Reactor (HFIR), and a conceptual fusion reactor (UWMAK-I). Detailed calculations are given only for cases not previously documented. Uncertainty estimates are included

Electron impact ionisation cross sections of iron oxides

Science.gov (United States)

Huber, Stefan E.; Mauracher, Andreas; Sukuba, Ivan; Urban, Jan; Maihom, Thana; Probst, Michael

2017-12-01

We report electron impact ionisation cross sections (EICSs) of iron oxide molecules, FexOx and FexOx+1 with x = 1, 2, 3, from the ionisation threshold to 10 keV, obtained with the Deutsch-Märk (DM) and binary-encounter-Bethe (BEB) methods. The maxima of the EICSs range from 3.10 to 9 . 96 × 10-16 cm2 located at 59-72 eV and 5.06 to 14.32 × 10-16 cm2 located at 85-108 eV for the DM and BEB approaches, respectively. The orbital and kinetic energies required for the BEB method are obtained by employing effective core potentials for the inner core electrons in the quantum chemical calculations. The BEB cross sections are 1.4-1.7 times larger than the DM cross sections which can be related to the decreasing population of the Fe 4s orbitals upon addition of oxygen atoms, together with the different methodological foundations of the two methods. Both the DM and BEB cross sections can be fitted excellently to a simple analytical expression used in modelling and simulation codes employed in the framework of nuclear fusion research. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-80308-2.

Neutron Cross Sections for Aluminium

Energy Technology Data Exchange (ETDEWEB)

Forsberg, Leif

1963-08-15

Total, elastic, inelastic, (n, 2n), (n, {alpha}), (n, p), and (n, {gamma}) cross sections for aluminium have been compiled from thermal to 100 MeV based upon literature search and theoretical interpolations and estimates. Differential elastic cross sections in the centre of mass system are represented by the Legendre coefficients. This method was chosen in order to obtain the best description of the energy dependence of the anisotropy.

High ET jet cross sections at CDF

International Nuclear Information System (INIS)

Flaugher, B.

1996-08-01

The inclusive jet cross section for p anti p collisions at √s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the Σ E T cross section at √s = 1.8 TeV and the central inclusive jet cross section at √s = 0.630 TeV will also be shown

Compound nucleus effects in spin-spin cross sections

International Nuclear Information System (INIS)

Thompson, W.J.

1976-01-01

By comparison with recent data, it is shown that spin-spin cross sections for low-energy neutrons may be dominated by a simple compound-elastic level-density effect, independent of spin-spin terms in the nucleon-nucleus optical-model potential. (Auth.)

Measurement of Scattering Cross Section with a Spectrophotometer with an Integrating Sphere Detector.

Science.gov (United States)

Gaigalas, A K; Wang, Lili; Karpiak, V; Zhang, Yu-Zhong; Choquette, Steven

2012-01-01

A commercial spectrometer with an integrating sphere (IS) detector was used to measure the scattering cross section of microspheres. Analysis of the measurement process showed that two measurements of the absorbance, one with the cuvette placed in the normal spectrometer position, and the second with the cuvette placed inside the IS, provided enough information to separate the contributions from scattering and molecular absorption. Measurements were carried out with microspheres with different diameters. The data was fitted with a model consisting of the difference of two terms. The first term was the Lorenz-Mie (L-M) cross section which modeled the total absorbance due to scattering. The second term was the integral of the L-M differential cross section over the detector acceptance angle. The second term estimated the amount of forward scattered light that entered the detector. A wavelength dependent index of refraction was used in the model. The agreement between the model and the data was good between 300 nm and 800 nm. The fits provided values for the microsphere diameter, the concentration, and the wavelength dependent index of refraction. For wavelengths less than 300 nm, the scattering cross section had significant spectral structure which was inversely related to the molecular absorption. This work addresses the measurement and interpretation of the scattering cross section for wavelengths between 300 nm and 800 nm.

Total reaction cross section for 12C+16O below the Coulomb barrier

International Nuclear Information System (INIS)

Cujec, B.; Barnes, C.A.

1976-01-01

The energy dependence of the total reaction cross section, sigma(E), for 12 C+ 16 0 has been measured over the range Esub(c.m.)=4-12 MeV, by detecting γ-rays from the various possible residual nuclei with two large NaI(Tl) detectors placed close to the target. This technique for measuring total reaction cross sections was explored in some detail and shown to yield reliable values for sigma(E). Although the principal emphasis of this work was placed on obtaining reliable cross sections, a preliminary study has been made of the suitability of various methods for extrapolating the cross section to still lower energies. The statistical model provides a good fit with a reasonable value for the strength function, 2 >/ =6.8x10 -2 , over the range Esub(c.m.)=6.5-12 MeV, but predicts cross sections which are much too large for Esub(c.m.)<6.5 MeV. Optical model fits at low energies are especially sensitive to the radius and diffuseness of the imaginary component of the potential and, since these are still poorly known at present, such extrapolations may be wrong by orders of magnitude. A simple barrier penetration model gives a moderately good fit to the data and seems to provide the safest extrapolation to lower energies at the present time. It is clear, however, that our knowledge of the heavy-ion reaction mechanism at low energies is incomplete, and that cross-section measurements at still lower energies are needed to establish the correct procedure for extrapolating heavy-ion reaction cross sections to low energies. (Auth.)

Effects of target shape and reflection on laser radar cross sections.

Science.gov (United States)

Steinvall, O

2000-08-20

Laser radar cross sections have been evaluated for a number of ideal targets such as cones, spheres, paraboloids, and cylinders by use of different reflection characteristics. The time-independent cross section is the ratio of the cross section of one of these forms to that of a plate with the same maximum radius. The time-dependent laser radar cross section involves the impulse response from the object shape multiplied by the beam's transverse profile and the surface bidirectional reflection distribution function. It can be clearly seen that knowledge of the combined effect of object shape and reflection characteristics is important for determining the shape and the magnitude of the laser radar return. The results of this study are of interest for many laser radar applications such as ranging, three-dimensional imaging-modeling, tracking, antisensor lasers, and target recognition.

Recommended evaluation procedure for photonuclear cross section

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Ouk; Chang, Jonghwa; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

In order to generate photonuclear cross section library for the necessary applications, data evaluation is combined with theoretical evaluation, since photonuclear cross sections measured cannot provide all necessary data. This report recommends a procedure consisting of four steps: (1) analysis of experimental data, (2) data evaluation, (3) theoretical evaluation and, if necessary, (4) modification of results. In the stage of analysis, data obtained by different measurements are reprocessed through the analysis of their discrepancies to a representative data set. In the data evaluation, photonuclear absorption cross sections are evaluated via giant dipole resonance and quasi-deutron mechanism. With photoabsorption cross sections from the data evaluation, theoretical evaluation is applied to determine various decay channel cross sections and emission spectra using equilibrium and preequilibrium mechanism. After this, the calculated results are compared with measured data, and in some cases the results are modified to better describe measurements. (author)

Exact quantum cross sections for a three dimensional angle dependent model for three body reactions.

Science.gov (United States)

Baer, M.; Kouri, D. J.

1971-01-01

Exact quantum mechanical reactive cross sections are reported for a three dimensional angle dependent model surface. The surface simulates an atom-heteronuclear diatom system A + BC leading to AB + C where atom B is much heavier than A or C. The molecules BC and AB are taken to be rotating vibrators which can dissociate. Results for two angle dependent potentials are given.

MPI version of NJOY and its application to multigroup cross-section generation

Energy Technology Data Exchange (ETDEWEB)

Alpan, A.; Haghighat, A.

1999-07-01

Multigroup cross-section libraries are needed in performing neutronics calculations. These libraries are referred to as broad-group libraries. The number of energy groups and group structure are highly dependent on the application and/or user's objectives. For example, for shielding calculations, broad-group libraries such as SAILOR and BUGLE with 47-neutron and 20-gamma energy groups are used. The common procedure to obtain a broad-group library is a three-step process: (1) processing pointwise ENDF (PENDF) format cross sections; (2) generating fine-group cross sections; and (3) collapsing fine-group cross sections to broad-group. The NJOY code is used to prepare fine-group cross sections by processing pointwise ENDF data. The code has several modules, each one performing a specific task. For instance, the module RECONR performs linearization and reconstruction of the cross sections, and the module GROUPR generates multigroup self-shielded cross sections. After fine-group, i.e., groupwise ENDF (GENDF), cross sections are produced, cross sections are self-shielded, and a one-dimensional transport calculation is performed to obtain flux spectra at specific regions in the model. These fluxes are then used as weighting functions to collapse the fine-group cross sections to obtain a broad-group cross-section library. The third step described is commonly performed by the AMPX code system. SMILER converts NJOY GENDF filed to AMPX master libraries, AJAX collects the master libraries. BONAMI performs self-shielding calculations, NITAWL converts the AMPX master library to a working library, XSDRNPM performs one-dimensional transport calculations, and MALOCS collapses fine-group cross sections to broad-group. Finally, ALPO is used to generate ANISN format libraries. In this three-step procedure, generally NJOY requires the largest amount of CPU time. This time varies depending on the user's specified parameters for each module, such as reconstruction tolerances

MPI version of NJOY and its application to multigroup cross-section generation

International Nuclear Information System (INIS)

Alpan, A.; Haghighat, A.

1999-01-01

Multigroup cross-section libraries are needed in performing neutronics calculations. These libraries are referred to as broad-group libraries. The number of energy groups and group structure are highly dependent on the application and/or user's objectives. For example, for shielding calculations, broad-group libraries such as SAILOR and BUGLE with 47-neutron and 20-gamma energy groups are used. The common procedure to obtain a broad-group library is a three-step process: (1) processing pointwise ENDF (PENDF) format cross sections; (2) generating fine-group cross sections; and (3) collapsing fine-group cross sections to broad-group. The NJOY code is used to prepare fine-group cross sections by processing pointwise ENDF data. The code has several modules, each one performing a specific task. For instance, the module RECONR performs linearization and reconstruction of the cross sections, and the module GROUPR generates multigroup self-shielded cross sections. After fine-group, i.e., groupwise ENDF (GENDF), cross sections are produced, cross sections are self-shielded, and a one-dimensional transport calculation is performed to obtain flux spectra at specific regions in the model. These fluxes are then used as weighting functions to collapse the fine-group cross sections to obtain a broad-group cross-section library. The third step described is commonly performed by the AMPX code system. SMILER converts NJOY GENDF filed to AMPX master libraries, AJAX collects the master libraries. BONAMI performs self-shielding calculations, NITAWL converts the AMPX master library to a working library, XSDRNPM performs one-dimensional transport calculations, and MALOCS collapses fine-group cross sections to broad-group. Finally, ALPO is used to generate ANISN format libraries. In this three-step procedure, generally NJOY requires the largest amount of CPU time. This time varies depending on the user's specified parameters for each module, such as reconstruction tolerances, temperatures

Simple systematization of vibrational excitation cross-section calculations for resonant electron-molecule scattering in the boomerang and impulse models.

Science.gov (United States)

Sarma, Manabendra; Adhikari, S; Mishra, Manoj K

2007-01-28

Vibrational excitation (nu(f), where psi(nu(i))(R,t) approximately =e(-iH(A(2))-(R)t/h phi(nu(i))(R) with time evolution under the influence of the resonance anionic Hamiltonian H(A(2) (-))(A(2) (-)=N(2)(-)/H(2) (-)) implemented using Lanczos and fast Fourier transforms. The target (A(2)) vibrational eigenfunctions phi(nu(i))(R) and phi(nu(f))(R) are calculated using Fourier grid Hamiltonian method applied to potential energy (PE) curves of the neutral target. Application of this simple systematization to calculate vibrational structure in e-N(2) and e-H(2) scattering cross-sections provides mechanistic insights into features underlying presence/absence of structure in e-N(2) and e-H(2) scattering cross-sections. The results obtained with approximate PE curves are in reasonable agreement with experimental/calculated cross-section profiles, and cross correlation functions provide a simple demarcation between the boomerang and impulse models.

Recommended activation detector cross sections (RNDL-82)

International Nuclear Information System (INIS)

Bondars, Kh.Ya.; Lapenas, A.A.

1984-01-01

The results of the comparison between measured and calculated average cross sections in 5 benchmark experiments are presented. Calculations have been based on the data from 10 libraries of evaluated cross sections. The recommended library (RNDL-82) of the activation detector cross sections has been created on the basis of the comparison. RNDL-82, including 26 reactions, and the basic characteristics of the detectors are presented. (author)

The γ total cross section and the photon structure functions

International Nuclear Information System (INIS)

Alexander, G.

1986-01-01

A review on the current experimental status of the photon-photon total hadronic cross section as a function of energy and Q 2 is given in addition to the results obtained for the leptonic and hadronic photon structure functions. The results are discussed in terms of the point-like part of the photon and non-perturbative VDM part. It is shown that the cross section at Q 2 = 0 is well described by VDM derived models

Activation cross section and isomeric cross section ratios for the (n ,2 n ) reaction on 153Eu

Science.gov (United States)

Luo, Junhua; Jiang, Li; Li, Suyuan

2017-10-01

The 153Eu(n ,2 n ) m1,m2,g152Eu cross section was measured by means of the activation technique at three neutron energies in the range 13-15 MeV. The quasimonoenergetic neutron beam was formed via the 3H(d ,n ) 4He reaction, in the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ-ray spectroscopy. The cross section of the population of the second high-spin (8-) isomeric state was measured along with the reaction cross section populating both the ground (3-) and the first isomeric state (0-). Cross sections were also evaluated theoretically using the numerical code TALYS-1.8, with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Organizational home care models across Europe: A cross sectional study.

Science.gov (United States)

Van Eenoo, Liza; van der Roest, Henriëtte; Onder, Graziano; Finne-Soveri, Harriet; Garms-Homolova, Vjenka; Jonsson, Palmi V; Draisma, Stasja; van Hout, Hein; Declercq, Anja

2018-01-01

Decision makers are searching for models to redesign home care and to organize health care in a more sustainable way. The aim of this study is to identify and characterize home care models within and across European countries by means of structural characteristics and care processes at the policy and the organization level. At the policy level, variables that reflected variation in health care policy were included based on a literature review on the home care policy for older persons in six European countries: Belgium, Finland, Germany, Iceland, Italy, and the Netherlands. At the organizational level, data on the structural characteristics and the care processes were collected from 36 home care organizations by means of a survey. Data were collected between 2013 and 2015 during the IBenC project. An observational, cross sectional, quantitative design was used. The analyses consisted of a principal component analysis followed by a hierarchical cluster analysis. Fifteen variables at the organizational level, spread across three components, explained 75.4% of the total variance. The three components made it possible to distribute home care organizations into six care models that differ on the level of patient-centered care delivery, the availability of specialized care professionals, and the level of monitoring care performance. Policy level variables did not contribute to distinguishing between home care models. Six home care models were identified and characterized. These models can be used to describe best practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wind Turbine Cross-Sectional Stiffness Analysis Using Internally Layered Solid Elements

DEFF Research Database (Denmark)

Couturier, Philippe; Krenk, Steen

2016-01-01

An efficient finite element modeling approach is presented for analyzing the general cross-sectional stiffness properties and stress distribution of thin- and thick-walled sections with isotropic and general anisotropic materials. The procedure is based on discretizing the walls of the section...

Timoshenko beam element with anisotropic cross-sectional properties

DEFF Research Database (Denmark)

Stäblein, Alexander; Hansen, Morten Hartvig

2016-01-01

Beam models are used for the aeroelastic time and frequency domain analysis of wind turbines due to their computational efficiency. Many current aeroelastic tools for the analysis of wind turbines rely on Timoshenko beam elements with classical crosssectional properties (EA, EI, etc.). Those cross......-sectional properties do not reflect the various couplings arising from the anisotropic behaviour of the blade material. A twonoded, three-dimensional Timoshenko beam element was therefore extended to allow for anisotropic cross-sectional properties. For an uncoupled beam, the resulting shape functions are identical...... to the original formulation. The new element was implemented into a co-rotational formulation and validated against natural frequencies and several static load cases of previous works....

Fast-neutron scattering cross sections of elemental silver

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.

1982-05-01

Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160 0 . Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V

Evaluation of 28,29,30Si neutron induced cross sections for ENDF/B-VI

International Nuclear Information System (INIS)

Hetrick, D.M.; Larson, D.C.; Larson, N.M.; Leal, L.C.; Epperson, S.J.

1997-04-01

Separate evaluations have been done for the three stable isotopes of silicon for ENDF/B-VI. The evaluations are based on analysis of experimental data, supplemented by results of nuclear model calculations. The computational methods and the parameters required as input to the nuclear model codes are reviewed. Discussion of the evaluated data given for resonance parameters, neutron induced reaction cross sections, associated angular and energy distributions, and gamma-ray production cross sections is included. Extensive comparisons of the evaluated cross sections to measured data are shown in this report. The evaluations include all necessary data to allow KERMA (Kinetic Energy Released in MAterials) and displacement cross sections to be calculated directly. These quantities are fundamental to studies of neutron heating and radiation damage

Methodology to carry out a sensitivity and uncertainty analysis for cross sections using a coupled model Trace-Parcs

International Nuclear Information System (INIS)

Reyes F, M. C.; Del Valle G, E.; Gomez T, A. M.; Sanchez E, V.

2015-09-01

A methodology was implemented to carry out a sensitivity and uncertainty analysis for cross sections used in a coupled model for Trace/Parcs in a transient of control rod fall of a BWR-5. A model of the reactor core for the neutronic code Parcs was used, in which the assemblies located in the core are described. Thermo-hydraulic model in Trace was a simple model, where only a component type Chan was designed to represent all the core assemblies, which it was within a single vessel and boundary conditions were established. The thermo-hydraulic part was coupled with the neutron part, first for the steady state and then a transient of control rod fall was carried out for the sensitivity and uncertainty analysis. To carry out the analysis of cross sections used in the coupled model Trace/Parcs during the transient, the Probability Density Functions for 22 parameters selected from the total of neutronic parameters that use Parcs were generated, obtaining 100 different cases for the coupled model Trace/Parcs, each one with a database of different cross sections. All these cases were executed with the coupled model, obtaining in consequence 100 different output files for the transient of control rod fall doing emphasis in the nominal power, for which an uncertainty analysis was realized at the same time generate the band of uncertainty. With this analysis is possible to observe the ranges of results of the elected responses varying the selected uncertainty parameters. The sensitivity analysis complements the uncertainty analysis, identifying the parameter or parameters with more influence on the results and thus focuses on these parameters in order to better understand their effects. Beyond the obtained results, because is not a model with real operation data, the importance of this work is to know the application of the methodology to carry out the sensitivity and uncertainty analyses. (Author)

Dielectronic recombination cross sections for H-like ions

International Nuclear Information System (INIS)

Pindzola, M.S.; Badnell, N.R.; Griffin, D.C.

1990-01-01

Dielectronic recombination cross sections for several H-like atomic ions are calculated in an isolated-resonance, distorted-wave approximation. Fine-structure and configuration-interaction effects are examined in detail for the O 7+ cross section. Hartree-Fock, intermediate-coupled, multiconfiguration dielectronic recombination cross sections for O 7+ are then compared with the recent experimental measurements obtained with the Test Storage Ring in Heidelberg. The cross-section spectra line up well in energy and the shape of the main resonance structures are comparable. The experimental integrated cross sections differ by up to 20% from theory, but this may be due in part to uncertainties in the electron distribution function

Comparative analysis among several cross section sets

International Nuclear Information System (INIS)

Caldeira, A.D.

1983-01-01

Critical parameters were calculated using the one dimensional multigroup transport theory for several cross section sets. Calculations have been performed for water mixtures of uranium metal, plutonium metal and uranium-thorium oxide, and for metallics systems, to determine the critical dimensions of geometries (sphere and cylinder). For this aim, the following cross section sets were employed: 1) multigroup cross section sets obtained from the GAMTEC-II code; 2) the HANSEN-ROACH cross section sets; 3) cross section sets from the ENDF/B-IV, processed by the NJOY code. Finally, we have also calculated the corresponding critical radius using the one dimensional multigroup transport DTF-IV code. The numerical results agree within a few percent with the critical values obtained in the literature (where the greatest discrepancy occured in the critical dimensions of water mixtures calculated with the values generated by the NJOY code), a very good results in comparison with similar works. (Author) [pt

Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

Science.gov (United States)

Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

2016-02-01

Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

Cross sections for fast-neutron interaction with ytterbium isotopes

International Nuclear Information System (INIS)

Luo, Junhua; Liu, Rong; Jiang, Li; Ge, Suhong; Liu, Zhenlai; Sun, Guihua

2013-01-01

Highlights: ► The cross sections for the (n,x) reactions on ytterbium isotopes have been measured. ► Mono-energetic neutron beams using the D + T reaction; Energies: 13.5 and 14.8 MeV. ► Neutron cross-section measurements by means of the activation technique. ► Reference reactions 93 Nb(n,2n) 92m Nb and 27 (n,α) 24 Na. ► Data for 172 Yb(n,p) 172 Tm and 176 Yb(n,d * ) 175 Tm are reported for the first time. - Abstract: Measurements of (n,2n), (n,p), and (n,d * ) (The expression (n,d * ) cross section used in this work includes a sum of (n,d), (n,np) and (n,pn) cross sections.) reaction cross-sections on ytterbium isotopes have been carried out in the range of 13.5–14.8 MeV using the activation technique. The monoenergetic neutron beams were produced via the 3 H(d,n) 3 He reaction. The neutron energies of different directions were determined using the Nb/Zr method. Samples were activated along with along with Nb and Al monitor foils to determine the incident neutron flux. Data are reported for the following reactions: 168 Yb(n,2n) 167 Yb, 170 Yb(n,2n) 169m+g Yb, 176 Yb(n,2n) 175m+g Yb, 172 Yb(n,p) 172 Tm, 173 Yb(n,p) 173 Tm, 176 Yb(n,d * ) 175 Tm, 174 Yb(n,p) 174 Tm, and 176 Yb(n,p) 176 Tm. The experimentally deduced cross-sections are compared with the existing experimental data. Furthermore, theoretical statistical model, based on the Hauser–Feshbach formalism, have been carried out using the HFTT

Fission cross section measurements at intermediate energies

International Nuclear Information System (INIS)

Laptev, Alexander

2005-01-01

The activity in intermediate energy particle induced fission cross-section measurements of Pu, U isotopes, minor actinides and sub-actinides in PNPI of Russia is reviewed. The neutron-induced fission cross-section measurements are under way in the wide energy range of incident neutrons from 0.5 MeV to 200 MeV at the GNEIS facility. In number of experiments at the GNEIS facility, the neutron-induced fission cross sections were obtained for many nuclei. In another group of experiments the proton-induced fission cross-section have been measured for proton energies ranging from 200 to 1000 MeV at 100 MeV intervals using the proton beam of PNPI synchrocyclotron. (author)

Partial cross sections near the higher resonances

International Nuclear Information System (INIS)

Falk-Vairant, P.; Valladas, G.

1961-07-01

As a continuation of the report given at the 10. Rochester Conference, recent measurements of charge-exchange cross section and π 0 production in π - -p interactions are presented here. Section 1 gives a summary of the known results for the elastic, inelastic, and charge-exchange cross sections. Section 2 presents the behavior of the cross sections in the T=1/2 state, in order to discuss the resonances at 600 and 890 MeV. Section 3 discusses the charge-exchange scattering and the interference term between the T=1/2 and T=3/2 states. Section 4 presents some comments on inelastic processes. This report is reprinted from 'Reviews of Modern Physics', Vol. 33, No. 3, 362-367, July, 1961

Experimental and theoretical electron-scattering cross-section data for dichloromethane

Science.gov (United States)

Krupa, K.; Lange, E.; Blanco, F.; Barbosa, A. S.; Pastega, D. F.; Sanchez, S. d'A.; Bettega, M. H. F.; García, G.; Limão-Vieira, P.; Ferreira da Silva, F.

2018-04-01

We report on a combination of experimental and theoretical investigations into the elastic differential cross sections (DCSs) and integral cross sections for electron interactions with dichloromethane, C H2C l2 , in the incident electron energy over the 7.0-30 eV range. Elastic electron-scattering cross-section calculations have been performed within the framework of the Schwinger multichannel method implemented with pseudopotentials (SMCPP), and the independent-atom model with screening-corrected additivity rule including interference-effects correction (IAM-SCAR+I). The present elastic DCSs have been found to agree reasonably well with the results of IAM-SCAR+I calculations above 20 eV and also with the SMC calculations below 30 eV. Although some discrepancies were found for 7 eV, the agreement between the two theoretical methodologies is remarkable as the electron-impact energy increases. Calculated elastic DCSs are also reported up to 10000 eV for scattering angles from 0° to 180° together with total cross section within the IAM-SCAR+I framework.

Electron Capture Cross Sections for Stellar Nucleosynthesis

Directory of Open Access Journals (Sweden)

P. G. Giannaka

2015-01-01

Full Text Available In the first stage of this work, we perform detailed calculations for the cross sections of the electron capture on nuclei under laboratory conditions. Towards this aim we exploit the advantages of a refined version of the proton-neutron quasiparticle random-phase approximation (pn-QRPA and carry out state-by-state evaluations of the rates of exclusive processes that lead to any of the accessible transitions within the chosen model space. In the second stage of our present study, we translate the abovementioned e--capture cross sections to the stellar environment ones by inserting the temperature dependence through a Maxwell-Boltzmann distribution describing the stellar electron gas. As a concrete nuclear target we use the 66Zn isotope, which belongs to the iron group nuclei and plays prominent role in stellar nucleosynthesis at core collapse supernovae environment.

Theoretical study of cross sections of proton-induced reactions on cobalt

Directory of Open Access Journals (Sweden)

Mustafa Yiğit

2018-04-01

Full Text Available Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on 59Co structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code. Keywords: Cobalt, Nuclear Structural Materials, Reaction Cross Section, TENDL Database

Thermal conduction by dark matter with velocity and momentum-dependent cross-sections

OpenAIRE

Vincent, Aaron C.; Scott, Pat

2013-01-01

We use the formalism of Gould and Raffelt to compute the dimensionless thermal conduction coefficients for scattering of dark matter particles with standard model nucleons via cross-sections that depend on the relative velocity or momentum exchanged between particles. Motivated by models invoked to reconcile various recent results in direct detection, we explicitly compute the conduction coefficients $\\alpha$ and $\\kappa$ for cross-sections that go as $v_{\\rm rel}^2$, $v_{\\rm rel}^4$, $v_{\\rm...

Differential Single-Capture Cross Sections for Fast Alpha–Helium Collisions

International Nuclear Information System (INIS)

Ghanbari-Adivi, Ebrahim; Ghavaminia, Hoda

2014-01-01

A four-body theoretical study of the single charge transfer process in collision of energetic alpha ions with helium atoms in their ground states is presented. The model utilizes the Coulomb–Born distorted wave approximation with correct boundary conditions to calculate the single-electron capture differential and integral cross sections. The influence of the dynamic and static electron correlations on the capture probability is investigated. The results of the calculations are compared with the recent experimental measurements for differential cross sections and with the other theoretical manipulations. The results for scattering at extreme forward angles are in good agreement with the experimental measurements, but in other scattering angles the agreement is poor. However, the present four-body results for integral cross sections are in excellent agreement with the experimental data. (author)

Classical scattering cross section in sputtering transport theory

International Nuclear Information System (INIS)

Zhang Zhulin

2002-01-01

For Lindhard scaling interaction potential scattering commonly used in sputtering theory, the authors analyzed the great difference between Sigmund's single power and the double power cross sections calculated. The double power cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m∼0.1). In particular, to solve the transport equations by K r -C potential interaction given by Urbassek few years ago, only the double power cross sections (m∼0.1) can yield better approximate results for the number of recoils. Therefore, the Sigmund's single power cross section might be replaced by the double power cross sections in low energy collision cascade theory

Extensive set of low-fidelity cross sections covariances in fast neutron region

International Nuclear Information System (INIS)

Pigni, M.T.; Herman, M.; Oblozinsky, P.

2008-01-01

We produced a large set of neutron cross section covariances in the energy range of 5 keV - 20 MeV. The covariance matrices were calculated for 307 isotopes divided into three major regions: structural materials, fission products, and heavy nuclei. These results have been developed to provide initial, but consistent estimates of covariance data for nuclear criticality safety applications. The methodology for the determination of such covariance matrices is presented. It combines the nuclear reaction model code EMPIRE which calculates sensitivity of cross sections to nuclear reaction model parameters, and the Bayesian code KALMAN that propagates uncertainties of the model parameters to cross sections. Taking into account large number of materials, only marginal reference to experimental data was made. The covariances were derived from the perturbation of several key model parameters selected by the sensitivity analysis. These parameters refer to the optical model potential, the level densities and the strength of the pre-equilibrium emission. This work represents the first try ever to generate nuclear data covariances on such a large scale. (authors)

Numerical computation of discrete differential scattering cross sections for Monte Carlo charged particle transport

International Nuclear Information System (INIS)

Walsh, Jonathan A.; Palmer, Todd S.; Urbatsch, Todd J.

2015-01-01

Highlights: • Generation of discrete differential scattering angle and energy loss cross sections. • Gauss–Radau quadrature utilizing numerically computed cross section moments. • Development of a charged particle transport capability in the Milagro IMC code. • Integration of cross section generation and charged particle transport capabilities. - Abstract: We investigate a method for numerically generating discrete scattering cross sections for use in charged particle transport simulations. We describe the cross section generation procedure and compare it to existing methods used to obtain discrete cross sections. The numerical approach presented here is generalized to allow greater flexibility in choosing a cross section model from which to derive discrete values. Cross section data computed with this method compare favorably with discrete data generated with an existing method. Additionally, a charged particle transport capability is demonstrated in the time-dependent Implicit Monte Carlo radiative transfer code, Milagro. We verify the implementation of charged particle transport in Milagro with analytic test problems and we compare calculated electron depth–dose profiles with another particle transport code that has a validated electron transport capability. Finally, we investigate the integration of the new discrete cross section generation method with the charged particle transport capability in Milagro.

Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables

CERN Document Server

Dittmaier, S; Passarino, G; Tanaka, R; Baglio, J; Bolzoni, P; Boughezal, R; Brein, O; Collins-Tooth, C; Dawson, S; Dean, S; Denner, A; Farrington, S; Felcini, M; Flechl, M; de Florian, D; Forte, S; Grazzini, M; Hackstein, C; Hahn, T; Harlander, R; Hartonen, T; Heinemeyer, S; Huston, J; Kalinowski, A; Krämer, M; Krauss, F; Lee, J S; Lehti, S; Maltoni, F; Mazumdar, K; Moch, S -O; Mück, A; Mühlleitner, M; Nason, P; Neu, C; Oleari, C; Olsen, J; Palmer, S; Petriello, F; Piacquadio, G; Pilaftsis, A; Potter, C T; Puljak, I; Qian, J; Rebuzzi, D; Reina, L; Rzehak, H; Schumacher, M; Slavich, P; Spira, M; Stöckli, F; Thorne, R S; Acosta, M Vazquez; Vickey, T; Vicini, A; Wackeroth, D; Warsinsky, M; Weber, M; Weiglein, G; Weydert, C; Yu, J; Zaro, M; Zirke, T

2011-01-01

This Report summarizes the results of the first 10 months' activities of the LHC Higgs Cross Sections Working Group. The main goal of the working group was to present the status-of-art on Higgs Physics at the LHC integrating all new results that have appeared in the last few years. The Report is more than a mere collection of the proceedings of the general meetings. The subgroups have been working in different directions. An attempt has been made to present the first Report from these subgroups in a complete and homogeneous form. The subgroups' contributions correspondingly comprise the main parts of the Report. A significant amount of work has been performed in providing higher-order corrections to the Higgs-boson cross sections and pinning down the theoretical uncertainty of the Standard Model predictions. This Report comprises explicit numerical results on total cross sections, leaving the issues of event selection cuts and differential distributions to future publications. The subjects for further study a...

Accurate Cross Sections for Microanalysis

OpenAIRE

Rez, Peter

2002-01-01

To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a...

180Ta/sup g,m/ production cross sections form the 180Hf(p,n) reaction

International Nuclear Information System (INIS)

Norman, E.B.; Renner, T.R.; Grant, P.J.

1981-01-01

Cross sections have been determined for the production of the J/sup π/ = 1 + 180 Ta/sup g/ and the J/sup π/= 9 - 180 Ta/sup m/ from the 180 Hf(p,n) reaction. The 180 Ta/sup g/ cross sections were determined from measurements of γ-rays emitted following the electron-capture and β-decay of this 8.1-hour state. Total 180 Ta production cross sections were determined from measurements of the thick-target (p,n) yield. 180 Ta/sup m/ cross sections were calculated by subtracting the 180 Ta/sup g/ cross sections from the total (p,n) cross sections. These measurements are compared with the results of a statistical-model evaporation calculation

The Gaussian Graphical Model in Cross-Sectional and Time-Series Data.

Science.gov (United States)

Epskamp, Sacha; Waldorp, Lourens J; Mõttus, René; Borsboom, Denny

2018-04-16

We discuss the Gaussian graphical model (GGM; an undirected network of partial correlation coefficients) and detail its utility as an exploratory data analysis tool. The GGM shows which variables predict one-another, allows for sparse modeling of covariance structures, and may highlight potential causal relationships between observed variables. We describe the utility in three kinds of psychological data sets: data sets in which consecutive cases are assumed independent (e.g., cross-sectional data), temporally ordered data sets (e.g., n = 1 time series), and a mixture of the 2 (e.g., n > 1 time series). In time-series analysis, the GGM can be used to model the residual structure of a vector-autoregression analysis (VAR), also termed graphical VAR. Two network models can then be obtained: a temporal network and a contemporaneous network. When analyzing data from multiple subjects, a GGM can also be formed on the covariance structure of stationary means-the between-subjects network. We discuss the interpretation of these models and propose estimation methods to obtain these networks, which we implement in the R packages graphicalVAR and mlVAR. The methods are showcased in two empirical examples, and simulation studies on these methods are included in the supplementary materials.

Differential photoproduction cross sections of the Σ0(1385), Λ(1405), and Λ(1520)

Science.gov (United States)

Moriya, K.; Schumacher, R. A.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bellis, M.; Bennett, R. P.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Collins, P.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Dey, B.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; Egiyan, H.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Fleming, J. A.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hakobyan, H.; Hanretty, C.; Heddle, D.; Hicks, K.; Ho, D.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Lewis, S.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Martinez, D.; Mayer, M.; McCracken, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Nasseripour, R.; Nepali, C. S.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Phelps, E.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Taylor, S.; Tian, Y.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Weinstein, L. B.; Williams, M.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

2013-10-01

We report the exclusive photoproduction cross sections for the Σ0(1385), Λ(1405), and Λ(1520) in the reactions γ+p→K++Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective-Lagrangian approach and fit to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Λ(1405) region are strikingly different for the Σ+π-, Σ0π0, and Σ-π+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.

Criticality benchmark comparisons leading to cross-section upgrades

International Nuclear Information System (INIS)

Alesso, H.P.; Annese, C.E.; Heinrichs, D.P.; Lloyd, W.R.; Lent, E.M.

1993-01-01

For several years criticality benchmark calculations with COG. COG is a point-wise Monte Carlo code developed at Lawrence Livermore National Laboratory (LLNL). It solves the Boltzmann equation for the transport of neutrons and photons. The principle consideration in developing COG was that the resulting calculation would be as accurate as the point-wise cross-sectional data, since no physics computational approximations were used. The objective of this paper is to report on COG results for criticality benchmark experiments in concert with MCNP comparisons which are resulting in corrections an upgrades to the point-wise ENDL cross-section data libraries. Benchmarking discrepancies reported here indicated difficulties in the Evaluated Nuclear Data Livermore (ENDL) cross-sections for U-238 at thermal neutron energy levels. This led to a re-evaluation and selection of the appropriate cross-section values from several cross-section sets available (ENDL, ENDF/B-V). Further cross-section upgrades anticipated

Measurement of the Cross Section of W-boson pair production at LEP

CERN Document Server

Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Button, A.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; van Dierendonck, D.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Moulik, T.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Nandakumar, R.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, A.; Weber, M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

2004-01-01

The cross section of W-boson pair-production is measured with the L3 detector at LEP. In a data sample corresponding to a total luminosity of 629.4/pb, collected at centre-of-mass energies ranging from 189 to 209 GeV, 9834 four-fermion events with W bosons decaying into hadrons or leptons are selected. The total cross section is measured with a precision of 1.4 % and agrees with the Standard Model expectation. Assuming charged-lepton universality, the branching fraction for hadronic W-boson decays is measured to be: Br(W-->hadrons) = 67.50 +- 0.42 (stat.) +- 0.30(syst.) %, in agreement with the Standard Model. Differential cross sections as a function of the W- production angle are also measured for the semi-leptonic channels qqev and qqmv.

Fission cross section calculations for 209Bi target nucleus based on fission reaction models in high energy regions

Directory of Open Access Journals (Sweden)

Kaplan Abdullah

2015-01-01

Full Text Available Implementation of projects of new generation nuclear power plants requires the solving of material science and technological issues in developing of reactor materials. Melts of heavy metals (Pb, Bi and Pb-Bi due to their nuclear and thermophysical properties, are the candidate coolants for fast reactors and accelerator-driven systems (ADS. In this study, α, γ, p, n and 3He induced fission cross section calculations for 209Bi target nucleus at high-energy regions for (α,f, (γ,f, (p,f, (n,f and (3He,f reactions have been investigated using different fission reaction models. Mamdouh Table, Sierk, Rotating Liquid Drop and Fission Path models of theoretical fission barriers of TALYS 1.6 code have been used for the fission cross section calculations. The calculated results have been compared with the experimental data taken from the EXFOR database. TALYS 1.6 Sierk model calculations exhibit generally good agreement with the experimental measurements for all reactions used in this study.

Flow in curved ducts of varying cross-section

Science.gov (United States)

Sotiropoulos, F.; Patel, V. C.

1992-07-01

Two numerical methods for solving the incompressible Navier-Stokes equations are compared with each other by applying them to calculate laminar and turbulent flows through curved ducts of regular cross-section. Detailed comparisons, between the computed solutions and experimental data, are carried out in order to validate the two methods and to identify their relative merits and disadvantages. Based on the conclusions of this comparative study a numerical method is developed for simulating viscous flows through curved ducts of varying cross-sections. The proposed method is capable of simulating the near-wall turbulence using fine computational meshes across the sublayer in conjunction with a two-layer k-epsilon model. Numerical solutions are obtained for: (1) a straight transition duct geometry, and (2) a hydroturbine draft-tube configuration at model scale Reynolds number for various inlet swirl intensities. The report also provides a detailed literature survey that summarizes all the experimental and computational work in the area of duct flows.

Benford's law and cross-sections of A(n,α)B reactions

International Nuclear Information System (INIS)

Liu, X.J.; Ni, D.D.; Zhang, X.P.; Ren, Z.Z.

2011-01-01

Benford's law, also called the first-digit law, states that in lists of numbers from many quite disparate databases, the leading digit is distributed in a non-uniform but actually logarithmic way. We have investigated the first-digit distribution of experimental cross-sections of A(n, α)B reactions. In the case of below-barrier α -particle emission from compound nucleus, it is found that the (n, α) reaction cross-sections approximately follow the first-digit distribution indicated by Benford's law. The origin of this first-digit distribution is discussed within the framework of the statistical model. In addition, Benford's law is used to test the evaluated cross-sections of A(n, α)B reactions. (orig.)

Evaluation of neutron and gamma-ray-production cross-section data for lead

International Nuclear Information System (INIS)

Fu, C.Y.; Perey, F.G.

1975-01-01

A survey was made of the available information on neutron and gamma-ray-production cross-section measurements of lead. From these and from relevant nuclear-structure information on the Pb isotopes, recommended neutron cross-section data sets for lead covering the neutron energy range from 0.00001 eV to 20.0 MeV have been prepared. The cross sections are derived from experimental results available to February 1972 and from calculations based on optical-model, DWBA, and Hauser--Feshbach theories. Comparisons which show good agreement between theoretical and experimental values are displayed in a number of graphs. Also presented graphically are smoothed total cross sections, Legendre coefficients for angular distributions, and a representative energy distribution of gamma rays from resonance capture. 15 tables, 36 figures, 104 references

Cross section homogenization analysis for a simplified Candu reactor

International Nuclear Information System (INIS)

Pounders, Justin; Rahnema, Farzad; Mosher, Scott; Serghiuta, Dumitru; Turinsky, Paul; Sarsour, Hisham

2008-01-01

The effect of using zero current (infinite medium) boundary conditions to generate bundle homogenized cross sections for a stylized half-core Candu reactor problem is examined. Homogenized cross section from infinite medium lattice calculations are compared with cross sections homogenized using the exact flux from the reference core environment. The impact of these cross section differences is quantified by generating nodal diffusion theory solutions with both sets of cross sections. It is shown that the infinite medium spatial approximation is not negligible, and that ignoring the impact of the heterogeneous core environment on cross section homogenization leads to increased errors, particularly near control elements and the core periphery. (authors)

Fission cross section measurements of actinides at LANSCE

Energy Technology Data Exchange (ETDEWEB)

Tovesson, Fredrik [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

Top quark production at the LHC (single top and tt-bar cross sections)

International Nuclear Information System (INIS)

Lange, J.

2014-01-01

With the large number of top quarks produced at the LHC, top quark physics enters an era of precision and properties measurements. This article reviews the recent advances in top quark cross section measurements performed by ATLAS and CMS using data recorded in 2011 with integrated luminosities up to 5 fb -1 . They include precision inclusive cross sections, the establishment of challenging channels, first differential cross section measurements and single top production. An overall good agreement with Standard Model predictions is observed

Methodology series module 3: Cross-sectional studies

Directory of Open Access Journals (Sweden)

Maninder Singh Setia

2016-01-01

Full Text Available Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case–control studies (participants selected based on the outcome status or cohort studies (participants selected based on the exposure status, the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design.

Methodology Series Module 3: Cross-sectional Studies.

Science.gov (United States)

Setia, Maninder Singh

2016-01-01

Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case-control studies (participants selected based on the outcome status) or cohort studies (participants selected based on the exposure status), the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design.

Improved activation cross sections for vanadium and titanium

International Nuclear Information System (INIS)

Muir, D.W.; Arthur, E.D.

1983-01-01

Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in 50 V and 51 V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions 46 Ti(n,2n) and 45 Ti(n,2n) in order to estimate the production of 44 Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years

Cross sections and oscillator strengths for electron-impact excitation of electronic states in polyatomic molecules. Application examples of the BEf- scaling model in optically-allowed transitions

International Nuclear Information System (INIS)

Kato, H.; Kawahara, H.; Hoshino, M.

2009-12-01

Integral cross sections for optically allowed electronic-state excitations by electron impact, are reviewed for polyatomic molecules by applying the Binary-Encounter-Bethe (BEB) scaling model. Following the context of the present review, the scaling model originally proposed by Yong-Ki Kim to determine electron-impact cross sections for ionization of atoms and molecules is also summarized briefly for its wide range of applications [Electron-Impact Cross Section Database, NIST, Y.-K. Kim]. The present report not only focuses on the need for the cross-section data, but also elucidates the verification of the scaling model in the general application for atoms and molecules. Since this report is for a data base, it is summarized for data base users by citing (copying) the descriptions in the original papers and the references within those papers in the style of a textbook. (author)

Compilation of cross-sections. Pt. 1

International Nuclear Information System (INIS)

Flaminio, V.; Moorhead, W.G.; Morrison, D.R.O.; Rivoire, N.

1983-01-01

A compilation of integral cross-sections for hadronic reactions is presented. This is an updated version of CERN/HERA 79-1, 79-2, 79-3. It contains all data published up to the beginning of 1982, but some more recent data have also been included. Plots of the cross-sections versus incident laboratory momentum are also given. (orig.)

Compilation of cross-sections. Pt. 4

International Nuclear Information System (INIS)

Alekhin, S.I.; Ezhela, V.V.; Lugovsky, S.B.; Tolstenkov, A.N.; Yushchenko, O.P.; Baldini, A.; Cobal, M.; Flaminio, V.; Capiluppi, P.; Giacomelli, G.; Mandrioli, G.; Rossi, A.M.; Serra, P.; Moorhead, W.G.; Morrison, D.R.O.; Rivoire, N.

1987-01-01

This is the fourth volume in our series of data compilations on integrated cross-sections for weak, electromagnetic, and strong interaction processes. This volume covers data on reactions induced by photons, neutrinos, hyperons, and K L 0 . It contains all data published up to June 1986. Plots of the cross-sections versus incident laboratory momentum are also given. (orig.)

Status of (n,2n) cross section measurements at Bruyeres-le-Chatel

International Nuclear Information System (INIS)

Frehaut, J.; Bertin, A.; Bois, R.; Jary, J.

1980-05-01

Cross sections for the (n,2n) reactions have been measured between threshold and 15 MeV for about 50 elements and separated isotopes using the large gadolinium-loaded liquid scintillator method and the 7 MV tandem Van de Graaff accelerator as a pulsed neutron source. The (n,2n) cross sections have been normalized to the fission cross section of 238 U; they are obtained with a relative accuracy of 4% to 10%. The systematic trends of the data obtained on series of separated isotopes are discussed, and some comparaisons with statistical model calculations are presented

14N + 10B fusion and elastic scattering cross section measurements near the interaction barrier

International Nuclear Information System (INIS)

Wu, S.C.; Overley, J.C.; Barnes, C.A.; Switkowski, Z.E.

1979-01-01

The 14 N + 10 B fusion reactions were studied at c.m. energies between 2.9 and 7.5 MeV by measuring the yields of γ-rays from the residual nuclei formed by particle evaporation from the compound system. Cross sections for formation of the evaporation residues 16 O, 19 F, 19 Ne, 20 Ne, 21 Ne, 22 Ne, 22 Na, 23 Na and 23 Mg, as well as the total cross section, were deduced from these yields with the aid of statistical model calculations. 14 N + 10 B elastic scattering differential cross sections were measured from 4.3 to 9.1 MeV at THETA 74.4 degrees, and from 3.3 to 8.3 MeV at THETA = 90.0 degrees. The elastic scattering cross sections were analyzed within the framework of the incoming-wave boundary condition (IWBC) model. The fusion cross sections calculated for the real ion-ion potential deduced from the IWBC model fit to the elastic scattering are in good agreement with the measured values

The Measurement of the Quasi-Elastic Neutrino-Nucleon Scattering Cross Section at the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Suwonjandee, Narumon [Cincinnati U.

2004-01-01

The quasi-elastic neutrino nucleon cross section measurement has been measured in the low energy region less than 100 Ge V. The data agree well with the model proposed by C. H. Llewellyn Smith. This model predicts that the quasi-elastic cross section should be constant in the high enery region. The NuTeV experiment at Fermilab provides data which allows us to measure the quasi-elastic cross section for both neutrinos and anti-neutrinos at high energy. We find that $\\sigma^{Neucleon}_{qe}(v) = 0.94 \\pm 0.03(stat.) \\pm 0.07(syst.)$, and $\\sigma^{Neucleon}_{qe}(\\bar\

/sup 12/C(γ,n) cross section from 30 to 100 MeV

International Nuclear Information System (INIS)

Harty, P.D.; Thompson, M.N.; O'Keefe, G.J.

1988-01-01

This paper reports a measurement of the differential photoneutron cross section of /sup 12/C at 65 0 , between E/sub γ/ = 30 and 100 MeV. Tagged photons, monochromatic to within 2.6 MeV, were used, thus allowing the cross sections to a wide range of final states to be observed. The results are compared to the photoproton cross section of /sup 12/C, which was measured previously, under similar conditions. Comparisons are also made with calculations based on the quasi-deuteron model, and with calculations by Gari and Hebach, and Cavinato et al. These latter calculations incorporate two-body effects by the inclusion of meson exchange currents. The agreement between these calculations and the measured cross section is in contrast to predictions of a direct, single-nucleon knockout model of the reaction mechanism, indicating the importance of two-body effects in the photoreaction process for energies greater than 50 MeV

Capture cross sections for very heavy systems

International Nuclear Information System (INIS)

Rowley, N.; Grar, N.; Ntshangase, S.S.

2006-01-01

In intermediate-mass systems, collective excitations of the target and projectile can greatly enhance the sub-barrier capture cross section σ cap by giving rise to a distribution of Coulomb barriers. For such systems, capture essentially leads directly to fusion (formation of a compound nucleus (CN)), which then decays through the emission of light particles (neutrons, protons, and alpha particles). Thus the evaporation-residue (ER) cross section is essentially equal to σ cap . For heavier systems the experimental situation is significantly more complicated due to the presence of quasifission (QF) (rapid separation into two fragments before the CN is formed) and by fusion-fission (FF) of the CN itself. Thus three cross sections need to be measured in order to evaluate σ cap . Although the ER essentially recoil along the beam direction. QF and FF fragments are scattered to all angles and require the measurement of angular distribution in order to obtain the excitation function and barrier distribution for capture. Two other approaches to this problem exist. If QF is not important, one can still measure just the ER cross section and try to reconstruct the corresponding σ cap through use of an evaporation-model code that takes account of the FF degree of freedom. Some earlier results on σ cap obtained in this way will be re-analyzed with detail coupled-channels calculations, and the extra-push phenomenon discussed. One may also try to obtain σ cap by exploiting unitarity, that is, by measuring instead the flux of particles corresponding to quasielastic (QE) scattering from the Coulomb barrier. Some new QE results obtained for the 86 Kr + 208 Pb system at iThemba LABS in South Africa will be presented [ru

2nd-order optical model of the isotopic dependence of heavy ion absorption cross sections for radiation transport studies

Science.gov (United States)

Cucinotta, Francis A.; Yan, Congchong; Saganti, Premkumar B.

2018-01-01

Heavy ion absorption cross sections play an important role in radiation transport codes used in risk assessment and for shielding studies of galactic cosmic ray (GCR) exposures. Due to the GCR primary nuclei composition and nuclear fragmentation leading to secondary nuclei heavy ions of charge number, Z with 3 ≤ Z ≥ 28 and mass numbers, A with 6 ≤ A ≥ 60 representing about 190 isotopes occur in GCR transport calculations. In this report we describe methods for developing a data-base of isotopic dependent heavy ion absorption cross sections for interactions. Calculations of a 2nd-order optical model solution to coupled-channel solutions to the Eikonal form of the nucleus-nucleus scattering amplitude are compared to 1st-order optical model solutions. The 2nd-order model takes into account two-body correlations in the projectile and target ground-states, which are ignored in the 1st-order optical model. Parameter free predictions are described using one-body and two-body ground state form factors for the isotopes considered and the free nucleon-nucleon scattering amplitude. Root mean square (RMS) matter radii for protons and neutrons are taken from electron and muon scattering data and nuclear structure models. We report on extensive comparisons to experimental data for energy-dependent absorption cross sections for over 100 isotopes of elements from Li to Fe interacting with carbon and aluminum targets. Agreement between model and experiments are generally within 10% for the 1st-order optical model and improved to less than 5% in the 2nd-order optical model in the majority of comparisons. Overall the 2nd-order optical model leads to a reduction in absorption compared to the 1st-order optical model for heavy ion interactions, which influences estimates of nuclear matter radii.

Application of cross-sectional time series modeling for the prediction of energy expenditure from heart rate and accelerometry

Science.gov (United States)

Accurate estimation of energy expenditure (EE) in children and adolescents is required for a better understanding of physiological, behavioral, and environmental factors affecting energy balance. Cross-sectional time series (CSTS) models, which account for correlation structure of repeated observati...

NDS multigroup cross section libraries

International Nuclear Information System (INIS)

DayDay, N.

1981-12-01

A summary description and documentation of the multigroup cross section libraries which exist at the IAEA Nuclear Data Section are given in this report. The libraries listed are available either on tape or in printed form. (author)

Particle-driven gravity currents in non-rectangular cross section channels

International Nuclear Information System (INIS)

Zemach, T.

2015-01-01

We consider a high-Reynolds-number gravity current generated by suspension of heavier particles in fluid of density ρ i , propagating along a channel into an ambient fluid of the density ρ a . The bottom and top of the channel are at z = 0, H, and the cross section is given by the quite general −f 1 (z) ≤ y ≤ f 2 (z) for 0 ≤ z ≤ H. The flow is modeled by the one-layer shallow-water equations obtained for the time-dependent motion which is produced by release from rest of a fixed volume of mixture from a lock. We solve the problem by the finite-difference numerical code to present typical height h(x, t), velocity u(x, t), and volume fraction of particles (concentration) ϕ(x, t) profiles. The methodology is illustrated for flow in typical geometries: power-law (f(z) = z α and f(z) = (H − z) α , where α is positive constant), trapezoidal, and circle. In general, the speed of propagation of the flows driven by suspensions decreases compared with those driven by a reduced gravity in homogeneous currents. However, the details depend on the geometry of the cross section. The runout length of suspensions in channels of power-law cross sections is analytically predicted using a simplified depth-averaged “box” model. The present approach is a significant generalization of the classical gravity current problem. The classical formulation for a rectangular channel is now just a particular case, f(z) = const., in the wide domain of cross sections covered by this new model

Measurement of Neutrino and Antineutrino Total Charged-Current Cross Sections on Carbon with MINERvA

Energy Technology Data Exchange (ETDEWEB)

Ren, Lu [Univ. of Pittsburgh, PA (United States)

2017-01-01

This thesis presents a measurement of charged-current inclusive cross sections of muon neutrino and antineutrino interaction on carbon, and antineutrino to neutrino cross section ratio, r, in the energy range 2 - 22 GeV, with data collected in the MINERA experiment. The dataset corresponds to an exposure of 3.2 x 10²⁰ protons on target (POT) for neutrinos and 1.01020 POT for antineutrinos. Measurement of neutrino and antineutrino charged-current inclusive cross sections provides essential constraints for future long baseline neutrino oscillation experiment at a few GeV energy range. Our measured antineutrino cross section has an uncertainty in the range 6.1% - 10.5% and is the most precise measurement below 6 GeV to date. The measured r has an uncertainty of 5.0% - 7.5%. This is the rst measurement below 6 GeV since Gargamelle in 1970s. The cross sections are measured as a function of neutrino energy by dividing the eciency corrected charged-current sample with extracted uxes. Fluxes are obtained using the low- method, which uses low hadronic energy subsamples of charged-current inclusive sample to extract ux. Measured cross sections show good agreement with the prediction of neutrino interaction models above 7 GeV, and are about 10% below the model below 7 GeV. The measured r agrees with the GENIE model [1] over the whole energy region. The measured cross sections and r are compared with world data.

Development of modern CANDU PHWR cross-section libraries for SCALE

International Nuclear Information System (INIS)

Shoman, Nathan T.; Skutnik, Steven E.

2016-01-01

Highlights: • New ORIGEN libraries for CANDU 28 and 37-element fuel assemblies have been created. • These new reactor data libraries are based on modern ENDF/B-VII.0 cross-section data. • The updated CANDU data libraries show good agreement with radiochemical assay data. • Eu-154 overestimated when using ENDF-VII.0 due to a lower thermal capture cross-section. - Abstract: A new set of SCALE fuel lattice models have been developed for the 28-element and 37-element CANDU fuel assembly designs using modern cross-section data from ENDF-B/VII.0 in order to produce new reactor data libraries for SCALE/ORIGEN depletion analyses. These new libraries are intended to provide users with a convenient means of evaluating depletion of CANDU fuel assemblies using ORIGEN through pre-generated cross sections based on SCALE lattice physics calculations. The performance of the new CANDU ORIGEN libraries in depletion analysis benchmarks to radiochemical assay data were compared to the previous version of the CANDU libraries provided with SCALE (based on WIMS-AECL models). Benchmark comparisons with available radiochemical assay data indicate that the new cross-section libraries perform well at matching major actinide species (U/Pu), which are generally within 1–4% of experimental values. The library also showed similar or better results over the WIMS-AECL library regarding fission product species and minor actinoids (Np, Am, and Cm). However, a notable exception was in calculated inventories of "1"5"4Eu and "1"5"5Eu, where the new library employing modern nuclear data (ENDF/B-VII.0) performed substantially poorer than the previous WIMS-AECL library (which used ENDF-B/VI.8 cross-sections for these species). The cause for this discrepancy appears to be due to differences in the "1"5"4Eu thermal capture cross-section between ENDF/B-VI.8 and ENDF/B-VII.0, an effect which is exacerbated by the highly thermalized flux of a CANDU heavy water reactor compared to that of a typical

Terahertz radar cross section measurements.

Science.gov (United States)

Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

2010-12-06

We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.

Neutron-induced fission cross sections

International Nuclear Information System (INIS)

Weigmann, H.

1991-01-01

In the history of fission research, neutron-induced fission has always played the most important role. The practical importance of neutron-induced fission rests upon the fact that additional neutrons are produced in the fission process, and thus a chain reaction becomes possible. The practical applications of neutron-induced fission will not be discussed in this chapter, but only the physical properties of one of its characteristics, namely (n,f) cross sections. The most important early summaries on the subject are the monograph edited by Michaudon which also deals with the practical applications, the earlier review article on fission by Michaudon, and the review by Bjornholm and Lynn, in which neutron-induced fission receives major attention. This chapter will attempt to go an intermediate way between the very detailed theoretical treatment in the latter review and the cited monograph which emphasizes the applied aspects and the techniques of fission cross-section measurements. The more recent investigations in the field will be included. Section II will survey the properties of cross sections for neutron-induced fission and also address some special aspects of the experimental methods applied in their measurement. Section Ill will deal with the formal theory of neutron-induced nuclear reactions for the resolved resonance region and the region of statistical nuclear reactions. In Section IV, the fission width, or fission transmission coefficient, will be discussed in detail. Section V will deal with the broader structures due to incompletely damped vibrational resonances, and in particular will address the special case of thorium and neighboring isotopes. Finally, Section VI will briefly discuss parity violation effects in neutron-induced fission. 74 refs., 14 figs., 3 tabs

Parameterization of α-nucleus total reaction cross section at intermediate energies

International Nuclear Information System (INIS)

Alvi, M A; Abdulmomen, M A

2008-01-01

Applying a Coulomb correction factor to the Glauber model we have derived a closed expression for α-nucleus total reaction cross section, σ R . Under the approximation of rigid projectile model, the elastic S-matrix element S el (b) is evaluated from the phenomenological N-α amplitude and a Gaussian fit to the Helm's model form factor. Excellent agreements with the experimental data have been achieved by performing two-parameter fits to the α-nucleus σ R data in the energy range about 75 to 193 MeV. One of the parameters was found to be energy independent while the other, as expected, shows the energy dependence similar to that of N-α total cross section.

Absolute charge-changing cross sections for fast helium ions-C sub 6 sub 0 collisions

CERN Document Server

Nose, K; Shiraishi, K; Keizaki, T; Itoh, A

2003-01-01

Absolute charge-changing cross sections for fast helium ions passing through a C sub 6 sub 0 gas target have been measured. The measurements were carried out for incident projectile energies at 1.0MeV and 1.5MeV. The measured cross sections are compared with calculated values from Bohr-Lindhard model and Bohr model. In addition, we have obtained equilibrium charge state fractions and average equilibrium charge of helium ions passing through C sub 6 sub 0 , by using the measured cross sections.

Nuclear fission and neutron-induced fission cross-sections

Energy Technology Data Exchange (ETDEWEB)

James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

1981-01-01