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)
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
Temperature-dependent absorption cross sections for hydrogen peroxide vapor
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.
Ideal gas scattering kernel for energy dependent cross-sections
International Nuclear Information System (INIS)
Rothenstein, W.; Dagan, R.
1998-01-01
A third, and final, paper on the calculation of the joint kernel for neutron scattering by an ideal gas in thermal agitation is presented, when the scattering cross-section is energy dependent. The kernel is a function of the neutron energy after scattering, and of the cosine of the scattering angle, as in the case of the ideal gas kernel for a constant bound atom scattering cross-section. The final expression is suitable for numerical calculations
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.
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
Cross-sectional dependence in panel data analysis
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
Distorted eikonal cross sections: A time-dependent view
International Nuclear Information System (INIS)
Turner, R.E.
1982-01-01
For Hamiltonians with two potentials, differential cross sections are written as time-correlation functions of reference and distorted transition operators. Distorted eikonal differential cross sections are defined in terms of straight-line and reference classical trajectories. Both elastic and inelastic results are obtained. Expressions for the inelastic cross sections are presented in terms of time-ordered cosine and sine memory functions through the use of the Zwanzig-Feshbach projection-operator method
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
International Nuclear Information System (INIS)
Trofimov, Yu.N.
1991-01-01
The radiative neutron capture cross-section of nuclei has been derived as a function of neutron excess on the basis of the exponential dependence of the cross-section on the reaction energy. It is shown that unknown cross-sections of stable and radioactive nuclei may be evaluated by using the isotonic and isotopic dependence together with available reference cross-section measurements. (author). 4 refs, 3 figs
Creation of problem-dependent Doppler-broadened cross sections in the KENO Monte Carlo code
International Nuclear Information System (INIS)
Hart, Shane W.D.; Celik, Cihangir; Maldonado, G. Ivan; Leal, Luiz
2016-01-01
Highlights: • A quick method of Doppler broadening one- and two-dimensional cross sections has been added to KENO. • The method uses a finite difference method to broaden data to user defined temperatures. • Various problems and benchmarks were run to showcase results. • Results with the Doppler broadened cross sections are closer to benchmark results. - Abstract: This paper introduces a quick method for improving the accuracy of Monte Carlo simulations by generating one- and two-dimensional cross sections at a user-defined temperature before performing transport calculations. A finite difference method is used to Doppler-broaden cross sections to the desired temperature, and unit-base interpolation is done to generate the probability distributions for double differential two-dimensional thermal moderator cross sections at any arbitrarily user-defined temperature. The accuracy of these methods is tested using a variety of contrived problems. In addition, various benchmarks at elevated temperatures are modeled, and results are compared with benchmark results. The problem-dependent cross sections are observed to produce eigenvalue estimates that are closer to the benchmark results than those without the problem-dependent cross sections.
Thermal conduction by dark matter with velocity and momentum-dependent cross-sections
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...
Exact quantum cross sections for a three dimensional angle dependent model for three body reactions.
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.
Unit root tests for cross-sectionally dependent panels : The influence of observed factors
Becheri, I.G.; Drost, F.C.; van den Akker, R.
This paper considers a heterogeneous panel unit root model with cross-sectional dependence generated by a factor structure—the factor common to all units being an observed covariate. The model is shown to be Locally Asymptotically Mixed Normal (LAMN), with the random part of the limiting Fisher
Estimation of Fractionally Integrated Panels with Fixed Effects and Cross-Section Dependence
DEFF Research Database (Denmark)
Ergemen, Yunus Emre; Velasco, Carlos
We consider large N, T panel data models with fixed effects, common factors allowing cross-section dependence, and persistent data and shocks, which are assumed fractionally integrated. In a basic setup, the main interest is on the fractional parameter of the idiosyncratic component, which...
Testing for Unit Roots in Small Panels with Short-run and Long-run Cross-sectional Dependencies
Yoosoon Chang; Wonho Song
2009-01-01
An IV approach, using as instruments non-linear transformations of the lagged levels, is explored to test for unit roots in panels with general dependency and heterogeneity across cross-sectional units. We allow not only for the cross-sectional dependencies of innovations, but also for the presence of co-integration across cross-sectional levels. Unbalanced panels and panels with differing individual short-run dynamics and cross-sectionally related dynamics are also permitted. We also more ca...
POINT 2011: ENDF/B-VII.1 Beta2 Temperature Dependent Cross Section Library
Energy Technology Data Exchange (ETDEWEB)
Cullen, D E
2011-04-07
This report is one in the series of 'POINT' reports that over the years have presented temperature dependent cross sections for the then current version of ENDF/B. In each case I have used my personal computer at home and publicly available data and codes. I have used these in combination to produce the temperature dependent cross sections used in applications and presented in this report. I should mention that today anyone with a personal computer can produce these results. The latest ENDF/B-VII.1 beta2 data library was recently and is now freely available through the National Nuclear Data Center (NNDC), Brookhaven National Laboratory. This release completely supersedes all preceding releases of ENDF/B. As distributed the ENDF/B-VII.1 data includes cross sections represented in the form of a combination of resonance parameters and/or tabulated energy dependent cross sections, nominally at 0 Kelvin temperature. For use in our applications the ENDF/B-VII.1 library has been processed into cross sections at eight neutron reactor like temperatures, between 0 and 2100 Kelvin, in steps of 300 Kelvin (the exception being 293.6 Kelvin, for exact room temperature at 20 Celsius). It has also been processed to five astrophysics like temperatures, 1, 10, 100 eV, 1 and 10 keV. For reference purposes, 300 Kelvin is approximately 1/40 eV, so that 1 eV is approximately 12,000 Kelvin. At each temperature the cross sections are tabulated and linearly interpolable in energy. All results are in the computer independent ENDF-6 character format [R2], which allows the data to be easily transported between computers. In its processed form the POINT 2011 library is approximately 16 gigabyte in size and is distributed on one compressed DVDs (see, below for the details of the contents of each DVD).
Time-dependent density functional theory description of total photoabsorption cross sections
Tenorio, Bruno Nunes Cabral; Nascimento, Marco Antonio Chaer; Rocha, Alexandre Braga
2018-02-01
The time-dependent version of the density functional theory (TDDFT) has been used to calculate the total photoabsorption cross section of a number of molecules, namely, benzene, pyridine, furan, pyrrole, thiophene, phenol, naphthalene, and anthracene. The discrete electronic pseudo-spectra, obtained in a L2 basis set calculation were used in an analytic continuation procedure to obtain the photoabsorption cross sections. The ammonia molecule was chosen as a model system to compare the results obtained with TDDFT to those obtained with the linear response coupled cluster approach in order to make a link with our previous work and establish benchmarks.
Isospin dependent Boltzmann-langevin equation and the production cross section of 19Na
International Nuclear Information System (INIS)
Ming Zhaoyu; Zhang Fengshou; Chen Liewen; Zhu Zhiyuan; Zhang Wenlong; Guo Zhongyan; Xiao Guoqing
2000-01-01
A new transport model (isospin dependent Boltzmann-Langevin equation) is developed and it is shown that this model can regenerate the experimental data for reaction of 12 C + 12 C at 28.7 MeV/u. The production cross section of 19 Na is systematically studied for reactions of 17-20,22 Ne + 12 C at 28.7 MeV/u. It is found that a neutron deficient projectile has larger 19 Na cross section than a stable projectile
Temperature-dependent cross sections for meson-meson nonresonant reactions in hadronic matter
International Nuclear Information System (INIS)
Zhang Yiping; Xu Xiaoming; Ge Huijun
2010-01-01
We present a potential of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections and of which the large-distance part exhibits a temperature-dependent constant value. The Schroedinger equation with this temperature-dependent potential yields a temperature dependence of the mesonic quark-antiquark relative-motion wave function and of meson masses. The temperature dependence of the potential, the wave function and the meson masses brings about temperature dependence of cross sections for the nonresonant reactions ππ→ρρ for I=2, KK→K*K* for I=1, KK*→K*K* for I=1, πK→ρK* for I=3/2, πK*→ρK* for I=3/2, ρK→ρK* for I=3/2 and πK*→ρK for I=3/2. As the temperature increases, the rise or fall of peak cross sections is determined by the increased radii of initial mesons, the loosened bound states of final mesons, and the total-mass difference of the initial and final mesons. The temperature-dependent cross sections and meson masses are parametrized.
Measurement of the $Z/A$ dependence of neutrino charged-current total cross-sections
Kayis-Topaksu, A; Van Dantzig, R; De Jong, M; Konijn, J; Melzer, O; Oldeman, R G C; Pesen, E; Van der Poel, C A F J; Spada, F R; Visschers, J L; Güler, M; Serin-Zeyrek, M; Kama, S; Sever, R; Tolun, P; Zeyrek, M T; Armenise, N; Catanesi, M G; De Serio, M; Ieva, M; Muciaccia, M T; Radicioni, E; Simone, S; Bülte, A; Winter, Klaus; El-Aidi, R; Van de Vyver, B; Vilian, P; Wilquet, G; Saitta, B; Di Capua, E; Ogawa, S; Shibuya, H; Artamonov, A V; Brunner, J; Chizhov, M; Cussans, D G; Doucet, M; Fabre, Jean-Paul; Hristova, I R; Kawamura, T; Kolev, D; Litmaath, M; Meinhard, H; Panman, J; Papadopoulos, I M; Ricciardi, S; Rozanov, A; Saltzberg, D; Tsenov, R V; Uiterwijk, J W E; Zucchelli, P; Goldberg, J; Chikawa, M; Arik, E; Song, J S; Yoon, C S; Kodama, K; Ushida, N; Aoki, S; Hara, T; Delbar, T; Favart, D; Grégoire, G; Kalinin, S; Makhlyoueva, I V; Gorbunov, P; Khovanskii, V D; Shamanov, V V; Tsukerman, I; Bruski, N; Frekers, D; Rondeshagen, D; Wolff, T; Hoshino, K; Kawada, J; Komatsu, M; Miyanishi, M; Nakamura, M; Nakano, T; Narita, K; Niu, K; Niwa, K; Nonaka, N; Sato, O; Toshito, T; Buontempo, S; Cocco, A G; D'Ambrosio, N; De Lellis, G; De Rosa, G; Di Capua, F; Ereditato, A; Fiorillo, G; Marotta, A; Messina, M; Migliozzi, P; Pistillo, C; Santorelli, R; Scotto-Lavina, L; Strolin, P; Tioukov, V; Nakamura, K; Okusawa, T; Dore, U; Loverre, P F; Ludovici, L; Maslennikov, A L; Righini, P; Rosa, G; Santacesaria, R; Satta, A; Barbuto, E; Bozza, C; Grella, G; Romano, G; Sirignano, C; Sorrentino, S; Sato, Y; Tezuka, I
2003-01-01
A relative measurement of total cross-sections is reported for polyethylene, marble, iron, and lead targets for the inclusive charged-current reaction nu_mu + N -> mu^- + X. The targets, passive blocks of ~100kg each, were exposed simultaneously to the CERN SPS wide-band muon-neutrino beam over a period of 18 weeks. Systematics effects due to differences in the neutrino flux and detector efficiency for the different target locations were minimised by changing the position of the four targets on their support about every two weeks. The relative neutrino fluxes on the targets were monitored within the same experiment using charged-current interactions in the calorimeter positioned directly downstream of the four targets. From a fit to the Z/A dependence of the total cross-sections a value is deduced for the effective neutron-to-proton cross-section ratio.
Measurement of the Z/A dependence of neutrino charged-current total cross-sections
Kayis-Topasku, A; Dantzig, R V
2003-01-01
A relative measurement of total cross-sections is reported for polyethylene, marble, iron, and lead targets for the inclusive charged-current reaction nu submu + N -> mu sup - + X. The targets, passive blocks of propor to 100 kg each, were exposed simultaneously to the CERN SPS wide-band muon-neutrino beam over a period of 18 weeks. Systematic effects due to differences in the neutrino flux and detector efficiency for the different target locations were minimised by changing the position of the four targets on their support about every two weeks. The relative neutrino fluxes on the targets were monitored within the same experiment using charged-current interactions in the calorimeter positioned directly downstream of the four targets. From a fit to the Z/A dependence of the total cross-sections a value is deduced for the effective neutron-to-proton cross-section ratio. (orig.)
Isotopic dependence of photoneutron cross sections around Strontium (Z=38) and Cesium (Z=55) nuclei
International Nuclear Information System (INIS)
Nakamura, T.; Uno, Y.; Yamadera, A.; Kase, T.
1992-01-01
We measured the average cross sections of (γ,n) reactions for 84 Sr, 86 Sr, 88 Sr, 85 Rb, 87 Rb, 98 Ru and 104 Ru isotopes in giant resonance region (9 to 25 MeV) using Bremsstrahlung radiation of 60 MeV maximum energy. We investigated the isotopic dependence of the average (γ,n) cross sections in giant resonance region from our experimental data and those estimated from other experimental data for Ge, Se, Zr, Mo, Sn, Te, Ce, Nd and Sm isotopes. As a result, we found that the average cross section data become highest for nuclei of neutron magic number of N = 50 and 82 except for Mo nucleus
Energy Technology Data Exchange (ETDEWEB)
Kopyra, Janina [Faculty of Science, Siedlce University, 3 Maja 54, 08-110 Siedlce (Poland); Abdoul-Carime, Hassan, E-mail: hcarime@ipnl.in2p3.fr [Université de Lyon, Université Claude Bernard Lyon1, Institut de Physique Nucléaire de Lyon, CNRS/IN2P3 UMR 5822, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France)
2015-05-07
Providing experimental values for absolute Dissociative Electron Attachment (DEA) cross sections for nucleobases at realistic biological conditions is a considerable challenge. In this work, we provide the temperature dependence of the cross section, σ, of the dehydrogenated thymine anion (T − H){sup −} produced via DEA. Within the 393-443 K temperature range, it is observed that σ varies by one order of magnitude. By extrapolating to a temperature of 313 K, the relative DEA cross section for the production of the dehydrogenated thymine anion at an incident energy of 1 eV decreases by 2 orders of magnitude and the absolute value reaches approximately 6 × 10{sup −19} cm{sup 2}. These quantitative measurements provide a benchmark for theoretical prediction and also a contribution to a more accurate description of the effects of ionizing radiation on molecular medium.
Energy dependence of fusion evaporation-residue cross sections in the 28Si+12C reaction
International Nuclear Information System (INIS)
Vineyard, M.F.; Mateja, J.F.; Beck, C.; Atencio, S.E.; Dennis, L.C.; Frawley, A.D.; Henderson, D.J.; Janssens, R.V.F.; Kemper, K.W.; Kovar, D.G.; Maguire, C.F.; Padalino, S.J.; Prosser, F.W.; Stephans, G.S.F.; Tiede, M.A.; Wilkins, B.D.; Zingarelli, R.A.
1993-01-01
Fusion evaporation-residue cross sections for the 28 Si+ 12 C reaction have been measured in the energy range 18≤E c.m. ≤136 MeV using time-of-flight techniques. Velocity distributions of mass-identified reaction products were used to identify evaporation residues and to determine the complete-fusion cross sections at high energies. The data are in agreement with previously established systematics which indicate an entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models
Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure
Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fallon, S. R.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration
2017-06-01
We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=1.6 ×10-41 cm2 (σp=5 ×10-40 cm2 ) at 35 GeV c-2 , almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.
CREST : a computer program for the calculation of composition dependent self-shielded cross-sections
International Nuclear Information System (INIS)
Kapil, S.K.
1977-01-01
A computer program CREST for the calculation of the composition and temperature dependent self-shielded cross-sections using the shielding factor approach has been described. The code includes the editing and formation of the data library, calculation of the effective shielding factors and cross-sections, a fundamental mode calculation to generate the neutron spectrum for the system which is further used to calculate the effective elastic removal cross-sections. Studies to explore the sensitivity of reactor parameters to changes in group cross-sections can also be carried out by using the facility available in the code to temporarily change the desired constants. The final self-shielded and transport corrected group cross-sections can be dumped on cards or magnetic tape in a suitable form for their direct use in a transport or diffusion theory code for detailed reactor calculations. The program is written in FORTRAN and can be accommodated in a computer with 32 K work memory. The input preparation details, sample problem and the listing of the program are given. (author)
The isospin dependent nucleon–nucleon inelastic cross section in the nuclear medium
Directory of Open Access Journals (Sweden)
Qingfeng Li
2017-10-01
Full Text Available The calculation of the energy-, density-, and isospin-dependent Δ production cross sections in nucleon–nucleon (NN scattering σNN→NΔ⁎ has been performed within the framework of the relativistic BUU approach. The NΔ cross sections are calculated in Born approximation taking into account the effective mass splitting of the nucleons and Δs in asymmetric matter. Due to the different mass splitting for neutron, proton and differently charged Δs, it is shown that, similar to the NN elastic ones, the reductions of NΔ inelastic cross sections in isospin-asymmetric nuclear medium are different from each other for all the individual channels and the effect is largest and of opposite sign for the Δ++ and Δ− states. This approach is also compared to calculations without effective mass splitting and with splitting derived from Dirac–Brueckerner (DB calculations. The isospin dependence of the NΔ cross sections is expected to influence the production of π+ and π− mesons as well as their yield ratio, and thus affect the use of the latter quantity as a probe of the stiffness of the symmetry energy at supranormal densities.
Point 2004 A Temperature Dependent ENDF/B-VI, Release 8 Cross Section Library
International Nuclear Information System (INIS)
Cullen, D E
2004-01-01
The ENDF/B data library has recently been updated and is now freely available through the National Nuclear Data Center (NNDC), Brookhaven National Laboratory. This most recent library is identified as ENDF/B-VI, Release 8. Release 8 completely supersedes all preceding releases. Release 8 will be the last release of ENDF/B-VI; the next release of ENDF/B data will be for the new ENDF/B-VII library. As distributed the ENDF/B-VI, Release 8 data includes cross sections represented in the form of a combination of resonance parameters and/or tabulated energy dependent cross sections, nominally at 0 Kelvin temperature. For use in applications this library has been processed into the form of temperature dependent cross sections at eight neutron reactor like temperatures, between 0 and 2100 Kelvin, in steps of 300 Kelvin. It has also been processed to five astrophysics like temperatures, 1, 10, 100 eV, 1 and 10 keV. For reference purposes, 300 Kelvin is approximately 1/40 eV, so that 1 eV is approximately 12,000 Kelvin. At each temperature the cross sections are tabulated and linearly interpolable in energy. All results are in the computer independent ENDF/B-VI character format [1], which allows the data to be easily transported between computers. In its processed form this library is approximately 4.3 gigabyte in size and is distributed on a single DVD
Isthmus Dependent Atrial Flutter Cycle Length Correlates with Right Atrial Cross-Sectional Area
Directory of Open Access Journals (Sweden)
Kousik Krishnan
2009-05-01
Full Text Available Background: Right atrial flutter cycle length can prolong in the presence of antiarrhythmic drug therapy. We hypothesized that the cycle length of right atrial isthmus dependent flutter would correlate with right atrial cross-sectional area measurements. Methods: 60 patients who underwent ablation for electrophysiologically proven isthmus dependent right atrial flutter, who were not on Class I or Class III antiarrhythmic drugs and had recent 2-dimensional echocardiographic data comprised the study group. Right atrial length and width were measured in the apical four chamber view. Cross-sectional area was estimated by multiplying the length and width. 35 patients had an atrial flutter rate ≥250 bpm (Normal Flutter Group and 25 patients had an atrial flutter rate < 250 bpm (Slow Flutter Group. Results: Mean atrial flutter rate was 283 bpm in the normal flutter group and 227 bpm in the slow flutter group. Mean atrial flutter cycle length was 213 ms in the Normal Flutter Group and 265 ms in the Slow Flutter Group (p<0.0001. Mean right atrial cross sectional area was 1845 mm2 in the Normal Flutter group and 2378 mm2 in the Slow Flutter Group, (p< 0.0001. Using linear regression, CSA was a significant predictor of cycle length (β =0.014 p = 0.0045. For every 1 mm2 increase in cross-sectional area, cycle length is 0.014 ms longer.Conclusion: In the absence of antiarrhythmic medications, right atrial cross sectional area enlargement correlates with atrial flutter cycle length. These findings provide further evidence that historical rate-related definitions of typical isthmus dependent right atrial are not mechanistically valid.
Dependence of extinction cross-section on incident polarization state and particle orientation
International Nuclear Information System (INIS)
Yang Ping; Wendisch, Manfred; Bi Lei; Kattawar, George; Mishchenko, Michael; Hu, Yongxiang
2011-01-01
This note reports on the effects of the polarization state of an incident quasi-monochromatic parallel beam of radiation and the orientation of a hexagonal ice particle with respect to the incident direction on the extinction process. When the incident beam is aligned with the six-fold rotational symmetry axis, the extinction is independent of the polarization state of the incident light. For other orientations, the extinction cross-section for linearly polarized light can be either larger or smaller than its counterpart for an unpolarized incident beam. Therefore, the attenuation of a quasi-monochromatic radiation beam by an ice cloud depends on the polarization state of the beam if ice crystals within the cloud are not randomly oriented. Furthermore, a case study of the extinction of light by a quartz particle is also presented to illustrate the dependence of the extinction cross-section on the polarization state of the incident light.
Helicity dependence of the total inclusive cross section on the deuteron
Energy Technology Data Exchange (ETDEWEB)
Ahrens, J. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Altieri, S. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, I-27100 Pavia (Italy); Annand, J.R.M. [Department of Physics and Astronomy, University of Glasgow (United Kingdom); Arends, H.-J.; Beck, R. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Blackston, M.A. [Department of Physics, Duke University, Durham, NC 27708 (United States); Braghieri, A. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); D' Hose, N. [CEA Saclay, DSM/DAPNIA/SPhN, F-91191 Gif-sur-Yvette Cedex (France); Dutz, H. [Physikalisches Institut, Universitaet Bonn, D-53115 Bonn (Germany); Heid, E.; Jahn, O. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Klein, F. [Physikalisches Institut, Universitaet Bonn, D-53115 Bonn (Germany); Kondratiev, R. [INR, Academy of Science, Moscow (Russian Federation); Lang, M. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Lisin, V. [INR, Academy of Science, Moscow (Russian Federation); Martinez Fabregate, M. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); McGeorge, J.C. [Department of Physics and Astronomy, University of Glasgow (United Kingdom); Meyer, W. [Inst. fuer Experimentalphysik, Ruhr-Universitaet Bochum, D-44801 Bochum (Germany); Panzeri, A. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, I-27100 Pavia (Italy); Pedroni, P. [INFN, Sezione di Pavia, I-27100 Pavia (Italy)], E-mail: pedroni@pv.infn.it (and others)
2009-03-02
A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200
Helicity dependence of the total inclusive cross section on the deuteron
International Nuclear Information System (INIS)
Ahrens, J.; Altieri, S.; Annand, J.R.M.; Arends, H.-J.; Beck, R.; Blackston, M.A.; Braghieri, A.; D'Hose, N.; Dutz, H.; Heid, E.; Jahn, O.; Klein, F.; Kondratiev, R.; Lang, M.; Lisin, V.; Martinez Fabregate, M.; McGeorge, J.C.; Meyer, W.; Panzeri, A.; Pedroni, P.
2009-01-01
A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200 γ <800 MeV. The experiment used a 4π detection system, a circularly polarized tagged photon beam and a frozen spin target which provided longitudinally polarized deuterons. These new results are a significant improvement on the existing data and allow a detailed comparison with state-of-the-art calculations
Abd Halim Ahmad; Siti Nurazira Mohd Daud; W.N.W. Azman-Saini
2010-01-01
The purpose of this paper is to re-examine whether mean reversion property hold for 15 emerging stock markets for the period 1985 to 2006. Utilizing a panel stationarity test that is able to account for multiple structural breaks and cross sectional dependence, we find that the emerging stock markets follow a random walk process. However, further analysis on individual series show that the majority of stock prices in emerging markets are governed by a mean reverting process. This result, whic...
Jet-radius dependence of inclusive-jet cross sections in deep inelastic scattering at HERA
International Nuclear Information System (INIS)
Chekanov, S.; Derrick, M.; Magill, S.
2006-12-01
Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities Q 2 >125 GeV 2 with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb -1 . Jets were identified in the Breit frame using the k T cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of Q 2 and the jet transverse energy, E T,B jet . The dependence on R of the inclusive-jet cross section has been measured for Q 2 > 125 and 500 GeV 2 and found to be linear with R in the range studied. Next-to-leading-order QCD calculations give a good description of the measurements for 0.5 s (M Z ) has been extracted from the measurements of the inclusive-jet cross-section dσ/dQ 2 with R=1 for Q 2 > 500 GeV 2 : α s (M Z )=0.1207±0.0014(stat.) -0.0028 +0.0030 (exp.) -0.0 023 +0.0022 (th.). The variation of α s with E T,B jet is in good agreement with the running of α s as predicted by QCD. (orig.)
A dependence of quasielastic charged-current neutrino-nucleus cross sections
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 dependence of J/ψ-nucleon inelastic cross section on the Feynman variable
International Nuclear Information System (INIS)
Duan Chungui; Liu Na; Miao Wendan
2011-01-01
By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios R Fe/Be (x F ). It is shown that the energy loss effect of beam proton on R Fe/Be (x F ) is more important than the nuclear effects on parton distribution functions in the high Feynman variable x F region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable x F and increases linearly with x F in the region x F > 0.2. (authors)
A cross-sectional study on tobacco use and dependence among women: Does menthol matter?
Rosenbloom, Judith; Rees, Vaughan W; Reid, Kathleen; Wong, Jeannie; Kinnunen, Taru
2012-11-27
The question of whether mentholation of cigarettes enhances tobacco dependence has generated conflicting findings. Potential mediating factors in a putative relationship between menthol use and tobacco dependence may include race and gender. While an association between menthol use and dependence is mixed, research on the role of race solely among women smokers is scarce. This study examined whether women menthol smokers have higher tobacco use and dependence than non-menthol smokers. Further, the study investigated differences between White and African American smokers. A cross-sectional study was conducted among 928 women seeking tobacco dependence treatment in Boston, Massachusetts. Measures obtained included preferred brand and menthol content, dependence markers (cigarettes per day (CPD); time to first cigarette in the morning; number of and longest previous quit attempts) and smoking history (age of initiation; years smoking; menthol or non-menthol cigarette preference). Analysis of variance (ANOVA) was used to detect interactions between menthol preference by race for continuous variables, and Pearson's chi-squared test was used for analyses with dichotomous variables. A greater proportion of menthol smokers smoked their first cigarette within five minutes of waking (p preferences. However, African American smokers smoked fewer CPD (pbrand for longer (p= .04). Women menthol smokers showed signs of greater tobacco dependence than non-menthol smokers. African Americans smoked fewer CPD but nevertheless had evidence of greater dependence.
Energy Dependent Removal Cross-Sections in Fast Neutron Shielding Theory
International Nuclear Information System (INIS)
Groenroos, Henrik
1965-05-01
The analytical approximations behind the energy dependent removal cross-section concept of Spinney is investigated and its predictions compared with exact values calculated by Case's singular integral method. The exact values are obtained in plane infinite geometry for the two absorption ratios Σ a /Σ t = 0. 1 and Σ a /Σ t = 0.7 over a range of 20 mfp and for varying degrees of forward anisotrophy in the elastic scattering. The latter is characterized by choosing a suitable general scattering function. It is shown that Spinney's original definition follows if Grosjean's formalism, i. e. the matching of moments, is applied. The prediction of the neutron flux is remarkably accurate, and mostly within 50 % for the spatial range and cases investigated. A definition of the removal cross-sections based on matching the exact asymptotic solution to the exponential part of the approximate solution is found to give less accurate flux values than Spinney's model. A third way to define a removal cross-section independent of the spatial coordinates is the variational method. The possible uses of this technique is briefly commented upon
Energy Dependent Removal Cross-Sections in Fast Neutron Shielding Theory
Energy Technology Data Exchange (ETDEWEB)
Groenroos, Henrik
1965-05-15
The analytical approximations behind the energy dependent removal cross-section concept of Spinney is investigated and its predictions compared with exact values calculated by Case's singular integral method. The exact values are obtained in plane infinite geometry for the two absorption ratios {sigma}{sub a}/{sigma}{sub t} = 0. 1 and {sigma}{sub a}/{sigma}{sub t} = 0.7 over a range of 20 mfp and for varying degrees of forward anisotrophy in the elastic scattering. The latter is characterized by choosing a suitable general scattering function. It is shown that Spinney's original definition follows if Grosjean's formalism, i. e. the matching of moments, is applied. The prediction of the neutron flux is remarkably accurate, and mostly within 50 % for the spatial range and cases investigated. A definition of the removal cross-sections based on matching the exact asymptotic solution to the exponential part of the approximate solution is found to give less accurate flux values than Spinney's model. A third way to define a removal cross-section independent of the spatial coordinates is the variational method. The possible uses of this technique is briefly commented upon.
The tunneling magnetoresistance current dependence on cross sectional area, angle and temperature
Directory of Open Access Journals (Sweden)
Z. H. Zhang
2015-03-01
Full Text Available The magnetoresistance of a MgO-based magnetic tunnel junction (MTJ was studied experimentally. The magnetoresistance as a function of current was measured systematically on MTJs for various MgO cross sectional areas and at various temperatures from 7.5 to 290.1 K. The resistance current dependence of the MTJ was also measured for different angles between the two ferromagnetic layers. By considering particle and angular momentum conservation of transport electrons, the current dependence of magnetoresistance can be explained by the changing of spin polarization in the free magnetic layer of the MTJ. The changing of spin polarization is related to the magnetoresistance, its angular dependence and the threshold current where TMR ratio equals zero. A phenomenological model is used which avoid the complicated barrier details and also describes the data.
POINT 2012: ENDF/B-VII.1 Final Temperature Dependent Cross Section Library
International Nuclear Information System (INIS)
Cullen, D.E.
2012-01-01
This report is one in the series of 'POINT' reports that over the years have presented temperature dependent cross sections for the then current version of ENDF/B [R1]. In each case I have used my personal computer at home and publicly available data and codes: (1) publicly available nuclear data (the current ENDF/B data, available on-line at the National Nuclear Data Center, Brookhaven National Laboratory, http://www.nndc.bnl.gov/) and, (2) publicly available computer codes (the current PREPRO codes, available on-line at the Nuclear Data Section, IAEA, Vienna, Austria, http://www-nds.iaea.or.at/ndspub/endf/prepro/) and, (3) My own personal computer located in my home. I have used these in combination to produce the temperature dependent cross sections used in applications and described in this report. I should mention that today anyone with a personal computer can produce these results: by its very nature I consider this data to be born in the public domain.
POINT 2012: ENDF/B-VII.1 Final Temperature Dependent Cross Section Library
Energy Technology Data Exchange (ETDEWEB)
Cullen, D E
2012-02-26
This report is one in the series of 'POINT' reports that over the years have presented temperature dependent cross sections for the then current version of ENDF/B [R1]. In each case I have used my personal computer at home and publicly available data and codes: (1) publicly available nuclear data (the current ENDF/B data, available on-line at the National Nuclear Data Center, Brookhaven National Laboratory, http://www.nndc.bnl.gov/) and, (2) publicly available computer codes (the current PREPRO codes, available on-line at the Nuclear Data Section, IAEA, Vienna, Austria, http://www-nds.iaea.or.at/ndspub/endf/prepro/) and, (3) My own personal computer located in my home. I have used these in combination to produce the temperature dependent cross sections used in applications and described in this report. I should mention that today anyone with a personal computer can produce these results: by its very nature I consider this data to be born in the public domain.
New measurements of spin-dependent n-p cross sections
International Nuclear Information System (INIS)
Raichle, B. W.; Gould, C. R.; Haase, D. G.; Seely, M. L.; Walston, J. R.; Tornow, W.; Wilburn, W. S.; Penttilae, S. I.; Hoffmann, G. W.
1999-01-01
We report on new measurements of the spin-dependent neutron-proton total cross-section differences in longitudinal and transverse geometries (Δσ L and Δσ T respectively) and between 5 and 20 MeV. These transmission experiments involve a polarized neutron beam and polarized proton target. The polarized neutron beam was produced as a secondary beam via charged-particle induced neutron-production reactions. The proton target was cryogenically cooled and dynamically polarized. These data will be used to extract ε 1 , the phase-shift parameter which characterizes the strength of the tensor interaction at low energy
Panel Data with Cross-Sectional Dependence Characterized by a Multi-Level Factor Structure
DEFF Research Database (Denmark)
Rodríguez-Caballero, Carlos Vladimir
A panel data model with a multi-level cross-sectional dependence is proposed. The factor structure is driven by top-level common factors as well as non-pervasive factors. I propose a simple method to filter out the full factor structure that overcomes limitations in standard procedures which may...... mix up both levels of unobservable factors and may hamper the identification of the model. The model covers both stationary and non-stationary cases and takes into account other relevant features that make the model well suited to the analysis of many types of time series frequently addressed...
Sub-LET Threshold SEE Cross Section Dependency with Ion Energy
Garcia Alia, Ruben; Brandenburg, Sytze; Brugger, Markus; Daly, Eamonn; Ferlet-Cavrois, Veronique; Gaillard, Remi; Hoeffgen, Stefan; Menicucci, Alessandra; Metzger, Stefan; Zadeh, Ali; Muschitiello, Michele; Noordeh, Emil; Santin, Giovanni; CERN. Geneva. ATS Department
2015-01-01
This study focuses on the ion species and energy dependence of the heavy ion SEE cross section in the sub-let threshold region through a set of experimental data. In addition, a Monte Carlo based model is introduced and applied, showing a good agreement with the data in the several hundred MeV/n range while evidencing large discrepancies with the measurements in the 10-30 MeV/n interval, notably for the NE ion. Such discrepancies are carefully analysed and discussed.
The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy
International Nuclear Information System (INIS)
Rashdan, M.; Farhan, A.M.; Hassib, E.; Kareem, W. Abdel
2006-01-01
The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy is investigated within the multiple scattering theory. The multiple integrals are evaluated by Monte Carlo method as well as by the optical limit approximation of the Glauber model. Calculations are performed for 14-23 N, 16-24 O and 18-26 F isotopes colliding with carbon target around 1 GeV. It is found that rms radii and the density distributions show a halo structure of 22 N, 23 O and 24 F
Infrared cross-sections and integrated band intensities of propylene: Temperature-dependent studies
Es-sebbar, Et-touhami
2014-01-01
Propylene, a by-product of biomass burning, thermal cracking of hydrocarbons and incomplete combustion of fossil fuels, is a ubiquitous molecule found in the environment and atmosphere. Accurate infrared (IR) cross-sections and integrated band intensities of propylene are essential for quantitative measurements and atmospheric modeling. We measured absolute IR cross-sections of propylene using Fourier Transform Infrared (FTIR) Spectroscopy over the wavenumber range of 400-6500cm-1 and at gas temperatures between 296 and 460K. We recorded these spectra at spectral resolutions ranging from 0.08 to 0.5cm-1 and measured the integrated band intensities for a number of vibrational bands in certain spectral regions. We then compared the integrated band intensities measured at room temperature with values derived from the National Institute of Standards and Technology (NIST) and the Pacific Northwest National Laboratory (PNNL) databases. Our results agreed well with the results reported in the two databases with a maximum deviation of about 4%. The peak cross-sections for the primary bands decreased by about 20-54% when the temperature increased from 296 to 460K. Moreover, we determined the integrated band intensities as a function of temperature for certain features in various spectral regions; we found no significant temperature dependence over the range of temperatures considered here. We also studied the effect of temperature on absorption cross-section using a Difference Frequency Generation (DFG) laser system. We compared the DFG results with those obtained from the FTIR study at certain wavenumbers over the 2850-2975cm-1 range and found a reasonable agreement with less than 10% discrepancy. © 2013 Elsevier Ltd.
Jet-radius dependence of inclusive-jet cross sections in deep inelastic scattering at HERA
Energy Technology Data Exchange (ETDEWEB)
Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Laboratory, Argonne, IL (US)] (and others)
2006-12-15
Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities Q{sup 2}>125 GeV{sup 2} with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb{sup -1}. Jets were identified in the Breit frame using the k{sub T} cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of Q{sup 2} and the jet transverse energy, E{sub T,B}{sup jet}. The dependence on R of the inclusive-jet cross section has been measured for Q{sup 2} > 125 and 500 GeV{sup 2} and found to be linear with R in the range studied. Next-to-leading-order QCD calculations give a good description of the measurements for 0.5<=R<=1. A value of {alpha}{sub s}(M{sub Z}) has been extracted from the measurements of the inclusive-jet cross-section d{sigma}/dQ{sup 2} with R=1 for Q{sup 2} > 500 GeV{sup 2}: {alpha}{sub s}(M{sub Z})=0.1207{+-}0.0014(stat.){sub -0.0028}{sup +0.0030}(exp.){sub -0.0023}{sup +0.0022}(th.). The variation of {alpha}{sub s} with E{sub T,B}{sup jet} is in good agreement with the running of {alpha}{sub s} as predicted by QCD. (orig.)
International Nuclear Information System (INIS)
Lell, R.M.; Hanan, N.A.
1987-01-01
Effects of multigroup neutron cross section generation procedures on core physics parameters for compact fast spectrum reactors have been examined. Homogeneous and space-dependent multigroup cross section sets were generated in 11 and 27 groups for a representative fast reactor core. These cross sections were used to compute various reactor physics parameters for the reference core. Coarse group structure and neglect of space-dependence in the generation procedure resulted in inaccurate computations of reactor flux and power distributions and in significant errors regarding estimates of core reactivity and control system worth. Delayed neutron fraction was insensitive to cross section treatment, and computed reactivity coefficients were only slightly sensitive. However, neutron lifetime was found to be very sensitive to cross section treatment. Deficiencies in multigroup cross sections are reflected in core nuclear design and, consequently, in system mechanical design
Limit Theory for Panel Data Models with Cross Sectional Dependence and Sequential Exogeneity.
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.
International Nuclear Information System (INIS)
Ganapol, B.D.
1987-01-01
For almost 20 yr, the main thrust of the author's research has been the generation of as many benchmark solutions to the time-dependent monoenergetic neutron transport equation as possible. The major motivation behind this effort has been to provide code developers with highly accurate numerical solutions to serve as standards in the assessment of numerical transport algorithms. In addition, these solutions provide excellent educational tools since the important physical features of neutron transport are still present even though the problems solved are idealized. A secondary motivation, though of equal importance, is the intellectual stimulation and understanding provided by the combination of the analytical, numerical, and computational techniques required to obtain these solutions. Therefore, to further the benchmark development, the added complication of time-dependent cross sections in the one-group transport equation is considered here
Measurement of the energy dependence of the total photon-proton cross section at HERA
Energy Technology Data Exchange (ETDEWEB)
Abramowicz, H. [Tel Aviv Univ. (Israel). Raymond and Beverly Sackler Faculty of Exact Sciences; Univ. Coll. London (United Kingdom); Krakow Univ. of Technology (Poland). Faculty of Physics, Mathematics and Applied Computer Science; Abt, I. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Adamczyk, L. [AGH-Univ. of Science and Technology, Cracow (PL). Faculty of Physics and Applied Computer Science] (and others)
2010-10-15
The energy dependence of the photon-proton total cross section, {sigma}{sub tot}{sup {gamma}}{sup p}, was determined from e{sup +}p scattering data collected with the ZEUS detector at HERA at three values of the center-of-mass energy, W, of the {gamma}p system in the range 194
Low energy neutron scattering for energy dependent cross sections. General considerations
Energy Technology Data Exchange (ETDEWEB)
Rothenstein, W; Dagan, R [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering
1996-12-01
We consider in this paper some aspects related to neutron scattering at low energies by nuclei which are subject to thermal agitation. The scattering is determined by a temperature dependent joint scattering kernel, or the corresponding joint probability density, which is a function of two variables, the neutron energy after scattering, and the cosine of the angle of scattering, for a specified energy and direction of motion of the neutron, before the interaction takes place. This joint probability density is easy to calculate, when the nucleus which causes the scattering of the neutron is at rest. It can be expressed by a delta function, since there is a one to one correspondence between the neutron energy change, and the cosine of the scattering angle. If the thermal motion of the target nucleus is taken into account, the calculation is rather more complicated. The delta function relation between the cosine of the angle of scattering and the neutron energy change is now averaged over the spectrum of velocities of the target nucleus, and becomes a joint kernel depending on both these variables. This function has a simple form, if the target nucleus behaves as an ideal gas, which has a scattering cross section independent of energy. An energy dependent scattering cross section complicates the treatment further. An analytic expression is no longer obtained for the ideal gas temperature dependent joint scattering kernel as a function of the neutron energy after the interaction and the cosine of the scattering angle. Instead the kernel is expressed by an inverse Fourier Transform of a complex integrand, which is averaged over the velocity spectrum of the target nucleus. (Abstract Truncated)
Salameh, P; Salamé, J; Waked, M; Barbour, B; Zeidan, N; Baldi, I
2014-02-14
The objective of this study was to measure the correlates, including normative beliefs, associated with waterpipe (WP) and cigarette smoking prevalence and dependence. A cross-sectional study was carried out using a proportionate cluster sample of Lebanese students in 17 public and private universities. Of the 4900 distributed questionnaires, 3384 (69.1%) were returned to the field worker. All available students during break times were approached, with no exclusion criteria. sociodemographic variables, detailed active and passive smoking, in addition to items of the tobacco dependence scales were all evaluated. Correlates to WP smoking were studying in a private university (adjusted OR, aOR=1.50 (1.26 to 1.79); pinfluence were found on smoking behaviour and dependence. Although the role of parents was not visible in decreasing the risk of smoking WP, their protective influence seemed more important on WP dependence (β=-1.09(-1.79 to -0.28); p1; pinfluenced by parents' and friends' opinions, and idols' smoking status. Future research is necessary to further improve our understanding of motives for WP smoking and dependence.
Charge-state dependence of binary-encounter-electron cross sections and peak energies
International Nuclear Information System (INIS)
Hidmi, H.I.; Richard, P.; Sanders, J.M.; Schoene, H.; Giese, J.P.; Lee, D.H.; Zouros, T.J.M.; Varghese, S.L.
1993-01-01
The charge-state dependence of the binary-encounter-electron (BEE) double-differential cross section (DDCS) at 0 degree with respect to the beam direction resulting from collisions of 1 MeV/amu H + , C q+ , N q+ , O q+ , F q+ , Si q+ , and Cl q+ , and 0.5 MeV/amu Cu q+ with H 2 is reported. The data show an enhancement in the BEE DDCS as the charge state of the projectile is decreased, in agreement with the data reported by Richard et al. [J. Phys. B 23, L213 (1990)]. The DDCS enhancement ratios observed for the three-electron isoelectronic sequence C 3+ :C 6+ , N 4+ :N 7+ , O 5+ :O 8+ , and F 6+ :F 9+ are about 1.35, whereas a DDCS enhancement of 3.5 was observed for Cu 4+ . The BEE enhancement with increasing electrons on the projectile has been shown by several authors to be due to the non-Coulomb static potential of the projectile and additionally to the e-e exchange interaction. An impulse-approximation (IA) model fits the shape of the BEE DDCS and predicts a Z p 2 dependence for the bare-ion cross sections. The IA also predicts a binary peak energy that is independent of q and Z p and below the classical value of 4t, where t is the energy of electrons traveling with the projectile velocity. We observed a BEE energy shift ΔE (ΔE=4t-E peak , where E peak is the measured energy at the peak of the binary encounter electrons) that is approximately independent of q for the low-Z p ions, whereas the measured ΔE values for Si, Cl, and Cu were found to be q dependent
Shape-dependent conversion efficiency of Si nanowire solar cells with polygonal cross-sections
International Nuclear Information System (INIS)
He, Yan; Yu, Wangbing; Ouyang, Gang
2016-01-01
A deeper insight into shape-dependent power conversion efficiency (PCE) of Si nanowire (SiNW) solar cells with polygonal cross-sectional shapes, including trigon, tetragon, hexagon, and circle, has been explored based on the atomic-bond-relaxation approach and detailed balance principle. It has been found that the surface effect induced by the loss-coordination atoms located at edges and surfaces, as well as the thermal effect, plays the dominant roles for the band shift and PCE of SiNWs due to the lattice strain occurrence at the self-equilibrium state. Our predictions are consistent with the available evidences, providing an important advance in the development of Si-based nanostructures for the desirable applications.
Huang, Jiayu; Liu, Shu; Zhang, Dong H.; Krems, Roman V.
2018-04-01
Because the de Broglie wavelength of ultracold molecules is very large, the cross sections for collisions of molecules at ultracold temperatures are always computed by the time-independent quantum scattering approach. Here, we report the first accurate time-dependent wave packet dynamics calculation for reactive scattering of ultracold molecules. Wave packet dynamics calculations can be applied to molecular systems with more dimensions and provide real-time information on the process of bond rearrangement and/or energy exchange in molecular collisions. Our work thus makes possible the extension of rigorous quantum calculations of ultracold reaction properties to polyatomic molecules and adds a new powerful tool for the study of ultracold chemistry.
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.
Infrared cross-sections and integrated band intensities of propylene: Temperature-dependent studies
Es-sebbar, Et-touhami; Alrefae, Majed; Farooq, Aamir
2014-01-01
intensities of propylene are essential for quantitative measurements and atmospheric modeling. We measured absolute IR cross-sections of propylene using Fourier Transform Infrared (FTIR) Spectroscopy over the wavenumber range of 400-6500cm-1 and at gas
International Nuclear Information System (INIS)
Candelore, N.R.; Kerrick, W.E.; Johnson, E.G.; Gast, R.C.; Dei, D.E.; Fields, D.L.
1982-09-01
The PACER Monte Carlo program for the CDC-7600 performs fixed source or eigenvalue calculations of spatially dependent neutron spectra in rod-lattice geometries. The neutron flux solution is used to produce few group, flux-weighted cross sections spatially averaged over edit regions. In general, PACER provides environmentally dependent flux-weighted few group microscopic cross sections which can be made time (depletion) dependent. These cross sections can be written in a standard POX output file format. To minimize computer storage requirements, PACER allows separate spectrum and edit options. PACER also calculates an explicit (n, 2n) cross section. The PACER geometry allows multiple rod arrays with axial detail. This report provides details of the neutron kinematics and the input required
Temperature dependence of knocking-out cross sections of a bound atom from the lattice site
International Nuclear Information System (INIS)
Zhdanov, S.K.; Pletnev, V.V.
1981-01-01
The total cross section of atom knocking-out from the lattice site is calculated with the atom binding in the lattice site taken into account. The intermediate case of atom being preads over the bottom of a spherical potential well is considered (the case of intermediate temperatures). Thus the target temperature parameter enters the equation for the total cross section of atom knocking-out
Smoking dependence and common psychiatric disorders in medical students: Cross-sectional study
International Nuclear Information System (INIS)
Ashor, A.W.
2012-01-01
Objectives: Exploring the variable effect of the degree of smoking dependence on the level of anxiety and depression symptoms among medical students. Methodology: This cross-section study, conducted in the Department of Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad-Iraq from December 2010 to May 2011, involving 300 medical students selected by cluster random sampling techniques. Those students completed the Hamilton rating scale for anxiety, Zung self-report depression scale and the Fagerstrom test for nicotine dependence with a value of six or more regarded as heavy smokers, and a value less than six considered as light smokers. Results: The response rate was 89%, heavy smokers were significantly older and start smoking at an earlier age than non- and light smokers (p=0.001). Heavy smokers associated with high chance of depressive symptoms in comparison with non-smokers (OR=4.8, C.I.=1.752-13.677) and light smokers (OR=4.2, C.I.=1.042-17.161). Regarding anxiety symptoms, heavy smokers demonstrate high chance of anxiety symptoms in comparison with non-smokers (OR=5.2, C.I.=1.826-15.176), and light smokers (OR=4.5, C.I.=1.318-15.526). Conclusions: Heavy smokers differ from non- and light smokers, associated with high risk of anxiety and depression, therefore heavy smoking tends to deteriorate rather than ameliorate these symptoms. (author)
Psychosexual disorders: A cross-sectional study among opioid-dependent individuals
Directory of Open Access Journals (Sweden)
M I Singh Sethi
2017-01-01
Full Text Available Context: Punjab is in hold of a drug abuse-related epidemic, and the prevalence of opioid misuse is increased in the last few decades. A large-scale epidemiological data on sexual disorders among opioid users are lacking in literature. Aim: The aim of this articles was to study the prevalence of sexual disorders in patients with opioid dependence. Settings and Design: A cross-sectional study was conducted at a de-addiction clinic of a tertiary care centre from Punjab, India. Methods and Materials: A total of 109 consecutive patients attending the de-addiction clinic and fulfilling the eligibility criteria were assessed for sexual dysfunction by a predesigned, pretested, semistructured questionnaire. International Index of Erectile Function (IIEF-15 was administered to all patients to explore various aspects of sexual dysfunction. Statistical Analysis: Collected data were analyzed by SPSS version 20 using appropriate statistical test. Results: Mean age of participants was 29.9 years, 67% were married and heroin was the opioid of choice for 81.7%. Impaired sexual desire (59.6% was the commonest psychosexual problem, followed by decreased orgasmic function (57.8%, erectile dysfunction (56.4%, decreased overall satisfaction (52.2%, and decreased intercourse satisfaction (46.7%. Conclusions: The prevalence of all types of sexual dysfunction was found to be statistically significant with more than 1 year of opioid use. These findings can be used to motivate the patients to enter a rehabilitation program at an earlier stage of opioid dependence. Opioid-dependent individuals should be thoroughly investigated for sexual dysfunction and its treatment should be made an integral part of de-addiction and rehabilitation program.
International Nuclear Information System (INIS)
Shimoura, S.
1992-01-01
The relation between nuclear density distribution and interaction cross section is discussed in terms of Glauber model. Based on the model, density distribution of neutron drip-line nucleus 11 Be and 11 Li is determined experimentally from incident energy dependence of interaction cross sections of 11 Be and 11 Li on light targets. The obtained distributions have long tails corresponding to neutron halos of loosely bound neutrons. (Author)
International Nuclear Information System (INIS)
Angeli, Istvan
1990-01-01
The dependence of total neutron cross section on mass number can be calculated by the black nucleus formula, according to the optical model. The fine structure of mass number dependence is studied, and a correction factor formula is given on the basis of a semi-classical optical model. Yielding results in good agreement with experimental data. In addition to the mass number dependence, the neutron-energy dependence can also be calculated using this model. (K.A.)
Energy dependence of fusion evaporation-residue cross sections in the 28Si+28Si reaction
International Nuclear Information System (INIS)
Vineyard, M.F.; Bauer, J.S.; Gosdin, C.H.; Trotter, R.S.; Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D.; Rosner, G.; Chowdhury, P.; Ikezoe, H.; Kuhn, W.; Kolata, J.J.; Hinnefeld, J.D.; Maguire, C.F.; Mateja, J.F.; Prosser, F.W.; Stephans, G.S.F.
1990-01-01
Velocity distributions of mass-identified evaporation residues produced in the 28 Si+ 28 Si reaction have been measured at bombarding energies of 174, 215, 240, 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and total cross sections were extracted at all six bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with lower energy data and the predictions of existing models
Computation of temperature-dependent legendre moments of a double-differential elastic cross section
International Nuclear Information System (INIS)
Arbanas, G.; Dunn, M.E.; Larson, N.M.; Leal, L.C.; Williams, M.L.; Becker, B.; Dagan, R.
2011-01-01
A general expression for temperature-dependent Legendre moments of a double-differential elastic scattering cross section was derived by Ouisloumen and Sanchez [Nucl. Sci. Eng. 107, 189-200 (1991)]. Attempts to compute this expression are hindered by the three-fold nested integral, limiting their practical application to just the zeroth Legendre moment of an isotropic scattering. It is shown that the two innermost integrals could be evaluated analytically to all orders of Legendre moments, and for anisotropic scattering, by a recursive application of the integration by parts method. For this method to work, the anisotropic angular distribution in the center of mass is expressed as an expansion in Legendre polynomials. The first several Legendre moments of elastic scattering of neutrons on 238 U are computed at T=1000 K at incoming energy 6.5 eV for isotropic scattering in the center of mass frame. Legendre moments of the anisotropic angular distribution given via Blatt-Biedenharn coefficients are computed at 1 keV. The results are in agreement with those computed by the Monte Carlo method. (author)
International Nuclear Information System (INIS)
Liu Jianye; Xing Yongzhong; Guo Wenjun
2003-01-01
We study the isospin effects of the mean field and two-body collision on the nucleon emissions at the intermediate energy heavy-ion collisions by using an isospin-dependent transport theory. The calculated results show that the nucleon emission number N n depends sensitively on the isospin effect of nucleon-nucleon cross section and weakly on the isospin-dependent mean field for neutron-poor system in higher beam energy region. In particular, the correlation between the medium correction of two-body collision and the momentum-dependent interaction enhances the dependence of nucleon emission number N n on the isospin effect of nucleon-nucleon cross section. On the contrary, the ratio of the neutron-proton ratio of the gas phase to the neutron-proton ratio of the liquid phase, i.e., the degree of isospin fractionation [(N/Z) gas ] b /[(N/Z) liq ] b depends sensitively on the isospin-dependent mean field and weakly on the isospin effect of two-body collision for neutron-rich system in the lower beam energy region. In this case, N n and [(N/Z) gas ] b /[(N/Z) liq ] b are the probes for extracting the information about the isospin-dependent nucleon-nucleon cross section in the medium and the isospin-dependent mean field, respectively
International Nuclear Information System (INIS)
Brown, Forrest B.; Martin, William R.
2001-01-01
We have investigated Monte Carlo schemes for analyzing particle transport through media with exponentially varying time-dependent cross sections. For such media, the cross sections are represented in the form Σ(t) = Σ 0 e -at (1) or equivalently as Σ(x) = Σ 0 e -bx (2) where b = av and v is the particle speed. For the following discussion, the parameters a and b may be either positive, for exponentially decreasing cross sections, or negative, for exponentially increasing cross sections. For most time-dependent Monte Carlo applications, the time and spatial variations of the cross-section data are handled by means of a stepwise procedure, holding the cross sections constant for each region over a small time interval Δt, performing the Monte Carlo random walk over the interval Δt, updating the cross sections, and then repeating for a series of time intervals. Continuously varying spatial- or time-dependent cross sections can be treated in a rigorous Monte Carlo fashion using delta-tracking, but inefficiencies may arise if the range of cross-section variation is large. In this paper, we present a new method for sampling collision distances directly for cross sections that vary exponentially in space or time. The method is exact and efficient and has direct application to Monte Carlo radiation transport methods. To verify that the probability density function (PDF) is correct and that the random-sampling procedure yields correct results, numerical experiments were performed using a one-dimensional Monte Carlo code. The physical problem consisted of a beam source impinging on a purely absorbing infinite slab, with a slab thickness of 1 cm and Σ 0 = 1 cm -1 . Monte Carlo calculations with 10 000 particles were run for a range of the exponential parameter b from -5 to +20 cm -1 . Two separate Monte Carlo calculations were run for each choice of b, a continuously varying case using the random-sampling procedures described earlier, and a 'conventional' case where the
Measurement of Z dependence of elastic scattering cross-sections of 0. 145 MeV gamma rays
Energy Technology Data Exchange (ETDEWEB)
Ghumman, B S [Punjabi Univ., Patiala (India). Dept. of Physics
1981-11-01
The Z dependence of elastic scattering cross-sections of 0.145 MeV gamma rays is investigated at large scattering angles. Measurements are made with scatterers of Pb, W, Sn, Ag, Mo, Zn, Cu, Fe and Al at scattering angles from 75 deg to 150 deg. The experimental results are compared with the available theoretical and experimental data.
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
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...
Ellis-Gibbings, L.; Krupa, K.; Colmenares, R.; Blanco, F.; Muńoz, A.; Mendes, M.; Ferreira da Silva, F.; Limá Vieira, P.; Jones, D. B.; Brunger, M. J.; García, G.
2016-09-01
Recent theoretical and experimental studies have provided a complete set of differential and integral electron scattering cross section data from furfural over a broad energy range. The energy loss distribution functions have been determined in this study by averaging electron energy loss spectra for different incident energies and scattering angles. All these data have been used as input parameters for an event by event Monte Carlo simulation procedure to obtain the electron energy deposition patterns and electron ranges in liquid furfural. The dependence of these results on the input cross sections is then analysed to determine the uncertainty of the simulated values.
Measurement of the cross section of charmed hadrons and the nuclear dependence alpha
Energy Technology Data Exchange (ETDEWEB)
Blanco-Covarrubias, Ernesto Alejandro [Autonomous Univ. of San Luis Potosi, San Luis Potosi (Mexico)
2009-12-03
With data from the SELEX experiment we study charm hadro-production. We report the differential production cross sections as function of the longitudinal and transverse momentum, as well as for two different target materials, of 14 charmed hadron and/or their decay modes. This is the most extensive study to date. SELEX is a fixed target experiment at Fermilab with high forward acceptance; it took data during 1996-1997 with 600 GeV/c Σ^{-} and π^{-}, and 540 GeV/c proton and π^{+} beams. It used 5 target foils (two copper and three diamond). We use the results to determine α, used in parametrizing the production cross section as ∞ A^{α}, where A is the mass number of the target nuclei. We found within our statistics that α is independent of the longitudinal momentum fraction x_{F} in the interval 0.1 < x_{F} < 1.0, with α = 0.778 ± 0.014. The average value of α} for charm production by pion beams is α _{meson} = 0.850 ± 0.028. This is somewhat larger than the corresponding average α_{baryon} = 0.755 ± 0.016 for charm production by baryon beams (Σ^{-} and protons).
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.
Serdyuchenko, Anna; Gorshelev, Victor; Chehade, Wissam; Weber, Mark; Burrows, John P.
We report on the work devoted to the up-to-date measurements of the ozone absorption cross-sections. The main goal of the project is to produce a consolidated and consistent set of high resolution cross-sections for satellite spectrometers series that allows a derivation of the harmonized long term data set. The generation of long-term datasets of atmospheric trace gases is a major need and prerequisite for climate and air quality related studies. At present there are three atmospheric chemistry instruments (GOME1, SCIAMACHY and GOME2) in operation and two more spectrometers (GOME2) to be launched five years apart in the next decade resulting in a time series covering two or more decades of ozone observations. Information from different sensors has to be com-bined for a consistent long-term data record, since the lifetime of individual satellite missions is limited. The harmonization of cross-sections is carried out by combination of new experimental work with re-evaluation of the existing cross-sections data. New laboratory measurements of ozone cross-section are underway that will improve a) absolute scaling of cross-sections, b) temper-ature dependence of cross-sections (using very low temperatures starting at 190 K and higher sampling of temperatures up to room temperature) and c) improved wavelength calibration. We take advantage of a Fourier transform spectrometer (visible, near IR) and Echelle spectropho-tometer (UV, visible) to extend the dynamic range of the system (covering several orders of magnitude in cross-sections from UV up to the near IR). We plan to cover the spectral range 220 -1000 nm at a spectral resolution of 0.02 nm in UV/VIS with absolute intensity accuracy of at least 2%, and wavelength accuracy better than 0.001 nm in the temperature range 193-293 K in 10 K steps. A lot of attention is paid to the accuracy of determining the temperature of the ozone flow and new methods for absolute calibration of relative spectra. This work is in
ZZ CANDULIB-AECL, Burnup-Dependent ORIGEN-S Cross-Section Libraries for Candu Reactor Fuels
International Nuclear Information System (INIS)
2002-01-01
and fission cross sections were obtained from collapsed 89-group ENDF/B-V and -VI data from the WIMS-AECL lattice code. Other reaction cross sections were obtained from the SCALE 27-group ENDF/B-IV data. In all, cross sections for more than 200 important actinides and fission products were updated with burnup-dependent data. The source of the nuclear decay data and cross sections not updated were the base ORIGEN-S libraries distributed with the SCALE 4.2 code package. The burnup-dependent cross sections were generated using eight burnup intervals that extend up to a burnup of approximately 12000 MWd/MgU. The cross sections for each interval are stored in positions on the ORIGEN-S library and are accessed by referencing the position number. The burnup values associated with each position are listed below. They are the same for both the 37-element and 28-element libraries. Library Position → Burnup (MWd/MgU): 1 → 240; 2 → 720; 3 → 1440; 4 → 2880; 5 → 4800; 6 → 6720; 7 → 8640; 8 → 10560
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)
International Nuclear Information System (INIS)
Egodapitiya, K. N.; Sharma, S.; Laforge, A. C.; Schulz, M.
2011-01-01
We have measured double differential cross sections (DDCS) for proton fragment formation for fixed projectile energy losses as a function of projectile scattering angle in 75 keV p + H 2 collisions. An oscillating pattern was observed in the angular dependence of the DDCS with a frequency about twice as large as what we found earlier for nondissociative ionization. Possible origins for this frequency doubling are discussed.
International Nuclear Information System (INIS)
Trautmann, D.; Kauer, T.
1989-01-01
We present the application of the SCA-model to impact-parameter and energy-dependent K-shell ionization cross sections for several projectile-target combinations. Then we discuss the successes and failures of the SCA-description and investigate the additional approximations still existing in this approach. It is shown that after the introduction of a fully time-dependent perturbed electronic boundstate wave function many of the former discrepancies between experiment and theory can be resolved and in general very good agreement is obtained. (orig.)
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
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
Rodríguez-González, Ana María; Rodríguez-Míguez, Eva; Duarte-Pérez, Ana; Díaz-Sanisidro, Eduardo; Barbosa-Álvarez, Ángel; Clavería, Ana
2017-03-01
To describe the burden of informal carers of dependent people and to identify related variables. Descriptive observational cross-sectional study. Primary Health Care in the southern area of Pontevedra. 97 caregivers of dependent persons. We collected socioeconomic data and health conditions from caregivers and dependent persons, time spent on the daily care and caregiver burden (Zarit abbreviate) through a personal interview. Besides the description of the sample-including their burden level-, a contrast mean was used to identify characteristics that influenced in punctuation of Zarit scale. A logistic regression was used to analyse characteristics that increase the likelihood to experiment burden. 61.9% of caregivers are subject to intense burden. The item on the scale which contributes most to the caregiver burden is the lack of time for oneself, followed by the negative effects of interpersonal relationships. Contrast means shows that degree of relationship, number of care hours, caregiver health and aggressiveness of dependent persons produce significant differences in Zarit scale. Physic and psychological health of caregivers and aggressiveness of dependent persons is associated with the likelihood of developing caregiver burden. Informal caregivers of dependent persons show a high level of burden, both related to their characteristics and those of the dependent persons. Caregiver burden rethinks the need for public policies focused on dependence to adopt an integrative caregiver-dependent vision. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.
Kimergård, A; Foley, M; Davey, Z; Dunne, J; Drummond, C; Deluca, P
2017-09-01
Codeine misuse and dependence poses a clinical and public health challenge. However, little is known about dependence and treatment needs in the UK and Ireland. To characterize codeine use, dependence and help-seeking behaviour. An online cross-sectional survey advertised on Facebook, Twitter, health and drug websites and e-mail circulars. The survey collected data on demographics and codeine use amongst adults from the UK and Ireland. The Severity of Dependence Scale measured the level of codeine dependence. The sample of 316 respondents had a mean age of 35.3 years (SD = 12.3) and 67% were women. Of the 316 respondents, 54 scored ≥5 on the Severity of Dependence Scale indicating codeine dependence (17.1%). Our study found that codeine dependence is a problem with both prescribed and 'over-the-counter' codeine. Codeine dependence was associated with daily use of codeine, faking or exaggerating symptoms to get a prescription for codeine and 'pharmacy shopping' ( P addiction treatment demand through increased identification and referrals in primary care. © The Author 2017. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com
International Nuclear Information System (INIS)
Aquilanti, V.; Casavecchia, P.
1976-01-01
Electronic excitation leading to light emission in the wavelength range 350--800 nm has been studied by a crossed ion--atom beam technique for (K + , K) collisions, and the results are interpreted in terms of properties of the potential energy curves for the molecular ion K + 2 . The investigated velocity range is (1.3--12) x10 6 cm s -1 . The total cross section for the process K + (3p 6 1 S 0 ) +K(4s 2 S 1 / 2 ) →K + (3p 6 1 S 0 ) +K(4p 2 P 3 / 2 , 1 / 2 ) increases from threshold up to approx.10 -15 cm 2 at a velocity of approx.4.5x10 6 cm s -1 , and shows an oscillatory structure. The magnitude and over-all velocity dependence are attributed to a Σ--Pi curve crossing, and the oscillations to an interference effect, which is treated as an inelastic ''glory'' phenomenon. Cross sections for production of each of the fine structure components of K(4p), 2 P 3 / 2 , and 2 P 1 / 2 , have also been measured. Their ratio, which in the investigated velocity range is different from the statistical value, shows additional oscillations, which are discussed in terms of long range interference between alternate semiclassical paths
Dependence on the cross section of Λ and anti-Λ strange baryons production with the mass number
International Nuclear Information System (INIS)
Gandelman, Miriam Mendes.
1992-07-01
In this work the A dependence of the λ and λ - production cross sections is studied using the E769 data for the 250 GeV/cπ - beam interacting on Be, Cu, Al and W targets. The measured mean value of α in the region - 0.2 f t - . No difference is measured between the values of α for λ and λ - : α is a global decreasing function of x f and has no significant variation with p t . (author). 31 refs, 48 figs, 16 tabs
Energy Technology Data Exchange (ETDEWEB)
Ahrens, J.; Arends, H.J.; Aulenbacher, K.; Beck, R.; Drechsel, D.; Harrach, D. van; Heid, E. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Altieri, S. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, I-27100 Pavia (Italy); Annand, J.R.M. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Anton, G. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Bradtke, C.; Goertz, S.; Harmsen, J. [Institut fuer Experimentalphysik, Ruhr-Universitaet Bochum, D-44801 Bochum (Germany); Braghieri, A. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); d' Hose, N. [CEA Saclay, DSM/DAPNIA/SPhN, F-91191 Gif-sur-Yvette Cedex (France); Dutz, H. [Physikalisches Institut, Universitaet Bonn, D-53115 Bonn (Germany); Grabmayr, P. [Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany); Hansen, K. [Department of Physics, University of Lund, Lund (Sweden); Hasegawa, S. [Department of Physics, Nagoya University, Chikusa-ku, Nagoya (Japan); Hasegawa, T. [Faculty of Engineering, Miyazaki University, Miyazaki (Japan); Helbing, K.; Holvoet, H.; Van Hoorebeke, L.; Horikawa, N.; Iwata, T.; Jahn, O.; Jennewein, P.; Kageya, T.; Kiel, B.; Klein, F.; Kondratiev, R.; Kossert, K.; Krimmer, J.; Lang, M.; Lannoy, B.; Leukel, R.; Lisin, V.; Matsuda, T.; McGeorge, J.C.; Meier, A.; Menze, D.; Meyer, W.; Michel, T.; Naumann, J.; Panzeri, A.; Pedroni, P.; Pinelli, T.; Preobrajenski, I.; Radtke, E.; Reichert, E.; Reicherz, G.; Rohlof, Ch.; Rosner, G.; Ryckbosch, D.; Sauer, M.; Schoch, B.; Schumacher, M.; Seitz, B.; Speckner, T.; Takabayashi, N.; Tamas, G.; Thomas, A.; Van de Vyver, R.; Wakai, A.; Weihofen, W.; Wissmann, F.; Zapadtka, F.; Zeitler, G.
2003-06-01
The helicity dependence of the (vector)({gamma})(vector)(p){yields}p{eta} reaction has been measured for the first time at a center-of-mass angle {theta}{sup *}{sub {eta}}=70 in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4{pi}-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis. (orig.)
First measurement of the helicity-dependent vector gamma)vector(p)->p eta differential cross-section
Ahrens, J; Aulenbacher, K; Beck, R; Drechsel, D; Von Harrach, D; Heid, E; Altieri, S; Annand, J R M; Anton, G; Bradtke, C; Görtz, S; Harmsen, J; Braghieri, A; D'Hose, N; Dutz, H; Grabmayr, P; Hansen, K; Hasegawa, S; Hasegawa, T; Helbing, K; Holvoet, H; Van Hoorebeke, L; Horikawa, N; Iwata, T; Jahn, O; Jennewein, P; Kageya, T; Kiel, B; Klein, F; Kondratiev, R; Kossert, K; Krimmer, J; Lang, M; Lannoy, B; Leukel, R; Lisin, V; Matsuda, T; McGeorge, J C; Meier, A; Menze, D; Meyer, Werner T; Michel, T; Naumann, J; Panzeri, A; Pedroni, P; Pinelli, T; Preobrajenski, I; Radtke, E; Reichert, E; Reicherz, G; Rohlof, C; Rosner, G; Ryckbosch, D; Sauer, M C; Schoch, B; Schumacher, M; Seitz, B; Speckner, T; Takabayashi, N; Tamas, G; Thomas, A; Van De Vyver, R; Wakai, A; Weihofen, W; Wissmann, F; Zapadtka, F; Zeitler, G
2003-01-01
The helicity dependence of the vector(gamma)vector(p)->p eta reaction has been measured for the first time at a center-of-mass angle theta sup * subeta=70 in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4 pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis. (orig.)
Floodplain Cross Section Lines
Department of Homeland Security — This table is required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally any FIRM...
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
Nakajima, Motohiro; Hoffman, Richard; al'Absi, Mustafa
2017-05-01
Chronic khat use is associated with negative health consequences. However, no study has fully characterized individuals who are khat dependent. This paper examines socio-demographic and psychosocial correlates of adult khat dependence. A total of 270 khat users (129 women) in Yemen completed face-to-face interviews and provided demographic information and data on patterns of khat use, subjective mood, and sleep quality. The Severity of Dependence Scale-Khat (SDS-khat) was used to assess level of khat dependence. A series of analysis of variance was conducted. Khat users, on average, used khat for 5.2 hours a day (SD = 2.3) for 5.7 days a week (SD = 2.0). Individuals who screened positive for khat dependence reported longer duration of khat sessions per day, higher frequency of khat use per week, greater levels of negative mood and sleep disturbances, and were more likely to endorse physical symptoms after khat use (P < 0.05). Future research should elucidate mechanisms responsible for khat dependence symptomatology.
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.
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.
International Nuclear Information System (INIS)
Judson, R.S.; McGarrah, D.B.; Sharafeddin, O.A.; Kouri, D.J.; Hoffman, D.K.
1991-01-01
We compare three time-dependent wave packet methods for performing elastic scattering calculations from screened Coulomb potentials. The three methods are the time-dependent amplitude density method (TDADM), what we term a Cayley-transform method (CTM), and the Chebyshev propagation method of Tal-Ezer and Kosloff. Both the TDADM and the CTM are based on a time-dependent integral equation for the wave function. In the first, we propagate the time-dependent amplitude density, |ζ(t)right-angle=U|ψ(t)right-angle, where U is the interaction potential and |ψ(t)right-angle is the usual time-dependent wave function. In the other two, the wave function is propagated. As a numerical example, we calculate phase shifts and cross sections using a screened Coulomb, Yukawa type potential over the range 200--1000 eV. One of the major advantages of time-dependent methods such as these is that we get scattering information over this entire range of energies from one propagation. We find that in most cases, all three methods yield comparable accuracy and are about equally efficient computationally. However for l=0, where the Coulomb well is not screened by the centrifugal potential, the TDADM requires smaller grid spacings to maintain accuracy
International Nuclear Information System (INIS)
Nazlioglu, Saban; Lebe, Fuat; Kayhan, Selim
2011-01-01
The purpose of this study is to determine the direction causality between nuclear energy consumption and economic growth in OECD countries. The empirical model that includes capital and labor force as the control variables is estimated for the panel of fourteen OECD countries during the period 1980-2007. Apart from the previous studies in the nuclear energy consumption and economic growth relationship, this study utilizes the novel panel causality approach, which allows both cross-sectional dependency and heterogeneity across countries. The findings show that there is no causality between nuclear energy consumption and economic growth in eleven out of fourteen cases, supporting the neutrality hypothesis. As a sensitivity analysis, we also conduct Toda-Yamamoto time series causality method and find out that the results from the panel causality analysis are slightly different than those from the time-series causality analysis. Thereby, we can conclude that the choice of statistical tools in analyzing the nature of causality between nuclear energy consumption and economic growth may play a key role for policy implications. - Highlights: → Causality between nuclear energy consumption and economic growth is examined for OECD countries. → Panel causality method, which allows cross-sectional dependency and heterogeneity, is utilized. → The neutrality hypothesis is supported.
Hussain, Azmina; Zaheer, Sidra; Shafique, Kashif
2018-03-13
Betel quid (BQ) is one of the fourth most commonly used substance globally. Though BQ is a psycho-active substance, yet little has been explored regarding dependency on it particularly among adolescents. Therefore, in this study, we aimed to determine adolescents' dependency on BQ, along with their intrapersonal, interpersonal and environmental determinants of dependency. This cross-sectional study focused on 2200 school-going adolescents of Karachi, Pakistan in 2016. Primary outcome was dependency on BQ among adolescents. Both univariate and multivariate regressions were used to estimate crude and adjusted odds ratios (after adjustments for all intrapersonal, interpersonal, and environmental factors) with 95% confidence level. Out of 2200 students, 874 (39.7%) were found to be BQ users amongst whom 69 (7.9%) were dependent on BQ. Comparing the groups with only areca nut users as reference category, betel quid with tobacco additives chewers were considerably dependent (OR = 14.08, 95% CI 3.64-54.16). The individuals who chewed >5 chews per day (OR = 1.87, 95% CI 1.08-3.29) and chronic users (>1year) (OR = 2.02, 95% CI 1.09-3.74) were more likely to be dependent. Older students (>12 years) (OR = 2.12, 95% CI 1.06-4.23), and who studied in government schools were significantly dependent (OR = 3.32, 95% CI 1.80-6.10) than those who studied in private schools. In conclusion, intrapersonal characteristics like more than 5 chews per day, chronic chewers of more than a year, BQ with tobacco chewers, older adolescents and children studying in government schools were significantly associated with BQ dependency.
Energy Technology Data Exchange (ETDEWEB)
Arora, S K; Allawadhi, K L; Sood, B S [Punjabi Univ., Patiala (India). Nuclear Science Labs.
1980-08-28
The energy dependence of L-shell photoelectric cross sections for lead in the energy region 17-50 keV has been investigated. The method utilises external conversion x-rays as the source of photons and it yields relative rather than absolute cross sections, but is simpler and more accurate. The results show fairly good agreement with theory.
International Nuclear Information System (INIS)
Haldoupis, C.; Nielsen, E.; Schlegel, K.
1990-01-01
By using a data set that includes simultaneous STARE and EISCAT measurements made at a common magnetic flux tube E region in the ionosphere, we investigate the dependence of relative scattering cross section of 1-meter auroral irregularities on the destabilizing E x B electron drift, or alternatively the electric field, and the E region ambient electron density. The analysis showed that both, the E field and mean electron density are the decisive factors in determining the strength of radar auroral echoes at magnetic aspect angles near perpendicularity. We have found that at instability threshold, i.e., when the E field strength is in the 15 to 20 mV/m range, the backscatter power level is affected strongly by the mean electron density. Above threshold, the wave saturation amplitudes are determined mainly by the combined action of electron drift velocity magnitude, V d , and mean electron density, N e , in a way that the scattering cross section, or the electron density fluctuation level, increases with electric field magnitude but at a rate which is larger when the ambient electron density is lower. The analysis enabled us to infer an empirical functional relationship which is capable of predicting reasonably well the intensity of STARE echoes from EISCAT E field and electron density data. In this functional relationship, the received power at threshold depends on N e 2 whereas, from threshold to perhaps more than 50 mV/m, the power increases nonlinearly with drift velocity as V d n where the exponent n is approximately proportional to N e -1/2 . The results support the Farley-Bunemann instability as the primary instability mechanism, but the existing nonlinear treatment of the theory, which includes wave-induced cross field diffusion, cannot account for the observed role of electron density in the saturation of irregularity amplitudes
International Nuclear Information System (INIS)
Macias, A.; Riera, A.; Yanez, M.
1983-01-01
A treatment of the He + -H collision is presented in an impact-parameter formalism for collision energies 0.5--30 keV. The origin dependence of the calculated total cross sections is studied in detail. It is shown that the branching ratio between reactions He + (1s)+H(1s)→He + (1s)+H(2n) and He + (1s)+H(1s)→He(1s2p)+H + oscillates as a function of the origin of electronic coordinates chosen in the calculation. This oscillation is strong enough so that at nuclear velocity 0.5 a.u., either both reactions are competitive or one of them can have a cross section for the reaction He(1s 2 )+H + →He + (1s)+H(1s) can either be negligble or comparable to those of the other reactions. We study the oscillatory behavior of the charge-exchange-transition probability as a function of 1/v. We show the similarity, for high velocity, between nonresonant and resonant change-exhange processes, the origin of the damping factor, and the influence of the rotatioal coupling on the transition probabilities as functions of 1/v. A connection between Lichten's and Denkov's models is established
Energy Technology Data Exchange (ETDEWEB)
Macias, A.; Riera, A.; Yanez, M.
1983-01-01
A treatment of the He/sup +/-H collision is presented in an impact-parameter formalism for collision energies 0.5--30 keV. The origin dependence of the calculated total cross sections is studied in detail. It is shown that the branching ratio between reactions He/sup +/(1s)+H(1s)..-->..He/sup +/(1s)+H(2n) and He/sup +/(1s)+H(1s)..-->..He(1s2p)+H/sup +/ oscillates as a function of the origin of electronic coordinates chosen in the calculation. This oscillation is strong enough so that at nuclear velocity 0.5 a.u., either both reactions are competitive or one of them can have a cross section for the reaction He(1s/sup 2/)+H/sup +/..-->..He/sup +/(1s)+H(1s) can either be negligble or comparable to those of the other reactions. We study the oscillatory behavior of the charge-exchange-transition probability as a function of 1/v. We show the similarity, for high velocity, between nonresonant and resonant change-exhange processes, the origin of the damping factor, and the influence of the rotatioal coupling on the transition probabilities as functions of 1/v. A connection between Lichten's and Denkov's models is established.
Schüssler, Sandra; Dassen, Theo; Lohrmann, Christa
2016-10-01
Chronic diseases, like dementia, can lead to care dependency and nursing care problems. This study aims to compare the degree of care dependency and the prevalence of nursing care problems (pressure ulcer, incontinence, malnutrition, falls, restraints) between residents with and without dementia and between the stages of dementia. A cross-sectional design was chosen and a total of 277 residents with and 249 residents without dementia from nine Austrian nursing homes were assessed by staff using standardized instruments. Significantly more residents with than without dementia are completely or to a great extent care dependent (54.5 vs. 16.9 %). The comparison of care dependency between the stages of dementia indicates a large difference between moderate and severe dementia (completely care dependent: 9.3 vs. 44.3 %). The comparison of the assessed nursing care problems between residents with and without dementia reveals a significant difference only with regard to incontinence (urinary: 84.2 vs. 53.2 %, fecal: 50.9 vs. 17.7 %, double: 49.1 vs. 14.9 %). Urinary incontinence is high even in early dementia at 64 %, reaching 94 % in severe dementia. Fecal- and double incontinence are comparatively much lower in early dementia (both types 12 %) and rise to more than 80 % (both types) in severe dementia. These results highlight areas in which dementia care needs further improvements. The authors suggest maximizing residents' independence to stabilize care dependency and improve incontinence care. Furthermore, longitudinal studies are recommended to deepen insight into the development of care dependency and nursing care problems in dementia residents.
Directory of Open Access Journals (Sweden)
Mehmet Akif DESTEK
2016-05-01
Full Text Available In this study, the long term relationship between military spending and economic growth in newly industrialized countries is analyzed with panel data methods for the years of 1988-2013. The study, where panel unit root, panel co-integration, panel co-integration estimator and panel causality tests that allow cross-sectional dependence are used, shows that the feedback hypothesis is valid in newly industrialized countries. And when these countries are analyzed separately, it is seen that the growth hypothesis is valid for India, Malaysia, Mexico and South Africa; the neutrality hypothesis is valid for China, Indonesia, Philippines, Thailand and Turkey and the growth detriment hypothesis is valid for Brazil.
Directory of Open Access Journals (Sweden)
Mamta Parashar
2016-01-01
Full Text Available Introduction: Workers represent half the world′s population and are major contributors to economic and social development. Tobacco consumption in construction site workers has been considered a big challenge. Objectives: (1 To assess the prevalence of nicotine dependence among tobacco users. (2 To study the correlates of nicotine dependence among the construction site workers. Methodology: A cross sectional study was conducted using a predesigned and pretested structured proforma. The study was conducted among all construction site workers aged 18yrs and above in campus of Hamdard Institute of Medical Sciences and Research and associated HAH centenary hospital, New Delhi.Karl Fagerstrom Nicotine Dependence Questionnaire was used to assess dependence on nicotine. Results: The mean age of construction site workers was 32.04±11.6 years. Among the workers, majority (91% were tobacco user. Among the users, 60% found it difficult to refrain from smoking/chewing in places where use of tobacco is not allowed (e.g. hospitals, government offices, cinemas, Libraries etc. 55% of the users smoked or chewed tobacco during the first hours after waking than during the rest of the day. On multivariate analysis, the factors which were found to be significantly associated with nicotine dependence were lower income group (OR 2.57, CI:1.66-3.99, smokeless tobacco use (OR 2.36,CI:1.30-4.27 and lower education (OR = 2.86 (95% CI 1.97-4.16 for illiterate. Discussion: The prevalence of tobacco use (91% among construction workers is very high compared to that in the general population. Recognition of construction sites as work places and proper implementation of law is needed.
Directory of Open Access Journals (Sweden)
Ferri Cleusa P
2008-08-01
Full Text Available Abstract Background Demographic ageing, and the health transition will soon lead to large increases in the number of dependent older people in low and middle income countries. Despite its importance, this topic has not previously been studied. Methods A cross sectional catchment area one-phase survey of health conditions, dependency, care arrangements and caregiver strain among 2011 people aged 65 years and over in Santo Domingo, Dominican Republic Results 7.1% of participants required much care and a further 4.7% required at least some care. The prevalence of dependency increased sharply with increasing age. Dependent older people were less likely than others to have a pension and much less likely to have paid work, but no more likely to benefit from financial support from their family. Needing much care was strongly associated with comorbidity between cognitive, psychological and physical health problems. However, dementia made the strongest independent contribution. Among those needing care, those with dementia stood out as being more disabled, as needing more care (particularly support with core activities of daily living, and as being more likely to have paid caregivers. Dementia caregivers experienced more strain than caregivers of those with other health conditions, an effect mediated by behavioural and psychological symptoms. Conclusion Dependency among older people is nearly as prevalent in Dominican Republic as in developed western settings. Non-communicable diseases, particularly dementia are the main contributing factors. Attention needs to be directed towards the development of age-appropriate healthcare, a long-term care policy, and mechanisms for ensuring the social protection of older persons.
Molla, Zemenay; Dube, Lamesa; Krahl, Wolfgang; Soboka, Matiwos
2017-07-17
Tobacco smoking is a health care issue in developed as well as in developing countries. Tobacco smoking among people with mental illness is significantly higher than in the general population. Tobacco smoking has negative effects on physical, mental and financial well-being of people with mental illness but little is known about tobacco dependence among mental health service users in sub-Saharan African countries, including Ethiopia. Therefore, this study attempted to assess the prevalence of tobacco dependence and associated factors among mental health service users at Jimma University teaching hospital. A cross-sectional study was conducted among 305 male and 117 female mental health service users at Jimma University teaching Hospital in 2014. The Fagerstrom Test for Nicotine Dependence (FTND) was used to assess tobacco dependence. Logistic regression analysis was used for bivariate and multivariate analysis. Variables with a P value of service users with tobacco dependence were males. There was a significant association between tobacco dependence and high school education (AOR 3.02, 95% CI 1.07, 8. 48), alcohol use disorder (AOR 4.14, 95% CI = 1.54, 11.11), daily khat chewing (AOR 13.51, 95% CI = 4.27, 42.74), chewing khat 2-3 times per week (AOR 5.09, 95% CI = 1.37,18.95), chewing khat once a week (AOR 4.31, 95%CI = 1.04,17.78), having friends who smoke tobacco (AOR 4.88, 95% CI = 2.12, 11.25) and being diagnosed with schizophrenia compared to a diagnosis of major depression (AOR 5.26, 95% CI = 2.07, 13.37). However, daily attendance at a place of worship (AOR 0.46, 95% CI = 0.22, 0.95) was associated negatively with tobacco dependence. In this study, there was a high prevalence of tobacco dependence among mental health services users. There is a pressing need to increase availability of psychological and pharmacological interventions to reduce tobacco dependence and tobacco-related medical illness in this vulnerable group.
Franques, P; Auriacombe, M; Piquemal, E; Verger, M; Brisseau-Gimenez, S; Grabot, D; Tignol, J
2003-03-01
Animal research has outlined a vulnerability trait to drug dependence like behavior. The behavioral characteristic of this vulnerability is hyperactivity in response to a novel environment of which sensation seeking (SS) has been suggested as a possible equivalent in humans. If this is the case, SS should be more frequent in drug dependent and risky sports practicing subjects then controls. The objective of this study was to determine if opioid dependent subjects (ODS) and regular paragliders (RP) would be more SS then normal controls. Cross sectional study. Three groups of 34 individuals (total 102) matched for age and sex were selected from ODS seeking treatment, a paragliding club, and a college staff. Global and sub-scores of the Zuckerman sensation seeking scale (SSS). Non parametric statistics (Kruskal Wallis and Wilcoxon 2-Sample Tests) were used given the non-normal distribution of SSS scores in the ODS and RP groups. Significant differences were found across the three groups for the Thrill and Adventure Seeking (TAS) (P = 0.001), dishinibition (Dis) (P = 0.0003) and total score (P = 0.001). ODS and RP scored significantly higher than controls on two (Dis and the TAS scales). RP also scored significantly higher on the Boredom Susceptibility (BS) scale (P = 0.04). Our results show that RP and ODS differ from controls and have some similarities based on the SSS. In this study, the ODS and the RP could express different forms of a general tendency to seek intense and abrupt sensations through various behaviors. Our results in humans are in favor of the hypothesis that the behavioral trait of vulnerability to drug dependence behavior is expressed through SS. Copyright 2002 Elsevier Science Ireland Ltd.
International Nuclear Information System (INIS)
Wang, Fengyan; Lin, Jui-San; Liu, Kopin
2014-01-01
Polarization-dependent differential cross section (PDDCS) is one of the three-vector correlations (k, k ′ , j) in molecular collisions, which provides the most detailed insights into the steric requirements of chemical reactions, i.e., how the reactivity depends on the polarization of reagents. Only quite recently has such quantity been fully realized experimentally in the study of the reaction of the aligned CHD 3 (v 1 = 1, |jK〉 = |10〉) molecules with Cl( 2 P 3/2 ) atoms. Theoretically, PDDCS is a relatively new concept; experimental realization of the theoretical construct requires some careful considerations that are not readily available in the literature. Here, we present the “know-how” behind the full PDDCS measurements to fill the gaps and to provide a clear roadmap for future applications. To make the connection apparent between the methodology presented here and the stereodynamics revealed in previous reports, the same Cl + aligned CHD 3 reaction is used for illustration
Huang, Yuting; Dodds, Eric D
2013-10-15
Carbohydrates play numerous critical roles in biological systems. Characterization of oligosaccharide structures is essential to a complete understanding of their functions in biological processes; nevertheless, their structural determination remains challenging in part due to isomerism. Ion mobility spectrometry provides the means to resolve gas phase ions on the basis of their shape-to-charge ratios, thus providing significant potential for separation and differentiation of carbohydrate isomers. Here, we report on the determination of collisional cross sections for four groups of isomeric carbohydrates (including five isomeric disaccharides, four isomeric trisaccharides, two isomeric pentasaccharides, and two isomeric hexasaccharides) as their group I metal ion adducts (i.e., [M + Li](+), [M + Na](+), [M + K](+), [M + Rb](+), and [M + Cs](+)). In all, 65 collisional cross sections were measured, the great majority of which have not been previously reported. As anticipated, the collisional cross sections of the carbohydrate metal ion adducts generally increase with increasing metal ion radius; however, the collisional cross sections were found to scale with the group I cation size in isomer specific manners. Such measurements are of substantial analytical value, as they illustrate how the selection of charge carrier influences carbohydrate ion mobility determinations. For example, certain pairs of isomeric carbohydrates assume unique collisional cross sections upon binding one metal ion, but not another. On the whole, these data suggest a role for the charge carrier as a probe of carbohydrate structure and thus have significant implications for the continued development and application of ion mobility spectrometry for the distinction and resolution of isomeric carbohydrates.
International Nuclear Information System (INIS)
Cullen, D.E.
1979-01-01
Program RECENT reconstructs energy-dependent neutron total, elastic, capture, and fission cross sections from a combination of resonance parameters and tabulated background cross sections in the ENDF/B format. Entire evaluations, not just cross sections, are written to the result file, which is in ENDF/B format. The output includes the original resonance parameters in a form that can be used in Doppler broadening and self-shielding calculations. A listing of the source deck is available on request. 5 figures, 5 tables
International Nuclear Information System (INIS)
Aid, S.; Andreev, V.; Andrieu, B.
1996-03-01
The Q 2 dependence and the total cross sections for charged and neutral current processes are measured in e ± p reactions for transverse momenta of the outgoing lepton larger than 25 GeV. Comparable size of cross sections for the neutral current process and for the weak charged current process are observed above Q 2 ∼5000 GeV 2 . Using the shape and magnitude of the charged current cross section we determine a propagator mass of m W =84 -7 +10 GeV. (orig.)
Jørgensen, Marie Birk; Villadsen, Ebbe; Burr, Hermann; Punnett, Laura; Holtermann, Andreas
2016-01-01
Objectives To investigate if participation in workplace health promotion (WHP) depends on the work environment. Methods Questionnaire data on participation in WHP activities (smoking cessation, healthy diet, exercise facilities, weekly exercise classes, contact with health professionals, health screenings) and the work environment (social support, fatiguing work, physical, quantitative and emotional demands, job control and WHP availability setting) were collected cross-sectionally in 2010 in a representative sample (n=10 605) of Danish workers. Binary regression analyses of the association between work environment characteristics and participation in WHP were conducted and adjusted for age, gender and industry. Results WHP offered during leisure time was associated with lower participation in all measured activities compared with when offered during working hours. Low social support and fatiguing work were associated with low participation in WHP. No associations with participation in WHPs were observed for physical work or quantitative demands, work pace or job strain. However, high physical demands/low job control and high emotional demands/low job control were associated with low participation. Conclusions Lower participation in WHP was associated with programmes during leisure, low social support, very fatiguing work and high physical or emotional demands with low job control. This suggests that to obtain proper effect of health promotion in a workplace setting, a good work environment is essential. PMID:27279474
Jørgensen, Marie Birk; Villadsen, Ebbe; Burr, Hermann; Punnett, Laura; Holtermann, Andreas
2016-06-08
To investigate if participation in workplace health promotion (WHP) depends on the work environment. Questionnaire data on participation in WHP activities (smoking cessation, healthy diet, exercise facilities, weekly exercise classes, contact with health professionals, health screenings) and the work environment (social support, fatiguing work, physical, quantitative and emotional demands, job control and WHP availability setting) were collected cross-sectionally in 2010 in a representative sample (n=10 605) of Danish workers. Binary regression analyses of the association between work environment characteristics and participation in WHP were conducted and adjusted for age, gender and industry. WHP offered during leisure time was associated with lower participation in all measured activities compared with when offered during working hours. Low social support and fatiguing work were associated with low participation in WHP. No associations with participation in WHPs were observed for physical work or quantitative demands, work pace or job strain. However, high physical demands/low job control and high emotional demands/low job control were associated with low participation. Lower participation in WHP was associated with programmes during leisure, low social support, very fatiguing work and high physical or emotional demands with low job control. This suggests that to obtain proper effect of health promotion in a workplace setting, a good work environment is essential. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Hussain, Azmina; Zaheer, Sidra; Shafique, Kashif
2018-05-09
Betel quid (BQ) chewing in children is initiated in their adolescence. It is pivotal to understand adolescents' reasons behind chewing BQ. In this study, we aimed to evaluate the reasons for BQ chewing amongst adolescents using reasons for betel quid chewing scale (RBCS) and their associated dependency on it. This is a cross-sectional school based survey. Out of 2200 adolescents from 26 schools of Karachi, 874 BQ chewers were assessed for their reasons of BQ chewing and dependency on it. Regression analyses were employed to report crude and adjusted (after adjusting for all reasons of BQ chewing) effect sizes with 95% confidence interval and P-value was set significant at < 0.05. Students who believed that BQ chewing relaxes them (stimulation construct) were twice as likely to be dependent on BQ (OR = 2.36, 95% CI (1.20-4.65) as compared with others. Participants who thought it eases their decision making (stimulation construct), were sizably more likely to be dependent on BQ (OR = 9.65, 95% CI (4.15-22.43) than those who did not consider ease in decision making important. Adolescents who considered not chewing as rude (social/cultural construct), were thrice more likely to be dependent on BQ (OR = 2.50, 95% CI (1.11-5.63) than others. Stimulation remained fundamental chewing reason followed by social/cultural trigger amongst adolescents. Any future intervention may get favorable results if it addresses ways to overcome stimulation and social/cultural barriers that are strongly associated with BQ chewing and dependency.
Knott, Gene; Tuley, Michael
2004-01-01
This is the second edition of the first and foremost book on this subject for self-study, training, and course work. Radar cross section (RCS) is a comparison of two radar signal strengths. One is the strength of the radar beam sweeping over a target, the other is the strength of the reflected echo sensed by the receiver. This book shows how the RCS ?gauge? can be predicted for theoretical objects and how it can be measured for real targets. Predicting RCS is not easy, even for simple objects like spheres or cylinders, but this book explains the two ?exact? forms of theory so well that even a
Rao, Ravindra; Mandal, Piyali; Gupta, Rishab; Ramshankar, Prashanth; Mishra, Ashwani; Ambekar, Atul; Jhanjee, Sonali; Dhawan, Anju
2016-02-01
Substance abuse and criminality share a complex relationship. The rates of substance use among the prisoners, and that of criminal acts among substance users in community setting are high. Data from South Asian countries, including from India are inadequate. This study aimed to assess the pattern of criminal acts among opioid-dependent subjects and their substance use pattern in the month before, during and after imprisonment. Using a cross-sectional study design and purposive sampling, opioid-dependent subjects (n=101) attending two community drug treatment clinics who have had any contact with the law were assessed using a specifically-designed tool to record criminal acts and substance use before, during and after last imprisonment. Most subjects (93%) had committed illegal acts in their lifetime. Physical assault was the most common illegal act, while 23% reported selling drugs and 9% reported committing serious crimes. About 95% were arrested and 92% had spent time in police lockups. About 29% were arrested for drugs possession or drug use, and 3% of injecting drug users arrested for carrying injection equipment. About 85% had been imprisoned at least once, of whom 88% used psychoactive substances in the 1-month period before their last imprisonment. Opioids were the most common substances used daily (68%), followed by cannabis (34%) and alcohol (22%). Ninety-seven percent reported the availability of substances in prisons, and 65% also used substances during their last imprisonment. Cannabis (35%) was the most common substances used in prison followed by opioids (19%). Seventy-six percent used substances soon after prison release, and 13% of opioid users experienced opioid overdose soon after prison release. Use of cannabis, injecting drugs, and opioid use before imprisonment were predictors of substance use in prison. Opioid-dependent people have various contacts with the law, including imprisonment. Many users are dependent on substances during prison
Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR
Es-sebbar, Et-touhami; Bé nilan, Yves; Farooq, Aamir
2013-01-01
synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV
International Nuclear Information System (INIS)
Poenitz, W.P.
1980-01-01
The evaluation of several energy-dependent neutron cross sections which are of importance for practical applications is considered. The evaluation process is defined as the procedure which is used to derive the best knowledge of these cross sections based on the available direct experimental data information, and, using theoretical models, on the auxiliary data base. The experimental data base represents a multiple overdetermination of the unknown cross sections with various correlations between the measured values. Obtaining the least-squares estimator is considered as the standard mathematical procedure to derive a consistent set of evaluated cross section values. Various approximations made in order to avoid the monstrous system of normal equations are considered and the feasibility of the exact solution is demonstrated. The variance-covariance of the result, its reliability and the improvements obtained in iterative steps are discussed. Finally, the inclusion of auxiliary, supplementary information is considered. 45 references
Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR
Es-sebbar, Et-touhami
2013-01-01
Vacuum ultraviolet (VUV) and infrared (IR) absorption cross-section measurements of 1-butene (1-C4H8; CH2=CHCH2CH3; Butylene) are reported over the temperature range of 296-529K. The VUV measurements are performed between 115 and 205nm using synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV and IR absorption cross-sections are compared with available literature data and are found to be in good agreement. The oscillator strength for the electronic transition (A1A\\'→X1A\\') around 150-205nm is determined to be 0.32±0.01.The gas temperature has a strong effect on both VUV and IR spectra. Measurements made in the VUV region show that the peak value of the band cross-section decreases and the background continuum increases with increasing gas temperature. This behavior is due to a change in the rotational and vibrational population distribution of 1-butene molecule. Similar changes in rotational population are observed in the IR spectra. Moreover, variation of the IR spectra with temperature is used to measure the enthalpy difference between syn and skew conformations of 1-butene and is found to be 0.24±0.03. kcal/mol, which is in excellent agreement with values reported in the literature. The measurements reported in this work will provide the much-needed spectroscopic information for the development of high-temperature quantitative diagnostics in combustion applications and validation of atmospheric chemistry models of extra-solar planets. © 2012 Elsevier Ltd.
Labudde, R. A.
1972-01-01
An attempt has been made to keep the programs as subroutine oriented as possible. Usually only the main programs are directly concerned with the problem of total cross sections. In particular the subroutines POLFIT, BILINR, GASS59/MAXLIK, SYMOR, MATIN, STUDNT, DNTERP, DIFTAB, FORDIF, EPSALG, REGFAL and ADSIMP are completely general, and are concerned only with the problems of numerical analysis and statistics. Each subroutine is independently documented.
International Nuclear Information System (INIS)
Winkler, G.
1988-01-01
The impact of sample and target properties on the accuracy of experimental nuclear cross section data is discussed in the context of the basic requirements in order to obtain reliable results from the respective measurements from the user's point of view. Special emphasis is put on activation measurements with fast neutrons. Some examples are given and suggestions are made based on experiences and recent investigations by the author and his coworkers. (author). Abstract only
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.)
Energy Technology Data Exchange (ETDEWEB)
Bordenave-Montesquieu, A.; Boudjema, M.; Benoit-Cattin, P.; Gleizes, A.; Moretto-Capelle, P.
1989-01-01
The q dependence of cross sections for double capture into autoionising states has been investigated by electron spectroscopy. It is shown that they are independent of the ionic core. Our results are compared with all other available experimental data obtained at 10 qkeV collision energy.
International Nuclear Information System (INIS)
Bordenave-Montesquieu, A.; Boudjema, M.; Benoit-Cattin, P.; Gleizes, A.; Moretto-Capelle, P.
1989-01-01
The q dependence of cross sections for double capture into autoionising states has been investigated by electron spectroscopy. It is shown that they are independent of the ionic core. Our results are compared with all other available experimental data obtained at 10 qkeV collision energy
Czech Academy of Sciences Publication Activity Database
Sobolev, Yu. G.; Penionzhkevich, Y. E.; Aznabaev, D.; Zemlyanaya, E. V.; Ivanov, M. P.; Kabdrakhimova, G. D.; Kabyshev, A. M.; Knyazev, A.; Kugler, Andrej; Lashmanov, N. A.; Lukyanov, K. V.; Maj, A.; Maslov, V. A.; Mendibayev, K.; Skobelev, N. K.; Slepnev, R. S.; Smirnov, V. V.; Testov, D.
2017-01-01
Roč. 48, č. 6 (2017), s. 922-926 ISSN 1063-7796 R&D Projects: GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : energy dependence * cross section Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 0.681, year: 2016
Measurement of the helicity-dependent total cross-section for the γn→ p π-π0 reaction
International Nuclear Information System (INIS)
Ahrens, J.; Arends, H.J.; Beck, R.; Heid, E.; Jahn, O.; Lang, M.; Martinez-Fabregate, M.; Tamas, G.; Thomas, A.; Altieri, S.; Panzeri, A.; Pinelli, T.; Annand, J.R.M.; McGeorge, J.C.; Protopopescu, D.; Rosner, G.; Blackston, M.A.; Weller, H.R.; Bradtke, C.; Dutz, H.; Klein, F.; Rohlof, C.; Braghieri, A.; Pedroni, P.; Hose, N. d'; Fix, A.; Kondratiev, R.; Lisin, V.; Meyer, W.; Reicherz, G.; Rostomyan, T.; Ryckbosch, D.
2011-01-01
The helicity dependence of the total cross-section for the γn→pπ - π 0 reaction has been measured for the first time at incident photon energies from 450 to 800MeV. The measurement was performed with the large-acceptance detector DAPHNE at the tagged photon beam facility of the MAMI accelerator in Mainz. Both the measured unpolarized and the helicity-dependent observables are not well described by the existing theoretical models. (orig.)
Argento, D.; Reedy, R. C.; Stone, J.
2010-12-01
Cosmogenic Nuclides (CNs) are a critical new tool for geomorphology, allowing researchers to date Earth surface events and measure process rates [1]. Prior to CNs, many of these events and processes had no absolute method for measurement and relied entirely on relative methods [2]. Continued improvements in CN methods are necessary for expanding analytic capability in geomorphology. In the last two decades, significant progress has been made in refining these methods and reducing analytic uncertainties [1,3]. Calibration data and scaling methods are being developed to provide a self consistent platform for use in interpreting nuclide concentration values into geologic data [4]. However, nuclide dependent scaling has been difficult to address due to analytic uncertainty and sparseness in altitude transects. Artificial target experiments are underway, but these experiments take considerable time for nuclide buildup in lower altitudes. In this study, a Monte Carlo method radiation transport code, MCNPX, is used to model the galactic cosmic-ray radiation impinging on the upper atmosphere and track the resulting secondary particles through a model of the Earth’s atmosphere and lithosphere. To address the issue of nuclide dependent scaling, the neutron flux values determined by the MCNPX simulation are folded in with estimated cross-section values [5,6]. Preliminary calculations indicate that scaling of nuclide production potential in free air seems to be a function of both altitude and nuclide production pathway. At 0 g/cm2 (sea-level) all neutron spallation pathways have attenuation lengths within 1% of 130 g/cm2. However, the differences in attenuation length are exacerbated with increasing altitude. At 530 g/cm2 atmospheric height (~5,500 m), the apparent attenuation lengths for aggregate SiO2(n,x)10Be, aggregate SiO2(n,x)14C and K(n,x)36Cl become 149.5 g/cm2, 151 g/cm2 and 148 g/cm2 respectively. At 700 g/cm2 atmospheric height (~8,400m - close to the highest
International Nuclear Information System (INIS)
Aydin, A.; Yalim, H.A.; Tel, E.; Sarer, B.; Unal, R.; Sarpuen, I.H.; Kaplan, A.; Dag, M.
2009-01-01
This study aims to show the dependence on the choice of the ratio of the level density parameters a f and a n corresponding to the saddle point of fission and equilibrium deformation of nucleus, respectively, of the proton induced fission cross sections of some subactinide targets. The method was employed using different level density parameter ratios for each fission cross section calculation in ALICE/ASH computer code. The ALICE/ASH code calculations were compared both with the available experimental data and with the Prokofiev systematics data. It is found that the fission cross sections dependent heavily on the choice of level density parameter ratio in the fission and neutron emission channels, a f /a n , for some subactinide nuclei. To get a good description of the measured fission cross sections for subactinide nuclei, we used a ratio of the level density parameters in the fission and neutron emission channels, a f /a n , depending both on the target-nucleus and on the energy of the projectile, in agreement with results published in literature.
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)
Yu, W.; Gao, C.-Z.; Zhang, Y.; Zhang, F. S.; Hutton, R.; Zou, Y.; Wei, B.
2018-03-01
We calculate electron capture and ionization cross sections of N2 impacted by the H+ projectile at keV energies. To this end, we employ the time-dependent density-functional theory coupled nonadiabatically to molecular dynamics. To avoid the explicit treatment of the complex density matrix in the calculation of cross sections, we propose an approximate method based on the assumption of constant ionization rate over the period of the projectile passing the absorbing boundary. Our results agree reasonably well with experimental data and semi-empirical results within the measurement uncertainties in the considered energy range. The discrepancies are mainly attributed to the inadequate description of exchange-correlation functional and the crude approximation for constant ionization rate. Although the present approach does not predict the experiments quantitatively for collision energies below 10 keV, it is still helpful to calculate total cross sections of ion-molecule collisions within a certain energy range.
THE WEAK s-PROCESS IN MASSIVE STARS AND ITS DEPENDENCE ON THE NEUTRON CAPTURE CROSS SECTIONS
International Nuclear Information System (INIS)
Pignatari, M.; Herwig, F.; Gallino, R.; Bisterzo, S.; Heil, M.; Wiescher, M.; Kaeppeler, F.
2010-01-01
The slow neutron capture process in massive stars (weak s process) produces most of the s-process isotopes between iron and strontium. Neutrons are provided by the 22 Ne(α,n) 25 Mg reaction, which is activated at the end of the convective He-burning core and in the subsequent convective C-burning shell. The s-process-rich material in the supernova ejecta carries the signature of these two phases. In the past years, new measurements of neutron capture cross sections of isotopes beyond iron significantly changed the predicted weak s-process distribution. The reason is that the variation of the Maxwellian-averaged cross sections (MACS) is propagated to heavier isotopes along the s path. In the light of these results, we present updated nucleosynthesis calculations for a 25 M sun star of Population I (solar metallicity) in convective He-burning core and convective C-burning shell conditions. In comparison with previous simulations based on the Bao et al. compilation, the new measurement of neutron capture cross sections leads to an increase of s-process yields from nickel up to selenium. The variation of the cross section of one isotope along the s-process path is propagated to heavier isotopes, where the propagation efficiency is higher for low cross sections. New 74 Ge, 75 As, and 78 Se MACS result in a higher production of germanium, arsenic, and selenium, thereby reducing the s-process yields of heavier elements by propagation. Results are reported for the He core and for the C shell. In shell C-burning, the s-process nucleosynthesis is more uncertain than in the He core, due to higher MACS uncertainties at higher temperatures. We also analyze the impact of using the new lower solar abundances for CNO isotopes on the s-process predictions, where CNO is the source of 22 Ne, and we show that beyond Zn this is affecting the s-process yields more than nuclear or stellar model uncertainties considered in this paper. In particular, using the new updated initial
Directory of Open Access Journals (Sweden)
M. Dieterle
2017-07-01
Full Text Available The double-polarization observable E and the helicity-dependent cross sections σ1/2 and σ3/2 have been measured for the first time for single π0 photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the π0 meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the π0N final state. A comparison to data measured with a free proton target showed that the absolute scale of the cross sections is significantly modified by nuclear final-state interaction (FSI effects. However, there is no significant effect on the asymmetry E since the σ1/2 and σ3/2 components appear to be influenced in a similar way. Thus, the best approximation of the two helicity-dependent cross sections for the free neutron is obtained by combining the asymmetry E measured with quasi-free neutrons and the unpolarized cross section corrected for FSI effects under the assumption that the FSI effects are similar for neutrons and protons.
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)
XCOM: Photon Cross Sections Database
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.
Dogan, Eyup; Seker, Fahri
2016-07-01
This empirical study analyzes the impacts of real income, energy consumption, financial development and trade openness on CO2 emissions for the OECD countries in the Environmental Kuznets Curve (EKC) model by using panel econometric approaches that consider issues of heterogeneity and cross-sectional dependence. Results from the Pesaran CD test, the Pesaran-Yamagata's homogeneity test, the CADF and the CIPS unit root tests, the LM bootstrap cointegration test, the DSUR estimator, and the Emirmahmutoglu-Kose Granger causality test indicate that (i) the panel time-series data are heterogeneous and cross-sectionally dependent; (ii) CO2 emissions, real income, the quadratic income, energy consumption, financial development and openness are integrated of order one; (iii) the analyzed data are cointegrated; (iv) the EKC hypothesis is validated for the OECD countries; (v) increases in openness and financial development mitigate the level of emissions whereas energy consumption contributes to carbon emissions; (vi) a variety of Granger causal relationship is detected among the analyzed variables; and (vii) empirical results and policy recommendations are accurate and efficient since panel econometric models used in this study account for heterogeneity and cross-sectional dependence in their estimation procedures.
Chen, Junsheng; Žídek, Karel; Chábera, Pavel; Liu, Dongzhou; Cheng, Pengfei; Nuuttila, Lauri; Al-Marri, Mohammed J; Lehtivuori, Heli; Messing, Maria E; Han, Keli; Zheng, Kaibo; Pullerits, Tõnu
2017-05-18
All-inorganic colloidal perovskite quantum dots (QDs) based on cesium, lead, and halide have recently emerged as promising light emitting materials. CsPbBr 3 QDs have also been demonstrated as stable two-photon-pumped lasing medium. However, the reported two photon absorption (TPA) cross sections for these QDs differ by an order of magnitude. Here we present an in-depth study of the TPA properties of CsPbBr 3 QDs with mean size ranging from 4.6 to 11.4 nm. By using femtosecond transient absorption (TA) spectroscopy we found that TPA cross section is proportional to the linear one photon absorption. The TPA cross section follows a power law dependence on QDs size with exponent 3.3 ± 0.2. The empirically obtained power-law dependence suggests that the TPA process through a virtual state populates exciton band states. The revealed power-law dependence and the understanding of TPA process are important for developing high performance nonlinear optical devices based on CsPbBr 3 nanocrystals.
Energy Technology Data Exchange (ETDEWEB)
Komarov, V I; Kosarev, G E; Reshetnikov, G P; Savchenko, O V; Tesh, Z
1974-12-31
The high energy parts of the spectra of fast deuterons, which are knocked out from Li, Be and C targets by protons at a 5.5 deg lab. angle with proton energies of 666, 578, 484 and 382 MeV were measured. The cross sections of quasi-elastic deuteron knock-out obtained are compared with the corresponding cross sections of elastic pd-scattering at energies mentioned above. The evaluations of the effective number of two-nucleon clusters are discussed, which have been obtained taking into account (in the Glauber approximation) the incident proton and knocked-out deuteron interactions with nuclear nucleons. The results show the common behavior of the scattering mechanism responsible for elastic pd- and quasi-elastic proton backward scattering with large momentum transfer to two-nucleon clusters. The energy dependence of the deuteron production cross section at the energy kinematically corresponding to the p + N yields d + pi process on tanget nucleons is close to that of the cross section for the p + p yields d + pi /sup +/ process. (auth)
Energy Technology Data Exchange (ETDEWEB)
Akkuş, T.; Şahin, Y.; Yılmaz, D., E-mail: ddemir@atauni.edu.tr
2016-01-01
Highlights: • The azimuthal and polar angle dependence of L X-ray for Yb is investigated. • The azimuthal angle dependence of Ll and Lα X-rays are observed. • The azimuthal anisotropy of Lβ and Lγ X-rays are not observed. • The polar anisotropy of Ll and Lα X-rays are observed. • The polar anisotropy of Lβ and Lγ X-rays are not observed. - Abstract: The azimuthal and polar angle dependence of L X-ray was investigated in the same experimental setup to remove the existing ambiguity about alignments measurements. We measured Ll, Lα, Lβ and Lγ X-ray differential cross sections of Yb for several different azimuthal angles (30°, 20°, 10°, 0°, −10° and −20°) and polar angles (90°, 100°, 110°, 120°, 130° and 140°) at 59.54 keV photon energy by using a Si(Li) detector. The azimuthal angle dependence of Ll and Lα X-rays were observed. The azimuthal anisotropy of Lβ and Lγ X-rays were not observed. On the other hand, differential cross-sections for Lβ and Lγ X-rays were found independent on the polar angle within experimental error, those for Ll and Lα X-rays depended on the polar angles. Azimuthal and polar angles dependence of L X-ray differential cross-sections contrast with the other experimental and theoretical results, which report evidence of the isotropic emission of Ll and Lα X-rays following photoionization.
Energy Technology Data Exchange (ETDEWEB)
Ahrens, J.; Arends, H.J.; Beck, R.; Heid, E.; Jahn, O.; Lang, M.; Martinez-Fabregate, M.; Tamas, G.; Thomas, A. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Altieri, S.; Panzeri, A.; Pinelli, T. [INFN, Sezione di Pavia, Pavia (Italy); Universita di Pavia, Dipartimento di Fisica Nucleare e Teorica, Pavia (Italy); Annand, J.R.M.; McGeorge, J.C.; Protopopescu, D.; Rosner, G. [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Blackston, M.A.; Weller, H.R. [Duke University, Department of Physics, Durham, NC (United States); Bradtke, C.; Dutz, H.; Klein, F.; Rohlof, C. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Braghieri, A.; Pedroni, P. [INFN, Sezione di Pavia, Pavia (Italy); Hose, N. d' [DSM/DAPNIA/SPhN, CEA Saclay, Gif-sur-Yvette Cedex (France); Fix, A. [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation); Kondratiev, R.; Lisin, V. [Academy of Science, INR, Moscow (Russian Federation); Meyer, W.; Reicherz, G. [Ruhr-Universitaet Bochum, Insitut fuer Experimentalphysik, Bochum (Germany); Rostomyan, T. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium); INFN, Sezione di Pavia, Pavia (Italy); Ryckbosch, D. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium)
2011-03-15
The helicity dependence of the total cross-section for the {gamma}n{yields}p{pi}{sup -}{pi}{sup 0} reaction has been measured for the first time at incident photon energies from 450 to 800MeV. The measurement was performed with the large-acceptance detector DAPHNE at the tagged photon beam facility of the MAMI accelerator in Mainz. Both the measured unpolarized and the helicity-dependent observables are not well described by the existing theoretical models. (orig.)
Zhao, Yi; Bi, Xiao-Jun; Yin, Peng-Fei; Zhang, Xinmin
2018-03-01
Searching for γ rays from dwarf spheroidal galaxies (dSphs) is a promising approach to detect dark matter (DM) due to the high DM densities and low baryon components in dSphs. The Fermi-LAT observations from dSphs have set stringent constraints on the velocity independent annihilation cross section. However, the constraints from dSphs may change in velocity dependent annihilation scenarios because of the different velocity dispersions in galaxies. In this work, we study how to set constraints on the velocity dependent annihilation cross section from the combined Fermi-LAT observations of dSphs with the kinematic data. In order to calculate the γ ray flux from the dSph, the correlation between the DM density profile and velocity dispersion at each position should be taken into account. We study such correlation and the relevant uncertainty from kinematic observations by performing a Jeans analysis. Using the observational results of three ultrafaint dSphs with large J-factors, including Willman 1, Reticulum II, and Triangulum II, we set constraints on the p-wave annihilation cross section in the Galaxy as an example.
Directory of Open Access Journals (Sweden)
Behrooz Hashemi Domeneh
2014-01-01
Full Text Available Background: Opium dependence is one of the most challenging health problems in the developing countries as well as Iran. Among several health problems due to opium dependence, there are limited reports indicating the presence of lead in opium. The aim of this study is to investigate the blood lead level (BLL in oral and inhalational opium dependents and its association with anemia. Materials and Methods: A cross-sectional study was done among 86 opium dependent patients who were referred to five large detoxification centers in Tehran city and 48 healthy individuals. BLL was assessed using the atomic absorption spectrometry technique. Multivariate analysis of variance and binary logistic regression analysis were performed for statistical assessment using SPSS version 18 for Windows. Results: The highest BLL was detected in oral opium dependent group (mean = 11.75, standard deviation (SD = 6.06 in comparison to inhalational opium dependent group (mean = 7.07, SD = 3.61 and healthy control group (mean = 6.05, SD = 1.83. Anemia was detected in 38% of oral-opium dependent and 43% of inhalational-opium dependent group. Age (odds ratio (OR: 1.06, 95% confidence interval (CI: 1.03-1.09 and opium dependence (OR: 3.59, 95% CI: 1.69-7.59 were significant predictors of anemia in these patients (P < 0.001. Conclusion: The results of this study confirmed the higher BLL in opium dependents, especially with an oral form of consumption.
International Nuclear Information System (INIS)
Federer, W.
1982-01-01
An apparatus for investigations of reaction channels of inelastic ion collisions with a gas target by photon spectroscopy is described. The incoming energy can be varied between 0 and 1800 eV and the emitted light can be observed in the range 2000-9000 A. First the emission spectra of He + -Ar and Ar + -He collisions is measured and interpreted. Then the energy dependence of several line intensities are measured and transformed to absolute emission cross-sections. Several types of cross section versus energy curves are distinguished. They are finally interpreted in the framework of a semiclassical model of a quasi-molecule built from the two colliding partners. (G.Q.)
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
Ebishima, Hironori; Kurosaki, Kenichi; Yoshimatsu, Jun; Shiraishi, Isao
2017-08-01
This study aimed to determine fetal echocardiographic features of tetralogy of Fallot in association with postnatal outcomes. The Z-scores of the main and bilateral pulmonary arteries and the aorta were measured, and the following variables were calculated in 13 fetuses with tetralogy of Fallot: pulmonary artery-to-aorta ratio and main pulmonary artery cross-section ratio - the main pulmonary artery diameter squared divided by the sum of the diameter squared of the left and right pulmonary arteries. Fetuses were classified as having ductus arteriosus-dependent or ductus arteriosus-independent pulmonary circulation. We included two infants with pulmonary atresia and six infants with ductus-dependent pulmonary circulation, who underwent systemic-to-pulmonary shunt surgeries at ⩽1 month of age. The Z-scores of the main pulmonary artery and the pulmonary artery-to-aorta ratio in fetuses with ductus-dependent pulmonary circulation were lesser than those in fetuses with ductus independence, but not significantly. The main pulmonary artery cross-section ratio in fetuses with ductus dependence was significantly lesser (0.65±0.44 versus 1.56±0.48, ptetralogy of Fallot.
Accurate Cross Sections for Microanalysis
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...
International Nuclear Information System (INIS)
Lebedenko, V. N.; Bewick, A.; Currie, A.; Davidge, D.; Dawson, J.; Horn, M.; Howard, A. S.; Jones, W. G.; Joshi, M.; Liubarsky, I.; Lyons, K.; Quenby, J. J.; Sumner, T. J.; Thorne, C.; Walker, R. J.; Araujo, H. M.; Edwards, B.; Barnes, E. J.; Ghag, C.; Murphy, A. StJ.
2009-01-01
We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of ∼450 kg·days fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of σ n =1.9x10 -2 pb at 55 GeV/c 2 WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes 129 Xe and 131 Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of ∼2.
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
Uwakwe, Richard; Ibeh, Christian C; Modebe, Anne Ifeoma; Bo, Emeka; Ezeama, Nkiru; Njelita, Ifeoma; Ferri, Cleusa P; Prince, Martin J
2009-09-01
To describe the prevalence and determinants of dependence in older Nigerians and associations with informal care and health service utilization. A single-phase cross-sectional catchment area survey. Dunukofia, a rural community in southeastern Nigeria. One thousand two hundred thirty-eight adults aged 65 and older, for whom full data were available on 914. The full 10/66 Dementia Research Group survey protocol was applied, including ascertainment of depression, cognitive impairment, physical impairments, and self-reported diagnoses. The interviewer rated dependence as not needing care, needing some care, or needing much care. The prevalence of dependence and the independent contribution of underlying health conditions were estimated. Sources of income, care arrangements, caregiver strain, and health service use are described according to level of dependence. The prevalence of dependence was 24.3% (95% confidence interval=22.1-26.5%), with a concentration in participants aged 80 and older. Only 1% of participants received a pension, and fewer than 7% had paid work. Those who were dependent were less likely than others to receive income from their family. Cognitive impairment, physical impairments, stroke, and depression were each independently associated with dependence. Depression made the largest contribution. Dependence was strongly associated with health service use (particularly private doctor and traditional healer services) and with high levels of out-of-pocket expenditure. In Nigeria, dependence is an important outcome given rapid demographic aging and increases in chronic disease prevalence in all developing regions. Enhancing the social protection of dependent older adults should be a policy priority. Cognitive and mental disorders are important contributors to disability and dependence; more attention should be given to their prevention, detection, and treatment.
Demir, L; Kurucu, Y; Karabulut, A; Sahin, Y; 10.1016/S0969-806X(02)00501-7
2003-01-01
Ll, L alpha , L beta and L gamma X-ray differential cross-sections, fluorescence cross-sections and L/sub i/-subshell ( sigma /sub L1/, sigma /sub L2/, and sigma /sub L3/) fluorescence cross-sections were measured for Er, Ta, W, Au, Hg, and Tl at an excitation energy of 59.6 keV using a Si(Li) detector. The differential cross-sections for these elements have been measured at different angles varying from 54 degrees to 153 degrees at intervals of 9 degrees . The Ll and L alpha groups in the L X-ray lines are found to be spatially anisotropic, while those in the L beta and L gamma peaks are isotropic. Experimental and theoretical values of L X-ray fluorescence cross- sections and L/sub i/-subshell X-ray fluorescence cross-sections were compared. (20 refs).
van der Pol, P.; Liebregts, N.; Brunt, T.; van Amsterdam, J.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.
2014-01-01
Background and Aims Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated
van der Pol, Peggy; Liebregts, Nienke; Brunt, Tibor; van Amsterdam, Jan; de Graaf, Ron; Korf, Dirk J.; van den Brink, Wim; van Laar, Margriet
2014-01-01
Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated whether consumers of
[Fast neutron cross section measurements
International Nuclear Information System (INIS)
Knoll, G.F.
1992-01-01
From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ''clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ''data production'' phase
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...
International Nuclear Information System (INIS)
Barashenkov, V.S.
1990-01-01
The tables of inelastic and total cross sections of π ± mesons interactions with nuclei 4 He- 238 U are presented. The tables are obtained by theoretical analysis of known experimental data for energies higher some tens of MeV. 1 ref.; 1 tab
Song, Hai-Xi; Sun, Xiao-Qi; Lu, Jing; Zhou, Lan
2018-01-01
We study a quantum electrodynamics (QED) system made of a two-level atom and a semi-infinite rectangular waveguide, which behaves as a perfect mirror in one end. The spatial dependence of the atomic spontaneous emission has been included in the coupling strength relevant to the eigenmodes of the waveguide. The role of retardation is studied for the atomic transition frequency far away from the cutoff frequencies. The atom-mirror distance introduces different phases and retardation times into the dynamics of the atom interacting resonantly with the corresponding transverse modes. It is found that the upper state population decreases from its initial as long as the atom-mirror distance does not vanish, and is lowered and lowered when more and more transverse modes are resonant with the atom. The atomic spontaneous emission can be either suppressed or enhanced by adjusting the atomic location for short retardation time. There are partial revivals and collapses due to the photon reabsorbed and re-emitted by the atom for long retardation time. Supported by National Natural Science Foundation of China under Grant Nos. 11374095, 11422540, 11434011, and 11575058, National Fundamental Research Program of China (the 973 Program) under Grant No. 2012CB922103, and Hunan Provincial Natural Science Foundation of China under Grant No. 11JJ7001
Rivero Santamaría, Alejandro; Dayou, Fabrice; Rubayo-Soneira, Jesus; Monnerville, Maurice
2017-03-02
The dynamics of the Si( 3 P) + OH(X 2 Π) → SiO(X 1 Σ + ) + H( 2 S) reaction is investigated by means of the time-dependent wave packet (TDWP) approach using an ab initio potential energy surface recently developed by Dayou et al. ( J. Chem. Phys. 2013 , 139 , 204305 ) for the ground X 2 A' electronic state. Total reaction probabilities have been calculated for the first 15 rotational states j = 0-14 of OH(v=0,j) at a total angular momentum J = 0 up to a collision energy of 1 eV. Integral cross sections and state-selected rate constants for the temperature range 10-500 K were obtained within the J-shifting approximation. The reaction probabilities display highly oscillatory structures indicating the contribution of long-lived quasibound states supported by the deep SiOH/HSiO wells. The cross sections behave with collision energies as expected for a barrierless reaction and are slightly sensitive to the initial rotational excitation of OH. The thermal rate constants show a marked temperature dependence below 200 K with a maximum value around 15 K. The TDWP results globally agree with the results of earlier quasi-classical trajectory (QCT) calculations carried out by Rivero-Santamaria et al. ( Chem. Phys. Lett. 2014 , 610-611 , 335 - 340 ) with the same potential energy surface. In particular, the thermal rate constants display a similar temperature dependence, with TDWP values smaller than the QCT ones over the whole temperature range.
Liu, Jie; Shang, Suhang; Li, Pei; Deng, Meiying; Chen, Chen; Jiang, Yu; Dang, Liangjun; Qu, Qiumin
2017-09-08
Cigarette smoking is a modifiable risk factor for cognitive impairment, while the relationship between current smoking and cognitive impairment is not fully understood. The objectives were to identify a possible association between current smoking and cognitive impairment depending on age in the Chinese rural population. Data for the study consisted of 1,782 participants (40 years and older) who lived in a rural village in the vicinity of Xi'an, China. Data about smoking history and cognitive function were collected. Cognitive function was scored by the Mini-Mental State Examination. The effect of age on the relationship between current smoking and cognitive impairment was analyzed with interaction and stratified analysis by logistic regression models. Interaction analysis showed that current smoking is positively related with cognitive impairment (odds ratio [OR]=9.067; 95% confidence interval [95% CI] 1.305-62.979; P=.026). However, the interaction term, age by current smoking, is negatively related with cognitive impairment (OR=0.969; 95%CI 0.939-0.999; P=.045). Stratified logistic regression showed that in the 40-65 years of age sublayer, OR of current smoking is 1.966 (P=.044), whereas in the>65 years of age sublayer, the OR is 0.470 (P=.130). This means that the association between current smoking and cognitive impairment with age might be positive (OR>1) in lower age sublayers, but no significant difference in higher age sublayers. In conclusion, current smoking might be positively associated with cognitive impairment in the middle-aged but the relationship declines with increasing age. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Kotov, A.A.; Gavrikov, Yu.A.; Vaishnene, L.A.; Vovchenko, V.G.; Poliakov, V.V.; Fedorov, O.Ya.; Chestnov, Yu.A.; Shchetkovskiy, A.I [Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, Orlova roscha 1, 188300 (Russian Federation); Fukahori, T. [Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 319-1195 (Japan)
2005-07-01
The results of the total fission cross sections measurements for {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu nuclei at the energy proton range 200-1000 MeV are presented. Experiments were carried out at 1 GeV synchrocyclotron of Petersburg Nuclear Physics Institute (Gatchina). The measurement method is based on the registration in coincidence of both complementary fission fragments by two gas parallel plate avalanche counters, located at a short distance and opposite sides of investigated target. The insensitivity of parallel plate avalanche counters to neutron and light charged particles allowed us to place the counters together with target immediately in the proton beam providing a large solid angle acceptance for fission fragment registration and reliable identification of fission events. The proton flux on the target to be studied was determined by direct counting of protons by scintillation telescope. The measured energy dependence of the total fission cross sections is presented. Obtained results are compared with other experimental data as well as with calculation in the frame of the cascade evaporation model. (authors)
Photoelectric absorption cross sections with variable abundances
Balucinska-Church, Monika; Mccammon, Dan
1992-01-01
Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.
Directory of Open Access Journals (Sweden)
Haoran Zhang
2013-01-01
Full Text Available The study was to survey and assess the drug dependence and abuse potential of tramadol with no history of substance abuse. Subjects of tramadol dependence with no prior history of substance abuse were surveyed by interview. Physical dependence of tramadol was assessed using 10 items opiate withdrawal scale (OWS, and psychological dependence was assessed by Addiction Research Center Inventory—Chinese Version (ARCI-CV. Twenty-three male subjects (the median age was 23.4±4.1 years referred to the addiction unit in Medical Hospital of Guangzhou with tramadol abuse problems were included in this cross-sectional study. The control group included 87 heroin addicts, 60 methamphetamine (MA abusers, and 50 healthy men. The scores of OWS of tramadol were 0.83–2.30; the mean scores of identifying euphoric effects–MBG, sedative effects–PCAG, and psychotomimetic effects–LSD of ARCI were 8.96±3.08, 6.52±3.25, and 6.65±2.50, respectively, F = 4.927, P0.05 but were higher than those in healthy men (P<0.05. Tramadol with no history of substance abuse has a clear risk of producing high abuse potential under the long-term infrequent abuse and the high doses.
Distortion dependent intersystem crossing
DEFF Research Database (Denmark)
Stephansen, Anne Boutrup; Sølling, Theis Ivan
2017-01-01
. The effect is observed to increase in the presence of methyl-groups on the pinnacle carbon-atoms, where largest extents of r and p orbital-mixing are observed. This is fully consistent with the time-resolved spectroscopy data: Toluene and p-xylene show evidence for ultrafast triplet formation competing......The competition between ultrafast intersystem crossing and internal conversion in benzene, toluene, and p-xylene is investigated with time-resolved photoelectron spectroscopy and quantum chemical calculations. By exciting to S2 out-of-plane symmetry breaking, distortions are activated at early...... times whereupon spin-forbidden intersystem crossing becomes (partly) allowed. Natural bond orbital analysis suggests that the pinnacle carbon atoms distorting from the aromatic plane change hybridization between the planar Franck-Condon geometry and the deformed (boat-shaped) S2 equilibrium geometry...
Tabali, Manuela; Ostermann, Thomas; Jeschke, Elke; Dassen, Theo; Heinze, Cornelia
2013-03-11
Studies on health-related quality of life (HRQOL) are missing for nursing home residents independent from their health conditions or interventions after admission. Our aim was to analyse if the care dependency of nursing home residents influence their HRQOL and to describe HRQOL of nursing home residents at the time of admission. Eleven German nursing homes were randomly selected for a cross-sectional multicentre study from April 2008 until December 2009. HRQOL was measured with the Nottingham Health Profile (NHP) in the six domains "Physical Mobility", "Energy", "Pain", "Social Isolation", "Emotional Reaction" and "Sleep". Domain scores range from zero (good subjective health status) to 100 (poor subjective health status). Care dependency was evaluated using the Care Dependency Scale, age, sex, cognitive status and diseases were documented by the research assistants. Multivariate regression analysis was performed to quantify the influence of care dependency on HRQOL. 120 residents were included in total. HRQOL was mostly reduced in the domains "Physical Mobility" and "Energy" (mean scores >43.0), while impairment differences in the domains "Pain", "Social Isolation", "Emotional Reaction" and "Sleep" were only moderate (≤25.0). HRQOL was not influenced by the age. Women (n = 85) had a significantly poorer HRQOL in the domain "Pain" than men (mean score women: 29.5 ± 31.5; males: 14.9 ± 17.2; p = 0.011). Care dependency had an influence on the domain "Sleep" (ß = -0.195, p = 0.031), while the other domains were not influenced by care dependency. Residents with a low care dependency scored significantly lower (better HRQOL) in the domain "Sleep" than residents with a high care dependency (mean score 15.3; SD ± 19.0 versus mean score 32.8 SD ± 33.2; p dependency has no influence on the HRQOL from the nursing home residents' perspective apart from the domain "Sleep". High care dependency residents have a lower HRQOL in the
Taddeucci, T. N.; Rapaport, J.; Bainum, D. E.; Goodman, C. D.; Foster, C. C.; Gaarde, C.; Larsen, J.; Goulding, C. A.; Horen, D. J.; Masterson, T.; Sugarbaker, E.
1982-02-01
Information concerning the ratio of the isovector effective interaction strengths |JστJτ| may be obtained from the ratio of (p,n) Gamow-Teller and isobaric analog state 0° differential cross sections. We have examined 0° (p,n) data for the energy range 5-200 MeV and find that for energies larger than 50 MeV and for targets with A=7-42 the product of the interaction-strength and distortion-factor ratios |JστJτ|(NστNτ)12 appears to be mass independent and linear as a function of bombarding energy. NUCLEAR REACTIONS 7Li, 13, 14C, 26Mg, 37Cl, 41Ca(p,n), measured σ(θ=0°), GT, IAS transitions, Ep=60-200 MeV. Deduced energy dependence, interaction strength ratio |JστJτ|.
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
Cross sections for charm production by neutrinos
Energy Technology Data Exchange (ETDEWEB)
Ushida, N [Aichi Univ. of Education, Kariya (Japan). Dept. of Physics; Kondo, T [Fermi National Accelerator Lab., Batavia, IL (USA); Fujioka, G; Fukushima, J; Takahashi, Y; Tatsumi, S; Yokoyama, C [Kobe Univ. (Japan). Dept. of Physics; Homma, Y; Tsuzuki, Y [Kobe Univ. (Japan). Coll. of Liberal Arts; Bahk, S
1983-02-03
The production of charmed particles has been measured using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative cross section for charged current charmed particle production is sigma(v -> ..mu../sup -/c)/sigma(v -> ..mu../sup -/) = 6.5 +- 1.9/1.8%, and the energy dependence of the cross section is presented. One event with charm pair production was observed. A limit of sigma(v -> ..mu..canti c)/sigma(v -> ..mu..c) < 6% (90% CL) is found for the ratio of charged current pair and single charm production.
Negative ion detachment cross sections
International Nuclear Information System (INIS)
Champion, R.L.; Doverspike, L.D.
1992-10-01
The authors have measured absolute cross sections for electron detachment and charge exchange for collision of O and S with atomic hydrogen, have investigated the sputtering and photodesorption of negative ions from gas covered surfaces, and have begun an investigation of photon-induced field emission of electrons from exotic structures. Brief descriptions of these activities as well as future plans for these projects are given below
Multilevel parametrization of fissile nuclei resonance cross sections
International Nuclear Information System (INIS)
Lukyanov, A.A.; Kolesov, V.V.; Janeva, N.
1987-01-01
Because the resonance interference has an important influence on the resonance structure of neutron cross sections energy dependence at lowest energies, multilevel scheme of the cross section parametrization which take into account the resonance interference is used for the description with the same provisions in the regions of the interferential maximum and minimum of the resonance cross sections of the fissile nuclei
Directory of Open Access Journals (Sweden)
Kenneth D. Hoadley
2017-11-01
Full Text Available Active chlorophyll a fluorescence is an essential tool for understanding photosynthetic activity within cnidarian/dinoflagellate symbioses. Fluorescence measurement is typically achieved by utilizing a blue or red monochromatic excitation light source. However, algal photosynthetic pigments can differ in their absorption spectra, potentially leading to excitation wavelength dependent measurements of maximal and light acclimated PSII photosynthetic quantum yield (Fv/Fm or Fq′/Fm′ and functional absorption cross section (σPSII or σPSII′. Here we utilized an open source hardware development platform to construct a multispectral excitation fluorometer to assess spectrally dependent differences in photochemistry within four different Symbiodinium species (two of each ITS2-type A4 and B1. Multivariate analysis of light acclimated photochemical signatures showed separation between most alga types. These spectrally dependent differences in light acclimated PSII efficiency and PSII functional absorption cross section likely reflect changes in light harvesting compounds, their connectivity to the PSII reaction centers and the balance between photochemical and non-photochemical fluorescence quenching. Additionally, acclimation to low (20 μmol photons m−2 s−1 and high (200 μmol photons m−2 s−1 light conditions was examined in two of these symbionts types (ITS-2 type A4 and B1 As expected, chlorophyll a cell−1 decreased under high light acclimation in both symbionts. However, only A4 saw a subsequent reduction in absorbance whereas cellular volume decreased in the B1 (S. minutum symbiont. In response to high light acclimation, Fv/Fm was significantly lower at all excitation wavelengths for the B1 symbiont where as efficiencies remained the same for A4. However, high-light acclimated Fq′/Fm′ levels decreased in both symbionts, but only when measured using the 615 or 625 nm excitation wavelengths. Non-photochemical quenching within the
Energy Technology Data Exchange (ETDEWEB)
Morcelle, Viviane; Gomes, P.R.S.; Lubian, J.; Mendes Junior, D.R. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lichtenthaeler, R.; Guimaraes, V.; Lepine-Szily, A.; Camargo, O.; Faria, P.N. de; Gasquez, L.; Morais, M.C.; Condori, R.P.; Pires, K.C.C.; Scarduelli, V. [Universidade de Sao Paulo (USP), SP (Brazil); Barioni, A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Shorto, J.M.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Zamora, J.C. [Technische Universitaet Darmstadt (Germany); Aguilera, E.; Martinez-Quiroz, E. [Instituto Nacional de Investigaciones Nucleares (Mexico); Kolata, J.; Jiang, H. [University of Notre Dame, IN (United States); Bechetti, F.D.; Lamm, L.O. [Michigan University, MI (United States); Lizcano, D. [Universidad Autonoma del Estado de Mexico (Mexico)
2012-07-01
Full text: Elastic scattering measurements were performed at energies around the Coulomb barrier at the Tandem Accelerators of the Sao Paulo (USP - Brazil ) and Notre Dame (UND - USA) Universities. The {sup 7}Be is a radioactive nucleus and has been produced by the reaction {sup 6}He({sup 6}Li,{sup 9}Be) and impinged on {sup 27}Al and {sup 197}Au secondary targets using a double superconducting systems RIBRAS ( USP ) and Twinsol (UND). The elastic scattering angular distributions were analyzed through the optical model calculations, using the Woods- Saxon form factors [1] and the Sao Paulo potential [2] to fit the experimental data. The total reaction cross sections were also derived and compared with others presented at the literature for other systems. In addition, a study of the nuclear potential energy dependence has been carried out in this work in the dispersion relation context. Due to the fact that {sup 7}Be has a small breakup threshold energy, the results can provide significant information of the influence of the breakup channel on the reactions involving this projectile. For this purpose, {chi}{sup 2}- data analysis with different kind of potentials were performed to identify the energy dependence of the real (V) and imaginary (W) parts of the potential. [1] L.C. Chamon et al., Phys. Rev. C 66, (2002) 014610. [2] R.D. Wood e D.S. Saxon, Phys. Rev. 95 ( 1954) 577. (author)
Wind Turbine Radar Cross Section
Directory of Open Access Journals (Sweden)
David Jenn
2012-01-01
Full Text Available The radar cross section (RCS of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical design, are shown. The unique electromagnetic scattering features, the effect of materials, and methods of mitigating wind turbine clutter are also discussed.
Björk, Sabine; Juthberg, Christina; Lindkvist, Marie; Wimo, Anders; Sandman, Per-Olof; Winblad, Bengt; Edvardsson, David
2016-08-22
Earlier studies in nursing homes show a high prevalence of cognitive impairment, dependency in activities of daily living (ADL), pain, and neuropsychiatric symptoms among residents. The aim of this study was to explore the prevalence of the above among residents in a nationally representative sample of Swedish nursing homes, and to investigate whether pain and neuropsychiatric symptoms differ in relation to gender, cognitive function, ADL-capacity, type of nursing-home unit and length of stay. Cross-sectional data from 188 randomly selected nursing homes were collected. A total of 4831 residents were assessed for cognitive and ADL function, pain and neuropsychiatric symptoms. Data were analysed using descriptive statistics and the chi-square test. The results show the following: the prevalence of cognitive impairment was 67 %, 56 % of residents were ADL-dependent, 48 % exhibited pain and 92 % exhibited neuropsychiatric symptoms. The prevalence of pain did not differ significantly between male and female residents, but pain was more prevalent among cognitively impaired and ADL-dependent residents. Pain prevalence was not significantly different between residents in special care units for people with dementia (SCU) and general units, or between shorter-and longer-stay residents. Furthermore, the prevalence of neuropsychiatric symptoms did not differ significantly between male and female residents, between ADL capacities or in relation to length of stay. However, residents with cognitive impairment and residents in SCUs had a significantly higher prevalence of neuropsychiatric symptoms than residents without cognitive impairment and residents in general units. The prevalence rates ascertained in this study could contribute to a greater understanding of the needs of nursing-home residents, and may provide nursing home staff and managers with trustworthy assessment scales and benchmark values for further quality assessment purposes, clinical development work and
[Fast neutron cross section measurements
International Nuclear Information System (INIS)
1991-01-01
In the 14 MeV Neutron Laboratory, we have continued the development of a facility that is now the only one of its kind in operation in the United States. We have refined the klystron bunching system described in last year's report to the point that 1.2 nanosecond pulses have been directly measured. We have tested the pulse shape discrimination capability of our primary NE 213 neutron detector. We have converted the RF sweeper section of the beamline to a frequency of 1 MHz to replace the function of the high voltage pulser described in last year's report which proved to be difficult to maintain and unreliable in its operation. We have also overcome several other significant experimental difficulties, including a major problem with a vacuum leak in the main accelerator column. We have completed additional testing to prove the remainder of the generation and measurement systems, but overcoming some of these experimental difficulties has delayed the start of actual data taking. We are now in a position to begin our first series of ring geometry elastic scattering measurements, and these will be underway before the end of the current contract year. As part of our longer term planning, we are continuing the conceptual analysis of several schemes to improve the intensity of our current pulsed beam. These include the provision of a duoplasmatron ion source and/or the provision of preacceleration bunching. Additional details are given later in this report. A series of measurements were carried out at the Tandem Dynamatron Facility involving the irradiation of a series of yttrium foils and the determination of activation cross sections using absolute counting techniques. The experimental work has been completed, and final analysis of the cross section data will be completed within several months
Total dissociation cross section of halo nuclei
Energy Technology Data Exchange (ETDEWEB)
Formanek, J. [Karlova Univ., Prague (Czech Republic). Fakulta Matematicko-Fyzikalni; Lombard, R.J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire
1996-10-01
Calculations of the total dissociation cross section is performed in the impact parameter representation. The case of {sup 11}Be and {sup 11}Li loosing one and two neutron(s), respectively, by collision on a {sup 12}C target, which remains in its ground state are discussed. The results are found to depend essentially on the rms radius of the halo wave function. (author). 12 refs.
Measurement of angular dependence of M X-ray production cross-sections in Re, Bi and U at 5.96 keV
International Nuclear Information System (INIS)
Apaydin, G.; Tirasoglu, E.; Sogut, O.
2008-01-01
The M X-ray production differential cross sections in Re, Bi and U elements have been measured at the 5.96 keV incident photon energy in an angular range 135 - 155 degrees. The measurements were performed using a Fe 55 source and a Si(Li) detector. It appears that, after photoionization of inner shells, the vacancy state has equal population of magnetic substates and the subsequent X-ray emission is isotropic. Total M X-ray production cross sections from the decay at the 5.96 keV photon energies are found to be in good agreement with the calculated theoretical results using the theoretical values of M shell photoionization cross section. (authors)
Campêlo, Selva Rios; Barbosa, Maria Alves; Dias, Danilo Rocha; Caixeta, Camila Cardoso; Leles, Cláudio Rodrigues; Porto, Celmo Celeno
2017-11-17
Quality of life must be one of the main purposes for the treatment of drug users, requiring a better understanding of the association between the quality of life and the severity of dependency. This study aimed to investigate the correlation between severity of substance use in various areas of human functioning and quality of life of illicit drug users in a psychosocial care center for alcohol and drugs. This cross-sectional study included 60 participants - illicit drug users - treated at a psychosocial care center for alcohol and drugs. Participants were evaluated with the short version of World Health Organization Quality of Life (WHOQOL-Bref) instrument to measure the quality of life, the 6th version of Addiction Severity Index (ASI-6) to assess the severity of dependence in several areas and the Mini International Neuropsychiatric Interview (MINI) to identify the presence of psychiatric disorders. Pearson and Spearman correlation tests and linear regression were applied to verify the association between the severity of dependence and the quality of life, and Student's t-test to compare the mean quality of life between individuals with and without psychiatric comorbidities. Negative correlation was found between the severity of dependence on the drugs dimensions: alcohol, psychiatric, medical, legal, family/social support and family/social problems of ASI-6, and the quality of life domains measured by the WHOQOL-Bref. The evidence was strongest in the psychiatric and medical dimensions. There was a significant difference in the quality of life mean among participants presenting or not presenting psychiatric comorbidities, for the psychological domain in anxiety disorders, and for the physical and psychological domains in mood disorders. The quality of life decreased as the severity of dependence increased, with different results in the various areas of the participant's life. This result emphasizes the need for training the professional team which works in the
Validation of evaluated neutron standard cross sections
International Nuclear Information System (INIS)
Badikov, S.; Golashvili, T.
2008-01-01
Some steps of the validation and verification of the new version of the evaluated neutron standard cross sections were carried out. In particular: -) the evaluated covariance data was checked for physical consistency, -) energy-dependent evaluated cross-sections were tested in most important neutron benchmark field - 252 Cf spontaneous fission neutron field, -) a procedure of folding differential standard neutron data in group representation for preparation of specialized libraries of the neutron standards was verified. The results of the validation and verification of the neutron standards can be summarized as follows: a) the covariance data of the evaluated neutron standards is physically consistent since all the covariance matrices of the evaluated cross sections are positive definite, b) the 252 Cf spectrum averaged standard cross-sections are in agreement with the evaluated integral data (except for 197 Au(n,γ) reaction), c) a procedure of folding differential standard neutron data in group representation was tested, as a result a specialized library of neutron standards in the ABBN 28-group structure was prepared for use in reactor applications. (authors)
International Nuclear Information System (INIS)
Soliman, N.F.
2012-01-01
In k 0 - Neutron Activation Analysis (k 0 -NAA), the conversion from the tabulated Q 0 (ratio of the resonance integral to thermal neutron cross-section)to Q 0 (α) (α is the shape factor of the epithermal neutron flux, indicating the deviation of the epithermal neutron spectrum from the ideal 1/E shape) are calculated using a FORTRAN program. The calculations are done for most elements that can be detected by neutron activation using different values of the parameter (α) ranging from -0.1≤α≤+0.1. The obtained data are used to study the dependence of the values (α) on the irradiation position factor in (k 0 -NAA)equation for some selected isotopes differ in their resonance energy and its Q 0 values. The results show that, the irradiation factor is affective mainly for low thermal tro epithermal flux ratio f especially for Q 0 value greater than 50. so consequently determining the irradiation parameters α value is not needed for irradiation positions that rich with thermal neutron. But for high f values the irradiation position factor should be taken into account. On the other hand the constructed FORTRAN program can be used to calculate the value Q 0 (α) directly for different value of α
K+ nucleus total cross sections
International Nuclear Information System (INIS)
Sawafta, R.
1990-01-01
The scattering of K + mesons from nuclei has attracted considerable interest in the last few years. The K + holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K + is capable of probing the entire volume of the nucleus. Single scattering of the K + with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K + is used to compare the nucleon in the nucleus with a free nucleon
Terahertz radar cross section measurements.
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 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
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.
Chen, Junsheng; Zidek, Karel; Chabera, Pavel; Liu, Dongzhou; Cheng, Pengfei; Nuuttila, Lauri; Al-Marri, Mohammed J.; Lehtivuori, Heli; Messing, Maria E.; Han, Keli; Zheng, Kaibo; Pullerits, Tonu
2017-01-01
All-inorganic colloidal perovskite quantum dots (QDs) based on cesium, lead, and halide have recently emerged as promising light emitting materials. CsPbBr3 QDs have also been demonstrated as stable two-photon-pumped lasing medium. However, the reported two photon absorption (TPA) cross sections for
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)
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
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.
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)
Czech Academy of Sciences Publication Activity Database
Roithová, Jana; Thissen, R.; Žabka, Ján; Franceschi, P.; Dutuit, O.; Herman, Zdeněk
2003-01-01
Roč. 228, - (2003), s. 487-495 ISSN 1387-3806 R&D Projects: GA ČR GA203/00/0632 Grant - others:Barrande(FR) 2002-013-01 04713TC/2002 Institutional research plan: CEZ:AV0Z4040901 Keywords : Dications * integral cross-sections * charge transfer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.361, year: 2003
Energy Technology Data Exchange (ETDEWEB)
Lundgren, G
1967-11-15
Using the fast chopper at the Stockholm reactor R1 a comparison between the (n, {gamma}) cross sections for thorium and copper has been made in the energy interval 0.1 to 3.4 eV. The (n, {gamma}) cross section for copper follows the 1/v law sufficiently well in this energy interval to be used as a 1/v standard. The deviation at 3.4 eV does not exceed 5 %. The capture cross section, {sigma}, for thorium decreases more rapidly than 1/v and the deviation is found to be close to 60 % at 3.4 eV. If one assumes that the deviation is caused essentially by a single negative resonance this should be located at 5.1 {+-} 0.5 eV. Furthermore, if a value of 24 meV for {gamma}{sub {gamma}}, the radiation width for the negative resonance, is used one finds that {gamma}{sub n}{sup 0}, the reduced neutron width for the same resonance, amounts to 1.82 {+-} 0.25 meV. Using these parameters together with the resonance parameters for the positive resonances a value of the total microscopic scattering cross section at 0.025 eV has been calculated as 12.2 {+-} 0.4 b. A value of the contributions above 0.5 eV to the resonance integral from the 'tail' of the negative resonance and the 1/v - parts of the positive resonances has also been calculated giving the result 1.6 b. Finally, the g-factor (Westcott's nomenclature) for a Maxwellian spectrum at 20 deg C becomes 0.994.
International Nuclear Information System (INIS)
Said, K.; Damamme, G.; Si Ahmed, A.; Moya, G.; Kallel, A.
2014-01-01
Highlights: • A novel approach for the analysis of the secondary electron emission in connection with the surface density of trapped charges. • Experimental estimation of the effective cross section for electron–hole recombination and electron trapping in defects. • A simplified charge transport and trapping model which corroborates qualitatively the interpretation of the results. - Abstract: The evolution of the secondary electron emission from sapphire and polycrystalline alumina during electron irradiation, achieved in a scanning electron microscope at room temperature, is derived from the measurement of the induced and the secondary electron currents. The semi-logarithmic plot of the secondary electron emission yield versus the surface density of trapped charges displays a plateau followed by a linear variation. For positive charging, the slope of the linear part, whose value is of about 10 −9 cm 2 , is independent of the primary electron energy, the microstructure and the impurities. It is interpreted as an effective microscopic cross section for electron–hole recombination. For negative charging of sapphire, the slope is associated with an effective electron trapping cross section close to 10 −11 cm 2 , which can be assigned to the dominant impurity trap. These effective values reflect the multiple interactions leading to the accumulation of charges. The yield corresponding to the plateau is controlled by the initial density of impurity traps. A charge transport and trapping >model, based on simplifying assumptions, confirms qualitatively these inferences
MXS cross-section preprocessor user's manual
International Nuclear Information System (INIS)
Parker, F.; Ishikawa, M.; Luck, L.
1987-03-01
The MXS preprocessor has been designed to reduce the execution time of programs using isotopic cross-section data and to both reduce the execution time and improve the accuracy of shielding-factor interpolation in the SIMMER-II accident analysis program. MXS is a dual-purpose preprocessing code to: (1) mix isotopes into materials and (2) fit analytic functions to the shelf-shielding data. The program uses the isotope microscopic neutron cross-section data from the CCCC standard interface file ISOTXS and the isotope Bondarenko self-shielding data from the CCCC standard interface file BRKOXS to generate cross-section and self-shielding data for materials. The materials may be a mixture of several isotopes. The self-shielding data for the materials may be the actual shielding factors or a set of coefficients for functions representing the background dependence of the shielding factors. A set of additional data is given to describe the functions necessary to interpolate the shielding factors over temperature
How to extract cross sections from TDHF
International Nuclear Information System (INIS)
Le Tourneux, Jean
1979-01-01
In spite of all the recent progress in solving numerically TDHF (Time Dependent Hartree-Fock) equations for heavy-ion collisions, this method is still far from lending itself readily to the computation of cross sections, except in the case of fusion. The theory presented here is purely formal so far and would lead to fairly heavy calculations in practice. It solves the problem of channel identification in the outgoing asymptotic region of TDHF solutions. It throws a bridge between TDHF and more traditional theories of nuclear reactions, which are time-independent
Corporate Social Responsibility: A Cross Sectional Examination of Incentivization.
1995-09-01
which address organizational behavior: Corporate Social Responsibility ( CSR ), Expense Preference Approach (EPA), Resource Dependency Theory (RDT...i V *>V CORPORATE SOCIAL RESPONSIBILITY : A CROSS SECTIONAL EXAMINATION OF INCENTIVIZATION THESIS Jennifer A. Block, B.S. First Lieutenant, USAF...Distribution/ Availability Codes Dist m Avail and/or Special \\&\\W 0\\1 CORPORATE SOCIAL RESPONSIBILITY : A CROSS SECTIONAL EXAMINATION OF
Tearing mode stability of tokamak plasmas with elliptical cross section
International Nuclear Information System (INIS)
Carreras, B.A.; Holmes, J.A.; Hicks, H.R.; Lynch, V.E.
1981-02-01
The effect of the ellipticity of the plasma cross section on tearing mode stability is investigated. The induced coupling between modes is shown to be destabilizing; however, the modification of the equilibrium tends to stabilize the tearing modes. The net effect depends on the manner in which the equilibrium is modified as the plasma cross-section shape is changed
Systematics of new isotopic production cross sections from neon projectiles
International Nuclear Information System (INIS)
Chen, C.X.; Guzik, T.G.; McMahon, M.; Wefel, J.P.; Flores, I.; Lindstrom, P.J.; Tull, C.E.; Mitchell, J.W.; Cronqvist, M.; Crawford, H.J.
1996-02-01
New isotopic production cross sections from 22 Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.)
Systematics of new isotopic production cross sections from neon projectiles
Energy Technology Data Exchange (ETDEWEB)
Chen, C X; Guzik, T G; McMahon, M; Wefel, J P [Louisiana State Univ., Baton Rouge, LA (United States); Flores, I; Lindstrom, P J; Tull, C E [Lawrence Berkeley Lab., CA (United States); Mitchell, J W [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Cronqvist, M; Crawford, H J [California Univ., Berkeley, CA (United States). Space Sciences Lab.; and others
1996-02-01
New isotopic production cross sections from {sup 22}Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.). 9 refs.
Fusion cross sections from measurements of delayed X-rays
International Nuclear Information System (INIS)
Pacheco, A.J.; Gregorio, D.E. di; Fernandez Niello, J.O; Elgue, M.
1988-01-01
The program XRAY is a FORTRAN 77 computer code for the extraction of fusion cross sections from delayed X-ray measurements. This is accomplished by calculating the theoretical expressions of the time dependence of the evaporation-residue cross sections and taking them as adjustable parameters in a χ 2 minimization procedure. (orig.)
Systematics of fission cross sections at the intermediate energy region
Energy Technology Data Exchange (ETDEWEB)
Fukahori, Tokio; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
1997-03-01
The systematics was obtained with fitting experimental data for proton induced fission cross sections of Ag, {sup 181}Ta, {sup 197}Au, {sup 206,207,208}Pb, {sup 209}Bi, {sup 232}Th, {sup 233,235,238}U, {sup 237}Np and {sup 239}Pu above 20 MeV. The low energy cross section of actinoid nuclei is omitted from systematics study, since the cross section has a complicated shape and strongly depends on characteristic of nucleus. The fission cross sections calculated by the systematics are in good agreement with experimental data. (author)
Richardson, Andrea S; Troxel, Wendy M; Ghosh-Dastidar, Madhumita B; Beckman, Robin; Hunter, Gerald P; DeSantis, Amy S; Colabianchi, Natalie; Dubowitz, Tamara
2017-01-19
Low-income African American adults are disproportionately affected by obesity and are also least likely to engage in recommended levels of physical activity (Flegal et al. JAMA 303(3):235-41, 2010; Tucker et al. Am J Prev Med 40(4):454-61, 2011). Moderate-to-vigorous physical activity (MVPA) is an important factor for weight management and control, as well as for reducing disease risk (Andersen et al. Lancet 368(9532):299-304, 2006; Boreham and Riddoch J Sports Sci 19(12):915-29, 2001; Carson et al. PLoS One 8(8):e71417, 2013). While neighborhood greenspace and walkability have been associated with increased MVPA, evidence also suggests that living in areas with high rates of crime limits MVPA. Few studies have examined to what extent the confluence of neighborhood greenspace, walkability and crime might impact MVPA in low-income African American adults nor how associations may vary by age and sex. In 2013 we collected self-reported data on demographics, functional limitations, objective measures of MVPA (accelerometry), neighborhood greenspace (geographic information system), and walkability (street audit) in 791 predominantly African-American adults (mean age 56 years) living in two United States (U.S.) low-income neighborhoods. We also acquired data from the City of Pittsburgh on all crime events within both neighborhoods. To examine cross-sectional associations of neighborhood-related variables (i.e., neighborhood greenspace, walkability and crime) with MVPA, we used zero-inflated negative binomial regression models. Additionally, we examined potential interactions by age (over 65 years) and sex on relationships between neighborhood variables and MVPA. Overall, residents engaged in very little to no MVPA regardless of where they lived. However, for women, but not men, under the age of 65 years, living in more walkable neighborhoods was associated with more time engaged in MVPA in (β = 0.55, p = 0.007) as compared to their counterparts living in less
Directory of Open Access Journals (Sweden)
Andrea S. Richardson
2017-01-01
Full Text Available Abstract Background Low-income African American adults are disproportionately affected by obesity and are also least likely to engage in recommended levels of physical activity (Flegal et al. JAMA 303(3:235-41, 2010; Tucker et al. Am J Prev Med 40(4:454-61, 2011. Moderate-to-vigorous physical activity (MVPA is an important factor for weight management and control, as well as for reducing disease risk (Andersen et al. Lancet 368(9532:299-304, 2006; Boreham and Riddoch J Sports Sci 19(12:915-29, 2001; Carson et al. PLoS One 8(8:e71417, 2013. While neighborhood greenspace and walkability have been associated with increased MVPA, evidence also suggests that living in areas with high rates of crime limits MVPA. Few studies have examined to what extent the confluence of neighborhood greenspace, walkability and crime might impact MVPA in low-income African American adults nor how associations may vary by age and sex. Methods In 2013 we collected self-reported data on demographics, functional limitations, objective measures of MVPA (accelerometry, neighborhood greenspace (geographic information system, and walkability (street audit in 791 predominantly African-American adults (mean age 56 years living in two United States (U.S. low-income neighborhoods. We also acquired data from the City of Pittsburgh on all crime events within both neighborhoods. Exposure: To examine cross-sectional associations of neighborhood-related variables (i.e., neighborhood greenspace, walkability and crime with MVPA, we used zero-inflated negative binomial regression models. Additionally, we examined potential interactions by age (over 65 years and sex on relationships between neighborhood variables and MVPA. Results Overall, residents engaged in very little to no MVPA regardless of where they lived. However, for women, but not men, under the age of 65 years, living in more walkable neighborhoods was associated with more time engaged in MVPA in (β = 0.55, p = 0
Hansen, Anne Helen; Høye, Anne
2015-10-22
Overall, men are less likely than women to seek health care services for mental health problems, but differences between genders in higher age groups are equivocal. The aim of the current study was to investigate the association between gender and the use of psychiatric outpatient specialist services in Norway, both in a general population and in a subpopulation with self-reported anxiety and/or depression. Using questionnaires from 12,982 participants (30-87 years) in the cross-sectional sixth Tromsø Study (2007-8) we estimated proportions reporting anxiety/depression, and proportions using psychiatric outpatient specialist services in a year. By logistic regressions we studied the association between gender and the use of psychiatric outpatient specialist services. Analyses were adjusted for age, marital status, income, education, self-reported degree of anxiety/depression, and GP visits last year. Analyses were also performed for genders separately. Anxiety/depression was reported by 21.5 % of women and 12.3 % of men in the general population. Visits to psychiatric outpatient services during one year were reported by 4.6 % of women and 3.3 % of men. The general population's probability of a visit was significantly lower among men compared to women in ages 30-49 years (odds ratio [OR] 0.58, confidence interval [CI] 0.39-0.84, p-value [p] = 0.004), whereas men used services slightly more than women in ages 50 years and over (OR 1.36, CI 1.00-1.83, p = 0.047). Among those with anxiety/depression 13.5 % of women and 10.5 % of men visited psychiatric outpatient services in a year. We found no statistically significant gender differences in the use of services in this subgroup. Other factors associated with services use in women with anxiety/depression were higher education, more severe anxiety/depression, and GP visits the last year, whereas in men only a more severe anxiety/depression was associated with psychiatric outpatient visits. Overall, the use of
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.
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
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
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)
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)
Polynomial parameterized representation of macroscopic cross section for PWR reactor
International Nuclear Information System (INIS)
Fiel, Joao Claudio B.
2015-01-01
The purpose of this work is to describe, by means of Tchebychev polynomial, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 U 92 enrichment. Analyzed cross sections are: fission, scattering, total, transport, absorption and capture. This parameterization enables a quick and easy determination of the problem-dependent cross-sections to be used in few groups calculations. The methodology presented here will enable to provide cross-sections values to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by parameterized cross-sections functions, when compared with the cross-section generated by SCALE code calculations, or when compared with K inf , generated by MCNPX code calculations, show a difference of less than 0.7 percent. (author)
International Nuclear Information System (INIS)
Wang, M.; Keller, J.; Boulmer, J.; Weiner, J.
1987-01-01
We report new results on the direct measurement of the associative ionization (AI) cross section in collisions between velocity-selected and spin-oriented Na(3p) atoms. Improvements in the Doppler-shift velocity-selection technique permit measurement over an energy range spanning more than two orders of magnitude from subthermal to suprathermal regions. Spin orientations, parallel and antiparallel, enable determination of the excitation function (velocity dependence of the AI cross section) for the separate singlet and triplet manifolds of Na 2 states contributing to the AI process
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
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)
International Nuclear Information System (INIS)
Sonika; Roy, B.J.; Parmar, A.; Jha, V.; Pal, U.K.; Pandit, S.K.; Parkar, V.V.; Ramachandran, K.; Mahata, K.; Pal, A.; Santra, S.; Mohanty, A.K.; Sinha, T.; Parihari, A.
2014-01-01
Measurement and detailed analysis of elastic scattering and inelastic excitations in 206 Pb( 18 O, 18 O) have been reported here. First, the elastic scattering cross-section was calculated with a bare double folded real potential. The DF potential consists of folding of a harmonic oscillator density distribution to simulate 18 O with the sum of two Fermi density distributions for the proton and neutron in 206 Pb with correct normalizations. Our measured higher energy data for the same system was first analyzed with this DF potential
Loprinzi, Paul D; Kane, Christy J; Mahoney, Sara; Walker, Jerome F
2015-02-01
The association between nicotine dependence and physical activity (PA) is relatively unknown. No study has concurrently examined the cross-sectional and longitudinal associations between PA and nicotine dependence, which was the primary purpose of this study. A secondary purpose was to examine how well nicotine dependence and PA behavior track over a two-year period. Data from the 2003-2005 National Youth Smoking Cessation Survey (NYSCS) were used, with young adults (18-24 yrs; n=1168) being followed over a two-year period. Physical activity was assessed using a questionnaire and nicotine dependence was assessed using the modified Fagerstrom Test for Nicotine Dependence scale. This study identified three notable findings: 1) baseline PA and nicotine dependence demonstrated a bidirectional, cross-sectional association (e.g., β=-0.23; 95% CI: -0.44 to -0.02; p=0.02); 2) when examined longitudinally, nicotine dependence influenced PA (OR=0.90; 95% CI: 0.82-0.99; p=0.04), but there was no evidence of the reverse pathway (i.e., PA influencing 2-year follow-up smoking status [OR=0.95; 95% CI: 0.66-1.39; p=0.82) or nicotine dependence (β=0.05; 95% CI: -0.14 to 0.24, p=0.61]); and 3) both PA (OR=3.52, 95% CI: 2.68-4.69; pdependence (β=0.52; 95% CI: 0.46-0.58, pphysical activity and nicotine dependence) track over time, but nicotine dependence appears to be driving the cross-sectional relationship between nicotine dependence and physical activity, as opposed to the reverse pathway. Copyright © 2014 Elsevier Inc. All rights reserved.
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)
Measurements of fission cross-sections. Chapter 4
International Nuclear Information System (INIS)
James, G.D.
1981-01-01
The steps involved in the measurement of fission cross sections are summarized and the range of techniques available are considered. Methods of fission detection are described with particular emphasis on the neutron energy dependent properties of the fission process and the details of fragment energy loss which can lead to energy-dependent changes in detector efficiency. Selected examples of fission cross-section measurements are presented and methods of data reduction, storage, analysis and evaluation, are examined. Finally requested accuracies for fission cross section data are compared to estimated available accuracies. (U.K.)
First measurement of the Rayleigh cross section
Naus, H.; Ubachs, W.
2000-01-01
Rayleigh cross section for N2, Ar and SF6 was performed using the technique of cavity ring-down spectroscopy (CRDS). The experiment was based on the assumption that scattering cross section is equal to the extinction in the absence of absorption. The theory explains the molecular origin of
Total cross section of highly excited strings
International Nuclear Information System (INIS)
Lizzi, F.; Senda, I.
1990-01-01
The unpolarized total cross section for the joining of two highly excited strings is calculated. The calculation is performed by taking the average overall states in the given excitation levels of the initial strings. We find that the total cross section grows with the energy and momentum of the initial states. (author). 8 refs, 1 fig
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.)
Total cross section results for deuterium electrodisintegration
International Nuclear Information System (INIS)
Skopik, D.M.; Murphy, J.J. II; Shin, Y.M.
1976-01-01
Theoretical total cross sections for deuterium electrodisintegration are presented as a function of incident electron energy. The cross section has been calculated using virtual photon theory with Partovi's photodisintegration calculation for E/subx/ > 10 MeV and effective range theory for E/subx/ 2 H(e, n) reaction in Tokamak reactors
Model cross section calculations using LAHET
International Nuclear Information System (INIS)
Prael, R.E.
1992-01-01
The current status of LAHET is discussed. The effect of a multistage preequilibrium exciton model following the INC is examined for neutron emission benchmark calculations, as is the use of a Fermi breakup model for light nuclei rather than an evaporation model. Comparisons are made also for recent fission cross section experiments, and a discussion of helium production cross sections is presented
Vibrational enhancement of total breakup cross sections
International Nuclear Information System (INIS)
Haftel, M.I.; Lim, T.K.
1984-01-01
This paper considers the role of multi-two-body bound states, namely vibrational excitations, on total three-body breakup cross-sections. Total cross-sections are usually easy to measure, and they play a fundamental role in chemical kinetics. (orig.)
Interference analysis of fission cross section
International Nuclear Information System (INIS)
Toshkov, S.A.; Yaneva, N.B.
1976-01-01
The formula for the reaction cross-section based on the R-matrix formalism considering the interference between the two neighbouring resonances, referred to the same value of total momentum was used for the analysis of the cross-section of resonance neutron induced fission of 230Pu. The experimental resolution and thermal motion of the target nuclei were accounted for numerical integration
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.)
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)
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
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)
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
International Nuclear Information System (INIS)
Fathi, R.; Akbarabadi, F.S.; Bolorizadeh, M.A.; Brunger, M.J.
2015-01-01
A 3-body Faddeev type formalism is applied to calculate the total excitation cross sections in the collision of a bare ion, A q+ (1 ≤ q ≤ 4), with atomic hydrogen, leading to the excitation of its 2s and 3s states. These calculations were undertaken at energies in the range 1 MeV-7 MeV. The first order electronic and nuclear amplitudes are included in the model, in order to calculate the differential and total excitation cross sections leading to the first order form factors. The present results are compared with the available data in the literature, specifically those from mono-centric close-coupling calculations. The Z-dependence of the 2s and 3s excitation cross sections are also determined, and compared with corresponding data available in the literature. Saturation is observable in the excitation cross sections in the 1-7 MeV energy region, which depends on the ratio of projectile's and target's nuclear charge. (authors)
van Zyl, Paulina; Botha, Julie; van Wyk, Michelle; Breytenbach, Jaco; Nel, Christiaan; van Niekerk, Michael; Breytenbach, Wilma
2015-01-01
This study was conducted to determine the prevalence of hazardous, harmful and dependent drinking among hostel-dwelling students on the main campus of the University of the Free State (UFS), and the influence of sex and academic year on the habit. A quarter of all hostel-dwelling students of UFS were selected by systematic random sampling. Willing participants completed a questionnaire comprising a demographic section and the Alcohol Use Disorders Identification Test (AUDIT). Of the 339 participants with total AUDIT scores, 15.6% exhibited hazardous drinking, 4.1% harmful drinking and 5.6% alcohol dependence. Male students had a statistically significant higher prevalence (32.8%) of hazardous, harmful or dependent drinking than female students (18.9%). Women, however, are biologically more vulnerable to the ill effects of alcohol due to altered pharmacokinetics and pharmacodynamics of alcohol. In addition, intoxicated women suffer more biological and social risks. When the cut-off point for hazardous drinking was adapted to account for the increased biological vulnerability of women, the difference between female and male participants was no longer significant. First year male students were less likely to engage in unsafe drinking than senior students. Female students in the alcohol dependent category showed an increasing trend over advancing academic year. Follow-up studies are needed to confirm whether a significant difference in hazardous drinking of first year male students compared to seniors reflects the influence of university policy or merely precedes drinking acculturation.
Hills, J. G.
1992-06-01
Over 125,000 encounters between a hard binary with equal mass, components and orbital eccentricity of 0, and intruders with solar masses ranging from 0.01 to 10,000 are simulated. Each encounter was followed up to a maximum of 5 x 10 exp 6 integration steps to allow long-term 'resonances', temporary trinary systems, to break into a binary and a single star. These simulations were done over a range of impact parameters to find the cross sections for various processes occurring in these encounters. A critical impact parameter found in these simulations is the one beyond which no exchange collisions can occur. The energy exchange between the binary and a massive intruder decreases greatly in collisions with Rmin of not less than Rc. The semimajor axes and orbital eccentricity of the surviving binary also drops rapidly at Rc in encounters with massive intruders. The formation of temporary trinary systems is important for all intruder masses.
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
International Nuclear Information System (INIS)
Fort, J.; Bolzinger, T.; Corno, D.; Ebding, T.; Pesnelle, A.
1978-01-01
The velocity dependence of both the Penning and rearrangement ionization cross sections sigma/sub PI/ and sigma/sub RI/ for H 2 /sup ts+/ and HeH + ion production, as well as total ionization cross section sigma/sub TI/, resulting from the collisions of He (2 1 S) and He (2 3 S) with H 2 is measured over the relative-velocity range 2400--5300 m/sec (0.04--0.20 eV energy range) in a crossed-beam experiment by a time-of-flight technique. Characteristic cross-section ratios sigma/sub RI//sigma/sub TI/ and the relative magnitude of the cross sections sigma/sub RI/, sigma/sub PI/, and sigma/sub TI/ are reported. Comparison with some recent theoretical calculations is made; we observe a fair agreement in the triplet case except for sigma/sub RI/, but a strong difference in the singlet case
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
Sudakov resummation of multiparton QCD cross sections
Bonciani, R; Mangano, Michelangelo L; Nason, P
2003-01-01
We present the general expressions for the resummation, up to next-to-leading logarithmic accuracy, of Sudakov-type logarithms in processes with an arbirtrary number of hard-scattering partons. These results document the formulae used by the authors in several previous phenomenological studies. The resummation formulae presented here, which are valid for phase-space factorizable observables, determine the resummation correction in a process-independent fashion. All process dependence is encoded in the colour and flavour structure of the leading order and virtual one-loop amplitudes, and in Sudakov weights associated to the cross section kinematics. We explicitly illustrate the application to the case of Drell--Yan and prompt-photon production.
Sudakov resummation of multiparton QCD cross sections
International Nuclear Information System (INIS)
Bonciani, Roberto; Catani, Stefano; Mangano, Michelangelo L.; Nason, Paolo
2003-01-01
We present the general expressions for the resummation, up to next-to-leading logarithmic accuracy, of Sudakov-type logarithms in processes with an arbitrary number of hard-scattering partons. These results document the formulae used by the authors in several previous phenomenological studies. The resummation formulae presented here, which are valid for phase-space factorizable observables, determine the resummation correction in a process-independent fashion. All process dependence is encoded in the colour and flavour structure of the leading order and virtual one-loop amplitudes, and in Sudakov weights associated to the cross section kinematics. We explicitly illustrate the application to the case of Drell-Yan and prompt-photon production
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)
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
A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.
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.)
Differential Top Cross-section Measurements
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.
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
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
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.
Calculation of the resonance cross section functions
International Nuclear Information System (INIS)
Slipicevic, K.F.
1967-11-01
This paper includes the procedure for calculating the Doppler broadened line shape functions ψ and χ which are needed for calculation of resonance cross section functions. The obtained values are given in tables
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)
Measurement of multinucleon transfer cross-sections
Indian Academy of Sciences (India)
Keywords. Ni(C, ), Fe(C, ), =C, C, B, B, Be, Be, Be, Be, Li, Li; = 60 MeV; measured reaction cross-section; elastic scattering angular distribution; deduced transfer probabilities and enhancement factors.
Capture cross sections on unstable nuclei
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.
Calculation of the resonance cross section functions
Energy Technology Data Exchange (ETDEWEB)
Slipicevic, K F [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)
1967-11-15
This paper includes the procedure for calculating the Doppler broadened line shape functions {psi} and {chi} which are needed for calculation of resonance cross section functions. The obtained values are given in tables.
Pion-nucleus cross sections approximation
International Nuclear Information System (INIS)
Barashenkov, V.S.; Polanski, A.; Sosnin, A.N.
1990-01-01
Analytical approximation of pion-nucleus elastic and inelastic interaction cross-section is suggested, with could be applied in the energy range exceeding several dozens of MeV for nuclei heavier than beryllium. 3 refs.; 4 tabs
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
Tachyonic ionization cross sections of hydrogenic systems
Energy Technology Data Exchange (ETDEWEB)
Tomaschitz, Roman [Department of Physics, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima 739-8526 (Japan)
2005-03-11
Transition rates for induced and spontaneous tachyon radiation in hydrogenic systems as well as the transversal and longitudinal ionization cross sections are derived. We investigate the interaction of the superluminal radiation field with matter in atomic bound-bound and bound-free transitions. Estimates are given for Ly-{alpha} transitions effected by superluminal quanta in hydrogen-like ions. The tachyonic photoelectric effect is scrutinized, in the Born approximation and at the ionization threshold. The angular maxima occur at different scattering angles in the transversal and longitudinal cross sections, which can be used to sift out longitudinal tachyonic quanta in a photon flux. We calculate the tachyonic ionization and recombination cross sections for Rydberg states and study their asymptotic scaling with respect to the principal quantum number. At the ionization threshold of highly excited states of order n {approx} 10{sup 4}, the longitudinal cross section starts to compete with photoionization, in recombination even at lower levels.
a cross-sectional analytic study 2014
African Journals Online (AJOL)
Assessment of HIV/AIDS comprehensive correct knowledge among Sudanese university: a cross-sectional analytic study 2014. ... There are limited studies on this topic in Sudan. In this study we investigated the Comprehensive correct ...
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.
Parameterized representation of macroscopic cross section for PWR reactor
International Nuclear Information System (INIS)
Fiel, João Cláudio Batista; Carvalho da Silva, Fernando; Senra Martinez, Aquilino; Leal, Luiz C.
2015-01-01
Highlights: • This work describes a parameterized representation of the homogenized macroscopic cross section for PWR reactor. • Parameterization enables a quick determination of problem-dependent cross-sections to be used in few group calculations. • This work allows generating group cross-section data to perform PWR core calculations without computer code calculations. - Abstract: The purpose of this work is to describe, by means of Chebyshev polynomials, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 92 U enrichment. The cross-section data analyzed are fission, scattering, total, transport, absorption and capture. The parameterization enables a quick and easy determination of problem-dependent cross-sections to be used in few group calculations. The methodology presented in this paper will allow generation of group cross-section data from stored polynomials to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by the proposed methodology when compared with results from the SCALE code calculations show very good agreement
Methods for calculating anisotropic transfer cross sections
International Nuclear Information System (INIS)
Cai, Shaohui; Zhang, Yixin.
1985-01-01
The Legendre moments of the group transfer cross section, which are widely used in the numerical solution of the transport calculation can be efficiently and accurately constructed from low-order (K = 1--2) successive partial range moments. This is convenient for the generation of group constants. In addition, a technique to obtain group-angle correlation transfer cross section without Legendre expansion is presented. (author)
Heisenberg rise of total cross sections
International Nuclear Information System (INIS)
Ezhela, V.V.; Yushchenko, O.P.
1988-01-01
It is shown that on the basis of the original idea of Heisenberg on the quasiclassical picture of extended particle interactions one can construct a satisfactory description of the total cross sections, elastic cross sections, elastic diffractive slopes and mean charged multiplicities in the cm energy range from 5 to 900 GeV, and produce reasonable extrapolations up to several tens of TeV. 14 refs.; 7 figs.; 2 tabs
Evaluation methods for neutron cross section standards
International Nuclear Information System (INIS)
Bhat, M.R.
1980-01-01
Methods used to evaluate the neutron cross section standards are reviewed and their relative merits, assessed. These include phase-shift analysis, R-matrix fit, and a number of other methods by Poenitz, Bhat, Kon'shin and the Bayesian or generalized least-squares procedures. The problems involved in adopting these methods for future cross section standards evaluations are considered, and the prospects for their use, discussed. 115 references, 5 figures, 3 tables
International Nuclear Information System (INIS)
Corden, M.J.; Dowell, J.D.; Garvey, J.; Homer, R.J.; Jobes, M.; Kenyon, I.R.; McMahon, T.J.; Owen, R.C.; Sumorok, K.C.T.; Vallance, R.J.
1982-01-01
J/PSI production on hydrogen and tungsten targets has been compared at 39.5 GeV/c and the variation of the A-dependence of the J/PSI cross section as a function of psub(t) 2 and xsub(F) has been measured. The A-dependence parameter, α, rises with increasing p 2 2 and falls with increasing xsub(F). Both effects are shown not to be due to the Fermi motion of nucleons in the tungsten nucleus. (orig.)
Kinetic description of the total photoabsorption cross section: correlation effects
International Nuclear Information System (INIS)
Ferreira Filho, L.G.; Nemes, M.C.
1986-02-01
It is shown that the inclusion of correlation effects in describing the nuclear photoabsorption cross section leads to a Breit-Wigner type curve with energy dependent width. It is also shown that a very slow energy dependence is enough to reproduce the data up to ∼ 139 MeV. (Author) [pt
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.
Neutron standard cross sections in reactor physics - Need and status
International Nuclear Information System (INIS)
Carlson, A.D.
1990-01-01
The design and improvement of nuclear reactors require detailed neutronics calculations. These calculations depend on comprehensive libraries of evaluated nuclear cross sections. Most of the cross sections that form the data base for these evaluations have been measured relative to neutron cross-section standards. The use of these standards can often simplify the measurement process by eliminating the need for a direct measurement of the neutron fluence. The standards are not known perfectly, however; thus the accuracy of a cross-section measurement is limited by the uncertainty in the standard cross section relative to which it is measured. Improvements in a standard cause all cross sections measured relative to that standard to be improved. This is the reason for the emphasis on improving the neutron cross-section standards. The continual process of measurement and evaluation has led to improvements in the accuracy and range of applicability of the standards. Though these improvements have been substantial, this process must continue in order to obtain the high-quality standards needed by the user community
Top quark production cross-section measurements
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 ...
Homogenized group cross sections by Monte Carlo
International Nuclear Information System (INIS)
Van Der Marck, S. C.; Kuijper, J. C.; Oppe, J.
2006-01-01
Homogenized group cross sections play a large role in making reactor calculations efficient. Because of this significance, many codes exist that can calculate these cross sections based on certain assumptions. However, the application to the High Flux Reactor (HFR) in Petten, the Netherlands, the limitations of such codes imply that the core calculations would become less accurate when using homogenized group cross sections (HGCS). Therefore we developed a method to calculate HGCS based on a Monte Carlo program, for which we chose MCNP. The implementation involves an addition to MCNP, and a set of small executables to perform suitable averaging after the MCNP run(s) have completed. Here we briefly describe the details of the method, and we report on two tests we performed to show the accuracy of the method and its implementation. By now, this method is routinely used in preparation of the cycle to cycle core calculations for HFR. (authors)
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.
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.
NNLO jet cross sections by subtraction
Energy Technology Data Exchange (ETDEWEB)
Somogyi, G.; Bolzoni, P. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Trocsanyi, Z. [CERN PH-TH, on leave from University of Debrecen and Institute of Nuclear Research of HAS, H-4001 P.O.Box 51 (Hungary)
2010-08-15
We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] 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.
NNLO jet cross sections by subtraction
International Nuclear Information System (INIS)
Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.
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 Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] 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.
Optical Model and Cross Section Uncertainties
Energy Technology Data Exchange (ETDEWEB)
Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.
2009-10-05
Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.
Covariance Evaluation Methodology for Neutron Cross Sections
Energy Technology Data Exchange (ETDEWEB)
Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.
2008-09-01
We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.
Ji, Ailing; Lou, Peian; Dong, Zongmei; Xu, Chunrong; Zhang, Pan; Chang, Guiqiu; Li, Ting
2018-03-16
To describe the prevalence of alcohol dependence and to explore the relationship between alcohol dependence and newly detected hypertension in China. A multistage stratified cluster sampling method was used to obtain samples from February to June 2013. The Michigan Alcoholism Screening Test was used to estimate alcohol dependence level. A standard questionnaire measured other independent variables. Enumeration data were analyzed using chi-square; quantitative data were analyzed using t-tests. Spearman correlation analysis and multivariate logistic regression analysis were performed to identify the relationship between alcohol dependence and hypertension. The alcohol dependence rate was 11.56%; 22.02% of males (3854/17501) and 1.74% of females (324/18656) were classified as alcohol dependent. The newly detected hypertension rate was 9.46% (3422/36157). Significant associations were found between alcohol dependence levels and blood pressure (P < 0.01). Alcohol dependence was positively correlated with systolic blood pressure (r = 0.071, P < 0.01) and diastolic blood pressure (r = 0.077, P < 0.01) and was an independent risk factor for hypertension after adjusting for confounders (low alcohol dependence: odds ratio [OR] = 1.44, 95% confidence intervals [CI] = 1.14-1.81, P < 0.01; light alcohol dependence: OR = 1.35, 95% CI = 1.11-1.64, P < 0.01; medium alcohol dependence: OR = 1.83, 95% CI = 1.40-2.41, P < 0.01). Alcohol dependence was high and associated with hypertension. Health education and precautions against alcoholism should be implemented in Xuzhou city.
International Nuclear Information System (INIS)
Barabanov, A.L.
1985-01-01
Experimental data on dependence of fission cross section Σsub(f) (epsilon) and angular anisotropy W(epsilon, 0 deg)/W(epsilon, 90 deg) of sup(235)U fission fragment escape by neutrons with energy epsilon=100 and 200 keV on orientation of target nuclei are analyzed. 235 U (Isup(πsub(0))=7/2sup(-)) nuclei were orientated at the expense of interaction of quadrupole nucleus momenta with nonuniform electric field of uranyl-rubidium nitrate crystal at crystal cooling to T=0.2 K. The analysis was carried out with three different sets of permeability factors T(epsilon). Results of the analysis weakly depend on T(epsilon) choice. It is shown that a large number of adjusting parameters (six fissionabilities γsup(f)(Jsup(π), epsilon) and six momenta sub(Jsup(π))) permit to described experimental data on Σsub(f)(epsilon) and W(epsilon, 0 deg)/W(epsilon, 90 deg), obtained at epsilon=200 keV by introducing essential dependence of γsup(f)(Jsup(π), epsilon) and sub(Jsup(π)) on Jsup(π). Estimations of fission cross sections Σsub(f)(epsilon) and angular distribution W(epsilon, n vector) up to T approximately equal to 0.01 K in two geometries of the experiment: the orientation axis is parallel and perpendicular to momentum direction p vector of incident neutrons, are conducted
van Hemel-Ruiter, M.E.; Wiers, R.W.; Brook, F.G.; de Jong, P.J.
2016-01-01
BACKGROUND: Research in adults shows that substance dependent individuals demonstrate attentional bias (AB) for substance-related stimuli. This study investigated the role of AB in adolescents diagnosed with alcohol, cannabis, amphetamine or GHB dependency on entering therapy and six months later,
Ecological Panel Inference from Repeated Cross Sections
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
Stability of tokamaks with elongated cross section
International Nuclear Information System (INIS)
An, C.H.; Bateman, G.
1978-08-01
Fixed boundary n = 1 MHD instabilities are studied computationally as a function of diamagnetism (β/sub pol/) and current profile in elongated toroidal equilibria (1 2) or a diamagnetic plasma (β/sub pol/ > 1) with only a mildly elongated cross section
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
(, 3) Differential cross section of He
Indian Academy of Sciences (India)
The angular distribution of the ﬁve-fold differential cross section for the electron impact double ionization of He (21 ) and He (23 ) has been studied. The kinematical conditions for maxima/minima in the angular distribution for the two cases have been compared. The two-step process for the double ionization is found to ...
Precise relative cross sections for np scattering
International Nuclear Information System (INIS)
Goetz, J.; Brogli-Gysin, C.; Hammans, M.; Haffter, P.; Henneck, R.; Jourdan, J.; Masson, G.; Qin, L.M.; Robinson, S.; Sick, I.; Tuccillo, M.
1994-01-01
We present data on the differential cross section for neutron-proton scattering for an incident neutron energy of 67 MeV. These data allow a precise determination of the 1 P 1 phase which, in phase-shift analyses, is strongly correlated with the S-D amplitude which we are measuring via different observables. ((orig.))
Symmetric charge transfer cross section of uranium
International Nuclear Information System (INIS)
Shibata, Takemasa; Ogura, Koichi
1995-03-01
Symmetric charge transfer cross section of uranium was calculated under consideration of reaction paths. In the charge transfer reaction a d 3/2 electron in the U atom transfers into the d-electron site of U + ( 4 I 9/2 ) ion. The J value of the U atom produced after the reaction is 6, 5, 4 or 3, at impact energy below several tens eV, only resonant charge transfer in which the product atom is ground state (J=6) takes place. Therefore, the cross section is very small (4-5 x 10 -15 cm 2 ) compared with that considered so far. In the energy range of 100-1000eV the cross section increases with the impact energy because near resonant charge transfer in which an s-electron in the U atom transfers into the d-electron site of U + ion. Charge transfer cross section between U + in the first excited state (289 cm -1 ) and U in the ground state was also obtained. (author)
LAMBDA p total cross-section measurement
CERN PhotoLab
1970-01-01
A view of the apparatus used for the LAMBDA p total cross-section measurement at the time of its installation. The hyperons decaying into a proton and a pion in the conical tank in front were detected in the magnet spectrometer in the upper half of the picture. A novel detection technique using exclusively multiwire proportional chambers was employed.
van Hemel-Ruiter, Madelon E; Wiers, Reinout W; Brook, Frank G; de Jong, Peter J
2016-02-01
Research in adults shows that substance dependent individuals demonstrate attentional bias (AB) for substance-related stimuli. This study investigated the role of AB in adolescents diagnosed with alcohol, cannabis, amphetamine or GHB dependency on entering therapy and six months later, and the role of executive control (EC) as a moderator of the relationship between problem severity and AB. Seventy-eight young substance-dependent (SD) patients (mean age=19.5), and 64 healthy controls (HC; mean age=19.0) were tested. Thirty-eight SD patients took part at 6-month follow-up (FU). AB was indexed by a visual probe task, EC by the attention network task, problem severity by the short alcohol (or drug) use disorder identification test and the severity of dependence questionnaire. SD patients demonstrated an AB for substance stimuli presented for 500 ms and 1250 ms, with the latter related to severity of dependence. There was a nonsignificant tendency indicating that EC was higher in HC than SD participants, but EC did not moderate the relationship between AB and dependency. Substance use, dependency, EC and AB remained unchanged in the 6 month FU period. Young SD patients showed a stronger relatively early as well as maintained AB toward substance cues. A stronger maintained attention was related to higher severity of dependence. Further, there were some indications that EC might play a role in adolescent substance use. The finding that at FU AB and problem severity were not decreased, and EC was not increased underlines the persistent character of addiction. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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)
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
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
Van Eck, Richard N.; Fu, Hongxia; Drechsel, Paul V. J.
2015-01-01
Air traffic control (ATC) operations are critical to the U.S. aviation infrastructure, making ATC training a critical area of study. Because ATC performance is heavily dependent on visual processing, it is important to understand how to screen for or promote relevant visual processing abilities. While conventional wisdom has maintained that such…
Phase shifts as functions of the cross section
Atkinson, D.; Kaekebeke, M.; de Roo, M.
1975-01-01
We show that an elastic scattering amplitute may be defined as an implicit function of the differential cross section. A practical method is given for a numerical investigation of this dependence, both in the elastic and in the inelastic regions. In particular, we consider the case of a polynomial
Modelling interaction cross sections for intermediate and low energy ions
International Nuclear Information System (INIS)
Toburen, L.H.; Shinpaugh, J.L.; Justiniano, E.L.B.
2002-01-01
When charged particles slow in tissue they undergo electron capture and loss processes than can have profound effects on subsequent interaction cross sections. Although a large amount of data exists for the interaction of bare charged particles with atoms and molecules, few experiments have been reported for these 'dressed' particles. Projectile electrons contribute to an impact-parameter-dependent screening of the projectile charge that precludes straightforward scaling of energy loss cross sections from those of bare charged particles. The objective of this work is to develop an analytical model for the energy-loss-dependent effects of screening on differential ionisation cross sections that can be used in track structure calculations for high LET ions. As a first step a model of differential ionisation cross sections for bare ions has been combined with a simple screening model to explore cross sections for intermediate and low energy dressed ions in collisions with atomic and molecular gas targets. The model is described briefly and preliminary results compared to measured electron energy spectra. (author)
Directory of Open Access Journals (Sweden)
Víviam Vargas Barros
Full Text Available Dispositional mindfulness can be described as the mental ability to pay attention to the present moment, non-judgmentally. There is evidence of inverse relation between dispositional mindfulness and insomnia and substance use, but as of yet, no studies evaluating the specific association between dispositional mindfulness and the components of hypnotic use disorder.To evaluate the association between dispositional mindfulness and the components of dependence among female chronic hypnotic users.Seventy-six women, chronic users of hypnotics, who resorted to Mindfulness-Based Relapse Prevention for the cessation of hypnotic use were included in the study. The Five Facet Mindfulness Questionnaire (FFMQ evaluated the levels and facets of mindfulness, and the subscales of the Benzodiazepine Dependence Questionnaire (BENDEP assessed dependence on hypnotics. We also evaluated sociodemographic variables and symptoms of insomnia and anxiety. The associations between the FFMQ facets and the BENDEP subscales were evaluated with binomial logistic regression, adjusted for income, schooling, anxiety, and insomnia.We observed associations between facets of the FFMQ and specific aspects of hypnotic dependence. The facet "observing" was inversely associated with the "concern about lack of availability of the hypnotic" [aOR = 0.87 95% CI (0.79-0.97], and the facet "non-reacting to inner experience" with "noncompliance with the prescription recommendations" [aOR = 0.86 95% CI (0.75-0.99]. The total score of the FFMQ was inversely associated to those two dependence subscales [aOR = 0.94 95% CI (0.89-0.99]. "Observing" and "non-reactivity to inner experience" were also inversely associated with the "impairments related to the withdrawal symptoms" [aOR = 0.84 95% CI (0.73-0.97] and [aOR = 0.78 95% CI (0.63-0.96], respectively. The FFMQ was not associated with "awareness of problematic hypnotic use".Dispositional mindfulness, specifically the facets "observing" and "non
Barros, Víviam Vargas; Opaleye, Emérita Sátiro; Demarzo, Marcelo; Bowen, Sarah; Curado, Daniela Fernández; Hachul, Helena; Noto, Ana Regina
2018-01-01
Dispositional mindfulness can be described as the mental ability to pay attention to the present moment, non-judgmentally. There is evidence of inverse relation between dispositional mindfulness and insomnia and substance use, but as of yet, no studies evaluating the specific association between dispositional mindfulness and the components of hypnotic use disorder. To evaluate the association between dispositional mindfulness and the components of dependence among female chronic hypnotic users. Seventy-six women, chronic users of hypnotics, who resorted to Mindfulness-Based Relapse Prevention for the cessation of hypnotic use were included in the study. The Five Facet Mindfulness Questionnaire (FFMQ) evaluated the levels and facets of mindfulness, and the subscales of the Benzodiazepine Dependence Questionnaire (BENDEP) assessed dependence on hypnotics. We also evaluated sociodemographic variables and symptoms of insomnia and anxiety. The associations between the FFMQ facets and the BENDEP subscales were evaluated with binomial logistic regression, adjusted for income, schooling, anxiety, and insomnia. We observed associations between facets of the FFMQ and specific aspects of hypnotic dependence. The facet "observing" was inversely associated with the "concern about lack of availability of the hypnotic" [aOR = 0.87 95% CI (0.79-0.97)], and the facet "non-reacting to inner experience" with "noncompliance with the prescription recommendations" [aOR = 0.86 95% CI (0.75-0.99)]. The total score of the FFMQ was inversely associated to those two dependence subscales [aOR = 0.94 95% CI (0.89-0.99)]. "Observing" and "non-reactivity to inner experience" were also inversely associated with the "impairments related to the withdrawal symptoms" [aOR = 0.84 95% CI (0.73-0.97)] and [aOR = 0.78 95% CI (0.63-0.96)], respectively. The FFMQ was not associated with "awareness of problematic hypnotic use". Dispositional mindfulness, specifically the facets "observing" and "non
Removal cross section for 14 mev neutrons in constructional materials
International Nuclear Information System (INIS)
Vasvary, L.; Divos, F.; Peto, G.; Csikai, J.; Mumba, N.K.
1985-01-01
Using flight time difference the direct and scattered neutrons and gammas produced in the target head and samples were separated. With this method the attenuation of primary neutrons and gammas originating from the target head has been studied. Thickness dependence of the secondary gamma yield from extended samples of Al, Fe, Pb, paraffin and reinforced concrete was also measured. Results indicate a geometry dependence of the removal cross sections
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)
Rotational averaging of multiphoton absorption cross sections
Energy Technology Data Exchange (ETDEWEB)
Friese, Daniel H., E-mail: daniel.h.friese@uit.no; Beerepoot, Maarten T. P.; Ruud, Kenneth [Centre for Theoretical and Computational Chemistry, University of Tromsø — The Arctic University of Norway, N-9037 Tromsø (Norway)
2014-11-28
Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.
Measurements of neutron spallation cross section. 2
Energy Technology Data Exchange (ETDEWEB)
Kim, E.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Imamura, M.; Nakao, N.; Shibata, S.; Uwamino, Y.; Nakanishi, N.; Tanaka, Su.
1997-03-01
Neutron spallation cross section of {sup 59}Co(n,xn){sup 60-x}Co, {sup nat}Cu(n,sp){sup 56}Mn, {sup nat}Cu(n,sp){sup 58}Co, {sup nat}Cu(n,xn){sup 60}Cu, {sup nat}Cu(n,xn){sup 61}Cu and {sup nat}Cu(n,sp){sup 65}Ni was measured in the quasi-monoenergetic p-Li neutron fields in the energy range above 40 MeV which have been established at three AVF cyclotron facilities of (1) INS of Univ. of Tokyo, (2) TIARA of JAERI and (3) RIKEN. Our experimental data were compared with the ENDF/B-VI high energy file data by Fukahori and the calculated cross section data by Odano. (author)
Structured ion impact: Doubly differential cross sections
International Nuclear Information System (INIS)
DuBois, R.D.
1987-01-01
The electron emission in coincidence with a projectile that has been ionized has been measured, thus making it possible to separate and identify electrons resulting from these various mechanisms. In 1985, coincidence doubly differential cross sections were measured for 400 to 750 keV/atomic mass unit (amu) He + impact on He, Ne, Ar, Kr, and H 2 O. Cross sections were measured for selected angles and for electron energies ranging from 10 to 1000 eV. Because of the coincidence mode of measurement, the total electron emission was subdivided into its target emission and its projectile emission components. The most interesting findings were that target ionization does not account for the electron emission spectrum at lower electron energies. A sizable percentage of these low-energy electrons were shown to originate as a result of simultaneous projectile/target ionizations. Similar features were observed for all targets and impact energies that were studied
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.
Absolute partial photoionization cross sections of ethylene
Grimm, F. A.; Whitley, T. A.; Keller, P. R.; Taylor, J. W.
1991-07-01
Absolute partial photoionization cross sections for ionization out of the first four valence orbitals to the X 2B 3u, A 2B 3g, B 2A g and C 2B 2u states of the C 2H 4+ ion are presented as a function of photon energy over the energy range from 12 to 26 eV. The experimental results have been compared to previously published relative partial cross sections for the first two bands at 18, 21 and 24 eV. Comparison of the experimental data with continuum multiple scattering Xα calculations provides evidence for extensive autoionization to the X 2B 3u state and confirms the predicted shape resonances in ionization to the A 2B 3g and B 2A g states. Identification of possible transitions for the autoionizing resonances have been made using multiple scattering transition state calculations on Rydberg excited states.
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...
Test of RIPL-2 cross section calculations
International Nuclear Information System (INIS)
Herman, M.
2002-01-01
The new levels and optical segments and microscopic HF-BCS level densities (part of the density segment) were tested in practical calculations of cross sections for neutron induced reactions on 22 targets (40-Ca, 47-Ti, 52-Cr, 55-Mn, 58-Ni, 63-Cu, 71-Ga, 80-Se, 92-Mo, 93-Nb, 100-Mo, 109-Ag, 114-Cd, 124-Sn, 127-I, 133-Cs, 140-Ce, 153-Eu, 169-Tm, 186-W, 197-Au, 208-Pb). For each target all reactions involving up to 3 neutron, 1 proton and 1 α-particle emissions (subject to actual reaction thresholds) were considered in the incident energy range from 1 keV up to 20 MeV (in some cases up to 27 MeV). In addition, total, elastic, and neutron capture cross sections were calculated
Double differential cross sections of ethane molecule
Kumar, Rajeev
2018-05-01
Partial and total double differential cross sections corresponding to various cations C2H6+, C2H4+, C2H5+, C2H3+, C2H2+, CH3+, H+, CH2+, C2H+, H2+, CH+, H3+, C2+ and C+ produced during the direct and dissociative electron ionization of Ethane (C2H6) molecule have been calculated at fixed impinging electron energies 200 and 500eV by using modified Jain-Khare semi empirical approach. The calculation for double differential cross sections is made as a function of energy loss suffered by primary electron and angle of incident. To the best of my knowledge no other data is available for the comparison.
Cross sections required for FMIT dosimetry
International Nuclear Information System (INIS)
Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.
1980-01-01
The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies
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
New SCALE-4 features related to cross-section processing
International Nuclear Information System (INIS)
Petrie, L.M.; Landers, N.F.; Greene, N.M.; Parks, C.V.
1991-01-01
The SCALE code system has a standardized scheme for processing problem-dependent cross section from problem-independent waste libraries. Some improvements and new capabilities in the processing scheme have been incorporated into the new Version 4 release of the SCALE system. The new features include the capability to consider annular cylindrical and spherical unit cells, and improved Dancoff factor formulation, and changes to the NITAWL-II module to perform resonance self-shielding with reference to infinite dilute values. A review of these major changes in the cross-section processing scheme for SCALE-4 is presented in this paper
Electron collision cross sections and radiation chemistry
International Nuclear Information System (INIS)
Hatano, Y.
1983-01-01
A survey is given of the cross section data needs in radiation chemistry, and of the recent progress in electron impact studies on dissociative excitation of molecules. In the former some of the important target species, processes, and collision energies are presented, while in the latter it is demonstrated that radiation chemistry is a source of new ideas and information in atomic collision research. 37 references, 4 figures
Absolute photoionization cross sections of atomic oxygen
Samson, J. A. R.; Pareek, P. N.
1985-01-01
The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.
Measurements of Fission Cross Sections of Actinides
Wiescher, M; Cox, J; Dahlfors, M
2002-01-01
A measurement of the neutron induced fission cross sections of $^{237}$Np, $^{241},{243}$Am and of $^{245}$Cm is proposed for the n_TOF neutron beam. Two sets of fission detectors will be used: one based on PPAC counters and another based on a fast ionization chamber (FIC). A total of 5x10$^{18}$ protons are requested for the entire fission measurement campaign.
Cross section of the CMS solenoid
Tejinder S. Virdee, CERN
2005-01-01
The pictures show a cross section of the CMS solenoid. One can see four layers of the superconducting coil, each of which contains the superconductor (central part, copper coloured - niobium-titanium strands in a copper coating, made into a "Rutherford cable"), surrounded by an ultra-pure aluminium as a magnetic stabilizer, then an aluminium alloy as a mechanical stabilizer. Besides the four layers there is an aluminium mechanical piece that includes pipes that transport the liquid helium.
Cross sections for multistep direct reactions
International Nuclear Information System (INIS)
Demetriou, Paraskevi; Marcinkowski, Andrzej; Marianski, Bohdan
2002-01-01
Inelastic scattering and charge-exchange reactions have been analysed at energies ranging from 14 to 27 MeV using the modified multistep direct reaction theory (MSD) of Feshbach, Kerman and Koonin. The modified theory considers the non-DWBA matrix elements in the MSD cross section formulae and includes both incoherent particle-hole excitations and coherent collective excitations in the continuum, according to the prescriptions. The results show important contributions from multistep processes at all energies considered. (author)
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
Inclusive jet cross section at D0
International Nuclear Information System (INIS)
Bhattacharjee, M.
1996-09-01
Preliminary measurement of the central (|η| ≤ 0.5) inclusive jet cross sections for jet cone sizes of 1.0, 0.7, and 0.5 at D null based on the 1992-1993 (13.7 pb -1 ) and 1994-1995 (90 pb -1 ) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made
Fully double-logarithm-resummed cross sections
International Nuclear Information System (INIS)
Albino, S.; Bolzoni, P.; Kniehl, B.A.; Kotikov, A.
2011-01-01
We calculate the complete double logarithmic contribution to cross sections for semi-inclusive hadron production in the modified minimal-subtraction (MS-bar) scheme by applying dimensional regularization to the double logarithm approximation. The full double logarithmic contribution to the coefficient functions for inclusive hadron production in e + e - annihilation is obtained in this scheme for the first time. Our result agrees with all fixed order results in the literature, which extend to next-to-next-to-leading order.
Atomic-process cross section data, 1
International Nuclear Information System (INIS)
1974-12-01
Compiled by the Data Study Group, the data are intended for fusion plasma physics research. Cross sections of the latest experimental and theoretic studies cover the processes involving H,D,T as principal plasma materials as well as photons and electrons: emission and absorption of electromagnetic wave, electron collision, ion collision, recombination, neutral atom mutual collision, etc. Edition is so made to enable the future renewal by users. (J.P.N.)
Neutron capture cross section of ^243Am
Jandel, M.
2009-10-01
The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for neutron capture cross section measurement on ^243Am. The high granularity of DANCE (160 BaF2 detectors in a 4π geometry) enables the efficient detection of prompt gamma-rays following neutron capture. DANCE is located on the 20.26 m neutron flight path 14 (FP14) at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE). The methods and techniques established in [1] were used for the determination of the ^243Am neutron capture cross section. The cross sections were obtained in the range of neutron energies from 0.02 eV to 400 keV. The resonance region was analyzed using SAMMY7 and resonance parameters were extracted. The results will be compared to existing evaluations and calculations. Work was performed under the auspices of the U.S. Department of Energy at Los Alamos National Laboratory by the Los Alamos National Security, LLC under Contract No. DE-AC52-06NA25396 and at Lawrence Livermore National Laboratory by the Lawrence Livermore National Security, LLC under Contract No. DE-AC52-07NA27344. [4pt] [1] M. Jandel et al., Phys. Rev. C78, 034609 (2008)
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.
Measurement of actinide neutron cross sections
International Nuclear Information System (INIS)
Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald
2003-01-01
The maintenance of strong scientific expertise is critical to the U.S. nuclear attribution community. It is particularly important to train students in actinide chemistry and physics. Neutron cross-section data are vital components to strategies for detecting explosives and fissile materials, and these measurements require expertise in chemical separations, actinide target preparation, nuclear spectroscopy, and analytical chemistry. At the University of California, Berkeley and the Lawrence Berkeley National Laboratory we have trained students in actinide chemistry for many years. LBNL is a leader in nuclear data and has published the Table of Isotopes for over 60 years. Recently, LBNL led an international collaboration to measure thermal neutron capture radiative cross sections and prepared the Evaluated Gamma-ray Activation File (EGAF) in collaboration with the IAEA. This file of 35, 000 prompt and delayed gamma ray cross-sections for all elements from Z=1-92 is essential for the neutron interrogation of nuclear materials. LBNL has also developed new, high flux neutron generators and recently opened a 1010 n/s D+D neutron generator experimental facility
Quality Quantification of Evaluated Cross Section Covariances
International Nuclear Information System (INIS)
Varet, S.; Dossantos-Uzarralde, P.; Vayatis, N.
2015-01-01
Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the 85 Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations
Total neutron cross section for 181Ta
Directory of Open Access Journals (Sweden)
Schilling K.-D.
2010-10-01
Full Text Available The neutron time of flight facility nELBE, produces fast neutrons in the energy range from 0.1 MeV to 10 MeV by impinging a pulsed relativistic electron beam on a liquid lead circuit [1]. The short beam pulses (∼10 ps and a small radiator volume give an energy resolution better than 1% at 1 MeV using a short flight path of about 6 m, for neutron TOF measurements. The present neutron source provides 2 ⋅ 104 n/cm2s at the target position using an electron charge of 77 pC and 100 kHz pulse repetition rate. This neutron intensity enables to measure neutron total cross section with a 2%–5% statistical uncertainty within a few days. In February 2008, neutron radiator, plastic detector [2] and data acquisition system were tested by measurements of the neutron total cross section for 181Ta and 27Al. Measurement of 181Ta was chosen because lack of high quality data in an anergy region below 700 keV. The total neutron cross – section for 27Al was measured as a control target, since there exists data for 27Al with high resolution and low statistical error [3].
NNLO jet cross sections by subtraction
Somogyi, G.; Bolzoni, P.; Trócsányi, Z.
2010-08-01
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 Refs. [G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 06, 024 (2005), arXiv:hep-ph/0502226; G. Somogyi and Z. Trócsányi, (2006), arXiv:hep-ph/0609041; G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 01, 070 (2007), arXiv:hep-ph/0609042; G. Somogyi and Z. Trócsányi, JHEP 01, 052 (2007), arXiv:hep-ph/0609043] 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.
Multilevel Cross-Dependent Binary Longitudinal Data
Serban, Nicoleta; Staicu, Ana-Maria; Carroll, Raymond J.
2013-01-01
processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic
Directory of Open Access Journals (Sweden)
Baptiste eFAUVEL
2014-10-01
Full Text Available Because of permanent use-dependent cerebral plasticity, all lifelong individuals’ experiences are believed to influence the cognitive aging quality. In old individuals, both former and current musical practices have been associated with better verbal skills, visual memory, processing speed, and planning function. This work sought for an interaction between musical practice and cognitive aging by comparing musician and nonmusician individuals for two periods of life (late adulthood and old age. Long-term memory, auditory verbal short-term memory, processing speed, nonverbal reasoning, and verbal fluencies were assessed. In study 1, measures of processing speed and auditory verbal short-term memory showed significant better performances for musicians compared with controls, but both groups displayed the same age-related difference. For verbal fluencies, musician individuals scored higher and displayed different age effects compared with controls. In study 2, we revealed that the life period at training onset (childhood versus adulthood was associated with phonemic, but not semantic fluency performances (musicians who had started practice in adulthood did not perform better on phonemic fluency compared with nonmusicians. For these two measures, current frequency of training did not account for musicians’ scores. These patterns of results are discussed by confronting the hypothesis of a transformative effect of musical practice with non-causal explanation.
Fauvel, Baptiste; Groussard, Mathilde; Mutlu, Justine; Arenaza-Urquijo, Eider M; Eustache, Francis; Desgranges, Béatrice; Platel, Hervé
2014-01-01
Because of permanent use-dependent brain plasticity, all lifelong individuals' experiences are believed to influence the cognitive aging quality. In older individuals, both former and current musical practices have been associated with better verbal skills, visual memory, processing speed, and planning function. This work sought for an interaction between musical practice and cognitive aging by comparing musician and non-musician individuals for two lifetime periods (middle and late adulthood). Long-term memory, auditory-verbal short-term memory, processing speed, non-verbal reasoning, and verbal fluencies were assessed. In Study 1, measures of processing speed and auditory-verbal short-term memory were significantly better performed by musicians compared with controls, but both groups displayed the same age-related differences. For verbal fluencies, musicians scored higher than controls and displayed different age effects. In Study 2, we found that lifetime period at training onset (childhood vs. adulthood) was associated with phonemic, but not semantic, fluency performances (musicians who had started to practice in adulthood did not perform better on phonemic fluency than non-musicians). Current frequency of training did not account for musicians' scores on either of these two measures. These patterns of results are discussed by setting the hypothesis of a transformative effect of musical practice against a non-causal explanation.
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)
Reaction cross section calculation of some alkaline earth elements
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.
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.
Cross-Sectional Transport Imaging in a Multijunction Solar Cell
Energy Technology Data Exchange (ETDEWEB)
Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard
2015-06-14
Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.
Systematics in total (n,2n) cross sections at 14 MeV
Energy Technology Data Exchange (ETDEWEB)
Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Nuclear Science Labs.
1976-11-20
The 14-15 MeV (n,2n) cross sections are found to depend mainly on the asymmetry parameter and the Q-value. No shell effects are found to exist in these cross sections. The total (n,2n) cross sections are found to be well predicted by an empirical relation which takes into account the Q-value and the asymmetry parameter in addition to the geometrical cross section.
Penning ionization cross sections of excited rare gas atoms
International Nuclear Information System (INIS)
Ukai, Masatoshi; Hatano, Yoshihiko.
1988-01-01
Electronic energy transfer processes involving excited rare gas atoms play one of the most important roles in ionized gas phenomena. Penning ionization is one of the well known electronic energy transfer processes and has been studied extensively both experimentally and theoretically. The present paper reports the deexcitation (Penning ionization) cross sections of metastable state helium He(2 3 S) and radiative He(2 1 P) atoms in collision with atoms and molecules, which have recently been obtained by the authors' group by using a pulse radiolysis method. Investigation is made of the selected deexcitation cross sections of He(2 3 S) by atoms and molecules in the thermal collisional energy region. Results indicate that the cross sections are strongly dependent on the target molecule. The deexcitation probability of He(2 3 S) per collision increases with the excess electronic energy of He(2 3 S) above the ionization potential of the target atom or molecule. Another investigation, made on the deexcitation of He(2 1 P), suggests that the deexcitation cross section for He(2 1 P) by Ar is determined mainly by the Penning ionization cross section due to a dipole-dipole interaction. Penning ionization due to the dipole-dipole interaction is also important for deexcitation of He(2 1 P) by the target molecules examined. (N.K.)
Shang, Suhang; Li, Pei; Deng, Meiying; Jiang, Yu; Chen, Chen; Qu, Qiumin
2016-01-01
Hypertension is a modifiable risk factor for cognitive impairment, although the relationship between hypertension and cognitive impairment is not fully understood. The objective of this study was to investigate the effect of age on the relationship between blood pressure and cognitive impairment. Blood pressure and global cognitive function information was collected from 1799 participants (age 40-85) who lived in a village in the suburbs of Xi'an, China, during in-person interviews. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score lower than the cutoff value. The effect of age on the relationship between blood pressure parameters [systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MABP), and high blood pressure (HBP, SBP≥140 mm Hg and/or DBP≥90 mm Hg)] and cognitive impairment was analyzed by logistic regression models using interaction and stratified analysis. Blood pressure and age were regarded as both continuous and categorical data. A total of 231 participants were diagnosed as having cognitive impairment based on our criteria. Interaction analysis for the total population showed that SBP (when regarded as continuous data) was positively correlated with cognitive impairment (OR = 1.130 [95% CI, 1.028-1.242] per 10mmHg, P = 0.011); however, the age by SBP interaction term was negatively correlated with cognitive impairment (OR = 0.989 [95% CI, 0.982-0.997] per 10mmHg×year, P = 0.006), indicating that the relationship between SBP and cognitive impairment was age-dependent (OR = 1.130×0.989(age-55.5) per 10mmHg,40 ≤age≤85). When the blood pressure and age were considered as binary data, the results were similar to those obtained when they were considered as continuous variables. Stratified multivariate analysis revealed that the relationship between SBP (when regarded as continuous data) and cognitive impairment was positive for patients aged 40-49 years (OR = 1.349 [95% CI: 1
Energy Technology Data Exchange (ETDEWEB)
Gandelman, Miriam Mendes
1992-07-01
In this work the A dependence of the {lambda} and {lambda}{sup -} production cross sections is studied using the E769 data for the 250 GeV/c{pi}{sup -} beam interacting on Be, Cu, Al and W targets. The measured mean value of {alpha} in the region - 0.2 < x{sub f} < 0.3 and p{sub t} < 2 GeV/c is 1.03 {+-} 0.02 for the {lambda} baryon and 1.01 {+-} 0.02 for the {lambda}{sup -}. No difference is measured between the values of {alpha} for {lambda} and {lambda}{sup -}: {alpha} is a global decreasing function of x{sub f} and has no significant variation with p{sub t}. (author). 31 refs, 48 figs, 16 tabs.
Doroszkiewicz, Halina; Sierakowska, Matylda; Muszalik, Marta
2018-01-01
The aim of the study was to evaluate the usefulness of the Polish version of the Care Dependency Scale (CDS) in predicting care needs and health risks of elderly patients admitted to a geriatric unit. This was a cross-sectional study of 200 geriatric patients aged ≥60 years, chronologically admitted to a geriatrics unit in Poland. The study was carried out using the Polish version of the CDS questionnaire to evaluate biopsychosocial needs and the level of care dependency. The mean age of the participating geriatric patients was 81.8±6.6. The mean result of the sum of the CDS index for all the participants was 55.3±15.1. Detailed analysis of the results of evaluation of the respondents' functional condition showed statistically significant differences in the levels of care dependency. Evaluation of the patients' physical performance in terms of the ability to do basic activities of daily living (ADL) and instrumental ADL (I-ADL) showed statistically significant differences between the levels of care dependency. Patients with high dependency were more often prone to pressure ulcers - 13.1±3.3, falls (87.2%), poorer emotional state - 6.9±3.6, mental function - 5.1±2.8, and more often problems with locomotion, vision, and hearing. The results showed that locomotive disability, depression, advanced age, and problem with vision and hearing are connected with increasing care dependency. CDS evaluation of each admitted geriatric patient enables us to predict the care needs and health risks that need to be reduced and the disease states to be improved. CDS evaluation should be accompanied by the use of other instruments and assessments to evaluate pressure ulcer risk, fall risk, and actions toward the improvement of subjective well-being, as well as correction of vision and hearing problems where possible and assistive devices for locomotion.
Mechanized evaluation of neutron cross-sections
International Nuclear Information System (INIS)
Horsley, A.; Parker, J.B.
1967-01-01
The evaluation work to provide accurate and consistent neutron cross-section data for multigroup neutronics calculations is not fully exploiting the available theoretical and experimental results; this has been so particularly since the introduction of on-line data handling techniques enabled experimenters to turn out vast quantities of numbers. This situation can be radically improved only by mechanizing the evaluation processes. Systems such as the SC1SRS tape will not only largely overcome the task of collecting data but will provide speedy access to it; by using computers and graph-plotting machines to tabulate and display this data, the labour of evaluation can be very greatly reduced. With some types of cross-section there is hope that by using modern curve-fitting techniques the actual evaluation and statistical accounting of the data can be performed automatically. Some areas where automatic evaluation would seem likely to succeed are specified and a discussion of the mathematical difficulties incurred, such as the elimination of anomalous data, is given. Particularly promising is the use of splines in the mechanized evaluation of data. Splines are the mathematical analogues of the draughtsman's spline used in drawing smooth curves. Their principal properties are the excellent approximations they give to the derivatives of a function; in contrast to conventional polynomial fitting, this feature ensures good interpolation and, when required, stable extrapolation. Various methods of using splines in data graduation and the problem of marrying these methods to standard statistical procedures are examined. The results of work done at AWRE with cubic splines on the mechanized evaluation of neutron scattering total cross-section and angular distribution data are presented. (author)
LEP vacuum chamber, cross-section
CERN PhotoLab
1983-01-01
Cross-section of the final prototype for the LEP vacuum chamber. The elliptic main-opening is for the beam. The small channel to the left is for the cooling water, to carry away the heat deposited by the synchrotron radiation. The square channel to the right houses the Non-Evaporable Getter (NEG) pump. The chamber is made from extruded aluminium. Its outside is clad with lead, to stop the synchrotron radiation emitted by the beam. For good adherence between Pb and Al, the Al chamber was coated with a thin layer of Ni. Ni being slightly magnetic, some resulting problems had to be overcome. See also 8301153.
Hyperon magnetic moments and total cross sections
International Nuclear Information System (INIS)
Lipkin, H.J.
1982-06-01
The new data on both total cross sections and magnetic moments are simply described by beginning with the additive quark model in an SU(3) limit where all quarks behave like strange quarks and breaking both additivity and SU(3) simultaneously with an additional non-additive mechanism which affects only nonstrange quark contributions. The suggestion that strange quarks behave more simply than nonstrange may provide clues to underlying structure or dynamics. Small discrepancies in the moments are analyzed and shown to provide serious difficulties for most models if they are statistically significant. (author)
Neutron capture cross section of $^{93}$Zr
We propose to measure the neutron capture cross section of the radioactive isotope $^{93}$Zr. This project aims at the substantial improvement of existing results for applications in nuclear astrophysics and emerging nuclear technologies. In particular, the superior quality of the data that can be obtained at n_TOF will allow on one side a better characterization of s-process nucleosynthesis and on the other side a more accurate material balance in systems for transmutation of nuclear waste, given that this radioactive isotope is widely present in fission products.
Fission cross section measurements for minor actinides
Energy Technology Data Exchange (ETDEWEB)
Fursov, B. [IPPE, Obninsk (Russian Federation)
1997-03-01
The main task of this work is the measurement of fast neutron induced fission cross section for minor actinides of {sup 238}Pu, {sup 242m}Am, {sup 243,244,245,246,247,248}Cm. The task of the work is to increase the accuracy of data in MeV energy region. Basic experimental method, fissile samples, fission detectors and electronics, track detectors, alpha counting, neutron generation, fission rate measurement, corrections to the data and error analysis are presented in this paper. (author)
Charge changing cross sections of relativistic uranium
International Nuclear Information System (INIS)
Gould, H.; Greiner, D.; Lindstrom, P.; Symons, T.J.M.; Crawford, H.; Thieberger, P.; Wegner, H.
1984-11-01
We report equilibrium charge state distributions of uranium at energies of 962 MeV/nucleon, 437 MeV/nucleon and 200 MeV/nucleon in low Z and high Z targets and the cross sections for U 92+ reversible U 91+ and U 91+ reversible U 90+ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx. = 5% bare U 92+ at 200 MeV/nucleon and 85% U 92+ at 962 MeV/nucleon. 7 references, 5 figures
Charge changing cross sections of relativistic uranium
Energy Technology Data Exchange (ETDEWEB)
Gould, H; Greiner, D; Lindstrom, P; Symons, T J.M.; Crawford, H; Thieberger, P; Wegner, H
1985-05-15
We report equilibrium charge state distributions of uranium at energies of 962 MeV/nucleon, 437 MeV/nucleon and 200 MeV/nucleon in low Z and high Z targets and the cross sections for U/sup 92 +/reversibleU/sup 91 +/ and U/sup 91 +/reversibleU/sup 90 +/ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx.=5% bare U/sup 92 +/ at 200 MeV/nucleon and 85% U/sup 92 +/ at 962 MeV/nucleon.
Measurement of thermal neutron capture cross section
International Nuclear Information System (INIS)
Huang Xiaolong; Han Xiaogang; Yu Weixiang; Lu Hanlin; Zhao Wenrong
2001-01-01
The thermal neutron capture cross sections of 71 Ga(n, γ) 72 Ga, 94 Zr(n, γ) 95 Zr and 191 Ir(n, γ) 192 Ir m1+g,m2 reactions were measured by using activation method and compared with other measured data. Meanwhile the half-life of 72 Ga was also measured. The samples were irradiated with the neutron in the thermal column of heavy water reactor of China Institute of Atomic Energy. The activities of the reaction products were measured by well-calibrated Ge(Li) detector
Empirical continuation of the differential cross section
International Nuclear Information System (INIS)
Borbely, I.
1978-12-01
The theoretical basis as well as the practical methods of empirical continuation of the differential cross section into the nonphysical region of the cos theta variable are discussed. The equivalence of the different methods is proved. A physical applicability condition is given and the published applications are reviewed. In many cases the correctly applied procedure turns out to provide nonsignificant or even incorrect structure information which points to the necessity for careful and statistically complete analysis of the experimental data with a physical understanding of the analysed process. (author)
L-shell photoelectric cross section measurements
Energy Technology Data Exchange (ETDEWEB)
Arora, S K; Allawadhi, K L; Sood, B S [Punjabi Univ., Patiala (India). Nuclear Science Labs.
1981-05-14
L-shell photoelectric cross sections in Ta, W, Au, Pb, Th and U at 59.5 keV have been determined using three different versions of Sood's method of measuring the absolute yield of fluorescent x-rays when a target is irradiated with a known flux of photons. The results obtained by all the methods agree with one another showing that no hidden systematic errors are involved in the measurements. The present results are found to compare well with the theoretical calculations of Scofield (Lawrence Livermore Laboratory Report No 51326).
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
ZZ SNLRML, Dosimetry Cross-Section Recommendations
International Nuclear Information System (INIS)
1996-01-01
Description of program or function: Format: SAND-II; Number of groups: 640 group SAND-II group structure. Nuclides: Cd, B, Au, S, Ni, Li, F, Na, Mg, Al, Si, P, Sc, Ti, Mn, Fe, Co, Cu, Zn, Zr, Nb, Mo, Rh, Ag, In, I, Th, U, Np, Pu, Am. Origin: ENDF/B-VI, ENDF/B-V, IRDF-90, JENDL-3, JEF 2.2 and GLUCS data with special modifications from private communications. Weighting spectrum: flat. SNLRML is a reactor dosimetry library that draws upon all available evaluated cross section libraries and selects the best evaluation for application to research reactor spectrum determinations. Many of the components of the SNLRML come from the ENDF/B-VI and IRDF-90 (DLC-0161) libraries. The library format was selected for easy interface with spectrum determination codes such as SAND-II (CCC-0112 and LSL-M2 (PSR-233) and the new PSR-0345/SNL/SAND-II has been enhanced to interface with SNLRML. The data is recommended for spectrum determination applications and for the prediction of neutron activation of typical radiation sensor materials. The library has been tested for consistency of the cross section in wide variety of neutron environments. The results and cautions from this testing have been documented. The data has been interfaced with radiation transport codes, such as TWODANT-SYS (CCC-0547) and MCNP (CCC-0200), in order to compare calculated and measured activities for benchmark reactor experiments
Pion production cross sections and associated parameters
International Nuclear Information System (INIS)
Bradbury, J.N.
1985-01-01
Negative pions have been used for radiotherapy at the meson factories LAMPF (USA), SIN (Switzerland), and TRIUMF (Canada) and have been planned for use at new meson facilities under construction (USSR) and at proposed dedicated medical facilities. Providing therapeutically useful dose rates of pions requires a knowledge of the pion production cross sections as a function of primary proton energy (500 to 1000 MeV), pion energy (less than or equal to100 MeV), production angle, and target material. The current status of the data base in this area is presented including theoretical guidelines for extrapolation purposes. The target material and geometry, as well as the proton and pion beam parameters, will affect the electron (and muon) contamination in the beam which may have an important effect on both the LET characteristics of the dose and the dose distribution. In addition to cross-section data, channel characteristics such as length of pion trajectory, solid-angle acceptance, and momentum analysis will affect dose rate, distribution, and quality. Such considerations are briefly addressed in terms of existing facilities and proposed systems. 16 refs., 6 figs
International Nuclear Information System (INIS)
Cacciari, M.; Frixione, S.; Mangano, M.L.; Nason, P.; Ridolfi, G.
2004-01-01
We update the theoretical predictions for the tbar-t production cross-section at the Tevatron, taking into account the most recent determinations of systematic uncertainties in the extraction of the proton parton densities. (author)
Cacciari, M; Mangano, Michelangelo L; Nason, P; Ridolfi, G
2004-01-01
We update the theoretical predictions for the t-tbar production cross-section at the Tevatron, taking into account the most recent determinations of systematic uncertainties in the extraction of the proton parton densities.
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
Status of neutron cross sections for reactor dosimetry
International Nuclear Information System (INIS)
Vlasov, M.F.; Fabry, A.; McElroy, W.N.
1977-03-01
The status of current international efforts to develop standardized sets of evaluated energy-dependent (differential) neutron cross sections for reactor dosimetry is reviewed. The status and availability of differential data are considered, some recent results of the data testing of the ENDF/B-IV dosimetry file using 252 Cf and 235 U benchmark reference neutron fields are presented, and a brief review is given of the current efforts to characterize and identify dosimetry benchmark radiation fields
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
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)
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
Measurement of proton inelastic scattering cross sections on fluorine
Energy Technology Data Exchange (ETDEWEB)
Chiari, M., E-mail: chiari@fi.infn.it [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Caciolli, A. [Department of Physics and Astronomy, University of Padua and INFN Padua, Padova (Italy); Calzolai, G. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Climent-Font, A. [CMAM, Universidad Autonoma de Madrid, Madrid (Spain); Lucarelli, F.; Nava, S. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy)
2016-10-01
Differential cross-sections for proton inelastic scattering on fluorine, {sup 19}F(p,p’){sup 19}F, from the first five excited levels of {sup 19}F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm{sup 2}) evaporated on a self-supporting C thin film (30 μg/cm{sup 2}). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF{sub 2}) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.
Measurement of MA fission cross sections at YAYOI
Energy Technology Data Exchange (ETDEWEB)
Ohkawachi, Yasushi; Ohki, Shigeo; Wakabayashi, Toshio [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center
1998-03-01
Fission cross section ratios of minor actinide nuclides (Am-241, Am-243) relative to U-235 in the fast neutron energy region have been measured using a back-to-back (BTB) fission chamber at YAYOI fast neutron source reactor. A small BTB fission chamber was developed to measure the fission cross section ratios in the center of the core at YAYOI reactor. Dependence of the fission cross section ratios on neutron spectra was investigated by changing the position of the detector in the reactor core. The measurement results were compared with the fission cross sections in the JENDL-3.2, ENDF/B-VI and JEF-2.2 libraries. It was found that calculated values of Am-241 using the JENDL-3.2, ENDF/B-VI and JEF-2.2 data are lower by about 15% than the measured value in the center of the core (the neutron average energy is 1.44E+6(eV)). And, good agreement can be seen the measured value and calculated value of Am-243 using the JENDL-3.2 data in the center of the core (the neutron average energy is 1.44E+6)(eV), but calculated values of Am-243 using the ENDF/B-VI and JEF-2.2 data are lower by 11% and 13% than the measured value. (author)
K sup + nucleus total cross sections
Energy Technology Data Exchange (ETDEWEB)
Sawafta, R.
1990-01-01
The scattering of K{sup +} mesons from nuclei has attracted considerable interest in the last few years. The K{sup +} holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K{sup +} is capable of probing the entire volume of the nucleus. Single scattering of the K{sup +} with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K{sup +} is used to compare the nucleon in the nucleus with a free nucleon.
Differential cross section of atomic hydrogen photoionization
International Nuclear Information System (INIS)
Kondratovich, V.D.; Ostrovskij, V.N.
1986-01-01
Differential cross-section of atomic hydrogen photoeffect in external electric field was investigated in semiclassical approximation. Interference was described. It occurred due to the fact that infinite number of photoelectron trajectories leads to any point of classically accessible motion region. Interference picture can reach macroscopic sizes. The picture is determined by location of function nodes, describing finite electron motion along one of parabolic coordinates. The squares of external picture rings are determined only by electric field intensity in the general case at rather high energies. Quantum expression for photocurrent density was obtained using Green function in superposition of Coulomb and uniform field as well as semiclassical approximation. Possible applications of macroscopic interference picture to specification of atom ionization potentials, selective detection of atoms or particular molecules, as well as weak magnetic field and observation of Aaronov-Bom effect are discussed
Angle-averaged Compton cross sections
International Nuclear Information System (INIS)
Nickel, G.H.
1983-01-01
The scattering of a photon by an individual free electron is characterized by six quantities: α = initial photon energy in units of m 0 c 2 ; α/sub s/ = scattered photon energy in units of m 0 c 2 ; β = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV
Plasma-based radar cross section reduction
Singh, Hema; Jha, Rakesh Mohan
2016-01-01
This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...
ISSUES IN NEUTRON CROSS SECTION COVARIANCES
Energy Technology Data Exchange (ETDEWEB)
Mattoon, C.M.; Oblozinsky,P.
2010-04-30
We review neutron cross section covariances in both the resonance and fast neutron regions with the goal to identify existing issues in evaluation methods and their impact on covariances. We also outline ideas for suitable covariance quality assurance procedures.We show that the topic of covariance data remains controversial, the evaluation methodologies are not fully established and covariances produced by different approaches have unacceptable spread. The main controversy is in very low uncertainties generated by rigorous evaluation methods and much larger uncertainties based on simple estimates from experimental data. Since the evaluators tend to trust the former, while the users tend to trust the latter, this controversy has considerable practical implications. Dedicated effort is needed to arrive at covariance evaluation methods that would resolve this issue and produce results accepted internationally both by evaluators and users.
Partial cross sections in H- photodetachment
International Nuclear Information System (INIS)
Halka, M.
1993-04-01
This dissertation reports experimental measurements of partial decay cross sections in the H - photodetachment spectrum. Observed decays of the 1 P 0 H -** (n) doubly-excitedresonances to the H(N=2) continuum are reported for n=2,3, and 4 from 1990 runs in which the author participated. A recent analysis of 1989 data revealing effects of static electric fields on the partial decay spectrum above 13.5 eV is also presented. The experiments were performed at the High Resolution Atomic Beam Facility. the Los Alamos Meson Physics Facility, with a relativistic H - beam (β=0.842)intersecting a ND:YAG laser. Variation of the intersection angle amounts to Doppler-shifting the photon energy, allowing continuous tuning of the laser energy as viewed from the moving ions' frame
Angle-averaged Compton cross sections
Energy Technology Data Exchange (ETDEWEB)
Nickel, G.H.
1983-01-01
The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.
Electroweak Boson Cross-Section Measurements
The ATLAS collaboration
2009-01-01
This report summarises the ATLAS prospects for the measurement of W and Z pro- duction cross-section at the LHC. The electron and muon decay channels are considered. Focusing on the early data taking phase, strategies are presented that allow a fast and robust extraction of the signals. An overall uncertainty of about 5% can be achieved with 50 pb−1 in the W channels, where the background uncertainty dominates (the luminosity measurement uncertainty is not discussed here). In the Z channels, the expected preci- sion is 3%, the main contribution coming from the lepton selection efﬁciency uncertainty. Extrapolating to 1 fb−1 , the uncertainties shrink to incompressible values of 1-2%, de- pending on the ﬁnal state. This irreducible uncertainty is essentially driven by strong interaction effects, notably parton distribution uncertainties and non-perturbative effects, affecting the W and Z rapidity and transverse momentum distributions. These effects can be constrained by measuring these distributions. Al...
Reaction cross section for Ne isotopes
International Nuclear Information System (INIS)
Panda, R.N.; Sahu, B.K.; Patra, S.K.
2012-01-01
In the present contribution, first the bulk properties are calculated, such as binding energy (BE), root mean square charge radius r ch , matter radius r m and quadrupole deformation parameter β 2 for 18-32 Ne isotopes in the Relativistic mean field (RMF) and effective field theory motivated RMF (E-RMF) formalisms . Then the total nuclear reaction cross section σR is analyzes for the scattering of 20 Ne and 28-32 Ne from a 12 C target at 240 MeV/nucleon by using the RMF model. Thus the objective of the present study is to calculate the bulk properties as well as a systematic analysis of σR over a range of neutron rich nuclei in the frame work of Glauber model
Topological supersymmetric structure of hadron cross sections
International Nuclear Information System (INIS)
Gauron, P.; Nicolescu, B.; Ouvry, S.
1980-12-01
Recently a way of fully implementing unitarity in the framework of a Dual Topological Unitarization theory, including not only mesons but also baryons, was found. This theory consists in the topological description of hadron interactions involving confined quarks in terms of two 2-dimensional surfaces (a closed 'quantum' surface and a bounded 'classical' surface). We show that this description directly leads, at the zeroth order of the topological expansion, to certain relations between hadron cross-sections, in nice agreement with experimental data. A new topological suppression mechanism is shown to play an important dynamical role. We also point out a new topological supersymmetry property, which leads to realistic experimental consequences. A possible topological origin of the rho and ω universality relations emerges as a by-product of our study
Neutron scattering cross sections of uranium-238
International Nuclear Information System (INIS)
Beghian, L.E.; Kegel, G.H.R.; Marcella, T.V.; Barnes, B.K.; Couchell, G.P.; Egan, J.J.; Mittler, A.; Pullen, D.J.; Schier, W.A.
1979-01-01
The University of Lowell high-resolution time-of-flight spectrometer was used to measure angular distributions and 90-deg excitation functions for neutrons scattered from 238 U in the energy range from 0.9 to 3.1 MeV. This study was limited to the elastic and the first two inelastic groups, corresponding to states of 238 U at 45 keV (2 + ) and 148 keV (4 + ). Angular distributions were measured at primary neutron energies of 1.1, 1.9, 2.5, and 3.1 MeV for the same three neutron groups. Whereas the elastic data are in fair agreement with the evaluation in the ENDF/B-IV file, there is substantial disagreement between the inelastic measurements and the evaluated cross sections. 12 figures
Directory of Open Access Journals (Sweden)
Doroszkiewicz H
2018-05-01
Full Text Available Halina Doroszkiewicz,1 Matylda Sierakowska,2 Marta Muszalik3 1Department of Geriatrics, Medical University of Bialystok, Bialystok, Poland; 2Department of Integrated Medical Care, Medical University of Bialystok, Bialystok, Poland; 3Department and Clinic of Geriatrics, Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland Objective: The aim of the study was to evaluate the usefulness of the Polish version of the Care Dependency Scale (CDS in predicting care needs and health risks of elderly patients admitted to a geriatric unit.Methods: This was a cross-sectional study of 200 geriatric patients aged ≥60 years, chronologically admitted to a geriatrics unit in Poland. The study was carried out using the Polish version of the CDS questionnaire to evaluate biopsychosocial needs and the level of care dependency.Results: The mean age of the participating geriatric patients was 81.8±6.6. The mean result of the sum of the CDS index for all the participants was 55.3±15.1. Detailed analysis of the results of evaluation of the respondents’ functional condition showed statistically significant differences in the levels of care dependency. Evaluation of the patients’ physical performance in terms of the ability to do basic activities of daily living (ADL and instrumental ADL (I-ADL showed statistically significant differences between the levels of care dependency. Patients with high dependency were more often prone to pressure ulcers – 13.1±3.3, falls (87.2%, poorer emotional state – 6.9±3.6, mental function – 5.1±2.8, and more often problems with locomotion, vision, and hearing. The results showed that locomotive disability, depression, advanced age, and problem with vision and hearing are connected with increasing care dependency.Conclusion: CDS evaluation of each admitted geriatric patient enables us to predict the care needs and health risks that need to be reduced and the disease states to be improved. CDS
Fission cross-section normalization problems
International Nuclear Information System (INIS)
Wagemans, C.; Ghent Rijksuniversiteit; Deruytter, A.J.
1983-01-01
The present measurements yield σsub(f)-data in the neutron energy from 20 MeV to 30 keV directly normalized in the thermal region. In the keV-region these data are consistent with the absolute σsub(f)-measurements of Szabo and Marquette. For the secondary normalization integral I 2 values have been obtained in agreement with those of Gwin et al. and Czirr et al. which were also directly normalized in the thermal region. For the I 1 integral, however, puzzling low values have been obtained. This was also the case for σsub(f)-bar in neutron energy intervals containing strong resonances. Three additional measurements are planned to further investigate these observations: (i) maintaining the actual approx.2π-geometry but using a 10 B-foil for the neutron flux detection (ii) using a low detection geometry with a 10 B- as well as a 6 Li-flux monitor. Only after these measurements definite conclusions on the I 1 and I 2 integrals can be formulated and final σsub(f)-bar-values can be released. The present study also gives some evidence for a correlation between the integral I 2 and the neutron flux monitor used. The influence of a normalization via I 1 or I 2 on the final cross-section has been shown. The magnitude of possible normalization errors is illustrated. Finally, since 235 U is expected to be an ''easy'' nucleus (low α-activity high σsub(f)-values), there are some indications that the important discrepancies still present in 235 U(n,f) cross-section measurements might partially be due to errors in the neutron flux determination
Electron capture cross sections by O+ from atomic He
International Nuclear Information System (INIS)
Joseph, Dwayne C; Saha, Bidhan C
2009-01-01
The adiabatic representation is used in both the quantal and semi classical molecular orbital close coupling methods (MOCC) to evaluate charge exchange cross sections. Our results show good agreement with experimental cross sections
Electron capture cross sections by O+ from atomic He
Joseph, Dwayne C.; Saha, Bidhan C.
2009-11-01
The adiabatic representation is used in both the quantal and semi classical molecular orbital close coupling methods (MOCC) to evaluate charge exchange cross sections. Our results show good agreement with experimental cross sections
Single-level resonance parameters fit nuclear cross-sections
Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.
1970-01-01
Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.
Total and ionization cross sections of electron scattering by fluorocarbons
International Nuclear Information System (INIS)
Antony, B K; Joshipura, K N; Mason, N J
2005-01-01
Electron impact total cross sections (50-2000 eV) and total ionization cross sections (threshold to 2000 eV) are calculated for typical plasma etching molecules CF 4 , C 2 F 4 , C 2 F 6 , C 3 F 8 and CF 3 I and the CF x (x 1-3) radicals. The total elastic and inelastic cross sections are determined in the spherical complex potential formalism. The sum of the two gives the total cross section and the total inelastic cross section is used to calculate the total ionization cross sections. The present total and ionization cross sections are found to be consistent with other theories and experimental measurements, where they exist. Our total cross section results for CF x (x = 1-3) radicals presented here are first estimates on these species
Mid-IR Absorption Cross-Section Measurements of Hydrocarbons
Alrefae, Majed Abdullah
2013-01-01
-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform
Electron-impact-excitation cross sections of hydrogenlike ions
International Nuclear Information System (INIS)
Fisher, V.I.; Ralchenko, Y.V.; Bernshtam, V.A.; Goldgirsh, A.; Maron, Y.; Vainshtein, L.A.; Bray, I.; Golten, H.
1997-01-01
Convergent close-coupling (CCC) and Coulomb-Born with exchange and normalization (CBE) methods are used to study electron-impact excitation of hydrogenlike ions. The nl→n ' l ' cross sections demonstrate (i) good agreement between the CCC and CBE results, (ii) a scaling over ion nuclear charge z, (iii) a domination of the dipole (l ' =l±1) contributions in total n→n ' cross sections, and (iv) significant effect of electron exchange in the energy range x n,n ' ). For ions with z>5 the n→n ' cross sections obtained in the CCC and CBE approximations agree with each other to better than 10% for any x. An accuracy of the cross sections scaling over z 4 depends on z: for z=6 endash 18 the scaling is accurate to better than 10% (quantitative analysis is done for n ' 4 scaling more significantly (at x about unity). The n→n ' cross sections are presented by a formula which fits our CCC and CBE results with an accuracy to better than 10% (for transitions with n ' 5). The new Gaunt factor G(x) suggested for the widely used Van Regemorter formula [Astrophys. J. 136, 906 (1962)] makes this formula accurate to better than 50% in the x>3 range and to better than 20% in the x>100 range. It is shown that the semiempirical formula by Vainshtein, Sobelman, and Yukov provides an accuracy to better than 50% for any incident electron energy. For x<2 this formula is accurate to better than 30%. These accuracy assessments are based on a comparison with our CCC and CBE results. copyright 1997 The American Physical Society
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
Effective cross sections of U-235 and Au in a TRIGA-type reactor core
International Nuclear Information System (INIS)
Harasawa, S.; Auu, G.A.
1992-01-01
The dependence of effective cross sections of gold and uranium for neutron spectrum in Rikkyo University Reactor (TRIGA Mark- II, RUR) fuel cell was studied using computer calculations. The dependence of thermal neutron spectrum with temperature was also investigated. The effective cross section of gold in water of the fuel cell at 32degC was 90.3 barn and the fission cross section of U-235, 483 barn. These two values are similar to the cross sections for neutron energy of 0.034 eV. (author)
Extinction cross-section suppression and active acoustic invisibility cloaking
Mitri, F. G.
2017-10-01
Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility.
Extinction cross-section suppression and active acoustic invisibility cloaking
International Nuclear Information System (INIS)
Mitri, F G
2017-01-01
Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility. (letter)
Performance of Traffic Noise Barriers with Varying Cross-Section
Directory of Open Access Journals (Sweden)
Sanja Grubeša
2011-05-01
Full Text Available The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM. Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.
Integral bounds for N-body total cross sections
International Nuclear Information System (INIS)
Osborn, T.A.; Bolle, D.
1979-01-01
We study the behavior of the total cross sections in the three- and N-body scattering problem. Working within the framework of the time-dependent two-Hilbert space scattering theory, we give a simple derivation of integral bounds for the total cross section for all processes initiated by the collision of two clusters. By combining the optical theorem with a trace identity derived by Jauch, Sinha, and Misra, we find, roughly speaking, that if the local pairwise interaction falls off faster than r -3 , then sigma/sub tot/(E) must decrease faster than E/sup -1/2/ at high energy. This conclusion is unchanged if one introduces a class of well-behaved three-body interactions
Electron attachment cross sections obtained from electron attachment spectroscopy
International Nuclear Information System (INIS)
Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.
1988-01-01
Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)
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)
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
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
International Nuclear Information System (INIS)
Guryn, W.
1998-02-01
The authors are describing an experiment to study proton-proton (pp) elastic scattering experiment at the Relativistic Heavy Ion Collider (RHIC). Using both polarized and unpolarized beams, the experiment will study pp elastic scattering from √s = 50 GeV to √s = 500 GeV in two kinematical regions. In the Coulomb Nuclear Interference (CNI) region, 0.0005 2 , they will measure and study the s dependence of the total and elastic cross sections, σ tot and σ el ; the ratio of the real to the imaginary part of the forward elastic scattering amplitude, ρ; and the nuclear slope parameter of the pp elastic scattering, b. In the medium |t|-region, |t| 2 , they plan to study the evolution of the dip structure with s, as observed at ISR in the differential elastic cross section, dσ el /dt, and the s and |t| dependence of b. With the polarized beams the following can be measured: the difference in the total cross sections as function of initial transverse spin states Δσ T , the analyzing power, A N , and the transverse spin correlation parameter A NN . The behavior of the analyzing power A N at RHIC energies in the dip region of dσ el /dt, where a pronounced structure was found at fixed-target experiments will be studied. The relation of pp elastic scattering to the beam polarization measurement at RHIC is also discussed
International Nuclear Information System (INIS)
Guryn, W.
1995-01-01
The author is describing an experiment to study proton-proton (pp) elastic scattering experiment at the Relativistic Heavy Ion Collider (RHIC). Using both polarized and unpolarized beams, the experiment will study pp elastic scattering from √s = 60 GeV to √s = 500 GeV in two kinematical regions .In the Coulomb Nuclear Interference (CNI) region, 0.0005 2 , we will measure and study the s dependence of the total and elastic cross sections, σ tot and σ el ; the ratio of the real to the imaginary part of the forward elastic scattering amplitude, ρ; and the nuclear slope parameter of the pp elastic scattering, b. In the medium |t|, |t| ≤ 1.5 (GeV/c) 2 , we plan to study the evolution of the dip structure with s, as observed at ISR in the differential elastic cross section, dσ el /dt, and the s and |t| dependence of b. With the polarized beams the following can be measured: the difference in the total cross sections as function of initial transverse spin stated Δσ T , the analyzing power, A N , and the transverse spin correlation parameter A NN . The behavior of the analyzing power A N at RHIC energies in the dip region of dσ el /dt, where a pronounced structure was found at fixed-target experiments will be studied
Accurate measurements of neutron activation cross sections
International Nuclear Information System (INIS)
Semkova, V.
1999-01-01
The applications of some recent achievements of neutron activation method on high intensity neutron sources are considered from the view point of associated errors of cross sections data for neutron induced reaction. The important corrections in -y-spectrometry insuring precise determination of the induced radioactivity, methods for accurate determination of the energy and flux density of neutrons, produced by different sources, and investigations of deuterium beam composition are considered as factors determining the precision of the experimental data. The influence of the ion beam composition on the mean energy of neutrons has been investigated by measurement of the energy of neutrons induced by different magnetically analysed deuterium ion groups. Zr/Nb method for experimental determination of the neutron energy in the 13-15 MeV energy range allows to measure energy of neutrons from D-T reaction with uncertainty of 50 keV. Flux density spectra from D(d,n) E d = 9.53 MeV and Be(d,n) E d = 9.72 MeV are measured by PHRS and foil activation method. Future applications of the activation method on NG-12 are discussed. (author)
[Fast neutron cross section measurements]: Progress report
International Nuclear Information System (INIS)
1988-01-01
As projected in our previous proposal, the past year on the cross section project at the University of Michigan has been one primarily of construction and assembly of our 14 MeV pulsed Neutron Facility. All the components of the system have now been either purchased or fabricated in our shop facilities and have been assembled in their final configuration. We are now in the process of testing the rf components that have been designed to deliver voltage to both the pulser and buncher stages. We expect that the system will be operational by the end of the current contract year. We have also accomplished the design and construction of several other major pieces of equipment that are needed to begin fast neutron time-of-flight measurements. These include the primary proton recoil detector, and a californium fission chamber needed in the efficiency calibration of the primary detector. We have also added considerable concrete shielding designed to lower the neutron background in the experimental area. 10 figs., 5 tabs
Neutron cross section measurements at ORELA
International Nuclear Information System (INIS)
Dabbs, J.W.T.
1979-01-01
ORELA (Oak Ridge Electron Linear Accelerator) has been for the last decade the most powerful and useful pulsed neutron time-of-flight facility in the world, particularly in the broad midrange of neutron energies (10 eV to 1 MeV). This position will be enhanced with the addition of a pulse narrowing prebuncher, recently installed and now under test. Neutron capture, fission, scattering, and total cross sections are measured by members of the Physics and Engineering Physics Divisions of ORNL, and by numerous guests and visitors. Several fundamental and applied measurements are described, with some emphasis on instrumentation used. The facility comprises the accelerator and its target(s), 10 evacuated neutron flight paths having 18 measurement stations at flight path distances 8.9 to 200 meters, and a complex 4-computer data acquisition system capable of handling some 17,000 32-bit events/s from a total of 12 data input ports. The system provides a total of 2.08 x 10 6 words of data storage on 3 fast disk units. In addition, a dedicated PDP-10 timesharing system with a 250-megabyte disk system and 4 PDP-15 graphic display satellites permits on-site data reduction and analysis. More than 10 man-years of application software development supports the system, which is used directly by individual experiments. 12 figures, 1 table
Resonance capture cross section of 207Pb
Domingo-Pardo, C.; Aerts, G.; Alvarez-Pol, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Bisterzo, S.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Dolfini, R.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fitzpatrick, L.; Frais-Koelbl, H.; Fujii, K.; Furman, W.; Gallino, R.; Goncalves, I.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Kadi, Y.; Kappeler, F.; Karamanis, D.; Karadimos, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krticka, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; Oshima, M.; O'Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.
2006-01-01
The radiative neutron capture cross section of 207Pb has been measured at the CERN neutron time of flight installation n_TOF using the pulse height weighting technique in the resolved energy region. The measurement has been performed with an optimized setup of two C6D6 scintillation detectors, which allowed us to reduce scattered neutron backgrounds down to a negligible level. Resonance parameters and radiative kernels have been determined for 16 resonances by means of an R-matrix analysis in the neutron energy range from 3 keV to 320 keV. Good agreement with previous measurements was found at low neutron energies, whereas substantial discrepancies appear beyond 45 keV. With the present results, we obtain an s-process contribution of 77(8)% to the solar abundance of 207Pb. This corresponds to an r-process component of 23(8)%, which is important for deriving the U/Th ages of metal poor halo stars.
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
Female medical leadership: cross sectional study.
Kvaerner, K J; Aasland, O G; Botten, G S
1999-01-09
To assess the relation between male and female medical leadership. Cross sectional study on predictive factors for female medical leadership with data on sex, age, specialty, and occupational status of Norwegian physicians. Oslo, Norway. 13 844 non-retired Norwegian physicians. Medical leaders, defined as physicians holding a leading position in hospital medicine, public health, academic medicine, or private health care. 14.6% (95% confidence interval 14.0% to 15.4%) of the men were leaders compared with 5.1% (4.4% to 5.9%) of the women. Adjusted for age men had a higher estimated probability of leadership in all categories of age and job, the highest being in academic medicine with 0.57 (0.42 to 0.72) for men aged over 54 years compared with 0.39 (0.21 to 0.63) for women in the same category. Among female hospital physicians there was a positive relation between the proportion of women in their specialty and the probability of leadership. Women do not reach senior positions as easily as men. Medical specialties with high proportions of women have more female leaders.
New resonance cross section calculational algorithms
International Nuclear Information System (INIS)
Mathews, D.R.
1978-01-01
Improved resonance cross section calculational algorithms were developed and tested for inclusion in a fast reactor version of the MICROX code. The resonance energy portion of the MICROX code solves the neutron slowing-down equations for a two-region lattice cell on a very detailed energy grid (about 14,500 energies). In the MICROX algorithms, the exact P 0 elastic scattering kernels are replaced by synthetic (approximate) elastic scattering kernels which permit the use of an efficient and numerically stable recursion relation solution of the slowing-down equation. In the work described here, the MICROX algorithms were modified as follows: an additional delta function term was included in the P 0 synthetic scattering kernel. The additional delta function term allows one more moments of the exact elastic scattering kernel to be preserved without much extra computational effort. With the improved synthetic scattering kernel, the flux returns more closely to the exact flux below a resonance than with the original MICROX kernel. The slowing-down calculation was extended to a true B 1 hyperfine energy grid calculatn in each region by using P 1 synthetic scattering kernels and tranport-corrected P 0 collision probabilities to couple the two regions. 1 figure, 6 tables
Neutron cross section libraries for analysis of fusion neutronics experiments
International Nuclear Information System (INIS)
Kosako, Kazuaki; Oyama, Yukio; Maekawa, Hiroshi; Nakamura, Tomoo
1988-03-01
We have prepared two computer code systems producing neutron cross section libraries to analyse fusion neutronics experiments. First system produces the neutron cross section library in ANISN format, i.e., the multi-group constants in group independent format. This library can be obtained by using the multi-group constant processing code system MACS-N and the ANISN format cross section compiling code CROKAS. Second system is for the continuous energy cross section library for the MCNP code. This library can be obtained by the nuclear data processing system NJOY which generates pointwise energy cross sections and the cross section compiling code MACROS for the MCNP library. In this report, we describe the production procedures for both types of the cross section libraries, and show six libraries with different conditions in ANISN format and a library for the MCNP code. (author)
Bowers, Katherine; Dolan, Lawrence M; Deka, Ranjan; Jackson, Chandra L; Khoury, Jane C
2018-01-01
Objectives Despite improvements in treatment modalities, large-for-gestational age (LGA) prevalence has remained between 30% and 40% among infants of mothers with type 1 insulin-dependent diabetes mellitus (TIDM). Our objective was to estimate LGA prevalence and examine the association between gestational weight gain (GWG) and prepregnancy body mass index (BMI) with LGA among mothers with TIDM. Design Cross-sectional study. Setting Regional data in Cincinnati, Ohio, from the Diabetes in Pregnancy Program Project (PPG), a prospective cohort for the period 1978–1993; national data from Consortium on Safe Labor (CSL), a multicentre cross-sectional study for the period 2002–2008. Participants The study included 333 pregnancies in the PPG and 358 pregnancies in the CSL. Pregnancies delivered prior to 23 weeks’ gestation were excluded. Women with TIDM in the PPG were identified according to physician confirmation of ketoacidosis, and/or c-peptide levels, and by International Classification of Diseases, ninth version codes within the CSL. LGA was identified as birth weight >90th percentile according to gestational age, race and sex. Main outcome measures LGA at birth. Results Mean±SD maternal age at delivery was 26.4±5.1 years for PPG women and 27.5±6.0 years for CSL women, p=0.008. LGA prevalence did not significantly differ between cohorts (PPG: 40.2% vs CSL: 36.6%, p=0.32). More women began pregnancy as overweight in the later cohort (PPG (16.8%) vs CSL (27.1%), pIOM) guidelines was higher in the later CSL (56.2%) vs PPG (42.3%) cohort, pIOM guidelines had a lower LGA prevalence in CSL (PPG: 30.6% vs CSL: 13.7%), p=0.001. Conclusions Normal-weight women with GWG within IOM guidelines experienced a lower LGA prevalence, supporting the importance of adherence to IOM guidelines for GWG to reduce LGA. High BMI and GWG may be hindering a reduction in LGA prevalence. PMID:29602844
Preparation of next generation set of group cross sections. 3
International Nuclear Information System (INIS)
Kaneko, Kunio
2002-03-01
This fiscal year, based on the examination result about the evaluation energy range of heavy element unresolved resonance cross sections, the upper energy limit of the energy range, where ultra-fine group cross sections are produced, was raised to 50 keV, and an improvement of the group cross section processing system was promoted. At the same time, reflecting the result of studies carried out till now, a function producing delayed neutron data was added to the general-purpose group cross section processing system , thus the preparation of general purpose group cross section processing system has been completed. On the other hand, the energy structure, data constitution and data contents of next generation group cross section set were determined, and the specification of a 151 groups next generation group cross section set was defined. Based on the above specification, a concrete library format of the next generation cross section set has been determined. After having carried out the above-described work, using the general-purpose group cross section processing system , which was complete in this study, with use of the JENDL-3. 2 evaluated nuclear data, the 151 groups next generation group cross section of 92 nuclides and the ultra fine group resonance cross section library for 29 nuclides have been prepared. Utilizing the 151 groups next generation group cross section set and the ultra-fine group resonance cross-section library, a bench mark test calculation of fast reactors has been performed by using an advanced lattice calculation code. It was confirmed, by comparing the calculation result with a calculation result of continuous energy Monte Carlo code, that the 151 groups next generation cross section set has sufficient accuracy. (author)
ROBERTS, DA; BECCHETTI, FD; BROWN, JA; JANECKE, J; PHAM, K; ODONNELL, TW; WARNER, RE; RONNINGEN, RM; WILSCHUT, HW
1995-01-01
A primary O-17 beam has been used to produce a 22.3 MeV/nucleon F-18(m) isomeric secondary beam via a single nucleon transfer reaction on a carbon target. The total nuclear reaction cross sections for F-18(m) and F-18(g.s.) in silicon were measured in a stack of seven silicon solid-state detectors.
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
Energy and angle differential cross sections for the electron-impact double ionization of helium
International Nuclear Information System (INIS)
Colgan, James P.; Pindzola, M.S.; Robicheaux, F.
2008-01-01
Energy and angle differential cross sections for the electron-impact double ionization of helium are calculated using a non-perturbative time-dependent close-coupling method. Collision probabilities are found by projection of a time evolved nine dimensional coordinate space wave function onto fully antisymmetric products of spatial and spin functions representing three outgoing Coulomb waves. At an incident energy of 106 eV, we present double energy differential cross sections and pentuple energy and angle differential cross sections. The pentuple energy and angle differential cross sections are found to be in relative agreement with the shapes observed in recent (e,3e) reaction microscope experiments. Integration of the differential cross sections over all energies and angles yields a total ionization cross section that is also in reasonable agreement with absolute crossed-beams experiments.
Sensitivity of LWR fuel cycle costs to uncertainties in detailed thermal cross sections
International Nuclear Information System (INIS)
Ryskamp, J.M.; Becker, M.; Harris, D.R.
1979-01-01
Cross sections averaged over the thermal energy (< 1 or 2 eV) group have been shown to have an important economic role for light-water reactors. Cost implications of thermal cross section uncertainties at the few-group level were reported earlier. When it has been determined that costs are sensitive to a specific thermal-group cross section, it becomes desirable to determine how specific energy-dependent cross sections influence fuel cycle costs. Multigroup cross-section sensitivity coefficients vary with fuel exposure. By changing the shape of a cross section displayed on a view-tube through an interactive graphics system, one can compute the change in few-group cross section using the exposure dependent sensitivity coefficients. With the changed exposure dependent few-group cross section, a new fuel cycle cost is computed by a sequence of batch depletion, core analysis, and fuel batch cost code modules. Fuel cycle costs are generally most sensitive to cross section uncertainties near the peak of the hardened Maxwellian flux
Mid-IR Absorption Cross-Section Measurements of Hydrocarbons
Alrefae, Majed Abdullah
2013-05-01
helium-neon (HeNe) laser at 3.39 μm is used to measure the absorption cross-section of the fuels mentioned above. The dependence on temperature, pressure and bath gas (helium, argon and nitrogen) is also examined. The temperature and pressure ranges of this study are 296 – 800 K and 250 – 1000 Torr, respectively. These are the first measured cross-sections at HeNe laser wavelength that are applicable at combustion-relevant conditions.
Microscopic description of production cross sections including deexcitation effects
Sekizawa, Kazuyuki
2017-07-01
Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable. Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compound-nucleus deexcitation model, GEMINI++. Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using the particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wave function after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely used grazing calculations. Results: The method is applied to describe cross sections for multinucleon transfer processes in 40Ca+124Sn (Ec .m .≃128.54 MeV ), 48Ca+124Sn (Ec .m .≃125.44 MeV ), 40Ca+208Pb (Ec .m .≃208.84 MeV ), 58Ni+208Pb (Ec .m .≃256.79 MeV ), 64Ni+238U (Ec .m .≃307.35 MeV ), and 136Xe+198Pt (Ec .m .≃644.98 MeV ) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in grazing calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one proton, compared to the grazing
Partial radiative recombination cross sections for excited states of hydrogen
International Nuclear Information System (INIS)
Fazio, P.M.
1984-01-01
In calculating the radiative recombination cross sections for interstellar H II regions, usually only the electric dipole term in the expansion of the interaction Hamiltonian is kept. The dipole and quadrupole transition strengths in closed analytical form are calculated here using the Coulomb wave functions because results for any electron energy and for recombination into any angular momentum state of hydrogen are needed. Several interesting effects are found. First, the transition probabilities are maximum for recombination into specific intermediate angular momentum states at low energies (w < 2eV) and where the free state angular momentum is greater than that of the bound state. Further, that specific intermediate angular momentum state depends on the kinetic energy of the free electron. This behavior is in contrast to the normal behavior of the transition strengths where recombination into s states is greatest and decreases with increasing angular momentum. Second, the quadrupole matrix elements vanish for certain velocities of the free electron. This leads to minima in the corresponding quadrupole cross sections when plotted as a function of the free electron's kinetic energy. Finally, the partial cross sections for highly excited states are greater than previously calculated because of the additional effects of the quadrupole transitions
Fission fragment angular distributions and fission cross section validation
International Nuclear Information System (INIS)
Leong, Lou Sai
2013-01-01
The present knowledge of angular distributions of neutron-induced fission is limited to a maximal energy of 15 MeV, with large discrepancies around 14 MeV. Only 238 U and 232 Th have been investigated up to 100 MeV in a single experiment. The n-TOF Collaboration performed the fission cross section measurement of several actinides ( 232 Th, 235 U, 238 U, 234 U, 237 Np) at the n-TOF facility using an experimental set-up made of Parallel Plate Avalanche Counters (PPAC), extending the energy domain of the incident neutron above hundreds of MeV. The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. I will show the methods we used to reconstruct the full angular resolution by the tracking of fission fragments. Below 10 MeV our results are consistent with existing data. For example in the case of 232 Th, below 10 MeV the results show clearly the variation occurring at the first (1 MeV) and second (7 MeV) chance fission, corresponding to transition states of given J and K (total spin and its projection on the fission axis), and a much more accurate energy dependence at the 3. chance threshold (14 MeV) has been obtained. In the spallation domain, above 30 MeV we confirm the high anisotropy revealed in 232 Th by the single existing data set. I'll discuss the implications of this finding, related to the low anisotropy exhibited in proton-induced fission. I also explore the critical experiments which is valuable checks of nuclear data. The 237 Np neutron-induced fission cross section has recently been measured in a large energy range (from eV to GeV) at the n-TOF facility at CERN. When compared to previous measurements, the n-TOF fission cross section appears to be higher by 5-7 % beyond the fission threshold. To check the relevance of n-TOF data, we simulate a criticality experiment performed at Los Alamos with a 6 kg sphere of 237 Np. This
Status of multigroup cross-section data for shielding applications
International Nuclear Information System (INIS)
Roussin, R.W.; Maskewitz, B.F.; Trubey, D.K.
1983-01-01
Multigroup cross-section libraries for shielding applications in formats for direct use in discrete ordinates or Monte Carlo codes have long been a part of the Data Library Collection (DLC) of the Radiation Shielding Information Center (RSIC). In recent years libraries in more flexible and comprehensive formats, which allow the user to derive his own problem-dependent sets, have been added to the collection. The current status of both types is described, as well as projections for adding data libraries based on ENDF/B-V
Phenomenological dirac optical potential for neutron cross sections
Energy Technology Data Exchange (ETDEWEB)
Maruyama, Shin-ichi; Kitsuki, Hirohiko; Shigyo, Nobuhiro; Ishibashi, Kenji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering
1997-03-01
Because of limitation on neutron-incident data, it is difficult to obtain global optical model potential for neutrons. In contrast, there are some global optical model potentials for proton in detail. It is interesting to convert the proton-incident global optical potentials into neutron-incident ones. In this study we introduce (N-Z)/A dependent symmetry potential terms into the global proton-incident optical potentials, and then obtain neutron-incident ones. The neutron potentials reproduce total cross sections in an acceptable degree. However, a comparison with potentials proposed by other authors brings about a confused situation in the sign of the symmetry terms. (author)
A high precision method for normalization of cross sections
International Nuclear Information System (INIS)
Aguilera R, E.F.; Vega C, J.J.; Martinez Q, E.; Kolata, J.J.
1988-08-01
It was developed a system of 4 monitors and a program to eliminate, in the process of normalization of cross sections, the dependence of the alignment of the equipment and those condition of having centered of the beam. It was carried out a series of experiments with the systems 27 Al + 70, 72, 74, 76 Ge, 35 Cl + 58 Ni, 37 Cl + 58, 60, 62, 64 Ni and ( 81 Br, 109 Rh) + 60 Ni. For these experiments the typical precision of 1% was obtained in the normalization. It is demonstrated theoretical and experimentally the advantage of this method on those that use 1 or 2 monitors. (Author)
Improved resonance formulas for cross sections of fissile elements
International Nuclear Information System (INIS)
Segev, M.
1978-01-01
The Adler--Adler cross-section formalism with energy-dependent parameters is a practical approximation to the R-matrix formalism, on the basis of the smallness of the s-wave neutron width in fissile elements. Attempts were made to represent experimental cross sections by the Adler--Adler formulas through an initial representation by the Reich--Moore approximation of R-matrix and a subsequent conversion of the Reich--Moore formulas to the Adler--Adler formulas. Adler and Adler foresaw difficulties in associating their formulas with approximate R-matrix theories such as those of Reich and Moore. Indeed, it is shown that, due to the nonunitarity of the Adler--Adler formalism on the one hand and the unitarity, by definition, of the Reich--Moore formalism on the other hand, the conversion from the latter to the former is ambiguous. Examples are shown to demonstrate that this ambiguity results in numerical inaccuracies, sometimes very large ones, for neutron widths that are not extremely small. Improved Adler--Adler-type formulas have been derived from the R-matrix formalism. In these formulas, the multipliers of the Breit--Wigner resonance lines exhibit more explicit energy dependence than their original counterparts, mainly in the form of additional terms in the formula for the total cross section. The conversion from Reich--Moore cross sections to the improved resonance formulas is shown to be much less ambiguous and to produce very accurate cross sections. In particular, the inaccuracies encountered with the Reich--Moore to Adler--Adler conversion are eliminated. A computer code, PEDRA, was written to perform the conversion from a given set of Reich--Moore parameters to the parameters required in the improved formulas. The numerical algorithm of this code is based on an adaptation with modifications of the numerical approach of de Saussure--Perez in the POLLA code, which converts Reich--Moore parameters to Adler--Adler parameters. 7 figures, 1 table
Directory of Open Access Journals (Sweden)
Turner Kenrick
2009-07-01
Full Text Available Abstract Background Smoke-free policy aims to protect the health of the population by reducing exposure to environmental tobacco smoke (ETS, and World Health Organisation (WHO guidance notes that these policies are only successful if there is full and proper enforcement. We aimed to investigate the problem of resistance to smoking restrictions and specifically compliance with smoke-free policy. We hypothesised that an explanation for non-compliance would lie in a measurable difference between the smoking behaviours of compliant and non-compliant smokers, specifically that non-compliance would be associated with nicotine dependence and different reasons for smoking. Methods We conducted a questionnaire-based, descriptive, cross-sectional study of hospital employees. Seven hundred and four members of staff at Addenbrooke's Hospital, Cambridge, UK, completed the questionnaire, of whom 101 were smokers. Comparison between compliant and non-compliant smokers was made based on calculated scores for the Fagerström test and the Horn-Waingrow scale, and level of agreement with questions about attitudes. For ordinal data we used a linear-by-linear association test. For non-parametric independent variables we used the Mann-Whitney test and for associations between categorical variables we used the chi-squared test. Results The demographic composition of respondents corresponded with the hospital's working population in gender, age, job profile and ethnicity. Sixty nine smokers reported they were compliant while 32 were non-compliant. Linear-by-linear association analysis of the compliant and non-compliant smokers' answers for the Fagerström test suggests association between compliance and nicotine dependence (p = 0.049. Mann-Whitney test analysis suggests there is a statistically significant difference between the reasons for smoking of the two groups: specifically that non-compliant smokers showed habitual smoking behaviour (p = 0.003. Overall
Intermediate structure studies of 234U cross sections
International Nuclear Information System (INIS)
James, G.D.; Schindler, R.H.
1976-01-01
Neutron induced fission and total cross sections of 234 U have been measured over the neutron energy range from a few eV to several MeV. Neutron and fission widths for 118 cross section resonances below 1500 eV have been determined and give a class I level spacing of 10.64 + -0.46 eV and a neutron strength function of (0.857 +- 0.108)x10 -4 . These fine structure resonances comprise a narrow intermediate structure resonance in the sub-threshold fission cross section of 234 U. Parameters for the Lorentzian energy dependence of the mean fission width are deduced on the assumption that, relative to this mean, the observed fission widths have a Porter-Thomas distribution. Two large fission widths measured for resonances at 1092.5 eV and 1134 eV may indicate the presence of a second narrow intermediate structure resonance at about this energy. The class II level spacing derived from the observation of 7 resonances below 13 keV is 2.1 +-0.3 keV. Pronounced breaks in the fission cross section at 310 keV, 550 keV and 720 keV are assumed to be due to β-vibrational levels in the second minimum of the Strutinsky potential. Fluctuations due to the presence of class II resonances are strongly evident for each of these vibrational levels. It is shown that the fluctuations near 310 keV are consistent with parameters deduced from the low energy data and this enables parameters for the double humped fission barrier potential to be obtained
Average cross sections for the 252Cf neutron spectrum
International Nuclear Information System (INIS)
Dezso, Z.; Csikai, J.
1977-01-01
A number of average cross sections have been measured for 252 Cf neutrons in (n, γ), (n,p), (n,2n), (n,α) reactions by the activation method and for fission by fission chamber. Cross sections have been determined for 19 elements and 45 reactions. The (n,γ) cross section values lie in the interval from 0.3 to 200 mb. The data as a function of target neutron number increases up to about N=60 with minimum near to dosed shells. The values lie between 0.3 mb and 113 mb. These cross sections decrease significantly with increasing the threshold energy. The values are below 20 mb. The data do not exceed 10 mb. Average (n,p) cross sections as a function of the threshold energy and average fission cross sections as a function of Zsup(4/3)/A are shown. The results obtained are summarized in tables
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
Calculation of atom displacement cross section for structure material
International Nuclear Information System (INIS)
Liu Ping; Xu Yiping
2015-01-01
The neutron radiation damage in material is an important consideration of the reactor design. The radiation damage of materials mainly comes from atom displacements of crystal structure materials. The reaction cross sections of charged particles, cross sections of displacements per atom (DPA) and KERMA are the basis of radiation damage calculation. In order to study the differences of DPA cross sections with different codes and different evaluated nuclear data libraries, the DPA cross sections for structure materials were calculated with UNF and NJOY codes, and the comparisons of results were given. The DPA cross sections from different evaluated nuclear data libraries were compared. And the comparison of DPA cross sections between NJOY and Monte Carlo codes was also done. The results show that the differences among these evaluated nuclear data libraries exist. (authors)
Damage energy and displacement cross sections: survey and sensitivity. [Neutrons
Energy Technology Data Exchange (ETDEWEB)
Doran, D.G.; Parkin, D.M.; Robinson, M.T.
1976-10-01
Calculations of damage energy and displacement cross sections using the recommendations of a 1972 IAEA Specialists' Meeting are reviewed. The sensitivity of the results to assumptions about electronic energy losses in cascade development and to different choices respecting the nuclear cross sections is indicated. For many metals, relative uncertainties and sensitivities in these areas are sufficiently small that adoption of standard displacement cross sections for neutron irradiations can be recommended.
Total cross sections for heavy flavour production at HERA
Frixione, Stefano; Nason, P; Ridolfi, G; Frixione, S; Mangano, M L; Nason, P; Ridolfi, G
1995-01-01
We compute total cross sections for charm and bottom photoproduction at HERA energies, and discuss the relevant theoretical uncertainties. In particular we discuss the problems arising from the small-x region, the uncertainties in the gluon parton density, and the uncertainties in the hadronic component of the cross section. Total electroproduction cross sections, calculated in the Weizs\\"acker-Williams approximation, are also given.
Compact fitting formulas for electron-impact cross sections
International Nuclear Information System (INIS)
Kim, Y.K.
1992-01-01
Compact fitting formulas, which contain four fitting constants, are presented for electron-impact excitation and ionization cross sections of atoms and ions. These formulas can fit experimental and theoretical cross sections remarkably well, when resonant structures are smoothed out, from threshold to high incident electron energies (<10 keV), beyond which relativistic formulas are more appropriate. Examples of fitted cross sections for some atoms and ions are presented. The basic form of the formula is valid for both atoms and molecules
Microscopic cross-section measurements by thermal neutron activation
International Nuclear Information System (INIS)
Avila L, J.
1987-08-01
Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained
Precise measurements of neutron capture cross sections for FP
International Nuclear Information System (INIS)
Nakamura, Shoji; Harada, Hideo; Katoh, Toshio
2000-01-01
The thermal neutron capture cross sections (σ 0 ) and the resonance integrals (I 0 ) of some fission products (FP), such as 137 Cs, 90 Sr, 99 Tc, 129 I and 135 Cs, were measured by the activation and γ-ray spectroscopic methods. Moreover, the cross section measurements were done for other FP elements, such as 127 I, 133 Cs and 134 Cs. This paper provides the summary of the FP cross section measurements, which have been performed by authors. (author)
Damage energy and displacement cross sections: survey and sensitivity
International Nuclear Information System (INIS)
Doran, D.G.; Parkin, D.M.; Robinson, M.T.
1976-10-01
Calculations of damage energy and displacement cross sections using the recommendations of a 1972 IAEA Specialists' Meeting are reviewed. The sensitivity of the results to assumptions about electronic energy losses in cascade development and to different choices respecting the nuclear cross sections is indicated. For many metals, relative uncertainties and sensitivities in these areas are sufficiently small that adoption of standard displacement cross sections for neutron irradiations can be recommended
A method for measuring light ion reaction cross sections
International Nuclear Information System (INIS)
Carlson, R.F.; Ingemarsson, A.; Lantz, M.
2005-03-01
An experimental procedure for measuring reaction cross sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross sections for five different sizes of the solid angles in steps from 99.1 to 99.8% of the total solid angle. The final reaction cross section values are obtained by extrapolation to the full solid angle
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
Direct measurement of the Rayleigh scattering cross section in various gases
International Nuclear Information System (INIS)
Sneep, Maarten; Ubachs, Wim
2005-01-01
Using the laser-based technique of cavity ring-down spectroscopy extinction measurements have been performed in various gases straightforwardly resulting in cross sections for Rayleigh scattering. For Ar and N 2 measurements are performed in the range 470-490nm, while for CO 2 cross sections are determined in the wider range 470-570nm. In addition to these gases also for N 2 O, CH 4 , CO, and SF 6 the scattering cross section is determined at 532nm, a wavelength of importance for lidar applications and combustion laser diagnostics. In O 2 the cross section at 532nm is found to depend on pressure due to collision-induced light absorption. The obtained cross sections validate the cross sections for Rayleigh scattering as derived from refractive indices and depolarization ratios through Rayleigh's theory at the few %-level, although somewhat larger discrepancies are found for CO, N 2 O and CH 4
SENSIT: a cross-section and design sensitivity and uncertainty analysis code
International Nuclear Information System (INIS)
Gerstl, S.A.W.
1980-01-01
SENSIT computes the sensitivity and uncertainty of a calculated integral response (such as a dose rate) due to input cross sections and their uncertainties. Sensitivity profiles are computed for neutron and gamma-ray reaction cross sections of standard multigroup cross section sets and for secondary energy distributions (SEDs) of multigroup scattering matrices. In the design sensitivity mode, SENSIT computes changes in an integral response due to design changes and gives the appropriate sensitivity coefficients. Cross section uncertainty analyses are performed for three types of input data uncertainties: cross-section covariance matrices for pairs of multigroup reaction cross sections, spectral shape uncertainty parameters for secondary energy distributions (integral SED uncertainties), and covariance matrices for energy-dependent response functions. For all three types of data uncertainties SENSIT computes the resulting variance and estimated standard deviation in an integral response of interest, on the basis of generalized perturbation theory. SENSIT attempts to be more comprehensive than earlier sensitivity analysis codes, such as SWANLAKE
Fragmentation cross sections outside the limiting-fragmentation regime
Sümmerer, K
2003-01-01
The empirical parametrization of fragmentation cross sections, EPAX, has been successfully applied to estimate fragment production cross sections in reactions of heavy ions at high incident energies. It is checked whether a similar parametrization can be found for proton-induced spallation around 1 GeV, the range of interest for ISOL-type RIB facilities. The validity of EPAX for medium-energy heavy-ion induced reactions is also checked. Only a few datasets are available, but in general EPAX predicts the cross sections rather well, except for fragments close to the projectile, where the experimental cross sections are found to be larger.
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.
Positive Scattering Cross Sections using Constrained Least Squares
International Nuclear Information System (INIS)
Dahl, J.A.; Ganapol, B.D.; Morel, J.E.
1999-01-01
A method which creates a positive Legendre expansion from truncated Legendre cross section libraries is presented. The cross section moments of order two and greater are modified by a constrained least squares algorithm, subject to the constraints that the zeroth and first moments remain constant, and that the standard discrete ordinate scattering matrix is positive. A method using the maximum entropy representation of the cross section which reduces the error of these modified moments is also presented. These methods are implemented in PARTISN, and numerical results from a transport calculation using highly anisotropic scattering cross sections with the exponential discontinuous spatial scheme is presented
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.
Adjustement of multigroup cross sections using fast reactor integral data
International Nuclear Information System (INIS)
Renke, C.A.C.
1982-01-01
A methodology for the adjustment of multigroup cross section is presented, structured with aiming to compatibility the limitated number of measured values of integral parameters known and disponible, and the great number of cross sections to be adjusted the group of cross section used is that obtained from the Carnaval II calculation system, understanding as formular the sets of calculation methods and data bases. The adjustment is realized, using the INCOAJ computer code, developed in function of one statistical formulation, structural from the bayer considerations, taking in account the measurement processes of cross section and integral parameters defined on statistical bases. (E.G.) [pt
Neutron cross section measurements for the Fast Breeder Program
International Nuclear Information System (INIS)
Block, R.C.
1979-06-01
This research was concerned with the measurement of neutron cross sections of importance to the Fast Breeder Reactor. The capture and total cross sections of fission products ( 101 102 104 Ru, 143 145 Nd, 149 Sm, 95 97 Mo, Cs, Pr, Pd, 107 Pd, 99 Tc) and tag gases (Kr, 78 80 Kr) were measured up to 100 keV. Filtered neutron beams were used to measure the capture cross section of 238 U (with an Fe filter) and the total cross section of Na (with a Na filter). A radioactive neutron capture detector was developed. A list of publications is included
Neutron cross sections in the unresolved resonance region
International Nuclear Information System (INIS)
Janeva, N.; Lukyanov, A.; Koyumdjieva, N.; Volev, K.
2005-01-01
In this work a development of the characteristic function model, created to reveal the resonance cross section structure in the unresolved resonance region is presented. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. To determine average values of the cross sections and their functionals the function of joint statistical distribution of the R-matrix real and imaginary parts should be used. The characteristic function of such distribution is determined and the resonance ladder for the unresolved region is optimized to calculate the group averaged functionals in the same way as it is in the resolved resonance region. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. The neutron width energy dependence leads to some deformation in the shape of resonances. This deformation is most apparent near the inelastic scattering threshold. For the case when the inelastic channel momentum is zero we present the formula for level shape bellow and over the inelastic threshold and the calculated resonance deformation in dependence of the position of the resonance in respect to the threshold. (authors)
Neutrino-nucleon cross section measurements in NOMAD
Wu, Qun
2006-01-01
The NOMAD (Neutrino Oscillation MAgnetic Detector) experiment, using the SPS (Super Proton Syncrotron) neutrino beam (1 GeV < E [nu] < 200 GeV) at CERN (European Organization for Nuclear Research), has collected more than 1.7 million neutrino induced charged and neutral current (CC and NC) events. This data is the largest high resolution neutrino nucleon scattering data to date and is ideal for precision measurements and searches in neutrino-physics. This thesis presents the precise measurement of the inclusive neutrino CC cross section in 2.5 GeV < E [nu] < 150 GeV region. The linear dependence of the inclusive CC cross section ([Special characters omitted.] ) versus the incoming neutrino energy ( E [nu] ) is observed in the high energy region of 30 GeV < E [nu] < 150 GeV. Especially, the measurement in 2.5 GeV < E [nu] < 30 GeV region provides the first precise determination of [Special characters omitted.] . The significant deviation from the linear dependence for [Special character...
Behaviour of cross-sections for exclusive and inclusive processes at high energies
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvili, M.A.; Petrov, V.A.
1976-11-01
The character of the functional dependence of the cross-sections for inclusive and exclusive reactions on the energy of colliding particles has been established on the basis of the principles of casuality, spectrality and unitarity
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.
Approximation of the cross-sections for charged-particle emission reactions near the threshold
International Nuclear Information System (INIS)
Badikov, S.A.; Pashchenko, A.B.
1990-01-01
We perform an analytical approximation of the energy dependence of the cross-sections for the reactions (n,p) and (n,γ) from the BOSPOR library, correct them for the latest differential and integral experimental data using the common features, characteristic of the energy dependence of the threshold reaction cross-section and making some physical assumptions. 19 refs, 1 fig., 1 tab
Learning Recursion: Multiple Nested and Crossed Dependencies
Directory of Open Access Journals (Sweden)
Meinou de Vries
2011-06-01
Full Text Available Language acquisition in both natural and artificial language learning settings crucially depends on extracting information from ordered sequences. A shared sequence learning mechanism is thus assumed to underlie both natural and artificial language learning. A growing body of empirical evidence is consistent with this hypothesis. By means of artificial language learning experiments, we may therefore gain more insight in this shared mechanism. In this paper, we review empirical evidence from artificial language learning and computational modeling studies, as well as natural language data, and suggest that there are two key factors that help deter-mine processing complexity in sequence learning, and thus in natural language processing. We propose that the specific ordering of non-adjacent dependencies (i.e. nested or crossed, as well as the number of non-adjacent dependencies to be resolved simultaneously (i.e. two or three are important factors in gaining more insight into the boundaries of human sequence learning; and thus, also in natural language processing. The implications for theories of linguistic competence are discussed.
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
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
6,7Li + 28Si total reaction cross sections at near barrier energies
International Nuclear Information System (INIS)
Pakou, A.; Musumarra, A.; Pierroutsakou, D.; Alamanos, N.; Assimakopoulos, P.A.; Divis, N.; Doukelis, G.; Gillibert, A.; Harissopulos, S.; Kalyva, G.; Kokkoris, M.; Lagoyannis, A.; Mertzimekis, T.J.; Nicolis, N.G.; Papachristodoulou, C.; Perdikakis, G.; Roubos, D.; Rusek, K.; Spyrou, S.; Zarkadas, Ch.
2007-01-01
Total reaction cross section measurements for the 6,7 Li + 28 Si systems have been performed at near-barrier energies. The results indicate that, with respect to the potential anomaly at barrier, 6 Li and 7 Li on light targets exhibit similar energy dependence on the imaginary potential. Comparisons are made with 6,7 Li cross sections on light and heavy targets, extracted via previous elastic scattering measurements and also with CDCC calculations. Energy dependent parametrisations are also obtained for total reaction cross sections of 6,7 Li on Si, as well as on any target, at near barrier energies
238U subthreshold neutron induced fission cross section
International Nuclear Information System (INIS)
Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.
1976-01-01
High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb
Learning of Cross-Sectional Anatomy Using Clay Models
Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon
2009-01-01
We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…
Photoionization cross sections: present status and future needs
International Nuclear Information System (INIS)
Manson, S.T.
1988-01-01
The existing experimental data situation for photoionization cross section of ground-state atoms, excited states and positive ions is reviewed. The ability of theory to predict these cross sections is also discussed. The likely progress for the near future is presented [pt
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)
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
Graphs of neutron cross section data for fusion reactor development
International Nuclear Information System (INIS)
Asami, Tetsuo; Tanaka, Shigeya
1979-03-01
Graphs of neutron cross section data relevant to fusion reactor development are presented. Nuclides and reaction types in the present compilation are based on a WRENDA request list from Japan for fusion reactor development. The compilation contains various partial cross sections for 55 nuclides from 6 Li to 237 Np in the energy range up to 20 MeV. (author)
Evaluated activation cross-sections and intercomparison of the ...
Indian Academy of Sciences (India)
mental data cross-section with the theoretical codes, to study the quality of the theoretical ... the cross-section, angular distribution, double differential data, gamma ..... TALYS. TENDL. Figure 6. Excitation function of the 87Sr(p, 2n)86Y reaction.
Differential bremsstrahlung and pair production cross sections at high energies
International Nuclear Information System (INIS)
Olsen, Haakon A.
2003-01-01
Detailed differential cross sections for high energy bremsstrahlung and pair production are derived with specific attention to the differences between the two processes, which are considerable. For the integrated cross sections, which are the only cross sections specifically known until now, the final state integration theorem guarantees that the exact cross section formulas can be exchanged between bremsstrahlung and pair production by the same substitution rules as for the Born-approximation Bethe-Heitler cross sections, for any amount of atomic screening. In fact the theorem states that the Coulomb corrections to the integrated bremsstrahlung and pair production cross sections are identical for any amount of screening. The analysis of the basic differential cross sections leads to fundamental physical differences between bremsstrahlung and pair production. Coulomb corrections occur for pair production in the strong electric field of the atom for 'large' momentum transfer of the order of mc. For bremsstrahlung, on the other hand, the Coulomb corrections take place at a 'large' distance from the atom of the order of ((ℎ/2π)/mc)ε, with a 'small' momentum transfer mc/ε, where ε is the initial electron energy in units of mc 2 . And the Coulomb corrections can be large, of the order of larger than (Z/137) 2 , which is considerably larger than the integrated cross section corrections
Total Cross Sections at High Energies An update
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.
pp production cross sections and the constraint method
International Nuclear Information System (INIS)
Anjos, J.C.; Santoro, A.F.S.; Souza, M.H.G.
1983-01-01
A method of constructing production cross sections that satisfy the constraints represented by the first few moments is shown to give an excellent account of the data when applied to the high energy pp production cross section ν sub(n) (s) plotted as functions of n. (Author) [pt
International Nuclear Information System (INIS)
1997-01-01
The data base relevant to an evaluation of the 10 B(n,α) standard cross sections have been improved through interlaboratory collaboration. Changes in the evaluated 10 B(n,α) cross sections resulted form the measurements made since the ENDF/B-VI evaluation have been estimated. 12 refs, 4 figs
The effect of the decay data on activation cross section
International Nuclear Information System (INIS)
Huang Xiaolong
2002-01-01
The effect of the decay data on evaluation of activation cross section is investigated. Present work shows that these effects must be considered carefully when activation cross section is evaluated. Sometime they are main reason for causing the discrepancies among the experimental data
Tables of RCN-2 fission-product cross section evaluation
International Nuclear Information System (INIS)
Gruppelaar, H.
1979-05-01
This report (continuation of ECN-13 and ECN-33) describes the third part of the RCN-2 evaluation of neutron cross sections for fission product nuclides in KEDAK format. It contains evaluated data for nine nuclides, i.e. 142 Nd, 143 Nd, 144 Nd, 145 Nd, 146 Nd, 147 Nd, 148 Nd, 150 Nd and 147 Pm. Most emphasis has been given to the evaluation of the radiative capture cross section, in order to provide a data base for adjustment calculations using results of integral measurements. Short evaluation reports are given for this cross section. The evaluated capture cross sections are compared with recent experimental differential and integral data. Graphs are given of the capture cross sections at neutron energies above 1 keV, in which also adjusted point cross sections, based upon integral STEK and CFRMF data have been plotted. Moreover, the results are compared with those of the well-known ENDF/B-IV evaluation for fission product nucleides. Finally, evaluation summaries are given, which include tables of other important neutron cross sections, such as the total, elastic scattering and inelastic scattering cross sections
Nuclear characteristics of Pu fueled LWR and cross section sensitivities
Energy Technology Data Exchange (ETDEWEB)
Takeda, Toshikazu [Osaka Univ., Suita (Japan). Faculty of Engineering
1998-03-01
The present status of Pu utilization to thermal reactors in Japan, nuclear characteristics and topics and cross section sensitivities for analysis of Pu fueled thermal reactors are described. As topics we will discuss the spatial self-shielding effect on the Doppler reactivity effect and the cross section sensitivities with the JENDL-3.1 and 3.2 libraries. (author)
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)
Q.C.D. estimates of hadronic cross sections
International Nuclear Information System (INIS)
Navelet, H.; Peschanski, R.
1983-03-01
Estimates for hadron-hadron cross-sections are made using the leading log approximation of Q.C.D. The rise of the total inelastic pp cross-sections at high energy is reproduced, thanks to the competition between the small parton-parton interaction and the large multiplicity of gluons predicted by Q.C.D
Second order effects in adjustment processes of cross sections
International Nuclear Information System (INIS)
Silva, F.C. da; D'Angelo, A.; Gandini, A.; Rado, V.
1982-01-01
An iterative processe, that take in account the non linear effects of some integral quantities in relation to cross sections, is used to execute an adjustment of cross sections of some elements that constitute the fast reactors shielding. (E.G.) [pt
WHEELSET AXLE WITH THE CAVITY OF UNIFORM CROSS SECTION
Directory of Open Access Journals (Sweden)
S. R. Kolesnykov
2014-10-01
Full Text Available Purpose. Due to operation in complex loading conditions, the rolling stock wheelsets should provide high reliability, since the train traffic safety largely depends on them. Design and technical condition of wheelsets affect the smoothness, intensity of forces generated by the interaction between the car and track, and the motion resistance. Specificity of the axle operation consists in the fact that it undergoes the bending stresses under loading. These stresses are unevenly distributed along the cross-sectional area, reaching the highest values in the outer fibers and the minimal values in the internal ones. This aspect sets the problem of replacement of the uniform cross section with the hollow cross section. The disadvantages of hollow axle design, which are used at the present time, should include a significant manufacturing complexity of the variable section cavity. The purpose is to develop a modernized design of the wheelset axle. Methodology. A construction of the hollow axle having an inner longitudinal cylindrical through hole of the constant diameter throughout its length was proposed. The item is made of steel seamless tube. The inner surface of the tube is treated by mechanical means to remove the voltage concentrations in the internal longitudinal cylindrical through hole, which has a constant diameter along the entire length of the axle. Findings. Application of this design will facilitate manufacturing of the hollow axle and the machining of the inner longitudinal through hole, while retaining all the use advantages of the hollow axle in the rolling stock wheel pairs. Another use advantage of the hollow axle of this design is the absence of partial heterogeneity of the metal, which is inevitably, occurs during the solid axles blanking. Originality. A new design of the wheelset hollow axle of railway rolling stock was proposed. Practical value. Introduction of the new design simplifying the manufacture and mechanical treatment of
MOX Cross-Section Libraries for ORIGEN-ARP
International Nuclear Information System (INIS)
Gauld, I.C.
2003-01-01
The use of mixed-oxide (MOX) fuel in commercial nuclear power reactors operated in Europe has expanded rapidly over the past decade. The predicted characteristics of MOX fuel such as the nuclide inventories, thermal power from decay heat, and radiation sources are required for design and safety evaluations, and can provide valuable information for non-destructive safeguards verification activities. This report describes the development of computational methods and cross-section libraries suitable for the analysis of irradiated MOX fuel with the widely-used and recognized ORIGEN-ARP isotope generation and depletion code of the SCALE (Standardized Computer Analyses for Licensing Evaluation) code system. The MOX libraries are designed to be used with the Automatic Rapid Processing (ARP) module of SCALE that interpolates appropriate values of the cross sections from a database of parameterized cross-section libraries to create a problem-dependent library for the burnup analysis. The methods in ORIGEN-ARP, originally designed for uranium-based fuels only, have been significantly upgraded to handle the larger number of interpolation parameters associated with MOX fuels. The new methods have been incorporated in a new version of the ARP code that can generate libraries for low-enriched uranium (LEU) and MOX fuel types. The MOX data libraries and interpolation algorithms in ORIGEN-ARP have been verified using a database of declared isotopic concentrations for 1042 European MOX fuel assemblies. The methods and data are validated using a numerical MOX fuel benchmark established by the Organization for Economic Cooperation and Development (OECD) Working Group on burnup credit and nuclide assay measurements for irradiated MOX fuel performed as part of the Belgonucleaire ARIANE International Program
Differences between cross-section libraries for neutron dosimetry
International Nuclear Information System (INIS)
Tardelli, T.C.; Stecher, L.C.; Coelho, T.S.; Castro, V.A. De; Cavalieri, T.A.; Menzel, F.; Giarola, R.S.; Domingos, D.B.; Yoriyaz, H.
2013-01-01
Absorbed dose calculations depend on a consistent set of nuclear data used in simulations in computer codes. Nuclear data are stored in libraries, however, the information available about the differences in dose caused by different libraries are rare. The libraries are processed by a computer system to be able to be used by a radiation transport code. One of the systems capable of processing nuclear data is the NJOY system. The objective of this study is to evaluate the nuclear data libraries for neutrons available in the literature, and to quantify the differences in absorbed dose obtained using the libraries JENDL 4.0, JEFF 3.3.1 and ENDF/B.VII. The absorbed dose calculation was performed on a simple geometric model, as spheres, and in anthropomorphic model of the human body based on the ICRP-110 for neutron transport simulation using the MCNP5 code. The results were compared with literature data. The results obtained with cross sections from the libraries JEFF and ENDF/B.VII have shown to be identical in most cases, except for one case where the difference has exceeded 10%. The results obtained with JENDL library has shown to be considerably different in most cases comparing to other two libraries. Some differences were over 200%. The dose calculations showed differences between the libraries, which is justified by differences in the cross sections. It has been observed that the cross sections values of certain nuclides assume quite different values in different libraries. These differences in turn cause considerable differences in dose calculations. (author)
Measurement of the diffractive cross section in deep inelastic scattering
International Nuclear Information System (INIS)
Derrick, M.; Krakauer, D.; Magill, S.
1996-02-01
Diffractive scattering of γ*p→X+N, where N is either a proton or a nucleonic system with M N X of the system X up to 15 GeV at average Q 2 values of 14 and 31 GeV 2 . The diffractive cross section dσ diff /dM X is, within errors, found to rise linearly with W. Parameterizing the W dependence by the form dσ diff /dM X ∝(W 2 )sup((2 anti α IP -2)) the DIS data yield for the pomeron trajectory anti α IP =1.23±0.02(stat)±0.04(syst) averaged over t in the measured kinematic range assuming the longitudinal photon contribution to be zero. This value for the pomeron trajectory is substantially larger than anti α IP extracted from soft interactions. The value of anti α IP measured in this analysis suggests that a substantial part of the diffractive DIS cross section originates form processes which can be described by perturbative QCD. From the measured diffractive cross sections the diffractive structure function of the proton F 2 D(3) (β, Q 2 , x IP ) has been determined, where β is the momentum fraction of the struck quark in the pomeron. The form F 2 D(3) =constant. (1/x IP ) a gives a good fit to the data in all β and Q 2 intervals with a=1.46±0.04(stat)±0.08(syst). (orig.)
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.
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...
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
Electron collision cross section sets of TMS and TEOS vapours
Kawaguchi, S.; Takahashi, K.; Satoh, K.; Itoh, H.
2017-05-01
Reliable and detailed sets of electron collision cross sections for tetramethylsilane [TMS, Si(CH3)4] and tetraethoxysilane [TEOS, Si(OC2H5)4] vapours are proposed. The cross section sets of TMS and TEOS vapours include 16 and 20 kinds of partial ionization cross sections, respectively. Electron transport coefficients, such as electron drift velocity, ionization coefficient, and longitudinal diffusion coefficient, in those vapours are calculated by Monte Carlo simulations using the proposed cross section sets, and the validity of the sets is confirmed by comparing the calculated values of those transport coefficients with measured data. Furthermore, the calculated values of the ionization coefficient in TEOS/O2 mixtures are compared with measured data to confirm the validity of the proposed cross section set.
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
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
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
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.
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
Multilevel Cross-Dependent Binary Longitudinal Data
Serban, Nicoleta
2013-10-16
We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this article are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements.
Preparation of TEM specimen by cross-section technique
International Nuclear Information System (INIS)
Hamada, Shozo
1986-01-01
Transmission electron microscopy (TEM) is applied to the direct observation of the depth dependent damage structure in ion-irradiated stainless steel by using the cross-section technique; obtaining the TEM specimen from a slice of the irradiated stainless steel with thick Ni plating. Here has been developed the specimen preparation method of cross-section technique without heat treatment, which was necessary in the conventional method to strengthen the bonding between Ni and stainless steel. Nickel plating with good bonding to stainless steel is enabled by the following manner. First, the irradiated stainless steel is immersed in the Wood's nickel solution at room temperature for 60s to activate the surface, followed by the stricking for 300s at a current density of 300 A/m 2 in the solution to make fine and homogeneous nucleation of Ni on the stainless steel. Then, the sample is plated with Ni in the Watt's nickel plating solution at 333 K with current density of 900 ∼ 1,000 A/m 2 . The TEM disc is obtained by mechanical slicing from the specimen with Ni plating of more than 3 mm thickness. Electropolishing is accomplished by using both Ballmann method and jet electropolishing to perforate the disc accurately at the aimed point for the observation of the damage structure. (author)
Research on Fast-Doppler-Broadening of neutron cross sections
International Nuclear Information System (INIS)
Li, S.; Wang, K.; Yu, G.
2012-01-01
A Fast-Doppler-Broadening method is developed in this work to broaden Continuous Energy neutron cross-sections for Monte Carlo calculations. Gauss integration algorithm and parallel computing are implemented in this method, which is unprecedented in the history of cross section processing. Compared to the traditional code (NJOY, SIGMA1, etc.), the new Fast-Doppler-Broadening method shows a remarkable speedup with keeping accuracy. The purpose of using Gauss integration is to avoid complex derivation of traditional broadening formula and heavy load of computing complementary error function that slows down the Doppler broadening process. The OpenMP environment is utilized in parallel computing which can take full advantage of modern multi-processor computers. Combination of the two can reduce processing time of main actinides (such as 238 U, 235 U) to an order of magnitude of 1∼2 seconds. This new method is fast enough to be applied to Online Doppler broadening. It can be combined or coupled with Monte Carlo transport code to solve temperature dependent problems and neutronics-thermal hydraulics coupled scheme which is a big challenge for the conventional NJOY-MCNP system. Examples are shown to determine the efficiency and relative errors compared with the NJOY results. A Godiva Benchmark is also used in order to test the ACE libraries produced by the new method. (authors)
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.
Meeting cross-section requirements for nuclear-energy design
Energy Technology Data Exchange (ETDEWEB)
Weisbin, C.R.; de Saussure, G.; Santoro, R.T. (Oak Ridge National Lab., TN (USA)); Gilai, T. (Ben-Gurion Univ. of the Negev, Beersheba (Israel))
1982-01-01
Current requirements in cross-section data that are essential to nuclear-energy programmes are summarized and explained and some insight into how these data might be obtained is provided. The six sections of the paper describe: design parameters and target accuracies; data collection, evaluation and analysis; determination of high-accuracy differential nuclear data for technological applications; status of selected evaluated nuclear data; analysis of benchmark testing; identification of important cross sections and inferred needs.
Total cross sections for pion charge exchange on the proton
International Nuclear Information System (INIS)
Breitschopf, J.
2006-01-01
This work describes the measurement of total SCX cross sections employing a new 4π scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4π detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH 2 target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole Δ-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4±1.5)%. The exact value depends on the SCX literature data included and on the parameters of the Δ 0 Breit-Wigner resonance describing the p 33 -waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin symmetry breaking. Interestingly
Total cross sections for pion charge exchange on the proton
Energy Technology Data Exchange (ETDEWEB)
Breitschopf, J.
2006-04-28
This work describes the measurement of total SCX cross sections employing a new 4{pi} scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4{pi} detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH{sub 2} target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole {delta}-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4{+-}1.5)%. The exact value depends on the SCX literature data included and on the parameters of the {delta}{sup 0} Breit-Wigner resonance describing the p{sub 33}-waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin
International Nuclear Information System (INIS)
Eccles, J.; Secrest, D.
1977-01-01
A study is made of the ''conservation of the total cross section'' and the ''equivalence of the total cross section'' rules for scattering from H 2 . It is shown that these rules are a better approximation than the random phase approximation would indicate. Cross section formulas are given for scattering atoms from m/sub j/ state selected molecules and it is shown that total cross sections for state selected molecules depend on the anisotropic part of the interaction potential, while the spin-averaged total cross section often depends only on the spherically symmetric part of the interaction potential. The total spin-averaged cross section is thus independent of the initial rotation state of the molecule and depends only on the relative collision energy. It is further demonstrated that isotopic substitution, which shifts the center of mass changing the symmetric part of the interaction potential, has too small an effect on the total cross section to be useful as a means of determining the anisotropy of the potential
Formulation and Analysis of the Quantum Radar Cross Section
Brandsema, Matthew J.
In radar, the amount of returns that an object sends back to the receiver after being struck by an electromagnetic wave is characterized by what is known as the radar cross section, denoted by sigma typically. There are many mechanisms that affect how much radiation is reflected back in the receiver direction, such as reflectivity, physical contours and dimensions, attenuation properties of the materials, projected cross sectional area and so on. All of these characteristics are lumped together in a single value of sigma, which has units of m2. Stealth aircrafts for example are designed to minimize its radar cross section and return the smallest amount of radiation possible in the receiver direction. A new concept has been introduced called quantum radar, that uses correlated quantum states of photons as well as the unique properties of quantum mechanics to ascertain information on a target at a distance. At the time of writing this dissertation, quantum radar is very much in its infancy. There still exist fundamental questions about the feasibility of its implementation, especially in the microwave spectrum. However, what has been theoretically determined, is that quantum radar has a fundamental advantage over classical radar in terms of resolution and returns in certain regimes. Analogous to the classical radar cross section (CRCS), the concept of the quantum radar cross section (QRCS) has been introduced. This quantity measures how an object looks to a quantum radar be describing how a single photon, or small cluster of photons scatter off of a macroscopic target. Preliminary simulations of the basic quantum radar cross section equation have yielded promising results showing an advantage in sidelobe response in comparison to the classical RCS. This document expands upon this idea by providing insight as to where this advantage originates, as well as developing more rigorous simulation analysis, and greatly expanding upon the theory. The expanded theory presented
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.
Evaluation of kerma in carbon and the carbon cross sections
International Nuclear Information System (INIS)
Axton, E.J.
1992-02-01
A preliminary simultaneous least squares fit to measurements of kerma in carbon, and carbon cross sections taken from the ENDF/B-V file was carried out. In the calculation the shapes of the total cross section and the various partial cross sections were rigid but their absolute values were allowed to float in the fit within the constraints of the ENDF/B-V uncertainties. The construction of the ENDF/B-V file imposed improbable shapes, particularly in the case of the (12)C(n,n'3(alpha)) reaction, which were incompatible with direct measurements of kerma and of the reaction cross sections. Consequently a new evaluation of the cross section data became necessary. Since the available time was limited the new evaluation concentrated particularly on those aspects of the ENDF/B-V carbon file which would have most impact on kerma calculations. Following the new evaluation of cross sections new tables of kerma factors were produced. Finally, the simultaneous least squares fit to measurements of kerma and the new cross section file was repeated
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.
Positron induced scattering cross sections for hydrocarbons relevant to plasma
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.
The total collision cross section in the glory region
International Nuclear Information System (INIS)
Biesen, J.J.H. van den.
1982-01-01
Chapter 1 presents a calculation of approximate total cross sections in the glory region from noble gas potentials. The relations between the main features of the total cross section and the properties of the potential to which these are sensitive are extensively investigated in chapter II. A beam apparatus has been developed, which allows for accurate measurements on the total cross section. All effects due to the finite angular and velocity resolution of the apparatus can be eliminated from the data to yield actual total cross sections as a function of the relative velocity. This facilitates a comparison to total cross sections predicted by potentials available in the literature. A brief description of the apparatus and of the data reduction is given in chapter III. The total cross section data obtained for various noble gas combinations are presented and analysed in chapter IV, where also a large number of potentials proposed in the literature is tested. In chapter V the quenching of the glories in the case of a non-spherical interaction is analysed. Subsequently, total cross section data for some atom-molecule systems are discussed. (Auth.)
Nucleus-nucleus total reaction cross sections
International Nuclear Information System (INIS)
DeVries, R.M.; Peng, J.C.
1980-01-01
We compare sigma/sub R/(E) for nucleus-nucleus systems (obtained from existing direct measurements and derived from elastic scattering data) with nucleon-nucleon and nucleon-nucleus data. The energy dependence of sigma/sub R/(E) for nucleus-nucleus systems is found to be quite rapid; there appears to be no evidence for an energy independent, geometric sigma/sub R/. Simple parameter free microscopic calculations are able to quantitatively reproduce the data and thus, emphasize the dominance of nucleon-nucleon interactions in medium energy nucleus-nucleus collisions
Absorptive coding metasurface for further radar cross section reduction
Sui, Sai; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Feng, Mingde; Xu, Zhuo; Qu, Shaobo
2018-02-01
Lossless coding metasurfaces and metamaterial absorbers have been widely used for radar cross section (RCS) reduction and stealth applications, which merely depend on redirecting electromagnetic wave energy into various oblique angles or absorbing electromagnetic energy, respectively. Here, an absorptive coding metasurface capable of both the flexible manipulation of backward scattering and further wideband bistatic RCS reduction is proposed. The original idea is carried out by utilizing absorptive elements, such as metamaterial absorbers, to establish a coding metasurface. We establish an analytical connection between an arbitrary absorptive coding metasurface arrangement of both the amplitude and phase and its far-field pattern. Then, as an example, an absorptive coding metasurface is demonstrated as a nonperiodic metamaterial absorber, which indicates an expected better performance of RCS reduction than the traditional lossless coding metasurface and periodic metamaterial-absorber. Both theoretical analysis and full-wave simulation results show good accordance with the experiment.
Scattering cross section of unequal length dipole arrays
Singh, Hema; Jha, Rakesh Mohan
2016-01-01
This book presents a detailed and systematic analytical treatment of scattering by an arbitrary dipole array configuration with unequal-length dipoles, different inter-element spacing and load impedance. It provides a physical interpretation of the scattering phenomena within the phased array system. The antenna radar cross section (RCS) depends on the field scattered by the antenna towards the receiver. It has two components, viz. structural RCS and antenna mode RCS. The latter component dominates the former, especially if the antenna is mounted on a low observable platform. The reduction in the scattering due to the presence of antennas on the surface is one of the concerns towards stealth technology. In order to achieve this objective, a detailed and accurate analysis of antenna mode scattering is required. In practical phased array, one cannot ignore the finite dimensions of antenna elements, coupling effect and the role of feed network while estimating the antenna RCS. This book presents the RCS estimati...
Poster - 18: New features in EGSnrc for photon cross sections
Energy Technology Data Exchange (ETDEWEB)
Ali, Elsayed; Mainegra-Hing, Ernesto; Rogers, David W.O. [The Ottawa Hospital Cancer Centre, National Research Council Canada, Carleton University (Canada)
2016-08-15
Purpose: To implement two new features in the EGSnrc Monte Carlo system. The first is an option to account for photonuclear attenuation, which can contribute a few percent to the total cross section at the higher end of the energy range of interest to medical physics. The second is an option to use exact NIST XCOM photon cross sections. Methods: For the first feature, the photonuclear total cross sections are generated from the IAEA evaluated data. In the current, first-order implementation, after a photonuclear event, there is no energy deposition or secondary particle generation. The implementation is validated against deterministic calculations and experimental measurements of transmission signals. For the second feature, before this work, if the user explicitly requested XCOM photon cross sections, EGSnrc still used its own internal incoherent scattering cross sections. These differ by up to 2% from XCOM data between 30 keV and 40 MeV. After this work, exact XCOM incoherent scattering cross sections are an available option. Minor interpolation artifacts in pair and triplet XCOM cross sections are also addressed. The default for photon cross section in EGSnrc is XCOM except for the new incoherent scattering cross sections, which have to be explicitly requested. The photonuclear, incoherent, pair and triplet data from this work are available for elements and compounds for photon energies from 1 keV to 100 GeV. Results: Both features are implemented and validated in EGSnrc.Conclusions: The two features are part of the standard EGSnrc distribution as of version 4.2.3.2.
International Nuclear Information System (INIS)
Konshin, V.A.
1981-01-01
Neutron cross section calculational methods for actinides in the unresolved resonance energy range (1-150 kev) are discussed, with a special emphasis on calculation of width fluctuation factors for the generalized distribution, as well as for a sub-threshold fission. It is shown that the energy dependence of sub(J), the (n,n') -process competition and the structure in neutron cross section has to be taken into account in the energy range considered. Analysis of different approaches in the statistical theory for heavy nuclei neutron cross-section calculation is given, and it is shown to be important to allow for the (n,γf)-reaction in neutron cross section calculations for fissile nuclei. The use of the non-spherical potential, the Lorentzian spectral factor and the Fermi-gas model involving the collective modes enables to obtain the self-consistent data for all neutron cross sections, including σnγ. (author)
Measurements of effective total macroscopic cross sections and effective energy of continuum beam
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Hisao [Rikkyo Univ., Yokosuka, Kanagawa (Japan). Inst. for Atomic Energy
1998-03-01
Two practically useful quantities are introduced in this study to characterize a continuum neutron beam and to describe transmission phenomena of the beam in field of quantitative neutron radiography: an effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section defined at the monochromatic energy. The effective energy was evaluated by means of energy dependence of ETM cross section. To realize the method a beam quality indicator (BQI) has been proposed recently. Several effective energies were measured for non-filtered, filtered neutron beams, and outputs of neutron guide tubes in world by the BQI. A thermal neutron beam and three beams modulated by Pb filters with different thicknesses are studied to measure ETM cross sections for various materials and summarized in a table. Validity of the effective energy determined by the BQI is discussed relating with ETM cross sections of materials. (author)
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.
Total cross section for relativistic positronium interaction with atom
International Nuclear Information System (INIS)
Pak, A.S.; Tarasov, A.V.
1985-01-01
Total cross sections of interaction of positronium relativistic atoms with atoms are calculated. Calculations are conducted within the framework of potential theory in Born approximaton. Contributions in total cross section of coherent (σsub(coh)) and incoherent (σsub(inc)) parts are analyzed. It is shown that for light elements σsub(inc) value is comparable with σsub(coh), and for heavy ones the ratio σsub(inc)/σsub(coh) sufficiently exceeds Zsup(-1) (Z-charge of the atomic nucleus. Numerical calculation results are presented. A conclusion is made on importance of the coherent part account during the calculation of total cross sections
Actinide neutron-induced fission cross section measurements at LANSCE
Energy Technology Data Exchange (ETDEWEB)
Tovesson, Fredrik K [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 in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.
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.
Drell-Yan cross section in the jet calculus scheme
International Nuclear Information System (INIS)
Tanaka, Hidekazu; Kobayashi, Hirokazu
2009-01-01
We calculate factorized cross sections for lepton pair production mediated by a virtual photon in hadron-hadron collisions using the jet calculus scheme, in which a kinematical constraint due to parton radiation is taken into account. This method guarantees a proper phase space boundary for subtraction terms. Some properties of the calculated cross sections are examined. We also discuss matching between the hard scattering cross sections and parton showers at the next-to-leading logarithmic (NLL) order of quantum chromodynamics (QCD). (author)
Habit, Production, and the Cross-Section of Stock Returns
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...
Use of nuclear reaction models in cross section calculations
International Nuclear Information System (INIS)
Grimes, S.M.
1975-03-01
The design of fusion reactors will require information about a large number of neutron cross sections in the MeV region. Because of the obvious experimental difficulties, it is probable that not all of the cross sections of interest will be measured. Current direct and pre-equilibrium models can be used to calculate non-statistical contributions to neutron cross sections from information available from charged particle reaction studies; these are added to the calculated statistical contribution. Estimates of the reliability of such calculations can be derived from comparisons with the available data. (3 tables, 12 figures) (U.S.)
Comparison of fission and capture cross sections of minor actinides
International Nuclear Information System (INIS)
Nakagawa, Tsuneo; Iwamoto, Osamu
2003-01-01
The fission and capture cross sections of minor actinides given in JENDL-3.3 are compared with other evaluated data and experimental data. The comparison was made for 32 nuclides of Th-227, 228, 229, 230, 233, 234, Pa-231, 232, 233, U-232, 234, 236, 237, Np-236, 237, 238, Pu-236, 237, 238, 242, 244, Am-241, 242, 242m, 243, Cm-242, 243, 244, 245, 246, 247 and 248. Given in the present report are figures of these cross sections and tables of cross sections at 0.0253 eV and resonance integrals. (author)
LHCb cross-section measurements with heavy flavour jets
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.
Cross sections and transport properties for Na+ in (DXE gas
Directory of Open Access Journals (Sweden)
Nikitović Željka D.
2016-01-01
Full Text Available In this work we select most probable reactions of alkali metal ion Na+ with dimethoxyethane (DXE molecule. Appropriate gas phase enthalpies of formation for the products were used to calculate scattering cross section as a function of kinetic energy with Denpoh-Nanbu theory. Calculated cross sections were compared with existing experimental results obtained by guided ion beam tandem mass spectrometry. Three body association reactions of ions with DXE is studied and compared to experimental results. Calculated cross sections were used to obtain transport parameters for alkali metal ion in DXE gas. [Projekat Ministarstva nauke Republike Srbije, br. ON 171037 i br. III 410011
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
A method for measuring light ion reaction cross-sections
International Nuclear Information System (INIS)
Carlson, R.F.; Ingemarsson, A.; Lantz, M.; Arendse, G.J.; Auce, A.; Cox, A.J.; Foertsch, S.V.; Jacobs, N.M.; Johansson, R.; Nyberg, J.; Peavy, J.; Renberg, P.-U.; Sundberg, O.; Stander, J.A.; Steyn, G.F.; Tibell, G.; Zorro, R.
2005-01-01
An experimental procedure for measuring reaction cross-sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross-sections for five different sizes of the solid angle in steps from 99.1% to 99.8% of the total solid angle. The final reaction cross-section values are obtained by extrapolation to the full solid angle
Testing of cross section libraries for TRIGA criticality benchmark
International Nuclear Information System (INIS)
Snoj, L.; Trkov, A.; Ravnik, M.
2007-01-01
Influence of various up-to-date cross section libraries on the multiplication factor of TRIGA benchmark as well as the influence of fuel composition on the multiplication factor of the system composed of various types of TRIGA fuel elements was investigated. It was observed that keff calculated by using the ENDF/B VII cross section library is systematically higher than using the ENDF/B-VI cross section library. The main contributions (∼ 2 20 pcm) are from 235 U and Zr. (author)
Evaluation of fusion-evaporation cross-section calculations
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.
Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier
International Nuclear Information System (INIS)
Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.
2008-01-01
Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions
Cross-Sectional Analysis of Longitudinal Mediation Processes.
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.