WorldWideScience

Sample records for absolute cross sections

  1. Absolute cross sections for dissociative electron attachment to HCCCN

    New absolute cross sections for dissociative electron attachment to HCCCN (cyanoacetylene or propiolonitrile) in the range of 0–10 eV electron energy are presented here, which have been determined from a new analysis of previously reported data (Graupner et al 2006 New J. Phys. 8 117). The highest cross sections are observed for the formation of CN− at 5.3 eV and CCCN− at 5.1 eV; approximately 0.06 Å2 and 0.05 Å2 respectively. As part of the re-analysis, it was necessary to determine absolute cross sections for electron-impact ionization of HCCCN with the binary-encounter Bethe method. These electron-impact ionization absolute cross sections for HCCCN are also presented here; the maximum value was found to be ∼6.6 Å2 at ∼80 eV. (paper)

  2. Absolute Total np and pp Cross Section Determinations

    Arndt, R A; Laptev, A B; Strakovsky, I I; Workman, R L

    2008-01-01

    Absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses of NN scattering data. These cross sections are compared with most recent ENDF/B and JENDL data files, and the Nijmegen partial-wave analysis. Systematic deviations from the ENDF/B and JENDL evaluations are found to exist in the low-energy region.

  3. Absolute cross-section of turbojet aviation engine calculation

    Ryabokon, Evgen

    2012-01-01

    The calculation method of three-dimensional model of turbojet aviation engine is offered, thus the form of turbine vanes with spiralling is described like parametric surface. The method allows make the calculation of absolute cross-section (ACS) of turbojet aviation engines with different geometrical parameters. The calculation results of ACS of aviation engine are presented.

  4. Absolute photoionization cross-section of the propargyl radical

    Savee, John D.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L. [Sandia National Laboratories, Combustion Research Facility, Livermore, California 94551 (United States); Soorkia, Satchin [Institut des Sciences Moleculaires d' Orsay, Universite Paris-Sud 11, Orsay (France); Selby, Talitha M. [Department of Chemistry, University of Wisconsin, Washington County Campus, West Bend, Wisconsin 53095 (United States)

    2012-04-07

    Using synchrotron-generated vacuum-ultraviolet radiation and multiplexed time-resolved photoionization mass spectrometry we have measured the absolute photoionization cross-section for the propargyl (C{sub 3}H{sub 3}) radical, {sigma}{sub propargyl}{sup ion}(E), relative to the known absolute cross-section of the methyl (CH{sub 3}) radical. We generated a stoichiometric 1:1 ratio of C{sub 3}H{sub 3} : CH{sub 3} from 193 nm photolysis of two different C{sub 4}H{sub 6} isomers (1-butyne and 1,3-butadiene). Photolysis of 1-butyne yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(26.1{+-}4.2) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(23.4{+-}3.2) Mb, whereas photolysis of 1,3-butadiene yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(23.6{+-}3.6) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(25.1{+-}3.5) Mb. These measurements place our relative photoionization cross-section spectrum for propargyl on an absolute scale between 8.6 and 10.5 eV. The cross-section derived from our results is approximately a factor of three larger than previous determinations.

  5. The absolute threshold photodetachment cross-section of Al-

    The total absolute photodetachment cross-section of the aluminum anion, Al-, is calculated in the threshold spectral region for photons of wave numbers 3400 - 3650cm-1 using the zero-core contribution (ZCC) model. A computer least-squares curve fit is used to test the validity of the Wigner threshold law and the deviation from recent experimental measurements of the relative photodetachment cross-section. It is found that the best agreements is achieved with a smaller core radius rο=1.60 Angstrom rather than the value of 1.82 Angstrom used earlier. (authors). 22 refs., 5 figs., 1 tab

  6. Absolute cross sections for electron collisions with diacetylene: Elastic scattering, vibrational excitation and dissociative attachment

    We present absolute experimental cross sections for elastic scattering, vibrational excitation by electron impact and for dissociative electron attachment to 1,3-butadiyne, as well as calculations of the elastic cross sections.

  7. Absolute measurements of neutron cross sections. Progress report

    In the photoneutron laboratory, we have completed a major refurbishing of experimental facilities and begun work on measurements of the capture cross section in thorium and U-238. In the 14 MeV neutron experimental bay, work continues on the measurement of 14 MeV neutron induced reactions of interest as standards or because of their technological importance. First results have been obtained over the past year, and we are extending these measurements along the lines outlined in our proposal of a year ago

  8. Absolute cross-section normalization of magnetic neutron scattering data

    Xu, Guangyong; Xu, Zhijun; Tranquada, J. M.

    2013-01-01

    We discuss various methods to obtain the resolution volume for neutron scattering experiments, in order to perform absolute normalization on inelastic magnetic neutron scattering data. Examples from previous experiments are given. We also try to provide clear definitions of a number of physical quantities which are commonly used to describe neutron magnetic scattering results, including the dynamic spin correlation function and the imaginary part of the dynamic susceptibility. Formulas that c...

  9. Absolute Differential Cross Sections for Elastic Scattering of Electrons from CO at Intermediate and High Energies

    SHI De-Heng; LIU Yu-Fang; SUN Jin-Feng; YANG Xiang-Dong; ZHU Zun-Lue

    2005-01-01

    @@ The additivity rule model together with the complex optical model potential correlated by the concept of bonded atoms, which considers the overlapping effect of electron clouds between two atoms in a molecule, is firstly employed to calculate the absolute differential cross sections for electrons scattered by carbon monoxide at intermediate and high energies at the Hartree-Fock level. A comparison of elastic differential cross section results, obtained by using the correlated complex optical model potential, with the available experimental data,shows a significant improvement over the uncorrelated ones. The differential cross sections obtained by using the correlated complex optical model potential are in very good agreement with the experimental data. It is shown that the additivity rule model together with the correlated complex optical model potential is suitable for the calculations of the absolute differential cross sections of e-CO scattering.

  10. Absolute Absorption Cross Sections from Photon Recoil in a Matter-Wave Interferometer

    Eibenberger, Sandra; Cheng, Xiaxi; Cotter, J. P.; Arndt, Markus

    2014-06-01

    We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light field of a probe laser some molecules will absorb a single photon. These absorption events impart a momentum recoil which shifts the position of the molecule relative to the unperturbed beam. Averaging over the shifted and unshifted components within the beam leads to a reduction of the fringe visibility, enabling the absolute absorption cross section to be extracted with high accuracy. This technique is independent of the molecular density, it is minimally invasive and successfully eliminates many problems related to photon cycling, state mixing, photobleaching, photoinduced heating, fragmentation, and ionization. It can therefore be extended to a wide variety of neutral molecules, clusters, and nanoparticles.

  11. Absolute absorption cross sections from photon recoil in a matter-wave interferometer

    Eibenberger, Sandra; Cotter, J P; Arndt, Markus

    2014-01-01

    We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light field of a probe laser some molecules will absorb a single photon. These absorption events impart a momentum recoil which shifts the position of the molecule relative to the unperturbed beam. Averaging over the shifted and unshifted components within the beam leads to a reduction of the fringe visibility, enabling the absolute absorption cross section to be extracted with high accuracy. This technique is independent of the molecular density, it is minimally invasive and successfully eliminates all problems related to photon-cycling, state-mixing, photo-bleaching, photo-induced heating, fragmentation and ionization. It can therefore be extended to a wide variety of neutral molecules, clusters and nanoparticles.

  12. Absolute cross sections for dissociative electron attachment to acetylene and diacetylene

    May, Olivier; Fedor, Juraj; Ibănescu, Bogdan C.; Allan, Michael

    2008-01-01

    Absolute cross sections for the production of the two astronomy-relevant negative ions H−C≡C⁻ and H−C≡C−C≡C⁻ by dissociative electron attachment to acetylene C₂H₂ and diacetylene C₄H₂ were measured (with a ±25% error bar). Acetylene yielded the C₂H⁻ ion at an electron energy of 2.95  eV with a cross section of 3.6±0.9  pm² and also the C₂⁻ ion at 8.1  eV with a cross section of 4.1±1  pm². Diacetylene yielded the C₄H⁻ ion at 2.5  eV with a cross section of 3.0±0.8  pm² and at 5.25  eVwith a c...

  13. Measurements of absolute absorption cross sections of ozone in the 185- to 254-nm wavelength region and the temperature dependence

    Yoshino, K.; Esmond, J. R.; Freeman, D. E.; Parkinson, W. H.

    1993-01-01

    Laboratory measurements of the relative absorption cross sections of ozone at temperatures 195, 228, and 295 K have been made throughout the 185 to 254 nm wavelength region. The absolute absorption cross sections at the same temperatures have been measured at several discrete wavelengths in the 185 to 250 nm region. The absolute cross sections of ozone have been used to put the relative cross sections on a firm absolute basis throughout the 185 to 255 nm region. These recalibrated cross sections are slightly lower than those of Molina and Molina (1986), but the differences are within a few percent and would not be significant in atmospheric applications.

  14. Absolute measurement of the 242Pu neutron-capture cross section

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  15. Absolute measurement of $sup 235$U fission cross-section for 2200 m/sec neutrons

    Borcea, C.; Borza, A.; Buta, A.

    1973-12-31

    The results of an absolute fission cross-section measurement of /sup 235/ U are presented; the thermal neutrons were selected by the time-of-flight method. The principle of the method and the experimental apparatus are described. The method had the advantage of avoiding the use of an intermediate cross section in the neutron flux determination by choice of a B target thick enough to absorb all thermal neutrons. Target preparation, efficiency determination, corrections, etc., are reported. The value determined was 581.7 plus or minus 7.8 barns. (6 figures, 4 tables) (RWR)

  16. Absolute triple differential cross sections for photo-double ionization of helium-experiment and theory

    Braeuning, H. [Department of Physics, Kansas State University, Manhattan, KA 66506 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Doerner, R.; Braeuning-Demian, A.; Mergel, V.; Schmidt-Boecking, H. [Institut fuer Kernphysik, Universitaet Frankfurt, August-Euler-Strasse 6, D60486 Frankfurt (Germany); Cocke, C.L.; Carnes, K.; Richard, P. [Department of Physics, Kansas State University, Manhattan, KA 66506 (United States); Prior, M.H.; Dreuil, S. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kraessig, B. [Argonne National Laboratory, Argonne, IL 60439 (United States); Kheifets, A.S. [Australian National University, Canberra ACT 0200 (Australia); Bray, I. [Flinders University, GPO Box 2100, Adelaide 5001 (Australia); Ullrich, J. [Universitaet Freiburg, 79104 Freiburg (Germany)

    1998-12-14

    We have measured absolute triple differential cross sections for photo-double ionization of helium at 20 eV excess. The measurement covers the full ranges of energy sharing and emission angles of the two photoelectrons. We compare our data for selected geometries with the convergent close-coupling (CCC) calculations as well as 2SC calculations by Pont and Shakeshaft and 3C calculations by Maulbetsch and Briggs. In terms of the absolute magnitude and the trend in the shapes of the triple differential cross section for different geometries we find good agreement of the CCC and published 2SC calculations with our measurement, though differences with respect to the observed shape of individual patterns still exist. (author)

  17. Absolute X-ray emission cross section measurements of Fe K transitions

    Hell, Natalie; Brown, Gregory V.; Beiersdorfer, Peter; Boyce, Kevin R.; Grinberg, Victoria; Kelley, Richard L.; Kilbourne, Caroline; Leutenegger, Maurice A.; Porter, Frederick Scott; Wilms, Jörn

    2016-06-01

    We have measured the absolute X-ray emission cross sections of K-shell transitions in highly charged L- and K-shell Fe ions using the LLNL EBIT-I electron beam ion trap and the NASA GSFC EBIT Calorimeter Spectrometer (ECS). The cross sections are determined by using the ECS to simultaneously record the spectrum of the bound-bound K-shell transitions and the emission from radiative recombination from trapped Fe ions. The measured spectrum is then brought to an absolute scale by normalizing the measured flux in the radiative recombination features to their theoretical cross sections, which are well known. Once the spectrum is brought to an absolute scale, the cross sections of the K-shell transitions are determined. These measurements are made possible by the ECS, which consists of a 32 channel array, with 14 channels optimized for detecting high energy photons (hν > 10 keV) and 18 channels optimized for detecting low energy photons (hν collection area, relatively high energy resolution, and a large bandpass; all properties necessary for this measurement technique to be successful. These data will be used to benchmark cross sections in the atomic reference data bases underlying the plasma modeling codes used to analyze astrophysical spectra, especially those measured by the Soft X-ray Spectrometer calorimeter instrument recently launched on the Hitomi X-ray Observatory.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and supported by NASA grants to LLNL and NASA/GSFC and by ESA under contract No. 4000114313/15/NL/CB.

  18. On the absolute photoionization cross section and dissociative photoionization of cyclopropenylidene.

    Holzmeier, Fabian; Fischer, Ingo; Kiendl, Benjamin; Krueger, Anke; Bodi, Andras; Hemberger, Patrick

    2016-04-01

    We report the determination of the absolute photoionization cross section of cyclopropenylidene, c-C3H2, and the heat of formation of the C3H radical and ion derived by the dissociative ionization of the carbene. Vacuum ultraviolet (VUV) synchrotron radiation as provided by the Swiss Light Source and imaging photoelectron photoion coincidence (iPEPICO) were employed. Cyclopropenylidene was generated by pyrolysis of a quadricyclane precursor in a 1 : 1 ratio with benzene, which enabled us to derive the carbene's near threshold absolute photoionization cross section from the photoionization yield of the two pyrolysis products and the known cross section of benzene. The cross section at 9.5 eV, for example, was determined to be 4.5 ± 1.4 Mb. Upon dissociative ionization the carbene decomposes by hydrogen atom loss to the linear isomer of C3H(+). The appearance energy for this process was determined to be AE(0K)(c-C3H2; l-C3H(+)) = 13.67 ± 0.10 eV. The heat of formation of neutral and cationic C3H was derived from this value via a thermochemical cycle as Δ(f)H(0K)(C3H) = 725 ± 25 kJ mol(-1) and Δ(f)H(0K)(C3H(+)) = 1604 ± 19 kJ mol(-1), using a previously reported ionization energy of C3H. PMID:26975696

  19. Absolute experimental cross sections for the electron impact ionization of rubidium. Technical summary report

    The absolute cross sections for the double, triple, and quadruple ionization of Rb+ ions by electron impact have been measured from below their respective thresholds to approximately 3000 eV. This determination has been accomplished using a crossed beam facility in which monoenergetic beams of ions and electrons are caused to intersect at right angles in a well-defined collision volume. Multiply charged, product ions born as a result of the electron impact are deflected into their respective detectors by cascaded electrostatic analyzers. The multiply charged beam current component is measured by means of a vibrating reed electrometer operating in the rate-of-charge mode. The required singly charged rubidium ions are produced in a thermionic ion source and pass through a series of focusing, collimating and deflecting structures before entering the interaction region. A thermionically generated, rectangular electron beam intercepts the target ions in a spatially designated collision volume. Just prior to entering this interaction region the two beams can be made to pass through a movable slit scanner which determines their spatial profiles. The various charged particle currents, energies and beam current density distributions represent the experimental data from which the desired absolute cross sections have been determined. The results obtained with this technique are compared with available theoretical predictions of the appropriate cross sections

  20. Absolute absorption cross-section measurements of ozone in the wavelength region 238-335 nm and the temperature dependence

    Yoshino, K.; Freeman, D. E.; Esmond, J. R.; Parkinson, W. H.

    1988-01-01

    The absolute absorption cross-section of ozone has been experimentally determined at the temperatures 195, 228, and 295 K at several discrete wavelengths in the 238-335-nm region. The present results for ozone at 295 K are found to be in agreement with those of Hearn (1961). Absolute cross-section measurements of ozone at 195 K have confirmed previous (Freeman et al., 1984) relative cross-section measurements throughout the 240-335-nm region.

  1. Absolute measurements of the fast neutron capture cross section of 115In

    The 115In(n,#betta#)/sup 116m1/In cross section has been absolutely determined at neutron energies of 23, 265 and 964 keV. These energies are the median neutron energies of the three photo-neutron sources. Sb-Be, Na-CD2 and Na-Be, utilized in this work. The measurements are independent of other cross section data except for corrections amounting to less than 10%. Independent determinations of the reaction rate, detector efficiency, neutron source strength, scalar flux and target masses were performed. Reaction rates were determined by beta counting of the /sup 116ml/In decay activity using a 4π gas flow proportional counter. Detector efficiency was measured using 4π#betta#-#betta# coincidence counting techniques and the foil absorber method of efficiency extrapolation for correction of complex decay scheme effects. Photoneutron source emission rates were determined by intercomparison with the NBS-II calibrated 252Cf spontaneous fission neutron source in the University of Michigan Manganese Bath. The normalized scalar flux was calculated from the neutron emission angular distribution results of the Monte Carlo computer program used to model neutron and gamma transport in the source. Target mass determinations were made with a microbalance. Correction factors were applied for competing reaction activities, neutron scattering from experiment components, room-return induced activities, spectral effects in the manganese bath and the neutron energy spectra of the photoneutron sources. Experimental cross section results were normalized to the source median energy using energy spectra d cross section shape data. The absolute cross sections obtained for the 115In(n,#betta#)/sup 116ml/In reaction were 588 +- 12, 196 +- 4 and 200 +- 3 millibarns at 23, 265 and 964 keV, respectively

  2. Measurement of the absolute values of cross-sections in neutron photoproduction (1962)

    The absolute values of photoneutrons production cross-sections for the case of intermediate and heavy nuclei (lanthanium, cerium, tantalum, gold, lead and bismuth) are determined with an error of 15 per cent. The results obtained agree with theories in which the giant resonance is explained by the collective motion of the protons against the neutrons. The effect of the nuclear deformation on the shape of the giant resonance is seen in the case of Ta181, it will be possible to determine the quadrupole momenta of deformed nuclei with a good accuracy when we shall increase the statistics of measurements. (author)

  3. Absolute absorption cross-section and photolysis rate of I2

    J. M. C. Plane

    2004-05-01

    Full Text Available Following recent observations of molecular iodine (I2 in the coastal marine boundary layer (MBL (Saiz-Lopez and Plane, 2004, it has become important to determine the absolute absorption cross-section of I2 at reasonably high resolution, and also to evaluate the rate of photolysis of the molecule in the lower atmosphere. The absolute absorption cross-section (σ of gaseous I2 at room temperature and pressure (295 K, 760 Torr was therefore measured between 182 and 750 nm using a Fourier Transform spectrometer at a resolution of 4 cm−1 (0.1 nm at λ=500 nm. The maximum absorption cross-section in the visible region was observed at λ=533.0 nm to be σ=(4.84±0.60×10−18cm2 molecule−1. The spectrum is available as supplementary material accompanying this paper. The photo-dissociation rate constant (J of gaseous I2 was also measured directly in a solar simulator, yielding J(I2=0.12±0.03 s−1 for the lower troposphere. This agrees well with the value of 0.15±0.03 s−1 calculated using the measured absorption cross-section, terrestrial solar flux for clear sky conditions and assuming a photo-dissociation yield of unity. A two-stream radiation transfer model was then used to determine the variation in photolysis rate with solar zenith angle (SZA, from which an analytic expression is derived for use in atmospheric models. Photolysis appears to be the dominant loss process for I2 during daytime, and hence an important source of iodine atoms in the lower atmosphere.

  4. Absolute absorption cross-section and photolysis rate of I2

    A. Saiz-Lopez

    2004-01-01

    Full Text Available Following recent observations of molecular iodine (I2 in the coastal marine boundary layer (MBL (Saiz-Lopez and Plane, 2004, it has become important to determine the absolute absorption cross-section of I2 at reasonably high resolution, and also to evaluate the rate of photolysis of the molecule in the lower atmosphere. The absolute absorption cross-section (σ of gaseous I2 at room temperature and pressure (295K, 760Torr was therefore measured between 182 and 750nm using a Fourier Transform spectrometer at a resolution of 4cm-1 (0.1nm at λ=500nm. The maximum absorption cross-section in the visible region was observed at λ=533.0nm to be σ=(4.24±0.50x10-18cm2molecule-1. The spectrum is available as supplementary material accompanying this paper. The photo-dissociation rate constant (J of gaseous I2 was also measured directly in a solar simulator, yielding J(I2=0.12±0.03s-1 for the lower troposphere. This is in excellent agreement with the value of 0.12±0.015s-1 calculated using the measured absorption cross-section, terrestrial solar flux for clear sky conditions and assuming a photo-dissociation yield of unity. A two-stream radiation transfer model was then used to determine the variation in photolysis rate with solar zenith angle (SZA, from which an analytic expression is derived for use in atmospheric models. Photolysis appears to be the dominant loss process for I2 during daytime, and hence an important source of iodine atoms in the lower atmosphere.

  5. Absolute luminosity and proton-proton total cross section measurement for the ATLAS experiment at LHC

    The Large Hadron Collider (LHC) at CERN in Geneva will soon deliver collisions with an energy never reached in a particle accelerator. An energy in the center of mass of 10 and ultimately 14 TeV will allow to go beyond the borders of the physics known so far. ATLAS, the largest detector ever built, will hunt the Higgs boson and search for new physics beyond the Standard Model. Any physical process is described by a cross section that measures its probability to occur. The events resulting from a given process are registered by ATLAS. To determine their according cross section, one has to know the luminosity. For the ATLAS experiment, a relative measurement of the luminosity can be done using the response of several sub-detectors. However to calibrate these detectors, an absolute measurement has to be performed. The ALFA detector has been designed to measure the elastic scattering spectrum that will allow to determine the absolute luminosity and the proton-proton total cross section. This provides an accurate calibration tool at a percent level. These detectors, located 240 m away from the interaction point, are called roman pots, a mechanical system that allows to approach a scintillating fiber tracker a few millimeters to the beam center. The simulation of the measurement requires to use a charged particles transport program. This program has to be carefully chosen because the determination of the protons lost during their travel from the interaction point to the detector has a major impact on the acceptance computation. The systematical uncertainties affecting the luminosity and the total cross section measurements are also determined using the full simulation chain. The ALFA detector operates in a complex environment and consequently its design requires a great care. A large tests campaign has been performed on the front end electronics. The results and the corresponding data analysis have shown that all requirement where fulfilled. A test beam has been

  6. Absolute cross sections for helium single and double ionization in collisions with fast, highly charged projectiles

    Absolute cross sections for single and double ionization of helium have been measured for highly charged (24 ≤ q ≤ 92) and fast (3.6 MeV/u ≤ Ep ≤ 1 GeV/u) heavy-ion impact. The ratio of double to single ionization is found to deviate drastically from the prediction of first order theories: In the strong perturbation regime they fall below the scaling of Knudsen et al. (1984) even for 120 MeV/u U91+ impact, whereas a dramatic increase by a factor of 4 is observed in the regime of low perturbations for 0.5 and 1 GeV/u Kr36+ impact. At low reduced energies of Ep/q 2, as has been observed previously for the regime of strong coupling. (orig.)

  7. Absolute differential and total cross sections for neutral fragments from dissociative collisions of triatomic hydrogen like ions on He

    Yousif, F B [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Fuentes, B E [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apdo Postal 70542, 04510 Coyoacan, Mexico, DF (Mexico); MartInez, H [Instituto de Ciencias FIsicas, Universidad Nacional Autonoma de Mexico, Apdo Postal 48-3, 62210, Cuernavaca, Morelos (Mexico)

    2010-12-14

    Neutral fragment products from dissociative collisions of triatomic hydrogen like ions incident on He atoms were studied. Absolute differential and total cross sections are reported here in the energy range of 1.00-5.00 keV and scattering angles between -5.0{sup 0} and 5.0{sup 0}. The differential cross sections show decreasing behaviour with a slight structure around 2.0{sup 0}. The total cross sections for all triatomic molecular ions studied in this work are found to be comparable for the same velocity (E/M). The measured cross sections are between 0.7 x 10{sup -17} cm{sup 2} and 0.9 x 10{sup -16} cm{sup 2}. The present results for the neutral total cross section correlate very well with previously measured total ions cross section for H{sup +}{sub 3}, D{sup +}{sub 3} and HD{sup +}{sub 2} on He.

  8. Absolute differential and total cross sections for neutral fragments from dissociative collisions of triatomic hydrogen like ions on He

    Yousif, F. B.; Fuentes, B. E.; Martínez, H.

    2010-12-01

    Neutral fragment products from dissociative collisions of triatomic hydrogen like ions incident on He atoms were studied. Absolute differential and total cross sections are reported here in the energy range of 1.00-5.00 keV and scattering angles between -5.0° and 5.0°. The differential cross sections show decreasing behaviour with a slight structure around 2.0°. The total cross sections for all triatomic molecular ions studied in this work are found to be comparable for the same velocity (E/M). The measured cross sections are between 0.7 × 10-17 cm2 and 0.9 × 10-16 cm2. The present results for the neutral total cross section correlate very well with previously measured total ions cross section for H+3, D+3 and HD+2 on He.

  9. Absolute high-resolution Se+ photoionization cross-section measurements with Rydberg-series analysis

    Absolute single photoionization cross-section measurements for Se+ ions were performed at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the photo-ion merged-beams technique. Measurements were made at a photon energy resolution of 5.5 meV from 17.75 to 21.85 eV spanning the 4s24p34S3/2o ground-state ionization threshold and the 2P3/2o,2P1/2o,2D5/2o, and2D3/2o metastable state thresholds. Extensive analysis of the complex resonant structure in this region identified numerous Rydberg series of resonances and obtained the Se2+ 4s24p23P2 and 4s24p21S0 state energies. In addition, particular attention was given to removing significant effects in the measurements due to a small percentage of higher-order undulator radiation.

  10. A semi-empirical formula for calculation of absolute cross sections for ionization and excitation of atoms by electrons

    Vriens, L.

    1965-01-01

    A simple analytical expression for the absolute ionization and (optically allowed) excitation cross sections, as a function of the electron energy, is “derived”. In this expression there are two parameters. The first one is proportional to the optical oscillator strength and the second one is depend

  11. Absolute total cross sections for the scattering of 2--18-eV electrons by cesium atoms

    Absolute total cross sections for the scattering of electrons by cesium atoms between 2 and 18 eV have been measured using the atomic-recoil technique in the scattering-out mode. Our results are somewhat lower than those of Visconti, Slevin, and Rubin [Phys. Rev. A 3, 1310 (1971)] above 2 eV

  12. Absolute total cross sections for the scattering of 2--18-eV electrons by cesium atoms

    Jaduszliwer, B.; Chan, Y.C. (Electronics Technology Center, The Aerospace Corporation, P. O. Box 92957, Los Angeles, California 90009 (United States))

    1992-01-01

    Absolute total cross sections for the scattering of electrons by cesium atoms between 2 and 18 eV have been measured using the atomic-recoil technique in the scattering-out mode. Our results are somewhat lower than those of Visconti, Slevin, and Rubin (Phys. Rev. A 3, 1310 (1971)) above 2 eV.

  13. Absolute cross sections for electronic excitation of pyrimidine by electron impact

    Regeta, Khrystyna; Allan, Michael [Department of Chemistry, University of Fribourg, Chemin du Musée 9, CH-1700 Fribourg (Switzerland); Mašín, Zdeněk [Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Straße 2A, 12489 Berlin (Germany); Gorfinkiel, Jimena D. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2016-01-14

    We measured differential cross sections for electron-impact electronic excitation of pyrimidine, both as a function of electron energy up to 18 eV, and of scattering angle up to 180°. The emphasis of the present work is on recording detailed excitation functions revealing resonances in the excitation process. The differential cross sections were summed to obtain integral cross sections. These are compared to results of R-matrix calculations, which successfully reproduce both the magnitude of the cross section and the major resonant features. Comparison of the experiment to the calculated contributions of different symmetries to the integral cross section permitted assignment of several features to specific core-excited resonances. Comparison of the resonant structure of pyrimidine with that of benzene revealed pronounced similarities and thus a dominant role of π–π{sup ∗} excited states and resonances. Electron energy loss spectra were measured as a preparation for the cross section measurements and vibrational structure was observed for some of the triplet states. A detailed analysis of the electronic excited states of pyrimidine is also presented.

  14. Absolute cross sections for projectile electron loss accompanied by target multiple ionization in collisions of He+ with noble gases

    Santos, A. C. F.; Sigaud, G. M.; Melo, W. S.; Sant'Anna, M. M.; Montenegro, E. C.

    2011-02-01

    Absolute cross sections for projectile electron loss accompanied by target multiple ionization in collisions between He+ ions and noble gases have been measured for energies between 1.0 and 3.5 MeV. The data have been compared with other absolute cross sections that exist in the literature for the same projectile, and with calculations for the screening mode (nucleus-electron interaction) using both perturbative (plane-wave Born approximation (PWBA)) and non-perturbative (extended classical-impulse free-collision model, sudden approximation and coupled-channel method) approaches, and for the antiscreening mode (electron-electron interaction) within the PWBA. The energy dependence of the average number of active electrons for the antiscreening has been described by means of a simple function, which is 'universal' for noble gases but projectile dependent. A previously developed method has been employed to obtain the number of active electrons for each target subshell in the high-velocity regime.

  15. Absolute cross sections for projectile electron loss accompanied by target multiple ionization in collisions of He+ with noble gases

    Absolute cross sections for projectile electron loss accompanied by target multiple ionization in collisions between He+ ions and noble gases have been measured for energies between 1.0 and 3.5 MeV. The data have been compared with other absolute cross sections that exist in the literature for the same projectile, and with calculations for the screening mode (nucleus-electron interaction) using both perturbative (plane-wave Born approximation (PWBA)) and non-perturbative (extended classical-impulse free-collision model, sudden approximation and coupled-channel method) approaches, and for the antiscreening mode (electron-electron interaction) within the PWBA. The energy dependence of the average number of active electrons for the antiscreening has been described by means of a simple function, which is 'universal' for noble gases but projectile dependent. A previously developed method has been employed to obtain the number of active electrons for each target subshell in the high-velocity regime.

  16. Absolute differential, elastic integrated and moment transfer cross sections for electron-OCS collisions at intermediate and high energies

    Shi De-Heng; Sun Jin-Feng; Zhu Zun-Lue; Ma Heng; Liu Yu-Fang; Yang Xiang-Dong

    2007-01-01

    A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between atoms in a molecule, is firstly employed to calculate the absolute differential, elastic integrated and moment transfer cross sections for electron scattering by OCS over the incident energy range from 200 to 1000 eV using the additivity rule model at Hartree-Fock level. The calculated results are compared with those obtained by experiment and other theories wherever available, and good agreement is obtained over a wide energy range. It is shown that the additivity rule model together with the modified potential is completely suitable for calculating the absolute differential, elastic integrated and moment transfer cross sections of electron scattering by molecules such as OCS.

  17. Absolute total and partial cross sections for ionization of nucleobases by proton impact in the Bragg peak velocity range

    Tabet, J.; Eden, S.; Feil, S.; Abdoul-Carime, H.; Farizon, B.; Farizon, M.; Ouaskit, S.; Märk, T.D.

    2010-01-01

    We present experimental results for 80 keV proton impact ionization of nucleobases (adenine, cytosine, thymine and uracil) based on an event by event analysis of the different ions produced combined with an absolute target density determination. We are able to disentangle in detail the various proton ionization channels from mass analyzed product ion signals in coincidence with the charge-analyzed projectile. Thus, for the first time, cross sections and fragmentation patterns are compared for...

  18. Absolute elastic differential electron scattering cross sections in the intermediate energy region. III - SF6 and UF6

    Srivastava, S. K.; Trajmar, S.; Chutjian, A.; Williams, W.

    1976-01-01

    A recently developed technique has been used to measure the ratios of elastic differential electron scattering cross sections (DCS) for SF6 and UF6 to those of He at electron impact energies of 5, 10, 15, 20, 30, 40, 50, 60, and 75 eV and at scattering angles of 20 to 135 deg. In order to obtain the absolute values of DCS from these ratios, He DCS of McConkey and Preston have been employed in the 20 to 90 deg range. At angles in the 90 to 135 deg range the recently determined cross sections of Srivastava and Trajmar have been utilized. From these DCS, elastic integral and momentum transfer cross sections have been obtained.

  19. Fusion cross sections for 12C+128Te and the deduction of absolute average angular momenta

    Fusion cross sections have been measured for 12C+128Te from Ec.m.=40.4 to 56.6 MeV by direct detection and identification of evaporation residues using a time-of-flight technique. Average angular momenta for fusion are deduced from a sharp cutoff approximation at energies above the Coulomb barrier. These values of left-angle l right-angle and those already obtained from isomer ratio measurements are in very good agreement in the energy region where both methods should be valid

  20. Absolute measurement of 115In capture cross section at 144 and 565 keV

    The cross section of 115In(n, γ) 116mIn reaction are measured at 144 keV and 565 keV neutron energy by activation technique. The neutron fluence is measured by using H2 and CH4 filled proportional counter. A 4πβ counter is used to determine the β activities of 116mIn. The efficiency of the β detector is determined by 4πβ-γ coincidence techniques. A Monte-Carlo program is used to calculate the effect for neutron scattering from target, sample and holder. The results are compared with others

  1. Absolute cross sections for photoionization of Xeq+ ions (1 ⩽ q ⩽ 5) at the 3d ionization threshold

    The photon-ion merged-beams technique has been employed at the new Photon-Ion spectrometer at PETRA III for measuring multiple photoionization of Xeq+ (q = 1–5) ions. Total ionization cross sections have been obtained on an absolute scale for the dominant ionization reactions of the type hν + Xeq+ → Xer+ + (q − r)e− with product charge states q + 2 ⩽ r ⩽ q + 5. Prominent ionization features are observed in the photon-energy range 650–750 eV, which are associated with excitation or ionization of an inner-shell 3d electron. Single-configuration Dirac–Fock calculations agree quantitatively with the experimental cross sections for non-resonant photoabsorption, but fail to reproduce all details of the measured ionization resonance structures. (paper)

  2. Measurement of the absolute vμ-CCQE cross section at the SciBooNE experiment

    Aunion, Jose Luis Alcaraz [Autonomous Univ. of Barcelona (Spain)

    2010-07-01

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 1020 protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 1020 POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  3. Measurement of the absolute νμ-CCQE cross section at the SciBooNE experiment

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 1020 protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 1020 POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  4. ABSOLUTE CROSS SECTIONS FOR ONE-PHONON RAMAN SCATTERING FROM SEVERAL INSULATORS AND SEMICONDUCTORS

    Calleja, J; H. Vogt; Cardona, M.

    1981-01-01

    Using the Brillouin-Raman method we have measured the Raman scattering efficiencies for the Ɖ phonons of GaP, ZnTe, ZnSe, ZnS as well as CaF2, SrF2, BaF2. The results for the zincblende-type materials allow us to calibrate in absolute scattering efficiency units the resonance Raman curves found in the literature. From the calibrated resonances the deformation potential do is deduced on the basis of a parabolic band model. For the fluorides the scattering efficiency is attributed to the adge e...

  5. Method for the absolute measurement of the total pair production cross section near threshold using a source of variable energy

    A method for the absolute measurement of the total pair production cross section in germanium near threshold is presented, using a source of photons of variable energy. This source is constituted by Compton scattered photons in lead. The incident beam is produced by the collimation of an intense source of 60Co (8 Ci). By continuous variation of the scattering angle one obtains a continuous variation of the energy of the photons impinging on the target. Measurements are presented for energies ranging between 1240 and 1263 keV and between 1180 and 1207 keV by steps of 2.8 keV. The results are compared with the predictions of different theories (Born approximation, exact calculation without and with screening effects). (Auth.)

  6. Determination of fission cross-section and absolute fission yields using track-cum gamma-ray spectrometric technique

    The fission cross-section of 233Pa(2nth, f) using fission track technique has been determined for the first time using thermal neutron flux of the reactor APSARA. This is important from the point of view of advance heavy water reactor (AHWR), which is to be described. On the other hand, the yields of fission products in the fast neutron induced fission of minor actinides are important from the point accelerator driven sub critical system (ADSS). In view of that, absolute yields of fission products in the fast neutron induced fission of 238U, 237Np, 238,240Pu, 243Am and 244Cm have been determined using the fission track-cum gamma-ray spectrometric technique. The total number of fission occurring in the target was estimated by track technique, whereas the activities of the fission products have been determined using gamma-ray spectrometric technique. Detailed procedure and its importance are to be discussed. (author)

  7. Determination of the absolute two-photon ionization cross section of He by an XUV free electron laser

    The resonant and non-resonant two-photon single ionization processes of He were investigated using intense free electron laser light in the extreme ultraviolet (XUV) region (53.4-61.4 nm) covering the 1s-2p and 1s-3p resonant transitions of He. On the basis of the dependences of the yield of He+ on the XUV light-field intensity at 53.4, 58.4, 56.0 and 61.4 nm, the absolute values of the two-photon ionization cross sections of He at the four different wavelengths and their dependence on the light-field intensity were determined for the first time. (fast track communication)

  8. Absolute differential and total cross sections for charge transfer of O{sup +} ground and mixed states ions in N{sub 2}

    Martinez, H [Centro de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos, PO Box 48-3, 62251, Cuernavaca, Morelos (Mexico); Hernandez, C L [Centro de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos, PO Box 48-3, 62251, Cuernavaca, Morelos (Mexico); Yousif, F B [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Avenida Universidad 1001, 62210, Cuernavaca, Morelos (Mexico)

    2006-06-14

    We report measurements of the total and absolute differential cross sections for charge transfer of ground- and excited-states O{sup +} ions at 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 5 keV in collisions with N{sub 2} at scattering angles -5.2{sup 0} {<=} {theta} {<=} +5.2{sup 0} in the laboratory frame. Total cross sections for ground- and mixed state ions are compared with previous measurements. The behaviour of the absolute differential cross sections display an expected decreasing behaviour with increasing angle. The mixed state ions cross sections are considerably higher than those measured for the ground state ions.

  9. Absolute cross sections for photoionization of Xe$^{q+}$ ions (1 $\\le$ q $\\le$ 5) at the 3d ionization threshold

    Schippers, S; Buhr, T; Borovik, A; Hellhund, J; Holste, K; Huber, K; Schäfer, H -J; Schury, D; Klumpp, S; Mertens, K; Martins, M; Flesch, R; Ulrich, G; Rühl, E; Jahnke, T; Lower, J; Metz, D; Schmidt, L P H; Schöffler, M; Williams, J B; Glaser, L; Scholz, F; Seltmann, J; Viefhaus, J; Dorn, A; Wolf, A; Ullrich, J; Müller, A

    2014-01-01

    The photon-ion merged-beams technique has been employed at the new Photon-Ion spectrometer at PETRA III (PIPE) for measuring multiple photoionization of Xe$^{q+}$ (q=1-5) ions. Total ionization cross sections have been obtained on an absolute scale for the dominant ionization reactions of the type h\

  10. Measurement of Absolute Atomic Collision Cross Section with Helium Using 87Rb Atoms Confined in Magneto-Optic and Magnetic Traps

    WANG Ji-Cheng; ZHOU Ke-Ya; WANG Yue-Yuan; LIAO Qing-Hong; LIU Shu-Tian

    2011-01-01

    We present the measurements and calculations of the absolute total collision cross sections for a room-temperature gas of helium using 87 Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap. The loss rates from the magneto-optic trap and the pure magnetic trap are compared and show significant differences. The collision cross sections as a function of trap depth for helium gas are obtained. These findings are significant for extracting the information about the different cross sections when the trap depth is changed.%@@ We present the measurements and calculations of the absolute total collision cross sections for a room-temperature gas of helium using 87Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap.The loss rates from the magneto-optic trap and the pure magnetic trap are compared and show significant differences.The collision cross sections as a function of trap depth for helium gas are obtained.These findings are significant for extracting the information about the different cross sections when the trap depth is changed.

  11. Absolute photoionization cross section from the 6s6p {sup 1,3}P{sub 1} excited states of barium

    Kalyar, M A; Rafiq, M; Sami-ul-Haq; Baig, M A [Atomic and Molecular Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2007-06-28

    We present photoionization cross section measurements from the 6s6p {sup 1}P{sub 1} and {sup 3}P{sub 1} excited states of barium at and above the first ionization threshold. The experiments have been performed using a thermionic diode ion detector in a space charge limited mode in conjunction with a Nd:YAG laser system and the saturation technique to determine the photoionization cross sections. The absolute values of the photoionization cross section from the 6s6p {sup 1}P{sub 1} and {sup 3}P{sub 1} excited states at the first ionization threshold have been determined as 90 {+-} 14 Mb and 102 {+-} 15 Mb, respectively. The measured values of the photoionization cross section from the 6s6p {sup 1}P{sub 1} excited state are compared with available experimental and theoretical work, while the absolute photoionization cross sections from the 6s6p {sup 3}P{sub 1} excited state are reported for the first time.

  12. Absolute L-shell ionization and X-ray production cross sections of Lead and Thorium by 16-45 keV electron impact

    Rahangdale, H V; De, S; Santos, J P; Mitra, D; Guerra, M; Saha, S

    2015-01-01

    The absolute L subshell specific electron impact ionization cross sections near the ionization threshold (16 < E < 45 keV) of Lead and Thorium are obtained from the measured L X-ray production cross sections. Monte Carlo simulation is done to account for the effect of the backscattered electrons and the final experimental results are compared with calculations performed using distorted wave Born approximation and the modified relativistic binary encounter Bethe model.The sensitivity of the results on the atomic parameters is explored. Observed agreements and discrepancies between the experimental results and theoretical estimates, and their dependence on the specific atomic parameters are reported.

  13. Absolute cascade-free cross-sections for the 2S to 2P transition in Zn(+) using electron-energy-loss and merged-beams methods

    Smith, Steven J.; Man, K.-F.; Chutjian, A.; Mawhorter, R. J.; Williams, I. D.

    1991-01-01

    Absolute cascade-free excitation cross-sections in an ion have been measured for the resonance 2S to 2P transition in Zn(+) using electron-energy-loss and merged electron-ion beams methods. Measurements were carried out at electron energies of below threshold to 6 times threshold. Comparisons are made with 2-, 5-, and 15-state close-coupling and distorted-wave theories. There is good agreement between experiment and the 15-state close-coupling cross-sections over the energy range of the calculations.

  14. Absolute photo-absorption cross sections and electronic state spectroscopy of selected fluorinated hydrocarbons relevant to the plasma processing industry

    Photo-absorption cross sections have been measured for methyl iodide, CF3I (310 nm>λ>110 nm) and dichlorodifluoromethane, CCl2F2 (225 nm>λ>110 nm) using synchrotron radiation. Electron energy loss spectroscopy was also used to probe the electronic and vibronic excitation of CF3I. Electronic states have been assigned to each of the observed absorption bands incorporating both valence and Rydberg transitions. The measured VUV cross sections are used to derive the photolysis rates in the terrestrial atmosphere and hence determine the potential importance of each gas in global warming and ozone depletion

  15. Experimental and theoretical determinations of the absolute ionization cross section of alkali metals by electron impact in the energy range from 100 to 2000 eV

    The absolute electron impact ionization cross sections for the alkali metals in the energy range between 100 eV and 2000 eV were measured by the non-modulated crossed beam technique. The neutral beam of alkali atoms is produced by a Knudsen cell and crossed at right angles with the electron beam. The ions formed are collected on a plate and their intensity determined with a D.C. amplifier. The neutral beam is condensed on a cold trap cooled with liquid nitrogen, this temperature being much lower than that required to obtain total condensation. The amount of metal deposited is measured by the isotopic dilution technique and by atomic absorption, and the density of the atoms in the neutral beam is calculated. The total absolute ionization cross sections can then be determined. All possible errors have been carefully analyzed and their magnitudes estimated. The absolute ionization cross section for Li at an energy of 500 eV is: QLi = 0,358 x 10-16 cm2. This value is half of that obtained by Mac Farland and Kinney. The partial ionization cross sections for the singly and multiply charged ions is determined with a mass spectrometer attached to this apparatus. For the singly charged ions, the variation of the cross section with the energy of the ionizing electrons is in agreement with the optically allowed transition law: Q = A log BE/E. From the variation of Q with E, the squared matrix elements of the transition moment (|Mi|)2 are determined for all the elements studied. New calculations of the ionization cross section of Li and Na were performed in the framework of the Born-Bethe approximation as modified by Gaudin and Botter to take into account collisions with large momentum variation of the incident electron. Hartree-Fock type wave functions for the ground state atom (tabulated by Clementi) were used. The calculated values are in good agreement with our experimental results and with the former theoretical results calculated by various methods. This work also

  16. Calculated absolute electron-impact ionization cross sections for AlO, Al2O, and WOx (x=1-3)

    Deutsch, H.; Hilpert, K.; Becker, K.; Probst, M.; Märk, T. D.

    2001-02-01

    The Deutsch-Märk (DM) formalism was used to calculate absolute electron impact ionization cross sections for the metal oxide molecules AlO, Al2O, and WOx (x=1-3). These molecules are important in materials research and they are also found as impurities in the plasma edge of fusion reactors. We also calculated ionization cross sections for the atoms Al and W. In the case of the Al-containing compounds, we find an unexpected ordering of the maximum ionization cross section σmax, σmax(AlO)<σmax(Al)<σmax(Al2O). Furthermore, the maximum ionization cross section for all four W-containing compounds W, WO, WO2, and WO3 is roughly the same with σmax values in the range of 6-7×10-16 cm2. These findings can be understood by analyzing the DM calculations for these species as well as on the basis of semi-classical arguments. In addition, calculations using the semi-empirical modified additivity rule confirm the trends in the cross section ordering for, respectively, the Al-containing and W-containing compounds that was predicted by the DM formalism, at least qualitatively.

  17. High-resolution absolute photoabsorption cross sections for Ne in the 1s2s and 1s2p resonant double excitation

    Kato, Masahiro [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba, Ibaraki 305-8568 (Japan); Morishita, Yuichiro [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba, Ibaraki 305-8568 (Japan); Koike, Fumihiro [School of Medicine, Kitasato University, Kitasato, Sagamihara 228-8555 (Japan); Fritzsche, Stephan [Physics Department, Kassel University, Heinrich-Plett-strasse 40, D-34132 Kassel (Germany); Yamaoka, Hitoshi [RIKEN, Harima Institute, Sayo, Hyogo 679-5148 (Japan); Tamenori, Yusuke [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan (Japan); Okada, Kazumasa [Department of Chemistry, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Matsudo, Takahisa [Department of Chemistry, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Gejo, Tatsuo [University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Suzuki, Isao H [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba, Ibaraki 305-8568 (Japan); Saito, Norio [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba, Ibaraki 305-8568 (Japan)

    2006-04-28

    The high-resolution absolute photoabsorption cross sections with an absolute photon energy scale for Ne 1s2p/1s2s double excitation in the energy region of 900-940 eV have been measured using a multi-electrode ionization chamber and monochromatized synchrotron radiation. The Ne [1s2p]({sup 3,1}P)nln'l' doubly excited states observed in the energy range of 900-920 eV are analysed with the aid of theoretical calculations based on the multiconfiguration Dirac-Fock method. The second strongest peak in this energy region is assigned to be [1s2p]({sup 3}P)3p4p.

  18. Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Schmidt, H. T.; Cederquist, H.; Zettergren, H., E-mail: henning@fysik.su.se [Department of Physics, Stockholm University, S-106 91 Stockholm (Sweden); Zhang, Y. [Department of Mathematics, Faculty of Physics, M. V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Rousseau, P.; Maclot, S.; Delaunay, R.; Adoui, L. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen (France); Domaracka, A.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen Cedex 05 (France); Schlathölter, T. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2014-06-14

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

  19. Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH+) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH+ + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C6H5). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures

  20. Measurement and Calculation of Absolute Single and Multiple Charge Exchange Cross Sections for Fe^(q+) Ions Impacting H_2O

    Simcic, J.; Schultz, D R; Mawhorter, R.J.; greenwood, jason; Winstead, C.; McKoy, B. V.; S. J. Smith; Chutjian, A.

    2010-01-01

    Charge exchange (CE) plays a fundamental role in the collisions of solar- and stellar-wind ions with lunar and planetary exospheres, comets, and circumstellar clouds. Reported herein are absolute cross sections for single, double, triple, and quadruple CE of Fe^(q+) (q = 5-13) ions with H_2O at a collision energy of 7q keV. One measured value of the pentuple CE is also given for Fe^(9+) ions. An electron cyclotron resonance ion source is used to provide currents of the highly charged Fe ions....

  1. Velocity dependence of the absolute total ionization cross section for collisions of argon atoms with singlet and triplet metastable helium atoms

    Measurements of the velocity dependence of the absolute total ionization cross section of argon atoms upon impact with selected metastable states of helium atoms are reported. A low voltage dc discharge was used as the source of the excited atoms, and a rotating slotted disk selector was used for velocity selection of the excited atoms. Selection of the electronic spin state of the excited atoms was accomplished by irradiation of the excited atoms with radiation from a helium discharge lamp. Ionization of the argon target atoms by metastable helium atoms was studied by the gas cell technique in which all ionization products were collected. The ionization measurements were of sufficient precision to allow simultaneous determination of the cross section and the second electron ejection efficiency for each metastable state of helium. The secondary electron ejection efficiency of triplet metastable helium atoms on an electroplated gold surface was determined to be 0.440 +- 0.018 in the presence of argon gas. The secondary electron ejection efficiency of singlet metastable atoms was determined to be 0.582 +- 0.024 under similar conditions. The total ionization cross section for the He(23S)-Ar system was found to increase almost linearly from 8.8 to 21.95 A2 with an increase of relative velocity from 1162 to 2787 m/sec. After an initial increase of the cross section from 9.8 A2 to 26.2 A2 with an increase in relative velocity from 989 m/sec to 2058 m/sec, the velocity dependence of the cross section of the He(21S)-Ar system entered a saturation region in which the cross section changed very little with relative velocity. The collision energy dependence of the He(23S)-Ar system was also used to determine the values of adjustable parameters present in a current theory based on the potential curve model for Penning and associative Penning ionization

  2. Absolute measurement of excitation cross sections for the 2P-states of atomic hydrogen in charge exchange collisions of protons in argon and nitrogen

    Cross sections for the excitation of the 2P-states of atomic hydrogen in charge exchange collisions of protons in argon and nitrogen were measured by observing the Lyman-α radiation emitted in transitions from this state. For the measurement of the target gas pressure, a modified ionization gauge was developed, which eliminated distortions of pressure measurements due to charging effects on the glass envelope. Because of the lack of light standards in the vacuum ultraviolet region of the spectrum, the major problem of the measurements was the absolute calibration of the L/sub alpha/-photometer. This calibration was obtained from coincidence measurements of H/sub alpha/- and L/sub alpha/-photons in the presence of an electric field. The measurements were corrected for the effect of Doppler shift on photometer sensitivity. For the evaluation of the coincidence measurements, the branching ratio of H/sub alpha/-transitions to the 2S-state and the polarization of Lyman-α radiation, emitted in cascade processes, were needed. These quantities were obtained from quantum mechanical calculations of a hydrogen atom in a weak electric field. Cross sections for the 2P-states were obtained in the energy range from 0.5 to 30 keV. The 2P-cross sections in argon had maxima of 2.23 x 10-17 and 2.68 x 10-17 cm2 at 3.35 and 11.86 keV, respectively, and in N2 maxima of 2.17 x 10-17 and 2.10 x 10-17 cm2 were observed at 3.39 and 11.3 keV, respectively. The energy dependence of the measured cross sections is in agreement with that of published measurements. Differences in the absolute values are discussed

  3. Fast-electron ejection from C, Ni, Ag and Au foils by 36 Ar 18 + (95 MeV/u): Measurements of absolute cross-sections

    de Filippo, E.; Lanzanó, G.; Rothard, H.; Volant, C.; Aiello, S.; Anzalone, A.; Arena, N.; Geraci, M.; Giustolisi, F.; Pagano, A.

    2004-07-01

    Doubly differential electron velocity spectra induced by 36Ar18 + (95 MeV/ u) from thin target foils (C, Ni, Ag, Au) were measured at GANIL (Caen, France) by means of the ARGOS multidetector and the time-of-flight technique. The main features observed in the forward spectra are convoy electrons, binary-encounter electrons, and (for the Au target only) a high-velocity tail which we attribute to a “Fermi shuttle” acceleration mechanism. Backward spectra do not show distinct structures. The spectra allow us to determine absolute singly differential cross-sections as a function of the target material and the emission angle. The convoy electron yield increases with the target atomic number, but for C their yield is so small that our experiment is not able to detect them. Absolute doubly differential cross-sections for binary-encounter electron ejection from C targets are well described by a transport theory which is based on the relativistic electron impact approximation (EIA) for electron production and which accounts for angular deflection, energy loss and energy straggling of the transmitted electrons.

  4. Measurement of Absolute Cross-Sections of Fission Induced by 156-MeV Protons, Using Mica as a Fission Fragment Detector

    The fission of elements of medium Z induced by 156-MeV protons is difficult to demonstrate, owing to the particularly small cross-section of the reaction. The detection of fission fragments by means of sheets of mica seemed to be a technique well suited to this type of experiment. In the sheets of synthetic mica that we used it was only the fission fragments that left microscopically identifiable traces. Moreover, these samples contain very few impurities likely to undergo fission, so practically no parasitic traces are observed. The targets consisted of metals of not less than 99.999% purity. We determined the absolute cross-sections.of fission induced by 156-MeV protons in the case of lanthanum (5 μb) and praseodymium (6 μb), and estimated those of cadmium, indium, tin and antimony (≤ 0.1 μb). The sheets of mica were placed on each side of the metal sheet. The kinetics of the reaction explain why more traces were found on the mica sheets placed on the from face. As thick targets were used to take account of self-absorption, we determined (in the case of uranium and gold) the ratio of yields between a thin target and a thick target, and then extrapolated our results to the other elements. We made checks by comparing the absolute cross-sections for fission (induced by 156-MeV protons) in uranium, bismuth, gold and tantalum, as obtained by this method, with those obtained by counters at this energy. The observed agreement was very good. (author)

  5. Absolute Doubly Differential Cross Sections for Ejection of Electrons in - and Five-Body Collisions of 20 TO 114-KEV Protons on Atomic and Molecular Hydrogen.

    Kerby, George W., III

    A crossed-beam experiment was performed to detect ejected electrons from ground-state atomic and molecular hydrogen after collisions with 20- to 114-keV protons. Because a pure atomic hydrogen target is not readily attainable, a method has been devised which yields atomic to molecular hydrogen doubly differential cross section (DDCS) ratios. Since the molecular hydrogen DDCS's were independently measured, the atomic cross sections could be directly calculated. Absolute cross sections differential in electron energy and angle were measured for electron energies ranging from 1.5 to 400 eV and scattering angles from 15^circ to 165^circ with respect to the fast beam. Electrons and ions were energy analyzed by an electrostatic hemispherical analyzer, which has an energy resolution of 5% and is rotatable in the scattering plane about the collision center. Atomic hydrogen is produced by a radio-frequency discharge of the type devised by J. Slevin. Hydrogen gas effuses from a 1 mm diameter nozzle in a nearly cos theta distribution. The projectile beam intersects the thermal gas targets 4 mm below the tip of the nozzle. Dissociation fractions of 74% and atomic hydrogen densities of 7 times 10 ^{11} cm^ {-3} were typical. The fraction of dissociated hydrogen was measured by detecting the reduced 9-eV ion signal from the molecular target when the RF is on. This characteristic ion signal originates from the coulomb breakup of the molecule and dissociative channels of excited H _sp{2}{+}. An auxiliary experiment was performed to determine the target densities with the aid of a low-resolution magnetic mass spectrometer after the slow recoil ions were extracted from the collision volume by a weak electric field. Comparisons of the atomic cross sections are made with theories such as the classical-trajectory Monte Carlo (CTMC) method, the plane-wave Born approximation (PWBA) and the continuum-distorted-wave eikonal-initial-state (CDW-EIS) approximation.

  6. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed. PMID:27587105

  7. Retraction notice to "Measurements of total absolute collision cross section of ultracold Rb atom using magneto-optic and pure magnetic traps" [Chinese Optics Letters 9, 060201 (2011)

    Jicheng Wang; Yueyuan Wang; Yueke Wang; Guangyu Fang; Shutian Liu

    2011-01-01

    This article "Measurements of total absolute collision cross section of ultracold Rb atom using magneto-optic and pure magnetic traps",which was published on Chinese Optics Letters (9,060201 (2011)) has been retracted at the request of the authors.Reason:The first author,Jicheng Wang,participated in a related research in Professor Kirk Madison's group in the Department of Physics & Astronomy at the University of British Columbia,Canada from September 2008 to February 2010.Some of the experimental data have not been authorized for publication,even though they have been consented to be used by Jicheng Wang in his own research.The authors apologize to Professor K.Madison for misunderstanding,and to Chinese Optics Letters and the readers of Chinese Optics Letters for any inconvenience this mistake may have caused.

  8. Assessment of experimental d-PIGE γ-ray production cross sections for 12C, 14N and 16O and comparison with absolute thick target yields

    Csedreki, L.; Halász, Z.; Kiss, Á. Z.

    2016-08-01

    Measured differential cross sections for deuteron induced γ-ray emission from the reactions 12C(d,pγ)13C, (Eγ = 3089 keV), 14N(d,pγ)15N (Eγ = 8310 keV) and 16O(d,pγ)17O (Eγ = 871 keV) available in the literature were assessed. In order to cross check the assessed γ-ray production cross section data, thick target γ-yields calculated from the differential cross sections were compared with available measured thick target yields. Recommended differential cross section data for each reaction were deduced for particle induced γ-ray emission (PIGE) applications.

  9. Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+ e^- --> D D-bar Cross Sections at the psi(3770)

    Dobbs, S; Seth, K K; Tomaradze, A G; Ecklund, K M; Love, W; Savinov, V; López, A; Mehrabyan, S; Méndez, H; Ramírez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P

    2007-01-01

    Using 281 /pb of e^+ e^- collisions recorded at the psi(3770)resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D0 and six D^+ modes, we obtain reference branching fractions B(D0 --> K^-pi^+) = (3.891 +- 0.035 +- 0.059 +- 0.035)% and B(D^+ --> K^-pi^+pi^+) = (9.15 +- 0.10 +- 0.16 +- 0.07)%, where the first uncertainty is statistical, the second is all systematic errors other than final state radiation (FSR), and the third is the systematic uncertainty due to FSR. We include FSR in these branching fractions by allowing for additional unobserved photons in the final state. Using an independent determination of the integrated luminosity, we also extract the cross sections sigma(e+e- --> D0 D0-bar) = (3.66+- 0.03 +- 0.06) nb and sigma(e+e- --> D^+ D^-) = (2.91+- 0.03 +- 0.05) nb at a center of mass energy, E_cm = 3774 +- 1 MeV.

  10. FEMA DFIRM Cross Sections

    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...

  11. A study of the atmospherically relevant reaction between molecular chlorine and dimethylsulfide (DMS): Establishing the reaction intermediate and measurement of absolute photoionization cross-sections

    In a study using UV photoelectron spectroscopy (PES) of the atmospherically relevant reactionCH3SCH3+Cl2->CH3SCH2Cl+HClbands associated with a reaction intermediate have been observed. These have been assigned to ionization of the covalently bound molecule (CH3)2SCl2 on the basis of the intensity of the observed bands as a function of reaction time, molecular orbital calculations of vertical ionization energies and evidence from infrared spectroscopy. A method has also been developed, with the flow-tube/PE spectrometer combination used, to measure photoionization cross-sections of the reagents and products at the photon energy utilized and this has allowed the photoionization cross-section of the intermediate to be estimated. This work augments an earlier study in which the rate constant of the reaction between CH3SCH3 (DMS) and Cl2 has been measured at room temperature

  12. High precision absolute differential cross-section measurements for proton-proton elastic scattering at 491.9, 575.5, 641.6, 728.2, and 793.0 MeV

    The proton-proton absolute elastic differential cross section, σpp(θ), has been measured at incident proton beam energies of 491.9, 575.5, 641.6, 728.2, and 793.0 MeV at laboratory scattering angles of ∼15 degree to ∼42 degree with a total uncertainty on the order of 1%. The measurements were made at the Clinton P. Anderson Los Alamos Meson Physics Facility (LAMPF) and employed a new beam counting technique which provided a better overall beam normalization compared to previous experiments of this type. The cross section was measured with CH2 targets and a primary liquid, LH2, target to determine the uncertainties in some systematic corrections. Extreme care was taken to reduce individual systematic errors to less than 0.5%

  13. Trends in absolute and relative educational inequalities in four modifiable ischaemic heart disease risk factors: repeated cross-sectional surveys from the Nord-Trøndelag Health Study (HUNT 1984–2008

    Ernstsen Linda

    2012-04-01

    Full Text Available Abstract Background There has been an overall decrease in incident ischaemic heart disease (IHD, but the reduction in IHD risk factors has been greater among those with higher social position. Increased social inequalities in IHD mortality in Scandinavian countries is often referred to as the Scandinavian “public health puzzle”. The objective of this study was to examine trends in absolute and relative educational inequalities in four modifiable ischaemic heart disease risk factors (smoking, diabetes, hypertension and high total cholesterol over the last three decades among Norwegian middle-aged women and men. Methods Population-based, cross-sectional data from The Nord-Trøndelag Health Study (HUNT: HUNT 1 (1984–1986, HUNT 2 (1995–1997 and HUNT 3 (2006–2008, women and men 40–59 years old. Educational inequalities were assessed using the Slope Index of Inequality (SII and The Relative Index of Inequality (RII. Results Smoking prevalence increased for all education groups among women and decreased in men. Relative and absolute educational inequalities in smoking widened in both genders, with significantly higher absolute inequalities among women than men in the two last surveys. Diabetes prevalence increased in all groups. Relative inequalities in diabetes were stable, while absolute inequalities increased both among women (p = 0.05 and among men (p = 0.01. Hypertension prevalence decreased in all groups. Relative inequalities in hypertension widened over time in both genders. However, absolute inequalities in hypertension decreased among women (p = 0.05 and were stable among men (p = 0.33. For high total cholesterol relative and absolute inequalities remained stable in both genders. Conclusion Widening absolute educational inequalities in smoking and diabetes over the last three decades gives rise to concern. The mechanisms behind these results are less clear, and future studies are needed to assess if educational

  14. Total Cross Sections

    G. GiacomelliBologna University and INFN

    2014-01-01

    The measurements of the hadron-hadron total cross sections are the first measurements performed when a new hadron accelerator opens up a new energy region; the measurements were made as function of the incoming beam momentum or c.m. energy and have often been repeated with improved accuracy and finer energy spacing.

  15. Absolute cross section for loss of supercoiled topology induced by 10 eV electrons in highly uniform /DNA/1,3-diaminopropane films deposited on highly ordered pyrolitic graphite

    Boulanouar, Omar; Fromm, Michel [Laboratoire de Chimie Physique et Rayonnements – Alain Chambaudet, LRC CEA, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, F-25030 Besançon cedex (France); Bass, Andrew D.; Cloutier, Pierre; Sanche, Léon [Groupe en Sciences des Radiations, Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Québec J1H 5N4 (Canada)

    2013-08-07

    It was recently shown that the affinity of doubly charged, 1-3 diaminopropane (Dap{sup 2+}) for DNA permits the growth on highly ordered pyrolitic graphite (HOPG) substrates, of plasmid DNA films, of known uniform thickness [O. Boulanouar, A. Khatyr, G. Herlem, F. Palmino, L. Sanche, and M. Fromm, J. Phys. Chem. C 115, 21291–21298 (2011)]. Post-irradiation analysis by electrophoresis of such targets confirms that electron impact at 10 eV produces a maximum in the yield of single strand breaks that can be associated with the formation of a DNA{sup −} transient anion. Using a well-adapted deterministic survival model for the variation of electron damage with fluence and film thickness, we have determined an absolute cross section for strand-break damage by 10 eV electrons and inelastic scattering attenuation length in DNA-Dap complex films.

  16. Withdrawal of Chinese Physics Letters 28 (2011) 043401 “Measurement of Absolute Atomic Collision Cross Section with Helium Using 87Rb Atoms Confined in Magneto-Optic and Magnetic Traps” by WANG Ji-Cheng et al.

    WANG Ji-Cheng; ZHOU Ke-Ya; WANG Yue-Yuan; LIAO Qing-Hong; LIU Shu-Tian

    2011-01-01

    We announce the withdrawal of the article entitled “Measurement of Absolute Atomic Collision Cross Section with Helium Using 87Rb Atoms Confined in Magneto-Optic and Magnetic Traps”,which was published in Chinese Physics Letters [28(4)(2011)043401].The first author,Jicheng Wang,had participated in related research with Professor Kirk Madison's group at the Department of Physics & Astronomy at the University of British Columbia,Canada from September 2008 to February 2010.Even though consent had been granted for some of the experimental data to be used by Jicheng Wang in his own thesis,its publication had not been authorized.We apologize to Professor K.Madison for the misunderstanding,and to Chinese Physics Letters and the readers of Chinese Physics Letters for any inconvenience this mistake may have caused.%We announce the withdrawal of the article entitled "Measurement of Absolute Atomic Collision Cross Section with Helium Using 87Rb Atoms Confined in Magneto-Optic and Magnetic Traps", which was published in Chinese Physics Letters [28(4) (2011)043401]. The first author, Jicheng Wang, had participated in related research with Professor Kirk Madison's group at the Department of Physics & Astronomy at the University of British Columbia, Canada from September 2008 to February 2010. Even though consent had been granted for some of the experimental data to be used by Jicheng Wang in his own thesis, its publication had not been authorized. We apologize to Professor K. Madison for the misunderstanding, and to Chinese Physics Letters ad the readers of Chinese Physics Letters for any inconvenience this mistake may have caused.

  17. Neutrino Cross section Future

    Gollapinni, Sowjanya

    2016-01-01

    The study of neutrino-nucleus interactions has recently received renewed attention due to their importance in interpreting the neutrino oscillation data. Over the past few years, there has been continuous disagreement between neutrino cross section data and predictions due to lack of accurate nuclear models suitable for modern experiments which use heavier nuclear targets. Also, the current short and long-baseline neutrino oscillation experiments focus in the few GeV region where several distinct neutrino processes come into play resulting in complex nuclear effects. Despite recent efforts, more experimental input is needed to improve nuclear models and reduce neutrino interaction systematics which are currently dominating oscillation searches together with neutrino flux uncertainties. A number of new detector concepts with diverse neutrino beams and nuclear targets are currently being developed to provide necessary inputs required for next generation oscillation experiments. This paper summarizes these effor...

  18. Group cross sections calculations

    Just a few methods have been developped to compute multigroup cross-sections from ENDF data. We have developped an original method in order to get accuracy and to reduce the number of discretization points in the same time; this is why we have tried to use polynomial integration. In this paper, we describe this method: in the first part, we recall some physical hypothesis generally used to solve the linear Boltzmann equation: that is the frame in which the numerical method has been developped. Polynomial methods are really powerfull only if discretization points are suitably chosen. This choice is explained in the next part of this paper. In conclusion, some numerical results are given to illustrate our method

  19. Diffractive and rising cross sections

    The energy dependence of the diffractive component of the proton-proton cross section is discussed and its contribution to the rise of the total cross section at high energies is examined. 17 refs., 9 figs

  20. [Fast neutron cross section measurements

    This paper discusses the following topics: 14 MeV pulsed neutron facility; detection and measurement system; 238U capture cross sections at 23 and 964 keV using photon neutron sources; capture cross sections of Au-197 at 23 and 964 keV; and yttrium nuclear cross section measurement

  1. [Fast neutron cross section measurements

    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

  2. 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.

  3. (n,2n) cross sections

    Most of the fission products and a few of the actinides in ENDF/B-V do not have (n,2n) cross sections. A complete set of these cross sections is presented in the multigroup structure defined. These were constructed for future use in the DANDE Code System

  4. Cross Sections and Lorentz Violation

    Colladay, Don; Kostelecky, Alan

    2001-01-01

    The derivation of cross sections and decay rates in the Lorentz-violating standard-model extension is discussed. General features of the physics are described, and some conceptual and calculational issues are addressed. As an illustrative example, the cross section for the specific process of electron-positron pair annihilation into two photons is obtained.

  5. Measurement of fission cross sections

    A review is presented on the recent progress in the experiment of fission cross section measurement, including recent activity in Japan being carried out under the project of nuclear data measurement. (author)

  6. The total charm cross section

    R. Vogt

    2007-01-01

    We assess the theoretical uncertainties on the total charm cross section. We discuss the importance of the quark mass, the scale choice and the parton densities on the estimate of the uncertainty. We conclude that due to the small charm quark mass, which amplifies the effect of the other parameters in the calculation, the uncertainty on the total charm cross section is difficult to quantify.

  7. Ratios of dijet production cross sections as a function of the absolute difference in rapidity between jets in proton-proton collisions at $\\sqrt{s}$ = 7 TeV

    Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Teischinger, Florian; Wagner, Philipp; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Sunil; Benucci, Leonardo; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Luyckx, Sten; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Olbrechts, Annik; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wickens, John; Adler, Volker; Beernaert, Kelly; Cimmino, Anna; Costantini, Silvia; Garcia, Guillaume; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Ceard, Ludivine; De Favereau De Jeneret, Jerome; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; Correa Martins Junior, Marcos; De Jesus Damiao, Dilson; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Custódio, Analu; Da Costa, Eliza Melo; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Soares Jorge, Luana; Sznajder, Andre; Souza Dos Anjos, Tiago; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Karadzhinova, Aneliya; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Wang, Siguang; Zhu, Bo; Zou, Wei; Cabrera, Andrés; Gomez Moreno, Bernardo; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Kovac, Marko; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Luetic, Jelena; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Ellithi Kamel, Ali; Khalil, Shaaban; Mahmoud, Mohammed; Radi, Amr; Hektor, Andi; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Tiko, Andres; Azzolini, Virginia; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Czellar, Sandor; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Daci, Nadir; Dahms, Torsten; Dobrzynski, Ludwik; Elgammal, Sherif; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Thiebaux, Christophe; Veelken, Christian; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Juillot, Pierre; Karim, Mehdi; Le Bihan, Anne-Catherine; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Baty, Clement; Beauceron, Stephanie; Beaupere, Nicolas; Bedjidian, Marc; Bondu, Olivier; Boudoul, Gaelle; Boumediene, Djamel; Brun, Hugues; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Falkiewicz, Anna; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Le Grand, Thomas; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Viret, Sébastien; Lomidze, David; Anagnostou, Georgios; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Erdmann, Martin; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klimkovich, Tatsiana; Klingebiel, Dennis; Kreuzer, Peter; Lanske, Dankfried; Lingemann, Joschka; Magass, Carsten; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Weber, Martin; Bontenackels, Michael; Cherepanov, Vladimir; Davids, Martina; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Linn, Alexander; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Zoeller, Marc Henning; Aldaya Martin, Maria; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Castro, Elena; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Flossdorf, Alexander; Flucke, Gero; Geiser, Achim; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Olzem, Jan; Petrukhin, Alexey; Pitzl, Daniel; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Rosin, Michele; Salfeld-Nebgen, Jakob; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Tomaszewska, Justyna; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Blobel, Volker; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Erfle, Joachim; Gebbert, Ulla; Görner, Martin; Hermanns, Thomas; Höing, Rebekka Sophie; Kaschube, Kolja; Kaussen, Gordon; Kirschenmann, Henning; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Nowak, Friederike; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schröder, Matthias; Schum, Torben; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Barth, Christian; Berger, Joram; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Feindt, Michael; Gruschke, Jasmin; Guthoff, Moritz; Hackstein, Christoph; Hartmann, Frank; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Katkov, Igor; Komaragiri, Jyothsna Rani; Kuhr, Thomas; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Nürnberg, Andreas; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Peiffer, Thomas; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Renz, Manuel; Röcker, Steffen; Saout, Christophe; Scheurer, Armin; Schieferdecker, Philipp; Schilling, Frank-Peter; Schmanau, Mike; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Wagner-Kuhr, Jeannine; Weiler, Thomas; Zeise, Manuel; Ziebarth, Eva Barbara; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Triantis, Frixos A; Aranyi, Attila; Bencze, Gyorgy; Boldizsar, Laszlo; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Kapusi, Anita; Krajczar, Krisztian; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Beni, Noemi; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Karancsi, János; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Jindal, Monika; Kaur, Manjit; Kohli, Jatinder Mohan; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Anil; Singh, Jasbir; Singh, Supreet Pal; Ahuja, Sudha; Choudhary, Brajesh C; Kumar, Ashok; Kumar, Arun; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Shivpuri, Ram Krishen; Banerjee, Sunanda; Bhattacharya, Satyaki; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Sarkar, Subir; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Ganguly, Sanmay; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Saha, Anirban; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Mondal, Naba Kumar; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Hesari, Hoda; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Manna, Norman; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pompili, Alexis; Pugliese, Gabriella; Romano, Francesco; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Tupputi, Salvatore; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; De Cosa, Annapaola; Dogangun, Oktay; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Mazzucato, Mirco; Meneguzzo, Anna Teresa; Nespolo, Massimo; Perrozzi, Luca; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Triossi, Andrea; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Berzano, Umberto; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Caponeri, Benedetta; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Romeo, Francesco; Santocchia, Attilio; Taroni, Silvia; Valdata, Marisa; Azzurri, Paolo; Bagliesi, Giuseppe; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Palmonari, Francesco; Rizzi, Andrea; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Fanelli, Cristiano; Grassi, Marco; Longo, Egidio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Pandolfi, Francesco; Paramatti, Riccardo; Rahatlou, Shahram; Sigamani, Michael; Soffi, Livia; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Castello, Roberto; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Vilela Pereira, Antonio; Belforte, Stefano; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Marone, Matteo; Montanino, Damiana; Penzo, Aldo; Heo, Seong Gu; Nam, Soon-Kwon; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kong, Dae Jung; Park, Hyangkyu; Ro, Sang-Ryul; Son, Dong-Chul; Kim, Jae Yool; Kim, Zero Jaeho; Song, Sanghyeon; Jo, Hyun Yong; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Seo, Eunsung; Sim, Kwang Souk; Choi, Minkyoo; Kang, Seokon; Kim, Hyunyong; Kim, Ji Hyun; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Cho, Yongjin; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Lee, Byounghoon; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Martínez-Ortega, Jorge; Sánchez-Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A; Krofcheck, David; Bell, Alan James; Butler, Philip H; Doesburg, Robert; Reucroft, Steve; Silverwood, Hamish; Ahmad, Muhammad; Asghar, Muhammad Irfan; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Shah, Mehar Ali; Shoaib, Muhammad; Brona, Grzegorz; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Bialkowska, Helena; Boimska, Bozena; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Nayak, Aruna; Pela, Joao; Ribeiro, Pedro Quinaz; Seixas, Joao; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Belotelov, Ivan; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Karjavin, Vladimir; Konoplyanikov, Viktor; Kozlov, Guennady; Lanev, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Evstyukhin, Sergey; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pivovarov, Grigory; Toropin, Alexander; Troitsky, Sergey; Epshteyn, Vladimir; Erofeeva, Maria; Gavrilov, Vladimir; Kossov, Mikhail; Krokhotin, Andrey; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Khein, Lev; Kodolova, Olga; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Proskuryakov, Alexander; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Ekmedzic, Marko; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Soares, Mara Senghi; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Piedra Gomez, Jonatan; Vizan Garcia, Jesus Manuel; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bernet, Colin; Bialas, Wojciech; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Breuker, Horst; Bunkowski, Karol; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; Curé, Benoît; D'Enterria, David; De Roeck, Albert; Di Guida, Salvatore; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Gaddi, Andrea; Georgiou, Georgios; Gerwig, Hubert; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Giunta, Marina; Glege, Frank; Gomez-Reino Garrido, Robert; Govoni, Pietro; Gowdy, Stephen; Guida, Roberto; Guiducci, Luigi; Hansen, Magnus; Harris, Philip; Hartl, Christian; Harvey, John; Hegner, Benedikt; Hinzmann, Andreas; Hoffmann, Hans Falk; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Kousouris, Konstantinos; Lecoq, Paul; Lenzi, Piergiulio; Lourenco, Carlos; Maki, Tuula; Malberti, Martina; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Mavromanolakis, Georgios; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Nesvold, Erik; Nguyen, Matthew; Orimoto, Toyoko; Orsini, Luciano; Palencia Cortezon, Enrique; Perez, Emmanuelle; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Polese, Giovanni; Quertenmont, Loic; Racz, Attila; Reece, William; Rodrigues Antunes, Joao; Rolandi, Gigi; Rommerskirchen, Tanja; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Santanastasio, Francesco; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Spiropulu, Maria; Stoye, Markus; Tsirou, Andromachi; Veres, Gabor Istvan; Vichoudis, Paschalis; Wöhri, Hermine Katharina; Worm, Steven; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Bäni, Lukas; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Chen, Zhiling; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Dünser, Marc; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Lecomte, Pierre; Lustermann, Werner; Martinez Ruiz del Arbol, Pablo; Mohr, Niklas; Moortgat, Filip; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pape, Luc; Pauss, Felicitas; Peruzzi, Marco; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Sawley, Marie-Christine; Starodumov, Andrei; Stieger, Benjamin; Takahashi, Maiko; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Hannsjoerg Artur; Wehrli, Lukas; Weng, Joanna; Aguilo, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Otiougova, Polina; Robmann, Peter; Snoek, Hella; Verzetti, Mauro; Chang, Yuan-Hann; Chen, Kuan-Hsin; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Zong-Kai; Lu, Yun-Ju; Mekterovic, Darko; Volpe, Roberta; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Shi, Xin; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wang, Minzu; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Hos, Ilknur; Kangal, Evrim Ersin; Karapinar, Guler; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Uzun, Dilber; Vergili, Latife Nukhet; Vergili, Mehmet; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilin, Bugra; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yalvac, Metin; Yildirim, Eda; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Levchuk, Leonid; Bostock, Francis; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Basso, Lorenzo; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Jackson, James; Kennedy, Bruce W; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R; Womersley, William John; Bainbridge, Robert; Ball, Gordon; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Lyons, Louis; Magnan, Anne-Marie; Marrouche, Jad; Mathias, Bryn; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rogerson, Samuel; Rompotis, Nikolaos; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sparrow, Alex; Tapper, Alexander; Tourneur, Stephane; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardle, Nicholas; Wardrope, David; Whyntie, Tom; Barrett, Matthew; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Hatakeyama, Kenichi; Liu, Hongxuan; Scarborough, Tara; Henderson, Conor; Avetisyan, Aram; Bose, Tulika; Carrera Jarrin, Edgar; Fantasia, Cory; Heister, Arno; St John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Bhattacharya, Saptaparna; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Tsang, Ka Vang; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Caulfield, Matthew; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Gardner, Michael; Houtz, Rachel; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Mall, Orpheus; Miceli, Tia; Nelson, Randy; Pellett, Dave; Robles, Jorge; Rutherford, Britney; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Andreev, Valeri; Arisaka, Katsushi; Cline, David; Cousins, Robert; Duris, Joseph; Erhan, Samim; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Jarvis, Chad; Plager, Charles; Rakness, Gregory; Schlein, Peter; Tucker, Jordan; Valuev, Vyacheslav; Weber, Matthias; Babb, John; Clare, Robert; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Jeng, Geng-Yuan; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Nguyen, Harold; Paramesvaran, Sudarshan; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; Evans, David; Golf, Frank; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Mangano, Boris; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pi, Haifeng; Pieri, Marco; Ranieri, Riccardo; Sani, Matteo; Sfiligoi, Igor; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Wasserbaech, Steven; Würthwein, Frank; Yagil, Avraham; Yoo, Jaehyeok; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Koay, Sue Ann; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Mccoll, Nickolas; Pavlunin, Viktor; Rebassoo, Finn; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; Vlimant, Jean-Roch; West, Christopher; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Di Marco, Emanuele; Duarte, Javier; Gataullin, Marat; Ma, Yousi; Mott, Alexander; Newman, Harvey B; Rogan, Christopher; Timciuc, Vladlen; Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Jun, Soon Yung; Liu, Yueh-Feng; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Dinardo, Mauro Emanuele; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T; Gaz, Alessandro; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Zang, Shi-Lei; Agostino, Lorenzo; Alexander, James; Chatterjee, Avishek; Eggert, Nicholas; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Biselli, Angela; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Atac, Muzaffer; Bakken, Jon Alan; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bloch, Ingo; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Cooper, William; Eartly, David P; Elvira, Victor Daniel; Esen, Selda; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Green, Dan; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jensen, Hans; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Lincoln, Don; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Miao, Ting; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Pivarski, James; Pordes, Ruth; Prokofyev, Oleg; Schwarz, Thomas; Sexton-Kennedy, Elizabeth; Sharma, Seema; Spalding, William J; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Goldberg, Sean; Hugon, Justin; Kim, Bockjoo; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Remington, Ronald; Rinkevicius, Aurelijus; Schmitt, Michael; Scurlock, Bobby; Sellers, Paul; Skhirtladze, Nikoloz; Snowball, Matthew; Wang, Dayong; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F; Prosper, Harrison; Sekmen, Sezen; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Dorney, Brian; Hohlmann, Marcus; Kalakhety, Himali; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Kunde, Gerd J; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silkworth, Christopher; Silvestre, Catherine; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Duru, Firdevs; Griffiths, Scott; Lae, Chung Khim; McCliment, Edward; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Bonato, Alessio; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Tran, Nhan Viet; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Kenny Iii, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Stringer, Robert; Tinti, Gemma; Wood, Jeffrey Scott; Zhukova, Victoria; Barfuss, Anne-Fleur; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kirn, Malina; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Peterman, Alison; Rossato, Kenneth; Rumerio, Paolo; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C; Twedt, Elizabeth; Alver, Burak; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Kim, Yongsun; Klute, Markus; Lee, Yen-Jie; Li, Wei; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Sung, Kevin; Velicanu, Dragos; Wenger, Edward Allen; Wolf, Roger; Wyslouch, Bolek; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cooper, Seth; Cushman, Priscilla; Dahmes, Bryan; De Benedetti, Abraham; Franzoni, Giovanni; Gude, Alexander; Haupt, Jason; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rekovic, Vladimir; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Cremaldi, Lucien Marcus; Godang, Romulus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Summers, Don; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R; Dominguez, Aaron; Eads, Michael; Jindal, Pratima; Keller, Jason; Kravchenko, Ilya; Lazo-Flores, Jose; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Wan, Zongru; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Brinkerhoff, Andrew; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Ziegler, Jill; Bylsma, Ben; Durkin, Lloyd Stanley; Hill, Christopher; Killewald, Phillip; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Vuosalo, Carl; Williams, Grayson; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hegeman, Jeroen; Hunt, Adam; Laird, Edward; Lopes Pegna, David; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Raval, Amita; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E; Benedetti, Daniele; Bolla, Gino; Bortoletto, Daniela; De Mattia, Marco; Everett, Adam; Gutay, Laszlo; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T; Leonardo, Nuno; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Vidal Marono, Miguel; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Guragain, Samir; Parashar, Neeti; Adair, Antony; Boulahouache, Chaouki; Cuplov, Vesna; Ecklund, Karl Matthew; Geurts, Frank JM; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Garcia-Bellido, Aran; Goldenzweig, Pablo; Gotra, Yury; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Petrillo, Gianluca; Sakumoto, Willis; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Arora, Sanjay; Atramentov, Oleksiy; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hits, Dmitry; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Richards, Alan; Rose, Keith; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Safonov, Alexei; Sakuma, Tai; Sengupta, Sinjini; Suarez, Indara; Tatarinov, Aysen; Toback, David; Akchurin, Nural; Bardak, Cemile; Damgov, Jordan; Dudero, Phillip Russell; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Libeiro, Terence; Mane, Poonam; Roh, Youn; Sill, Alan; Volobouev, Igor; Wigmans, Richard; Appelt, Eric; Brownson, Eric; Engh, Daniel; Florez, Carlos; Gabella, William; Gurrola, Alfredo; Issah, Michael; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Conetti, Sergio; Cox, Bradley; Francis, Brian; Goadhouse, Stephen; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Wood, John; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Mattson, Mark; Milstène, Caroline; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Belknap, Donald; Bellinger, James Nugent; Bernardini, Jacopo; Borrello, Laura; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Efron, Jonathan; Friis, Evan; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Pierro, Giuseppe Antonio; Ross, Ian; Savin, Alexander; Smith, Wesley H; Swanson, Joshua

    2012-01-01

    A study of dijet production in proton-proton collisions was performed at $\\sqrt{s}$ = 7 TeV for jets with pt > 35 GeV and abs(y) < 4.7 using data collected with the CMS detector at the LHC in 2010. Events with at least one pair of jets are denoted as "inclusive". Events with exactly one pair of jets are called "exclusive". The ratio of the cross section of all pairwise combinations of jets to the exclusive dijet cross section as a function of the rapidity difference between jets abs(Delta(y)) is measured for the first time up to abs(Delta(y)) = 9.2. The ratio of the cross section for the pair consisting of the most forward and the most backward jet from the inclusive sample to the exclusive dijet cross section is also presented. The predictions of the Monte Carlo event generators PYTHIA6 and PYTHIA8 agree with the measurements. In both ratios the HERWIG++ generator exhibits a more pronounced rise versus abs(Delta(y)) than observed in the data. The BFKL-motivated generators CASCADE and HEJ+ARIADNE predict f...

  8. Revolutionizing Cross-sectional Imaging

    Fan, Yifang; Luo, Liangping; Lin, Wentao; Li, Zhiyu; Zhong, Xin; Shi, Changzheng; Newman, Tony; Zhou, Yi; Lv, Changsheng; Fan, Yuzhou

    2014-01-01

    Cross-sectional imaging is so important that, six Nobel Prizes have been awarded to the field of nuclear magnetic resonance alone because it revolutionized clinical diagnosis. The BigBrain project supported by up to 1 billion euro each over a time period of 10 years predicts to "revolutionize our ability to understand internal brain organization" (Evan 2013). If we claim that cross-sectional imaging diagnosis is only semi-quantitative, some may believe because no doctor would ever tell their patient that we can observe the changes of this cross-sectional image next time. If we claim that BigBrain will make no difference in clinical medicine, then few would believe because no doctor would ever tell their patient to scan this part of the image and compare it with that from the BigBrain. If we claim that the BigBrain Project and the Human Brain Project have defects in their key method, one might believe it. But this is true. The key lies in the reconstruction of any cross-sectional image along any axis. Using Ga...

  9. Terahertz radar cross section measurements

    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...

  10. Cross sections for nuclear astrophysics

    General properties of low-energy cross sections and of reaction rates are presented. We describe different models used in nuclear astrophysics: microscopic models, the potential model, and the R-matrix method. Two important reactions, 7Be(p,γ)8B and 12C(α,γ)16O, are then briefly discussed. (author)

  11. Metonymy and Cross Section Demand

    Evstigneev, Igor V.; Hildenbrand, Werner; Jerison, Michael

    1996-01-01

    Cross section consumer expenditure data are frequently used to make conclusions about consumer demand behavior. Such conclusions, however, can only be justified under certain assumptions, which are often left unstated in the empirical demand literature. An assumption of this type, the metonymy hypothesis, was stated rigorously and then exploited by Hardle, Hildenbrand and Jerison when analyzing the monotonicity property of aggregate demand functions. The purpose of the present paper is to exa...

  12. Wind Turbine Radar Cross Section

    David Jenn; Cuong Ton

    2012-01-01

    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 axi...

  13. New activation cross section data

    New nuclear cross section libraries (known as USACT92) have been created for activation calculations. A point-wise file was created from merging the previous version of the activation library, the U.S. Nuclear Data Library (ENDF/B-VI), and the European Activation File (EAF-2). 175 and 99 multi-group versions were also created. All the data are available at the National Energy Research Supercomputer Center

  14. Microscopic cross sections: An utopia?

    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)

  15. [Fast neutron cross section measurements

    In this report, we outline the progress achieved in two distinct under the DOE-sponsored cross section project: the initial results obtained from the pulsed 14 MeV neutron facility, and a cooperative effort with Argonne National Laboratory in the measurement of fast neutron cross sections in yttrium. In the 14 MeV neutron laboratory, this year has seen the maturation of the project into one in which initial scattering measurements are now underway. We have improved the accelerator and ion source in several significant ways, so that neutron intensities have now been proven to be adequate for our series of elastic scattering angular distribution measurements outlined in our initial proposal of two years ago. We have successfully tested all components of the time-of-flight spectrometer and recorded initial neutron spectra from the ring targets that we have obtained for our first angular distribution measurements. Examples of the time-of-flight spectra that have been obtained are given later in this report. At the present time, the accelerator is operating with the highest degree of reliability that we have experienced since installing the pulsing system. Improvements made over the past year have not only increased the available neutron intensity, but also increased our capability to deal with inevitable component failures that require repair or replacement. The measurements carried out in conjunction with Argonne have contributed significantly to the available database on fast neutron interactions in yttrium. Results indicate that the cross section for the 89 Y(n,p)89Sr reaction is substantially higher than represented in ENDF/B-VI

  16. Wind Turbine Radar Cross Section

    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.

  17. Near-Threshold Photodetachment Cross Section of (SF6)(n)(-) Cluster Anions: The Ion Core Structure.

    Luzon, Itamar; Nagler, Maoz; Chandrasekaran, Vijayanand; Heber, Oded; Strasser, Daniel

    2016-01-21

    Photodetachment cross sections as a function of photon energy are measured for cold (SF6)n(-) cluster anions stored in an electrostatic ion beam trap. Absolute photodetachment cross sections near the adiabatic limit are reported. The strong dependence of the SF6(-) absolute photodetachment cross section on the anion equilibrium bond length leads to the conclusion that the excess charge is localized on a SF6(-) ion core that is only subtly perturbed by the neighboring cluster units. PMID:26667587

  18. Electron-Impact Ionization Cross Section Database

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  19. Discussion on cross section measurement for DD-bar production around Ψ (3770)

    We give a brief discussion on the measurement of the cross section for DD-bar production around the Ψ (3770) resonance, and point out a new calculation of the cross sections based on the absolute measurements. Compared with single tag and double tag analyses, the new calculation provides us with many more opportunities to perform the cross section measurement. (authors)

  20. Evaluation of cross section for 103Rh

    A completely new evaluation for the neutron cross sections is presented. The experimental data mainly referred to EXFOR, and the recommended cross sections are compared with ENDF/B-6, BROND-2, JENDL-3.2 and JEF-2

  1. Relative vs. absolute physiological measures as predictors of mountain bike cross-country race performance.

    Gregory, John; Johns, David P; Walls, Justin T

    2007-02-01

    The aims of this study were to document the effect terrain has on the physiological responses and work demands (power output) of riding a typical mountain bike cross-country course under race conditions. We were particularly interested in determining whether physiological measures relative to mass were better predictors of race performance than absolute measures. Eleven A-grade male cross-country mountain bike riders (VO2max 67.1 +/- 3.6 ml x kg(-1) x min(-1)) performed 2 tests: a laboratory-based maximum progressive exercise test, and a 15.5-km (six 2.58-km laps) mountain bike cross-country time trial. There were significant differences among the speed, cadence, and power output measured in each of 8 different terrain types found in the cross-country time trial course. The highest average speed was measured during the 10-15% downhill section (22.7 +/- 2.6 km x h(-1)), whereas the cadence was highest in the posttechnical flat sections (74.3 +/- 5.6 rpm) and lowest on the 15-20% downhill sections (6.4 +/- 12.1 rpm). The highest mean heart rate (HR) was obtained during the steepest (15-20% incline) section of the course (179 +/- 8 b x min(-1)), when the power output was greatest (419.8 +/- 39.7 W). However, HR remained elevated relative to power output in the downhill sections of the course. Physiological measures relative to total rider mass correlated more strongly to average course speed than did absolute measures (peak power relative to mass r = 0.93, p < 0.01, vs. peak power r = 0.64, p < 0.05; relative VO2max r = 0.80, p < 0.05, vs. VO2max r = 0.66, p < 0.05; power at anaerobic threshold relative to mass r = 0.78, p < 0.05, vs. power at anaerobic threshold r = 0.5, p < 0.05). This suggests that mountain bike cross-country training programs should focus upon improving relative physiological values rather than focusing upon maximizing absolute values to improve performance. PMID:17313256

  2. Photoproduction total cross section and shower development

    Cornet, F.; García Canal, C. A.; Grau, A.; Pancheri, G.; Sciutto, S. J.

    2015-12-01

    The total photoproduction cross section at ultrahigh energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  3. Photoproduction total cross section and shower development

    Cornet, F; Grau, A; Pancheri, G; Sciutto, S J

    2015-01-01

    The total photoproduction cross section at ultra-high energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air-showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  4. JENDL gas-production cross section file

    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)

  5. Temperature dependence of the HNO3 UV absorption cross sections

    Burkholder, James B.; Talukdar, Ranajit K.; Ravishankara, A. R.; Solomon, Susan

    1993-01-01

    The temperature dependence of the HNO3 absorption cross sections between 240 and 360 K over the wavelength range 195 to 350 nm has been measured using a diode array spectrometer. Absorption cross sections were determined using both (1) absolute pressure measurements at 298 K and (2) a dual absorption cell arrangement in which the absorption spectrum at various temperatures is measured relative to the room temperature absorption spectrum. The HNO3 absorption spectrum showed a temperature dependence which is weak at short wavelengths but stronger at longer wavelengths which are important for photolysis in the lower stratosphere. The 298 K absorption cross sections were found to be larger than the values currently recommended for atmospheric modeling (DeMore et al., 1992). Our absorption cross section data are critically compared with the previous measurements of both room temperature and temperature-dependent absorption cross sections. Temperature-dependent absorption cross sections of HNO3 are recommended for use in atmospheric modeling. These temperature dependent HNO3 absorption cross sections were used in a two-dimensional dynamical-photochemical model to demonstrate the effects of the revised absorption cross sections on loss rate of HNO3 and the abundance of NO2 in the stratosphere.

  6. [Fast neutron cross section measurements

    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

  7. Recent fission cross section standards measurements

    Wasson, O.A.

    1985-01-01

    The /sup 235/U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to /sup 235/U. However, the more difficult /sup 235/U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the /sup 235/U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs.

  8. Recent fission cross section standards measurements

    The 235U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to 235U. However, the more difficult 235U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the 235U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs

  9. SNL RML recommended dosimetry cross section compendium

    Griffin, P.J.; Kelly, J.G.; Luera, T.F. [Sandia National Labs., Albuquerque, NM (United States); VanDenburg, J. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  10. Radar Cross-section Measurement Techniques

    V.G. Borkar

    2010-03-01

    Full Text Available Radar cross-section (RCS is an important study parameter for defence applications specially dealing with airborne weapon system. The RCS parameter guides the detection range for a target and is therefore studied to understand the effectiveness of a weapon system. It is not only important to understand the RCS characteristics of a target but also to look into the diagnostic mode of study where factors contributing to a particular RCS values are studied. This further opens up subject like RCS suppression and stealth. The paper discusses the RCS principle, control, and need of measurements. Classification of RCS in terms of popular usage is explained with detailed theory of RF imaging and inverse synthetic aperture radar (ISAR. The various types of RCS measurement ranges are explained with brief discussion on outdoor RCS measurement range. The RCS calibration plays a critical role in referencing the measurement to absolute values and has been described.The RCS facility at Reseach Centre Imarat, Hyderabad, is explained with some details of different activities that are carried out including RAM evaluation, scale model testing, and diagnostic imaging.Defence Science Journal, 2010, 60(2, pp.204-212, DOI:http://dx.doi.org/10.14429/dsj.60.341

  11. Vertically stabilized elongated cross-section tokamak

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  12. Background-cross-section-dependent subgroup parameters

    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)

  13. Absolute Integral Cross Sections for the State-selected Ion–Molecule Reaction N2+(X2Σg+ v+ = 0–2) + C2H2 in the Collision Energy Range of 0.03–10.00 eV

    Xu, Yuntao; Xiong, Bo; Chung Chang, Yih; Ng, C. Y.

    2016-08-01

    Using the vacuum ultraviolet laser pulsed field ionization-photoion source, together with the double-quadrupole–double-octopole mass spectrometer developed in our laboratory, we have investigated the state-selected ion–molecule reaction {{{{N}}}2}+({X}2{{{{Σ }}}{{g}}}+; v + = 0–2, N+ = 0–9) + C2H2, achieving high internal-state selectivity and high kinetic energy resolution for reactant {{{{N}}}2}+ ions. The charge transfer (CT) and hydrogen-atom transfer (HT) channels, which lead to the respective formation of product {{{C}}}2{{{{H}}}2}+ and N2H+ ions, are observed. The vibrationally selected absolute integral cross sections for the CT [σ CT(v +)] and HT [[σ HT(v +)] channels obtained in the center-of-mass collision energy (E cm) range of 0.03–10.00 eV reveal opposite E cm dependences. The σ CT(v +) is found to increase as E cm is decreased, and is consistent with the long-range exothermic CT mechanism, whereas the E cm enhancement observed for the σ HT(v +) suggests effective coupling of kinetic energy to internal energy, enhancing the formation of N2H+. The σ HT(v +) curve exhibits a step at E cm = 0.70–1.00 eV, suggesting the involvement of the excited {{{C}}}2{{{{H}}}2}+({A}2{{{{Σ }}}{{g}}}+) state in the HT reaction. Contrary to the strong E cm dependences for σ CT(v +) and σ HT(v +), the effect of vibrational excitation of {{{{N}}}2}+ on both the CT and HT channels is marginal. The branching ratios and cross sections for the CT and HT channels determined in the present study are useful for modeling the atmospheric compositions of Saturn's largest moon, Titan. These cross sections and branching ratios are also valuable for benchmarking theoretical calculations on chemical dynamics of the titled reaction.

  14. Measurement of the 242Pu neutron capture cross section

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  15. Cross Sections for Electron Collisions with Methane

    Song, Mi-Young, E-mail: mysong@nfri.re.kr; Yoon, Jung-Sik [Plasma Technology Research Center, National Fusion Research Institute, 814-2 Osikdo-dong, Gunsan, Jeollabuk-do 573-540 (Korea, Republic of); Cho, Hyuck [Department of Physics, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Itikawa, Yukikazu [Institute of Space and Astronautical Science, Sagamihara 252-5210 (Japan); Karwasz, Grzegorz P. [Faculty of Physics, Astronomy and Applied Informatics, University Nicolaus Copernicus, Grudziadzka 5, 87100 Toruń (Poland); Kokoouline, Viatcheslav [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Nakamura, Yoshiharu [6-1-5-201 Miyazaki, Miyamae, Kawasaki 216-0033 (Japan); Tennyson, Jonathan [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  16. Measurements of neutron capture cross sections

    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 238U 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)

  17. Compilation of cross-sections. Pt. 2

    A compilation of integrated 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. This volume II contains cross-sections for K+ and K- induced reactions. (orig.)

  18. Ion and electron impact ionization cross sections

    Several current projects are described in which cross sections of interest to radiation physics are being measured. These include total and multiple ionization cross sections for protons on several gases covering a wide energy range, the measurement of cross sections differential in the angle and energy of ejected electrons for several gases including water vapor, and a review of proton ionization data. The work on water vapor has also been extended to electron and neutral hydrogen impact. A brief discussion is also given of some systematics of ionization cross sections. 13 references

  19. Improved Empirical Parametrization of Fragmentation Cross Sections

    Sümmerer, Klaus

    2012-01-01

    A new version is proposed for the universal empirical formula, EPAX, which describes fragmentation cross sections in high-energy heavy-ion reactions. The new version, EPAX 3, can be shown to yield cross sections that are in better agreement with experimental data for the most neutron-rich fragments than the previous version. At the same time, the very good agreement of EPAX 2 with data on the neutron-deficient side has been largely maintained. Comparison with measured cross sections show that the bulk of the data is reproduced within a factor of about 2, for cross sections down to the pico-barn range.

  20. Damage cross section library (DAMSIG77)

    The damage cross sections of various materials are converted to a data format, which can be used as library for the program SAND-II. The materials available in this library are graphite, stainless steel, aluminium, silicium, chromium, iron, nickel, copper, zirconium, molybdenum, tungsten, vanadium and niobium. A number of these materials have more than one cross section set, originating from different evaluations. Cross sections for some activation reactions, commonly used to determine thermal and fast neutron fluences have been included too. Moreover, also some artificial cross sections are introduced in this library which can be used to derive values for some physical quantities which may characterize neutron spectra

  1. Simultaneous evaluation of interrelated cross sections by generalized least-squares and related data file requirements

    Though several cross sections have been designated as standards, they are not basic units and are interrelated by ratio measurements. Moreover, as such interactions as 6Li + n and 10B + n involve only two and three cross sections respectively, total cross section data become useful for the evaluation process. The problem can be resolved by a simultaneous evaluation of the available absolute and shape data for cross sections, ratios, sums, and average cross sections by generalized least-squares. A data file is required for such evaluation which contains the originally measured quantities and their uncertainty components. Establishing such a file is a substantial task because data were frequently reported as absolute cross sections where ratios were measured without sufficient information on which reference cross section and which normalization were utilized. Reporting of uncertainties is often missing or incomplete. The requirements for data reporting will be discussed

  2. Compilation of cross-sections. Pt. 1

    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.)

  3. Compilation of cross-sections. Pt. 4

    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 KL0. It contains all data published up to June 1986. Plots of the cross-sections versus incident laboratory momentum are also given. (orig.)

  4. Fission cross section calculations for Pa isotopes

    Based on the recently measured cross-section values for the neutron-induced fission of 231Pa and our experience gained with other isotopes, new self consistent neutron cross section calculations for n+231Pa have been performed up to 30 MeV. The results are quite different to the existing evaluations, especially above the first chance fission threshold. (authors)

  5. Nucleon-XcJ Dissociation Cross Sections

    冯又层; 许晓明; 周代翠

    2002-01-01

    Nucleon-XcJ dissociation cross sections are calculated in a constituent interexchange model in which quark-quark potential is derived from the Buchmüller-Tye quark-anti-quark potential. These new cross sections for dominant reaction channels depend on the centre-of-mass energy of the nucleon and the charmonium.

  6. Recommended evaluation procedure for photonuclear cross section

    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)

  7. Comparative analysis among several cross section sets

    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)

  8. Photoproton cross section for 17O

    The measurement of the 17O(γ,p)16N reaction from threshold to an excitation energy of 44 MeV is presented. These results have been summed with the previously measured total photoneutron cross section to provide an approximation to the total photoabsorption cross section of 17O. The magnitude of the 17O photoabsorption cross section at the peak of the Giant Dipole Resonance is considerably less than the equivalent value for the photoabsorption cross sections of 16O and 18O. In addition, the integrated total photoabsorption cross section for 17O (up to 40 MeV) exhausts only about 58% of the sum rule; the values for the cases of 16O and 18O are significantly larger than this. The present data along with results from other reaction channels of this nucleus, were used to make spin, parity, and isospin assignments for several states in 17O. 48 refs., 4 tabs., 7 figs

  9. Photoneutron cross sections for the silicon isotopes

    The photoneutron cross sections for 28Si, 29Si, and 30Si have been measured up to 33 MeV with monoenergetic photons from the annihilation in flight of fast positrons, using neutron multiplicity counting. Average neutron energies were obtained simultaneously with the cross-section data by the ring-ratio technique. The giant dipole resonance for 28Si and 30Si exhibit appreciable fragmentation; that for 29Si does not. The (γ,2n) cross section for 30Si is large; that for 29Si is consistent with zero. The (γ,1n) cross section for 30Si decreases sharply with energy to values near zero as the (γ,2n) cross section grows, then increases to appreciable values as the (γ,2n) cross section diminishes; this extreme behavior, although never seen before, is attributable to the competition between the (γ,n), (γ,2n), and (γ,pn) decay channels. Some properties of the isospin components of the giant resonance are inferred. Other features of the data, including the integrated cross sections, are found to be similar in many respects to corresponding results for the oxygen and magnesium isotopes. The 28Si nucleus is found to be a better core for 29Si and 30Si than might have been expected from previous descriptions of its open-shell character

  10. The 42Ca photoneutron cross section

    The measurement of the 42Ca(γ,nsub(t)) is reported here over the energy range 10.5 - 28 MeV. Bremsstrahlung radiation from the 35 MeV Betatron at this University was used to measure a yield curve of photoneutrons, from which the (γ,nsub(t)) cross section was derived. Since proton and neutron emission are the major decay modes of the giant dipole resonance, summing these cross sections approximates the photo-absorption cross section. With this information the theoretical predictions can be checked

  11. Compilation of cross-sections. Pt. 3

    A compilation of integrated 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, particularly those from the CERN Collider, have also been included. Plots of the cross-sections versus incident laboratory momentum are also given. This volume III contains cross-sections for p and anti p induced reactions. (orig.)

  12. Screening corrections to the Rutherford cross section

    Differential cross sections for elastic p-Au scattering were measured in the energy range between 0.2 and 0.8 MeV for scattering angles from 300 to 1500 in order to determine corrections to the Rutherford cross section due to the screening of the nuclear charge by the atomic electrons. Furthermore, differential cross sections have been calculated in the weakly screening region using various screening functions. A simple analytical expression has been derived for the representation of both experimental and theoretical results. (orig.)

  13. Cross sections for K- and L-shell excitation in energetic ion-atom collisions

    Absolute K- and L-shell vacancy production cross sections have been determined from Auger-electron measurements in various heavy-ion-atom collisions. Collision systems with atomic numbers Z between 5 and 18 and with projectile energies varied between 6 and 600 keV were investigated. From cross section plots for some exemplary collision systems general trends are indicated and discussed in terms of the molecular-orbital (MO) model. Cross section ratios are deduced and compared to theoretical predictions

  14. Differential cross sections of positron hydrogen collisions

    于荣梅; 濮春英; 黄晓玉; 殷复荣; 刘旭焱; 焦利光; 周雅君

    2016-01-01

    We make a detailed study on the angular differential cross sections of positron–hydrogen collisions by using the momentum-space coupled-channels optical (CCO) method for incident energies below the H ionization threshold. The target continuum and the positronium (Ps) formation channels are included in the coupled-channels calculations via a complex equivalent-local optical potential. The critical points, which show minima in the differential cross sections, as a function of the scattering angle and the incident energy are investigated. The resonances in the angular differential cross sections are reported for the first time in this energy range. The effects of the target continuum and the Ps formation channels on the different cross sections are discussed.

  15. A nuclear cross section data handbook

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  16. Systematics of (n,2n) Cross Sections

    2008-01-01

    <正>The experimental data of (n, 2n) cross sections were collected and evaluated as complete as possible. There are 640 sets of experimental data for 130 nuclei. The data were fitted to the expressions that describe the

  17. Absorption Cross Section of Static Einstein-Maxwell Dilation Axion Black Hole for Scalar Particles

    LIU Chang-Qing; JING Ji-Liang

    2007-01-01

    The absorption cross section of the static Einstein-Maxwell dilaton axion (EMDA) black hole for scalar particles is investigated.It is shown that the ratio of the absorption cross section of the EMDA black hole to that of the Schwarzschild black hole decreases as the absolute value of the dilaton increases,and it becomes zero as the dilaton tends to its extremal value.It is also shown that the absorption cross section decreases as both the v and the absolute value of the dilaton increase,and it decreases as the mass of the particle decreases.

  18. Methods for calculating anisotropic transfer cross sections

    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)

  19. Neutron capture cross sections from Surrogate measurements

    Scielzo N.D.; Dietrich F.S.; Escher J.E.

    2010-01-01

    The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ) cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.

  20. Neutron capture cross sections from Surrogate measurements

    Scielzo N.D.

    2010-03-01

    Full Text Available The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.

  1. Photoneutron cross section of 34S

    Using an enriched 34S target, the reaction 34S(γ,sn)33S has been measured from below threshold (10.4 MeV) to 28 MeV by directly counting the photoneutrons as a function of bremsstrahlung energy. The resultant cross section shows gross splitting in the GDR region. The integrated cross section is discussed in the light of the systematics of similar nuclei having two neutrons outside a doubly closed shell/sub-shell core

  2. Photoneutron cross section of 34S

    Using an enriched 34S target, the reaction 34S(γ, sn) has been measured from below threshold (10.4 MeV) to 28 MeV by directly counting the photoneutrons as a function of bremsstrahlung energy. The resultant cross section shows gross splitting in the GDR region. The integrated cross section is discussed in the light of the systematics of similar nuclei having two neutrons outside a doubly closed shell/sub-shell core. (orig.)

  3. Evaluation methods for neutron cross section standards

    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

  4. Elastic electron scattering cross sections for molecular hydrogen

    Khakoo, M. A.; Trajmar, S.

    1986-01-01

    Using an electron-beam - molecular-beam apparatus and employing the relative flow technique, ratios of the differential elastic scattering cross sections (DCSs of H2 to He were measured at incident electron energies of 15-100 eV and over the angular range of 10-125 degrees. From these ratios, the absolute elastic DCSs for H2 were determined by normalization to accurate, available elastic DCSs of He. Since pure rotational structure was not resolved in this work, the DCSs reported are the sum of elastic and rotational excitations of H2 at room temperature. The reliability of the relative flow normalization to He was checked at each energy and angle by performing similar elastic DCS measurements on Ne (for which the cross sections are known). The resulting absolute Ne DCSs were found to be in good agreement (within 10 percent with the Ne elastic DCSs measured previously (Register and Trajmar, 1984). From the DCSs, integral and momentumtransfer cross sections were calculated. The present results are compared with other recent measurements.

  5. Photoproton cross section for 14C

    Using bremsstrahlung, the 14C(γ,p) reaction cross section has been measured from threshold to 29 MeV. The integrated cross section up to 30 MeV is 18±3 MeV mb. Above 23.5 MeV, the reported cross section includes a contribution, estimated at 3.5 MeV mb, due to the 14C(γ,d) and 14Cγ,pn) reactions. Essentially the entire 14C(γ,p) cross section results from decay of T> dipole states. From knowledge of other decay channels estimates of the cross section, integrated to 30 MeV for the T and T> components of the giant resonance (GDR) of 81 MeV mb and 43 MeV mb are obtained. The splitting of the mean energies of the GDR isospin components is 8.5 MeV. Comparisons with several shell-model calculations are made with the data, and general agreement is found. A comparison of photonuclear absorption cross sections for 12,1314C and 16,17,18 O shows dramatic redistribution of dipole strength as neutrons are added to the core nuclei. 41 refs., 1 tab., 7 figs

  6. abo-cross: Hydrogen broadening cross-section calculator

    Barklem, P. S.; Anstee, S. D.; O'Mara, B. J.

    2015-07-01

    Line broadening cross sections for the broadening of spectral lines by collisions with neutral hydrogen atoms have been tabulated by Anstee & O'Mara (1995), Barklem & O'Mara (1997) and Barklem, O'Mara & Ross (1998) for s-p, p-s, p-d, d-p, d-f and f-d transitions. abo-cross, written in Fortran, interpolates in these tabulations to make these data more accessible to the end user. This code can be incorporated into existing spectrum synthesis programs or used it in a stand-alone mode to compute line broadening cross sections for specific transitions.

  7. A Pebble Bed Reactor cross section methodology

    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.

  8. Isotope effect in dissociative electron attachment cross sections in acetylene

    May, Olivier; Fedor, Juraj; Allan, Michael, E-mail: olivier.may@unifr.c [Department of Chemistry, University of Fribourg, Chemin du Muse 9, 1700 Fribourg (Switzerland)

    2009-11-01

    We present absolute cross section measurement of dissociative electron attachment to C{sub 2}H{sub 2} and C{sub 2}D{sub 2}. The C{sub 2}H{sup -}/ C{sub 2}D{sup -} band at 3 eV shows pronounced isotope effect with the cross section for C{sub 2}H{sub 2} being 14.7 times larger than that for C{sub 2}D{sub 2}. The light fragments H{sup -} and D{sup -} dominate the second dissociative electron attachment band around 8 eV. These bands exhibit much weaker isotope effects which is in agreement with their assignment to Feshbach resonances.

  9. Reduction Methods for Total Reaction Cross Sections

    Gomes, P. R. S.; Mendes Junior, D. R.; Canto, L. F.; Lubian, J.; de Faria, P. N.

    2016-03-01

    The most frequently used methods to reduce fusion and total reaction excitation functions were investigated in a very recent paper Canto et al. (Phys Rev C 92:014626, 2015). These methods are widely used to eliminate the influence of masses and charges in comparisons of cross sections for weakly bound and tightly bound systems. This study reached two main conclusions. The first is that the fusion function method is the most successful procedure to reduce fusion cross sections. Applying this method to theoretical cross sections of single channel calculations, one obtains a system independent curve (the fusion function), that can be used as a benchmark to fusion data. The second conclusion was that none of the reduction methods available in the literature is able to provide a universal curve for total reaction cross sections. The reduced single channel cross sections keep a strong dependence of the atomic and mass numbers of the collision partners, except for systems in the same mass range. In the present work we pursue this problem further, applying the reduction methods to systems within a limited mass range. We show that, under these circumstances, the reduction of reaction data may be very useful.

  10. Elastic differential cross sections for electron collisions with polyatomic molecules

    Experimental data for electron-polyatomic molecule collisions are reviewed in connection with fusion and processing plasmas, as well as with the associated environmental issues. The electron scattering experiments for differential cross section (DCS) measurements for various processes, such as elastic scattering, have been performed across a broad range of energies (1-100 eV), mainly, at Sophia University since 1978, and some done under the collaborations with the Australian National University, Flinders University, and the Chungnam National University. As a benchmark cross section, elastic DCS are essential for the absolute scale conversion of inelastic DCS, as well as for testing computational methods. The need for cross-section data for a wide variety of molecular species is also discussed, because there is an urgent need to develop an international program to provide the scientific and technological communities with authoritative cross sections for electron-molecule interactions. Note that the detailed comparison with other data available is not given here. Ruther, other available data can be found in the references we cite. This course of action was adopted to keep this report to a sensible length, so that only our numerical data is provided here. (author)

  11. Neutron capture cross sections of 151,153Eu

    The neutron capture cross section of 151,153Eu nuclei was measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos Neutron Science Center (LANSCE). Neutrons were produced at the Lujan Neutron Scattering Center and their energies were determined by the time-of-flight technique. The relative yield versus neutron incident energy from 0.1 eV to 2.0 keV for both 151Eu(n,) and 153Eu(n,) reactions was derived from events gated on the total energy and multiplicity measured by the DANCE array. The absolute cross section was determined by scaling the relative yield to the measured cross sections of well-known resonances. The shape of the yield curve agrees well with previous measurements in the resonance region for both 151Eu and 153Eu capture cross sections. New data are reported for neutron incident energies between 100 eV and 2.0 keV. The trend of data in the 0.3 keV to 2.0 keV region of neutron incident energy is consistent with the ENDF/BVI and the measurements of Macklin and Young. Crucial skills, acquired from these measurements in the early implementation of DANCE, are important to plan future experiments, which will yield results up to a few hundred keV neutron incident energy

  12. Prospects for Precision Neutrino Cross Section Measurements

    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.

  13. Neutron cross section of methane hydrate

    Kiyanagi, Y.; Date, S.; Horikawa, T.; Takamine, J.; Iwasa, H.; Kamiyama, T. [Graduate School of Eng., Hokkaido Univ., Sapporo (Japan); Uchida, T.; Ebinuma, T.; Narrita, H. [National Inst. of Advanced Industrial Science, Tsukisamu, Sapporo (Japan); Bennington, S.M. [ISIS Dept., Rutherford Appleton, Chilton, Didcot, Oxon (United Kingdom)

    2004-03-01

    To estimate the neutronic characteristics of methane hydrate and also to synthesize cross section data for simulation we need neutron scattering data ranging wide energy and momentum region. We performed inelastic neutron scattering experiments to get information about the neutron cross section on methane hydrate. It was found that at high momentum transfer region rotational mode as well as vibration mode showed recoil like behavior. On the other hand, at low momentum region, as well known, free rotation like energy levels were observed. The energy level of ice in methane hydrate was very similar to normal ice. The results suggest that the rough expression of the cross section of the methane hydrate is presented by linear combination of the methane and ice. (orig.)

  14. Radiation pressure cross section for fluffy aggregates

    We apply the discrete dipole approximation (DDA) to estimate the radiation pressure cross section for fluffy aggregates by computing the asymmetry parameter and the cross sections for extinction and scattering. The ballistic particle-cluster aggregate and the ballistic cluster-cluster aggregate consisting of either dielectric or absorbing material are considered to represent naturally existing aggregates. We show that the asymmetry parameter perpendicular to the direction of wave propagation is maximized where the wavelength is comparable to the aggregate size, which may be characterized by the area-equivalent radius or the radius of gyration rather than the volume-equivalent radius. The asymmetry parameter for the aggregate depends on the morphology of the particle, but not on the constituent material. Therefore, the dependence of the radiation pressure cross section on the material composition arises mainly from that of the extinction and scattering cross sections, in other words, the single-scattering albedo. We find that aggregates consisting of high-albedo material show a large deviation of radiation pressure from the direction of incident radiation. When the aggregates are illuminated by blackbody radiation, the deviation of the radiation pressure increases with increasing temperature of the blackbody. Since the parallel component of the radiation pressure cross section for the aggregates is smaller than that for the volume-equivalent spheres at the size parameter close to unity, the Planck-mean radiation pressure cross section for the aggregates having radius comparable to the effective wavelength of radiation shows a lower value, compared with the volume-equivalent sphere. Consequently, the slope of the radiation pressure force per mass of the particle as a function of particle mass shows a lower maximum for the aggregates than for compact spherical particles. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Saturation Effects in Hadronic Cross Sections

    Shoshi, Arif I.; Steffen, Frank D.

    2002-01-01

    We compute total and differential elastic cross sections of high-energy hadronic collisions in the loop-loop correlation model that provides a unified description of hadron-hadron, photon-hadron, and photon-photon reactions. The impact parameter profiles of pp and gamma*p collisions are calculated. For ultra-high energies the hadron opacity saturates at the black disc limit which tames the growth of the hadronic cross sections in agreement with the Froissart bound. We compute the impact param...

  16. Precise neutron inelastic cross section measurements

    Negret, Alexandru

    2012-11-01

    The design of a new generation of nuclear reactors requires the development of a very precise neutron cross section database. Ongoing experiments performed at dedicated facilities aim to the measurement of such cross sections with an unprecedented uncertainty of the order of 5% or even smaller. We give an overview of such a facility: the Gamma Array for Inelastic Neutron Scattering (GAINS) installed at the GELINA neutron source of IRMM, Belgium. Some of the most challenging difficulties of the experimental approach are emphasized and recent results are shown.

  17. Charged particle reaction cross sections and nucleosynthesis

    The role of proton and α-particle induced reactions in carbon, neon, oxygen and silicon burning in massive stars is surveyed. The problems associated with determining thermonuclear reaction rates for reactions with widely spaced resonances and with closely spaced or overlapping resonances are discussed and the associated experimental approaches are reviewed. Experimental techniques which have been used in the measurement of reaction cross sections are discussed and their strengths and weaknesses are identified. Recent developments in attempts to establish reliable statistical-model codes for calculation of reaction cross sections are presented and discussed. The results of experimental tests of statistical model codes are summarised and evaluated

  18. Neutron capture cross sections from surrogate measurements

    The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. The method is applied to the 155Gd(n,γ) reaction. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ) cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications. (authors)

  19. Covariance Evaluation Methodology for Neutron Cross Sections

    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.

  20. Atlas of neutron capture cross sections

    This report describes neutron capture cross sections in the range 10-5 eV - 20 MeV as evaluated and compiled in recent activation libraries. The selected subset comprise the (n,γ) cross sections for a total of 739 targets for the elements H (Z = 1, Z = 1) to Cm (Z = 96, A = 238) totaling 972 reactions. Plots of the point-wise data are shown and comparisons are made with the available experimental values at thermal energy, 30 keV and 14.5 MeV. 10 refs, 7 tabs

  1. Optical Model and Cross Section Uncertainties

    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.

  2. Verification of important cross section data

    Full text: Continuing efforts in nuclear data development have made the design of a fusion power system less uncertain. The fusion evaluated nuclear data library (FENDL) development effort since 1987 under the leadership of the IAEA Nuclear Data Section has provided a credible international library for the investigation and design of the International Thermonuclear Engineering Reactor (ITER). Integral neutronics experiments are being carried out for ITER and fusion power plant blanket and shield assemblies to validate the available nuclear database and to identify deficiencies for further improvement. Important cross section data need experimental verifications if these data are evaluated based on physics model calculations and there are no measured data points available. A particular reaction cross section is Si28(n,x)Al27, which is the important cross section to determine whether the low activation SiC composite structure can be qualified as low level nuclear waste after life time exposure in the first wall neutron environment in a fusion power plant. Measurements of helium production data for candidate fusion materials are also needed, particularly at energies above 14 MeV for the assessment of materials damage in the IFMIF neutron spectrum. To a less extent, it appears that V51(n,x)Ti50 reaction cross section also needs to be measured to further confirm a recent new evaluation of vanadium for ENDF/B-VII. (author)

  3. Energy and angle differential cross sections for the electron-impact double ionization of helium

    Colgan, James P [Los Alamos National Laboratory; Pindzola, M S [AUBURN; Robicheaux, F [AUBURN

    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.

  4. Symmetric charge transfer cross section of uranium

    Symmetric charge transfer cross section of uranium was calculated under consideration of reaction paths. In the charge transfer reaction a d3/2 electron in the U atom transfers into the d-electron site of U+(4I9/2) 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 cm2) 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)

  5. Electron impact excitation cross sections for carbon

    Ganas, P. S.

    1981-04-01

    A realistic analytic atomic independent particle model is used to generate wave functions for the valence and excited states of carbon. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, we calculate generalized oscillator strengths and integrated cross sections for various excitations from the 2p 2( 3P O) valence state.

  6. Electron impact excitation cross sections for carbon

    A realistic analytic atomic independent particle model is used to generate wave functions for the valence and excited states of carbon. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, we calculate generalized oscillator strengths and integrated cross sections for various excitations from the 2p2(3P0) valence state. (orig.)

  7. Top quark cross sections and differential distributions

    Kidonakis, Nikolaos

    2011-01-01

    I present results for the top quark pair total cross section and the top quark transverse momentum distribution at Tevatron and LHC energies. I also present results for single top quark production. All calculations include NNLO corrections from NNLL threshold resummation.

  8. Neutron cross sections of importance to astrophysics

    Neutron reactions of importance to the various stellar burning cycles are discussed. The role of isomeric states in the branched s-process is considered for particular cases. Neutron cross section needs for the 187Re-187Os, 87Rb-87Sr clocks for nuclear cosmochronology are discussed. Other reactions of interest to astrophysical processes are presented. 35 references

  9. Fusion cross sections and the new dynamics

    The prediction of the need for an extra push over the interaction barrier in order to make the heavier nuclei fuse is made the basis of a simple algebraic theory for the energy-dependence of the fusion cross-section. A comparison with recent experiments promises to provide a quantitative test of the New Dynamics

  10. LSP-Nucleus Elastic Scattering Cross Sections

    Vergados, J. D.; Kosmas, T. S.

    1997-01-01

    We calculate LSP-nucleus elastic scattering cross sections using some representative input in the restricted SUSY parameter space. The coherent matrix elements are computed throughout the periodic table while the spin matrix elements for the proposed $^{207}Pb$ target which has a rather simple nuclear structure. The results are compared to those given from other cold dark matter detection targets.

  11. Neutron Capture Cross Sections for Radioactive Nuclei

    Tonchev, Anton; Bedrossian, Peter; Escher, Jutta; Scielzo, Nicholas

    2015-10-01

    Accurate neutron-capture cross sections for radioactive nuclei near or far away from the line of beta stability are crucial for understanding the nucleosynthesis of heavy elements. 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 observables that can constrain Hauser-Feshbach statistical model calculations of capture cross sections. Specifically, we will consider photon scattering, transfer reactions, and beta-delayed neutron emission. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes far from stability will be discussed. This work was performed under the auspices of US DOE by LLNL under contract DE-AC52-07NA27344. Funding was provided via the LDRD-ERD-069 project.

  12. Modelisation of the fission cross section

    The neutron cross sections of four nuclear systems (n+235U, n+233U, n+241Am and n+237Np) are studied in the present document. The target nuclei of the first case, like 235U and 239Pu, have a large fission cross section after the absorption of thermal neutrons. These nuclei are called 'fissile' nuclei. The other type of nuclei, like 237Np and 241Am, 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)

  13. Measurement cross sections for radioisotopes production

    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- - 47Sc, 67Cu - β+ - 44Sc, 64Cu, 82Sr/82Rb, 68Ge/68Ga - and α emitters - 211At. 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 - natCu or natNi - is used to correct beam loss whereas degrader foils are used to lower beam energy. We chose to study the natTi(p,X)47Sc and 68Zn(p,2p)67Cu 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 68Zn - 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)

  14. A New Neutrino Cross Section Data Ressource

    Whalley, M R

    2005-01-01

    We describe a new web based data resource being developed to provide access to accurate and validated cross sections of low energy neutrino and antineutrino interactions. The proposed content of this database are outlined which cover total and differential cross from inclusive, quasi-elastic and exclusive pion production processes from charged and neutral current interactions. Efforts to obtain these data, which come mainly from old bubble chamber experiments, are described as well as the implementation of an embryonic web site to make the resource generally accessible.

  15. (n,α) cross section measurement of gaseous sample using gridded ionization chamber. Cross section determination

    We are developing a method of (n,α) 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 12C(n,α0)9Be measurement. We applied this method to the 16O(n,α)13C cross section around 14.1 MeV. (author)

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

    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)

  17. Total electron scattering cross sections for methanol and ethanol at intermediate energies

    Silva, D G M; Tejo, T; Lopes, M C A [Departamento de Fisica, ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, CEP 36036-330 (Brazil); Muse, J; Romero, D; Khakoo, M A, E-mail: cristina.lopes@ufjf.edu.b [Department of Physics, California State University, Fullerton, CA 92831 (United States)

    2010-01-14

    Absolute total cross section (TCS) measurements of electron scattering from gaseous methanol and ethanol molecules are reported for impact energies from 60 to 500 eV, using the linear transmission method. The attenuation of intensity of a collimated electron beam through the target volume is used to determine the absolute TCS for a given impact energy, using the Beer-Lambert law to first approximation. Besides these experimental measurements, we have also determined TCS using the additivity rule.

  18. Cross-section analysis for TRADE fuel

    The TRIGA core includes bounded hydrogen in Zirconium hydride in its fuel meat allowing for fast reactivity transients. The inherent safety mechanism is based on the immediate increase of neutron up-scattering by the hydrogen as a result of a fuel temperature increase. The temperature dependent resonance absorption is the second safety feature. The special fuel type together with the introduction of an external source within it for the TRADE project necessitates an accurate evaluation of the bounded hydrogen cross section generation technique as well as of the resonance treatment. By comparing deterministic tools and Monte Carlo solution methods the generated bounded isotopes cross sections are analysed. Further, the importance of the Doppler and the thermal up-scattering effects are quantified and the sensitivities to the solution method are discussed. (authors)

  19. The photoneutron cross section of 20Ne

    The photoneutron cross section of 20Ne has been measured over a photon energy range 16 to 29 MeV in steps of 100 keV. The giant dipole resonance is resolved into three strong peaks below 21 MeV and at least two broader resonances at higher excitations. This structure is consistent with earlier measurements of poorer resolution and shows a correlation with the recent calculations of Schmid and Do Dang. Comparisons with high resolution neutron time-of-flight and electron scattering data indicate that there appear to exist in the giant resonance of 20Ne, regions of structure roughly 2-3 MeV wide which exhibit localised characteristics related to the excitation mechanisms. The role of deformation and configuration splitting effects in the cross section are discussed and possible directions of further study are noted which might clarify the situation more fully

  20. Structured ion impact: Doubly differential cross sections

    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 H2O. 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

  1. Elliptical cross section fuel rod study II

    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

  2. Jet cross sections and PDF constraints

    CMS Collaboration

    2012-01-01

    A measurement of inclusive jet and dijet production cross sections is presented. Data from LHC proton-proton collisions at $\\sqrt{s}=7\\TeV$, corresponding to $4.67\\fbinv$ of integrated luminosity, have been collected with the CMS detector. Jets are reconstructed with the anti-$k_T$ clustering algorithm of size parameter $R=0.7$, extending to rapidity $|y|=2.5$, transverse momentum $\\pt=2\\TeV$, and dijet invariant mass $M_{JJ}=5\\TeV$. The measured cross sections are corrected for detector effects and compared to perturbative QCD predictions at next-to-leading order, using various sets of parton distribution functions.

  3. Electron capture cross sections for stellar nucleosynthesis

    Giannaka, P G

    2015-01-01

    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 quasi-particle 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 above mentioned $e^-$-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 $^{66}Zn$ isotope, which belongs to the iron group nuclei and plays prominent role in stellar nucleosynthesis at core collapse supernovae environment.

  4. Measurements of neutron spallation cross section. 2

    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)

  5. Reinforced concrete columns of variable cross section

    Brant, N.F.A.

    1984-01-01

    The results of a series of 19 full scale tests carried out on pin-ended reinforced concrete columns are reported. The columns tested had either tapered rectangular sections along the length or octagonal cross sections. All columns, except the last 6, were subjected to uniaxial eccentricities at one of the ends (the stronger end), and a nominally concentric load at the other end. For the case of the last six columns the loading applied at the stronger end was biaxially eccentric. For each of t...

  6. Electron collision cross sections and radiation chemistry

    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

  7. Atomic-process cross section data, 1

    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.)

  8. 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.

  9. Neutron cross section standards and instrumentation

    This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the second year of a three-year interagency agreement. This program includes a broad range of data measurements and evaluations. An emphasis has been focused on the 10B cross sections where serious discrepancies in the nuclear data base remain. In particular, there are important problems with the interpretation of the helium gas production associated with diagnostic measurements of interest in nuclear technology. The enhanced use of this isotope for medical treatment is also of significance. New measurements of neutron reaction cross sections for 10B are in progress in collaboration with scientists at the Oak Ridge National Laboratory. New experiments are in progress on the important dosimetry standards 237Np(n,f) and 239Pu(n,f) below 1 MeV neutron energy. In addition, new measurements of charged-particle production in basic biological elements for medical applications are underway. Further measurements are planned or in progress in collaborations which include fission fragment energy and angular distributions, and neutron energy spectra and angular distributions from neutron-induced fission. Also measurements of angular distributions of neutrons from scattering on protons, and determinations of capture cross section of gold are planned for a later time. Data evaluation will shift to include a unified international effort to motivate new measurements and evaluations. In response to the requests of the measurement community, NIST is beginning the formation of a national depository for fissionable isotope mass standards. This action will preserve for future measurements the valuable and irreplaceable critical samples whose masses and composition have been carefully determined and documented over the past 30 years of the nuclear program

  10. Neutron capture cross section measurement techniques

    A review of currently-used techniques to measure neutron capture cross sections is presented. Measurements involving use of total absorption and Moxon-Rae detectors are based on low-resolution detection of the prompt γ-ray cascades following neutron captures. In certain energy ranges activation methods are convenient and useful. High resolution γ-ray measurements with germanium detectors can give information on the parameters of resonance capture states. The use of these techniques is described. (U.S.)

  11. Fusion cross sections at deep subbarrier energies

    Hagino, K.; Rowley, N.; Dasgupta, M

    2003-01-01

    A recent publication reports that heavy-ion fusion cross sections at extreme subbarrier energies show a continuous change of their logarithmic slope with decreasing energy, resulting in a much steeper excitation function compared with theoretical predictions. We show that the energy dependence of this slope is partly due to the asymmetric shape of the Coulomb barrier, that is its deviation from a harmonic shape. We also point out that the large low-energy slope is consistent with the surprisi...

  12. How to calculate colourful cross sections efficiently

    Gleisberg, Tanju; Krauss, Frank

    2008-01-01

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  13. Jet cross sections in leptoproduction from QCD

    We have calculated the longitudinal and other polarization dependent cross sections for jet production in deep inelastic ep, νp and anti νp scattering up to order αsub(s) of the quark-gluon coupling constant. Fragmentation of final state partons into hadrons is taken into account. Distributions in thrust, p2sub(Tin) and p2sub(Tout) are predicted for all three reactions and various values of W and Q. (orig.)

  14. 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.

  15. Neutron cross section standards and instrumentation

    1992-09-01

    This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the second year of a three-year interagency agreement. This program includes a broad range of data measurements and evaluations. An emphasis has been focused on the (sup 10)B cross sections where serious discrepancies in the nuclear data base remain. In particular, there are important problems with the interpretation of the helium gas production associated with diagnostic measurements of interest in nuclear technology. The enhanced use of this isotope for medical treatment is also of significance. New measurements of neutron reaction cross sections for (sup 10)B are in progress in collaboration with scientists at the Oak Ridge National Laboratory. New experiments are in progress on the important dosimetry standards (sup 237)Np(n,f) and (sup 239)Pu(n,f) below 1 MeV neutron energy. In addition, new measurements of charged-particle production in basic biological elements for medical applications are underway. Further measurements are planned or in progress in collaborations which include fission fragment energy and angular distributions, and neutron energy spectra and angular distributions from neutron-induced fission. Also measurements of angular distributions of neutrons from scattering on protons, and determinations of capture cross section of gold are planned for a later time. Data evaluation will shift to include a unified international effort to motivate new measurements and evaluations. In response to the requests of the measurement community, NIST is beginning the formation of a national depository for fissionable isotope mass standards. This action will preserve for future measurements the valuable and irreplaceable critical samples whose masses and composition have been carefully determined and documented over the past 30 years of the nuclear program.

  16. Fusion cross sections measurements with MUSIC

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  17. Inclusive jet cross section at D0

    Bhattacharjee, M. [Delhi Univ. (India). Dept. of Physics and Astrophysics

    1996-09-01

    Preliminary measurement of the central ({vert_bar}{eta}{vert_bar} {<=} 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 {ital pb}{sup -1}) and 1994-1995 (90 {ital pb}{sup -1}) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made.

  18. The Pa-233 fission cross section

    The energy dependent neutron-induced fission cross section of 233Pa has for the first time been measured directly with mono-energetic neutrons. This isotope is produced in the thorium fuel cycle and serves as an intermediate step between the 232Th source material and the 233U fuel material. Four neutron energies between 1.0 and 3.0 MeV have been measured in a first campaign. Some preliminary results are presented and compared to literature. (author)

  19. Total neutron cross section for 181Ta

    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 crosssection for 27Al was measured as a control target, since there exists data for 27Al with high resolution and low statistical error [3].

  20. Cross-section reconstruction during uniaxial loading

    The inelastic response of materials to applied uniaxial loading is typically measured using tensile or compressive specimens of an initially circular cross-section. Under deformation, this cross-section may become elliptical due to anisotropic material behaviour. An optical technique for measuring the elliptical deformation of anisotropic, homogeneous cylindrical specimens undergoing uniaxial deformation is presented. It enables the quantification of anisotropic deformation in situ and provides data for material characterization. Three or more silhouette views of a specimen are obtained using multiple cameras or mirrored views. The positions of the edges are computed using a sub-pixel edge detection method, and 3D tangent rays from the camera through these positions are calculated. These bounding tangents are used as the basis for an elliptical fit by least squares at cross-sections along the length of the specimen. Stochastic error estimates are performed by simulation of the experiment. Error estimates, for the experimental set-up used, are also calculated by reconstructing elliptical prisms of precisely measured dimensions. Example reconstructions from specimens of rolled titanium deformed plastically in tension at quasi-static (7 × 10−4 s−1) and high strain rates (3 × 103 s−1) are presented

  1. Measurement of fast-neutron capture cross sections for 75As

    2001-01-01

    The cross sections of the 75As(n,γ)76As reaction were measured in the neutron energy range from 0.50 to 1.50 MeV by using the activation technique. Neutrons were produced via the T(p,n)3He reaction and the cross sections of the 197Au(n,γ)198Au reaction were used to determine the absolute neutron flux. Present results are compared with existing measurements and evaluations.

  2. Averaging cross section data so we can fit it

    Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). NNDC

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  3. Averaging cross section data so we can fit it

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  4. Nuclear interaction cross sections for proton radiotherapy

    Chadwick, M B; Arendse, G J; Cowley, A A; Richter, W A; Lawrie, J J; Newman, R T; Pilcher, J V; Smit, F D; Steyn, G F; Koen, J W; Stander, J A

    1999-01-01

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  5. 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.

  6. Charge changing cross sections of relativistic uranium

    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 U92+ reversible U91+ and U91+ reversible U90+ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx. = 5% bare U92+ at 200 MeV/nucleon and 85% U92+ at 962 MeV/nucleon. 7 references, 5 figures

  7. Fission cross section measurements for minor actinides

    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)

  8. Neutron absorption cross section of uranium-236

    U-236 neutron absorption was measured as a function of neutron time-of-flight from 20 eV to 1 MeV. The neutron flux was monitored with a 6Li glass scintillator. Average cross sections from 3 keV to 1 MeV were derived. Estimated uncertainties were less than 5% below 600 keV and increased to 9.5% at 1 MeV. Resonance parametrization from 20 eV to a few keV remains to be done. 17 refs., 5 figs., 3 tabs

  9. LEP vacuum chamber, cross-section

    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.

  10. Critical behavior of cross sections at LHC

    Dremin, I M

    2016-01-01

    Recent experimental data on elastic scattering of high energy protons show that the critical regime has been reached at LHC energies. The approach to criticality is demonstrated by increase of the ratio of elastic to total cross sections from ISR to LHC energies. At LHC it reaches the value which can result in principal change of the character of proton interactions. The treatment of new physics of hollowed toroid-like hadrons requires usage of another branch of the unitarity condition. Its further fate is speculated and interpreted with the help of the unitarity condition in combination with present experimental data. The gedanken experiments to distinguish between different possibilities are proposed.

  11. Total cross section for inclusive electron scattering in the low Q2 region

    Absolute cross sections for inclusive electron scattering on H, D, Be, Al and Si have been measured in the kinematical region 0.08(GeV/c)2 2 2 and 0.3 GeV 0. A careful treatment of radiative corrections due to elastic electron nucleus scattering, quasielastic and inelastic scattering or the bound nucleons has been applied to the measured cross sections. The comparion of the nuclear cross sections with the elementary ones leads to a value of Asub(e)sub(f)sub(f) < A with a rapid onset this effect at small values of the scaling variable x'. (orig.)

  12. 30 CFR 779.25 - Cross sections, maps, and plans.

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Cross sections, maps, and plans. 779.25 Section... RESOURCES § 779.25 Cross sections, maps, and plans. (a) The application shall include cross sections, maps..., maps and plans included in a permit application as required by this section shall be prepared by,...

  13. Optimising neutron polarisers--measuring a single cross-section

    Goossens, D.J.; Cussen, L.D. E-mail: lcu@ansto.gov.au

    2002-09-01

    This article is part of a series of works exploring the optimisation of neutron polarisation analysis measurements. It deals with measurements of individual spin flip and non-spin flip neutron scattering cross-sections. An instrumental quality factor is presented. The optimum effective thickness for gaseous spin polarised {sup 3}He transmission filters is derived and presented. Cu{sub 2}MnAl Heusler alloy polarising monochromators and supermirror devices are considered using the quality factor. Absolute comparisons are made between these different types of polarisers. The effect of instrumental background is calculated for a wide range of experimental situations. Even very small backgrounds can have a very large effect on the quality of measurements achievable indicating that great attention must be paid to background reduction on polarisation analysis instruments.

  14. Optimising neutron polarisers--measuring a single cross-section

    Goossens, D J

    2002-01-01

    This article is part of a series of works exploring the optimisation of neutron polarisation analysis measurements. It deals with measurements of individual spin flip and non-spin flip neutron scattering cross-sections. An instrumental quality factor is presented. The optimum effective thickness for gaseous spin polarised sup 3 He transmission filters is derived and presented. Cu sub 2 MnAl Heusler alloy polarising monochromators and supermirror devices are considered using the quality factor. Absolute comparisons are made between these different types of polarisers. The effect of instrumental background is calculated for a wide range of experimental situations. Even very small backgrounds can have a very large effect on the quality of measurements achievable indicating that great attention must be paid to background reduction on polarisation analysis instruments.

  15. Measurement of the fast neutron capture cross section of 238U relative to 235U(n,f)

    The capture cross section of 238U was measured using the activation technique and 235U(n,f) as a reference cross section. Capture events were measured by detection of two prominent γ-transitions in the decay of the 239U daughter nuclide, 239Np, employing a high resolution Ge(Li) detector. The system was calibrated with samples activated in a thermal neutron flux relative to the capture cross section of gold, and with an absolutely calibrated α-emitter, 243Am, which decays to 239Np. Cross section measurements were carried out in the neutron energy range from 30 keV to 3 MeV. Emphasis was on absolute values between 150 keV and 1 MeV where the 238U(n,γ) cross section and its cross section is small. Background from fission products was found to restrict the accuracy of the measured data at energies > 1.5 MeV

  16. The Elusive p-air Cross Section

    Block, Martin M

    2006-01-01

    For the $\\pbar p$ and $pp$ systems, we have used all of the extensive data of the Particle Data Group[K. Hagiwara {\\em et al.} (Particle Data Group), Phys. Rev. D 66, 010001 (2002).]. We then subject these data to a screening process, the ``Sieve'' algorithm[M. M. Block, physics/0506010.], in order to eliminate ``outliers'' that can skew a $\\chi^2$ fit. With the ``Sieve'' algorithm, a robust fit using a Lorentzian distribution is first made to all of the data to sieve out abnormally high $\\delchi$, the individual i$^{\\rm th}$ point's contribution to the total $\\chi^2$. The $\\chi^2$ fits are then made to the sieved data. We demonstrate that we cleanly discriminate between asymptotic $\\ln s$ and $\\ln^2s$ behavior of total hadronic cross sections when we require that these amplitudes {\\em also} describe, on average, low energy data dominated by resonances. We simultaneously fit real analytic amplitudes to the ``sieved'' high energy measurements of $\\bar p p$ and $pp$ total cross sections and $\\rho$-values for $\\...

  17. Cross-section measurements for radioactive samples

    The measurement of (n,p), (n,α) and (n,γ) cross sections for radioactive nuclei is of interest to both nuclear physics and astrophysics. For example, using these reactions, properties of levels in nuclei at high excitation energies, which are difficult or impossible to study using other reactions, can be investigated. Also, reaction rates for both big-bang and stellar nucleosynthesis can be obtained from these measurements. In the past, the large background associated with the sample activity limited these types of measurements to radioisotopes with very long half-lives. The advent of the low-energy, high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Examples of (n,p) measurements on samples with half lives as short as fifty-three days will be given. The nuclear physics and astrophysics to be learned from these data will be discussed. Additional difficulties are encountered when making (n,γ) rather than (n,p) or (n,α) measurements. However, with a properly-designed detector, and the high peak neutron intensities now available, (n,γ) measurements can be made for nuclei with half lives as short as several months. Progress on the Los Alamos (n,γ) cross-section measurement program for radioactive samples will be discussed. 39 refs., 7 figs

  18. Calculation of cross sections for heavy isotopes

    In the present work an integrated system of codes for basic neutron data evaluation were assembled and built. Complete evaluations for the isotopes 240Pu, 241Pu, 242Pu and 238Pu were performed. The following cross sections: total, elastic, radiative capture, fission, total inelastic, partial inelastic, (n,2n), (n,3n) and differential elastic were evaluated as well as the average number of neutrons per neutron-induced fission and the average elastic scattering cosine in the lab system.The data for the plutonium isotopes were incorporated into the German KEDAK file. A method was developed for calculating the energy distributions of the second and third secondary neutrons from the A(n,2n) and (n,3n) reactions in the framework of the compound nucleus theory, and utilizing the nuclear data of the nuclei A, A-1, A-2. This method was used to generate the 238U secondary neutron energy distributions in the incident neutron energy range of 6 to 15 MeV. A nuclear data evaluation for 237U in the resolved inelastic scattering range (10-700 keV) was performed. The compound elastic and partial inelastic scattering cross sections were used in the 238U secondary neutron energy distribution calculations. (B.G.)

  19. Windowed multipole for cross section Doppler broadening

    Josey, C.; Ducru, P.; Forget, B.; Smith, K.

    2016-02-01

    This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

  20. Double-differential cross-sections of slow neutron scattering by water at high temperatures

    The absolute double-differential scattering cross-sections for light water are measured for two incident neutron energies of 25 meV and 256 meV in the temperature range from 300 to 600 K. The experimental curves are compared with calculations based on two models for frequency distribution functions of water

  1. 30 CFR 783.25 - Cross sections, maps, and plans.

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Cross sections, maps, and plans. 783.25 Section... ENVIRONMENTAL RESOURCES § 783.25 Cross sections, maps, and plans. (a) The application shall include cross sections, maps, and plans showing— (1) Elevations and locations of test borings and core samplings;...

  2. Temperature dependence of the cross section for the fragmentation of thymine via dissociative electron attachment

    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.

  3. 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...

  4. Partial cross sections in H- photodetachment

    This dissertation reports experimental measurements of partial decay cross sections in the H- photodetachment spectrum. Observed decays of the 1P0 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

  5. Radar Cross Section of Moving Objects

    Gholizade, H

    2013-01-01

    I investigate the effects of movement on radar cross section calculations. The results show that relativistic effects (the constant velocity case) can change the RCS of moving targets by changing the incident plane wave field vectors. As in the Doppler effect, the changes in the fields are proportional to $\\frac{v}{c}$. For accelerated objects, using the Newtonian equations of motion yields an effective electric field (or effective current density) on the object due to the finite mass of the conducting electrons. The results indicate that the magnetic moment of an accelerated object is different from that of an un-accelerated object, and this difference can change the RCS of the object. Results for moving sphere and non-uniformly rotating sphere are given and compared with static (\\textbf{v}=0) case.

  6. Elastic cross sections in an RSIIp scenario

    The elastic differential cross section is calculated at low energies (below 100 MeV) for the elements 3He, 20Ne, 40Ar, 14N, 12C, and for the 208Pb using a finite electromagnetic potential, which is obtained by considering a Randall–Sundrum II scenario modified by the inclusion of p compact extra-dimensions. The length scale is adjusted in the potential to compare with known experimental data and to set bounds for the parameter of the model. The effective four-dimensional (4D) electromagnetic potential is produced by a point charge, as seen from the three-brane that contains it, in uniform motion in an RSIIp scenario. (paper)

  7. Lunar Radar Cross Section at Low Frequency

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  8. Calculated medium energy fission cross sections

    An analysis has been made of medium-energy nucleon induced fission of 238U and 237Np using detailed models of fission, based upon the Bohr-Wheeler formalism. Two principal motivations were associated with these calculations. The first was determination of barrier parameters for proton-rich uranium and neptunium isotopes normally not accessible in lower energy reactions. The second was examination of the consistency between (p,f) experimental data versus new (n,f) data that has recently become available. Additionally, preliminary investigations were also made concerning the effect of fission dynamics on calculated fission cross sections at higher energies where neutron emission times may be significantly less than those associated with fission

  9. GLUCS: a generalized least-squares program for updating cross section evaluations with correlated data sets

    The PDP-10 FORTRAN IV computer programs INPUT.F4, GLUCS.F4, and OUTPUT.F4, which employ Bayes' theorem (or generalized least-squares) for simultaneous evaluation of reaction cross sections, are described. Evaluations of cross sections and covariances are used as input for incorporating correlated data sets, particularly ratios. These data are read from Evaluated Nuclear Data File (ENDF/B-V) formatted files. Measured data sets, including ratios and absolute and relative cross section data, are read and combined with the input evaluations by means of the least-squares technique. The resulting output evaluations have not updated only cross sections and covariances, but also cross-reaction covariances. These output data are written into ENDF/B-V format

  10. Cross section for Ly-alpha emission by electron impact on methane

    Orient, O. J.; Srivastava, S. K.

    1981-01-01

    Utilizing Lyman-alpha emission cross sections for H2 as secondary standards, absolute values of Lyman-alpha emission cross sections for CH4 have been obtained for electron impact energies varying from threshold to 100 eV. A crossed electron beam-molecular beam geometry was employed and the Lyman-alpha radiation was detected at 90 deg and 45 deg with respect to the incident electron beam by a solar blind photomultiplier in tandem with an oxygen filter. The results are compared with previous measurements. Appreciable differences among the various experimental data are found.

  11. Photoneutron cross sections measured by Saclay and Livermore

    The differences between the Saclay and Livermore photoneutron cross sections are discussed. It is shown that the differences between Saclay and Livermore (γ,n) and (γ,2n) cross sections arise from the neutron multiplicity sorting. (Author)

  12. 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.

  13. Residual diagnostics for cross-section time series regression models

    Baum, Christopher F

    2001-01-01

    These routines support the diagnosis of groupwise heteroskedasticity and cross-sectional correlation in the context of a regression model fit to pooled cross-section time series (xt) data. Copyright 2001 by Stata Corporation.

  14. Total cross sections for neutron-nucleus scattering

    Suryanarayana, S. V.; H. Naik; Ganesan, S; Kailas, S; Choudhury, R. K.; Kim, Guinyum

    2010-01-01

    Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross section...

  15. Electron Elastic-Scattering Cross-Section Database

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  16. Cross sections for electron impact excitation of molecules

    The discussion in this chapter is restricted to elastic scattering, rotational, vibrational, and electronic excitation and total scattering cross sections in electron molecule collisions. Experimental data on differential, integral and momentum transfer cross sections are surveyed and short remarks are made on experimental techniques and theoretical approaches used for generating cross section data. 11 references, 3 figures

  17. Finite sum expressions for elastic and reaction cross sections

    Nuclear cross section calculations are often performed by using the partial wave method or the Eikonal method through Glauber theory. The expressions for the total cross section, total elastic cross section, and total reaction cross section in the partial wave method involve infinite sums and do not utilize simplifying approximations. Conversely, the Eikonal method gives these expressions in terms of integrals but utilizes the high energy and small angle approximations. In this paper, by using the fact that the lth partial wave component of the T-matrix can be very accurately approximated by its Born term, the infinite sums in each of the expressions for the differential cross section, total elastic cross section, total cross section, and total reaction cross section are re-written in terms of finite sums plus closed form expressions. The differential cross sections are compared to the Eikonal results for 16O+16O,12C+12C, and p+12C elastic scattering. Total cross sections, total reaction cross sections, and total elastic cross sections are compared to the Eikonal results for 12C+12C scattering

  18. The correlation of integral experiments and high-energy cross-sections

    The correlation of integral experiments and high-energy cross-sections. Recent work on the correlation of integral experiments and high-energy cross-sections is discussed. The importance of integral data where cross-section measurements are inadequate is pointed out. The sensitivity of estimates of fast fission of U238 to inelastic cross-sections and energy degradation in the MeV energy range is shown by comparison of integral data with Monte Carlo calculations. It is shown that the Snell experiment is a sensitive index to the absolute values of inelastic cross-sections above 1.4 MeV. The results of attempts by the Brookhaven Cross-Section Evaluation Group to reconcile measurements of inelastic cross-sections of U238 are given. Other areas where integral data and critical experiments can be used to reduce computational uncertainties are the fast effect in beryllium, and η of U233 at intermediate energies. Critical experiments can reduce the present uncertainty in Be (n, 2n) cross-sections and in intermediate energy values of η23. (author)

  19. A Robust Hash Function Using Cross-Coupled Chaotic Maps with Absolute-Valued Sinusoidal Nonlinearity

    Wimol San-Um

    2016-01-01

    Full Text Available This paper presents a compact and effective chaos-based keyed hash function implemented by a cross-coupled topology of chaotic maps, which employs absolute-value of sinusoidal nonlinearity, and offers robust chaotic regions over broad parameter spaces with high degree of randomness through chaoticity measurements using the Lyapunov exponent. Hash function operations involve an initial stage when the chaotic map accepts initial conditions and a hashing stage that accepts input messages and generates the alterable-length hash values. Hashing performances are evaluated in terms of original message condition changes, statistical analyses, and collision analyses. The results of hashing performances show that the mean changed probabilities are very close to 50%, and the mean number of bit changes is also close to a half of hash value lengths. The collision tests reveal the mean absolute difference of each character values for the hash values of 128, 160 and 256 bits are close to the ideal value of 85.43. The proposed keyed hash function enhances the collision resistance, comparing to MD5 and SHA1, and the other complicated chaos-based approaches. An implementation of hash function Android application is demonstrated.

  20. Production cross sections from phenomenological constraints

    Hadronic production cross sections ν sub(n) (s) satisfying exactly the high energy empirical laws known for the first, second and third multiplicity moments are determined. The result is obtained in the form of a second order linear differential equation for ν sub(n) (s) which allows one to calculate explicitly all successive moments. In particular, the fourth moment is in excellent agreement with the data. The asymptotic solution of the equation for ν sub(n) (s) is given analytically. KNO scaling turns out to be an asymptotic property of the solution. The full solution for ν sub(n) (s) is studied numerically and the KNO plot is compared with the data. No free parameters are left to be adjusted except for an overall normalization constant. As expected, KNO scaling sets in rather quickly with increasing n and the agreement with the data is progressively good. This agreement becomes excellent for the whole interval of n/ for which data exist (O) approximately equal to 2. It turns out that the asymptotic solution, given in analytic terms, is an excellent approximation to the data and can thus be used for practical purposes instead of the full solution for calculating ν sub(n) (s). (author)

  1. Resonance capture cross section of 207Pb

    Domingo-Pardo, C; Aerts, G; Alvarez-Pol, H; Alvarez-Velarde, F; Andrzejewski, J; Andriamonje, Samuel A; Assimakopoulos, P A; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Cano-Ott, D; Capote, R; Carrapico, C; Chepel, V; Cennini, P; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gallino, R; Gonçalves, I; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Käppeler, F K; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, 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, Heinz; 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, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente6, 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.

  2. Differential cross section and related integrals for the Moliere potential

    The Moliere potential is widely used in radiation damage simulation studies. It is not much used in analytical transport theory calculations because of the awkward expression for the differential cross section corresponding to the potential. A two step process is followed to obtain a useful cross section: adopting the Lindhard, Nielsen and Scharff (LNS) approximations in order to generate a simpler form of the Moliere cross section and then creating a simple, easy-to-use, fit to that approximate form. Within the framework of the LNS treatment of atomic cross sections, our fit is accurate to 6%. Simple forms for the total cross section and several related quantities are presented. (author)

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

    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

  4. Proton-nucleus cross section at high energies

    Wibig, Tadeusz; Sobczynska, Dorota

    1998-01-01

    Cross sections for proton inelastic collision with different nuclei are described within the Glauber and multiple scattering approximations. A significant difference between approximate `Glauber' formula and exact calculations with a geometrical scaling assumption for very high-energy cross section is shown. Experimental values of proton-proton cross sections obtained using extensive air shower data are based on the relationship of proton-proton and respective proton-air absorption cross sect...

  5. New numerical methods for nuclear cross section processing

    Nuclear data allow to describe how a particle interacts with matter. These data are therefore at the basis of neutron transport and reactor physics calculations. Once measured and evaluated, they are given in libraries as a list of parameters. Before they can be used in neutron transport calculations, processing is required which includes taking into account several physical phenomena. This can be done by several softwares, such as NJOY, which all have the drawback to use old numerical methods derived from the same algorithms. For nuclear safety applications, it is important to rely on independent methods, to have a comparison point and to isolate the effects of the treatment on the final results. Moreover, it is important to properly master processing accuracy during its different steps. The objective of this PhD is then to develop independent numerical methods that can guarantee nuclear data processing within a given precision and to implement them practically, with the creation of the GAIA software. Our first step was the reconstruction of cross sections from the parameters given in libraries, with different approximations of the R-matrix theory. Reconstruction using the general formalism, without any approximation, has also been implemented, which has required the development of a new method to calculate the R-matrix. Tests have been performed on all existing formalisms, including the newest one. They have shown a good agreement between GAIA and NJOY. Reconstruction of angular differential cross sections directly from R-matrix parameters, using the Blatt-Biedenharn formula, has also been implemented and tested. The cross sections we have obtained at this point correspond to a target nucleus at absolute zero temperature. Because of thermal agitation, these cross sections are subject to a Doppler effect that is taken into account by integrating them with Solbrig's kernel. Our second step was then to calculate this integral. First, we have elaborated and

  6. Reference solution for cross section parametrization

    Core calculations of nuclear reactors are usually performed by core physics codes (e.g. with NEM or FDM solvers) in diffusion or SP3 approximation of the transport equation. For each fuel type parameterized data libraries are prepared by means of a lattice code. The data libraries are burnup dependent, and the parameterization covers the hyperspace of admissible values of all operational parameters (fuel temperature, moderator density, boron concentration etc.) This approach has two weak spots. The first is, that it is difficult to make perfect parameterization of the data library because of relatively broad range of the parameter values and the fact that the parameters' effect on the macroscopic cross-sections are not mutually independent. The second is that even for perfect parameterizations with precise approximations of the data changes with respect to the feedback parameters the so-called history effects are neglected. It is generally difficult to assess the cumulative errors arising due to the approximative parameterization of the data libraries and due to the history effects. It is as well difficult to assess the efficiency of techniques developed in order to incorporate the history effect in the data library (such as time integration). In this paper we present a tool for reference core calculations in which the above stated approximations are eliminated. This paper presents the solution method, its implementation, as well as the results of a demonstration calculation showing the improvement of the calculation results over the traditional approach, assessing the magnitude of history and parameterization effects importance. The most important feature of the presented method is that it provides the perfect parameterization of macroscopic data, allowing the core physics code developers to understand sources of modeling uncertainties by completely removing the parameterization error (including, unlike other approaches, a complete representation of the

  7. Experimental Photoionization Cross-Section Measurements in the Ground and Metastable State Threshold Region of Se+

    Sterling, N C; Bilodeau, R C; Kilcoyne, A L D; Red, E C; Phaneuf, R A; Aguilar, A

    2010-01-01

    Absolute photoionization cross-section measurements are reported for Se+ in the photon energy range 18.0-31.0 eV, which spans the ionization thresholds of the 4S_{3/2} ground state and the low-lying 2P_{3/2,1/2} and 2D_{5/2,3/2} metastable states. The measurements were performed using the Advanced Light Source synchrotron radiation facility. Strong photoexcitation-autoionization resonances due to 4p-->nd transitions are seen in the cross-section spectrum and identified with a quantum-defect analysis.

  8. Threshold-energy region in the electron-excitation cross sections of the sodium resonant transition

    Ying, C. H.; Perales, F.; Vušković, L.; Bederson, B.

    1993-08-01

    We present measurements of absolute excitation differential cross sections for electron scattering by ground-state sodium in the 3P manifold at 2.3, 2.4, 2.5, 2.6, 3.0, 3.3, and 3.7 eV in the angular range 1° to 60°. No calibration or normalization procedures are involved. Comparisons with computational results of the close-coupling approximation and experimentally obtained ΔMs- and ΔML-changing cross sections are made.

  9. Absorption cross section measurements for 252Cf spontaneous fission neutrons (LWBR development program)

    Absolute absorption cross sections have been measured for 232Th and 197Au for 252Cf spontaneous fission neutrons. Irradiations were performed in an exceptionally low mass source-foil arrangement, providing a ''pure'' spectrum with few corrections. Calibration of the activation detector was achieved by irradiating identical foils in the National Bureau of Standards (NBS) Standard Thermal Flux. A simple ratio technique was also used to obtain an independent estimate of the relative 232Th to 197Au integral cross sections, yielding a value in good agreement with that above. This technique was extended to 181Ta, 98Mo, and 63Cu. (5 tables, 3 figures) (U.S.)

  10. Resonance Averaged Photoionization Cross Sections for Astrophysical Models

    Bautista, M A; Pradhan, A K

    1997-01-01

    We present ground state photoionization cross sections of atoms and ions averaged over resonance structures for photoionization modeling of astrophysical sources. The detailed cross sections calculated in the close-coupling approximation using the R-matrix method, with resonances delineated at thousands of energies, are taken from the Opacity Project database TOPbase and the Iron Project, including new data for the low ionization stages of iron Fe I--V. The resonance-averaged cross sections are obtained by convolving the detailed cross sections with a Gaussian distribution over the autoionizing resonances. This procedure is expected to minimize errors in the derived ionization rates that could result from small uncertainties in computed positions of resonances, while preserving the overall resonant contribution to the cross sections in the important near threshold regions. The detailed photoionization cross sections at low photon energies are complemented by new relativistic distorted-wave calculations for Z1...