Low-energy pion-nucleon scattering
International Nuclear Information System (INIS)
Gibbs, W.R.; Ai, L.; Kaufmann, W.B.
1998-01-01
An analysis of low-energy charged pion-nucleon data from recent π ± p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f 2 =0.0756±0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P 31 and P 13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the Σ term. Off-shell amplitudes are also provided. copyright 1998 The American Physical Society
Extracting the σ-term from low-energy pion-nucleon scattering
Ruiz de Elvira, Jacobo; Hoferichter, Martin; Kubis, Bastian; Meißner, Ulf-G.
2018-02-01
We present an extraction of the pion-nucleon (π N) scattering lengths from low-energy π N scattering, by fitting a representation based on Roy-Steiner equations to the low-energy data base. We show that the resulting values confirm the scattering-length determination from pionic atoms, and discuss the stability of the fit results regarding electromagnetic corrections and experimental normalization uncertainties in detail. Our results provide further evidence for a large π N σ-term, {σ }π N=58(5) {{MeV}}, in agreement with, albeit less precise than, the determination from pionic atoms.
Charge exchange during pion-nucleon scattering at low energy: experiment and analysis
International Nuclear Information System (INIS)
Vernin, Pascal
1972-01-01
This research thesis lies within the frame of a more general study of pion-nucleon scattering according to the following processes: π + p → π + p; π - p → π - p; π - p → π 0 n. It more precisely addresses the last reaction, so-called charge exchange. Pion-nucleon interactions are described by phase shifts of scattering waves. But the measurement of one of these phase shifts (that of the S wave) requires very low energy pions, and could not have been performed until now with a good precision. In order to fill this gap, the author performed charge exchange experiments at 180 deg. and for energies of 22.6, 33.9 and 42.6 MeV. After a recall on involved theoretical data, the author describes the experimental setup, and reports the detailed study of problems raised by neutron detection. He shows that the analysis of experimental data allows (a 3 - a 1 ) to be obtained with a precision which, without being as high as desired, is nevertheless satisfying [fr
Roy-Steiner-equation analysis of pion-nucleon scattering
Meißner, U.-G.; Ruiz de Elvira, J.; Hoferichter, M.; Kubis, B.
2017-03-01
Low-energy pion-nucleon scattering is relevant for many areas in nuclear and hadronic physics, ranging from the scalar couplings of the nucleon to the long-range part of two-pion-exchange potentials and three-nucleon forces in Chiral Effective Field Theory. In this talk, we show how the fruitful combination of dispersion-theoretical methods, in particular in the form of Roy-Steiner equations, with modern high-precision data on hadronic atoms allows one to determine the pion-nucleon scattering amplitudes at low energies with unprecedented accuracy. Special attention will be paid to the extraction of the pion-nucleon σ-term, and we discuss in detail the current tension with recent lattice results, as well as the determination of the low-energy constants of chiral perturbation theory.
A relativistic, meson exchange model of pion-nucleon scattering
International Nuclear Information System (INIS)
Pearces, B.C.; Jennings, B.K.
1990-06-01
A relativistic meson exchange approach to the pion-nucleon interaction is developed using a three-dimensional relativistic two-body propagator, and the results using different propagators are compared. The relativistic approach is able to describe low energy scattering up to 400 MeV above threshold, while preserving the soft pion theorems. The different propagators give similar results, as the form factors necessary to get a fit suppress much of the multiple scattering. (Author) (24 refs., 4 tabs., 6 figs.)
Pion-nucleon scattering: from chiral perturbation theory to Roy-Steiner equations
Kubis, Bastian; Hoferichter, Martin; de Elvira, Jacobo Ruiz; Meißner, Ulf-G.
2016-11-01
Ever since Weinberg's seminal predictions of the pion-nucleon scattering amplitudes at threshold, this process has been of central interest for the study of chiral dynamics involving nucleons. The scattering lengths or the pion-nucleon σ-term are fundamental quantities characterizing the explicit breaking of chiral symmetry by means of the light quark masses. On the other hand, pion-nucleon dynamics also strongly affects the long-range part of nucleon-nucleon potentials, and hence has a far-reaching impact on nuclear physics. We discuss the fruitful combination of dispersion-theoretical methods, in the form of Roy-Steiner equations, with chiral dynamics to determine pion-nucleon scattering amplitudes at low energies with high precision.*
Roy-Steiner equations for pion-nucleon scattering
Ditsche, C.; Hoferichter, M.; Kubis, B.; Meißner, U.-G.
2012-06-01
Starting from hyperbolic dispersion relations, we derive a closed system of Roy-Steiner equations for pion-nucleon scattering that respects analyticity, unitarity, and crossing symmetry. We work out analytically all kernel functions and unitarity relations required for the lowest partial waves. In order to suppress the dependence on the high energy regime we also consider once- and twice-subtracted versions of the equations, where we identify the subtraction constants with subthreshold parameters. Assuming Mandelstam analyticity we determine the maximal range of validity of these equations. As a first step towards the solution of the full system we cast the equations for the π π to overline N N partial waves into the form of a Muskhelishvili-Omnès problem with finite matching point, which we solve numerically in the single-channel approximation. We investigate in detail the role of individual contributions to our solutions and discuss some consequences for the spectral functions of the nucleon electromagnetic form factors.
Pion-nucleon scattering in the chiral bag model
International Nuclear Information System (INIS)
Israilov, Z.Z.; Musakhanov, M.M.
1981-01-01
Pion-nucleon scattering in the (3.3) resonance region in the framework of chiral bag model(CBM) is considered. The effective Hamiltonian of πNΔ-system in the framework of the CBM contains πNN, πNΔ, πΔΔ interaction terms with the formfactor which is essentially dependent on the size and shape of the quark bag. The iteration of the Born graphs of this model provides successful description of the (3.3) and (3.1) scattering where the values of the parameters agree with CBM [ru
Energy Technology Data Exchange (ETDEWEB)
Yao, De-Liang [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Siemens, D. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Bernard, V. [Groupe de Physique Théorique, Institut de Physique Nucléaire, UMR 8606,CNRS, University Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex (France); Epelbaum, E. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Gasparyan, A.M. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); SSC RF ITEP, Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Gegelia, J. [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Tbilisi State University, 0186 Tbilisi (Georgia); Krebs, H. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Meißner, Ulf-G. [Helmholtz Institut für Strahlen- und Kernphysik andBethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany)
2016-05-05
We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P-partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.
Non-Regge and hyper-Regge effects in pion-nucleon charge exchange scattering at high energies
International Nuclear Information System (INIS)
Joynson, D.; Leader, E.; Nicolescu, B.; Paris-6 Univ., 75; Lopez, C.
1975-04-01
The experimental data on the charge exchange differential cross-section and on the difference on the π + p and π - p total cross-sections between 5GeV/c to 200GeV/c are shown to be incompatible with conventional Regge asymptotic behavior. It is shown that an additional term is required which grows in importance with energy. The precise form of the new term cannot be ascertained, but it is shown that it corresponds to a singularity at J=1 in the complex angular momentum plane. Amongst the possible types of additional term there are two which have been closely analysed: a non-Regge behavior, a hyper-Regge term which have allowed very striking predictions in particular for the charge exchange polarisation [fr
On lattice gauge theories and on backward pion-nucleon scattering
International Nuclear Information System (INIS)
Karsten, L.H.
1979-01-01
The thesis is in two parts. In the first part the author studies weak coupling perturbation theory of lattice gauge theories. In the second part the author studies the backward pion-nucleon scattering in the freamework of an effective action approach. (Auth.)
International Nuclear Information System (INIS)
Safronov, A.N.
2007-01-01
Full text: The pion-nucleon dynamics is one of the most fundamental problems in nuclear and particle physics. It is now widely believed that QCD is fundamental theory of strong interactions. On this basis all hadron-hadron interactions are completely determined by the underlying quark-gluon dynamics. However, due to the formidable mathematical problems raised by the non-perturbative character of QCD at low and intermediate energies, we are still far from a quantitative understanding hadron-hadron interactions from this point of view. Recently the relativistic approaches to constructing effective interaction operators between strongly interacting composite particles has been proposed on the basis of analytic S-matrix theory and methods for solving the inverse quantum scattering problem. The kernel of Marchenko equation in theory of inverse scattering problem can be expressed in terms of the discontinuity of the partial wave amplitude on dynamic cut in the complex s=k 2 plane, k being the relative momentum of colliding particles. The discontinuities of partial-wave amplitudes are determined by model-independent quantities (renormalized vertex constants and amplitudes of sub-processes involving on-mass-shell particles off physical region) and can be calculated by methods of relativistic quantum field theory within various dynamical approaches. In particular, effective field theory can be used to calculate the discontinuities across dynamical cuts closest to physical region. In present work a new manifestly Poincare-invariant approach to solving the inverse scattering problem is developed with allowance for inelasticity effects. The equations of the N/D method are used as dynamical equations in this approach. With the help of N/D-equations it was earlier shown that solution of a scattering problem in case of nonzero angular momentum does not exist for arbitrary discontinuity of partial-wave amplitude. The method is elaborated allowing to determine contributions of
Determination of the pion-nucleon coupling constant and s-wave scattering lengths
Samaranayake, V K
1972-01-01
Presently available values of D/sub +or-/, the real parts of the pi /sup +or-/p elastic scattering amplitudes in the forward direction in the laboratory frame, obtained by extrapolation of experimental data to the forward direction, have been fitted up to a pion lab. kinetic energy of 2 GeV using forward dispersion relation. A substantial number of data points have to be discarded to obtain a reasonable goodness of fit. Above 300 MeV the values of D/sub +or-/ obtained from the CERN phase shift analysis are strongly favoured compared with those from the Saclay analysis. The final results for the pion-nucleon coupling constant and s-wave scattering lengths are: 10/sup 3/f/sup 2 /=76.3+or-2.0, 10/sup 3/D/sub +/( mu )=-102.4+or-5.2, 10/sup 3/D/sub - /( mu )=104.8+or-5.4, 10/sup 3/(a/sub 1/-a/sub 3/)=270.6+or-11.3, 10 /sup 3/(a/sub 1/+2a/sub 3/)=3.1+or-8.0. The errors quoted take account of experimental uncertainties and also attempt to include systematic errors arising from the unphysical continuum and from the v...
N → Δ (1232) electromagnetic transition form factor and pion-nucleon dynamics at moderate energies
International Nuclear Information System (INIS)
Jurewicz, A.
1980-01-01
The dependence of the electromagnetic N → Δ (1232) transition form factor G/sup asterisk//sub M/(q 2 ) on q 2 , the four-momentum transfer squared, has been calculated with the use of relativistic dispersion relations supplemented with some dynamical assumptions. In the first place, they regard the phase of the magnetic dipole amplitude of electroproduction of pions on nucleons in the p 33 final state beyond the region of elastic unitarity. Namely, over the range from the lowest inelastic threshold up to 1780 MeV pion-nucleon c.m. energy, the phase in question has been identified with the real part of the respective phase shift of pion-nucleon scattering. Secondly, contributions to the dispersion integral from the higher energy region have been neglected. Finally, the polynomial ambiguity which appears in the problem has been fixed by requiring that the foregoing amplitude of electroproduction vanishes, independently of q 2 , at the upper end of the integration interval as defined above. These assumptions which preserve unitarity were shown previously to lead to very good results when applied to the calculation of the multipole amplitudes M/sup() 3/2/ 1 /sub +/ and E/sup() 3/2/ 1 /sub +/ of photopion production on nucleons in the Δ (1232) region. Now it is also shown that G/sup asterisk//sub M/(q 2 ) calculated in that fashion follows remarkably well the data over the whole range 0 2 2 currently covered by quantitative experimental studies. Some speculation concerning a possible dynamical rooting of the foregoing assumptions is presented
Isospin breaking in pion-nucleon scattering at threshold by radiative processes
Ericson, Torleif Eric Oskar
2006-01-01
We investigate the dispersive contribution by radiative processes such as (pi- proton to neutron gamma) and (pi- proton to Delta gamma) to the pion-nucleon scattering lengths of charged pions in the heavy baryon limit. They give a large isospin violating contribution in the corresponding isoscalar scattering length, but only a small violation in the isovector one. These terms contribute 6.3(3)% to the 1s level shift of pionic hydrogen and give a chiral constant F_pi^2f_1=-25.8(8) MeV.
A phenomenological determination of the pion-nucleon scattering lengths from pionic hydrogen
Ericson, Torleif Eric Oskar; Wycech, S
2005-01-01
A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon scattering length, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order (alpha)**2 log(alpha) in the limit of a short-range hadronic interaction. We infer a charged pion-proton scattering length of 0.0870(5) in units of inverse pion mass, which gives for the charged pion-proton-neutron coupling, through the GMO relation, a value of 14.04(17).
a Phenomenological Determination of the Pion-Nucleon Scattering Lengths from Pionic Hydrogen
Ericson, T. E. O.; Loiseau, B.; Wycech, S.
A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon (πN) scattering length ah, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order α2 log α in the limit of a short-range hadronic interaction. We infer ahπ ^-p=0.0870(5)m-1π which gives for the πNN coupling through the GMO relation g2π ^± pn/(4π )=14.04(17).
Determination of the pion-nucleon coupling constant and scattering lengths
Ericson, Torleif Eric Oskar; Thomas, A W
2002-01-01
We critically evaluate the isovector GMO sum rule for forward pion-nucleon scattering using the recent precision measurements of negatively charged pion-proton and pion-deuteron scattering lengths from pionic atoms. We deduce the charged-pion-nucleon coupling constant, with careful attention to systematic and statistical uncertainties. This determination gives, directly from data a pseudoscalar coupling constant of 14.17+-0.05(statistical)+-0.19(systematic) or a pseudovector one of 0.0786(11). This value is intermediate between that of indirect methods and the direct determination from backward neutron-proton differential scattering cross sections. We also use the pionic atom data to deduce the coherent symmetric and antisymmetric sums of the negatively charged pion-proton and pion-neutron scattering lengths with high precision. The symmetric sum gives 0.0017+-0.0002(statistical)+-0.0008 (systematic) and the antisymmetric one 0.0900+-0.0003(statistical)+-0.0013(systematic), both in units of inverse charged pi...
Forward pion-nucleon charge exchange reaction and Regge constraints
International Nuclear Information System (INIS)
Huang Fei; Sibirtsev, A.; Krewald, S.; Hanhart, C.; Haidenbauer, J.; Meibner, U.-G.
2009-01-01
We present our recent study of pion-nucleon charge exchange amplitudes above 2 GeV. We analyze the forward pion-nucleon charge exchange reaction data in a Regge model and compare the resulting amplitudes with those from the Karlsruhe-Helsinki and George-Washington-University partial-wave analyses. We explore possible high-energy constraints for theoretical baryon resonance analyses in the energy region above 2 GeV. Our results show that for the pion-nucleon charge exchange reaction, the appropriate energy region for matching meson-nucleon dynamics to diffractive scattering should be around 3 GeV for the helicity flip amplitude. (authors)
[Measurements of observables of pion-nucleon reactions]. Progress report
International Nuclear Information System (INIS)
Sadler, M.E.
1985-01-01
This document reports the progress of the research of pion reactions. These include (1) a study to measure observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross section measurements at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Individual experiments will be indexed separately
Determination of the pion-nucleon coupling constant and scattering lengths
International Nuclear Information System (INIS)
Ericson, T.E.O.; Loiseau, B.; Thomas, A.W.
2002-01-01
We critically evaluate the isovector Goldberger-Miyazawa-Oehme (GMO) sum rule for forward πN scattering using the recent precision measurements of π - p and π - d scattering lengths from pionic atoms. We deduce the charged-pion-nucleon coupling constant, with careful attention to systematic and statistical uncertainties. This determination gives, directly from data, g c 2 (GMO)/4π=14.11±0.05(statistical)±0.19(systematic) or f c 2 /4π=0.0783(11). This value is intermediate between that of indirect methods and the direct determination from backward np differential scattering cross sections. We also use the pionic atom data to deduce the coherent symmetric and antisymmetric sums of the pion-proton and pion-neutron scattering lengths with high precision, namely, (a π - p +a π - n )/2=[-12±2(statistical)±8(systematic)]x10 -4 m π -1 and (a π - p -a π - n )/2=[895±3(statistical)±13 (systematic)]x10 -4 m π -1 . For the need of the present analysis, we improve the theoretical description of the pion-deuteron scattering length
Relativistic generalizations of simple pion-nucleon models
International Nuclear Information System (INIS)
McLeod, R.J.; Ernst, D.J.
1981-01-01
A relativistic, partial wave N/D dispersion theory is developed for low energy pion-nucleon elastic scattering. The theory is simplified by treating crossing symmetry only to lowest order in the inverse nucleon mass. The coupling of elastic scattering to inelastic channels is included by taking the necessary inelasticity from experimental data. Three models are examined: pseudoscalar coupling of pions and nucleons, pseudovector coupling, and a model in which all intermediate antinucleons are projected out of the amplitude. The phase shifts in the dominant P 33 channel are quantitatively reproduced for P/sub lab/ 33 phase shifts. Thus a model of the pion-nucleon interaction which does not include antinucleon degrees of freedom is found to be unphysical
The pion-nucleon scattering lengths from pionic hydrogen and deuterium
Energy Technology Data Exchange (ETDEWEB)
Schroeder, H.-C.; Badertscher, A.; Goudsmit, P.F.A.; Janousch, M.; Leisi, H.J.; Matsinos, E.; Sigg, D.; Zhao, Z.G. [ETH Zurich, Inst. for Particle Physics, Zurich (Switzerland); Chatellard, D.; Egger, J.P. [Neuchatel Univ. (Switzerland). Inst. de Physique; Gabathuler, K.; Hauser, P.; Simons, L.M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Rusi El Hassani, A.J. [Dept. de Physique, Faculte des Sciences et Technique, Tanger (Morocco)
2001-07-01
This is the final publication of the ETH Zurich-Neuchatel-PSI collaboration on the pionic hydrogen and deuterium precision X-ray experiments. We describe the recent hydrogen 3p-1s measurement, report on the determination of the Doppler effect correction to the transition line width, analyze the deuterium shift measurement and discuss implications of the combined hydrogen and deuterium results. From the pionic hydrogen 3p-1s transition experiments we obtain the strong-interaction energy level shift {epsilon}{sub 1s} = -7.108{+-}0.013 (stat.){+-}0.034 (syst.) eV and the total decay width {gamma}{sub 1s} = 0.868{+-}0.040 (stat.){+-}0.038 (syst.) eV of the 1s state. Taking into account the electromagnetic corrections we find the hadronic {pi}N s-wave scattering amplitude a{sub {pi}{sup -}p{yields}{pi}{sup -}p} = 0.0883{+-}0.0008 m{sub {pi}}{sup -1} for elastic scattering and a{sub {pi}{sup -}p{yields}{pi}{sup 0}n} = -0.128{+-}0.006 m{sub {pi}} {sup -1} for single charge exchange, respectively. We then combine the pionic hydrogen results with the 1s level shift measurement on pionic deuterium and test isospin symmetry of the strong interaction: our data are still compatible with isospin symmetry. The isoscalar and isovector {pi}N scattering lengths (within the framework of isospin symmetry) are found to be b{sub 0} = -0.0001{sup +0.0009}{sub -0.0021} m{sub {pi}}{sup -1} and b{sub 1} = -0.0885{sup +0.0010}{sub -0.0021} m{sub {pi}} {sup -1}, respectively. Using the GMO sum rule, we obtain from b{sub 1} a new value of the {pi}N coupling constant (g{sub {pi}}{sub N} = 13.21{sub -0.05}{sup +0.11}) from which follows the Goldberger-Treiman discrepancy {delta}{sub GT}=0.027{sub -0.008}{sup +0.012}. The new values of b{sub 0} and g{sub {pi}}{sub N} imply an increase of the nucleon sigma term by at least 9 MeV. (orig.)
Pion-nucleon scattering in P11 channel and the Roper resonance
International Nuclear Information System (INIS)
Bugaev, K.A.; Yang, Shin Nan; Lee, T.S.H.
1996-01-01
The πN scattering in P 11 channel is investigated within the two-channel model of Pearce and Afnan. The model consists of: (1) vertex interactions b → πN, π∇ with b denoting either a bare nucleon or a bare Roper state, (2) a background potential υ πB,πB with B = N,∇. Assuming that υ πB,πB can be phenomenologically parameterized as a separable form and the πN inelasticity can be accounted for by dressing the ∇ in the π∇ channel by a ∇ ↔ πN vertex, it is found that the fit to the P 11 phase shifts up to 1 GeV favors a large mass of the bare Roper state. Our results are consistent with the findings of Pearce and Afnan that if the mass of the bare Roper state is restricted to be ≤1600 MeV, then a physical Roper will have a width which is too narrow causing a rapid variation of the phase shifts at energies near the resonance energy
PION-NUCLEON COUPLING-CONSTANT
STOKS,; TIMMERMANS, R; DESWART, JJ
In view of the persisting misunderstandings about the determination of the pion-nucleon coupling constants in the Nijmegen multienergy partial-wave analyses of pp, np, and ppBAR scattering data, we present additional information which may clarify several points of discussion. We comment on several
International Nuclear Information System (INIS)
Sadler, M.E.
1986-03-01
Progress is reported for the past year in pion scattering programs. The measurements include: (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF)
International Nuclear Information System (INIS)
Sadler, M.E.; Isenhower, L.D.
1990-01-01
This report discusses the following: pion-nucleon program; a search for neutral pions from the spontaneous fission of 252 Cf; elastic and inelastic pion scattering on 3 H and 3 He; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral B mesons; measurement of π - p → π 0 n in the cusp region at the Leningrad Nuclear Physics Institute (LNPI); a test of consistency of low-energy pion-nucleon differential cross sections with total cross sections; and design of a high energy photon calorimeter for the neutral meson spectrometer
International Nuclear Information System (INIS)
Boos, E.G.; Izbasarov, M.; Temiraliyev, T.; Samoilov, V.V.; Tursunov, R.A.
2005-01-01
Full text: The analysis has been undertaken for the energy ratio K π ± (partial coefficient of inelasticity) taken away by charged pions at laboratory coordinate system in pion-nucleon and pion-carbon interactions at momentum 40 GeV/s. It is shown that distribution of partial inelasticity coefficients for elementary act is more narrow than the same distribution for carbon nucleus. The mean number of charged mesons (n π ± t) grows with enlarging of partial inelasticity coefficient, being larger for interactions of π - -mesons with carbon nuclei in comparison with corresponding distribution in elementary act. The similar picture is observed for one-nucleon and multi-nucleon events selected from π - - C -interactions by the value of total electric charge of all secondary particles (except for the identified protons) and by the value of target mass
Extraction of the pion-nucleon sigma-term from the spectrum of exotic baryons
International Nuclear Information System (INIS)
Schweitzer, P.
2004-01-01
The pion-nucleon sigma-term is extracted on the basis of the soliton picture of the nucleon from the mass spectrum of usual and the recently observed exotic baryons, assuming that they have positive parity. The value found is consistent with that inferred by means of conventional methods from pion-nucleon scattering data. The study can also be considered as a phenomenological consistency check of the soliton picture of baryons. (orig.)
Pion-nucleon vertex function and the Chew-Low model
International Nuclear Information System (INIS)
Nutt, W.T.
1977-01-01
We provide an interpretation of the cutoff function used in the Chew-Low theory of pion-nucleon scattering. It is shown that this function may be related to the pion-pion interaction which is not explicitly considered in the Chew-Low approach. Using a previously developed model for the pion-nucleon vertex function, we then perform a ''parameter-free'' Chew-Low calculation which predicts the P 33 resonance quite well
Determination of the pion-nucleon coupling constant
International Nuclear Information System (INIS)
Samaranayake, V.K.
1977-06-01
Forward dispersion relations are used to determine the pion-nucleon coupling constant and S-wave scattering lengths using a least squares fit with additional parameters introduced to take account of the uncertainties in the calculation of dispersion integrals. The values obtained are: f 2 = (78.0+- 2.1).10 -3 , a 1 -a 3 = (272.4+- 12.3).10 -3 , a 1 +2a 3 = (15.1+-10.4).10 -3
High-Precision Determination of the Pion-Nucleon σ Term from Roy-Steiner Equations
Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.
2015-08-01
We present a determination of the pion-nucleon (π N ) σ term σπ N based on the Cheng-Dashen low-energy theorem (LET), taking advantage of the recent high-precision data from pionic atoms to pin down the π N scattering lengths as well as of constraints from analyticity, unitarity, and crossing symmetry in the form of Roy-Steiner equations to perform the extrapolation to the Cheng-Dashen point in a reliable manner. With isospin-violating corrections included both in the scattering lengths and the LET, we obtain σπ N=(59.1 ±1.9 ±3.0 ) MeV =(59.1 ±3.5 ) MeV , where the first error refers to uncertainties in the π N amplitude and the second to the LET. Consequences for the scalar nucleon couplings relevant for the direct detection of dark matter are discussed.
Matching Pion-Nucleon Roy-Steiner Equations to Chiral Perturbation Theory
Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.
2015-11-01
We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy constants including a comprehensive analysis of systematic uncertainties and correlations. We study the convergence of the chiral series by investigating the chiral expansion of threshold parameters up to the same order and discuss the role of the Δ (1232 ) resonance in this context. Results for the low-energy constants are also presented in the counting scheme usually applied in chiral nuclear effective field theory, where they serve as crucial input to determine the long-range part of the nucleon-nucleon potential as well as three-nucleon forces.
Effective pion--nucleon interaction in nuclear matter
International Nuclear Information System (INIS)
Celenza, L.S.; Liu, L.C.; Nutt, W.; Shakin, C.M.
1976-01-01
We discuss the modification of the interaction between a pion and a nucleon in the presence of an infinite medium of nucleons (nuclear matter). The theory presented here is covariant and is relevant to the calculation of the pion--nucleus optical potential. The specific effects considered are the modifications of the nucleon propagator due to the Pauli principle and the modification of the pion and nucleon propagators due to collisions with nucleons of the medium. We also discuss in detail the pion self-energy in the medium, paying close attention to off-shell effects. These latter effects are particularly important because of the rapid variation with energy of the fundamental pion--nucleon interaction. Numerical results are presented, the main feature being the appearance of a significant damping width for the (3, 3) resonance
International Nuclear Information System (INIS)
Sadler, M.E.; Isenhower, L.D.
1987-01-01
This report describes the progress made in the past year and future plans for the pion scattering programs in which Abilene Christian University is collaborating. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF). The experiments are performed in collaboration with UCLA, George Washington University, LAMPF Groups MP-4, MP-10 and MP-13, and Catholic University. The measurements include: (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π/sup +-/ on 3 H and 3 He
Pion-nucleon vertex function with one nucleon off shell
International Nuclear Information System (INIS)
Mizutani, T.; Rochus, P.
1979-01-01
The pion-nucleon vertex function with an off-mass-shell nucleon is obtained through sideways dispersion relations with the P 11 and S 11 pion-nucleon phase shifts as only input. Contrary to the recent calculation of Nutt and Shakin, we find that the proper and improper vertex functions behave quite differently, indicating the importance of the nucleon propagator dressing. In particular the proper vertex function is found to have two poles in the unphysical region
International Nuclear Information System (INIS)
Sadler, M.E.
1987-03-01
This report describes the progress made in the past year in the pion scattering programs in which Abilene Christian University is collaborating. The measurements include (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/e, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Highlights of the progress in 1986 to 87 include (1) first measurement of the spin rotation parameters A and R for π +- p → π +- p scattering at 427 to 657 MeV/e, for which the principal investigator received support from Associated Western Universities (AWU) and ACU for sabbatical leave in Los Alamos, (2) final publication of the data for the differential cross sections and analyzing powers for π +- p elastic scattering at 378 to 687 MeV/c, (3) final publication of forward-angle differential cross sections for π - p → π 0 n at 101 to 147 MeV/c, and (4) continued development of analysis capabilities on the ACU VAX-11/785, including full implementation of the LAMPF Q system MAPPER and DISSPLA graphics software. TEDI and TEX word processing and the associated hardware to utilize the software. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF). The experiments are performed in collaboration with UCLA, George Washington University, LAMPF Groups MP-4, MP-10 and MP-13, and Catholic University. 37 refs., 13 figs., 1 tab
Pion-nucleon scattering in the Chiral bag model
International Nuclear Information System (INIS)
Israilov, Z.Z.; Musakhanov, M.M.
1981-01-01
The effective hamiltonian of the πNΔ-system in the framework of the Chiral Bag Model (CBM) contains πNN-, πNΔ-, πΔΔ-interaction terms with a form factor which is esstentially dependent on the size and shape of the quark bag. The interation of the Born graphs of this model provides successful description of the (3,3) and (3,1) phase shifts [in the (3,3) resonance region] where the values of the paramters agree with the CBM. (orig.)
International Nuclear Information System (INIS)
Menezes, A.M.M.
1985-01-01
The pion-nucleon scattering for energies up to 300 MeV is studied by means of a theoretical model based on chiral symmetry, implemented by effective lagrangians. The interaction between the pion and the nucleon is mediated by only four particles: nucleon, delta, rho e sigma. The amplitudes associated to the delta and sigma contain free parameters, that must be extracted from experiment. The set of values obtained from fits below and above threshold disagree, indicating that, in the context of the model, a unified description in both regions is not possible. The results above threshold are sensitive to the method of unitarization employed. The method adopted in this work has a simple physical meaning and the ressonating wave associated to the delta is quite well reproduced. (Author) [pt
Pion-nucleon sigma term in the global color model of QCD
International Nuclear Information System (INIS)
Chang Lei; Liu Yuxin; Guo Hua
2005-01-01
We study the pion-nucleon sigma term in vacuum and in nuclear matter in the framework of global color model of QCD. With the effective gluon propagator being taken as the δ-function in momentum space of Munczek-Nomirovsky model, we estimate that the sigma term at chiral limit in the vacuum is 9/2 times the current quark mass and it decreases with the nuclear matter density. With the presently obtained in-medium pion-nucleon sigma term, we study the in-medium chiral quark condensate and obtain a reasonable variation behavior against the nuclear matter density
The Status of the Pion-Nucleon Coupling Constant
Swart, J. J. de; Rentmeester, M. C. M.; Timmermans, R. G. E.
1998-01-01
Abstract: A review is given of the various determinations of the different piNN coupling constants in analyses of the low-energy pp, np, pbarp, and pi-p scattering data. The most accurate determinations are in the energy-dependent partial-wave analyses of the NN data. The recommended value is f^2 =
Separable-potential model for the pion--nucleon interaction
International Nuclear Information System (INIS)
Nutt, W.T.
1976-01-01
A separable potential which fits the low and intermediate π-N scattering is proposed which is more convenient for application than those separable models which use Regge parameterizations of the very high energy phase shifts. The form factors for this model are equal to zero for momenta q greater than 1 GeV/c, and are expected to provide more reasonable off-shell behavior than the form factors obtained from those models based on the Regge extrapolation
Delta: the first pion nucleon resonance - its discovery and applications
International Nuclear Information System (INIS)
Nagle, D.E.
1984-07-01
It is attempted to recapture some of the fun and excitement of the pion-scattering work that led to the discovery of what is now called the delta particle. How significant this discovery was became apparent only gradually. That the delta is alive today and thriving at Los Alamos (as well as other places) is described
Energy Technology Data Exchange (ETDEWEB)
Araujo, Vanilse da Silva
1997-12-31
In this work we study the effects of chiral symmetry in the pion-nucleon coupling constant in the context of the linear {sigma}- model. First, we introduce the linear {sigma}-model and we discuss the phenomenological hypothesis of CVC and PCAC. Next, we calculate the coupling constant g+{pi}{sub NN}(q{sup 2}) and the nucleon pionic mean square radius considering the contribution of all the diagrams up to one-loop in the framework of the linear {sigma}-model for different values of the mass of the sigma meson and we compare them with the phenomenological form factors. Finally we make an extension of the linear {sigma}-model that consists of taking into account the mass differences of ions and nucleons into the Lagrangian of the model, to study the change dependence of g{sub {pi}nn} (q{sup 2}) and of the mean square radius. (author) 21 refs., 17 figs., 4 tabs.
The nucleon as a test case to calculate vector-isovector form factors at low energies
Leupold, Stefan
2018-01-01
Extending a recent suggestion for hyperon form factors to the nucleon case, dispersion theory is used to relate the low-energy vector-isovector form factors of the nucleon to the pion vector form factor. The additionally required input, i.e. the pion-nucleon scattering amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the nucleons and optionally the Delta baryons. Two methods to include pion rescattering are compared: a) solving the Muskhelishvili-Omnès (MO) equation and b) using an N/D approach. It turns out that the results differ strongly from each other. Furthermore the results are compared to a fully dispersive calculation of the (subthreshold) pion-nucleon amplitudes based on Roy-Steiner (RS) equations. In full agreement with the findings from the hyperon sector it turns out that the inclusion of Delta baryons is not an option but a necessity to obtain reasonable results. The magnetic isovector form factor depends strongly on a low-energy constant of the NLO Lagrangian. If it is adjusted such that the corresponding magnetic radius is reproduced, then the results for the corresponding pion-nucleon scattering amplitude (based on the MO equation) agree very well with the RS results. Also in the electric sector the Delta degrees of freedom are needed to obtain the correct order of magnitude for the isovector charge and the corresponding electric radius. Yet quantitative agreement is not achieved. If the subtraction constant that appears in the solution of the MO equation is not taken from nucleon+Delta chiral perturbation theory but adjusted such that the electric radius is reproduced, then one obtains also in this sector a pion-nucleon scattering amplitude that agrees well with the RS results.
An improved optical potential for low-energy pion-nucleus scattering
International Nuclear Information System (INIS)
Khankhasaev, M.Kh.; Topil'skaya, N.S.
1988-01-01
A new procedure for calculating the imaginary part the of Stricker, McManus and Carr (SMC) optical potential is proposed. It is based on an approximate expression for the pion-nucleon scattering amplitude including nuclear structure effects. It is shown that the resulting potential with the absorption parameters fitted to the pionic atom data provides a good description of the scattering up to 50 MeV
A New Optimal Bound on Logarithmic Slope of Elastic Hadron-Hadron Scattering
Ion, D B
2005-01-01
In this paper we prove a new optimal bound on the logarithmic slope of the elastic slope when: elastic cross section and differential cross sections in forward and backward directions are known from experimental data. The results on the experimental tests of this new optimal bound are presented in Sect. 3 for the principal meson-nucleon elastic scatterings: pion-nucleon, kaon-nucleon at all available energies. Then we have shown that the saturation of this optimal bound is observed with high accuracy practically at all available energies in meson-nucleon scattering.
Pionic atoms, the relativistic mean-field theory and the pion-nucleon scattering lenghts
International Nuclear Information System (INIS)
Goudsmit, P.F.A.; Leisi, H.J.; Matsinos, E.
1991-01-01
Analysing pionic-atom data of isoscalar nuclei within the relativistic mean-field (RMF) theory, we determine the pseudoscalar πNN mixing parameter x=0.24±0.06 (syst.) and the strength of the nuclear scalar meson field for pions, S π =-34±14 (syst.) MeV. We show that these values are compatible with the elementary π-N interaction. Our RMF model provides a solution to the long-standing problem of the s-wave repulsion. (orig.)
International Nuclear Information System (INIS)
Sadler, M.E.; Isenhower, L.D.
1992-01-01
This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments
Energy Technology Data Exchange (ETDEWEB)
Sadler, M.E.; Isenhower, L.D.
1992-02-15
This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)
Energy Technology Data Exchange (ETDEWEB)
Devereux, M.J.
1979-05-01
Elastic pion scattering from /sup 9/Be, /sup 28/Si, /sup 58/Ni, and /sup 208/Pb at 162 MeV is analyzed and compared with an optical model theory which incorporates a pion--nucleon range. Excellent fits to the data are obtained in all but one case. The fitted values of the pion--nucleon range, as well as other fitted values are listed. 108 references.
International Nuclear Information System (INIS)
Pierrard, J.; Bruneton, C.; Bystricky, J.; Cozzika, G.; Deregel, J.; Ducros, Y.; Gaidot, A.; Khantine-Langlois, F.; Lehar, F.; Lesquen, A. de; Merlo, J.P.; Miyashita, S.; Movchet, J.; Raoul, J.C.; Van Rossum, L.; Kanavets, V.P.
1975-01-01
The spin rotation parameter R in pp and π + p elastic scattering at 45GeV/c has been measured at the Serpukhov accelerator, for /t/ ranging from 0.2 to 0.5(GeV/c) 2 . The results are presented, together with previous R measurements at 3.8, 6, 16 and 40GeV/c, and are compared with the predictions of Regge pole models. The equality of the values for R in proton-proton and pion-proton scattering, within the experimental errors, is a test of factorization of the residues. An s-channel helicity amplitude analysis for pion-nucleon scattering at 40GeV/c is made using all available data. Significant results are obtained for the non flip amplitude in isoscalar exchange and for flip amplitudes on both isovector and isoscalar exchanges. The helicity flip in isoscalar exchange is non negligible. The energy dependence of this amplitude, at 6, 16 and 40GeV/c, is compared with predictions of Regge pole models [fr
Study of elastic pion scattering from 9Be, 28Si, 58Ni, and 208Pb at 162 MeV
International Nuclear Information System (INIS)
Devereux, M.J.
1979-05-01
Elastic pion scattering from 9 Be, 28 Si, 58 Ni, and 208 Pb at 162 MeV is analyzed and compared with an optical model theory which incorporates a pion--nucleon range. Excellent fits to the data are obtained in all but one case. The fitted values of the pion--nucleon range, as well as other fitted values are listed. 108 references
Precision calculation of threshold πd scattering, πN scattering lengths, and the GMO sum rule
Baru, V.; Hanhart, C.; Hoferichter, M.; Kubis, B.; Nogga, A.; Phillips, D. R.
2011-12-01
We use chiral perturbation theory (ChPT) to calculate the πd scattering length with an accuracy of a few percent, including isospin-violating corrections in both the two- and three-body sectors. In particular, we provide the technical details of a recent letter (Baru et al., 2011) [1], where we used data on pionic deuterium and pionic hydrogen atoms to extract the isoscalar and isovector pion-nucleon scattering lengths a and a. We study isospin-breaking contributions to the three-body part of a due to mass differences, isospin violation in the πN scattering lengths, and virtual photons. This last class of effects is ostensibly infrared enhanced due to the smallness of the deuteron binding energy. However, we show that the leading virtual-photon effects that might undergo such enhancement cancel, and hence the standard ChPT counting provides a reliable estimate of isospin violation in a due to virtual photons. Finally, we discuss the validity of the Goldberger-Miyazawa-Oehme sum rule in the presence of isospin violation, and use it to determine the charged-pion-nucleon coupling constant.
Energy Technology Data Exchange (ETDEWEB)
Baru, V. [Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44870 Bochum (Germany); Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Theoretical and Experimental Physics, B. Cheremushinskaya 25, 117218 Moscow (Russian Federation); Hanhart, C. [Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Hoferichter, M., E-mail: hoferichter@hiskp.uni-bonn.de [Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Kubis, B. [Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Nogga, A. [Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany)
2011-12-15
We use chiral perturbation theory (ChPT) to calculate the {pi}{sup -}d scattering length with an accuracy of a few percent, including isospin-violating corrections in both the two- and three-body sectors. In particular, we provide the technical details of a recent letter (Baru et al., 2011) , where we used data on pionic deuterium and pionic hydrogen atoms to extract the isoscalar and isovector pion-nucleon scattering lengths a{sup +} and a{sup -}. We study isospin-breaking contributions to the three-body part of a{sub {pi}}{sup -}{sub d} due to mass differences, isospin violation in the {pi}N scattering lengths, and virtual photons. This last class of effects is ostensibly infrared enhanced due to the smallness of the deuteron binding energy. However, we show that the leading virtual-photon effects that might undergo such enhancement cancel, and hence the standard ChPT counting provides a reliable estimate of isospin violation in a{sub {pi}}{sup -}{sub d} due to virtual photons. Finally, we discuss the validity of the Goldberger-Miyazawa-Oehme sum rule in the presence of isospin violation, and use it to determine the charged-pion-nucleon coupling constant.
Nuclear spin-orbit interaction from chiral pion-nucleon dynamics
International Nuclear Information System (INIS)
Kaiser, N.
2002-01-01
Using the two-loop approximation of chiral perturbation theory, we calculate the momentum and density dependent nuclear spin-orbit strength U ls (p,k f ). This quantity is derived from the spin-dependent part of the interaction energy Σ spin =((i)/(2))σ→·(q→xp→)U ls (p,k f ) of a nucleon scattering off weakly inhomogeneous isospin symmetric nuclear matter. We find that iterated 1π-exchange generates at saturation density, k f0 =272.7 MeV, a spin-orbit strength at p=0 of U ls (0,k f0 )≅35 MeV fm 2 , in perfect agreement with the empirical value used in the shell model. This novel spin-orbit strength is neither of relativistic nor of short range origin. The potential V ls underlying the empirical spin-orbit strength Ubar ls =V ls r ls 2 becomes a rather weak one, V ls ≅17 MeV, after the identification r ls =m π -1 as suggested by the present calculation. We observe, however, a strong p-dependence of U ls (p,k f0 ) leading even to a sign change above p=200 MeV. This and other features of the emerging spin-orbit Hamiltonian which go beyond the usual shell model parametrization leave questions about the ultimate relevance of the spin-orbit interaction generated by 2π-exchange for a finite nucleus. We also calculate the complex-valued isovector single-particle potential U I (p,k f )+iW I (p,k f ) in isospin asymmetric nuclear matter proportional to τ 3 (N-Z)/(N+Z). For the real part we find reasonable agreement with empirical values and the imaginary part vanishes at the Fermi-surface p=k f
New experimental results on the pion-nucleon interaction investigation in the resonance region
Sumachev, V. V.; Beloglazov, Yu. A.; Kovalev, A. I.; Kozlenko, N. G.; Kruglov, S. P.; Kulbardis, A. A.; Novinsky, D. V.; Trautman, V. Yu.; Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Sulimov, A. D.; Svirida, D. N.; Bazhanov, N. A.; Bunyatova, E. I.
2002-03-01
The spin rotation parameters A and R were measured for the elastic pion-proton scattering by the PNPI-ITEP collaboration in the D13 (1700), ΔS31(1900), ΔP33(1920) and ΔD33 (1940) resonances region. These resonances were absent in the set of partial wave analysis (PWA) of the Virginia Polytechnic Institute group (VPI), but was included in the tables of the Review of Particle Physics. The main goal of the experimental program was to resolve the current PWA’s disagreement in spin rotation parameters value predictions. Simultaneously with A and R the polarization parameter P was measured with the purpose to improve the experimental data base and estimate the experimental systematic errors. Our results for spin rotation parameters A and | R| are in agreement with PWA VPI predictions.
Pion-Skyrmion scattering: collective coordinates at work
International Nuclear Information System (INIS)
Peskin, M.E.
1985-06-01
It is argued that the Skryme model, and more generally, the picture of the nucleon as a chiral soliton, can give a qualitatively correct picture of pion-nucleon scattering, considering both group-theoretic and more scheme-dependent results. The properties of the nucleon and its excited states in large-N quantum chromodynamics are discussed qualitatively. Then the pion-nucleon S-matrix is reduced. It is found that the model succeeds at the first level of calculation in producing many of the features of pion-nucleon scattering which are revealed by experiment, but that many aspects of the description need to be better understood, including the treatment of nonleading corrections near threshold and the inclusion of inelastic channels. 22 refs., 8 figs
Energy Technology Data Exchange (ETDEWEB)
Sadler, M.E.; Isenhower, L.D.
1992-02-15
This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)
Experimental studies of pion-nucleus interactions at intermediate energies
International Nuclear Information System (INIS)
1991-01-01
This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting π 0 mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized 3 He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure
International Nuclear Information System (INIS)
Efrosinin, V.P.; Zaikin, D.A.
1983-01-01
Possible reasons of disagreement between estimates of the pion-nucleon σ term obtained by the method of dispersion relations with extrapolation to the Chang-Dashen point and by alternative methods, making no use of such extrapolation are investigated. One of the reasons may be, that the πN amplitude is not analytic in the variable t at ν=0. A method, which is not so strongly influenced by the nonanalyticity, is suggested to estimate the σ term making use of the threshold data for the πN amplitude. Relation between the scale and chiral invariance breakings is discussed and the resulting estimate of the σ term is presented. Both estimates give close results (42 and 34 MeV) which do not contradict one another within the uncertainties of the methods
Sumachev, V. V.; Beloglazov, Yu. A.; Filimonov, E. A.; Kovalev, A. I.; Kozlenko, N. G.; Kruglov, S. P.; Kulbardis, A. A.; Lopatin, I. V.; Novinsky, D. V.; Shchedrov, V. A.; Trautman, V. Yu.; Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Sulimov, A. D.; Svirida, D. N.; Bazhanov, N. A.; Bunyatova, E. I.
2008-10-01
The existing models of baryons usually predict considerably more resonance (three or more in number) than it was found by investigation of elastic pion-nucleon scattering. This disagreement invites further investigation of the pion-nucleon interaction and among other things the measurement of spin rotation parameters A and R in the elastic pion-nucleon scattering. Recent experiments of the PNPI and PNPI-ITEP collaborations resolved a part of twofold ambiguities of the existing partial wave analyses (PWA). These results were used in the last PWA of the George Washington University group SP06. The proposal for the additional spin rotation parameters A and R measurement in the resonance region is motivated. Such additional measurements are necessary to resolve remaining twofold ambiguities of the existing PWAs.
Invariant potential for elastic pion--nucleus scattering. Technical report No. 75-075
International Nuclear Information System (INIS)
Cammarata, J.B.; Banerjee, M.K.
1975-04-01
From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus an invariant potential for crossing symmetric, elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model is the Exclusion Principle restriction on the pion-bound nucleon interaction, the effects of the binding of nucleons, a kinematic transformation of energy from the lab to the πN center of mass frames, and the Fermi motion and recoil of the target nucleons. From a numerical study of the effects of these processes on the π- 12 C total cross section, the relative importance of each is determined. Other processes contributing to the elastic scattering of pions not included in the present model are also discussed. (9 figures) (U.S.)
How Precisely can we Determine the $\\piNN$ Coupling Constant from the Isovector GMO Sum Rule?
Loiseau, B; Thomas, A W
1999-01-01
The isovector GMO sum rule for zero energy forward pion-nucleon scattering iscritically studied to obtain the charged pion-nucleon coupling constant usingthe precise negatively charged pion-proton and pion-deuteron scattering lengthsdeduced recently from pionic atom experiments. This direct determination leadsto a pseudoscalar charged pion-nucleon coupling constant of 14.23 +- 0.09(statistic) +- 0.17 (systematic). We obtain also accurate values for thepion-nucleon scattering lengths.
International Nuclear Information System (INIS)
Elster, C.
1994-08-01
The research supported by this grant includes application of many-body scattering theory to nuclear systems and studies of few-body systems described by effective hadronic field theories. During the second year of the current grant from the US Department of Energy considerable progress was made in bringing all first order effects into the nonrelativistic elastic nucleon-nucleus scattering in a consistent fashion. This work is directed towards completely and reliably calculating the first order term in a Watson expansion including a modification through the nuclear medium. The research effort in few-body physics was concentrated on finishing a study on the sensitivity of the np backward angle differential cross section to the size of the pion nucleon coupling constant and setting up a framework to investigate the low energy behavior of energy dependent meson-exchange potentials. Completed and ongoing research efforts in the two main areas mentioned above are discussed in the following two sections
Pion inelastic scattering and the pion-nucleus effective interaction
International Nuclear Information System (INIS)
Carr, J.A.
1983-01-01
This work examines pion inelastic scattering with the primary purpose of gaining a better understanding of the properties of the pion-nucleus interaction. The main conclusion of the work is that an effective interaction which incorporates the most obvious theoretical corrections to the impulse approximation does a good job of explaining pion elastic and inelastic scattering from zero to 200 MeV without significant adjustments to the strength parameters of the force. Watson's multiple scattering theory is used to develop a theoretical interaction starting from the free pion-nucleon interaction. Elastic scattering was used to calibrate the isoscalar central interaction. It was found that the impulse approximation did poorly at low energy, while the multiple scattering corrections gave good agreement with all of the data after a few minor adjustments in the force. The distorted wave approximation for the inelastic transition matrix elements are evaluated for both natural and unnatural parity excitations. The isoscalar natural parity transitions are used to test the reaction theory, and it is found that the effective interaction calibrated by elastic scattering produces good agreement with the inelastic data. Calculations are also shown for other inelastic and charge exchange reactions. It appears that the isovector central interaction is reasonable, but the importance of medium corrections cannot be determined. The unnatural parity transitions are also reasonably described by the theoretical estimate of the spin-orbit interaction, but not enough systematic data exists to reach a firm conclusion
Kinematic aspects of pion-nucleus elastic scattering
International Nuclear Information System (INIS)
Weiss, D.L.; Ernst, D.J.
1982-01-01
The inclusion of relativistic kinematics in the theory of elastic scattering of pions from nuclei is examined. The investigation is performed in the context of the first order impulse approximation which incorporates the following features: (1) Relative momentum are defined according to relativistic theories consistent with time reversal invariance. (2) The two-nucleon interaction is a new, multichannel, separable potential model consistent with the most recent data derived from a recent nonpotential model of Ernst and Johnson. (3) The recoil of the pion-nucleon interacting pair and its resultant nonlocality are included. (4) The Fermi integral is treated by an optimal factorization approximation. It is shown how a careful definition of an intrinsic target density leads to an unambiguous method for including the recoil of the target. The target recoil corrections are found to be large for elastic scattering from 4 He and not negligible for scattering from 12 C. Relativistic potential theory kinematics, kinematics which result from covariant reduction approaches, and kinematics which result from replacing masses by energies in nonrelativistic formulas are compared. The relativistic potential theory kinematics and covariant reduction kinematics are shown to produce different elastic scattering at all pion energies examined (T/sub π/<300 MeV). Simple extensions of nonrelativistic kinematics are found to be reasonable approximations to relativistic potential theory
High energy elastic hadron scattering
International Nuclear Information System (INIS)
Fearnly, T.A.
1986-04-01
The paper deals with the WA7 experiment at the CERN super proton synchrotron (SPS). The elastic differential cross sections of pion-proton, kaon-proton, antiproton-proton, and proton-proton at lower SPS energies over a wide range of momentum transfer were measured. Some theoretical models in the light of the experimental results are reviewed, and a comprehensive impact parameter analysis of antiproton-proton elastic scattering over a wide energy range is presented. A nucleon valence core model for high energy proton-proton and antiproton-proton elastic scattering is described
Low energy positron scattering from helium
International Nuclear Information System (INIS)
Sullivan, J.P.; Jones, A.; Caradonna, P.; Makochekanwa, C.; Buckman, S.J.
2008-01-01
A new experiment has been developed for high resolution studies of positron scattering from atoms and molecules. Based on the Surko trap technology, a pulsed positron beam has been used to obtain preliminary measurements of low energy, differential elastic scattering cross sections from helium. The operation of the beamline is described and preliminary absolute cross section values for scattering energies of 5, 10 and 15 eV are presented and compared with contemporary theoretical calculations
Pion nucleus scattering lengths
International Nuclear Information System (INIS)
Huang, W.T.; Levinson, C.A.; Banerjee, M.K.
1971-09-01
Soft pion theory and the Fubini-Furlan mass dispersion relations have been used to analyze the pion nucleon scattering lengths and obtain a value for the sigma commutator term. With this value and using the same principles, scattering lengths have been predicted for nuclei with mass number ranging from 6 to 23. Agreement with experiment is very good. For those who believe in the Gell-Mann-Levy sigma model, the evaluation of the commutator yields the value 0.26(m/sub σ//m/sub π/) 2 for the sigma nucleon coupling constant. The large dispersive corrections for the isosymmetric case implies that the basic idea behind many of the soft pion calculations, namely, slow variation of matrix elements from the soft pion limit to the physical pion mass, is not correct. 11 refs., 1 fig., 3 tabs
Energy Technology Data Exchange (ETDEWEB)
Becher,
2002-08-08
After contrasting the low energy effective theory for the baryon sector with one for the Goldstone sector, I use the example of pion nucleon scattering to discuss some of the progress and open issues in baryon chiral perturbation theory.
Energy transfer in scattering by rotating potentials
Indian Academy of Sciences (India)
Quantum mechanical scattering theory is studied for time-dependent Schrödinger operators, in particular for particles in a rotating potential. Under various assumptions about the decay rate at infinity we show uniform boundedness in time for the kinetic energy of scattering states, existence and completeness of wave ...
Energy Transfer in Scattering by Rotating Potentials
Indian Academy of Sciences (India)
Quantum mechanical scattering theory is studied for time-dependent Schrödinger operators, in particular for particles in a rotating potential. Under various assumptions about the decay rate at infinity we show uniform boundedness in time for the kinetic energy of scattering states, existence and completeness of wave ...
Energy transfer in scattering by rotating potentials
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Abstract. Quantum mechanical scattering theory is studied for time-dependent. Schrödinger operators, in particular for particles in a rotating potential. Under various assumptions about the decay rate at infinity we show uniform boundedness in time for the kinetic energy of scattering states, existence and completeness of ...
Electromagnetic and gravitational scattering at Planckian energies
International Nuclear Information System (INIS)
Das, S.; Majumdar, P.
1994-11-01
The scattering of pointlike particles at very large center of mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions is re-examined in the particular case when one of the particles carries magnetic charge. At Planckian center-of-mass energies, when gravitational dominance is normally expected, the presence of magnetic charge is shown to produce dramatic modifications to the scattering cross section as well as to the holomorphic structure of the scattering amplitude. (author). 20 refs
Determination of the negatively charged pion-proton scattering length from pionic hydrogen
Ericson, Torleif Eric Oskar; Wycech, S
2003-01-01
We derive a closed, model independent, expression for the electromagnetic correction factor to the hadronic scattering length extracted from a hydrogenic atom with an extended charge and in the limit of a short ranged hadronic interaction to terms of order ((alpha)**2)(log(alpha)) in the limit of a non-relativistic approach. A hadronic negatively charged pion-proton scattering length of 0.0870(5), in units of inverse charged pion-mass, is deduced, leading to a pion-nucleon coupling constant from the GMO relation equals to 14.00(19).
Zero energy scattering calculation in Euclidean space
International Nuclear Information System (INIS)
Carbonell, J.; Karmanov, V.A.
2016-01-01
We show that the Bethe–Salpeter equation for the scattering amplitude in the limit of zero incident energy can be transformed into a purely Euclidean form, as it is the case for the bound states. The decoupling between Euclidean and Minkowski amplitudes is only possible for zero energy scattering observables and allows determining the scattering length from the Euclidean Bethe–Salpeter amplitude. Such a possibility strongly simplifies the numerical solution of the Bethe–Salpeter equation and suggests an alternative way to compute the scattering length in Lattice Euclidean calculations without using the Luscher formalism. The derivations contained in this work were performed for scalar particles and one-boson exchange kernel. They can be generalized to the fermion case and more involved interactions.
Zero energy scattering calculation in Euclidean space
Energy Technology Data Exchange (ETDEWEB)
Carbonell, J. [Institut de Physique Nucléaire, Université Paris-Sud, IN2P3-CNRS, 91406 Orsay Cedex (France); Karmanov, V.A., E-mail: karmanov@sci.lebedev.ru [Lebedev Physical Institute, Leninsky Prospekt 53, 119991 Moscow (Russian Federation)
2016-03-10
We show that the Bethe–Salpeter equation for the scattering amplitude in the limit of zero incident energy can be transformed into a purely Euclidean form, as it is the case for the bound states. The decoupling between Euclidean and Minkowski amplitudes is only possible for zero energy scattering observables and allows determining the scattering length from the Euclidean Bethe–Salpeter amplitude. Such a possibility strongly simplifies the numerical solution of the Bethe–Salpeter equation and suggests an alternative way to compute the scattering length in Lattice Euclidean calculations without using the Luscher formalism. The derivations contained in this work were performed for scalar particles and one-boson exchange kernel. They can be generalized to the fermion case and more involved interactions.
Medium energy hadron scattering from nuclei
International Nuclear Information System (INIS)
Ginocchio, J.N.; Wenes, G.
1986-01-01
The Glauber approximation for medium energy scattering of hadronic projectiles from nuclei is combined with the interacting boson model of nuclei to produce a transition matrix for elastic and inelastic scattering in algebraic form which includes coupling to all the intermediate states. We present closed form analytic expresions for the transition matrix elements for the three dynamical symmetries of the interacting boson model; that is for, a spherical quadrupole vibrator, a γ unstable rotor, and both prolate and oblate axially symmetric rotors. We give examples of application of this formalism to proton scattering from 154 Sm and 154 Gd. 27 refs., 5 figs., 1 tab
Theorems of low energy in Compton scattering
International Nuclear Information System (INIS)
Chahine, J.
1984-01-01
We have obtained the low energy theorems in Compton scattering to third and fouth order in the frequency of the incident photon. Next we calculated the polarized cross section to third order and the unpolarized to fourth order in terms of partial amplitudes not covered by the low energy theorems, what will permit the experimental determination of these partial amplitudes. (Author) [pt
Quantum scattering at low energies
DEFF Research Database (Denmark)
Derezinski, Jan; Skibsted, Erik
to derive (oscillatory) asymptotics of the standard short-range and Dollard type --matrices for the subclasses of potentials where both kinds of -matrices are defined. For potentials whose leading part is we show that the location of singularities of the kernel of experiences an abrupt change from passing...... from positive energies to the limiting energy . This change corresponds to the behaviour of the classical orbits. Under stronger conditions we extract the leading term of the asymptotics of the kernel of at its singularities; this leading term defines a Fourier integral operator in the sense...
Quantum scattering at low energies
DEFF Research Database (Denmark)
Derezinski, Jan; Skibsted, Erik
2009-01-01
appropriate weighted spaces. These results are used to derive (oscillatory) asymptotics of the standard short-range and Dollard type S-matrices for the subclasses of potentials where both kinds of S-matrices are defined. For potentials whose leading part is −γ|x|−μ we show that the location of singularities...... of the kernel of S(λ) experiences an abrupt change from passing from positive energies λ to the limiting energy λ=0 . This change corresponds to the behaviour of the classical orbits. Under stronger conditions one can extract the leading term of the asymptotics of the kernel of S(λ) at its singularities....
Wavefield separation by energy norm Born scattering
Sun, Bingbing
2017-08-17
In Reflection Based Waveform Inversion, the gradient is computed by cross-correlating the direct and Born scattered wavefield with their adjoints applied to the data residuals. In this case, the transmitted part of the Born scattered wavefield produces high wavenumber artifacts, which would harm the convergence of the inversion process. We propose an efficient Energy Norm Born Scattering (ENBS) to attenuate the transmission components of the Born modeling, and allow it to produce only reflections. ENBS is derived from the adjoint of the Energy Norm (inverse scattering) imaging condition and in order to get deeper insights of how this method works, we show analytically that given an image, in which reflectivity is represented by a Dirac delta function, ENBS attenuates transmission energy perfectly. We use numerical examples to demonstrate that ENBS works in both the time and the frequency domain. We also show that in reflection waveform inversion (RWI) the wave path constructed by ENBS would be cleaner and free of high wavenumber artifacts associated with conventional Born scattering.
Energy transfer in scattering by rotating potentials
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
In this section we study bounds of the kinetic energy on incoming and outgoing scattering states. These bounds follow from ... Let H(t) = H0 + Vt be a self-adjoint family of operators which satisfies (2.1), (2.2) and generates a unitary propagator U(t,s) ...... Math. Soc. Transl. of Math. Monographs (RI: Providence) (1992) vol. 105.
High energy proton-nucleus scattering
International Nuclear Information System (INIS)
Beurtey, R.M.
1977-01-01
This paper is restricted to an overall global criticism of what has been produced, experimentally and theoretically, during the past ten years, concerning elastic proton scattering at intermediate energy: theoretical models and approximations, phenomenological analysis, criticisms and suggestions on experimental methods
Electron scattering from sodium at intermediate energies
International Nuclear Information System (INIS)
Mitroy, J.; McCarthy, I.E.
1986-10-01
A comprehensive comparison is made between theoretical calculations and experimental data for intermediate energy (≥ 10 eV) electron scattering from sodium vapour. The theoretical predictions of coupled-channels calculations (including one, two or four channels) do not agree with experimental values of the differential cross sections for elastic scattering or the resonant 3s to 3p excitation. Increasingly-more-sophisticated calculations, incorporating electron correlations in the target states, and also including core-excited states in the close-coupling expansion, are done at a few selected energies in an attempt to isolate the cause of the discrepancies between theory and experiment. It is found that these more-sophisticated calculations give essentially the same results as the two- and four-channel calculations using Hartree-Fock wavefunctions. Comparison of the sodium high-energy elastic differential cross sections with those of neon suggests that the sodium differential cross section experiments may suffer from systematic errors. There is also disagreement, at the higher energies, between theoretical values for the scattering parameters and those that are derived from laser-excited superelastic scattering and electron photon coincidence experiments. When allowance is made for the finite acceptance angle of the electron spectrometers used in the experiments by convoluting the theory with a function representing the distribution of electrons entering the electron spectrometer it is found that the magnitudes of the differences between theory and experiment are reduced
Surface analysis with low energy ion scattering
International Nuclear Information System (INIS)
Taglauer, E.; Heiland, W.
1976-01-01
Principles and applications of low energy ion scattering for surface analysis are presented. Basic features are the binary collision concept, the scattering cross-sections and the ion neutralization process. The potential and the limitations of the method are outlined. Some pertinent experimental aspects are considered. In a number of examples the performance of the technique is demonstrated for qualitative composition analysis and for studies of surface structures. Finally a few comparisons are made with other techniques, such as AES, LEED, or SIMS. (orig.) [de
Attenuation of Scattered Thermal Energy Atomic Oxygen
Banks, Bruce A.; Seroka, Katelyn T.; McPhate, Jason B.; Miller, Sharon K.
2011-01-01
The attenuation of scattered thermal energy atomic oxygen is relevant to the potential damage that can occur within a spacecraft which sweeps through atomic oxygen in low Earth orbit (LEO). Although there can be significant oxidation and resulting degradation of polymers and some metals on the external surfaces of spacecraft, there are often openings on a spacecraft such as telescope apertures, vents, and microwave cavities that can allow atomic oxygen to enter and scatter internally to the spacecraft. Atomic oxygen that enters a spacecraft can thermally accommodate and scatter to ultimately react or recombine on surfaces. The atomic oxygen that does enter a spacecraft can be scavenged by use of high erosion yield polymers to reduce its reaction on critical surfaces and materials. Polyoxymethylene and polyethylene can be used as effective atomic oxygen scavenging polymers.
Hadron production in high energy muon scattering
International Nuclear Information System (INIS)
Hicks, R.G.
1978-01-01
An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10 10 muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s/ 0 and Λ 0 decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references
Low-energy electron scattering from methane
International Nuclear Information System (INIS)
Bundschu, C.T.; Gibson, J.C.; Buckman, S.J.; Brunger, M.J.; Gianturco, F.A.
1997-01-01
Absolute differential cross sections for elastic scattering and vibrational excitation (ν 2.4 , ν 1.3 ) of CH 4 have been measured at incident energies between 0.6 and 5.4 eV. These cross sections have also been extrapolated and integrated in order to derive integral and momentum transfer cross sections which are compared with the results of previous single-collision and electron swarm experiments. Elastic differential cross sections have also been calculated using a body-fixed (BF), single-centre expansion (SCE) for the close-coupled (CC) equations. There is excellent agreement between the present data and the most recent elastic scattering results of Boesten and Tanaka, but substantial discrepancies between these two data sets and several previous measurements. There is also excellent agreement at most energies between the present measured and calculated elastic cross sections. (author)
Entanglement creation in low-energy scattering
Energy Technology Data Exchange (ETDEWEB)
Weder, Ricardo [Institut National de Recherche en Informatique et en Automatique Paris-Rocquencourt, Projet POEMS, Domaine de Voluceau-Rocquencourt, BP 105, F-78153, Le Chesnay Cedex (France)
2011-12-15
We study the entanglement creation in the low-energy scattering of two particles in three dimensions, for a general class of interaction potentials that are not required to be spherically symmetric. The incoming asymptotic state, before the collision, is a product of two normalized Gaussian states. After the scattering, the particles are entangled. We take as a measure of the entanglement the purity of one of them. We provide a rigorous explicit computation, with error bound, of the leading order of the purity at low energy. The entanglement depends strongly on the difference of the masses. It takes its minimum when the masses are equal, and it increases rapidly with the difference of the masses. It is quite remarkable that the anisotropy of the potential gives no contribution to the leading order of the purity, in spite of the fact that entanglement is a second-order effect.
High-Energy Compton Scattering Light Sources
Hartemann, Fred V; Barty, C; Crane, John; Gibson, David J; Hartouni, E P; Tremaine, Aaron M
2005-01-01
No monochromatic, high-brightness, tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray sources include: nuclear resonance fluorescence spectroscopy, time-resolved positron annihilation spectroscopy, and MeV flash radiography. The peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale with the electron beam brightness and the drive laser pulse energy. This gamma 2
Low Energy Electron Scattering from Fuels
Lopes, M. C. A.; Silva, D. G. M.; Bettega, M. H. F.; da Costa, R. F.; Lima, M. A. P.; Khakoo, M. A.; Winstead, C.; McKoy, V.
2012-11-01
In order to understand and optimize processes occurring during the ignition of plasma and its consequences in post-discharge for an internal combustion engine, especially considering the spark plug, we have produced in this work some basic information necessary to modeling spark ignition in alcohol- fuelled engines. Total cross sections of electron scattering by methanol and ethanol molecules in the energy range from 60 to 500 eV are reported, using the linear transmission method based on the Beer-Lambert law to first approximation. Aditionally to that, measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering were also discussed, for impact energies of 1, 2, 5, 10, 15, 20, 30, 50, and 100 eV and for scattering angles of 5°-130°. The measurements were obtained using the relative flow method with an aperture source, and calculations using two different implementations of the Schwinger multichannel method, one that takes all electrons into account and is adapted for parallel computers, and another that uses pseudopotentials and considers only the valence electrons.
Low energy electron scattering from fuels
International Nuclear Information System (INIS)
Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M.
2011-01-01
Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist
Low energy electron scattering from fuels
Energy Technology Data Exchange (ETDEWEB)
Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M. [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil). Dept. de Fisica; Yates, Brent; Hong, Ling; Khakoo, Murtadha A. [California State University at Fullerton, CA (US). Physics Department; Bettega, Marcio H.F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Costa, Romarly F. da [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Lima, Marco A.P. [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE/CNPEM), Campinas, SP (Brazil)
2011-07-01
Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist
Virtual compton scattering at low energy
International Nuclear Information System (INIS)
Lhuillier, D.
1997-09-01
The work described in this PhD is a study of the Virtual Compton scattering (VCS) off the proton at low energy, below pion production threshold. Our experiment has been carried out at MAMI in the collaboration with the help of two high resolution spectrometers. Experimentally, the VCS process is the electroproduction of photons off a liquid hydrogen target. First results of data analysis including radiative corrections are presented and compared with low energy theorem prediction. VCS is an extension of the Real Compton Scattering. The virtuality of the incoming photon allows us to access new observables of the nucleon internal structure which are complementarity to the elastic form factors: the generalized polarizabilities (GP). They are function of the squared invariant mass of the virtual photo. The mass limit of these observables restore the usual electric and magnetic polarizabilities. Our experiment is the first measurement of the VCS process at a virtual photon mass equals 0.33 Ge V square. The experimental development presents the analysis method. The high precision needed in the absolute cross-section measurement required an accurate estimate of radiative corrections to the VCS. This new calculation, which has been performed in the dimensional regulation scheme, composes the theoretical part of this thesis. At low q', preliminary results agree with low energy theorem prediction. At higher q', substraction of low energy theorem contribution to extract GP is discussed. (author)
Low energy pion-16O scattering
International Nuclear Information System (INIS)
Wafelbakker, C.K.
1981-01-01
In spite of some outward appearances, the modern microscopic theories of the pion-nucleus (πA) interaction are not fundamentally very different from each other. They can all be derived from the same source, multiple-scattering theory. They all treat the first-order optical potential in a comparatively detailed way and in all of them it is necessary to incorporate higher-order effects in general and pion-annihilation in particular phenomenologically. Basically the same physical features can be embodied in all of them. The presentation of the theoretical scheme underlying the present thesis is designed to stress this conceptual unity of current πA theory. In this thesis the methods developed by De Kam to incorporate Pauli- and binding-corrections to the impulse-approximation first-order optical potential for 4 He are extended to a more complicated nucleus, 16 O, for the first time. In concreto two situations are considered: π- 16 O scattering at energies below nucleon-knockout threshold (13.5 MeV) - 7 and 12 MeV - and at energies 40 and 49.7 MeV, above nucleon-knockout threshold but still well within the low-energy region. (Auth.)
Low energy scattering with a nontrivial pion
International Nuclear Information System (INIS)
Fariborz, Amir H.; Jora, Renata; Schechter, Joseph
2007-01-01
An earlier calculation in a generalized linear sigma model showed that the well-known current algebra formula for low energy pion-pion scattering held even though the massless Nambu Goldstone pion contained a small admixture of a two-quark two-antiquark field. Here we turn on the pion mass and note that the current algebra formula no longer holds exactly. We discuss this small deviation and also study the effects of a SU(3) symmetric quark mass type term on the masses and mixings of the eight SU(3) multiplets in the model. We calculate the s-wave scattering lengths, including the beyond current algebra theorem corrections due to the scalar mesons, and observe that the effect of the scalar mesons is to improve the agreement with experiment. In the process, we uncover the way in which linear sigma models give controlled corrections (due to the presence of scalar mesons) to the current algebra scattering formula. Such a feature is commonly thought to exist only in the nonlinear sigma model approach
Low Energy Electron Scattering from Fuels
Lopes, M. Cristina A.
2012-06-01
We report an investigation of processes that occur during the ignition of the plasma and its consequences in post-discharge time for an internal combustion engine, in order to find the appropriate parameters to be used in cars that operate with lean mixtures air-fuel. The relevance of this theme has attracted much attention, and has been one of the subjects of collaboration between experimental and theoretical groups in the USA and Brazil. We have produced some basic information necessary to modeling spark ignition in alcohol- fuelled engines. Total cross sections of electron scattering by methanol and ethanol molecules were obtained, using the linear transmission method based on the Beer-Lambert law to first approximation. Measurements and calculations of differential cross sections for low-energy (rotationally unresolved) electron scattering were also obtained, for scattering angles of 5 --130 . The measurements were taken using the relative flow method with an aperture source, and calculations using two different implementations of the Schwinger multichannel method, one that takes all electrons into account and is adapted for parallel computers, and another that uses pseudopotentials and considers only the valence electrons. Additionally to these, computer simulation studies of electronic discharge in mixtures of ethanol were performed, using a Zero-Dimensional Plasma Kinetic solver. Previous reported models for combustion of ethanol and cross sections data for momentum transfer of electron collisions with ethanol were used. The time evolutions of the main species densities are reported and the ignition time delay discussed.
High energy gravitational scattering: a numerical study
Marchesini, Giuseppe
2008-01-01
The S-matrix in gravitational high energy scattering is computed from the region of large impact parameters b down to the regime where classical gravitational collapse is expected to occur. By solving the equation of an effective action introduced by Amati, Ciafaloni and Veneziano we find that the perturbative expansion around the leading eikonal result diverges at a critical value signalling the onset of a new regime. We then discuss the main features of our explicitly unitary S-matrix down to the Schwarzschild's radius R=2G s^(1/2), where it diverges at a critical value b ~ 2.22 R of the impact parameter. The nature of the singularity is studied with particular attention to the scaling behaviour of various observables at the transition. The numerical approach is validated by reproducing the known exact solution in the axially symmetric case to high accuracy.
Intermediate energy nucleon-deuteron scattering theory.
Wilson, J. W.
1973-01-01
Sloan's conclusion (1969) that terms of the multiple-scattering series beyond single scattering contribute only to S- and P-wave amplitudes in an S-wave separable model is examined. A comparison of experiments with the calculation at 146 MeV shows that the conclusion is valid in nucleon-deuteron scattering applications.
Scattering of high energy electrons on deuteron
International Nuclear Information System (INIS)
Grossetete, B.
1964-12-01
The aim of this work is to obtain information on the neutron form factor from the study of the scattering of electrons on deuterium. The first part is dedicated to the theoretical study of the elastic and inelastic scattering. We introduce different form factors: Sachs form factor, the Pauli and Dirac form factors, they appear in the analytic expression of the scattering cross-section. We show how the deuteron form factors can be deduced from neutron's and proton's form factors. In the case of the inelastic scattering we show how the cross section can be broken into components associated to partial waves and we obtain different formulas for the inelastic cross-section based on the Breit formula or the Durand formalism. The second part is dedicated to the experiment setting of electron scattering on deuterium. The elastic scattering experiment has been made on solid or liquid CD 2 targets while inelastic scattering has been studied on a liquid target. We have used an electron beam produced by the Orsay linear accelerator and the scattered electrons have been analysed by a magnetic spectrometer and a Cerenkov detector. The results give a very low value (slightly positive)for the charge form factor of the neutron and a magnetic form factor for the neutron slightly below that of the proton [fr
Finite energy sum rules in potential scattering
International Nuclear Information System (INIS)
Graham, N.; Jaffe, R.L.; Quandt, M.; Weige, H.
2001-01-01
We study scattering theory identities previously obtained as consistency conditions in the context of one-loop quantum field theory calculations. We prove the identities using Jost function techniques and study applications
Inelastic x-ray scattering at modest energy resolution
International Nuclear Information System (INIS)
Finkelstein, K. D.; Tischler, J. Z.; Larson, B. C.
1997-01-01
We report results from the development of an inelastic scattering spectrometer designed to take advantage of high energy synchrotron radiation available at CHESS. The device allows a large increase of the effective scattering volume in the sample by permitting measurements to be made in an energy range up to 25 KeV. The highest useable energy appears limited by the efficiency of the analyzers under consideration. At 20 KeV a novel 4-bounce, sagittal focusing monochromator passes 10e11 photons/second with Darwin width limited energy resolution. In the scattering plane, the monochromator images the electron beam producing a small scattering source for the analyzing optics. Analyzer systems under study include a cooled mosaic crystal in para-focusing geometry, and an adjustable spherically bent silicon crystal respectively for parallel and point-by-point collection of the energy loss spectrum. This paper discusses the optical configurations presents results from our early measurements and suggests directions for improvements
High energy asymptotics of the scattering amplitude for the ...
Indian Academy of Sciences (India)
We find an explicit function approximating at high energies the kernel of the scattering matrix with arbitrary accuracy. Moreover, the same function gives all diagonal singularities of the kernel of the scattering matrix in the angular variables. Author Affiliations. D Yafaev1. Department of Mathematics, University Rennes-1, ...
High energy scattering in gravity and supergravity
DEFF Research Database (Denmark)
B. Giddings, Steven; Schmidt-Sommerfeld, Maximilian; Andersen, Jeppe Rosenkrantz
2010-01-01
We investigate features of perturbative gravity and supergravity by studying scattering in the ultraplanckian limit, and sharpen arguments that the dynamics is governed by long-distance physics. A simple example capturing aspects of the eikonal resummation suggests why short distance phenomena...... and in particular divergences or nonrenormalizability do not necessarily play a central role in this regime. A more profound problem is apparently unitarity. These considerations can be illustrated by showing that known gravity and supergravity amplitudes have the same long-distance behavior, despite the extra...... a physical scattering process, and ultraplanckian scattering exhibiting Regge behavior. These arguments sharpen the need to find a nonperturbative completion of gravity with mechanisms which restore unitarity in the strong gravity regime....
Intermediate energy proton and light-ion scattering
International Nuclear Information System (INIS)
Moss, J.M.
1981-01-01
A review is presented of recent (1979-81) developments in the field of intermediate-energy proton and light-ion scattering from nuclei. New theoretical and calculational techniques of particular interest to experimentalists are discussed. Emphasis is placed on topics in nuclear structure physics - giant resonances, pion-condensation precursor phenomena, and polarization transfer (spin-flip) experiments - where intermediate energy proton and light-ion scattering has made new and unique contributions
Spin effects in high energy hadron-hadron scattering
International Nuclear Information System (INIS)
Goloskokov, S.V.; Kuleshov, S.P.; Selyugin, O.V.
1991-01-01
The spin-flip amplitudes of the meson-nucleon and nucleon-nucleon scattering are calculated in the framework of the dynamic model taking into account the interactions at large distances. The consideration of the strong form factors at the corresponding vertex and preasymptotic contributions allowed us to describe correctly the differential cross sections and spin effects of hadron-hadron scattering at high energies. On this basis predictions at high and superhigh energies are made. (orig.)
Virtual Compton Scattering At High Energy
Zhang, C
2000-01-01
In this dissertation we develop a theoretical framework in the context of perturbative QuantumChromoDynamics (pQCD) for studying non-forward scattering processes. In particular, we investigate a non-forward unequal mass virtual Compton scattering amplitude by performing the general operator product expansion (OPE) and the formal renormalization group (RG) analysis. We discuss the general tensorial decomposition of the amplitude to obtain the invariant amplitudes in the non- forward kinematic region. We study the OPE to identify the relevant operators and their reduced matrix elements, as well as the corresponding Wilson coefficients. We find that the OPE now should be done in double moments with new moment variables. There are in the expansion new sets of leading twist operators which have overall derivatives. They mix under renormalization in a well- defined way. We compute the evolution kernels from which the anomalous dimensions for these operators can be extracted. We also obtain explicitly the lowest ord...
International Nuclear Information System (INIS)
Ecker, G.
1996-06-01
After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In the pion-nucleon system, the linear σ model is contrasted with chiral perturbation theory. The heavy-nucleon expansion is used to construct the effective pion-nucleon Lagrangian to third order in the low-energy expansion, with applications to nucleon Compton scattering. (author)
Evaluation of a scattering correction method for high energy tomography
Tisseur, David; Bhatia, Navnina; Estre, Nicolas; Berge, Léonie; Eck, Daniel; Payan, Emmanuel
2018-01-01
One of the main drawbacks of Cone Beam Computed Tomography (CBCT) is the contribution of the scattered photons due to the object and the detector. Scattered photons are deflected from their original path after their interaction with the object. This additional contribution of the scattered photons results in increased measured intensities, since the scattered intensity simply adds to the transmitted intensity. This effect is seen as an overestimation in the measured intensity thus corresponding to an underestimation of absorption. This results in artifacts like cupping, shading, streaks etc. on the reconstructed images. Moreover, the scattered radiation provides a bias for the quantitative tomography reconstruction (for example atomic number and volumic mass measurement with dual-energy technique). The effect can be significant and difficult in the range of MeV energy using large objects due to higher Scatter to Primary Ratio (SPR). Additionally, the incident high energy photons which are scattered by the Compton effect are more forward directed and hence more likely to reach the detector. Moreover, for MeV energy range, the contribution of the photons produced by pair production and Bremsstrahlung process also becomes important. We propose an evaluation of a scattering correction technique based on the method named Scatter Kernel Superposition (SKS). The algorithm uses a continuously thickness-adapted kernels method. The analytical parameterizations of the scatter kernels are derived in terms of material thickness, to form continuously thickness-adapted kernel maps in order to correct the projections. This approach has proved to be efficient in producing better sampling of the kernels with respect to the object thickness. This technique offers applicability over a wide range of imaging conditions and gives users an additional advantage. Moreover, since no extra hardware is required by this approach, it forms a major advantage especially in those cases where
Evaluation of a scattering correction method for high energy tomography
Directory of Open Access Journals (Sweden)
Tisseur David
2018-01-01
Full Text Available One of the main drawbacks of Cone Beam Computed Tomography (CBCT is the contribution of the scattered photons due to the object and the detector. Scattered photons are deflected from their original path after their interaction with the object. This additional contribution of the scattered photons results in increased measured intensities, since the scattered intensity simply adds to the transmitted intensity. This effect is seen as an overestimation in the measured intensity thus corresponding to an underestimation of absorption. This results in artifacts like cupping, shading, streaks etc. on the reconstructed images. Moreover, the scattered radiation provides a bias for the quantitative tomography reconstruction (for example atomic number and volumic mass measurement with dual-energy technique. The effect can be significant and difficult in the range of MeV energy using large objects due to higher Scatter to Primary Ratio (SPR. Additionally, the incident high energy photons which are scattered by the Compton effect are more forward directed and hence more likely to reach the detector. Moreover, for MeV energy range, the contribution of the photons produced by pair production and Bremsstrahlung process also becomes important. We propose an evaluation of a scattering correction technique based on the method named Scatter Kernel Superposition (SKS. The algorithm uses a continuously thickness-adapted kernels method. The analytical parameterizations of the scatter kernels are derived in terms of material thickness, to form continuously thickness-adapted kernel maps in order to correct the projections. This approach has proved to be efficient in producing better sampling of the kernels with respect to the object thickness. This technique offers applicability over a wide range of imaging conditions and gives users an additional advantage. Moreover, since no extra hardware is required by this approach, it forms a major advantage especially in those
Inelastic α-particle scattering at intermediate energy
International Nuclear Information System (INIS)
Bauer, T.S.; Beurtey, R.; Boudard, A.; Bruge, G.; Catz, H.; Couvert, P.; Escudie, J.L.; Fontaine, J.M.; Garcon, M.; Lugol, J.C.; Matoba, M.; Platchkov, S.; Rouger, M.; Terrien, Y.
1979-01-01
The rigid body approximation is used to extend the Glauber formalism to the analysis of inelastic scattering of 1.37 GeV α particles by 24 Mg and 58 Ni. Angular distributions for low-lying states in 24 Mg and 58 Ni are analyzed in this framework together with previously published data for Ca isotopes. Intermediate energy α particle scattering is tested as a tool to observe the isoscalar giant quadrupole resonance. Energy weighted sum rules are drawn from the analysis of L = 2 angular distributions measured in the proper energy range. Comparison is made with existing data
Elastic positron-cadmium scattering at low energies
International Nuclear Information System (INIS)
Bromley, M. W. J.; Mitroy, J.
2010-01-01
The elastic and annihilation cross sections for positron-cadmium scattering are reported up to the positronium-formation threshold (at 2.2 eV). The low-energy phase shifts for the elastic scattering of positrons from cadmium were derived from the bound and pseudostate energies of a very large basis configuration-interaction calculation of the e + -Cd system. The s-wave binding energy is estimated to be 126±42 meV, with a scattering length of A scat =(14.2±2.1)a 0 , while the threshold annihilation parameter, Z eff , was 93.9±26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Z eff of 91±17 at a collision energy of about 490±50 meV.
[Medium energy particle physics
International Nuclear Information System (INIS)
Nefkens, B.M.K.
1985-10-01
Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of 3 H, 3 He, 4 He; Detailed Balance in pd right reversible γ 3 H; Interaction Dynamics); and Search for the Rare Decay Μ + → e + + γ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects
Renormalized two-body low-energy scattering
DEFF Research Database (Denmark)
Skibsted, Erik
For a class of long-range potentials, including ultra-strong perturbations of the attractive Coulomb potential in dimension d≥3, we introduce a stationary scattering theory for Schrödinger operators which is regular at zero energy. In particular it is well defined at this energy, and we use...
Pion scattering and nuclear dynamics
International Nuclear Information System (INIS)
Johnson, M.B.
1988-01-01
A phenomenological optical-model analysis of pion elastic scattering and single- and double-charge-exchange scattering to isobaric-analog states is reviewed. Interpretation of the optical-model parameters is briefly discussed, and several applications and extensions are considered. The applications include the study of various nuclear properties, including neutron deformation and surface-fluctuation contributions to the density. One promising extension for the near future would be to develop a microscopic approach based on powerful momentum-space methods brought to existence over the last decade. In this, the lowest-order optical potential as well as specific higher-order pieces would be worked out in terms of microscopic pion-nucleon and delta-nucleon interactions that can be determined within modern meson-theoretical frameworks. A second extension, of a more phenomenological nature, would use coupled-channel methods and shell-model wave functions to study dynamical nuclear correlations in pion double charge exchange. 35 refs., 11 figs., 1 tab
Parity nonconservation in polarized electron scattering at high energies
Energy Technology Data Exchange (ETDEWEB)
Prescott, C.Y.
1979-10-01
Recent observations of parity violation in inelastic scattering of electrons at high energy is discussed with reference to the process e(polarized) + D(unpolarized) ..-->.. e + X. The kinetics of this process, the idealized case of scattering from free quark targets, experimental techniques and results, and relations to atomic physics of parity violation in bismuth and thallium atoms with a model independent analysis. 17 references. (JFP)
Parity nonconservation in polarized electron scattering at high energies
International Nuclear Information System (INIS)
Prescott, C.Y.
1979-10-01
Recent observations of parity violation in inelastic scattering of electrons at high energy is discussed with reference to the process e(polarized) + D(unpolarized) → e + X. The kinetics of this process, the idealized case of scattering from free quark targets, experimental techniques and results, and relations to atomic physics of parity violation in bismuth and thallium atoms with a model independent analysis. 17 references
Elastic scattering of low energy electrons by hydrogen molecule
International Nuclear Information System (INIS)
Freitas, L.C.G.; Mu-Tao, L.; Botelho, L.F.
1987-01-01
The coherent version of the Renormalized Multiple-Centre Potential Model (RMPM) has been extended to treat the elastic scattering of low energy electrons by H2 molecule. The intramolecular Multiple Scattering (MS) effect has also been included. The comparison against the experimental data shows that the inclusion of the MS improves significantly with experiment. The extension of the present method to study electron-polyatomic molecule interaction is also discussed. (author) [pt
K-p elastic scattering at high energies
International Nuclear Information System (INIS)
Covolan, R.J.M.
1985-01-01
The K - p elastic scattering is analysed in the following energy range 4,5 ≤ √s ≤ 19,5 GeV. The scattering amplitude is supposed pure imaginary and a numerical fit of the differential cross section is made. By means of the Chou-Yang model is obtained the form factor and mean square radius of the K - and compared with the experimental data. (author) [pt
International Nuclear Information System (INIS)
Lindenbaum, S.J.
1988-01-01
The first experiment at the Nevis Cyclotron by Bernardini, Booth and Lindenbaum demonstrated that nuclear stars are produced by a nucleon-nucleon cascade within the nucleon. This solved a long standing problem in Cosmic rays and made it clear that where they overlap cosmic ray investigation would not be competitive with accelerator investigations. The initial experiments at the Brookhaven Cosmotron by Lindenbaum and Yuan demonstrated that low energy pion nucleon scattering and pion production were unexpectedly mostly due to excitation of the isotopic spin = angular momentum = 3/2 isobaric state of the nucleon. This contradicted the Fermi statistical theory and led to the Isobar model proposed by the author and a collaborator. The initial experiments at the AGS by the author and collaborators demonstrated that the Pomeronchuck Theorem would not come true till at least several hundred GeV. These scattering experiments led to the development of the ''On-line Computer Technique'' by the author and collaborators which is now the almost universal technique in high energy physics. The first accomplishment which flowed from this technique led to contradiction of the Regge pole theory as a dynamical asymptotic theory, by the author and collaborators. The first critical experimental proof of the forward dispersion relation in strong interactions was accomplished by the author and collaborators. They were then used as a crystal ball to predict that ''Asymptopia''---the theoretically promised land where all asymptotic theorems come true---would not be reached till at least 25,000 BeV and probably not before 1,000,000 BeV. 26 refs., 11 figs., 2 tabs
Scattering of polarized low-energy electrons by ferromagnetic metals
International Nuclear Information System (INIS)
Helman, J.S.
1981-01-01
A source of spin polarized electrons with remarkable characteristics based on negative electron affinity (NEA) GaAs has recently been developed. It constitutes a unique tool to investigate spin dependent interactions in electron scattering processes. The characteristics and working principles of the source are briefly described. Some theoretical aspects of the scattering of polarized low-energy electrons by ferromagnetic metals are discussed. Finally, the results of the first polarized low-energy electron diffraction experiment using the NEA GaAs source are reviewed; they give information about the surface magnetization of ferromagnetic Ni (110). (Author) [pt
Hard scattering in high-energy QCD
Mangano, Michelangelo L
2000-01-01
I review the recent results in the field of QCD at high energy presented to this Conference. In particular, I will concentrate on measurements of $\\as$ from studies of event structures and jet rates, jet production in hadronic collisions, and heavy quark production.
Incoherent scattering can favorably influence energy filtering in nanostructured thermoelectrics.
Singha, Aniket; Muralidharan, Bhaskaran
2017-08-11
Investigating in detail the physics of energy filtering through a single planar energy barrier in nanostructured thermoelectric generators, we reinforce the non-trivial result that the anticipated enhancement in generated power at a given efficiency via energy filtering is a characteristic of systems dominated by incoherent scattering and is absent in ballistic devices. In such cases, assuming an energy dependent relaxation time τ(E) = kE r , we show that there exists a minimum value r min beyond which generation can be enhanced by embedding nanobarriers. For bulk generators with embedded nanobarriers, we delve into the details of inter sub-band scattering and show that it has finite contribution to the enhancement in generation. We subsequently discuss the realistic aspects, such as the effect of smooth transmission cut-off and show that for r > r min , the optimized energy barrier is just sufficiently wide enough to scatter off low energy electrons, a very wide barrier being detrimental to the performance. Analysis of the obtained results should provide general design guidelines for enhancement in thermoelectric generation via energy filtering. Our non-equilibrium approach is typically valid in the absence of local quasi-equilibrium and hence sets the stage for future advancements in thermoelectric device analysis, for example, Peltier cooling near a barrier interface.
Scattering at zero energy for attractive homogeneous potentials
DEFF Research Database (Denmark)
Derezinski, Jan; Skibsted, Erik
2009-01-01
We compute up to a compact term the zero-energy scattering matrix for a class of potentials asymptotically behaving as −γ|x|−μ with 0 < μ < 2 and γ > 0. It turns out to be the propagator for the wave equation on the sphere at time ....
Scattered ionizing radiations from low-energy focus plasma and ...
Indian Academy of Sciences (India)
Scattered ionizing radiation emissions from a low-energy plasma focus (0.1. kJ Mather-type) device ... widely used in personnel moni- toring (dosimetry) service for ionizing radiation, medical, industrial and research ... Thermoluminescence dosimeter (TLD-500) (high sensitivity, simple re-use and minimum fading) chips are ...
Photon Scattering and Reflection in Diagnostic Energy Domain
International Nuclear Information System (INIS)
Simovic, R.; Markovic, S.; Ljubenov, V.; Ilic, R. D.
2008-01-01
Dependence of reflected photons angular and energy distributions on the parameter c' - probability for large angle scattering, is treated in this paper. Simulation of photon reflection was performed by the FOTELP code for a normal incidence of photons into infinite slabs of common shielding materials. (author)
Spin polarization effects in low-energy elastic electron scattering
International Nuclear Information System (INIS)
Beerlage, M.J.M.
1982-01-01
This work describes experiments on the role of spin polarization in elastic electron scattering. Chapter I introduces the topic and in chapter II elastic scattering of 10-50 eV electrons from Ar and Kr in the angular range between 40 0 and 110 0 is studied. Noble gases have been chosen as targets in view of their relative theoretical simplicity. Below 25 eV scattered intensities measured by various authors exhibit severe disagreements. However, in the entire energy range, the spin polarization results can reasonably well be used to point out the shortcomings of the available theoretical data. The main topic of chapter III is the first attempt to determine the magnitude of a polarization phenomenon - in elastic electron scattering from the optically active camphor molecule - of which the existence has recently been predicted qualitatively from the absence of parity symmetry in such molecules. Besides these studies on gaseous targets the author has initiated a scattering experiment on crystal surfaces, using spin polarized electrons. Within the framework of this project a large new experimental arrangement has been built up. It consists of a spin polarized electron source and a LEED scattering chamber. Design, construction and test results, showing the usefulness of the set-up, are described in the last chapter. (Auth.)
Low-energy positron scattering by pyrimidine
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Alessandra Souza; Pastega, Diego F.; Bettega, Márcio H. F., E-mail: bettega@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná (Brazil)
2015-12-28
This work reports elastic integral and differential cross sections for positron collisions with pyrimidine, for energies up to 20 eV. The cross sections were computed with the Schwinger multichannel method in the static plus polarization approximation. We also employed the Born closure procedure to account for the long range potential due to the permanent dipole moment of the molecule. Our results are compared with the experimental total cross section of Zecca et al. [J. Phys. B 43, 215204 (2010)], the experimental grand-total, quasi-elastic integral and differential cross section of Palihawadana et al. [Phys. Rev. A 88, 12717 (2013)]. We also compare our results with theoretical integral and differential cross sections obtained by Sanz et al. [Phys. Rev. A 88, 62704 (2013)] with the R-matrix and the independent atom model with screening-corrected additivity rule methods, and with the results computed by Franz and Gianturco [Phys. Rev. A 88, 042711 (2013)] using model correlation-polarization potentials. The agreement between the theory and the experiment is encouraging.
Elastic scattering and low PT physics at ISR energies
International Nuclear Information System (INIS)
Giacomelli, G.
1986-01-01
There is now a good knowledge of the forward parameters in pp and antipp elastic scattering at ISR energies. The experimental data suggest that in antipp elastic scattering the dip at /t/ ∼ 50 GeV. There are non statistical fluctuations for the average transverse momentum. The radius of the pion emitting region, as computed from the study of Bose-Einstein correlations, is the same for pp and antipp interactions. The multiplicity distribution in the KNO form has a y-dependence. 10 refs
Spin observables in proton-neutron scattering at intermediate energy
International Nuclear Information System (INIS)
Spinka, H.
1986-05-01
A summary of np elastic scattering spin measurements at intermediate energy is given. Preliminary results from a LAMPF experiment to measure free neutron-proton elastic scattering spin-spin correlation parameters are presented. A longitudinally polarized proton target was used. These measurements are part of a program to determine the neutron-proton amplitudes in a model independent fashion at 500, 650, and 800 MeV. Some new proton-proton total cross sections in pure helicity states (Δσ/sub L/(pp)) near 3 GeV/c are also given. 37 refs., 2 figs
Planckian energy scattering and surface terms in the gravitational action
Fabbrichesi, Marco E; Veneziano, Gabriele; Vilkovisky, G A
1994-01-01
This is a revised version of our previous paper by the same name and preprint number. It contains various changes, two figures and new results in sect.5. We propose a new approach to four-dimensional Planckian-energy scattering in which the phase of the ${\\cal S}$-matrix is written---to leading order in $\\hbar$ and to all orders in $R/b =Gs/J$---in terms of the surface term of the gravity action and of a boundary term for the colliding quanta. The proposal is checked at the leading order in $R/b$ and also against some known examples of scattering in strong gravitational fields.
Theoretical interpretation of medium energy nucleon nucleus inelastic scattering
International Nuclear Information System (INIS)
Lagrange, Christian
1970-06-01
A theoretical study is made of the medium energy nucleon-nucleus inelastic scattering (direct interaction), by applying the distorted wave Born approximation such as can be deduced from the paired equation method. It is applied to the interpretation of the inelastic scattering of 12 MeV protons by 63 Cu; this leads us to make use of different sets of wave functions to describe the various states of the target nucleus. We analyze the nature of these states and the shape of the nucleon-nucleus interaction potential, and we compare the results with those obtained from other theoretical and experimental work. (author) [fr
Multiple scattering in the nuclear rearrangement reactions at medium energy
International Nuclear Information System (INIS)
Tekou, A.
1980-09-01
It is shown that the multiple scattering mechanism is very important in the transfer of the large momenta involved in the nuclear rearrangement reactions at medium energy. In contrast to the usual belief, the reaction cross-section is not very sensitive to the high momenta components of the nuclear wave function. The multiple scattering mechanism is especially important in 4 He(p,d) 3 He reaction around 800 MeV. Here the collisions involving two nucleons of the target nucleus are dominant. The triple collisions contribution is also important. The four collision contribution is negligible in the forward direction and sizeable at large angles. Thus, using the K.M.T. approach in DWBA calculations, the second order term of the optical potential must be included. So, is it not well established that the second term of the K.M.T. optical potential is important for the proton elastic scattering on light nuclei. (author)
Parity nonconservation in proton scattering at higher energies
International Nuclear Information System (INIS)
Mischke, R.E.
1987-01-01
Parity-nonconservation experiments in the scattering of longitudinally-polarized protons at incident proton momenta of 1.5 GeV/c and 6 GeV/c are examined. These experiments indicate a change with energy of the total cross section correlated with proton helicity that was unexpected. This energy dependence is due to the strong part of the interaction and may indicate the role of a diquark component in the nucleon. New experiments at higher energies are needed to confirm such a model. Future experiments can benefit from an analysis of sources of systematic error that have been encountered in the experiments discussed here. 43 refs., 3 figs
Alpha-nucleus elastic scattering at intermediate energies
International Nuclear Information System (INIS)
Bonin, B.; Alamanos, N.; Berthier, B.; Bruge, G.; Faraggi, H.; Lugol, J.C.; Mittig, W.; Papineau, L.; Yavin, A.I.; Buenerd, M.; Bauhoff, W.
1985-01-01
Elastic scattering of 288, 340, 480 and 699 MeV Alpha-particles was measured on 208 Pb, 116 Sn and 58 Ni. The data were analysed in terms of a phenomenological optical model. The optical potentials obtained were found to vary consistently with the target nucleus and the incident energy. The radial zone where the potentials are well determined was studied in detail. The data for 208 Pb were also analysed with a folding model. The energy dependence of the strong-absorption radius and of the reaction cross section shows that the nuclear surface becomes slightly transparent for incident energies above 150 MeV per nucleon. (orig.)
Transverse energy distribution and hard constituent scattering in hadronic collisions
Directory of Open Access Journals (Sweden)
Torsten Åkesson
1983-01-01
Full Text Available We estimate the contributions to the total transverse energy spectrum from hard constituent scattering and the soft hadronic spectrum in hadron collisions. The transverse energy at which jet production starts to dominate is found to be essentially independent of the cms-energy (for large enough s and roughly a linear function of rapidity and azimuthal angle interval included. Calculations are presented for pp collisions at s= 25and60GeV, andp¯p interactions at s= 540GeV.
Large-angle hadron scattering at high energies
International Nuclear Information System (INIS)
Goloskokov, S.V.; Kudinov, A.V.; Kuleshov, S.P.
1981-01-01
Basing on the quasipotential Logunov-Tavkhelidze approach, corrections to the amplitude of high-energy large-angle meson-nucleon scattering are estimated. The estimates are compared with the available experimental data on pp- and π +- p-scattering, so as to check the adequacy of the suggested scheme to account for the preasymptotic deffects. The compared results are presented in the form of tables and graphs. The following conclusions are drawn: 1. the account for corrections, due to the long-range interaction, to the amplituda gives a good aghreee main asymptotic termment between the theoretical and experimental data. 2. in the case of π +- p- scattering the corrections prove to be comparable with the main asymptotic term up to the values of transferred pulses psub(lambdac)=50 GeV/c, which results in a noticeable deviation form the quark counting rules at such energies. Nevertheless, the preasymptotic formulae do well, beginning with psub(lambdac) approximately 6 GeV/c. In case of pp-scattering the corrections are mutually compensated to a considerable degree, and the deviation from the quark counting rules is negligible
Characteristic energy range of electron scattering due to plasmaspheric hiss
Ma, Q.; Li, W.; Thorne, R. M.; Bortnik, J.; Reeves, G. D.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Baker, D. N.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Angelopoulos, V.
2016-12-01
We investigate the characteristic energy range of electron flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic electron flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed energy of significant electron decay increases with decreasing L shell and is well correlated with the energy band corresponding to the first adiabatic invariant μ = 4-200 MeV/G. The electron diffusion coefficients due to hiss scattering are calculated at L = 2-6, and the modeled energy band of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed energy range of electron decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2-D Fokker-Planck simulation of the electron phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV-1 MeV electrons with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower energies and more flattened distributions at higher energies. Our study provides reasonable estimates of the electron populations that can be most significantly affected by plasmaspheric hiss and the consequent electron decay profiles.
Do we understand elastic scattering up to LHC energies?
Energy Technology Data Exchange (ETDEWEB)
Soffer, Jacques [Physics Department, Temple University, Philadelphia, PA 19122-6082 (United States)
2013-04-15
The measurements of high energy (bar sign)pp and pp elastic at ISR, SPS, and Tevatron colliders have provided usefull informations on the behavior of the scattering amplitude. A large step in energy domain is accomplished with the LHC collider presently running, giving a unique opportunity to improve our knowledge on the asymptotic regime of the elastic scattering amplitude and to verify the validity of our theoretical approach, to describe the total cross section {sigma}{sub tot}(s), the total elastic cross section {sigma}{sub el}(s), the ratio of the real to imaginary parts of the forward amplitude {rho}(s) and the differential cross section d{sigma} (s,t)/dt.
A theory of low energy π-3He elastic scattering
International Nuclear Information System (INIS)
Geffen, F.M.M. van.
1991-01-01
The main aim of this work is the construction of a first-order optical potential for the scattering of pions by 3 He at low energy with as few approximations as possible. In particular the Fermi motion is treated extremely carefully by using microscopic 3 He wave functions and by performing the complete Fermi-integral. Differential cross-sections and analyzing powers have been calculated. In a detailed comparison between the first-order optical with one which results from using the semi-factored approximation, it became clear that the latter has the following shortcomings: 1. the dependence of the subenergy on the pion-nucleus scattering angle, and 2. the independence of this energy on the relative motion of the spectator nucleons. (author). 101 refs.; 15 figs.; 3 tabs
Unifying logarithmic and factorial behavior in high-energy scattering
International Nuclear Information System (INIS)
Cornwall, J.M.; Morris, D.A.
1995-01-01
The elegant instanton calculus of Lipatov and others used to find factorially divergent behavior (g N N exclamation point) for N g much-gt 1 in gφ 4 perturbation theory is strictly only applicable when all external momenta vanish; a description of high-energy 2→N scattering with N massive particles is beyond the scope of such techniques. On the other hand, a standard multiperipheral treatment of scattering with its emphasis on leading logarithms gives a reasonable picture of high-energy behavior but does not result in factorial divergences. Using a straightforward graphical analysis we present a unified picture of both these phenomena as they occur in the two-particle total cross section of gφ 4 theory. We do not attempt to tame the unitarity violations associated with either multiperipheralism or the Lipatov technique at strong coupling
Supersymmetric quantum mechanics, phase equivalence, and low energy scattering anomalies
International Nuclear Information System (INIS)
Amado, R.D.; Cannata, F.; Dedonder, J.P.
1991-01-01
Supersymmetric quantum mechanics links two Hamiltonians with the same scattering (phase equivalence) but different number of bound states. We examine the Green's functions for these Hamiltonians as a prelude to embedding the two-body dynamics in a many-body system. We study the effect of the elimination of a two-body bound state near zero energy for the Efimov effect and Beg's theorem
Recent developments on high-energy gravitational scattering
CERN. Geneva
2015-01-01
After a quick reminder of earlier results I will discuss some recent progress in the high-energy gravitational scattering of particles, strings, and branes and, in particular: 1. Gravitational bremsstrahlung; 2. Causality constraints in the presence of higher derivative corrections; 3. Absorption of an energetic closed string by a stack of D-branes. These developments should eventually help us understand how information is preserved in the quantum analog of classical gravitational collapse.
Muon energy estimate through multiple scattering with the MACRO detector
Energy Technology Data Exchange (ETDEWEB)
Ambrosio, M.; Antolini, R.; Auriemma, G.; Bakari, D.; Baldini, A.; Barbarino, G.C.; Barish, B.C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bloise, C.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Candela, A.; Carboni, M.; Caruso, R.; Cassese, F.; Cecchini, S.; Cei, F.; Chiarella, V.; Choudhary, B.C.; Coutu, S.; Cozzi, M.; De Cataldo, G.; De Deo, M.; Dekhissi, H.; De Marzo, C.; De Mitri, I.; Derkaoui, J.; De Vincenzi, M.; Di Credico, A.; Dincecco, M.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Gray, L.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D.S.; Lindozzi, M.; Lipari, P.; Longley, N.P.; Longo, M.J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M.N.; Michael, D.G.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolo, D.; Nolty, R.; Orth, C.; Osteria, G.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C.W.; Perrone, L.; Petrera, S.; Pistilli, P.; Popa, V.; Raino, A.; Reynoldson, J.; Ronga, F.; Rrhioua, A.; Satriano, C.; Scapparone, E. E-mail: eugenio.scapparone@bo.infn.it; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M. E-mail: maximiliano.sioli@bo.infn.it; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J.L.; Sulak, L.R.; Surdo, A.; Tarle, G.; Tatananni, E.; Togo, V.; Vakili, M.; Walter, C.W.; Webb, R
2002-10-21
Muon energy measurement represents an important issue for any experiment addressing neutrino-induced up-going muon studies. Since the neutrino oscillation probability depends on the neutrino energy, a measurement of the muon energy adds an important piece of information concerning the neutrino system. We show in this paper how the MACRO limited streamer tube system can be operated in drift mode by using the TDCs included in the QTPs, an electronics designed for magnetic monopole search. An improvement of the space resolution is obtained, through an analysis of the multiple scattering of muon tracks as they pass through our detector. This information can be used further to obtain an estimate of the energy of muons crossing the detector. Here we present the results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines, to provide a full check of the electronics and to exploit the feasibility of such a multiple scattering analysis. We show that by using a neural network approach, we are able to reconstruct the muon energy for E{sub {mu}}<40 GeV. The test beam data provide an absolute energy calibration, which allows us to apply this method to MACRO data.
8B + 208Pb Elastic Scattering at Coulomb Barrier Energies
La Commara, M.; Mazzocco, M.; Boiano, A.; Boiano, C.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Signorini, C.; Strano, E.; Torresi, D.; Yamaguchi, H.; Kahl, D.; Di Meo, P.; Grebosz, J.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Iwasa, N.; Jeong, S. C.; Jia, H. M.; Kim, Y. H.; Kimura, S.; Kubono, S.; Lin, C. J.; Miyatake, H.; Mukai, M.; Nakao, T.; Nicoletto, M.; Sakaguchi, Y.; Sánchez-Benítez, A. M.; Soramel, F.; Teranishi, T.; Wakabayashi, Y.; Watanabe, Y. X.; Yang, L.; Yang, Y. Y.
2018-02-01
The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (Sp = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.
CT energy weighting in the presence of scatter and limited energy resolution
Energy Technology Data Exchange (ETDEWEB)
Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53201 (United States)
2010-03-15
Purpose: Energy-resolved CT has the potential to improve the contrast-to-noise ratio (CNR) through optimal weighting of photons detected in energy bins. In general, optimal weighting gives higher weight to the lower energy photons that contain the most contrast information. However, low-energy photons are generally most corrupted by scatter and spectrum tailing, an effect caused by the limited energy resolution of the detector. This article first quantifies the effects of spectrum tailing on energy-resolved data, which may also be beneficial for material decomposition applications. Subsequently, the combined effects of energy weighting, spectrum tailing, and scatter are investigated through simulations. Methods: The study first investigated the effects of spectrum tailing on the estimated attenuation coefficients of homogeneous slab objects. Next, the study compared the CNR and artifact performance of images simulated with varying levels of scatter and spectrum tailing effects, and reconstructed with energy integrating, photon-counting, and two optimal linear weighting methods: Projection-based and image-based weighting. Realistic detector energy-response functions were simulated based on a previously proposed model. The energy-response functions represent the probability that a photon incident on the detector at a particular energy will be detected at a different energy. Realistic scatter was simulated with Monte Carlo methods. Results: Spectrum tailing resulted in a negative shift in the estimated attenuation coefficient of slab objects compared to an ideal detector. The magnitude of the shift varied with material composition, increased with material thickness, and decreased with photon energy. Spectrum tailing caused cupping artifacts and CT number inaccuracies in images reconstructed with optimal energy weighting, and did not impact images reconstructed with photon counting weighting. Spectrum tailing did not significantly impact the CNR in reconstructed images
CT energy weighting in the presence of scatter and limited energy resolution
International Nuclear Information System (INIS)
Schmidt, Taly Gilat
2010-01-01
Purpose: Energy-resolved CT has the potential to improve the contrast-to-noise ratio (CNR) through optimal weighting of photons detected in energy bins. In general, optimal weighting gives higher weight to the lower energy photons that contain the most contrast information. However, low-energy photons are generally most corrupted by scatter and spectrum tailing, an effect caused by the limited energy resolution of the detector. This article first quantifies the effects of spectrum tailing on energy-resolved data, which may also be beneficial for material decomposition applications. Subsequently, the combined effects of energy weighting, spectrum tailing, and scatter are investigated through simulations. Methods: The study first investigated the effects of spectrum tailing on the estimated attenuation coefficients of homogeneous slab objects. Next, the study compared the CNR and artifact performance of images simulated with varying levels of scatter and spectrum tailing effects, and reconstructed with energy integrating, photon-counting, and two optimal linear weighting methods: Projection-based and image-based weighting. Realistic detector energy-response functions were simulated based on a previously proposed model. The energy-response functions represent the probability that a photon incident on the detector at a particular energy will be detected at a different energy. Realistic scatter was simulated with Monte Carlo methods. Results: Spectrum tailing resulted in a negative shift in the estimated attenuation coefficient of slab objects compared to an ideal detector. The magnitude of the shift varied with material composition, increased with material thickness, and decreased with photon energy. Spectrum tailing caused cupping artifacts and CT number inaccuracies in images reconstructed with optimal energy weighting, and did not impact images reconstructed with photon counting weighting. Spectrum tailing did not significantly impact the CNR in reconstructed images
Muon energy estimate through multiple scattering with the MACRO detector
Ambrosio, M; Auriemma, G; Bakari, D; Baldini, A; Barbarino, G C; Barish, B C; Battistoni, G; Becherini, Y; Bellotti, R; Bemporad, C; Bernardini, P; Bilokon, H; Bloise, C; Bower, C; Brigida, M; Bussino, S; Cafagna, F; Calicchio, M; Campana, D; Candela, A; Carboni, M; Caruso, R; Cassese, F; Cecchini, S; Cei, F; Chiarella, V; Choudhary, B C; Coutu, S; Cozzi, M; De Cataldo, G; De Deo, M; Dekhissi, H; De Marzo, C; De Mitri, I; Derkaoui, J; De Vincenzi, M; Di Credico, A; Dincecco, M; Erriquez, O; Favuzzi, C; Forti, C; Fusco, P; Giacomelli, G; Giannini, G; Giglietto, N; Giorgini, M; Grassi, M; Gray, L; Grillo, A; Guarino, F; Gustavino, C; Habig, A; Hanson, K; Heinz, R; Iarocci, E; Katsavounidis, E; Katsavounidis, I; Kearns, E; Kim, H; Kyriazopoulou, S; Lamanna, E; Lane, C; Levin, D S; Lindozzi, M; Lipari, P; Longley, N P; Longo, M J; Loparco, F; Maaroufi, F; Mancarella, G; Mandrioli, G; Margiotta, A; Marini, A; Martello, D; Marzari-Chiesa, A; Mazziotta, M N; Michael, D G; Monacelli, P; Montaruli, T; Monteno, M; Mufson, S; Musser, J; Nicolò, D; Nolty, R; Orth, C; Osteria, G; Palamara, O; Patera, V; Patrizii, L; Pazzi, R; Peck, C W; Perrone, L; Petrera, S; Pistilli, P; Popa, V; Rainó, A; Reynoldson, J; Ronga, F; Rrhioua, A; Satriano, C; Scapparone, E; Scholberg, K; Sciubba, A; Serra, P; Sioli, M; Sirri, G; Sitta, M; Spinelli, P; Spinetti, M; Spurio, M; Steinberg, R; Stone, J L; Sulak, L R; Surdo, A; Tarle, G; Tatananni, E; Togo, V; Vakili, M; Walter, C W; Webb, R
2002-01-01
Muon energy measurement represents an important issue for any experiment addressing neutrino-induced up-going muon studies. Since the neutrino oscillation probability depends on the neutrino energy, a measurement of the muon energy adds an important piece of information concerning the neutrino system. We show in this paper how the MACRO limited streamer tube system can be operated in drift mode by using the TDCs included in the QTPs, an electronics designed for magnetic monopole search. An improvement of the space resolution is obtained, through an analysis of the multiple scattering of muon tracks as they pass through our detector. This information can be used further to obtain an estimate of the energy of muons crossing the detector. Here we present the results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines, to provide a full check of the electronics and to exploit the feasibility of such a multiple scattering analysis. We show that by using a neural network approach, we are able to r...
Precocious scaling in antiproton-proton scattering at low energies
International Nuclear Information System (INIS)
Ion, D.B.; Petrascu, C.; Topor Pop, V.; Popa, V.
1993-08-01
The scaling of the diffraction peak in antiproton-proton scattering has been investigated from nera threshold up to 3 GeV/c laboratory momenta. It was shown that the scaling of the differential cross sections are evidentiated with a surprising accuracy not only at high energies, but also at very low ones (e.g. p LAB = 0.1 - 0.5 GeV/c), beyond the resonance and exotic resonance regions. This precocious scaling strongly suggests that the s-channel helicity conservation (SCHC) can be a peculiar property that should be tested in antiproton-proton interaction not only at high energies but also at low energy even below p LAB = 1 GeV/c. (author). 36 refs, 9 figs
Protons scattering on Li isotopes at intermediate energies
International Nuclear Information System (INIS)
Zhusupov, M.A.; Imambekov, O.; Sanfirova, A.V.; Ibraeva, E.T.
2003-01-01
The protons scattering differential cross section on the 6,7,8 Li nuclei are calculated within the framework the Glauber-Sitenko multiple scattering theory at intermediate energies (from 100 to 1000 MeV). In the calculations the multi-cluster wave functions (αt for 7 Li, αnp for 6 Li, and αtn for 8 Li) considering within potential cluster model have been used. Differential cross sections for 6 Li, 7 Li, 8 Li and 9 Li nuclei are similar: absolute cross sections are almost the same, diffraction minimum for large A shifting to the field of the least scattering angles that reflecting increase of the material radius. For the 11 Li the differential cross section absolute value is smaller about in two time than for the rest isotopes. At present it is reliably established, that the 11 Li nucleus has an exotic structure - the nine-nucleon core ( 9 Li) around which the two-neutron halo is rotating. The principal characteristics of the Li nuclei are presented in tabular form
Low-energy electron scattering from molecules, biomolecules and surfaces
Carsky, Petr
2011-01-01
Since the turn of the 21st century, the field of electron molecule collisions has undergone a renaissance. The importance of such collisions in applications from radiation chemistry to astrochemistry has flowered, and their role in industrial processes such as plasma technology and lighting are vital to the advancement of next generation devices. Furthermore, the development of the scanning tunneling microscope highlights the role of such collisions in the condensed phase, in surface processing, and in the development of nanotechnology.Low-Energy Electron Scattering from Molecules, Biomolecule
Construction of two-dimensional Schrodinger operator with given scattering amplitude at fixed energy
International Nuclear Information System (INIS)
Novikov, R.G.
1986-01-01
The classical necessary properties of the scattering amplitude (reciprocity and unitarity) are, provided its L 2 norm is small, sufficient for the existence of a two-dimensional Schrodinger operator with the given scattering amplitude at fixed energy
The effects of low-energy scattering on positron implantation
Energy Technology Data Exchange (ETDEWEB)
Ritley, K.A. (Dept. of Physics and Materials Research Laboratory, Univ. of Illinois, Urbana, IL (United States)); Lynn, K.G.; Ghosh, V.; Welch, D.O. (Brookhaven National Lab., Upton, NY (United States))
1992-01-01
Existing Monte Carlo models are capable of simulating the behavior of positrons incident at keV energies, then following the energy loss process to arbitrary final kinetic energies of from 20 eV to 100 eV. This work describes a Monte Carlo simulation of the final stages of positron thermalization in Al, from 25 eV to thermal energies, via the mechanisms of conduction-electron and longitudinal acoustic phonon scattering. The latter stages of thermalization can have important effects on the stopping profiles and mean depth. A novel way to obtain information about positron energy loss by considering the time-evolution of a point-concentration (delta-function distribution) of positrons is described. The effects of a positive positron work function are examined for the first time in the context of a positron Monte Carlo calculation. Finally, some issues relating to the agreement of Monte Carlo calculations with experimental data are discussed. 6 figs., 16 refs.
The effects of low-energy scattering on positron implantation
Energy Technology Data Exchange (ETDEWEB)
Ritley, K.A. [Dept. of Physics and Materials Research Laboratory, Univ. of Illinois, Urbana, IL (United States); Lynn, K.G.; Ghosh, V.; Welch, D.O. [Brookhaven National Lab., Upton, NY (United States)
1992-12-31
Existing Monte Carlo models are capable of simulating the behavior of positrons incident at keV energies, then following the energy loss process to arbitrary final kinetic energies of from 20 eV to 100 eV. This work describes a Monte Carlo simulation of the final stages of positron thermalization in Al, from 25 eV to thermal energies, via the mechanisms of conduction-electron and longitudinal acoustic phonon scattering. The latter stages of thermalization can have important effects on the stopping profiles and mean depth. A novel way to obtain information about positron energy loss by considering the time-evolution of a point-concentration (delta-function distribution) of positrons is described. The effects of a positive positron work function are examined for the first time in the context of a positron Monte Carlo calculation. Finally, some issues relating to the agreement of Monte Carlo calculations with experimental data are discussed. 6 figs., 16 refs.
Analysis of α-12C elastic scattering at intermediate energies by the S-matrix model
Berezhnoy, Yu. A.; Onyshchenko, G. M.; Pilipenko, V. V.
The results of calculations of differential cross-sections for α-12C elastic scattering by the S-matrix model are presented for 10 energy values in the energy range 65MeV ≤ Eα ≤ 386MeV in a wide range of scattering angles. The behavior of various scattering characteristics as functions of the projectile energy is analyzed. It is shown that the chosen parametrization of S-matrix allows describing correctly the Fraunhofer oscillations of the cross-sections in the region of small scattering angles and the rainbow scattering pattern in the region of sufficiently large angles.
International Nuclear Information System (INIS)
Floyd, C.E.; Beatty, P.T.; Ravin, C.E.
1988-01-01
The Fourier deconvolution algorithm for scatter compensation in digital chest radiography has been evaluated in four anatomically different regions at three energies. A shift invariant scatter distribution shape, optimized for the lung region at 140 kVp, was applied at 90 kVp and 120 kVp in the lung, retrocardiac, subdiaphragmatic, and thoracic spine regions. Scatter estimates from the deconvolution were compared with measured values. While some regional variation is apparent, the use of a shift invariant scatter distribution shape (optimized for a given energy) produces reasonable scatter compensation in the chest. A different set of deconvolution parameters were required at the different energies
Energy loss of light ions scattered off Al(110) single crystal surfaces at low energy
Hausmann, S; Hofner, C; Schlathölter, Thomas; Franke, H; Narmann, A; Heiland, W
We present energy loss data taken after grazing incidence scattering of H+, H-0, He2+, He+, and He-0 off an Al(110) surface, The data is evaluated by means of a procedure that allows to extract surface electron density parameters. The obtained density parameters will be compared to those obtained
High-energy scatterings of many electroweak gauge bosons
International Nuclear Information System (INIS)
Dunn, C.; Yan, T.M.
1991-01-01
We present an application of the equivalence theorem and the multispinor representation of gauge fields to the standard model of electroweak interactions at very high energies. The equivalence theorem allows us to efficiently treat the longitudinal vector bosons while the multispinor formalism makes the transverse vector bosons easy to handle. We generalize the work of Berends and Giele to derive a recursion relation for a current consisting of a pair of longitudinal vector bosons plus any number of transverse vector bosons. It is shown that for longitudinal vector bosons plus any number of transverse vector bosons. Consideration of a U(N), rather than an SU(N), gauge theory enables us to incorporate the mixing in the SU(2)xU(1) electroweak theory and to derive certain sum rules for the currents for transverse gauge bosons. We also give explicit expressions for four-particle and five-particle scattering amplitudes involving a pair of longitudinal vector bosons. (orig.)
p-barp elastic scattering at high energies
International Nuclear Information System (INIS)
Padua, A.B. de.
1986-01-01
The p-bar p elastic scattering is analysed in the energy range 9.78 pp werefitted under the hypothesis of a pure imaginary amplitude and writted as a sum of exponentials, that is, a(s,t) = a(s,O) Σ n i=l α i exp β i t. Using the parameters a(s,O), α i and β i we obtained the absorption constante K- pp , the form factor and the mean square radius of the - p matter distribution by the Chou-Yang model. These calculations reveal a dip around -t ≅ 1.3 (GeV/c) 2 at 31 and 62 GeV. (author) [pt
On selection rules and inelastic electron scattering at intermediate energies
International Nuclear Information System (INIS)
Nuroh, K.
1986-12-01
Correlation effects are included in the Bethe-Born theory for the generalized oscillator strength of inelastic scattering of electrons on atoms. The formulation is such as to allow for the calculation of relative line strengths of multiplets. It is used to analyze line strengths of the 4d → 4f transition in La 3+ and Ce 4+ within LS-coupling. The analysis indicates that only singlet states of the intermediate 4d 9 4f configuration are allowed. Calculated line strengths are compared with a recent core electron energy loss spectra of metallic La and tetravalent CeO 2 and there is an overall qualitative agreement between theory and experiment. (author). 11 refs, 4 figs, 2 tabs
Scattering of low-energy pions by p-shell nuclei
International Nuclear Information System (INIS)
Khankhasaev, M.Kh.
1987-01-01
Low-energy pion-carbon scattering (up to 50 MeV) is analysed in the framework of the unitary approach based on the method of evolution in the coupling constant. It is shown that at pion energy ∼ 50 MeV the differential cross section arises as a result of the strong interference between the pure potential scattering and absorption channels. In this energy region the scattering data are very sensitive to the dynamics of the pion-nucleus interaction
International Nuclear Information System (INIS)
Rolfe, R.M.
1976-12-01
The goal of the research was to investigate proton scattering on nuclei at intermediate energies and in particular to investigate proton scattering on helium. A theoretical investigation of the helium nucleus and the nature of the intermediate energy interaction, design and optimization of an energy-loss spectrometer facility for proton-nucleus scattering, and the unique superfluid helium target and experimental design are discussed
International Nuclear Information System (INIS)
Durand, Gerard.
1974-01-01
First the different theories used for studying pion-nucleus scattering and especially Glauber microscopic model and Kisslinger optical model are summarized. From the comparison of these two theories it was concluded that Kisslinger's was better for studying pion-nucleus scattering near the (3/2-3/2) resonance. The potential was developed, with a local corrective term, proposed by this author. This new term arises from taking into account correctly the Lorentz transformation from the pion-nucleon center of mass to the pion nucleus center of mass system. A coupled-channel formalism was developed allowing the study of pion-nucleus elastic scattering and also the study of single and double charge exchange reactions on nucleus with N>Z. The influence of the new term and the shape of nucleon densities on π- 12 C scattering was studied near 200MeV. It was found that at the nucleus surface the neutron density was larger than the proton density. On the other hand, a maximum of sensibility to the different nuclear parameters was found near 180MeV and for elastic scattering angles greater than 100 deg. The calculations of the total cross section for simple and double charge exchange for 13 C and 63 Cu yielded results simular to those of previous theories and showed the same discrepancy between theory and experiment in the resonance region [fr
Assessment of Coulomb shifts in nucleon scattering resonances on light nuclei at low energies
International Nuclear Information System (INIS)
Takibaev, N.Zh.; Uzakova, Zh.; Abdanova, L.
2003-01-01
The assessments of the Coulomb forces contribution to position and width of the resonances at nucleons scattering on light nuclei within low energy field are given. In particular the shifts of resonances in amplitudes arising in the processes protons scattering on light nuclei relatively neutrons scattering resonance characteristics on these nuclei are considered
Measurements of the electron energy spectrum by using small-angle Thomson scattering
International Nuclear Information System (INIS)
Popov, S. S.; Burdakov, A. V.; Vyacheslavov, L. N.; Ivantsivskii, M. V.; Ovchar, V. K.; Polosatkin, S. V.; Rovenskikh, A. F.; Fedotov, M. G.
2008-01-01
A novel diagnostic method is developed for studying the high-energy plasma electron component in the GOL-3 facility by using small-angle Thomson scattering. The method is based on the enhancement of the spectral density of scattered radiation as compared to the conventional large-angle scattering technique.
Measurements of the electron energy spectrum by using small-angle Thomson scattering
Popov, S. S.; Burdakov, A. V.; Vyacheslavov, L. N.; Ivantsivskii, M. V.; Ovchar, V. K.; Polosatkin, S. V.; Rovenskikh, A. F.; Fedotov, M. G.
2008-03-01
A novel diagnostic method is developed for studying the high-energy plasma electron component in the GOL-3 facility by using small-angle Thomson scattering. The method is based on the enhancement of the spectral density of scattered radiation as compared to the conventional large-angle scattering technique.
Energy spectrum of Compton scattering of laser photons on relativistic electrons
International Nuclear Information System (INIS)
Ando, Hiroaki; Yoneda, Yasuharu
1976-01-01
The high energy photons in gamma-ray region are obtainable by the Compton scattering of laser photons on relativistic electrons. But the motion of the electrons in the storage ring is not necessarily uniform. In the study of the uneven effect, the energy distribution of scattered photons is derived from the assumed momentum distribution of incident electrons. It is generally impossible to derive the momentum distribution of incident electrons from the energy spectrum of scattered photons. The additional conditions which make this possible in a special case are considered. A calculational method is examined for deriving the energy spectrum of scattered photons from the assumed momentum distribution of incident electrons. (Mori, K.)
International Nuclear Information System (INIS)
Agre, M.Ya.
1996-01-01
A compact expression for the cross section of light scattering by aligned atomic systems is derived. It is shown that in above-threshold or resonant scattering, when the channel of luminous energy dissipation is open, circular dichroism effects can be observed in the angular distribution and the degree of polarization of the scattered light. In such cases circular polarization of the scattered light is also induced when the incident light has no circular polarization
High-energy scaling of Compton scattering light sources
Directory of Open Access Journals (Sweden)
F. V. Hartemann
2005-10-01
Full Text Available No monochromatic (Δω_{x}/ω_{x}10^{20} photons/(mm^{2}×mrad^{2}×s×0.1% bandwidth], tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray and γ-ray sources include the following: nuclear resonance fluorescence spectroscopy and isotopic imaging, time-resolved positron annihilation spectroscopy, and MeV flash radiography. In this paper, the peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale quadratically with the normalized energy, γ; inversely with the electron beam duration, Δτ, and the square of its normalized emittance, ε; and linearly with the bunch charge, eN_{e}, and the number of photons in the laser pulse, N_{γ}: B[over ^]_{x}∝γ^{2}N_{e}N_{γ}/ε^{2}Δτ. This γ^{2} scaling shows that for low normalized emittance electron beams (1 nC, 1 mm·mrad, 100 MeV, and tabletop laser systems (1–10 J, 5 ps the x-ray peak brightness can exceed 10^{23} photons/(mm^{2}×mrad^{2}×s×0.1% bandwidth near ℏω_{x}=1 MeV; this is confirmed by three-dimensional codes that have been benchmarked against Compton scattering experiments performed at Lawrence Livermore National Laboratory. The interaction geometry under consideration is head-on collisions, where the x-ray flash duration is shown to be equal to that of the electron bunch, and which produce the highest peak brightness for compressed electron beams. Important nonlinear effects, including spectral broadening, are also taken into account in our analysis; they show that there is an optimum laser pulse duration in this geometry, of the order of a few picoseconds, in sharp contrast with the initial approach to laser-driven Compton scattering sources where femtosecond laser systems were thought to be mandatory. The analytical expression for the peak on-axis brightness derived here is a powerful tool to
High energy deep inelastic scattering in perturbative quantum chromodynamics
International Nuclear Information System (INIS)
Wallon, S.
1996-01-01
In this PhD thesis, we deal with high energy Deep Inelastic Scattering in Perturbative Quantum Chromodynamics (QCD). In this work, two main topics are emphasized: The first one deals with dynamics based on perturbative renormalization group, and on perturbative Regge approaches. We discuss the applicability of these predictions, the possibility of distinguishing them in the HERA experiments, and their unification. We prove that the perturbative Regge dynamic can be successfully applied to describe the HERA data. Different observables are proposed for distinguishing these two approaches. We show that these two predictions can be unified in a system of equations. In the second one, unitarization and saturation problems in high energy QCD are discussed. In the multi-Regge approach, equivalent to the integrable one-dimensional XXX Heisenberg spin chain, we develop methods in order to solve this system, based on the Functional Bethe Ansatz. In the dipole model context, we propose a new formulation of unitarity and saturation effects, using Wilson loops. (author)
Unitary scattering theory of low-energy pions by light nuclei: applications
International Nuclear Information System (INIS)
Khankhasaev, M.Kh.
1989-01-01
The results of a unified description of both the low-energy scattering data and the pionic atom data for 4 He, 12 C and 16 O within the framework of the unitary scattering-approach are presented. Strong influence of the pion absorption on the elastic scattering channel at low energies is demonstrated. It is shown that a unique set of parameters of the absorption correction provides good quantitative description of the pion elastic scattering data at energies up to 50 MeV. 48 refs.; 13 figs.; 6 tabs
Positive energy Weinberg states for the solution of scattering problems
International Nuclear Information System (INIS)
Rawitscher, G.
1982-01-01
Positive energy Weinberg states are defined and numerically calculated in the presence of a general complex Woods-Saxon potential. The numerical procedure is checked for the limit of a square well potential for which the Weinberg states and the corresponding eigenvalues are known. A finite number M of these (auxiliary) positive energy Weinberg states are then use as a set of basis functions in order to provide a separable approximation of rank M, V/sub M/, to a potential V, and also to the scattering matrix element S which obtains as a result of the presence of V, S/sub M/. Both V/sub M/ and S/sub M/ are obtained by means of algebraic manipulations which involve the matrix elements of V calculated in terms of the auxiliary postive energy Weinberg states Next, expressions are derived which enable one to iteratively correct for the error in V--V/sub M/. These expressions are a modified version of the quasi-particle method of Weinberg. The convergence of S/sub M/ to S, as well as the first order interation of the error in S/sub M/ is examined as a function M for a numerical example which uses a complex Woods-Saxon potential for V and assumes zero angular momentum. With M = 5 and one iteration an error of less than 10% in S is achieved; for M = 8 the error is less than 1%. The method is expected to be useful for the solution of large systems of coupled equations by matrix techniques or when a part of the potential is non-local
International Nuclear Information System (INIS)
Broome, J.
1965-11-01
The programme SCATTER is a KDF9 programme in the Egtran dialect of Fortran to generate normalized angular distributions for elastically scattered neutrons from data input as the coefficients of a Legendre polynomial series, or from differential cross-section data. Also, differential cross-section data may be analysed to produce Legendre polynomial coefficients. Output on cards punched in the format of the U.K. A. E. A. Nuclear Data Library is optional. (author)
High energy x-ray reflectivity and scattering study from spectrum-x-gamma flight mirrors
DEFF Research Database (Denmark)
Christensen, Finn Erland; Budtz-Jørgensen, Carl; Frederiksen, P. Kk
1993-01-01
Line radiation from Fe K-alpha(1), Cu K-alpha(1), and Ag K-alpha(1) is used to study the high energy X-ray reflectivity and scattering behavior of flight-quality X-ray mirrors having various Al substrates. When both the specular and the scattered radiation are integrated, near theoretical...... reflectivities are found for all mirrors. Results of scattering studies show that scattering is strongly correlated with the Al foil type. Mirrors based on new 0.4 mm Al foil are found to have a typical scattering FWHM of about 1.1 arcmin, whereas mirrors based on 0.3 mm Al foil have an FWHM of greater than 1.......5 arcmin. For all mirrors and for all energies, the scattering is found to exhibit the characteristic asymmetries predicted by a first order vector scattering theory....
On low energy scattering theory with Coulomb potentials
International Nuclear Information System (INIS)
Gibson, A.G.
1985-09-01
The scattering length is a very useful characteristic of the scattering phenomena. But in the presence of a combined potential (e.g. in nuclear physics, when Coulomb, the polarization and the strong potentials are to be added), the analytical definition of the scattering length in not unambigous and strictly defined. This problem is discussed in detail, the various alternatives are examined and compared. A practical suggestion is given for the proper choice of the definition and for the calculation of scattering length. Numerical solutions of the Schroedinger equation are compared with the results of different definitions. Some questions of application to nuclear physics are discussed. (D.Gy.)
International Nuclear Information System (INIS)
Narita, Yuichiro; Iida, Hidehiro
1999-01-01
Accuracy and limitation of energy-window based scatter correction techniques have been evaluated for myocardial 201 Tl SPECT by means of Monte Carlo simulation. In particular, projection view-dependency of energy distribution of the scattered photons was evaluated. Two geometrical configurations were simulated; namely a homogeneous cylindrical radioactivity located asymmetrically in a homogeneous cylindrical phantom, and a homogeneous ring radioactivity positioned at the myocardial region of a human thorax phantom. Energy spectra were recorded for each projection, and accuracy of the triple-energy window (TEW) method was then evaluation for both phantoms. The energy distribution of the scattered photons was apparently dependent on the projection view. TEW also demonstrated systematic overcorrection for the scatter because of multiple photo peaks around 80 keV, and more importantly, the error was highly dependent on the projection view. The error reached to 35-38% for the view that is the closest to the 201 Tl radioactivity (anterior view in case of the myocardial ring phantom), and was approximately 20% in the opposite view. This view-dependency of the error remained for other energy window settings, and was found to cause significant artifact in the reconstructed myocardial images, typically causing a defect in the anterior myocardial wall. Thus, this study demonstrated the need for optimizing the window settings for each projection view in all energy window-based scatter correction methods. (author)
Phonon Surface Scattering and Thermal Energy Distribution in Superlattices.
Kothari, Kartik; Maldovan, Martin
2017-07-17
Thermal transport at small length scales has attracted significant attention in recent years and various experimental and theoretical methods have been developed to establish the reduced thermal conductivity. The fundamental understanding of how phonons move and the physical mechanisms behind nanoscale thermal transport, however, remains poorly understood. Here we move beyond thermal conductivity calculations and provide a rigorous and comprehensive physical description of thermal phonon transport in superlattices by solving the Boltzmann transport equation and using the Beckman-Kirchhoff surface scattering theory with shadowing to precisely describe phonon-surface interactions. We show that thermal transport in superlattices can be divided in two different heat transport modes having different physical properties at small length scales: layer-restricted and extended heat modes. We study how interface conditions, periodicity, and composition can be used to manipulate the distribution of thermal energy flow among such layer-restricted and extended heat modes. From predicted frequency and mean free path spectra of superlattices, we also investigate the existence of wave effects. The results and insights in this paper advance the fundamental understanding of heat transport in superlattices and the prospects of rationally designing thermal systems with tailored phonon transport properties.
Low energy K+scattering on N = Z nuclei
Indian Academy of Sciences (India)
periments, to measure these cross-sections, were carried out at Brookhaven National Lab- oratory. Whereas the total K·–12C scattering cross-sections had been ... Koltun [7] have incorporated the contribution of K· scattering on the virtual pion present in the nucleus. This additional contribution lifts the cross-section towards ...
Multiple scattering of low energy ions in matter: Influence of energy loss and interaction potential
Energy Technology Data Exchange (ETDEWEB)
Mekhtiche, A. [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria); Faculté des Sciences et de la Technologie, Université Yahia Farès de Médéa (Algeria); Khalal-Kouache, K., E-mail: kkouache@yahoo.fr [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria)
2015-07-01
In this paper, the effect of inelastic energy loss and interaction potential on transmitted ions at low energy is studied. For this purpose, angular distributions of slow He{sup +} ions transmitted through thin Ag films are calculated using the theory of multiple scattering. Thin films (20–50 Å at 2 keV and 50–200 Å at 10 keV) are considered so that the total path length of transmitted ions can be approximated by the value of the target thickness in this calculation. The corresponding values of the relative energy loss ΔE/E are comprised between 0.04 and 0.17. We show that even if low values of the thickness are considered, the total energy loss of ions in the target should be included in the calculation. These calculated angular distributions are also influenced by the potential used to describe the interaction between the incident ion and the target atom.
Gou, F.; Gleeson, M. A.; Kleyn, A. W.
2006-01-01
We have simulated CF scattering from Si(100) using the molecular dynamics method. Translational energy loss spectra are presented. The shape of the energy loss distribution as a result of internal energy release is analyzed. At the classical turning point, the internal energy of the molecule is
Characterizing the behavior of scattered radiation in multi-energy x-ray imaging
Energy Technology Data Exchange (ETDEWEB)
Sossin, Artur, E-mail: artur.sossin@gmail.com [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Rebuffel, V.; Tabary, J. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Univ Lyon, INSA-Lyon, Université Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Centre Léon Bérard, CREATIS UMR 5220 U1206, F-69373 Lyon (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)
2017-04-01
Scattered radiation results in various undesirable effects in medical diagnostics, non-destructive testing (NDT) and security x-ray imaging. Despite numerous studies characterizing this phenomenon and its effects, the knowledge of its behavior in the energy domain remains limited. The present study aims at summarizing some key insights on scattered radiation originating from the inspected object. In addition, various simulations and experiments with limited collimation on both simplified and realistic phantoms were conducted in order to study scatter behavior in multi-energy x-ray imaging. Results showed that the spectrum shape of the scatter component can be considered preserved in the first approximation across the image plane for various acquisition geometries and phantoms. The variations exhibited by the scatter spectrum were below 10% for most examined cases. Furthermore, the corresponding spectrum shape proved to be also relatively invariant for different experimental angular projections of one of the examined phantoms. The observed property of scattered radiation can potentially lead to the decoupling of spatial and energy scatter components, which can in turn enable speed ups in scatter simulations and reduce the complexity of scatter correction.
Kihara, G.; Kotsubo, Y.; Yoshimoto, Y.; Kinefuchi, I.; Takagi, S.
2016-11-01
The interaction between water molecules and solid surfaces has a great impact on water vapor flows in nanostructures. We conduct molecular beam scattering experiments covering the incident energy range corresponding to the thermal energy at room temperature to investigate the scattering behavior of water molecules on silicon and graphite surfaces. The incident energy dependence of the scattering distributions exhibits opposite trends on these surfaces. Molecular dynamics simulations reveal that the difference is caused by the inertia effect of the incident molecules and the surface corrugations.
Energy and angle resolved ion scattering spectroscopy: new possibilities for surface analysis
International Nuclear Information System (INIS)
Hellings, G.J.A.
1986-01-01
In this thesis the design and development of a novel, very sensitive and high-resolving spectrometer for surface analysis is described. This spectrometer is designed for Energy and Angle Resolved Ion Scattering Spectroscopy (EARISS). There are only a few techniques that are sensitive enough to study the outermost atomic layer of surfaces. One of these techniques, Low-Energy Ion Scattering (LEIS), is discussed in chapter 2. Since LEIS is destructive, it is important to make a very efficient use of the scattered ions. This makes it attractive to simultaneously carry out energy and angle dependent measurements (EARISS). (Auth.)
High energy nucleus-nucleus scattering and matter radius of unstable nucleus
International Nuclear Information System (INIS)
Sato, H.; Okuhara, Y.
1985-07-01
The interaction cross sections of high energy nucleus-nucleus scattering have been studied with the Glauber Model and Hartree-Fock like variational calculation for the nuclear structure. It is found that the experimental interaction cross sections of the light unstable nucleus-stable nucleus scatterings measured by INS-LBL collaboration are well reproduceable. (author)
International Nuclear Information System (INIS)
Winslow, A.M.
1975-01-01
The multi-frequency grey method is extended to include Compton scattering. In this way one arrives at an expression for the total Compton scattering energy exchange rate, which, for a Planckian radiation field, reduces to a well known formula. 15 references, 5 graphs
Equivalent local potentials and phase approach to low-energy scattering parameters
Energy Technology Data Exchange (ETDEWEB)
Jana, A.K.; Nandi, T.K.; Paul, A.K.; Talukdar, B. (Department of Physics, Santiniketan, West Bengal (India))
1994-01-01
It is shown that the use of the McTavish-Kermode-Melhem-type equivalent local potentials linearizes algorithms of the variable-phase approach needed to compute the low-energy scattering parameters. A case study is presented to demonstrate the merit of the linearized equations, with particular emphasis on the relationship between the interpolating scattering length function and potential functions. (Author).
A calculation of Zsub(eff) for low-energy positron-hydrogen-molecule scattering
International Nuclear Information System (INIS)
Armour, E.A.G.; Baker, D.J.
1985-01-01
The value of Zsub(eff), the effective number of electrons per molecule available to the positron for annihilation, is calculated for low-energy positron-hydrogen-molecule scattering using the scattering wavefunctions obtained in recent detailed ab initio calculations. The results are higher than those obtained in previous calculations but much lower than the experimental value. (author)
Jo, Byung-Du; Lee, Young-Jin; Kim, Dae-Hong; Jeon, Pil-Hyun; Kim, Hee-Joung
2014-03-01
In conventional digital radiography (DR) using a dual energy subtraction technique, a significant fraction of the detected photons are scattered within the body, resulting in the scatter component. Scattered radiation can significantly deteriorate image quality in diagnostic X-ray imaging systems. Various methods of scatter correction, including both measurement and non-measurement-based methods have been proposed in the past. Both methods can reduce scatter artifacts in images. However, non-measurement-based methods require a homogeneous object and have insufficient scatter component correction. Therefore, we employed a measurement-based method to correct for the scatter component of inhomogeneous objects from dual energy DR (DEDR) images. We performed a simulation study using a Monte Carlo simulation with a primary modulator, which is a measurement-based method for the DEDR system. The primary modulator, which has a checkerboard pattern, was used to modulate primary radiation. Cylindrical phantoms of variable size were used to quantify imaging performance. For scatter estimation, we used Discrete Fourier Transform filtering. The primary modulation method was evaluated using a cylindrical phantom in the DEDR system. The scatter components were accurately removed using a primary modulator. When the results acquired with scatter correction and without correction were compared, the average contrast-to-noise ratio (CNR) with the correction was 1.35 times higher than that obtained without correction, and the average root mean square error (RMSE) with the correction was 38.00% better than that without correction. In the subtraction study, the average CNR with correction was 2.04 (aluminum subtraction) and 1.38 (polymethyl methacrylate (PMMA) subtraction) times higher than that obtained without the correction. The analysis demonstrated the accuracy of scatter correction and the improvement of image quality using a primary modulator and showed the feasibility of
The nucleon-nucleus scattering at intermediate energies
International Nuclear Information System (INIS)
Auger, J.-P.
1976-01-01
The Glauber model has the merit to connect directly the nucleon-nucleus elastic differential cross section with the nucleon-nucleon amplitude and nuclear densities. The general agreement between the 1 GeV proton elastic scattering differential cross sections calculated without adjustable parameter and the experimental data (from He 4 to Pb 208 ) is rather satisfactory up to 2. - 2.5 fm -1 momentum transfer. Although the 1 GeV proton elastic scattering experiments constitute at present one of the best method in determining neutron densities, it seems that self-consistent calculations bring the best knowledge of these densities. The model independent analysis performed with electron and proton scattering experiments show that the difference between neutron and proton r.m.s. radius cannot be determined better than 25-30% for Pb 208 [fr
Energy Technology Data Exchange (ETDEWEB)
Anderson, E. K.; Boadle, R. A.; Machacek, J. R.; Makochekanwa, C.; Sullivan, J. P. [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia); Chiari, L. [ARC Centre for Antimatter-Matter Studies, Flinders University, GPO Box 2100, Adelaide, 5001 SA (Australia); Buckman, S. J., E-mail: Stephen.buckman@anu.edu.au [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia); Institute of Mathematical Sciences, University of Malaya, Kuala Lumpur (Malaysia); Brunger, M. J. [ARC Centre for Antimatter-Matter Studies, Flinders University, GPO Box 2100, Adelaide, 5001 SA (Australia); Institute of Mathematical Sciences, University of Malaya, Kuala Lumpur (Malaysia); Garcia, G. [Instituto de Fısica Fundamental, Consejo Superior de Investigationes Cientıficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain); Blanco, F. [Departamento de Fısica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Ingolfsson, O. [Department of Chemistry, Science Institute, University of Iceland, Reykjavík 107 (Iceland)
2014-07-21
Measurements of the grand total and total positronium formation cross sections for positron scattering from uracil have been performed for energies between 1 and 180 eV, using a trap-based beam apparatus. Angular, quasi-elastic differential cross section measurements at 1, 3, 5, 10, and 20 eV are also presented and discussed. These measurements are compared to existing experimental results and theoretical calculations, including our own calculations using a variant of the independent atom approach.
International Nuclear Information System (INIS)
Balagyra, V.S.; Ryabka, P.M.
1999-01-01
For measuring the charged particle energy calculations of mean square angles of electron beam multiple Coulomb scattering at output combined accelerator target were undertaken according to seven theoretical models. Mollier method showed the best agreement with experiments
Theoretical predictions for pp and panti p elastic scattering in the TeV energy domain
International Nuclear Information System (INIS)
Bourrely, C.; Martin, A.
1984-01-01
We present theoretical predictions on total cross-sections and elastic scattering in the TeV energy domain obtained from the present experimental situation at the ISR and the panti p Collider. (orig.)
Relativistic description of directly interacting pions and nucleons
International Nuclear Information System (INIS)
Heller, L.
1976-01-01
The expected magnitudes of the leading relativistic effects on an off-energy-shell T matrix element are estimated using the Bakamjian--Thomas formulation of relativistic potential theory. For pion-nucleon scattering at medium energy, the two largest corrections are expected to result from the use of relativistic relative momenta rather than nonrelativistic values. The importance of additional terms depends upon the detailed behavior of the T matrix
On the possibility of thin layers thickness determination with low energy proton scattering
Bulgadaryan, D.; Kurnaev, V.; Sinelnikov, D.; Efimov, N.
2017-12-01
The analysis of erosion and redeposition processes plays an important role in the physics of fusion devices. In this work we present the results of computer simulation of plasma-facing materials surface analysis by use of the keV-energy proton scattering spectroscopy. It is shown that this technique can be used for the non-destructive analysis of thin surface layers. Energy spectra that correspond to different scattering and target parameters are presented.
Review of the inverse scattering problem at fixed energy in quantum mechanics
Sabatier, P. C.
1972-01-01
Methods of solution of the inverse scattering problem at fixed energy in quantum mechanics are presented. Scattering experiments of a beam of particles at a nonrelativisitic energy by a target made up of particles are analyzed. The Schroedinger equation is used to develop the quantum mechanical description of the system and one of several functions depending on the relative distance of the particles. The inverse problem is the construction of the potentials from experimental measurements.
Analysis of the low-energy $\\pi^\\pm p$ elastic-scattering data
Matsinos, Evangelos; Rasche, Guenther
2012-01-01
We report the results of a phase-shift analysis (PSA) of the low-energy $\\pi^\\pm p$ elastic-scattering data. Following the method which we had set forth in our previous PSA (Matsinos et al., 2006), we first investigate the self-consistency of the low-energy $\\pi^\\pm p$ elastic-scattering databases, via two separate analyses of (first) the $\\pi^+ p$ and (subsequently) the $\\pi^- p$ elastic-scattering data. There are two main differences to our previous PSA: a) we now perform only one test for ...
Rohe, R. C.; Valentine, J. D.
1996-12-01
A Compton scatter camera (CSC) design is proposed for imaging radioisotopes used as biotracers. A clinical version may increase sensitivity by a factor of over 100, while maintaining or improving spatial resolution, as compared with existing Anger cameras that use lead collimators. This novel approach is based on using energy subtraction (/spl Delta/E=E/sub 0/-E/sub SC/, where E/sub 0/, /spl Delta/E, and E/sub SC/ are the energy at the emitted gamma ray, the energy deposited by the initial Compton scatter, and the energy of the Compton scattered photon) to determine the amount of energy deposited in the primary system. The energy subtraction approach allows the requirement of high energy resolution to be placed on a secondary detector system instead of the primary detector system. Requiring primary system high energy resolution has significantly limited previous CSC designs for medical imaging applications. Furthermore, this approach is dependent on optimizing the camera design for data acquisition of gamma rays that undergo only one Compton scatter in a low-Z primary detector system followed by total absorption of the Compton scattered photon in a high-Z secondary detector system. The proposed approach allows for a more compact primary detector system, a more simplified pulse processing interface, and a much less complicated detector cooling scheme as compared with previous CSC designs. Analytical calculations and Monte Carlo simulation results for some specific detector materials and geometries are presented.
Energy Technology Data Exchange (ETDEWEB)
Braicovich, L., E-mail: lucio.braicovich@polimi.it; Minola, M.; Dellea, G.; Ghiringhelli, G. [CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133 (Italy); Le Tacon, M. [Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Moretti Sala, M.; Morawe, C.; Peffen, J.-Ch.; Yakhou, F.; Brookes, N. B. [European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043 (France); Supruangnet, R. [Synchrotron Light Research Institute, Nakhon Ratchasima (Thailand)
2014-11-15
Resonant Inelastic X-ray Scattering (RIXS) in the soft x-ray range is an element-specific energy-loss spectroscopy used to probe the electronic and magnetic excitations in strongly correlated solids. In the recent years, RIXS has been progressing very quickly in terms of energy resolution and understanding of the experimental results, but the interpretation of spectra could further improve, sometimes decisively, from a full knowledge of the polarization of incident and scattered photons. Here we present the first implementation, in a high resolution soft-RIXS spectrometer used to analyze the scattered radiation, of a device allowing the measurement of the degree of linear polarization. The system, based on a graded W/B{sub 4}C multilayer mirror installed in proximity of the CCD detector, has been installed on the AXES spectrometer at the ESRF (European Synchrotron Radiation Facility); it has been fully characterized and it has been used for a demonstration experiment at the Cu L{sub 3} edge on a high-T{sub c} superconducting cuprate. The loss in efficiency suffered by the spectrometer equipped with this test facility was a factor 17.5. We propose also a more advanced version, suitable for a routine use on the next generation of RIXS spectrometers and with an overall efficiency up to 10%.
α4He elastic scattering at high energies
International Nuclear Information System (INIS)
Usmani, A.A.; Usmani, Q.N.
1988-03-01
Differential cross sections for α 4 He elastic scattering have been calculated at incident α particle momenta of 4.32, 5.07 and 7.0 GeV/c within the framework of the Glauber multiple scattering theory. The full Glauber amplitude is calculated using the Monte Carlo method for evaluating multidimensional integrals. We find that, in general, the more realistic double Gaussian model for the density brings theory closer to experiment as compared to the generally used single Gaussian model. Our results with the double Gaussian model are in fairly good agreement with the experimented data at 4.32 and 5.07 GeV/c. (author). 11 refs, 4 figs, 1 tab
Inverse scattering scheme for the Dirac equation at fixed energy
International Nuclear Information System (INIS)
Leeb, H.; Lehninger, H.; Schilder, C.
2001-01-01
Full text: Based on the concept of generalized transformation operators a new hierarchy of Dirac equations with spherical symmetric scalar and fourth component vector potentials is presented. Within this hierarchy closed form expressions for the solutions, the potentials and the S-matrix can be given in terms of solutions of the original Dirac equation. Using these transformations an inverse scattering scheme has been constructed for the Dirac equation which is the analog to the rational scheme in the non-relativistic case. The given method provides for the first time an inversion scheme with closed form expressions for the S-matrix for non-relativistic scattering problems with central and spin-orbit potentials. (author)
Strong matrix effect in low-energy He+ ion scattering from carbon
International Nuclear Information System (INIS)
Mikhailov, S.N.; Van den Oetelaar, L.C.A.; Brongersma, H.H.
1994-01-01
In low-energy ion scattering the contribution of neutralization processes to the scattered ion yield is very important in quantification. Neutralization of low-energy (1-3.5 keV) He + ions by carbon is found to be much stronger for graphitic than for carbidic carbon. The ion fraction for graphitic carbon for 2.5 keV 3 He + scattering over 136 is about 60 times lower than that for carbidic carbon. For the 4 He + isotope the effect is even larger. Such a strong matrix effect for one element has not been measured before in low-energy (1-3.5 keV) inert-gas ion scattering. The neutralization behaviour is discussed in terms of a special quasi-resonant neutralization process for graphite. ((orig.))
High-energy string-brane scattering: leading eikonal and beyond
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2010-01-01
We extend previous techniques for calculations of transplanckian-energy string-string collisions to the high-energy scattering of massless closed strings from a stack of N Dp-branes in Minkowski spacetime. We show that an effective non-trivial metric emerges from the string scattering amplitudes by comparing them against the semiclassical dynamics of high-energy strings in the extremal p-brane background. By changing the energy, impact parameter and effective open string coupling, we are able to explore various interesting regimes and to reproduce classical expectations, including tidal-force excitations, even beyond the leading-eikonal approximation.
High energy charge exchange np and antipp scattering using the dual fermion model
International Nuclear Information System (INIS)
Weigt, G.
1976-01-01
The five independent helicity amplitudes Phisub(i)(s, t) calculated by Mandelstam from the Neveu-Schwarz-Ramond model for fermion-antifermion scattering are used in the Regge limit for a phenomenological description of high energy np and antipp charge exchange scattering. A forward spike which widens with increasing energy as well as an energy dependence changing from lower to higher energy data are reproduced by these non-evasive dual Born amplitudes using π, A 2 and rho Regge pole t-channel exchanges. (author)
On the interaction potential in low energy ion scattering
International Nuclear Information System (INIS)
Chini, T.K.; Ghose, D.
1989-01-01
The shadow cones for 998 eV Li + → Ag and 2 keV Na + → Cu are calculated by classical scattering theory using Thomas-Fermi-Moliere potential, universal potential of Ziegler et al. and the Born-Mayer potential. It is found that the Born-Mayer potential with the parameters calculated by Andersen and Sigmund also predicts well the shape of the shadow cones. (orig.)
DEFF Research Database (Denmark)
Lagerburg, Vera; de Nijs, Robin; Holm, Søren
2012-01-01
One of the main problems in quantification of single photon emission computer tomography imaging is scatter. In iodine-123 (I-123) imaging, both the primary 159 keV photons and photons of higher energies are scattered. In this experimental study, different scatter correction methods, based...... on energy window subtraction, have been compared with each other....
Scattering of near-zero-energy electrons and positrons by H2
Zhang, J.-Y.
2014-04-15
The parameters for S-wave elastic scattering of near-zero-energy electrons and positrons by H2 molecules are calculated using the stabilization method with explicitly correlated Gaussians. The confined variational method is applied to optimize the Gaussians to describe the short-range interaction of incident e± with H2 in the fixed-nuclei approximation. For e+-H2 scattering the scattering length of previous work [Phys. Rev. Lett. 103, 223202 (2009)] is substantially improved. More importantly, for e−-H2 scattering, from first principles, the scattering length is computed as a function of the internuclear distance. In the case that the two nuclei are at the equilibrium distance the results are in a good agreement with values derived from fitting experimental total and diffusion cross sections to the modified effective range theory.
Low-energy 4He+ scattering from deuterium adsorbed on stepped Pd(331)
International Nuclear Information System (INIS)
Ellis, W.P.; Bastasz, R.
1996-01-01
We have taken angle-resolved data for the scattering of low-energy ( 4 He + from deuterium adsorbed on a stepped Pd(331) surface. The impact geometry was up the staircase, that is, the 4 He + beam was perpendicular to and directly incident onto the unshadowed Pd ledge atoms. A strong quasi-elastic scattering signal of 4 He + from D ( 4 He + /D) was observed at a forward scattering angle of θ = 25 degrees and an incidence angle of α = 76 degrees from the (331) normal. The results agree with shadow cone calculations of scattering first from Pd ledge atoms followed by a second event, 4 He + /D. The resultant adsorption geometry shows D to reside in the quasi- threefold ledge site on the surface directly above the bulk fcc octahedral void. These results are consistent with the previous 4 He + scattering study of the geometrically related Pd(110)- D(ads) system
Practical scheme for low energy π-d scattering
International Nuclear Information System (INIS)
Avishai, Y.; Giraud, N.; Fayard, C.; Lamot, G.H.
1978-01-01
Recently, it became clear that the solution of the π-d scattering problem in the presence of pion absorption rests outside the Faddeev theory. The most one can expect from this theory is the N-N' model Afnan-Thomas, in which the Pauli principle is violated. In the present work, we impose the exclusion principle on the Afnan-Thomas model as an ad-hoc assumption, and get a modified set of equations in which the two nucleons are indentical through all intermediate states, and non-Faddeev terms with two successive pion emissions are included (but states of more than one pion are eliminated). (orig.) [de
The new frontiers of electron scattering at intermediate energy
International Nuclear Information System (INIS)
Frois, B.
1984-08-01
Recent advances in experimental techniques have produced a new generation of electron scattering data. This paper explores the frontiers of this field and shows how our prospects for the future may be modified. Nuclear structure has been determined with an unprecedented accuracy defining clearly the limits of the most advanced theoretical descriptions. Large meson exchange currents are measured quantitatively with precision. Recent data on the electrodisintegration of deuterium at threshold and on the magnetic form factor of 3 He and tritium show that the pionic exchange current is well understood. There is no satisfactory theoretical description of shorter range processes
Low-energy Scattering of Positronium by Atoms
Ray, Hasi
2007-01-01
The survey reports theoretical studies involving positronium (Ps) - atom scattering. Investigations carried out in last few decades have been briefly reviewed in this article. A brief description of close-coupling approximation (CCA), the first-Born approximation (FBA) and the Born-Oppenheimer approximation (BOA) for Ps-Atom systems are made. The CCA codes of Ray et a1 [1-6] are reinvestigated using very fine mesh-points to search for resonances. The article advocates the need for an extended basis set & a systematic study using CCAs.
Energy independent optical potential and inverse scattering from non-local potential
International Nuclear Information System (INIS)
Tam, K.C.
1982-01-01
An energy-independent optical potential for nucleon-nucleus scattering is formally derived. A simple relation between energy-dependent and energy-independent potentials is established, showing that the latter has the same thresholds as the former. A generalized dispersion relation for energy-independent potentials is found and compared with the conventional dispersion relations of the generalized energy-dependent optical potentials. An inverse scattering method for non-local potential is developed to obtain this energy-independent optical potential anti U. Unlike the case of local potential, in addition to the bound-state information, the knowledge of the off-shell effect in the continuum is required for a unique construction of this non-local potential. A numerical method, known as the interpolation method, is proposed for the calculation of anti U. It is shown that a unique construction of anti U can be attained with the elastic scattering wave function and all bound-state energies and functions. Another method, known as the perturbative method, is also proposed and applied to calculations of anti U for elastic (n, 40 Ca) scatterings from empirical energy-dependent optical model potentials U(E) of the Woods-Saxon type. The perturbative method is found to converge satisfactorily when the energy dependence of the underlying U(e) potential is weak, as in the case of the empirical optical model potentials. The anti U from both the inverse scattering method and the perturbative one has the same elastic scattering wave function as for U(E)
The two-nucleon system at next-to-next-to-next-to-leading order
Energy Technology Data Exchange (ETDEWEB)
Evgeny Epelbaum; Walter Gloeckle; Ulf-G. Meissner
2005-01-01
We consider the two-nucleon system at next-to-next-to-next-to-leading order (N{sup 3}LO) in chiral effective field theory. The two--nucleon potential at N{sup 3}LO consists of one-, two- and three-pion exchanges and a set of contact interactions with zero, two and four derivatives. In addition, one has to take into account various isospin--breaking and relativistic corrections. We employ spectral function regularization for the multi--pion exchanges. Within this framework, it is shown that the three-pion exchange contribution is negligibly small. The low--energy constants (LECs) related to pion-nucleon vertices are taken consistently from studies of pion-nucleon scattering in chiral perturbation theory. The total of 26 four--nucleon LECs has been determined by a combined fit to some np and pp phase shifts from the Nijmegen analysis together with the nn scattering length.
Patterns of High energy Massive String Scatterings in the Regge Regime
International Nuclear Information System (INIS)
Lee Jen Chi
2009-01-01
We calculate high energy massive string scattering amplitudes of open bosonic string in the Regge regime (RR). We found that the number of high energy amplitudes for each fixed mass level in the RR is much more numerous than that of Gross regime (GR) calculated previously. Moreover, we discover that the leading order amplitudes in the RR can be expressed in terms of the Kummer function of the second kind. In particular, based on a summation algorithm for Stirling number identities developed recently, we discover that the ratios calculated previously among scattering amplitudes in the GR can be extracted from this Kummer function in the RR. We conjecture and give evidences that the existence of these GR ratios in the RR persists to sub-leading orders in the Regge expansion of all string scattering amplitudes. Finally, we demonstrate the universal power-law behavior for all massive string scattering amplitudes in the RR. (author)
A bibliography of high energy two-body and inclusive scattering data
International Nuclear Information System (INIS)
Gault, F.D.; Read, B.J.; Roberts, R.G.
1977-09-01
A bibliography is presented of the data on high energy two-body and quasi-two-body final state scattering processes. This updated edition also covers one and two-particle inclusive production. It contains references to those published papers whose main purpose is to provide data on high energy two-body and inclusive hadronic scattering cross-sections rather than just properties of the produced particles. It covers the leading high energy physics journals and the period up to June 1977. The entries are grouped by process in the order indicated in the Table of Contents, and an author index is also provided. (author)
DEFF Research Database (Denmark)
de Nijs, Robin; Lagerburg, Vera; Klausen, Thomas L
2014-01-01
and the activity, which depends on the collimator type, the utilized energy windows and the applied scatter correction techniques. In this study, energy window subtraction-based scatter correction methods are compared experimentally and quantitatively. MATERIALS AND METHODS: (177)Lu SPECT images of a phantom...... technique, the measured ratio was close to the real ratio, and the differences between spheres were small. CONCLUSION: For quantitative (177)Lu imaging MEGP collimators are advised. Both energy peaks can be utilized when the ESSE correction technique is applied. The difference between the calculated...
High-Energy String Scattering Amplitudes and Signless Stirling Number Identity
Directory of Open Access Journals (Sweden)
Jen-Chi Lee
2012-07-01
Full Text Available We give a complete proof of a set of identities (7 proposed recently from calculation of high-energy string scattering amplitudes. These identities allow one to extract ratios among high-energy string scattering amplitudes in the fixed angle regime from high-energy amplitudes in the Regge regime. The proof is based on a signless Stirling number identity in combinatorial theory. The results are valid for arbitrary real values L rather than only for L=0,1 proved previously. The identities for non-integer real value L were recently shown to be realized in high-energy compactified string scattering amplitudes [He S., Lee J.C., Yang Y., arXiv:1012.3158]. The parameter L is related to the mass level of an excited string state and can take non-integer values for Kaluza-Klein modes.
Jo, Byung-Du; Lee, Young-Jin; Kim, Dae-Hong; Kim, Hee-Joung
2014-08-01
In conventional digital radiography (DR) using a dual energy subtraction technique, a significant fraction of the detected photons are scattered within the body, making up the scatter component. Scattered radiation can significantly deteriorate image quality in diagnostic X-ray imaging systems. Various methods of scatter correction, including both measurement- and non-measurement-based methods, have been proposed in the past. Both methods can reduce scatter artifacts in images. However, non-measurement-based methods require a homogeneous object and have insufficient scatter component correction. Therefore, we employed a measurement-based method to correct for the scatter component of inhomogeneous objects from dual energy DR (DEDR) images. We performed a simulation study using a Monte Carlo simulation with a primary modulator, which is a measurement-based method for the DEDR system. The primary modulator, which has a checkerboard pattern, was used to modulate the primary radiation. Cylindrical phantoms of variable size were used to quantify the imaging performance. For scatter estimates, we used discrete Fourier transform filtering, e.g., a Gaussian low-high pass filter with a cut-off frequency. The primary modulation method was evaluated using a cylindrical phantom in the DEDR system. The scatter components were accurately removed using a primary modulator. When the results acquired with scatter correction and without scatter correction were compared, the average contrast-to-noise ratio (CNR) with the correction was 1.35 times higher than that obtained without the correction, and the average root mean square error (RMSE) with the correction was 38.00% better than that without the correction. In the subtraction study, the average CNR with the correction was 2.04 (aluminum subtraction) and 1.38 (polymethyl methacrylate (PMMA) subtraction) times higher than that obtained without the correction. The analysis demonstrated the accuracy of the scatter correction and the
11. international conference on elastic and diffractive scattering: towards high energy frontiers
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
This conference is held every 2 years. Every time these conferences on elastic and diffractive scattering adapt their content to the most recent experimental and theoretical results concerning not only quantum chromodynamics (QCD) but also other fields of particle physics where diffractive physics is present. This year, besides classical themes such as: -) forward scattering, -) total cross-sections, -) real parts, and -) pomeron and odderon, the participants have addressed many other subjects such as: -) LHC physics, -) non-perturbative approaches to high-energy scattering, -) the dipole model, -) small-x evolution, -) hard diffraction in QCD, -) nuclear shadowing, -) diffractive Higgs studies, -) spin effects, -) 4-quarks and 5-quarks, or -) B-physics.
Parity violation in elastic N-N scattering at high energies
International Nuclear Information System (INIS)
Chiappetta, P.; Soffer, J.; Wu, Tai Tsun; Harvard Univ., Cambridge, MA
1981-09-01
We calculate the asymmetry in nucleon-nucleon elastic scattering at high energies arising from heavy boson exchange in the standard Weinberg-Salam model. By neglecting the strong interaction enhancement effects, our result for p-n scattering is one order of magnitude higher than for p-p scattering. Enhancement effects increase the p-p asymmetry which may become comparable to the p-n asymmetry. They are however too small if compared with the total cross section asymmetry measured at Argonne at 6 GeV/c on a water target
DEFF Research Database (Denmark)
Bekshaev, A. Ya; Angelsky, O. V.; Hanson, Steen Grüner
2012-01-01
Based on the Mie theory and on the incident beam model via superposition of two plane waves, we analyze numerically the momentum flux of the field scattered by a spherical, nonmagnetic microparticle placed within the spatially inhomogeneous circularly polarized paraxial light beam. The asymmetry...... between the forward- and backward-scattered momentum fluxes in the Rayleigh scattering regime appears due to the spin part of the internal energy flow in the incident beam. The transverse ponderomotive forces exerted on dielectric and conducting particles of different sizes are calculated and special...
11. international conference on elastic and diffractive scattering: towards high energy frontiers
International Nuclear Information System (INIS)
2005-01-01
This conference is held every 2 years. Every time these conferences on elastic and diffractive scattering adapt their content to the most recent experimental and theoretical results concerning not only quantum chromodynamics (QCD) but also other fields of particle physics where diffractive physics is present. This year, besides classical themes such as: -) forward scattering, -) total cross-sections, -) real parts, and -) pomeron and odderon, the participants have addressed many other subjects such as: -) LHC physics, -) non-perturbative approaches to high-energy scattering, -) the dipole model, -) small-x evolution, -) hard diffraction in QCD, -) nuclear shadowing, -) diffractive Higgs studies, -) spin effects, -) 4-quarks and 5-quarks, or -) B-physics
Impact picture for near-forward elastic scattering up to LHC energies
Soffer, Jacques; Wu, Tai Tsun
2015-01-01
We will recall the main feaatures of an accurate phenomenological model to describe successfully near-forward elastic scattering in a wide energy range, including ISR, SPS and Tevatron colliders. A large step in energy domain is accomplished with the LHC collider, presently running, giving the opportunity to confront the new data with the predictions of our theoretical approach.
Energy Technology Data Exchange (ETDEWEB)
Li Qingrun (CCAST (World Lab.), Beijing (China) Academia Sinica, Beijing, BJ (China). Inst. of High Energy Physics); Zhou Jinli (Guangxi Normal Univ., Guilin (China). Dept. of Physics)
1991-05-01
The {alpha}-particle model of {sup 12}C is examined by means of proton-{sup 12}C elastic scattering in the intermediate energy range. The results show that the model gives a satisfactory account of the experimental data. The parametrized proton-{sup 4}He amplitudes in the intermediate energy region are presented. (author).
International Nuclear Information System (INIS)
Bluemlein, J.
1993-08-01
The possibilities to measure structure functions, to extract parton distributions, and to measure α s and Λ QCD in current and future high energy deep inelastic scattering experiments are reviewed. A comparison is given for experiments at HERA, an ep option at LEP xLHC, and a high energy neutrino experiment. (orig.)
Czech Academy of Sciences Publication Activity Database
Werner, W. S. M.; Zemek, Josef; Jiříček, Petr
2010-01-01
Roč. 82, č. 15 (2010), 155422/1-155422/6 ISSN 1098-0121 R&D Projects: GA ČR GA202/09/0428 Institutional research plan: CEZ:AV0Z10100521 Keywords : inelastic electron scattering * elastic electron scattering * reflection electron energy loss spectroscopy * REELS Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010
International Nuclear Information System (INIS)
Lychagin, E.V.; Muzychka, A.Yu.; Nekhaev, G.V.; Strelkov, A.V.; Shvetsov, V.N.; Nesvizhevskij, V.V.; Tal'daev, R.R.
2001-01-01
Inelastic scattering of neutrons with small energy transfer of ∼10 -7 eV was investigated using gravitational UCN spectrometer. The probability of such a process at stainless steel and beryllium surfaces was measured. It was also estimated at copper surface. The measurement showed that the detected flux of neutrons scattered at beryllium and copper surfaces is ∼ 2 times higher at room temperature compared to that at the liquid nitrogen temperature. (author)
Transverse momentum cut-off hypothesis in high energy scattering in perturbation theory
Banerjee, H.; Sengupta, M.
1980-06-01
The hypothesis that transverse components of loop momenta are limited in high energy scattering is shown to imply that enhanced contributions from singular scaling in Feynman parameter space analysis should all cancel. Cancellation of singular scaling contributions is verified at the next to the leading-log level in the sixth order for fermion-fermion scattering in a Yang-Mills theory with SU( N)-gauge symmetry.
Medium energy hadron-nucleus scattering in the 1/N expansion formalism
International Nuclear Information System (INIS)
Kuyucak, S.; Morrison, I.
1992-01-01
The algebraic-eikonal approach to the medium energy hadron-nucleus scattering is generalized to arbitrary interactions and boson types using the 1/N expansion technique for the interacting boson model. The results are used in a comparative study of proton scattering from deformed nuclei in the sd and sdg boson models. The two models give almost identical results for a pure quadrupole interaction but widely differ when a hexadecapole interaction is included. 25 refs., 3 tabs., 7 figs
Elastic scattering of intermediate energy kaons from nuclei and its Coulomb effects
Energy Technology Data Exchange (ETDEWEB)
Zhang Zhenqiu; Kong Lingjiang; Liu Xianhui
1986-04-01
In the frame of the eikonal multiple scattering theory, using the basic parameters which are given by the different authors, the elastic scattering of the intermediate energy kaon mesons on /sup 12/C and /sup 40/Ca is studied. The Coulomb effect is calculated too. The results are in agreement with the experimental data. The Coulomb effect not only enhances the small angle differential cross section, but also fills up the dip of the differential cross section.
Anomalous resonance-radiation energy-transfer rate in a scattering dispersive medium
International Nuclear Information System (INIS)
Shekhtman, V.L.
1992-01-01
This paper describes a generalization of the concept of group velocity as an energy-transfer rate in a dispersive medium with complex refractive index when the polaritons, which are energy carriers, undergo scattering, in contrast to the classical concept of the group velocity of free polaritons (i.e., without scattering in the medium). The concept of delay time from quantum multichannel-scattering, theory is used as the fundamental concept. Based on Maxwell's equations and the new mathematical Φ-function method, a consistent conceptual definition of group velocity in terms of the ratio of the coherent-energy flux density to the coherent-energy density is obtained for the first time, and a critical analysis of the earlier (Brillouin) understanding of energy-transfer rate is given in the light of radiation-trapping theory and the quantum theory of resonance scattering. The role of generalized group velocity is examined for the interpretation of the phenomenon of multiple resonance scattering, or radiation diffusion. The question of causality for the given problem is touched upon; a new relationship is obtained, called the microcausality condition, which limits the anomalous values of group velocity by way of the indeterminacy principle and the relativistic causality principle for macroscopic time intervals directly measurable in experiment, whereby attention is focused on the connection of the given microcausality condition and the well-known Wigner inequality for the time delay of spherical waves. 22 refs
Spin effects in medium-energy electron-3He scattering
International Nuclear Information System (INIS)
van den Brand, J.F.J.; Alarcon, R.; Bauer, T.
1998-01-01
New physics can be accessed by scattering polarized electrons from a polarized 3 He internal gas target. It is discussed how the asymmetries for the reactions 3 vector He(vector e,e'), 3 vector He(vector e,e'p), 3 vector He(vector e,e'n), 3 vector He(vector e,e'd), and 3 vector He(vector e,e'pn) may provide precise information on the S' and the D-wave parts of the 3 He ground-state wave function, the neutron form factors, and the role of spin-dependent reaction mechanism effects. The experiment uses up to 900 MeV (polarized) electrons from the AmPS storage ring in Amsterdam, Netherlands, in combination with large acceptance electron and hadron detectors. (orig.)
Scaling laws in high-energy electron-nuclear scattering
Chemtob, Marc
1980-03-01
The approximate scaling behavior suggested by recent measurements of electron scattering form factors and inelastic structure functions of few-body nuclei (mass 2, 3, 4) is discussed in a relativistic impulse approximation model. The model is a straightforward extension incorporating spin of a nucleon parton model introduced in recent works. We present results for electric and magnetic form factors as well as inelastic structure functions near threshold. The important corrections to scaling which are present in the preasymptotic regions are found to be well accounted for by the type of binding effects included in the phenomenologically constructed infinite-momentum frame nuclear wave functions. While predicted form factors are very sensitive to the parameters in the wave functions it does not appear possible to associate unambiguous dynamical meaning to these parameters. We find that spin effects bring significant and useful corrections.
Correction for scatter in 3D brain PET using a dual energy window method
International Nuclear Information System (INIS)
Grootoonk, S.; Spinks, T.J.; Jones, T.; Sashin, D.; Spyrou, N.M.
1996-01-01
A method for scatter correction using dual energy window acquisition has been developed and implemented on data collected with a brain-PET tomograph operated in the septa retracted, 3D mode. Coincidence events are assigned to (i) an upper energy window where both photons deposit energy between 380 keV and 850 keV or (ii) a lower energy window where one or both photons deposit within 200 keV and 380 keV. Scaling parameters are derived from measurements of the ratios of counts from line sources due to scattered and unscattered events in the two energy windows in head-sized phantoms. A scaled subtraction of the two energy windows produces a distribution of scatter which is smoothed prior to subtraction from the upper energy window. In phantoms, the correction was found to restore the uniformity, contrast and linearity of activity concentration. Relative activity concentrations were restored to within 7% of their true values in a multicompartment phantom. The method was found to provide accurate correction for scattered events arising from activity outside the direct detector field of view. In a three-compartment phantom containing water, 18 F and 11 C scanned in dynamic, multiframe mode, the half-lives of the two isotopes were restored to within 2% of their true value. (author)
International Nuclear Information System (INIS)
Guerin, Bastien
2010-01-01
We developed and validated a fast Monte Carlo simulation of PET acquisitions based on the SimSET program modeling accurately the propagation of gamma photons in the patient as well as the block-based PET detector. Comparison of our simulation with another well validated code, GATE, and measurements on two GE Discovery ST PET scanners showed that it models accurately energy spectra (errors smaller than 4.6%), the spatial resolution of block-based PET scanners (6.1%), scatter fraction (3.5%), sensitivity (2.3%) and count rates (12.7%). Next, we developed a novel scatter correction incorporating the energy and position of photons detected in list-mode. Our approach is based on the reformulation of the list-mode likelihood function containing the energy distribution of detected coincidences in addition to their spatial distribution, yielding an EM reconstruction algorithm containing spatial and energy dependent correction terms. We also proposed using the energy in addition to the position of gamma photons in the normalization of the scatter sinogram. Finally, we developed a method for estimating primary and scatter photons energy spectra from total spectra detected in different sectors of the PET scanner. We evaluated the accuracy and precision of our new spatio-spectral scatter correction and that of the standard spatial correction using realistic Monte Carlo simulations. These results showed that incorporating the energy in the scatter correction reduces bias in the estimation of the absolute activity level by ∼ 60% in the cold regions of the largest patients and yields quantification errors less than 13% in all regions. (author)
Wahle, Chris W; Ross, David S; Thurston, George M
2013-09-28
We extend methods of solution of a light scattering partial differential equation for the free energy of mixing to apply to connected, isotropic ternary liquid composition domains that do not touch all three binary axes. To do so we mathematically analyze the problem of inferring needed Dirichlet boundary data, and solving for the free energy, with use of hypothetical static light scattering measurements that correspond to dielectric composition gradient vectors that have distinct directions. The physical idea behind the technique is that contrasting absorption properties of mixture components can result in such distinctly directed dielectric composition gradient vectors, due to their differing wavelength dependences of dielectric response. At suitably chosen wavelengths, contrasting light scattering efficiency patterns in the ternary composition triangle can then correspond to the same underlying free energy, and enlarge the scope of available information about the free energy, as shown here. We show how to use distinctly directed dielectric gradients to measure the free energy on both straight lines and curves within the ternary composition triangle, so as to provide needed Dirichlet conditions for light scattering partial differential equation solution. With use of Monte Carlo simulations of noisy light scattering data, we provide estimates of the overall system measurement time and sample spacing needed to determine the free energy to a desired degree of accuracy, for various angles between the assumed dielectric gradient vectors, and indicate how the measurement time depends on instrumental throughput parameters. The present analysis methods provide a way to use static light scattering to measure, directly, mixing free energies of many systems that contain such restricted liquid domains, including aqueous solutions of biological macromolecules, micellar mixtures and microemulsions, and many small molecule systems that are important in separation technology.
Improving quantitative dosimetry in 177Lu-DOTATATE SPECT by energy window-based scatter corrections
Lagerburg, Vera; Klausen, Thomas L.; Holm, Søren
2014-01-01
Purpose Patient-specific dosimetry of lutetium-177 (177Lu)-DOTATATE treatment in neuroendocrine tumours is important, because uptake differs across patients. Single photon emission computer tomography (SPECT)-based dosimetry requires a conversion factor between the obtained counts and the activity, which depends on the collimator type, the utilized energy windows and the applied scatter correction techniques. In this study, energy window subtraction-based scatter correction methods are compared experimentally and quantitatively. Materials and methods 177Lu SPECT images of a phantom with known activity concentration ratio between the uniform background and filled hollow spheres were acquired for three different collimators: low-energy high resolution (LEHR), low-energy general purpose (LEGP) and medium-energy general purpose (MEGP). Counts were collected in several energy windows, and scatter correction was performed by applying different methods such as effective scatter source estimation (ESSE), triple-energy and dual-energy window, double-photopeak window and downscatter correction. The intensity ratio between the spheres and the background was measured and corrected for the partial volume effect and used to compare the performance of the methods. Results Low-energy collimators combined with 208 keV energy windows give rise to artefacts. For the 113 keV energy window, large differences were observed in the ratios for the spheres. For MEGP collimators with the ESSE correction technique, the measured ratio was close to the real ratio, and the differences between spheres were small. Conclusion For quantitative 177Lu imaging MEGP collimators are advised. Both energy peaks can be utilized when the ESSE correction technique is applied. The difference between the calculated and the real ratio is less than 10% for both energy windows. PMID:24525900
Small-angle p-p elastic scattering at energies between 285 and 572 Me V
Aebischer, D; Greeniaus, L G; Hess, R; Junod, A; Lechanoine-Leluc, C; Nikles, J C; Rapin, D; Serre, Claude; Werren, D W
1976-01-01
Low energy proton-proton elastic scattering has been studied using an arrangement of multiwire proportional chambers at the CERN synchrocyclotron. Accurate measurements of the angular distribution for laboratory scattering angles in the range 1.5 to 10 degrees have been made at eight incident kinetic energies between 285 and 572 MeV. The interferences between the Coulomb and nuclear scattering amplitudes is used to determine the ratio alpha /sub p/=Re phi /sup N //sub +/(o)/Im phi /sup N//sub +/(o), where phi /sup N//sub +/(o) is the non-flip nuclear forward amplitude. alpha p is found to be positive and falling with energy, but is sensitive to the type of parameterization used. Reasonable consistency with dispersion relation calculations is obtained. (21 refs).
Eikonal propagators and high-energy parton-parton scattering in gauge theories
International Nuclear Information System (INIS)
Meggiolaro, Enrico
2001-01-01
In this paper we consider 'soft' high-energy parton-parton scattering processes in gauge theories, i.e., elastic scattering processes involving partons at very high squared energies s in the center of mass and small squared transferred momentum t (s→∞, t 2 ). By a direct resummation of perturbation theory in the limit we are considering, we derive expressions for the truncated-connected quark (antiquark) propagator in an external gluon field, as well as for the residue at the pole of the full unrenormalized propagator, both for scalar and fermion gauge theories. These are the basic ingredients to derive high-energy parton-parton scattering amplitudes, using the LSZ reduction formulae and a functional integral approach. The above procedure is also extended to include the case in which at least one of the partons is a gluon. The meaning and the validity of the results are discussed
Elastic scattering of polarized protons from 3He at intermediate energies
International Nuclear Information System (INIS)
Hasell, D.K.; Bracco, A.; Gubler, H.P.
1982-09-01
Using the polarized proton beam facility of the TRIUMF cyclotron, differential cross sections and analyzing powers have been measured in the angular range 20 0 - 150 0 c.m. for proton elastic scattering from 3 He at incident proton energies of 200, 300, 415 and 515 MeV. The differential cross sections exhibit a minimum at t = -0.33 (GeV/c) 2 which becomes more pronounced with increasing energy. There is evidence for the onset of a second minimum corresponding to the interference between double and triple scattering amplitudes. Large analyzing powers are observed at the lower energies. The data from the present analysis, together with data obtained from the literature in the energy range 100-1000 MeV, have been analyzed within the framework of the Glauber multiple scattering formalism. Nucleon-nucleon scattering parameters were taken from a global phase shift analysis of nucleon-nucleon elastic scattering data. Reasonable agreement with the data is obtained
Energy spectra and charge states of light atoms scattered by solid surface
International Nuclear Information System (INIS)
Parilis, E.S.; Verleger, V.K.
1980-01-01
The theories of backscattering and charge state formation of light atoms (H, D, and He) for the energy range 1 keV 0 0 and theta. The dependence of epsilonsub(max) on theta determines the mean effective range for the scattering at the angle theta. The appearance of surface peaks in the energy spectra of neutrals below energy E 0 + , Hsup(*), and H - . (orig.)
Molecular beam studies of energy transfer in scattering from crystal surfaces
International Nuclear Information System (INIS)
Guthrie, W.L.
1983-01-01
The translational energy distributions and angular distributions of D 2 O produced from the reaction of incident D 2 and O 2 on a (111) platinum single crystal surface have been measured through the use of a molecular beam-surface scattering apparatus equipped with a time-of-flight spectrometer. The translation energies were measured over the surface temperature range T/sub s/ = 664 K - 913 K and at scattering angles of 7 0 and 40 0 from the surface normal. The D 2 O translational energy, , was found to be approximately half the equilibrium value over the temperature range examined, with /2k varying from 280 K to 480 K. These results are discussed in terms of a non-equilibrium desorption model. The two-photon ionization spectrometer was built to investigate the internal rotational and vibrational energy distributions of NO scattered from Pt(111) surfaces. The rotational energy distributions were measured over the crystal temperature range of T/sub s/ = 400 K - 1200 K. The translational energy distributions and angular distributions were measured using the time-of-flight spectrometer over the crystal temperature range of 400 K - 110 K and for beam translational energies of 0.046 eV, 0.11 eV and 0.24 eV, so that complete energy exchange information for translation, rotation and vibration is available for this gas-surface system. Significant energy transfer was observed in all three modes
Spontaneous emission and scattering in a two-atom system: Conservation of probability and energy
International Nuclear Information System (INIS)
Berman, P. R.
2007-01-01
An explicit calculation of conservation of probability and energy in a two-atom system is presented. One of the atoms is excited initially and undergoes spontaneous emission. The field radiated by this atom can be scattered by the second atom. It is seen that the Weisskopf-Wigner approximation must be applied using a specific prescription to guarantee conservation of probability and energy. Moreover, for consistency, it is necessary to take into account the rescattering by the source atom of radiation scattered by the second atom
Double electron ionization in Compton scattering of high energy photons by helium atoms
International Nuclear Information System (INIS)
Amusia, M.Y.; Mikhailov, A.I.
1995-01-01
The cross section for double-electron ionization of two-electron atoms and ions in Compton scattering of high energy photons is calculated. It is demonstrated that its dependence on the incoming photon frequency is the same as that for single-electron ionization. The ratio of open-quotes double-to-singleclose quotes ionization in Compton scattering was found to be energy independent and almost identical with the corresponding value for photoionization. For the He atom it is 1.68%. This surprising result deserves experimental verification
Double electron ionization in Compton scattering of high energy photons by helium atoms
Energy Technology Data Exchange (ETDEWEB)
Amusia, M.Y.; Mikhailov, A.I. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation)
1995-08-01
The cross section for double-electron ionization of two-electron atoms and ions in Compton scattering of high energy photons is calculated. It is demonstrated that its dependence on the incoming photon frequency is the same as that for single-electron ionization. The ratio of {open_quotes}double-to-single{close_quotes} ionization in Compton scattering was found to be energy independent and almost identical with the corresponding value for photoionization. For the He atom it is 1.68%. This surprising result deserves experimental verification.
Fast scattering simulation tool for multi-energy x-ray imaging
Energy Technology Data Exchange (ETDEWEB)
Sossin, A., E-mail: artur.sossin@cea.fr [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Tabary, J.; Rebuffel, V. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)
2015-12-01
A combination of Monte Carlo (MC) and deterministic approaches was employed as a means of creating a simulation tool capable of providing energy resolved x-ray primary and scatter images within a reasonable time interval. Libraries of Sindbad, a previously developed x-ray simulation software, were used in the development. The scatter simulation capabilities of the tool were validated through simulation with the aid of GATE and through experimentation by using a spectrometric CdTe detector. A simple cylindrical phantom with cavities and an aluminum insert was used. Cross-validation with GATE showed good agreement with a global spatial error of 1.5% and a maximum scatter spectrum error of around 6%. Experimental validation also supported the accuracy of the simulations obtained from the developed software with a global spatial error of 1.8% and a maximum error of around 8.5% in the scatter spectra.
Energy-Dependent microscopic optical potential for p+{sup 9}Be elastic scattering
Energy Technology Data Exchange (ETDEWEB)
Maridi, H. M., E-mail: h.maridi@gmail.com [Physics Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen); Farag, M. Y. H., E-mail: yehiafarag@cu.edu.eg; Esmael, E. H. [Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen)
2016-06-10
The p+{sup 9}Be elastic scattering at an energy range up to 200 MeV/nucleon is analyzed using the single-folding model. The density- and isospin-dependent M3Y-Paris nucleon-nucleon (NN) interaction is used for the real part and the NN-scattering amplitude of the high-energy approximation for the imaginary one. The analysis reveals that the cross-section data are reproduced well at energies up to 100 MeV/nucleon by use of the partial-wave expansion. For higher energies, the eikonal approximation give results better than the partial-wave expansion calculations. The volume integrals of the optical-potential parts have systematic energy dependencies, and they are parameterized in empirical formulas.
Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei
Energy Technology Data Exchange (ETDEWEB)
Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)
2014-06-15
We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of {sup 4,6,i8}He, {sup 6,7}Li, and {sup 9,10}Be nuclei at low and intermediate incident energies up to 200MeV/nucleon. (orig.)
Nishimura, Tomoaki
2016-03-01
A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of 16O(4He, 4He)16O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.
High-energy pp¯ and pp forward elastic scattering and total cross sections
Block, M. M.; Cahn, R. N.
1985-04-01
The present status of elastic pp and pp¯ scattering in the high-energy domain is reviewed, with emphasis on the forward and near-forward regions. The experimental techniques for measuring σtot, ρ, and B are discussed, emphasizing the importance of the region in which the nuclear and Coulomb scattering interfere. The impact-parameter representation is exploited to give simple didactic demonstrations of important rigorous theorems based on analyticity, and to illuminate the significance of the slope parameter B and the curvature parameter C. Models of elastic scattering are discussed, and a criterion for the onset of "asymptopia" is given. A critique of dispersion relations is presented. Simple analytic functions are used to fit simultaneously the real and imaginary parts of forward scattering amplitudes for both pp and pp¯, obtained from experimental data for σtot and ρ. It is found that a good fit can be obtained using only five parameters (with a cross section rising as ln2s), over the energy range 5∞ are examined critically. The nuclear slope parameters B are also fitted in a model-independent fashion. Examination of the fits reveals a new regularity of the pp¯ and the pp systems. Predictions of all of the elastic scattering parameters are made at ultrahigh energies, and are compared to the available SPS collider measurements.
Neutron scattering from α-Ce at epithermal neutron energies
Indian Academy of Sciences (India)
the constant-ω integration within an energy bandwidth of ±30 meV around. 170 meV [13]. The continuous curve through the data shows the Ce3+ mag- netic form factor. The doted line shows the calculated form factor for an itinerant 4f electron band for α-Ce [14]. et al [14] calculated within the itinerant 4f band model for Ce.
Δ33 resonance in pion nucleus elastic, single, and double charge exchange scattering
International Nuclear Information System (INIS)
Johnson, M.B.
1983-01-01
The Δ 33 resonance is strongly excited in pion-nucleon scattering, but there is clearly only a limited amount of information that can be learned in scattering the pion from an isolated nucleon. One learns that there is a resonance of mass 1232 MeV, width 115 MeV, and, if one is willing to introduce a dynamical model, something about the off-shell extension of the amplitude. One stands to learn much more from pion-nucleus scattering because in this case the Δ 33 resonance has an opportunity to scatter from nucleons, and how this occurs is not well understood. What do we know about the Δ-N interaction for pion-nucleus scattering. The isobar-hole model was invented to deal directly with the Δ 33 -nucleus dynamics, and a phenomenological determination of the isobar shell-model potential was attempted. The unknown dynamics deltaU/sub Δ/ is contained in a central isoscalar spreading potential of strength W 0 and a spin orbit potential deltaU 0 = W 0 rho + spin-orbit. The real part of W 0 rho is measured relative to the nucleon-nucleus potential. From a more theoretical point of view, one would like to be able to calculate deltaU/sub Δ/, including its isospin dependence, from an underlying dynamical model which is formulated in terms of the basic effective meson-baryon couplings. Some salient properties of these couplings can be determined from models of quark-bag structure, which raises the exciting possibility of learning about these fundamental issues from pion scattering. Attempts at Los Alamos to build a theoretical framework to deal with these and other issues are described
The importance of anisotropic scattering in high energy neutron transport problems
International Nuclear Information System (INIS)
Prillinger, G.; Mattes, M.
1984-01-01
To describe the highly anisotropic scattering of very fast neutrons adequately the transport code ANISN has been improved. Fokker-Planck terms have been introduced into the transport equation which accurately describe the small changes in energy and angle. The new code has been tested for a d(50)-Be neutron source in a deep penetration iron problem. The influence of the forward peaked elastic scattering on the fast neutron spectrum is shown to be significant and can be handled efficiently in the new ANISN version. Since common cross-section libraries are limited by Legendre expansion, or by their upper energy boundary, or exclude elastic scattering above 20 MeV a special library has been created. (Auth.)
Three particle scattering at high energies in a model with eikonal Hamiltonian
International Nuclear Information System (INIS)
Kharchenko, V.F.; Kuzmichev, V.E.
1980-04-01
The three particle collision process 3 → 3 with relative motion of each pair of particles described by a model with eikonal Hamiltonian is investigated. No additional restrictions on the motion of the particles (such as the fixed scattering centre approximation) are imposed. A unique, exact analytical solution of the three-particle problem is then shown to exist. An explicit expression for the 3 → 3 amplitude in the general case off the energy shell is obtained as the result of the exact summation of the multiple scattering series. It is shown that this series terminates on the energy shell. A new formula for the mutual cancellation of terms in the multiple scattering series in a model with eikonal Hamiltonian is found. (orig.)
Study of polarization of protons scattered by carbon at low energy
International Nuclear Information System (INIS)
Durand, Jean-Louis
1965-01-01
This research thesis reports the development of a device for measuring the polarization of energized particles (less than 3 MeV). In order to perform this measurement, the author analysed the polarization of protons scattered by carbon by setting up an experiment of double scattering. This approach results in a good energy resolution, a well defined geometry of targets, and the absence of input window. However, a drawback is a high loss of energy by recoil nucleus. In a first part, the author presents some methods of production of polarized particles, and the principle of polarisation measurement on 1/2 spin particles by the double scattering method. He describes the apparatus, outlines its limitations, and describes the electronic assembly designed to record results. He reports the apparatus exploitation and the way measures have been performed. Errors are assessed. Experimental results are compared with theoretical results [fr
Triple parton scatterings in high-energy proton-proton collisions arXiv
d'Enterria, David
2017-01-01
A generic expression to compute triple parton scattering cross sections in high-energy proton-proton (pp) collisions is presented as a function of the corresponding single parton cross sections and the transverse parton profile of the proton encoded in an effective parameter σeff,TPS. The value of σeff,TPS is closely related to the similar effective cross section that characterizes double parton scatterings, and amounts to σeff,TPS=12.5±4.5 mb. Estimates for triple charm (cc¯) and bottom (bb¯) production in pp collisions at LHC and FCC energies are presented based on next-to-next-to-leading-order perturbative calculations for single cc¯, bb¯ cross sections. At s≈100 TeV, about 15% of the pp collisions produce three cc¯ pairs from three different parton-parton scatterings.
The use of low energy alkali ion scattering as a probe of surface structure
International Nuclear Information System (INIS)
Overbury, S.H.
1987-01-01
An overview is given of the use of low energy ion scattering as a probe of surface structure with emphasis on work done using alkali ions. Various schemes for extracting structural information from the ion energy and angle distribution are discussed in therms of advantages and disadvantages of each. The scattering potential, which is the primary nonstructural parameter needed for analysis, is discussed in terms of recent experimental results. The structures of clean and reconstructed surfaces are discussed, with examples of measurements of layer relaxations on the Mo (111) surface and missing row reconstructions on the Au (110) and Pt (110) surfaces. Studies of adsorbate covered surfaces are presented with respect to location of the adsorbate and its effect on the structure of the underlying substrate. Finally, examples are given which demonstrate the sensitivity of ion scattering to surface defects and disordering on reconstructed Au (110) and Pt (110) surfaces and reconstructed Mo (111) surfaces, and to ordering of adsorbates on Mo
Relativistic chiral SU(3) symmetry, large Nc sum rules and meson-baryon scattering
International Nuclear Information System (INIS)
Lutz, M.F.M.; Kolomeitsev, E.E.
2001-05-01
The relativistic chiral SU(3) Lagrangian is used to describe kaon-nucleon scattering imposing constraints from the pion-nucleon sector and the axial-vector coupling constants of the baryon octet states. We solve the covariant coupled-channel Bethe-Salpeter equation with the interaction kernel truncated at chiral order Q 3 where we include only those terms which are leading in the large N c limit of QCD. The baryon decuplet states are an important explicit ingredient in our scheme, because together with the baryon octet states they form the large N c baryon ground states of QCD. Part of our technical developments is a minimal chiral subtraction scheme within dimensional regularization, which leads to a manifest realization of the covariant chiral counting rules. All SU(3) symmetry-breaking effects are well controlled by the combined chiral and large N c expansion, but still found to play a crucial role in understanding the empirical data. We achieve an excellent description of the data set typically up to laboratory momenta of p lab ≅ 500 MeV. (orig.)
Interatomic scattering in energy dependent photoelectron spectra of Ar clusters
Energy Technology Data Exchange (ETDEWEB)
Patanen, M.; Benkoula, S.; Nicolas, C.; Goel, A. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Antonsson, E. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Physikalische und Theoretische Chemie Institut für Chemie und Biochemie, Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany); Neville, J. J. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick E3B 6E2 (Canada); Miron, C., E-mail: Catalin.Miron@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Extreme Light Infrastructure - Nuclear Physics (ELI-NP), ‘Horia Hulubei’ National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov (Romania)
2015-09-28
Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.
International Nuclear Information System (INIS)
Fabrikant, Ilya I.; Hotop, Hartmut; Allan, Michael
2005-01-01
Cross sections at low energies for vibrationally elastic and inelastic scattering, as well as electron attachment to SF 6 , have been calculated using a multichannel effective range theory (ERT) with complex boundary conditions. The most active vibrational modes, the totally symmetric mode ν 1 and the infrared active mode ν 3 , have been included in the calculation. The ERT parameters were fitted to reproduce the experimental total and attachment cross sections. Differential elastic and vibrational excitation cross sections have been measured at 30 deg. and 135 deg. using a spectrometer with hemispherical analyzers. The calculation reproduces correctly the magnitudes and shapes of the differential elastic and ν 1 , ν 3 , and 2ν 1 excitation cross sections, in particular the sharp structures at vibrational thresholds. The s- and p-wave phase shifts obtained in the present analysis differ from those recently derived by Field et al. [Phys. Rev. A, 69, 052716 (2004)
Low energy electron scattering from atoms: Search for nanocatalysts
Msezane, A. Z.; Felfli, Z.; Sokolovski, D.
2011-05-01
Manipulating the structure and the dynamics of metallic nanoparticles, attractive due to their optical, electronic and magnetic properties, including applications in catalysis, requires a fundamental understanding of the dynamic processes at the atomic level. The fundamental mechanism of catalysis at the atomic scale has already been proposed and demonstrated in Au, Pd and Au-Pd catalysis of H2O2 through the scrutiny of low energy electron elastic total cross sections (TCSs). The use of mixed precious metal catalysts can produce even higher activities compared to Au alone. Here the interplay between negative ion resonances and Ramsauer-Townsend minima that characterize low energy electron TCSs for Au is identified as the fundamental signature of nanoscale catalysts. Calculated electron elastic TCSs for Ag, Pt, Pd, Ru and Y atoms are presented as illustrations. The recent complex angular momentum methodology is used for the calculations. It is concluded that these atoms are suitable candidates for nanocatalysts individually or in combinations. Supported by U.S. DOE, AFOSR and CAU CFNM, NSF-CREST.
Radiative corrections to high-energy neutrino scattering
International Nuclear Information System (INIS)
Rujula, A. de; Petronzio, R.; Savoy-Navarro, A.
1979-01-01
Motivated by precise neutrino experiments, the electromagnetic radiative corrections to the data are reconsidered. The usefulness is investigated and the simplicity demonstrated of the 'leading log' approximation: the calculation to order α ln (Q/μ), α ln (Q/msub(q)). Here Q is an energy scale of the overall process, μ is the lepton mass and msub(q) is a hadronic mass, the effective quark mass in a parton model. The leading log radiative corrections to dsigma/dy distributions and to suitably interpreted dsigma/dx distributions are quark-mass independent. The authors improve upon the conventional leading log approximation and compute explicitly the largest terms that lie beyond the leading log level. In practice this means that the model-independent formulae, though approximate, are likely to be excellent estimates everywhere except at low energy or very large y. It is pointed out that radiative corrections to measurements of deviations from the Callan-Gross relation and to measurements of the 'sea' constituency of nucleons are gigantic. The QCD inspired study of deviations from scaling is of particular interest. The authors compute, beyond the leading log level, the radiative corrections of the QCD predictions. (Auth.)
High-energy gravitational scattering and the general relativistic two-body problem
Damour, Thibault
2018-02-01
A technique for translating the classical scattering function of two gravitationally interacting bodies into a corresponding (effective one-body) Hamiltonian description has been recently introduced [Phys. Rev. D 94, 104015 (2016), 10.1103/PhysRevD.94.104015]. Using this technique, we derive, for the first time, to second-order in Newton's constant (i.e. one classical loop) the Hamiltonian of two point masses having an arbitrary (possibly relativistic) relative velocity. The resulting (second post-Minkowskian) Hamiltonian is found to have a tame high-energy structure which we relate both to gravitational self-force studies of large mass-ratio binary systems, and to the ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano. We derive several consequences of our second post-Minkowskian Hamiltonian: (i) the need to use special phase-space gauges to get a tame high-energy limit; and (ii) predictions about a (rest-mass independent) linear Regge trajectory behavior of high-angular-momenta, high-energy circular orbits. Ways of testing these predictions by dedicated numerical simulations are indicated. We finally indicate a way to connect our classical results to the quantum gravitational scattering amplitude of two particles, and we urge amplitude experts to use their novel techniques to compute the two-loop scattering amplitude of scalar masses, from which one could deduce the third post-Minkowskian effective one-body Hamiltonian.
Calculation of the high-energy limit of the Born series for electron-molecule scattering
International Nuclear Information System (INIS)
Konaka, S.
1982-01-01
A new procedure is proposed to derive an analytical expression of the high-energy limit of the differential cross section for small-angle electron-molecule scattering. An integral transform of the spherical Bessel functions, appear in the multipole expansion of the Born series, allows one to evaluate the second Born integrals analytically without explicit use of wavefunctions. (author)
A new computer code for quantitative analysis of low-energy ion scattering data
Dorenbos, G; Breeman, M; Boerma, D.O
We have developed a computer program for the full analysis of low-energy ion scattering (LEIS) data, i.e. an analysis that is equivalent to the full calculation of the three-dimensional trajectories of beam particles through a number of layers in the solid, and ending in the detector. A dedicated
Energy and intensity distributions of 279 keV multiply scattered ...
Indian Academy of Sciences (India)
Abstract. An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. This also results in extrac- tion of intensity and energy distributions of multiply scattered events originating from interactions of 279 keV photons with thick targets of bronze.
Scattering of low energy noble gas ions from a metal surface
International Nuclear Information System (INIS)
Luitjens, S.B.
1980-01-01
Reflection of low energy (0.1-10 keV) noble gas ions can be used to analyse a solid surface. To study charge exchange processes, the ion fractions of neon and of argon, scattered from a Cu(100) surface, have been determined. (Auth.)
Reflection of slow ions: effect of anisotropy of scattering on energy spectra
International Nuclear Information System (INIS)
Vukanic, J.; Simovic, R.
1997-01-01
Transport calculations based on linear Boltzmann equation have been carried out analytically for the reflection of low energy light ions from heavy targets. The collision integral of the ion transport equation is replaced by P3 approximation in angle. For power potentials the influence of the anisotropy of scattering on universal path length distribution of reflected particles is investigated. (author)
Proton optical potential and scattering matrix for tin nuclei at sub-coulomb energies
International Nuclear Information System (INIS)
Guzhovskij, B.Ya.; Dzyuba, B.M.
1981-01-01
A unified set of parameters of the proton optical potential (OP) for the n nuclei is searched for in the below-Coulomb-barrier energy range. The set must describe well the experimental data on the pn-reaction total cross sections and on the angular distributions of elastically scattered protons at E [ru
Measurement of the primary and scatter dose in high energy photon beams
Energy Technology Data Exchange (ETDEWEB)
Van der Linden, P.M. [Catharina Ziekenhuis, Eindhoven (Netherlands). Radiotherapy Dept.; Tiourina, T.B.; Dries, W.
1995-12-01
A method is presented to measure the primary and scatter components separately in a water tank using a small cylindrical absorber. Results from this experiment are compared with Monte Carlo calculations. The measurement setup consists of a small cylindrical absorber placed on a central axis of the beam a few centimetres above the radiation detector. Both absorber and detector move along the central axis while absorbed dose is registered. As the primary radiation is fully blocked, only scatter component is measured when a cylindrical absorber is used. Measurements in open fields result in the total absorbed dose being the sum of primary and scatter components. The primary dose component can be derived by substraction. Absorbers with different diameters are used. With decreasing dimensions the relative contribution of the dose due to scatter radiation increases. A steep increase is observed when the range of laterally scattered electrons becomes comparable with the radius of the absorber. Two different Monte Carlo simulations have been performed: with and without secondary electron transport. The data obtained for the former case perfectly agrees with the experiment. The situation where the secondary electron is assumed zero (i.e. local energy deposition) simulates the Cunningham model. Our results show that the Cunningham model predicts lower scatter component under the block edge which can be important for these applications.
International Nuclear Information System (INIS)
Jabbari, N.; Hashemi-Malayeri, B.; Farajollahi, A. R.; Kazemnejad, A.
2007-01-01
In radiotherapy with electron beams, scattered radiation from an electron applicator influences the dose distribution in the patient. The contribution of this radiation to the patient dose is significant, even in modern accelerators. In most of radiotherapy treatment planning systems, this component is not explicitly included. In addition, the scattered radiation produced by applicators varies based on the applicator design as well as the field size and distance from the applicators. The aim of this study was to calculate the amount of scattered dose contribution from applicators. We also tried to provide an extensive set of calculated data that could be used as input or benchmark data for advanced treatment planning systems that use Monte Carlo algorithms for dose distribution calculations. Electron beams produced by a NEPTUN 10PC medical linac were modeled using the BEAMnrc system. Central axis depth dose curves of the electron beams were measured and calculated, with and without the applicators in place, for different field sizes and energies. The scattered radiation from the applicators was determined by subtracting the central axis depth dose curves obtained without the applicators from that with the applicator. The results of this study indicated that the scattered radiation from the electron applicators of the NEPTUN 10PC is significant and cannot be neglected in advanced treatment planning systems. Furthermore, our results showed that the scattered radiation depends on the field size and decreases almost linearly with depth. (author)
An investigation into electron scattering from pyrazine at intermediate and high energies
Energy Technology Data Exchange (ETDEWEB)
Sanz, A. G.; Fuss, M. C. [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid (Spain); Blanco, F. [Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Gorfinkiel, J. D. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Almeida, D.; Ferreira da Silva, F.; Limão-Vieira, P. [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Brunger, M. J. [ARC Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); García, G., E-mail: g.garcia@iff.csic.es [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid (Spain); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia)
2013-11-14
Total electron scattering cross sections for pyrazine in the energy range 10–500 eV have been measured with a new magnetically confined electron transmission-beam apparatus. Theoretical differential and integral elastic, as well as integral inelastic, cross sections have been calculated by means of a screening-corrected form of the independent-atom representation (IAM-SCAR) from 10 to 1000 eV incident electron energies. The present experimental and theoretical total cross sections show a good level of agreement, to within 10%, in the overlapping energy range. Consistency of these results with previous calculations (i.e., the R-matrix and Schwinger Multichannel methods) and elastic scattering measurements at lower energies, below 10 eV, is also discussed.
Quantitative considerations in medium energy ion scattering depth profiling analysis of nanolayers
Energy Technology Data Exchange (ETDEWEB)
Zalm, P.C.; Bailey, P. [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Reading, M.A. [Physics and Materials Research Centre, University of Salford, Salford M5 4WT (United Kingdom); Rossall, A.K. [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Berg, J.A. van den, E-mail: j.vandenberg@hud.ac.uk [International Institute for Accelerator Applications, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom)
2016-11-15
The high depth resolution capability of medium energy ion scattering (MEIS) is becoming increasingly relevant to the characterisation of nanolayers in e.g. microelectronics. In this paper we examine the attainable quantitative accuracy of MEIS depth profiling. Transparent but reliable analytical calculations are used to illustrate what can ultimately be achieved for dilute impurities in a silicon matrix and the significant element-dependence of the depth scale, for instance, is illustrated this way. Furthermore, the signal intensity-to-concentration conversion and its dependence on the depth of scattering is addressed. Notably, deviations from the Rutherford scattering cross section due to screening effects resulting in a non-coulombic interaction potential and the reduction of the yield owing to neutralization of the exiting, backscattered H{sup +} and He{sup +} projectiles are evaluated. The former mainly affects the scattering off heavy target atoms while the latter is most severe for scattering off light target atoms and can be less accurately predicted. However, a pragmatic approach employing an extensive data set of measured ion fractions for both H{sup +} and He{sup +} ions scattered off a range of surfaces, allows its parameterization. This has enabled the combination of both effects, which provides essential information regarding the yield dependence both on the projectile energy and the mass of the scattering atom. Although, absolute quantification, especially when using He{sup +}, may not always be achievable, relative quantification in which the sum of all species in a layer adds up to 100%, is generally possible. This conclusion is supported by the provision of some examples of MEIS derived depth profiles of nanolayers. Finally, the relative benefits of either using H{sup +} or He{sup +} ions are briefly considered.
Structure of spin-dependent scattering amplitude and spin effects at small angles at RHIC energies
International Nuclear Information System (INIS)
Akchurin, N.; Goloskokov, S.V.; Selyugin, O.V.
1997-01-01
Spin-dependent pomeron effects are analyzed for elastic pp-scattering and calculations for spin-dependent differential cross sections, analyzing power and double-spin correlation parameters are carried out for the energy range of the Relativistic Heavy Ion Collider (RHIC) at BNL. In this energy range, 50 ≤√≤500 GeV, the structure of pomeron-proton coupling can be measured at RHIC with colliding polarized proton beams
High-Energy antipp and pp Elastic Scattering and Nucleon Structure
International Nuclear Information System (INIS)
Islam, M.M.; Innocente, V.; Fearnley, T.; Sanguinetti, G.
1987-01-01
High-energy antipp and pp elastic data from the CERN Collider and the ISR are analyzed in the nucleon valence core model. Diffraction is described by a profile function that incorporates crossing symmetry and saturation of Froissart-Martin bound. The model is found to provide a very satisfactory description of the elastic scattering over the whole range of energy and momentum transfer. Implications of the analysis on QCD models of nucleon structure are pointed out
High-Energy antipp and pp Elastic Scattering and Nucleon Structure
Energy Technology Data Exchange (ETDEWEB)
Islam, M.M.; Innocente, V.; Fearnley, T.; Sanguinetti, G.
1987-07-15
High-energy antipp and pp elastic data from the CERN Collider and the ISR are analyzed in the nucleon valence core model. Diffraction is described by a profile function that incorporates crossing symmetry and saturation of Froissart-Martin bound. The model is found to provide a very satisfactory description of the elastic scattering over the whole range of energy and momentum transfer. Implications of the analysis on QCD models of nucleon structure are pointed out.
Total electron scattering cross section of Fluorocarbons at intermediate electron energies
Palihawadana, Prasanga; Villela, Gilberto; Ariyasinghe, Wickramasinghe
2008-10-01
Total electron scattering cross sections (TCS) of Tetrafluoromethane (CF4), Trifluoromethane (CHF3), Hexafluoroethane (C2F6) and Octafluorocyclobutane (C4F8) have been measured using the linear transmission technique for impact energies 0.10 -- 4.00 keV. These TCS are compared to existing experimental and theoretical TCS in the literature. Based on the present measurements, an empirical formula is developed to predict the TCS of fluorocarbons as a function of incident electron energy.
Wahle, Chris W; Ross, David S; Thurston, George M
2012-07-21
We provide a mathematical and computational analysis of light scattering measurement of mixing free energies of quaternary isotropic liquids. In previous work, we analyzed mathematical and experimental design considerations for the ternary mixture case [D. Ross, G. Thurston, and C. Lutzer, J. Chem. Phys. 129, 064106 (2008); C. Wahle, D. Ross, and G. Thurston, J. Chem. Phys. 137, 034201 (2012)]. Here, we review and introduce dimension-free general formulations of the fully nonlinear partial differential equation (PDE) and its linearization, a basis for applying the method to composition spaces of any dimension, in principle. With numerical analysis of the PDE as applied to the light scattering implied by a test free energy and dielectric gradient combination, we show that values of the Rayleigh ratio within the quaternary composition tetrahedron can be used to correctly reconstruct the composition dependence of the free energy. We then extend the analysis to the case of a finite number of data points, measured with noise. In this context the linearized PDE describes the relevant diffusion of information from light scattering noise to the free energy. The fully nonlinear PDE creates a special set of curves in the composition tetrahedron, collections of which form characteristics of the nonlinear and linear PDEs, and we show that the information diffusion has a time-like direction along the positive normals to these curves. With use of Monte Carlo simulations of light scattering experiments, we find that for a modest laboratory light scattering setup, about 100-200 samples and 100 s of measurement time are enough to be able to measure the mixing free energy over the entire quaternary composition tetrahedron, to within an L(2) error norm of 10(-3). The present method can help quantify thermodynamics of quaternary isotropic liquid mixtures.
Low-energy electron scattering at surfaces using STM tips as a field emission gun
International Nuclear Information System (INIS)
Mizuno, S.; Iwanaga, M.; Tochihara, H.
2004-01-01
Full text: The field emission from scanning tunnelling microscopy (STM) tips has the potential to probe small surface areas with electron beams. Several groups have demonstrated their capabilities. Intensity mapping of the secondary electrons and projection of the transmitted electrons have been shown to have high lateral resolution. Spin-polarized secondary electron microscopy, energy loss spectroscopy and scanning Auger electron microscopy have been also reported. We examined low-energy electron scattering at surfaces. Our final target is a development of a low-energy electron diffraction (LEED) technique using field emission from STM tips to determine structures of surface small regions. Our apparatus was designed based on a commercial STM system (UNISOKU USM-1100). The STM part was suspended by four springs to remove vibrations. The sample holder was mounted on a tube-type piezo scanner, while the tip was fixed rigidly on the holder. The bias voltages were applied to the sample up to +100 V. The tunnel current and the emission current were monitored on the tip. The emission current was fixed at 0.1 nA in the field emission mode. The apparatus was designed to detect backscattered electrons toward surface normal direction. The scattered electrons were guided by the electric field of the tip shield and an extractor, passed through a three-grid electron energy filter, and detected by a microchannel plate equipped with a phosphor screen. Tips were made of tungsten single crystal wire with a diameter of 0.25 mm. They have orientation of direction, and were sharpened by electrochemical etching with a NaOH solution of 2 N. The tips were welded on a tantalum wire for annealing in a preparation chamber. Field emission patterns and field ion microscopy images of them were obtained before and after experiments. The sensitivity and stability of the apparatus were sufficient to observe scattering patterns on the screen. We measured the kinetic energies of the scattered
Elastic scattering of low energy electrons in partially ionized dense semiclassical plasma
Energy Technology Data Exchange (ETDEWEB)
Dzhumagulova, K. N., E-mail: dzhumagulova.karlygash@gmail.com; Shalenov, E. O.; Ramazanov, T. S. [IETP, Al Farabi Kazakh National University, 71al Farabi Street, Almaty 050040 (Kazakhstan)
2015-08-15
Elastic scattering of electrons by hydrogen atoms in a dense semiclassical hydrogen plasma for low impact energies has been studied. Differential scattering cross sections were calculated within the effective model of electron-atom interaction taking into account the effect of screening as well as the quantum mechanical effect of diffraction. The calculations were carried out on the basis of the phase-function method. The influence of the diffraction effect on the Ramsauer–Townsend effect was studied on the basis of a comparison with results made within the effective polarization model of the Buckingham type.
Coexistence of a bound state and scattering at the same energy value: a quantum paradox
International Nuclear Information System (INIS)
Chabanov, V.M.; Zakhar'ev, B.N.
1998-01-01
The example of a multi-channel system which possesses both bound (not quasi-bound !) and scattering states at the same energy value E is demonstrated. A special interaction has ability to confine waves near the origin and simultaneously admit scattering (even with transparency) at the fixed spectral point. These interaction matrices and wave functions can be continued to the whole axis. As another multi-channel peculiarity having no one-channel analogues was found a class of absolutely transparent interaction matrices without bound states
E710, $p\\bar{p}$ Elastic Scattering at Tevatron Energies
Energy Technology Data Exchange (ETDEWEB)
Sadr, Sasan [Northwestern Univ., Evanston, IL (United States)
1993-11-01
Experiment E710, located at site EO of the Tevatron collider at Fermilab, was conceived in order to measure $p\\bar{p}$ elastic scattering. The measured parameters were: the total cross section $\\sigma_t$, the ratio of the real to the imaginary part of the forward scattering amplitude $p$, the nuclear slope parameter B, the nuclear curvature parameter C, the total elastic cross section $\\sigma_{el}$, and the single diffractive cross section $\\sigma_{sd}$. These measurements were taken at center-of-mass energies of $\\sqrt{s}$= 1.02 and 1.8 TeV.
Total and elastic electron scattering cross sections from Xe at intermediate and high energies
International Nuclear Information System (INIS)
Garcia, G; Pablos, J L de; Blanco, F; Williart, A
2002-01-01
Experimental total electron scattering cross sections from Xe in the energy range 300-5000 eV have been obtained with experimental errors of about 3%. The method was based on the measurement of the attenuation of a linear electron beam through a Xe gas cell in combination with an electron spectroscopy technique to analyse the energy of the transmitted electrons. Differential and integral elastic cross sections have been calculated using a scattering potential method which includes relativistic effects. The consistency of our theoretical and experimental results is also discussed in the paper. Finally, analytical formulae depending on two parameters, namely the number of target electrons and the atomic polarizability, are given to reproduce the experimental data for Ne, Ar, Kr and Xe in the energy range 500-10 000 eV
Observational constraints on dark matter-dark energy scattering cross section
Energy Technology Data Exchange (ETDEWEB)
Kumar, Suresh [BITS Pilani, Department of Mathematics, Rajasthan (India); Nunes, Rafael C. [Universidade Federal de Juiz de Fora, Departamento de Fisica, Juiz de Fora, MG (Brazil)
2017-11-15
In this letter, we report precise and robust observational constraints on the dark matter-dark energy scattering cross section, using the latest data from cosmic microwave background (CMB) Planck temperature and polarization, baryon acoustic oscillations (BAO) measurements and weak gravitational lensing data from Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). The scattering scenario consists of a pure momentum exchange between the dark components, and we find σ{sub d} < 10{sup -29} cm{sup 2} (m{sub dm}c{sup 2}/GeV) at 95% CL from the joint analysis (CMB + BAO + CFHTLenS), where m{sub dm} is a typical dark matter particle mass. We notice that the scattering among the dark components may influence the growth of large scale structure in the Universe, leaving the background cosmology unaltered. (orig.)
Correlations among observables in the neutron-deuteron elastic scattering at low energies
International Nuclear Information System (INIS)
Frederico, T.; Goldman, I.D.
1984-01-01
The 2 S amplitude of the n-d elastic scattering appears like function of the dublet ( 2 a) scattering length in the three nucleons calculations. The correlation of Kcotg 2 δ o with 2 a, with separable N-N potential calculations, is obtained and the result is independent of the N-N potential. The 2 δ o (n-d) values obtained with these lines, using 2 a=.65F (experimental value), agree with p-d data. 2 S and 4 S scattering amplitude and tritium energy (E T ) calculations are performed with the zero-range model and an alternative deduction is proposed. These results for the E T and Kcotg 2 δ o correlation with 2 a show the limitations of this model. (L.C.) [pt
International Nuclear Information System (INIS)
Neskovic, N.; Ciric, D.; Perovic, B.
1982-01-01
The survival probability in small angle scattering of low energy alkali ions from alkali covered metal surfaces is considered. The model is based on the momentum approximation. The projectiles are K + ions and the target is the (001)Ni+K surface. The incident energy is 100 eV and the incident angle 5 0 . The interaction potential of the projectile and the target consists of the Born-Mayer, the dipole and the image charge potentials. The transition probability function corresponds to the resonant electron transition to the 4s projectile energy level. (orig.)
Beam energy spread in FERMI(at)elettra gun and linac induced by intrabeam scattering
International Nuclear Information System (INIS)
Zholents, Alexander A; Zholents, Alexander A; Zolotorev, Max S.; Penco, Giuseppe
2008-01-01
Intrabeam scattering (IBS) of electrons in the pre-cathode area in the electron guns know in the literature as Boersh effect is responsible for a growth of the electron beam energy spread there. Albeit most visible within the electron gun where the electron beam density is large and the energy spread is small, the IBS acts all along the entire electron beam pass through the Linac. In this report we calculate the energy spread induced by IBS in the FERMI(at)elettra electron gun
Experimental validation of a multi-energy x-ray adapted scatter separation method
Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.
2016-12-01
Both in radiography and computed tomography (CT), recently emerged energy-resolved x-ray photon counting detectors enable the identification and quantification of individual materials comprising the inspected object. However, the approaches used for these operations require highly accurate x-ray images. The accuracy of the images is severely compromised by the presence of scattered radiation, which leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in CT. The aim of the present study was to experimentally evaluate a recently introduced partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. For this purpose, a prototype x-ray system was used. Several radiographic acquisitions of an anthropomorphic thorax phantom were performed. Reference primary images were obtained via the beam-stop (BS) approach. The attenuation images acquired from PASSSA-corrected data showed a substantial increase in local contrast and internal structure contour visibility when compared to uncorrected images. A substantial reduction of scatter induced bias was also achieved. Quantitatively, the developed method proved to be in relatively good agreement with the BS data. The application of the proposed scatter correction technique lowered the initial normalized root-mean-square error (NRMSE) of 45% between the uncorrected total and the reference primary spectral images by a factor of 9, thus reducing it to around 5%.
Small-angle neutron scattering study of a monoclonal antibody using free-energy constraints.
Clark, Nicholas J; Zhang, Hailiang; Krueger, Susan; Lee, Hyo Jin; Ketchem, Randal R; Kerwin, Bruce; Kanapuram, Sekhar R; Treuheit, Michael J; McAuley, Arnold; Curtis, Joseph E
2013-11-14
Monoclonal antibodies (mAbs) contain hinge-like regions that enable structural flexibility of globular domains that have a direct effect on biological function. A subclass of mAbs, IgG2, have several interchain disulfide bonds in the hinge region that could potentially limit structural flexibility of the globular domains and affect the overall configuration space available to the mAb. We have characterized human IgG2 mAb in solution via small-angle neutron scattering (SANS) and interpreted the scattering data using atomistic models. Molecular Monte Carlo combined with molecular dynamics simulations of a model mAb indicate that a wide range of structural configurations are plausible, spanning radius of gyration values from ∼39 to ∼55 Å. Structural ensembles and representative single structure solutions were derived by comparison of theoretical SANS profiles of mAb models to experimental SANS data. Additionally, molecular mechanical and solvation free-energy calculations were carried out on the ensemble of best-fitting mAb structures. The results of this study indicate that low-resolution techniques like small-angle scattering combined with atomistic molecular simulations with free-energy analysis may be helpful to determine the types of intramolecular interactions that influence function and could lead to deleterious changes to mAb structure. This methodology will be useful to analyze small-angle scattering data of many macromolecular systems.
Probing quark mass effects in low-energy hadron physics
International Nuclear Information System (INIS)
Ditsche, Christoph
2012-01-01
formalism and a solution strategy for a precision determination of the leading partial waves of the πN scattering amplitude in the low-energy region. They are specifically important to constrain the pion-nucleon σ-term, which measures the light-quark contributions to the nucleon mass and is still a subject of discussion. Starting from hyperbolic dispersion relations, we derive a closed system of Roy-Steiner equations that respects analyticity, unitarity, and especially crossing symmetry. Assuming Mandelstam analyticity, we determine the maximal kinematical ranges of validity of the equations for both the scattering process and the crossed annihilation process ππ→ anti NN. To suppress the dependence on the high-energy region, we also introduce subtractions into the Roy-Steiner system, identifying the subtraction constants with πN subthreshold parameters. The S- and P-waves of the crossed process feature prominently in dispersive analyses of the scalar nucleon form factor that is directly linked to the σ-term and the electromagnetic nucleon form factors, respectively. As a first step towards solving the full Roy-Steiner system, we study the solution of these partial waves by using Muskhelishvili-Omnes techniques. Due to the conceptual and methodological differences, both parts are presented in a self-contained fashion.
Excitation function of elastic scattering on 12C + 4He system, at low energies
International Nuclear Information System (INIS)
Perez-Torres, R.; Aguilera, E. F.; Martinez-Quiroz, E.; Murillo, G.; Belyaeva, T. L.; Maldonado-Velazquez, M.
2011-01-01
Interactions in the 12 C + 4 He system are of great interest in astrophysics and to help determine the relative abundances of elements in stars, at the end of helium burning [1, 2]. The Instituto Nacional de Investigaciones Nucleares (ININ) in Mexico, have made measurements of elastic scattering for this system, using the inverse kinematics method with thick white gas [3, 4], for E CM (0.5 - 4 MeV) θ CM = 180 o . In this work we obtain excitation functions of elastic scattering of 12 C + 4 He system with angular and energy dependence; E CM = 0.5 - 4 MeV and θ CM 100 o -170 o .Using inverse kinematics method with thick white gas and energy loss tables. (Author)
Study of the low-energy neutron inelastic scattering in deformed transitional nuclei: 186W
International Nuclear Information System (INIS)
Diaz, J.R.F.; Solorzano, R.C.
1983-01-01
A study of inelastic neutron scattering by the nucleus 186 W at an incident energy of 2.75 MeV using the coupled-channel method has been made. Consideration is made of the 2 + (0.122 MeV), 4 + (0.3966 MeV), 2 + (0.7375 MeV), 3 + (0.8618 MeV) and 4 + (1.031 MeV) excited states. It is shown that in this energy range the process may be described satisfactorily by the Davydov-Filippov model, considering 186 W as a deformed nucleus with non-axial symmetry, given the quadrupole and hexadecapole deformations. The scattering process through the compound nucleus is calculated according to the Hauser-Feshbach formula. It is shown that the presence of direct processes may be partly due to the non-axiality of 186 W. (author)
International Nuclear Information System (INIS)
Sung Sil Chu
2001-01-01
Scattered dose of therapeutic high energy radiation beams contributed significant unwanted dose to the patient. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large field of high energy radiation beam, was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5-10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the uterus from thorax field irradiation and was measured about 1mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks About 6 cm lead block shield reduced the scatter photon dose under 10mGy for 60Gy on abdomen field and almost reduced electron contamination. (author)
Rao, D V; Brunetti, A; Gigante, G E
2003-01-01
Total Compton, individual shell and Compton energy-absorption scattering cross-sections are evaluated in the energy region 0.005 to 10 MeV for H, C. N, O. P and Ca. Compton energy absorption cross-sections deviate numerically with available values. The cause of the numerical discrepancies are not fully understood but can be attributed to Doppler broadening of the Compton scattered photons through a given angle. (authors)
Malavasi, Lorenzo
2011-04-21
In this Perspective article we give an account of the application of total scattering methods and pair distribution function (PDF) analysis to the investigation of materials for clean energy applications such as materials for solid oxide fuel cells and lithium batteries, in order to show the power of this technique in providing new insights into the structure-property correlation in this class of materials.
Pion elastic scattering from polarized 13C in the energy region of the P33 resonance
International Nuclear Information System (INIS)
Yifen, Yen
1992-08-01
Asymmetries (A y ) and differential cross sections (dσ/dΩ) were measured for π + and π - elastic scattering using polarized and unpolarized 13 C targets. The experiment was done at the Los Alamos Meson Physics Facility with the pion beam from the Low Energy Pion channel. The scattered pions were detected with the Large Acceptance Spectrometer. The 13 C nuclei in 13 C-enriched 1-butanol were polarized by the dynamic nuclear polarilization method. Angular distributions of both A y and dσ/dΩ were measured below the P 33 resonance at the incident energy of 130 MeV for π + and π - , and above the resonance at 223 MeV for π + and at 226 MeV for π - . In addition, A y and dσ/dΩ were measured in a range of momentum transfers, 1.75 ≤ q ≤ 2.05 fm - , at several energies. At 130 MeV, the values of A y are significantly different from zero for π - scattering. For π + at 130 MeV and for both π - and π + at all other energies, the A y are mostly consistent with zero. Theoretical analyses were done using different nuclear structure models. The data were not reproduced by the presently available nuclear wave functions. It was found that the asymmetry is strongly sensitive to the quadrupole spin flip part of the transition. The data of this thesis complement measurements of the magnetic form factor from electron scattering. In attempts to fit both the asymmetry and the magnetic form factor, it was found that the pion asymmetry data are not reproduced by the wavefunctions which fit the magnetic form factor at low momentum transfers
High energy behaviour of the scattering amplitude in the presence of confined channels
International Nuclear Information System (INIS)
Gehlen, G.; Rittenberg, V.
1977-09-01
The two-channel potential scattering problem in three space-dimensions is considered in the case when one channel is permanently confined. Two examples of confining potentials are considered: the harmonic oscillator and the infinite well. The two cases give radically different results: for the infinite well there is no high energy limit; in the case of the harmonic oscillator the amplitude has properties similar to that of dual absorptive models. (orig.) [de
Effective actions for high energy scattering in QCD and in gravity
Lipatov, L. N.
2017-12-01
The scattering amplitudes in QCD and gravity at high energies are described in terms of reggeized gluons and gravitons, respectively. In particular, the BFKL Pomeron in N = 4 SUSY is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. The effective actions for the reggeized gluons and gravitons are local in their rapidities. The Euler-Lagrange equations for these effective theories are constructed and their solutions are used for calculations of corresponding Reggeon vertices and trajectories.
International Nuclear Information System (INIS)
Vorobyov, A.A.; Korolev, G.A.; Dobrovolsky, A.V.; Khanzadeev, A.V.; Petrov, G.E.; Spiridenkov, E.M.; Terrien, Y.; Lugol, J.C.; Saudinos, J.; Silverman, B.H.; Wellers, F.
1988-01-01
An experimental setup for measurements of absolute differential cross sections and analyzing powers in small angle elastic np scattering is described. The main part of the apparatus consists of a multielectrode ionization chamber IKAR filled with methane, serving as both a gas target and a recoil detector. The apparatus was used in measurements with a polarized neutron beam from the Saturne synchrotron (Saclay, France) in the energy range from 378 to 1135 MeV. (orig.)
Low-energy electron scattering from CO. 2: Ab-initio study using the frame-transformation theory
Chandra, N.
1976-01-01
The Wigner-Eisenbud R matrix method has been combined with the frame transformation theory to study electron scattering from molecular systems. The R matrix, calculated at the boundary point of the molecular core radius, has been transformed to the space frame in order to continue the solution of the scattering equations in the outer region where rotational motion of the nuclei is taken into account. This procedure has been applied to a model calculation of thermal energy electron scattering from CO.
Schreck, Simon; Pietzsch, Annette; Kennedy, Brian; Såthe, Conny; Miedema, Piter S; Techert, Simone; Strocov, Vladimir N; Schmitt, Thorsten; Hennies, Franz; Rubensson, Jan-Erik; Föhlisch, Alexander
2016-01-29
Thermally driven chemistry as well as materials' functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. Here we demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution is utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. We show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The weak perturbation to the potential energy surface through hydrogen bonding is observed as a trend towards softening of the ground state potential around the coordinating atom. The instrumental developments in high resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach. With this multidimensional potential energy surfaces that characterize collective phenomena such as (bio)molecular function or high-temperature superconductivity will become accessible in near future.
Baryon scattering at high energies. Wave function, impact factor, and gluon radiation
International Nuclear Information System (INIS)
Bartels, J.; Motyka, L.; Jagellonian Univ., Krakow
2007-11-01
The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons. We find that the baryonic impact factor can be written as a sum of three pieces: in the first one a subsystem consisting of two of the three quarks behaves very much like the quark-antiquark pair in γ * scattering, whereas the third quark acts as a spectator. The second term belongs to the odderon, whereas in the third (C-even) piece all three quarks participate in the scattering. This term is new and has no analogue in γ * scattering. We also study the small x evolution of gluon radiation for each of these three terms. The first term follows the same pattern of gluon radiation as the γ * -initiated quark-antiquark dipole, and, in particular, it contains the BFKL evolution followed by the 2→4 transition vertex (triple Pomeron vertex). The odderon-term is described by the standard BKP evolution, and the baryon couples to both known odderon solutions, the Janik-Wosiek solution and the BLV solution. Finally, the t-channel evolution of the third term starts with a three reggeized gluon state which then, via a new 3→4 transition vertex, couples to the four gluon (two-Pomeron) state. We briefly discuss a few consequences of these findings, in particular the pattern of unitarization of high energy baryon scattering amplitudes. (orig.)
Investigation of {sup 17}F+p elastic scattering at near-barrier energies
Energy Technology Data Exchange (ETDEWEB)
El-Azab Farid, M. [Assiut University, Physics Department, Assiut (Egypt); Ibraheem, Awad A. [Al-Azhar University, Physics Department, Assiut (Egypt); King Khalid University, Physics Department, Abha (Saudi Arabia); Al-Hajjaji, Arwa S. [Taiz University, Physics Department, Taiz (Yemen)
2015-10-15
The {sup 17}F +p elastic scattering at two near-barrier energies of 3.5 and 4.3 MeV/nucleon, have been analyzed in the framework of the single folding approach. The folded potentials are constructed by folding the density-dependent (DDM3Y) effective nucleon-nucleon interaction over the nuclear density of the one-proton halo nucleus {sup 17}F. Two versions of the density are considered. In addition, two versions of the one-nucleon knock-on exchange potentials are introduced to construct the real microscopic potentials. The derived potentials supplemented by phenomenological Woods-Saxon imaginary and spin-orbit potentials produced excellent description of the differential elastic scattering cross sections at the higher energy without need to introduce any renormalization. At the lower energy, however, in order to successfully reproduce the data, it is necessary to reduce the strength of the constructed real DDM3Y potential by about 25% of its original value. Furthermore, good agreement with data is obtained using the extracted microscopic DDM3Y potentials for both real and imaginary parts. Moreover, the interesting notch test is applied to investigate the sensitivity of the elastic scattering cross section to the radial distribution of the constructed microscopic potentials. The extracted reaction (absorption) cross sections are, also, investigated. (orig.)
Sparse frequencies data inversion and the role of multi-scattered energy
Alkhalifah, Tariq Ali
2017-05-26
In trying to extract a broad spectrum of model wavenumbers from the data, necessary to build a plausible model of the Earth, we are, in theory, bounded at the high end by the diffraction resolution limit, which is proportional to the highest usable frequency in the data. At the low end, and courtesy of our multi-dimensional acquisition, the principles behind diffraction tomography theoretically extend our range to zero-wavenumbers, mainly provided by transmissions like diving waves. Within certain regions of the subsurface (i.e. deep), we face the prospective of having a model wavenumber gap in representing the velocity. Here, I demonstrate that inverting for multi scattered energy, we can recover additional wavenumbers not provided by single scattering gradients, that may feed the high and low ends of the model wavenumber spectrum, as well as help us fill in the infamous intermediate wavenumber gap. Thus, I outline a scenario in which we acquire dedicated sparse frequency data, allowing for more time to inject more energy of those frequencies at a reduced cost. Such additional energy is necessary to the recording of more multi-scattered events. The objective of this new paradigm is a high resolution model of the Earth.
Energy deposition model based on electron scattering cross section data from water molecules
Energy Technology Data Exchange (ETDEWEB)
Munoz, A; Oiler, J C [Centra de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avenida Complutense 22, 28040 Madrid (Spain); Blanco, F [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Avenida Complutense s.n., 28040 Madrid (Spain); Gorfinkiel, J D [Department of Physiscs and Astronomy, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Limao-Vieira, P [Departamento de Fisica, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Maira-Vidal, A; Borge, M J G; Tengblad, O [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas (CSIC), Serrano 113-bis, 28006 Madrid, Spam (Spain); Huerga, C; Tellez, M [Hospital Universitario La Paz, paseo de la Castellana 261, 28046 Madrid (Spain); Garcia, G [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones CientifIcas (CSIC), Serrano 113-bis, 28006 Madrid (Spain)], E-mail: g.garcia@imaff.cfmac.csic.es
2008-10-01
A complete set of electrons scattering cross sections by water molecules over a broad energy range, from the me V to the Me V ranges, is presented in this study. These data have been obtained by combining experiments and calculations and cover most relevant processes, both elastic and inelastic, which can take place in the considered energy range. A new Monte Carlo simulation programme has been developed using as input parameter these cross sectional data as well as experimental energy loss spectra. The simulation procedure has been applied to obtain electron tracks and energy deposition plots in water when irradiated by a Ru-106 plaque as those used for brachytherapy of ocular tumours. Finally, the low energy electron tracks provided by the present model have been compared with those obtained with other codes available in the literature.
N-body quantum scattering theory in two Hilbert spaces. VII. Real-energy limits
International Nuclear Information System (INIS)
Chandler, C.; Gibson, A.G.
1994-01-01
A study is made of the real-energy limits of approximate solutions of the Chandler--Gibson equations, as well as the real-energy limits of the approximate equations themselves. It is proved that (1) the approximate time-independent transition operator T π (z) and an auxiliary operator M π (z), when restricted to finite energy intervals, are trace class operators and have limits in trace norm for almost all values of the real energy; (2) the basic dynamical equation that determines the operator M π (z), when restricted to the space of trace class operators, has a real-energy limit in trace norm for almost all values of the real energy; (3) the real-energy limit of M π (z) is a solution of the real-energy limit equation; (4) the diagonal (on-shell) elements of the kernels of the real-energy limit of T π (z) and of all solutions of the real-energy limit equation exactly equal the on-shell transition operator, implying that the real-energy limit equation uniquely determines the physical transition amplitude; and (5) a sequence of approximate on-shell transition operators converges strongly to the exact on-shell transition operator. These mathematically rigorous results are believed to be the most general of their type for nonrelativistic N-body quantum scattering theories
A consideration of Raman scattering in the estimation of the background in low energy TXRF
International Nuclear Information System (INIS)
Doi, M.; Shoji, T.; Yamada, T.; Wilson, R.
2000-01-01
Accurate estimation of the background in a TXRF spectrum is necessary for trace analysis. The tailing of large peaks in the spectrum is the main source of the background. Sum and escape peaks are also part of the background caused from an SSD detector. Estimation and subtraction of these peaks from the spectrum have been successful with sophisticated software. Raman scattering is another possible phenomenon that will give rise to a background peak in the spectrum. This paper explores this Raman phenomenon. We used the W-Mα line for the low energy TXRF experiments. The W-Mα is effective for exciting aluminum, magnesium and sodium atoms. The energy of the W-Mα line, 1.78 keV, is above and near the absorption edges of these elements and yet below the absorption edge of silicon, 1.84 keV. To obtain a monochromatic W-Mα line, we used a monochromator consisting of a total reflection mirror of silicon and a crystal of RAP(001). The reflectivity of this monochromator is smaller than that of a monochromator consisting of synthesized multilayers but the energy resolution is superior. We measured the spectra from a blank silicon wafer and a silicon wafer covered with a titanium layer. A peak caused by the elastic scattering of the incident W-Mα line is the main peak that appeared at 1.78 keV in each spectrum. There is another peak at 1.65 keV in the spectrum from the blank wafer. The ratio of the intensity of this peak to that of the main peak increases with the glancing angle. The peak at 1.65 keV does not appear in the spectrum taken from a silicon wafer covered with a titanium layer. There are no characteristic x-rays which have this same energy. Also, Compton scattering cannot account for a peak at that energy. We calculated energies of diffracted x-rays by the silicon crystal assuming that x-rays having a continuous spectrum are included in the incident x-rays. However, there are no diffracted x-rays which have an energy in this range. The binding energy of
Radiative corrections to the Planckian-energy scattering in quantum gravity
International Nuclear Information System (INIS)
Nguyen Suan Han
1999-04-01
It is shown that the contributions of the radiative corrections to the Planckian energy scattering in quantum gravity in the straight-line paths approximation are factorized and are determined by the quantity R(t), which depends only upon the square of momentum transfers and do not affect the asymptotic in s at high energies. The apparently our result corresponds to the correct account of contributions of the so-called 'soft gravitons', for which the straight-line path approximation is valid. (author)
Local nuclear slope and curvature in high energy pp and pp-bar elastic scattering
Energy Technology Data Exchange (ETDEWEB)
Desgrolard, P. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Kontros, J.; Lengyel, A.I. [Inst. of Electron Physics, Uzhgorod (Ukraine); Martynov, E.S. [National Academy of Sciences of Ukraine, Kiev (Ukraine). Bogolyubov Inst. for Theoretical Physics
1997-05-01
The local nuclear slope is reconstructed from the experimental angular distributions with a procedure that uses overlapping t-bins, for an energy that ranges from the ISR to the Sp-bar pS and the Tevatron. Predictions of several models of (p-bar,p) elastic scattering at high energy are tested. Only a model with two-components Pomeron and Odderon gives a satisfactory agreement with the (non fitted) slope data. The extreme sensitivity of the local nuclear curvature with the choice for a Pomeron model is emphasized. (author). 30 refs.
Measurements of low-energy e+--Ne and e+-Ar total scattering cross sections
International Nuclear Information System (INIS)
Charlton, M.; Laricchia, G.; Griffith, T.C.; Wright, G.L.; Heyland, G.R.
1984-01-01
Measurements of positron and electron-Ne total scattering cross sections are reported in the energy range 2-50 eV. e + -Ar total cross sections are presented in the energy range 2-20 eV. In both the e + -Ne and e + -Ar cases marked discrepancies are found with other recent measurements and these are discussed along with possible systematic errors which may affect the data. The e - -Ne measurements are found to be in excellent agreement with recent experiments. (author)
The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer
International Nuclear Information System (INIS)
Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Rhodes, N.J.; Schooneveld, E.M.
2008-01-01
The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A -1 . This opens a still unexplored region of the kinematical (q,ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure
The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer
Energy Technology Data Exchange (ETDEWEB)
Perelli Cippo, E.; Gorini, G.; Tardocchi, M. [Dipartimento di Fisica ' G. Occhialini' , Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Pietropaolo, A. [Dipartimento di Fisica ' G. Occhialini' , CNISM-Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); NAST Center - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: antonino.pietropaolo@mib.infn.it; Andreani, C.; Senesi, R. [Dipartimento di Fisica and Centro NAST - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Rhodes, N.J.; Schooneveld, E.M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire 0QX OX11 (United Kingdom)
2008-05-01
The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A{sup -1}. This opens a still unexplored region of the kinematical (q,{omega}) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.
Moeller scattering polarimetry for high energy e sup + e sup - linear colliders
Alexander, G
2002-01-01
The general features of the Moeller scattering and its use as an electron polarimeter are described and studied in view of the planned future high energy e sup + e sup - linear colliders. In particular the study concentrates on the TESLA collider which is planned to operate with longitudinal polarised beams at a centre of mass energy of the order of 0.5 TeV with a luminosity of 3.4x10 sup 3 sup 4 cm sup - sup 2 s sup - sup 1.
Universality of Low-Energy Scattering in 2+1 Dimensions: The Non Symmetric Case
Khuri, N.N.; Sabatier, Pierre C.; Wu, Tai Tsun; Martin, Andre; Sabatier, Pierre C.; Wu, Tai Tsun
2004-01-01
For a very large class of potentials, $V(\\vec{x})$, $\\vec{x}\\in R^2$, we prove the universality of the low energy scattering amplitude, $f(\\vec{k}', \\vec{k})$. The result is $f=\\sqrt{\\frac{\\pi}{2}}\\{1/log k)+O(1/(log k)^2)$. The only exceptions occur if $V$ happens to have a zero energy bound state. Our new result includes as a special subclass the case of rotationally symmetric potentials, $V(|\\vec{x}|)$.
The possibilities of least-squares migration of internally scattered seismic energy
Aldawood, Ali
2015-05-26
Approximate images of the earth’s subsurface structures are usually obtained by migrating surface seismic data. Least-squares migration, under the single-scattering assumption, is used as an iterative linearized inversion scheme to suppress migration artifacts, deconvolve the source signature, mitigate the acquisition fingerprint, and enhance the spatial resolution of migrated images. The problem with least-squares migration of primaries, however, is that it may not be able to enhance events that are mainly illuminated by internal multiples, such as vertical and nearly vertical faults or salt flanks. To alleviate this problem, we adopted a linearized inversion framework to migrate internally scattered energy. We apply the least-squares migration of first-order internal multiples to image subsurface vertical fault planes. Tests on synthetic data demonstrated the ability of the proposed method to resolve vertical fault planes, which are poorly illuminated by the least-squares migration of primaries only. The proposed scheme is robust in the presence of white Gaussian observational noise and in the case of imaging the fault planes using inaccurate migration velocities. Our results suggested that the proposed least-squares imaging, under the double-scattering assumption, still retrieved the vertical fault planes when imaging the scattered data despite a slight defocusing of these events due to the presence of noise or velocity errors.
DEFF Research Database (Denmark)
Hansen, Flemming Yssing; Bruch, Ludwig Walter
2007-01-01
Conditions likely to lead to enhanced inelastic atomic scattering that creates shear horizontal (SH) and longitudinal acoustic (LA) monolayer phonons are identified, specifically examining the inelastic scattering of He-4 atoms by a monolayer solid of Xe/Pt(111) at incident energies of 2-25 meV. ...
A Rejection Sampling Based Method for Determining Thermal Scattering Angle and Energy
Energy Technology Data Exchange (ETDEWEB)
Haugen, Carl C.; Forget, Benoit; Smith, Kord S.
2017-09-01
Most high performance computing systems being deployed currently and envisioned for the future are based on making use of heavy parallelism across many computational nodes and many concurrent cores. These types of heavily parallel systems often have relatively little memory per core but large amounts of computing capability. This places a significant constraint on how data storage is handled in many Monte Carlo codes. This is made even more significant in fully coupled multiphysics simulations, which requires simulations of many physical phenomena be carried out concurrently on individual processing nodes, which further reduces the amount of memory available for storage of Monte Carlo data. As such, there has been a move towards on-the-fly nuclear data generation to reduce memory requirements associated with interpolation between pre-generated large nuclear data tables for a selection of system temperatures. Methods have been previously developed and implemented in MIT’s OpenMC Monte Carlo code for both the resolved resonance regime and the unresolved resonance regime, but are currently absent for the thermal energy regime. While there are many components involved in generating a thermal neutron scattering cross section on-the-fly, this work will focus on a proposed method for determining the energy and direction of a neutron after a thermal incoherent inelastic scattering event. This work proposes a rejection sampling based method using the thermal scattering kernel to determine the correct outgoing energy and angle. The goal of this project is to be able to treat the full S (a, ß) kernel for graphite, to assist in high fidelity simulations of the TREAT reactor at Idaho National Laboratory. The method is, however, sufficiently general to be applicable in other thermal scattering materials, and can be initially validated with the continuous analytic free gas model.
Forward elastic scattering and total cross-section at very high energies
International Nuclear Information System (INIS)
Castaldi, R.
1985-01-01
The successful cooling technique of antiproton beams at CERN has recently allowed the acceleration of proton and antiproton bunches simultaneously circulating in opposite directions in the SPS. Hadron-hadron collisions could so be produced at a centre-of-mass energy one order of magnitude higher than previously available, thus opening a new wide range of energies to experimentation. This technique also made it possible to replace one of the two proton beams in the ISR by a beam of antiprotons, allowing a direct precise comparison, by the same detectors, of pp and anti pp processes at the same energies. The recent results are summarized of the forward elastic scattering and total cross-section in this new energy domain. (Mori, K.)
A novel scatter separation method for multi-energy x-ray imaging
Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.
2016-06-01
X-ray imaging coupled with recently emerged energy-resolved photon counting detectors provides the ability to differentiate material components and to estimate their respective thicknesses. However, such techniques require highly accurate images. The presence of scattered radiation leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in computed tomography (CT). The aim of the present study was to introduce and evaluate a partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. This evaluation was carried out with the aid of numerical simulations provided by an internal simulation tool, Sindbad-SFFD. A simplified numerical thorax phantom placed in a CT geometry was used. The attenuation images and CT slices obtained from corrected data showed a remarkable increase in local contrast and internal structure detectability when compared to uncorrected images. Scatter induced bias was also substantially decreased. In terms of quantitative performance, the developed approach proved to be quite accurate as well. The average normalized root-mean-square error between the uncorrected projections and the reference primary projections was around 23%. The application of PASSSA reduced this error to around 5%. Finally, in terms of voxel value accuracy, an increase by a factor >10 was observed for most inspected volumes-of-interest, when comparing the corrected and uncorrected total volumes.
Scattering of low energy electrons from N2 and CO molecules
International Nuclear Information System (INIS)
Polley, J.P.
1985-01-01
The relative total cross sections for e - -N 2 and e - -CO scattering are determined for incident energies between 9.50 and 25.00 eV. The experiments are performed using a crossed beams configuration. The gas molecules are introduced into the interaction region as a modulated supersonic molecular beam. The energy of the electron beam is defined and analyzed by a pair of trochoidal velocity selectors, which provide 50 MeV resolution. Modulation of the supersonic molecular beam allows the use of phase-sensitive detection to determine the decrease in the transmitted electron current due to the scattering of electrons by the target molecules, which is proportional to the total scattering cross section. Numerous structural features in the e - -N 2 and e - -CO spectra are observed that are due to the formation of temporary negative ions, or electron-molecule resonances. These features range in width from 50 MeV for the prominent window resonance at 11.48 eV in the e - -N 2 spectrum, to 4 or more volts for the shape resonances that peak at 19.5 eV in the e - -CO spectrum and 22.5 eV in the e - -N 2 spectrum. The results of these experiments are interpreted with a modified grandparent model
Use of low energy alkali ion scattering as a probe of surface structure
International Nuclear Information System (INIS)
Overbury, S.H.
1986-01-01
An overview is given of the use of low energy ion scattering as a probe of surface structure with emphasis on work done using alkali ions. Various schemes for extracting structural information from the ion energy and angle distributions are discussed in terms of advantages and disadvantages of each. The scattering potential which is the primary non-structural parameter needed for analysis, is discussed in terms of recent experimental results. The structure of clean and reconstructed surfaces are discussed, with examples of measurements of layer relaxations on the Mo(111) surface and missing row reconstructions on the Au(110) and Pt(110) surfaces. Studies of adsorbate covered surfaces are presented with respect to location of the adsorbate and its effect on the structure of the underlying substrate. Finally, examples are given which demonstrate the sensitivity of ion scattering to surface defects and disordering on reconstructed Au(110) and Pt(110) surfaces and unreconstructed Mo(111) surfaces, and to ordering of adsorbates on Mo(001). 47 refs., 12 figs
On stimulated scattering of laser light in inertial fusion energy targets
Energy Technology Data Exchange (ETDEWEB)
Nikolic, Lj [National Inst. for Fusion Science, The Graduate Univ. for Advanced Studies, Toki, Gifu (Japan); Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Ishiguro, S. [National Inst. for Fusion Science, Theory and Computer Simulation Center, Toki, Gifu (Japan); Sato, T. [JAMSTEC, Earth Simulator Center, Yokohama, Kanagawa (Japan)
2002-11-01
Propagation of a laser light through regions of an underdense plasma is an active research topic in laser fusion. In particular, a large effort has been invested in studies of stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) which can reflect laser energy and produce energetic particles to preheat a fusion energy target. Experiments, theory and simulations agree on a complex interplay between various laser-plasma instabilities. By particle-in-cell simulations of an underdense electron-plasma, we have found, apart from the standard SRS, a strong backscattering near the electron plasma frequency at densities beyond the quarter critical. This novel instability, recognized in recent experiments as stimulated laser scattering on a trapped electron-acoustic mode (SEAS), is absent from a classical theory of laser-parametric instabilities. A parametric excitation of SEAS instability, is explained by a three-wave resonant decay of the incident laser light into a standing backscattered wave and a slow trapped electron acoustic wave ({omega} < {omega}{sub p}). Large SEAS pulsations, eventually suppressed by relativistic heating of electrons, are observed in our simulations. This phenomenon seems relevant to future hohlraum target and fast ignition experiments. (author)
International Nuclear Information System (INIS)
Botje, M.A.J.
1984-01-01
This thesis describes measurements of proton-proton and proton-antiproton elastic scattering with the scattered particles emerging at small angles in the centre of mass (CM) system. These measurements have been performed at the CERN Intersecting Storage Rings (ISR). The direct comparison of pp and anti pp scattering in this energy range is of considerable interest. This is because measurements on pp scattering alone, have revealed that in the ISR energy range both elastic- and total pp cross-sections increase with increasing energy. It is the subject of this thesis to check the prediction that the proton-antiproton cross section will do the same. The present experiment measures the angular distribution of pp and anti pp elastic scattering at small angles (typically 1-10 mrad) and at different energies. From these measurements a comparison of the energy behaviour of the pp and anti pp forward nuclear scattering amplitudes is obtained. This behaviour can be described in terms of three parameters: the total cross-section, the ratio of the real-to-imaginary part of the forward nuclear amplitude and a parameter, the slope, characterising the dependence of the process on the squared four-momentum transfer between the incident and the scattered particle. (Auth.)
Effect of hyperon channels in low-energy k-d scattering
International Nuclear Information System (INIS)
Schick, L.H.; Gibson, B.F.
1978-01-01
Within the framework of a Faddeev formalism and an implicit hyperon channel approximation, we have calculated K - d elastic, total, and reaction cross sections for incident kaon laboratory momenta up to 120 Mev/c. We have used as input two different (slightly modified) multichannel M matrix fits to low-energy anti KN scattering, each of which contains explicitly the πY channels, as well as a single channel representation of the anti KN interaction in which the hyperon channels appear only through their contributions to the imaginary parts of the anti KN scattering lengths. The K - d cross sections obtained with the single channel anti KN input differ by only some 10% from those for which we used the multichannel anti KN input. The D - d cross sections calculated using anti KN input parameters from each of the two separate M matrix fits differ across the entire momentum range investigated by 25-35%. (orig.) [de
A simple nonbinary scattering model applicable to atomic collisions is crystals at 1ow energies
DEFF Research Database (Denmark)
Andersen, Hans Henrik; Sigmund, Peter
1966-01-01
the projectile and each ring atom is described by a Born-Mayer potential, and the scattering is assumed to be elastic and governed by the classical equations of motion. Because of symmetry, the problem can be reduced to plane motion of a particle in a potential of elliptic symmetry. The elliptic force field......Presents the solution of a special scattering problem which may be important in the theory of slowing-down of atomic particles in crystals. A projectile moves along the centre axis of a regular ring of n equal atoms which are free and do not interact with each other. The interaction between...... the asymptotic velocities of the ring atoms as well as the energy loss of the projectile. Furthermore, it can be decided whether the projectile is reflected by the ring. Both the feasibility of assumptions specifying the problem and the validity of different approximations made in the transformation from...
Pascal, Elena; Singh, Saransh; Callahan, Patrick G; Hourahine, Ben; Trager-Cowan, Carol; Graef, Marc De
2018-04-01
Transmission Kikuchi diffraction (TKD) has been gaining momentum as a high resolution alternative to electron back-scattered diffraction (EBSD), adding to the existing electron diffraction modalities in the scanning electron microscope (SEM). The image simulation of any of these measurement techniques requires an energy dependent diffraction model for which, in turn, knowledge of electron energies and diffraction distances distributions is required. We identify the sample-detector geometry and the effect of inelastic events on the diffracting electron beam as the important factors to be considered when predicting these distributions. However, tractable models taking into account inelastic scattering explicitly are lacking. In this study, we expand the Monte Carlo (MC) energy-weighting dynamical simulations models used for EBSD [1] and ECP [2] to the TKD case. We show that the foil thickness in TKD can be used as a means of energy filtering and compare band sharpness in the different modalities. The current model is shown to correctly predict TKD patterns and, through the dictionary indexing approach, to produce higher quality indexed TKD maps than conventional Hough transform approach, especially close to grain boundaries. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.
Critchley, A. D. J.
2003-10-01
The main emphasis of the diode research project at the Atomic Weapons Establishment (AWE) UK is to produce small diameter radiographic spot sizes at high dose to improve the resolution of the transmission radiographs taken during hydrodynamic experiments. Experimental measurements of conditions within the diodes of Pulsed Power driven flash x-ray machines are vital to provide a benchmark for electromagnetic PIC codes such as LSP which are used to develop new diode designs. The potential use of inverse Compton scattering (ICS) as a diagnostic technique in the determination of electron energies within the diode has been investigated. The interaction of a laser beam with a beam of high-energy electrons will create an ICS spectrum of photons. Theoretically, one should be able to glean information on the energies and positions of the electrons from the energy spectrum and differential cross section of the scattered photons. The feasibility of fielding this technique on various diode designs has been explored, and an experimental setup with the greatest likelihood of success is proposed.
On the energy dependence of the optical model of neutron scattering from niobium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Lawson, R.D.
1986-01-01
Neutron differential-elastic-scattering cross sections of niobium were measured from 1.5 to 10.0 MeV at intervals of 0 . The observed values were interpreted in the context of the spherical optical-statistical model. It was found that the volume integral of the real potential decreased with energy whereas the integral of the imaginary potential increased. The energy dependence in both cases was consistent with a linear variation. There is a dispersion relationship between the real and imaginary potentials, and when this was used, in conjunction with the experimental imaginary potential, it was possible to predict the observed energy dependence of the real potential to a good degree of accuracy, thus supporting the consistency of the data and its analysis. The real-potential well depths needed to give the correct binding energies of the 2dsub(5/2), 3ssub(1/2), 2dsub(3/2) and 1gsub(7/2) particle states and of the 1gsub(9/2) hole state are in reasonable agreement with those given by a linear extrapolation of our neutron-scattering-based potential. However, the well depths needed to give the observed of the 2psub(3/2), 1fsub(5/2) and 2psub(1/2) hole states are about 10% less than the extrapolated values. (orig.)
An improved theoretical value for Zsub(eff) for low-energy positron-hydrogen-molecule scattering
International Nuclear Information System (INIS)
Armour, E.A.G.; Baker, D.J.
1986-01-01
The value of Zsub(eff), the effective number of electrons per molecule available to the positron for annihilation, is calculated for low-energy positron-hydrogen-molecule scattering using a scattering wavefunction containing terms in which the positron-electron distance is included linearly as a factor. The results at very low energy are much closer to the experimental value than any that have been obtained previously. (author)
Energy Technology Data Exchange (ETDEWEB)
Wielunski, L.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics
1996-12-31
The sensitivity of hydrogen elastic recoil detection ( ERD ) is usually limited by the low energy background in the ERD spectrum. A number of 4.5 MeV He{sup ++} hydrogen ERD spectra from different hydrogen implanted samples are compared. The samples are chosen with different atomic numbers from low Z (carbon) to high Z (tungsten carbide) to observe the effects of multiple scattering and double scattering within the sample material. The experimental depth resolution and levels of the low energy background in ERD spectra are compared with theoretical predictions from multiple and double scattering. 10 refs., 2 tabs., 5 figs.
Low-energy scattering parameters for van der Waals perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Benofy, L.P.; Buendia, E.; Guardiola, R.; de Llano, M.
1986-06-01
The low-energy two-body scattering S- and P-wave parameters, together with a shape-dependent S-wave quantity, which appear in the well-known low-density expansions for the ground-state energy of many-boson and many-fermion systems, are accurately calculated for several central pair potentials for spin-polarized atoms, helium atoms, and nucleons. An integral-equation method allowing accurate determination of the coefficients of the above-mentioned parameters expanded in powers of the attraction strength of the pair potential is presented and applied. The results are needed for perturbation studies of ground-state energies of various quantum many-body systems.
S-wave elastic scattering of ${\\it o} $-Ps from $\\text {H} _2 $ at low energy
Zhang, J. -Y.
2018-03-08
The confined variational method is applied to investigate the low-energy elastic scattering of ortho-positronium from $\\\\text{H}_2$ by first-principles quantum mechanics. Describing the correlation effect with explicitly correlated Gaussians, we obtain accurate $S$-wave phase shifts and pick-off annihilation parameters for different incident momenta. By a least-squares fit of the data to the effective-range theory, we determine the $S$-wave scattering length, $A_s=2.06a_0$, and the zero-energy value of the pick-off annihilation parameter, $^1\\\\!\\\\text{Z}_\\\\text{eff}=0.1858$. The obtained $^1\\\\!\\\\text{Z}_\\\\text{eff}$ agrees well with the precise experimental value of $0.186(1)$ (J.\\\\ Phys.\\\\ B \\\\textbf{16}, 4065 (1983)) and the obtained $A_s$ agrees well with the value of $2.1(2)a_0$ estimated from the average experimental momentum-transfer cross section for Ps energy below 0.3 eV (J.\\\\ Phys.\\\\ B \\\\textbf{36}, 4191 (2003)).
A Precision Low-Energy Measurement of the Weak Mixing Angle in Moller Scattering
Energy Technology Data Exchange (ETDEWEB)
Mastromarino, P.
2005-01-26
The E-158 experiment at the Stanford Linear Accelerator Center (SLAC) measures the parity-violating cross-section asymmetry in electron-electron (Moeller) scattering at low Q{sup 2}. This asymmetry, whose Standard Model prediction is roughly -150 parts per billion (ppb), is directly proportional to (1-4 sin{sup 2} {theta}{sub W}), where {theta}{sub W} is the weak mixing angle. Measuring this asymmetry to within 10% provides an important test of the Standard Model at the quantum loop level and probes for new physics at the TeV scale. The experiment employs the SLAC 50 GeV electron beam, scattering it off a liquid hydrogen target. A system of magnets and collimators is used to isolate and focus the Moeller scattering events into an integrating calorimeter. The electron beam is generated at the source using a strained, gradient-doped GaAs photocathode, which produces roughly 5 x 10{sup 11} electrons/pulse (at a beam rate of 120 Hz) with {approx} 80% longitudinal polarization. The helicity of the beam can be rapidly switched, eliminating problems associated with slow drifts. Helicity-correlations in the beam parameters (charge, position, angle and energy) are minimized at the source and corrected for using precision beam monitoring devices.
Universality of low-energy scattering in 2+1 dimensions
International Nuclear Information System (INIS)
Chadan, K.; Khuri, N.N.; Martin, A.; Wu, T.T.
1998-01-01
For any relativistic quantum field theory in 2+1 dimensions, with no zero mass particles, and satisfying the standard axioms, we establish a remarkable low-energy theorem. The S-wave phase shift, δ 0 (k), k being the c.m. momentum, vanishes as either δ 0 →c/ln(k/m)or δ 0 →O(k 2 ) as k→0. The constant c is universal and c=π/2. This result follows only from the rigorously established analyticity and unitarity properties for 2-particle scattering. This kind of universality was first noted in non-relativistic potential scattering, albeit with an incomplete proof which missed, among other things, an exceptional class of potentials where δ 0 (k) is O(k 2 ) near k=0. We treat the potential scattering case with full generality and rigor, and explicitly define the exceptional class. Finally, we look at perturbation theory in φ 3 4 and study its relation to our non-perturbative result. The remarkable fact here is that in n-th order the perturbative amplitude diverges like (lnthinspk) n as k→0, while the full amplitude vanishes as (lnk) -1 . We show how these two facts can be reconciled. copyright 1998 The American Physical Society
Scattering of {sup 6}He at energies around the Coulomb barrier
Energy Technology Data Exchange (ETDEWEB)
Sanchez-BenItez, A M [Departamento de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain); Escrig, D [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Alvarez, M A G [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla (Spain)] [and others
2005-10-01
We have measured elastic cross sections of the scattering of {sup 6}He at E{sub Lab} = 14, 16, 17, 18 and 22 MeV on {sup 208}Pb in the angular ranges of 20 deg. - 64 deg. and 135 deg. - 170 deg. A significant amount of {sup 4}He events is found at energies well below the Coulomb barrier, that becomes dominant above it. Optical model calculations have been performed including a dynamic polarization potential. Very large imaginary diffuseness parameter is needed in order to describe the experimental distributions.
High-energy laser-summator based on Raman scattering principle
Eugeniy Mikhalovich, Zemskov; Zarubin, Peter Vasilievich; Cook, Joung
2013-02-01
This paper is a summary of the history, theory, and development efforts of summator, an all-in-one device that coherently combines multiple high-power laser beams, lowers the beam divergence, and shifts the wavelength based on stimulated Raman scattering principle in USSR from early 1960s to late 1970s. This was a part of the Terra-3 program, which was an umbrella program of highly classified high-energy laser weapons development efforts. Some parts of the Terra-3 program, specifically the terminal missile defense portion, were declassified recently, including the information on summator development efforts.
Elastic Scattering Of 6,7Li+80Se At Near And Above Barrier Energies
International Nuclear Information System (INIS)
Fimiani, L.; Marti, G. V.; Capurro, O. A.; Barbara, E. de; Testoni, J. E.; Zalazar, L.; Arazi, A.; Cardona, M. A.; Carnelli, P.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Fernandez Niello, J. O.
2010-01-01
In this work we propose to study the elastic scattering of the weakly bound projectiles 6,7 Li on an intermediate mass target 80 Se. From the experimental results presented here, precise angular distributions at energies below, around and above the nominal Coulomb barriers of the systems were obtained. The final goal of our work is to determine the characteristic parameters of the optical potential and use them to address the question of whether the usual threshold anomaly or the breakup threshold anomaly are present or not in these systems.
Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies
Alekseev, I. G.; Bazhanov, N. A.; Beloglazov, Yu. A.; Budkovsky, P. E.; Bunyatova, E. I.; Filimonov, E. A.; Kanavets, V. P.; Kovalev, A. I.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Shchedrov, V. A.; Sulimov, A. D.
2008-01-01
The asymmetry parameter P was measured for the elastic pion-proton scattering in the very backward angular region of theta_cm ~ 150-170^o at several pion beam energies in the invariant mass range containing most of the pion-proton resonances. The general goal of the experimental program was to provide new data for partial wave analyses in order to resolve their uncertainties in the baryon resonance region to allow the unambiguous baryon spectrum reconstructions. Until recently the parameter P...
Asgari, Afrouz; Ashoor, Mansour; Sohrabpour, Mostafa; Shokrani, Parvaneh; Rezaei, Ali
2015-05-01
Improving signal to noise ratio (SNR) and qualified images by the various methods is very important for detecting the abnormalities at the body organs. Scatter and attenuation of photons by the organs lead to errors in radiopharmaceutical estimation as well as degradation of images. The choice of suitable energy window and the radionuclide have a key role in nuclear medicine which appearing the lowest scatter fraction as well as having a nearly constant linear attenuation coefficient as a function of phantom thickness. The energy windows of symmetrical window (SW), asymmetric window (ASW), high window (WH) and low window (WL) using Tc-99m and Sm-153 radionuclide with solid water slab phantom (RW3) and Teflon bone phantoms have been compared, and Matlab software and Monte Carlo N-Particle (MCNP4C) code were modified to simulate these methods and obtaining the amounts of FWHM and full width at tenth maximum (FWTM) using line spread functions (LSFs). The experimental data were obtained from the Orbiter Scintron gamma camera. Based on the results of the simulation as well as experimental work, the performance of WH and ASW display of the results, lowest scatter fraction as well as constant linear attenuation coefficient as a function of phantom thickness. WH and ASW were optimal windows in nuclear medicine imaging for Tc-99m in RW3 phantom and Sm-153 in Teflon bone phantom. Attenuation correction was done for WH and ASW optimal windows and for these radionuclides using filtered back projection algorithm. Results of simulation and experimental show that very good agreement between the set of experimental with simulation as well as theoretical values with simulation data were obtained which was nominally less than 7.07 % for Tc-99m and less than 8.00 % for Sm-153. Corrected counts were not affected by the thickness of scattering material. The Simulated results of Line Spread Function (LSF) for Sm-153 and Tc-99m in phantom based on four windows and TEW method were
A wide-range magnetic spectrometer for electron scattering in medium energy range
International Nuclear Information System (INIS)
Mao Zhenlin
1988-01-01
A non-focusing magnetic spectrometer design for electron scattering in medium energy region is proposed. The positions read out from the position-sensitive detectors in the spectrometer are used for track reconstruction and momentum measurement by means of a computer program. The construction of this spectrometer is simple and there is no special technique and element for correction to aberration. It is suitable for usage of spectrometer with large solid angle and wide momentum range. The momentum resolution, momentum range and acceptance in a practical case are calculated by Monte Carlo simulation
Optimal removal of scattered particles at medium energy storage rings with internal target
International Nuclear Information System (INIS)
Steger, U.; Koch, H.R.; Schult, O.W.B.
1991-01-01
We have studied at which places projectiles that have been scattered by an internal target out of the acceptance of a medium energy storage ring, can be dumped locally so that the effort for shielding can be minimized. General arguments are given where slits should be installed and their effect on the useful ring acceptance is discussed. In addition we have carried out Monte Carlo simulations for the dispersion-free mode of operation of COSY, which show that ≅ 86% of the lost beam can be removed locally with the use of only two sets of slits. (orig.)
High-energy effective action from scattering of QCD shock waves
Energy Technology Data Exchange (ETDEWEB)
Ian Balitsky
2005-07-01
At high energies, the relevant degrees of freedom are Wilson lines - infinite gauge links ordered along straight lines collinear to the velocities of colliding particles. The effective action for these Wilson lines is determined by the scattering of QCD shock waves. I develop the symmetric expansion of the effective action in powers of strength of one of the shock waves and calculate the leading term of the series. The corresponding first-order effective action, symmetric with respect to projectile and target, includes both up and down fan diagrams and pomeron loops.
Effective actions for high energy scattering in QCD and in gravity
Directory of Open Access Journals (Sweden)
Lipatov L. N.
2017-01-01
Full Text Available The scattering amplitudes in QCD and gravity at high energies are described in terms of reggeized gluons and gravitons, respectively. In particular, the BFKL Pomeron in N = 4 SUSY is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. The effective actions for the reggeized gluons and gravitons are local in their rapidities. The Euler-Lagrange equations for these effective theories are constructed and their solutions are used for calculations of corresponding Reggeon vertices and trajectories.
Salam, A.
1956-04-01
Lectures with mathematical analysis are given on Dispersion Theory and Causality and Dispersion Relations for Pion-nucleon Scattering. The appendix includes the S-matrix in terms of Heisenberg Operators. (F. S.)
Energy dependence of the optical model of neutron scattering from niobium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Lawson, R.D.
1985-05-01
Neutron differential-elastic-scattering cross sections of niobium were measured from 1.5 to 10.0 MeV at intervals of less than or equal to200 keV below 4.0 MeV, and of approx. =500 keV from 4.0 to 10.0 MeV. Ten to more than fifty differential-cross-section values were determined at each incident energy, distributed over the angular range approx. =20 to 160 0 . The observed values were interpreted in the context of the spherical optical-statistical model. It was found that the volume integral of the real potential decreased with energy whereas the integral of the imaginary part increased. The energy dependence in both cases was consistent with a linear variation. There is a dispersion relationship between the real and imaginary potentials, and when this was used, in conjunction with the experimental imaginary potential, it was possible to predict the observed energy dependence of the real potential to a good degree of accuracy, thus supporting the consistency of the data and its analysis. The real-potential well depths needed to give the correct binding energies of the 2d/sub 5/2/, 3s/sub 1/2/, 2d/sub 3/2/ and 1g/sub 7/2/ particle states and of the 1g/sub 9/2/ hole state are in reasonable agreement with those given by a linear extrapolation of the scattering potential. However, the well depths needed to give the observed binding of the 2p/sub 3/2/, 1f/sub 5/2/ and 2p/sub 1/2/ hole states are about 10% less than the extrapolated values. 40 refs., 5 figs
Energy dependence of the optical model of neutron scattering from niobium
Energy Technology Data Exchange (ETDEWEB)
Smith, A.B.; Guenther, P.T.; Lawson, R.D.
1985-05-01
Neutron differential-elastic-scattering cross sections of niobium were measured from 1.5 to 10.0 MeV at intervals of less than or equal to200 keV below 4.0 MeV, and of approx. =500 keV from 4.0 to 10.0 MeV. Ten to more than fifty differential-cross-section values were determined at each incident energy, distributed over the angular range approx. =20 to 160/sup 0/. The observed values were interpreted in the context of the spherical optical-statistical model. It was found that the volume integral of the real potential decreased with energy whereas the integral of the imaginary part increased. The energy dependence in both cases was consistent with a linear variation. There is a dispersion relationship between the real and imaginary potentials, and when this was used, in conjunction with the experimental imaginary potential, it was possible to predict the observed energy dependence of the real potential to a good degree of accuracy, thus supporting the consistency of the data and its analysis. The real-potential well depths needed to give the correct binding energies of the 2d/sub 5/2/, 3s/sub 1/2/, 2d/sub 3/2/ and 1g/sub 7/2/ particle states and of the 1g/sub 9/2/ hole state are in reasonable agreement with those given by a linear extrapolation of the scattering potential. However, the well depths needed to give the observed binding of the 2p/sub 3/2/, 1f/sub 5/2/ and 2p/sub 1/2/ hole states are about 10% less than the extrapolated values. 40 refs., 5 figs.
Analyses of the energy-dependent single separable potential models for the NN scattering
International Nuclear Information System (INIS)
Ahmad, S.S.; Beghi, L.
1981-08-01
Starting from a systematic study of the salient features regarding the quantum-mechanical two-particle scattering off an energy-dependent (ED) single separable potential and its connection with the rank-2 energy-independent (EI) separable potential in the T-(K-) amplitude formulation, the present status of the ED single separable potential models due to Tabakin (M1), Garcilazo (M2) and Ahmad (M3) has been discussed. It turned out that the incorporation of a self-consistent optimization procedure improves considerably the results of the 1 S 0 and 3 S 1 scattering phase shifts for the models (M2) and (M3) up to the CM wave number q=2.5 fm -1 , although the extrapolation of the results up to q=10 fm -1 reveals that the two models follow the typical behaviour of the well-known super-soft core potentials. It has been found that a variant of (M3) - i.e. (M4) involving one more parameter - gives the phase shifts results which are generally in excellent agreement with the data up to q=2.5 fm -1 and the extrapolation of the results for the 1 S 0 case in the higher wave number range not only follows the corresponding data qualitatively but also reflects a behaviour similar to the Reid soft core and Hamada-Johnston potentials together with a good agreement with the recent [4/3] Pade fits. A brief discussion regarding the features resulting from the variations in the ED parts of all the four models under consideration and their correlations with the inverse scattering theory methodology concludes the paper. (author)
Nuclear Physics Laboratory technical progress report, [August 15, 1991--October 1, 1992
International Nuclear Information System (INIS)
1992-01-01
This report summarizes work carried out between August 15, 1991 and October 1, 1992 at the Nuclear Physics Laboratory of the University of Colorado, Boulder, under contracts DE-FG02-86ER-40269 and DE-FG02-87ER-40335 with the United States Department of Energy. These contracts support experimental and theoretical work in intermediate energy nuclear physics. The experimental program is very broadly based; it includes pion-nucleon and pion-nucleus studies at Los Alamos and TRIUMF inelastic pion scattering and charge exchange reactions at LAMPF, kaon-nucleus scattering at the AGS, and nucleon charge exchange at LAMPF/NTOF
Pion-nucleon charge-exchange polarization by Gribov Reggeon calculus and the derivative rule
International Nuclear Information System (INIS)
Ardill, R.W.B.; Koehler, P.; Moriarty, K.J.M.
1977-01-01
The phenomenological consequences of the Gribov Reggeon calculus for the reaction πsup(-)+p→πdeg+n at 6 GeV/c are investigated and the polarization is obtained. The derivative rules is used to calculate the helicity flip amplitude. The results are very encouraging and would seem to indicate that the Gribov Reggeon calculus can be considered a more satisfactory approach to two-body phenomenology than the absorption model
Pion-nucleon vertex function with an off-shell nucleon
International Nuclear Information System (INIS)
Nutt, W.T.; Shakin, C.M.
1977-01-01
A model calculation for the π-N vertex function is presented in the case in which there is a single off-mass-shell nucleon and a (nearly) on-mass-shell pion. Very strong effects due to the P 11 resonance at 1470 MeV are found. A simple parametrization of the vertex function is prvided in the case that at least one nucleon is on its mass shell. (Auth.)
Review of the Lujan neutron scattering center: basic energy sciences prereport February 2009
Energy Technology Data Exchange (ETDEWEB)
Hurd, Alan J [Los Alamos National Laboratory; Rhyne, James J [Los Alamos National Laboratory; Lewis, Paul S [Los Alamos National Laboratory
2009-01-01
The Lujan Neutron Scattering Center (Lujan Center) at LANSCE is a designated National User Facility for neutron scattering and nuclear physics studies with pulsed beams of moderated neutrons (cold, thermal, and epithermal). As one of five experimental areas at the Los Alamos Neutron Science Center (LANSCE), the Lujan Center hosts engineers, scientists, and students from around the world. The Lujan Center consists of Experimental Room (ER) 1 (ERl) built by the Laboratory in 1977, ER2 built by the Office of Basic Energy Sciences (BES) in 1989, and the Office Building (622) also built by BES in 1989, along with a chem-bio lab, a shop, and other out-buildings. According to a 1996 Memorandum of Agreement (MOA) between the Defense Programs (DP) Office of the National Nuclear Security Agency (NNSA) and the Office of Science (SC, then the Office of Energy Research), the Lujan Center flight paths were transferred from DP to SC, including those in ERI. That MOA was updated in 2001. Under the MOA, NNSA-DP delivers neutron beam to the windows of the target crypt, outside of which BES becomes the 'landlord.' The leveraging nature of the Lujan Center on the LANSCE accelerator is a substantial annual leverage to the $11 M BES operating fund worth approximately $56 M operating cost of the linear accelerator (LINAC)-in beam delivery.
Energy dependence of the charged multiplicity in deep inelastic scattering at HERA
Energy Technology Data Exchange (ETDEWEB)
Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Laboratory, Argonne, IL (US)] (and others)
2008-03-15
The charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 38.6 pb{sup -1}. The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region of the hadronic centre-of-mass frame. The KNO-scaling properties of the data were investigated and the energy dependence was studied using different energy scales. The data are compared to results obtained in e{sup +}e{sup -} collisions and to previous DIS measurements as well as to leading-logarithm parton-shower Monte Carlo predictions. (orig.)
Dagdigian, Paul J.
2018-01-01
The potential energy surface (PES) describing the interaction of the ethynyl (C2H) radical in its ground X˜ 2Σ+ electronic state with molecular hydrogen has been computed through restricted coupled cluster calculations including single, double, and (perturbative) triple excitations [RCCSD(T)], with the assumption of fixed molecular geometries. The computed points were fit to an analytical form suitable for time-independent quantum scattering calculations of rotationally inelastic cross sections and rate constants. A representative set of energy dependent state-to-state cross sections is presented and discussed. The PES and cross sections for collisions of H2(j = 0) are compared with a previous study [F. Najar et al., Chem. Phys. Lett. 614, 251 (2014)] of collisions of C2H with H2 treated as a spherical collision partner. Good agreement is found between the two sets of calculations when the H2 molecule in the present calculation is spherically averaged.
Semihard interactions in nuclear collisions based on a unified approach to high energy scattering
International Nuclear Information System (INIS)
Drescher, H.J.; Hladik, M.; Werner, K.; Ostapchenko, S.; Centre National de la Recherche Scientifique, 44 - Nantes
1998-01-01
Our ultimate goal is the construction of a model for interactions of two nuclei in the energy range between several tens of GeV up to several TeV per nucleon in the centre-of-mass system. Such nuclear collisions are very complex, being composed of many components, and therefore some strategy is needed to construct a reliable model. The central point of our approach is the hypothesis, that the behavior of high energy interactions is universal (universality hypothesis). A model for nuclear interactions in a modular fashion is proposed. The individual modules, based on the universality hypothesis, are identified as building blocks for more elementary interactions (like e + e - , lepton-proton), and can therefore be studied in a much simpler context. With these building blocks under control, a quite reliable model is developed for nucleus-nucleus scattering, providing in particular very useful tests for the complicated numerical procedures using Monte Carlo techniques. (author)
Energy dependence of the charged multiplicity in deep inelastic scattering at HERA
International Nuclear Information System (INIS)
Chekanov, S.; Derrick, M.; Magill, S.
2008-03-01
The charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 38.6 pb -1 . The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region of the hadronic centre-of-mass frame. The KNO-scaling properties of the data were investigated and the energy dependence was studied using different energy scales. The data are compared to results obtained in e + e - collisions and to previous DIS measurements as well as to leading-logarithm parton-shower Monte Carlo predictions. (orig.)
Neutrino-induced reactions and neutrino scattering with nuclei in low and high neutrino energy
Energy Technology Data Exchange (ETDEWEB)
Cheoun, Myung-Ki, E-mail: cheoun@ssu.ac.kr; Ha, Eunja; Yang, Ghil-Seok [Department of Physics and OMEG institute, Soongsil Univ., Seoul 156-743 (Korea, Republic of); Kim, K. S. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Kajino, T. [National Astronomical Observatory of Japan, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan)
2016-06-21
We reviewed present status regarding theoretical approaches for neutrino-induced reactions and neutrino scattering. With a short introduction of relevant data, our recent calculations by distorted-wave Born approximation (DWBA) for quasielastic region are presented for MiniBooNE data. We also discussed that one step-process estimated by the DWBA is comparable to the two-step process, which has been usually used in the neutrino-nucleosynthesis. For much higher energy neutrino data, such as NOMAD data, elementary process approach was shown to be useful instead of using complicated nuclear models. But, in the low energy region, detailed nuclear structure model, such as QRPA and shell model, turn out to be inescapable to explain the reaction data.
Electron scattering by Ne, Ar and Kr at intermediate and high energies, 0.5-10 keV
Energy Technology Data Exchange (ETDEWEB)
Garcia, G.; Roteta, M.; Manero, F. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Departamento de Fusion y Particulas Elementales, Madrid (Spain); Blanco, F. [Universidad Complutense de Madrid, Facultad de Fisica, Departamento de Fisica Atomica Molecular y Nuclear, Madrid (Spain); Williart, A. [Universidad Nacional de Educacion a Distancia, Facultad de Ciencias, Departamento de Fisica de los Materiales, Madrid (Spain)
1999-04-28
Semi-empirical total cross sections for electron scattering of noble gases (Ne, Ar and Kr) in the energy range 0.5-10 keV have been obtained by combining transmission-beam measurements for impact energies up to 6 keV with an asymptotic behaviour at higher energies according to the Born-Bethe approximation. The influence of the forward electron scattering on the experimental system has been evaluated by means of a Monte Carlo electron transport simulation. Theoretical values have also been obtained by applying the Born approximation in the case of inelastic processes and by means of an atomic scattering potential for the elastic part. The results of these calculations show an excellent agreement with the semi-empirical values in the above-mentioned energy range. (author)
Choi, Youngwoon; Hillman, Timothy R; Choi, Wonjun; Lue, Niyom; Dasari, Ramachandra R; So, Peter T C; Choi, Wonshik; Yaqoob, Zahid
2013-12-13
Multiple scatterings occurring in a turbid medium attenuate the intensity of propagating waves. Here, we propose a method to efficiently deliver light energy to the desired target depth in a scattering medium. We measure the time-resolved reflection matrix of a scattering medium using coherent time-gated detection. From this matrix, we derive and experimentally implement an incident wave pattern that optimizes the detected signal corresponding to a specific arrival time. This leads to enhanced light delivery at the target depth. The proposed method will lay a foundation for efficient phototherapy and deep-tissue in vivo imaging in the near future.
Study of the nuclear-coulomb low-energy scattering parameters on the basis of the p-matrix approach
International Nuclear Information System (INIS)
Babenko, V.A.; Petrov, N.M.
1993-01-01
The P-matrix approach application to the description of two charged strongly interacting particles nuclear-Coulomb scattering parameters is considered. The nuclear-Coulomb scattering length and effective range explicit expressions in terms of the P-matrix parameters are found. The nuclear-Coulomb low-energy parameters expansions in powers of small parameter β ≡ R/a b , involving terms with big logarithms, are obtained. The nuclear-Coulomb scattering length and effective range for the square-well and the delta-shell short range potentials are found in an explicit form. (author). 21 refs
International Nuclear Information System (INIS)
Yakosawa, A.
1977-01-01
Results of various asymmetry measurements in nucleon-nucleon scattering with polarized beams and targets at ZGS energies are presented. A possible direct-channel resonance in the pp system is discussed. Most of the discussion above ZGS energies are aimed at future measurements
Ojambati, O. S.; Mosk, A. P.; Vellekoop, I. M.; Lagendijk, A.; Vos, W.L.
2016-01-01
We show that the spatial distribution of the energy density of optimally shaped waves inside a scattering medium can be described by considering only a few of the lowest eigenfunctions of the diffusion equation. Taking into account only the fundamental eigenfunction, the total internal energy inside
Ojambati, Oluwafemi Stephen; Mosk, Allard; Vellekoop, Ivo Micha; Lagendijk, Aart; Vos, Willem L.
2016-01-01
We show that the spatial distribution of the energy density of optimally shaped waves inside a scattering medium can be described by considering only a few of the lowest eigenfunctions of the diffusion equation. Taking into account only the fundamental eigenfunction, the total internal energy inside
Forcella, Luigi; Visciglia, Nicola
2018-01-01
We consider a class of 1D NLS perturbed with a steplike potential. We prove that the nonlinear solutions satisfy the double scattering channels in the energy space. The proof is based on concentration-compactness/rigidity method. We prove moreover that in dimension higher than one, classical scattering holds if the potential is periodic in all but one dimension and is steplike and repulsive in the remaining one.
Elastic scattering of the intermediate energy kaon mesons on the nuclei and coulomb's effects
Energy Technology Data Exchange (ETDEWEB)
Zhang Zhenqiu; Kong Lingjiang; Liu Xianhui
1985-05-01
In the frame of the eikonal scattering theory, using the basic parameters which are given by the different authors, the elastic scattering of the intermediate energy kaon mesons /sup 12/C and /sup 40/Ca are studied. The Coulomb effect is calculated too. The results are agreement with the experimental data. The Coulombv effect does not only enhance the small angle differential cross section, but also fill up the dip of the differential cross section.
Analysing powers in free n vectorp forward elastic scattering at energies from 630 to 1000 MeV
International Nuclear Information System (INIS)
Korolev, G.A.; Khanzadeev, A.V.; Petrov, G.E.; Spiridenkov, E.M.; Vorobyov, A.A.; Terrien, Y.; Lugol, J.C.; Saudinos, J.; Silverman, B.H.; Wellers, F.
1985-01-01
The analysing powers in free n vectorp forward elastic scattering have been measured for incident neutron energies of 633, 784, 834, 934 and 985 MeV, and for momentum transfer 0.01 2 . The experiment used a recoil detector ionisation chamber which served at the same time as a gas target, and scintillation counters to measure the asymmetry of the scattered neutrons. (orig.)
Neutron scattering on natural iron at incident energies between 9.4 and 15.2 MeV
International Nuclear Information System (INIS)
Schmidt, D.; Mannhart, W.; Klein, H.; Nolte, R.
1994-11-01
Neutrons were scattered on a sample of natural iron at 12 incident energies in the range between 9.4 MeV and 15.2 MeV. Differential cross sections of the elastic scattering (natural iron) and of the inelastic scattering to the first excited level of 56 Fe (Q=-0.847 MeV) were determined for angles between 12.5 deg and 160 deg with total uncertainties between of 3% and 10%. Legendre polynomial least-squares fits resulted in integrated cross sections with uncertainties of 2% (elastic data) and 7% (inelastic data). The cross sections obtained in this work were compared with data from the literature. Inelastic scattering cross sections were determined within the scope of a pseudolevel analysis up to excitation energies of nearly 5.5 MeV. At higher excitation energies the scattering spectrum is contaminated by scattered breakup neutrons from the D+d source used hampering an analysis of the data. (orig.) [de
Low-energy electron-helium scattering in a Nd–YAG laser field
International Nuclear Information System (INIS)
Ajana, I.; Makhoute, A.; Khalil, D.
2014-01-01
Highlights: • Laser assisted electron helium excitation is studied at low incident energies. • The inclusion of the second-order Born contributions is significant at low incident energies. • The target distortion induced by the laser field should be taken into account. • The effect of the second term of the Born series is reduced as the energy increases. - Abstract: We study the electron-impact excitation of atomic helium, in the presence of a linearly polarized Nd–YAG laser field, accompanied by the transfer of ℓ photons, for low collision energy of 25 eV and laser intensity of 5.3 × 10 11 W cm −2 . The second-order Born approximation has been used to calculate the differential cross sections. Detailed calculations of the scattering amplitudes are performed by using the Sturmian basis expansion. A detailed analysis is made of the excitation of the 1 1 S → 2 1 S and 1 1 S → 2 1 P transitions. We discuss the behavior and the variation of the cross sections corresponding to the excitation process for various geometrical configurations
Narrow-band photon beam via laser Compton scattering in an energy recovery linac
Directory of Open Access Journals (Sweden)
T. Akagi
2016-11-01
Full Text Available Narrow-bandwidth photon beams in the x-ray and γ-ray energy ranges are expected to be applied in various fields. An energy recovery linac (ERL-based laser Compton scattering (LCS source employing a laser enhancement cavity can produce a high-flux and narrow-bandwidth photon beam. We conducted the first experiment of an ERL-based LCS source in combination with a laser enhancement cavity. We obtained LCS photons with an energy of 6.95±0.01 keV by colliding an electron beam of 20 MeV with a laser of 1064 nm wavelength. The photon flux at the interaction point was evaluated to be (2.6±0.1×10^{7} photons/s with an average beam current of 58 μA and an average laser power of 10 kW. The energy bandwidth was evaluated to be 0.4% (rms with an opening angle of 0.14 mrad. The technologies demonstrated in this experiment are applicable for future ERL-based LCS sources.
Elastic and inelastic scattering of 12C ions at intermediate energies
International Nuclear Information System (INIS)
Hostachy, J.Y.; Buenerd, M.; Chauvin, J.; Lebrun, D.; Martin, P.
1988-01-01
Elastic and inelastic scattering of 12 C ions on 12 C and 208 Pb targets have been measured at the incident energies per nucleon E/A=120 MeV/u and E/A=200 MeV/u. Optical-model analysis is reported and nuclear surface transparency effects are discussed, together with the nuclear potential-energy dependence. The transparency region extends down to a radial internuclear distance of about 3 fm for the 12 C- 12 C system and 8 fm for the 12 C- 208 Pb system. A decrease of the imaginary potential with increasing incident energy is deduced for the two systems. Anomalous collapse of the real potential in the surface region is observed for 12 C- 208 Pb system at 200 MeV/u. DWBA analysis of data on the 2 + , 4.4 MeV state of 12 C is reported and trends for the energy dependence of mean-field excitations are deduced. (orig.)
Four-jet production in single- and double-parton scattering within high-energy factorization
Energy Technology Data Exchange (ETDEWEB)
Kutak, Krzysztof; Maciula, Rafal; Serino, Mirko [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences,Radzikowskiego 152, 31-342 Kraków (Poland); Szczurek, Antoni [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences,Radzikowskiego 152, 31-342 Kraków (Poland); Faculty of Mathematics and Natural Sciences, University of Rzeszów,ul. Pigonia 1, 35-310 Rzeszów (Poland); Hameren, Andreas van [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences,Radzikowskiego 152, 31-342 Kraków (Poland)
2016-04-28
We perform a first study of 4-jet production in a complete high-energy factorization (HEF) framework. We include and discuss contributions from both single-parton scattering (SPS) and double-parton scattering (DPS). The calculations are performed for kinematical situations relevant for two experimental measurements (ATLAS and CMS) at the LHC. We compare our results to those reported by the ATLAS and CMS collaborations for different sets of kinematical cuts. The results of the HEF approach are compared with their counterparts for collinear factorization. For symmetric cuts the DPS HEF result is considerably smaller than the one obtained with collinear factorization. The mechanism leading to this difference is of kinematical nature. We conclude that an analysis of inclusive 4-jet production with asymmetric p{sub T}-cuts below 50 GeV would be useful to enhance the DPS contribution relative to the SPS contribution. In contrast to the collinear approach, the HEF approach nicely describes the distribution of the ΔS variable, which involves all four jets and their angular correlations.
Low energy peripheral scaling in nucleon–nucleon scattering and uncertainty quantification
Ruiz Simo, I.; Amaro, J. E.; Ruiz Arriola, E.; Navarro Pérez, R.
2018-03-01
We analyze the peripheral structure of the nucleon–nucleon interaction for LAB energies below 350 MeV. To this end we transform the scattering matrix into the impact parameter representation by analyzing the scaled phase shifts (L + 1/2) δ JLS (p) and the scaled mixing parameters (L + 1/2)ɛ JLS (p) in terms of the impact parameter b = (L + 1/2)/p. According to the eikonal approximation, at large angular momentum L these functions should become an universal function of b, independent on L. This allows to discuss in a rather transparent way the role of statistical and systematic uncertainties in the different long range components of the two-body potential. Implications for peripheral waves obtained in chiral perturbation theory interactions to fifth order (N5LO) or from the large body of NN data considered in the SAID partial wave analysis are also drawn from comparing them with other phenomenological high-quality interactions, constructed to fit scattering data as well. We find that both N5LO and SAID peripheral waves disagree more than 5σ with the Granada-2013 statistical analysis, more than 2σ with the 6 statistically equivalent potentials fitting the Granada-2013 database and about 1σ with the historical set of 13 high-quality potentials developed since the 1993 Nijmegen analysis.
Coherent scattering of $\\pi$ mesons from helium at high energies : 4 papers
Ekelöf, T J C
1972-01-01
[Article I: A measurement of the differential cross section for elastic pion-helium scattering at 7.76 GeV/c] Results are presented for the region of squared four-momentum transfers between −0.05 and −0.5 (GeV/c)2. The directions of the scattered pions and alpha particles were measured with spark chambers and the momentum of the alphas as obtained from pulse-height and time-of-flight measurements. The results are compared with calculations from the Glauber theory, showing good agreement over the whole momentum-transfer range including the interference-dip region. [Article II:A helium-recoil spectrometer] The instrument described is intended for the detection and measurement of particles from coherent interactions of high-energy particles with 4He nuclei. It allows the determination of the magnitude and the direction of the momenta of the helium recoils from interactions in a pressurized gas target. The measurements are carried out with spark chambers and scintillation counters. Recoils emitted at angles g...
Boschini, M.J.; Gervasi, M.; Giani, S.; Grandi, D.; Ivantchenko, V.; Pensotti, S.; Rancoita, P.G.; Tacconi, M.
2011-01-01
In the space environment, instruments onboard of spacecrafts can be affected by displacement damage due to radiation. The differential scattering cross section for screened nucleus--nucleus interactions - i.e., including the effects due to screened Coulomb nuclear fields -, nuclear stopping powers and non-ionization energy losses are treated from about 50\\,keV/nucleon up to relativistic energies.
Scattering of NH3 and ND3 with rare gas atoms at low collision energy.
Loreau, J; van der Avoird, A
2015-11-14
We present a theoretical study of elastic and rotationally inelastic collisions of NH3 and ND3 with rare gas atoms (He, Ne, Ar, Kr, Xe) at low energy. Quantum close-coupling calculations have been performed for energies between 0.001 and 300 cm(-1). We focus on collisions in which NH3 is initially in the upper state of the inversion doublet with j = 1, k = 1, which is the most relevant in an experimental context as it can be trapped electrostatically and Stark-decelerated. We discuss the presence of resonances in the elastic and inelastic cross sections, as well as the trends in the inelastic cross sections along the rare gas series and the differences between NH3 and ND3 as a colliding partner. We also demonstrate the importance of explicitly taking into account the umbrella (inversion) motion of NH3 in order to obtain accurate scattering cross sections at low collision energy. Finally, we investigate the possibility of sympathetic cooling of ammonia using cold or ultracold rare gas atoms. We show that some systems exhibit a large ratio of elastic to inelastic cross sections in the cold regime, which is promising for sympathetic cooling experiments. The close-coupling calculations are based on previously reported ab initio potential energy surfaces for NH3-He and NH3-Ar, as well as on new, four-dimensional, potential energy surfaces for the interaction of ammonia with Ne, Kr, and Xe, which were computed using the coupled-cluster method and large basis sets. We compare the properties of the potential energy surfaces corresponding to the interaction of ammonia with the various rare gas atoms.
Scaling laws in high-energy inverse compton scattering. II. Effect of bulk motions
International Nuclear Information System (INIS)
Nozawa, Satoshi; Kohyama, Yasuharu; Itoh, Naoki
2010-01-01
We study the inverse Compton scattering of the CMB photons off high-energy nonthermal electrons. We extend the formalism obtained by the previous paper to the case where the electrons have nonzero bulk motions with respect to the CMB frame. Assuming the power-law electron distribution, we find the same scaling law for the probability distribution function P 1,K (s) as P 1 (s) which corresponds to the zero bulk motions, where the peak height and peak position depend only on the power-index parameter. We solved the rate equation analytically. It is found that the spectral intensity function also has the same scaling law. The effect of the bulk motions to the spectral intensity function is found to be small. The present study will be applicable to the analysis of the x-ray and gamma-ray emission models from various astrophysical objects with nonzero bulk motions such as radio galaxies and astrophysical jets.
Medium corrections to the first order optical potential for low-energy pion-4He scattering
International Nuclear Information System (INIS)
Kam, J. de; Geffen, F. van; Velde, M. van der
1980-01-01
We study the Pauli-principle corrections for low energy π- 4 He elastic scattering. In our approach we take into account explicitly the spin and isospin dependence of the Pauli-principle effect. Furthermore we discuss the combined effect of the Pauli-principle correction and the nuclear binding. Contrary to the Pauli principle we treat the binding corrections in an approximate way, using an effective mass for the residual nucleus. In our calculations we use the first-order optical potential of Celenza, Liu and Shakin. The Pauli-principle correction is found to have a considerable effect on the differential cross section. Our results indicate that the Pauli-principle corrections are largely compensated by the nuclear binding. (orig.)
Quasielastic scattering charge exchange p3He→nFppp reaction at mean energies
International Nuclear Information System (INIS)
Blinov, A.V.; Vanyushin, I.A.; Grechko, V.E.
1988-01-01
The main characteristics of the quasi-elastic charge-exchange reaction p 3 He → n F ppp (where n F is fast neutron in the rest frame of 3 He nucleus) are studied making use of the ITEP 80-cm liquid-hydrogen bubble chamber exposed in the 3 He beams of 2.5 and 5 GeV/c momenta (the kinetic energy T p of the primary protons in the rest frame of the nucleus is, respectively, 0.318 and 0.978 GeV). The experimental data are compared with the Galuber - Sitenko multiple scattering theory predictions and with the pole-model calculations taking into account the final-state interaction of the spectator nucleons. In the mass spectrum of the 3p system at 3.05 GeV a prominent structure has been observed which cannot be described by the pole model. Possible resonance nature of this structure is discussed
Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies
Energy Technology Data Exchange (ETDEWEB)
Alekseev, I.G.; Budkovsky, P.E.; Kanavets, V.P.; Koroleva, L.I.; Morozov, B.V.; Nesterov, V.M.; Ryltsov, V.V.; Sulimov, A.D.; Svirida, D.N. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bazhanov, N.A.; Bunyatova, E.I.; Zolin, L.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Beloglazov, Yu.A.; Filimonov, E.A.; Kovalev, A.I.; Novinsky, D.V.; Shchedrov, V.A.; Sumachev, V.V.; Trautman, V.Yu. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation)
2009-02-15
The asymmetry parameter P was measured for the elastic pion-proton scattering in the very backward angular region of {theta}{sub CM}{approx}150-170 at several pion beam energies in the invariant-mass range containing most of the pion-proton resonances. The general goal of the experimental program was to provide new data for partial wave analyses in order to resolve their uncertainties in the baryon resonance region to allow the unambiguous baryon spectrum reconstructions. Until recently the parameter P was not measured in the examined domain that might be explained by the extremely low cross-section. At the same time the predictions of various partial wave analyses are far from agreement in some kinematic areas and specifically those areas were chosen for the measurements where the disagreement is most pronouncing. The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by the ITEP-PNPI Collaboration in the latest 5 years. (orig.)
Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies
Alekseev, I. G.; Bazhanov, N. A.; Beloglazov, Yu. A.; Budkovsky, P. E.; Bunyatova, E. I.; Filimonov, E. A.; Kanavets, V. P.; Kovalev, A. I.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Shchedrov, V. A.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Trautman, V. Yu.; Zolin, L. S.
2009-02-01
The asymmetry parameter P was measured for the elastic pion-proton scattering in the very backward angular region of θ_{CM}^{} ≈ 150 - 170° at several pion beam energies in the invariant-mass range containing most of the pion-proton resonances. The general goal of the experimental program was to provide new data for partial wave analyses in order to resolve their uncertainties in the baryon resonance region to allow the unambiguous baryon spectrum reconstructions. Until recently the parameter P was not measured in the examined domain that might be explained by the extremely low cross-section. At the same time the predictions of various partial wave analyses are far from agreement in some kinematic areas and specifically those areas were chosen for the measurements where the disagreement is most pronouncing. The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by the ITEP-PNPI Collaboration in the latest 5 years.
Similarities and differences between antipp and pp scattering at TeV energies and beyond
International Nuclear Information System (INIS)
Gauron, P.; Nicolescu, B.
1986-12-01
The significant difference between the pp and antipp elastic dσ/dt discovered at the CERN ISR, and the behaviour of the antipp dσ/dt at the CERN collider, which have profound implications for the asymptotic behaviour of hadron scattering amplitudes, are explained in terms of a model theory based upon general S-matrix principles and a dynamical assumption of ''maximal strength'' for the strong interactions. Our model theory provides an excellent description of the pp and antipp data in the huge range 10 ≤ √s ≤ 630 GeV for /t/ ≤2.5 (GeV) 2 . Several striking consequences of the theory will be testable at Tevatron energies and beyond
Non-cancellation of electroweak logarithms in high-energy scattering
Directory of Open Access Journals (Sweden)
Aneesh V. Manohar
2015-01-01
Full Text Available We study electroweak Sudakov corrections in high energy scattering, and the cancellation between real and virtual Sudakov corrections. Numerical results are given for the case of heavy quark production by gluon collisions involving the rates gg→tt¯,bb¯,tb¯W,tt¯Z,bb¯Z,tt¯H,bb¯H. Gauge boson virtual corrections are related to real transverse gauge boson emission, and Higgs virtual corrections to Higgs and longitudinal gauge boson emission. At the LHC, electroweak corrections become important in the TeV regime. At the proposed 100 TeV collider, electroweak interactions enter a new regime, where the corrections are very large and need to be resummed.
Energy Technology Data Exchange (ETDEWEB)
Rolfe, R.M.
1976-12-01
The goal of the research was to investigate proton scattering on nuclei at intermediate energies and in particular to investigate proton scattering on helium. A theoretical investigation of the helium nucleus and the nature of the intermediate energy interaction, design and optimization of an energy-loss spectrometer facility for proton-nucleus scattering, and the unique superfluid helium target and experimental design are discussed.
A new method of explosive detection based on dual-energy X-ray technology and forward-scattering
International Nuclear Information System (INIS)
Zhao Kun; Li Jianmin
2004-01-01
Based on dual-energy X-ray technology combined with forward-scattering, a brand new explosive detection method is presented. Dual-energy technology can give the information on the effective atomic number (Z eff ) of an irradiated component, while the intensity of the forward scattered photons can reveal the density information according to our research. Therefore, the existence of the explosive can be effectively identified by combining these two characteristic quantities. Compared with the earlier inspection approaches, the new one has a series of particular advantages, such as high detection rate, low false alarm rate, automatic alarm and so forth. The project is ongoing. (authors)
International Nuclear Information System (INIS)
Rosenwald, J.C.; Drouard, J.; Simonian, M.
1987-01-01
The lack of electronic equilibrium in high energy photon beams is significant in the build-up region, at the edge of the beams and at the edge of inhomogeneous structures. The authors propose to use the algorithms based on separation of primary and scatter and to include in the scatter tables a component representing the lack of electronic equilibrium for small depths and small field size. The value and limits of this approach are discussed and illustrated by several examples corresponding to different photon energies in the range 1 to 25 MV. Good agreement between calculations and measurements is obtained in most situations. 6 refs.; 5 figs
Comparative analysis of the low-energy He + ions scattering on Al and Al 2O 3 surfaces
Fomin, V. M.; Misko, V. R.; Devreese, J. T.; Brongersma, H. H.
1998-12-01
Using the Anderson-Muda-Newns approach, the neutralization rate and the ion survival probability have been calculated for the large angle scattering of low-energy He + ions by Al and by Al 2O 3. The two-band model of the electronic energy spectra is applied for the case of alumina. The electron promotion has been shown to play an important role in the processes of the He + ions scattering by aluminum and alumina. The experimentally observed absence of the matrix effect is discussed on the basis of the obtained results.
Comparative analysis of the low-energy He+ ions scattering on Al and Al2O3 surfaces
International Nuclear Information System (INIS)
Fomin, V.M.; Misko, V.R.; Devreese, J.T.; Brongersma, H.H.
1998-01-01
Using the Anderson-Muda-Newns approach, the neutralization rate and the ion survival probability have been calculated for the large angle scattering of low-energy He + ions by Al and by Al 2 O 3 . The two-band model of the electronic energy spectra is applied for the case of alumina. The electron promotion has been shown to play an important role in the processes of the He + ions scattering by aluminum and alumina. The experimentally observed absence of the matrix effect is discussed on the basis of the obtained results. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)
Compton scattering for spectroscopic detection of ultra-fast, high flux, broad energy range X-rays
Energy Technology Data Exchange (ETDEWEB)
Cipiccia, S.; Wiggins, S. M.; Brunetti, E.; Vieux, G.; Yang, X.; Welsh, G. H.; Anania, M.; Islam, M. R.; Ersfeld, B.; Jaroszynski, D. A. [Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Maneuski, D.; Montgomery, R.; Smith, G.; Hoek, M.; Hamilton, D. J.; Shea, V. O. [Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Issac, R. C. [Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Research Department of Physics, Mar Athanasius College, Kothamangalam 686666, Kerala (India); Lemos, N. R. C.; Dias, J. M. [GoLP/Instituto de Plasmas eFusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Symes, D. R. [Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, OX11 0QX Didcot (United Kingdom); and others
2013-11-15
Compton side-scattering has been used to simultaneously downshift the energy of keV to MeV energy range photons while attenuating their flux to enable single-shot, spectrally resolved, measurements of high flux X-ray sources to be undertaken. To demonstrate the technique a 1 mm thick pixelated cadmium telluride detector has been used to measure spectra of Compton side-scattered radiation from a Cobalt-60 laboratory source and a high flux, high peak brilliance X-ray source of betatron radiation from a laser-plasma wakefield accelerator.
Xu, Wei-Qing; Xu, Long-Quan; Qi, De-Guang; Chen, Tao; Liu, Ya-Wei; Zhu, Lin-Fan
2018-04-01
The differential cross sections and generalized oscillator strengths for the low-lying excitations of the valence-shell 1eg orbital electron in ethane have been measured for the first time at a high incident electron energy of 1500 eV and a scattering angular range of 1.5°-10°. A weak feature, termed X here, with a band center of about 7.5 eV has been observed, which was also announced by the previous experimental and theoretical studies. The dynamic behaviors of the generalized oscillator strengths for the 3s (8.7 eV), 3s+3p (9.31 eV, 9.41 eV), and X (˜7.5 eV) transitions on the momentum transfer squared have been obtained. The integral cross sections of these transitions from their thresholds to 5000 eV have been obtained with the aid of the BE-scaling (B is the binding energy and E is the excitation energy) method. The optical oscillator strengths of the above transitions determined by extrapolating their generalized oscillator strengths to the limit of the squared momentum transfer K2 → 0 are in good agreement with the ones from the photoabsorption spectrum [J. W. Au et al., Chem. Phys. 173, 209 (1993)], which indicates that the present differential cross sections, generalized oscillator strengths, and integral cross sections can serve as benchmark data.
International Nuclear Information System (INIS)
Rosenberg, L.; Spruch, L.
1996-01-01
Levinson close-quote s theorem relates the zero-energy phase shift δ for potential scattering in a given partial wave l, by a spherically symmetric potential that falls off sufficiently rapidly, to the number of bound states of that l supported by the potential. An extension of this theorem is presented that applies to single-channel scattering by a compound system initially in its ground state. As suggested by Swan [Proc. R. Soc. London Ser. A 228, 10 (1955)], the extended theorem differs from that derived for potential scattering; even in the absence of composite bound states δ may differ from zero as a consequence of the Pauli principle. The derivation given here is based on the introduction of a continuous auxiliary open-quote open-quote length phase close-quote close-quote η, defined modulo π for l=0 by expressing the scattering length as A=acotη, where a is a characteristic length of the target. Application of the minimum principle for the scattering length determines the branch of the cotangent curve on which η lies and, by relating η to δ, an absolute determination of δ is made. The theorem is applicable, in principle, to single-channel scattering in any partial wave for e ± -atom and nucleon-nucleus systems. In addition to a knowledge of the number of composite bound states, information (which can be rather incomplete) concerning the structure of the target ground-state wave function is required for an explicit, absolute, determination of the phase shift δ. As for Levinson close-quote s original theorem for potential scattering, no additional information concerning the scattering wave function or scattering dynamics is required. copyright 1996 The American Physical Society
Fomin, Vladimir M.; Devreese, Jozef T.
1996-03-01
The influence of the electron-electron interaction in the surface valence band on the low-energy ion scattering (LEIS) is investigated in the framework of the modified Muda---Newns approach. With this aim the Anderson-type electron-electron interaction term is taken into account in the Hamiltonian of the system and a resulting nonlinear set of equations of motion for the occupation number matrix is solved for various values of the effective electron-electron coupling constant U. It is demonstrated that for increasing U the steady-state value of the atomic level occupation number after the scattering increases. As a result, the ion survival probability is found, e. g., for the scattering of ^4He^+ ions from Cu to be a decreasing function of U. These results allow a consistent interpretation of the recent experimental data on low-energy He^+ ion scattering from metals. The work is supported by the C.E.C. Human Capital and Mobility Project "Quantification of Surface Analysis by Low Energy Ion Scattering". Also at the Technical University of Eindhoven, The Netherlands.
Energy dependence of the 6Li + 16O elastic scattering versus that of 7Li + 16O
International Nuclear Information System (INIS)
Rudchik, A.T.; Zelinskyi, R.M.; Chercas, K.A.; Rudchik, A.A.; Pirnak, V.M.; Ponkratenko, O.A.; Kemper, K.W.; Plujko, V.A.
2013-01-01
Existing data for the 6 Li + 16 O elastic scattering at E c.m. =3.27 -36.8MeV were analyzed within the optical model and coupled-reaction-channels method. The 6 Li + 16 O elastic and inelastic scattering as well as the reorientation of 6 Li and the simplest transfer reactions were included in the coupled-channels scheme. The 6 Li + 16 O potential parameters at different energies as well as their energy dependence were deduced by the use of the dispersion relation between the real and imaginary parts of the potential. The contributions of the 6 Li reorientation and transfer reactions to the 6 Li + 16 O elastic scattering channel were estimated at the different energies. It is found that the potential scattering dominates the interaction at smaller angles for all energies, with the transfers contributing significantly at larger angles at the highest energies studied. The real part of the 6 Li + 16 O deduced potential is in reasonable agreement with that of a corresponding folding potential. The isotopic difference between the 6 Li + 16 O and 7 Li + 16 O optical potentials is larger for the imaginary potentials. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Wallon, S.
1996-09-17
In this PhD thesis, we deal with high energy Deep Inelastic Scattering in Perturbative Quantum Chromodynamics (QCD). In this work, two main topics are emphasized: The first one deals with dynamics based on perturbative renormalization group, and on perturbative Regge approaches. We discuss the applicability of these predictions, the possibility of distinguishing them in the HERA experiments, and their unification. We prove that the perturbative Regge dynamic can be successfully applied to describe the HERA data. Different observables are proposed for distinguishing these two approaches. We show that these two predictions can be unified in a system of equations. In the second one, unitarization and saturation problems in high energy QCD are discussed. In the multi-Regge approach, equivalent to the integrable one-dimensional XXX Heisenberg spin chain, we develop methods in order to solve this system, based on the Functional Bethe Ansatz. In the dipole model context, we propose a new formulation of unitarity and saturation effects, using Wilson loops. (author). 120 refs.
International Nuclear Information System (INIS)
Bando, H.; Krenciglowa, E.M.
1976-01-01
The role of 2p1h correlations in 17 O is studied within a multiple-scattering formalism. An accurate, energy-dependent reaction matrix with orthogonalized plane-wave intermediate states is used to assess the relative importance of particle-particle and particle-hole correlations in the 17 O energies. The effect of energy dependence of the reaction matrix is closely examined. (Auth.)
Neutron scattering facilities at China Institute of Atomic Energy. Present and future situations
Energy Technology Data Exchange (ETDEWEB)
Ye, C.T.; Gou, C.; Yang, T.H. [China Institute of Atomic Energy, Beijing (China)
2001-03-01
The 15 MW Heavy Water Research Reactor (HWRR) at CIAE in Beijing is the only neutron source available for neutron scattering experiments in China at present. So far totally 5 neutron scattering spectrometers are installed at 4 beam tubes. A 60 MW new research reactor, China Advanced Research Reactor (CARR), now is being built at CIAE to meet the increasing demand of neutron scattering research in China. A brief description of HWRR, the presently existing neutron scattering equipments at HWRP, CARR, and the neutron scattering facilities to be installed at CARR are presented. (J.P.N.)
Song, Li-Hua; Xin, Shang-Fei; Liu, Na
2018-02-01
Semi-inclusive deep inelastic lepton-nucleus scattering provides a good opportunity to investigate the cold nuclear effects on quark propagation and hadronization. Considering the nuclear modification of the quark energy loss and nuclear absorption effects in final state, the leading-order computations on hadron multiplicity ratios for both hadronization occurring outside and inside the medium are performed with the nuclear geometry effect of the path length L of the struck quark in the medium. By fitting the HERMES two-dimensional data on the multiplicity ratios for positively and negatively charged pions and kaons produced on neon, the hadron–nucleon inelastic cross section {σ }h for different identified hadrons is determined, respectively. It is found that our predictions obtained with the analytic parameterizations of quenching weights based on BDMPS formalism and the nuclear absorption factor {N}A(z,ν ) are in good agreement with the experimental measurements. This indicates that the energy loss and nuclear absorption are the main nuclear effects inducing a reduction of the hadron yield for quark hadronization occurring outside and inside the nucleus, respectively.
Study of the proton-proton elastic scattering at high energies through eikonal models
International Nuclear Information System (INIS)
Martini, Alvaro Favinha
1995-01-01
The proton-proton elastic scattering in the center of mass energy region 23 to 63 GeV is investigated through a multiple diffraction model. As an introduction to the subject, a detailed review of the fundamental basis of the Multiple Diffraction Formalism and a survey of the multiple diffraction models (geometrical) currently used are presented. The goal of this investigation is to reformulate one of these models, which makes use of an elementary (parton-parton) amplitude purely imaginary and is not able to predict the ρ-parameter (the ratio of the forward real and imaginary parts of the hadronic amplitude). Introducing a real part for the elementary amplitude proportional to the imaginary part, improvements in the formalism are obtained. It is shown that this new approach is able to reproduce all experimental data on differential and integrated cross sections (total, elastic and inelastic), but not the ρ-parameter as function of the energy. Then, starting from fitting of this parameter an overall reproduction of the physical observables is obtained, with the exception of the dip region (diffractive minimum in the differential cross section) overall description are also not firmly reached in all these models. Finally, alternatives to improve the results in a future research are suggested and discussed. (author)
Update of Continuous-Energy Data for Hydrogen and SiO_{2} Thermal Scattering
Energy Technology Data Exchange (ETDEWEB)
Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parsons, Donald Kent [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-02-23
The Nuclear Data Team has released updated continuous-energy neutron data files for: 1) hydrogen, and 2) S (α; β) (thermal scattering) on SiO_{2}. A list of new ZAIDs and the data that is updated (Old ZAID) is given in Table 1. The old data are still accessible, but are not the default.
International Nuclear Information System (INIS)
Ghrayeb, R.; Purushotham, M.; Hou, M.; Bauer, E.
1987-01-01
Low-energy ion scattering is used in combination with computer simulation to study the interaction potential between 600-eV potassium ions and atoms in metallic surfaces. A special algorithm is described which is used with the computer simulation code marlowes. This algorithm builds up impact areas on the simulated solid surface from which scattering cross sections can be estimated with an accuracy better than 1%. This can be done by calculating no more than a couple of thousand trajectories. The screening length in the Moliere approximation to the Thomas-Fermi potential is fitted in such a way that the ratio between the calculated cross sections for double and single scattering matches the scattering intensity ratio measured experimentally and associated with the same mechanisms. The consistency of the method is checked by repeating the procedure for different incidence conditions and also by predicting the intensities associated with other surface scattering mechanisms. The screening length estimates are found to be insensitive to thermal vibrations. The calculated ratios between scattering cross sections by different processes are suggested to be sensitive enough to the relative atomic positions in order to be useful in surface-structure characterization
International Nuclear Information System (INIS)
Kolkoori, Sanjeevareddy; Jaenisch, Gerd-Ruediger; Deresch, Andreas
2016-01-01
In this contribution, we discuss the influence of scattered radiation on materials' effective attenuation coefficients at higher X-ray energies. The selected Xray spectra for the dual-energy experiments correspond to 3 MV and 7.5 MV acceleration potential of the used betatron. Experiments were performed on a test phantom containing step wedges of different low- and high-Z materials. We evaluated the ratio between low- and high-energy X-ray attenuation coefficients quantitatively based on simulated poly-energetic high-energy X-ray source spectra and the detector sensitivity using the ''analytical Radiographic Testing inspection simulation tool'' (aRTist) developed at BAM. Furthermore, the influence of scattered radiation is evaluated using an efficient Monte-Carlo simulation. The simulation results are compared quantitatively with experimental investigations. Finally, important applications of the proposed technique in the context of aviation security are discussed.
International Nuclear Information System (INIS)
Fonseca, Gabriel Paiva
2010-01-01
There are many radiosensitive epidermotropics diseases such as mycosis fungo-ids and the syndrome of Sezary, coetaneous neoplasics originated from type T lymphocytes. Several studies indicate the eradication of the disease when treated with linear accelerators emitting electron beams with energies between 4 to 10 MeV. However, this treatment technique presents innumerable technical challenges since the disease in general reaches all patient's body, becoming necessary not only a very large field size radiation beam, but also deliver superficial doses limited to the skin depth. To reach the uniformity in the dose distribution, many techniques had already been developed. Based on these previous studies and guided by the report no. 23 of the American Association of Physicists in Medi-cine (AAPM), the present study developed an energy scattering and degrading plates and made dosimetry (computational and experimental), supplying subsidies for a future installation of Total Skin Electron Therapy (TSET) at the Servico de Radioterapia do Hospital das Clinicas de Sao Paulo. As part of the plates design, first of all, the energy spectrum of the 6 MeV electron beam of the VARIAN 2100C accelerator was reconstructed through Monte Carlo simulations using the MCNP4C code and based on experimental data. Once the spectrum is built, several materials were analyzed for the plates design based on radial and axial dose distribution, production of rays-x and dose attenuation. The simulation results were validated by experimental measurements in order to obtain a large field of radiation with 200 cm x 80 cm that meets the specifications of the AAPM protocol. (author)
International Nuclear Information System (INIS)
Callahan, J.H.; Mowrey, R.C.; Ross, M.M.
1992-01-01
Since the original postulation of its icosahedral structure by Smalley and Kroto in 1985, C 60 (also known as buckminsterfullerene) has fascinated investigators in a variety of fields. With the publication of a synthetic method for the bulk production of C 60 , there has been an explosion of research interest in this molecule. A number of intriguing experimental results have been published, including work in the area of mass spectrometry. For example, at a workshop at the 1991 ASMS meeting, Schwartz and coworkers reported a remarkable result. They showed that high energy collisions of C 60 + with He resulted not only in the expected formation of collision-induced dissociation (CID) products such as C 56 + and C 58 + (C 2 loss is the main fragmentation pathway for C 60 ), but also in the formation of products such as C 56 + + 4 and C 58 + + 4. Careful experiments with He showed that the products were C 56 He + and C 58 He + , most likely formed by the uptake of He by C 60 + during the collision. Subsequent experiments in this laboratory were able to directly observe the C 60 He + product, the product ion shifts in kinetic energy by an amount equal to the center-of-mass collision energy, consistent with kinematic arguments. C 60 He + was also observed by the Gross group and the Schwarz group. Gross and coworkers also showed that inelastic scattering processes can be observed in the collision spectrum. More recently, the Anderson group has studied reverse processes, in which ions such as He + , Li + , and C + undergo collisions with C 60 and are taken up in the collision
DEFF Research Database (Denmark)
Toft-Petersen, Rasmus; Groitl, Felix; Kure, Mathias
2016-01-01
A thorough experimental characterization of a multiplexing backend with multiple energy analysis on a cold-neutron triple axis spectrometer (cTAS) is presented. The prototype employs two angular segments (2 theta-segments) each containing five vertically scattering analyzers (energy channels...... to the energy resolution of a standard cTAS. The dispersion relation of the antiferromagnetic excitations in MnF2 has been mapped out by performing constant energy transfer maps. These results show that the tested setup is virtually spurion free. In addition, focusing effects due to (mis...
Inelastic neutron scattering in the spin wave energy gap of the polydomain γ-Mn(12%Ge) alloy
International Nuclear Information System (INIS)
Jankowska-Kisielinska, J.; Mikke, K.
1999-01-01
The subject of the present experiment was the investigation of the inelastic neutron scattering (INS) for energy transfers lower than and close to the energy gap of the spin wave spectrum for long wavelengths. The aim was a search for the excitations at the magnetic Brillouin zone (MBZ) boundary in polydomain Mn(12%Ge) alloy. The present measurements were performed by a 3-axis spectrometer at Maria Reactor at IEA in Swierk. We observed the INS in the polydomain Mn(12%Ge) alloy for energies smaller than and close to the energy gap value of the spin wave spectrum at room temperature. The observed intensity can be treated as a sum of intensity of neutrons scattered on spin waves around magnetic Brillouin zone centre and that of neutrons scattered on fluctuations at the zone boundary. The intensity of both components for energies 2-6 MeV was found to be of the same order. For higher energies spin waves around magnetic zone centre dominate. (author)
Toyokawa, Masakazu; Yahiro, Masanobu; Matsumoto, Takuma; Kohno, Michio
2018-02-01
An important current subject is to clarify the properties of chiral three-nucleon forces (3NFs) not only in nuclear matter but also in scattering between finite-size nuclei. Particularly for elastic scattering, this study has just started and the properties are not understood for a wide range of incident energies (E_in). We investigate basic properties of chiral 3NFs in nuclear matter with positive energies by using the Brueckner-Hartree-Fock method with chiral two-nucleon forces at N3LO and 3NFs at NNLO, and analyze the effects of chiral 3NFs on 4He elastic scattering from targets ^{208}Pb, ^{58}Ni, and ^{40}Ca over a wide range of 30 ≲ E_in/A_P ≲ 200 MeV by using the g-matrix folding model, where A_P is the mass number of the projectile. In symmetric nuclear matter with positive energies, chiral 3NFs make the single-particle potential less attractive and more absorptive. The effects mainly come from the Fujita-Miyazawa 2π-exchange 3NF and become slightly larger as E_in increases. These effects persist in the optical potentials of 4He scattering. As for the differential cross sections of 4He scattering, chiral-3NF effects are large for E_in/A_P ≳ 60 MeV and improve the agreement of the theoretical results with the measured ones. Particularly for E_in/A_P ≳ 100 MeV, the folding model reproduces measured differential cross sections pretty well. Cutoff (Λ) dependence is investigated for both nuclear matter and 4He scattering by considering two cases of Λ=450 and 550 MeV. The uncertainty coming from the dependence is smaller than chiral-3NF effects even at E_in/A_P=175 MeV.
International Nuclear Information System (INIS)
Arretche, F.; Mazon, K.T.; Michelin, S.E.; Fujimoto, M.M.; Iga, I.; Lee, M.-T.
2008-01-01
Iterative Schwinger variational methods and the method of continued fractions, widely used for electron-molecule scattering, are applied for the first time to investigate positron-molecule interactions. Specifically, integral and differential cross sections for elastic positron scattering by CO in the (0.5-20) eV energy range are calculated and reported. In our calculation, a static plus correlation-polarization potential is used to represent the collisional dynamics. Our calculated results are in general agreement with the theoretical and experimental data available in the literature
Medium energy inelastic proton-nucleus scattering with spin dependent NN interaction
International Nuclear Information System (INIS)
Ahmad, I.; Auger, J.P.
1981-12-01
The previously proposed effective profile expansion method for the Glauber multiple scattering model calculation has been extended to the case of proton-nucleus inelastic scattering with spin dependent NN interaction. Using the method which turns out to be computationally simple and of relatively wider applicability, a study of sensitivity of proton-nucleus inelastic scattering calculation to the sometimes neglected momentum transfer dependence of the NN scattering amplitude has been made. We find that the calculated polarization is particularly sensitive in this respect. (author)
Strain relaxation of CdTe on Ge studied by medium energy ion scattering
Energy Technology Data Exchange (ETDEWEB)
Pillet, J.C., E-mail: jean-christophe.pillet@cea.fr [Univ. Grenoble Alpes, CEA, LETI, MINATEC campus, F38000 Grenoble (France); CEA, LETI, Département Optique et Photonique, F38054 Grenoble (France); Pierre, F. [Univ. Grenoble Alpes, CEA, LETI, MINATEC campus, F38000 Grenoble (France); CEA, LETI, Service de Caractérisation des Matériaux et Composants, F38054 Grenoble (France); Jalabert, D. [Univ. Grenoble Alpes, CEA, LETI, MINATEC campus, F38000 Grenoble (France); CEA-INAC/UJF-Grenoble 1 UMR-E, SP2M, LEMMA, Minatec Grenoble F-38054 (France)
2016-10-01
We have used the medium energy ion scattering (MEIS) technique to assess the strain relaxation in molecular-beam epitaxial (MBE) grown CdTe (2 1 1)/Ge (2 1 1) system. A previous X-ray diffraction study, on 10 samples of the same heterostructure having thicknesses ranging from 25 nm to 10 μm has allowed the measurement of the strain relaxation on a large scale. However, the X-ray diffraction measurements cannot achieve a stress measurement in close proximity to the CdTe/Ge interface at the nanometer scale. Due to the huge lattice misfit between the CdTe and Ge, a high degree of disorder is expected at the interface. The MEIS in channeling mode is a good alternative in order to profile defects with a high depth resolution. For a 21 nm thick CdTe layer, we observed, at the interface, a high density of Cd and/or Te atoms moved from their expected crystallographic positions followed by a rapid recombination of defects. Strain relaxation mechanisms in the vicinity of the interface are discussed.
Adolph, C; Akhunzyanov, R; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anfimov, N V; Anosov, V; Augsten, K; Augustyniak, W; Austregesilo, A; Azevedo, C D R; Badełek, B; Balestra, F; Ball, M; Barth, J; Beck, R; Bedfer, Y; Bernhard, J; Bicker, K; Bielert, E R; Birsa, R; Bodlak, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Buchele, M; Chang, W-C; Chatterjee, C; Chiosso, M; Choi, I; Chung, S-U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Dreisbach, Ch; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger jr, M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Fuchey, E; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Giarra, J; Giordano, F; Gnesi, I; Gorzellik, M; Grabmuller, S; Grasso, A; Grosse Perdekamp, M; Grube, B; Grussenmeyer, T; Guskov, A; Haas, F; Hahne, D; Hamar, G; von Harrach, D; Heinsius, F H; Heitz, R; Herrmann, F; Horikawa, N; d’Hose, N; Hsieh, C-Y; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jary, V; Joosten, R; Jorg, P; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O M; Kramer, M; Kremser, P; Krinner, F; Kroumchtein, Z V; Kulinich, Y; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lian, Y-S; Lichtenstadt, J; Longo, R; Maggiora, A; Magnon, A; Makins, N; Makke, N; Mallot, G K; Marianski, B; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G V; Meyer, M; Meyer, W; Mikhailov, Yu V; Mikhasenko, M; Mitrofanov, E; Mitrofanov, N; Miyachi, Y; Nagaytsev, A; Nerling, F; Neyret, D; Novy, J; Nowak, W-D; Nukazuka, G; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panzieri, D; Parsamyan, B; Paul, S; Peng, J-C; Pereira, F; Pesek, M; Peshekhonov, D V; Pierre, N; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Riedl, C; Roskot, M; Rossiyskaya, N S; Ryabchikov, D I; Rybnikov, A; Rychter, A; Salac, R; Samoylenko, V D; Sandacz, A; Santos, C; Sarkar, S; Savin, I A; Sawada, T; Sbrizzai, G; Schiavon, P; Schmidt, K; Schmieden, H; Schonning, K; Seder, E; Selyunin, A; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Smolik, J; Srnka, A; Steffen, D; Stolarski, M; Subrt, O; Sulc, M; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; Tasevsky, M; Tessaro, S; Tessarotto, F; Thibaud, F; Thiel, A; Tosello, F; Tskhay, V; Uhl, S; Veloso, J; Virius, M; Vondra, J; Wallner, S; Weisrock, T; Wilfert, M; ter Wolbeek, J; Zaremba, K; Zavada, P; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M; Zink, A
2016-01-01
Single hadron azimuthal asymmetries in the cross sections of positive and negative hadron production in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\\phi$ is obtained by means of a five-parameter fitting function that besides a $\\phi$-independent term includes four modulations predicted by theory: $\\sin\\phi$, $\\sin 2 \\phi$, $\\sin 3\\phi$ and $\\cos\\phi$. The amplitudes of the five terms have been first extracted for the data integrated over all kinematic variables. In further fits, the $\\phi$-dependence is determined as a function of one of three kinematic variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the other two. Except the $\\phi$-independent term, all the modulation amplitudes are very small, and no cl...
Constraints on low energy QCD parameters from η → 3π and π π scattering
Kolesár, Marián; Novotný, Jiří
2018-03-01
The η → 3π decays are a valuable source of information on low energy QCD. Yet they were not used for an extraction of the three flavor chiral symmetry breaking order parameters until now. We use a Bayesian approach in the framework of resummed chiral perturbation theory to obtain constraints on the quark condensate and pseudoscalar decay constant in the chiral limit. We compare our results with recent CHPT and lattice QCD fits and find some tension, as the η → 3π data seem to prefer a larger ratio of the chiral order parameters. The results also disfavor a very large value of the pseudoscalar decay constant in the chiral limit, which was found by some recent work. In addition, we present results of a combined analysis including η → 3π decays and π π scattering and though the picture does not changed appreciably, we find some tension between the data we use. We also try to extract information on the mass difference of the light quarks, but the uncertainties prove to be large.
International Nuclear Information System (INIS)
Song Yuanhong; Wang Younian; Miskovic, Z.L.
2005-01-01
Vicinage effects in the energy loss and the electron emission spectra are studied in the presence of Coulomb explosion of swift, heavy molecular ions, during their grazing scattering from a solid surface. The dynamic response of the surface is treated by means of the dielectric theory within the specular reflection model using the plasmon pole approximation for the bulk dielectric function, whereas the angle-resolved energy spectra of the electrons emitted from the surface are obtained on the basis of the first-order, time-dependent perturbation theory. The evolution of the charge states of the constituent ions in the molecule during scattering is described by a nonequilibrium extension of the Brandt-Kitagawa model. The molecule scattering trajectories and the corresponding Coulomb explosion dynamics are evaluated for the cases of the internuclear axis being either aligned in the beam direction or randomly oriented in the directions parallel to the surface. Our calculations show that the vicinage effect in the energy loss is generally weaker for heavy molecules than for light molecules. In addition, there is clear evidence of the negative vicinage effect in both the energy loss and the energy spectra of the emitted electrons for molecular ions at lower speeds and with the axis aligned in the direction of motion
High resolution medium energy ion scattering study of silicon oxidation and oxy nitridation
International Nuclear Information System (INIS)
Gusev, E.P.; Lu, H.C.; Garfunkel, E.; Gustafsson, T.
1998-01-01
Full text: Silicon oxide is likely to remain the material of choice for gate oxides in microelectronics for the foreseeable future. As device become ever smaller and faster, the thickness of these layers in commercial products is predicted to be less than 50 Angstroms in just a few years. An understanding of such devices will therefore likely to be based on microscopic concepts and should now be investigated by atomistic techniques. With medium energy ion scattering (MEIS) using an electrostatic energy analyzer, depth profiling of thin (<60 Angstroms) silicon oxide films on Si(100) with 3 - 5 Angstroms depth resolution in the near region has been done. The growth mechanism of thin oxide films on Si(100) has been studied, using sequential oxygen isotope exposures. It is found that the oxide films are stoichiometric to within approx. 10 Angstroms of the interface. It is also found that the oxidation reactions occur at the surface, in the transition region and at interface, with only the third region being included in the conventional (Deal-Grove) model for oxide formation. Nitrogen is sometimes added to gate oxides, as it has been found empirically that his improves some of the electrical properties. The role, location and even the amount of nitrogen that exists in such films are poorly understood, and represent interesting analytical challenges. MEIS data will be presented that address these questions, measured for a number of different processing conditions. We have recently demonstrated how to perform nitrogen nano-engineering in such ultrathin gate dielectrics, and these results will also be discussed
Low-Energy Electron Scattering Data for Chemical Plasma Treatment of Biomass
International Nuclear Information System (INIS)
Lima, Marco A.P.
2014-01-01
Full text: Replacing fossil fuels with biofuels from renewable sources is an important goal for reducing greenhouse gas emissions. Many countries are already using few percent of ethanol in the gasoline and few of them, with more aggressive programs, have developed flex fuel engines that can run with any mixture of gasoline and ethanol. An important point is how to produce ethanol in a sustainable way and with which technology? Biomass is a good candidate since it has cellulose and hemicellulose as source of sugars. In order to liberate these sugars for fermentation, it is important to learn how to separate the main components. Chemical routes (acid treatment) and biological routes (enzymatic hydrolysis) are combined and used for these purposes. Atmospheric plasmas can be useful for attacking the biomass in a controlled manner and low-energy electrons may have an important role in the process. Recently we have been studying the interaction of electrons with lignin subunits (phenol, guaiacol, p-coumaryl alcohol), cellulose components, β-D-glucose and cellobiose (β(1 - 4) linked glucose dimer) and hemicellulose components (β-D-xylose). We also obtained results for the amylose subunits α-D-glucose and maltose (α(1 - 4) linked glucose dimer). Altogether, the resonance spectra of lignin, cellulose and hemicellulose components establish a physical–chemical basis for electron-induced biomass pretreatment that could be applied to biofuel production. In my talk I will give a progress report on this matter. We will also discuss microsolvation effects on the electron-phenol scattering process and present our strategy to study molecular dissociation through electronic excitation of low energy triplet states. (author)
Xu, Hai-Bo; Zheng, Na
2015-07-01
A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path (which depends on the collimator angle) and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results can be used in density reconstruction, which depends on the transmission expressions. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)
Energy Technology Data Exchange (ETDEWEB)
Gauron, Pierre; Basarab Nicolescu [Theoretical Physics Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Leader Elliot [Birkbeck College, Malet Street, London WCIE 7HX (United Kingdom)
1999-10-01
We generalize a relation proposed recently by Giffon, Predazzi and Samokhin, linked to the behaviour of elastic scattering at asymptotically high energies. We demonstrate that their result, established within a limited class of possible asymptotic behaviour, is actually very general and can be proved in an essentially axiomatic framework. We discuss how this relation can be used as a basis for detecting new phenomena at RHIC and LHC energies. (authors)
Nuclear and partonic dynamics in high energy elastic nucleus-nucleus scattering
International Nuclear Information System (INIS)
Malecki, A.
1991-01-01
A hybrid description of diffraction which combines a geometrical modelling of multiple scattering with many-channel effects resulting from intrinsic dynamics on nuclear and sub-nuclear level is presented. The application to the 4 He- 4 He elastic scattering is very satisfactory. Our analysis suggests that at large momentum transfers the parton constituents of nucleons immersed in nuclei are deconfined. (author)
Study of exchange current contributions for the pion-deuteron scattering at intermediate energies
International Nuclear Information System (INIS)
Melo, S.W.A. de.
1983-01-01
The contribution of the pions exchange currents to the πd elastic scattering in the Δ(1232) resonance region is calculated using Feynman diagrams. The results show that the addition of exchange currents to the simple and double scattering terms improve the agreement with the experimental data. (L.C.) [pt
Theoretical aspects of the nucleon-nucleon workshop
International Nuclear Information System (INIS)
Silbar, R.R.
1984-01-01
This report concentrates on the inelastic NN system from 300 to 1500 MeV. Topics covered include the visibility of quark signals, dibaryons, the model dependence of predicted NN inelasticities, and a review of how well present conventional models compare with a rapidly expanding database. The general conclusion is that there is so far no clear evidence in the NN system at intermediate energies for unconventional dibaryon resonances. Short remarks are also made concerning one theoretical contribution on elastic scattering and on new experimental results for deuteron photo-disintegration and pion-nucleon charge exchange. 11 references
International Nuclear Information System (INIS)
Dodonoy, A.I.; Mashkova, E.S.; Molchanov, V.A.
1989-01-01
This paper is the third part of our review surface scattering. Part I, which was devoted to the scattering of ions by the surfaces of disordered solids, was published in 1972; Part II, concerning scattering by crystal surfaces, was published in 1974. Since the publication of these reviews the material contained in them has become obsolete in many respects. A more recent account of the status of the problem has been given in a number of studies, including the book by E.S. Mashkova and V.A. Molchanov, Medium-Energy Ion Scattering by Solid Surfaces (Atomizdat, Moscow, 1980), than extended version of which was published by North-Holland in 1985. We note, however, that at the time these reviews were written the study of fast recoil atoms had not been carried out systematically; the problem was studied only as a by-product of surface scattering and sputtering. For this reason, in the above-mentioned works and in other reviews the data relating to recoil atoms were considered only occasionally. In recent years there have appeared a number of works - theoretical, experimental and computer -specially devoted to the study of the ejection of recoil atoms under ion bombardment. A number of interesting effects, which are due to the crystal structure of the target, have been discovered. It therefore, appeared desirable to us to systematize the available material and to present it as Part III of our continuing review. (author)
Daudé, Thierry
2017-01-01
In this paper, the authors study the direct and inverse scattering theory at fixed energy for massless charged Dirac fields evolving in the exterior region of a Kerr-Newman-de Sitter black hole. In the first part, they establish the existence and asymptotic completeness of time-dependent wave operators associated to our Dirac fields. This leads to the definition of the time-dependent scattering operator that encodes the far-field behavior (with respect to a stationary observer) in the asymptotic regions of the black hole: the event and cosmological horizons. The authors also use the miraculous property (quoting Chandrasekhar)-that the Dirac equation can be separated into radial and angular ordinary differential equations-to make the link between the time-dependent scattering operator and its stationary counterpart. This leads to a nice expression of the scattering matrix at fixed energy in terms of stationary solutions of the system of separated equations. In a second part, the authors use this expression of ...
Energy Technology Data Exchange (ETDEWEB)
Hicks, R.G.
1978-01-01
An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10/sup 10/ muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s//sup 0/ and ..lambda../sup 0/ decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references.
Collective Thomson scattering based on CO2 laser for ion energy spectrum measurements in JT-60U
Kondoh, T.; Miura, Y.; Lee, S.; Richards, R. K.; Hutchinson, D. P.; Bennett, C. A.
2003-03-01
A collective Thomson scattering (CTS) diagnostic system based on a pulsed CO2 laser has been developed and brought into operation to establish a measurement technique for ion temperature and the energy spectrum of fast ions. The pulsed CO2 laser (wavelength 10.6 μm, beam energy 15 J, pulse width 1 μs) and a heterodyne receiver were installed on the JT-60U tokamak. Calculation of the scattered power spectrum from high temperature plasma in JT-60U shows that a good signal-to-noise value is expected for the bulk-ion temperature measurement. Calibration of the heterodyne receiver system has been carried out using a large area (12×12 cm2) blackbody radiation source. Commissioning of the CTS system by injecting the CO2 laser into the plasmas has been accomplished. However, a scattered signal has not yet been detected due to electrical noise originating from the pulsed lasers discharge and stray signal coming from mode impurities in the pulsed laser. After the electrical and stray light reduction, ion temperature will be evaluated from the scattered spectrum using the CTS system.
International Nuclear Information System (INIS)
Den Hartog, D.J.
1989-11-01
Thomson scattering measurements of the central electron temperature and density during the plasma current peak have been performed on the MST Reversed Field Pinch (RFP). This Thomson scattering diagnostic was calibrated for absolute electron density measurements. These measurements of T e and n e , when combined with profile assumptions, were used to calculate estimates of energy confinement time (τ E ) and poloidal beta (β θ ). A standard discharge with I p ∼ 400 kA, F ∼ -0.1, and θ ∼ 1.6 typically exhibited T e ∼ 275 eV, n e ∼ 2.0 x 10 13 cm -3 , τ E ≤ 1 ms, and β θ ≤ 8%. The results of a limited plasma current scaling study did not indicate a strong scaling of T e or τ E with I p . The Thomson scattering diagnostic was used in conjunction with a bolometer, VUV radiation monitor, and edge magnetic coils to study the loss of energy from the plasma. Results indicate that thermal transport from stochastic magnetic fields, particle loss, and radiation are important energy loss processes. The experiments done for this study included an F-scan, a paddle limiter insertion series, and an argon doping series. The plasma maintained a constant βτ during these perturbation experiments, suggesting that increases in one energy loss channel are compensated by drops in other channels and increases in input power to the plasma
International Nuclear Information System (INIS)
Lazur, V.Yu.; Khimich, I.V.
1977-01-01
Analytical properties of the elastic πN-scattering amplitude in in the cos THETA are proved in the Lehmann ellipse. The instrument for establishing analytical properties of the scattering amplitude in the cos THETA is the Jost-Lehmann-Dyson integral representation proved in terms of the localizable quantum field theory containing the strictly localizable theory and theory of moderate growth as particular cases. On this basis the Greenberg-Low restriction is obtained in frames of this class theories for the πN-scattering amplitude. This result gives a possibility to prove the ordinary dispersion relations with a finite number of subtraction in frames of the localizable quantum field theory
Limão-Vieira, P.; Horie, M.; Kato, H.; Hoshino, M.; Blanco, F.; García, G.; Buckman, S. J.; Tanaka, H.
2011-12-01
We report absolute elastic differential, integral and momentum transfer cross sections for electron interactions with CCl4. The incident electron energy range is 1.5-100 eV, and the scattered electron angular range for the differential measurements varies from 15°-130°. The absolute scale of the differential cross section was set using the relative flow technique with helium as the reference species. Comparison with previous total cross sections shows good agreement. Atomic-like behaviour in this scattering system is shown here for the first time, and is further investigated by comparing the CCl4 elastic cross sections to recent results on the halomethanes and atomic chlorine at higher impact energies [H. Kato, T. Asahina, H. Masui, M. Hoshino, H. Tanaka, H. Cho, O. Ingólfsson, F. Blanco, G. Garcia, S. J. Buckman, and M. J. Brunger, J. Chem. Phys. 132, 074309 (2010)], 10.1063/1.3319761.
Zhang, Xi; Jiang, Hongrui
2015-03-09
Photo-self-charging cells (PSCs) are compact devices with dual functions of photoelectric conversion and energy storage. By introducing a scattering layer in polymer-based quasi-solid-state dye-sensitized solar cells, two-electrode PSCs with highly compact structure were obtained. The charge storage function stems from the formed ion channel network in the scattering layer/polymer electrolyte system. Both the photoelectric conversion and the energy storage functions are integrated in only the photoelectrode of such PSCs. This design of PSC could continuously output power as a solar cell with considerable efficiency after being photo-charged. Such PSCs could be applied in highly-compact mini power devices.
Czech Academy of Sciences Publication Activity Database
Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Austregisilio, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.; Chaberny, D.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.; Dalla Torre, S.; Das, S.; Dasgupta, S. S.; Denisov, O.; Dhara, L.; Diaz, V.; Donskov, S.; Doshita, N.; Duic, V.; Dünnweber, W.; Efremov, A.V.; El Alaoui, A.; Eversheim, P.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Friedrich, J.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heinsius, F.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Jouravlev, N. I.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.; Kolosov, V.; Kondo, K.; Königsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V.; Korzenev, A.; Kotzinian, A.; Kouznetsov, O.; Kowalik, K.; Krämer, M.; Kral, A.; Kroumchtein, Z.; Kuhn, R.; Kunne, F.; Kurek, K.; Lauser, L.; Le Goff, J.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Meyer, W.; Michigami, T.; Mikhailov, Y.; Moinester, M.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Nunes, A.S.; Olshevsky, A.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Santos, H.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlütter, T.; Schmitt, L.; Schopferer, S.; Schröder, W.; Shevchenko, O.; Siebert, H.; Silva, L.; Sinha, L.; Sissakian, A.; Slunecka, M.; Smirnov, G.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.; Uhl, S.; Uman, I.; Virius, M.; Vlassov, N.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.
2010-01-01
Roč. 70, 1-2 (2010), s. 39-49 ISSN 1434-6044 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : deep-inelastic-scattering * dependent structure-function * single-spin asymmetries * semiinclusive electroproduction * proton-scattering * distributions * leptoproduction * target * dis * nucleons Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.248, year: 2010
Lund, E; Hughes, E W; Lopez Mateos, D; Salzburger, A; Strandlie, A
2008-01-01
In this paper we study the energy loss, its fluctuations, and the multiple scattering of particles passing through matter, with an emphasis on muons. In addition to the well-known Bethe-Bloch and Bethe-Heitler equations describing the mean energy loss from ionization and bremsstrahlung respectively, new parameterizations of the mean energy loss of muons from the direct e+e- pair production and photonuclear interactions are presented along with new estimates of the most probable energy loss and its fluctuations in the ATLAS calorimeters. Moreover, a new adaptive Highland/Moliere approach to finding the multiple scattering angle is taken to accomodate a wide range of scatterer thicknesses. Furthermore, tests of the muon energy loss, its fluctuations, and multiple scattering are done in the ATLAS calorimeters. The material effects described in this paper are all part of the simultaneous track and error propagation (STEP) algorithm of the common ATLAS tracking software.
Study of the elastic scattering of {sup 6}He on {sup 208}Pb at energies around the Coulomb barrier
Energy Technology Data Exchange (ETDEWEB)
Sanchez-Benitez, A.M. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain); Centre de Recherches du Cyclotron, Universite Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Escrig, D. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Alvarez, M.A.G.; Andres, M.V. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla (Spain); Angulo, C. [Centre de Recherches du Cyclotron, Universite Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Borge, M.J.G. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Cabrera, J. [Centre de Recherches du Cyclotron, Universite Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Cherubini, S. [INFN Laboratori Nazionali del Sud, I-95123 Catania (Italy); Demaret, P. [Centre de Recherches du Cyclotron, Universite Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Espino, J.M. [Dept. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla (Spain); Figuera, P. [INFN Laboratori Nazionali del Sud, I-95123 Catania (Italy); Freer, M. [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Garcia-Ramos, J.E. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain); Gomez-Camacho, J. [Dept. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla (Spain); Gulino, M. [INFN Laboratori Nazionali del Sud, I-95123 Catania (Italy); Kakuee, O.R. [Van der Graaff Laboratory, Nuclear Research Centre, AEOI, PO Box 14155-1339, Tehran (Iran, Islamic Republic of); Martel, I. [Dept. de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain)], E-mail: imartel@uhu.es; Metelko, C. [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Moro, A.M. [Dept. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, E-41080 Sevilla (Spain)] (and others)
2008-04-15
The elastic scattering of {sup 6}He on {sup 208}Pb has been measured at laboratory energies of 14, 16, 18 and 22 MeV. These data were analyzed using phenomenological Woods-Saxon form factors and optical model calculations. A semiclassical polarization potential was used to study the effect of the Coulomb dipole polarizability. Evidence for long range absorption, partially arising from Coulomb dipole polarizability, is reported. The energy variation of the optical potential was found to be consistent with the dispersion relations which connect the real and imaginary parts of the potential.
The spectral energy distribution of the scattered light from dark clouds
Mattila, Kalevi; Schnur, G. F. O.
1989-01-01
A dark cloud is exposed to the ambient radiation field of integrated starlight in the Galaxy. Scattering of starlight by the dust particles gives rise to a diffuse surface brightness of the dark nebula. The intensity and the spectrum of this diffuse radiation can be used to investigate, e.g., the scattering parameters of the dust, the optical thickness of the cloud, and as a probe of the ambient radiation field at the location of the cloud. An understanding of the scattering process is also a prerequisite for the isolation of broad spectral features due to fluorescence or to any other non-scattering origin of the diffuse light. Model calculations are presented for multiple scattering in a spherical cloud. These calculations show that the different spectral shapes of the observed diffuse light can be reproduced with standard dust parameters. The possibility to use the observed spectrum as a diagnostic tool for analyzing the thickness of the cloud and the dust particle is discussed.
The structural and compositional analysis of single crystal surfaces using low energy ion scattering
International Nuclear Information System (INIS)
Armour, D.G.; Van der Berg, J.A.; Verheij, IL.K.
1979-01-01
The use of ion scattering for surface composition and structure analysis has been reviewed. The extreme surface specificity of this technique has been widely used to obtain quitative information in a straightforward way, but the/aolc/currence of charge exchange processes, thermal lattice vibrations and multiple scattering have precluded quantitative analysis of experimental data. Examples are quoted to illustrate the progress that has been made in understanding these fundamental processes and in applying this knowledge to the development of the analytical capabilities of the technique. (author)
A simple nonbinary scattering model applicable to atomic collisions is crystals at 1ow energies
DEFF Research Database (Denmark)
Andersen, Hans Henrik; Sigmund, Peter
1966-01-01
the projectile and each ring atom is described by a Born-Mayer potential, and the scattering is assumed to be elastic and governed by the classical equations of motion. Because of symmetry, the problem can be reduced to plane motion of a particle in a potential of elliptic symmetry. The elliptic force field...... the elliptic to the spherical potential are investigated. Special attention is paid to proper definitions of collision time and collision length which are important in collisions in crystals. Limitations to classical scattering arising from the uncertainty principle prove to be more serious than assumed...
Ojambati, Oluwafemi S; Mosk, Allard P; Vellekoop, Ivo M; Lagendijk, Ad; Vos, Willem L
2016-08-08
We study the energy density of shaped waves inside a quasi-1D disordered waveguide. We find that the spatial energy density of optimally shaped waves, when expanded in the complete set of eigenfunctions of the diffusion equation, is well described by considering only a few of the lowest eigenfunctions. Taking into account only the fundamental eigenfunction, the total internal energy inside the sample is underestimated by only 2%. The spatial distribution of the shaped energy density is very similar to the fundamental eigenfunction, up to a cosine distance of about 0.01. We obtain the energy density of transmission eigenchannels inside the sample by numerical simulation of the scattering matrix. Computing the transmission-averaged energy density over all transmission channels yields the ensemble averaged energy density of shaped waves. From the averaged energy density, we reconstruct its spatial distribution using the eigenfunctions of the diffusion equation. The results of our study have exciting applications in controlled biomedical imaging, efficient light harvesting in solar cells, enhanced energy conversion in solid-state lighting, and low threshold random lasers.
Elastic scattering of 7Li + 27Al at several angles in the 7-11 MeV energy range
International Nuclear Information System (INIS)
Abriola, D.; Carnelli, P.; Arazi, A.; Figueira, J.M.; Capurro, O.A.; Cardona, M.A.; Fernandez Niello, J.O.; Hojman, D.; Fimiani, L.; Grinberg, P.; Martinez Heimann, D.; Marti, G.V.; Negri, A.E.; Pacheco, A.J.
2010-01-01
Elastic cross sections for the 7 Li + 27 Al system were measured at laboratory energies between 7 and 11 MeV in steps of 0.25 MeV, and angles between 135 o and 170 o in steps of 5 o . Excitation functions for the elastic scattering were measured using an array of eight Si surface-barrier detectors whereas a solid-state telescope was used to estimate and subtract background from other reactions. Contamination from α particles arising from the 7 Li breakup process at E lab ≥ 10 MeV makes the use of these energies inadvisable for RBS applications. The present results are compared with previous data obtained at 165 o (E lab ≤ 6 MeV), 140 o and 170 o (E lab ≤ 8 MeV). The experimental data were analyzed in terms of the Optical Model. Two different energy-independent potentials were found. These optical potentials allow an interpolation with physical meaning to other energies and scattering angles. The experimental cross sections will be uploaded to the IBANDL database.
Hong, Seung Hwan; Bok, Jin Mo; Zhang, Wentao; He, Junfeng; Zhou, X J; Varma, C M; Choi, Han-Yong
2014-08-01
There is an enormous interest in the renormalization of the quasiparticle (qp) dispersion relation of cuprate superconductors both below and above the critical temperature T_{c} because it enables the determination of the fluctuation spectrum to which the qp's are coupled. A remarkable discovery by angle-resolved photoemission spectroscopy (ARPES) is a sharp low-energy feature (LEF) in qp spectra well below the superconducting energy gap but with its energy increasing in proportion to T_{c} and its intensity increasing sharply below T_{c}. This unexpected feature needs to be reconciled with d-wave superconductivity. Here, we present a quantitative analysis of ARPES data from Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} (Bi2212) using Eliashberg equations to show that the qp scattering rate due to the forward scattering impurities far from the Cu-O planes is modified by the energy gap below T_{c} and shows up as the LEF. This is also a necessary step to analyze ARPES data to reveal the spectrum of fluctuations promoting superconductivity.
International Nuclear Information System (INIS)
Jung, M.; Kattein, J.; Kueck, H.; Leu, P.; Marne, K.D. de; Wedemeyer, R.; Wermes, N.
1981-05-01
Differential cross sections of proton Compton scattering have been measured at the Bonn 2.5 GeV synchrotron. 78 data points are presented as angular distributions at photon lab energies of 700, 750, 800, 850, 900, and 950 MeV. The c.m. scattering angle ranges from 40 0 to 130 0 , corresponding to a variation of the four momentum transfer squared between t = -0.10 to t = -0.96 GeV 2 at 700 and 950 MeV, respectively. Two additional differential cross sections have been measured at 1000 MeV, 35.6 0 and 47.4 0 . The angular distributions show forward peaks whose extrapolations to 0 0 are consistent with calculated forward cross sections taken from literature. The small angle data ( vertical stroke t vertical stroke approx. 2 ) together with the calculated cross sections at 0 0 are also consistent with the assumption of a slope parameter B of 5 GeV -2 . For the first time a re-rise of the angular distributions towards backward angles has been observed. It becomes less steep with increasing energy. The most interesting feature of the angular distributions is a sharp structure which appears between t = -0.55 GeV 2 at 700 MeV and t = -0.72 GeV 2 at 950 MeV. Such a rapid variation of the differential cross section with t has never been observed in elastic hadron-hadron scattering or photoproduction processes. It indicates the existence of a dynamical mechanism which could be a peculiarity of Compton scattering. (orig.)
Electron scattering from tetrahydrofuran
International Nuclear Information System (INIS)
Fuss, M C; Sanz, A G; García, G; Muñoz, A; Oller, J C; Blanco, F; Do, T P T; Brunger, M J; Almeida, D; Limão-Vieira, P
2012-01-01
Electron scattering from Tetrahydrofuran (C 4 H 8 O) was investigated over a wide range of energies. Following a mixed experimental and theoretical approach, total scattering, elastic scattering and ionization cross sections as well as electron energy loss distributions were obtained.
Multiple scattering in electron fluid and energy loss in multi-ionic targets
Energy Technology Data Exchange (ETDEWEB)
Deutsch, C., E-mail: claude.deutsch@u-psud.fr [LPGP, UParis-Sud, 91405-Orsay (France); Tahir, N.A. [GSI, 1Planck Str., 64291-Darmstadt (Germany); Barriga-Carrasco, M. [ETSII, UCastilla-la-Mancha, 13071 Ciudad-Real (Spain); Ceban, V. [LPGP, UParis-Sud, 91405-Orsay (France); Fromy, P. [CRI, UParis-Sud, 91405-Orsay (France); Gilles, D. [CEA/Saclay/DSM/IRFU/SAP, 91191-Gif-s-Yvette (France); Leger, D. [Laboratoire Monthouy, UValenciennes-Hainaut Cambresis (France); Maynard, G. [LPGP, UParis-Sud, 91405-Orsay (France); Tashev, B. [Department of Physics, KazNu, Tole Bi82, Almaty (Kazakhstan); Volpe, L. [Department of Physics, UMilano-Bicocca, Milano 20126 (Italy)
2014-01-01
Extensions of the standard stopping model (SSM) for ion projectiles interacting with dense targets of timely concern for ICF and WDM are reviewed. They include multiple scattering on partially degenerate electrons, low velocity ion slowing down in demixing H–He mixtures within Jovian planets core or multiionic target such as Kapton.
Remarks on the high-energy behavior of string scattering amplitudes in warped spacetimes. II
International Nuclear Information System (INIS)
Andreev, Oleg
2005-01-01
We study the Regge limit of string amplitudes within the model of Polchinski-Strassler for string scattering in warped spacetimes. We also present some numerical estimations of the Regge slopes and intercepts. It is quite remarkable that the real values of those are inside a range of ours
The leading eikonal operator in string-brane scattering at high energy
DEFF Research Database (Denmark)
Giuseppe, D'Appollonio; di Vecchia, Paolo; Russo, Rodolfo
2015-01-01
In this paper we present two (a priori independent) derivations of the eikonal operator in string-brane scattering. The rst one is obtained by summing surfaces with any number of boundaries, while in the second one the eikonal operator is derived from the three-string vertex in a suitable light-c...
A closed analytic form for p-d elastic scattering at high energy
International Nuclear Information System (INIS)
Li, Y.; Lo, S.
1983-01-01
Using a simple harmonic oscillator wave function for deuteron it is possible to give an analytic solution in closed form for p-d elastic scattering. It has the advantage of displaying clearly all the contributions separately (D-wave, spin flip etc.). It can also fit experimental data
Chi, Zhijun; Du, Yingchao; Huang, Wenhui; Tang, Chuanxiang
2017-12-01
The necessity for compact and relatively low cost x-ray sources with monochromaticity, continuous tunability of x-ray energy, high spatial coherence, straightforward polarization control, and high brightness has led to the rapid development of Thomson scattering x-ray sources. To meet the requirement of in-situ monochromatic computed tomography (CT) for large-scale and/or high-attenuation materials based on this type of x-ray source, there is an increasing demand for effective algorithms to correct the energy-angle correlation. In this paper, we take advantage of the parametrization of the x-ray attenuation coefficient to resolve this problem. The linear attenuation coefficient of a material can be decomposed into a linear combination of the energy-dependent photoelectric and Compton cross-sections in the keV energy regime without K-edge discontinuities, and the line integrals of the decomposition coefficients of the above two parts can be determined by performing two spectrally different measurements. After that, the line integral of the linear attenuation coefficient of an imaging object at a certain interested energy can be derived through the above parametrization formula, and monochromatic CT can be reconstructed at this energy using traditional reconstruction methods, e.g., filtered back projection or algebraic reconstruction technique. Not only can monochromatic CT be realized, but also the distributions of the effective atomic number and electron density of the imaging object can be retrieved at the expense of dual-energy CT scan. Simulation results validate our proposal and will be shown in this paper. Our results will further expand the scope of application for Thomson scattering x-ray sources.
Energy Technology Data Exchange (ETDEWEB)
Mekhtiche, A. [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria); Faculté des Sciences et de la Technologie, Université Yahia Farès de Médéa (Algeria); Khalal-Kouache, K., E-mail: kkouache@yahoo.fr [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria)
2016-09-01
In this paper, angular distributions of slow H{sup +} ions transmitted through different targets (Al, Ag and Au) are calculated using the model of Sigmund and Winterbon (SW) in the multiple scattering theory. Valdés and Arista (VA) developed a method extending the SW model by including the effect of energy loss in the calculation of angular distributions of transmitted ions. Another method has been proposed for such calculations: one can consider the SW model by using an average value for the energy of the ions inside the target. In this contribution, a new expression is proposed for the mean energy which gives a better agreement with the VA model than the precedent one at low energy. Different potentials have been considered to describe the interaction projectile-target atom in this study and the new expression is found to be independent of the interaction potential.
3He(p,p)3He scattering in the energy range 19 to 48 MeV
International Nuclear Information System (INIS)
Murdoch, B.T.; Hasell, D.K.; Sourkes, A.M.; van Oers, W.T.H.; Verheijen, P.J.T.; Brown, R.E.
1984-01-01
Differential cross sections for 3 He(p,p) 3 He elastic scattering have been measured at 11 energies in the laboratory energy range 19.5 to 47.5 MeV. The most forward c.m. angle for the angular distributions varies from 10.1 0 to 13.4 0 , and the most backward angle varies from 163.2 0 to 173.4 0 . The relative errors in the data are usually less than 2%, and the scale error is 1.5%. The present data, together with analyzing power and total reaction cross section data of others, have been subjected to an energy-dependent phase shift analysis. The extracted phase shifts and the differential cross sections are compared with the results of a simple resonating-group calculation
Schiró, Giorgio
2013-01-01
Neutron scattering measurements on protein powders reveal two deviations from harmonic dynamics at low temperature, whose molecular origin, physical nature and biological relevance are still matter of discussion. In this study we present a new experimental and theoretical approach to evidence the resolution dependence of anharmonic onsets: the use of strategically selected homomeric polypeptides allows revealing the exact resolution dependence; a two-site energy landscape model, where resolution effects are explicitly taken into account, is able to interpret quantitatively the experimental data in terms of energy landscape parameters. The energetic description provided by this analysis, together with recent experimental evidences obtained on chemically and structurally different peptide systems, allows us to connect the protein/water energy landscape structure with the two-wells water interaction potential proposed to explain the low-density→high-density liquid-liquid transition observed in supercooled water. Copyright © 2013 Elsevier B.V. All rights reserved.
Sadeghi-Khosravieh, Saba
The main goal of this thesis is to show the versatility of glancing angle deposition (GLAD) thin films in applications. This research is first focused on studying the effect of select deposition variables in GLAD thin films and secondly, to demonstrate the flexibility of GLAD films to be incorporated in two different applications: (1) as a reflective coating in low-level concentration photovoltaic systems, and (2) as an anode structure in dye-sensitized solar cells (DSSC). A particular type of microstructure composed of tilted micro-columns of titanium is fabricated by GLAD. The microstructures form elongated and fan-like tilted micro-columns that demonstrate anisotropic scattering. The thin films texture changes from fiber texture to tilted fiber texture by increasing the vapor incidence angle. At very large deposition angles, biaxial texture forms. The morphology of the thin films deposited under extreme shadowing condition and at high temperature (below recrystallization zone) shows a porous and inclined micro-columnar morphology, resulting from the dominance of shadowing over adatom surface diffusion. The anisotropic scattering behavior of the tilted Ti thin film coatings is quantified by bidirectional reflectance distribution function (BRDF) measurements and is found to be consistent with reflectance from the microstructure acting as an array of inclined micro-mirrors that redirect the incident light in a non-specular reflection. A silver-coating of the surface of the tilted-Ti micro-columns is performed to enhance the total reflectance of the Ti-thin films while keeping the anisotropic scattering behavior. By using such coating is as a booster reflector in a laboratory-scale low-level concentration photovoltaic system, the short-circuit current of the reference silicon solar cell by 25%. Finally, based on the scattering properties of the tilted microcolumnar microstructure, its scattering effect is studied as a part of titanium dioxide microstructure for the
Low energy RBS-channeling measurement system with the use of a time-of-flight scattered ion detector
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, Masataka; Kobayashi, Naoto; Hayashi, Nobuyuki [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)
1996-07-01
We have developed a low energy Rutherford backscattering spectrometry-ion channeling measurement system for the analysis of thin films and solid surfaces with the use of several tens keV hydrogen ions and a time-of-flight particle energy spectrometer. For the detection of the scattered ions new TOF spectrometer has been developed, which consists of two micro-channel-plate detectors. The pulsing of the primary ion beam is not necessary for this type of TOF measurement, and it is possible to observe continues scattered ion beams. The dimension of whole system is very compact compared to the conventional RBS-channeling measurement system with the use of MeV He ions. The energy resolution, {delta} E/E, for 25 keV H{sup +} was 4.1%, which corresponds to the depth resolution of 4.8 nm for silicon. The depth resolution of our system is better than that of conventional RBS system with MeV helium ions and solid state detectors. We have demonstrated the ion channeling measurement by this system with 25 keV hydrogen ions. The system can be available well to the analysis of thin films and solid surfaces with the use of the ion channeling effect. The observation of the reaction between Fe and hydrogen terminated silicon surface was also demonstrated. (J.P.N.)
Energy Technology Data Exchange (ETDEWEB)
Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)
2012-11-15
The proton elastic scattering data on some light exotic nuclei, namely, {sup 6,} {sup 8}He, {sup 9,} {sup 11}Li, and {sup 10,} {sup 11,} {sup 12}Be, at energies below than 100MeV/nucleon are analyzed using the single folding optical model. The real, imaginary, and spin-orbit parts of the optical potential (OP) are constructed only from the folded potentials and their derivatives using M3Y effective nucleon-nucleon interaction. These OP parts, their renormalization factors and their volume integrals are studied. The surface and spin-orbit potentials are important to fit the experimental data. Three model densities for halo nuclei are used and the sensitivity of the cross-sections to these densities is tested. The imaginary OP within high-energy approximation is used and compared with the single folding OP. This OP with few and limited fitting parameters, which have systematic behavior with incident energy, successfully describes the proton elastic scattering data with exotic nuclei. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Ludeking, L.D.
1979-01-01
Interactions of two composite clusters are treated in a multiple scattering framework whereby many-particle operators are decomposed into a systematic and finite series such that there is an ordered sequestering according to particle rank. Thus, an N-body operator is written as the superposition of all distinct groupings of interactions that occur between particle pairs, triplets, quartets, etc., such that all groupings contain at least one particle from each of the composite systems. It is demonstrated how the transition operator, a reaction operator, and an optical potential may be described in this context. The general structure of such decompositions is shown, and the connection to the standard multiple-scattering prescriptions, delineated. The direct reaction amplitude for stripping and pickup is described, and the two potential formula of Gell-Mann and Goldberger is derived. The multiple scattering formalism for direct reactions is constructed in the eikonal approximation. The sensitivity of the transition cross section to the target density and nucleon-nucleon density correlations are examined in this framework. The limitations of the zero-range approximation to the deuteron vertex function are examined by comparison with the finite-range vertex function at a range of energies. 25 figures, 5 tables.
High-energy behavior of fermion-meson and meson-meson scattering in a supersymmetric field theory
International Nuclear Information System (INIS)
Opoien, J.W.
1978-01-01
The high-energy behavior of fermion-boson and boson-boson scattering amplitudes of a supersymmetric field theory containing a spin-1/2 fermion field, a scalar field, and a pseudoscalar field is investigated. The results can be easily modified to apply to the Yukawa model and the neutral version of the linear sigma model. The results are also compared to those of fermion-fermion scattering in the same model. In the leading-logarithm approximation, ladders with fermions running along the sides in the t channel and mesons as rungs dominate in each order of two classes of diagrams. The sum of the dominant series give rise to fixed Regge cuts for all amplitudes in each of the three theories. All amplitudes in the supersymmetric theory possess a definite signature factor, while the amplitudes for fermion-fermion and fermion-antifermion scattering in the Y model and the sigma model lack it. The results of the supersymmetric theory are also compared to the results of the spontaneously broken non-Abelian gauge theory
Energy Technology Data Exchange (ETDEWEB)
Kabir, Al Amin [Kent State Univ., Kent, OH (United States)
2015-12-01
Analysis of high-energy electron scattering has been used to determine the charge radii of nuclei for several decades. Recent analysis of the Lamb shift in muonic hydrogen found an r.m.s. radius significantly different than the electron scattering result. To understand this puzzle we have analyzed the "LEDEX" data for the (e, e'p) reaction. This experiment includes measurements on several light nuclei, hydrogen, deuterium, lithium, boron, and carbon. To test our ability to measure absolute cross sections, as well as our ability to extract the charge radius, we tested our technique against the extremely well-measured carbon case and found excellent agreement using the Fourier-Bessel parametrization. We then extended the procedure to boron and lithium, which show nice agreement with the latest theoretical calculations. For hydrogen, we see clearly the limits of this technique and therefore, the charge radius is determined from the traditional extrapolation to q^{2} = 0. We will show that there is a model dependence in extracting the charge radius of hydrogen and its unambiguous determination is very difficult with available electron-scattering measurements.
International Nuclear Information System (INIS)
Ketkar, S.N.
1984-01-01
During the course of this work experiments were undertaken to measure the scattering cross-sections for high energy electrons scattering from various target systems. The experiments can be broadly classified into two categories, one dealing with rather small systems and the other dealing with large systems (at least in the view of physicists). Although the experimental aspects, in so much as the experimental measurement of the intensities of the scattered electron is concerned, is the same for both the cases the motivation for performing the experiment is totally different. In the first case, simple atomic and molecular target systems, namely He, H 2 and D 2 , are used. For such systems, good theoretical framework is available and critical comparisons of experimental cross sections are made with theoretical predictions. Attention is focussed mainly at small momentum transfer (up to 10A -1 ), and correlation and binding effects are studied. In the second case, somewhat larger molecular systems, namely naphthalene, anthraquinone, anthracene and dichromium tetraacetate are used. For such systems attention is focused at large momentum transfer (from 10 to 25 A -1 ) to obtain structural information about the molecules
International Nuclear Information System (INIS)
Nguen Suan Khan; Pervushin, V.N.
1975-01-01
An eikonal representation has been obtained for the amplitude of the πN-scattering in the asymptotic form into account the anomalous nucleon magnetic moment leads to the introduction of the additive term in to the eikonal phase which is responsible for the spin flip in the scattering process. The Coulomb interference is considered
Low energy 16O+208Pb elastic scattering: an attempt to analyze the microscopic effective potential
International Nuclear Information System (INIS)
Mau, N.V.; Ferrero, J.L.; Pacheco, J.C.; Bilwes, B.
1991-03-01
Elastic scattering of 16 O on 208 Pb is studied at 96, 104, 129.5, 192, 216.6 and 312.6 MeV. The 16 O+ 208 Pb potential is calculated first in the closure approximation model and compared to semi-phenomenological potentials. Then detailed contributions to the polarization real potential and to the imaginary potential due to the coupling of the elastic channels to the inelastic channels are calculated. The results are compared to the authors' model potential and used to test the main assumptions of the model. From that comparison a qualitative interpretation of the success of the model is proposed. At last the elastic scattering cross sections are calculated and compared to the data. (author) 41 refs., 6 figs., 5 tabs
Kneiss, U
2002-01-01
Photon scattering off bound nuclear states (nuclear resonance fluorescence (NRF)) and photoactivation of long-lived isomers are complementary to one another and share the principal advantage of a well-known reaction mechanism. The experimental progress achieved during the last years allows nowadays experiments of tremendously increased sensitivity opening new fields of applications. In the present lecture recent results are summarized from experiments performed at the well-established Bremsstrahlung photon scattering and photoactivation facilities of the 4.3 MV Stuttgart Dynamitron accelerator. Three current topics are discussed in details: The systematics of E1 two-phonon excitations of the type (2 sup + x 3 sup -) in nuclei near shell closures; the first observation of a population inversion of nuclear states, the precondition for a possible gamma-laser, by feeding from higher-lying photo-excited states (NRF experiments on sup 1 sup 0 sup 3 Rh); and the photoactivation of long-lived isomers. Here first resu...
The forward rainbow scattering of low energy protons by a graphene sheet
Ćosić, M.; Petrović, S.; Nešković, N.
2018-05-01
This article studies the rainbow scattering of 5-keV protons by the single sheet of free-standing graphene and its possible use as a tool for investigation of the ion-graphene interaction. The proton-graphene interaction potential was constructed by using the Doyle-Turner, ZBL, and Molière proton-carbon interaction potentials. The thermal motion of carbon atoms was included by averaging the potentials according to the Debye model. Proton trajectories were obtained by numerical solution of the corresponding Newton equations of motion. They were used to obtain the mapping of the proton initial positions to their scattering angles. Morphological properties of the introduced mapping including its multiplicity and the rainbow singularities were used to explain important features of the obtained angular distributions of transmitted protons.
Trzcinski, A; Müller, W F J; Trautmann, W; Zwieglinski, B; Auger, G; Bacri, C O; Begemann-Blaich, M L; Bellaize, N; Bittiger, R; Bocage, F; Borderie, B; Bougault, R; Bouriquet, B; Buchet, P; Charvet, J L; Chbihi, A; Dayras, R; Doré, D; Durand, D; Frankland, J D; Galíchet, E; Gourio, D; Guinet, D; Hudan, S; Hurst, B; Lautesse, P; Lavaud, F; Laville, J L; Leduc, C; Lefèvre, A; Legrain, R; López, O; Lynen, U; Nalpas, L; Orth, H; Plagnol, E; Rosato, E; Saija, A; Schwarz, C; Sfienti, C; Steckmeyer, J C; Tabacaru, G; Tamain, B; Turzó, K; Vient, E; Vigilante, M; Volant, C
2003-01-01
An efficient method of energy scale calibration for the CsI(Tl) modules of the INDRA multidetector (rings 6-12) using elastic and inelastic sup 1 sup 2 C+ sup 1 H scattering at E( sup 1 sup 2 C)=30 MeV per nucleon is presented. Background-free spectra for the binary channels are generated by requiring the coincident detection of the light and heavy ejectiles. The gain parameter of the calibration curve is obtained by fitting the proton total charge spectra to the spectra predicted with Monte-Carlo simulations using tabulated cross section data. The method has been applied in multifragmentation experiments with INDRA at GSI.
Energy Technology Data Exchange (ETDEWEB)
Trzcinski, A.; Lukasik, J.; Mueller, W.F.J.; Trautmann, W.; Zwieglinski, B. E-mail: bzw@fuw.edu.pl; Auger, G.; Bacri, Ch.O.; Begemann-Blaich, M.L.; Bellaize, N.; Bittiger, R.; Bocage, F.; Borderie, B.; Bougault, R.; Bouriquet, B.; Buchet, Ph.; Charvet, J.L.; Chbihi, A.; Dayras, R.; Dore, D.; Durand, D.; Frankland, J.D.; Galichet, E.; Gourio, D.; Guinet, D.; Hudan, S.; Hurst, B.; Lautesse, P.; Lavaud, F.; Laville, J.L.; Leduc, C.; Le Fevre, A.; Legrain, R.; Lopez, O.; Lynen, U.; Nalpas, L.; Orth, H.; Plagnol, E.; Rosato, E.; Saija, A.; Schwarz, C.; Sfienti, C.; Steckmeyer, J.C.; Tabacaru, G.; Tamain, B.; Turzo, K.; Vient, E.; Vigilante, M.; Volant, C
2003-04-01
An efficient method of energy scale calibration for the CsI(Tl) modules of the INDRA multidetector (rings 6-12) using elastic and inelastic {sup 12}C+{sup 1}H scattering at E({sup 12}C)=30 MeV per nucleon is presented. Background-free spectra for the binary channels are generated by requiring the coincident detection of the light and heavy ejectiles. The gain parameter of the calibration curve is obtained by fitting the proton total charge spectra to the spectra predicted with Monte-Carlo simulations using tabulated cross section data. The method has been applied in multifragmentation experiments with INDRA at GSI.
International Nuclear Information System (INIS)
Peterson, G.A.; Hicks, R.S.
1985-09-01
The University of Massachusetts Medium Energy Nuclear Physics Group reports the status of its experimental and theoretical programs. An overview of projects in elastic and quasi-elastic electron scattering which have been completed in the past year is given. Projects which have been designed and which will soon be started are described as well. Descriptions of the theoretical models for nucleon-nucleon interactions, nuclear structure, electromagnetic interactions, and weak interactions are given as well. Listings of the literature of the group are given
2017-03-06
technique. This method is a substitute for a former “ polar -integration” algorithm [16, 24, 25] for integra- 1We believe this example reveals the true power...same accuracy levels as the polar -integration approach, but it does not require use of a complex polar integration or otherwise specialized algorithm ...solution on surfaces given in formats derived from Computer Aided Design, also known as CAD, and it has lead to new solvers for problems of Scattering
Detailed calculation of low-energy positron scattering by the hydrogen molecular ion
International Nuclear Information System (INIS)
Armour, E.A.G.; Carr, J.M.; Franklin, C.P.
1996-01-01
Detailed calculations are made using the Kohn method of positron scattering by the hydrogen molecular ion below the positronium formation threshold at 9.45 eV. Phase shifts from the two-centre Coulomb value are obtained for the lowest partial wave of Σ g + symmetry using a very flexible trial function containing a large number of short-range correlation functions. The convergence of the results with respect to both the linear and non-linear parameters is explored. (author)
POMME: A medium energy deuteron polarimeter based on semi-inclusive d-carbon scattering
International Nuclear Information System (INIS)
Bonin, B.; Boudard, A.; Fanet, H.; Fergerson, R.W.; Garcon, M.; Giorgetti, C.; Habault, J.; Le Meur, J.; Lombard, R.M.; Lugol, J.C.; Mayer, B.; Mouly, J.P.; Tomasi-Gustafsson, E.; Morlet, M.; Wiele, J. van de; Willis, A.; Greeniaus, G.; British Columbia Univ., Vancouver; Gaillard, G.; Markowitz, P.; Perdrisat, C.F.; Abegg, R.; Hutcheon, D.A.
1990-01-01
POMME is the first calibrated deuteron polarimeter using a d + carbon semi-inclusive scattering reaction. We present the results of its calibration in the region T d =150-700 MeV, with the polarized deuteron beam from the synchrotron Saturne. A parametrization of the measured analyzing powers, and a discussion of the obtained efficiency and figure of merit are also given. (orig.)
Elastic scattering of polarized deuterons from 40Ca and 58Ni at intermediate energies
International Nuclear Information System (INIS)
Sen, N. van; Arvieux, J.; Yanlin, Y.; Gaillard, G.; Bonin, B.; Boudard, A.; Bruge, G.; Lugol, J.C.; Babinet, R.; Hasegawa, T.; Soga, F.; Cameron, J.M.; Neilson, G.C.; Sheppard, D.M.
1985-01-01
Angular distributions of cross section, and Asub(y) and Asub(yy) analyzing powers were measured for polarized deuteron elastic scattering from 58 Ni at 200, 400 and 700 MeV, and 40 Ca at 700 MeV. Phenomenological potentials were obtained from an optical model analysis of the data. The total reaction cross sections deduced were compared to predictions from the Glauber theory optical limit. (orig.)
Helium elastic scattering from carbon for 30 deg. to 150 deg. in the energy region from 2 to 4.8 MeV
International Nuclear Information System (INIS)
Bogdanovic Radovic, I.; Jaksic, M.; Benka, O.; Gurbich, A.F.
2002-01-01
The differential cross-sections for elastic scattering of 4 He ions by carbon atoms were measured at scattering angles of 30 deg., 45 deg., 60 deg., 135 deg. and 150 deg. in the energy range from 2 to 4.8 MeV. Up to now mostly data for angles larger than 150 deg. were published in the literature. A thick carbon target with a thin evaporated Cu layer on the surface was used for the measurement. The number of impinging projectiles was obtained from the He ions scattered by the Cu layer assuming Rutherford cross-sections. The carbon scattering cross-sections were then obtained from comparison of measured He energy spectra with the simulated ones. Above 2 MeV all evaluated cross-sections become non-Rutherford. Deviations from Rutherford cross-sections are about 50% for 30 deg. scattering angle and amount up to a factor 30 for 150 deg. scattering angle. The measured experimental cross-sections were compared with the calculated theoretical cross-sections and already published data. Satisfactory agreement was obtained for all measured scattering angles and energies
Muon Energy Reconstruction Through the Multiple Scattering Method in the NO$\\mathrm{\
Energy Technology Data Exchange (ETDEWEB)
Psihas Olmedo, Silvia Fernanda [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2015-01-01
Neutrino energy measurements are a crucial component in the experimental study of neutrino oscillations. These measurements are done through the reconstruction of neutrino interactions and energy measurements of their products. This thesis presents the development of a technique to reconstruct the energy of muons from neutrino interactions in the NO$\\mathrm{\
Muon Energy Reconstruction Through the Multiple Scattering Method in the NO$\\mathrm{\
Energy Technology Data Exchange (ETDEWEB)
Psihas Olmedo, Silvia Fernanda [Univ. of Minnesota, Duluth, MN (United States)
2013-06-01
Neutrino energy measurements are a crucial component in the experimental study of neutrino oscillations. These measurements are done through the reconstruction of neutrino interactions and energy measurements of their products. This thesis presents the development of a technique to reconstruct the energy of muons from neutrino interactions in the NO$\\mathrm{\
The leading eikonal operator in string-brane scattering at high energy
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2013-01-01
In this paper we present two (a priori independent) derivations of the eikonal operator in string-brane scattering. The first one is obtained by summing surfaces with any number of boundaries, while in the second one the eikonal operator is derived from the three-string vertex in a suitable light-cone gauge. This second derivation shows that the bosonic oscillators present in the leading eikonal operator are to be identified with the string bosonic oscillators in a suitable light-cone gauge, while the first one shows that it exponentiates recovering unitarity. This paper is a review of results obtained in two previous publications of the same authors.
Multi-channel normal speed gated integrator in the measurement of the laser scattering light energy
International Nuclear Information System (INIS)
Yang Dong; Yu Xiaoqi; Hu Yuanfeng
2005-01-01
With the method of integration in a limited time, a Multi-channel normal speed gated integrator based on VXI system has been developed for measuring the signals with changeable pulse width in laser scattering light experiment. It has been tested with signal sources in ICF experiment. In tests, the integral nonlinearity between the integral results of the gated integrator and that of an oscilloscope is less than 1%. In the ICF experiments the maximum error between the integral results of the gated integrator and that of oscilloscope is less than 3% of the full scale range of the gated integrator. (authors)
Oxygen adsorption on Cu(111) using low energy ion scattering spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Zhang, F.M.; Yao, J.; Shen, Y.G.; King, B.V.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics
1993-12-31
The surface structure and oxygen adsorption of Cu(l 11) have been studied by 2 keV Li{sup +}, He{sup +} and Ar{sup +} ion scattering . Incident and azimuthal dependences were measured for the clean and O-covered surfaces, and the surface geometry was analysed on the basis of the shadowing features. Experimental results under different oxygen exposures at room temperature showed that the Cu(l 11) surface undergoes a roughening transition and results in a reconstruction where Cu atoms are vertically displaced by about 0.23 Angstroms. 4 refs., 4 figs.
Energy and polarization dependence of resonant inelastic X-ray scattering in Nd2CuO4
International Nuclear Information System (INIS)
Hill, J.P.; Kao, C.C.; Haemaelaeinen, K.
1998-01-01
The authors report the energy and polarization dependence of resonant inelastic x-ray scattering from Nd 2 CuO 4 . An energy loss feature at ∼6 eV is observed in the vicinity of the Cu K-edge. Numerical calculations based on the Anderson impurity model identify this as a charge transfer excitation to the anti-bonding state. The incident polarization is shown to select the intermediate states participating in the resonance process. Resonances are observed at 8,990 eV and 9,000 eV with the incident polarization perpendicular and parallel to the CuO planes, respectively. In contrast to the single-site model calculations, no resonances are observed associated with the 1s3d 10 L intermediate states, suggesting non-local effects play a role
A 19-state R-matrix investigation of resonances in e--He scattering at low energies: Pt. 3
International Nuclear Information System (INIS)
Fon, W.C.; Lim, K.P.
1992-01-01
The authors have previously reported 11-state and 19-state R-matrix calculations of 1 1 S-2 3 S differential cross sections at low energies. The same R-matrix calculations are now extended to obtain the differential cross sections for excitation of the ground state of helium to the 2 1 S and 2 3 P states. Convergence studies are carried out between the R-matrix calculations and comparisons are made between the R-matrix calculations and experiments. The 19-state R-matrix results are presented at scattering angles 30 o , 55 o , 60 o , 90 o , 120 o , 125 o and 140 o from the excitation thresholds up to 23.8 eV. The calculations are performed at more than seven hundred energy points in order to depict the observed resonant profiles. (author)
Energy Technology Data Exchange (ETDEWEB)
Kirillin, I.V. [Akhiezer Institute for Theoretical Physics, National Science Center ' ' Kharkov Institute of Physics and Technology' ' , Kharkov (Ukraine); Shul' ga, N.F. [Akhiezer Institute for Theoretical Physics, National Science Center ' ' Kharkov Institute of Physics and Technology' ' , Kharkov (Ukraine); V.N. Karazin Kharkov National University, Kharkov (Ukraine); Bandiera, L. [INFN Sezione di Ferrara, Ferrara (Italy); Guidi, V.; Mazzolari, A. [INFN Sezione di Ferrara, Ferrara (Italy); Universita degli Studi di Ferrara, Dipartimento di Fisica e Scienze della Terra, Ferrara (Italy)
2017-02-15
An investigation on stochastic deflection of high-energy negatively charged particles in a bent crystal was carried out. On the basis of analytical calculation and numerical simulation it was shown that there is a maximum angle at which most of the beam is deflected. The existence of a maximum, which is taken in the correspondence of the optimal radius of curvature, is a novelty with respect to the case of positively charged particles, for which the deflection angle can be freely increased by increasing the crystal length. This difference has to be ascribed to the stronger contribution of incoherent scattering affecting the dynamics of negative particles that move closer to atomic nuclei and electrons. We therefore identified the ideal parameters for the exploitation of axial confinement for negatively charged particle beam manipulation in future high-energy accelerators, e.g., ILC or muon colliders. (orig.)
P-barp and pp elastic scattering from 10 GeV to 1000 GeV centre-of-mass energy
International Nuclear Information System (INIS)
Islam, M.M.; Fearnley, T.; Guillaud, J.P.
1984-01-01
Antiproton-proton and proton-proton elastic scattering are studied simultaneously over the energy range √s approx. (10-1000) GeV in a nucleon valence core model proposed earlier. The scattering is described as primarily due to two processes: diffraction and hard scattering. The latter originates from the scattering of a nucleon core off another core. Destructive interference between the two processes produces dips in p-barp and pp differential cross-sections. As energy increases beyond the ISR range (√s = (23-62) GeV), the dips get filled up, and eventually transform into shoulders or breaks at collider energies. Differences between p-barp and pp differential cross-sections persist even at collider energies. Comparison with ISR data shows that the model provides a quantitative description of pp elastic scattering in this energy range. Predictions of p-barp and pp differential cross-sections at future collider energies √s = 800 and 2000 GeV are given. In order to distinguish between competing models, need for measuring the p-barp differential cross-section at the ISR and SPS collider in the abs (t)-range (0.5-2.0) (GeV) 2 is stressed
anti pp and pp elastic scattering from 10 GeV to 1000 GeV centre-of-mass energy
Energy Technology Data Exchange (ETDEWEB)
Islam, M.M. (Connecticut Univ., Storrs (USA). Dept. of Physics); Fearnley, T. (University Coll., London (UK). Dept. of Physics and Astronomy); Guillaud, J.P. (Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique des Particules)
1984-06-21
Antiproton-proton and proton-proton elastic scattering are studied simultaneously over the energy range ..sqrt..anti s approx.= (10/1000) GeV in a nucleon valence core model proposed earlier. The scattering is described as primarily due to two processes: diffraction and hard scattering. The latter originates from the scattering of a nucleon core off another core. Destructive interference between the two processes produces dips in anti pp and pp differential cross-sections. As energy increases beyond the ISR range (..sqrt..anti s = (23/62) GeV), the dips get filled up, and eventually transform into shoulders or breaks at collider energies. Differences between anti pp and pp differential cross-sections persist even at collider energies. Comparison with ISR data shows that the model provides a quantitative description of pp elastic scattering in this energy range. Predictions of anti pp and pp differential cross-sections at future collider energies ..sqrt..s = 800 and 2000 GeV are given. In order to distinguish between competing models, need for measuring the anti pp differential cross-section at the ISR and SPS collider in the vertical stroketvertical stroke-range (0.5/2.0) (GeV)/sup 2/ is stressed.
P-barp and pp elastic scattering from 10 GeV to 1000 GeV centre-of-mass energy
Energy Technology Data Exchange (ETDEWEB)
Islam, M.M. (Connecticut Univ., Storrs (USA). Dept. of Physics); Fearnley, T. (University Coll., London (UK). Dept. of Physics and Astronomy); Guillaud, J.P. (L.A.P.P. - BP909, 74019 Annecy-Le-Vieux Cedex, France)
1984-06-21
Antiproton-proton and proton-proton elastic scattering are studied simultaneously over the energy range ..sqrt..s approx. (10-1000) GeV in a nucleon valence core model proposed earlier. The scattering is described as primarily due to two processes: diffraction and hard scattering. The latter originates from the scattering of a nucleon core off another core. Destructive interference between the two processes produces dips in p-barp and pp differential cross-sections. As energy increases beyond the ISR range (..sqrt..s = (23-62) GeV), the dips get filled up, and eventually transform into shoulders or breaks at collider energies. Differences between p-barp and pp differential cross-sections persist even at collider energies. Comparison with ISR data shows that the model provides a quantitative description of pp elastic scattering in this energy range. Predictions of p-barp and pp differential cross-sections at future collider energies ..sqrt..s = 800 and 2000 GeV are given. In order to distinguish between competing models, need for measuring the p-barp differential cross-section at the ISR and SPS collider in the abs (t)-range (0.5-2.0) (GeV)/sup 2/ is stressed.
Energy Technology Data Exchange (ETDEWEB)
Yamamoto, Hiroyuki; Baba, Yuji; Sasaki, T.A. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
1997-03-01
Dissociative scattering of molecular SiF{sub 3}{sup +} and SiF{sup +} ions from a Cu(100) single crystal surface has been investigated in the incident energy range from 5 eV to 200 eV with a scattering angle of 77deg. The scattered ion intensity of dissociative ions and parent molecular ions were measured as a function of incident ion energy. The observed data show that onset energies of dissociation for SiF{sub 3}{sup +} and SiF{sup +} ions are 30 eV and 40 eV, respectively. The obtained threshold energies are consistent with a impulsive collision model where the dissociation of incident ion is caused by vibrational excitation during collision. (author)
Comparison of proton-proton and proton-antiproton scattering at very high energies
International Nuclear Information System (INIS)
Gauron, P.; Nicolescu, B.; Univ. Pierre et Marie Curie, 75 - Paris; Leader, E.
1985-09-01
The ISR results on the differential cross-sections for pp and anti-pp show unambiguously that the crossing-odd amplitude is still important at very high energies. Comparison of ISR and CERN collider anti-pp data suggests that the crossing-odd amplitude is growing maximally fast with energy. We explore the phenomenological consequences of such a ''maximal odderon'' behaviour at TeV energies
Energy Technology Data Exchange (ETDEWEB)
Bordenave-Montesquieu, D.; Dagnac, R. (Toulouse-3 Univ., 31 (France). Centre de Physique Atomique)
1992-06-14
We studied the single-electron capture as well as the direct processes occurring when a He[sup 2+] ion is scattered by a He target. Doubly differential cross sections were measured for single-electron capture with a collision energy ranging from 2 to 8 keV and a scattering angle varying from 10' to 3[sup o]30' (laboratory frame). Single-electron capture into excited states of He[sup +] was found to be the dominant process, confirming a previous experimental study. Elastic scattering and ionization differential cross sections were measured for E = 6 keV. (Author).
Theory of inelastic ion-atom scattering at low and intermediate energies
Schmid, G. B.; Garcia, J. D.
1977-01-01
Ab initio calculations are presented of inelastic energy loss and ionization phenomena associated with Ar(+)-Ar collisions at small distances of closest approach and for laboratory collision energies ranging from several keV to several hundred keV. Outer-shell excitations are handled statistically; inner-shell excitations are calculated from the viewpoint of quasidiabatic molecular orbital promotion. Auger electron yield, average state of ionization, and average inelastic energy loss are calculated per collision as a function of distance of closest approach of the collision partners for several laboratory collision energies. Average charge-state probabilities per collision partner are calculated as a function of the average inelastic energy loss per atom. It is shown that the structure in the data is due to the underlying structure in the inner-shell independent-electron quasimolecular promotion probabilities.
Sibener, S. J.; Lee, Y. T.
1978-05-01
An experiment was performed which confirms the existence of an internal mode dependence of molecular sticking probabilities for collisions of molecules with a cold surface. The scattering of a velocity selected effusive beam of CCl{sub 4} from a 90 K CC1{sub 4} ice surface has been studied at five translational velocities and for two different internal temperatures. At a surface temperature of 90 K (approx. 99% sticking probability) a four fold increase in reflected intensity was observed for the internally excited (560 K) CC1{sub 4} relative to the room temperature (298 K) CC1{sub 4} at a translational velocity of 2.5 X 10{sup 4} cm/sec. For a surface temperature of 90 K all angular distributions were found to peak 15{sup 0} superspecularly independent of incident velocity.
Relativistic three-body approach to NN scattering at intermediate energies
International Nuclear Information System (INIS)
The Bethe-Salpeter equation for coupled-channel N-Δ scattering is extended to satisfy unitarity in the NN and NNπ sectors. The procedure eliminates the unitarity violations characteristic of the standard ladder Bethe-Salpeter equation in the inelastic region, and improves the description of pion production near threshold. Results are presented for the NN phase shift and a number of observables up to 1 GeV. In particular, the 1D 2 inelasticity is found to be considerably smaller than found from phase shift analysis. In this context, the importance of the pion deuteron channel for the inelasticity parameter of is pointed out. 33 refs., 16 figs., 4 tabs
Alekseev, M G; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Austregesilo, A; Badełek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, M P; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O Yu; Dhara, L; Diaz, V; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Efremov, A; El Alaoui, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M Jr; Fischer, H; Franco, C; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmüller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; von Harrach, D; Hasegawa, T; Heinsius, F H; Herrmann, F; Heß, C; Hinterberger, F; Horikawa, N; Höppner, Ch; d’Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuß, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konopka, R; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kowalik, K; Krämer, M; Kral, A; Kroumchtein, Z V; Kuhn, R; Kunne, F; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu V; Moinester, M A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J; Negrini, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Pawlukiewicz-Kaminska, B; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Robinet, F; Rocco, E; Rondio, E; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Santos, H; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlüter, T; Schmitt, L; Schopferer, S; Schröder, W; Shevchenko, O Yu; Siebert, H W; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Takekawa, S; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Uhl, S; Uman, I; Virius, M; Vlassov, N V; Vossen, A; Weitzel, Q; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhao, J; Zhuravlev, N; Zvyagin, A
2010-01-01
Azimuthal asymmetries in semi-inclusive production of positive (h^+) and negative hadrons (h^-) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed in several terms according to their expected modulation in the azimuthal angle phi of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton distribution and fragmentation functions. The amplitudes of all phi-modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be consistent with zero within statistical errors, while the constant terms are nonzero and equal for h^+ and h^- within the statistical errors. The dependencies of the phi-modulated terms versus the Bjorken momentum fraction x, the hadron fractional momentum z, and the hadron transverse momentum p_h^T were studied. The x dependence of the constant terms for both positive and negative hadrons is in agreement with the longitudin...
Hinterberger, F; Altmeier, M; Bauer, F; Bisplinghoff, J; Büsser, K; Busch, M; Colberg, T; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jonas, E; Krause, H; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuk, T; Meinerzhagen, A; Naehle, O; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Trelle, H J; Weise, E; Wellinghausen, A; Woller, K; Ziegler, R
2000-01-01
The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH sub 2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power A sub N and the polarization correlation parameters A sub N sub N , A sub S sub S and A sub S sub L are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d sigma/d OMEGA and A sub N data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.
Energy Technology Data Exchange (ETDEWEB)
Block, M.M. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics and Astronomy; Halzen, F. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Margolis, B. [McGill Univ., Montreal, Quebec (Canada). Dept. of Physics; White, A.R. [Argonne National Lab., IL (United States)
1993-12-31
Recent experimental results, namely, the remeasurement of the {rho} value by UA4/2 at {radical}s = 546 GeV, together with a new analysis by the E710 group of {sigma}{sub tot}, {rho} and B at {radical}s = 1800 GeV, as well as their measurement of {sigma}{sub tot} and B at {radical}s = 1020 GeV, have provided important anchor points for the high energy behavior of {anti p}p scattering. The authors analyze high energy {anti p}p and pp data, using two distinct (and dissimilar) analysis techniques: (1) asymptotic amplitude analysis, under the assumption that they have reached {open_quotes}asymptopia{close_quotes}, and (2) an eikonal model whose amplitudes are designed to mimic real QCD amplitudes. The former gives strong evidence for a log (s/s{sub 0}) dependence at current energies and not log{sup 2}(s/s{sub 0}), and demonstrates that odderons are not necessary to explain the experimental data. The latter gives a unitary model for extrapolation into true {open_quote}asymptopia{close_quote} from current energies, allowing them to predict the values of the total cross section at future supercolliders. Using their QCD-model, the authors obtain {sigma}{sub tot}(16 TeV)= 106 {+-} 4 mb and {sigma}{sub tot}(40 TeV) = 120 {+-} 5 mb.
Rheinstädter, Maikel C; Seydel, Tilo; Salditt, Tim
2007-01-01
We report a high energy-resolution neutron backscattering study to investigate slow motions on nanosecond time scales in highly oriented solid-supported phospholipid bilayers of the model system deuterated 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine, hydrated with heavy water. Wave-vector-resolved quasielastic neutron scattering is used to determine relaxation times tau , which can be associated with different molecular components, i.e., the lipid acyl chains and the interstitial water molecules in the different phases of the model membrane system. The inelastic data are complemented by both energy-resolved and energy-integrated in situ diffraction. From a combined analysis of the inelastic data in the energy and time domains, the corresponding character of the relaxation, i.e., the exponent of the exponential decay, is also determined. From this analysis we quantify two relaxation processes. We associate the fast relaxation with translational diffusion of lipid and water molecules while the slow process likely stems from collective dynamics.
High energy Compton scattering study of TiC and TiN
Energy Technology Data Exchange (ETDEWEB)
Joshi, Ritu; Bhamu, K.C.; Dashora, Alpa [Department of Physics, University College of Science, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Ahuja, B.L., E-mail: blahuja@yahoo.co [Department of Physics, University College of Science, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India)
2011-05-15
We present the experimental Compton profiles of TiC and TiN using 661.65 keV {gamma}-ray from 20 Ci {sup 137}Cs source. To explain our experimental data on momentum densities, we have computed the theoretical profiles, energy bands and density of states using linear combination of atomic orbitals scheme within the framework of density functional theory. In addition the energy bands, density of states and Fermi surfaces using full potential linearised augmented plane wave method have also been computed. Energy bands and density of states obtained from both the theoretical models show metallic character of TiC and TiN. The anisotropies in Compton line shapes and the Fermi surface topology are discussed in term of energy bands.
Suzuki, Kosuke; Suzuki, Ayahito; Ishikawa, Taiki; Itou, Masayoshi; Yamashige, Hisao; Orikasa, Yuki; Uchimoto, Yoshiharu; Sakurai, Yoshiharu; Sakurai, Hiroshi
2017-09-01
Compton scattering is one of the most promising probes for quantitating Li under in operando conditions, since high-energy X-rays, which have high penetration power, are used as the incident beam and the Compton-scattered energy spectrum has specific line-shapes for each element. An in operando quantitation method to determine the Li composition in electrodes has been developed by using line-shape (S-parameter) analysis of the Compton-scattered energy spectrum. In this study, S-parameter analysis has been applied to a commercial coin cell Li-ion rechargeable battery and the variation of the S-parameters during the charge/discharge cycle at the positive and negative electrodes has been obtained. By using calibration curves for Li composition in the electrodes, the change in Li composition of the positive and negative electrodes has been determined using the S-parameters simultaneously.
International Nuclear Information System (INIS)
Armour, E.A.G.; Plummer, M.
1989-01-01
An explanation is given of why it is necessary to include long-range polarisation functions in the trial function when carrying out Kohn calculations of low-energy positron (and electron) scattering by atoms and simple molecules. The asymptotic form of these functions in low-energy e + -H 2 scattering is deduced. Appropriate functions with this asymptotic form are used to represent the closed-channel part of the wavefunction in a Kohn calculation of the lowest partial wave of Σ u + symmetry in e + -H 2 scattering at very low energies. For k≤0.03a 0 -1 , the results obtained are in good agreement with those obtained using the Born approximation and the asymptotic forms of the static and polarisation potentials. The relationship is pointed out between this method of taking into account long-range polarisation and the polarised pseudostate method used in R-matrix calculations. (author)
Woods, A. D. B.; Brockhouse, Bertram N.; Sakamoto, M.; Sinclair, R. N.
1960-09-12
Energy distributions of neutrons scattered from various moderators and from several hydrogenous substances were measured at energy transfers of 0.02 to 0.24 ev. Results from experiments on graphite, light and heavy water, ice, ZrH, LiH, NaH, and NH4Cl are included. It is noted that the results are of a preliminary character; however, they are probably the most accurate measurements of high-energy transfers yet made. (J.R.D.)
Determination of the forward slope in $p~p$ and $\\bar p~p$ elastic scattering up to LHC energy
Bourrely, C; Wu, T T
2011-01-01
In the analysis of experimental data on $p p$ (or $\\bar p p$) elastic differential cross section it is customary to define an average forward slope $b$ in the form $\\exp{(-b|t|)}$ where $t$ is the momentum transfer. Taking as working example the results of experiments at Tevatron and SPS, we will show with the help of the impact picture approach, that this simplifying assumption hides interesting information on the complex non-flip scattering amplitude, and that the slope $b$ is not a constant. We investigate the variation of this slope parameter, including a model-independent way to extract this information from an accurate measurement of the elastic differential cross section. An extension of our results to the LHC energy domain is presented in view of future experiments.
Unified model for small-t and high-t scattering at high energies: predictions at RHIC and LHC
Energy Technology Data Exchange (ETDEWEB)
Martynov, E. [National Academy of Sciences of Ukraine, N.N. Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Nicolescu, B. [CNRS and Universite Pierre et Marie Curie, Theory Group, Laboratoire de Physique Nucleaire et des Hautes Energies (LPNHE), Paris (France)
2008-07-15
The urgency of predictions in the large-t region at LHC stimulated us to present a unified model of small- and high-t scattering at high energies. Our model is based on safe theoretical ground: analyticity, unitarity, Regge behavior, gluon exchange and saturation of bounds established in axiomatic quantum field theory. We make precise predictions for the behavior of the differential cross sections at high t, the evolution of the dip-shoulder structure localized in the region 0.5
International Nuclear Information System (INIS)
Krishnan, K.M.; Echer, C.J.
1991-04-01
Partial cross-sections required for electron energy-loss microanalysis have been measured for a series of high purity single crystal standards. For each sample four different scattering geometries were used. The experimental data were compared with theoretical calculations using both standard hydrogenic model and parametrized Hartree-Slater cross-sections. Best agreement between theory and experiment were observed for experiments performed in diffraction mode (image coupling) with the probe convergence angle (0. 84 mrad) much smaller than the spectrometer collection angle (6.84 mrad). In addition, specimen thicknesses from the region of microanalysis were measured by convergent beam electron diffraction. Absolute cross-section based on these measurements are also currently being determined. 10 refs., 2 figs
Specular reflection model study of the image effect in He+/a:Si scattering at low energy
International Nuclear Information System (INIS)
Hidouche, A.; Chami, A.C.; Boudouma, Y.; Boudjema, M.; Benazeth, C.
2005-01-01
Electronic polarization induced by low energy ions near solid surfaces at grazing incidence considerably modifies the collision geometry. This effect is studied by the comparison between experimental and simulated time of flight (ToF) spectra of helium ions scattered from amorphous Si for small incidence and emergence angles. In this work, we include the image effect and the external stopping power in a simulation code through the Specular Reflection Model (SRM). The image potential is computed by using the dielectric surface functions in the Random Phase Approximation (RPA), Plasmon Line Approximation (PLA) and static Thomas-Fermi approximation. With the later, it is found a better agreement with the experiment for the ionic part of the spectra
The beauty and charm production cross-sections in 250-GeV/C pion - nucleon interactions
Energy Technology Data Exchange (ETDEWEB)
Darling, Christopher Lynn [Yale Univ., New Haven, CT (United States)
1993-01-01
By determining the production cross sections for heavy flavor hadrons, we test the theoretical predictions from perturhative quantum chroma-dynamics (QCD). In the case of pion induced beauty production, the few published results do not resolve the issue of the applicability of perturbative QCD. This analysis is undertaken in order to help resolve this situation. We determine the total beauty and charm production cross sections using an analysis of single electron decay products. We extract the cross sections per nucleon from the two-dimensional distribution of electron p versus impact parameter ( d) to the primary vertex. We place an upper limit on the beauty production cross section of σ_{b$\\bar{b}$} < 105 nb at the 90% confidence level, where the limit includes both statistical and systematic errors. The charm production cross section is determined to be σ_{c}c = 13.9$+2.4/atop{-2.3}$ (stat) ± 1.8 (syst) μ.b, which is in good agreement with next-to-leading order QCD predictions and other measurements.
Chatterji, Tapan Kumar; Demmel, F; Jalarvo, Niina; Podlesnyak, Andrey; Chogondalli Muniraju, Naveen Kumar; Xiao, Yinguo; Brueckel, Thomas
2017-10-10
n order to understand the origin of the huge quasielastic magnetic scattering observed previously with a back-scattering neutron spectrometer we have re-investigated the low energy excitations in HoCrO$_3$ by inelastic neutron scattering in a much wider energy range with time-of-flight neutron spectrometers. The inelastic signals are due to the excitations between the ground state doublet of the Ho ion. The quasielastic signal is due to the fluctuation of the disordered Ho moments. At low temperature the intensity of quasielastic scattering is small. It starts increasing as the temperature increases above 30 K. At the same temperature the elastic intensity due to Ho moment ordering decreases in a similar way. This observation strengthens the hypothesis that the quasielastic scattering is due the fluctuations of the disordered Ho moments. The time scale of fluctuations has been determine from the quasielastic scattering and was found to vary from about 22 ps at T = 70 K to about 2.5 ps at T = 160 K. The stretched exponential line shape indicates a distribution of decay rates at low temperatures. © 2017 IOP Publishing Ltd.
Chatterji, T.; Demmel, F.; Jalarvo, N.; Podlesnyak, A.; Kumar, C. M. N.; Xiao, Y.; Brückel, T.
2017-11-01
In order to understand the origin of the huge quasielastic magnetic scattering observed previously with a back-scattering neutron spectrometer, we have re-investigated the low energy excitations in HoCrO3 by inelastic neutron scattering in a much wider energy range with time-of-flight neutron spectrometers. The inelastic signals are due to the excitations between the ground state doublet of the Ho ion. The quasielastic signal is due to the fluctuation of the disordered Ho moments. At low temperature the intensity of quasielastic scattering is small. It starts increasing as the temperature increases above 30 K. At the same temperature, the elastic intensity due to Ho moment ordering decreases in a similar way. This observation strengthens the hypothesis that the quasielastic scattering is due the fluctuations of the disordered Ho moments. The time scale of fluctuations has been determine from the quasielastic scattering and was found to vary from about 22 ps at T = 70 K to about 2.5 ps at T = 160 K. The stretched exponential line shape indicates a distribution of decay rates at low temperatures.
Gurbich, A. F.; Bokhovko, M. V.
2018-04-01
The alpha elastic scattering cross-sections for Ni, Cu, and Y were measured at the energies above the onset of the non-Rutherford scattering. The obtained experimental data along with data from literature were incorporated into the theoretical analysis in the framework of the optical model. The optimization of the model parameters provided a basis for the calculations of the differential cross-sections for Z = 28-38 elements in the energy range up to 10 MeV. The obtained cross sections were made available for common use through the SigmaCalc web site at http://sigmacalc.iate.obninsk.ru/.
Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV
Energy Technology Data Exchange (ETDEWEB)
Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)
2017-01-15
The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.
International Nuclear Information System (INIS)
Guiasu, I.
1978-01-01
The elastic γ-nucleon scattering represents an indirect powerful method for the nucleon structure investigation. Some theoretical aspects of this problem are treated in the presented thesis. After a general introduction into the subject and a short review of the up-to-date literature, the first chapter contains kinematics and dynamical preliminaries of reaction γ+N→γ+N. In chapter II, the low energy theorems are discussed and extended up to six power in the photon laboratory energies, ω; the six structure dependent constants which appear in the differential cross section in this order are defined and computed, and an extraction for the proton electromagnetic polarizabilities α,β from the experimental data is performed. A new dispersive analysis of the γ+N→γ+N process at photon laboratory energies lower than 450 Mev is introduced and used for numerical calculation in chapter III; some improvements are obtained in the comparison with the experimental data, with respect to other previous calculations. In the last chapter, two different sum rules for the difference (α-β) are established and numerically computed - these theoretical predictions agree with the values extracted from experience; based on the analyticity properties of the invariant amplitudes, an inequality is written down connecting an integral over the differential cross section of the process and the static properties of the nucleon (mass, charge, anomalous magnetic moment). (author)
Biegun, Aleksandra; Takatsu, Jun; Nakaji, Taku; van Goethem, Marc-Jan; van der Graaf, Emiel; Koffeman, E.; Visser, Jan; Brandenburg, Sijtze
2016-01-01
The novel proton radiography imaging technique has a large potential to be used in direct measurement of the proton energy loss (proton stopping power, PSP) in various tissues in the patient. The uncertainty of PSPs, currently obtained from translation of X-ray Computed Tomography (xCT) images,