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Sample records for 44ca 90zr scattering

  1. Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

    Escher, J E; Dietrich, F S

    2008-05-23

    In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

  2. Vibrational thermodynamics of Fe90Zr7B3 nanocrystalline alloy from nuclear inelastic scattering

    Stankov, S.; Miglierini, M.; Chumakov, A. I.;

    2010-01-01

    Recently we determined the iron-partial density of vibrational states (DOS) of nanocrystalline Fe(90)Zr(7)B(3) (Nanoperm), synthesized by crystallization of an amorphous precursor, for various stages of nanocrystallization separating the DOS of the nanograins from that of the interfaces [S. Stank...

  3. Comparison of Optical Models for 400 MeV alpha scattering off 90Zr and 92Mo

    Jones, Daniel; Howard, Kevin; Garg, Umesh; Senyigit, Menekse

    2015-10-01

    Nuclear incompressibility is an important parameter governing the equation of state of nuclear matter. From the measurable centroid energies of the Isoscalar Giant Monopole Resonance (ISGMR), the incompressibility of nuclear matter can be calculated. The first necessary step is to fit elastic scattering angular distributions for a particular reaction and test the obtained model dependent parameters by calculating low-lying discrete state distributions for target nuclei. This study tests the suitability of two optical models to reproduce the angular distributions of differential cross sections from elastic and inelastic scattering of 400-MeV alpha particles. The first model utilizes a single folded potential for both the real and imaginary volume terms, and the second utilizes a single folded potential for the real volume term, and a phenomenological Woods-Saxon potential for the imaginary volume term. The elastic distributions for two heavy isotopes, 90Zr and 92Mo, are analyzed and the best parameter sets for each are shown. From this comparison, it is concluded that the second model, the so called ``hybrid model,'' is better able to reproduce the angular distributions for both 90Zr and 92Mo. Future work will include the Multipole Decomposition Analysis (MDA) for each reaction. NSF/REU Program at Notre Dame.

  4. Inelastic heavy ion scattering on 90Zr and 208Pb at intermediate energies

    Heavy ion inelastic scattering has been investigated using the SPEG spectrometer at GANIL. It is shown that the use of such a high resolution spectrometer allows a quantitative study of the giant resonances excited in heavy ion collisions. The contribution of the pick-up break-up mechanism to the high excitation energy region (E > 30 MeV) is then discussed. Recent results obtained with 40Ar beams at two different incident energies show that target excitations are also present in this energy region

  5. Pygmy dipole strength in 90Zr

    Schwengner, R; Tsoneva, N; Benouaret, N; Beyer, R; Erhard, M; Grosse, E; Junghans, A R; Klug, J; Kosev, K; Lenske, H; Nair, C; Schilling, K D; Wagner, A

    2008-01-01

    The dipole response of the N=50 nucleus 90Zr was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. In this way we derived the photoabsorption cross section up to the neutron-separation energy. This cross section matches well the photoabsorption cross section obtained from (gamma,n) data and thus provides information about the extension of the dipole-strength distribution toward energies below the neutron-separation energy. An enhancement of E1 strength has been found in the range of 6 MeV to 11 MeV. Calculations within the framework of the quasiparticle-phonon model ascribe this strength to a vibration of the excessive neutrons against the N = Z neutron-proton c...

  6. Spin differences in the 90Zr compound nucleus induced by (p ,p') , (p ,d ) , and (p ,t ) surrogate reactions

    Ota, S.; Burke, J. T.; Casperson, R. J.; Escher, J. E.; Hughes, R. O.; Ressler, J. J.; Scielzo, N. D.; Thompson, I. J.; Austin, R. A. E.; Abromeit, B.; Foley, N. J.; McCleskey, E.; McCleskey, M.; Park, H. I.; Saastamoinen, A.; Ross, T. J.

    2015-11-01

    The effect of the production mechanism on the decay of a compound nucleus is investigated. The nucleus 90Zr was produced by three different reactions, namely 90Zr(p ,p') 90Zr , 91Zr(p ,d ) 90Zr , and 92Zr(p ,t ) 90Zr , which served as surrogate reactions for 89Zr(n ,γ ) . The spin-parity (Jπ) distributions of the states populated by these reactions were studied to investigate the surrogate reaction approach, which aims at indirectly determining cross sections for compound-nuclear reactions involving unstable targets such as 89Zr . Discrete γ rays, associated with transitions in 90Zr and 89Zr , were measured in coincidence with light ions for scattering angles of 25∘-60∘ and 90Zr excitation energies extending above the neutron separation energy. The measured transition systematics were used to gain insights into the Jπ distributions of 90Zr . The 90Zr(p ,p') reaction was found to produce fewer γ rays associated with transitions involving high spin states (J =6 -8 ℏ ) than the other two reactions, suggesting that inelastic scattering preferentially populates states in 90Zr that have lower spins than those populated in the transfer reactions investigated. The γ -ray production was also observed to vary by factors of 2-3 with the angle at which the outgoing particle was detected. These findings are relevant to the application of the surrogate reaction approach.

  7. Double γ decay in 90Zr

    The double γ decay between θ+n - θ+i of 90Zr was observed. The θ+n level was fed through the decay of 90 Sr. The experimental arrangement consisted of a double coincidence system between the two semiconductor detectors. (A.C.A.S.)

  8. Weak transition of 44Ca

    A study of the nuclear core contribution to the excited nuclear states was done, along with its theoretical evaluation and interpretation, in the light nuclei region. The 727 KeV gamma ray transition between the 1885 KeV O+ and 1157 KeV - 2+ states was detected, putting in evidence experimentally, the possibility of the 0+ state, characterized as core excitation, and found to be by + decay or electron capture from44,44mSc. The formation of the 2850 KeV state, due to 880 KeV transition from the 3667 KeV state, is re-discussed. The 564 KeV and 1684 KeV transitions from the 2850 KeV state to the 2285 KeV and 1157 KeV states, respectively, are also discussed. A new scheme is proposed for the 44Ca excited states. (Author)

  9. Study of the neutron decays of giant resonances excited by the inelastic scattering of {sup 36} Ar on {sup 90} Zr and {sup 94} Zr targets at 44 MeV/u: a signature of multiphonon states; Etude des decroissances par neutrons des resonances geantes excitees dans les reactions de diffusion inelastique d`{sup 36}Ar sur des cibles de {sup 90} Zr et {sup 94} Zr a 44MeV/u: une signature des etats multiphonons

    Pascalon-Rozier, V.

    1997-01-13

    In inelastic heavy ion scattering, to angles near to the grazing angle, giant resonances (GR) are excited with very large differential cross sections. It has been shown that multiphonon states, states built with several GR quanta, can also been excited. These states can be revealed through the measurement of their decay by light particle emission. In this thesis, we report on the study of inelastic scattering of {sup 36}Ar at 44 MeV/u on target of {sup 90}Zr and {sup 94}Zr, measured in coincidence with neutrons detected with the EDEN multidetector. The analysis of the inelastic spectra show evidence for a structure at high excitation energy, exhibiting characteristics compatible with a two-photon excitation. The construction of missing energy spectra allows us to the study of the GR and the high energy structure. In both nuclei, the GR presents a direct decay branch of 8%, which yields informations on the microscopic structure of the resonance. A two phonon state, interpreted as two weakly coupled GR`s, built on one top of the other, and each phonon is expected to exhibit the same direct decay pattern as the GR. Such a simple decay is observed in the data, proving that the structure observed is due to the excitation of the two phonon state in both nuclei studied. Finally, we present a theoretical development based on Random Phase Approximation calculation, predicting that the two phonon state should be very harmonic. This result is in agreement with experimental studies of double phonon states over a large range of nuclei (from A = 12 to 208) carried out with several different probes. (author). 70 refs.

  10. Pygmy dipole resonance and dipole polarizability in {sup 90}Zr

    Iwamoto, C.; Tamii, A.; Shima, T.; Hashimoto, T.; Suzuki, T.; Fujita, H.; Hatanaka, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Utsunomiya, H.; Akimune, H.; Yamagata, T.; Okamoto, A.; Kondo, T. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Nakada, H. [Department of Physics, Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage, Chiba 263-8522 (Japan); Kawabata, T. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Fujita, Y. [Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043 (Japan); Matsubara, H. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Shimbara, Y.; Nagashima, M. [Department of Physics, Niigata University, Niigata 950-21-2 (Japan); Sakuda, M.; Mori, T. [Department of Physics, Okayama University, Okayama 900-0082 (Japan); and others

    2014-05-02

    Electric dipole (E1) reduced transition probability B(E1) of {sup 90}Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability α{sub D} which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

  11. Neutrons transition densities for the $2^+-8^+$ multiplet of states in $^{90}$Zr

    Onegin, M. S.; Plavko, A. V.

    2003-01-01

    The neutron transition densities of the $2^+-8^+$ levels in $^{90}$Zr were extracted in the process of analysing ({\\bf p},p') scattering at 400 Mev. Its comparison with the proton transition densities for these levels was undertaken. The radial shapes of the experimental neutron and proton transition densities for each state were found to be different.

  12. Gamma-gamma directional correlations in 90Zr

    Directional correlations of γγ cascades in 90Zr have been measured employing a twelve-channel goniometer. The spin and parity 7+ is assigned to the 5060.0 keV level. The multipole mixing ratios of the involved γ-ray transitions have been determined. The γ-ray transition probabilities for some transitions are calculated and compared with predictions of the shell model for the 90Zr nucleus. (Auth.)

  13. Study of the neutron decay of isoscalar electric giant resonances in the nucleus 90Zr

    The present thesis studies mainly the decay of the giant resonance region in 90Zr by means of a coincidence experiment which was performed at the 6Li beam of the Karlsruhe Isochronous Cyclotron. After excitation by inelastic scattering especially the neutron decay of the giant monopole and quadrupole resonance was observed by means of a (6Li,6Li'n) coincidence measurement. One aim of this experiment was to determine the relative branching ratios of the neutron decay from the region of the giant quadrupole resonance to the single low-lying states of 89Zr. In order to obtain an average over the angular correlation function for L>2 the decay neutrons were spectroscoped in 16 angles. The evaluation of the experiments yielded important results for the understanding of the giant resonances in heavy nuclei. The giant monopole and quadrupole resonances in 90Zr decay dominantly statistically. (orig./HSI)

  14. Neutron-/sup 90/Zr mean field from a dispersive optical model analysis

    Elastic scattering cross sections have been measured for 8, 10, and 24 MeV neutrons incident on /sup 90/Zr. These measurements, together with other neutron elastic scattering and total cross section data available up to 29 MeV, are used in grid searches to obtain an optical model potential which contains a dispersion relation term. This potential is then extrapolated toward negative energies to predict bound single-particle state properties. An overall good description of the data at positive and negative energies is achieved

  15. Total reaction cross sections for 8Li + 90Zr at near-barrier energies

    Total reaction cross sections for the radioactive nucleus 8Li on 90Zr are reported at the near-barrier energies of 18.5 and 21.5MeV, derived from quasi-elastic scattering measurements. An analysis of the quasi-elastic scattering results is performed within an optical model framework using the BDM3Y1 interaction and total reaction cross sections are deduced. These quantities, appropriately reduced, are compared with previous data obtained in elastic scattering measurements with well and weakly bound projectiles on various targets and a formula for predicting total reaction cross sections with an uncertainty of ∝ 20 % is obtained. Further on, the ratios of direct to total reaction cross sections are estimated for 6,8Li on various targets and are compared with CDCC or CRC calculations. The energy dependence of the optical potential is also discussed. (orig.)

  16. Nuclear structure of 88Sr and 90Zr investigated by (e,e') and (p,p') reactions

    In this thesis the results are presented and discussed from two experiments, performed to investigate the nuclear structure of two N = 50 nuclei: a high resolution inelastic proton scattering experiment on 90Zr, described in chapter II, and a high resolution inelastic electron scattering experiment on 88Sr, described in chapters III and IV. The results obtained in the 88Sr(e,e') experiment for the 1+ state at 3.486 MeV excitation energy are described separately in chapter V. The 90Zr(p,p') experiment was performed at a bombarding energy of 25 MeV with a resolution of 12 to 16 keV. The 88Sr(e,e') measurements were performed at two laboratories with an overall resolution between 20 and 60 keV. (Auth.)

  17. Double gamma decay in 40Ca and 90Zr

    The rare double gamma decay of the first excited 0+ state in 40Ca and 90Zr has been measured with a segmented 4π NaI detector system, which allows suppression of the perturbing background due to positron annihilation in flight. In both cases the directional correlation of the two photons is found to be asymmetric around 900, which is explained by an interference of 2E1 and 2M1 transitions. The deduced M1 quenching factors agree with those from (e,e') and (p,p') measurements

  18. Transfer reactions for the /sup 50/Ti + /sup 90/Zr system below the Coulomb barrier

    The analysis of quasielastic cross section data for the /sup 90/Zr projectile plus /sup 50/Ti target system shows that the probability for /sup 50/Ti(/sup 90/Zr, /sup 49/Ti)/sup 91/Zr, 1n-transfer reaction near the barrier is much larger than estimates based on semiclassical theory. The probability for /sup 50/Ti(/sup 90/Zr,/sup 51/V)/sup 89/Y, 1p-transfer reaction, on the other hand, agrees with the same theory. The internuclear distance where the 1n-transfer probability first deviates from tunneling predictions coincides with the threshold of the fusion barrier distribution deduced from the experimental fusion cross sections of the /sup 50/Ti+/sup 90/Zr system, suggesting a common mechanism for the large enhancement of 1n-transfer and fusion cross sections

  19. Experimental constraints on the $\\gamma$-ray strength function in $^{90}$Zr using partial cross sections of the $^{89}$Y(p,$\\gamma$)$^{90}$Zr reaction

    Netterdon, L; Goriely, S; Mayer, J; Scholz, P; Spieker, M; Zilges, A

    2015-01-01

    Partial cross sections of the $^{89}$Y(p,$\\gamma$)$^{90}$Zr reaction have been measured to investigate the $\\gamma$-ray strength function in the neutron-magic nucleus $^{90}$Zr. For five proton energies between $E_p=3.65$ MeV and $E_p=4.70$ MeV, partial cross sections for the population of seven discrete states in $^{90}$Zr have been determined by means of in-beam $\\gamma$-ray spectroscopy. Since these $\\gamma$-ray transitions are dominantly of $E1$ character, the present measurement allows an access to the low-lying dipole strength in $^{90}$Zr. A $\\gamma$-ray strength function based on the experimental data could be extracted, which is used to describe the total and partial cross sections of this reaction by Hauser-Feshbach calculations successfully. Significant differences with respect to previously measured strength functions from photoabsorption data point towards deviations from the Brink-Axel hypothesis relating the photo-excitation and de-excitation strength functions.

  20. Excitation of giant resonances in {sup 208}Pb, {sup 120}Sn, {sup 90}Zr and {sup 60}Ni by 84 Mev/nucleon {sup 17}O ions

    Alamanos, N.; Liguori-Neto, R.; Roussel-Chomaz, P.; Rochais, L.; Auger, F.; Fernandez, B.; Gillibert, A.; Lacey, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (FR). Direction des Sciences de la Matiere; Blumenfeld, Y.; Frascaria, N.; Garon, J.P.; Roynette, J.C.; Scarpacci, J.A.; Suomijarvi, T. [Paris-11 Univ., 91 - Orsay (FR). Inst. de Physique Nucleaire; Barrette, J.; Mark, S.K.; Turcotte, R. [McGill Univ., Montreal, PQ (CA). Foster Radiation Lab.; Van der Woude, A.; Van der Berg, A.M. [Rijksuniversiteit Groningen (NL). Kernfysisch Versneller Inst.

    1991-12-31

    Elastic and inelastic scattering of 1435 MeV {sup 17}O ions on {sup 208}Pb, {sup 120}Sn, {sup 90}Zr and {sup 60}Ni have been measured. Parameters of the isoscalar giant monopole and quadrupole resonances are obtained. The quadrupole resonance exhausts {approx} 60% of the energy weighted sum rule while the observed monopole resonance corresponds to more than 100% of the sum rule.

  1. Calculation of neutron cross sections for 90Zr, 208Pb and 209Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides 90Zr, 208Pb and 209Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for 90Zr and Bechetti and Greenless for 208Pb and 209Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  2. (3He,t) reaction at 80MeV on 90Zr and 208Pb

    An experiment using the 80MeV 3He beam of the ISN cyclotron at Grenoble has been done on a target of 90Zr and another one of 208Bi. The 90Zr and 208Pb IAS angular distributions are fitted by DWBA calculations. For the previously reported Gamow Teller transition centered in 90Nb at 8.4MeV, two components are observed. The first one of M1 type is centered at 7.2MeV, the other one of unknown polarity at 9.7MeV

  3. Two-photon radiation in the 90Zr 0+→0+ transition

    An experiment on studying two-photon radiation in 0+→0+-transition with 1.76 MeV of 90Zr is described. Ratio of two-photon process and pair conversion probabilities Wγγ/Wπ=(7.4±1.4)x10-4 is obtained

  4. Deuteron excitation of the isoscalar breathing mode resonance in 90Zr, 120Sn, 208Pb

    With the new 108 MeV deuteron beam of the Orsay synchrocyclotron and the new experimental set up which allow measurements without background for angles as small as 40, a systematic study of the breathing mode has been undertaken and the results on 90Zr, 120Sn and 208Pb are reported

  5. Excitation of giant resonances in [sup 208]Pb, [sup 120]Sn, [sup 90]Zr and [sup 60]Ni by 84 MeV/nucleon [sup 17]O ions

    Liguori Neto, R. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Roussel-Chomaz, P. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Rochais, L. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Alamanos, N. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Auger, F. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Fernandez, B. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Gastebois, J. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Gillibert, A. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Lacey, R. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Miczaika, A. (DAPNIA/SPhN, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Pierroutsakou, D. (DAPNI

    1993-07-19

    Elastic and inelastic scattering of 1435 MeV [sup 17]O ions on [sup 208]Pb, [sup 120]Sn, [sup 90]Zr and [sup 60]Ni have been measured. Hindrance in the excitation of the first 3[sup -] states is observed. Parameters of the isoscalar giant monopole and quadrupole resonances are obtained. The quadrupole resonance exhausts [approx]55% of the energy-weighted sum rule while the observed monopole resonance corresponds to more than 100% of the sum rule. Strength is also observed at high excitation energy in all targets. (orig.)

  6. Exchange interactions in (FeT)90Zr10(T=Ru,Mn) metallic glasses (abstract)

    Recently there have been several theoretical reports about models of amorphous transition metal alloys which take into account the fluctuations of local magnetic moments due to structural disorder. It is predicted that the local atomic moment on an atom depends on the number of first near neighbors with short distances (contracted atoms) and it could be positive, negative, or negligible. An amorphous Fe endash Zr system could be a typical system to study these features which have a key role in determining the magnetic structure. Fe90Zr10 orders ferromagnetically at 230 K and exhibits a mixed state at T90Zr10. Mn is known to couple antiferromagnetically (AF) to Fe while Ru is expected to be nonmagnetic. We find that Mn reduces the Curie temperature (Tc) gradually while the spin freezing temperature (Tf) remains nearly constant. However, in the case of Ru, Tf drastically increases and 5 at.% Ru drives the system to a clear spin glass state. Hyperfine field studies show gradual evolution of AF coupled spins and their distribution, pointing out the existence of a well defined bimodal distribution. Fe endash Fe exchange is believed to become antiferromagnetic for Fe endash Fe distances 2Zr which is a closed packed structure). We propose that the dilution of Fe moment and the band modifications due to Ru substitution seemed to promote antiferromagnetic coupling in a Fe endash Zr system. copyright 1997 American Institute of Physics

  7. Gamow-Teller Resonance of 90Zr in a Relativistic Approach

    马中玉; 陈宝秋

    2003-01-01

    We establish the formalism of nuclear spin-isospin excitations, especially the Gamow-Teller resonance in a fully consistent relativistic random-phase approximation. A relativistic form of the Landau-Migdal parameter g′ is adopted as a residual spin-isospin correlation force. In the non-relativistic limit it reproduces the excitation energy of the giant Gamow-Teller resonance state obtained in the non-relativistic model. The Gamow-Teller resonance for finite nuclei is investigated in a relativistic approach for the first time. It is found that the Ikeda sum rule of90Zr is quenched about 8% in the Hartree as well as the correlated strengths due to the poles of the negative Dirac states at energies above 1 GeV.

  8. Estimated 55Mn and 90Zr cross section covariances in the fast neutron energy region

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

    2008-06-24

    We completed estimates of neutron cross section covariances for {sup 55}Mn and {sup 90}Zr, from keV range to 25 MeV, considering the most important reaction channels, total, elastic, inelastic, capture, and (n,2n). The nuclear reaction model code EMPIRE was used to calculate sensitivity to model parameters by perturbation of parameters that define the optical model potential, nuclear level densities and strength of the pre-equilibrium emission. The sensitivity analysis was performed with the set of parameters which reproduces the ENDF/B-VII.0 cross sections. The experimental data were analyzed and both statistical and systematic uncertainties were extracted from almost 30 selected experiments. Then, the Bayesian code KALMAN was used to combine the sensitivity analysis and the experiments to obtain the evaluated covariance matrices.

  9. Structure of isobaric analog states in 91Nb populated by the 90Zr(a,t) reaction

    Van der Molen, H K T; Van den Berg, A M; Daito, I; Fujimura, H; Fujita, Y; Fujiwara, M; Harakeh, M N; Ihara, F; Inomato, T; Ishibashi, K; Jänecke, J; Kalantar-Nayestanaki, N; Laurent, H; Lhenry, I; O'Donnell, T W; Rodin, V A; Tamii, A; Toyokawa, H; Urin, M H; Yoshida, H; Yosoi, M

    2001-01-01

    Decay via proton emission of isobaric analog states (IAS's) in $^{91}{Nb}$ was studied using the $^{90}{Zr}(\\alpha,t)$ reaction at $E_\\alpha$=180 MeV. This study provides information about the damping mechanism of these states. Decay to the ground state and low-lying phonon states in $^{90}{Zr}$ was observed. The experimental data are compared with theoretical predictions wherein the IAS `single-particle' proton escape widths are calculated in a continuum RPA approach. The branching ratios for decay to the phonon states are explained using a simple model.

  10. Neutron capture cross section of $^{90}$Zr Bottleneck in the s-process reaction flow

    Tagliente, G; Milazzo, P M; Moreau, C; Aerts, G; Abbondanno, U; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Bečvář, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Köhler, P; Kossionides, E; Krtička, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Santos, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M, C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2008-01-01

    The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. The small cross section of the neutron magic nucleus 90Zr, which accounts for more than 50% of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an important component of the structural materials used in traditional and advanced nuclear reactors. The (n,γ) cross section has been measured at CERN, using the n_TOF spallation neutron source. In total, 45 resonances could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the high resolution and low backgrounds at n_TOF. On average, the Γγ widths obtained in resonance analyses with the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the Maxwellian averaged cross section f...

  11. 89 Zr(n,γ)90 Zr from a surrogate reaction approach

    Ota, Shuya; Burke, J. T.; Casperson, R. J.; Escher, J. E.; Hughes, R. O.; Ressler, J. J.; Scielzo, N. D.; Thompson, I.; Austin, R. A. E.; McCleskey, E.; McCleskey, M.; Saastamoinen, A.; Ross, T.

    2015-04-01

    While recent studies have demonstrated the validity of the surrogate reaction approach for studying fission cross sections of short-lived actinides, its applicability for (n, γ) is still under investigation. We studied the γ-decay of 90 Zr produced by 91 Zr(p,d) and 92 Zr(p,t) in order to infer the 89 Zr(n, γ) cross sections. The experiments were carried out at the K150 Cyclotron facility at Texas A&M University with a 28.5-MeV proton beam. The reaction deuterons and tritons were measured at forward angles of 30-60° with the STARS (Silicon Telescope Array for Reaction Studies) array of three segmented Micron S2 silicon detectors. Compound nuclei with energies up to a few MeV above the neutron separation thresholds were populated. The coincident γ-rays were measured with the LiTeR (Livermore Texas Richmond) array of five Compton-suppressed HPGe clovers. We will present results of γ-emission probabilities of 89 Zr(n, γ) and some theoretical discussions. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52- 07NA27344. One of the authors, S. O. is supported by JSPS Postdoctoral Fellowship for Research Abroad.

  12. Hot fusion-evaporation cross sections of 44Ca-induced reactions with lanthanide targets

    Werke, T. A.; Mayorov, D. A.; Alfonso, M. C.; Tereshatov, E. E.; Folden, C. M.

    2015-11-01

    Background: Previously reported cross sections of 45Sc-induced reactions with lanthanide targets are much smaller than 48Ca-induced reactions on the same targets. 44Ca is one proton removed from 45Sc and could be used to produce nuclei with a relative neutron content between those produced in the 45Sc- and 48Ca-induced reactions. Purpose: As part of a systematic investigation of fusion-evaporation reactions, cross sections of 44Ca-induced reactions on lanthanide targets were measured. These results are compared to available data for 48Ca- and 45Sc-induced fusion-evaporation cross sections on the same lanthanide targets. Collectively, these data provide insight into the importance of the survival against fission of excited compound nuclei produced near spherical shell closures. Methods: A beam of 6+Ca at an energy of ≈5 MeV /u was delivered by the K500 superconducting cyclotron at the Cyclotron Institute at Texas A&M University. The desired evaporation residues were selected by the Momentum Achromat Recoil Spectrometer and identified via their characteristic α -decay energies. Excitation functions for the 44Ca+158Gd ,159Tb, and 162Dy reactions were measured at five or more energies each. A theoretical model was employed to study the fusion-evaporation process. Results: The 44Ca-induced reactions have x n cross sections that are two orders of magnitude larger than 45Sc-induced reactions but two orders of magnitude smaller than 48Ca-induced reactions on the same targets. Proton emission competes effectively with neutron emission for the 44Ca+159Tb and 162Dy reactions. The maximum 4 n cross sections in the 44Ca+158Gd ,159Tb, and 162Dy reactions were 2100 ± 230 ,230 ± 20 , and 130 ±20 μ b , respectively. The 44Ca+158Gd and 159Tb cross sections are in good agreement with the respective cross bombardments of 48Ca+154Gd and 45Sc+158Gd once differences in capture cross sections and compound nucleus formation probabilities are corrected for. Conclusions: Excitation

  13. Photon-induced multiple particle emissions of 90Zr and natZr from 10 to 140 MeV

    A comprehensive analysis of electrodisintegration yields of protons on 90Zr is proposed taking into account the giant dipole resonance, isovector giant quadrupole resonance (IVGQR), and quasideuteron contributions to the total photoabsorption cross section from 10 to 140 MeV. The calculation applies the MCMC intranuclear cascade to address the direct and pre-equilibrium emissions and another Monte Carlo-based algorithm to describe the evaporation step. The final results of the total photoabsorption cross section for 90Zr and relevant decay channels are obtained by fitting the (e,p) measurements from the National Bureau of Standards and show that multiple proton emissions dominate the photonuclear reactions at higher energies. These results provide a consistent explanation for the exotic and steady increase of the (e,p) yield and also a strong evidence of a IVGQR with a strength parameter compatible with the E2 energy-weighted sum rule. The inclusive photoneutron cross sections for 90Zr and natZr, derived from these results and normalized with the (e,p) data, are in agreement within 10% with both Livermore and Saclay data up to 140 MeV

  14. Dipole strength in {sup 89}Y and {sup 90}Zr up to the neutron-separation energy

    Schwengner, R.; Beyer, R.; Doenau, F.; Erhard, M.; Junghans, A.R.; Klug, J.; Kosev, K.; Nair, C.; Schilling, K.D.; Wagner, A. [Forschungszentrum Dresden-Rossendorf, 01314 Dresden (Germany); Rusev, G. [Forschungszentrum Dresden-Rossendorf, 01314 Dresden (Germany)]|[Duke University, Durham, NC 27708 (United States); Tsoneva, N. [Universitaet Giessen, 35392 Giessen (Germany); Benouaret, N. [Forschungszentrum Dresden-Rossendorf, 01314 Dresden (Germany)]|[Universite d' Alger, 16111 Alger, Algerie (Algeria); Grosse, E. [Forschungszentrum Dresden-Rossendorf, 01314 Dresden (Germany)]|[Technische Universitaet Dresden, 01062 Dresden (Germany)

    2008-07-01

    Dipole and quadrupole excitations in the semimagic N=50 nuclei {sup 89}Y and {sup 90}Zr were investigated at the superconducting electron linear accelerator ELBE with bremsstrahlung produced at electron energies from 9 to 13 MeV. About 200 {gamma} transitions in {sup 89}Y and 180 in {sup 90}Zr were identified up to about 11 and 12 MeV, respectively. Statistical methods were applied to estimate the contributions of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. The photoabsorption cross sections obtained in this way provide information about the dipole-strength function on the tail of the giant dipole resonance (GDR) towards energies below the neutron-separation energy. We observed extra dipole strength with respect to a smooth extrapolation of the GDR in the energy range from about 6 - 11 MeV. The observed extra strength is compared with results of calculations within the Quasiparticle-Phonon Model, which also make predictions about the nature of the strength.

  15. Nuclear Structure of the Closed Subshell Nucleus 90Zr Studied with the (n,n'(gamma)) Reaction

    Garrett, P E; Younes, Y; Becker, J A; Bernstein, L A; Baum, E M; DiPrete, D P; Gatenby, R A; Johnson, E L; McGrath, C A; Yates, S W; Devlin, M; Fotiades, N; Nelson, R O; Brown, B A

    2003-06-12

    States in {sup 90}Zr have been observed with the (n,n{prime}{gamma}) reaction using both spallation and monoenergetic accelerator-produced neutrons. A scheme comprised of 81 levels and 157 transitions was constructed concentrating on levels below 5.6 MeV in excitation energy. Spins have been determined by considering data from all experimental studies performed for {sup 90}Zr. Lifetimes have been deduced using the Doppler-shift attenuation method for many of the states and transition rates have been obtained. A spherical shell-model interpretation in terms of particle-hole excitations assuming a {sup 88}Sr closed core is given. In some cases, enhancements in B(M1) and B(E2) values are observed that cannot be explained by assuming simple particle-hole excitations. Shell-model calculations using an extended f pg-shell model space reproduce the spectrum of excited states very well, and the gross features of the B(M1) and B(E2) transition rates. Transition rates for individual levels show discrepancies between calculations and experimental values.

  16. Very low field ac-response at the loss of long range magnetic order in amorphous Fe90Zr10

    Low temperature ac-susceptibility measurements over 5 decades of ac-field (0.08-8000 A/m) have been carried out on amorphous ribbons of Fe90Zr10 and Fe91Zr9. The authors find that at very low fields (0.8 to 24 A/m) ac-response measurements eliminate the influence of domain and domain wall motion, the well known Hopkinson peak effects, to reveal clearly the reentrant characteristics. With such studies a reentrant freezing temperature Taf is unambiguously revealed with an evident knee in χ'(T) and a corresponding well defined peak in χ double-prime(T). The latter is found to be independent of the applied field (0.8 to 8 A/m) while being weakly dependent on the frequency (10--1,000 Hz). They thus find Tsf to be 25 K and 40 K respectively for Fe90Zr10 and Fe91Zr9 amorphous ribbons

  17. Reaction cross sections for protons on {sup 12}C, {sup 40}Ca, {sup 90}Zr and {sup 208}Pb at energies between 80 and 180 MeV

    Auce, A.; Ingemarsson, A.; Johansson, R. [and others

    2005-04-01

    Results of reaction cross section measurements on {sup 12}C, {sup 40}Ca, {sup 90}Zr and {sup 208}Pb at incident proton energies between 80 and 180 MeV and for {sup 58}Ni at 81 MeV are presented. The experimental procedure is described and the results are compared with earlier measurements and predictions using macroscopic and microscopic models.

  18. α-cluster model for the multiple emission of particles in the reaction 90Zr (e, α)

    We present a methodology based on the model of photoabsorption by a cluster N- α for a better understanding of the puzzling steady increase behavior of the 90 Zr (e, α) yield obtained experimentally in the energy range of the giant dipole resonance (RDG) and the quasi-deuteron (QD).The calculation takes into account the emission of protons, neutrons and alpha particles in the framework of the reaction (which was used for the Intranuclear Cascade model (MCMC)). The statistical decay of the compound nucleus is described by Monte Carlo techniques in terms of competition between evaporation of particles (p, n, d, α, 3 He t) and nuclear fission, but for our specific case (the reaction and + Zr 90 in an energy range between 20 and 140 MeV) the fission channel does not have a high probability of occurrence. The results reproduce quite successfully the experimental data, suggesting that pre-equilibrium emission of alpha particles are essential for the interpretation of this exotic increase of the cross sections. (Author)

  19. 87Y(n,γ and 89,90Zr(n,γ cross sections from a surrogate reaction approach

    Ota Shuya

    2015-01-01

    Full Text Available The surrogate reaction approach is an indirect method for determining nuclear reaction cross sections which cannot be measured directly or predicted reliably. While recent studies demonstrated the validity of the surrogate reaction approach for studying fission cross sections for short-lived actinides, its applicability for radiative neutron capture reactions ((n,γ is still under investigation. We studied the γ decay of excited 88Y and 90,91Zr nuclei produced by 89Y(p,d, 91Zr(p,d, and 92Zr(p,d reactions, respectively, in order to infer the 87Y(n,γ and 89, 90Zr(n,γ cross sections. The experiments were carried out at the K150 Cyclotron facility at Texas A&M University with a 28.5-MeV proton beam. The reaction deuterons were measured at forward angles of 25-60° with the array of three segmented Micron S2 silicon detectors. The compound nuclei with energies up to a few MeV above the neutron separation thresholds were populated. The coincident γ-rays were measured with the array of five Compton-suppressed HPGe clover detectors.

  20. 87Y(n,γ) and 89,90Zr(n,γ) cross sections from a surrogate reaction approach

    Ota, Shuya; Burke, J. T.; Casperson, R. J.; Escher, J. E.; Hughes, R. O.; Ressler, J. J.; Scielzo, N. D.; Thompson, I.; Austin, R. A. E.; McCleskey, E.; McCleskey, M.; Saastamoinen, A.; Ross, T.

    2015-05-01

    The surrogate reaction approach is an indirect method for determining nuclear reaction cross sections which cannot be measured directly or predicted reliably. While recent studies demonstrated the validity of the surrogate reaction approach for studying fission cross sections for short-lived actinides, its applicability for radiative neutron capture reactions ((n,γ)) is still under investigation. We studied the γ decay of excited 88Y and 90,91Zr nuclei produced by 89Y(p,d), 91Zr(p,d), and 92Zr(p,d) reactions, respectively, in order to infer the 87Y(n,γ) and 89, 90Zr(n,γ) cross sections. The experiments were carried out at the K150 Cyclotron facility at Texas A&M University with a 28.5-MeV proton beam. The reaction deuterons were measured at forward angles of 25-60° with the array of three segmented Micron S2 silicon detectors. The compound nuclei with energies up to a few MeV above the neutron separation thresholds were populated. The coincident γ-rays were measured with the array of five Compton-suppressed HPGe clover detectors.

  1. Relevance of single-particle and collective excitations in zirconium isotopes populated by neutron transfer reactions in the {sup 90}Zr+{sup 208}Pb system

    Pajtler, M. Varga, E-mail: maja.varga@fizika.unios.hr [Department of Physics, University of Osijek, Trg Ljudevita Gaja 6, 31000 Osijek (Croatia); Szilner, S.; Malenica, D. Jelavić; Mijatović, T.; Soić, N. [Ruer Bošković Institute, HR-10001, Zagreb (Croatia); Corradi, L.; Angelis, G. de; Fioretto, E.; Montanari, D.; Stefanini, A. M.; Valiente-Dobón, J. J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Gadea, A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Haas, F. [Institut Pluridisciplinaire Hubert Curien, CNRS-IN2P3 and Université de Strasbourg, F-67037 Strasbourg (France); Lunardi, S.; Mengoni, D.; Montagnoli, G.; Recchia, F.; Scarlassara, F. [Dipartimento di Fisica, Universitá di Padova, and Istituto Nazionale di Fisica Nucleare, I-35131 Padova (Italy); Märginean, N. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest-Magurele (Romania); Pollarolo, G. [Dipartimento di Fisica Teorica, Universitá di Torino,and Istituto Nazionale di Fisica Nucleare, I-10125 Torino (Italy); and others

    2015-10-15

    Multineutron transfer reaction {sup 90}Zr+{sup 208}Pb has been studied at the energy close to the Coulomb barrier energy by using the PRISMA + CLARA set-up. In this fragment-γ coincidence measurement, the selective properties of the reaction mechanism in the population of the specific states have been discussed. Based on the observed γ transitions of neutron transfer channels, namely {sup 89–94}Zr isotopes, their level schemes have been constructed and updated.

  2. Study of the unusual increase in the Curie temperature of the residual amorphous phase in nanocrystalline Fe90Zr7B2Cu1

    Nanocrystalline Fe90Zr7B2Cu1 with ferromagnetic BCC nanocrystals of about 10-20 nm size embedded in a residual amorphous matrix was produced from amorphous precursor by partial crystallization. A significant increase in the Curie temperature of the residual amorphous phase (TC) as compared to that of the amorphous precursor was found by combined bulk magnetic and Moessbauer measurements. The unusual increase of TC for alloys with different nanocrystalline fractions correlates with the quantity of the BCC phase

  3. Experimental constraints on the γ-ray strength function in 90Zr using partial cross sections of the Y89(p,γZr90 reaction

    L. Netterdon

    2015-05-01

    Full Text Available Partial cross sections of the Y89(p,γZr90 reaction have been measured to investigate the γ-ray strength function in the neutron–magic nucleus 90Zr. For five proton energies between Ep=3.65 MeV and Ep=4.70 MeV, partial cross sections for the population of seven discrete states in 90Zr have been determined by means of in-beam γ-ray spectroscopy. Since these γ-ray transitions are dominantly of E1 character, the present measurement allows an access to the low-lying dipole strength in 90Zr. A γ-ray strength function based on the experimental data could be extracted, which is used to describe the total and partial cross sections of this reaction by Hauser–Feshbach calculations successfully. Significant differences with respect to previously measured strength functions from photoabsorption data point towards deviations from the Brink–Axel hypothesis relating the photo-excitation and de-excitation strength functions.

  4. Emission of β+ Particles Via Internal Pair Production in the 0+ – 0+ Transition of 90Zr: Historical Background and Current Applications in Nuclear Medicine Imaging

    Marco D'Arienzo

    2013-03-01

    Full Text Available 90Y is traditionally considered as a pure β– emitter. However, the decay of this radionuclide has a minor branch to the 0+ first excited state of 90Zr at 1.76 MeV, that is followed by a β+/β– emission. This internal pair production has been largely studied in the past because it is generated by a rare electric monopole transition (E0 between the states 0+/0+ of 90Zr. The positronic emission has been recently exploited for nuclear medicine applications, i.e. positron emission tomography (PET acquisitions of 90Y-labelled radiopharmaceuticals, widely used as therapeutic agents in internal radiation therapy. To date, this topic is gaining increasing interest in the radiation dosimetry community, as the possibility of detecting β+ emissions from 90Y by PET scanners may pave the way for an accurate patient-specific dosimetry. This could lead to an explosion in scientific production in this field. In the present paper the historical background behind the study of the internal pair production of the 0+/0+ transition of 90Zr is presented along with most up to date measured branch ratio values. An overview of most recent studies that exploit β+ particles emitted from 90Y for PET acquisitions is also provided.

  5. Selective properties of neutron transfer reactions in the 90Zr + 208Pb system for the population of excited states in zirconium isotopes

    Nuclei produced via multineutron transfer channels have been studied in 90Zr + 208Pb close to the Coulomb barrier energy in a fragment-γ coincident measurement employing the PRISMA magnetic spectrometer coupled to the CLARA γ-array. The selective properties of the reaction mechanism have been discussed in terms of states and their strength excited in the neutron transfer channels leading to 89–94Zr isotopes. A strong population of yrast states, with energies up to ∼7.5 MeV has been observed

  6. Selective properties of neutron transfer reactions in the {sup 90}Zr + {sup 208}Pb system for the population of excited states in zirconium isotopes

    Varga Pajtler, M., E-mail: mvarga@fizika.unios.hr [Department of Physics, University of Osijek, HR-31000 Osijek (Croatia); Szilner, S. [Rudjer Bošković Institute, HR-10001 Zagreb (Croatia); Corradi, L.; Angelis, G. de; Fioretto, E. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Gadea, A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Haas, F. [Institut Pluridisciplinaire Hubert Curien, CNRS-IN2P3 and Université de Strasbourg, F-67037 Strasbourg (France); Lunardi, S. [Dipartimento di Fisica, Universitá di Padova, and Istituto Nazionale di Fisica Nucleare, I-35131 Padova (Italy); Jelavić Malenica, D. [Rudjer Bošković Institute, HR-10001 Zagreb (Croatia); Mărginean, N. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest-Magurele (Romania); Mengoni, D. [Dipartimento di Fisica, Universitá di Padova, and Istituto Nazionale di Fisica Nucleare, I-35131 Padova (Italy); Mijatović, T. [Rudjer Bošković Institute, HR-10001 Zagreb (Croatia); Montagnoli, G. [Dipartimento di Fisica, Universitá di Padova, and Istituto Nazionale di Fisica Nucleare, I-35131 Padova (Italy); Montanari, D. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Pollarolo, G. [Dipartimento di Fisica Teorica, Universitá di Torino, and Istituto Nazionale di Fisica Nucleare, I-10125 Torino (Italy); and others

    2015-09-15

    Nuclei produced via multineutron transfer channels have been studied in {sup 90}Zr + {sup 208}Pb close to the Coulomb barrier energy in a fragment-γ coincident measurement employing the PRISMA magnetic spectrometer coupled to the CLARA γ-array. The selective properties of the reaction mechanism have been discussed in terms of states and their strength excited in the neutron transfer channels leading to {sup 89–94}Zr isotopes. A strong population of yrast states, with energies up to ∼7.5 MeV has been observed.

  7. Neutron and proton optical potentials for 12C, 16O, 27Al, 56Fe, 90Zr and 208Pb up to 250 MeV

    In order to perform nuclear data evaluation without unphysical discontinuities, optical models should cover the whole mass and energy range of interest continuously. In this work, the best set of optical model parameters were obtained with energy dependent potential forms which incorporate effects of dispersion relationship for neutron and proton up to 250 MeV on 12C, 16O, 27Al, 56Fe, 90Zr and 208Pb. Applicability of adopting an identical geometrical factor for the real volume, imaginary volume and imaginary surface potentials has been investigated as well in the process of parameter search. (author)

  8. Resonances-Excitation Calculation Studies Investigation of Δ(3, 3) in Ground State of 90Zr Cold Finite Heavy Nucleus at Equilibrium and Under Large Compression

    A non-relativistic microscopic mean field theory of finite nuclei is investigated where the nucleus is described as a collection of nucleons and delta resonances. The ground state properties of 90Zr nucleus have been investigated at equilibrium and large amplitude compression using a realistic effective baryon-baryon Hamiltonian based on Reid Soft Core (RSC) potential. The sensitivity of the ground state properties is studied, such as binding energy, nuclear radius, radial density distribution, and single particle energies to the degree of compression. It is found that the most of increasing in the nuclear energy generated under compression is used to create the massive Δ particles. For 90Zr nucleus under compression at 2.5 times density of the normal nuclear density, the excited nucleons to Δ's are increased sharply up to 14% of the total number of constituents. This result is consistent with the values extracted from relativistic heavy-ion collisions. The single particle energy levels are calculated and their behaviors under compression are examined too. A good agreement between results with effective Hamiltonian and the phenomenological shell model for the low lying single-particle spectra is obtained. A considerable reduction in compressibility for the nucleus, and softening of the equation of state with the inclusion of the Δ's in the nuclear dynamics are suggested by the results. (nuclear physics)

  9. Scattering of intermediate energy protons

    The scattering of 1 GeV protons appears to be a powerful means of investigating nuclear matter. We worked with SPESI and the formalism of Kerman-Mc Manus and Thaler. The amplitude of nucleon-nucleon scattering was studied as were the aspects of 1 GeV proton scattering (multiple scattering, absorption, spin-orbit coupling, N-N amplitude, KMT-Glauber comparison, second order effects). The results of proton scattering on 16O, the isotopes of calcium, 58Ni, 90Zr and 208Pb are given

  10. Cyclotron production of high purity 44m,44Sc with deuterons from 44CaCO3 targets

    Introduction: Due to its longer half-life, 44Sc (T1/2 = 3.97 h) as a positron emitter can be an interesting alternative to 68Ga (T1/2 = 67.71 min). It has been already proposed as a PET radionuclide for scouting bone disease and is already available as a 44Ti/44Sc generator. 44Sc has an isomeric state, 44mSc (T1/2 = 58.6 h), which can be co-produced with 44Sc and that has been proved to be considered as an in-vivo PET generator 44mSc/44Sc. This work presents the production route of 44mSc/44Sc generator from 44Ca(d,2n), its extraction/purification process and the evaluation of its performances. Methods: Irradiation was performed in a low activity target station using a deuteron beam of 16 MeV, which favors the number of 44mSc atoms produced simultaneously to 44Sc. Typical irradiation conditions were 60 min at 0.2 μA producing 44 MBq of 44Sc with a 44Sc/44mSc activity ratio of 50 at end of irradiation. Separations of the radionuclides were performed by means of cation exchange chromatography using a DGA® resin (Triskem). Then, the developed process was applied with bigger targets, and could be used for preclinical studies. Results: The extraction/purification process leads to a radionucleidic purity higher than 99.99% (43Sc, 46Sc, 48Sc < DL). 44mSc/44Sc labeling towards DOTA moiety was performed in order to get an evaluation of the specific activities that could be reached with regard to all metallic impurities from the resulting source. Reaction parameters of radiolabeling were optimized, reaching yields over 95%, and leading to a specific activity of about 10–20 MBq/nmol for DOTA. A recycling process for the enriched 44Ca target was developed and optimized. Conclusion: The quality of the final batch with regard to radionucleidic purity, specific activity and metal impurities allowed a right away use for further radiopharmaceutical evaluation. This radionucleidic pair of 44mSc/44Sc offers a quite interesting PET radionuclide for being further evaluated as an in

  11. Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: A 44Ca stable isotope study

    The intestinal absorption of calcium includes at least three definable steps; transfer across the microvillar membrane, movement through the cytosolic compartment, and energy-dependent extrusion into the lamina propria, Tracing the movement of calcium through the epithelium has been hampered by lack of suitable techniques and, in this study, advantage was taken of ion microscopy in conjunction with cryosectioning and use of the stable isotope 44Ca to visualize calcium in transit during the absorptive process. The effect of vitamin D, required for optimal calcium absorption, was investigated. Twenty millimolar 44Ca was injected into the duodenal lumen in situ of vitamin D-deficient and vitamin D-replete chickens. At 2.5, 5.0, and 20.0 min after injection, duodenal tissue was obtained and processed for ion microscopic imaging. At 2.5 min. 44Ca was seen to be concentrated in the region subjacent to the microvillar membrane in tissue from both groups. At 5.0 and 20.0 min, a similar pattern of localization was evident in D-deficient tissues. In D-replete tissues, the distribution of 44Ca became more homogenous, indicating that vitamin D increased the rate of transfer of Ca2+ from the apical to the basolateral membrane, a function previously ascribed to the vitamin D-induced calcium-binding protein (28-kDa calbindin-D). Quantitative aspects of the calcium absorptive process were determined in parallel experiments with the radionuclide 47Ca. Complementary information on the localization of the naturally occurring isotopes of calcium (40Ca) and potassium (39K) is also described

  12. Cross section determination of threshold like (n,p), (n,α) and (n,2n) reactions with 14 MeV neutrons for the 50Ti, 68Zn and 90Zr nuclides

    Activation cross-sections at (14,4 + - 0,3) MeV neutron energy have been measured by means of conventional and cyclic activation techniques, utilizing an intense sealed tube neutron generator of cylindrical ion-acceleration structure (KORONA). The reactions investigated and the corresponding cross-sections (in mb) are: 50Ti(n,p) 50Sc(14,3 + - 2,1); 68Zn(n,p) sup(68g) Cu (5,0 + - 1); 68Zn(n,p) sup(68m) Cu (3,6 + - 0,6); 68Zn (n,α) 65Ni (10,3 + - 1,8); 90Zr (n,p) sup(90m) Y (9,8 +m - 1,7); 90Zr (n,α) sup(87m) Sr (3,2 + - 0,5); 90Zr (n,2n) sup(89m)Zr (75 + - 12). The neutron flux and the mean energy of the neutrons from the KORONA were also determined through the monitor reactions 27Al (n,A)24Na, 90Zr(n,2n)89Zr and 93Nb(n,2n) sup(92m) Nb. For comparison with the experimentally obtained results, the hitherto known cross-section data from the literature were careflly compiled, too, in this work. In the case of the 68Zn(n,p) sup(68g) Cu reaction, a special formulation was developed to calculate its cross-section, taking into consideration the most important fact that all the excited levels of 68Zn arising from the β- decay of sup(68g) Cu are also fed by the β- activity decay of sup(68m) Cu and by the isomeric transitions and internal conversions of this metastable state. (Author)

  13. Optical model studies of 6Li elastic scattering at 156 MeV

    Differential cross sections for 6Li elastic scattering at 156 MeV from 12C, 40Ca 90Zr and 208Pb are presented. The sensitivity to various potential forms is established by using Saxon Woods, Saxon-Woods-squred, density independent and density dependent folded potentials. The extent to which the experimental data determine the potentials and related quantities is discussed. (orig.)

  14. Equilibrium and pre-equilibrium calculations of cross-sections of (, ) reactions on 89Y, 90Zr and 94Mo targets used for the production of 89Zr, 90Nb and 94Tc positron-emitting radionuclides

    R Baldik; H Aytekin; E Tel

    2013-02-01

    In this study, the pre-equilibrium and equilibrium calculations of cross-sections of 89Y(, ), 90Zr$(p, xn)$ and 94Mo(, ) reactions, which were used for the production of 89Zr, 90Nb and 94Tc positron-emitting radioisotopes, have been investigated. Pre-equilibrium calculations have been performed at different proton incident energies by using the hybrid, geometry-dependent-hybrid and full exciton models. The Weisskopf–Ewing model is used for calculating the equilibrium effects at the same incident energies. The calculated results have been discussed and compared with the experimental results.

  15. Effects of relativistic kinematics in heavy ion elastic scattering

    Relativistic corrections to the reaction kinematic parameters were made for elastic scattering of 6Li, 12C and 40Ar from 40Ca, 90Zr and 208Pb targets at incident energies between 20 and 100 MeV/nucleon. The results of optical model calculations show that the effects of such corrections are important when describing the angular distributions of elastic scattering cross sections for heavy ion scattering at incident energies as low as around 40 MeV/nucleon. The effects on the total reaction cross sections on the other hand, were found to be small within the energy range studied when the optical model potential is fixed. (authors)

  16. In-situ Electric Field-Induced Modulation of Photoluminescence in Pr-doped Ba0.85Ca0.15Ti0.90Zr0.10O3 Lead-Free Ceramics

    Sun, Hai Ling; Wu, Xiao; Chung, Tat Hang; Kwok, K. W.

    2016-06-01

    Luminescent materials with dynamic photoluminescence activity have aroused special interest because of their potential widespread applications. One proposed approach of directly and reversibly modulating the photoluminescence emissions is by means of introducing an external electric field in an in-situ and real-time way, which has only been focused on thin films. In this work, we demonstrate that real-time electric field-induced photoluminescence modulation can be realized in a bulk Ba0.85Ca0.15Ti0.90Zr0.10O3 ferroelectric ceramic doped with 0.2 mol% Pr3+, owing to its remarkable polarization reversal and phase evolution near the morphotropic phase boundary. Along with in-situ X-ray diffraction analysis, our results reveal that an applied electric field induces not only typical polarization switching and minor crystal deformation, but also tetragonal-to-rhombohedral phase transformation of the ceramic. The electric field-induced phase transformation is irreversible and engenders dominant effect on photoluminescence emissions as a result of an increase in structural symmetry. After it is completed in a few cycles of electric field, the photoluminescence emissions become governed mainly by the polarization switching, and thus vary reversibly with the modulating electric field. Our results open a promising avenue towards the realization of bulk ceramic-based tunable photoluminescence activity with high repeatability, flexible controllability, and environmental-friendly chemical process.

  17. Effect of oxidizing and reducing atmospheres on Ba(Ti0.90Zr0.10O3:2V ceramics as characterized by piezoresponse force microscopy

    Francisco Moura

    2011-09-01

    Full Text Available The effect of annealing atmospheres (At amb, N2 and O2 on the electrical properties of Ba(Ti0.90Zr0.10O3:2V (BZT10:2V ceramics obtained by the mixed oxide method was investigated. X-ray photoelectron spectroscopy (XPS analysis indicates that oxygen vacancies present near Zr and Ti ions reduce ferroelectric properties, especially in samples treated in an ambient atmosphere (At amb. BZT10:2V ceramics sintered in a nitrogen atmosphere showed better dielectric behaviour at room temperature with a dielectric permittivity measured at a frequency of 10 kHz equal to 16800 with dielectric loss of 0.023. Piezoelectric force microscopy (PFM images reveal improvement in the piezoelectric coefficient by sintering the sample under nitrogen atmosphere. Thus, BZT10:2V ceramics sintered under a nitrogen atmosphere can be useful for practical applications which include nonvolatile digital memories, spintronics and data-storage media.

  18. An attempt of application of short lived 44K activity induced in the 44Ca(n,p)44K reaction using 14 MeV neutrons for total body calcium assessment in human subject

    The status of in vivo neutron activation analysis techniques for the measurement of total body calcium in human subject is reviewed. Relevant data on the nuclear characteristics of calcium isotopes during interaction with neutrons ranging from slow up to 14 MeV neutrons are presented. Physical aspects of the measurement of in vivo total body calcium (TBCa) using 44K activity induced in the 44Ca(n,p)44K(T1/2=22.3 min) reaction by 14 MeV neutrons are discussed. The measurement of delayed γ-ray emitted during decay of activities induced in enriched 44Ca, natCa, phantom filled with water solution of natural calcium and skeletal arm are considered. Results of measurements on the phantom and skeletal arm indicate a possibility to measure the TBCa using the 44K activity. (author)

  19. Inelastic electron scattering at low momentum transfer

    Recent advances of high energy resolution (ΔE approx. 30 keV FWHM) inelastic electron scattering at low momentum transfer (q -1) using selected experimental data from the Darmstadt electron linear accelerator are discussed. Strong emphasis is given to a comparison of the data with theoretical nuclear model predictions. Of the low multipolarity electric transitions investigated, as examples only E1 transitions to unnatural parity states in 11B and E2 transitions of the very fragmented isoscalar quadrupole giant resonance in 208Pb are considered. In 11B the role of the Os hole in the configuration of the 1/2+, 3/2+ and 5/2+ states is quantitatively determined via an interference mechanism in the transition probability. By comparison of the high resolution data with RPA calculations the E2 EWSR in 208Pb is found to be much less exhausted than anticipated from previous medium energy resolution (e,e) and hadron scattering experiments. In the case of M1 transitions it is shown that the simplest idealized independent particle shell-model prediction breaks down badly. In 28Si, ground-state correlations influence largely the detected M1 strength and such ground-state correlations are also responsible for the occurence of a strong M1 transition to a state at Ex = 10.319 MeV in 40Ca. In 90Zr only about 10% of the theoretically expected M1 strength is seen in (e,e) and in 140Ce and 208Pb none (detection limit 1-2 μ2K). In the case of 208Pb high resolution spectra exist now up to an excitation energy of Ex = approx. 12MeV. The continuous decrease of the M1 strength with mass number is corroborated by the behaviour of strong but very fragmented M2 transitions which are detected in 28Si, 90Zr, 140Ce and 208Pb concentrated at an excitation energy E x approx. 44A-1/3MeV. In 90Zr, the distribution of spacings and widths of the many Jπ = 2 states are consistent with a Wigner and Porter-Thomas distribution, respectively. (orig.) 891 KBE/orig. 892 ARA

  20. Analysis of 6Li Scattering at 240 MeV Using Different Nuclear Potentials

    Al-Ghamdi, A. H.; Ibraheem, Awad A.

    2016-06-01

    Angular distributions of the elastic and inelastic scattering cross sections of 6Li projectile on different heavy ion target nuclei including the 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn at energy of 240 MeV have been analyzed by using two different folded potentials based on the CDM3Y6 and São Paulo potentials for the real part of the optical potential, while the imaginary parts have a phenomenological Woods-Saxon shape. Coupled channel calculations for the low-lying 2+ state at 1.369, 1.779, 3.832, 1.454, 2.186, and 1.29 MeV for 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn, respectively, have been carried out, and the best fit values for B(EL) with the above models have been extracted by fitting the inelastic scattering cross section and compared with the values of previous works. The total reaction cross section and real and imaginary volume integrals have also been investigated.

  1. Oscillation damping effect in elastic scattering cross sections of intermediate energy α-particles by atomic nuclei

    A simulating pattern of a scattering matrix based on the calculational results at eikonal approximation is used for theoretical analysis of differential cross sections of elastic scattering of α-particles with energies Eα>or approx. 100 MeV by atomic nuclei, in which the effect of attenuation of diffraction oscillations is observed. Calculated and measured cross sections of elastic scattering of α-particles by 12C, 40Ca and 90Zr nuclei in the energy region from 104.0-1725 MeV agree well between each other. The scattering matrix used in calculations corresponds to strong nuclear refraction and takes into acount transparence of target nuclei (from 2 to 16%) for waves with small moments

  2. Piezoelectric properties of new ternary Bi1/2(Na, Li)1/2TiO3-(Bi1/2K1/2)TiO3-Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramics

    0.852[Bi1/2(Na1-x Lix)1/2]TiO3-0.110(Bi1/2K1/2)TiO3-0.038Ba0.85Ca0.15Ti0.90Zr0.10O3 (BNLT-BKT-BCTZ-x) new ternary piezoelectric ceramics were fabricated by the conventional solid-state method, and their piezoelectric properties as a function of the Li content were mainly investigated. A stable solid solution with a single perovskite structure has been formed, and the depolarization temperature (Td) of these ceramics was identified by using the temperature dependence of the dielectric loss. The Td value of these ceramics gradually decreases, while the Tm value increases with increasing the Li content. The dielectric constant increases and the dielectric loss decreases with increasing the Li content, and an enhanced piezoelectric behavior of d33∝223 pC/N and kp∝35.2 % has been demonstrated in these ceramics with x=0.06. (orig.)

  3. 16O elastic scattering at Elab = 94 MeV/nucleon

    Elastic scattering of 94 MeV/nucleon 16O on 40Ca, 90Zr, and 208Pb was measured, completing similar measurements on 12C and 28Si. Optical model analysis of the whole set of data shows that the sensitive region where the nuclear potential is determined moves inwards as the mass of the target decreases. This determination is more precise for light systems which present a strong negative angle scattering contribution in the angular distribution. The data have also been analyzed in the framework of the folding model using density independent and density dependent nucleon-nucleon interaction. In both cases, the resulting potentials have to be renormalized to get a good description of the data. The data are consistent with a smooth decrease with energy of both the real and imaginary potentials. (orig.)

  4. Investigation of exotic modes of spinning nuclei near 90Zr

    R Palit; S Saha

    2014-04-01

    Recently, a digital data acquisition system with 96 channels has been set up for the Indian National Gamma Array (INGA) consisting of 24 Compton-suppressed clover detectors. The digital system provides higher throughput, better energy resolution and better stability for the multidetector Compton-suppressed clover array compared to the previous conventional system with analog shaping. A number of nuclear spectroscopic experiments have been carried out using the array. Selected results from this array will be presented which highlight different excitations of nuclei near-shell gaps.

  5. Evaluation of cross-section data from threshold to 40-60 MeV for specific neutron reactions important for neutron dosimetry applications. Part 1: Evaluation of the excitation functions for the 27Al(n,α)24Na, 55Mn(n,2n)54Mn, 59Co(n,p)59Fe, 59Co(n,2n)58m+gCo and 90Zr(n,2n)89m+gZr reactions

    Evaluations of cross sections and their associated covariance matrices have been carried out for five dosimetry reactions: - excitation functions were re-evaluated for the 27Al(n,α)24Na, 55Mn(n,2n)54Mn and 90Zr(n,2n)89m+gZr reactions over the neutron energy range from threshold to 40 MeV; - excitation functions were re-evaluated for the 59Co(n,p)59Fe and 59Co(n,2n)58m+gCo reactions over the neutron energy range from threshold to 60 MeV. Uncertainties in the cross sections for all of those reactions were also derived in the form of relative covariance matrices. Benchmark calculations performed for 235U thermal fission and 252Cf spontaneous fission neutron spectra show that the integral cross sections calculated from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

  6. Collective aspects of 91Zr by (d,d/sup prime/) scattering at 17 MeV

    The 91Zr(d,d')91Zr( reaction has been investigated at 17 MeV incident energy. Up to 4.8 MeV excitation, 73 levels, some of them new, were identified. Angular distributions associated to approx.40 levels were attributed to pure L = 2, 3, or 5 excitations, concentrated in energy regions where the 90Zr core exhibits 2+, 3-, and 5- states. The partial deformation parameters β/sub L//sup prime/ obtained show agreement with those from low energy proton scattering for L = 2, but there is a systematic difference for L = 3 and L = 5, which is discussed. Attention is drawn to the high excitation probability of the first excited state of 91Zr, as measured by the β2approx. =0.18 value obtained, a factor of approx.2 above all other values for nuclei with A = 90 +- 2

  7. Collective aspects of /sup 91/Zr by (d,d/sup prime/) scattering at 17 MeV

    Horodynski-Matsushigue, L.B.; Borello-Lewin, T.; Dietzsch, O.

    1986-05-01

    The /sup 91/Zr(d,d')/sup 91/Zr( reaction has been investigated at 17 MeV incident energy. Up to 4.8 MeV excitation, 73 levels, some of them new, were identified. Angular distributions associated to approx.40 levels were attributed to pure L = 2, 3, or 5 excitations, concentrated in energy regions where the /sup 90/Zr core exhibits 2/sup +/, 3/sup -/, and 5/sup -/ states. The partial deformation parameters ..beta../sub L//sup prime/ obtained show agreement with those from low energy proton scattering for L = 2, but there is a systematic difference for L = 3 and L = 5, which is discussed. Attention is drawn to the high excitation probability of the first excited state of /sup 91/Zr, as measured by the ..beta../sub 2/approx. =0.18 value obtained, a factor of approx.2 above all other values for nuclei with A = 90 +- 2.

  8. Isospin Character of Low-Lying Pygmy Dipole States via Inelastic Scattering of $^{17}$O

    Crespi, F C L

    2015-01-01

    The γ decay from the pygmy states was measured in 208 Pb, 124 Sn and 90 Zr nuclei using the inelastic scattering of 17 O at 340 MeV. The emitted γ rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented ∆ E-E silicon telescopes. The multipolarity of the observed gamma transitions was determined with remarkable sensitivity thanks to angu lar distribution measurements. Cross sections and angular distributions of the γ rays and of the scattered particles were measured. The results are compared with ( γ , γ ’) and (p, p’) data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering a nd of the inelastic excitation of the 2+ and 3− states. For the dipole transitions, a form factor obtained by folding a microscopically calculated transition dens ity was used for the first time. This has allowed us to extract the isoscalar component of the ...

  9. Diffuse scattering

    While Bragg scattering is characteristic for the average structure of crystals, static local deviations from the average lattice lead to diffuse elastic scattering around and between Bragg peaks. This scattering thus contains information on the occupation of lattice sites by different atomic species and on static local displacements, even in a macroscopically homogeneous crystalline sample. The various diffuse scattering effects, including those around the incident beam (small-angle scattering), are introduced and illustrated by typical results obtained for some Ni alloys. (author) 7 figs., 41 refs

  10. Diffuse scattering

    Kostorz, G. [Eidgenoessische Technische Hochschule, Angewandte Physik, Zurich (Switzerland)

    1996-12-31

    While Bragg scattering is characteristic for the average structure of crystals, static local deviations from the average lattice lead to diffuse elastic scattering around and between Bragg peaks. This scattering thus contains information on the occupation of lattice sites by different atomic species and on static local displacements, even in a macroscopically homogeneous crystalline sample. The various diffuse scattering effects, including those around the incident beam (small-angle scattering), are introduced and illustrated by typical results obtained for some Ni alloys. (author) 7 figs., 41 refs.

  11. Critical scattering

    We outline the theoretical and experimental background to neutron scattering studies of critical phenomena at magnetic and structural phase transitions. The displacive phase transition of SrTiO3 is discussed, along with examples from recent work on magnetic materials from the rare-earth (Ho, Dy) and actinide (NpAs, NpSb, USb) classes. The impact of synchrotron X-ray scattering is discussed in conclusion. (author) 13 figs., 18 refs

  12. Critical scattering

    Stirling, W.G. [Liverpool Univ., Dep. of Physics, Liverpool (United Kingdom); Perry, S.C. [Keele Univ. (United Kingdom). Dept. of Physics

    1996-12-31

    We outline the theoretical and experimental background to neutron scattering studies of critical phenomena at magnetic and structural phase transitions. The displacive phase transition of SrTiO{sub 3} is discussed, along with examples from recent work on magnetic materials from the rare-earth (Ho, Dy) and actinide (NpAs, NpSb, USb) classes. The impact of synchrotron X-ray scattering is discussed in conclusion. (author) 13 figs., 18 refs.

  13. Scattering theory

    Friedrich, Harald

    2016-01-01

    This corrected and updated second edition of "Scattering Theory" presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is k...

  14. Scattering theory

    Written by the author of the widely acclaimed textbook. Theoretical Atomic Physics Includes sections on quantum reflection, tunable Feshbach resonances and Efimov states. Useful for advanced students and researchers. This book presents a concise and modern coverage of scattering theory. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. The level of abstraction is kept as low as at all possible, and deeper questions related to mathematical foundations of scattering theory are passed by. The book should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. It is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.

  15. Neutron scattering

    The annual report on hand gives an overview of the research work carried out in the Laboratory for Neutron Scattering (LNS) of the ETH Zuerich in 1990. Using the method of neutron scattering, it is possible to examine in detail the static and dynamic properties of the condensed material. In accordance with the multidisciplined character of the method, the LNS has for years maintained a system of intensive co-operation with numerous institutes in the areas of biology, chemistry, solid-state physics, crystallography and materials research. In 1990 over 100 scientists from more than 40 research groups both at home and abroad took part in the experiments. It was again a pleasure to see the number of graduate students present, who were studying for a doctorate and who could be introduced into the neutron scattering during their stay at the LNS and thus were in the position to touch on central ways of looking at a problem in their dissertation using this modern experimental method of solid-state research. In addition to the numerous and interesting ways of formulating the questions to explain the structure, nowadays the scientific programme increasingly includes particularly topical studies in connection with high temperature-supraconductors and materials research

  16. Gamow-Teller Resonance of 90Zr in a Relativistic Approach

    MAZhong-yu; CHENBao-qiu

    2003-01-01

    We establish the formalism of nuclear spin-isospin excitations, especially the Gamow-Teller (GT) resonance in a fully consistent relativistic random phase approximation. A relativistic form of the Landau-Migdal parameter g'=0.6 is adopted as a residual spin-isospin correlation force. In the non-relativistic limit it reproduces the excitation energy of the giant Gamow-Teller resonance state obtained in the non-relativistic model.

  17. Neutron scattering. Lectures

    The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  18. On scattered subword complexity

    Kása, Zoltán

    2011-01-01

    Special scattered subwords, in which the gaps are of length from a given set, are defined. The scattered subword complexity, which is the number of such scattered subwords, is computed for rainbow words.

  19. Imaging with Scattered Neutrons

    Ballhausen, H; Gähler, R; Trapp, M; Van Overberghe, A

    2006-01-01

    We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

  20. Bidirectional optical scattering facility

    Federal Laboratory Consortium — Goniometric optical scatter instrument (GOSI) The bidirectional reflectance distribution function (BRDF) quantifies the angular distribution of light scattered from...

  1. Neutron scattering. Lectures

    The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

  2. Neutron scattering. Lectures

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  3. Neutron scattering. Lectures

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  4. Neutron scattering. Lectures

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  5. Neutron scattering. Lectures

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  6. Imaging with Scattered Neutrons

    Ballhausen, H.; Abele, H.; Gaehler, R.; Trapp, M; Van Overberghe, A.

    2006-01-01

    We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-re...

  7. Quantum scattering theory

    Kouri, Donald J

    2017-01-01

    This book provides a detailed exposition of quantum scattering theory as applied to chemical physics. It includes the fundamental mathematics of scattering, details of how it applies to atom-molecule, molecule-molecule collisions, as well as collisions with surfaces. A variety of computational methods for solving scattering problems are presented. In addition, some discussion of fully quantal approximations is included. Both inelastic and reactive scattering are treated in detail. Both time-dependent and time-independent approaches to scattering theory and scattering computation are included. The book will reflect the research done over approximately 50 years by the author.

  8. Magnetic photon scattering

    The report reviews, at an introductory level, the theory of photon scattering from condensed matter. Magnetic scattering, which arises from first-order relativistic corrections to the Thomson scattering amplitude, is treated in detail and related to the corresponding interaction in the magnetic neutron diffraction amplitude. (author)

  9. Scattering by Black Holes

    Andersson, N

    2000-01-01

    This is a chapter on Black-hole Scattering that was commissioned for an Encyclopaedia on Scattering edited by Pike and Sabatier, to be published by Academic Press. The chapter surveys wave propagation in black-hole spacetimes, diffraction effects in wave scattering, resonances, quasinormal modes and related topics.

  10. Polarized Neutron Scattering

    Roessli, B.; Böni, P.

    2000-01-01

    The technique of polarized neutron scattering is reviewed with emphasis on applications. Many examples of the usefulness of the method in various fields of physics are given like the determination of spin density maps, measurement of complex magnetic structures with spherical neutron polarimetry, inelastic neutron scattering and separation of coherent and incoherent scattering with help of the generalized XYZ method.

  11. Study of the nucleus-nucleus interaction potential via 16O elastic scattering at 94 MeV/u

    The elastic scattering angular distributions of 16O at 94 MeV/u on 12C, 28Si, 40Ca, 90Zr, 208Pb targets have been measured. They have been analyzed in the framework of the optical model with Woods-Saxon potentials and in the framework of the folding model. Concerning the heaviest system 16O + 208Pb, these analyses show that the real potential is well-defined only in the vicinity of the strong absorption radius, whereas for the lighter systems, it is defined in a relatively wide region (2-3 fm), which corresponds to a strong overlap of the two nuclei, especially for the systems 16O + 28Si and 16O + 12C. This difference, between the 16O + 208Pb system and the other systems originates in the appearance of the far-side contribution which manifests itself in the angular distributions by the so-called Fraunhoefer oscillations. The imaginary part of the potential is determined only in the vicinity of the strong absorption radius. The large reduction of the strong absorption radius for all the studied systems as the energy increases shows that the nuclear surface transparency is strongly enhanced at intermediate energies. The calculations performed with folding potentials allowed a study of the nuclear potential strength, in a less ambiguous way than with phenomenological potentials. In the regions where they are well-defined, the real and imaginary potentials decrease regularly when the energy goes from 10 to 100 MeV/u. This decrease disagrees with the results of microscopic calculations which predict an increase or a saturation of the nuclear potential in this energy range

  12. Seasonal Sr/Ca, and 44Ca/40Ca co-variation in Arctica islandica

    Full text: We have studied the Ca isotopic variations and Sr/Ca ratios within an A. islandica shell in relation to temperature fluctuations of the ambient seawater with sub-seasonal resolution. The long-lived bivalve A. islandica dwells at 10-200 m depth throughout much of the North Atlantic continental shelf. Its shells represent a promising SST archive for boreal marine settings. The A. islandica shell used for this study was collected at 60-m depth near the former position of the Nantucket Shoals Lightship. The years 1956-1958 were analyzed for both, Sr/Ca ratios and δ44/40Ca, with 1957 being the best resolved. The δ44/40Ca are highly correlated with Sr/Ca ratios (r= 0.92 for 1957). The positive correlation of Sr/Ca ratios and temperature in A. islandica is in accordance with published data on other bivalves, but contrary to thermodynamic expectations and e.g. coral data. The same inversion is found for Ca isotope fractionation: the δ44/40Ca correlation with temperature of A. islandica is negative, while all δ44/40Ca temperature gradients published so far (inorganic precipitates and foraminifera data) show varying degrees of positive correlation. Thus, as for Sr/Ca, the temperature correlation of δ44/40Ca in A. islandica is not under thermodynamic control. It appears inevitable to conclude that biological effects dominate both, Sr incorporation and Ca isotope fractionation in A. islandica. Growth rates and food supply are parameters that might relate Sr/Ca ratios as well as Ca isotopic compositions to vital activity and thus indirectly to temperature. In any case the high correlation of Sr/Ca ratios and Ca isotope fractionation indicates a common metabolic process for the observed variations. (author)

  13. Introduction to neutron scattering

    Fischer, W.E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    We give here an introduction to the theoretical principles of neutron scattering. The relationship between scattering- and correlation-functions is particularly emphasized. Within the framework of linear response theory (justified by the weakness of the basic interaction) the relation between fluctuation and dissipation is discussed. This general framework explains the particular power of neutron scattering as an experimental method. (author) 4 figs., 4 refs.

  14. Muon-proton Scattering

    Borie, E.

    2012-01-01

    A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the approximation that the scattered lepton (usually an electron) is ultrarelativistic, with v/c approximately equal to 1. Here the cross section is calculated for all values of the energy. It agrees with the standard result in the appropriate limit.

  15. Scattering from black holes

    Futterman, J.A.H.; Handler, F.A.; Matzner, R.A.

    1987-01-01

    This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging.

  16. Scattering from black holes

    This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging

  17. Partially strong WW scattering

    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. However, this is generally not true. In some composite models or general two-Higgs-doublet models, the presence of a light Higgs boson does not guarantee complete unitarization of the WW scattering. After partial unitarization by the light Higgs boson, the WW scattering becomes strongly interacting until it hits one or more heavier Higgs bosons or other strong dynamics. We analyze how LHC experiments can reveal this interesting possibility of partially strong WW scattering.

  18. Multiple scattering tomography.

    Modregger, Peter; Kagias, Matias; Peter, Silvia; Abis, Matteo; Guzenko, Vitaliy A; David, Christian; Stampanoni, Marco

    2014-07-11

    Multiple scattering represents a challenge for numerous modern tomographic imaging techniques. In this Letter, we derive an appropriate line integral that allows for the tomographic reconstruction of angular resolved scattering distributions, even in the presence of multiple scattering. The line integral is applicable to a wide range of imaging techniques utilizing various kinds of probes. Here, we use x-ray grating interferometry to experimentally validate the framework and to demonstrate additional structural sensitivity, which exemplifies the impact of multiple scattering tomography. PMID:25062159

  19. Neutron scattering from fractals

    Kjems, Jørgen; Freltoft, T.; Richter, D.; Sinha, S. K.

    -angle neutron scattering studies of the variation with aggregation rate are presented. These results allow a very detailed comparison to be made with the theoretical scattering curves. Preliminary incoherent inelastic data on the low-frequency dynamics of hydroxylated silica particle aggregates show a clear...

  20. Neutron scattering by ferroelectrics

    Aksenov, V; Stamenkovic, S

    1989-01-01

    This book presents the recent theoretical and experimental developments of neutron scattering by ferroelectrics. A Model description of lattice dynamics of structurally unstable crystals (self-consistent phonon approximation, pseudo-spin formalism, coherent potential approximation etc.) is formulated. The effects of nonlinear excitations and lattice defects in neutron scattering are also discussed.

  1. Neutron scattering from fractals

    Kjems, Jørgen; Freltoft, T.; Richter, D.;

    1986-01-01

    -angle neutron scattering studies of the variation with aggregation rate are presented. These results allow a very detailed comparison to be made with the theoretical scattering curves. Preliminary incoherent inelastic data on the low-frequency dynamics of hydroxylated silica particle aggregates show a clear...

  2. Modelling Hyperboloid Sound Scattering

    Burry, Jane; Davis, Daniel; Peters, Brady; Ayres, Phil; Klein, John; Pena de Leon, Alexander; Burry, Mark

    The Responsive Acoustic Surfaces workshop project described here sought new understandings about the interaction between geometry and sound in the arena of sound scattering. This paper reports on the challenges associated with modelling, simulating, fabricating and measuring this phenomenon using...... both physical and digital models at three distinct scales. The results suggest hyperboloid geometry, while difficult to fabricate, facilitates sound scattering....

  3. Introductory theory of neutron scattering

    The paper comprises a set of six lecture notes which were delivered to the summer school on 'Neutron Scattering at a pulsed source', Rutherford Laboratory, United Kingdom, 1986. The lectures concern the physical principles of neutron scattering. The topics of the lectures include: diffraction, incoherent inelastic scattering, connection with the Schroedinger equation, magnetic scattering, coherent inelastic scattering, and surfaces and neutron optics. (UK)

  4. Investigation of the reaction 90Zr(p,γ) with in-beam γ-ray spectroscopy

    Erbacher Philipp; Endres A.; Glorius J.; Netterdon L.; Sonnabend K.; Thomas B; Zilges A.

    2015-01-01

    The p nucleus 92Mo is believed to be mainly produced through photodisintegration reactions in type II supernovae. However, this production scenario cannot solely account for the observed solar relative isotopic abundance of 92Mo. Additional production scenarios have been suggested to explain this discrepancy. One of these scenarios could be the production of 92Mo in type Ia supernovae via a chain of proton-capture reactions. To verify this scenario, an accurate knowledge of the involved react...

  5. Experimental investigation shell model excitations of 89Zr up to high spin and its comparison with 88,90Zr

    The excited states of nuclei near N=50 closed shell provide suitable laboratory for testing the interactions of shell model states, possible presence of high spin isomers and help in understanding the shape transition as the higher orbitals are occupied. In particular, the structure of N = 49 isotones (and Z =32 to 46) with one hole in N=50 shell gap have been investigated using different reactions. Interestingly, the high spin states in these isotones have contribution from particle excitations across the respective proton and neutron shell gaps and provide suitable testing ground for the prediction of shell model interactions describing theses excitations across the shell gap. In the literature, extensive study of the high spin states of heavier N = 49 isotones starting with 91Mo up to 95Pd are available. Limited information existed on the high spin states of lighter isotones. Therefore, the motivation of the present work is to extend the high spin structure of 89Zr and to characterize the structure of these levels through comparison with the large scale shell model calculations based on two new residual interactions in f5/2pg9/2 model space

  6. Scattering of periodic solitons

    Cova, R J

    2003-01-01

    With the help of numerical simulations we study N-soliton scattering (N=3,4) in the (2+1)-dimensional CP^1 model with periodic boundary conditions. When the solitons are scattered from symmetrical configurations the scattering angles observed agree with the earlier \\pi/N predictions based on the model on R_2 with standard boundary conditions. When the boundary conditions are not symmetric the angles are different from \\pi/N. We present an explanation of our observed patterns based on a properly formulated geodesic approximation.

  7. Elastic scattering of hadrons

    Dremin, I M

    2012-01-01

    When colliding, the high energy hadrons can either produce new particles or scatter elastically without change of their quantum num- bers and other particles produced. Namely elastic scattering of hadrons is considered in this review paper. Even though the inelastic processes dominate at high energies, the elastic scattering constitutes the notice- able part of the total cross section ranging between 18 and 25% with some increase at higher energies. The scattering proceeds mostly at small angles and reveals peculiar dependences at larger angles disclos- ing the geometrical structure of the colliding particles and di?erent dynamical mechanisms. The fast decreasing Gaussian peak at small angles is followed by the exponential (Orear) regime with some shoul- ders and dips and then by the power-like decrease. Results of various theoretical approaches are compared with exper- imental data. Phenomenological models pretending to describe this process are reviewed. The unitarity condition requires the exponen- tial re...

  8. Environment scattering in GADRAS.

    Thoreson, Gregory G.; Mitchell, Dean James; Theisen, Lisa Anne; Harding, Lee T.

    2013-09-01

    Radiation transport calculations were performed to compute the angular tallies for scattered gamma-rays as a function of distance, height, and environment. Green's Functions were then used to encapsulate the results a reusable transformation function. The calculations represent the transport of photons throughout scattering surfaces that surround sources and detectors, such as the ground and walls. Utilization of these calculations in GADRAS (Gamma Detector Response and Analysis Software) enables accurate computation of environmental scattering for a variety of environments and source configurations. This capability, which agrees well with numerous experimental benchmark measurements, is now deployed with GADRAS Version 18.2 as the basis for the computation of scattered radiation.

  9. Magnetic electron scattering

    We briefly review some of the motivations, early results, and techniques of magnetic elastic and inelastic electron-nucleus scattering. We then discuss recent results, especially those acquired at high momentum transfers. 50 refs., 19 figs

  10. Scattering from Electroweak Strings

    Lo, Hoi-Kwong

    1994-01-01

    The scattering of a charged fermion from an electroweak string is studied. Owing to an amplification of the wave function at the core radius, the cross sections for helicity flip processes can be largely enhanced. For $0

  11. LIDAR Thomson scattering

    This collection contains 21 papers on the application and development of LIDAR (Light Detection and Ranging) Thomson scattering techniques for the determination of spatially resolved electron temperature and density in magnetic confinement experiments, particularly tokamaks. Refs, figs and tabs

  12. Neutron scattering in dimers

    Gudel, H. U.; Furrer, A.; Kjems, Jørgen

    1986-01-01

    Insulating compounds containing dimers of transition metal and rare earth ions have been studied by inelastic neutron scattering (INS). Energy splittings can be directly determined, and the corresponding parameters are easily extracted from the experimental data. The intensities of dimer...

  13. Applied electromagnetic scattering theory

    Osipov, Andrey A

    2016-01-01

    Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...

  14. Scattering by bound nucleons

    Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)

  15. Scattering resonances in graphene

    Nazarov, V. U.; Silkin, V. M.; Krasovskii, E. E.

    2012-01-01

    We address the two-dimensional band-structure of graphene above the vacuum level in the context of discrete states immersed in the three-dimensional continuum. Scattering resonances are discovered that originate from the coupling of the in-plane and perpendicular motions, as elucidated by the analysis of an exactly solvable model. Some of the resonances turn into true bound states at high-symmetry $\\kv$ vectors. {\\it Ab initio} scattering theory verifies the existence of the resonances in rea...

  16. Neutron scattering in dimers

    Gudel, H. U.; Furrer, A.; Kjems, Jørgen

    Insulating compounds containing dimers of transition metal and rare earth ions have been studied by inelastic neutron scattering (INS). Energy splittings can be directly determined, and the corresponding parameters are easily extracted from the experimental data. The intensities of dimer excitati......Insulating compounds containing dimers of transition metal and rare earth ions have been studied by inelastic neutron scattering (INS). Energy splittings can be directly determined, and the corresponding parameters are easily extracted from the experimental data. The intensities of dimer...

  17. Catastrophes in surface scattering

    Theoretical and experimental studies concerning atom-surface interactions in the energy range from hyperthermal to approximately 100 eV are reported. An extended study of the interaction of low energetic alkalis (sodium and potassium) with a silver crystal is presented. Finally the ultimate experimental result in this research, the first observation of catastrophes in surface scattering, is shown. The results clearly indicate the strength of the catastrophe analysis in gas-surface scattering. 218 refs.; 40 figs.; 170 schemes; 4 tabs

  18. Scattering theory on graphs

    We consider the scattering theory for the Schroedinger operator -Dx2+V(x) on the graphs made of one-dimensional wires connected to external leads. We derive two expressions for the scattering matrix on arbitrary graphs. One involves matrices that couple arcs (oriented bonds), the other involves matrices that couple vertices. We discuss a simple way to tune the coupling between the graph and the leads. The efficiency of the formalism is demonstrated with a few known examples. (author)

  19. Neutron Compton Scattering

    Watson, Greg

    1996-01-01

    Neutron Compton scattering measurements have the potential to provide direct information about atomic momentum distributions and adiabatic energy surfaces in condensed matter. First applied to measuring the condensate fraction in superfluid helium, the technique has recently been extended to study a variety of classical and quantum liquids and solids. This article reviews the theoretical background for the interpretation of neutron Compton scattering, with emphasis on studies of solids.

  20. Polarized Proton Nucleus Scattering

    Kopeliovich, B. Z.; Trueman, T. L.

    2000-01-01

    We show that, to a very good approximation, the ratio of the spin-flip to the non-flip parts of the elastic proton-nucleus amplitude is the same as for proton-nucleon scattering at very high energy. The result is used to do a realistic calculation of the analyzing power A_N for pC scattering in the Coulomb-nuclear interference (CNI) region of momentum transfer.

  1. Scattering of periodic solitons

    Cova, R.J. [Carleton University, School of Mathematics and Statistics, 1125 Colonel by Drive, Ottawa, Ontario K1S 5B6 (Canada); Zakrzewski, W.J. [University of Durham, Dept. of Mathematical Sciences, Durham DH1 3LE (United Kingdom)]. e-mail: rcova@math.carleton.ca

    2004-07-01

    Through numerical simulations we study N-soliton scattering (N = 3, 4) in the (2 + 1)-dimensional CP{sup 1} model with periodic boundary conditions. Solitons colliding from symmetrical configurations scatter at {pi}/ N, as observed in the usual model with standard boundary conditions. When the initial configurations are not symmetric the angles differ from {pi}/ N. We describe our observed patterns based on a properly formulated geodesic approximation. (Author) 11 refs., 10 figs.

  2. Stimulated Thomson scattering

    The theory of stimulated Thomson scattering is investigated both quantum mechanically and classically. In the interaction of a collisionless plasma with two electromagnetic waves, both with frequencies well above the plasma frequency, energy is transferred from the high-frequency wave to the low-frequency wave via stimulated Thomson scattering. This process is mediated by the nonlinear interaction of the plasma electrons with a beat wave at the difference frequency between the two waves; this beat frequency must be well above the plasma frequency. The gain coefficient for stimulated Thomson scattering is calculated both quantum mechanically and classically, and identical results are obtained. The classical calculation also yields the first nonlinear term in the index of refraction due to stimulated Thomson scattering, as well as the details of the saturation of the gain and the index of refraction. The authors present explicit formulas for the gain coefficient and the index of refraction, in the unsaturated limit, for both very cold and very hot plasmas. The calculations indicate that it should be possible to detect stimulated Thomson scattering experimentally by means of polarization enhancement. In an appendix, the theory of stimulated Thomson scattering is used to treat the free-electron amplifier

  3. Electron scattering from atoms

    Methods for electron scattering fall into two main classes : coupled channels methods involve an expansion of the total wave function in target eigenstates; R-matrix methods use a CI expansion for the whole electron-plus-target problem in a finite region of space outside which the electron feels no potential (or only the residual Coulomb potential in the case of charged targets). This problem has no continuum. It has discrete states with arbitrarily-high energies. The wave functions for the finite-range problem are matched to the known external wave functions at the boundary. Experimental data from studies on electron-hydrogen scattering, electron sodium scattering, electron scattering to singlet and triplet states of helium and electron scattering to and from magnesium are reviewed. The coupled-channels-optical model, coupled-channels with ad hoc pseudostates, and R-matrix theory are complete calculations in that no aspects of scattering are omitted, although approximations are of course made. The methods are in at least semi-quantitative agreement with each other where comparison is possible. Experiments in general are in agreement with each other. However for all atoms there are significant disagreements between theory and experiment for small differential cross sections. Total cross sections agree quite well

  4. Proton inelastic scattering cannot be predicted from electron scattering results

    The prediction of proton inelastic scattering based on transition densities determined from electron scattering is critically examined. As an example, for the O3+ state in 16O, it is shown that abnormal parity amplitudes prevent an unambiguous prediction, and largely different results can be found for proton scattering while electron scattering results are identical

  5. Laser light scattering review

    Schaetzel, Klaus

    1989-08-01

    Since the development of laser light sources and fast digital electronics for signal processing, the classical discipline of light scattering on liquid systems experienced a strong revival plus an enormous expansion, mainly due to new dynamic light scattering techniques. While a large number of liquid systems can be investigated, ranging from pure liquids to multicomponent microemulsions, this review is largely restricted to applications on Brownian particles, typically in the submicron range. Static light scattering, the careful recording of the angular dependence of scattered light, is a valuable tool for the analysis of particle size and shape, or of their spatial ordering due to mutual interactions. Dynamic techniques, most notably photon correlation spectroscopy, give direct access to particle motion. This may be Brownian motion, which allows the determination of particle size, or some collective motion, e.g., electrophoresis, which yields particle mobility data. Suitable optical systems as well as the necessary data processing schemes are presented in some detail. Special attention is devoted to topics of current interest, like correlation over very large lag time ranges or multiple scattering.

  6. Neutron scattering at high pressure

    Mcwhan, D.B.

    1984-01-01

    The techniques to do elastic and inelastic neutron scattering at steady-state and pulsed sources are reviewed. The pressure cells available at most neutron scattering centres are capable of reaching pressures of the order of 5 GPa (50 kbar), and attempts to reach 10 GPa have been made. For elastic scattering, a comparison is made between neutron scattering and X-ray scattering at high pressure using rotating anode or synchrotron sources.

  7. Electron scattering off nuclei

    Two recently developed aspects related to the scattering of electrons off nuclei are presented. On the one hand, a model is introduced which emphasizes the relativistic aspects of the problem in the impulse approximation, by demanding strict maintenance of the algebra of the Poincare group. On the other hand, the second model aims at a more sophisticated description of the nuclear response in the case of collective excitations. Basically, it utilizes the RPA formalism with a new development which enables a more careful treatment of the states in the continuum as is the case for the giant resonances. Applications of both models to the description of elastic scattering, inelastic scattering to discrete levels, giant resonances and the quasi-elastic region are discussed. (Author)

  8. Applications of Compton scattering

    LUO Guang; ZHOU Shang-qi; HAN Zhong; CHEN Shuang-kou

    2006-01-01

    Compton scattering is used very widely. In this article, we depict an overall picture for its applications which are based on two basic theories. The first is the electron densitometry theory related to electron density. According to this theory its applications are in two fields: one is Compton scatter densitometry (CSD), the other is Compton scatter imaging (CSI). The second technique involves the electron momentum distribution and Compton profile. Applications of this technique are mainly the Compton profile analysis (CPA) and the Compton profile or the electron momentum distribution in physics and chemistry.Future research fields are suggested according to the current situation and limits of this technique and a promising prospect is unfolded.

  9. $\\Lambda$ Scattering Equations

    Gomez, Humberto

    2016-01-01

    The CHY representation of scattering amplitudes is based on integrals over the moduli space of a punctured sphere. We replace the punctured sphere by a double-cover version. The resulting scattering equations depend on a parameter $\\Lambda$ controlling the opening of a branch cut. The new representation of scattering amplitudes possesses an enhanced redundancy which can be used to fix, modulo branches, the location of four punctures while promoting $\\Lambda$ to a variable. Via residue theorems we show how CHY formulas break up into sums of products of smaller (off-shell) ones times a propagator. This leads to a powerful way of evaluating CHY integrals of generic rational functions, which we call the $\\Lambda$ algorithm.

  10. Instruments for neutron scattering

    The wide variety of science that can be presented with neutron scattering essentially boils down to determine two vectors, the momentum k of the neutron before it hits the sample and after it leaves the sample. All experimentally obtainable information is contained in the probability distribution W(k,k') of a neutron to undergo scattering takes it from k to k'. In this paper we will introduce the principles and concepts to understand what one is doing if one perform an experiment on a certain instrument We will describe the components of which almost all neutron scattering instruments are made up and their functions and show how these components can be combined to contribute in the best possible way to the solution of questions in a large number of scientific areas

  11. Quantum Optical Multiple Scattering

    Ott, Johan Raunkjær

    for the dipoles while treating them as quantum two-level systems and using the Born–Markov and rotating-wave approximations. Postponing the rotating-wave approximation to the very end of the formal calculations allows us to identify the different physical parameters of the dipole evolution in terms of...... first part we use a scattering-matrix formalism combined with results from random-matrix theory to investigate the interference of quantum optical states on a multiple scattering medium. We investigate a single realization of a scattering medium thereby showing that it is possible to create entangled...... states by interference of squeezed beams. Mixing photon states on the single realization also shows that quantum interference naturally arises by interfering quantum states. We further investigate the ensemble averaged transmission properties of the quantized light and see that the induced quantum...

  12. LOW ENERGY ION SCATTERING

    2007-01-01

    Low energy ion scattering (LEIS) is the study of the composition and structure of a surface by the detection of low energy ions with energies ranging from 100 eV to 10 keV elastically scattered off the surface. The extreme sensitivity to the outermost atomic layer makes it as a unique tool for surface analysis. In this paper, concepts of shadowing, blocking, and also polar and azimuthal scans have been described. Surface order and surface atom spacings are revealed by using these concepts and...

  13. Neutron scattering. Experiment manuals

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  14. Neutron scattering. Experiment manuals

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot-single-crystal diffractometer HEiDi, the three-axis spectrometer PANDA, the backscattering spectrometer SPHERES, the DNS neutron-polarization analysis, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering at KWS-1 and KWS-2, a very-small-angle neutron scattering diffractometer with focusing mirror, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  15. Electron-atom scattering

    The coupled-channels-optical method has been implemented using two different approximations to the optical potential. The half-on-shell optical potential involves drastic approximations for numerical feasibility but still gives a good semiquantitative description of the effect of uncoupled channels on electron scattering from hydrogen, helium and sodium. The distorted-wave optical potential makes no approximations other than the weak coupling approximation for uncoupled channels. In applications to hydrogen and sodium it shows promise of describing scattering phenomena excellently at all energies. 27 refs., 5 figs

  16. Neutron scattering. Experiment manuals

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  17. Scattering with absorptive interaction

    Cassing, W.; Stingl, M.; Weiguny, A.

    1982-07-01

    The S matrix for a wide class of complex and nonlocal potentials is studied, with special attention given to the motion of singularities in the complex k plane as a function of the imaginary coupling strength. Modifications of Levinson's theorem are obtained and discussed. Analytic approximations to the S matrix in the vicinity of narrow resonances are exhibited and compared to numerical results of resonating-group calculations. The problem of defining resonances in the case of complex interactions is discussed, making contact with the usual analysis of scattering in terms of Argand diagrams. NUCLEAR REACTIONS Scattering theory, S matrix for absorptive potentials.

  18. Neutron scattering. Experiment manuals

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2014-07-01

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot-single-crystal diffractometer HEiDi, the three-axis spectrometer PANDA, the backscattering spectrometer SPHERES, the DNS neutron-polarization analysis, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering at KWS-1 and KWS-2, a very-small-angle neutron scattering diffractometer with focusing mirror, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  19. Virtual Compton Scattering

    Helene Fonvieille

    2003-05-01

    Virtual Compton Scattering off the proton: {gamma}^+p --> {gamma}p is a new field of investigation of nucleon structure. Several dedicated experiments have been performed at low c.m. energy and various momentum transfers, yielding specific information on the proton. This talk reviews the concept of nucleon Generalized Polarizabilities and the present experimental status.

  20. Scattering theory. 2. ed.

    This corrected and updated second edition of ''Scattering Theory'' presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is kept as low as at all possible and deeper questions related to the mathematical foundations of scattering theory are passed by. It should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. The book is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.

  1. Inversion assuming weak scattering

    Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

    2013-01-01

    The study of weak scattering from inhomogeneous media or interface roughness has long been of interest in sonar applications. In an acoustic backscattering model of a stationary field of volume inhomogeneities, a stochastic description of the field is more useful than a deterministic description...

  2. Discrete scattering theory

    Techniques to study nonlinear differential difference equations have been developed only in the last few years. These methods use the scattering and inverse scattering transforms to obtain formal solutions to initial value problems. However, analytic questions about the scattering transform have not been dealt with extensively in the literature. In this thesis, the generalized eigenvalue equation (1) Spsi = Jpsi + JQ0psi + Q1Spsi, where psi is a 2 X 2 matrix, J = diag(z,z-1), Q0(Q1) is a strictly lower (upper) triangular 2 x 2 matrix valued summable sequence is studied. This problem is not self adjoint, and is a discretization of the equation studied by Albowitz et al and Beals and Coifman. The notion of a scattering transform is introduced, showing that it is injective, and with proceedings to obtain its analytic properties. It is shown that decay of the potential implies smoothness of the data, and conversely smoothness of the data implies decay of the potential. The data satisfies a symmetry condition along with additional constraints, and it is proved that when these are satisfied, eigenfunctions and potentials can be recovered from the data such that (1) holds. This theory is then applied to obtain a class of nonlinear differential difference evolution equations solvable by this method. How far these results extend to the k x k matrix case is also indicated

  3. Critical scattering by bubbles

    We apply the complex angular momentum theory to the problem of the critical scattering of light by spherical cavities in the high frequency limit (permittivity greater than the external media) (e.g, air bubble in water) (M.W.O.)

  4. Scattering theory. 2. ed.

    Friedrich, Harald [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2016-07-01

    This corrected and updated second edition of ''Scattering Theory'' presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is kept as low as at all possible and deeper questions related to the mathematical foundations of scattering theory are passed by. It should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. The book is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.

  5. Small angle neutron scattering

    Cousin Fabrice

    2015-01-01

    Full Text Available Small Angle Neutron Scattering (SANS is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ∼ 1 nm up to ∼ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ∼ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area… through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer, form factor analysis (I(q→0, Guinier regime, intermediate regime, Porod regime, polydisperse system, structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates, and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast. It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of

  6. Small angle neutron scattering

    Small Angle Neutron Scattering (SANS) is a technique that enables to probe the 3-D structure of materials on a typical size range lying from about 1 nm up to a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ∼ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nano-metric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area... ) through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some information that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer), form factor analysis (I(q→0), Guinier regime, intermediate regime, Porod regime, polydisperse system), structure factor analysis (2. Virial coefficient, integral equations, characterization of aggregates), and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast). It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of spectrometer

  7. Light scattering reviews 8 radiative transfer and light scattering

    Kokhanovsky, Alexander A

    2013-01-01

    Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

  8. Scattering by a nihility sphere

    Lakhtakia, A

    2006-01-01

    On interrogation by a plane wave, the back-scattering efficiency of a nihility sphere is identically zero, and its extinction and forward-scattering efficiencies are higher than those of a perfectly conducting sphere.

  9. Scattering of Fermions by Gravitons

    Ulhoa, S C; Khanna, Faqir C

    2016-01-01

    The interaction between gravitons and fermions is investigated in the teleparallel gravity. The scattering of fermions and gravitons in the weak field approximation is analyzed. The transition amplitudes of M$\\varnothing$ller, Compton and new gravitational scattering are calculated.

  10. LIDAR Thomson scattering

    This report on the IAEA Technical Committee Meeting on LIDAR (LIght Detection And Ranging) Thomson Scattering, held at the JET Joint Undertaking, Abingdon, Oxfordshire, United Kingdom, 8-10 April 1991, summarizes reviews of (1) the existing JET LIDAR system; (2) developments in solid state, visible and near IR lasers that are of potential interest for LIDAR applications; (3) possible laser sources, including Excimer and CO2 for their interesting pulse duration and repetition rate if suitable detectors can be found; (4) a compact design for a Nd phosphate glass system; (5) short pulse length (30-50 ps) laser requirements to obtain improved spatial resolution needed for the divertor region plasma in tokamaks; (6) a more advanced laser design using a so-called light boiler and wave front reversal (WFR) cells; (7) possibilities to use Nd:YAG laser wavelengths in a LIDAR system; a session on detectors and analysis methods describing (8) the new Scancross streaking intensifier; (9) detectors for LIDAR Thomson scattering (advantages of streak cameras, photomultipliers, and gated intensifiers); (10) results of investigations into the use of an AGAT streak camera as a possible LIDAR detector; (11) assessment experiments on a Hamamatsu streak camera planned for use on the Large Helical Device (heliotron); (12) studies on the usefulness of microchannel plate photomultipliers as detectors in the JET LIDAR system; (13) conventional Thomson scattering application of microchannel photomultipliers on the reversed-field pinch RFX; (14) a description of the Nd:YLF 10 Hz laser based scattering system for FTU; (15) the feasibility of a 8-10 Hz LIDAR system; (16) some aspects of Raman calibration of scattering systems; (17) use of statistical analysis of data for recovering calibrations of a data set; and, finally, a session on LIDAR systems for future devices, especially (18) ITER and BPX, with ITER requiring development of radiation hard optics capable of withstanding both thermal

  11. Slow Neutron Scattering by Benzene

    We have calculated the scattering of slow neutrons by the benzene molecule. The calculations are carried out within the framework of the time dependent formalism of Zemach and Glauber. Detailed account is taken of the effects of the molecular vibrations on the neutron scattering. Among the results explicitly calculated are the slow neutron total scattering cross-section as a function of energy and the energy angular distribution of singly scattered sections. (author)

  12. Cross-correlation laser scattering.

    Kam, Z; Rigler, R

    1982-01-01

    Cross-correlation between two detectors was applied to analyze laser light-scattering fluctuations. Laser scattering from random concentration fluctuations is spatially coherent over small angular areas that are inversely proportional in size to the dimension of the scattering volume. By cross-correlating scattering intensity fluctuations in different angles, the correlation due to relaxation of concentration fluctuations is practically eliminated, and correlations reflecting changes in the s...

  13. Electron scattering for exotic nuclei

    Toshimi Suda

    2014-11-01

    A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world’s first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density distributions of short-lived exotic nuclei by elastic electron scattering. The first collision between electrons and exotic nuclei will be observed in the year 2014.

  14. Electron scattering on molecular hydrogen

    The author considers scattering phenomena which occur when a beam of electrons interacts with a molecular hydrogen gas of low density. Depending on the energy loss of the scattered electrons one can distinguish elastic scattering, excitation and (auto)ionization of the H2-molecule. The latter processes may also lead to dissociation. These processes are investigated in four experiments in increasing detail. (Auth.)

  15. Low energy + scattering on = nuclei

    Swapan Das; Arun K Jain

    2003-11-01

    The data for the total cross-section of + scattering on various nuclei have been analysed in the Glauber multiple scattering theory. Energy-dependent +-nucleus optical potential is generated using the forward +-nucleon scattering amplitude and the nuclear density distribution. Along with this, the calculated total +-nucleus cross-sections using the effective +-nucleon cross-section inside the nucleus are also presented.

  16. Scattering with partial information

    Carney, Daniel; Semenoff, Gordon

    2016-01-01

    We study relativistic scattering when one only has access to a subset of the particles, using the language of quantum measurement theory. We give an exact, non-perturbative formula for the von Neumann entanglement entropy of an apparatus particle scattered off an arbitrary set of system particles, in either the elastic or inelastic regime, and show how to evaluate it perturbatively. We give general formulas for the late-time expectation values of apparatus observables. Some simple example applications are included: in particular, a protocol to verify preparation of coherent superpositions of spatially localized system states using position-space information in the outgoing apparatus state, at lowest order in perturbation theory in a weak apparatus-system coupling.

  17. Positron scattering from tetrahydrofuran

    Brunger, M. J.; Chiari, L.; Tattersall, W.; Anderson, E.; Machacek, J.; Makochekanwa, C.; Sullivan, J.; Buckman, S. J.

    2012-10-01

    We present recent experimental results for positron scattering from tetrahydrofuran. Being a model for the deoxyribose sugar rings in the nucleic acids backbone, tetrahydrofuran is of particular interest for investigating radiation damage in biomolecular systems. The measurements on this species were carried out using the atomic and molecular trap-based positron beamline at The Australian National University with an energy resolution of ˜60 meV. Total cross sections and integral cross sections for the positronium formation, elastic and inelastic (direct ionization and electronic excitation) scattering channels are presented over the energy range of 1-190 eV. Low-energy elastic differential cross sections are also presented at selected energies between 1 eV and 25 eV. A fairly good agreement is found with the total cross section results from the only existing previous experimental investigation on this target species by the Trento group.

  18. Seamount acoustic scattering

    Boehlert, George W.

    The cover of the March 1 issue of Eos showed a time series of acoustic scattering above Southeast Hancock Seamount (29°48‧N, 178°05‧E) on July 17-18, 1984. In a comment on that cover Martin Hovland (Eos, August 2, p. 760) argued that gas or “other far reaching causes” may be involved in the observed acoustic signals. He favors a hypothesis that acoustic scattering observed above a seeping pockmark in the North Sea is a combination of bubbles, stable microbubbles, and pelagic organisms and infers that this may be a more general phenomenon and indeed plays a role in the attraction of organisms to seamounts

  19. Coherent Scatter Imaging Measurements

    Ur Rehman, Mahboob

    In conventional radiography, anatomical information of the patients can be obtained, distinguishing different tissue types, e.g. bone and soft tissue. However, it is difficult to obtain appreciable contrast between two different types of soft tissues. Instead, coherent x-ray scattering can be utilized to obtain images which can differentiate between normal and cancerous cells of breast. An x-ray system using a conventional source and simple slot apertures was tested. Materials with scatter signatures that mimic breast cancer were buried in layers of fat of increasing thickness and imaged. The result showed that the contrast and signal to noise ratio (SNR) remained high even with added fat layers and short scan times.

  20. Protostring Scattering Amplitudes

    Thorn, Charles B

    2016-01-01

    We calculate some tree level scattering amplitudes for a generalization of the protostring, which is a novel string model implied by the simplest string bit models. These bit models produce a lightcone worldsheet which supports $s$ integer moded Grassmann fields. In the generalization we supplement this Grassmann worldsheet system with $d=24-s$ transverse coordinate worldsheet fields. The protostring corresponds to $s=24$ and the bosonic string to $s=0$. The interaction vertex is a simple overlap with no operator insertions at the break/join point. Assuming that $s$ is even we calculate the multi-string scattering amplitudes by bosonizing the Grassmann fields, each pair equivalent to one compactified bosonic field, and applying Mandelstam's interacting string formalism to a system of $s/2$ compactified and $d$ uncompactified bosonic worldsheet fields. We obtain all amplitudes for open strings with no oscillator excitations and for closed strings with no oscillator excitations and zero winding number. We then ...

  1. Molecular-beam scattering

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N2 from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl → NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(22P/sub 3/2/) and Na(32P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included

  2. Scatter fraction with simulations

    In this work, the authors revisit the measurements of Trout and Kelley, and Simpkin and Dixon, by means of Monte Carlo simulations. Starting with a simple cylindrical homogeneous phantom, the authors introduce a more realistic phantom and the effect of the bucky in the simulations. The results indicate that optimised shielding methodologies should not neglect the attenuation and scattering by the patient plus bucky. (authors)

  3. Molecular-beam scattering

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

  4. Means on scattered compacta

    Banakh, T.; Bonnet, R.; Kubiś, Wieslaw

    2014-01-01

    Roč. 2, č. 1 (2014), s. 5-10. ISSN 2299-3231 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : scattered compact space * mean operation Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/taa.2014.2.issue-1/taa-2014-0002/taa-2014-0002.xml

  5. Quantum scattering transformation

    There are three successful lines of development in one-dimensional mathematical physics: theory of quantum mechanics, theory of planar models in statistical mechanics, and inverse scattering method in classical field theory. It has been realized that the third method can be quantized to create a unified approach called Quantum Inverse Method, or quantum scattering transformation (QST). Recent developments are compiled in this text. Basic formula of QST are derived. Examples, for the nonlinear Schroedinger equation, and the Sine-Gordon equations, are given. A few problems are treated. The inverse problem of reconstructing the field variables from given scattering data is solved by the Gelfand-Levitan-Marchencko (GLM) equation. In summary, the QST model leads to the exact solution of field-theoretical models, and produces new models. It teaches that particles spectrum above the physical ground state can be considerably different from the predictions of perturbation theory. QST presents us with a ''prolific playground'' in quantum field theory and mathematical physics

  6. Neutron scattering in Australia

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains

  7. Neutron scattering in Australia

    Knott, R.B. [Australian Nuclear Science and Technology Organisation, Menai (Australia)

    1994-12-31

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains.

  8. Basic scattering theory

    This series of lectures on basic scattering theory were given as part of a course for postgraduate high energy physicists and were designed to acquaint the student with some of the basic language and formalism used for the phenomenological description of nuclear reactions and decay processes used for the study of elementary particle interactions. Well established and model independent aspects of scattering theory, which are the basis of S-matrix theory, are considered. The subject is considered under the following headings; the S-matrix, cross sections and decay rates, phase space, relativistic kinematics, the Mandelstam variables, the flux factor, two-body phase space, Dalitz plots, other kinematic plots, two-particle reactions, unitarity, the partial-wave expansion, resonances (single-channel case), multi-channel resonances, analyticity and crossing, dispersion relations, the one-particle exchange model, the density matrix, mathematical properties of the density matrix, the density matrix in scattering processes, the density matrix in decay processes, and the helicity formalism. Some exercises for the students are included. (U.K.)

  9. Scattering Solar Thermal Concentrators

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  10. Raman scattering in crystals

    A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs

  11. Raman scattering in crystals

    Edwards, D.F.

    1988-09-30

    A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

  12. Scattering configuration spaces

    Melrose, Richard; Singer, Michael

    2008-01-01

    For a compact manifold with boundary $X$ we introduce the $n$-fold scattering stretched product $X^n_{\\text{sc}}$ which is a compact manifold with corners for each $n,$ coinciding with the previously known cases for $n=2,3.$ It is constructed by iterated blow up of boundary faces and boundary faces of multi-diagonals in $X^n.$ The resulting space is shown to map smoothly, by a b-fibration, covering the usual projection, to the lower stretched products. It is anticipated that this manifold wit...

  13. Positron scattering by potassium

    Coupled-state calculations in a K(4s, 4p, 5s, 5p, 3d) + Ps(1s, 2s, 2p, 3s, 3p, 3d) approximation are reported for positron scattering by ground-state potassium in the energy range 0.5-60.0 eV. Comparison is made with the earlier work of Hewitt et al (1993, 1994) in a K(4s, 4p, 5s, 5p) + Ps(1s, 2s, 2p) approximation. For the first time cross sections for positronium formation in n = 3 states are obtained. (author)

  14. Multiple Parton Scattering in Nuclei: Quark-quark Scattering

    Schafer, Andreas; Wang, Xin-Nian; Zhang, Ben-Wei

    2007-01-01

    Modifications to quark and antiquark fragmentation functions due to quark-quark (antiquark) double scattering in nuclear medium are studied systematically up to order \\cal{O}(\\alpha_{s}^2)$ in deeply inelastic scattering (DIS) off nuclear targets. At the order $\\cal{O}(\\alpha_s^2)$, twist-four contributions from quark-quark (antiquark) rescattering also exhibit the Landau-Pomeranchuck-Midgal (LPM) interference feature similar to gluon bremsstrahlung induced by multiple parton scattering. Comp...

  15. Electromagnetic Scattering and Material Characterization

    Omar, Abbas

    2011-01-01

    Based on the author's more-than 30 years of experience, this first-of-its-kind volume presents a comprehensive and systematic analysis of electromagnetic fields and their scattering by material objects. The book considers all three categories of scattering environments commonly used for material measurements – unbounded regions, waveguides, and cavity resonators. The book covers such essential topics as electromagnetic field propagation, radiation, and scattering, containing mathematically rigorous approaches for the computation of electromagnetic fields and the explanation of their behavior.

  16. Heterodyne Near-Field Scattering

    Brogioli, D; Giglio, M; Giglio, Marzio

    2002-01-01

    We describe an optical technique based on the statistical analysis of the random intensity distribution due to the interference of the near-field scattered light with the strong transmitted beam. It is shown that, from the study of the two-dimensional power spectrum of the intensity, one derives the scattered intensity as a function of the scattering wave vector. Near-field conditions are specified and discussed. The substantial advantages over traditional scattering technique are pointed out, and is indicated that the technique could be of interest for wave lengths other than visible light.

  17. Light scattering by small particles

    Hulst, H C van de

    1981-01-01

    ""A must for researchers using the techniques of light scattering."" ? S. C. Snowdon, Journal of the Franklin InstituteThe measurement of light scattering of independent, homogeneous particles has many useful applications in physical chemistry, meteorology and astronomy. There is, however, a sizeable gap between the abstract formulae related to electromagnetic-wave-scattering phenomena, and the computation of reliable figures and curves. Dr. van de Hulst's book enables researchers to bridge that gap. The product of twelve years of work, it is an exhaustive study of light-scattering properties

  18. Stimulated Thomson scattering

    The theory of stimulated Thomson scattering is investigated both quantum mechanically and classically. Two monochromatic electromagnetic waves of like polarization travelling in opposite directions are allowed to interact for a time tau with the electrons in a collisionless plasma. The electromagnetic waves have frequencies well above the plasma frequency, and their difference frequency is allowed to range upward from the plasma frequency. With the difference frequency well above the plasma frequency, the rate at which energy is transferred from one wave to the other is calculated quantum mechanically, classically from a fluid theory, and classically from an independent electron theory. The rate is calculated in both the homogeneously broadened limit, and in the inhomogeneously broadened limit

  19. Elliptic scattering equations

    Cardona, Carlos

    2016-01-01

    Recently the CHY approach has been extended to one loop level using elliptic functions and modular forms over a Jacobian variety. Due to the difficulty in manipulating these kind of functions, we propose an alternative prescription that is totally algebraic. This new proposal is based on an elliptic algebraic curve embedded in a $\\mathbb{C}P^2$ space. We show that for the simplest integrand, namely the ${\\rm n-gon}$, our proposal indeed reproduces the expected result. By using the recently formulated $\\Lambda-$algorithm, we found a novel recurrence relation expansion in terms of tree level off-shell amplitudes. Our results connect nicely with recent results on the one-loop formulation of the scattering equations. In addition, this new proposal can be easily stretched out to hyperelliptic curves in order to compute higher genus.

  20. Neutron Scattering Stiudies

    Kegel, Gunter H.R.; Egan, James J

    2007-04-18

    This project covers four principal areas of research: Elastic and inelastic neutron scattering studies in odd-A terbium, thulium and other highly deformed nuclei near A=160 with special regard to interband transitions and to the investigation of the direct-interaction versus the compound-nucleus excitation process in these nuclei. Examination of new, fast photomultiplier tubes suitable for use in a miniaturized neutron-time-of-flight spectrometer. Measurement of certain inelastic cross sections of 238U. Determination of the multiplicity of prompt fission gamma rays in even-A fissile actinides. Energies and mean lives of fission isomers produced by fast fission of even-Z, even-A actinides. Study of the mean life of 7Be in different host matrices and its possible astro-physical significance.

  1. Surface enhanced Raman scattering

    Furtak, Thomas

    1982-01-01

    In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de­ veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would l...

  2. Scattering corrections in neutron radiography using point scattered functions

    Kardjilov, N.; de Beer, F.; Hassanein, R.; Lehmann, E.; Vontobel, P.

    2005-04-01

    Scattered neutrons cause distortions and blurring in neutron radiography pictures taken at small distances between the investigated object and the detector. This defines one of the most significant problems in quantitative neutron radiography. The quantification of strong scattering materials such as hydrogenous materials—water, oil, plastic, etc.—with a high precision is very difficult due to the scattering effect in the radiography images. The scattering contribution in liquid test samples (H 2O, D 2O and a special type oil ISOPAR L) at different distances between the samples and the detector, the so-called Point Scattered Function (PScF), was calculated with the help of MCNP-4C Monte Carlo code. Corrections of real experimental data were performed using the calculated PScF. Some of the results as well as the correction algorithm will be presented.

  3. Quantum scattering in one dimension

    Barlette, Vania E. [Centro Universitario Franciscano, Santa Maria, RS (Brazil); Leite, Marcelo M. [Departamento de Fisica, Instituto Tecnologico de Aeronautica, Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil); Adhikari, Sadhan K. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo, SP (Brazil)

    2000-09-01

    A self-contained discussion of non-relativistic quantum scattering is presented in the case of central potentials in one space dimension, which will facilitate the understanding of the more complex scattering theory in two and three dimensions. The present discussion illustrates in a simple way the concepts of partial-wave decomposition, phase shift, optical theorem and effective-range expansion. (author)

  4. Dynamic measurement of forward scattering

    Appel-Hansen, Jørgen; Rusch, W.

    1975-01-01

    A dynamic method for the measurement of forward scattering in a radio anechoic chamber is described. The quantity determined is the induced-field-ratio (IFR) of conducting cylinders. The determination of the IFR is highly sensitive to 1) multiple scattering between the cylinder and the obpring...

  5. Neutron scattering in magnetic fields

    The use of magnetic fields in neutron scattering experimentation is reviewed briefly. Two general areas of application can be distinguished. In one the field acts to change the properties of the scattering sample; in the second the field acts on the neutron itself. Several examples are discussed. Precautions necessary for high precision polarized beam measurements are reviewed. 33 references

  6. Neutron scattering in magnetic fields

    Koehler, W.C.

    1984-01-01

    The use of magnetic fields in neutron scattering experimentation is reviewed briefly. Two general areas of application can be distinguished. In one the field acts to change the properties of the scattering sample ; in the second the field acts on the neutron itself. Several examples are discussed. Precautions necessary for high precision polarized beam measurements are reviewed.

  7. Quantum scattering at low energies

    Derezinski, Jan; Skibsted, Erik

    For a class of negative slowly decaying potentials, including with , we study the quantum mechanical scattering theory in the low-energy regime. Using modifiers of the Isozaki--Kitada type we show that scattering theory is well behaved on the {\\it whole} continuous spectrum of the Hamiltonian...

  8. Quantum scattering at low energies

    Derezinski, Jan; Skibsted, Erik

    2009-01-01

    For a class of negative slowly decaying potentials, including V(x):=−γ|x|−μ with 0<μ<2 , we study the quantum mechanical scattering theory in the low-energy regime. Using appropriate modifiers of the Isozaki–Kitada type we show that scattering theory is well behaved on the whole continuous spectrum...

  9. Compton scattering on hadronic systems

    Compton scattering with real photons is studied for several hadronic systems, where special care is taken of the internal structure of the systems. The scattering on the deuteron is treated in terms of an analytically solvable model in the low energy region as in illustration for the general theory of low energy Compton scattering. For the 208Pb target nucleus a consistent treatment of the retardation leads to an interpretation of scattering data below and above the giant resonances up to energies of 50 MeV. Compton scattering in the Δ-resonance region is studied for the nucleon. The internal structure is described via a constituent quark model resulting in a proper treatment of the polarizabilities of the nucleon. The effect of binding on the polarizabilities is discussed on the basis of kinematical effects and modifictions due to the retardation. (orig.)

  10. Delbrueck scattering of monoenergetic photons

    The Delbrueck effect was experimentally investigated in high Z nuclei with monoenergetic photons in the range 6.8-11.4 MeV. Two different methods were used for measurements of the differential scattering cross-section, in the 25-140 deg range and in the forward direction (theta = 1.5 deg), respectively. The known Compton scattering cross-section was used in a new and unique way for the determination of the elastic scattering cross-section. Isolation of the contribution of the real Delbrueck amplitudes to the cross-section was crried out successfully. Experimental confirmation of the theoretical calculations of Papatzacos and Mork and measurement, for the first time, of the Rayleigh scattering in the 10 MeV region are also reported. One of the most interesting findings is the presence of Coulomb corrections in Delbrueck scattering at these energies. More theoretical effort is needed in this last direction. (author)

  11. Calculation of Thermal Scattering Kernels

    A long-standing programme at General Atomic has been the development of physical models to describe the scattering of slow neutrons from the various moderators and the numerical methods necessary for the computation of thermal neutron cross-sections and scattering kernels. This paper contains a review of the recent developments and improvements in the scattering descriptions and subsequent kernels for the moderators Be, C, H2O, D2O, CH2, H2 and D2. In particular for the moderators Be and C accurate phonon spectra, obtained by the root sampling technique, are presented along with comparisons to demonstrate how well the scattering models can predict the results of cross-section and spectral measurements. While the treatment of H2O is essentially that of Nelkin, curves of calculated and experimental neutron spectra are shown, which demonstrate that the inclusion of anisotropic effects for the molecular vibrations improve the agreement between theory and experiment. Following Butler's description of neutron scattering by D2O, a scattering kernel has been obtained which predicts quite accurately integral quantities such as neutron spectra and angular as well as total scattering cross-sections. An interesting result of the curves shown is that the inter- and intramolecular interference effects tend to cancel so that an incoherent approximation is quite adequate to calculate neutron spectra in D2O for the case of infinite media or weakly space-dependent problems. By utilizing the treatment by Lin and Koenig of the vibrational modes of infinite CH2 chains, a scattering kernel has been obtained which results in very good agreement between the predicted and experimental total cross-section and neutron spectra. Curves are presented to demonstrate this agreement between theory and experiment. Neutron spectra have been calculated for liquid hydrogen at boiling using a very accurate scattering description. These spectra are shown in the paper to be very sensitive both to

  12. Heavy-ion nucleus scattering

    Rahman, M A; Haque, S

    2003-01-01

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. sup 9 Be, sup 1 sup 6 O, sup 2 sup 0 Ne and sup 3 sup 2 S heavy-ion beams elastic scattering from sup 2 sup 8 Si, sup 2 sup 4 Mg and sup 4 sup 0 Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-paramet...

  13. Heavy-ion nucleus scattering

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. 9Be,16O, 20Ne and 32S heavy-ion beams elastic scattering from 28Si, 24Mg and 40Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-parameter formalism of the present quantal formulation and from the Strong Absorption Model for comparison. Typical fits are shown and the nuclear parameters obtained from the analyses of both approaches are presented. (author)

  14. Atomistic scattering close to an interface

    Half-space Green functions and T-matrix theory is used to predict that scattering on discrete dopants close to a perfect interface generates strong deviations from scattering in the bulk. Interference between the scattered wave and its reflection from the interface leads to a dipolar scattering rate. By introducing de-coherence the transition to bulk scattering is described quantitatively for strongly screened Coulomb scattering

  15. Atomistic scattering close to an interface

    Barker, J R; Watling, J R [Nanoelectronics Research Centre, Department of Electronics and Electrical Engineering, University of Glasgow, G12 8LT, Scotland (United Kingdom)

    2006-05-15

    Half-space Green functions and T-matrix theory is used to predict that scattering on discrete dopants close to a perfect interface generates strong deviations from scattering in the bulk. Interference between the scattered wave and its reflection from the interface leads to a dipolar scattering rate. By introducing de-coherence the transition to bulk scattering is described quantitatively for strongly screened Coulomb scattering.

  16. Radar interferometry persistent scatterer technique

    Kampes, Bert M

    2006-01-01

    Only book on Permanent Scatterer technique of radar interferometryExplains the Permanent Scatterer technique in detail, possible pitfalls, and details a newly developed stochastic model and estimator algorithm to cope with possible problems for the application of the PS techniqueThe use of Permanent Scatterer allows very precise measurements of the displacement of hundreds of points per square kilometerDescribes the only technique currently able to perform displacement measurements in the past, utilizing the ERS satellite data archive using data acquired from 1992-prese

  17. Quantitative scattering of melanin solutions

    Riesz, J; Meredith, P; Gilmore, Joel; Meredith, Paul; Riesz, Jennifer

    2005-01-01

    The optical scattering coefficient of a dilute, well solubilised eumelanin solution has been accurately measured as a function of incident wavelength, and found to contribute less than 6% of the total optical attenuation between 210 and 325nm. At longer wavelengths (325nm to 800nm) the scattering was less than the minimum sensitivity of our instrument. This indicates that UV and visible optical density spectra can be interpreted as true absorption with a high degree of confidence. The scattering coefficient vs wavelength was found to be consistent with Rayleigh Theory for a particle radius of 38+-1nm.

  18. Neutron scattering and hydrogen storage

    A.J. Ramirez-Cuesta

    2009-11-01

    Full Text Available Hydrogen has been identified as a fuel of choice for providing clean energy for transport and other applications across the world and the development of materials to store hydrogen efficiently and safely is crucial to this endeavour. Hydrogen has the largest scattering interaction with neutrons of all the elements in the periodic table making neutron scattering ideal for studying hydrogen storage materials. Simultaneous characterisation of the structure and dynamics of these materials during hydrogen uptake is straightforward using neutron scattering techniques. These studies will help us to understand the fundamental properties of hydrogen storage in realistic conditions and hence design new hydrogen storage materials.

  19. Fine structure of the isoscalar giant quadrupole resonance from high-resolution inelastic proton scattering experiments

    In the present work the phenomenon of fine structure in the region of the isoscalar giant quadrupole resonance in a number of heavy and medium-heavy nuclei is systematically investigated for the first time. High energy-resolution inelastic proton scattering experiments were carried out in September-October 2001 and in October 2003 at the iThemba LABS cyclotron facility in South Africa with an incident proton energy of 200 MeV. The obtained data with the energy resolution of triangle E58Ni,89Y,90Zr,120Sn,142Nd,166Er,208Pb), thereby establishing the global character of this phenomenon. Fine structure can be described using characteristic energy scales, appearing as a result of the decay of collective modes towards the compound nucleus through a hierarchy of couplings to complex degrees of freedom. For the extraction of the characteristic energy scales from the spectra an entropy index method and a novel technique based on the wavelet analysis are utilized. The global analysis of available data shows the presence of three groups of scales, according to their values. To the first group belong the scales with the values around and below 100 keV, which were detected in all the nuclei studied. The second group contains intermediate scales in the range of 100 keV to 1 MeV. These scales show large variations depending on the nuclear structure of the nucleus. The largest scales above 1 MeV are classified to the third group, describing the global structure of the resonance (the width). The interpretation of the observed scales is realized via the comparison with microscopic model calculations including the coupling of the initial one-particle-one-hole excitations to more complex configurations. A qualitative agreement of the experimentally observed scales with those obtained from the theoretical predictions supports the suggestion of the origin of fine structure from the coupling to the two-particle-two-hole states. However, quantitatively, large deviations are observed for

  20. Neutron scattering and models: Titanium

    Smith, A.B.

    1997-07-01

    Differential neutron elastic-scattering cross sections of elemental titanium were measured from 4.5 {r_arrow} 10.0 MeV in incident energy increments of {approx} 0.5 MeV. At each energy the measurements were made at forty or more scattering angles distributed between {approx} 17 and 160{degree}. Concurrently, differential neutron inelastic-scattering cross sections were measured for observed excitations of 0.975 {+-} 0.034, 1.497 {+-} 0.033, 2.322 {+-} 0.058, 3.252 {+-} 0.043, 3.700 {+-} 0.093, 4.317 {+-} 0.075 and 4.795 {+-} 0.100 MeV. All of the observed inelastically-scattered neutron groups were composites of contributions from several isotopes and/or levels. The experimental results were used to develop energy-average optical, statistical and coupled-channels models.

  1. Optical scattering on ferrofluid agglomerates

    Bacri, J. -C.; Salin, D.

    1982-01-01

    Direct microscopic observation of a thin sample of ionic ferrofluid, in the presence of a magnetic field, shows the existence of a locally hexagonal lattice of agglomerates. We have observed the unusual pattern of the light scattered by this array.

  2. Scattering by a nihility cylinder

    Lakhtakia, A

    2006-01-01

    The total scattering and the extinction efficiencies of a nihility cylinder of infinite length and circular cross--section are identical and independent of the polarization state of a normally incident plane wave.

  3. Unveiling small sphere's scattering behavior

    Tzarouchis, Dimitrios C; Sihvola, Ari

    2016-01-01

    A classical way for exploring the scattering behavior of a small sphere is to approximate Mie coefficients with a Taylor series expansion. This ansatz delivered a plethora of insightful results, mostly for small spheres supporting electric localized plasmonic resonances. However, many scattering aspects are still uncharted, especially for the case of magnetic resonances. Here, an alternative system ansatz is proposed based on the Pad\\'e approximants for the Mie coefficients. The extracted results reveal new aspects, such as the existence of a self-regulating radiative damping mechanism for the first magnetic resonance. Hence, a systematic way of exploring the scattering behavior is introduced, sharpening our understanding about sphere's scattering behavior and its emergent functionalities.

  4. Analytization of elastic scattering amplitude

    Troshin, S M

    2016-01-01

    Dependence of the real part of the elastic scattering amplitude on the transferred momentum -t at the asymptotical energies has been restored from the corresponding imaginary part on the basis of derivative analyticity relations (analytization).

  5. Quantum computation with scattering matrices

    Giorgadze, G.; Tevzadze, R.

    2006-01-01

    We discuss possible applications of the 1-D direct and inverse scattering problem to design of universal quantum gates for quantum computation. The potentials generating some universal gates are described.

  6. Resonantly scattering crystals and surfaces

    We examine coherence effects from forming a crystal of resonant scatterers by generalising the Fano model for autoionising resonances in electron scattering from atoms to a lattice of such scatterers. (We have in mind the case of neutron scattering from nuclei.) We solve this problem to yield two branches to the dispersion relation for the neutron in general and three when the resonance coincides with a Brillouin Zone boundary. The 'width' of the resonance is enhanced over the isolated nucleus, the best candidate for observation being the 2eV 185Re resonance near the Bragg condition. We use these results to calculate the reflection coefficient from a surface, revealing total external reflection near resonance. We discuss experimental feasibility in both the neutron and electron cases. (author)

  7. Polarized lepton-nucleon scattering

    Deep inelastic polarized lepton-nucleon scattering is reviewed in three lectures. The first lecture covers the polarized deep inelastic scattering formalism and foundational theoretical work. The second lecture describes the nucleon spin structure function experiments that have been performed up through 1993. The third lecture discusses implication of the results and future experiments aimed at high-precision measurements of the nucleon spin structure functions

  8. Nanocatalytic resonance scattering spectral analysis

    2010-01-01

    The resonance scattering spectral technique has been established using the synchronous scanning technique on spectrofluorometry.Because of its advantages of simplicity,rapidity and sensitivity,it has been widely applied to analyses of proteins,nucleic acids and inorganic ions.This paper summarizes the application of immunonanogold and aptamer modified nanogold(AptAu) catalytic resonance scattering spectral technique in combination with the work of our group,citing 53 references.

  9. Scattering Equations and KLT Orthogonality

    Cachazo, Freddy; He, Song; Yuan, Ellis Ye

    2013-01-01

    Several recent developments point to the fact that rational maps from n-punctured spheres to the null cone of D dimensional momentum space provide a natural language for describing the scattering of massless particles in D dimensions. In this note we identify and study equations relating the kinematic invariants and the puncture locations, which we call the scattering equations. We provide an inductive algorithm in the number of particles for their solutions and prove a remarkable property wh...

  10. Virtual photon-photon scattering

    Hoferichter, Martin; Colangelo, Gilberto; Procura, Massimiliano; Stoffer, Peter(Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, Bern, CH-3012, Switzerland)

    2014-01-01

    Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e+e− → hadrons. We review the main difficulties that impede such an approach for light-by-light scattering and identify the required ingredients from experiment. Amongst those, the most critical one is the scattering of two virtual photons into meson pairs. We analyze the analytic structure of the pr...

  11. Virtual photon-photon scattering

    Hoferichter, Martin; Colangelo, Gilberto; Procura, Massimiliano; Stoffer, Peter(Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, Bern, CH-3012, Switzerland)

    2013-01-01

    Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e^+e^- --> hadrons. We review the main difficulties that impede such an approach for light-by-light scattering and identify the required ingredients from experiment. Amongst those, the most critical one is the scattering of two virtual photons into meson pairs. We analyze the analytic structure of th...

  12. Proton-tetraneutron elastic scattering

    Sherrill, B. M.; Bertulani, C. A.

    2003-01-01

    We analyze the elastic scattering of protons on a 4n system. This was used as part of the detection technique of a recent experiment [1] to search for the 4n (tetraneutron) as a bound particle. We show that it is unlikely that this process alone could yield the events reported in ref. [1], unless the 4n has an anomalously large backward elastic scattering amplitude.

  13. Light scattering by cosmic particles

    Hovenier, J.W.; Min, M.

    2008-01-01

    We define cosmic particles as particles outside the Earth. Two types of cosmic particles can be distinguished, namely liquid and solid particles. The solid particles are often called grains or cosmic dust particles. Cosmic particles occur in a great variety of astronomical objects and environments. At light scattering conferences most attention is usually paid to Solar System bodies. The main purpose of this contribution is to provide a brief introduction to light scattering by cosmic particl...

  14. Polarized lepton-nucleon scattering

    Hughes, E.

    1994-02-01

    Deep inelastic polarized lepton-nucleon scattering is reviewed in three lectures. The first lecture covers the polarized deep inelastic scattering formalism and foundational theoretical work. The second lecture describes the nucleon spin structure function experiments that have been performed up through 1993. The third lecture discusses implication of the results and future experiments aimed at high-precision measurements of the nucleon spin structure functions.

  15. Cosmic Neutrino Last Scattering Surface

    Dodelson, Scott

    2009-01-01

    Neutrinos decoupled from the rest of the cosmic plasma when the Universe was less than one second old, far earlier than the photons which decoupled at t=380,000 years. Surprisingly, though, the last scattering surface of the neutrinos is much closer to us than that of the photons. Here we calculate the properties of the last scattering surfaces of the three species of neutrinos.

  16. Multiple magnetic scattering in small-angle neutron scattering of Nd–Fe–B nanocrystalline magnet

    Tetsuro Ueno; Kotaro Saito; Masao Yano; Masaaki Ito; Tetsuya Shoji; Noritsugu Sakuma; Akira Kato; Akira Manabe; Ai Hashimoto; Gilbert, Elliot P.; Uwe Keiderling; Kanta Ono

    2016-01-01

    We have investigated the influence of multiple scattering on the magnetic small-angle neutron scattering (SANS) from a Nd–Fe–B nanocrystalline magnet. We performed sample-thickness- and neutron-wavelength-dependent SANS measurements, and observed the scattering vector dependence of the multiple magnetic scattering. It is revealed that significant multiple scattering exists in the magnetic scattering rather than the nuclear scattering of Nd–Fe–B nanocrystalline magnet. It is considered that th...

  17. Eikonal Scattering at Strong Coupling

    Irizarry-Gelpi, Melvin Eloy

    The scattering of subatomic particles is a source of important physical phenomena. Decades of work have yielded many techniques for the computation of scattering amplitudes. Most of these techniques involve perturbative quantum field theory and thus apply only at weak coupling. Complementary to scattering is the formation of bound states, which are intrinsically nonperturbative. Regge theory arose in the late 1950s as an attempt to describe, with a single framework, both scattering and the formation of bound states. In Regge theory one obtains an amplitude with bound state poles after analytic continuation of a nonperturbative scattering amplitude, corresponding to a sum of an infinite number of Feynman diagrams at large energy and fixed momentum transfer (but with crossed kinematics). Thus, in order to obtain bound states at fixed energy, one computes an amplitude at large momentum transfer. In this dissertation we calculate amplitudes with bound states in the regime of fixed energy and small momentum transfer. We formulate the elastic scattering problem in terms of many-body path integrals, familiar from quantum mechanics. Then we invoke the semiclassical JWKB approximation, where the path integral is dominated by classical paths. The dynamics in the semiclassical regime are strongly coupled, as found by Halpern and Siegel. When the momentum transfer is small, the classical paths are simple straight lines and the resulting semiclassical amplitudes display a spectrum of bound states that agrees with the spectrum found by solving wave equations with potentials. In this work we study the bound states of matter particles with various types of interactions, including electromagnetic and gravitational interactions. Our work has many analogies with the work started by Alday and Maldacena, who computed scattering amplitudes of gluons at strong coupling with semiclassical quantum mechanics of strings in anti de-Sitter spacetime. We hope that in the future we can apply our

  18. Fundamentals of neutron scattering by condensed matter

    The purpose of this introductory lecture is to give the basic facts about the scattering of neutrons by condensed matter. This lecture is restricted to nuclear scattering, whereas magnetic scattering will be dealt with in an other course. Most of the formalism, however, can also be easily extended to magnetic scattering. (author) 17 figs., 3 tabs., 10 refs

  19. Fundamentals of neutron scattering by condensed matter

    Scherm, R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1996-12-31

    The purpose of this introductory lecture is to give the basic facts about the scattering of neutrons by condensed matter. This lecture is restricted to nuclear scattering, whereas magnetic scattering will be dealt with in an other course. Most of the formalism, however, can also be easily extended to magnetic scattering. (author) 17 figs., 3 tabs., 10 refs.

  20. High frequency and pulse scattering physical acoustics

    Pierce, Allan D

    1992-01-01

    High Frequency and Pulse Scattering investigates high frequency and pulse scattering, with emphasis on the phenomenon of echoes from objects. Geometrical and catastrophe optics methods in scattering are discussed, along with the scattering of sound pulses and the ringing of target resonances. Caustics and associated diffraction catastrophes are also examined.Comprised of two chapters, this volume begins with a detailed account of geometrically based approximation methods in scattering theory, focusing on waves transmitted through fluid and elastic scatterers and glory scattering; surface ray r

  1. Resonant elastic scattering, inelastic scattering and astrophysical reactions

    Nuclear reactions can occur at low kinetic energy. Low-energy reactions are characterized by a strong dependence on the structure of the compound nucleus. It turns out that it is possible to study the nuclear structure by measuring these reactions. In this course, three types of reactions are treated: Resonant Elastic Scattering (such as N14(p,p)N14), Inelastic Scattering (such as N14(p,p')N14*) and Astrophysical reactions (such as N14(p,γ)O15). (author)

  2. Neutron detector resolution for scattering

    Kolda, S.A. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1997-03-01

    A resolution function has been determined for scattered neutron experiments at Rensselaer Polytechnic Institute (RPI). This function accounts for the shifting and broadening of the resonance peak due to the additional path length, traveled by the neutron after scattering and prior to detection, along with the broadening of the resonance peak due to the bounce target. This resolution function has been parameterized both in neutron energy and size of the sample disk. Monte Carlo Neutron and Photon (MCNP) modeling has been used to determine the shape of the detector resolution function while assuming that the sample nucleus has an infinite mass. The shape of the function for a monoenergetic neutron point source has been compared to the analytical solution. Additionally, the parameterized detector resolution function has been used to broaden the scatter yield calculated from Evaluated Neutron Data File ENDF/B-VI cross section data for {sup 238}U. The target resolution function has been empirically determined by comparison of the broadened scatter yield and the experimental yield for {sup 238}U. The combined resolution function can be inserted into the SAMMY code to allow resonance analysis for scattering measurements.

  3. The total cross sections of heavy ion reaction and the nuclear transfer

    The total reaction cross section of the systems 12C + 12C, 12C + 40Ca, 12C + 90Zr, 12C + 208Pb, 40Ca + 40Ca, 40Ca + 208Pb + 90Zr + 90Zr, 90Zr + 208Pb and 208Pb + 208Pb for a wide range of energies has been calculated microscopically. A WKB expression for the imaginary phase shift in the impact paremeter representation has been employed. The imaginary part of the optical potential has been constructed by using the first term of multiple scattering theory with the effect of Pauli blocking incorporated into it. The inclusion of the nuclear and Coulomb interactions is shown to be important. The theoretical results do not show very good agreement with the experimental data at lower energies. This is attributed to the weak absorption contained in the imaginary potential of the ''tοA οB'' interaction, wich contained only quasifree knock-out as the dominant reaction mechanism. (author)

  4. Electromagnetic wave scattering by Schwarzschild black holes.

    Crispino, Luís C B; Dolan, Sam R; Oliveira, Ednilton S

    2009-06-12

    We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor, and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time. PMID:19658920

  5. Magnetic scattering and polarized neutrons

    The last few years have witnessed considerable progress in the use of polarized neutron beam techniques for the study of condensed matter physics. Among the methods actively pursued at present are neutron spin echo as pioneered by Mezei for ultra high resolution and the energy integrated magnetic scattering measurement technique developed by Brown and Ziebeck. We have concentrated on a medium resolution range utilizing 5 to 100 MeV polarized neutrons. In this review we discuss recent work at Brookhaven on the development of the triple axis neutron scattering technique with polarization analysis. We have now reached the stage where quantitative characterization, in absolute units, can be done for a wide range of energy and momentum transfers in paramagnetic scattering. We will discuss some examples of recent inelastic measurements on 3d ferromagnets as well as diffraction studies of multibilayer thin film structures

  6. Scattering Equations and KLT Orthogonality

    Cachazo, Freddy; Yuan, Ellis Ye

    2013-01-01

    Several recent developments point to the fact that rational maps from n-punctured spheres to the null cone of D dimensional momentum space provide a natural language for describing the scattering of massless particles in D dimensions. In this note we identify and study equations relating the kinematic invariants and the puncture locations, which we call the scattering equations. We provide an inductive algorithm in the number of particles for their solutions and prove a remarkable property which we call KLT Orthogonality. In a nutshell, KLT orthogonality means that "Parke-Taylor" vectors constructed from the solutions to the scattering equations are mutually orthogonal with respect to the Kawai-Lewellen-Tye (KLT) bilinear form. We end with comments on possible connections to gauge theory and gravity amplitudes in any dimension and to the high-energy limit of string theory amplitudes.

  7. Nuclear Scattering from Transition Metals

    Hira, Ajit; McKeough, James; Valerio, Mario; Cathey, Tommy

    2016-03-01

    In view of the continued interest in the scattering of light projectiles by metallic nuclei, we present a computational study of the interactions between different nuclear species of atoms such as H through F (Z neutron scattering can be used to record holographic images of materials. We have developed a FORTRAN computer program to compute stopping cross sections and scattering angles in Ag and other metals for the small nuclear projectiles, using Monte Carlo calculation. This code allows for different angles of incidence. Next, simulations were done in the energy interval from 50 to 210 keV. The computational results thus obtained are compared with relevant experimental data. The data are further analyzed to identify periodic trends in terms of the atomic number of the projectile. Such studies also have potential applications in nuclear physics and in nuclear medicine. Funding from National Science Foundation.

  8. Compton Scattering on Light Nuclei

    Shukla D.

    2010-04-01

    Full Text Available Compton scattering on light nuclei (A = 2, 3 has emerged as an effective avenue to search for signatures of neutron polarizabilities, both spin–independent and spin–dependent ones. In this discussion I will focus on the theoretical aspect of Compton scattering on light nuclei; giving first a brief overview and therafter concentrating on our Compton scattering calculations based on Chiral effective theory at energies of the order of pion mass. These elastic γd and γHe-3 calculations include nucleons, pions as the basic degrees of freedom. I will also discuss γd results where the ∆-isobar has been included explicitly. Our results on unpolarized and polarization observables suggest that a combination of experiments and further theoretical efforts will provide an extraction of the neutron polarizabilities.

  9. Helium atom scattering from surfaces

    1992-01-01

    High resolution helium atom scattering can be applied to study a number of interesting properties of solid surfaces with great sensitivity and accuracy. This book treats in detail experimental and theoretical aspects ofthis method as well as all current applications in surface science. The individual chapters - all written by experts in the field - are devoted to the investigation of surface structure, defect shapes and concentrations, the interaction potential, collective and localized surface vibrations at low energies, phase transitions and surface diffusion. Over the past decade helium atom scattering has gained widespread recognitionwithin the surface science community. Points in its favour are comprehensiveunderstanding of the scattering theory and the availability of well-tested approximation to the rigorous theory. This book will be invaluable to surface scientists wishing to make an informed judgement on the actual and potential capabilities of this technique and its results.

  10. New Techniques in Neutron Scattering

    Birk, Jonas Okkels

    Neutron scattering is an important experimental technique in amongst others solid state physics, biophysics, and engineering. This year construction of European Spallation Source (ESS) was commenced in Lund, Sweeden. The facility will use a new long pulsed source principle to obtain higher...... potential performance than any existing facility, however in order to use this pulse structure optimally many existing neutron scattering instruments will need to be redesigned. This defense will concentrate on the design and optimization of the inverse time-of-flight cold neutron spectrometer CAMEA. The...... unprecedented large fraction of neutrons scattered in the horizontal plane. Together with the ESS source this will produce an instrument that promises several orders of magnitude higher performance than the best currently existing neutron spectrometers. The design of CAMEA involved kinematic calculations...

  11. SCATTERING FROM RAMIFIED POLYMERIC SYSTEMS

    M.Benhamou

    2004-01-01

    Full Text Available Here, of great interest to us is a quantitative study of the scattering properties from ramified polymeric systems of arbitrary topology. We consider three types of systems, namely ramified polymers in solution, ramified polymer blends, or ternary mixtures made of two ramified polymers of different chemical nature immersed in a good solvent. To achieve the goal of the study, use is made of the Random Phase Approximation. First we determine the exact expression of the form factor of an ideal ramified polymer of any topology, from which we extract the exact expression of its gyration radius. Using the classical Zimm's formulae and the exact form factor, we determine all scattering properties of these three types of ramified polymeric systems. The main conclusion is that ramification of the chains induces drastic changes of the scattering properties.

  12. Parity violation and electron scattering

    I have been asked to set stage for the more specialized talks to follow and to review the history of parity nonconservation in electron scattering. In electron scattering, parity violation (PV) is the unique signal which allows us to study the weak interactions among the much stronger electromagnetic ones. It is observed through the detection of a pseudoscalar quantity in the cross section or rate of a reaction. These pseudoscalars usually involve a spin or polarization. Since it is known that spin effects are more sensitive to dynamics than differential or total cross sections, which are partially determined by geometry, PV measurements allow us to learn about the weak interactions and nucleon and nuclear structure. Because the weak interactions are of short range, the measurements are sensitive to different aspects of the target structure than the long range electromagnetic scattering. 15 refs., 7 figs

  13. Optical scattering measurement and analysis

    Stover, John C

    2012-01-01

    Newly included are scatter models for pits and particles as well as the use of wafer scanners to locate and size isolated surface features. New sections cover the multimillion-dollar wafer scanner business, establishing that microroughness is the noise, not the signal, in these systems. Scatter measurements, now routinely used to determine whether small-surface features are pits or particles and inspiring new technology that provides information on particle material, are also discussed. These new capabilities are now supported by a series of international standards, and a new chapter reviews t

  14. Invisibility cloaking in weak scattering

    Setälä, Tero; Hakkarainen, Timo; Ari T. Friberg; Hoenders, Bernhard J.

    2010-01-01

    We consider invisibility cloaking of a slab object in scalar wave theory within the first-order Born approximation. We show that in the forward direction cloaking is achieved for any object slab and incident field, whereas in the backward direction cloaking is possible at least for self-imaging fields. In both cases the scattering potential of the cloak slab depends on that of the object slab. The method of object-dependent cloaking using weak slab scatterers can be a useful addition to exist...

  15. Commercial applications of neutron scattering

    The fact that industry is now willing to pay the full commercial cost for certain neutron scattering experiments aimed at solving its urgent materials - related problems is a true testimony to the usefulness of neutrons as microscopic probes. This paper gives examples of such use of three techniques drawn mainly from our experience at AEA Technology Harwell Laboratory. These are diffraction to measure residual stress, small angle neutron scattering to examine hardening precipitates in ferritic steels brought about by irradiation, and reflectivity to study amorphous diamond layers deposited on silicon. In most cases it is the penetrative power of the neutron which proves to be its best asset for commercial industrial applicaitons. (author)

  16. [Inelastic electron scattering from surfaces

    This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned

  17. Summary of neutron scattering lengths

    All available neutron-nuclei scattering lengths are collected together with their error bars in a uniform way. Bound scattering lengths are given for the elements, the isotopes, and the various spin-states. They are discussed in the sense of their use as basic parameters for many investigations in the field of nuclear and solid state physics. The data bank is available on magnetic tape, too. Recommended values and a map of these data serve for an uncomplicated use of these quantities. (orig.)

  18. Entanglement entropy of scattering particles

    Peschanski, Robi; Seki, Shigenori

    2016-07-01

    We study the entanglement entropy between the two outgoing particles in an elastic scattering process. It is formulated within an S-matrix formalism using the partial wave expansion of two-body states, which plays a significant role in our computation. As a result, we obtain a novel formula that expresses the entanglement entropy in a high energy scattering by the use of physical observables, namely the elastic and total cross sections and a physical bound on the impact parameter range, related to the elastic differential cross-section.

  19. High energy elastic hadron scattering

    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

  20. Entanglement Entropy of Scattering Particles

    Peschanski, Robi

    2016-01-01

    We study the entanglement entropy between the two outgoing particles in an elastic scattering process. It is formulated within an S-matrix formalism using the partial wave expansion of two-body states, which plays a significant role in our computation. As a result, we obtain a novel formula that describes the entanglement entropy in a high energy scattering by the use of physical observables, namely the elastic and total cross sections and a physical bound on the impact parameter range, related to the elastic differential cross-section.

  1. Electron scattering off palladium isotopes

    The low-lying states of the even Pd isotopes are characterized by vibrator-like properties. In this thesis the results of an electron scattering experiment on the Pd isotopes, designed to study the description of such nuclei in the Anharmonic Vibrator Model (AVM) and the Interacting Boson Approximation (IBA), are presented and discussed. Data have been taken at the high-resolution electron scattering facility of NIKHEF-K and covered a momentum-transfer range of 0.4 to 2.5 fm-1. (Auth.)

  2. Cobalt silicide formation on a Si(1 0 0) substrate in the presence of an interfacial (Fe{sub 90}Zr{sub 10}) interlayer

    Abrass, Hameda A. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Theron, C.C., E-mail: Chris.Theron@up.ac.za [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Njoroge, E.G.; Berg, N.G. van der; Botha, A.J. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Yan, X.-L.; Terblans, J.J. [Department of Physics, University of the Free State, Bloemfontein 9300 (South Africa)

    2015-09-15

    The reaction between a thin film (126 nm) of Co and Si has been studied at 450 °C for 24 h under high vacuum conditions, in the presence of a FeZr barrier layer. Without a diffusion barrier layer between Co and Si, Co{sub 2}Si forms at 350 °C as the initial phase while CoSi{sub 2} forms at 550 °C. The FeZr barrier layer changed the flux of atoms arriving at the reaction interface. Co reacted with the Si from the substrate and formed a mixed layer of CoSi and CoSi{sub 2} in the interlayer region. The use of the FeZr diffusion barrier has been demonstrated to lower the temperature formation of CoSi{sub 2} to 450 °C. The reactions were characterised by Rutherford backscattering spectrometry, Auger electron spectroscopy depth profiling, X-ray diffraction using CoK{sub α} radiation and scanning electron microscopy.

  3. Nuclear matter and electron scattering

    Sick, I. [Dept. fuer Physik und Astronomie, Univ. Basel (Switzerland)

    1998-06-01

    We show that inclusive electron scattering at large momentum transfer allows a measurement of short-range properties of nuclear matter. This provides a very valuable constraint in selecting the calculations appropriate for predicting nuclear matter properties at the densities of astrophysical interest. (orig.)

  4. Neutron scattering and models: Chromium

    Differential neutron elastic-scattering cross sections of elemental chromium are measured from 4.5 ∼ 10 MeV in steps of ∼ 0.5 MeV and at ≥ 40 scattering angles distributed between ∼ 17 degree--160 degree. Concurrently differential cross sections for the inelastic neutron excitation of the yrast 2+ (1.434 MeV) level in d52Cr are determined. In addition, broad inelastically-scattered neutron groups are observed corresponding to composite excitation of levels up to ∼ 5.5 MeV in the various chromium isotopes. These experimental results are combined with low-energy values previously reported from this laboratory, with recent ∼ 8 → 15 MeV data measured at the Physikalisch-Technische Bundesanstalt and with a 21.6 MeV result from the literature to form an extensive neutron-scattering data base which is interpreted in the context of spherical-optical and coupled-channels (rotational and vibrational) models. These models reasonably describe the observables but indicate rather large energy-dependent parameter trends at low energies similar to those previously reported near the peak of the So strength function in studies at this laboratory. The physical implications of the measurements and models are discussed including deformation, coupling, dispersive and asymmetry effects

  5. Bibliography for thermal neutron scattering

    Bibliographic references are given for measurements, calculations, reviews and basic studies of thermal neutron scattering and dynamical properties of condensed matter. This is the sixth edition covering 3,326 articles collected up to 1978. The edition being the final issue of the present bibliography series, a forthcoming edition will be published in a new form of bibliography. (author)

  6. Inelastic scattering on 100Ru

    Aspects of the nuclear structure of 100Ru whe investigated by means of the scattering of 100Ru (p,p')100Ru* with 16 MeV protons, where 21 states were investigated. The emergent protons were analysed by a magnetic spectrograph, of the enge type with a typical resolution of ≅ 9 KeV. (A.C.A.S.)

  7. Moliere's multiple scattering theory revisited

    Voskresenskaya, O.; Tarasov, A.

    2012-01-01

    A part of Moliere's multiple scattering theory concerning the determination of the screening angular parameter is revised. An universal form of the Coulomb corrections to the screening angle, the exponential part of the distribution function, and the angular distribution is discussed within the small-angle approximation of this theory. The accuracy of the Moliere theory in determining the screening angle is estimated.

  8. Neutron scattering science in Australia

    Knott, Robert [Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

    1999-10-01

    Neutron scattering science in Australia is making an impact on a number of fields in the scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a wide range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans are in progress to replace the present research reactor with a modern multi-purpose research reactor to offer the most advanced neutron scattering facilities. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. (author)

  9. Gravitational Laser Back-Scattering

    Novaes, S. F.; Spehler, D.

    1993-01-01

    A possible way of producing gravitons in the laboratory is investigated. We evaluate the cross section electron + photon $\\rightarrow$ electron + graviton in the framework of linearized gravitation, and analyse this reaction considering the photon coming either from a laser beam or from a Compton back-scattering process.

  10. Remark on pion scattering lengths

    Black, Deirdre; Jora, Renata; Park, Nae Woong; Schechter, Joseph; Shahid, M Naeem

    2009-01-01

    It is noted that the pattern of chiral perturbation theory predictions for both the isotopic spin 0 and isotopic spin 2 s-wave pion-pion scattering lengths to orders $p^2$, $p^4$ and $p^6$ seems to agree with the corresponding pattern of the tree level predictions of the SU(2) linear sigma model.