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Sample records for recoil energy relevant

  1. Recoil separator ERNA: acceptances in angle and energy

    NASA Astrophysics Data System (ADS)

    Rogalla, D.; Schürmann, D.; Strieder, F.; Aliotta, M.; DeCesare, N.; DiLeva, A.; Lubritto, C.; D'Onofrio, A.; Gialanella, L.; Imbriani, G.; Kluge, J.; Ordine, A.; Roca, V.; Röcken, H.; Rolfs, C.; Romano, M.; Schümann, F.; Terrasi, F.; Trautvetter, H. P.

    2003-11-01

    For improved cross-section measurements of the reaction 12C(α,γ) 16O in inverted kinematics, a recoil separator ERNA is developed at the 4 MV Dynamitron tandem accelerator in Bochum to detect directly the 16O recoils with high efficiency. Due to the emission of the capture γ-rays, the kinematically forward directed 16O recoils are described by an angle and energy spread. Thus, the acceptances in angle and energy of ERNA must cover these spreads in order to extract reliable cross-section values. We report on such acceptance measurements over the energy range Ecm=0.7-5.0 MeV, using an 16O pilot beam.

  2. Ionization efficiency study for low energy nuclear recoils in germanium

    NASA Astrophysics Data System (ADS)

    Barker, D.; Wei, W.-Z.; Mei, D.-M.; Zhang, C.

    2013-08-01

    We used the internal conversion (E0 transition) of germanium-72 to indirectly measure the low energy nuclear recoils of germanium. Together with a reliable Monte Carlo package, in which we implement the internal conversion process, the data was compared to the Lindhard (k = 0.159) and Barker-Mei models. A shape analysis indicates that both models agree well with data in the region of interest within 4%. The most probable value (MPV) of the nuclear recoils obtained from the shape analysis is 17.5 ± 0.12 (sys) ±0.035 (stat) keV with an average path-length of 0.014 μm.

  3. Neutron absorbed dose determination by calculations of recoil energy.

    PubMed

    Wrobel, F; Benabdesselam, M; Iacconi, P; Lapraz, D

    2004-01-01

    The aim of this work is to calculate the absorbed dose to matter due to neutrons in the 5-150 MeV energy range. Materials involved in the calculations are Al2O3, CaSO4 and CaS, which may be used as dosemeters and have already been studied for their luminescent properties. The absorbed dose is assumed to be mainly due to the energy deposited by the recoils. Elastic reactions are treated with the ECIS code while for the non-elastic ones, a Monte Carlo code has been developed and allowed to follow the nucleus decay and to determine its characteristics (nature and energy). Finally, the calculations show that the absorbed dose is mainly due to non-elastic process and that above 20 MeV this dose decreases slightly with the neutron energy. PMID:15353750

  4. Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter

    NASA Astrophysics Data System (ADS)

    Sorensen, Peter; Dahl, Carl Eric

    2011-03-01

    We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.

  5. Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter

    SciTech Connect

    Sorensen, P; Dahl, C E

    2011-02-14

    We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al.. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well-described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.

  6. MIMAC low energy electron-recoil discrimination measured with fast neutrons

    NASA Astrophysics Data System (ADS)

    Riffard, Q.; Santos, D.; Guillaudin, O.; Bosson, G.; Bourrion, O.; Bouvier, J.; Descombes, T.; Muraz, J.-F.; Lebreton, L.; Maire, D.; Colas, P.; Giomataris, I.; Busto, J.; Fouchez, D.; Brunner, J.; Tao, C.

    2016-08-01

    MIMAC (MIcro-TPC MAtrix of Chambers) is a directional WIMP Dark Matter detector project. Direct dark matter experiments need a high level of electron/recoil discrimination to search for nuclear recoils produced by WIMP-nucleus elastic scattering. In this paper, we proposed an original method for electron event rejection based on a multivariate analysis applied to experimental data acquired using monochromatic neutron fields. This analysis shows that a 105 rejection power is reachable for electron/recoil discrimination. Moreover, the efficiency was estimated by a Monte-Carlo simulation showing that a 105 electron rejection power is reached with a 86.49 ± 0.17% nuclear recoil efficiency considering the full energy range and 94.67 ± 0.19% considering a 5 keV lower threshold.

  7. A curved detection-slit to improve ERD (Elastic Recoil Detection) energy/depth resolution

    SciTech Connect

    Brice, D.K.; Doyle, B.L.

    1989-01-01

    Recoil atoms detected in Elastic Recoil Detection (ERD) experiments emerge from an initial collision area along cones of constant energy due to the cylindrical symmetry of the elastic scattering cross section. The constant energy cones therefore intercept planar slit plates placed before the detectors in conic sections. For ease of fabrication slits are typically configured as long narrow rectangles, and as a result energy resolution is adversely affected. It has been shown that the kinematic broadening caused by using rectangular slits is minimized when L = 2 (W z tan/Theta//sub recoil/)/sup 1/2/ where W is the slit width, L is the slit length, z is the slit-target distance and /Theta//sub recoil/ is the lab-frame recoil angle. The improved energy resolution which results when rectangular slits are replaced by appropriate curved slits is examined here. Formulas are given for the conic sections associated with the curved slits as a function of experimental geometry. When slit dimensions are small compared with the full extent of the conic section slit geometry can be accurately approximated as the arc of a circle with radius R/sub c/ = z tan/Theta//sub recoil/. Energy loss effects on the resolution are also accounted for in our treatment. The use of curved slits with L = 4 (W z tan/Theta//sub recoil/)/sup 1/2/ is shown to improve kinematic broadening by /approximately/50% as compared to optimized rectangular slits of the same area. 2 refs., 5 figs.

  8. Modeling ionization and recombination from low energy nuclear recoils in liquid argon

    NASA Astrophysics Data System (ADS)

    Foxe, M.; Hagmann, C.; Jovanovic, I.; Bernstein, A.; Joshi, T. H.; Kazkaz, K.; Mozin, V.; Pereverzev, S. V.; Sangiorgio, S.; Sorensen, P.

    2015-09-01

    Coherent elastic neutrino-nucleus scattering (CENNS) is an as-yet undetected, flavor-independent neutrino interaction predicted by the Standard Model. Detection of CENNS could offer benefits for detection of supernova and solar neutrinos in astrophysics, or for detection of antineutrinos for nuclear reactor monitoring and nuclear nonproliferation. One challenge with detecting CENNS is the low energy deposition associated with a typical CENNS nuclear recoil. In addition, nuclear recoils result in lower ionization yields than those produced by electron recoils of the same energy. While a measurement of the nuclear recoil ionization yield in liquid argon in the keV energy range has been recently reported, a corresponding model for low-energy ionization yield in liquid argon does not exist. For this reason, a Monte Carlo simulation has been developed to predict the ionization yield at sub-10 keV energies. The model consists of two distinct components: (1) simulation of the atomic collision cascade with production of ionization, and (2) the thermalization and drift of ionization electrons in an applied electric field including local recombination. As an application of our results we report updated estimates of detectable ionization in liquid argon from CENNS at a nuclear reactor.

  9. Mass calibration of the energy axis in ToF-E elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Meersschaut, J.; Laricchiuta, G.; Sajavaara, T.; Vandervorst, W.

    2016-03-01

    We report on procedures that we have developed to mass-calibrate the energy axis of ToF-E histograms in elastic recoil detection analysis. The obtained calibration parameters allow one to transform the ToF-E histogram into a calibrated ToF-M histogram.

  10. Modeling ionization and recombination from low energy nuclear recoils in liquid argon

    SciTech Connect

    Foxe, Michael P.; Hagmann, Chris; Jovanovic, Igor; Bernstein, A.; Joshi, T.; Kazkaz, K.; Mozin, Vladimir V.; Pereverzev, S. V.; Sangiorgio, Samuele; Sorensen, Peter F.

    2015-09-01

    Coherent neutrino-nucleus scattering (CNNS) is an as-yet undetected, flavor-independent neutrino interaction predicted by the Standard Model. CNNS is a flavor-blind interaction, which offers potential benefits for its use in nonproliferation (nuclear reactor monitoring) and astrophysics (supernova and solar neutrinos) applications. One challenge with detecting CNNS is the low energy deposition associated with a typical CNNS nuclear recoil. In addition, nuclear recoils are predicted to result in lower ionization yields than those produced by electron recoils of the same energy. This ratio of nuclear- and electron-induced ionization, known as the nuclear quenching factor, is unknown at energies typical for CNNS interactions in liquid xenon (LXe) and liquid argon (LAr), detector media being considered for CNNS detection. While there have been recent measurements [1] of the ionization yield from nuclear recoils in LAr, there is no universal model for nuclear quenching and ionization yield. For this reason, a Monte Carlo simulation has been developed to predict the ionization yield at sub-10 keV energies. The local ionization yield of a recoiling atom in the medium is calculated first. The ejected electrons are subsequently tracked in the electric field resulting from both the local electric charges and the externally applied drift field. The dependence of the ionization yield on the drift electric field is obtained by combining the calculated ionization yield for the initial collision cascade with the electron escape probability. An updated estimate of the CNNS signal expected in a LAr detector operated near a nuclear power reactor is presented.

  11. A coherent understanding of low-energy nuclear recoils in liquid xenon

    SciTech Connect

    Sorensen, Peter

    2010-09-01

    Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (∼<10 GeV) particle dark matter by looking for nuclear recoils of only a few keV, just above the detector threshold. Yet in this energy regime a correct treatment of the detector threshold and resolution remains unclear. The energy dependence of the scintillation yield of liquid xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.

  12. A coherent understanding of low-energy nuclear recoils in liquid xenon

    NASA Astrophysics Data System (ADS)

    Sorensen, Peter

    2010-09-01

    Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (lesssim10 GeV) particle dark matter by looking for nuclear recoils of only a few keV, just above the detector threshold. Yet in this energy regime a correct treatment of the detector threshold and resolution remains unclear. The energy dependence of the scintillation yield of liquid xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.

  13. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  14. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D.; Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Camsonne, A.

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J. P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D. W. Higinbotham; R. J. Holt; C. W. de Jager; M. K. Jones; L. J. Kaufman; E. R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K. D. Paschke; C. F. Perdrisat; V. Punjabi; I. A. Qattan; R. D. Ransome; P. E. Reimer; B. Reitz; A. Saha; E. C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G. M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; and L. Zhu

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  16. Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu

    2007-02-26

    We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.

  17. Low energy electron/recoil discrimination for directional Dark Matter detection

    SciTech Connect

    Billard, J.; Mayet, F.; Santos, D. E-mail: mayet@lpsc.in2p3.fr

    2012-07-01

    Directional detection is a promising Dark Matter search strategy. Even though it could accommodate to a sizeable background contamination, electron/recoil discrimination remains a key and challenging issue as for direction-insensitive detectors. The measurement of the 3D track may be used to discriminate electrons from nuclear recoils. While a high rejection power is expected above 20 keV ionization, a dedicated data analysis is needed at low energy. After identifying discriminant observables, a multivariate analysis, namely a Boosted Decision Tree, is proposed, enabling an efficient event tagging for Dark Matter search. We show that it allows us to optimize rejection while keeping a rather high efficiency which is compulsory for rare event search.With respect to a sequential analysis, the rejection is about ∼ 20 times higher with a multivariate analysis, for the same Dark Matter exclusion limit.

  18. Development of bubble chambers with enhanced stability and sensitivity to low-energy nuclear recoils

    SciTech Connect

    Bolte, W.J.; Collar, Juan I.; Crisler, M.; Hall, J.; Holmgren, D.; Nakazawa, D.; Odom, B.; O'Sullivan, K.; Plunkett, R.; Ramberg, E.; Raskin, A.; Sonnenschein, A.; Vieira, J.D.; /Chicago U., EFI /KICP, Chicago /Fermilab

    2005-03-01

    The viability of using a Bubble Chamber for rare event searches and in particular for the detection of dark matter particle candidates is considered. Techniques leading to the deactivation of inhomogeneous nucleation centers and subsequent enhanced stability in such a detector are described. Results from prototype trials indicate that sensitivity to low-energy nuclear recoils like those expected from Weakly Interacting Massive Particles can be obtained in conditions of near total insensitivity to minimum ionizing backgrounds. An understanding of the response of superheated heavy refrigerants to these recoils is demonstrated within the context of existing theoretical models. We comment on the prospects for the detection of supersymmetric dark matter particles with a large CF{sub 3}I chamber.

  19. Precision measurement of quenching factors for low-energy nuclear recoils at TUNL

    NASA Astrophysics Data System (ADS)

    Rich, Grayson; Barbeau, Phil; Howell, Calvin; Karwowski, Hugon

    2014-03-01

    With detector technologies becoming increasingly sensitive to exotic events, a thorough understanding of signal yield as a function of deposited energy is required for appropriate interpretation of results from cutting edge detector systems. Elastic neutron scattering is a probe which has been used to mimic the nuclear recoils which may be produced in detection media by light-WIMP interactions or coherent neutrino-nucleus scattering (CNS). We have built at the Triangle Universities Nuclear Laboratory (TUNL) a facility which produces pulsed, collimated, low-energy, quasi-monoenergetic neutron beams using the 7Li(p,n) reaction, resulting in fluxes of ~ 1 neutrons / (s . cm2) at ~90 cm from the neutron-production target. The first precision results from this facility are reported for ultra-low-energy recoils in NaI(Tl) and CsI(Na) and future plans are outlined, including measurements on candidate materials for a CNS detector that can potentially be fielded at the Spallation Neutron Source of Oak Ridge National Laboratory as a part the Coherent Scatter Initiative (CSI). We discuss the implications of new, precise measurements of quenching factors on neutrino detectors and on current- and next-generation light-WIMP searches, particularly the DAMA experiment.

  20. Exact calculations of nuclear-recoil energies from prompt gamma decays resulting from neutron capture

    SciTech Connect

    Kinney, J.H.

    1981-07-20

    The results of an accurate determination of the recoil spectrum from (n, ..gamma..) reactions in molybdenum are presented. The recoil spectrum has been calculated from nuclear level structure data and measured branching ratios. Angular correlations between successive gammas have been accounted for using the standard theoretical techniques of Racah algebra and the density matrix formalism.

  1. Elastic recoil detection

    NASA Astrophysics Data System (ADS)

    Bik, W. M. A.; Habraken, F. H. P. M.

    1993-07-01

    In elastic recoil detection (ERD) one determines the yield and energy of particles ejected out of the surface region of samples under MeV ion bombardment. By application of this surface and thin film analysis technique one can obtain quantitative information concerning the depth distribution of light elements in a sample to be analysed. The quantitativity and the depth resolving power are based on knowledge of the recoil cross section and the stopping power of high-energy ions in matter. This paper reviews the fundamentals of this technique and the various experimental methods for recoil identification. Furthermore, important features for material analysis, such as detection limits, depth resolution and elemental range are discussed. Some emphasis is put on the conversion of the spectral contribution of the elements to atomic concentrations in the films for several representative cases. Throughout the review numerous examples are given to illustrate the features of ERD and to demonstrate empirically the accuracy of the quantification method.

  2. Precision Determination of Electron Scattering Angle by Differential Nuclear Recoil Energy Method

    SciTech Connect

    Liyanage, Nilanga; Saenboonruang, Kiadtisak

    2015-09-01

    The accurate determination of the scattered electron angle is crucial to electron scattering experiments, both with open-geometry large-acceptance spectrometers and ones with dipole-type magnetic spectrometers for electron detection. In particular, for small central-angle experiments using dipole-type magnetic spectrometers, in which surveys are used to measure the spectrometer angle with respect to the primary electron beam, the importance of the scattering angle determination is emphasized. However, given the complexities of large experiments and spectrometers, the accuracy of such surveys is limited and insufficient to meet demands of some experiments. In this article, we present a new technique for determination of the electron scattering angle based on an accurate measurement of the primary beam energy and the principle of differential nuclear recoil. This technique was used to determine the scattering angle for several experiments carried out at the Experimental Hall A, Jefferson Lab. Results have shown that the new technique greatly improved the accuracy of the angle determination compared to surveys.

  3. Precision determination of electron scattering angle by differential nuclear recoil energy method

    SciTech Connect

    Liyanage, N.; Saenboonruang, K.

    2015-12-01

    The accurate determination of the scattered electron angle is crucial to electron scattering experiments, both with open-geometry large-acceptance spectrometers and ones with dipole-type magnetic spectrometers for electron detection. In particular, for small central-angle experiments using dipole-type magnetic spectrometers, in which surveys are used to measure the spectrometer angle with respect to the primary electron beam, the importance of the scattering angle determination is emphasized. However, given the complexities of large experiments and spectrometers, the accuracy of such surveys is limited and insufficient to meet demands of some experiments. In this article, we present a new technique for determination of the electron scattering angle based on an accurate measurement of the primary beam energy and the principle of differential nuclear recoil. This technique was used to determine the scattering angle for several experiments carried out at the Experimental Hall A, Jefferson Lab. Results have shown that the new technique greatly improved the accuracy of the angle determination compared to surveys.

  4. High acceptance recoil polarimeter

    SciTech Connect

    The HARP Collaboration

    1992-12-05

    In order to detect neutrons and protons in the 50 to 600 MeV energy range and measure their polarization, an efficient, low-noise, self-calibrating device is being designed. This detector, known as the High Acceptance Recoil Polarimeter (HARP), is based on the recoil principle of proton detection from np[r arrow]n[prime]p[prime] or pp[r arrow]p[prime]p[prime] scattering (detected particles are underlined) which intrinsically yields polarization information on the incoming particle. HARP will be commissioned to carry out experiments in 1994.

  5. COSY Simulations to Guide Commissioning of the St. George Recoil Mass Separator

    NASA Astrophysics Data System (ADS)

    Schmitt, Jaclyn; Moran, Michael; Seymour, Christopher; Gilardy, Gwenaelle; Meisel, Zach; Couder, Manoel

    2015-10-01

    The goal of St. George (STrong Gradient Electromagnetic Online Recoil separator for capture Gamma ray Experiments) is to measure (α, γ) cross sections relevant to stellar helium burning. Recoil separators such as St. George are able to more closely approach the low astrophysical energies of interest because they collect reaction recoils rather than γ-rays, and thus are not limited by room background. In order to obtain an accurate cross section measurement, a recoil separator must be able to collect all recoils over their full range of expected energy and angular spread. The energy acceptance of St. George is currently being measured, and the angular acceptance will be measured soon. Here we present the results of COSY ion optics simulations and magnetic field analyses which were performed to help guide the commissioning measurements and diagnostic upgrades required to complete those measurements. National Science Foundation Research Experiences for Undergraduates program.

  6. Ab initio molecular dynamics investigations of low-energy recoil events in Ni and NiCo

    DOE PAGESBeta

    Liu, Bin; Yuan, Fenglin; Jin, Ke; Zhang, Yanwen; Weber, William J.

    2015-10-06

    Low-energy recoil events in pure Ni and the equiatomic NiCo alloy are studied using ab initio molecular dynamics simulations. We found that the threshold displacement energies are strongly dependent on orientation and weakly dependent on composition. The minimum threshold displacement energies are along the [1 1 0] direction in both pure Ni and the NiCo alloy. Compared to pure Ni, the threshold displacement energies increase slightly in the NiCo alloy due to stronger bonds in the alloy, irrespective of the element type of the PKA. A single Ni interstitial occupying the center of a tetrahedron formed by four Ni atomsmore » and a <1 0 0> split interstitial is produced in pure Ni by the recoils, while only the <1 0 0> split interstitial is formed in the NiCo alloy. Compared to the replacement sequences in pure Ni, anti-site defect sequences are observed in the alloy, which have high efficiency for both producing defects and transporting energy outside of the cascade core. These results provide insights into energy transfer processes occurring in equiatomic alloys under irradiation.« less

  7. Ab initio molecular dynamics investigations of low-energy recoil events in Ni and NiCo

    SciTech Connect

    Liu, Bin; Yuan, Fenglin; Jin, Ke; Zhang, Yanwen; Weber, William J.

    2015-10-06

    Low-energy recoil events in pure Ni and the equiatomic NiCo alloy are studied using ab initio molecular dynamics simulations. We found that the threshold displacement energies are strongly dependent on orientation and weakly dependent on composition. The minimum threshold displacement energies are along the [1 1 0] direction in both pure Ni and the NiCo alloy. Compared to pure Ni, the threshold displacement energies increase slightly in the NiCo alloy due to stronger bonds in the alloy, irrespective of the element type of the PKA. A single Ni interstitial occupying the center of a tetrahedron formed by four Ni atoms and a <1 0 0> split interstitial is produced in pure Ni by the recoils, while only the <1 0 0> split interstitial is formed in the NiCo alloy. Compared to the replacement sequences in pure Ni, anti-site defect sequences are observed in the alloy, which have high efficiency for both producing defects and transporting energy outside of the cascade core. These results provide insights into energy transfer processes occurring in equiatomic alloys under irradiation.

  8. A G/NARRLI Effort. Measuring the Ionization Yield of Low-Energy Nuclear Recoils in Liquid Argon

    SciTech Connect

    Joshi, Tenzing Henry Yatish

    2014-01-01

    Liquid argon has long been used for particle detection due to its attractive drift properties, ample abundance, and reasonable density. The response of liquid argon to lowenergy O(102 -1044 eV) interactions is, however, largely unexplored. Weakly interacting massive particles such as neutrinos and hypothetical dark-matter particles (WIMPs) are predicted to coherently scatter on atomic nuclei, leaving only an isolated low-energy nuclear recoil as evidence. The response of liquid argon to low-energy nuclear recoils must be studied to determine the sensitivity of liquid argon based detectors to these unobserved interactions. Detectors sensitive to coherent neutrino-nucleus scattering may be used to monitor nuclear reactors from a distance, to detect neutrinos from supernova, and to test the predicted behavior of neutrinos. Additionally, direct detection of hypothetical weakly interacting dark matter would be a large step toward understanding the substance that accounts for nearly 27% of the universe. In this dissertation I discuss a small dual-phase (liquid-gas) argon proportional scintillation counter built to study the low-energy regime and several novel calibration and characterization techniques developed to study the response of liquid argon to low-energy O(102 -104 eV) interactions.

  9. Rupture and recoil of bent-core liquid crystal filaments.

    PubMed

    Salili, S M; Ostapenko, T; Kress, O; Bailey, C; Weissflog, W; Harth, K; Eremin, A; Stannarius, R; Jákli, A

    2016-05-25

    The recoil process of free-standing liquid crystal filaments is investigated experimentally and theoretically. We focus on two aspects, the contraction speed of the filament and a spontaneously formed undulation instability. At the moment of rupture, the filaments buckle similarly to the classical Euler buckling of elastic rods. The tip velocity decays with decreasing filament length. The wavelength of buckling affinely decreases with the retracting filament tip. The energy gain related to the decrease of the total length and surface area of the filaments is mainly dissipated by layer rearrangements during thickening of the fibre. A flow back into the meniscus is relevant only in the final stage of the recoil process. We introduce a model for the quantitative description of the filament retraction speed. The dynamics of this recoil behaviour may find relevance as a model for biology-related filaments. PMID:27140824

  10. A recoil separator for nuclear astrophysics SECAR

    NASA Astrophysics Data System (ADS)

    Berg, G. P. A.; Bardayan, D. W.; Blackmon, J. C.; Chipps, K. A.; Couder, M.; Greife, U.; Hager, U.; Montes, F.; Rehm, K. E.; Schatz, H.; Smith, M. S.; Wiescher, M.; Wrede, C.; Zeller, A.

    2016-06-01

    A recoil separator SECAR has been designed to study radiative capture reactions relevant for the astrophysical rp-process in inverse kinematics for the Facility for Rare Isotope Beams (FRIB). We describe the design, layout, and ion optics of the recoil separator and present the status of the project.

  11. Measurement of the beam-recoil polarization in low-energy virtual Compton scattering from the proton

    NASA Astrophysics Data System (ADS)

    Doria, L.; Janssens, P.; Achenbach, P.; Ayerbe Gayoso, C.; Baumann, D.; Bensafa, I.; Benali, M.; Beričič, J.; Bernauer, J. C.; Böhm, R.; Bosnar, D.; Correa, L.; D'Hose, N.; Defaÿ, X.; Ding, M.; Distler, M. O.; Fonvieille, H.; Friedrich, J.; Friedrich, J. M.; Laveissière, G.; Makek, M.; Marroncle, J.; Merkel, H.; Mihovilovič, M.; Müller, U.; Nungesser, L.; Pasquini, B.; Pochodzalla, J.; Postavaru, O.; Potokar, M.; Ryckbosch, D.; Sánchez Majos, S.; Schlimme, B. S.; Seimetz, M.; Širca, S.; Tamas, G.; Van de Vyver, R.; Van Hoorebeke, L.; Van Overloop, A.; Walcher, Th.; Weinriefer, M.; A1 Collaboration

    2015-11-01

    Double-polarization observables in the reaction e ⃗p →e'p ⃗'γ have been measured at Q2=0.33 (GeV/c ) 2 . The experiment was performed at the spectrometer setup of the A1 Collaboration using the 855 MeV polarized electron beam provided by the Mainz Microtron (MAMI) and a recoil proton polarimeter. From the double-polarization observables the structure function PLT ⊥ is extracted for the first time, with the value (-15.4 ±3 .3(stat .)-2.4+1.5(syst.)) GeV-2 , using the low-energy theorem for virtual Compton scattering. This structure function provides a hitherto unmeasured linear combination of the generalized polarizabilities of the proton.

  12. Relevant energy ranges for astrophysical reaction rates

    SciTech Connect

    Rauscher, Thomas

    2010-04-15

    Effective energy windows (Gamow windows) of astrophysical reaction rates for (p,gamma), (p,n), (p,alpha), (alpha,gamma), (alpha,n), (alpha,p), (n,gamma), (n,p), and (n,alpha) on targets with 10<=Z<=83 from proton to neutron dripline are calculated using theoretical cross sections. It is shown that widely used approximation formulas for the relevant energy ranges are not valid for a large number of reactions relevant to hydrostatic and explosive nucleosynthesis. The influence of the energy dependence of the averaged widths on the location of the Gamow windows is discussed and the results are presented in tabular form.

  13. Ab Initio Molecular Dynamics Simulations of Low-Energy Recoil Events in ThO2, CeO2, and ZrO2

    SciTech Connect

    Xiao, Haiyan Y.; Zhang, Yanwen; Weber, William J.

    2012-08-13

    Ab initio molecular dynamics simulations of low-energy recoil events in ThO2, CeO2, and ZrO2 have been carried out to determine the threshold displacement energies, resulting defect configurations, dynamics of defect generation, and role of charge transfer during the process. The results reveal that, in most cases, these fluorite structure oxides exhibit a similar response to low-energy recoils. A variety of different defect configurations are created, consisting mainly of vacancies and interstitials. Charge transfer occurs during the dynamic displacement process. Local charge redistribution leads to cation and O vacancies being negatively and positively charged, respectively. Likewise, due to charge redistribution, the cation and O interstitials are less positively and negatively charged, respectively, than the ions on lattice sites in perfect MO2.

  14. Ab initio molecular dynamics simulations of low energy recoil events in ThO2, CeO2 and ZrO2

    SciTech Connect

    Xiao, Haiyan; Zhang, Yanwen; Weber, William J

    2012-01-01

    Ab initio molecular dynamics simulations of low energy recoil events in ThO2, CeO2 and ZrO2 have been carried out to determine the threshold displacement energies, resulting defect configurations, dynamics of defect generation, and role of charge transfer during the process. The results reveal that, in most cases, these fluorite structure oxides exhibit a similar response to low-energy recoils. A variety of different defect configurations are created, consisting mainly of vacancies and interstitials. Charge transfer occurs during the dynamic displacement process. Local charge redistribution leads to cation and O vacancies being negatively and positively charged, respectively. Likewise, due to charge redistribution, the cation and O interstitials are less positively and negatively charged, respectively, than the ions on lattice sites in perfect MO2.

  15. Molecular dynamics simulations of point defect production in cementite and Cr23C6 inclusions in α-iron: Effects of recoil energy and temperature

    NASA Astrophysics Data System (ADS)

    Henriksson, K. O. E.

    2016-06-01

    The number of point defects formed in spherical cementite and Cr23C6 inclusions embedded into ferrite (α-iron) has been studied and compared against cascades in pure versions of these materials (only ferrite, Fe3C, or Cr23C6 in a cell). Recoil energies between 100 eV and 3 keV and temperatures between 400 K and 1000 K were used. The overall tendency is that the number of point defects — such as antisites, vacancy and interstitials — increases with recoil energy and temperature. The radial distributions of defects indicate that the interface between inclusions and the host tend to amplify and restrict the defect formation to the inclusions themselves, when compared to cascades in pure ferrite and pure carbide cells.

  16. Measurement and model prediction of proton-recoil track length distributions in NTA film dosimeters for neutron energy spectroscopy and retrospective dose assessment

    NASA Astrophysics Data System (ADS)

    Taulbee, Timothy D.

    The goal of this research was to determine whether neutron dose reconstruction could be improved through re-analysis of historic NTA films worn by workers in the 1950 through the 1970s. To improve neutron dose reconstruction, the underlying neutron energy spectra is critical in determining the organ dose due to energy dependence of the dose conversion factor as well as the application of radiation weighting factors used in epidemiology and probability of causation calculations. Monte Carlo models of proton-recoil track length distributions were developed and benchmarked against measurement data for both NTA and Ilford films. These models, when applied to several NTA film dosimeter configurations, demonstrated that proton-recoil track length distributions change based upon incident neutron energy. The neutron energy spectra changes that result from the general work environment such as source term and shielding can subsequently be modeled to predict the response of the NTA film dosimeter. An Automatic NTA Film Analyzer has been designed and developed to determine if the difference in proton-recoil track length distributions predicted by the Monte Carlo models could be measured and whether these differences could be correlated to the incident neutron energy spectra. The design required the development of a 2D-3D hybrid track recognition algorithm for a three dimensional analysis of the NTA film in order to accurately determine the proton-recoil track length for subsequent neutron energy determination. NTA films exposed to a plutonium fluoride (PuF4) and polonium boron (PoB) calibration sources were measured and compared. The proton-recoil track lengths were used to reconstruct the incident neutron energy spectra demonstrating the functionality of the analyzer and that reconstruction of the neutron energy spectra from NTA films is feasible. These measurements were compared to the Monte Carlo models and confirmed the applicability of using models to determine the NTA

  17. Recoil Separators for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Blackmon, J. C.

    2004-10-01

    Hydrogen and helium capture reactions are important in many astrophysical environments. Measurements in inverse kinematics using recoil separators have demonstrated a particularly sensitive technique for studying low-yield capture reactions.(M. S. Smith, C. E. Rolfs, and C. A. Barnes, Nucl. Instrum. Meth. Phys. Res. A306) (1991) 233. This approach allows a low background rate to be achieved with a high detection efficiency (about 50%) for the particles of interest using a device with only modest acceptance. Recoil separators using a variety of ion-optic configurations have been installed at numerous accelerator facilities in the past decade and have been used to measure, for example, alpha capture reactions using stable beams(D. Rogalla et al.), Eur. Phys. J. 6 (1999) 471. and proton capture reactions using radioactive ion beams.(S. Bishop et al.), Phys. Rev. Lett. 90 (2003) 162501. Measurements in inverse kinematics are the only viable means for studying reactions on short-lived nuclei that are crucial for understanding stellar explosions, and a recoil separator optimized for the measurement of capture reactions with radioactive ion beams figures prominently into the design of the low energy experimental area at the Rare Isotope Accelerator (RIA). The operational requirements for such a device will be outlined, and recoil separator designs and characteristics will be presented.

  18. Towards increased policy relevance in energy modeling

    SciTech Connect

    Worrell, Ernst; Ramesohl, Stephan; Boyd, Gale

    2003-07-29

    Historically, most energy models were reasonably equipped to assess the impact of a subsidy or change in taxation, but are often insufficient to assess the impact of more innovative policy instruments. We evaluate the models used to assess future energy use, focusing on industrial energy use. We explore approaches to engineering-economic analysis that could help improve the realism and policy relevance of engineering-economic modeling frameworks. We also explore solutions to strengthen the policy usefulness of engineering-economic analysis that can be built from a framework of multi-disciplinary cooperation. We focus on the so-called ''engineering-economic'' (or ''bottom-up'') models, as they include the amount of detail that is commonly needed to model policy scenarios. We identify research priorities for the modeling framework, technology representation in models, policy evaluation and modeling of decision-making behavior.

  19. Direct measurements of (p, γ) cross-sections at astrophysical energies using radioactive beams and the Daresbury Recoil Separator

    NASA Astrophysics Data System (ADS)

    Bardayan, D. W.; Chipps, K. A.; Fitzgerald, R. P.; Blackmon, J. C.; Chae, K. Y.; Champagne, A. E.; Greife, U.; Hatarik, R.; Kozub, R. L.; Matei, C.; Moazen, B. H.; Nesaraja, C. D.; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Shriner, J. F.; Smith, M. S.

    2009-12-01

    There are a number of astrophysical environments in which the path of nucleosynthesis proceeds through proton-rich nuclei. These nuclei have traditionally not been available as beams, and thus proton-capture reactions on these nuclei could only be studied indirectly. At the Holifield Radioactive Ion Beam Facility (HRIBF), some of the first direct measurements of ( p, γ) cross-sections on radioactive beams have been made. The Daresbury Recoil Separator (DRS) has been used to separate the recoils of interest from the unreacted primary beam and identify them in an isobutane-filled ionization counter. First data from 17F ( p, γ 18Ne and 7Be ( p, γ 8B measurements are presented.

  20. Direct Measurements of (p,gamma) Cross Sections at Astrophysical Energies using Radioactive Beams and the Daresbury Recoil Separator

    SciTech Connect

    Bardayan, Daniel W; Chipps, K.; Fitzgerald, R. P.; Blackmon, Jeff C; Chae, K. Y.; Champagne, A. E.; Greife, U.; Hatarik, Robert; Kozub, R. L.; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; Pain, Steven D; Peters, W. A.; Pittman, S. T.; ShrinerJr., J. F.; Smith, Michael Scott

    2009-01-01

    There are a number of astrophysical environments in which the path of nucleosynthesis leads through proton-rich nuclei. These nuclei have traditionally not been available as beams, and thus proton-capture reactions on these nuclei could only be studied indirectly. At the Holifield Radioactive Ion Beam Facility (HRIBF), some of the first direct measurements of (p,gamma) cross sections on radioactive beams have been made. The Daresbury Recoil Separator (DRS) has been used to separate the recoils of interest from the unreacted primary beam and identify them in an isobutane-filled ionization counter. First data from 17F(p,gamma)18Ne and 7B(p,gamma)8B measurements are presented.

  1. Direct measurments of (p,gamma) cross sections at astrophysical energies using radioactive beams and the Daresbury Recoil Separator

    SciTech Connect

    Bardayan, Daniel W; Chipps, K.; Fitzgerald, R. P.; Blackmon, Jeff C; Chae, Kyung Yuk; Champagne, A. E.; Greife, Uwe; Hatarik, Robert; Kozub, R. L.; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; Pain, Steven D; Peters, W. A.; Pittman, S. T.; ShrinerJr., J. F.; Smith, Michael Scott

    2009-01-01

    There are a number of astrophysical environments in which the path of nucleosynthesis proceeds through proton-rich nuclei. Radioactive nuclei have traditionally not been available as beams, and thus proton-capture reactions on these nuclei could only be studied indirectly. At the Holifield Radioactive Ion Beam Facility (HRIBF), some of the first direct measurements of (p,g ) cross sections on radioactive beams have been made. The Daresbury Recoil Separator (DRS) has been used to separate the recoils of interest from the unreacted primary beam and identify them in an isobutane-filled ionization counter. Data from 17F(p,g )18Ne and 7Be(p,g )8B measurements are presented.

  2. Studies of electrochemical oxidation of Zircaloy nuclear reactor fuel cladding using time-of-flight-energy elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Whitlow, H. J.; Zhang, Y.; Wang, Y.; Winzell, T.; Simic, N.; Ahlberg, E.; Limbäck, M.; Wikmark, G.

    2000-03-01

    The trend towards increased fuel burn-up and higher operating temperatures in order to achieve more economic operation of nuclear power plants places demands on a better understanding of oxidative corrosion of Zircaloy (Zry) fuel rod cladding. As part of a programme to study these processes we have applied time-of-flight-energy elastic recoil detection (ToF-E ERD), electrochemical impedance measurements and scanning electron microscopy to quantitatively characterise thin-oxide films corresponding to the pre-transition oxidation regime. Oxide films of different nominal thickness in the 9-300 nm range were grown on a series of rolled Zr and Zry-2 plates by anodisation in dilute H 2SO 4 with applied voltages. The dielectric thickness of the oxide layer was determined from the electrochemical impedance measurements and the surface topography characterised by scanning electron microscopy. ToF-E ERD with a 60 MeV 127I 11+ ion beam was used to determine the oxygen content and chemical composition of the oxide layer. In the Zr samples, the oxygen content (O atom cm -2) that was determined by ERD was closely similar to the O content derived from impedance measurements from the dielectric film. The absolute agreement was well within the uncertainty associated with the stopping powers. Moreover, the measured composition of the thick oxide layers corresponded to ZrO 2 for the films thicker than 65 nm where the oxide layer was resolved in the ERD depth profile. Zry-2 samples exhibited a similar behaviour for small thickness ( ⩽130 nm) but had an enhanced O content at larger thicknesses that could be associated either with enhanced rough surface topography or porous oxide formation that was correlated with the presence of Second Phase Particles (SPP) in Zry-2. The concentration of SPP elements (Fe, Cr, Ni) in relation to Zr was the same in the outer 9×10 17 atom cm -2 of oxide as in the same thickness of metal. The results also revealed the presence of about 1 at.% 32S in the

  3. Elastic recoil detection analysis for large recoil angles (LA-ERDA)

    NASA Astrophysics Data System (ADS)

    Bogdanović Radović, I.; Steinbauer, E.; Benka, O.

    2000-09-01

    In this paper, elastic recoil detection (ERD) measurements at recoil angle of 60° using ion-induced electron emission (IEE) for particle identification are presented. In our IEE system for particle identification, recoiled target atoms and scattered projectiles penetrate a set of thin carbon foils before their energy is analyzed in a solid state detector. Particle identification is based on the fact that the total number of electrons emitted from the foils depends on the particle nuclear charge. This method is characterized by its low minimum detectable energy, which stimulated us to study ERDA at 60°. Due to collision kinematics and due to the angular dependence of the scattering cross-sections, it is expected that the sensitivity can be significantly improved. In this work, the detection efficiency of the IEE particle identification system for H recoils at energies below 1 MeV was determined. LA-ERDA measurements were performed with 4He and 12C projectiles using two different types of samples with a well-known amount and depth distribution of H atoms near the surface. Sample 1 consisted of a 50 μg/cm 2 melamine layer evaporated on a flat Si substrate, sample 2 was a Si wafer with implanted H. Sensitivity and depth resolution were measured using LA-ERDA with a recoil angle of 60° and ERDA with recoil angles of 30° and 45°. The results for different recoil geometries and projectiles are discussed and compared with theoretical predictions.

  4. Recoil by Auger electrons: Theory and application

    SciTech Connect

    Demekhin, Ph. V.; Scheit, S.; Cederbaum, L. S.

    2009-10-28

    General equations accounting for the molecular dynamics induced by the recoil of a fast Auger electron are presented. The implications of the degree of localization of the molecular orbitals of diatomic molecules involved in the Auger decay are analyzed. It is shown that the direct and exchange terms of the Auger transition matrix element may give rise to opposite signs and hence to opposite directions of the recoil momenta transferred to the nuclear vibrational motion. Consequently, these terms have a different impact on the recoil-induced nuclear dynamics in the final Auger decay state. The developed theory is applied to study the influence of the recoil on the interatomic Coulombic decay (ICD) following the K-LL Auger decay of the Ne dimer. Our calculations illustrate a significant effect of the recoil of nuclei on the computed wave packets propagating on the potential energy curve populated by the Auger decay. The corresponding final states of the Auger process decay further by ICD. We show that the recoil momentum imparted onto the nuclei modifies the computed ICD spectra considerably.

  5. Recoil separator ERNA: gas target and beam suppression

    NASA Astrophysics Data System (ADS)

    Gialanella, L.; Schürmann, D.; Strieder, F.; Di Leva, A.; De Cesare, N.; D'Onofrio, A.; Imbriani, G.; Klug, J.; Lubritto, C.; Ordine, A.; Roca, V.; Röcken, H.; Rolfs, C.; Rogalla, D.; Romano, M.; Schümann, F.; Terrasi, F.; Trautvetter, H. P.

    2004-04-01

    For improved cross-section measurements of the reaction 12C(α,γ) 16O in inverted kinematics, a recoil separator ERNA is developed at the 4 MV Dynamitron tandem accelerator in Bochum to detect directly the 16O recoils with high efficiency. The 16O recoils are produced by the 12C projectiles in a windowless 4He gas target. We report on the pressure profile of the gas target, the beam suppression by the separator, and the first observation of the 16O recoils at selected energies.

  6. Thermal recoil force, telemetry, and the Pioneer anomaly

    SciTech Connect

    Toth, Viktor T.; Turyshev, Slava G.

    2009-02-15

    Precision navigation of spacecraft requires accurate knowledge of small forces, including the recoil force due to anisotropies of thermal radiation emitted by spacecraft systems. We develop a formalism to derive the thermal recoil force from the basic principles of radiative heat exchange and energy-momentum conservation. The thermal power emitted by the spacecraft can be computed from engineering data obtained from flight telemetry, which yields a practical approach to incorporate the thermal recoil force into precision spacecraft navigation. Alternatively, orbit determination can be used to estimate the contribution of the thermal recoil force. We apply this approach to the Pioneer anomaly using a simulated Pioneer 10 Doppler data set.

  7. Determination of concentration profiles by elastic recoil detection with a ΔE-E gas telescope and high energy incident heavy ions

    NASA Astrophysics Data System (ADS)

    Stoquert, J. P.; Guillaume, G.; Hage-Ali, M.; Grob, J. J.; Ganter, C.; Siffert, P.

    1989-12-01

    The Elastic Recoil Detection (ERD) method has been used to determine the profile of a wide range of elements simultaneously in a thin layer (1μm) with a depth resolution of a few hundred Å and high sensitivity. Z separation is achieved by a ΔE(gas)-E(solid) telescope. Results for 127I (up to 240 MeV) incident ions used to profile thin films of dielectrics (SiOxNyHz), amorphous semiconductors (a-GaAs: H) and superconductors (YBaCuO, BiSrCaCuO) are reported. It has been considered previously that ERD is of interest for analysis of light elements. We show that high energy heavy incident ions extend the field of application of the ERD method to all elements with an approximately constant depth resolution and sensitivity.

  8. Relevance of the second law of thermodynamics to energy conservation

    SciTech Connect

    Not Available

    1980-01-01

    An analysis is presented of the potential relevance of the use of analytical tools based on the Second Law of thermodynamics to existing federal programs for energy conservation in the industrial, transportation, buildings, and utility sectors in the US. (LCL)

  9. Interpreting Recoil for Undergraduate Students

    ERIC Educational Resources Information Center

    Elsayed, Tarek A.

    2012-01-01

    The phenomenon of recoil is usually explained to students in the context of Newton's third law. Typically, when a projectile is fired, the recoil of the launch mechanism is interpreted as a reaction to the ejection of the smaller projectile. The same phenomenon is also interpreted in the context of the conservation of linear momentum, which is…

  10. Interpreting Recoil for Undergraduate Students

    NASA Astrophysics Data System (ADS)

    Elsayed, Tarek A.

    2012-04-01

    The phenomenon of recoil is usually explained to students in the context of Newton's third law. Typically, when a projectile is fired, the recoil of the launch mechanism is interpreted as a reaction to the ejection of the smaller projectile. The same phenomenon is also interpreted in the context of the conservation of linear momentum, which is closely related to Newton's third law. Since the actual microscopic causes of recoil differ from one problem to another, some students (and teachers) may not be satisfied with understanding recoil through the principles of conservation of linear momentum and Newton's third law. For these students, the origin of the recoil motion should be presented in more depth.

  11. Energy dependence of incomplete fusion processes in the {sup 16}O+{sup 181}Ta system: Measurement and analysis of forward-recoil-range distributions at E{sub lab}<=7 MeV/nucleon

    SciTech Connect

    Singh, Devendra P.; Unnati,; Yadav, Abhishek; Singh, B. P.; Prasad, R.; Singh, Pushpendra P.; Sharma, Manoj Kumar; Golda, K. S.; Kumar, Rakesh; Sinha, A. K.

    2010-05-15

    To study the energy dependence of incomplete fusion processes, the recoil range distributions for the reactions {sup 181}Ta({sup 16}O,xn), {sup 181}Ta({sup 16}O,pxn), {sup 181}Ta({sup 16}O,alphan), {sup 181}Ta({sup 16}O,alpha2n), {sup 181}Ta({sup 16}O,alpha3n), and {sup 181}Ta({sup 16}O,2alpha3n) have been measured at approx =81-, 90-, and 96 MeV beam energies. The disentanglement of the complete and incomplete fusion processes have been done in terms of full and partial linear momentum transfer from the projectile to the target nucleus. The measurements have been done using recoil catcher technique. The experimentally measured forward recoil range distributions have been interpreted in terms of breakup fusion model. Detailed analysis of the data indicates that incomplete fusion processes have significant contribution at energies as low as approx =5 MeV/nucleon and their contribution is found to increase with energy.

  12. Measurement of the B to Xs gammaBranching Fraction and Photon Energy Spectrum usingthe Recoil Method

    SciTech Connect

    Aubert, B.

    2007-12-04

    We present a measurement of the branching fraction and photon energy spectrum for the decay B {yields} X{sub s}{gamma} using data from the BABAR experiment. The data sample corresponds to an integrated luminosity of 210 fb{sup -1}, from which approximately 680,000 B{bar B} events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the second B meson, an isolated high-energy photon is identified. We measure {Beta}(B {yields} X{sub s}{gamma}) = (3.66 {+-} 0.85{sub stat} {+-} 0.60{sub syst}) x 10{sup -4} for photon energies E{sub {gamma}} above 1.9 GeV in the B rest frame. From the measured spectrum we calculate the first and second moments for different minimum photon energies, which are used to extract the heavy-quark parameters m{sub b} and {mu}{sub {pi}}{sup 2}. In addition, measurements of the direct CP asymmetry and isospin asymmetry are presented.

  13. A Study of Nuclear Recoils in Liquid Argon Time Projection Chamber for the Direct Detection of WIMP Dark Matter

    SciTech Connect

    Cao, Huajie

    2014-11-01

    Robust results of WIMP direct detection experiments depend on rm understandings of nuclear recoils in the detector media. This thesis documents the most comprehensive study to date on nuclear recoils in liquid argon - a strong candidate for the next generation multi-ton scale WIMP detectors. This study investigates both the energy partition from nuclear recoil energy to secondary modes (scintillation and ionization) and the pulse shape characteristics of scintillation from nuclear recoils.

  14. Recoil Based Fuel Breeding Fuel Structure

    SciTech Connect

    Popa-Simil, Liviu

    2008-07-01

    Nuclear transmutation reactions are based on the absorption of a smaller particle as neutron, proton, deuteron, alpha, etc. The resulting compound nucleus gets out of its initial lattice mainly by taking the recoil, also with help from its sudden change in chemical properties. The recoil implantation is used in correlation with thin and ultra thin materials mainly for producing radiopharmaceuticals and ultra-thin layer radioactive tracers. In nuclear reactors, the use of nano-particulate pellets could facilitate the recoil implantation for breeding, transmutation and partitioning purposes. Using enriched {sup 238}U or {sup 232}Th leads to {sup 239}Pu and {sup 233}U production while using other actinides as {sup 240}Pu, {sup 241}Am etc. leads to actinide burning. When such a lattice is immersed into a radiation resistant fluid (water, methanol, etc.), the recoiled product is transferred into the flowing fluid and removed from the hot area using a concentrator/purifier, preventing the occurrence of secondary transmutation reactions. The simulation of nuclear collision and energy transfer shows that the impacted nucleus recoils in the interstitial space creating a defect or lives small lattices. The defect diffuses, and if no recombination occurs it stops at the lattices boundaries. The nano-grains are coated in thin layer to get a hydrophilic shell to be washed by the collection liquid the particle is immersed in. The efficiency of collection depends on particle magnitude and nuclear reaction channel parameters. For {sup 239}Pu the direct recoil extraction rate is about 70% for {sup 238}UO{sub 2} grains of 5 nm diameters and is brought up to 95% by diffusion due to {sup 239}Neptunium incompatibility with Uranium dioxide lattice. Particles of 5 nm are hard to produce so a structure using particles of 100 nm have been tested. The particles were obtained by plasma sputtering in oxygen atmosphere. A novel effect as nano-cluster radiation damage robustness and cluster

  15. Accurate hydrogen depth profiling by reflection elastic recoil detection analysis

    SciTech Connect

    Verda, R. D.; Tesmer, Joseph R.; Nastasi, Michael Anthony,; Bower, R. W.

    2001-01-01

    A technique to convert reflection elastic recoil detection analysis spectra to depth profiles, the channel-depth conversion, was introduced by Verda, et al [1]. But the channel-depth conversion does not correct for energy spread, the unwanted broadening in the energy of the spectra, which can lead to errors in depth profiling. A work in progress introduces a technique that corrects for energy spread in elastic recoil detection analysis spectra, the energy spread correction [2]. Together, the energy spread correction and the channel-depth conversion comprise an accurate and convenient hydrogen depth profiling method.

  16. Recoil-α-fission and recoil-α-α-fission events observed in the reaction 48Ca + 243Am

    NASA Astrophysics Data System (ADS)

    Forsberg, U.; Rudolph, D.; Andersson, L.-L.; Di Nitto, A.; Düllmann, Ch. E.; Fahlander, C.; Gates, J. M.; Golubev, P.; Gregorich, K. E.; Gross, C. J.; Herzberg, R.-D.; Heßberger, F. P.; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, K.; Sarmiento, L. G.; Schädel, M.; Yakushev, A.; Åberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Dobaczewski, J.; Eberhardt, K.; Even, J.; Gerl, J.; Jäger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nazarewicz, W.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Shi, Yue; Thörle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Türler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2016-09-01

    Products of the fusion-evaporation reaction 48Ca + 243Am were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Amongst the detected thirty correlated α-decay chains associated with the production of element Z = 115, two recoil-α-fission and five recoil- α- α-fission events were observed. The latter five chains are similar to four such events reported from experiments performed at the Dubna gas-filled separator, and three such events reported from an experiment at the Berkeley gas-filled separator. The four chains observed at the Dubna gas-filled separator were assigned to start from the 2n-evaporation channel 289115 due to the fact that these recoil- α- α-fission events were observed only at low excitation energies. Contrary to this interpretation, we suggest that some of these recoil- α- α-fission decay chains, as well as some of the recoil- α- α-fission and recoil-α-fission decay chains reported from Berkeley and in this article, start from the 3n-evaporation channel 288115.

  17. Recoil ion charge state distribution following the beta(sup +) decay of {sup 21}Na

    SciTech Connect

    Scielzo, Nicholas D.; Freedman, Stuart J.; Fujikawa, Brian K.; Vetter, Paul A.

    2003-01-03

    The charge state distribution following the positron decay of 21Na has been measured, with a larger than expected fraction of the daughter 21Ne in positive charge states. No dependence on either the positron or recoil nucleus energy is observed. The data is compared to a simple model based on the sudden approximation. Calculations suggest a small but important contribution from recoil ionization has important consequences for precision beta decay correlation experiments detecting recoil ions.

  18. Force optimized recoil control system

    NASA Astrophysics Data System (ADS)

    Townsend, P. E.; Radkiewicz, R. J.; Gartner, R. F.

    1982-05-01

    Reduction of the recoil force of high rate of fire automatic guns was proven effective. This system will allow consideration of more powerful guns for use in both helicopter and armored personnel carrier applications. By substituting the large shock loads of firing guns with a nearly constant force, both vibration and fatigue problems that prevent mounting of powerful automatic guns is eliminated.

  19. Australian Science and Technology with Relevance to Beamed Energy Propulsion

    SciTech Connect

    Froning, H. David Jr

    2008-04-28

    Although Australia has no Beamed Energy Propulsion programs at the present time, it is accomplishing significant scientific and technological activity that is of potential relevance to Beamed Energy Propulsion (BEP). These activities include: continual upgrading and enhancement of the Woomera Test Facility, Which is ideal for development and test of high power laser or microwave systems and the flight vehicles they would propel; collaborative development and test, with the US and UK of hypersonic missiles that embody many features needed by beam-propelled flight vehicles; hypersonic air breathing propulsion systems that embody inlet-engine-nozzle features needed for beam-riding agility by air breathing craft; and research on specially conditioned EM fields that could reduce beamed energy lost during atmospheric propagation.

  20. Inverse Kinematics Studies of Intermediate-Energy Reactions Relevant for SEE and Medical Problems

    NASA Astrophysics Data System (ADS)

    Aichelin, J.; Bargholtz, Ch.; Blomgren, J.; Budzanowski, A.; Chubarov, M.; Czech, B.; Ekström, C.; Gerén, L.; Jakobsson, B.; Kolozhvari, A.; Lozhkin, O.; Murin, Yu.; Nomokonov, P.; Olsson, N.; Persson, H.; Pljuschev, V.; Skwirczynska, I.; Tang, H. H. K.; Tegnér, P.-E.; Westerberg, L.; Zartova, I.; Zubkov, M.; Watanabe, Y.

    2005-05-01

    The lack of systematic experimental checks on the intermediate-energy nuclear model simulations of heavily ionizing recoils from nucleon-nucleus collisions — critical inputs for the Single Event Effect analysis of microelectronics and dosimetry calculations including high-LET components in the cancer tumor radiation therapy — has been a primary motivation for a new experiment planned at the CELSIUS nuclear storage ring of The Svedberg Laboratory, Uppsala, Sweden. Details of the experiment and the first results from a feasibility study are presented here.

  1. Stimulated Rayleigh resonances and recoil-induced effects

    SciTech Connect

    Courtois, J.Y.; Grynberg, G.

    1996-12-31

    The organization of this paper is as follows. We present in Section II the basic ideas about stimulated Rayleigh scattering by considering more particularly the situation where it arises from a relaxation process going on in the material system, and we describe a few experimental observations made in atomic and molecular physics. We then consider the case of nonstationary two-level atoms, and we derive the shape and characteristics of the recoil-induced resonances (Section III). In particular, we show that these resonances can be interpreted either as originating from a stimulated Rayleigh effect or as a stimulated Raman phenomena between atomic energy-momentum states having different momenta. Finally, to make a clear distinction between the physical phenomena that pertain directly to recoil-induced processes (i.e., that actually permit the measurement of the photon recoil) and those for which the introduction of the recoil constitutes a mere physical convenience, we review in Section IV some indisputable manifestations of the photon recoil in atomic and molecular physics. 92 refs., 22 figs.

  2. Calculation of recoil implantation profiles using known range statistics

    NASA Technical Reports Server (NTRS)

    Fung, C. D.; Avila, R. E.

    1985-01-01

    A method has been developed to calculate the depth distribution of recoil atoms that result from ion implantation onto a substrate covered with a thin surface layer. The calculation includes first order recoils considering projected range straggles, and lateral straggles of recoils but neglecting lateral straggles of projectiles. Projectile range distributions at intermediate energies in the surface layer are deduced from look-up tables of known range statistics. A great saving of computing time and human effort is thus attained in comparison with existing procedures. The method is used to calculate recoil profiles of oxygen from implantation of arsenic through SiO2 and of nitrogen from implantation of phosphorus through Si3N4 films on silicon. The calculated recoil profiles are in good agreement with results obtained by other investigators using the Boltzmann transport equation and they also compare very well with available experimental results in the literature. The deviation between calculated and experimental results is discussed in relation to lateral straggles. From this discussion, a range of surface layer thickness for which the method applies is recommended.

  3. Nuclear Recoil Calibration of DarkSide-50

    NASA Astrophysics Data System (ADS)

    Edkins, Erin; DarkSide Collaboration

    2016-03-01

    DarkSide-50 dark matter experiment is a liquid argon time projection chamber (TPC) surrounded by a liquid scintillator active neutron veto, designed for the direct detection of Weakly Interacting Massive Particles (WIMPs). The success of such an experiment is dependent upon a detailed understanding of both the expected signal and backgrounds, achieved using radioactive calibration sources of known energies. Nuclear recoils provide a measurement of both the expected signal and the most dangerous background, as nuclear recoils from neutrons cannot be distinguished from a dark matter signal on an event-by-event basis in the TPC. In this talk, I will present the DS-50 calibration system, and analysis of the results of the calibration of DarkSide-50 to nuclear recoils using radioactive neutron sources. See also the DS-50 presentations by X. Xiang and G. Koh.

  4. Accounting for Recoil Effects in Geochronometers: A New Model Approach

    NASA Astrophysics Data System (ADS)

    Lee, V. E.; Huber, C.

    2012-12-01

    dated grain is a major control on the magnitude of recoil loss, the first feature is the ability to calculate recoil effects on isotopic compositions for realistic, complex grain shapes and surface roughnesses. This is useful because natural grains may have irregular shapes that do not conform to simple geometric descriptions. Perhaps more importantly, the surface area over which recoiled nuclides are lost can be significantly underestimated when grain surface roughness is not accounted for, since the recoil distances can be of similar characteristic lengthscales to surface roughness features. The second key feature is the ability to incorporate dynamical geologic processes affecting grain surfaces in natural settings, such as dissolution and crystallization. We describe the model and its main components, and point out implications for the geologically-relevant chronometers mentioned above.

  5. Retention studies of recoiling daughter nuclides of 225Ac in polymer vesicles.

    PubMed

    Wang, G; de Kruijff, R M; Rol, A; Thijssen, L; Mendes, E; Morgenstern, A; Bruchertseifer, F; Stuart, M C A; Wolterbeek, H T; Denkova, A G

    2014-02-01

    Alpha radionuclide therapy is steadily gaining importance and a large number of pre-clinical and clinical studies have been carried out. However, due to the recoil effects the daughter recoil atoms, most of which are alpha emitters as well, receive energies that are much higher than the energies of chemical bonds resulting in decoupling of the radionuclide from common targeting agents. Here, we demonstrate that polymer vesicles (i.e. polymersomes) can retain recoiling daughter nuclei based on an experimental study examining the retention of (221)Fr and (213)Bi when encapsulating (225)Ac. PMID:24374072

  6. Retention studies of recoiling daughter nuclides of 225Ac in polymer vesicles.

    PubMed

    Wang, G; de Kruijff, R M; Rol, A; Thijssen, L; Mendes, E; Morgenstern, A; Bruchertseifer, F; Stuart, M C A; Wolterbeek, H T; Denkova, A G

    2014-02-01

    Alpha radionuclide therapy is steadily gaining importance and a large number of pre-clinical and clinical studies have been carried out. However, due to the recoil effects the daughter recoil atoms, most of which are alpha emitters as well, receive energies that are much higher than the energies of chemical bonds resulting in decoupling of the radionuclide from common targeting agents. Here, we demonstrate that polymer vesicles (i.e. polymersomes) can retain recoiling daughter nuclei based on an experimental study examining the retention of (221)Fr and (213)Bi when encapsulating (225)Ac.

  7. Direct Measurement of Photon Recoil from a Levitated Nanoparticle

    NASA Astrophysics Data System (ADS)

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-06-01

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency Ω0 , this measurement backaction adds quanta ℏΩ0 to the oscillator's energy at a rate Γrecoil, a process called photon recoil heating, and sets bounds to coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure Γrecoil. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to microkelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for the realization of quantum ground-state cooling protocols and the measurement of ultrasmall forces.

  8. Direct Measurement of Photon Recoil from a Levitated Nanoparticle.

    PubMed

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-06-17

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency Ω_{0}, this measurement backaction adds quanta ℏΩ_{0} to the oscillator's energy at a rate Γ_{recoil}, a process called photon recoil heating, and sets bounds to coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure Γ_{recoil}. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to microkelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for the realization of quantum ground-state cooling protocols and the measurement of ultrasmall forces. PMID:27367388

  9. A recoil detector for the measurement of antiproton-proton elastic scattering at angles close to 90°

    NASA Astrophysics Data System (ADS)

    Hu, Q.; Bechstedt, U.; Gillitzer, A.; Grzonka, D.; Khoukaz, A.; Klehr, F.; Lehrach, A.; Prasuhn, D.; Ritman, J.; Sefzick, T.; Stockmanns, T.; Täschner, A.; Wuestner, P.; Xu, H.

    2014-10-01

    The design and construction of a recoil detector for the measurement of recoil protons of antiproton-proton elastic scattering at scattering angles close to are described. The performance of the recoil detector has been tested in the laboratory with radioactive sources and at COSY with proton beams by measuring proton-proton elastic scattering. The results of laboratory tests and commissioning with beam are presented. Excellent energy resolution and proper working performance of the recoil detector validate the conceptual design of the KOALA experiment at HESR to provide the cross section data needed to achieve a precise luminosity determination at the PANDA experiment.

  10. The mechanics of elastic loading and recoil in anuran jumping.

    PubMed

    Astley, Henry C; Roberts, Thomas J

    2014-12-15

    Many animals use catapult mechanisms to produce extremely rapid movements for escape or prey capture, resulting in power outputs far beyond the limits of muscle. In these catapults, muscle contraction loads elastic structures, which then recoil to release the stored energy extremely rapidly. Many arthropods employ anatomical 'catch mechanisms' to lock the joint in place during the loading period, which can then be released to allow joint motion via elastic recoil. Jumping vertebrates lack a clear anatomical catch, yet face the same requirement to load the elastic structure prior to movement. There are several potential mechanisms to allow loading of vertebrate elastic structures, including the gravitational load of the body, a variable mechanical advantage, and moments generated by the musculature of proximal joints. To test these hypothesized mechanisms, we collected simultaneous 3D kinematics via X-ray Reconstruction of Moving Morphology (XROMM) and single-foot forces during the jumps of three Rana pipiens. We calculated joint mechanical advantage, moment and power using inverse dynamics at the ankle, knee, hip and ilio-sacral joints. We found that the increasing proximal joint moments early in the jump allowed for high ankle muscle forces and elastic pre-loading, and the subsequent reduction in these moments allowed the ankle to extend using elastic recoil. Mechanical advantage also changed throughout the jump, with the muscle contracting against a poor mechanical advantage early in the jump during loading and a higher mechanical advantage late in the jump during recoil. These 'dynamic catch mechanisms' serve to resist joint motion during elastic loading, then allow it during elastic recoil, functioning as a catch mechanism based on the balance and orientation of forces throughout the limb rather than an anatomical catch. PMID:25520385

  11. The mechanics of elastic loading and recoil in anuran jumping.

    PubMed

    Astley, Henry C; Roberts, Thomas J

    2014-12-15

    Many animals use catapult mechanisms to produce extremely rapid movements for escape or prey capture, resulting in power outputs far beyond the limits of muscle. In these catapults, muscle contraction loads elastic structures, which then recoil to release the stored energy extremely rapidly. Many arthropods employ anatomical 'catch mechanisms' to lock the joint in place during the loading period, which can then be released to allow joint motion via elastic recoil. Jumping vertebrates lack a clear anatomical catch, yet face the same requirement to load the elastic structure prior to movement. There are several potential mechanisms to allow loading of vertebrate elastic structures, including the gravitational load of the body, a variable mechanical advantage, and moments generated by the musculature of proximal joints. To test these hypothesized mechanisms, we collected simultaneous 3D kinematics via X-ray Reconstruction of Moving Morphology (XROMM) and single-foot forces during the jumps of three Rana pipiens. We calculated joint mechanical advantage, moment and power using inverse dynamics at the ankle, knee, hip and ilio-sacral joints. We found that the increasing proximal joint moments early in the jump allowed for high ankle muscle forces and elastic pre-loading, and the subsequent reduction in these moments allowed the ankle to extend using elastic recoil. Mechanical advantage also changed throughout the jump, with the muscle contracting against a poor mechanical advantage early in the jump during loading and a higher mechanical advantage late in the jump during recoil. These 'dynamic catch mechanisms' serve to resist joint motion during elastic loading, then allow it during elastic recoil, functioning as a catch mechanism based on the balance and orientation of forces throughout the limb rather than an anatomical catch.

  12. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C; Yonas, Gerold

    2013-11-12

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  13. Gas powered fluid gun with recoil mitigation

    DOEpatents

    Grubelich, Mark C.; Yonas, Gerold

    2016-03-01

    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  14. Photon Recoil Momentum in Dispersive Media

    SciTech Connect

    Campbell, Gretchen K.; Leanhardt, Aaron E.; Mun, Jongchul; Boyd, Micah; Streed, Erik W.; Ketterle, Wolfgang; Pritchard, David E.

    2005-05-06

    A systematic shift of the photon recoil momentum due to the index of refraction of a dilute gas of atoms has been observed. The recoil frequency was determined with a two-pulse light grating interferometer using near-resonant laser light. The results show that the recoil momentum of atoms caused by the absorption of a photon is n({Dirac_h}/2{pi})k, where n is the index of refraction of the gas and k is the vacuum wave vector of the photon. This systematic effect must be accounted for in high-precision atom interferometry with light gratings.

  15. First measurement of the ionization yield of nuclear recoils in liquid argon

    SciTech Connect

    Joshi, T.; Sangiorgio, Samuele; Bernstein, A.; Foxe, Michael P.; Hagmann, Chris; Jovanovic, Igor; Kazkaz, K.; Mozin, Vladimir V.; Norman, E. B.; Pereverzev, S. V.; Rebassoo, Finn O.; Sorensen, Peter F.

    2014-05-01

    Liquid phase argon has long been used as a target medium for particle detection via scintillation light. Recently there has been considerable interest in direct detection of both hypothetical darkmatter particles and coherent elastic neutrino nucleus scattering. These as-yet unobserved neutral particle interactions are expected to result in a recoiling argon atom O(keV), generally referred to in the literature as a nuclear recoil. This prompts the question of the available electromagnetic signal in a liquid argon detector. In this Letter we report the first measurement of the ionization yield (Qy), detected electrons per unit energy, resulting from nuclear recoils in liquid argon, measured at 6.7 keV. This is also the lowest energy measurement of nuclear recoils in liquid argon.

  16. A telescope proton recoil spectrometer for fast neutron beam-lines

    NASA Astrophysics Data System (ADS)

    Cazzaniga, C.; Rebai, M.; Tardocchi, M.; Croci, G.; Nocente, M.; Ansell, S.; Frost, C. D.; Gorini, G.

    2015-07-01

    Fast neutron measurements were performed on the VESUVIO beam-line at the ISIS spallation source using a new telescope proton recoil spectrometer. Neutrons interact on a plastic target. Proton production is mainly due to elastic scattering on hydrogen nuclei and secondly due to interaction with carbon nuclei. Recoil protons are measured by a proton spectrometer, which uses in coincidence a 2.54 cm thick YAP scintillator and a 500μm thick silicon detector, measuring the full proton recoil energy and the partial deposited energy in transmission, respectively. Recoil proton spectroscopy measurements (up to Ep = 60MeV) have been interpreted by using Monte Carlo simulations of the beam-line. This instrument is of particular interest for the characterization of the ChipIr beam-line at ISIS, which was designed to feature an atmospheric-like neutron spectrum for the irradiation of micro-electronics.

  17. Theoretical research relevant to medium energy upgrades and experiments

    SciTech Connect

    Goldman, T.; Benesh, C.; Carlson, J.

    1996-07-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This work provides theoretical research results for sources of pions, neutrons, neutrinos and heavy ions. The authors have undertaken specific calculations in neutrino-nucleus scattering and to analyze constraints on exotic decays relevant to the study of neutrino oscillations. They have also performed calculations regarding neutrino cosmology and astrophysics relevant to the experimental study of neutrino masses. They analyzed the constraints of data on T-violation in neutron decay and the nucleon-nucleon (NN) interaction which will be important for the understanding of experiments with cold and ultra-cold neutrons. They completed several specific calculations which were essential to predict (pion, kaon) hypernuclear production and pion-induced reactions studying baryonic resonances. They also calculated the nuclear spectroscopy of nuclei far from stability that can be studied experimentally.

  18. Energy efficiency in waste-to-energy and its relevance with regard to climate control.

    PubMed

    Ragossnig, Arne M; Wartha, Christian; Kirchner, Andreas

    2008-02-01

    This article focuses on systematically highlighting the ways to optimize waste-to-energy plants in terms of their energy efficiency as an indicator of the positive effect with regard to climate control. Potentials for increasing energy efficiency are identified and grouped into categories. The measures mentioned are illustrated by real-world examples. As an example, district cooling as a means for increasing energy efficiency in the district heating network of Vienna is described. Furthermore a scenario analysis shows the relevance of energy efficiency in waste management scenarios based on thermal treatment of waste with regard to climate control. The description is based on a model that comprises all relevant processes from the collection and transportation up to the thermal treatment of waste. The model has been applied for household-like commercial waste. The alternatives compared are a combined heat and power incinerator, which is being introduced in many places as an industrial utility boiler or in metropolitan areas where there is a demand for district heating and a classical municipal solid waste incinerator producing solely electrical power. For comparative purposes a direct landfilling scenario has been included in the scenario analysis. It is shown that the energy efficiency of thermal treatment facilities is crucial to the quantity of greenhouse gases emitted.

  19. Transport of Radioactive Material by Alpha Recoil

    SciTech Connect

    Icenhour, A.S.

    2005-05-19

    The movement of high-specific-activity radioactive particles (i.e., alpha recoil) has been observed and studied since the early 1900s. These studies have been motivated by concerns about containment of radioactivity and the protection of human health. Additionally, studies have investigated the potential advantage of alpha recoil to effect separations of various isotopes. This report provides a review of the observations and results of a number of the studies.

  20. Measurement of neutron and charged particle contamination in high energy medical therapy x-ray beams using recoil track registration in polycarbonate foils

    SciTech Connect

    Sanders, M. E.; Morgan, K. Z.; McGinley, P. H.

    1980-01-01

    The production of photoneutrons and high-energy charged particles by betatrons and linear accelerators used in radiotherapy is measured. It is concluded there exists sufficient contamination in high-energy x-ray beams to be a consideration in certain radiotherapy situations. (ACR)

  1. Regional characteristics relevant to advanced technology cogeneration development. [industrial energy

    NASA Technical Reports Server (NTRS)

    Manvi, R.

    1981-01-01

    To assist DOE in establishing research and development funding priorities in the area of advanced energy conversion technoloy, researchers at the Jet Propulsion Laboratory studied those specific factors within various regions of the country that may influence cogeneration with advanced energy conversion systems. Regional characteristics of advanced technology cogeneration possibilities are discussed, with primary emphasis given to coal derived fuels. Factors considered for the study were regional industry concentration, purchased fuel and electricity prices, environmental constraints, and other data of interest to industrial cogeneration.

  2. Spallation recoil and age of presolar grains in meteorites

    NASA Astrophysics Data System (ADS)

    Ott, U.; Begemann, F.

    2000-01-01

    We have determined the recoil losses from silicon carbide grain size fractions of spallation neon produced by irradiation with 1.6 GeV protons. During the irradiation the SiC grains were dispersed in paraffin wax in order to avoid re-implantation into neighboring grains. Analysis for spallogenic 21Ne of grain size separates in the size range 0.3 μm to 6 μm and comparison with the 22Na activity of the SiC+paraffin mixture indicates an effective recoil range of 2-3 μm with no apparent effect from acid treatments such as routinely used in the isolation of meteoritic SiC grains. Our results indicate that the majority of presolar SiC grains in primitive meteorites, which are ~μm-sized, will have lost essentially all spallogenic Ne produced by cosmic ray interaction in the interstellar medium. This argues against the validity of previously published presolar ages of Murchison SiC (~10 to ~130 Ma; increasing with grain size; Lewis et al., 1994), where recoil losses had been based on calculated recoil energies. It is argued that the observed variations in meteoritic SiC grain size fractions of 21Ne/22Ne ratios are more likely due to the effects of nucleosynthesis in the He burning shell of the parent AGB stars which imposes new boundary conditions on nuclear parameters and stellar models. It is suggested that spallation-Xe produced on the abundant Ba and REE in presolar SiC, rather than spallogenic Ne, may be a promising approach to the presolar age problem. There is a hint in the currently available Xe data (Lewis et al., 1994) that the large (>1 μm) grains may be younger than the smaller (<1 μm) ones.

  3. Hands-on-Entropy, Energy Balance with Biological Relevance

    NASA Astrophysics Data System (ADS)

    Reeves, Mark

    2015-03-01

    Entropy changes underlie the physics that dominates biological interactions. Indeed, introductory biology courses often begin with an exploration of the qualities of water that are important to living systems. However, one idea that is not explicitly addressed in most introductory physics or biology textbooks is important contribution of the entropy in driving fundamental biological processes towards equilibrium. From diffusion to cell-membrane formation, to electrostatic binding in protein folding, to the functioning of nerve cells, entropic effects often act to counterbalance deterministic forces such as electrostatic attraction and in so doing, allow for effective molecular signaling. A small group of biology, biophysics and computer science faculty have worked together for the past five years to develop curricular modules (based on SCALEUP pedagogy). This has enabled students to create models of stochastic and deterministic processes. Our students are first-year engineering and science students in the calculus-based physics course and they are not expected to know biology beyond the high-school level. In our class, they learn to reduce complex biological processes and structures in order model them mathematically to account for both deterministic and probabilistic processes. The students test these models in simulations and in laboratory experiments that are biologically relevant such as diffusion, ionic transport, and ligand-receptor binding. Moreover, the students confront random forces and traditional forces in problems, simulations, and in laboratory exploration throughout the year-long course as they move from traditional kinematics through thermodynamics to electrostatic interactions. This talk will present a number of these exercises, with particular focus on the hands-on experiments done by the students, and will give examples of the tangible material that our students work with throughout the two-semester sequence of their course on introductory

  4. A Double Scattering Analytical Model For Elastic Recoil Detection Analysis

    SciTech Connect

    Barradas, N. P.; Lorenz, K.; Alves, E.; Darakchieva, V.

    2011-06-01

    We present an analytical model for calculation of double scattering in elastic recoil detection measurements. Only events involving the beam particle and the recoil are considered, i.e. 1) an ion scatters off a target element and then produces a recoil, and 2) an ion produces a recoil which then scatters off a target element. Events involving intermediate recoils are not considered, i.e. when the primary ion produces a recoil which then produces a second recoil. If the recoil element is also present in the stopping foil, recoil events in the stopping foil are also calculated. We included the model in the standard code for IBA data analysis NDF, and applied it to the measurement of hydrogen in Si.

  5. Proton-recoil detectors for time-of-flight measurements of neutrons with kinetic energies from some tens of keV to a few MeV

    NASA Astrophysics Data System (ADS)

    Beyer, R.; Grosse, E.; Heidel, K.; Hutsch, J.; Junghans, A. R.; Klug, J.; Légrády, D.; Nolte, R.; Röttger, S.; Sobiella, M.; Wagner, A.

    2007-06-01

    For experiments at the superconducting electron accelerator ELBE, where neutrons in the kinetic energy region from some tens of keV to a few MeV will be produced by bremsstrahlung, neutron-time-of-flight detectors have been developed. These detectors are made from the plastic scintillator material EJ-200. Efficiency calibration showed more than 10% efficiency for kinetic energies down to 30 keV. The calibration was done at the "accelerator facility for fast neutron research" at Physikalisch-Technische Bundesanstalt in Braunschweig, using pulsed quasi-monoenergetic neutron fields with a well-determined fluence. The low detection threshold was obtained by coincident readout of two Hamamatsu R2059-01 photomultiplier tubes per scintillator and by triggering just below the single-photo-electron peak of these photomultiplier tubes, which additionally gives a well-reproduceable detection threshold.

  6. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    DOE PAGESBeta

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0more » to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.« less

  7. Measurement of scintillation and ionization yield and scintillation pulse shape from nuclear recoils in liquid argon

    NASA Astrophysics Data System (ADS)

    Cao, H.; Alexander, T.; Aprahamian, A.; Avetisyan, R.; Back, H. O.; Cocco, A. G.; Dejongh, F.; Fiorillo, G.; Galbiati, C.; Grandi, L.; Guardincerri, Y.; Kendziora, C.; Lippincott, W. H.; Love, C.; Lyons, S.; Manenti, L.; Martoff, C. J.; Meng, Y.; Montanari, D.; Mosteiro, P.; Olvitt, D.; Pordes, S.; Qian, H.; Rossi, B.; Saldanha, R.; Sangiorgio, S.; Siegl, K.; Strauss, S. Y.; Tan, W.; Tatarowicz, J.; Walker, S.; Wang, H.; Watson, A. W.; Westerdale, S.; Yoo, J.; Scene Collaboration

    2015-05-01

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V /cm . For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V /cm . We also report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from Krm83 internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni ) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  8. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    SciTech Connect

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  9. Experimental Concept for a Precision Measurement of Nuclear Recoil Ionization Yields for Low Mass WIMP Searches

    NASA Astrophysics Data System (ADS)

    Saab, T.; Figueroa-Feliciano, E.

    2016-07-01

    Understanding the response of dark matter detectors at the lowest recoil energies is important for correctly interpreting data from current experiments or predicting the sensitivity of future experiments to low mass weakly interacting massive particles. In particular, the ionization yield is essential for determining the correct recoil energy of candidate nuclear recoil events; however, few measurements in cryogenic crystals exist below 1 keV. Using the voltage-assisted calorimetric ionization detection technique with a mono-energetic neutron source, we show that it is possible to determine the ionization yield in cryogenic crystals down to an energy to 100 eV. This measurement will also determine the statistics of ionization production at these low energies.

  10. Measurement of nuclear recoil quenching factors in CaWO 4

    NASA Astrophysics Data System (ADS)

    Jagemann, Th.; Feilitzsch, F. v.; Hagn, H.; Jochum, J.; Potzel, W.; Rau, W.; Stark, M.; Westphal, W.

    2006-11-01

    The CRESST experiment, aiming at the direct detection of WIMPs via nuclear recoils, is currently using scintillating CaWO4 crystals. The WIMP-nucleus cross section for elastic scattering as well as the scintillation efficiency differ considerably for recoils from Ca, W and O in these crystals. Therefore a discriminating detector calibration is essential in order to improve WIMP parameter claims. At the tandem accelerator of the Maier-Leibnitz-Laboratory (MLL) in Garching, Germany, a neutron scattering facility is operated for the determination of the individual quenching factors (QF) in the bulk of a CaWO4 crystal to better understand the detector response to neutron background and a possible WIMP signal. First measurements at room temperature reveal QF(O) = 7.8 ± 0.3% (recoil energy 1.0-2.2 MeV), QF(Ca) = 6.3 ± 1.6% (recoil energy 0.4-1 MeV), QF(W) < 3.0% (2σ, recoil energy 0.1 MeV).

  11. Recoil separator ERNA: ion beam specifications

    NASA Astrophysics Data System (ADS)

    Rogalla, D.; Aliotta, M.; Barnes, C. A.; Campajola, L.; D'Onofrio, A.; Fritz, E.; Gialanella, L.; Greife, U.; Imbriani, G.; Ordine, A.; Ossmann, J.; Roca, V.; Rolfs, C.; Romano, M.; Sabbarese, C.; Schürmann, D.; Schümann, F.; Strieder, F.; Theis, S.; Terrasi, F.; Trautvetter, H. P.

    For improved measurements of the key astrophysical reaction 12C(α,γ)16O in inverted kinematics, a recoil separator ERNA is being developed at the 4 MV Dynamitron tandem accelerator in Bochum to detect directly the 16O recoils with about 50% efficiency. Calculations of the ion beam optics including all filtering and focusing elements of ERNA are presented. Since the 12C projectiles and the 16O recoils have essentially the same momentum, and since the 12C ion beam emerging from the accelerator passes through a momentum filter (analysing magnet), the 12C ion beam must be as free as possible from 16O contamination for ERNA to succeed. In the present work, the 16O contamination was reduced from a level of 1 × 10-11 to a level below 2 × 10-29 by the installation of Wien filters both before and after the analysing magnet. The measurement of these and other beam specifications involved other parts of the final ERNA layout - sequentially a Wien filter, a 60˚ dipole magnet, another Wien filter, and a ΔE-E telescope. The setup led to a measured suppression factor of 5 × 10-18 for the 12C ion beam. The experiments also indicate that an almost free choice of the charge state for the 16O recoils is possible in the separator.

  12. Proton recoil scintillator neutron rem meter

    DOEpatents

    Olsher, Richard H.; Seagraves, David T.

    2003-01-01

    A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

  13. Revealing compressed stops using high-momentum recoils

    DOE PAGESBeta

    Macaluso, Sebastian; Park, Michael; Shih, David; Tweedie, Brock

    2016-03-22

    In this study, searches for supersymmetric top quarks at the LHC have been making great progress in pushing sensitivity out to higher mass, but are famously plagued by gaps in coverage around lower-mass regions where the decay phase space is closing off. Within the common stop-NLSP/neutralino-LSP simplified model, the line in the mass plane where there is just enough phase space to produce an on-shell top quark remains almost completely unconstrained. Here, we show that is possible to define searches capable of probing a large patch of this difficult region, with S/B ~ 1 and significances often well beyond 5σ.more » The basic strategy is to leverage the large energy gain of LHC Run 2, leading to a sizable population of stop pair events recoiling against a hard jet. The recoil not only re-establishes a ET, but also leads to a distinctive anti-correlation between the ET and the recoil jet transverse vectors when the stops decay all-hadronically. Accounting for jet combinatorics, backgrounds, and imperfections in ET measurements, we estimate that Run 2 will already start to close the gap in exclusion sensitivity with the first few 10s of fb–1. By 300 fb–1, exclusion sensitivity may extend from stop masses of 550 GeV on the high side down to below 200 GeV on the low side, approaching the “stealth” point at mt¯ = mt and potentially overlapping with limits from tt¯ cross section and spin correlation measurements.« less

  14. Revealing compressed stops using high-momentum recoils

    NASA Astrophysics Data System (ADS)

    Macaluso, Sebastian; Park, Michael; Shih, David; Tweedie, Brock

    2016-03-01

    Searches for supersymmetric top quarks at the LHC have been making great progress in pushing sensitivity out to higher mass, but are famously plagued by gaps in coverage around lower-mass regions where the decay phase space is closing off. Within the common stop-NLSP/neutralino-LSP simplified model, the line in the mass plane where there is just enough phase space to produce an on-shell top quark remains almost completely unconstrained. Here, we show that is possible to define searches capable of probing a large patch of this difficult region, with S/B ˜ 1 and significances often well beyond 5 σ. The basic strategy is to leverage the large energy gain of LHC Run 2, leading to a sizable population of stop pair events recoiling against a hard jet. The recoil not only re-establishes a [InlineMediaObject not available: see fulltext.] signature, but also leads to a distinctive anti-correlation between the [InlineMediaObject not available: see fulltext.] and the recoil jet transverse vectors when the stops decay all-hadronically. Accounting for jet combinatorics, backgrounds, and imperfections in [InlineMediaObject not available: see fulltext.] measurements, we estimate that Run 2 will already start to close the gap in exclusion sensitivity with the first few 10s of fb-1. By 300 fb-1, exclusion sensitivity may extend from stop masses of 550 GeV on the high side down to below 200 GeV on the low side, approaching the "stealth" point at {m}_{overline{t}}={m}_t and potentially overlapping with limits from toverline{t} cross section and spin correlation measurements.

  15. Decay data measurements on 213Bi using recoil atoms.

    PubMed

    Marouli, M; Suliman, G; Pommé, S; Ammel, R Van; Jobbágy, V; Stroh, H; Dikmen, H; Paepen, J; Dirican, A; Bruchertseifer, F; Apostolidis, C; Morgenstern, A

    2013-04-01

    In this work, (213)Bi has been separated from an open (225)Ac source by collecting recoil atoms onto a glass plate in vacuum. The activity of such recoil sources has been measured as a function of time, using an ion-implanted planar Si detector in quasi-2π geometry. From these measurements, a new half-life value of T1/2((213)Bi)=45.62 (6)min was derived. Additionally, high-resolution alpha-spectrometry measurements were performed at a solid angle of 0.4% of 4πsr, to verify the energies and emission probabilities of the α-emissions from (213)Bi. Using (225)Ac, (221)Fr, (217)At and (213)Po peaks as reference peaks, the measured (213)Bi α-peak energies at Eα,0=5878 (4)keV and Eα,1=5560 (4)keV were about 10keV higher than validated data. The relative α-particle emission probabilities of (213)Bi, Pα,0=0.9155 (11) and Pα,1=0.0845 (11), and the (213)Bi alpha branching factor, Pα=1-Pβ=2.140 (10)%, are compatible with recommended values, but have a higher accuracy.

  16. RELATIVISTIC SUPPRESSION OF BLACK HOLE RECOILS

    SciTech Connect

    Kesden, Michael; Sperhake, Ulrich; Berti, Emanuele

    2010-06-01

    Numerical-relativity simulations indicate that the black hole produced in a binary merger can recoil with a velocity up to v {sub max} {approx_equal} 4000 km s{sup -1} with respect to the center of mass of the initial binary. This challenges the paradigm that most galaxies form through hierarchical mergers, yet retain supermassive black holes (SBHs) at their centers despite having escape velocities much less than v {sub max}. Interaction with a circumbinary disk can align the binary black hole spins with their orbital angular momentum, reducing the recoil velocity of the final black hole produced in the subsequent merger. However, the effectiveness of this alignment depends on highly uncertain accretion flows near the binary black holes. In this paper, we show that if the spin S {sub 1} of the more massive binary black hole is even partially aligned with the orbital angular momentum L, relativistic spin precession on sub-parsec scales can align the binary black hole spins with each other. This alignment significantly reduces the recoil velocity even in the absence of gas. For example, if the angle between S {sub 1} and L at large separations is 10{sup 0} while the second spin S {sub 2} is isotropically distributed, the spin alignment discussed in this paper reduces the median recoil from 864 km s{sup -1} to 273 km s{sup -1} for maximally spinning black holes with a mass ratio of 9/11. This reduction will greatly increase the fraction of galaxies retaining their SBHs.

  17. Study of nuclear recoils in liquid argon with monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Regenfus, C.; Allkofer, Y.; Amsler, C.; Creus, W.; Ferella, A.; Rochet, J.; Walter, M.

    2012-07-01

    In the framework of developments for liquid argon dark matter detectors we assembled a laboratory setup to scatter neutrons on a small liquid argon target. The neutrons are produced mono-energetically (Ekin = 2.45 MeV) by nuclear fusion in a deuterium plasma and are collimated onto a 3" liquid argon cell operating in single-phase mode (zero electric field). Organic liquid scintillators are used to tag scattered neutrons and to provide a time-of-flight measurement. The setup is designed to study light pulse shapes and scintillation yields from nuclear and electronic recoils as well as from alpha particles at working points relevant for dark matter searches. Liquid argon offers the possibility to scrutinise scintillation yields in noble liquids with respect to the population strength of the two fundamental excimer states. Here we present experimental methods and first results from recent data towards such studies.

  18. Sub-barrier reactions measured using a recoil mass separator

    SciTech Connect

    Betts, R.R.

    1988-01-01

    Few data exist in the sub-barrier region for reaction channels other than fusion. In particular, our experimental knowledge of quasi-elastic transfer reactions is sparse, despite the belief that this particular channel may be dominant in determining some features of the sub-barrier fusion enhancement. Transfer reactions are governed primarily by the closet approach of the colliding nuclei which, at low energies, results in a strong backward peaking of the angular distribution in the center-of-mass frame. For situations where the projectile has a significant fraction of the target mass, as is so in most cases of interest, the backscattered projectile-like fragment has such low energy that the usual techniques of measurement and identification become invalid. Here, we report on a solution to this problem which allows a systematic study of many aspects of transfer reactions in the energy regime of interest. We exploit the fact that associated with the low-energy backscattered projectile-like fragment is a complementary target-like fragment which recoils to forward angles with a large fraction of the incident beam energy. These target-like fragments were detected and identified using the Daresbury Recoil Mass Separator thus allowing the measurement of quasi-elastic transfer over hitherto inaccessible energy range from the vicinity of the barrier to several tens of MeV below. The experiments described here used VYNi beams of energies ranging from 180 to 260 MeV provided by the Daresbury Laboratory Nuclear Structure Facility tandem accelerator. Data on sub-barrier transfer for targets of /sup 116,118,120,122,124/Sn and /sup 144,148,150,152,154/Sm were obtained. 16 refs., 10 figs., 2 tabs.

  19. Medium modifications with recoil polarization

    SciTech Connect

    Brand, J.F.J. van den; Ent, R.

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  20. Dynamical simulations of radiation damage induced by 10 keV energetic recoils in UO 2

    NASA Astrophysics Data System (ADS)

    Tian, X. F.; Gao, T.; Long, Chongsheng; Li, JiuKai; Jiang, Gang; Xiao, Hongxing

    2011-08-01

    We have performed classical molecular dynamics simulations to simulate the primary damage state induced by 10 keV energetic recoils in UO 2. The numbers versus time and the distance distributions for the displaced uranium and oxygen atoms were investigated with the energetic recoils accelerated along four different directions. The simulations suggest that the direction of the primary knock-on atom (PKA) has no effect on the final primary damage state. In addition, it was found that atomic displacement events consisted of replacement collision sequences in addition to the production of Frenkel pairs. The spatial distribution of defects introduced by 10 keV collision cascades was also presented and the results were similar to that of energetic recoils with lower energy.

  1. Analytical calculation of the electron-line radiative-recoil corrections to muonium hyperfine splitting

    NASA Astrophysics Data System (ADS)

    Eides, M. I.; Karshenboim, S. G.; Shelyuto, V. A.

    1986-09-01

    An analytical calculation of electron-line radiative corrections to muonium hyperfine splitting is presented. The classic non-recoil and leading logarithmic radiative-recoil contribution is re-evaluated and a new term is obtained, which was not known previously in analytical form. This new term is found to be [ {α(Zα)}/{π 2}]( {m e}/{m μ})E F[6ζ(3)+3π 2 ln 2+ {1}/{2}π 2+ {17}/{18}], where EF is the Fermi energy.

  2. A Measurement of the Recoil Polarization of Electroproduced {Lambda}(1116)

    SciTech Connect

    Simeon McAleer

    2002-01-01

    The CEBAF Large Acceptance Spectrometer at the Thomas Jefferson National Laboratory was used to study the reaction e + p {yields} e{prime} + K{sup +} + {Lambda}(1116) for events where {Lambda}(1116) subsequently decayed via the channel {Lambda}(1116) {yields} p + {pi}{sup -}. Data were taken at incident electron beam energies of 2.5, 4.0, and 4.2 GeV during the 1999 E1C run period. They hyperon production spectra span the Q{sup 2} range from 0.5 to 2.8 GeV{sup 2} and nearly the entire range in the center of mass angles. The proton angular distribution in the {Lambda}(1116) rest frame is used to deduce the recoil polarization of the hyperon, and the W and cos {theta}{sub cm}{sup K+} dependence of the recoil polarization will be presented. The data show sizeable negative polarizations for the {Lambda}(1116) as a function of both cos {theta}{sub cm}{sup K+} and W.

  3. Complex decay patterns in atomic core photoionization disentangled by ion-recoil measurements

    SciTech Connect

    Guillemin, Renaud; Bomme, Cedric; Marin, Thierry; Journel, Loic; Marchenko, Tatiana; Kushawaha, Rajesh K.; Piancastelli, Maria Novella; Simon, Marc; Trcera, Nicolas

    2011-12-15

    Following core 1s ionization and resonant excitation of argon atoms, we measure the recoil energy of the ions due to momentum conservation during the emission of Auger electrons. We show that such ion momentum spectroscopy can be used to disentangle to some degree complex decay patterns, involving both radiative and nonradiative decays.

  4. Calibration of a compact magnetic proton recoil neutron spectrometer

    NASA Astrophysics Data System (ADS)

    Zhang, Jianfu; Ouyang, Xiaoping; Zhang, Xianpeng; Ruan, Jinlu; Zhang, Guoguang; Zhang, Xiaodong; Qiu, Suizheng; Chen, Liang; Liu, Jinliang; Song, Jiwen; Liu, Linyue; Yang, Shaohua

    2016-04-01

    Magnetic proton recoil (MPR) neutron spectrometer is considered as a powerful instrument to measure deuterium-tritium (DT) neutron spectrum, as it is currently used in inertial confinement fusion facilities and large Tokamak devices. The energy resolution (ER) and neutron detection efficiency (NDE) are the two most important parameters to characterize a neutron spectrometer. In this work, the ER calibration for the MPR spectrometer was performed by using the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), and the NDE calibration was performed by using the neutron generator at CIAE. The specific calibration techniques used in this work and the associated accuracies were discussed in details in this paper. The calibration results were presented along with Monte Carlo simulation results.

  5. Neutron electric form factor via recoil polarimetry

    SciTech Connect

    Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Plaster, Bradley; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Breuer, Herbert; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Howell, Calvin; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Mitchell, Joseph; Mkrtchyan, Hamlet; Opper, Allena; Perdrisat, Charles; Punjabi, Vina; Raue, Brian; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng

    2003-05-01

    The ratio of the electric to the magnetic form factor of the neutron, G_En/G_Mn, was measured via recoil polarimetry from the quasielastic d({pol-e},e'{pol-n)p reaction at three values of Q^2 [viz., 0.45, 1.15 and 1.47 (GeV/c)^2] in Hall C of the Thomas Jefferson National Accelerator Facility. Preliminary data indicate that G_En follows the Galster parameterization up to Q^2 = 1.15 (GeV/c)^2 and appears to rise above the Galster parameterization at Q^2 = 1.47 (GeV/c)^2.

  6. Experimental status of 7Be production and destruction at astrophysical relevant energies

    NASA Astrophysics Data System (ADS)

    Di Leva, A.; Gialanella, L.; Strieder, F.

    2016-01-01

    The production and destruction of 7Be plays a significant role in the Big Bang Nucleosynthesis as well as in the framework of the solar neutrino. The 3He(α, γ)7Be reaction cross sections has been measured several times in the last decades, but the precision achieved on reaction rate determinations at the relevant astrophysical energies is not yet satisfactory. The experimental status of this reaction will be critically reviewed, and the theoretical descriptions available will be discussed.

  7. Angular Momentum Transport in Accretion Disks and Relevance of Thermal Energy Content and Transport

    NASA Astrophysics Data System (ADS)

    Coppi, P. S.; Coppi, B.

    2003-04-01

    Considering thin accretion disks where the magnetic energy is comparable to the thermal energy is relevant to theoretical models of magnetized jets originating from disks. In these regimes the only known modes that can induce outward transport of angular momentum, as needed for the accretion process to occur, are tridimensional, locally corotating with the disk, which, if described by the linearized ideal MHD approximation, have radial profiles with two sets of characteristic singularities(B. Coppi and P.S. Coppi, Phys. Rev. Lett.), 87, 051101-1 (2001). The more important of these two sets corresponds to the radius where the relevant Doppler shifted frequency equals that of the slow magnetosonic mode (ω ^2≃ k_allel^2c_s^2v_A^2/(c_s^2+v_A^2)). Thus the finiteness of the plasma temperature is a key factor in the excitation of these modes. Nonlinear effects are shown to be more important than ``dissipative'' processes to describe the transition across the singularities. The connection between transport of angular momentum and that of thermal energy that is central to the explanation of the ``spontaneous rotation'' phenomenon in laboratory plasmas by the relevant accretion theory(B. Coppi, Nucl. Fusion), 42, 1 (2002) is discussed and the difference of the phsyical regimes of these plasmas relative to those characterizing accretion disks is pointed out.

  8. Constraints on the Nature of CID-42: Recoil Kick or Supermassive Black Hole Pair?

    NASA Technical Reports Server (NTRS)

    Blecha, Laura; Civano, Francesca; Elvis, Martin; Loeb, Abraham

    2012-01-01

    The galaxy CXOC J100043.1+020637, also known as CID-42, is a highly unusual object. An apparent galaxy merger remnant, it displays signatures of both an inspiraling, kiloparsecscale active galactic nucleus (AGN) pair and of a recoiling AGN with a kick velocity approximately greater than 1300 km s(exp -1). Among recoiling AGN candidates, CID-42 alone has both spatial offsets (in optical and X-ray bands) and spectroscopic offsets. In order to constrain the relative likelihood of both scenarios, we develop models using hydrodynamic galaxy merger simulations coupled with radiative transfer calculations. Our gas-rich, major merger models are generally well matched to the galactic morphology and to the inferred stellar mass and star formation rate. We show that a recoiling supermassive black hole (SMBH) in CID-42 should be observable as an AGN at the time of observation. However, in order for the recoiling AGN to produce narrow-line emission, it must be observed shortly after the kick while it still inhabits a dense gaseous region, implying a large total kick velocity (vk approximately greater than 2000 km s(exp -1)). For the dual AGN scenario, an unusually large broad-line offset is required, and the best match to the observed morphology requires a galaxy that is less luminous than CID-42. Further, the lack of X-ray emission from one of the two optical nuclei is not easily attributed to an intrinsically quiescent SMBH or to a Compton-thick galactic environment. While the current data do not allow either the recoiling or the dual AGN scenario for CID-42 to be excluded, our models highlight the most relevant parameters for distinguishing these possibilities with future observations. In particular, high-quality, spatially-resolved spectra that can pinpoint the origin of the broad and narrow line features will be critical for determining the nature of this unique source.

  9. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis.

    PubMed

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-01

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si3N4 membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  10. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis

    SciTech Connect

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-15

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si{sub 3}N{sub 4} membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  11. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-01

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si3N4 membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  12. A Novel Nuclear Recoil Calibration in the LUX Detector Using a D-D Neutron Generator

    NASA Astrophysics Data System (ADS)

    Verbus, James; LUX Collaboration

    2015-04-01

    The LUX dark matter search experiment is a 350 kg two-phase liquid/gas xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. I will describe a novel calibration of nuclear recoils (NR) in liquid xenon (LXe) performed in-situ in the LUX detector using mono-energetic 2.45 MeV neutrons produced by a D-D neutron generator. This technique was used to measure the NR charge yield in LXe (Qy) to < 1 keV recoil energy with an absolute determination of the deposited energy. The LUX Qy result is a factor of × 5 lower in energy compared to any other previous measurement in the field, and provides a significant improvement in calibration uncertainties. We also present a measurement of the NR light yield in LXe (Leff) to recoil energies as low as ~ 2 keV using the LUX D-D data. The Leff result is also lower in energy with smaller uncertainties than has been previously achieved. These absolute, ultra-low energy calibrations of the NR signal yields in LXe are a clear confirmation of the detector response used for the first LUX WIMP search analysis. Strategies for extending this calibration technique to even lower energies and smaller uncertainties will be discussed.

  13. α -decay chains of recoiled superheavy nuclei: A theoretical study

    NASA Astrophysics Data System (ADS)

    Niyti, Sawhney, Gudveen; Sharma, Manoj K.; Gupta, Raj K.

    2015-05-01

    A systematic theoretical study of α -decay half-lives in the superheavy mass region of the periodic table of elements is carried out by extending the quantum-mechanical fragmentation theory based on the preformed cluster model (PCM) to include temperature (T ) dependence in its built-in preformation and penetration probabilities of decay fragments. Earlier, the α -decay chains of the isotopes of Z =115 were investigated by using the standard PCM for spontaneous decays, with"hot-optimum" orientation effects included, which required a constant scaling factor of 104 to approach the available experimental data. In the present approach of the PCM (T ≠0 ), the temperature effects are included via the recoil energy of the residual superheavy nucleus (SHN) left after x -neutron emission from the superheavy compound nucleus. The important result is that the α -decay half-lives calculated by the PCM (T ≠0 ) match the experimental data nearly exactly, without using any scaling factor of the type used in the PCM. Note that the PCM (T ≠0 ) is an equivalent of the dynamical cluster-decay model for heavy-ion collisions at angular momentum ℓ =0 . The only parameter of model is the neck-length parameter Δ R , which for the calculated half-lives of α -decay chains of various isotopes of Z =113 to 118 nuclei formed in "hot-fusion" reactions is found to be nearly constant, i.e., Δ R ≈0.95 ±0.05 fm for all the α -decay chains studied. The use of recoiled residue nucleus as a secondary heavy-ion beam for nuclear reactions has also been suggested in the past.

  14. Benchmark interaction energies for biologically relevant noncovalent complexes containing divalent sulfur.

    PubMed

    Mintz, Benjamin J; Parks, Jerry M

    2012-01-26

    Molecules containing divalent sulfur can participate in significant noncovalent interactions. Computing accurate noncovalent interaction energies using ab initio quantum chemical methods requires a proper description of electron correlation effects. Coupled-cluster theory with single and double substitutions and perturbative triple substitutions, CCSD(T), using extrapolation to the complete basis set (CBS) limit has become the method of choice for computing accurate interaction energies of noncovalently bound complexes. Here, interaction energies are computed for several biologically relevant hydrogen-bonded and dispersion-bound complexes that contain divalent sulfur. Eight-point estimated CCSD(T)/CBS dissociation curves along the noncovalent interaction vector are computed for each complex. As a comparison of high-accuracy ab initio methods, interaction energies are also calculated for each complex using the correlation-consistent Composite Approach (ccCA). We find that, on average, the two methods yield energies within 0.1 kcal mol(-1) of each other. The interaction energies provided here should be useful for developing and assessing the accuracy of more approximate ab initio, density functional theory, semiempirical, and classical force field approaches.

  15. Blood lactate concentration after exposure to conducted energy weapons (including TASER® devices): is it clinically relevant?

    PubMed

    Jauchem, James R

    2013-09-01

    In previous studies, blood lactate concentration (BLac) consistently increased in anesthetized animals and in human subjects after exposures to TASER(®) conducted energy weapons (CEWs). Some have suggested the increased BLac would have detrimental consequences. In the current review, the following are evaluated: (a) the nature of muscle contractions due to CEWs, (b) general aspects of increased BLac, (c) previous studies of conventional neuromuscular electrical stimulation and CEW exposures, and (d) BLac in disease states. On the basis of these analyses, one can conclude that BLac, per se (independent of acidemia), would not be clinically relevant immediately after short-duration CEW applications, due to the short time course of any increase.

  16. Relevance of deep-subsurface microbiology for underground gas storage and geothermal energy production.

    PubMed

    Gniese, Claudia; Bombach, Petra; Rakoczy, Jana; Hoth, Nils; Schlömann, Michael; Richnow, Hans-Hermann; Krüger, Martin

    2014-01-01

    This chapter gives the reader an introduction into the microbiology of deep geological systems with a special focus on potential geobiotechnological applications and respective risk assessments. It has been known for decades that microbial activity is responsible for the degradation or conversion of hydrocarbons in oil, gas, and coal reservoirs. These processes occur in the absence of oxygen, a typical characteristic of such deep ecosystems. The understanding of the responsible microbial processes and their environmental regulation is not only of great scientific interest. It also has substantial economic and social relevance, inasmuch as these processes directly or indirectly affect the quantity and quality of the stored oil or gas. As outlined in the following chapter, in addition to the conventional hydrocarbons, new interest in such deep subsurface systems is rising for different technological developments. These are introduced together with related geomicrobiological topics. The capture and long-termed storage of large amounts of carbon dioxide, carbon capture and storage (CCS), for example, in depleted oil and gas reservoirs, is considered to be an important options to mitigate greenhouse gas emissions and global warming. On the other hand, the increasing contribution of energy from natural and renewable sources, such as wind, solar, geothermal energy, or biogas production leads to an increasing interest in underground storage of renewable energies. Energy carriers, that is, biogas, methane, or hydrogen, are often produced in a nonconstant manner and renewable energy may be produced at some distance from the place where it is needed. Therefore, storing the energy after its conversion to methane or hydrogen in porous reservoirs or salt caverns is extensively discussed. All these developments create new research fields and challenges for microbiologists and geobiotechnologists. As a basis for respective future work, we introduce the three major topics, that is

  17. A gun recoil system employing a magnetorheological fluid damper

    NASA Astrophysics Data System (ADS)

    Li, Z. C.; Wang, J.

    2012-10-01

    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment.

  18. Modeling the Observability of Recoiling Black Holes as Offset Quasars

    NASA Astrophysics Data System (ADS)

    Blecha, Laura; Torrey, Paul; Vogelsberger, Mark; Genel, Shy; Springel, Volker; Sijacki, Debora; Snyder, Gregory; Bird, Simeon; Nelson, Dylan; Xu, Dandan; Hernquist, Lars

    2015-08-01

    The merger of two supermassive black holes (SMBHs) imparts a gravitational-wave (GW) recoil kick to the remnant SMBH. In extreme cases these kicks may be thousands of km/s -- enough to easily eject them from their host galaxies. Moderate recoil kicks may also cause substantial displacements of the SMBH, however. An actively-accreting, recoiling SMBH may be observable as an offset quasar. Prior to the advent of a space-based GW observatory, detections of these offset quasars may offer the best chance for identifying recent SMBH mergers. Indeed, observational searches for recoiling quasars have already identified several promising candidates. However, systematic searches for recoils are currently hampered by large uncertainties regarding how often offset quasars should be observable, where they are most likely to be found, and whether BH spin alignment prior to merger is efficient at suppressing large recoils. Motivated by this, we have developed a model for the observable population of recoiling quasars in a cosmological framework, utilizing detailed information about the progenitor galaxies from state-of-the-art cosmological hydrodynamic simulations (the Illustris Project). The model for offset quasar lifetimes includes a physically-motivated, time-dependent model for accretion onto kicked SMBHs, and results are analyzed for a range of possible BH spin alignment models. We find that the observability of offset quasars depends strongly on the efficiency of pre-merger spin alignment, with promising indications that observations of recoils could distinguish between at least the extreme limits of spin alignment models. Our results also suggest that observable offset quasars should inhabit preferred types of host galaxies, where again these populations depend on the degree of pre-merger spin alignment. These findings will be valuable for planned and future dedicated searches for recoiling quasars, and they indicate that such objects might be used to place indirect

  19. A predictive theory for elastic scattering and recoil of protons from 4He

    SciTech Connect

    Hupin, Guillaume; Quaglioni, Sofia; Navratil, Petr

    2014-12-08

    Low-energy cross sections for elastic scattering and recoil of protons from 4He nuclei (also known as α particles) are calculated directly by solving the Schrodinger equation for five nucleons interacting through accurate two- and three-nucleon forces derived within the framework of chiral effective field theory. Precise knowledge of these processes at various proton backscattering/recoil angles and energies is needed for the ion-beam analysis of numerous materials, from the surface layers of solids, to thin films, to fusion-reactor materials. Indeed, the same elastic scattering process, in two different kinematic configurations, can be used to probe the concentrations and depth profiles of either hydrogen or helium. Furthermore, we compare our results to available experimental data and show that direct calculations with modern nuclear potentials can help to resolve remaining inconsistencies among data sets and can be used to predict these cross sections when measurements are not available.

  20. Black hole as a point radiator and recoil effect on the brane world.

    PubMed

    Frolov, Valeri; Stojković, Dejan

    2002-10-01

    A small black hole attached to a brane in a higher-dimensional space emitting quanta into the bulk may leave the brane as a result of a recoil. We construct a field theory model in which such a black hole is described as a massive scalar particle with internal degrees of freedom. In this model, the probability of transition between the different internal levels is identical to the probability of thermal emission calculated for the Schwarzschild black hole. The discussed recoil effect implies that the thermal emission of the black holes, which might be created by interaction of high energy particles in colliders, could be terminated and the energy nonconservation can be observed in the brane experiments.

  1. A predictive theory for elastic scattering and recoil of protons from 4He

    DOE PAGESBeta

    Hupin, Guillaume; Quaglioni, Sofia; Navratil, Petr

    2014-12-08

    Low-energy cross sections for elastic scattering and recoil of protons from 4He nuclei (also known as α particles) are calculated directly by solving the Schrodinger equation for five nucleons interacting through accurate two- and three-nucleon forces derived within the framework of chiral effective field theory. Precise knowledge of these processes at various proton backscattering/recoil angles and energies is needed for the ion-beam analysis of numerous materials, from the surface layers of solids, to thin films, to fusion-reactor materials. Indeed, the same elastic scattering process, in two different kinematic configurations, can be used to probe the concentrations and depth profiles ofmore » either hydrogen or helium. Furthermore, we compare our results to available experimental data and show that direct calculations with modern nuclear potentials can help to resolve remaining inconsistencies among data sets and can be used to predict these cross sections when measurements are not available.« less

  2. Recoil excitation of vibrational structure in the carbon 1s photoelectron spectrum of CF4.

    PubMed

    Thomas, T Darrah; Kukk, Edwin; Sankari, Rami; Fukuzawa, Hironobu; Prümper, Georg; Ueda, Kiyoshi; Püttner, Ralph; Harries, James; Tamenori, Yusuke; Tanaka, Takahiro; Hoshino, Masamitsu; Tanaka, Hiroshi

    2008-04-14

    The carbon 1s photoelectron spectrum of CF4 measured at photon energies from 330 to 1500 eV shows significant contributions from nonsymmetric vibrational modes. These increase linearly as the photon energy increases. The excitation of these modes, which is not predicted in the usual Franck-Condon point of view, arises from the recoil momentum imparted to the carbon atom in the ionization process. A theory is presented for quantitative prediction of the recoil effect; the predictions of this theory are in agreement to the measurements. The experiments also yield the vibrational frequencies of the symmetric and asymmetric stretching modes in core-ionized CF4, the change in CF bond length upon ionization, -0.61 pm, and the Lorentzian linewidth of the carbon 1s hole, 67 meV.

  3. Difference between a Photon's Momentum and an Atom's Recoil

    SciTech Connect

    Gibble, Kurt

    2006-08-18

    When an atom absorbs a photon from a laser beam that is not an infinite plane wave, the atom's recoil is less than ({Dirac_h}/2{pi})k in the propagation direction. We show that the recoils in the transverse directions produce a lensing of the atomic wave functions, which leads to a frequency shift that is not discrete but varies linearly with the field amplitude and strongly depends on the atomic state detection. The same lensing effect is also important for microwave atomic clocks. The frequency shifts are of the order of the naive recoil shift for the transverse wave vector of the photons.

  4. First Measurement of Beam-Recoil Observables Cx and Cz

    SciTech Connect

    R. Bradford; R.A. Schumacher; G. Adams; M.J. Amaryan; P. Ambrozewicz; E. Anciant; M. Anghinolfi; B. Asavapibhop; G. Asryan; G. Audit; H. Avakian; H. Bagdasaryan; N. Baillie; J.P. Ball; N.A. Baltzell; S. Barrow; V. Batourine; M. Battaglieri; K. Beard; I. Bedlinskiy; M. Bektasoglu; M. Bellis; N. Benmouna; B.L. Berman; N. Bianchi; A.S. Biselli; B.E. Bonner; S. Bouchigny; S. Boiarinov; D. Branford; W.J. Briscoe; W.K. Brooks; S. B¨ultmann; V.D. Burkert; C. Butuceanu; J.R. Calarco; S.L. Careccia; D.S. Carman; B. Carnahan; S. Chen; P.L. Cole; A. Coleman; P. Collins; P. Coltharp; D. Cords; † P. Corvisiero; D. Crabb; H. Crannell; V. Crede; J.P. Cummings; R. De Masi; E. De Sanctis; R. De Vita; P.V. Degtyarenko; H. Denizli; L. Dennis; A. Deur; K.V. Dharmawardane; R. Dickson; C. Djalali; G.E. Dodge; J. Donnelly; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; O.P. Dzyubak; H. Egiyan; K.S. Egiyan; L. El Fassi; L. Elouadrhiri; A. Empl; P. Eugenio; R. Fatemi; G. Fedotov; G. Feldman; R.J. Feuerbach; T.A. Forest; H. Funsten; M. Garcon; G. Gavalian; G.P. Gilfoyle; K.L. Giovanetti; F.X. Girod; J.T. Goetz; A. Gonenc; R.W. Gothe; K.A. Griffioen; M. Guidal; M. Guillo; N. Guler; L. Guo; V. Gyurjyan; C. Hadjidakis; K. Hafidi; H. Hakobyan; R.S. Hakobyan; J. Hardie; D. Heddle; F.W. Hersman; K. Hicks; I. Hleiqawi; M. Holtrop; J. Hu; M. Huertas; C.E. Hyde-Wright; Y. Ilieva; D.G. Ireland; B.S. Ishkhanov; E.L. Isupov; M.M. Ito; D. Jenkins; H.S. Jo; K. Joo; H.G. Juengst; N. Kalantarians; J.D. Kellie; M. Khandaker; K.Y. Kim; K. Kim; W. Kim; A. Klein; F.J. Klein; M. Klusman; M. Kossov; L.H. Kramer; V. Kubarovsky; J. Kuhn; S.E. Kuhn; S.V. Kuleshov; J. Lachniet; J.M. Laget; J. Langheinrich; D. Lawrence; A.C.S. Lima; K. Livingston; H.Y. Lu; K. Lukashin; M. MacCormick; J.J. Manak; C. Marchand; N. Markov; S. McAleer; B. McKinnon; J.W.C. McNabb; B.A. Mecking; M.D. Mestayer; C.A. Meyer; T. Mibe; K. Mikhailov; M. Mirazita; R. Miskimen; V. Mokeev; K. Moriya; S.A. Morrow; M. Moteabbed; V. Muccifora; J. Mueller; G.S. Mutchler; P. Nadel-Turonski; J. Napolitano; R. Nasseripour; N. Natasha; S. Niccolai; G. Niculescu; I. Niculescu; B.B. Niczyporuk; M.R. Niroula; R.A. Niyazov; M. Nozar; G.V. O’Rielly; M. Osipenko; A.I. Ostrovidov; K. Park; E. Pasyuk; C. Paterson; S.A. Philips; J. Pierce; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; I. Popa; S. Pozdniakov; B.M. Preedom; J.W. Price; Y. Prok; D. Protopopescu; L.M. Qin; B.P. Quinn; B.A. Raue; G. Riccardi; G. Ricco; M. Ripani; B.G. Ritchie; F. Ronchetti; G. Rosner; P. Rossi; D. Rowntree; P.D. Rubin; F. Sabatie; J. Salamanca; C. Salgado; J.P. Santoro; V. Sapunenko; V.S. Serov; A. Shafi; Y.G. Sharabian; J. Shaw; N.V. Shvedunov; S. Simionatto; A.V. Skabelin; E.S. Smith; L.C. Smith; D.I. Sober; D. Sokhan; M. Spraker; A. Stavinsky; S.S. Stepanyan; S. Stepanyan; B.E. Stokes; P. Stoler; I.I. Strakovsky; S. Strauch; M. Taiuti; S. Taylor; D.J. Tedeschi; U. Thoma; R. Thompson; A. Tkabladze; S. Tkachenko; L. Todor; C. Tur; M. Ungaro; M.F. Vineyard; A.V. Vlassov; K. Wang; D.P. Watts; L.B. Weinstein; H. Weller; D.P. Weygand; M. Williams; E. Wolin; M.H. Wood; A. Yegneswaran; J. Yun; L. Zana; J. Zhang; B. Zhao; and Z.W. Zhao

    2007-03-01

    Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\\vec\\gamma + p \\to K^+ + \\vec\\Lambda$ and $\\vec\\gamma + p \\to K^+ + \\vec\\Sigma^0$. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies $W$ between 1.6 and 2.53 GeV, and for $-0.85<\\cos\\theta_{K^+}^{c.m.}< +0.95$. For the $\\Lambda$, the polarization transfer coefficient along the photon momentum axis, $C_z$, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient, $C_x$, is smaller than $C_z$ by a roughly constant difference of unity. Most significantly, the {\\it total} $\\Lambda$ polarization vector, including the induced polarization $P$, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the $\\Sigma^0$ this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.

  5. Energy-Water Nexus Relevant to Baseload Electricity Source Including Mini/Micro Hydropower Generation

    NASA Astrophysics Data System (ADS)

    Fujii, M.; Tanabe, S.; Yamada, M.

    2014-12-01

    Water, food and energy is three sacred treasures that are necessary for human beings. However, recent factors such as population growth and rapid increase in energy consumption have generated conflicting cases between water and energy. For example, there exist conflicts caused by enhanced energy use, such as between hydropower generation and riverine ecosystems and service water, between shale gas and ground water, between geothermal and hot spring water. This study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in enhancing energy use. Among various kinds of renewable energy sources, we target baseload sources, especially focusing on renewable energy of which installation is required socially not only to reduce CO2 and other greenhouse gas emissions but to stimulate local economy. Such renewable energy sources include micro/mini hydropower and geothermal. Three municipalities in Japan, Beppu City, Obama City and Otsuchi Town are selected as primary sites of this study. Based on the calculated potential supply and demand of micro/mini hydropower generation in Beppu City, for example, we estimate the electricity of tens through hundreds of households is covered by installing new micro/mini hydropower generation plants along each river. However, the result is based on the existing infrastructures such as roads and electric lines. This means that more potentials are expected if the local society chooses options that enhance the infrastructures to increase micro/mini hydropower generation plants. In addition, further capacity building in the local society is necessary. In Japan, for example, regulations by the river law and irrigation right restrict new entry by actors to the river. Possible influences to riverine ecosystems in installing new micro/mini hydropower generation plants should also be well taken into account. Deregulation of the existing laws relevant to rivers and

  6. Reaction mechanisms in the system {sup 20}Ne+{sup 165}Ho: Measurement and analysis of forward recoil range distributions

    SciTech Connect

    Singh, D.; Ali, R.; Ansari, M. Afzal; Rashid, M. H.; Guin, R.; Das, S. K.

    2009-05-15

    Keeping in view the study of complete and incomplete fusion of heavy ions with a target, the forward recoil range distributions of several evaporation residues produced at 164 MeV {sup 20}Ne-ion beam energy have been measured for the system {sup 20}Ne+{sup 165}Ho. The recoil catcher activation technique followed by off-line gamma spectroscopy has been employed. Measured forward recoil range distributions of these evaporation residues show evidence of several incomplete fusion channels in addition to complete fusion. The entire and partial linear momentum transfers inferred from these recoil range distributions were used to identify the evaporation residues formed by complete and incomplete fusion mechanisms. The results indicate the occurrence of incomplete fusion involving the breakup of {sup 20}Ne into {sup 4}He+{sup 16}O and/or {sup 8}Be+{sup 12}C followed by fusion of one of the fragments with target nucleus {sup 165}Ho. Complete and incomplete fusion reaction channels have been identified in the production of various evaporation residues and an attempt has been made to separate out relative contributions of complete and incomplete fusion components from the analysis of the measured recoil range distribution data. The total contribution of complete and incomplete fusion channels has also been estimated.

  7. Nuclear Recoil Calibrations in the LUX Detector Using Direct and Backscattered D-D Neutrons

    NASA Astrophysics Data System (ADS)

    Rhyne, Casey; LUX Collaboration

    2016-03-01

    The LUX dark matter search experiment is a 350 kg two-phase liquid/gas xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. I will discuss the latest calibration of the nuclear recoil (NR) response in liquid xenon (LXe), performed in-situ in the LUX detector using mono-energetic 2.45 MeV neutrons produced via the Adelphi Technologies, Inc. DD108 D-D neutron generator. The calibration measured the NR charge yield in LXe (Qy) to 0.7 keVnr recoil energy with an absolute determination of deposited energy and the NR light yield in LXe (Ly) to recoil energies of 1.1 keVnr, both of which improve upon all previous measurements. I will then focus in depth on the extension of this calibration using a new technique for generating a beam of sub-300 keV quasi-mono-energetic neutrons via the backscatter of 2.45 MeV neutrons off a deuterium-based reflector. Current simulations work optimizing the technique, its advantages, and its impact on future research will be discussed, including the extension of the NR Qy calibration down to 0.14 keVnr, an independent NR Ly calibration, and an a priori estimate of the expected 8B solar neutrino-nucleus coherent scattering signal in the upcoming LUX-ZEPLIN experiment.

  8. Missing Mass Recoiling Against the Charged D

    SciTech Connect

    Cain, Hillary

    2003-09-05

    This paper chronicles the investigation of a peak in the BaBar mass data set of mass recoiling against charged D*s. Our hypothesis is that the peak at 2620 MeV is a reflection of the D{sub s}* and {pi} system. Specifically, we explored the idea that the peak might be a reflection from the decay B {yields} D**{sup -} D*{sub s}{sup +} with the D**{sup -} {yields} D*{sup -} {pi}. Theoretically, when the D**{sup -} decays, the trajectory of the resulting {pi} will form an angle with the D*{sub s}{sup +}, and different angles impart difference masses to the system over a range of a GeV or so. If quantum mechanics dictates that their paths will form a particular angle more often than others, a peak would appear in the histogram of their collective mass. Using the Monte Carlo model of particle collision events, Anders Ryd's EVTGEN program, C++ code derived from GeneratorsQA, and PAW, we tested the hypothesis that the peak might be a reflection of the system, but found that this possible explanation could not account for the peak. No 2620 MeV peak appears in the histogram of the system mass. We therefore discount the hypothesis and conclude that some other reflection, statistical fluctuation, or particle is causing the peak.

  9. Electron energy transport in ion waves and its relevance to laser-produced plasmas

    SciTech Connect

    Bell, A.R.

    1983-01-01

    Electron energy transport in plasmas is examined in the context of ion waves which are intermediate between collisionless isothermal ion acoustic waves and collisional adiabatic sound waves. The conductivity is found to be much less than the Spitzer-Haerm result for wavelengths less than 1000 electron mean free paths. This is expected to be relevant to laser-produced ablating plasmas in which the temperature can vary considerably over a distance of 10 to 100 mean free paths. The reduction in conductivity is independent of the wave amplitude thus differing from the reduction due to saturation found recently by numerical solution of the Fokker--Planck equation. At short wavelengths the heat flow approaches an upper limit which depends on the phase velocity of the wave. Diffusive ion wave damping is strong over a large range of wavelengths.

  10. Relevance of deep-subsurface microbiology for underground gas storage and geothermal energy production.

    PubMed

    Gniese, Claudia; Bombach, Petra; Rakoczy, Jana; Hoth, Nils; Schlömann, Michael; Richnow, Hans-Hermann; Krüger, Martin

    2014-01-01

    This chapter gives the reader an introduction into the microbiology of deep geological systems with a special focus on potential geobiotechnological applications and respective risk assessments. It has been known for decades that microbial activity is responsible for the degradation or conversion of hydrocarbons in oil, gas, and coal reservoirs. These processes occur in the absence of oxygen, a typical characteristic of such deep ecosystems. The understanding of the responsible microbial processes and their environmental regulation is not only of great scientific interest. It also has substantial economic and social relevance, inasmuch as these processes directly or indirectly affect the quantity and quality of the stored oil or gas. As outlined in the following chapter, in addition to the conventional hydrocarbons, new interest in such deep subsurface systems is rising for different technological developments. These are introduced together with related geomicrobiological topics. The capture and long-termed storage of large amounts of carbon dioxide, carbon capture and storage (CCS), for example, in depleted oil and gas reservoirs, is considered to be an important options to mitigate greenhouse gas emissions and global warming. On the other hand, the increasing contribution of energy from natural and renewable sources, such as wind, solar, geothermal energy, or biogas production leads to an increasing interest in underground storage of renewable energies. Energy carriers, that is, biogas, methane, or hydrogen, are often produced in a nonconstant manner and renewable energy may be produced at some distance from the place where it is needed. Therefore, storing the energy after its conversion to methane or hydrogen in porous reservoirs or salt caverns is extensively discussed. All these developments create new research fields and challenges for microbiologists and geobiotechnologists. As a basis for respective future work, we introduce the three major topics, that is

  11. Superconducting Nuclear Recoil Sensor for Directional Dark Matter Detection

    NASA Astrophysics Data System (ADS)

    Junghans, Ann; Baldwin, Kevin; Hehlen, Markus; Lafler, Randy; Loomba, Dinesh; Phan, Nguyen; Weisse-Bernstein, Nina

    The Universe consists of 72% dark energy, 23% dark matter and only 5% of ordinary matter. One of the greatest challenges of the scientific community is to understand the nature of dark matter. Current models suggest that dark matter is made up of slowly moving, weakly interacting massive particles (WIMPs). But detecting WIMPs is challenging, as their expected signals are small and rare compared to the large background that can mimic the signal. The largest and most robust unique signature that sets them apart from other particles is the day-night variation of the directionality of dark matter on Earth. This modulation could be observed with a direction-sensitive detector and hence, would provide an unambiguous signature for the galactic origin of WIMPs. There are many studies underway to attempt to detect WIMPs both directly and indirectly, but solid-state WIMP detectors are widely unexplored although they would present many advantages to prevalent detectors that use large volumes of low pressure gas. We present first results of a novel multi-layered architecture, in which WIMPs would interact primarily with solid layers to produce nuclear recoils that then induce measureable voltage pulses in adjacent superconductor layers. This work was supported by the U.S. Department of Energy through the LANL Laboratory Directed Research and Development Program.

  12. Recoil splitting of x-ray-induced optical fluorescence

    SciTech Connect

    Gavrilyuk, S.; Aagren, H.; Gel'mukhanov, F.; Sun, Y.-P.; Levin, S.

    2010-03-15

    We show that the anisotropy of the recoil velocity distribution of x-ray-ionized atoms or molecules leads to observable splittings in subsequent optical fluorescence or absorption when the polarization vector of the x rays is parallel to the momentum of the fluorescent photons. The order of the magnitude of the recoil-induced splitting is about 10 {mu}eV, which can be observed using Fourier or laser-absorption spectroscopic techniques.

  13. RECOILING SUPERMASSIVE BLACK HOLES IN SPIN-FLIP RADIO GALAXIES

    SciTech Connect

    Liu, F. K.; Wang Dong; Chen Xian

    2012-02-20

    Numerical relativity simulations predict that coalescence of supermassive black hole (SMBH) binaries leads not only to a spin flip but also to a recoiling of the merger remnant SMBHs. In the literature, X-shaped radio sources are popularly suggested to be candidates for SMBH mergers with spin flip of jet-ejecting SMBHs. Here we investigate the spectral and spatial observational signatures of the recoiling SMBHs in radio sources undergoing black hole spin flip. Our results show that SMBHs in most spin-flip radio sources have mass ratio q {approx}> 0.3 with a minimum possible value q{sub min} {approx_equal} 0.05. For major mergers, the remnant SMBHs can get a kick velocity as high as 2100 km s{sup -1} in the direction within an angle {approx}< 40 Degree-Sign relative to the spin axes of remnant SMBHs, implying that recoiling quasars are biased to be with high Doppler-shifted broad emission lines while recoiling radio galaxies are biased to large apparent spatial off-center displacements. We also calculate the distribution functions of line-of-sight velocity and apparent spatial off-center displacements for spin-flip radio sources with different apparent jet reorientation angles. Our results show that the larger the apparent jet reorientation angle is, the larger the Doppler-shifting recoiling velocity and apparent spatial off-center displacement will be. We investigate the effects of recoiling velocity on the dust torus in spin-flip radio sources and suggest that recoiling of SMBHs would lead to 'dust-poor' active galactic nuclei. Finally, we collect a sample of 19 X-shaped radio objects and for each object give the probability of detecting the predicted signatures of recoiling SMBH.

  14. The relevance of rooftops: Analyzing the microscale surface energy balance in the Chicago region

    NASA Astrophysics Data System (ADS)

    Khosla, Radhika

    interior through the roof, and the physical properties of the surface. These results hold particular relevance for urban heat island mitigation strategies. Based on the results of this work, recommendations are proposed for widespread adoption of various techniques that enhance building energy efficiency (particularly targeting rooftops), mitigate the negative impacts of the urban heat island, and overcome the current barriers to transforming the market.

  15. Recoil velocity at second post-Newtonian order for spinning black hole binaries

    NASA Astrophysics Data System (ADS)

    Racine, Étienne; Buonanno, Alessandra; Kidder, Larry

    2009-08-01

    We compute the flux of linear momentum carried by gravitational waves emitted from spinning binary black holes at second post-Newtonian (2PN) order for generic orbits. In particular we provide explicit expressions of three new types of terms, namely, next-to-leading order spin-orbit terms at 1.5 post-Newtonian (1.5PN) order, spin-orbit tail terms at 2PN order, and spin-spin terms at 2PN order. Restricting ourselves to quasicircular orbits, we integrate the linear-momentum flux over time to obtain the recoil velocity as function of orbital frequency. We find that in the so-called superkick configuration the higher-order spin corrections can increase the recoil velocity up to a factor ˜3 with respect to the leading-order PN prediction. Whereas the recoil velocity computed in PN theory within the adiabatic approximation can accurately describe the early inspiral phase, we find that its fast increase during the late inspiral and plunge, and the arbitrariness in determining until when it should be trusted, makes the PN predictions for the total recoil not very accurate and robust. Nevertheless, the linear-momentum flux at higher PN orders can be employed to build more reliable resummed expressions aimed at capturing the nonperturbative effects until merger. Furthermore, we provide expressions valid for generic orbits, and accurate at 2PN order, for the energy and angular momentum carried by gravitational waves emitted from spinning binary black holes. Specializing to quasicircular orbits we compute the spin-spin terms at 2PN order in the expression for the evolution of the orbital frequency and found agreement with Mikóczi, Vasúth, and Gergely. We also verified that in the limit of extreme mass ratio our expressions for the energy and angular momentum fluxes match the ones of Tagoshi, Shibata, Tanaka, and Sasaki obtained in the context of black hole perturbation theory.

  16. The influence of osmotic pressure on the lifespan of cellularly inspired energy-relevant materials

    NASA Astrophysics Data System (ADS)

    Kapania, Esha; Guillen, Katherine; Freeman, Eric; Philen, Michael

    2014-04-01

    Bimolecular unit cells have recently become a focus for biologically-inspired smart materials. This is largely due their ability to exhibit many of the same properties as the natural cell membrane. In this study, two lipid monolayers formed at a water/oil interface are brought together, creating a lipid bilayer at their interface with each droplet containing a different concentration of ions. This ionic concentration gradient leads to the development of a membrane potential across the bilayer as ions begin to passively diffuse across the membrane at varying rates, providing the proof of concept for energy storage through cellular mechanics. The focus of the study is to determine the influence of osmotic pressure on the lifespan of the lipid bilayer. We hypothesize that the greater osmotic pressure that develops from a greater ionic concentration gradient will prove to have a negative impact on the lifespan of the bilayer membrane, causing it to rupture sooner. This is due to the substantial amount of osmotic swelling that will occur to compensate for the ionic concentration gradient. This study will demonstrate how osmotic pressure will continue to be a limiting factor in the effectiveness and stability of cellularly-inspired energy relevant materials.

  17. (Bio)Chemical Tailoring of Biogenic 3-D Nanopatterned Templates with Energy-Relevant Functionalities

    SciTech Connect

    Sandhage, Kenneth H; Kroger, Nils

    2014-09-08

    The overall aim of this research has been to obtain fundamental understanding of (bio)chemical methodologies that will enable utilization of the unique 3-D nanopatterned architectures naturally produced by diatoms for the syntheses of advanced functional materials attractive for applications in energy harvesting/conversion and storage. This research has been conducted in three thrusts: Thrust 1 (In vivo immobilization of proteins in diatom biosilica) is directed towards elucidating the fundamental mechanism(s) underlying the cellular processes of in vivo immobilization of proteins in diatom silica. Thrust 2 (Shape-preserving reactive conversion of diatom biosilica into porous, high-surface area inorganic replicas) is aimed at understanding the fundamental mechanisms of shape preservation and nanostructural evolution associated with the reactive conversion and/or coating-based conversion of diatom biosilica templates into porous inorganic replicas. Thrust 3 (Immobilization of energy-relevant enzymes in diatom biosilica and onto diatom biosilica-derived inorganic replicas) involves use of the results from both Thrust 1 and 2 to develop strategies for in vivo and in vitro immobilization of enzymes in/on diatom biosilica and diatom biosilica-derived inorganic replicas, respectively. This Final Report describes progress achieved in all 3 of these thrusts.

  18. Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Kinoshita, N.; Hayashi, K.; Ueno, S.; Yatsu, Y.; Yokoyama, A.; Takahashi, N.

    2016-02-01

    Background: The p nuclei, which are not produced by neutron capture processes, are present with a typical isotopic abundance of 0.01%-0.3%. Abundance decreases with an increase in atomic number. However, the neutron-magic isotopes of 92Mo and 144Sm exhibit unusually large abundances in comparison. A combination of proton and α -particle capture reactions and neutron emission reactions are key to understanding this issue. Currently, complex network calculations do not have access to much experimental data, and hence require theoretically predicted reaction rates in order to estimate final abundances produced in nucleosynthesis. Purpose: Few experimental cross sections of (p ,γ) reactions on heavy nuclides with mass numbers of 130-150 have been reported. The 144Sm(p ,γ )145Eu reaction is the main destruction pathway for the nucleosynthesis of the 144Sm nuclide. In the present paper, experimental cross sections of the 144Sm(p ,γ )145Eu reaction at a range including astrophysically relevant energies for the p process were determined to compare with theoretical predictions using the Hauser-Feshback statistical model. Methods: The 144Sm was deposited on a high-purity Al foil with the molecular plating method. Stacks consisting of Ta degrader foils, 144Sm targets, and Cu foils used as flux monitors were irradiated with 14.0-MeV proton beams. The 144Sm(p ,γ )145Eu cross sections were determined from the 145Eu activities and the proton fluence estimated from the 65Zn activity in the Cu monitor foil. The proton energies bombarded on each 144Sm target were estimated using srim2013. Results: We determined the 144Sm(p ,γ )145Eu cross sections at proton energies between 2.8 and 7.6 MeV. These energies encompass nucleosynthesis temperatures between 3 and 5 GK. The cross sections at energies higher than 3.8 MeV agreed well with theoretically predicted cross sections using talys using the generalized superfluid (GS) model for level densities. However, calculations using non

  19. Measurement of the W boson mass and width using a novel recoil model

    SciTech Connect

    Wetstein, Matthew J.

    2009-01-01

    This dissertation presents a direct measurement of the W boson mass (MW) and decay width (ΓW) in 1 fb-1 of W → ev collider data at D0 using a novel method to model the hadronic recoil. The mass is extracted from fits to the transverse mass MT, pT(e), and ET distributions. The width is extracted from fits to the tail of the MT distribution. The electron energy measurement is simulated using a parameterized model, and the recoil is modeled using a new technique by which Z recoils are chosen from a data library to match the pT and direction of each generated W boson. We measure the the W boson mass to be MW = 80.4035 ± 0.024(stat) ± 0.039(syst) from the MT, MW = 80.4165 ± 0.027(stat) ± 0.038(syst) from the pT(e), and MW = 80.4025 ± 0.023(stat) ± 0.043(syst) from the ET distributions. ΓW is measured to be ΓW = 2.025 ± 0.038(stat) ± 0.061(syst) GeV.

  20. Median recoil direction as a WIMP directional detection signal

    SciTech Connect

    Green, Anne M.; Morgan, Ben

    2010-03-15

    Direct detection experiments have reached the sensitivity to detect dark matter weakly interacting massive particles (WIMPs). Demonstrating that a putative signal is due to WIMPs, and not backgrounds, is a major challenge, however. The direction dependence of the WIMP scattering rate provides a potential WIMP 'smoking gun'. If the WIMP distribution is predominantly smooth, the Galactic recoil distribution is peaked in the direction opposite to the direction of Solar motion. Previous studies have found that, for an ideal detector, of order 10 WIMP events would be sufficient to reject isotropy, and rule out an isotropic background. We examine how the median recoil direction could be used to confirm the WIMP origin of an anisotropic recoil signal. Specifically, we determine the number of events required to confirm the direction of solar motion as the median inverse recoil direction at 95% confidence. We find that for zero background 31 events are required, a factor of {approx}2 more than are required to simply reject isotropy. We also investigate the effect of a nonzero isotropic background. As the background rate is increased the number of events required increases, initially fairly gradually and then more rapidly, once the signal becomes subdominant. We also discuss the effect of features in the speed distribution at large speeds, as found in recent high resolution simulations, on the median recoil direction.

  1. The exergy of thermal radiation and its relevance in solar energy conversion

    NASA Astrophysics Data System (ADS)

    Wright, Sean Edward

    Driven by the importance of optimizing energy systems and technologies, the field of exergy analysis was developed to better illuminate process inefficiencies and evaluate performance. Exergy analysis provides important information and understanding that cannot be obtained from energy analysis. The field of exergy analysis is well formulated and understood except for thermal radiation (TR) heat transfer. The exergy flux, or maximum work obtainable, from TR has not been unambiguously determined. Moreover, many thermodynamic textbooks are misleading by incorrectly implying that the entropy and exergy transport with TR is calculated by using the same expressions that apply to heat conduction. Research on the exergy of TR was carried out by Petela. However, many researchers have considered Petela's analysis of the exergy of TR to be irrelevant to the conversion of TR fluxes. Petela's thermodynamic approach is considered irrelevant because, others argue, that it neglects fundamental issues that are specific to the conversion of fluxes, issues that are unusual in the context of exergy analysis. The purpose of the research in this thesis is to determine, using fundamental thermodynamic principles, the exergy flux of TR with an arbitrary spectrum and its relevance to solar radiation (SR) conversion. In this thesis it is shown that Petela's result can be used for the exergy flux of blackbody radiation (BR) and represents the upper limit to the conversion of SR approximated as BR. The thesis shows this by resolving a number of fundamental issues: (1)Inherent Irreversibility; (2)Definition of the Environment; (3)Inherent Emission; (4)Threshold Behaviour; (5)Effect of Concentrating TR. This thesis also provides a new expression, based on inherent irreversibility, for the exergy flux of TR with an arbitrary spectrum. Previous analysis by Karlsson assumes that reversible conversion of non-blackbody radiation (NBR) is theoretically possible, whereas this thesis presents evidence

  2. The Hubble diagram for a system within dark energy: influence of some relevant quantities

    NASA Astrophysics Data System (ADS)

    Saarinen, J.; Teerikorpi, P.

    2014-08-01

    Aims: We study the influence of relevant quantities, including the density of dark energy (DE), to the predicted Hubble outflow around a system of galaxies. In particular, we are interested in the difference between two models: 1) the standard ΛCDM model, with the everywhere constant DE density, and 2) the "Swiss cheese model", where the Universe is as old as the standard model and the DE density is zero on short scales, including the environment of the system. Methods: We calculated the current predicted outflow patterns of dwarf galaxies around the Local Group-like system, using different values for the mass of the group, the local DE density, and the time of ejection of the dwarf galaxies, which are treated as test particles. These results are compared with the observed Hubble flow around the Local Group. Results: The predicted distance-velocity relations around galaxy groups are not very sensitive indicators of the DE density, owing to the observational scatter and the uncertainties caused by the mass used for the group and a range in the ejection times. In general, the Local Group outflow data agree with the local DE density being equal to the global one, if the Local Group mass is about 4 × 1012 M⊙; a lower mass ≲ 2 × 1012 M⊙ could suggest a zero local DE density. The dependence of the inferred DE density on the mass is a handicap in this and other common dynamical methods. This emphasizes the need to use different approaches together, for constraining the local DE density.

  3. Effect of the energy of recoil atoms on conductivity compensation in moderately doped n-Si and n-SiC under irradiation with MeV electrons and protons

    NASA Astrophysics Data System (ADS)

    Kozlovski, V. V.; Lebedev, A. A.; Emtsev, V. V.; Oganesyan, G. A.

    2016-10-01

    Processes of radiation defect formation and conductivity compensation in silicon and silicon carbide irradiated with 0.9 MeV electrons are considered in comparison with the electron irradiation at higher energies. The experimental values of the carrier removal rate at the electron energy of 0.9 MeV are nearly an order of magnitude smaller than the similar values of the parameter for higher energy electrons (6-9 MeV). At the same time, the formation cross-section of primary radiation defects (Frenkel pairs, FPs) is nearly energy-independent in this range. It is assumed that these differences are due to the influence exerted by the energy of primary knocked-on atoms (PKAs). As the PKA energy increases, the average distance between the genetically related FPs grows and, as a consequence, the fraction of FPs unrecombined under irradiation becomes larger. The FP recombination radius is estimated (∼1.1 nm), which makes it possible to ascertain the charge state of the recombining components. Second, the increase in the PKA energy enables formation of new, more complex secondary radiation defects. At electron energies exceeding 15 MeV, the average PKA energies are closer to the values obtained under irradiation with 1 MeV protons, compared with an electron irradiation at the same energy. As for the radiation-induced defect formation, the irradiation of silicon with MeV protons can be, in principle, regarded as a superposition of the irradiation with 1 MeV electrons and that with silicon ions having energy of ∼1 keV, with the "source" of silicon ions generating these ions uniformly across the sample thickness.

  4. Energy spectra of primary knock-on atoms under neutron irradiation

    NASA Astrophysics Data System (ADS)

    Gilbert, M. R.; Marian, J.; Sublet, J.-Ch.

    2015-12-01

    Materials subjected to neutron irradiation will suffer from a build-up of damage caused by the displacement cascades initiated by nuclear reactions. Previously, the main "measure" of this damage accumulation has been through the displacements per atom (dpa) index, which has known limitations. This paper describes a rigorous methodology to calculate the primary atomic recoil events (often called the primary knock-on atoms or PKAs) that lead to cascade damage events as a function of energy and recoiling species. A new processing code SPECTRA-PKA combines a neutron irradiation spectrum with nuclear recoil data obtained from the latest nuclear data libraries to produce PKA spectra for any material composition. Via examples of fusion relevant materials, it is shown that these PKA spectra can be complex, involving many different recoiling species, potentially differing in both proton and neutron number from the original target nuclei, including high energy recoils of light emitted particles such as α-particles and protons. The variations in PKA spectra as a function of time, neutron field, and material are explored. The application of PKA spectra to the quantification of radiation damage is exemplified using two approaches: the binary collision approximation and stochastic cluster dynamics, and the results from these different models are discussed and compared.

  5. Order-of-Magnitude Estimate of Fast Neutron Recoil Rates in Proposed Neutrino Detector at SNS

    SciTech Connect

    Iverson, Erik B.

    2006-02-01

    Yuri Efremenko (UT-K) and Kate Scholberg (Duke) indicated, during discussions on 12 January 2006 with the SNS Neutronics Team, interest in a new type of neutrino detector to be placed within the proposed neutrino bunker at SNS, near beam-line 18, against the RTBT. The successful operation of this detector and its associated experiments would require fast-neutron recoil rates of approximately one event per day of operation or less. To this end, the author has attempted the following order-of-magnitude estimate of this recoil rate in order to judge whether or not a full calculation effort is needed or justified. For the purposes of this estimate, the author considers a one-dimensional slab geometry, in which fast and high-energy neutrons making up the general background in the target building are incident upon one side of an irbon slab. This iron slab represents the neutrino bunker walls. If we assume that a significant fraction of the dose rate throughout the target building is due to fast or high-energy neutrons, we can estimate the flux of such neutrons based upon existing shielding calculations performed for radiation protection purposes. In general, the dose rates within the target building are controlled to be less than 0.25 mrem per hour. A variety of calculations have indicated that these dose rates have significant fast and high-energy neutron components. Thus they can estimate the fast neutron flux incident on the neutrino bunker, and thereby the fast neutron flux inside that bunker. Finally, they can estimate the neutron recoil rate within a nominal detector volume. Such an estimate is outlined in Table 1.

  6. Recoil Polarization and Beam-Recoil Double Polarization Measurement of {eta} Electroproduction on the Proton in the Region of the S{sub 11}(1535) Resonance

    SciTech Connect

    Merkel, H.; Achenbach, P.; Ayerbe Gayoso, C.; Bernauer, J. C.; Boehm, R.; Distler, M. O.; Doria, L.; Friedrich, J.; Mueller, U.; Nungesser, L.; Pochodzalla, J.; Sanchez Majos, S.; Schlimme, B. S.; Tiator, L.; Walcher, Th.; Weinriefer, M.; Bosnar, D.; Makek, M.; Cheymol, B.; Fonvieille, H.

    2007-09-28

    The beam-recoil double polarization P{sub x{sup '}}{sup h} and P{sub z{sup '}}{sup h} and the recoil polarization P{sub y{sup '}} were measured for the first time for the p(e-vector,e{sup '}p-vector){eta} reaction at a four-momentum transfer of Q{sup 2}=0.1 GeV{sup 2}/c{sup 2} and a center of mass production angle of {theta}=120 deg. at the Mainz Microtron MAMI-C. With a center of mass energy range of 1500 MeV

  7. Electrochemical and in situ spectroscopic studies of materials of relevance to energy storage and electrocatalysis

    NASA Astrophysics Data System (ADS)

    Mo, Yibo

    In situ X-ray absorption (XAS), surface enhanced Raman spectroscopy (SERS) and rotating ring disk electrode techniques have been employed for the characterization of materials of relevance to electrochemical energy storage and electrocatalysis. In particular, analysis of in situ Ir LIII-edge extended X-ray absorption fine structure (EXAFS) of IrO2 films electrodeposited on Au substrates yielded Ir-O bond lengths decreasing in the sequence 2.02, 1.97 and 1.93 A, for Ir3+, Ir4+ and Ir5+ sites, respectively. Although features consistent with the presence of crystalline IrO2 in the highly hydrated films were found from in situ SERS, the lack of intense shells in the FT of the EXAFS function beyond the nearest oxygen neighbors indicates that the films by and large do not display long range order. In similar studies, the Fourier transform of the k3-weighted Ru K-edge EXAFS of electrodeposited RuO2 films recorded in situ were characterized by two shells attributed to Ru-O and Ru-Ru interactions at 1.94(1) and 3.12(2) A, in agreement with results obtained ex situ for Ru4+ in hydrous RuO2, whereas films in the reduced state yielded a single Ru-O interaction shell at 2.02(1) A. Extensions of these in situ XAS to the study of electrocatalysts for the nitrite reduction made it possible to identify and characterize the electronic and structural properties of a nitrosyl iron porphyrin adduct adsorbed on an electrode surface via the analysis of Fe K-edge XAS data. The effects of Se and S ad-atoms on the electrocatalytic activity of Pt electrodes have been examined using RRDE techniques. In acid, within a rather narrow range of coverages, both S- and Se-modified Pt surfaces promote the 2-electron reduction of dioxygen to hydrogen peroxide at ca. 100% faradaic efficiency over a wide potential region. Also developed were methods for immobilizing unsupported dispersed high area Pt particles a glassy carbon (GC) disk of a rotating Pt(ring)/GC(disk) electrode assembly allowing

  8. Epitaxial silicide formation on recoil-implanted substrates

    SciTech Connect

    Hashimoto, Shin; Egashira, Kyoko; Tanaka, Tomoya; Etoh, Ryuji; Hata, Yoshifumi; Tung, R. T.

    2005-01-15

    An epitaxy-on-recoil-implanted-substrate (ERIS) technique is presented. A disordered surface layer, generated by forward recoil implantation of {approx}0.7-3x10{sup 15} cm{sup -2} of oxygen during Ar plasma etching of surface oxide, is shown to facilitate the subsequent epitaxial growth of {approx}25-35-nm-thick CoSi{sub 2} layers on Si(100). The dependence of the epitaxial fraction of the silicide on the recoil-implantation parameters is studied in detail. A reduction in the silicide reaction rate due to recoil-implanted oxygen is shown to be responsible for the observed epitaxial formation, similar to mechanisms previously observed for interlayer-mediated growth techniques. Oxygen is found to remain inside the fully reacted CoSi{sub 2} layer, likely in the form of oxide precipitates. The presence of these oxide precipitates, with only a minor effect on the sheet resistance of the silicide layer, has a surprisingly beneficial effect on the thermal stability of the silicide layers. The agglomeration of ERIS-grown silicide layers on polycrystalline Si is significantly suppressed, likely from a reduced diffusivity due to oxygen in the grain boundaries. The implications of the present technique for the processing of deep submicron devices are discussed.

  9. Reaction {gamma}p {sup {yields}} {eta}' (958) p and polarization of recoil protons

    SciTech Connect

    Tryasuchev, V. A.

    2006-02-15

    On the basis of the isobar model extended by including the t-channel, the cross sections for and single-polarization features of the reaction {gamma}p {sup {yields}} {eta}'p are calculated for incident-photon energies up to 5 GeV, two poorly studied resonances, S{sub 11}(1978) and P{sub 13}(2080), being taken into account in this calculation. In order to reduce the ambiguities in the choice of resonances and their parameters that make it possible to reproduce the experimental differential cross sections, it is proposed to measure the polarization of recoil protons in the reaction being considered.

  10. Initial results of the commissioning of the HRIBF recoil mass spectrometer

    SciTech Connect

    Gross, C.J.; Akovali, Y.A.; Brinkman, M.J.; Mas, J.; McConnell, J.W.; Milner, W.T.; Shapira, D.; Ginter, T.N.; James, A.N.

    1996-10-01

    The recoil mass spectrometer at the Holifield Radioactive Ion Beam Facility is currently undergoing commissioning tests. This new spectrometer is designed to transmit ions with rigidities of K = 100 resulting from fusion-evaporation reactions using inverse-kinematics. The device consists of two sections: a momentum separator to provide beam rejection and a mass separator for product identification. Using normal-kinematic and symmetric reactions, the commissioning tests have shown that the A/Q acceptance is almost {+-}5%, the energy acceptance is approximately {+-}12%, and there has been little, if any, primary beam observed on the focal plane. Commissioning tests are presently underway with reactions using inverse-kinematics.

  11. Lifetime measurement of the 41+ state of 58Ni with the recoil distance method

    NASA Astrophysics Data System (ADS)

    Loelius, C.; Iwasaki, H.; Brown, B. A.; Honma, M.; Bader, V. M.; Baugher, T.; Bazin, D.; Berryman, J. S.; Braunroth, T.; Campbell, C. M.; Dewald, A.; Gade, A.; Kobayashi, N.; Langer, C.; Lee, I. Y.; Lemasson, A.; Lunderberg, E.; Morse, C.; Recchia, F.; Smalley, D.; Stroberg, S. R.; Wadsworth, R.; Walz, C.; Weisshaar, D.; Westerberg, A.; Whitmore, K.; Wimmer, K.

    2016-08-01

    The quadrupole transition rate for the 41+→21+ transition of 58Ni was determined from an application of the recoil distance method with the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA). The present result of the B (E 2 ;41+→21+) was found to be 50-6+11e2fm4 , which is about three times smaller than the literature value, indicating substantially less collectivity than previously believed. Shell model calculations performed with the GXPF1A effective interaction agree with the present data and the validity of the standard effective charges in understanding collectivity in the nickel isotopes is discussed.

  12. Analytic calculation of radiative-recoil corrections to muonium hyperfine splitting: Electron-line contribution

    SciTech Connect

    Eides, M.I.; Karshenboim, S.G.; Shelyuto, V.A. )

    1991-02-01

    The detailed account of analytic calculation of radiative-recoil correction to muonium hyperfine splitting, induced by electron-line radiative insertions, is presented. The consideration is performed in the framework of the effective two-particle formalism. A good deal of attention is paid to the problem of the divergence cancellation and the selection of graphs, relevant to radiative-recoil corrections. The analysis is greatly facilitated by use of the Fried-Yennie gauge for radiative photons. The obtained set of graphs turns out to be gauge-invariant and actual calculations are performed in the Feynman gauge. The main technical tricks, with the help of which we have effectively utilized the existence in the problem of the small parameter-mass ratio and managed to perform all calculations in the analytic form are described. The main intermediate results, as well as the final answer, {delta}E{sub rr} = ({alpha}({Zeta}{alpha})/{pi}{sup 2})(m/M)E{sub F}(6{zeta}(3) + 3{pi}{sup 2} In 2 + {pi}{sup 2}/2 + 17/8), are also presented.

  13. Assessing Secondary School Students' Understanding of the Relevance of Energy in Their Daily Lives

    ERIC Educational Resources Information Center

    Lay, Yoon-Fah; Khoo, Chwee-Hoon; Treagust, David F.; Chandrasegaran, A. L.

    2013-01-01

    The purpose of this study was to investigate the levels of energy literacy among 276 Form 2 (Grade 8) Malaysian students as no similar study has been previously conducted in the country, as well as the contribution of students' energy-related knowledge and attitudes on their energy-related behaviors. This was a non-experimental quantitative…

  14. A recoil resilient lumen support, design, fabrication and mechanical evaluation

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Arash; Ali, Mohamed Sultan Mohamed; Takahata, Kenichi; Al-Sarawi, Said; Abbott, Derek

    2013-06-01

    Stents are artificial implants that provide scaffolding to a cavity inside the body. This paper presents a new luminal device for reducing the mechanical failure of stents due to recoil, which is one of the most important issues in stenting. This device, which we call a recoil-resilient ring (RRR), is utilized standalone or potentially integrated with existing stents to address the problem of recoil. The proposed structure aims to minimize the need for high-pressure overexpansion that can induce intra-luminal trauma and excess growth of vascular tissue causing later restenosis. The RRR is an overlapped open ring with asymmetrical sawtooth structures that are intermeshed. These teeth can slide on top of each other, while the ring is radially expanded, but interlock step-by-step so as to keep the final expanded state against compressional forces that normally cause recoil. The RRRs thus deliver balloon expandability and, when integrated with a stent, bring both radial rigidity and longitudinal flexibility to the stent. The design of the RRR is investigated through finite element analysis (FEA), and then the devices are fabricated using micro-electro-discharge machining of 200-µm-thick Nitinol sheet. The standalone RRR is balloon expandable in vitro by 5-7 Atm in pressure, which is well within the recommended in vivo pressure ranges for stenting procedures. FEA compression tests indicate 13× less reduction of the cross-sectional area of the RRR compared with a typical stainless steel stent. These results also show perfect elastic recovery of the RRR after removal of the pressure compared to the remaining plastic deformations of the stainless steel stent. On the other hand, experimental loading tests show that the fabricated RRRs have 2.8× radial stiffness compared to a two-column section of a commercial stent while exhibiting comparable elastic recovery. Furthermore, testing of in vitro expansion in a mock artery tube shows around 2.9% recoil, approximately 5-11

  15. Measurement and calculation of recoil pressure produced during CO{sub 2} laser interaction with ice

    SciTech Connect

    Semak, V.V.; Knorovsky, G.A.; Maccallum, D.O.; Noble, D.R.; Kanouff, M.P.

    1999-12-09

    Evaporation is a classical physics problem which, because of its significant importance for many engineering applications, has drawn considerable attention by previous researchers. Classical theoretical models [Ta. I. Frenkel, Kinetic Theory of Liquids, Clarendon Press, Oxford, 1946] represent evaporation in a simplistic way as the escape of atoms with highest velocities from a potential well with the depth determined by the atomic binding energy. The processes taking place in the gas phase above the rapidly evaporating surface have also been studied in great detail [S.I.Anisimov and V. A. Khokhlov, Instabilities in Lasser-Matter Interaction, CRC Press, Boca Raton, 1995]. The description of evaporation utilizing these models is known to adequately characterize drilling with high beam intensity, e.g., >10{sup 7} W/cm{sup 2}. However, the interaction regimes when beam intensity is relatively low, such as during welding or cutting, lack both theoretical and experimental consideration of the evaporation. It was shown recently that if the evaporation is treated in accordance with Anisimov et.al.'s approach, then predicted evaporation recoil should be a substantial factor influencing melt flow and related heat transfer during laser beam welding and cutting. To verify the applicability of this model for low beam intensity interaction, the authors compared the results of measurements and calculations of recoil pressure generated during laser beam irradiation of a target. The target material used was water ice at {minus}10 C. The displacement of a target supported in a nearly frictionless air bearing under irradiation by a defocused laser beam from a 14 kW CO{sub 2} laser was recorded and Newton's laws of motion used to derive the recoil pressure.

  16. Cars and Kinetic Energy--Some Simple Physics with Real-World Relevance

    ERIC Educational Resources Information Center

    Parthasarathy, Raghuveer

    2012-01-01

    Understanding energy usage is crucial to understanding modern civilization, as well as many of the challenges it faces. Energy-related issues also offer real-world examples of important physical concepts, and as such have been the focus of several articles in "The Physics Teacher" in the past few decades (e.g., Refs. 1-5, noted further below).…

  17. Characterization of the CRESST detectors by neutron induced nuclear recoils

    NASA Astrophysics Data System (ADS)

    Coppi, C.; Ciemniak, C.; von Feilitzsch, F.; Gütlein, A.; Hagn, H.; Isaila, C.; Jochum, J.; Kimmerle, M.; Lanfranchi, J.-C.; Pfister, S.; Potzel, W.; Rau, W.; Roth, S.; Rottler, K.; Sailer, C.; Scholl, S.; Usherov, I.; Westphal, W.

    CRESST is an experiment for the direct detection of dark matter particles via nuclear recoils. The CRESST detectors, based on CaWO4 scintillating crystals, are able to discriminate γ and β background by simultaneously measuring the light and phonon signals produced by particle interactions. The discrimination of the background is possible because of the different light output (Quenching Factor, QF) for nuclear and electron recoils. In this article a measurement is shown, aimed at the determination of the QFs of the different nuclei (O, Ca, W) of the detector crystal at 40-60 mK using an 11 MeV neutron beam produced at the Maier-Leibnitz-Laboratorium in Garching (MLL).

  18. Dynamical formation of horizons in recoiling D-branes

    SciTech Connect

    Ellis, John; Mavromatos, N. E.; Nanopoulos, D. V.

    2000-10-15

    A toy calculation of string or D-particle interactions within a world-sheet approach indicates that quantum recoil effects -- reflecting the gravitational back reaction on space-time foam due to the propagation of energetic particles -- induces the appearance of a microscopic event horizon, or ''bubble,'' inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a ''bounce'' solution. Within such ''bubbles,'' massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially 3 for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3-branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface.

  19. Dynamical formation of horizons in recoiling D-branes

    NASA Astrophysics Data System (ADS)

    Ellis, John; Mavromatos, N. E.; Nanopoulos, D. V.

    2000-10-01

    A toy calculation of string or D-particle interactions within a world-sheet approach indicates that quantum recoil effects-reflecting the gravitational back reaction on space-time foam due to the propagation of energetic particles-induces the appearance of a microscopic event horizon, or ``bubble,'' inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a ``bounce'' solution. Within such ``bubbles,'' massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially 3 for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3-branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface.

  20. Recoil-induced subradiance in an ultracold atomic gas

    SciTech Connect

    Cola, M. M.; Bigerni, D.; Piovella, N.

    2009-05-15

    Subradiance, i.e., the cooperative inhibition of spontaneous emission by destructive interatomic interference, can be realized in a cold atomic sample confined in a ring cavity and lightened by a two-frequency laser. The atoms, scattering the photons of the two laser fields into the cavity mode, recoil and change their momentum. Under proper conditions the atomic initial momentum state and the first two momentum recoil states form a three-level degenerate cascade. A stationary subradiant state is obtained after the scattered photons have left the cavity, leaving the atoms in a coherent superposition of the three collective momentum states. Both a semiclassical description of the process and the quantum subradiant state with its Wigner function are given. Antibunching, quantum correlations, and entanglement between the atomic modes of the subradiant state are demonstrated.

  1. Recoiling supermassive black holes: a search in the nearby universe

    SciTech Connect

    Lena, D.; Robinson, A.; Axon, D. J.; Merritt, D.; Marconi, A.; Capetti, A.; Batcheldor, D.

    2014-11-10

    The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed Hubble Space Telescope archival images of 14 nearby core ellipticals, finding evidence for small (≲ 10 pc) displacements between the active galactic nucleus (AGN; the location of the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding objects that may be affected by large-scale isophotal asymmetries, we consider six galaxies to have detected displacements, including M87, where a displacement was previously reported by Batcheldor et al. In individual objects, these displacements can be attributed to residual gravitational recoil oscillations following a major or minor merger within the last few gigayears. For plausible merger rates, however, there is a high probability of larger displacements than those observed, if SBH coalescence took place in these galaxies. Remarkably, the AGN-photocenter displacements are approximately aligned with the radio source axis in four of the six galaxies with displacements, including three of the four having relatively powerful kiloparsec-scale jets. This suggests intrinsic asymmetries in radio jet power as a possible displacement mechanism, although approximate alignments are also expected for gravitational recoil. Orbital motion in SBH binaries and interactions with massive perturbers can produce the observed displacement amplitudes but do not offer a ready explanation for the alignments.

  2. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, A.R.; Gruen, D.M.; Lamich, G.J.

    1994-09-13

    A time-of-flight direct recoil and ion scattering spectrometer beam line is disclosed. The beam line includes an ion source which injects ions into pulse deflection regions and separated by a drift space. A final optics stage includes an ion lens and deflection plate assembly. The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions. 23 figs.

  3. Recoil Polarization for Neutral Pion Electroproduction near the Delta Resonance

    SciTech Connect

    Kelly, James J

    2003-10-01

    We have measured angular distributions for recoil polarization in the p(e,e'p)p0 reaction at Q2»1(GeV/c)2 with 1.16 |lte| W |lte|1.36 GeV across the D resonance. The data are compared with representative models and a truncated Legendre analysis is compared with a more general multipole analysis.

  4. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, Alan R.; Gruen, Dieter M.; Lamich, George J.

    1994-01-01

    A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

  5. The velocity and recoil of DNA bands during gel electrophoresis

    NASA Astrophysics Data System (ADS)

    Keiner, Louis E.; Holzwarth, G.

    1992-09-01

    The velocity and recoil of bands of DNA containing 48.5 to 4800 kilobasepairs (kb) were measured during pulsed-field gel electrophoresis by a video imaging and analysis system. When a 10 V/cm electric field was first applied, the velocity showed an initial sharp peak after approximately 1 s whose amplitude depended on the molecular weight of the DNA and the rest time and polarity of the previous pulse. For example, G DNA (670 kb) exhibited an initial velocity peak of 13 μm/s. The velocity then oscillated through a shallow minimum and small maximum before reaching a 5.0 μm/s plateau. After the field was turned off, the bands moved backward (recoiled). The band position obeyed a stretched-exponential relation, x = x0 exp[ - (t/τ)β] with amplitude x0 equal to approximately 1/10th of the DNA contour length and β≊0.6; for S. pombe DNA, x0 was a remarkable 165 μm. Both the initial velocity spike and the recoil arise from the presence of a significant fraction of U-shaped molecules with low configurational entropy. The initial velocity spike is exploited in field-inversion gel electrophoresis to generate the ``antiresonance,'' which is the basis of size-dependent mobility. Recent computer simulations which include tube-length fluctuations and tube leakage are in excellent accord with the measured velocities.

  6. Anatomy of the Binary Black Hole Recoil: A Multipolar Analysis

    NASA Technical Reports Server (NTRS)

    Schnittman, Jeremy; Buonanno, Alessandra; vanMeter, James R.; Baker, John G.; Boggs, William D.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.

    2007-01-01

    We present a multipolar analysis of the recoil velocity computed in recent numerical simulations of binary black hole coalescence, for both unequal masses and non-zero, non-precessing spins. We show that multipole moments up to and including 1 = 4 are sufficient to accurately reproduce the final recoil velocity (= 98%) and that only a few dominant modes contribute significantly to it (2 95%). We describe how the relative amplitude, and more importantly, the relative phase, of these few modes control the way in which the recoil builds up throughout the inspiral, merger, and ring-down phases. We also find that the numerical results can be reproduced, to a high level of accuracy, by an effective Newtonian formula for the multipole moments obtained by replacing in the Newtonian formula the radial separation with an effective radius computed from the numerical data. Beyond the merger, the numerical results are reproduced by a superposition of three Kerr quasi-normal modes. Analytic formulae, obtained by expressing the multipole moments in terms of the fundamental QNMs of a Kerr BH, are able to explain the onset and amount of '.anti-kick" for each of the simulations. Lastly, we apply this multipolar analysis to understand the remarkable difference between the amplitudes of planar and non-planar kicks for equal-mass spinning black holes.

  7. Recoiling from a Kick in the Head-On Case

    NASA Technical Reports Server (NTRS)

    Choi, Dae-Il; Kelly, Bernard J.; Boggs, William D.; Baker, John G.; Centrella, Joan; Van Meter, James

    2007-01-01

    Recoil "kicks" induced by gravitational radiation are expected in the inspiral and merger of black holes. Recently the numerical relativity community has begun to measure the significant kicks found when both unequal masses and spins are considered. Because understanding the cause and magnitude of each component of this kick may be complicated in inspiral simulations, we consider these effects in the context of a simple test problem. We study recoils from collisions of binaries with initially head-on trajectories, starting with the simplest case of equal masses with no spin; adding spin and varying the mass ratio, both separately and jointly. We find spin-induced recoils to be significant even in head-on configurations. Additionally, it appears that the scaling of transverse kicks with spins is consistent with post-Newtonian (PN) theory, even though the kick is generated in the nonlinear merger interaction, where PN theory should not apply. This suggests that a simple heuristic description might be effective in the estimation of spin-kicks.

  8. The recoil proton polarization in. pi. p elastic scattering

    SciTech Connect

    Seftor, C.J.

    1988-09-01

    The polarization of the recoil proton for ..pi../sup +/p and ..pi../sup -/p elastic scattering has been measured for various angles at 547 MeV/c and 625 MeV/c by a collaboration involving The George Washington University; the University of California, Los Angeles; and Abilene Christian University. The experiment was performed at the P/sup 3/ East experimental area of the Los Alamos Meson Physics Facility. Beam intensities varied from 0.4 to 1.0 x 10/sup 7/ ..pi../sup -/'s/sec and from 3.0 to 10.0 x 10/sup 7/ ..pi../sup +/'s/sec. The beam spot size at the target was 1 cm in the horizontal direction by 2.5 cm in the vertical direction. A liquid-hydrogen target was used in a flask 5.7 cm in diameter and 10 cm high. The scattered pion and recoil proton were detected in coincidence using the Large Acceptance Spectrometer (LAS) to detect and momentum analyze the pions and the JANUS recoil proton polarimeter to detect and measure the polarization of the protons. Results from this experiment are compared with previous measurements of the polarization, with analyzing power data previously taken by this group, and to partial-wave analysis predictions. 12 refs., 53 figs., 18 tabs.

  9. Measurement of Recoil Losses and Ranges for Spallation Products Produced in Proton Interactions with Al, Si, Mg at 200 and 500 MeV

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.

    2005-01-01

    Cosmic rays interact with extraterrestrial materials to produce a variety of spallation products. If these cosmogenic nuclides are produced within an inclusion in such material, then an important consideration is the loss of the product nuclei, which recoil out of the inclusion. Of course, at the same time, some atoms of the product nuclei under study may be knocked into the inclusion from the surrounding material, which is likely to have a different composition to that of the inclusion [1]. For example, Ne-21 would be produced in presolar grains, such as SiC, when irradiated in interstellar space. However, to calculate a presolar age, one needs to know how much 21Ne is retained in the grain. For small grains, the recoil losses might be large [2, 3] To study this effect under laboratory conditions, recoil measurements were made using protons with energies from 66 - 1600 MeV on Si, Al and Ba targets [3, 4, 5].

  10. A stretch/compress scheme for a high temporal resolution detector for the magnetic recoil spectrometer time (MRSt)

    DOE PAGESBeta

    Hilsabeck, T. J.; Frenje, J. A.; Hares, J. D.; Wink, C. W.

    2016-08-02

    Here we present a time-resolved detector concept for the magnetic recoil spectrometer for time-resolved measurements of the NIF neutron spectrum. The measurement is challenging due to the time spreading of the recoil protons (or deuterons) as they transit an energy dispersing magnet system. Ions arrive at the focal plane of the magnetic spectrometer over an interval of tens of nanoseconds. We seek to measure the time-resolved neutron spectrum with 20 ps precision by manipulating an electron signal derived from the ions. A stretch-compress scheme is employed to remove transit time skewing while simultaneously reducing the bandwidth requirements for signal recording.more » Simulation results are presented along with design concepts for structures capable of establishing the required electromagnetic fields.« less

  11. A stretch/compress scheme for a high temporal resolution detector for the magnetic recoil spectrometer time (MRSt)

    NASA Astrophysics Data System (ADS)

    Hilsabeck, T. J.; Frenje, J. A.; Hares, J. D.; Wink, C. W.

    2016-11-01

    A time-resolved detector concept for the magnetic recoil spectrometer for time-resolved measurements of the NIF neutron spectrum is presented. The measurement is challenging due to the time spreading of the recoil protons (or deuterons) as they transit an energy dispersing magnet system. Ions arrive at the focal plane of the magnetic spectrometer over an interval of tens of nanoseconds. We seek to measure the time-resolved neutron spectrum with 20 ps precision by manipulating an electron signal derived from the ions. A stretch-compress scheme is employed to remove transit time skewing while simultaneously reducing the bandwidth requirements for signal recording. Simulation results are presented along with design concepts for structures capable of establishing the required electromagnetic fields.

  12. First high-statistics and high-resolution recoil-ion data from the WITCH retardation spectrometer

    NASA Astrophysics Data System (ADS)

    Finlay, P.; Breitenfeldt, M.; Porobić, T.; Wursten, E.; Ban, G.; Beck, M.; Couratin, C.; Fabian, X.; Fléchard, X.; Friedag, P.; Glück, F.; Herlert, A.; Knecht, A.; Kozlov, V. Y.; Liénard, E.; Soti, G.; Tandecki, M.; Traykov, E.; Van Gorp, S.; Weinheimer, Ch.; Zákoucký, D.; Severijns, N.

    2016-07-01

    The first high-statistics and high-resolution data set for the integrated recoil-ion energy spectrum following the β^+ decay of 35Ar has been collected with the WITCH retardation spectrometer located at CERN-ISOLDE. Over 25 million recoil-ion events were recorded on a large-area multichannel plate (MCP) detector with a time-stamp precision of 2ns and position resolution of 0.1mm due to the newly upgraded data acquisition based on the LPC Caen FASTER protocol. The number of recoil ions was measured for more than 15 different settings of the retardation potential, complemented by dedicated background and half-life measurements. Previously unidentified systematic effects, including an energy-dependent efficiency of the main MCP and a radiation-induced time-dependent background, have been identified and incorporated into the analysis. However, further understanding and treatment of the radiation-induced background requires additional dedicated measurements and remains the current limiting factor in extracting a beta-neutrino angular correlation coefficient for 35Ar decay using the WITCH spectrometer.

  13. Excitation of positive ions by low-energy electrons - Relevance to the Io Torus

    NASA Astrophysics Data System (ADS)

    Smith, S. J.; Chutjian, A.; Mawhorter, R. J.; Williams, I. D.; Shemansky, D. E.

    1993-03-01

    The importance of measuring electron-ion excitation cross sections in singly and multiply charged positive ions is outlined, and recent results for Mg II and O II ions are given using the JPL's electron energy-loss merged-beams apparatus. Theoretical comparisons are given with two five-state close-coupling calculations. The energy variation of the collision strength is fitted with a semiempirical analytic function which includes approximations to polarization, resonance, and exchange contributions. In O II, first spectra anywhere of electron excitation of the optically allowed transitions are presented. In addition, excitations of two low lying, optically forbidden transitions are detected for the first time.

  14. The Final Merger of Massive Black Holes: Recoils, Gravitational Waves, and Electromagnetic Signatures

    NASA Technical Reports Server (NTRS)

    Centrella, Joan M.

    2010-01-01

    The final merger of two massive black holes produces a powerful burst of gravitational radiation, emitting more energy than all the stars in the observable universe combined. The resulting gravitational waveforms will be easily detectable by the space-based LISA out to redshifts z greater than 10, revealing the masses and spins of the black holes to high precision. If the merging black holes have unequal masses, or asymmetric spins, the final black hole that forms can recoil with a velocity exceeding 1000 km/s. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new results that are revealing the dynamics and waveforms of binary black hole mergers, recoil velocities, and the possibility of accompanying electromagnetic outbursts.

  15. Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.

    PubMed

    Komatsubara, T; Sasa, K; Ohshima, H; Kimura, H; Tajima, Y; Takahashi, T; Ishii, S; Yamato, Y; Kurosawa, M

    2008-07-01

    In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method. PMID:18509666

  16. Oxygen recoil implant from SiO{sub 2} layers into single-crystalline silicon

    SciTech Connect

    Wang, G.; Chen, Y.; Li, D.; Oak, S.; Srivastav, G.; Banerjee, S.; Tasch, A.; Merrill, P.; Bleiler, R.

    2001-06-01

    It is important to understand the distribution of recoil-implanted atoms and the impact on device performance when ion implantation is performed at a high dose through surface materials into single crystalline silicon. For example, in ultralarge scale integration impurity ions are often implanted through a thin layer of screen oxide and some of the oxygen atoms are inevitably recoil implanted into single-crystalline silicon. Theoretical and experimental studies have been performed to investigate this phenomenon. We have modified the Monte Carlo ion implant simulator, UT-Marlowe (B. Obradovic, G. Wang, Y. Chen, D. Li, C. Snell, and A. F. Tasch, UT-MARLOWE Manual, 1999), which is based on the binary collision approximation, to follow the full cascade and to dynamically modify the stoichiometry of the Si layer as oxygen atoms are knocked into it. CPU reduction techniques are used to relieve the demand on computational power when such a full cascade simulation is involved. Secondary ion mass spectrometry (SIMS) profiles of oxygen have been carefully obtained for high dose As and BF{sub 2} implants at different energies through oxide layers of various thicknesses, and the simulated oxygen profiles are found to agree very well with the SIMS data. {copyright} 2001 American Institute of Physics.

  17. Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.

    PubMed

    Komatsubara, T; Sasa, K; Ohshima, H; Kimura, H; Tajima, Y; Takahashi, T; Ishii, S; Yamato, Y; Kurosawa, M

    2008-07-01

    In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method.

  18. Relevance of behavioral and social models to the study of consumer energy decision making and behavior

    SciTech Connect

    Burns, B.A.

    1980-11-01

    This report reviews social and behavioral science models and techniques for their possible use in understanding and predicting consumer energy decision making and behaviors. A number of models and techniques have been developed that address different aspects of the decision process, use different theoretical bases and approaches, and have been aimed at different audiences. Three major areas of discussion were selected: (1) models of adaptation to social change, (2) decision making and choice, and (3) diffusion of innovation. Within these three areas, the contributions of psychologists, sociologists, economists, marketing researchers, and others were reviewed. Five primary components of the models were identified and compared. The components are: (1) situational characteristics, (2) product characteristics, (3) individual characteristics, (4) social influences, and (5) the interaction or decision rules. The explicit use of behavioral and social science models in energy decision-making and behavior studies has been limited. Examples are given of a small number of energy studies which applied and tested existing models in studying the adoption of energy conservation behaviors and technologies, and solar technology.

  19. Some Simple Arguments about Cost Externalization and its Relevance to the Price of Fusion Energy

    SciTech Connect

    Budny, R.; Winfree, R.

    1999-09-27

    The primary goal of fusion energy research is to develop a source of energy that is less harmful to the environment than are the present sources. A concern often expressed by critics of fusion research is that fusion energy will never be economically competitive with fossil fuels, which in 1997 provided 75% of the world's energy. And in fact, studies of projected fusion electricity generation generally project fusion costs to be higher than those of conventional methods. Yet it is widely agreed that the environmental costs of fossil fuel use are high. Because these costs aren't included in the market price, and furthermore because many governments subsidize fossil fuel production, fossil fuels seem less expensive than they really are. Here we review some simple arguments about cost externalization which provide a useful background for discussion of energy prices. The collectively self-destructive behavior that is the root of many environmental problems, including fossil fuel use, was termed ''the tragedy of the commons'' by the biologist G. Hardin. Hardin's metaphor is that of a grazing commons that is open to all. Each herdsman, in deciding whether to add a cow to his herd, compares the benefit of doing so, which accrues to him alone, to the cost, which is shared by all the herdsmen using the commons, and therefore adds his cow. In this way individually rational behavior leads to the collective destruction of the shared resource. As Hardin pointed out, pollution is one kind of tragedy of the commons. CO{sub 2} emissions and global warming are in this sense classic tragedies.

  20. Molecular modeling of the effects of 40Ar recoil in illite particles on their K-Ar isotope dating

    NASA Astrophysics Data System (ADS)

    Szczerba, Marek; Derkowski, Arkadiusz; Kalinichev, Andrey G.; Środoń, Jan

    2015-06-01

    The radioactive decay of 40K to 40Ar is the basis of isotope age determination of micaceous clay minerals formed during diagenesis. The difference in K-Ar ages between fine and coarse grained illite particles has been interpreted using detrital-authigenic components system, its crystallization history or post-crystallization diffusion. Yet another mechanism should also be considered: natural 40Ar recoil. Whether this recoil mechanism can result in a significant enough loss of 40Ar to provide observable decrease of K-Ar age of the finest illite crystallites at diagenetic temperatures - is the primary objective of this study which is based on molecular dynamics (MD) computer simulations. All the simulations were performed for the same kinetic energy (initial velocity) of the 40Ar atom, but for varying recoil angles that cover the entire range of their possible values. The results show that 40Ar recoil can lead to various deformations of the illite structure, often accompanied by the displacement of OH groups or breaking of the Si-O bonds. Depending on the recoil angle, there are four possible final positions of the 40Ar atom with respect to the 2:1 layer at the end of the simulation: it can remain in the interlayer space or end up in the closest tetrahedral, octahedral or the opposite tetrahedral sheet. No simulation angles were found for which the 40Ar atom after recoil passes completely through the 2:1 layer. The energy barrier for 40Ar passing through the hexagonal cavity from the tetrahedral sheet into the interlayer was calculated to be 17 kcal/mol. This reaction is strongly exothermic, therefore there is almost no possibility for 40Ar to remain in the tetrahedral sheet of the 2:1 layer over geological time periods. It will either leave the crystal, if close enough to the edge, or return to the interlayer space. On the other hand, if 40Ar ends up in the octahedral sheet after recoil, a substantially higher energy barrier of 55 kcal/mol prevents it from leaving

  1. Using inertial fusion implosions to measure the T+He3 fusion cross section at nucleosynthesis-relevant energies

    DOE PAGESBeta

    Zylstra, A. B.; Herrmann, H. W.; Johnson, M. Gatu; Kim, Y. H.; Frenje, J. A.; Hale, G.; Li, C. K.; Rubery, M.; Paris, M.; Bacher, A.; et al

    2016-07-11

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of 6Li in low-metallicity stars. Using high energy-density plasmas we measure the T(3He,γ)6Li reaction rate, a candidate for anomalously high 6Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. In conclusion, this is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.

  2. Using Inertial Fusion Implosions to Measure the T+^{3}He Fusion Cross Section at Nucleosynthesis-Relevant Energies.

    PubMed

    Zylstra, A B; Herrmann, H W; Johnson, M Gatu; Kim, Y H; Frenje, J A; Hale, G; Li, C K; Rubery, M; Paris, M; Bacher, A; Brune, C R; Forrest, C; Glebov, V Yu; Janezic, R; McNabb, D; Nikroo, A; Pino, J; Sangster, T C; Séguin, F H; Seka, W; Sio, H; Stoeckl, C; Petrasso, R D

    2016-07-15

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of ^{6}Li in low-metallicity stars. Using high-energy-density plasmas we measure the T(^{3}He,γ)^{6}Li reaction rate, a candidate for anomalously high ^{6}Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. This is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.

  3. Using Inertial Fusion Implosions to Measure the T + 3He Fusion Cross Section at Nucleosynthesis-Relevant Energies

    NASA Astrophysics Data System (ADS)

    Zylstra, A. B.; Herrmann, H. W.; Johnson, M. Gatu; Kim, Y. H.; Frenje, J. A.; Hale, G.; Li, C. K.; Rubery, M.; Paris, M.; Bacher, A.; Brune, C. R.; Forrest, C.; Glebov, V. Yu.; Janezic, R.; McNabb, D.; Nikroo, A.; Pino, J.; Sangster, T. C.; Séguin, F. H.; Seka, W.; Sio, H.; Stoeckl, C.; Petrasso, R. D.

    2016-07-01

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of 6Li in in low-metallicity stars. Using high-energy-density plasmas we measure the T (3He, ,γ )6Li reaction rate, a candidate for anomalously high 6Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. This is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.

  4. Using Inertial Fusion Implosions to Measure the T+^{3}He Fusion Cross Section at Nucleosynthesis-Relevant Energies.

    PubMed

    Zylstra, A B; Herrmann, H W; Johnson, M Gatu; Kim, Y H; Frenje, J A; Hale, G; Li, C K; Rubery, M; Paris, M; Bacher, A; Brune, C R; Forrest, C; Glebov, V Yu; Janezic, R; McNabb, D; Nikroo, A; Pino, J; Sangster, T C; Séguin, F H; Seka, W; Sio, H; Stoeckl, C; Petrasso, R D

    2016-07-15

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of ^{6}Li in low-metallicity stars. Using high-energy-density plasmas we measure the T(^{3}He,γ)^{6}Li reaction rate, a candidate for anomalously high ^{6}Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. This is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics. PMID:27472118

  5. Cars and Kinetic Energy -- Some Simple Physics with Real-World Relevance

    NASA Astrophysics Data System (ADS)

    Parthasarathy, Raghuveer

    2012-10-01

    Understanding energy usage is crucial to understanding modern civilization, as well as many of the challenges it faces. Energy-related issues also offer real-world examples of important physical concepts, and as such have been the focus of several articles in The Physics Teacher in the past few decades (e.g., Refs. 1-5, noted further below). Here, I illustrate how a basic understanding of kinetic energy—a topic encountered early in any introductory physics course—enables significant insights into the nature of automobile transportation. Specifically, we can accurately predict how much power the average driver in the United States uses, and explain what determines this, without needing to consider any aspects of mechanical engineering or engine design.

  6. Measurement of the Ca40(α,γ)Ti44 reaction relevant for supernova nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Vockenhuber, C.; Ouellet, C. O.; The, L.-S.; Buchmann, L.; Caggiano, J.; Chen, A. A.; Crawford, H.; D'Auria, J. M.; Davids, B.; Fogarty, L.; Frekers, D.; Hussein, A.; Hutcheon, D. A.; Kutschera, W.; Laird, A. M.; Lewis, R.; O'Connor, E.; Ottewell, D.; Paul, M.; Pavan, M. M.; Pearson, J.; Ruiz, C.; Ruprecht, G.; Trinczek, M.; Wales, B.; Wallner, A.

    2007-09-01

    The short-lived nuclide Ti44 is an important nuclide for the understanding of explosive nucleosynthesis. The main production reaction, Ca40(α,γ)Ti44, has been studied in inverse kinematics with the recoil mass spectrometer DRAGON located at the TRIUMF-ISAC facility in Vancouver, Canada. The temperature range relevant for α-rich freeze-out during a core-collapse supernova has been covered entirely with a Ca40 beam of 0.60 to 1.15 MeV/nucleon. All relevant quantities for the calculation of the astrophysical reaction rate have been measured directly. Because of many previously undiscovered resonances, the reaction rate derived from the energy dependent Ti44 yield is higher than the one based on previous prompt γ-ray studies commonly used in supernova models. The presented new rate results in an increased Ti44 production in supernovae.

  7. Energy absorption buildup factors of human organs and tissues at energies and penetration depths relevant for radiotherapy and diagnostics.

    PubMed

    Manohara, S R; Hanagodimath, S M; Gerward, L

    2011-11-15

    Energy absorption geometric progression (GP) fitting parameters and the corresponding buildup factors have been computed for human organs and tissues, such as adipose tissue, blood (whole), cortical bone, brain (grey/white matter), breast tissue, eye lens, lung tissue, skeletal muscle, ovary, testis, soft tissue, and soft tissue (4-component), for the photon energy range 0.015-15 MeV and for penetration depths up to 40 mfp (mean free path). The chemical composition of human organs and tissues is seen to influence the energy absorption buildup factors. It is also found that the buildup factor of human organs and tissues changes significantly with the change of incident photon energy and effective atomic number, Z(eff). These changes are due to the dominance of different photon interaction processes in different energy regions and different chemical compositions of human organs and tissues. With the proper knowledge of buildup factors of human organs and tissues, energy absorption in the human body can be carefully controlled. The present results will help in estimating safe dose levels for radiotherapy patients and also useful in diagnostics and dosimetry. The tissue-equivalent materials for skeletal muscle, adipose tissue, cortical bone, and lung tissue are also discussed. It is observed that water and MS20 are good tissue equivalent materials for skeletal muscle in the extended energy range.

  8. A surface energy analysis of mucoadhesion: contact angle measurements on polycarbophil and pig intestinal mucosa in physiologically relevant fluids.

    PubMed

    Lehr, C M; Bouwstra, J A; Boddé, H E; Junginger, H E

    1992-01-01

    The possible role of surface energy thermodynamics in mucoadhesion was investigated with Polycarbophil and pig intestinal mucosa. In separate experiments, the surface energy parameters of the substrate (mucosa) and the adhesive (polymer film) were determined by contact angle measurements on captive air/octane bubbles in three physiologically relevant test fluids (isotonic saline, artificial gastric fluid, and artificial intestinal fluid). Whereas the swollen Polycarbophil films were relatively hydrophilic as indicated by small water contact angles (22, 23, and 16 degrees), the water contact angles measured on mucosal tissue were significantly larger (61, 48, and 57 degrees). Hence, mucus was found to possess an appreciable hydrophobicity. The measured adhesive performance (force of detachment) between Polycarbophil and pig small intestinal mucosa was highest in nonbuffered saline medium, intermediate in gastric fluid, and minimal in intestinal fluid. In agreement with this trend, the mismatch in surface polarities between substrate and adhesive, calculated from the contact angle data, increased in the same order.

  9. Collisions between low-energy electrons and small polyatomic targets of biological relevance

    NASA Astrophysics Data System (ADS)

    Hargreaves, Leigh

    2016-05-01

    Over the last decade, cross section measurements and calculations for DNA prototype molecules have received significant attention from the collisions community, due to the potential applications of this data in modelling electron transport through biological matter with a view to improving radiation dosimetry. Such data are additionally interesting from a fundamental aspect, as small carbon-based molecules are ideal targets for considering effects including target conformation, long-range dynamical interactions and coupling effects between the various degrees of freedom on the scattering properties of the target. At the California State University Fullerton, we have made a series of measurements of the elastic, vibrationally inelastic and electronically inelastic cross sections for a variety of small polyatomic targets, including water and the basic alcohols, ethylene, toluene and several fluorinated alkanes. These processes are important in a range of applications, primarily for modelling electron transport and thermalization, and energy deposition to a biological media. The data were obtained using a high resolution electron energy-loss spectrometer, operating in a crossed beam configuration with a moveable aperture gas source. The gas source design facilitates both an expedient and highly accurate method of removing background signal, and removes uncertainties from the data due to uncertainties in the beam profile. We have also performed scattering calculations employing the Schwinger Multichannel method, in collaboration with the California institute of technology, to compare with our measurements. In this talk, I will present an overview of our recent data and future research plans.

  10. The repair of environmentally relevant DNA double strand breaks caused by high linear energy transfer irradiation--no simple task.

    PubMed

    Moore, Shaun; Stanley, Fintan K T; Goodarzi, Aaron A

    2014-05-01

    High linear energy transfer (LET) ionising radiation (IR) such as radon-derived alpha particles and high mass, high energy (HZE) particles of cosmic radiation are the predominant forms of IR to which humanity is exposed throughout life. High-LET forms of IR are established carcinogens relevant to human cancer, and their potent mutagenicity is believed, in part, to be due to a greater incidence of clustered DNA double strand breaks (DSBs) and associated lesions, as ionization events occur within a more confined genomic space. The repair of such DNA damage is now well-documented to occur with slower kinetics relative to that induced by low-LET IR, and to be more reliant upon homology-directed repair pathways. Underlying these phenomena is the relative inability of non-homologous end-joining (NHEJ) to adequately resolve high-LET IR-induced DSBs. Current findings suggest that the functionality of the DNA-dependent protein kinase (DNA-PK), comprised of the Ku70-Ku80 heterodimer and the DNA-PK catalytic subunit (DNA-PKcs), is particularly perturbed by high-LET IR-induced clustered DSBs, rendering DNA-PK dependent NHEJ less relevant to resolving these lesions. By contrast, the NHEJ-associated DNA processing endonuclease Artemis shows a greater relevance to high-LET IR-induced DSB repair. Here, we will review the cellular response to high-LET irradiation, the implications of the chronic, low-dose modality of this exposure and molecular pathways that respond to high-LET irradiation induced DSBs, with particular emphasis on NHEJ factors. PMID:24565812

  11. Fundamental Studies of Charge Migration and Delocalization Relevant to Solar Energy Conversion

    SciTech Connect

    Michael J. Therien

    2012-06-01

    This program aimed to understand the molecular-level principles by which complex chemical systems carry out photochemical charge separation, transport, and storage, and how these insights could impact the design of practical solar energy conversion and storage devices. Towards these goals, this program focused on: (1) carrying out fundamental mechanistic and transient dynamical studies of proton-coupled electron-transfer (PCET) reactions; (2) characterizing and interrogating via electron paramagnetic resonance (EPR) spectroscopic methods novel conjugated materials that feature large charge delocalization lengths; and (3) exploring excitation delocalization and migration, as well as polaron transport properties of meso-scale assemblies that are capable of segregating light-harvesting antennae, nanoscale wire-like conduction elements, and distinct oxidizing and reducing environments.

  12. Theoretical and experimental studies of electrified interfaces relevant to energy storage.

    SciTech Connect

    Templeton, Jeremy Alan; Jones, Reese E.; Lee, Jonathan W.; Mandadapu, Kranthi Kiran; Kliewer, Christopher Jesse; Sasaki, Darryl Yoshio; Kane, Marie C.; Reyes, Karla Rosa; Hayden, Carl C.

    2013-12-01

    Advances in technology for electrochemical energy storage require increased understanding of electrolyte/electrode interfaces, including the electric double layer structure, and processes involved in charging of the interface, and the incorporation of this understanding into quantitative models. Simplified models such as Helmholtz's electric double-layer (EDL) concept don't account for the molecular nature of ion distributions, solvents, and electrode surfaces and therefore cannot be used in predictive, high-fidelity simulations for device design. This report presents theoretical results from models that explicitly include the molecular nature of the electrical double layer and predict critical electrochemical quantities such as interfacial capacitance. It also describes development of experimental tools for probing molecular properties of electrochemical interfaces through optical spectroscopy. These optical experimental methods are designed to test our new theoretical models that provide descriptions of the electric double layer in unprecedented detail.

  13. B -> D* l nu at zero recoil: an update

    SciTech Connect

    Bailey, Jon A.; Bazavov, A.; Bernard, C.; Bouchard, C.M.; DeTar, C.; El-Khadra, A.X.; Freeland, E.D.; Gamiz, E.; Gottlieb, Steven; Heller, U.M.; Hetrick, J.E.

    2010-11-01

    We present an update of our calculation of the form factor for {bar B} {yields} D*{ell}{bar {nu}} at zero recoil, with higher statistics and finer lattices. As before, we use the Fermilab action for b and c quarks, the asqtad staggered action for light valence quarks, and the MILC ensembles for gluons and light quarks (Luescher-Weisz married to 2+1 rooted staggered sea quarks). In this update, we have reduced the total uncertainty on F(1) from 2.6% to 1.7%.

  14. Projectile paths corrected for recoil and air resistance

    NASA Astrophysics Data System (ADS)

    Kemp, H. R.

    1986-01-01

    The angle of projection of a bullet is not the same as the angle of the bore of the firearm just before firing. This is because recoil alters the direction of the barrel as the bullet moves along the barrel. Neither is the angle of projection of an arrow the same as the direction of the arrow just before it is projected. The difficulty in obtaining the angle of projection limits the value of the standard equation for trajectories relative to a horizontal plane. Furthermore, air resistance makes this equation unrealistic for all but short ranges.

  15. Precision lifetime measurements using the recoil distance method

    SciTech Connect

    Kruecken, R.

    2000-02-01

    The recoil distance method (RDM) for the measurements of lifetimes of excited nuclear levels in the range from about 1 ps to 1,000 ps is reviewed. The New Yale Plunger Device for RDM experiments is introduced and the Differential Decay Curve Method for their analysis is reviewed. Results from recent RDM experiments on SD bands in the mass-190 region, shears bands in the neutron deficient lead isotopes, and ground state bands in the mass-130 region are presented. Perspectives for the use of RDM measurements in the study of neutron-rich nuclei are discussed.

  16. Recoil separator ERNA: charge state distribution, target density, beam heating, and longitudinal acceptance

    NASA Astrophysics Data System (ADS)

    Schürmann, D.; Strieder, F.; Di Leva, A.; Gialanella, L.; De Cesare, N.; D'Onofrio, A.; Imbriani, G.; Klug, J.; Lubritto, C.; Ordine, A.; Roca, V.; Röcken, H.; Rolfs, C.; Rogalla, D.; Romano, M.; Schümann, F.; Terrasi, F.; Trautvetter, H. P.

    2004-10-01

    For improved cross section measurements of the reaction 12C(α,γ)16O in inverted kinematics, a recoil separator ERNA is developed at the 4 MV Dynamitron tandem accelerator in Bochum to detect directly the 16O recoils with high efficiency. The 16O recoils are produced by the 12C projectiles in a windowless 4He gas target. We report on the charge state distribution of the 16O recoils, the gas target density, the beam heating of the gas target, and the acceptance of the separator along the extended gas target.

  17. Survey of Laser Markets Relevant to Inertial Fusion Energy Drivers, information for National Research Council

    SciTech Connect

    Bayramian, A J; Deri, R J; Erlandson, A C

    2011-02-24

    Development of a new technology for commercial application can be significantly accelerated by leveraging related technologies used in other markets. Synergies across multiple application domains attract research and development (R and D) talent - widening the innovation pipeline - and increases the market demand in common components and subsystems to provide performance improvements and cost reductions. For these reasons, driver development plans for inertial fusion energy (IFE) should consider the non-fusion technology base that can be lveraged for application to IFE. At this time, two laser driver technologies are being proposed for IFE: solid-state lasers (SSLs) and KrF gas (excimer) lasers. This document provides a brief survey of organizations actively engaged in these technologies. This is intended to facilitate comparison of the opportunities for leveraging the larger technical community for IFE laser driver development. They have included tables that summarize the commercial organizations selling solid-state and KrF lasers, and a brief summary of organizations actively engaged in R and D on these technologies.

  18. Silicon shallow doping by erbium and oxygen recoils implantation

    NASA Astrophysics Data System (ADS)

    Feklistov, K. V.; Cherkov, A. G.; Popov, V. P.

    2016-09-01

    In order to get shallow high doping of Si with optically active complexes ErOn, Er followed by O recoils implantation was realized by means of subsequent Ar+ 250-290 keV implantation with doses 2×1015-1×1016 cm-2 through 50-nm deposited films of Er and then SiO2, accordingly. High Er concentration up to 5×1020 cm-3 to the depth of 10 nm was obtained after implantation. However, about a half of the Er implanted atoms become part of surface SiO2 during post-implantation annealing at 950 °C for 1 h in the N2 ambient under a SiO2 cap. The mechanism of Er segregation into the cap oxide following the moving amorphous-crystalline interface during recrystallization was rejected by the transmission electron microscopy (TEM) analysis. Instead, the other mechanism of immobile Er atoms and redistribution of recoil-implanted O atoms toward cap oxide was proposed. It explains the observed formation of two Er containing phases: Er-Si-O phase with a high O content adjacent to the cap oxide and deeper O depleted Er-Si phase. The correction of heat treatments is proposed in order to avoid the above-mentioned problems.

  19. Development of a compact magnetic proton recoil spectrometer for measurement of deuterium-tritium neutrons

    SciTech Connect

    Zhang, Jianfu Ouyang, Xiaoping; Zhang, Xianpeng; Qiu, Suizheng; Zhang, Guoguang; Ruan, Jinlu; Zhang, Xiaodong; Yang, Shaohua; Song, Jiwen; Liu, Linyue; Li, Hongyun

    2015-12-15

    A new compact magnetic proton recoil (MPR) neutron spectrometer has been designed for precise measurement of deuterium-tritium (DT) neutrons. This design is presented emphasizing the magnetic analyzing system, which is based on a compact quadrupole-dipole (QD) electromagnet. The focal plane detector (FPD) is also discussed with respect to application for the next step. The characteristics of the MPR spectrometer were calculated by using Monte Carlo simulation. A preliminary experiment was performed to test the magnetic analyzing system and the proton images of the FPD. Since the QD electromagnet design allows for a larger foil thickness and solid angle to be utilized, the MPR spectrometer defined in this paper can achieve neutron detection efficiency more than 5 × 10{sup −7} at an energy resolution of 1.5% for measuring DT neutrons.

  20. Neutron scattering facility for the calibration of the response to nuclear recoils

    NASA Astrophysics Data System (ADS)

    Jochum, J.; Chambon, B.; Drain, D.; von Feilitzsch, F.; Gascon, J.; Huber, M.; Jagemann, T.; de Jésus, M.; Lachenmaier, T.; Lanfranchi, J.-C.; Martineau, O.; Potzel, W.; Rüdig, A.; Schnagl, J.; Simon, E.; Stark, M.; Stern, M.; Wulandari, H.

    2002-02-01

    A possibility to search for elementary particles as dark matter candidates is to detect elastic scattering with cryogenic detectors. For the interpretation of the data one has to determine the detector response to nuclear recoils, the so-called quenching factors. They can differ for the heat-, for the scintillation- and for the ionization-signal and can be measured by scattering of neutrons. The CRESST- and the EDELWEISS-collaborations have set up a neutron scattering facility for cryogenic detectors at the tandem-accelerator of the Munich `Maier-Leibniz-Labor.' The scattering angle and the time-of-flight of the neutrons are measured by an array of liquid scintillator cells. The pulsed high energy (11 MeV) neutron beam is created by nuclear reaction of a 11B on a H2-gas target. The set-up and the results of first tests are presented. .

  1. Development of a new Recoil Distance Technique using Coulomb Excitation in Inverse Kinematics

    SciTech Connect

    Rother, Wolfram; Dewald, Alfred; Ilie, Gabriela; Pissulla, Thomas; Melon, Barbara; Jolie, Jan; Pascovici, Gheorghe; Iwasaki, Hironori; Hackstein, Matthias; Zell, Karl-Oskar; Julin, Rauno; Jones, Peter; Greenlees, Paul; Rahkila, Panu; Uusitalo, Juha; Scholey, Cath; Harissopulos, Sotirios; Lagoyannis, Anastasios; Konstantinopoulos, Theodore; Grahn, Tuomas

    2009-01-28

    We report on an experiment using Coulomb excitation in inverse kinematics in combination with the plunger technique for measuring lifetimes of excited states of the projectiles. Aside from the investigation of E(5) features in {sup 128}Xe, the aim was to explore the special features of such experiments which are also suited to be used with radioactive beams. The measurement was performed at the JYFL with the Koeln coincidence plunger device and the JUROGAM spectrometer using a {sup 128}Xe beam impinging on a {sup nat}Fe target at a beam energy of 525 MeV. Recoils were detected by means of 32 solar cells placed at extreme forward angles. Particle-gated {gamma}-singles and {gamma}{gamma}-coincidences were measured at different target-degrader distances. Details of the experiment and first results are presented.

  2. The role of localized recoil in the formation of Kikuchi patterns.

    PubMed

    Winkelmann, Aimo; Vos, Maarten

    2013-02-01

    In electron scattering from crystals, diffraction spots are replaced by Kikuchi patterns at high momentum transfer. Kikuchi pattern formation is based on the concept of effective incoherent electron sources (or detectors) inside a crystal. The resulting incoherence is a consequence of energy transfer connected with the momentum transfer in large-angle scattering events. We identify atomic recoil as a key incoherent process giving rise to electron Kikuchi patterns in the scope of the "channeling-in and channeling-out" model of electron backscatter diffraction (EBSD) and electron channeling patterns (ECP) in the scanning electron microscope (SEM). Using model calculations, we explore the characteristic role of the localization of the incoherent scattering event at specific places within the unit cell. In this way, we explain why sometimes inelastic losses do cause Kikuchi-type contrast, and sometimes inelastic losses result in the disappearance of this contrast in the SEM.

  3. Shielding design for the Magnetic Recoil Spectrometer (MRS) at OMEGA and the NIF using TART2002

    NASA Astrophysics Data System (ADS)

    Casey, D. T.; Glebov, V. Yu.; Haan, S.; Wilson, D. C.; Leeper, R.

    2005-10-01

    A Magnetic Recoil Spectrometer (MRS) is currently being developed, at both OMEGA and the NIF, for measurements of down-scattered neutrons from which ρR of cryogenic DT implosions can be inferred. As is the case for complementary methods to measure ρR,ootnotetextC. K. Li et al, Phys. Plasmas 8, 4902 (2001) minimizing the effect of the background is critical for successful implementation. The established minimum S/B of 20, folded with CR-39 neutron response, determines the tolerable neutron fluence. The transport code TART2002 was used to calculate the neutron fluence at the MRS detector and provided input for design of the shielding for the MRS. This poster will present the current status of this project. This work was supported in part by LLE, LLNL, the U.S. DoE, the Univ. of Rochester, and the N.Y. State Energy Research and Development Authority.

  4. Development of a compact magnetic proton recoil spectrometer for measurement of deuterium-tritium neutrons.

    PubMed

    Zhang, Jianfu; Ouyang, Xiaoping; Qiu, Suizheng; Zhang, Guoguang; Ruan, Jinlu; Zhang, Xiaodong; Zhang, Xianpeng; Yang, Shaohua; Song, Jiwen; Liu, Linyue; Li, Hongyun

    2015-12-01

    A new compact magnetic proton recoil (MPR) neutron spectrometer has been designed for precise measurement of deuterium-tritium (DT) neutrons. This design is presented emphasizing the magnetic analyzing system, which is based on a compact quadrupole-dipole (QD) electromagnet. The focal plane detector (FPD) is also discussed with respect to application for the next step. The characteristics of the MPR spectrometer were calculated by using Monte Carlo simulation. A preliminary experiment was performed to test the magnetic analyzing system and the proton images of the FPD. Since the QD electromagnet design allows for a larger foil thickness and solid angle to be utilized, the MPR spectrometer defined in this paper can achieve neutron detection efficiency more than 5 × 10(-7) at an energy resolution of 1.5% for measuring DT neutrons.

  5. Development of a compact magnetic proton recoil spectrometer for measurement of deuterium-tritium neutrons.

    PubMed

    Zhang, Jianfu; Ouyang, Xiaoping; Qiu, Suizheng; Zhang, Guoguang; Ruan, Jinlu; Zhang, Xiaodong; Zhang, Xianpeng; Yang, Shaohua; Song, Jiwen; Liu, Linyue; Li, Hongyun

    2015-12-01

    A new compact magnetic proton recoil (MPR) neutron spectrometer has been designed for precise measurement of deuterium-tritium (DT) neutrons. This design is presented emphasizing the magnetic analyzing system, which is based on a compact quadrupole-dipole (QD) electromagnet. The focal plane detector (FPD) is also discussed with respect to application for the next step. The characteristics of the MPR spectrometer were calculated by using Monte Carlo simulation. A preliminary experiment was performed to test the magnetic analyzing system and the proton images of the FPD. Since the QD electromagnet design allows for a larger foil thickness and solid angle to be utilized, the MPR spectrometer defined in this paper can achieve neutron detection efficiency more than 5 × 10(-7) at an energy resolution of 1.5% for measuring DT neutrons. PMID:26724081

  6. Statistical and Spectral Analysis of Wind Characteristics Relevant to Wind Energy Assessment Using Tower Measurements in Complex Terrain

    DOE PAGESBeta

    Belu, Radian; Koracin, Darko

    2013-01-01

    The main objective of the study was to investigate spatial and temporal characteristics of the wind speed and direction in complex terrain that are relevant to wind energy assessment and development, as well as to wind energy system operation, management, and grid integration. Wind data from five tall meteorological towers located in Western Nevada, USA, operated from August 2003 to March 2008, used in the analysis. The multiannual average wind speeds did not show significant increased trend with increasing elevation, while the turbulence intensity slowly decreased with an increase were the average wind speed. The wind speed and direction weremore » modeled using the Weibull and the von Mises distribution functions. The correlations show a strong coherence between the wind speed and direction with slowly decreasing amplitude of the multiday periodicity with increasing lag periods. The spectral analysis shows significant annual periodicity with similar characteristics at all locations. The relatively high correlations between the towers and small range of the computed turbulence intensity indicate that wind variability is dominated by the regional synoptic processes. Knowledge and information about daily, seasonal, and annual wind periodicities are very important for wind energy resource assessment, wind power plant operation, management, and grid integration.« less

  7. Double and single ionization of He and other targets studied using cold target recoil momentum spectroscopy

    SciTech Connect

    Doerner, R.; Feagin, J. M.; Brauning, H.; Jagutzki, O.; Jung, M.; Kanter, E. P.; Khemliche, H.; Kravis, S.; Mergel, V.; Prior, M. H.; Schmidt-Boeking, H.; Spielberger, L.; Ullrich, J.; Unverzagt, M.; Vogt, T.

    1997-04-01

    Double ionization of an atom by a single photon is the simplest and most fundamental many-electron process. The ejection of two electrons following the absorption of one photon is strictly prohibited in an independent electron approximation. Thus determining the probability of double photoionization alone is already a challenging test of the understanding of electron-electron correlation. Furthermore, in the slow breakup of a bound system into three charged particles, the final state wave function must represent a high degree of few-body Coulomb correlation involving the simultaneous interaction of all three particles. The case of double photoionization is again particularly well suited to study this problem as the energy and the angular momentum delivered to the system can be very well controlled. Helium, as the most basic three body system, has been the target of extensive studies over the past decades. The purpose of this project has been to study double and single ionization using cold target recoil ion momentum spectroscopy (COLTRIMS). This technique has been widely applied within the area of ion-atom collisions to study the dynamics of energy and momentum transfer in collisions between few-electron systems, and the entire technical machinery has been transferred to photon-atom collisions. The technique uses space- and time-imaging of He{sup +} and He{sup ++} recoil ions created in photon-He collisions to measure the full momentum vector of each ion produced. Event-mode recording is used and a solid angle of nearly 4{pi} is realized, allowing an extremely high data-collection efficiency. In order to reduce the initial momentum spread of the He target a precooled supersonic He jet is used.

  8. Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

    NASA Astrophysics Data System (ADS)

    Hall, G. N.; Izumi, N.; Landen, O. L.; Tommasini, R.; Holder, J. P.; Hargrove, D.; Bradley, D. K.; Lumbard, A.; Cruz, J. G.; Piston, K.; Lee, J. J.; Romano, E.; Bell, P. M.; Carpenter, A. C.; Palmer, N. E.; Felker, B.; Rekow, V.; Allen, F. V.

    2016-11-01

    Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro-channel plate) to provide gating and high DQE at the 40-200 keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Experiments were performed at energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.

  9. A RUNAWAY BLACK HOLE IN COSMOS: GRAVITATIONAL WAVE OR SLINGSHOT RECOIL?

    SciTech Connect

    Civano, F.; Elvis, M.; Lanzuisi, G.; Hao, H.; Aldcroft, T.; Jahnke, K.; Zamorani, G.; Comastri, A.; Bolzonella, M.; Blecha, L.; Loeb, A.; Bongiorno, A.; Brusa, M.; Leauthaud, A.; Mainieri, V.; Piconcelli, E.; Salvato, M.; Scoville, N.; Trump, J.; Vignali, C.

    2010-07-01

    We present a detailed study of a peculiar source detected in the COSMOS survey at z = 0.359. Source CXOC J100043.1+020637, also known as CID-42, has two compact optical sources embedded in the same galaxy. The distance between the two, measured in the HST/ACS image, is 0.''495 {+-} 0.''005 that, at the redshift of the source, corresponds to a projected separation of 2.46 {+-} 0.02 kpc. A large ({approx}1200 km s{sup -1}) velocity offset between the narrow and broad components of H{beta} has been measured in three different optical spectra from the VLT/VIMOS and Magellan/IMACS instruments. CID-42 is also the only X-ray source in COSMOS, having in its X-ray spectra a strong redshifted broad absorption iron line and an iron emission line, drawing an inverted P-Cygni profile. The Chandra and XMM-Newton data show that the absorption line is variable in energy by {Delta}E = 500 eV over four years and that the absorber has to be highly ionized in order not to leave a signature in the soft X-ray spectrum. That these features-the morphology, the velocity offset, and the inverted P-Cygni profile-occur in the same source is unlikely to be a coincidence. We envisage two possible explanations, both exceptional, for this system: (1) a gravitational wave (GW) recoiling black hole (BH), caught 1-10 Myr after merging; or (2) a Type 1/Type 2 system in the same galaxy where the Type 1 is recoiling due to the slingshot effect produced by a triple BH system. The first possibility gives us a candidate GW recoiling BH with both spectroscopic and imaging signatures. In the second case, the X-ray absorption line can be explained as a BAL-like outflow from the foreground nucleus (a Type 2 AGN) at the rearer one (a Type 1 AGN), which illuminates the otherwise undetectable wind, giving us the first opportunity to show that fast winds are present in obscured active galactic nuclei (AGNs), and possibly universal in AGNs.

  10. Beam suppression of the DRAGON recoil separator for 3He(α,γ)7Be

    NASA Astrophysics Data System (ADS)

    Sjue, S. K. L.; Nara Singh, B. S.; Adsley, P.; Buchmann, L.; Carmona-Gallardo, M.; Davids, B.; Fallis, J.; Fulton, B. R.; Galinski, N.; Hager, U.; Hass, M.; Howell, D.; Hutcheon, D. A.; Laird, A. M.; Martin, L.; Ottewell, D.; Reeve, S.; Ruiz, C.; Ruprecht, G.; Triambak, S.

    2013-02-01

    Preliminary studies in preparation for an absolute cross-section measurement of the radiative capture reaction 3He(α,γ)7Be with the DRAGON recoil separator have demonstrated beam suppression >1014 at the 90% confidence level. A measurement of this cross section by observation of 7Be recoils at the focal plane of the separator should be virtually background free.

  11. Analytical calculation of radiative-recoil corrections to muonium hyperfine splitting: Muon-line contribution

    SciTech Connect

    Eides, M.I.; Karshenboim, S.G.; Shelyuto, V.A. )

    1991-02-01

    Analytic expression for radiative-recoil corrections to muonium ground-state hyperfine splitting induced by muon-line radiative insertions is obtained. This result completes the program of analytic calculation of all radiative-recoil corrections. The perspectives of further muonium hyperfine splitting investigations are also discussed.

  12. Optimal control of gun recoil in direct fire using magnetorheological absorbers

    NASA Astrophysics Data System (ADS)

    Singh, Harinder J.; Wereley, Norman M.

    2014-05-01

    Optimal control of a gun recoil absorber is investigated for minimizing recoil loads and maximizing rate of fire. A multi-objective optimization problem was formulated by considering the mechanical model of the recoil absorber employing a spring and a magnetorheological (MR) damper. The damper forces are predicted by evaluating pressure drops using a nonlinear Bingham-plastic model. The optimization methodology provides multiple optimal design configurations with a trade-off between recoil load minimization and increased rate of fire. The configurations with low or high recoil loads imply low or high rate of fire, respectively. The gun recoil absorber performance is also analyzed for perturbations in the firing forces. The adaptive control of the MR damper for varying gun firing forces provides a smooth operation by returning the recoil mass to its battery position (ready to reload and fire) without incurring an end-stop impact. Furthermore, constant load transmissions are observed with respect to the recoil stroke by implementing optimal control during the simulated firing events.

  13. Deconvoluting nonaxial recoil in Coulomb explosion measurements of molecular axis alignment

    NASA Astrophysics Data System (ADS)

    Christensen, Lauge; Christiansen, Lars; Shepperson, Benjamin; Stapelfeldt, Henrik

    2016-08-01

    We report a quantitative study of the effect of nonaxial recoil during Coulomb explosion of laser-aligned molecules and introduce a method to remove the blurring caused by nonaxial recoil in the fragment-ion angular distributions. Simulations show that nonaxial recoil affects correlations between the emission directions of fragment ions differently from the effect caused by imperfect molecular alignment. The method, based on analysis of the correlation between the emission directions of the fragment ions from Coulomb explosion, is used to deconvolute the effect of nonaxial recoil from experimental fragment angular distributions. The deconvolution method is then applied to a number of experimental data sets to correct the degree of alignment for nonaxial recoil, to select optimal Coulomb explosion channels for probing molecular alignment, and to estimate the highest degree of alignment that can be observed from selected Coulomb explosion channels.

  14. Differential cross sections and recoil polarizations for the reaction γp→K+Σ0

    DOE PAGESBeta

    Dey, B.; Meyer, C. A.; Bellis, M.; McCracken, M. E.; Williams, M.; Adhikari, K. P.; Aghasyan, M.; Anghinolfi, M.; Ball, J.; Battaglieri, M.; et al

    2010-08-06

    Here, high-statistics measurements of differential cross sections and recoil polarizations for the reactionmore » $$\\gamma p \\rightarrow K^+ \\Sigma^0$$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($$\\sqrt{s}$$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $$K^{+}p\\pi^{-}$$($$\\gamma$$) and $$K^{+}p$$($$\\pi^-,\\gamma$$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $$\\sqrt{s}$$ coverage. Above $$\\sqrt{s} \\approx 2.5$$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($$P_\\Sigma$$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $$P_\\Sigma$$ is of the same magnitude but opposite sign as $$P_\\Lambda$$, in agreement with the static SU(6) quark model prediction of $$P_\\Sigma \\approx -P_\\Lambda$$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $$P_\\Sigma$$ and $$P_\\Lambda$$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.« less

  15. Prompt and delayed spectroscopy of {sup 142}Tb using recoil-isomer tagging

    SciTech Connect

    Mason, P. J. R.; Cullen, D. M.; Kishada, A. M.; Rigby, S. V.; Varley, B. J.; Scholey, C.; Eeckhaudt, S.; Grahn, T.; Greenlees, P. T.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Leppaenen, A.-P.; Maentyniemi, K.; Nieminen, P.; Nyman, M.; Pakarinen, J.

    2009-02-15

    Recoil-isomer tagging has been used to characterize the states built upon an I{sup {pi}}=8{sup +} isomer in {sup 142}Tb. High-spin states of the neutron-deficient nucleus {sup 142}Tb were populated using an {sup 54}Fe beam, accelerated onto a {sup 92}Mo target of thickness {approx}500 {mu}g/cm{sup 2} at energies of 245, 252, and 265 MeV using the K130 cyclotron at the University of Jyvaeskylae, Finland. Use of the JUROGAM target-position Ge-detector array coupled with the GREAT focal-plane spectrometer at the RITU gas-filled recoil separator has significantly increased the efficiency of the isomer-tagging technique. The rotational band built upon the I{sup {pi}}=8{sup +} isomeric state was established with isomer-tagged {gamma}-{gamma} coincidence data and angular distributions were measured for some of the more intensely populated states. Two previously unobserved bands that bypass the isomer were also established. The new data have been interpreted within the framework of the cranked-shell model. The data show good agreement with the calculated triaxial nuclear shape with {gamma}=-30 deg. for the {sup 142m2}Tb isomeric state. The B(M1)/B(E2) branching ratios, nuclear alignment, signature splitting, and reduced transition probability, B(E1), of the isomeric state have been systematically compared with those of the neighboring nuclei. These comparisons give further evidence for the {pi}h{sub 11/2} x {nu}h{sub 11/2} configuration of the isomer.

  16. Dielectric barrier structure with hollow electrodes and its recoil effect

    SciTech Connect

    Yu, Shuang; Chen, Qunzhi; Liu, Jiahui; Wang, Kaile; Jiang, Zhe; Sun, Zhili; Zhang, Jue; Fang, Jing

    2015-06-15

    A dielectric barrier structure with hollow electrodes (HEDBS), in which gas flow oriented parallel to the electric field, was proposed. Results showed that with this structure, air can be effectively ignited, forming atmospheric low temperature plasma, and the proposed HEDBS could achieve much higher electron density (5 × 10{sup 15}/cm{sup 3}). It was also found that the flow condition, including outlet diameter and flow rate, played a key role in the evolution of electron density. Optical emission spectroscopy diagnostic results showed that the concentration of reactive species had the same variation trend as the electron density. The simulated distribution of discharge gas flow indicated that the HEDBS had a strong recoil effect on discharge gas, and could efficiently promote generating electron density as well as reactive species.

  17. Spectroscopy of {sup 144}Ho using recoil-isomer tagging

    SciTech Connect

    Mason, P. J. R; Cullen, D. M.; Scholey, C.; Greenlees, P. T.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Peura, P.; Puurunen, A.; Rahkila, P.; Ruotsalainen, P.; Sorri, J.; Saren, J.; Uusitalo, J.; Xu, F. R.

    2010-02-15

    Excited states in the proton-unbound odd-odd nucleus {sup 144}Ho have been populated using the {sup 92}Mo({sup 54}Fe,pn){sup 144}Ho reaction and studied using the recoil-isomer-tagging technique. The alignment properties and signature splitting of the rotational band above the I{sup p}i=(8{sup +}){sup 144m}Ho isomer have been analyzed and the isomer confirmed to have a pih{sub 11/2} x nuh{sub 11/2} two-quasiparticle configuration. The configuration-constrained blocking method has been used to calculate the shapes of the ground and isomeric states, which are both predicted to have triaxial nuclear shapes with |gamma|approx =24 deg.

  18. Molecular Dynamics Simulation of Energetic Uranium Recoil Damage in Zircon

    SciTech Connect

    Devanathan, Ram; Corrales, Louis R.; Weber, William J.; Chartier, Alain; Meis, Constantin

    2006-10-11

    Defect production and amorphization due to energetic uranium recoils in zircon (ZrSiO4), which is a promising ceramic nuclear waste form, is studied using molecular dynamics simulations with a partial charge model. An algorithm that distinguishes between undamaged crystal, crystalline defects and amorphous regions is used to develop a fundamental understanding of the primary damage state. The amorphous cascade core is separated from the surrounding crystal by a defect-rich region. Small, chemically inhomogeneous amorphous clusters are also produced around the core. The amorphous regions consist of under-coordinated Zr and polymerized Si leading to amorphization and phase separation on a nanometer scale into Zr- and Si-rich regions. This separation could play an important role in the experimentally observed formation of nanoscale ZrO2 in ZrSiO4 irradiated at elevated temperatures.

  19. Recoil Polarization for Delta Excitation in Pion Electroproduction

    SciTech Connect

    J. J. Kelly; R. E. Roche; Z. Chai; M. K. Jones; O. Gayou; A. J. Sarty; S. Frullani; K. Aniol; E. J. Beise; F. Benmokhtar; W. Bertozzi; W. U. Boeglin; T. Botto; E. J. Brash; H. Breuer; E. Brown; E. Burtin; J. R. Calarco; C. Cavata; C. C. Chang; N. S. Chant; J.-P. Chen; M. Coman; D. Crovelli; R. De Leo; S. Dieterich; S. Escoffier; K. G. Fissum; V. Garde; F. Garibaldi; S. Georgakopoulus; S. Gilad; R. Gilman; C. Glashausser; J.-O. Hansen; D. W. Higinbotham; A. Hotta; G. M. Huber; H. Ibrahim; M. Iodice; C. W. de Jager; X. Jiang; A. Klimenko; A. Kozlov; G. Kumbartzki; M. Kuss; L. Lagamba; G. Laveissiere; J. J. LeRose; R. A. Lindgren; N. Liyanage; G. J. Lolos; R. W. Lourie; D. J. Margaziotis; F. Marie; P. Markowitz; S. McAleer; D. Meekins; R. Michaels; B. D. Milbrath; J. Mitchell; J. Nappa; D. Neyret; C. F. Perdrisat; M. Potokar; V. A. Punjabi; T. Pussieux; R. D. Ransome; P. G. Roos; M. Rvachev; A. Saha; S. Sirca; R. Suleiman; S. Strauch; J. A. Templon; L. Todor; P. E. Ulmer; G. M. Urciuoli; L. B. Weinstein; K. Wijesooriya; B. Wojtsekhowski; X. Zheng; and L. Zhu

    2005-08-01

    We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W=1.23 GeV at Q{sup 2}=1.0 (GeV/c){sup 2}, obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re(S1+/M1+)=-(6.84+/-0.15)% and Re(E1+/M1+)=-(2.91+/-0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and sp truncation.

  20. B{yields}D* at zero recoil revisited

    SciTech Connect

    Gambino, Paolo; Mannel, Thomas; Uraltsev, Nikolai

    2010-06-01

    We examine the B{yields}D* form factor at zero recoil using a continuum QCD approach rooted in the heavy quark sum rules framework. A refined evaluation of the radiative corrections as well as the most recent estimates of higher-order power terms together with more careful continuum calculation are included. An upper bound on the form factor of F(1) < or approx. 0.93 is derived, based on just the positivity of inelastic contributions. A model-independent estimate of the inelastic contributions shows they are quite significant, lowering the form factor by about 6% or more. This results in an unbiased estimate F(1){approx_equal}0.86 with about 3% uncertainty in the central value.

  1. Importance of the recoil contribution in Two Step 2 mechanism for the electron impact double ionization process

    NASA Astrophysics Data System (ADS)

    Li, C.; Staicu Casagrande, E. M.; Lahmam-Bennani, A.

    2014-04-01

    The second order, Two-Step-2 (TS2) mechanism for electron impact double ionization (DI) of various targets at intermediate incident energy is investigated based on a kinematical analysis which assumes the DI to result from two successive (e,2e) single ionization (SI) events. The results show that under the present kinematics, the inclusion of the recoil scattering in each of these (e,2e)-SI steps (in previous studies only the binary scattering was considered) allows a more detailed understanding of the various peaks observed in the experimental angular distributions of the ejected electrons in both (e,3-1e) and (e,3e) experiments.

  2. Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

    SciTech Connect

    McCracken, Michael E.

    2010-02-01

    We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies; results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.

  3. Relevancy 101

    NASA Technical Reports Server (NTRS)

    Lynnes, Chris; Newman, Doug

    2016-01-01

    Where we present an overview on why relevancy is a problem, how important it is and how we can improve it. The topic of relevancy is becoming increasingly important in earth data discovery as our audience is tuned to the accuracy of standard search engines like Google.

  4. Measurement of the {sup 40}Ca({alpha},{gamma}){sup 44}Ti reaction relevant for supernova nucleosynthesis

    SciTech Connect

    Vockenhuber, C.; Buchmann, L.; Caggiano, J.; Crawford, H.; Davids, B.; Fogarty, L.; Hutcheon, D. A.; O'Connor, E.; Ottewell, D.; Pavan, M. M.; Ruiz, C.; Ruprecht, G.; Trinczek, M.; Ouellet, C. O.; Chen, A. A.; Pearson, J.; Wales, B.; The, L.-S.; D'Auria, J. M.; Frekers, D.

    2007-09-15

    The short-lived nuclide {sup 44}Ti is an important nuclide for the understanding of explosive nucleosynthesis. The main production reaction, {sup 40}Ca({alpha},{gamma}){sup 44}Ti, has been studied in inverse kinematics with the recoil mass spectrometer DRAGON located at the TRIUMF-ISAC facility in Vancouver, Canada. The temperature range relevant for {alpha}-rich freeze-out during a core-collapse supernova has been covered entirely with a {sup 40}Ca beam of 0.60 to 1.15 MeV/nucleon. All relevant quantities for the calculation of the astrophysical reaction rate have been measured directly. Because of many previously undiscovered resonances, the reaction rate derived from the energy dependent {sup 44}Ti yield is higher than the one based on previous prompt {gamma}-ray studies commonly used in supernova models. The presented new rate results in an increased {sup 44}Ti production in supernovae.

  5. γp ->K^+λ Differential Cross Section and Recoil Polarization Measurements from the CLAS g11a Dataset

    NASA Astrophysics Data System (ADS)

    McCracken, Michael

    2009-05-01

    We present measurements of γp ->K^+λ differential cross section and λ recoil polarization from the CLAS g11a dataset. The measurements cover the center-of-mass energy range from 1.62 GeV to 2.84 GeV and a wide range of center-of-mass angles (-0.90<=θCM^K<=0.90). We have analyzed this reaction via both the K^+p&-circ; and K^+p (missing &-circ;) final-state topologies independently and found the results to be in excellent agreement. Previous γp ->K^+λ differential cross section results from the CLAS (Bradford, et al. 2005) and SAPHIR (Glander, et al., 2004) Collaborations show discrepancies in magnitude at most energies and a discrepancy in scale and shape at √s 1.9 GeV. These discrepancies have been problematic for interpretations of K^+λ photoproduction mechanisms. These new g11a differential cross section results show excellent agreement with the previous CLAS result. The recoil polarization results show agreement with previous data from the CLAS, SAPHIR, and GRAAL experiments, and are a 500 MeV extension of the observed energy range.

  6. A recoil-proton spectrometer based on a p-i-n diode implementing pulse-shape discrimination.

    PubMed

    Agosteo, S; D'Angelo, G; Fazzi, A; Foglio Para, A; Pola, A; Ventura, L; Zotto, P

    2004-01-01

    A recoil-proton spectrometer was created by coupling a p-i-n diode with a polyethylene converter. The maximum detectable energy, imposed by the thickness of the totally depleted layer, is approximately 6 MeV. The minimum detectable energy is limited by the contribution of secondary electrons generated by photons in the detector assembly. This limit is approximately 1.5 MeV at full-depletion voltage and was decreased using pulse-shape discrimination. The diode was set up in the 'reverse-injection' configuration (i.e. with the N+ layer adjacent to the converter). This configuration provides longer collection times for the electron-hole pairs generated by the recoil-protons. The pulse-shape discrimination was based on the zero-crossing time of bipolar signals from a (CR)2-(RC)2 filter. The detector was characterised using monoenergetic neutrons generated in the Van De Graaff CN accelerator at the INFN-Laboratori Nazionali di Legnaro. The energy limit for discrimination proved to be approximately 900 keV. PMID:15353700

  7. A Novel method for modeling the recoil in W boson events at hadron collider

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Aguilo, Ernest; Ahsan, Mahsana; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls /Northeastern U.

    2009-07-01

    We present a new method for modeling the hadronic recoil in W {yields} {ell}{nu} events produced at hadron colliders. The recoil is chosen from a library of recoils in Z {yields} {ell}{ell} data events and overlaid on a simulated W {yields} {ell}{nu} event. Implementation of this method requires that the data recoil library describe the properties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming 1 fb{sup -1} of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the high precision measurements that will be possible with data from Run II of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.

  8. Spreading and recoil of a surfactant-containing water drop on glass-supported alcohol films.

    PubMed

    Chowdhury, Devasish; Sarkar, Surya Protim; Kalita, Dipankar; Sarma, Tridib Kumar; Paul, Anumita; Chattopadhyay, Arun

    2004-02-17

    In this paper we report the experimental observation of spreading and recoil of surfactant-containing water drops on various alcohol films supported on glass slides. The time evolution of spreading and recoil behavior was recorded by placing a web camera above the drop. We observed that the drop spread the fastest on CH3OH, followed by C2H5OH, and the slowest on i-PrOH. On the other hand, the recoil behavior was just the opposite. The drop recoiled the slowest on CH3OH and fastest on i-PrOH, while it recoiled in an intermediate time on C2H5OH. In addition, concentration of surfactant in the drop played a prominent role in the spreading and recoil time of the drop, with higher surfactant concentration making the drop spread and recoil faster. The time evolution of spreading velocity of the drop on different alcohol films at various surfactant concentrations occurred with a Gaussian distribution and the peak velocity was reached earliest on CH3OH followed by C2H5OH, while on i-PrOH it took the longest time. The recoil behavior was similar. The variation of velocity as a function of radius exhibited oscillatory behavior, indicating the existence of an interfacial phenomenon. We also report the observation that spreading of the drop occurred without observable fingering instability. Further, we observed by Fourier transform infrared (FTIR) spectroscopic measurements that the drop had mixed with the alcohol films as it spread. Miscibility of the alcohol in the film with the drop, alcohol evaporation cooling-induced temperature gradient, and Marangoni effect probably play important roles in the spreading and recoil behavior of the drop.

  9. Energy deposition at the bone-tissue interface from nuclear fragments produced by high-energy nucleons

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Hajnal, Ferenc; Wilson, John W.

    1990-01-01

    The transport of nuclear fragmentation recoils produced by high-energy nucleons in the region of the bone-tissue interface is considered. Results for the different flux and absorbed dose for recoils produced by 1 GeV protons are presented in a bidirectional transport model. The energy deposition in marrow cavities is seen to be enhanced by recoils produced in bone. Approximate analytic formulae for absorbed dose near the interface region are also presented for a simplified range-energy model.

  10. Recent Results from the Commissioning of the HRIBF Recoil Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Ginter, T. N.; Hamilton, J. H.; Ramayya, A. V.; Gross, C. J.; Johnson, J. W.; Shapira, D.; Akovali, Y. A.; Brinkman, M. J.; Mas, J.; McConnell, J. W.; Milner, W. T.; James, A. N.

    1997-04-01

    The Recoil Mass Spectrometer (RMS) at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory (Managed by Lockheed Martin Energy Research Corporation for the U.S. Department of Energy.) is designed (Cole, J. D., et al.) al., Nucl. Instrum. Methods B70 (1992), 343. to transmit ions with rigidities of up to K = 100 resulting from fusion-evaporation and other nuclear reactions. Commissioning tests (We would like to acknowledge the work performed by P. F. Mantica, J. J. Das, and R. L. Auble on the installation of the RMS.) have been under way on the RMS and auxiliary detectors at its target position and focal plane. These tests, performed using normal and symmetric kinematic reactions, have shown that the RMS has an A/Q acceptance of ± 5% and an energy acceptance of ± 10%. A mass resolution M/ΔM of 470 was obtained using a ^58Ni beam on a ^60Ni target, with little primary beam observed at the focal plane. Recent results from these tests will be presented.

  11. Fast thermometry for trapped atoms using recoil-induced resonance

    NASA Astrophysics Data System (ADS)

    Zhao, Yan-Ting; Su, Dian-Qiang; Ji, Zhong-Hua; Zhang, Hong-Shan; Xiao, Lian-Tuan; Jia, Suo-Tang

    2015-09-01

    We have employed recoil-induced resonance (RIR) with linewidth on the order of 10 kHz to demonstrate the fast thermometry for ultracold atoms. We theoretically calculate the absorption spectrum of RIR which agrees well with the experimental results. The temperature of the ultracold sample derived from the RIR spectrum is T = 84±4.5 μK, which is close to 85 μK that measured by the method of time-of-flight absorption imaging. To exhibit the fast measurement advantage in applying RIR to the ultracold atom thermometry, we study the dependence of ultracold sample temperature on the trapping beam frequency detuning. This method can be applied to determine the translational temperature of molecules in photoassociation dynamics. Project supported by the National Basic Research Development Program of China (Grant No. 2012CB921603), the National High Technology Research and Development Program of China (Grant No. 2011AA010801), the National Natural Science Foundation of China (Grant Nos. 61275209, 11304189, 61378015, and 11434007), and Program for Changjiang Scholars and Innovative Research Team in Universities of China (Grant No. IRT13076).

  12. Automation of experiments at Dubna Gas-Filled Recoil Separator

    NASA Astrophysics Data System (ADS)

    Tsyganov, Yu. S.

    2016-01-01

    Approaches to solving the problems of automation of basic processes in long-term experiments in heavy ion beams of the Dubna Gas-Filled Recoil Separator (DGFRS) facility are considered. Approaches in the field of spectrometry, both of rare α decays of superheavy nuclei and those for constructing monitoring systems to provide accident-free experiment running with highly radioactive targets and recording basic parameters of experiment, are described. The specific features of Double Side Silicon Strip Detectors (DSSSDs) are considered, special attention is paid to the role of boundary effects of neighboring p-n transitions in the "active correlations" method. An example of an off-beam experiment attempting to observe Zeno effect is briefly considered. Basic examples for nuclear reactions of complete fusion at 48Ca ion beams of U-400 cyclotron (LNR, JINR) are given. A scenario of development of the "active correlations" method for the case of very high intensity beams of heavy ions at promising accelerators of LNR, JINR, is presented.

  13. Elastic recoil of coronary stents: a comparative analysis.

    PubMed

    Barragan, P; Rieu, R; Garitey, V; Roquebert, P O; Sainsous, J; Silvestri, M; Bayet, G

    2000-05-01

    Minimum elastic recoil (ER) has became an essential feature of new coronary stents when deployed in artheromatous lesions of various morphologies. The ER of coronary stent might be an important component of 6-month restenosis rate by minimizing the luminal loss. We evaluated the intrinsic ER of 23 coronary stents with a mechanical test bench. The amount of ER for one size of stent (3.0 mm) was quantified using a 3D optical contactless machine (Smartscope MVP, Rochester, NY). The stents were expanded on their own balloon for the precrimped stents; the uncrimped stents were expended using identical 3.0-mm balloons. Two types of measurements were done without exterior stress and with a 0.2-bar exterior stress, directly on the stent at the end of balloon expansion, immediately after balloon deflation, and then 30 min, 60 min, and 120 min after. ER ranged from 1.54%+/-0.81% (Bestent BES 15) to 16.51%+/-2.89% (Paragon stent) without stress (P<0.01) and from 2.35%+/-1.14% (Bestent BES 15) to 18.34%+/-2.41% (Cook GR2) under 0.2-bar pressure (P<0.0001). Furthermore, there was a significant reduction between the mean result of tubular stents (TS) and coil stents (CS). The results of in vitro mechanical tests may confirm strongly the interest of a minimum ER in the prevention of the 6-month restenosis. PMID:10816295

  14. Development and evaluation of a collection apparatus for recoil products for study of the deexcitation process of (235m)U.

    PubMed

    Shigekawa, Y; Kasamatsu, Y; Shinohara, A

    2016-05-01

    The nucleus (235m)U is an isomer with extremely low excitation energy (76.8 eV) and decays dominantly through the internal conversion (IC) process. Because outer-shell electrons are involved in the IC process, the decay constant of (235m)U depends on its chemical environment. We plan to study the deexcitation process of (235m)U by measuring the energy spectra of IC electrons in addition to the decay constants for various chemical forms. In this paper, the preparation method of (235m)U samples from (239)Pu by using alpha-recoil energy is reported. A Collection Apparatus for Recoil Products was fabricated, and then collection efficiencies under various conditions were determined by collecting (224)Ra recoiling out of (228)Th electrodeposited and precipitated sources. The pressure in the apparatus (vacuum or 1 atm of N2 gas) affected the variations of the collection efficiencies depending on the negative voltage applied to the collector. The maximum values of the collection efficiencies were mainly affected by the thickness of the (228)Th sources. From these results, the suitable conditions of the (239)Pu sources for preparation of (235m)U were determined. In addition, dissolution efficiencies were determined by washing collected (224)Ra with solutions. When (224)Ra was collected in 1 atm of N2 gas and dissolved with polar solutions such as water, the dissolution efficiencies were nearly 100%. The method of rapid dissolution of recoil products would be applicable to rapid preparation of short-lived (235m)U samples for various chemical forms. PMID:27250424

  15. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A. B.; Nygren, D.

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase o_ers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  16. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    DOE PAGESBeta

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at themore » 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.« less

  17. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    SciTech Connect

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  18. Analysis of hydrogen adsorption and surface binding configuration on tungsten using direct recoil spectrometry

    SciTech Connect

    Kolasinski, R. D.; Hammond, K. D.; Whaley, J. A.; Buchenauer, D. A.; Wirth, B. D.

    2014-12-03

    In our work, we apply low energy ion beam analysis to examine directly how the adsorbed hydrogen concentration and binding configuration on W(1 0 0) depend on temperature. We exposed the tungsten surface to fluxes of both atomic and molecular H and D. We then probed the H isotopes adsorbed along different crystal directions using 1–2 keV Ne+ ions. At saturation coverage, H occupies two-fold bridge sites on W(1 0 0) at 25 °C. Moreover, the H coverage dramatically changes the behavior of channeled ions, as does reconstruction of the surface W atoms. For the exposure conditions examined here, we find that surface sites remain populated with H until the surface temperature reaches 200 °C. Then, we observe H rapidly desorbing until only a residual concentration remains at 450 °C. Development of an efficient atomistic model that accurately reproduces the experimental ion energy spectra and azimuthal variation of recoiled H is underway.

  19. Potku - New analysis software for heavy ion elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Arstila, K.; Julin, J.; Laitinen, M. I.; Aalto, J.; Konu, T.; Kärkkäinen, S.; Rahkonen, S.; Raunio, M.; Itkonen, J.; Santanen, J.-P.; Tuovinen, T.; Sajavaara, T.

    2014-07-01

    Time-of-flight elastic recoil detection (ToF-ERD) analysis software has been developed. The software combines a Python-language graphical front-end with a C code computing back-end in a user-friendly way. The software uses a list of coincident time-of-flight-energy (ToF-E) events as an input. The ToF calibration can be determined with a simple graphical procedure. The graphical interface allows the user to select different elements and isotopes from a ToF-E histogram and to convert the selections to individual elemental energy and depth profiles. The resulting sample composition can be presented as relative or absolute concentrations by integrating the depth profiles over user-defined ranges. Beam induced composition changes can be studied by displaying the event-based data in fractions relative to the substrate reference data. Optional angular input data allows for kinematic correction of the depth profiles. This open source software is distributed under the GPL license for Linux, Mac, and Windows environments.

  20. A recoil ion momentum spectrometer for molecular and atomic fragmentation studies.

    PubMed

    Khan, Arnab; Tribedi, Lokesh C; Misra, Deepankar

    2015-04-01

    We report the development and performance studies of a newly built recoil ion momentum spectrometer for the study of atomic and molecular fragmentation dynamics in gas phase upon the impact of charged particles and photons. The present design is a two-stage Wiley-McLaren type spectrometer which satisfies both time and velocity focusing conditions and is capable of measuring singly charged ionic fragments up-to 13 eV in all directions. An electrostatic lens has been introduced in order to achieve velocity imaging. Effects of the lens on time-of-flight as well as on the position have been investigated in detail, both, by simulation and in experiment. We have used 120 keV proton beam on molecular nitrogen gas target. Complete momentum distributions and kinetic energy release distributions have been derived from the measured position and time-of-flight spectra. Along with this, the kinetic energy release spectra of fragmentation of doubly ionized nitrogen molecule upon various projectile impacts are presented.

  1. A recoil ion momentum spectrometer for molecular and atomic fragmentation studies

    SciTech Connect

    Khan, Arnab; Tribedi, Lokesh C.; Misra, Deepankar

    2015-04-15

    We report the development and performance studies of a newly built recoil ion momentum spectrometer for the study of atomic and molecular fragmentation dynamics in gas phase upon the impact of charged particles and photons. The present design is a two-stage Wiley-McLaren type spectrometer which satisfies both time and velocity focusing conditions and is capable of measuring singly charged ionic fragments up-to 13 eV in all directions. An electrostatic lens has been introduced in order to achieve velocity imaging. Effects of the lens on time-of-flight as well as on the position have been investigated in detail, both, by simulation and in experiment. We have used 120 keV proton beam on molecular nitrogen gas target. Complete momentum distributions and kinetic energy release distributions have been derived from the measured position and time-of-flight spectra. Along with this, the kinetic energy release spectra of fragmentation of doubly ionized nitrogen molecule upon various projectile impacts are presented.

  2. Analysis of hydrogen adsorption and surface binding configuration on tungsten using direct recoil spectrometry

    DOE PAGESBeta

    Kolasinski, R. D.; Hammond, K. D.; Whaley, J. A.; Buchenauer, D. A.; Wirth, B. D.

    2014-12-03

    In our work, we apply low energy ion beam analysis to examine directly how the adsorbed hydrogen concentration and binding configuration on W(1 0 0) depend on temperature. We exposed the tungsten surface to fluxes of both atomic and molecular H and D. We then probed the H isotopes adsorbed along different crystal directions using 1–2 keV Ne+ ions. At saturation coverage, H occupies two-fold bridge sites on W(1 0 0) at 25 °C. Moreover, the H coverage dramatically changes the behavior of channeled ions, as does reconstruction of the surface W atoms. For the exposure conditions examined here, wemore » find that surface sites remain populated with H until the surface temperature reaches 200 °C. Then, we observe H rapidly desorbing until only a residual concentration remains at 450 °C. Development of an efficient atomistic model that accurately reproduces the experimental ion energy spectra and azimuthal variation of recoiled H is underway.« less

  3. Radiative-recoil corrections to hyperfine splitting: Polarization insertions in the muon factor

    SciTech Connect

    Eides, Michael I.; Shelyuto, Valery A.

    2009-09-01

    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium due to insertions of a one-loop polarization operator in the muon factor. The contribution produced by electron polarization insertions is enhanced by the large logarithm of the electron-muon mass ratio. We obtained all single-logarithmic and nonlogarithmic radiative-recoil corrections of order {alpha}{sup 3}(m/M)E{sub F} generated by the diagrams with electron and muon polarization insertions.

  4. Investigation on modeling and controability of a magnetorheological gun recoil damper

    NASA Astrophysics Data System (ADS)

    Hu, Hongsheng; Wang, Juan; Wang, Jiong; Qian, Suxiang; Li, Yancheng

    2009-07-01

    Magnetorheological (MR) fluid as a new smart material has done well in the vibration and impact control engineering fields because of its good electromechanical coupling characteristics, preferable dynamic performance and higher sensitivity. And success of MRF has been apparent in many engineering applied fields, such as semi-active suspension, civil engineering, etc. So far, little research has been done about MR damper applied into the weapon system. Its primary purpose of this study is to identify its dynamic performance and controability of the artillery recoil mechanism equipped with MR damper. Firstly, based on the traditional artillery recoil mechanism, a recoil dynamic model is developed in order to obtain an ideal rule between recoil force and its stroke. Then, its effects of recoil resistance on the stability and firing accuracy of artillery are explored. Because MR gun recoil damper under high impact load shows a typical nonlinear character and there exists a shear-thinning phenomenon, to establish an accurate dynamic model has been a seeking aim of its design and application for MR damper under high impact load. Secondly, in this paper, considering its actual bearing load, an inertia factor was introduced to Herschel-Bulkley model, and some factor's effect on damping force are simulated and analyzed by using numerical simulation, including its dynamic performance under different flow coefficients and input currents. Finally, both of tests with the fixed current and different On-Off control algorithms have been done to confirm its controability of MR gun recoil damper under high impact load. Experimental results show its dynamic performances of the large-scale single-ended MR gun recoil damper can be changed by altering the applied currents and it has a good controllability.

  5. Atomistic Simulation of Track Formation by Energetic Recoils in Zircon

    SciTech Connect

    Moreira, Pedro A.; Devanathan, Ramaswami; Weber, William J.

    2010-09-17

    We have performed classical molecular dynamics simulations of fission track formation in zircon. We simulated the passage of a swift heavy ion through crystalline zircon using cylindrical thermal spikes with energy deposition (dE/dx) of 2.5 to 12.8 keV/nm and radius of 3 nm. At a low dE/dx of 2.55 keV/nm, the structural damage recovered almost completely and a damage track was not produced. At higher values of dE/dx, tracks were observed and the radius of the track increased with increasing dE/dx. Our structural analysis shows amorphization in the core of the track and phase separation into Si-rich regions near the center of the track and Zr-rich regions near the periphery. These simulations establish a threshold dE/dx for fission-track formation in zircon that is relevant to thermo-chronology and nuclear waste immobilization.

  6. Influence of elastic recoil on restenosis after successful coronary angioplasty in unstable angina pectoris.

    PubMed

    Ardissino, D; Di Somma, S; Kubica, J; Barberis, P; Merlini, P A; Eleuteri, E; De Servi, S; Bramucci, E; Specchia, G; Montemartini, C

    1993-03-15

    The elastic behavior of the dilated coronary vessel has been reported to affect the immediate results of coronary angioplasty. To determine whether elastic recoil may also influence the long-term restenosis process, 98 consecutive patients with unstable angina and 1-vessel disease were studied. An automated coronary quantitative program was used for the assessment of balloon and coronary luminal diameters. Elastic recoil was defined as the percent reduction between minimal balloon diameter at the highest inflation pressure and minimal lesion diameter immediately after coronary angioplasty. Follow-up coronary arteriography was performed 8 to 12 months after the procedure in all patients. The mean elastic recoil averaged 17.7 +/- 16% and was correlated to the degree of residual stenosis immediately after coronary angioplasty (r = 0.64; p < 0.001). Restenosis, defined as > 50% diameter stenosis at follow-up, developed in 53 patients (54%). There was no correlation between the degree of elastic recoil and the changes in minimal lesion diameter observed during follow-up, whereas a positive correlation between the amount of elastic recoil and the incidence of restenosis was documented (r = 0.84; p < 0.05). Thus, the elastic properties of the dilated vessel do not influence the active process of restenosis. However, because elastic recoil negatively influences the initial results of angioplasty, it is more likely that further reductions in lumen diameter during follow-up can reach a threshold of obstruction considered critical for a binary definition of restenosis. PMID:8447261

  7. The magnetic recoil spectrometer (MRSt) for time-resolved measurements of the neutron spectrum at the National Ignition Facility (NIF)

    DOE PAGESBeta

    Frenje, J. A.; Hilsabeck, T. J.; Wink, C. W.; Bell, P.; Bionta, R.; Cerjan, C.; Gatu Johnson, M.; Kilkenny, J. D.; Li, C. K.; Séguin, F. H.; et al

    2016-08-02

    The next-generation magnetic recoil spectrometer for time-resolved measurements of the neutron spectrum has been conceptually designed for the National Ignition Facility. This spectrometer, called MRSt, represents a paradigm shift in our thinking about neutron spectrometry for inertial confinement fusion applications, as it will provide simultaneously information about the burn history and time evolution of areal density (ρR), apparent ion temperature (Ti), yield (Yn), and macroscopic flows during burn. From this type of data, an assessment of the evolution of the fuel assembly, hotspot, and alpha heating can be made. According to simulations, the MRSt will provide accurate data with amore » time resolution of ~20 ps and energy resolution of ~100 keV for total neutron yields above ~1016. Lastly, at lower yields, the diagnostic will be operated at a higher-efficiency, lower-energy-resolution mode to provide a time resolution of ~20 ps.« less

  8. The magnetic recoil spectrometer (MRSt) for time-resolved measurements of the neutron spectrum at the National Ignition Facility (NIF)

    NASA Astrophysics Data System (ADS)

    Frenje, J. A.; Hilsabeck, T. J.; Wink, C. W.; Bell, P.; Bionta, R.; Cerjan, C.; Gatu Johnson, M.; Kilkenny, J. D.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.

    2016-11-01

    The next-generation magnetic recoil spectrometer for time-resolved measurements of the neutron spectrum has been conceptually designed for the National Ignition Facility. This spectrometer, called MRSt, represents a paradigm shift in our thinking about neutron spectrometry for inertial confinement fusion applications, as it will provide simultaneously information about the burn history and time evolution of areal density (ρR), apparent ion temperature (Ti), yield (Yn), and macroscopic flows during burn. From this type of data, an assessment of the evolution of the fuel assembly, hotspot, and alpha heating can be made. According to simulations, the MRSt will provide accurate data with a time resolution of ˜20 ps and energy resolution of ˜100 keV for total neutron yields above ˜1016. At lower yields, the diagnostic will be operated at a higher-efficiency, lower-energy-resolution mode to provide a time resolution of ˜20 ps.

  9. Search for Event Rate Modulation in XENON100 Electronic Recoil Data.

    PubMed

    Aprile, E; Aalbers, J; Agostini, F; Alfonsi, M; Anthony, M; Arazi, L; Arisaka, K; Arneodo, F; Balan, C; Barrow, P; Baudis, L; Bauermeister, B; Breur, P A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Cardoso, J M R; Cervantes, M; Coderre, D; Colijn, A P; Contreras, H; Cussonneau, J P; Decowski, M P; de Perio, P; Di Giovanni, A; Duchovni, E; Fattori, S; Ferella, A D; Fieguth, A; Fulgione, W; Gao, F; Garbini, M; Geis, C; Goetzke, L W; Grignon, C; Gross, E; Hampel, W; Hasterok, C; Itay, R; Kaether, F; Kaminsky, B; Kessler, G; Kish, A; Landsman, H; Lang, R F; Le Calloch, M; Lellouch, D; Levinson, L; Levy, C; Lindemann, S; Lindner, M; Lopes, J A M; Lyashenko, A; Macmullin, S; Marrodán Undagoitia, T; Masbou, J; Massoli, F V; Mayani, D; Melgarejo Fernandez, A J; Meng, Y; Messina, M; Micheneau, K; Miguez, B; Molinario, A; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Orrigo, S E A; Pakarha, P; Persiani, R; Piastra, F; Pienaar, J; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Rizzo, A; Rosendahl, S; Dos Santos, J M F; Sartorelli, G; Schindler, S; Schreiner, J; Schumann, M; Scotto Lavina, L; Selvi, M; Shagin, P; Simgen, H; Teymourian, A; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C; Wall, R; Wang, H; Weber, M; Weinheimer, C; Zhang, Y

    2015-08-28

    We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1σ for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8σ, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8σ. PMID:26371638

  10. A Critical Review of Alpha Radionuclide Therapy-How to Deal with Recoiling Daughters?

    PubMed

    de Kruijff, Robin M; Wolterbeek, Hubert T; Denkova, Antonia G

    2015-01-01

    This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET). Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium), 223Ra, and 225Ac (actinium) can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue. PMID:26066613

  11. A Critical Review of Alpha Radionuclide Therapy—How to Deal with Recoiling Daughters?

    PubMed Central

    de Kruijff, Robin M.; Wolterbeek, Hubert T.; Denkova, Antonia G.

    2015-01-01

    This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET). Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium), 223Ra, and 225Ac (actinium) can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue. PMID:26066613

  12. Extremely fast prey capture in pipefish is powered by elastic recoil.

    PubMed

    Van Wassenbergh, Sam; Strother, James A; Flammang, Brooke E; Ferry-Graham, Lara A; Aerts, Peter

    2008-03-01

    The exceptionally high speed at which syngnathid fishes are able to rotate their snout towards prey and capture it by suction is potentially caused by a catapult mechanism in which the energy previously stored in deformed elastic elements is suddenly released. According to this hypothesis, tension is built up in tendons of the post-cranial muscles before prey capture is initiated. Next, an abrupt elastic recoil generates high-speed dorsal rotation of the head and snout, rapidly bringing the mouth close to the prey, thus enabling the pipefish to be close enough to engulf the prey by suction. However, no experimental evidence exists for such a mechanism of mechanical power amplification during feeding in these fishes. To test this hypothesis, inverse dynamical modelling based upon kinematic data from high-speed videos of prey capture in bay pipefish Syngnathus leptorhynchus, as well as electromyography of the muscle responsible for head rotation (the epaxial muscle) was performed. The remarkably high instantaneous muscle-mass-specific power requirement calculated for the initial phase of head rotation (up to 5795 W kg(-1)), as well as the early onset times of epaxial muscle activity (often observed more than 300 ms before the first externally discernible prey capture motion), support the elastic power enhancement hypothesis.

  13. The study of exotic N approx equal 82 nuclei using the Daresbury recoil mass separator

    SciTech Connect

    McNeill, J.H.; Chishti, A.A.; Gelletly, W.; Hotchkis, M.A.C.; Varley, B.J.; Blomqvist, J.; Daly, P.J.; Piiparinen, M.; Woods, P.J.; Manchester Univ. . Schuster Lab.; Manne Siegbahn Inst.; Purdue Univ., Lafayette, IN . Dept. of Chemistry; Jyvaeskylae Univ. . Dept. of Physics; Edinburgh Univ. . Dept. of Physics)

    1989-01-01

    Experiments using the Daresbury Recoil Mass Separator have identified microsecond isomers in the exotic N {equals} 82, 83 nuclei {sup 153}Yb, {sup 153}Lu, {sup 154}Hf, and have established their decay schemes. The results for {sup 153}Lu and {sup 154}Hf, together with those for lighter N {equals} 82 isotones, provide an outstanding illustration of the dependence of E2 transition rates between J{sup n} states on the subshell occupation, and demonstrate that half-filling of the {pi}h{sub 11/2} subshell in the N {equals} 82 series occurs just below Z {equals} 71 {sup 153}Lu. The result of the isomer in the even-odd N {equals} 83 nucleus {sup 153}Yb shows that the isomerism is due to a low-energy E2 transition rather than an E3 transition as in lighter N {equals} 83 even-odd isotones, which is another consequence of the {pi}h{sub 11/2} subshell being about half-filled. Furthermore, the long-lived isomer observed in the odd-odd N {equals} 83 nucleus {sup 154}Lu also reflects that the {pi}h{sub 11/2} subshell is close to being half-filled. 23 refs., 12 figs., 4 tabs.

  14. Relevant Links

    Atmospheric Science Data Center

    2016-07-11

    ... A Burning Question Feature Article: Absorption of Solar Radiation by Clouds FIRE ARM Archive SHEBA Archive ... SRB SRB Home Page SSE American Solar Energy Society (ASES)  - A national organization dedicated to advancing the ...

  15. Imprints of recoiling massive black holes on the hot gas of early-type galaxies

    NASA Astrophysics Data System (ADS)

    Devecchi, B.; Rasia, E.; Dotti, M.; Volonteri, M.; Colpi, M.

    2009-04-01

    Anisotropic gravitational radiation from a coalescing black hole (BH) binary is known to impart recoil velocities of up to ~1000kms-1 to the remnant BH. In this context, we study the motion of a recoiling BH inside a galaxy modelled as a Hernquist sphere, and the signature that the hole imprints on the hot gas, using N-body/smoothed particle hydrodynamics simulations. Ejection of the BH results in a sudden expansion of the gas ending with the formation of a gaseous core, similarly to what is seen for the stars. A cometary tail of particles bound to the BH is initially released along its trail. As the BH moves on a return orbit, a nearly spherical swarm of hot gaseous particles forms at every apocentre: this feature can live up to ~108 years. If the recoil velocity exceeds the sound speed initially, the BH shocks the gas in the form of a Mach cone in density near each supersonic pericentric passage. We find that the X-ray fingerprint of a recoiling BH can be detected in Chandra X-ray maps out to a distance of Virgo. For exceptionally massive BHs, the Mach cone and the wakes can be observed out to a few hundred of milliparsec. The detection of the Mach cone is of twofold importance as it can be a probe of high-velocity recoils, and an assessment of the scatter of the MBH - Mbulge relation at large BH masses.

  16. IMP-8 observations of the spectra, composition, and variability of solar heavy ions at high energies relevant to manned space missions.

    PubMed

    Tylka, A J; Dietrich, W F

    1999-06-01

    In more than 25 years of almost continuous observations, the University of Chicago's Cosmic Ray Telescope (CRT) on IMP-8 has amassed a unique database on high-energy solar heavy ions of potential relevance to manned spaceflight. In the very largest particle events, IMP-8/CRT has even observed solar Fe ions above the Galactic cosmic ray background up to approximately 800 MeV/nucleon, an energy sufficiently high to penetrate nearly 25 g/cm2 of shielding. IMP-8/CRT observations show that high-energy heavy-ion spectra are often surprisingly hard power laws, without the exponential roll-offs suggested by stochastic acceleration fits to lower energy measurements alone. Also, in many solar particle events the Fe/O ratio grows with increasing energy, contrary to the notion that ions with higher mass-to-charge ratios should be less abundant at higher energies. Previous studies of radiation hazards for manned spaceflight have often assumed heavy-ion composition and steeply-falling energy spectra inconsistent with these observations. Conclusions based on such studies should therefore be re-assessed. The significant event-to-event variability observed in the high-energy solar heavy ions also has important implications for strategies in building probabilistic models of solar particle radiation hazards. PMID:11543141

  17. Recoiling black holes: prospects for detection and implications of spin alignment

    NASA Astrophysics Data System (ADS)

    Blecha, Laura; Sijacki, Debora; Kelley, Luke Zoltan; Torrey, Paul; Vogelsberger, Mark; Nelson, Dylan; Springel, Volker; Snyder, Gregory; Hernquist, Lars

    2016-02-01

    Supermassive black hole (BH) mergers produce powerful gravitational wave emission. Asymmetry in this emission imparts a recoil kick to the merged BH, which can eject the BH from its host galaxy altogether. Recoiling BHs could be observed as offset active galactic nuclei (AGN). Several candidates have been identified, but systematic searches have been hampered by large uncertainties regarding their observability. By extracting merging BHs and host galaxy properties from the Illustris cosmological simulations, we have developed a comprehensive model for recoiling AGN. Here, for the first time, we model the effects of BH spin alignment and recoil dynamics based on the gas richness of host galaxies. We predict that if BH spins are not highly aligned, seeing-limited observations could resolve offset AGN, making them promising targets for all-sky surveys. For randomly oriented spins, ≲ 10 spatially offset AGN may be detectable in Hubble Space Telescope-Cosmological Evolution Survey, and >103 could be found with the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS), the Large Synoptic Survey Telescope (LSST), Euclid, and the Wide-Field Infrared Survey Telescope (WFIRST). Nearly a thousand velocity offset AGN are predicted within the Sloan Digital Sky Survey (SDSS) footprint; the rarity of large broad-line offsets among SDSS quasars is likely due in part to selection effects but suggests that spin alignment plays a role in suppressing recoils. None the less, in our most physically motivated model where alignment occurs only in gas-rich mergers, hundreds of offset AGN should be found in all-sky surveys. Our findings strongly motivate a dedicated search for recoiling AGN.

  18. Fluence measurement of fast neutron fields with a highly efficient recoil proton telescope using active pixel sensors.

    PubMed

    Taforeau, J; Higueret, S; Husson, D; Kachel, M; Lebreton, L

    2014-10-01

    The spectrometer ATHENA (Accurate Telescope for High-Energy Neutron metrology Applications) is being developed at the LNE-IRSN and aims at characterising energy and fluence of fast neutron fields. The detector is a recoil proton telescope and measures neutron fields in the range of 5-20 MeV. This telescope is intended to become a primary standard for both energy and fluence measurements. The neutron detection is achieved by a polyethylene radiator for n-p conversion, three 50-µm-thick silicon sensors that use CMOS technology for proton tracking and a 3-mm-thick silicon diode to measure the residual proton energy. The use of CMOS sensors and silicon diode, owing to a large detection solid angle, increases the intrinsic efficiency of the detector by a factor of 10 compared with conventional designs. The ability of the spectrometer to determine the neutron energy was demonstrated and reported elsewhere. This paper focuses on the fluence measurement of monoenergetic neutron fields in the range of 5-20 MeV. Experimental investigations, performed at the AMANDE facility, indicate a good estimation of neutron fluence at various energies. In addition, a complete description of uncertainties budget is presented in this paper and a Monte Carlo propagation of uncertainty sources leads to a fluence measurement with a precision ∼3-5 % depending on the neutron energy.

  19. Observation of Collective Atomic Recoil Motion in a Degenerate Fermion Gas

    SciTech Connect

    Wang Pengjun; Fu Zhengkun; Chai Shijie; Zhang Jing; Deng, L.; Hagley, E. W.

    2011-05-27

    We demonstrate collective atomic recoil motion with a dilute, ultracold, degenerate fermion gas in a single spin state. By utilizing an adiabatically decompressed magnetic trap with an aspect ratio different from that of the initial trap, a momentum-squeezed fermion cloud is achieved. With a single pump pulse of the proper polarization, we observe, for the first time, multiple wave-mixing processes that result in distinct collective atomic recoil motion modes in a degenerate fermion cloud. Contrary to the case with Bose condensates, no pump-laser detuning asymmetry is present.

  20. Radiative recoil corrections to hyperfine splitting: Polarization insertions in the electron factor

    SciTech Connect

    Eides, M. I.; Shelyuto, V. A.

    2010-01-15

    We consider three-loop radiative recoil corrections to hyperfine splitting in muonium due to insertions of the one-loop polarization operator in the electron factor. The contribution generated by electron polarization insertions is a cubic polynomial in the large logarithm of the electron-muon mass ratio. The leading logarithm cubed and logarithm squared terms are well known for some time. We calculate all single-logarithmic and nonlogarithmic radiative recoil corrections of the order {alpha}{sup 3}(m/M)E{sub F} generated by diagrams with the electron and muon polarization insertions.

  1. A detector for filtering γ-ray spectra from weak fusion evaporation reactions out of strong background and for Doppler correction: The recoil filter detector, RFD

    NASA Astrophysics Data System (ADS)

    Męczyński, W.; Bednarczyk, P.; Grębosz, J.; Heese, J.; Janicki, M.; Maier, K. H.; Merdinger, J. C.; Spohr, K.; Ziębliński, M.; Styczeń, J.

    2007-10-01

    A detector has been designed and built to assist in-beam γ-ray spectroscopy with fusion-evaporation reactions. It measures with high efficiency the evaporation residues that recoil out of a thin target into the angular interval from 1.8° to 9.0° at an adjustable distance of 1000-1350 mm from a target, in coincidence with γ-rays detected in a Ge-detector array. This permits filtering of such γ-rays out of a much stronger background of other reaction products and scattered beam. Evaporation residues are identified by their time-of-flight and the pulse height using a pulsed beam. The velocity vector of the γ-emitting recoil is also measured in the event-by-event mode, facilitating to correct the registered γ-ray energy for the Doppler shift, with the resulting significant improvement of the energy resolution. The heavy-ion detection scheme uses emission of secondary electrons caused by the recoiling ions when hitting a thin foil. These electrons are then electrostatically accelerated and focused onto a small scintillator that measures the summed electron energy, which is proportional to the number of electrons. The detector is able to operate at high frequency of the order of 1 MHz and detect very heavy nuclei with as low kinetic energy as 5 MeV. The paper describes the properties of the detector and gives examples of measurements with the OSIRIS, GAREL+ and EUROBALL IV γ-ray spectrometers. The usefulness of the technique for spectroscopic investigations of nuclei with a continuous beam is also discussed.

  2. ANALYSIS OF ACCELERATOR BASED NEUTRON SPECTRA FOR BNCT USING PROTON RECOIL SPECTROSCOPY

    SciTech Connect

    WIELOPOLSKI,L.; LUDEWIG,H.; POWELL,J.R.; RAPARIA,D.; ALESSI,J.G.; LOWENSTEIN,D.I.

    1998-11-06

    Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p,n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark

  3. Analysis of accelerator based neutron spectra for BNCT using proton recoil spectroscopy

    SciTech Connect

    Wielopolski, L.; Ludewig, H.; Powell, J.R.; Raparia, D.; Alessi, J.G.; Lowenstein, D.I.

    1999-03-01

    Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase 1/2 clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra, alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p,n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark

  4. Collaborative Research: Nanopore Confinement of C-H-O Mixed Volatile Fluids Relevant to Subsurface Energy Systems

    SciTech Connect

    Grady, Brian P.

    2015-03-11

    The scientific objective of this proposal was to obtain a fundamental atomic- to macro-scale understanding of the sorptivity, structure and dynamics of simple and complex hydrocarbon (HC) fluids at mineral surfaces or within nanoporous matrices over temperatures, pressures and compositions encountered in near-surface and shallow crustal environments. The research supported by this award was complementary to that conducted by the group of Prof. David cole at Ohio State University. The scope of the present award was to utilize molecular-level modeling to provide critically important insights into the interfacial properties of mineral-volatile systems, assist in the interpretation of experimental data and predict fluid behavior beyond the limits of current experimental capability. During the past three years the effort has focused primarily on the behavior of C-H volatiles including methane (CH4) and propane (C3H8), mixed-volatile systems including hydrocarbon - CO2 with and without H2O present. The long-range goal is to quantitatively link structure, dynamics and reactivity in complex mineral-/C-H-O systems from the atomic to the molecular to the macroscopic levels. The results are relevant to areas of growing importance such as gas shale, HC-bearing hydrothermal systems, and CO2 storage.

  5. {phi} decay: A relevant source for K{sup -} production at energies available at the GSI Schwerionen-Synchrotron (SIS)?

    SciTech Connect

    Agakishiev, G.; Destefanis, M.; Gilardi, C.; Kirschner, D.; Kuehn, W.; Lange, J. S.; Metag, V.; Mishra, D.; Pechenov, V.; Pechenova, O.; Cavalcanti, T. Perez; Spataro, S.; Spruck, B.; Balanda, A.; Dybczak, A.; Michalska, B.; Otwinowski, J.; Przygoda, W.; Salabura, P.; Trebacz, R.

    2009-08-15

    We present phase space distributions and multiplicities of K{sup +}, K{sup -}, and {phi} mesons produced in Ar+KCl reactions at a kinetic beam energy of 1.756 GeV/nucleon and measured with the HADES spectrometer. The inverse slope parameters and yields of kaons supplement the systematics of previous measurements. The percentage of K{sup -} mesons coming from {phi} decay is found to be 18{+-}7%.

  6. Sound production by a recoiling system in the pempheridae and terapontidae.

    PubMed

    Parmentier, Eric; Fine, Michael L; Mok, Hin-Kiu

    2016-06-01

    Sound-producing mechanisms in fishes are extraordinarily diversified. We report here original mechanisms of three species from two families: the pempherid Pempheris oualensis, and the terapontids Terapon jarbua and Pelates quadrilineatus. All sonic mechanisms are built on the same structures. The rostral part of the swimbladder is connected to a pair of large sonic muscles from the head whereas the posterior part is fused with bony widenings of vertebral bodies. Two bladder regions are separated by a stretchable fenestra that allows forward extension of the anterior bladder during muscle contraction. A recoiling apparatus runs between the inner face of the anterior swimbladder and a vertebral body expansion. The elastic nature of the recoiling apparatus supports its role in helping the swimbladder to recover its initial position during sonic muscle relaxation. This system should aid fast contraction (between 100 and 250Hz) of sonic muscles. There are many differences between species in terms of the swimbladder and its attachments to the vertebral column, muscle origins, and morphology of the recoiling apparatus. The recoiling apparatus found in the phylogenetically-related families (Glaucosomatidae, Pempheridae, Terapontidae) could indicate a new character within the Percomorpharia. J. Morphol. 277:717-724, 2016. © 2016 Wiley Periodicals, Inc.

  7. Measurement of Nuclear Recoils in the CDMS II Dark Matter Search

    SciTech Connect

    Fallows, Scott Mathew

    2014-12-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for \\background- free" operation of CDMS II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space.

  8. Integral cross section measurements and product recoil velocity distributions of Xe(2+) + N2 hyperthermal charge-transfer collisions.

    PubMed

    Hause, Michael L; Prince, Benjamin D; Bemish, Raymond J

    2016-07-28

    Charge exchange from doubly charged rare gas cations to simple diatomics proceeds with a large cross section and results in populations of many vibrational and electronic product states. The charge exchange between Xe(2+) and N2, in particular, is known to create N2 (+) in both the A and B electronic states. In this work, we present integral charge exchange cross section measurements of the Xe(2+) + N2 reaction as well as axial recoil velocity distributions of the Xe(+) and N2 (+) product ions for collision energies between 0.3 and 100 eV in the center-of-mass (COM) frame. Total charge-exchange cross sections decrease from 70 Å(2) to about 40 Å(2) with increasing collision energy through this range. Analysis of the axial velocity distributions indicates that a Xe(2+) - N2 complex exists at low collision energies but is absent by 17.6 eV COM. Analysis of the axial velocity distributions reveals evidence for complexes with lifetimes comparable to the rotational period at low collision energies. The velocity distributions are consistent with quasi-resonant single charge transfer at high collision energies. PMID:27475363

  9. Integral cross section measurements and product recoil velocity distributions of Xe2+ + N2 hyperthermal charge-transfer collisions

    NASA Astrophysics Data System (ADS)

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2016-07-01

    Charge exchange from doubly charged rare gas cations to simple diatomics proceeds with a large cross section and results in populations of many vibrational and electronic product states. The charge exchange between Xe2+ and N2, in particular, is known to create N2 + in both the A and B electronic states. In this work, we present integral charge exchange cross section measurements of the Xe2+ + N2 reaction as well as axial recoil velocity distributions of the Xe+ and N2 + product ions for collision energies between 0.3 and 100 eV in the center-of-mass (COM) frame. Total charge-exchange cross sections decrease from 70 Å2 to about 40 Å2 with increasing collision energy through this range. Analysis of the axial velocity distributions indicates that a Xe2+ - N2 complex exists at low collision energies but is absent by 17.6 eV COM. Analysis of the axial velocity distributions reveals evidence for complexes with lifetimes comparable to the rotational period at low collision energies. The velocity distributions are consistent with quasi-resonant single charge transfer at high collision energies.

  10. A Modified activation method for reaction total cross section and yield measurements at low astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Artemov, S. V.; Igamov, S. B.; Karakhodjaev, A. A.; Radyuk, G. A.; Tojiboyev, O. R.; Salikhbaev, U. S.; Ergashev, F. Kh.; Nam, I. V.; Aliev, M. K.; Kholbaev, I.; Rumi, R. F.; Khalikov, R. I.; Eshkobilov, Sh. Kh.; Muminov, T. M.

    2016-07-01

    The activation method is proposed for collection of the sufficient statistics during the investigation of the nuclear astrophysical reactions at low energies with the short-living residual nuclei formation. The main feature is a multiple cyclical irradiation of a target by an ion beam and measurement of the radioactivity decay curve. The method was tested by the yield measurement of the 12C(p,γ)13N reaction with detecting the annihilation γγ- coincidences from 13N(β+ν)13C decay at the two-arm scintillation spectrometer.

  11. Investigating the Nexus of Climate, Energy, Water, and Land at Decision-Relevant Scales: The Platform for Regional Integrated Modeling and Analysis (PRIMA)

    SciTech Connect

    Kraucunas, Ian P.; Clarke, Leon E.; Dirks, James A.; Hathaway, John E.; Hejazi, Mohamad I.; Hibbard, Kathleen A.; Huang, Maoyi; Jin, Chunlian; Kintner-Meyer, Michael C.W.; Kleese van Dam, Kerstin; Leung, Lai-Yung R.; Li, Hongyi; Moss, Richard H.; Peterson, Marty J.; Rice, Jennie S.; Scott, Michael J.; Thomson, Allison M.; Voisin, Nathalie; West, Tristram O.

    2015-04-01

    The Platform for Regional Integrated Modeling and Analysis (PRIMA) is an innovative modeling system developed at Pacific Northwest National Laboratory (PNNL) to simulate interactions among natural and human systems at scales relevant to regional decision making. PRIMA brings together state-of-the-art models of regional climate, hydrology, agriculture, socioeconomics, and energy systems using a flexible coupling approach. The platform can be customized to inform a variety of complex questions and decisions, such as the integrated evaluation of mitigation and adaptation options across a range of sectors. Research into stakeholder decision support needs underpins the platform's application to regional issues, including uncertainty characterization. Ongoing numerical experiments are yielding new insights into the interactions among human and natural systems on regional scales with an initial focus on the energy-land-water nexus in the upper U.S. Midwest. This paper focuses on PRIMA’s functional capabilities and describes some lessons learned to date about integrated regional modeling.

  12. Gravitational Recoil of Inspiraling Black Hole Binaries to Second Post-Newtonian Order

    NASA Astrophysics Data System (ADS)

    Blanchet, Luc; Qusailah, Moh'd. S. S.; Will, Clifford M.

    2005-12-01

    The loss of linear momentum by gravitational radiation and the resulting gravitational recoil of black hole binary systems may play an important role in the growth of massive black holes in early galaxies. We calculate the gravitational recoil of nonspinning black hole binaries at the second post-Newtonian order (2 PN) beyond the dominant effect, obtaining, for the first time, the 1.5 PN correction term due to tails of waves and the next 2 PN term. We find that the maximum value of the net recoil experienced by the binary due to the inspiral phase up to the innermost stable circular orbit (ISCO) is of the order of 22 km s-1. We then estimate the kick velocity accumulated during the plunge from the ISCO up to the horizon by integrating the momentum flux using the 2 PN formula along a plunge geodesic of the Schwarzschild metric. We find that the contribution of the plunge dominates over that of the inspiral. For a mass ratio m2/m1=1/8, we estimate a total recoil velocity (due to both adiabatic and plunge phases) of 100+/-20 km s-1. For a ratio of 0.38, the recoil is maximum, and we estimate it to be 250+/-50 km s-1. In the limit of small mass ratio, we estimate V/c~0.043(+/-20%)(m2/m1)2. Our estimates are consistent with, but span a substantially narrower range than, those of Favata and coworkers.

  13. Theoretical study of inversion and topomerization processes of substituted cyclohexanes: the relevance of the energy 3D hypersurface.

    PubMed

    del Fernández-Alonso, María Carmen; Cañada, Javier; Jiménez-Barbero, Jesús; Cuevas, Gabriel

    2005-04-01

    Although the potential energy surface of highly symmetric cyclohexane has been extensively reviewed, no attention has been paid to the study of the effect of substitution of a methylene group by a heteroatom. The substitution may cause changes in molecular symmetry as well as the dipole moment, and the unshared electron pairs associated with the heteroatom may also introduce changes in molecular reactivity. However, these phenomena are not yet completely understood. To address these issues, a rigorous description of the inversion-topomerization process of methylcyclohexane and a revision of the conformational potential energy of oxane and thiane are presented. Moreover, the usefulness of providing a three-dimensional representation of these processes is discussed. In the case of methylcyclohexane, calculations show that three transition states are associated with inversion and four more with topomerization. In contrast, for oxane and thiane, only two transition states are involved with inversion and two with topomerization. Two fundamental conclusions can be drawn from this study. The first is that the inversion process occurs through elementary, stages that we have denoted "conformational elemental stages", which is an analogous term to that used for reaction mechanism description (minima-transition state-minima) where several elemental steps take place. The second conclusion is that two independent processes, inversion and topomerization, are connected by some common conformers. The inversion process controls the ring interchange, while topomerization allows exchange between skewed boats.

  14. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency.

    PubMed

    Hanada, M; Kojima, A; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications. PMID:26932050

  15. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency.

    PubMed

    Hanada, M; Kojima, A; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications.

  16. Cross sections for proton-induced reactions on Pd isotopes at energies relevant for the {gamma} process

    SciTech Connect

    Dillmann, I.; Coquard, L.; Domingo-Pardo, C.; Kaeppeler, F.; Marganiec, J.; Uberseder, E.; Giesen, U.; Heiske, A.; Feinberg, G.; Hentschel, D.; Hilpp, S.; Leiste, H.; Rauscher, T.; Thielemann, F.-K.

    2011-07-15

    Proton-activation reactions on natural and enriched palladium samples were investigated via the activation technique in the energy range of E{sub p}=2.75-9 MeV, close to the upper end of the respective Gamow window of the {gamma} process. We have determined cross sections for {sup 102}Pd(p, {gamma}){sup 103}Ag, {sup 104}Pd(p, {gamma}){sup 105}Ag, and {sup 105}Pd(p, n){sup 105}Ag, as well as partial cross sections of {sup 104}Pd(p, n){sup 104}Ag{sup g}, {sup 105}Pd(p, {gamma}){sup 106}Ag{sup m}, {sup 106}Pd(p, n){sup 106}Ag{sup m}, and {sup 110}Pd(p, n){sup 110}Ag{sup m} with uncertainties between 3% and 15% for constraining theoretical Hauser-Feshbach rates and for direct use in {gamma}-process calculations.

  17. High-Intensity Scattering Processes of Relativistic Electrons in Vacuum and Their Relevance to High-Energy Astrophysics

    SciTech Connect

    Hartemann, Frederic V.; Troha, Anthony L.; Baldis, Hector A.; Gupta, Atul; Kerman, Arthur K.; Landahl, Eric C.; Luhmann, Neville C. Jr.; Van Meter, James R.

    2000-04-01

    The recent advent of ultra-short pulse, high-intensity lasers, together with advances in other novel technologies, such as high-gradient radiofrequency photoinjectors, have afforded researchers the possibility to simulate astrophysical conditions in the laboratory. Laser-produced plasmas have been successfully used to simulate astrophysical plasmas and supernovae in the laboratory for several years. Now, femtosecond laser systems operating in the terawatt to petawatt range are available, as are synchronized relativistic electron bunches with subpicosecond durations and terahertz bandwidths. With these tools, experiments have been conducted to study phenomena related to supernova explosions, stellar winds, solar coronae, cosmic rays, planetary and celestial matter, and interstellar plasmas. Other experiments have been proposed to investigate Unruh radiation, as well as ponderomotive scattering, which can accelerate electrons in vacuum to relativistic energies using the extremely high gradients in a three-dimensional laser focus. The nonlinear Doppler shift induced by ultrarelativistic radiation pressure is shown to yield complex nonlinear Compton backscattered spectra. Finally, strong radiative corrections are expected when the Doppler-upshifted laser wavelength approaches the Compton scale. These are discussed within the context of high-field classical electrodynamics, a new discipline borne out of the aforementioned innovations. (c) 2000 The American Astronomical Society.

  18. Measurement of 23Na(α,p)26Mg at Energies Relevant to 26Al Production in Massive Stars.

    PubMed

    Tomlinson, J R; Fallis, J; Laird, A M; Fox, S P; Akers, C; Alcorta, M; Bentley, M A; Christian, G; Davids, B; Davinson, T; Fulton, B R; Galinski, N; Rojas, A; Ruiz, C; de Séréville, N; Shen, M; Shotter, A C

    2015-07-31

    26Al is an important radioisotope in astrophysics that provides evidence of ongoing nucleosynthesis in the Galaxy. The 23Na(α, p)26Mg reaction has been identified by a sensitivity study as being one of the most important reactions for the production of 26Al in the convective C/Ne burning shell of massive stars. Owing to large uncertainties in previous experimental data, model calculations are used for the reaction rate of 23Na(α, p)26Mg in this sensitivity study. Current experimental data suggest a reaction rate a factor of ∼40 higher than model calculations. However, a new measurement of this reaction cross section has been made in inverse kinematics in the energy range E(c.m.)=1.28-3.15  MeV at TRIUMF, and found to be in reasonable agreement with the model calculation. A new reaction rate is calculated and tight constraints on the uncertainty in the production of 26Al, due to this reaction, are determined. PMID:26274415

  19. Measurement of 23Na(α,p)26Mg at Energies Relevant to 26Al Production in Massive Stars.

    PubMed

    Tomlinson, J R; Fallis, J; Laird, A M; Fox, S P; Akers, C; Alcorta, M; Bentley, M A; Christian, G; Davids, B; Davinson, T; Fulton, B R; Galinski, N; Rojas, A; Ruiz, C; de Séréville, N; Shen, M; Shotter, A C

    2015-07-31

    26Al is an important radioisotope in astrophysics that provides evidence of ongoing nucleosynthesis in the Galaxy. The 23Na(α, p)26Mg reaction has been identified by a sensitivity study as being one of the most important reactions for the production of 26Al in the convective C/Ne burning shell of massive stars. Owing to large uncertainties in previous experimental data, model calculations are used for the reaction rate of 23Na(α, p)26Mg in this sensitivity study. Current experimental data suggest a reaction rate a factor of ∼40 higher than model calculations. However, a new measurement of this reaction cross section has been made in inverse kinematics in the energy range E(c.m.)=1.28-3.15  MeV at TRIUMF, and found to be in reasonable agreement with the model calculation. A new reaction rate is calculated and tight constraints on the uncertainty in the production of 26Al, due to this reaction, are determined.

  20. Simulating Makrofol as a detector for neutron-induced recoils.

    PubMed

    Zhang, G; Becker, F; Urban, M; Xuan, Y

    2011-03-01

    The response of solid-state nuclear track detector is extremely dependent on incident angles of neutrons, which determine the angular distribution of secondary particles. In this paper, the authors present a method to investigate the angular response of Makrofol detectors. Using the C++-based Monte-Carlo tool-kit Geant4 in combination with SRIM and our MATLAB codes, we simulated the angular response of Makrofol. The simulations were based on the restricted energy loss model, and the concept of energy threshold and critical angle. Experiments were carried out with (252)Cf neutrons to verify the simulation results.

  1. A combined segmented anode gas ionization chamber and time-of-flight detector for heavy ion elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Ström, Petter; Petersson, Per; Rubel, Marek; Possnert, Göran

    2016-10-01

    A dedicated detector system for heavy ion elastic recoil detection analysis at the Tandem Laboratory of Uppsala University is presented. Benefits of combining a time-of-flight measurement with a segmented anode gas ionization chamber are demonstrated. The capability of ion species identification is improved with the present system, compared to that obtained when using a single solid state silicon detector for the full ion energy signal. The system enables separation of light elements, up to Neon, based on atomic number while signals from heavy elements such as molybdenum and tungsten are separated based on mass, to a sample depth on the order of 1 μm. The performance of the system is discussed and a selection of material analysis applications is given. Plasma-facing materials from fusion experiments, in particular metal mirrors, are used as a main example for the discussion. Marker experiments using nitrogen-15 or oxygen-18 are specific cases for which the described improved species separation and sensitivity are required. Resilience to radiation damage and significantly improved energy resolution for heavy elements at low energies are additional benefits of the gas ionization chamber over a solid state detector based system.

  2. Recrystallization of bulk and plasma-coated tungsten with accumulated thermal energy relevant to Type-I ELM in ITER H-mode operation

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Su; Lim, Sun-Taek; Jin, Younggil; Lee, Jin Young; Song, Jae-Min; Kim, Gon-Ho

    2015-08-01

    The recrystallization of bulk tungsten is investigated under various thermal loads that are relevant to the accumulation energy during Type-I ELM in ITER H-mode operation. A thermal plasma torch is used to examine only the thermal load effect on the material; therefore, the charge and atomic effects are ignored. In this condition, recrystallization is observed in bulk W with a surface temperature above 1700 °C. The effect becomes severe with a finite recrystallization thickness near the surface, which introduces vertical cracking along grain boundaries with increasing thermal load. However, plasma-sprayed tungsten (PS-W) is not crystallized because neighboring lamellas merge, destroying their interlayer and producing no vertical cracks. This is attributed to an annealing effect in PS-W. Therefore, these results suggest that a multilayer W structure is advantageous in the fabrication of W, especially for long pulse operation in a future fusion reactor.

  3. Nuclear recoil corrections to the Lamb shift of hydrogen and light hydrogenlike ions

    NASA Astrophysics Data System (ADS)

    Yerokhin, V. A.; Shabaev, V. M.

    2016-06-01

    Accurate calculations of the nuclear recoil effect on the Lamb shift of hydrogenlike atoms are presented. Numerical results are reported for the n s states with n ≤5 and for the 2 p1 /2 and 2 p3 /2 states. The calculations are performed to the first order in the electron-nucleus mass ratio and to all orders in the nuclear binding strength parameter Z α (where Z is the nuclear charge number and α is the fine structure constant). The obtained results provide accurate predictions for the higher-order remainder beyond the known Z α -expansion terms. In the case of hydrogen, the remainder was found to be much larger than anticipated. This result resolves the previously reported disagreement between the numerical all-order and the analytical Z α -expansion approaches for the nuclear recoil effect on the hydrogen Lamb shift.

  4. What Can We Learn From Proton Recoils about Heavy-Ion SEE Sensitivity?

    NASA Technical Reports Server (NTRS)

    Ladbury, Raymond L.

    2016-01-01

    The fact that protons cause single-event effects (SEE) in most devices through production of light-ion recoils has led to attempts to bound heavy-ion SEE susceptibility through use of proton data. Although this may be a viable strategy for some devices and technologies, the data must be analyzed carefully and conservatively to avoid over-optimistic estimates of SEE performance. We examine the constraints that proton test data can impose on heavy-ion SEE susceptibility.

  5. Lifetimes in neutron-rich fission fragments using the differential recoil distance method

    SciTech Connect

    Kruecken, R.; Chou, W.-T.; Cooper, J. R.; Beausang, C. W.; Barton, C. J.; Caprio, M. A.; Casten, R. F.; Hecht, A. A.; Novak, J. R.; Pietralla, N.

    2001-07-01

    Lifetimes in the neutron-rich nuclei {sup 104}Mo, {sup 110}Ru, and {sup 144}Ba were measured using the differential recoil distance method. The experiment was performed with a {sup 252}Cf fission source inside the New Yale Plunger Device. {gamma} rays were detected by the SPEctrometer for Experiments with Doppler shifts at Yale (SPEEDY) while fission fragments with the appropriate kinematics were detected by an array of photocells.

  6. Production of soft X-ray emitting slow multiply charged ions - Recoil ion spectroscopy

    NASA Technical Reports Server (NTRS)

    Sellin, I. A.; Elston, S. B.; Forester, J. P.; Griffin, P. M.; Pegg, D. J.; Peterson, R. S.; Thoe, R. S.; Vane, C. R.; Wright, J. J.; Groeneveld, K.-O.

    1977-01-01

    S ions with a mean charge state of about 14+ and Cl ions with a mean charge state of 12+ were used to study Ne L-shell vacancy production. The ions caused copious production of NeII-NeVIII excited states with approximately 10 to the minus 18 sq cm cross sections. The induced recoil velocities might have application to a significantly higher resolution spectroscopy than is possible with beam-foil methods.

  7. Lung recoil during rapid vital capacity expirations simulated by gas compression.

    PubMed

    Webster, P M; Loring, S H; Butler, J P; Hoppin, F G

    1980-07-01

    Excised dog lobes were inflated to a transpulmonary pressure (PL) of about 30 cmH2O, and their airways were occluded. Then they were rapidly compressed to a volume where PL was about zero, simulating forced expiratory maneuvers. Since there was no airflow during the compression, PL was a direct measure of lung recoil. Lung volume (VL) was calculated from absolute airway pressure using Boyle's law. At ambient temperature, lung recoil pressure during compressive maneuvers simulating forced vital capacity expirations (Pdyn) was less than that during quasi-static (30 s) compressions (Pst). Typically the dynamic component (i.e., Pst--Pdyn) decreased from about 2 cmH2O near total lung capacity to no difference at the end of the compression. Cooling the lobes to 15 degrees C increased Pst-Pdyn, and warming the lobes to 37 degrees C reduced Pst-Pdyn almost to zero. We suggest that the driving force of lung recoil during expirations is adequately modeled by the quasi-static VL/PL relationship, though a small correction should be made for excised lungs at room temperature. PMID:7399986

  8. Einstein-Bohr recoiling double-slit gedanken experiment performed at the molecular level

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Jing; Miao, Quan; Gel'Mukhanov, Faris; Patanen, Minna; Travnikova, Oksana; Nicolas, Christophe; Ågren, Hans; Ueda, Kiyoshi; Miron, Catalin

    2015-02-01

    Double-slit experiments illustrate the quintessential proof for wave-particle complementarity. If information is missing about which slit the particle has traversed, the particle, behaving as a wave, passes simultaneously through both slits. This wave-like behaviour and corresponding interference is absent if ‘which-slit’ information exists. The essence of Einstein-Bohr's debate about wave-particle duality was whether the momentum transfer between a particle and a recoiling slit could mark the path, thus destroying the interference. To measure the recoil of a slit, the slits should move independently. We showcase a materialization of this recoiling double-slit gedanken experiment by resonant X-ray photoemission from molecular oxygen for geometries near equilibrium (coupled slits) and in a dissociative state far away from equilibrium (decoupled slits). Interference is observed in the former case, while the electron momentum transfer quenches the interference in the latter case owing to Doppler labelling of the counter-propagating atomic slits, in full agreement with Bohr's complementarity.

  9. Properties enhancement and recoil loop characteristics for hot deformed nanocrystalline NdFeB permanent magnets

    NASA Astrophysics Data System (ADS)

    Liu, Z. W.; Huang, Y. L.; Hu, S. L.; Zhong, X. C.; Y Yu, H.; Gao, X. X.

    2014-06-01

    Nanocrystalline NdFeB magnets were prepared by spark plasma sintering (SPS) and SPS followed by HD using melt spun ribbons as the starting materials. The microstructure of SPSed and HDed magnets were analyzed. The effects of process including temperature and compression ratio on the microstructure and properties were investigated. High magnetic properties were obtained in anisotropic HDed magnets. The combination of Zn and Dy additions was successfully employed to improve the coercivity and thermal stability of the SPSed magnets. Open recoil loops were found in these magnets with Nd-rich composition and without soft magnetic phase for the first time. The relationship between the recoil loops and microstructure for SPS and HD NdFeB magnets were investigated. The investigations showed that the magnetic properties of SPS+HDed magnets are related to the extent of the aggregation of Nd-rich phase, which was formed during HD due to existence of porosity in SPSed precursor. Large local demagnetization fields induced by the Nd-rich phase aggregation leads to the open loops and significantly reduced the coercivity. By reducing the recoil loop openness, the magnetic properties of HDed NdFeB magnets were successfully improved.

  10. Low Energy Sputtering Events at Free Surfaces near Anti-Phase and Grain Boundaries in Ni3Al

    SciTech Connect

    Gao, Fei; Bacon, David J.; Lai, Wenshen; Kurtz, Richard J.

    2006-09-21

    Atomic recoil events on free surfaces orthogonal to two different anti-phase boundaries (APBs) and two grain boundaries (GBs) in Ni3Al are simulated using molecular dynamics methods. The threshold energy for sputtering, Esp, and adatom creation, Ead, are determined as a function of recoil direction. The study is relevant to FEG STEM experiments on preferential Al sputtering and/or enhancement of the Ni-Al ratio near boundaries. Surfaces intersected by {l_brace}110{r_brace} and {l_brace}111{r_brace} APBs have minimum Esp of 6.5 eV for an Al atom on the Ni-Al mixed (M) surface, which is close to the value of 6.0 eV for a perfect M surface. High values of Esp of an Al atom generally occur at large angle to the surface normal and depend strongly on the detailed atomic configuration of the surface. The mean Esp averaged over all recoil directions reveals that APBs have a small effect on the threshold sputtering. However, the results for Ead imply that an electron beam could create more Al adatoms on surfaces intersected by APBs than on those without. The equilibrium, minimum energy structures for a (001) surface intersected by either Sigma5[001](210) or Sigma25[001](340) symmetric tilt grain boundaries are computed. Esp for surface Al atoms near these GBs increases monotonically with increasing recoil angle to the surface normal, with a minimum value which is only about 1 eV different from that obtained for a perfect surface. Temperature up to 300 K has no effect on this result. It is concluded that the experimental observations of preferential sputtering are due to effects beyond those for Esp studied here. Possible reasons for this are discussed.

  11. Production and Recoil Loss of Cosmogenic Nuclides in Presolar Grains

    NASA Astrophysics Data System (ADS)

    Trappitsch, Reto; Leya, Ingo

    2016-05-01

    Presolar grains are small particles that condensed in the vicinity of dying stars. Some of these grains survived the voyage through the interstellar medium (ISM) and were incorporated into meteorite parent bodies at the formation of the Solar System. An important question is when these stellar processes happened, i.e., how long presolar grains were drifting through the ISM. While conventional radiometric dating of such small grains is very difficult, presolar grains are irradiated with galactic cosmic rays (GCRs) in the ISM, which induce the production of cosmogenic nuclides. This opens the possibility to determine cosmic-ray exposure (CRE) ages, i.e., how long presolar grains were irradiated in the ISM. Here, we present a new model for the production and loss of cosmogenic 3He, 6,7Li, and 21,22Ne in presolar SiC grains. The cosmogenic production rates are calculated using a state-of-the-art nuclear cross-section database and a GCR spectrum in the ISM consistent with recent Voyager data. Our findings are that previously measured 3He and 21Ne CRE ages agree within the (sometimes large) 2σ uncertainties and that the CRE ages for most presolar grains are smaller than the predicted survival times. The obtained results are relatively robust since interferences from implanted low-energy GCRs into the presolar SiC grains and/or from cosmogenic production within the meteoroid can be neglected.

  12. Recoil-range studies of heavy products of multinucleon transfer from /sup 18/O to /sup 245/Cm and /sup 249/Cf

    SciTech Connect

    McFarland, R.M.

    1982-09-01

    Recoil range distributions were measured for alpha and spontaneous fission activities made in the bombardment of /sup 245/Cm and /sup 249/Cf with /sup 18/O from 6.20 MeV/nucleon down to the interaction barrier. The shape of the distributions indicates tht transfers of up to four protons take place via a combination of quasi-elastic (QET) and deep inelastic (DIT) mechanisms, rather than complete fusion-de-excitation (CF) or massive transfer (MT). Angular distributions constructed from recoil range distributions, assuming QET/DIT, indicate that the QET component contributes more significantly to the heavy product residue cross section than the DIT, even though primary cross sections are expected to be higher for DIT than for QET. This may be explained qualitatively as a result of the high excitation energies associated with DIT; the very negative Q/sub gg/ of projectile stripping for these systems combined with the lower expected optimal Q/sub rxn/ of QET compared to DIT can give QET products comparatively low excitation.

  13. Complete and incomplete fusion reactions in the {sup 16}O+{sup 169}Tm system: Excitation functions and recoil range distributions

    SciTech Connect

    Sharma, Manoj Kumar; Unnati,; Sharma, B.K.; Singh, B.P.; Prasad, R.; Bhardwaj, H.D.; Kumar, Rakesh; Golda, K.S.

    2004-10-01

    With the view to study complete and incomplete fusion in heavy ion induced reactions, experiments have been carried out for measuring excitation functions for several reactions in the system {sup 16}O+{sup 169}Tm at energies near the Coulomb barrier to well above it, using an activation technique. The measured excitation functions have been compared with those calculated theoretically using three different computer codes viz., ALICE-91, CASCADE and PACE2. The enhancement of experimentally measured cross sections for alpha emission channels over their theoretical prediction has been attributed to the fact that these residues are formed not only by complete fusion but also through incomplete fusion. In order to separate out the relative contributions of complete and incomplete fusion, the recoil range distributions of eight residues produced in the interaction of {sup 16}O with {sup 169}Tm at {approx_equal}87 MeV have been measured. The recoil range distributions indicate significant contributions from incomplete fusion at {approx_equal}87 MeV for some of the channels.

  14. Measurements of fuel and ablator ρR in Symmetry-Capsule implosions with the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

    SciTech Connect

    Gatu Johnson, M. Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Bionta, R. M.; Casey, D. T.; Caggiano, J. A.; Hatarik, R.; Khater, H. Y.; Sayre, D. B.; Knauer, J. P.; Sangster, T. C.; Herrmann, H. W.; Kilkenny, J. D.

    2014-11-15

    The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range of 4–20 MeV. This paper describes MRS measurements of DT-fuel and CH-ablator ρR in DT gas-filled symmetry-capsule implosions at the NIF. DT-fuel ρR's of 80–140 mg/cm{sup 2} and CH-ablator ρR's of 400–680 mg/cm{sup 2} are inferred from MRS data. The measurements were facilitated by an improved correction of neutron-induced background in the low-energy part of the MRS spectrum. This work demonstrates the accurate utilization of the complete MRS-measured neutron spectrum for diagnosing NIF DT implosions.

  15. Measurements of fuel and ablator ρR in Symmetry-Capsule implosions with the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility.

    PubMed

    Gatu Johnson, M; Frenje, J A; Li, C K; Séguin, F H; Petrasso, R D; Bionta, R M; Casey, D T; Caggiano, J A; Hatarik, R; Khater, H Y; Sayre, D B; Knauer, J P; Sangster, T C; Herrmann, H W; Kilkenny, J D

    2014-11-01

    The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range of 4-20 MeV. This paper describes MRS measurements of DT-fuel and CH-ablator ρR in DT gas-filled symmetry-capsule implosions at the NIF. DT-fuel ρR's of 80-140 mg/cm(2) and CH-ablator ρR's of 400-680 mg/cm(2) are inferred from MRS data. The measurements were facilitated by an improved correction of neutron-induced background in the low-energy part of the MRS spectrum. This work demonstrates the accurate utilization of the complete MRS-measured neutron spectrum for diagnosing NIF DT implosions. PMID:25430283

  16. FastPixN, a new integrated pixel chip for a future fast version of the IRSN - recoil proton telescope.

    PubMed

    Kachel, M; Husson, D; Higueret, S; Taforeau, J; Lebreton, L

    2014-10-01

    A first prototype of recoil proton telescope (RPT) is currently working at the AMANDE facility, being developed as a collaboration between IPHC Strasbourg and the LNE-IRSN. The device, able to measure both energy and fluence of neutron fields in the range of 5-20 MeV, has to be improved further, in order to reduce the considerable inelastic background generated by the neutrons inside the RPT itself. To achieve faster running cycles, the present complementary metal-oxide-semiconductor pixels used for proton tracking are to be replaced by a new integrated chip, specially developed for this application. The authors present a first version of this new element, with individual pixels readout at a 200-MHz frequency, with a fast 4-bit ADC for each column of 64 pixels. The measured performances point to a complete frame treatment in only 12.6 µs. With a readout speed multiplied by a factor 400 over the existing device, the authors expect a considerable improvement of the telescope at AMANDE, with the potential to reach neutron fluence rates up to 10(7) n cm(-2) s(-1) or more.

  17. Applications of in-situ and ex-situ spectroscopic techniques for the study of electrode materials with relevance to energy generation and energy storage

    SciTech Connect

    Scherson, D.A.

    1995-10-01

    The demand for high energy density battery systems is expected to grow markedly during the next decade due to the advent of new generation of powerful, light-weight portable computers, cellular telephones, and power tools. The prospects of acquiring a larger share of an expanding and indeed highly competitive market have prompted battery producers to search for means of improving the overall performance of rechargeable battery systems, including the possible replacement of conventional electrodes with promising novel materials. In addition to economic considerations, there exists a pressing need to reduce or eliminate the use of toxic metals, which can contaminate the soil and water supplies and jeopardize human welfare, and thus comply with stringent constraints imposed by environmental regulatory agencies. The risks associated with this latter problem could be greatly alleviated by establishing programs, such as those in effect in some countries in western Europe, to control the indiscriminate disposal of batteries into refuse processing facilities and landfills. However, no such policy has, as yet, been instituted in the US.

  18. Earthdata Search: The Relevance of Relevance

    NASA Technical Reports Server (NTRS)

    Quinn, Patrick

    2016-01-01

    Through recent usability studies, the issue of relevance became increasingly clear in the Earthdata Search Client. After all, if a user can't find the data they are looking for, nothing else we do matters. This presentation walks through usability testing findings and recent relevance improvements made to the Earthdata Search Client.

  19. Quantitative angiographic assessment of elastic recoil after percutaneous transluminal coronary angioplasty.

    PubMed

    Rensing, B J; Hermans, W R; Beatt, K J; Laarman, G J; Suryapranata, H; van den Brand, M; de Feyter, P J; Serruys, P W

    1990-11-01

    Little is known about the elastic behavior of the coronary vessel wall directly after percutaneous transluminal coronary angioplasty (PTCA). Minimal luminal cross-sectional areas of 151 successfully dilated lesions were studied in 136 patients during balloon inflation and directly after withdrawal of the balloon. The circumvent geometric assumptions about the shape of the stenosis after PTCA, a videodensitometric analysis technique was used for the assessment of vascular cross-sectional areas. Elastic recoil was defined as the difference between balloon cross-sectional area of the largest balloon used at the highest pressure and minimal luminal cross-sectional area after PTCA. Mean balloon cross-sectional area was 5.2 +/- 1.6 mm2 with a mean minimal cross-sectional area of 2.8 +/- 1.4 mm2 immediately after inflation. Oversizing of the balloon (balloon artery ratio greater than 1) led to more recoil (0.8 +/- 0.3 vs 0.6 +/- 0.3 mm, p less than 0.001), suggestive of an elastic phenomenon. A difference in recoil of the 3 main coronary branches was observed: left anterior descending artery 2.7 +/- 1.3 mm2, circumflex artery 2.3 +/- 1.2 mm2 and right coronary artery 1.9 +/- 1.5 mm2 (p less than 0.025). The difference was still statistically significant if adjusted for reference area. Thus, nearly 50% of the theoretically achievable cross-sectional area (i.e., balloon cross-sectional area) is lost shortly after balloon deflation.

  20. Control of recoil losses in nanomechanical SiN membrane resonators

    NASA Astrophysics Data System (ADS)

    Borrielli, A.; Marconi, L.; Marin, F.; Marino, F.; Morana, B.; Pandraud, G.; Pontin, A.; Prodi, G. A.; Sarro, P. M.; Serra, E.; Bonaldi, M.

    2016-09-01

    In the context of a recoil damping analysis, we have designed and produced a membrane resonator equipped with a specific on-chip structure working as a "loss shield" for a circular membrane. In this device the vibrations of the membrane, with a quality factor of 107, reach the limit set by the intrinsic dissipation in silicon nitride, for all the modes and regardless of the modal shape, also at low frequency. Guided by our theoretical model of the loss shield, we describe the design rationale of the device, which can be used as effective replacement of commercial membrane resonators in advanced optomechanical setups, also at cryogenic temperatures.

  1. Calculated yield of isomer depletion due to NEEC for {sup 93m}Mo recoils

    SciTech Connect

    Karamian, S. A.; Carroll, J. J.

    2012-11-15

    In the present work, quantitative calculations were carried out for production and depletion of the {sup 93m}Mo isomer in a relatively simple experiment using {sup 91}Zr beam ions. Such studies could be arranged at existing and operating accelerator facilities, e.g. at GSI or in JINR. The {sup 93m}Mo nuclei produced in a He gas target due to the {sup 4}He({sup 91}Zr, 2n) reaction will recoil into a gas stopper with a high velocity, being then depleted due to NEEC in highly-ionized species.

  2. Recoil polarization measurements of the proton electromagnetic form factor ratio at high momentum transfer

    SciTech Connect

    Andrew Puckett

    2009-12-01

    Electromagnetic form factors are fundamental properties of the nucleon that describe the effect of its internal quark structure on the cross section and spin observables in elastic lepton-nucleon scattering. Double-polarization experiments have become the preferred technique to measure the proton and neutron electric form factors at high momentum transfers. The recently completed GEp-III experiment at the Thomas Jefferson National Accelerator Facility used the recoil polarization method to extend the knowledge of the proton electromagnetic form factor ratio GpE/GpM to Q2 = 8.5 GeV2. In this paper we present the preliminary results of the experiment.

  3. Direct recoil radon emanation from crystalline phases. Influence of moisture content

    NASA Astrophysics Data System (ADS)

    Barillon, Rémi; Özgümüs, Ahmet; Chambaudet, Alain

    2005-06-01

    This paper is devoted to the study of the radon emanation coefficient vs. water mass fraction for mineral samples. Modeling is performed considering only the direct recoil phenomena and assuming planar pores with high lengths-to-width aspect ratios. Water is assumed either to fill the pore alternatively with air or to form a continuous film on the pore surface. This modeling is applied to uranium mine tailings for which the pore size distribution was experimentally measured. It enables a good description of the change of the experimental radon emanation coefficients with the moisture content of the studied samples.

  4. The alpha-recoil effects of uranium in the Oklo reactor

    NASA Astrophysics Data System (ADS)

    Sheng, Z. Z.; Kuroda, P. K.

    1984-12-01

    A series of acid-leaching experiments have been carried out on a sample of uranium ore from reactor zone number 10 of the Oklo mines in Gabon. Anomalously high U-234/U-238 ratios were observed accompanied by modestly increased U-235/U-238 ratios in uranium fractions. These results, which can be interpreted as being due to the alpha-recoil effects of U-238 and Pu-239, provide a convenient way of calculating the conversion factor (the fraction of uranium atoms converted to plutonium) of the natural reactors from radiochemical data, obviating the necessity for mass-spectrometric measurements.

  5. g-FACTOR Measurements of Picosecond States:. Opportunities and Limitations of the Recoil-In Method

    NASA Astrophysics Data System (ADS)

    Stone, N. J.; Stone, J. R.; Bingham, C. R.; Fischer, C. Froese; Jönsson, P.

    2008-08-01

    This paper reports a new a-priori approach to the calibration of attenuations observed in Recoil-in-Vacuum angular distribution experiments which should allow extraction of g-factors for states of picosecond (ps) lifetime in many nuclei, of both odd-A and even-A without the need for extensive experimentally based calibration. The methods used and results for Ge and Mo isotopes are discussed, with outline applications to both on-line beam/target Coulomb excitation and fission fragment experiments.

  6. Ischemic stroke secondary to aortic dissection following rifle butt recoil chest injury: a case report.

    PubMed

    Rao, Mamatha; Panduranga, Prashanth; Al-Mukhaini, Mohammed; Al-Jufaili, Mahmood; Valiath, John

    2011-11-01

    Ischemic stroke secondary to aortic dissection is not uncommon. We present a patient with left hemiplegia secondary to Stanford type A aortic dissection extending to the supra-aortic vessels, which was precipitated by rifle butt recoil chest injury. The diagnosis of aortic dissection was delayed due to various factors. Finally, the patient underwent successful Bentall procedure with complete resolution of symptoms. This case emphasizes the need for caution in the use of firearms for recreation and to take precautions in preventing such incidents. In addition, this case illustrates the need for prompt cardiovascular physical examination in patients presenting with stroke.

  7. Ischemic Stroke Secondary to Aortic Dissection Following Rifle Butt Recoil Chest Injury: A Case Report

    PubMed Central

    Rao, Mamatha; Panduranga, Prashanth; Al-Mukhaini, Mohammed; Al-Jufaili, Mahmood; Valiath, John

    2011-01-01

    Ischemic stroke secondary to aortic dissection is not uncommon. We present a patient with left hemiplegia secondary to Stanford type A aortic dissection extending to the supra-aortic vessels, which was precipitated by rifle butt recoil chest injury. The diagnosis of aortic dissection was delayed due to various factors. Finally, the patient underwent successful Bentall procedure with complete resolution of symptoms. This case emphasizes the need for caution in the use of firearms for recreation and to take precautions in preventing such incidents. In addition, this case illustrates the need for prompt cardiovascular physical examination in patients presenting with stroke. PMID:22253955

  8. Binary and Recoil Collisions in Strong Field Double Ionization of Helium

    SciTech Connect

    Staudte, A.; Villeneuve, D. M.; Corkum, P. B.; Ruiz, C.; Becker, A.; Schoeffler, M.; Schoessler, S.; Meckel, M.; Doerner, R.; Zeidler, D.; Weber, Th.

    2007-12-31

    We have investigated the correlated momentum distribution of both electrons from nonsequential double ionization of helium in a 800 nm, 4.5x10{sup 14} W/cm{sup 2} laser field. Using very high resolution coincidence techniques, we find a so-far unobserved fingerlike structure in the correlated electron momentum distribution. The structure can be interpreted as a signature of the microscopic dynamics in the recollision process. We identify features corresponding to the binary and recoil lobe in field-free (e,2e) collisions. This interpretation is supported by analyzing ab initio solutions of a fully correlated three-dimensional helium model.

  9. Experimental evidence of the vapor recoil mechanism in the boiling crisis.

    PubMed

    Nikolayev, V S; Chatain, D; Garrabos, Y; Beysens, D

    2006-11-01

    Boiling crisis experiments are carried out in the vicinity of the liquid-gas critical point of H2. A magnetic gravity compensation setup is used to enable nucleate boiling at near critical pressure. The measurements of the critical heat flux that defines the threshold for the boiling crisis are carried out as a function of the distance from the critical point. The obtained power law behavior and the boiling crisis dynamics agree with the predictions of the vapor recoil mechanism and disagree with the classical vapor column mechanism.

  10. Photodissociation of laboratory oriented molecules: Revealing molecular frame properties of nonaxial recoil

    SciTech Connect

    Brom, Alrik J. van den; Rakitzis, T. Peter; Janssen, Maurice H.M.

    2004-12-15

    We report the photodissociation of laboratory oriented OCS molecules. A molecular beam of OCS molecules is hexapole state-selected and spatially oriented in the electric field of a velocity map imaging lens. The oriented OCS molecules are dissociated at 230 nm with the linear polarization set at 45 deg. to the orientation direction of the OCS molecules. The CO({nu}=0,J) photofragments are quantum state-selectively ionized by the same 230 nm pulse and the angular distribution is measured using the velocity map imaging technique. The observed CO({nu}=0,J) images are strongly asymmetric and the degree of asymmetry varies with the CO rotational state J. From the observed asymmetry in the laboratory frame we can directly extract the molecular frame angles between the final photofragment recoil velocity and the permanent dipole moment and the transition dipole moment. The data for CO fragments with high rotational excitation reveal that the dissociation dynamics is highly nonaxial, even though conventional wisdom suggests that the nearly limiting {beta} parameter results from fast axial recoil dynamics. From our data we can extract the relative contribution of parallel and perpendicular transitions at 230 nm excitation.

  11. Recoil effects due to electron shake-off following the beta decay of 6 He

    NASA Astrophysics Data System (ADS)

    Drake, Gordon W. F.; Schulhoff, Eva

    2016-05-01

    There are currently several experiments in progress to search for new physics beyond the Standard Model by high precision studies of angular correlations in the β decay of the helium isotope 6He to form 6Li +e- +νe. After the β decay process, the atomic electrons of 6 Li+ adjust to the sudden change of nuclear charge from 2 to 3. We calculate the probabilities for electron shake-up and shake-off, including recoil effects, by the use of a Stieltjes imaging representation of the final states. A variety of sum rules provides tight consistency checks on the accuracy of the results. Results obtained previously indicate that there is a 7 σ disagreement between theory and experiment for the additional nuclear recoil induced by the emission of atomic shake-off electrons. This disagreement will be further studied, and the results extended to the 1 s 2 p3 P and metastable 1 s 2 s3 S states as initial states of 6 He before β-decay. Research supported by the Natural Sciences and Engineering Research Council of Canada.

  12. Off-resonance photoemission dynamics studied by recoil frame F1s and C1s photoelectron angular distributions of CH{sub 3}F

    SciTech Connect

    Stener, M. Decleva, P.; Mizuno, T.; Yagishita, A.; Yoshida, H.

    2014-01-28

    F1s and C1s photoelectron angular distributions are considered for CH{sub 3}F, a molecule which does not support any shape resonance. In spite of the absence of features in the photoionization cross section profile, the recoil frame photoelectron angular distributions (RFPADs) exhibits dramatic changes depending on both the photoelectron energy and polarization geometry. Time-dependent density functional theory calculations are also given to rationalize the photoionization dynamics. The RFPADs have been compared with the theoretical calculations, in order to assess the accuracy of the theoretical method and rationalize the experimental findings. The effect of finite acceptance angles for both ionic fragments and photoelectrons has been included in the calculations, as well as the effect of rotational averaging around the fragmentation axis. Excellent agreement between theory and experiment is obtained, confirming the good quality of the calculated dynamical quantities (dipole moments and phase shifts)

  13. A personal neutron monitoring system based on CR-39 recoil proton track detectors: assessment of Hp(10) using image process algorithms.

    PubMed

    Bedogni, R; Fantuzzi, E

    2002-01-01

    At the Individual Monitoring Service (IMS) of the ENEA Institute for Radiation Protection (IRP), the Hp(10) fast neutron dosemeter consists of a CR-39 (PADC, poly allyl diglycol carbonate) recoil protons track detector. The tracks across the detector surface are magnified through a chemical etching procedure and counted by a semi-automated system which consists of a microscope, a camera and a PC. A new analysis system, based on the National Instruments vision tools, was developed. The track area distribution for each reading field is recorded and numerical algorithms were developed in order to correct the energy dependence of the response and to recognise the tracks due to the background. This improves the dose evaluation system in terms of accuracy and discrimination or the background. PMID:12382731

  14. Electron-ion recombination in nuclear recoils tracks in nonpolar liquids. Calculation of the effect of external electric field on the escape probability

    NASA Astrophysics Data System (ADS)

    Mateja, Piotr; Wojcik, Mariusz

    2016-07-01

    A computer simulation method is applied to study electron-ion recombination in tracks of low-energy nuclear recoils in nonpolar liquids in which the electron transport can be described as ideal diffusion. The electron escape probability is calculated as a function of applied electric field, both for the field parallel to the track and for the field perpendicular to the track. The dependence of escape probability on the field direction is the stronger, the longer the ionization track, with a significant effect being found already for tracks of ~100 nm length. The results are discussed in the context of possible applications of nonpolar molecular liquids as target media in directional dark matter detectors.

  15. Rutherford forward scattering and elastic recoil detection (RFSERD) as a method for characterizing ultra-thin films

    DOE PAGESBeta

    Lohn, Andrew J.; Doyle, Barney L.; Stein, Gregory J.; Mickel, Patrick R.; Stevens, Jim E.; Marinella, Matthew J.

    2014-04-03

    We present a novel ion beam analysis technique combining Rutherford forward scattering and elastic recoil detection (RFSERD) and demonstrate its ability to increase efficiency in determining stoichiometry in ultrathin (5-50 nm) films as compared to Rutherford backscattering. In the conventional forward geometries, scattering from the substrate overwhelms the signal from light atoms but in RFSERD, scattered ions from the substrate are ranged out while forward scattered ions and recoiled atoms from the thin film are simultaneously detected in a single detector. Lastly, the technique is applied to tantalum oxide memristors but can be extended to a wide range of materialsmore » systems.« less

  16. Rutherford forward scattering and elastic recoil detection (RFSERD) as a method for characterizing ultra-thin films

    SciTech Connect

    Lohn, Andrew J.; Doyle, Barney L.; Stein, Gregory J.; Mickel, Patrick R.; Stevens, Jim E.; Marinella, Matthew J.

    2014-04-03

    We present a novel ion beam analysis technique combining Rutherford forward scattering and elastic recoil detection (RFSERD) and demonstrate its ability to increase efficiency in determining stoichiometry in ultrathin (5-50 nm) films as compared to Rutherford backscattering. In the conventional forward geometries, scattering from the substrate overwhelms the signal from light atoms but in RFSERD, scattered ions from the substrate are ranged out while forward scattered ions and recoiled atoms from the thin film are simultaneously detected in a single detector. Lastly, the technique is applied to tantalum oxide memristors but can be extended to a wide range of materials systems.

  17. Angular anisotropy parameters and recoil-ion momentum distribution in two-photon double ionization of helium

    SciTech Connect

    Kheifets, A. S.; Ivanov, I. A.; Bray, Igor

    2007-08-15

    We present convergent-close-coupling (CCC) calculations of the angular anisotropy parameters {beta}{sub 2},{beta}{sub 4} and the recoil ion momentum distribution d{sigma}/dp in two-photon double ionization (TPDI) of helium. In a stark contrast to single-photon double ionization (SPDI), where the {beta}{sub 2} parameter varies widely changing the angular distribution from isotropic to nearly dipole for slow and fast photoelectrons, respectively, the {beta} parameters for TPDI show very little change. The angular distribution of the recoil ion is fairly isotropic in TPDI as opposed to a strong alignment with the polarization of light in SPDI.

  18. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    SciTech Connect

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; McKernan, M. A.; Moran, M.; Rygg, J. R.; Yeoman, M. F.; Zacharias, R.; Leeper, R. J.; Fletcher, K.; Farrell, M.; Jasion, D.; Kilkenny, J.; Paguio, R.

    2013-04-18

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  19. New recoil transfer chamber for thermalization of heavy ions produced in fusion-evaporation reactions

    NASA Astrophysics Data System (ADS)

    Alfonso, M. C.; Tereshatov, E. E.; DeVanzo, M. J.; Sefcik, J. A.; Bennett, M. E.; Mayorov, D. A.; Werke, T. A.; Folden, C. M.

    2015-10-01

    A new Recoil Transfer Chamber (RTC) has been designed, fabricated, and characterized at the Cyclotron Institute at Texas A&M University. The design is based on a gas stopper that was previously in routine use at the National Superconducting Cyclotron Laboratory. This new RTC uses He gas to stop ions, and a combination of a static electric field and gas flow to maximize the extraction efficiency. In offline experiments, a 228Th source was used to produce 216Po which was successfully extracted even though it has a short half-life. In online experiments using the products of the 118Sn(40Ar, 6n)152Er reaction, an efficiency of several tens of percent was measured.

  20. Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF

    SciTech Connect

    Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

    2012-05-03

    A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  1. Stability diagram of the collective atomic recoil laser with thermal atoms

    NASA Astrophysics Data System (ADS)

    Tomczyk, H.; Schmidt, D.; Georges, C.; Slama, S.; Zimmermann, C.

    2015-06-01

    We experimentally investigate cold thermal atoms in a single sidedly pumped optical ring resonator for temperatures between 0.4 and 9 μ K . The threshold for collective atomic recoil lasing (CARL) is recorded for various pump-cavity detunings. The resulting stability diagram is interpreted by simulating the classical CARL equations. We find that the stability diagram for thermal atoms shows the same asymmetry as observed for Bose-Einstein condensates in previous experiments. Whereas for condensates the asymmetry is well explained by a Dicke-type quantum model we here discuss a simplified classical model. It complements the quantum model and provides an intuitive explanation based on the change in the long-range atomic interaction with pump-cavity detuning.

  2. First measurements of the absolute neutron spectrum using the Magnetic Recoil Spectrometer (MRS) at the NIF

    NASA Astrophysics Data System (ADS)

    Frenje, J.; Casey, D.; Li, C.; Seguin, F.; Petrasso, R.; Bionta, R.; Cerjan, C.; Eckart, M.; Haan, S.; Hatchett, S.; Khater, H.; Landen, O.; MacKinnon, A.; Moran, M.; Rygg, J.; Kilkenny, J.; Glebov, V.; Sangster, T.; Meyerhofer, D.; Magoon, J.; Fletcher, K.; Leeper, R.

    2010-11-01

    Proper assembly of capsule mass, as manifested through evolution of fuel areal density (ρR), is fundamentally important for achieving hot-spot ignition planned at the National Ignition Facility (NIF). Experimental information about ρR and ρR asymmetries, Ti and yield is therefore essential for understanding how this assembly occurs. To obtain this information, a neutron spectrometer, called the Magnetic-Recoil Spectrometer (MRS) has been implemented on the NIF. Its primary objective is to measure the absolute neutron spectrum in the range 5 to 30 MeV, from which ρR, Ti and yield can be directly inferred for both low-yield tritium-hydrogen-deuterium (THD) and high-yield DT implosions. In this talk, the results from the first measurements of the absolute neutron spectrum produced in exploding pusher and THD implosions will be presented. This work was supported in part by the U.S. DOE, LLNL and LLE.

  3. Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium: Diagrams with Polarization Loops

    SciTech Connect

    Eides, Michael I.; Shelyuto, Valery A.

    2009-09-25

    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with electron and muon vacuum polarizations. We calculate single-logarithmic and nonlogarithmic contributions of order alpha{sup 3}(m/M)E{sub F} generated by gauge invariant sets of diagrams with electron and muon polarization insertions in the electron and muon factors. Combining these corrections with the older results, we obtain total contribution to hyperfine splitting generated by all diagrams with electron and muon polarization loops. The calculation of this contribution completes an important stage in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz. The new results improve the theory of hyperfine splitting and affect the value of the electron-muon mass ratio extracted from experimental data on muonium hyperfine splitting.

  4. The B {r{underscore}arrow} D*{ell}{nu} form factor at zero recoil

    SciTech Connect

    Simone, J.N.; Hashimoto, S.; El-Khadra, A.X.; Kronfeld, A.S.; Mackenzie, P.B.; Ryan, S.M.

    2000-01-26

    The authors describe a model independent lattice QCD method for determining the deviation from unity for h{sub A{sub 1}}, the B {r{underscore}arrow} D*{ell}{nu} form factor at zero recoil. They extend the double ratio method previously used to determine the B {r{underscore}arrow} D{ell}{nu} form factor. The bulk of statistical and systematic errors cancel in the double ratios they consider, yielding form factors which promise to reduce present theoretical uncertainties in the determination of {vert{underscore}bar}V{sub cb}{vert{underscore}bar}. They present results from a prototype calculation at a single lattice spacing corresponding to {beta} = 5.7.

  5. Superradiant rayleigh scattering and collective atomic recoil lasing in a ring cavity.

    PubMed

    Slama, S; Bux, S; Krenz, G; Zimmermann, C; Courteille, Ph W

    2007-02-01

    Collective interaction of light with an atomic gas can give rise to superradiant instabilities. We experimentally study the sudden buildup of a reverse light field in a laser-driven high-finesse ring cavity filled with ultracold thermal or Bose-Einstein condensed atoms. While superradiant Rayleigh scattering from atomic clouds is normally observed only at very low temperatures (i.e., well below 1 microK), the presence of the ring cavity enhances cooperativity and allows for superradiance with thermal clouds as hot as several 10 microK. A characterization of the superradiance at various temperatures and cooperativity parameters allows us to link it to the collective atomic recoil laser.

  6. Lifetime measurement of 2+- state in 74Zn by recoil-distance Doppler-shift method

    NASA Astrophysics Data System (ADS)

    Niikura, M.; Mouginot, B.; Azaiez, F.; Franchoo, S.; Matea, I.; Stefan, I.; Verney, D.; Assie, M.; Bednarczyk, P.; Borcea, C.; Burger, A.; Burgunder, G.; Buta, A.; Cáceres, L.; Cléement, E.; Coquard, L.; de Angelis, G.; de France, G.; de Oliveira Santos, F.; Dewald, A.; Dijon, A.; Dombradi, Z.; Fiori, E.; Fransen, C.; Friessner, G.; Gaudefroy, L.; Georgiev, G.; Grévy, S.; Hackstein, M.; Harakeh, M. N.; Ibrahim, F.; Kamalou, O.; Kmiecik, M.; Lozeva, R.; Maj, A.; Mihai, C.; Möller, O.; Myalski, S.; Negoita, F.; Pantelica, D.; Perrot, L.; Pissulla, Th.; Rotaru, F.; Rother, W.; Scarpaci, J. A.; Stodel, C.; Thomas, J. C.; Ujic, P.

    2013-09-01

    We have performed the first direct lifetime measurement of the 2+- state in 74Zn. The neutron-rich 74Zn beam was produced by in-flight fragmentation of 76Ge at the Grand Accélérateur National d'Ions Lourds and separated with the LISE spectrometer. The lifetime of the 2+- state was measured by the recoil-distance Doppler-shift method with the Cologne plunger device combined with the EXOGAM detectors. The lifetime of the 2+- state in 74Zn was determined to be 27.0(24) ps, which corresponds to a reduced transition probability B(E2; 2+- -> 0+) = 370(33) e2fm4.

  7. Doppler- and recoil-free laser excitation of Rydberg states via three-photon transitions

    SciTech Connect

    Ryabtsev, I. I.; Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A.

    2011-11-15

    Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a starlike geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a particular laser excitation scheme 5S{sub 1/2}{yields}5P{sub 3/2}{yields}6S{sub 1/2}{yields}nP in Rb atoms have shown that, compared to the one- and two-photon laser excitation, this approach provides much narrower linewidth and longer coherence time for both cold atom samples and hot vapors, if the intermediate one-photon resonances of the three-photon transition are detuned by more than respective single-photon Doppler widths. This method can be used to improve fidelity of Rydberg quantum gates and precision of spectroscopic measurements in Rydberg atoms.

  8. ASTROPHYSICS. Exclusion of leptophilic dark matter models using XENON100 electronic recoil data.

    PubMed

    2015-08-21

    Laboratory experiments searching for galactic dark matter particles scattering off nuclei have so far not been able to establish a discovery. We use data from the XENON100 experiment to search for dark matter interacting with electrons. With no evidence for a signal above the low background of our experiment, we exclude a variety of representative dark matter models that would induce electronic recoils. For axial-vector couplings to electrons, we exclude cross sections above 6 × 10(-35) cm(2) for particle masses of m(χ) = 2 GeV/c(2). Independent of the dark matter halo, we exclude leptophilic models as an explanation for the long-standing DAMA/LIBRA signal, such as couplings to electrons through axial-vector interactions at a 4.4σ confidence level, mirror dark matter at 3.6σ, and luminous dark matter at 4.6σ. PMID:26293959

  9. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF.

    PubMed

    Casey, D T; Frenje, J A; Johnson, M Gatu; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Magoon, J; Meyerhofer, D D; Sangster, T C; Shoup, M; Ulreich, J; Ashabranner, R C; Bionta, R M; Carpenter, A C; Felker, B; Khater, H Y; LePape, S; MacKinnon, A; McKernan, M A; Moran, M; Rygg, J R; Yeoman, M F; Zacharias, R; Leeper, R J; Fletcher, K; Farrell, M; Jasion, D; Kilkenny, J; Paguio, R

    2013-04-01

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  10. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    SciTech Connect

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; and others

    2013-04-15

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  11. ASTROPHYSICS. Exclusion of leptophilic dark matter models using XENON100 electronic recoil data.

    PubMed

    2015-08-21

    Laboratory experiments searching for galactic dark matter particles scattering off nuclei have so far not been able to establish a discovery. We use data from the XENON100 experiment to search for dark matter interacting with electrons. With no evidence for a signal above the low background of our experiment, we exclude a variety of representative dark matter models that would induce electronic recoils. For axial-vector couplings to electrons, we exclude cross sections above 6 × 10(-35) cm(2) for particle masses of m(χ) = 2 GeV/c(2). Independent of the dark matter halo, we exclude leptophilic models as an explanation for the long-standing DAMA/LIBRA signal, such as couplings to electrons through axial-vector interactions at a 4.4σ confidence level, mirror dark matter at 3.6σ, and luminous dark matter at 4.6σ.

  12. Measurement of the (211)Pb half-life using recoil atoms from (219)Rn decay.

    PubMed

    Aitken-Smith, P M; Collins, S M

    2016-04-01

    The radioactive half-life of (211)Pb was measured, by α-particle counting of samples of radiochemically pure (211)Pb in equilibrium with its α-emitting progeny, (211)Bi and (211)Po. The samples were prepared by the collection of (215)Po recoil atoms from the decay of the (219)Rn decay progeny produced from a (223)Ra sample onto stainless steel discs. The radioactive decay of the (211)Pb was measured utilising a 2π proportional counter operating on the α plateau. A half-life of 36.164 (13)min was determined, which is in agreement with currently available literature. A full uncertainty budget is presented. A recommended half-life of T1/2((211)Pb)=36.161 (17)min has been evaluated from the current literature values. PMID:26773817

  13. Measurement of the (211)Pb half-life using recoil atoms from (219)Rn decay.

    PubMed

    Aitken-Smith, P M; Collins, S M

    2016-04-01

    The radioactive half-life of (211)Pb was measured, by α-particle counting of samples of radiochemically pure (211)Pb in equilibrium with its α-emitting progeny, (211)Bi and (211)Po. The samples were prepared by the collection of (215)Po recoil atoms from the decay of the (219)Rn decay progeny produced from a (223)Ra sample onto stainless steel discs. The radioactive decay of the (211)Pb was measured utilising a 2π proportional counter operating on the α plateau. A half-life of 36.164 (13)min was determined, which is in agreement with currently available literature. A full uncertainty budget is presented. A recommended half-life of T1/2((211)Pb)=36.161 (17)min has been evaluated from the current literature values.

  14. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    DOE PAGESBeta

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; et al

    2013-04-18

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describesmore » ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.« less

  15. Recoil Decay Tagging Study Of Transitional Proton Emitters 145,146,147Tm

    SciTech Connect

    Robinson, A.P.; Woods, P.J.; Davinson, T.; Liu, Z.; Davids, C.N.; Seweryniak, D.; Carpenter, M.P.; Hammond, N.; Janssens, R.V.F.; Mukherjee, G.; Sinha, S.; Blank, B.; Freeman, S.J.; Hoteling, N.; Shergur, J.; Walters, W.B.; Scholey, C.; Sonzogni, A.A.; Woehr, A.

    2005-04-05

    Gamma rays from the transitional proton emitting nuclei 145,146,147Tm have been observed using the recoil-decay tagging technique. The ground state band of 147Tm was confirmed and extended and the unfavoured signature sequence was observed. A ground state rotational band with properties of a decoupled h11/2 band was observed in 145Tm. In addition coincidences between the proton fine structure line and the 2+{yields}0+ {gamma}-ray transition in 144Er were detected at the focal plane of the FMA. This is the first time that coincidences between proton radioactive decays and {gamma} rays have been seen. The particle decay of 146Tm has been measured with improved statistics and a rotational band similar to 147Tm has been observed.

  16. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; McKernan, M. A.; Moran, M.; Rygg, J. R.; Yeoman, M. F.; Zacharias, R.; Leeper, R. J.; Fletcher, K.; Farrell, M.; Jasion, D.; Kilkenny, J.; Paguio, R.

    2013-04-01

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  17. Origin of open recoil curves in L10-A1 FePt exchange coupled nanocomposite thin film

    NASA Astrophysics Data System (ADS)

    Goyal, Rajan; Kapoor, Akanksha; Lamba, S.; Annapoorni, S.

    2016-11-01

    Mixed phase FePt systems with intergranular coupling may be looked upon as natural exchange spring systems. The coupling strength between the soft and hard phase in these systems can be analyzed using recoil curves. However, the origin of open recoil curves depicting the breakdown of exchange coupling or anisotropy variation in hard phase is still an ambiguity and requires an in-depth analysis. In order to investigate this, an analysis of the recoil curves for L10-A1 FePt nanocomposite thin films of varying thickness have been performed. The switching field distribution reveals that the maximum of openness of recoil curve is directly proportional to the amount of uncoupled soft phase present in the system. The coupling between the hard and soft phase is also found to increase with the thickness of the film. Monte Carlo simulations on a model three dimensional array of interacting nanomagnetic grains provide further insight into the effect of inter granular exchange interactions between the soft and hard phases.

  18. Laser-tissue interaction with fs pulses: measurement of the recoil momentum by laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Sessa, Gaetano; Travaglini, Michele; Mittnacht, Dirk; Foth, Hans-Jochen

    2003-07-01

    Currently ultra short pulses with pluse duration close to 100 fs are investigated for tissue ablation to perform laser surgery in a microscopic scale without any damage to the remaining tissue. Several groups showed already that the risk of thermal damage can be avoided; however the ablated material leaves the surface with a high velocity which leads to significant recoil momentum to the tissue. This paper focuses on the experimental set-up to measure this momentum transfer. Various set-ups had been developd over the last years like a pendulum that is highly senstive but cannot ensure that in a train of pulses each pulse will impact at exactly the same spot. A sliding rod in a glass tube ensured the constant impact point but is sensitive to several environmental conditions, which are hard to control. Recently, special swing plates were designed as vibration disks. The small sample was mounted in the center of this plate and exposed by fs pulses of a TiSa laser. The beam of a laser Doppler vibrometer was focused onto the backside of the plate monitored its motion. This set-up enabled us to measure the recoil momentum. While the total momentum transfer could be well determined to Δp=6 10-3 g mm/s, the question about a mechanical damage, for example for hair cells in the inner ear is much more difficult to answer, since this depends on the time in which the ablated materials leaves the surface. Evaporation times of 40 ps would lead to serious risk ofhar cell damage.

  19. A LARGE SYSTEMATIC SEARCH FOR CLOSE SUPERMASSIVE BINARY AND RAPIDLY RECOILING BLACK HOLES

    SciTech Connect

    Eracleous, Michael; Boroson, Todd A.; Halpern, Jules P.; Liu Jia

    2012-08-01

    We have carried out a systematic search for subparsec supermassive black hole (BH) binaries among z {approx}< 0.7 Sloan Digital Sky Survey quasars. These are predicted by models of supermassive BH and host galaxy coevolution, therefore their census and population properties constitute an important test of these models. In our working hypothesis, one of the two BHs accretes at a much higher rate than the other and carries with it the only broad emission line region of the system, making the system analogous to a single-lined spectroscopic binary star. Accordingly, we used spectroscopic principal component analysis to search for broad H{beta} emission lines that are displaced from the quasar rest frame by |{Delta} v| {approx}> 1000 km s{sup -1}. This method also yields candidates for rapidly recoiling BHs. Of the 88 candidates, several were previously reported in the literature. We found a correlation between the peak offset and skewness of the broad H{beta} profiles, suggesting a common physical explanation for these profiles. We carried out follow-up spectroscopic observations of 68 objects to search for changes in the peak velocities of the H{beta} lines. We measured statistically significant changes in 14 objects, with implied accelerations between -120 and +120 km s{sup -1} yr{sup -1}. Interpreting the offset broad emission lines as signatures of supermassive binaries is subject to many caveats. Many more follow-up observations over a long temporal baseline are needed to characterize the variability pattern of the broad lines and test that it is consistent with orbital motion. The possibility that some of the objects in this sample are rapidly recoiling BHs remains open.

  20. INTERACTION OF RECOILING SUPERMASSIVE BLACK HOLES WITH STARS IN GALACTIC NUCLEI

    SciTech Connect

    Li Shuo; Liu, F. K.; Berczik, Peter; Spurzem, Rainer; Chen Xian E-mail: fkliu@bac.pku.edu.cn

    2012-03-20

    Supermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. The coalescence of the SMBHBs is a distinct source of gravitational wave (GW) radiation. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. Numerical relativity suggests that the post-merger supermassive black hole (SMBH) gets a kick velocity up to 4000 km s{sup -1} due to the anisotropic GW radiations. Here, we investigate the dynamical coevolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is {approx}10{sup -6} M{sub Sun} yr{sup -1}, which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about {approx}0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.

  1. A Large Systematic Search for Close Supermassive Binary and Rapidly Recoiling Black Holes

    NASA Astrophysics Data System (ADS)

    Eracleous, Michael; Boroson, Todd A.; Halpern, Jules P.; Liu, Jia

    2012-08-01

    We have carried out a systematic search for subparsec supermassive black hole (BH) binaries among z <~ 0.7 Sloan Digital Sky Survey quasars. These are predicted by models of supermassive BH and host galaxy coevolution, therefore their census and population properties constitute an important test of these models. In our working hypothesis, one of the two BHs accretes at a much higher rate than the other and carries with it the only broad emission line region of the system, making the system analogous to a single-lined spectroscopic binary star. Accordingly, we used spectroscopic principal component analysis to search for broad Hβ emission lines that are displaced from the quasar rest frame by |Δ v| >~ 1000 km s-1. This method also yields candidates for rapidly recoiling BHs. Of the 88 candidates, several were previously reported in the literature. We found a correlation between the peak offset and skewness of the broad Hβ profiles, suggesting a common physical explanation for these profiles. We carried out follow-up spectroscopic observations of 68 objects to search for changes in the peak velocities of the Hβ lines. We measured statistically significant changes in 14 objects, with implied accelerations between -120 and +120 km s-1 yr-1. Interpreting the offset broad emission lines as signatures of supermassive binaries is subject to many caveats. Many more follow-up observations over a long temporal baseline are needed to characterize the variability pattern of the broad lines and test that it is consistent with orbital motion. The possibility that some of the objects in this sample are rapidly recoiling BHs remains open.

  2. Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

    NASA Technical Reports Server (NTRS)

    Berger, Pascal; Sayir, Ali; Berger, Marie-Helene

    2004-01-01

    The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

  3. Active regulation of longitudinal arch compression and recoil during walking and running.

    PubMed

    Kelly, Luke A; Lichtwark, Glen; Cresswell, Andrew G

    2015-01-01

    The longitudinal arch (LA) of the human foot compresses and recoils in response to being cyclically loaded. This has typically been considered a passive process, however, it has recently been shown that the plantar intrinsic foot muscles have the capacity to actively assist in controlling LA motion. Here we tested the hypothesis that intrinsic foot muscles, abductor hallucis (AH), flexor digitorum brevis (FDB) and quadratus plantae (QP), actively lengthen and shorten during the stance phase of gait in response to loading of the foot. Nine participants walked at 1.25 m s⁻¹ and ran at 2.78 and 3.89 m s⁻¹ on a force-instrumented treadmill while foot and ankle kinematics were recorded according to a multisegment foot model. Muscle-tendon unit (MTU) lengths, determined from the foot kinematics, and intramuscular electromyography (EMG) signals were recorded from AH, FDB and QP. Peak EMG amplitude was determined during the stance phase for each participant at each gait velocity. All muscles underwent a process of slow active lengthening during LA compression, followed by a rapid shortening as the arch recoiled during the propulsive phase. Changes in MTU length and peak EMG increased significantly with increasing gait velocity for all muscles. This is the first in vivo evidence that the plantar intrinsic foot muscles function in parallel to the plantar aponeurosis, actively regulating the stiffness of the foot in response to the magnitude of forces encountered during locomotion. These muscles may therefore contribute to power absorption and generation at the foot, limit strain on the plantar aponeurosis and facilitate efficient foot ground force transmission.

  4. Active regulation of longitudinal arch compression and recoil during walking and running

    PubMed Central

    Kelly, Luke A.; Lichtwark, Glen; Cresswell, Andrew G.

    2015-01-01

    The longitudinal arch (LA) of the human foot compresses and recoils in response to being cyclically loaded. This has typically been considered a passive process, however, it has recently been shown that the plantar intrinsic foot muscles have the capacity to actively assist in controlling LA motion. Here we tested the hypothesis that intrinsic foot muscles, abductor hallucis (AH), flexor digitorum brevis (FDB) and quadratus plantae (QP), actively lengthen and shorten during the stance phase of gait in response to loading of the foot. Nine participants walked at 1.25 m s−1 and ran at 2.78 and 3.89 m s−1 on a force-instrumented treadmill while foot and ankle kinematics were recorded according to a multisegment foot model. Muscle–tendon unit (MTU) lengths, determined from the foot kinematics, and intramuscular electromyography (EMG) signals were recorded from AH, FDB and QP. Peak EMG amplitude was determined during the stance phase for each participant at each gait velocity. All muscles underwent a process of slow active lengthening during LA compression, followed by a rapid shortening as the arch recoiled during the propulsive phase. Changes in MTU length and peak EMG increased significantly with increasing gait velocity for all muscles. This is the first in vivo evidence that the plantar intrinsic foot muscles function in parallel to the plantar aponeurosis, actively regulating the stiffness of the foot in response to the magnitude of forces encountered during locomotion. These muscles may therefore contribute to power absorption and generation at the foot, limit strain on the plantar aponeurosis and facilitate efficient foot ground force transmission. PMID:25551151

  5. Ab initio molecular dynamics simulations of threshold displacement energies in SrTiO3

    SciTech Connect

    Liu, Bin; Xiao, Haiyan; Zhang, Yanwen; Aidhy, Dilpuneet S; Weber, William J

    2013-01-01

    Ab initio molecular dynamics simulations have been carried out to study low-energy recoil events in SrTiO3. The threshold displacement energies are shown to be strongly dependent on both the orientation and the corresponding atomic arrangement. The minimum threshold displacement energies are 13 eV for an O recoil along the <100> O-O chain, 25 eV for a Sr recoil along the <100> Sr-Sr chain and 38 eV for a Ti recoil along the <110> Ti-Ti chain. The weighted average threshold displacement energies along the primary crystallographic directions are 35.7, 53.5 and > 64.9 eV for O, Sr and Ti, respectively. The interstitial configurations produced by the recoil events are <100> and <111> split-interstitials for O and Sr, respectively, together with a Ti interstitial occupying a distorted bridge position between two Sr sites. It is found that the recoil events in SrTiO3 are partial- charge transfer assisted processes, and the partial- charge transfer plays an important role in these recoil events.

  6. The uncertainty analysis on energy scale due to the variation of W value for liquid xenon dark matter detector

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Mei, Dongming; Cubed Collaboration

    2016-03-01

    The average energy expended per electron-ion pair, W value, is critical in understanding a liquid xenon detector energy response to low energy recoils. The reduction of scintillation and ionization yield for electronic recoils and nuclear recoils are explained using the scintillation quenching mechanism due to the variation of the average energy expended per electron hole pair, W value, which includes the energy lost to scintillation and phonon generation. We show the theoretical calculation of scintillation efficiency with W value in comparison with experimental data. The impact of variation of W value on the analysis of energy scale is discussed in detail. We conclude that the W value determined with experimental data depends on recoil energy and particle type. This work is supported by NSF in part by the NSF OIA 1434142, DOE Grant DE-FG02-10ER46709, and the State of South Dakota.

  7. Culturally Relevant Pedagogy

    ERIC Educational Resources Information Center

    Irvine, Jacqueline Jordan

    2010-01-01

    Many teachers have only a cursory understanding of culturally relevant pedagogy, and their efforts to bridge the cultural gap often fall short. Culturally relevant pedagogy is a term that describes effective teaching in culturally diverse classrooms. It can be a daunting idea to understand and implement. Yet people tend to appreciate culturally…

  8. Making Science Relevant

    ERIC Educational Resources Information Center

    Eick, Charles; Deutsch, Bill; Fuller, Jennifer; Scott, Fletcher

    2008-01-01

    Science teachers are always looking for ways to demonstrate the relevance of science to students. By connecting science learning to important societal issues, teachers can motivate students to both enjoy and engage in relevant science (Bennet, Lubben, and Hogarth 2007). To develop that connection, teachers can help students take an active role in…

  9. The Relevant Counselor.

    ERIC Educational Resources Information Center

    Herr, Edwin L.

    1986-01-01

    Addresses the questions of school counselors' obsolescence and relevance. Cites examples of national indicators of support for school counselors. Suggests the need for sharpening the counselor's role and reducing the unevenness in guidance services' availability. (ABB)

  10. The Quasar SDSS J105041.35+345631.3: Black Hole Recoil or Extreme Double-Peaked Emitter?

    NASA Astrophysics Data System (ADS)

    Shields, G. A.; Rosario, D. J.; Smith, K. L.; Bonning, E. W.; Salviander, S.; Kalirai, J. S.; Strickler, R.; Ramirez-Ruiz, E.; Dutton, A. A.; Treu, T.; Marshall, P. J.

    2009-12-01

    The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km s-1 relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, a binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region. The absence of narrow lines at the broad line redshift argues against superposition. New Keck spectra of J1050+3456 place tight constraints on the binary model. The combination of large velocity shift and symmetrical Hβ profile, as well as aspects of the narrow line spectrum, make J1050+3456 an interesting candidate for black hole recoil. Other aspects of the spectrum, however, suggest that the object is most likely an extreme case of a "double-peaked emitter." We discuss possible observational tests to determine the true nature of this exceptional object.

  11. Temperature Dependence and Recoil-free Fraction Effects in Olivines Across the Mg-Fe Solid Solution

    NASA Technical Reports Server (NTRS)

    Sklute, E. C.; Rothstein, Y.; Dyar, M. D.; Schaefer, M. W.; Menzies, O. N.; Bland, P. A.; Berry, F. J.

    2005-01-01

    Olivine and pyroxene are the major ferromagnesian minerals in most meteorite types and in mafic igneous rocks that are dominant at the surface of the Earth. It is probable that they are the major mineralogical components at the surface of any planetary body that has undergone differentiation processes. In situ mineralogical studies of the rocks and soils on Mars suggest that olivine is a widespread mineral on that planet s surface (particularly at the Gusev site) and that it has been relatively unaffected by alteration. Thus an understanding of the characteristics of Mossbauer spectra of olivine is of great importance in interpreting MER results. However, variable temperature Mossbauer spectra of olivine, which are needed to quantify recoil-free fraction effects and to understand the temperature dependence of olivine spectra, are lacking in the literature. Thus, we present here a study of the temperature dependence and recoil-free fraction of a series of synthetic olivines.

  12. Laser-tissue interaction with fs pulses: measurement of the recoil momentum by laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Mittnacht, Dirk; Sessa, Gaetano; Travaglini, Michele; Foth, Hans-Jochen

    2004-06-01

    In the field of otolaryngology a precise contactless treatment of the bones in the middle ear is eligible. For this reason lasers are investgiated for the use in this field. The main risk during laser surgery in the middle ear (e.g. stapedotomy) is the damage of hair cells in the inner ear due to heat diffusion or high pressure fluctuations. While the temperature problem has been resolved by shortening the pulse durations; the transfer of a recoil momentum due to the ablation process rises as another problem. To measure this momentum, special spring plates were designed as vibration disks for the mounting of the tissue. The probes were exposed to amplified Ti:Sapphire laser pulses with a pulse length of 45 fs and a power density up to 5,6×1013 W/cm2. The beam of a laser Doppler vibrometer was focused on backside of the plate to monitor its motion. The results were compared to a damage threshold of hair cells in the inner ear calculated by a literature value for the Sound Pressure Level (SPL)-Threshold. The results lead to SPL values below the critical value of 160 dB. Measurements with higher time resolution and high speed photography are used to approve these results.

  13. Laser-tissue interaction with fs pulses: measurement of the recoil momentum by laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Mittnacht, Dirk, IV; Sessa, Gaetano; Travaglini, Michele; Foth, Hans-Jochen

    2003-10-01

    In the field of otolaryngology a precise contactless treatment of the bones in the middle ear is eligible. For this reason lasers are investigated for the use in this field. The main risk during laser surgery in the middle ear (e.g. stapedotomy) is the damage of hair cells in the inner ear due to heat diffusion or high pressure fluctuations. While the temperature problem has been resolved by shortening the pulse durations; the transfer of a recoil momentum due to the ablation process rises as another problem. To measure this momentum, special spring plates were designed as vibration disks for the mounting of the tissue. The probes were exposed to amplified Ti:Sapphire Laser pulses with a pulse length of 100fs and a power density up to 6,4*1013W/cm2. The beam of a Laser Doppler Vibrometer was focused on backside of the plate to monitor its motion. The results were compared to a damage threshold of hair cells in the inner ear calculated by a literature value for the Sound Pressure Level (SPL)-Threshold. The first results lead to SPL values below the critical value but measurements with a higher time resolution are necessary to verify this conclusion.

  14. Observation of a resonance in B+ → K+ μ+ μ- decays at low recoil.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Cowie, E; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hess, M; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Martynov, A; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palczewski, T; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-09-13

    A broad peaking structure is observed in the dimuon spectrum of B+ → K+ μ+ μ- decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B+ → K+ μ+ μ- decay and a resonance and has a statistical significance exceeding six standard deviations. The mean and width of the resonance are measured to be 4191(-8)(+9)  MeV/c2 and 65(-16)(+22)  MeV/c2, respectively, where the uncertainties include statistical and systematic contributions. These measurements are compatible with the properties of the ψ(4160) meson. First observations of both the decay B+ → ψ(4160)K+ and the subsequent decay ψ(4160) → μ+ μ- are reported. The resonant decay and the interference contribution make up 20% of the yield for dimuon masses above 3770  MeV/c2. This contribution is larger than theoretical estimates. PMID:24074076

  15. Enhancement of surface properties of SAE 1020 by chromium plasma immersion recoil implantation

    NASA Astrophysics Data System (ADS)

    Ueda, M.; Mello, C. B.; Beloto, A. F.; Rossi, J. O.; Reuther, H.

    2007-04-01

    SAE 1020 steel is commonly used as concrete reinforcement and small machine parts, but despite its good mechanical properties, as ductility, hardness and wear resistance, it is susceptible to severe corrosion. It is well known that chromium content above 12% in Fe alloys increases their corrosion resistance. In order to obtain this improvement, we studied the introduction of chromium atoms into the matrix of SAE 1020 steel by recoil implantation process using a plasma immersion ion implantation (PIII) system. Potentiodynamic scans showed that the presence of Cr film leads to a gain in the corrosion potential, from -650 mV to -400 mV. After PIII treatment, the corrosion potential increased further to -340 mV, but the corrosion current density presented no significant change. Vickers microhardness tests showed surface hardness increase of up to about 27% for the treated samples. Auger electron spectroscopy showed that, for a 30 nm film, Cr was introduced for about 20 nm into the steel matrix. Tribology tests, of pin-on-disk type, showed that friction coefficient of treated samples was reduced by about 50% and a change in wear mechanism, from adhesive to abrasive mode, occurred.

  16. alpha-Actin: disposition, quantities, and estimated effects on lung recoil and compliance.

    PubMed

    Oldmixon, E H; Carlsson, K; Kuhn, C; Butler, J P; Hoppin, F G

    2001-07-01

    We have investigated the basis and implications of pneumoconstriction by measuring disposition and quantities of alpha-smooth muscle actin in rat and guinea pig lungs and modeling its effects on lung recoil and compliance. A robust marker of contractility, alpha-smooth muscle actin appears in smooth muscle or myofibroblast-like cells in pleura, airways, blood vessels, and alveolar ductal tissues. In each site, we measured its transected area by immunofluorescent staining and frequency-modulated scanning confocal microscopy. We incorporated these data in a model of the parenchyma consisting of an extensive elastic network with embedded contractile structures. We conclude that contraction at any one of these sites alone can decrease parenchymal compliance by 20-30% during tidal breathing. This is due mostly to the stiffness of activated contractile elements undergoing passive cycling; constant muscle tension would have little effect. The magnitude of the effect corresponds with known responses of the lung to hypocapnia, consistent with a homeostatic function in which gas exchange is defended by redistributing ventilation away from overventilated units. PMID:11408464

  17. Hydrogen uptake in Zircaloy-2 reactor fuel claddings studied with elastic recoil detection

    NASA Astrophysics Data System (ADS)

    Rajasekhara, S.; Doyle, B. L.; Enos, D. G.; Clark, B. G.

    2013-04-01

    The recent trend towards a high burn-up discharge spent nuclear fuel necessitates a thorough understanding of hydrogen uptake in Zr-based cladding materials that encapsulate spent nuclear fuel. Although it is challenging to experimentally replicate exact conditions in a nuclear reactor that lead to hydrogen uptake in claddings, in this study we have attempted to understand the kinetics of hydrogen uptake by first electrolytically charging Zircaloy-2 (Zr-2) cladding material for various durations (100 to 2,600 s), and subsequently examining hydrogen ingress with elastic recoil detection (ERD) and transmission electron microscopy (TEM). To understand the influence of irradiation damage defects on hydrogen uptake, an analogous study was performed on ion - irradiated (0.1, 1 and 25 dpa) Zr-2. Analysis of ERD data from the un-irradiated Zr-2 suggests that the growth of the hydride layer is diffusion controlled, and preliminary TEM results support this assertion. In un-irradiated Zr-2, the diffusivity of hydrogen in the hydride phase was found to be approximately 1.1 × 10-11 cm2/s, while the diffusivity in the hydride phase for lightly irradiated (0.1 and 1 dpa) Zr-2 is an order of magnitude lower. Irradiation to 25 dpa results in a hydrogen diffusivity that is comparable to the un-irradiated Zr-2. These results are compared with existing literature on hydrogen transport in Zr - based materials.

  18. Observation of a resonance in B+ → K+ μ+ μ- decays at low recoil.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Cowie, E; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hess, M; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Martynov, A; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palczewski, T; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-09-13

    A broad peaking structure is observed in the dimuon spectrum of B+ → K+ μ+ μ- decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B+ → K+ μ+ μ- decay and a resonance and has a statistical significance exceeding six standard deviations. The mean and width of the resonance are measured to be 4191(-8)(+9)  MeV/c2 and 65(-16)(+22)  MeV/c2, respectively, where the uncertainties include statistical and systematic contributions. These measurements are compatible with the properties of the ψ(4160) meson. First observations of both the decay B+ → ψ(4160)K+ and the subsequent decay ψ(4160) → μ+ μ- are reported. The resonant decay and the interference contribution make up 20% of the yield for dimuon masses above 3770  MeV/c2. This contribution is larger than theoretical estimates.

  19. Effect of recoiled O on damage regrowth and electrical properties of through-oxide implanted Si

    SciTech Connect

    Sadana, D.K.; Wu, N.R.; Washburn, J.; Current, M.; Morgan, A.; Reed, D.; Maenpaa, M.

    1982-10-01

    High dose (4 to 7.5 x 10/sup 15/ cm/sup -2/) As implantations into p-type (100) Si have been carried out through a screen-oxide of thicknesses less than or equal to 775A and without screen oxide. The effect of recoiled O on damage annealing and electrical properties of the implanted layers has been investigated using a combination of the following techniques: TEM, RBS/MeV He/sup +/ channeling, SIMS and Hall measurements in conjunction with chemical stripping and sheet resistivity measurements. The TEM results show that there is a dramatically different annealing behavior of the implantation damage for the through oxide implants (Case I) as compared to implants into bare silicon (Case II). Comparison of the structural defect profiles with O distributions obtained by SIMS demonstrated that retardation in the secondary damage growth in Case I can be directly related with the presence of O. Weak-beam TEM showed that a high density of fine defect clusters (less than or equal to 50A) were present both in Case I and Case II. The electrical profiles showed only 30% of the total As to be electrically active. The structural and electrical results have been explained by a model that entails As-O, Si-O and As-As complex formation and their interaction with the dislocations.

  20. Heavy ion elastic recoil detection analysis set up for electronic sputtering studies

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Avasthi, D. K.; Tripathi, A.; Kabiraj, D.; Sugathan, P.; Chaudhary, G. K.; Barua, P.

    2006-04-01

    Heavy ion elastic recoil detection analysis (ERDA) set up with a large solid angle (greater than or similar to 4.8 msr) Delta E - E position-sensitive telescope detector is developed at Inter University Accelerator Centre as a dedicated facility for the study of electronic sputtering of thin films under swift heavy ion (SHI) irradiation. The detector consists of a gas ionization chamber (Delta E ) and a solid-state surface barrier detector ( E ) housed in a same assembly. The electronic sputtering yield (atoms/ion) is determined by analyzing on-line fluence-dependent ERDA data obtained from a variety of thin films. Large erosion (> 10 5 atoms/ion) of carbon from a-C:H by 150 MeV Ag 13+ ions, evolution of nitrogen (greater than or similar to 880 atoms/ion) from copper nitride and depletion of oxygen (greater than or similar to 1000 atoms/ion) from copper oxide film under 200 MeV Au 15+ ion impact are studied and reported in this work. The electronic sputtering of these materials is discussed on the basis of the thermal spike model of SHI and solid interaction.

  1. Three-loop radiative-recoil corrections to hyperfine splitting generated by one-loop fermion factors

    SciTech Connect

    Eides, Michael I.; Grotch, Howard; Shelyuto, Valery A.

    2004-10-01

    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with one-loop radiative photon insertions both in the electron and muon lines. An analytic result for these nonlogarithmic corrections of order {alpha}(Z{sup 2}{alpha})(Z{alpha})(m/M)E{sub F} is obtained. This result constitutes a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz.

  2. Neutron spectrum measurements using proton recoil proportional counters: results of measurements of leakage spectra for the Little Boy assembly

    SciTech Connect

    Bennett, E.F.; Yule, T.J.

    1984-01-01

    Measurements of degraded fission-neutron spectra using recoil proportional counters are done routinely for studies involving fast reactor mockups. The same techniques are applicable to measurements of neutron spectra required for personnel dosimetry in fast neutron environments. A brief discussion of current applications of these methods together with the results of a measurement made on the LITTLE BOY assembly at Los Alamos are here described.

  3. Relative optically stimulated luminescence and thermoluminescence efficiencies of Al{sub 2}O{sub 3}:C dosimeters to heavy charged particles with energies relevant to space and radiotherapy dosimetry

    SciTech Connect

    Sawakuchi, G. O.; Yukihara, E. G.; McKeever, S. W. S.; Benton, E. R.; Gaza, R.; Uchihori, Y.; Yasuda, N.; Kitamura, H.

    2008-12-15

    This article presents a comprehensive characterization of the thermoluminescence (TL) and optically stimulated luminescence (OSL) relative luminescence efficiencies of carbon-doped aluminum (Al{sub 2}O{sub 3}:C) for heavy charged particles (HCPs) with atomic numbers ranging from 1 (proton) to 54 (xenon) and energies ranging from 7 to 1000 MeV/u, and investigates the dependence of the Al{sub 2}O{sub 3}:C response on experimental conditions. Relative luminescence efficiency values are presented for 19 primary charge/energy combinations, plus 31 additional charge/energy combinations obtained by introducing absorbers in the primary beam. Our results show that for energies of hundreds of MeV/u the data can be described by a single curve of relative luminescence efficiency versus linear energy transfer (LET). This information is needed to compensate for the reduced OSL efficiency to high-LET particles in such applications as space dosimetry. For lower energies, the relative luminescence efficiency as function of LET cannot be described by a single curve; instead, it separates into different components corresponding to different particles. We also present data on the low-LET dose response of Al{sub 2}O{sub 3}:C, measured under the same experimental conditions in which the relative luminescence efficiencies to HCPs were obtained, providing information relevant to future theoretical investigations of HCP energy deposition and luminescence production in Al{sub 2}O{sub 3}:C.

  4. Electron-configuration-reset time-differential recoil-in-vacuum technique for excited-state g-factor measurements on fast exotic beams

    SciTech Connect

    Stuchbery, Andrew E.; Mantica, Paul F.; Wilson, Anna N.

    2005-04-01

    A modified version of the time-differential recoil-in-vacuum (or plunger) technique is proposed as a method for measuring the g factors of excited states in rapidly moving exotic nuclei with Z < or approx. 20.

  5. Response of LiF:Mg,Ti thermoluminescent dosimeters at photon energies relevant to the dosimetry of brachytherapy (<1 MeV)

    SciTech Connect

    Tedgren, Aasa Carlsson; Hedman, Angelica; Grindborg, Jan-Erik; Carlsson, Gudrun Alm

    2011-10-15

    Purpose: High energy photon beams are used in calibrating dosimeters for use in brachytherapy since absorbed dose to water can be determined accurately and with traceability to primary standards in such beams, using calibrated ion chambers and standard dosimetry protocols. For use in brachytherapy, beam quality correction factors are needed, which include corrections for differences in mass energy absorption properties between water and detector as well as variations in detector response (intrinsic efficiency) with radiation quality, caused by variations in the density of ionization (linear energy transfer (LET) -distributions) along the secondary electron tracks. The aim of this work was to investigate experimentally the detector response of LiF:Mg,Ti thermoluminescent dosimeters (TLD) for photon energies below 1 MeV relative to {sup 60}Co and to address discrepancies between the results found in recent publications of detector response. Methods: LiF:Mg,Ti dosimeters of formulation MTS-N Poland were irradiated to known values of air kerma free-in-air in x-ray beams at tube voltages 25-250 kV, in {sup 137}Cs- and {sup 60}Co-beams at the Swedish Secondary Standards Dosimetry Laboratory. Conversions from air kerma free-in-air into values of mean absorbed dose in the dosimeters in the actual irradiation geometries were made using EGSnrc Monte Carlo simulations. X-ray energy spectra were measured or calculated for the actual beams. Detector response relative to that for {sup 60}Co was determined at each beam quality. Results: An increase in relative response was seen for all beam qualities ranging from 8% at tube voltage 25 kV (effective energy 13 keV) to 3%-4% at 250 kV (122 keV effective energy) and {sup 137}Cs with a minimum at 80 keV effective energy (tube voltage 180 kV). The variation with effective energy was similar to that reported by Davis et al.[Radiat. Prot. Dosim. 106, 33-43 (2003)] with our values being systematically lower by 2%-4%. Compared to the

  6. A novel technique for single-shot energy-resolved 2D x-ray imaging of plasmas relevant for the inertial confinement fusion

    SciTech Connect

    Labate, L.; Koester, P.; Levato, T.; Gizzi, L. A.

    2012-10-15

    A novel x-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any x-ray photon energy range, over a large domain, on a single-shot basis. The device (named energy-encoded pinhole camera) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available x-ray spectral domain is only limited by the quantum efficiency of scientific-grade x-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasma can be obtained at any x-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent inertial confinement fusion related experiments will be reported in order to detail the new diagnostic.

  7. Relevance, Derogation and Permission

    NASA Astrophysics Data System (ADS)

    Stolpe, Audun

    We show that a recently developed theory of positive permission based on the notion of derogation is hampered by a triviality result that indicates a problem with the underlying full-meet contraction operation. We suggest a solution that presupposes a particular normal form for codes of norms, adapted from the theory of relevance through propositional letter sharing. We then establish a correspondence between contractions on sets of norms in input/output logic (derogations), and AGM-style contractions on sets of formulae, and use it as a bridge to migrate results on propositional relevance from the latter to the former idiom. Changing the concept accordingly we show that positive permission now incorporates a relevance requirement that wards off triviality.

  8. Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

    PubMed

    Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

    2015-09-01

    We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

  9. The Limits to Relevance

    NASA Astrophysics Data System (ADS)

    Averill, M.; Briggle, A.

    2006-12-01

    Science policy and knowledge production lately have taken a pragmatic turn. Funding agencies increasingly are requiring scientists to explain the relevance of their work to society. This stems in part from mounting critiques of the "linear model" of knowledge production in which scientists operating according to their own interests or disciplinary standards are presumed to automatically produce knowledge that is of relevance outside of their narrow communities. Many contend that funded scientific research should be linked more directly to societal goals, which implies a shift in the kind of research that will be funded. While both authors support the concept of useful science, we question the exact meaning of "relevance" and the wisdom of allowing it to control research agendas. We hope to contribute to the conversation by thinking more critically about the meaning and limits of the term "relevance" and the trade-offs implicit in a narrow utilitarian approach. The paper will consider which interests tend to be privileged by an emphasis on relevance and address issues such as whose goals ought to be pursued and why, and who gets to decide. We will consider how relevance, narrowly construed, may actually limit the ultimate utility of scientific research. The paper also will reflect on the worthiness of research goals themselves and their relationship to a broader view of what it means to be human and to live in society. Just as there is more to being human than the pragmatic demands of daily life, there is more at issue with knowledge production than finding the most efficient ways to satisfy consumer preferences or fix near-term policy problems. We will conclude by calling for a balanced approach to funding research that addresses society's most pressing needs but also supports innovative research with less immediately apparent application.

  10. The role of physiological elements in the future therapies of rheumatoid arthritis. II. The relevance of energy redistribution in the process of chronic inflammation*

    PubMed Central

    Rzodkiewicz, Przemysław; Wojtecka-Łukasik, Elżbieta

    2015-01-01

    The reasons for development of chronic inflammation are complex and not fully understood. One of the factors affecting the prolongation of inflammation is changes in cell metabolism, occurring at the center of the inflammatory process. In chronic inflammation there is an imbalance between the processes of storage and consumption of energy reserves. Hypoxia that is a consequence of edema results in transition of white blood cells to anaerobic metabolism. Neutrophils, lymphocytes and macrophages produce active oxygen metabolites which on one hand facilitate the elimination of pathogens, and on the other hand, can cause damage to healthy cells located in the inflamed tissue. In this paper, we discuss the importance of disturbed redistribution of energy as one of the main reasons for transformation of the acute inflammatory process into the chronic one. PMID:27407224

  11. Tuning of the stability and energy levels of singlet exciton fission relevant excited states of pentacenes by site-specific substitution.

    PubMed

    Shen, Li; Chen, Yuhan; Li, Xiyou; Li, Chungang

    2016-05-01

    Pentacene crystals or oligomers undergo efficient singlet exciton fission (SF) after photo-excitation, which is expected to be useful in overcoming the Shockley-Queisser theoretical limit of solar cells. However, pentacenes are extremely unstable in air due to oxidation by oxygen. In this work, we designed a group of pentacene compounds with different substituents at different positions. The energy levels of HOMO and LUMO, which are believed to be closely related to the stability of pentacene, were calculated. The relationship between the molecular structure and the stability was discussed. The driving force for SF was estimated from the difference between the energy of first singlet excited state (E(S1)) and the energy of two triplet excited state (2×E(T1)) following equation E(S1)-2E(T1). Strong electron-withdrawing groups can stabilize pentacene compounds significantly, but induce a decrease on the driving force of SF slightly. Electron-donating groups destabilize the pentacene compounds dramatically and hence the introduction of electron donating groups to pentacene is not recommended. TIPS is an ideal group to improve the stability of pentacene compounds. TIPS does not change the driving force of SF significantly. Sulfur containing groups are also efficient on stabilizing pentacene compounds. These groups increase the driving force of SF at ɑ position, and recued the driving force of SF at other positions. The results of this work provide a theoretical ground for rational design of new SF molecules based on pentacenes. PMID:27131283

  12. Tuning of the stability and energy levels of singlet exciton fission relevant excited states of pentacenes by site-specific substitution.

    PubMed

    Shen, Li; Chen, Yuhan; Li, Xiyou; Li, Chungang

    2016-05-01

    Pentacene crystals or oligomers undergo efficient singlet exciton fission (SF) after photo-excitation, which is expected to be useful in overcoming the Shockley-Queisser theoretical limit of solar cells. However, pentacenes are extremely unstable in air due to oxidation by oxygen. In this work, we designed a group of pentacene compounds with different substituents at different positions. The energy levels of HOMO and LUMO, which are believed to be closely related to the stability of pentacene, were calculated. The relationship between the molecular structure and the stability was discussed. The driving force for SF was estimated from the difference between the energy of first singlet excited state (E(S1)) and the energy of two triplet excited state (2×E(T1)) following equation E(S1)-2E(T1). Strong electron-withdrawing groups can stabilize pentacene compounds significantly, but induce a decrease on the driving force of SF slightly. Electron-donating groups destabilize the pentacene compounds dramatically and hence the introduction of electron donating groups to pentacene is not recommended. TIPS is an ideal group to improve the stability of pentacene compounds. TIPS does not change the driving force of SF significantly. Sulfur containing groups are also efficient on stabilizing pentacene compounds. These groups increase the driving force of SF at ɑ position, and recued the driving force of SF at other positions. The results of this work provide a theoretical ground for rational design of new SF molecules based on pentacenes.

  13. Is Information Still Relevant?

    ERIC Educational Resources Information Center

    Ma, Lia

    2013-01-01

    Introduction: The term "information" in information science does not share the characteristics of those of a nomenclature: it does not bear a generally accepted definition and it does not serve as the bases and assumptions for research studies. As the data deluge has arrived, is the concept of information still relevant for information…

  14. The Relevance of Literature.

    ERIC Educational Resources Information Center

    Dunham, L. L.

    1971-01-01

    The "legacy" of the humanities is discussed in terms of relevance, involvement, and other philosophical considerations. Reasons for studying foreign literature in language classes are developed in the article. Comment is also made on attitudes and ideas culled from the writings of Clifton Fadiman, Jean Paul Sartre, and James Baldwin. (RL)

  15. Relevance and Definition.

    ERIC Educational Resources Information Center

    Watson, Rita

    1995-01-01

    Examined whether the use of superordinate terms in 206 children's definitions is predictable by relevance theory. Children (ages 5-10) gave definitions for 16 basic-level words and 4 superordinate words from natural kind and artifact semantic domains. Superordinate terms were used more frequently when they supported more inferences. Findings…

  16. Reading, Writing and Relevance.

    ERIC Educational Resources Information Center

    Hoffman, Mary

    This monograph presents classroom activities that were designed to encourage children to read and write in a self-reliant and responsible manner. The activities were chosen for their relevance to the children involved and because the vocabulary involved was interesting, familiar, and worth remembering and using again. The topics are arranged in…

  17. Azimuthal asymmetry of recoil electrons in neutrino-electron elastic scattering as signature of neutrino nature

    NASA Astrophysics Data System (ADS)

    Sobków, W.; Błaut, A.

    2016-05-01

    In this paper, we analyze the theoretically possible scenario beyond the standard model in order to show how the presence of the exotic scalar, tensor, {V}+{A} weak interactions in addition to the standard vector-axial ({V}-{A}) ones may help to distinguish the Dirac from Majorana neutrinos in the elastic scattering of an (anti)neutrino beam off the unpolarized electrons in the relativistic limit. We assume that the incoming (anti)neutrino beam comes from the polarized muon decay at rest and is the left-right chiral superposition with assigned direction of the transversal spin polarization with respect to the production plane. Our analysis is carried out for the flavour (current) neutrino eigenstates. It means that the transverse neutrino polarization estimates are the same both for the Dirac and Majorana cases. We display that the azimuthal asymmetry in the angular distribution of recoil electrons is generated by the interference terms between the standard and exotic couplings, which are proportional to the transversal (anti)neutrino spin polarization and independent of the neutrino mass. This asymmetry for the Majorana neutrinos is larger than for the Dirac ones. We also indicate the possibility of utilizing the azimuthal asymmetry measurements to search for the new CP-violating phases. Our study is based on the assumption that the possible detector (running for 1 year) has the shape of a flat circular ring, while the intense neutrino source is located in the centre of the ring and polarized perpendicularly to the ring. In addition, the large low-threshold, real-time detector is able to measure with a high resolution both the polar angle and the azimuthal angle of outgoing electron momentum. Our analysis is model-independent and consistent with the current upper limits on the non-standard couplings.

  18. Recoil-Implantation Of Multiple Radioisotopes Towards Wear Rate Measurements And Particle Tracing In Prosthetic Joints

    SciTech Connect

    Warner, Jacob A.; Timmers, Heiko; Smith, Paul N.; Scarvell, Jennifer M.; Gladkis, Laura

    2011-06-01

    This study demonstrates a new method of radioisotope labeling of ultra-high molecular weight polyethylene inserts in prosthetic joints for wear studies. The radioisotopes {sup 97}Ru, {sup 100}Pd, {sup 100}Rh, and {sup 101m}Rh are produced in fusion evaporation reactions induced by {sup 12}C ions in a {sup 92}Zr target foil. The fusion products recoil-implant into ultra-high molecular weight polyethylene plugs, machined to fit into the surface of the inserts. During laboratory simulations of the joint motion, a wear rate of the labeled polyethylene may be measured and the pathways of wear debris particles can be traced by detecting characteristic gamma-rays. The concentration profiles of the radioisotopes extend effectively uniformly from the polyethylene surface to a depth of about 4 {mu}m. The multiplicity of labeling and the use of several gamma-ray lines aids with avoiding systematic measurement uncertainties. Two polyethylene plugs were labeled and one was fitted into the surface of the tibial insert of a knee prosthesis, which had been worn in. Actuation over close to 100,000 cycles with a 900 N axial load and a 24 deg. flexion angle removed (14{+-}1)% of the gamma-ray activity from the plug. Most of this activity dispersed into the serum lubricant identifying this as the important debris pathway. Less than 1% activity was transferred to the femoral component of the prosthesis and the measured activity on the tibial tray was insignificant. Assuming uniform wear across the superior surface of the insert, a wear rate of (12{+-}3) mm{sup 3}/Megacycle was determined. This is consistent with wear rate measurements under similar conditions using other techniques.

  19. Synthesis of H2 in dirty ice mantles by fast ion energy loss: New experimental results increase the relevance of this mechanism

    NASA Technical Reports Server (NTRS)

    Pirranello, Valero; Brown, W. L.; Lanzerotti, L. J.; Averna, D. A.

    1989-01-01

    Recent experimental results support the importance of H2 production in molecular clouds by cosmic ray bombardment of the mantles of grains. The formation of molecules different from those originally present in the irradiated layer can be explained by the production of molecular fragments induced by the release of energy if the impinging fast particle. One way of considering the process is in terms of a transiently hot cylinder, initially about 50 A in diameter, that exists around the track of an individual fast ion. Since ice has a relatively low thermal conductivity, energy lost by the ion in the ice layers remains confined around the track for time long enough to be thermalized. The hot cylinder increases in diameter and decreases in temperature on a time scale of 10(exp -11) to 10(exp -10) sec. Molecular fragments that are formed in this high temperature region acquire enough mobility to recombine with different partners, forming new molecules. A Monte Carlo simulation of the interaction between cosmic rays and grain mantles, at various depths in the core of a spherical molecular cloud, was performed. The simulation was continued until 40,000 ions had hit each grain of the type and size chosen. During the performed experiments thin icy films made of H2O and CD4 mixed in the gas phase and deposited on a cold finger at 9 K were irradiated with 1.5 MeV helium beams. Among synthesized molecules were found H2, HD, and D2.

  20. Light response of YAP:Ce and LaBr3:Ce scintillators to 4-30 MeV protons for applications to Telescope Proton Recoil neutron spectrometers

    NASA Astrophysics Data System (ADS)

    Cazzaniga, C.; Cremona, A.; Nocente, M.; Rebai, M.; Rigamonti, D.; Tardocchi, M.; Croci, G.; Ericsson, G.; Fazzi, A.; Hjalmarsson, A.; Mazzocco, M.; Strano, E.; Gorini, G.

    2016-06-01

    The light response of two thin inorganic scintillators based on YAP:Ce and LaBr3:Ce crystals has been measured with protons in the 4-8 MeV energy range at the Uppsala tandem accelerator and in the 8-26 MeV energy range at the Legnaro tandem accelerator. The crystals have been calibrated in situ with 137Cs and 60Co γ-ray sources. The relative light yields of protons with respect to gammas have been measured and are here reported to be (96±2)% and (80±2)% for YAP:Ce and LaBr3:Ce, respectively. The results open up to the development of a Telescope Proton Recoil spectrometer based on either of the two crystals as alternative to a silicon based spectrometer for applications to high neutron fluxes.

  1. Measurement of the production rate of the charm jet recoiling against the W boson using the D0 detector at the Fermilab Tevatron Collider

    SciTech Connect

    Ahsan, Mahsana

    2008-01-01

    This dissertation describes a measurement of the rate of associated production of the W boson with the charm jet in the proton and anti-proton collisions at the center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. The measurement has direct sensitivity to the strange quark content inside the proton. A direct measurement of the momentum distribution of the strange quark inside the proton is essential for a reliable calculation of new physics signal as well as the background processes at the collider experiments. The identification of events containing a W boson and a charm jet is based on the leptonic decays of the W boson together with a tagging technique for the charm jet identification based on the semileptonic decay of the charm quark into the muon. The charm jet recoiling against the W boson must have a minimum transverse momentum of 20 GeV and an absolute value of pseudorapidity less than 2.5. This measurement utilizes the data collected by the D0 detector at the Fermilab Collider. The measured rate of the charm jet production in association with the W boson in the inclusive jet production with the W boson is 0.074 ± 0.023, which is in agreement with the theoretical predictions at the leading order in Quantum Chromodynamics.

  2. Recent studies of the effects of sugars on brain systems involved in energy balance and reward: Relevance to low calorie sweeteners.

    PubMed

    Murray, Susan; Tulloch, Alastair; Criscitelli, Kristen; Avena, Nicole M

    2016-10-01

    The alarmingly high rates of overweight and obesity pose a serious global health threat. Numerous factors can result in weight gain, one of which is excess consumption of caloric sweeteners. In an effort to aid weight loss efforts, many people have switched from caloric sweeteners to low calorie sweeteners, which provide sweet taste without the accompanying calories. In this review, we present an overview of the animal literature produced in the last 5years highlighting the effects of sugar consumption on neural pathways involved in energy balance regulation and reward processing. We also examine the latest evidence that is beginning to elucidate the effects of low calorie sweeteners on these neural pathways, as well as how homeostatic and hedonic systems interact in response to, or to influence, sugar consumption.

  3. Recent studies of the effects of sugars on brain systems involved in energy balance and reward: Relevance to low calorie sweeteners.

    PubMed

    Murray, Susan; Tulloch, Alastair; Criscitelli, Kristen; Avena, Nicole M

    2016-10-01

    The alarmingly high rates of overweight and obesity pose a serious global health threat. Numerous factors can result in weight gain, one of which is excess consumption of caloric sweeteners. In an effort to aid weight loss efforts, many people have switched from caloric sweeteners to low calorie sweeteners, which provide sweet taste without the accompanying calories. In this review, we present an overview of the animal literature produced in the last 5years highlighting the effects of sugar consumption on neural pathways involved in energy balance regulation and reward processing. We also examine the latest evidence that is beginning to elucidate the effects of low calorie sweeteners on these neural pathways, as well as how homeostatic and hedonic systems interact in response to, or to influence, sugar consumption. PMID:27068180

  4. An energy spread correction for ERDA hydrogen depth profiling

    SciTech Connect

    Verda, R. D.; Nastasi, Michael Anthony,

    2002-01-01

    A technique for hydrogen depth profiling by reflection elastic recoil detection analysis called the channel-depth conversion was introduced by Verda, et al.' However, the energy spread in elastic recoil detection analysis spectra, which causes a broadening in the energy range and leads to errors in depth profiling, was not addressed by this technique. Here we introduce a technique to addresses this problem, called the energy spread correction. Together, the energy spread correction and the channel-depth conversion techniques comprise the depth profiling method presented in this work.

  5. Effective atomic numbers and electron densities of some human tissues and dosimetric materials for mean energies of various radiation sources relevant to radiotherapy and medical applications

    NASA Astrophysics Data System (ADS)

    Kurudirek, Murat

    2014-09-01

    Effective atomic numbers, Zeff, and electron densities, neff, are convenient parameters used to characterise the radiation response of a multi-element material in many technical and medical applications. Accurate values of these physical parameters provide essential data in medical physics. In the present study, the effective atomic numbers and electron densities have been calculated for some human tissues and dosimetric materials such as Adipose Tissue (ICRU-44), Bone Cortical (ICRU-44), Brain Grey/White Matter (ICRU-44), Breast Tissue (ICRU-44), Lung Tissue (ICRU-44), Soft Tissue (ICRU-44), LiF TLD-100H, TLD-100, Water, Borosilicate Glass, PAG (Gel Dosimeter), Fricke (Gel Dosimeter) and OSL (Aluminium Oxide) using mean photon energies, Em, of various radiation sources. The used radiation sources are Pd-103, Tc-99, Ra-226, I-131, Ir-192, Co-60, 30 kVp, 40 kVp, 50 kVp (Intrabeam, Carl Zeiss Meditec) and 6 MV (Mohan-6 MV) sources. The Em values were then used to calculate Zeff and neff of the tissues and dosimetric materials for various radiation sources. Different calculation methods for Zeff such as the direct method, the interpolation method and Auto-Zeff computer program were used and agreements and disagreements between the used methods have been presented and discussed. It has been observed that at higher Em values agreement is quite satisfactory (Dif.<5%) between the adopted methods.

  6. The XMM-Newton spectrum of a candidate recoiling supermassive black hole: An elusive inverted P-Cygni profile

    SciTech Connect

    Lanzuisi, G.; Civano, F.; Marchesi, S.; Hickox, R.; Comastri, A.; Cappelluti, N.; Costantini, E.; Elvis, M.; Fruscione, A.; Mainieri, V.; Jahnke, K.; Komossa, S.; Piconcelli, E.; Vignali, C.; Brusa, M.

    2013-11-20

    We present a detailed spectral analysis of new XMM-Newton data of the source CXOC J100043.1+020637, also known as CID-42, detected in the COSMOS survey at z = 0.359. Previous works suggested that CID-42 is a candidate recoiling supermassive black hole (SMBH) showing also an inverted P-Cygni profile in the X-ray spectra at ∼6 keV (rest) with an iron emission line plus a redshifted absorption line (detected at 3σ in previous XMM-Newton and Chandra observations). Detailed analysis of the absorption line suggested the presence of ionized material flowing into the black hole at high velocity. In the new long XMM-Newton observation, while the overall spectral shape remains constant, the continuum 2-10 keV flux decrease of ∼20% with respect to previous observation and the absorption line is undetected. The upper limit on the intensity of the absorption line is EW < 162 eV. Extensive Monte Carlo simulations show that the nondetection of the line is solely due to variation in the properties of the inflowing material, in agreement with the transient nature of these features, and that the intensity of the line is lower than the previously measured with a probability of 98.8%. In the scenario of CID-42 as a recoiling SMBH, the absorption line can be interpreted as being due to an inflow of gas with variable density that is located in the proximity of the SMBH and recoiling with it. New monitoring observations will be requested to further characterize this line.

  7. Extra-large remnant recoil velocities and spins from near-extremal-Bowen-York-spin black-hole binaries

    SciTech Connect

    Dain, Sergio; Lousto, Carlos O.; Zlochower, Yosef

    2008-07-15

    We evolve equal-mass, equal-spin black-hole binaries with specific spins of a/m{sub H}{approx}0.925, the highest spins simulated thus far and nearly the largest possible for Bowen-York black holes, in a set of configurations with the spins counteraligned and pointing in the orbital plane, which maximizes the recoil velocities of the merger remnant, as well as a configuration where the two spins point in the same direction as the orbital angular momentum, which maximizes the orbital hangup effect and remnant spin. The coordinate radii of the individual apparent horizons in these cases are very small and the simulations require very high central resolutions (h{approx}M/320). We find that these highly spinning holes reach a maximum recoil velocity of {approx}3300 km s{sup -1} (the largest simulated so far) and, for the hangup configuration, a remnant spin of a/m{sub H}{approx}0.922. These results are consistent with our previous predictions for the maximum recoil velocity of {approx}4000 km s{sup -1} and remnant spin; the latter reinforcing the prediction that cosmic censorship is not violated by merging highly spinning black-hole binaries. We also numerically solve the initial data for, and evolve, a single maximal-Bowen-York-spin black hole, and confirm that the 3-metric has an O(r{sup -2}) singularity at the puncture, rather than the usual O(r{sup -4}) singularity seen for nonmaximal spins.

  8. Fluorescence Resonance Energy Transfer (FRET) and Proximity Ligation Assays Reveal Functionally Relevant Homo- and Heteromeric Complexes among Hyaluronan Synthases HAS1, HAS2, and HAS3*

    PubMed Central

    Bart, Geneviève; Vico, Nuria Ortega; Hassinen, Antti; Pujol, Francois M.; Deen, Ashik Jawahar; Ruusala, Aino; Tammi, Raija H.; Squire, Anthony; Heldin, Paraskevi; Kellokumpu, Sakari; Tammi, Markku I.

    2015-01-01

    In vertebrates, hyaluronan is produced in the plasma membrane from cytosolic UDP-sugar substrates by hyaluronan synthase 1–3 (HAS1–3) isoenzymes that transfer N-acetylglucosamine (GlcNAc) and glucuronic acid (GlcUA) in alternative positions in the growing polysaccharide chain during its simultaneous extrusion into the extracellular space. It has been shown that HAS2 immunoprecipitates contain functional HAS2 homomers and also heteromers with HAS3 (Karousou, E., Kamiryo, M., Skandalis, S. S., Ruusala, A., Asteriou, T., Passi, A., Yamashita, H., Hellman, U., Heldin, C. H., and Heldin, P. (2010) The activity of hyaluronan synthase 2 is regulated by dimerization and ubiquitination. J. Biol. Chem. 285, 23647–23654). Here we have systematically screened in live cells, potential interactions among the HAS isoenzymes using fluorescence resonance energy transfer (FRET) and flow cytometric quantification. We show that all HAS isoenzymes form homomeric and also heteromeric complexes with each other. The same complexes were detected both in Golgi apparatus and plasma membrane by using FRET microscopy and the acceptor photobleaching method. Proximity ligation assays with HAS antibodies confirmed the presence of HAS1-HAS2, HAS2-HAS2, and HAS2-HAS3 complexes between endogenously expressed HASs. C-terminal deletions revealed that the enzymes interact mainly via uncharacterized N-terminal 86-amino acid domain(s), but additional binding site(s) probably exist in their C-terminal parts. Of all the homomeric complexes HAS1 had the lowest and HAS3 the highest synthetic activity. Interestingly, HAS1 transfection reduced the synthesis of hyaluronan obtained by HAS2 and HAS3, suggesting functional cooperation between the isoenzymes. These data indicate a general tendency of HAS isoenzymes to form both homomeric and heteromeric complexes with potentially important functional consequences on hyaluronan synthesis. PMID:25795779

  9. Potential effects of alpha-recoil on uranium-series dating of calcrete

    USGS Publications Warehouse

    Neymark, L.A.

    2011-01-01

    Evaluation of paleosol ages in the vicinity of Yucca Mountain, Nevada, at the time the site of a proposed high-level nuclear waste repository, is important for fault-displacement hazard assessment. Uranium-series isotope data were obtained for surface and subsurface calcrete samples from trenches and boreholes in Midway Valley, Nevada, adjacent to Yucca Mountain. 230Th/U ages of 33 surface samples range from 1.3 to 423 thousand years (ka) and the back-calculated 234U/238U initial activity ratios (AR) are relatively constant with a mean value of 1.54 ± 0.15 (1σ), which is consistent with the closed-system behavior. Subsurface calcrete samples are too old to be dated by the 230Th/U method. U-Pb data for post-pedogenic botryoidal opal from a subsurface calcrete sample show that these subsurface calcrete samples are older than ~ 1.65 million years (Ma), old enough to have attained secular equilibrium had their U-Th systems remained closed. However, subsurface calcrete samples show U-series disequilibrium indicating open-system behavior of 238U daughter isotopes, in contrast with the surface calcrete, where open-system behavior is not evident. Data for 21 subsurface calcrete samples yielded calculable 234U/238U model ages ranging from 130 to 1875 ka (assuming an initial AR of 1.54 ± 0.15, the mean value calculated for the surface calcrete samples). A simple model describing continuous α-recoil loss predicts that the 234U/238U and 230Th/238U ARs reach steady-state values ~ 2 Ma after calcrete formation. Potential effects of open-system behavior on 230Th/U ages and initial 234U/238U ARs for younger surface calcrete were estimated using data for old subsurface calcrete samples with the 234U loss and assuming that the total time of water-rock interaction is the only difference between these soils. The difference between the conventional closed-system and open-system ages may exceed errors of the calculated conventional ages for samples older than ~ 250 ka, but is

  10. Improvements in Fabrication of Elastic Scattering Foils Used to Measure Neutron Yield by the Magnetic Recoil Spectrometer

    DOE PAGESBeta

    Reynolds, H. G.; Schoff, M. E.; Farrell, M. P.; Gatu Johnson, M.; Bionta, R. M.; Frenje, J. A.

    2016-08-01

    The magnetic recoil spectrometer uses a deuterated polyethylene polymer (CD2) foil to measure neutron yield in inertial confinement fusion experiments. Higher neutron yields in recent experiments have resulted in primary signal saturation in the detector CR-39 foils, necessitating the fabrication of thinner CD2 foils than established methods could provide. A novel method of fabricating deuterated polymer foils is described. The resulting foils are thinner, smoother, and more uniform in thickness than the foils produced by previous methods. Here, these new foils have successfully been deployed at the National Ignition Facility, enabling higher neutron yield measurements than previous foils, with nomore » primary signal saturation.« less

  11. First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the {sup 244}Pu({sup 48}Ca,3-4n) reaction

    SciTech Connect

    Gates, J. M.; Duellmann, Ch. E.; Schaedel, M.; Ackermann, D.; Block, M.; Bruechle, W.; Essel, H. G.; Hartmann, W.; Hessberger, F. P.; Huebner, A.; Jaeger, E.; Khuyagbaatar, J.; Kindler, B.; Krier, J.; Kurz, N.; Lommel, B.; Schaffner, H.; Schausten, B.; Schimpf, E.; Steiner, J.

    2011-05-15

    Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of {sup 48}Ca to irradiate targets of {sup 206-208}Pb, which led to the production of {sup 252-254}No isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ({sup 288-291}114) were produced in irradiations of {sup 244}Pu targets with {sup 48}Ca beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of {sup 288-291}114. A new {alpha}-decay branch in {sup 281}Ds was observed, leading to the new nucleus {sup 277}Hs.

  12. Subaru and e-Merlin observations of NGC 3718. Diaries of a supermassive black hole recoil?

    NASA Astrophysics Data System (ADS)

    Markakis, K.; Dierkes, J.; Eckart, A.; Nishiyama, S.; Britzen, S.; García-Marín, M.; Horrobin, M.; Muxlow, T.; Zensus, J. A.

    2015-08-01

    photometric and spectroscopic characteristics. These characteristics combined with the observed spatial NIR and radio emission offsets, the relative redshift between the broad and the narrow Hα line, the limited star formation activity, and AGN feedback strongly imply the existence of a supermassive black hole recoil. Finally, we discuss a possible interpretation that could naturally incorporate all these findings into one physically consistent picture. Appendices are available in electronic form at http://www.aanda.orgBased on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  13. Psychological Relevance and Information Science.

    ERIC Educational Resources Information Center

    Harter, Stephen P.

    1992-01-01

    Explores the theory of psychological relevance and its relationship to information retrieval, and provides an extended example. Topics discussed include information need, the search process, the nature of information, topical relevance, relevance judgments and retrieval testing, information retrieval and bibliometrics, and suggestions for further…

  14. A new value for the half-life of 10Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting

    NASA Astrophysics Data System (ADS)

    Korschinek, G.; Bergmaier, A.; Faestermann, T.; Gerstmann, U. C.; Knie, K.; Rugel, G.; Wallner, A.; Dillmann, I.; Dollinger, G.; von Gostomski, Ch. Lierse; Kossert, K.; Maiti, M.; Poutivtsev, M.; Remmert, A.

    2010-01-01

    The importance of 10Be in different applications of accelerator mass spectrometry (AMS) is well-known. In this context the half-life of 10Be has a crucial impact, and an accurate and precise determination of the half-life is a prerequisite for many of the applications of 10Be in cosmic-ray and earth science research. Recently, the value of the 10Be half-life has been the centre of much debate. In order to overcome uncertainties inherent in previous determinations, we introduced a new method of high accuracy and precision. An aliquot of our highly enriched 10Be master solution was serially diluted with increasing well-known masses of 9Be. We then determined the initial 10Be concentration by least square fit to the series of measurements of the resultant 10Be/ 9Be ratio. In order to minimize uncertainties because of mass bias which plague other low-energy mass spectrometric methods, we used for the first time Heavy-Ion Elastic Recoil Detection (HI-ERD) for the determination of the 10Be/ 9Be isotopic ratios, a technique which does not suffer from difficult to control mass fractionation. The specific activity of the master solution was measured by means of accurate liquid scintillation counting (LSC). The resultant combination of the 10Be concentration and activity yields a 10Be half-life of T1/2 = 1.388 ± 0.018 (1 s, 1.30%) Ma. In a parallel but independent study (Chmeleff et al. [11]), found a value of 1.386 ± 0.016 (1.15%) Ma. Our recommended weighted mean and mean standard error for the new value for 10Be half-life based on these two independent measurements is 1.387 ± 0.012 (0.87%) Ma.

  15. Spectroscopy of transfermium nuclei using the GABRIELA set up at the focal plane of the VASSILISSA recoil separator

    SciTech Connect

    Hauschild, K.; Lopez-Martens, A.; Dorvaux, O.; Piot, J.; Curien, D.; Gall, B.; Yeremin, A. V.; Chelnokov, M. L.; Chepigin, V. I.; Isaev, A. V.; Izosimov, I. N.; Kabachenko, A. P.; Katrasev, D. E.; Kuznetsov, A. N.; Malyshev, O. N.; Popeko, A. G.; Sokol, E. A.; Svirikhin, A. I.; Wiborg-Hagen, T.; Nyhus, H. T

    2010-06-01

    An IN2P3-JINR collaboration has launched a project called GABRIELA at the Flerov Laboratory for Nuclear Reactions (FLNR) within the Joint Institute for Nuclear Research (JINR) in Dubna (Russia). The goal of the project is to perform gamma-ray and internal conversion electron spectroscopy of heavy nuclei produced in fusion-evaporation reactions and transported to the focal plane of the recoil separator VASSILISSA. During five experimental campaigns of GABRIELA, the detection system has gained in sensitivity and new spectroscopic information has been obtained for {sup 249}Fm, {sup 251}Fm, {sup 253}No and {sup 255}Lr. In this contribution new results for {sup 253}No will be discussed.

  16. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF.

    PubMed

    Casey, D T; Frenje, J A; Gatu Johnson, M; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Knauer, J P; Meyerhofer, D D; Sangster, T C; Bionta, R M; Bleuel, D L; Döppner, T; Glenzer, S; Hartouni, E; Hatchett, S P; Le Pape, S; Ma, T; MacKinnon, A; McKernan, M A; Moran, M; Moses, E; Park, H-S; Ralph, J; Remington, B A; Smalyuk, V; Yeamans, C B; Kline, J; Kyrala, G; Chandler, G A; Leeper, R J; Ruiz, C L; Cooper, G W; Nelson, A J; Fletcher, K; Kilkenny, J; Farrell, M; Jasion, D; Paguio, R

    2012-10-01

    A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  17. BlackMax: A black-hole event generator with rotation, recoil, split branes, and brane tension

    SciTech Connect

    Dai Dechang; Starkman, Glenn; Stojkovic, Dejan; Issever, Cigdem; Tseng, Jeff; Rizvi, Eram

    2008-04-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, nonzero brane tension, and black-hole recoil due to Hawking radiation (although not all simultaneously). The generator can be interfaced with Herwig and Pythia. The main code can be downloaded from http://www-pnp.physics.ox.ac.uk/{approx}issever/BlackMax/blackmax.html.

  18. FAST TRACK COMMUNICATION: The gravitational-wave recoil from the ringdown phase of coalescing black hole binaries

    NASA Astrophysics Data System (ADS)

    Le Tiec, Alexandre; Blanchet, Luc; Will, Clifford M.

    2010-01-01

    The gravitational recoil or 'kick' of a black hole formed from the merger of two orbiting black holes, and caused by the anisotropic emission of gravitational radiation, is an astrophysically important phenomenon. We combine (i) an earlier calculation, using post-Newtonian theory, of the kick velocity accumulated up to the merger of two non-spinning black holes, (ii) a 'close-limit approximation' calculation of the radiation emitted during the ringdown phase, and based on a solution of the Regge-Wheeler and Zerilli equations using initial data accurate to second post-Newtonian order. We prove that ringdown radiation produces a significant 'anti-kick'. Adding the contributions due to inspiral, merger and ringdown phases, our results for the net kick velocity agree with those from numerical relativity to 10-15% over a wide range of mass ratios, with a maximum velocity of 180 km s-1 at a mass ratio of 0.38.

  19. Advances in the helium-jet coupled on-line mass separator RAMA. [Recoil Atom Mass Analyzer

    SciTech Connect

    Moltz, D M; Aysto, J; Cable, M D; Parry, R F; Haustein, P E; Wouters, J M; Cerny, J

    1980-01-01

    General improvements to the on-line mass separator RAMA (Recoil Atom Mass Analyzer) have yielded a greater reliability and efficiency for some elements. A new utilitarian helium-jet chamber has been installed to facilitate quick target and degrader foil changes in addition to a new ion source holder. A higher efficiency hollow-cathode, cathode-extraction ion source, for lower melting point elements (< 1200/sup 0/C) has also been designed. Tests with the beta-delayed proton emitter /sup 37/Ca showed a factor of five increase in yield over the old hollow-cathode, anode-extraction source. A differentially-pumped-tape drive system compatible with both ..gamma..-..gamma.. and ..beta..-..gamma.. experiments has been incorporated into the general detection system. All major operating parameters will soon be monitored by a complete stand-alone microprocessor system which will eventually be upgraded to a closed-loop control system.

  20. 5.0 GHz Continuum eEVN Observations of the Recoiling Supermassive Black Hole Candidate SDSSS J113323.97+550415.8

    NASA Astrophysics Data System (ADS)

    Perez-Torres, M.; Piconcelli, N. Ramirez-Olivencia E.; Alberdi, A.; Komossa, S.; Herrero-Illana, R.

    2015-04-01

    We report electronic European VLBI Network (eEVN) radio observations of the recoiling supermassive black hole (SMBH) candidate SDSSS J113323.97+550415.8 (=SDSS1133), in the outskirts of the nearby (D=28.9 Mpc) galaxy Mrk 177 (Koss et al.

  1. B → Dℓν form factors at nonzero recoil and |Vcb| from 2+1-flavor lattice QCD

    DOE PAGESBeta

    Bailey, Jon A.

    2015-08-10

    We present the first unquenched lattice-QCD calculation of the hadronic form factors for the exclusive decay B¯→Dℓν¯ at nonzero recoil. We carry out numerical simulations on 14 ensembles of gauge-field configurations generated with 2+1 flavors of asqtad-improved staggered sea quarks. The ensembles encompass a wide range of lattice spacings (approximately 0.045 to 0.12 fm) and ratios of light (up and down) to strange sea-quark masses ranging from 0.05 to 0.4. For the b and c valence quarks we use improved Wilson fermions with the Fermilab interpretation, while for the light valence quarks we use asqtad-improved staggered fermions. We extrapolate ourmore » results to the physical point using rooted staggered heavy-light meson chiral perturbation theory. We then parametrize the form factors and extend them to the full kinematic range using model-independent functions based on analyticity and unitarity. We present our final results for f+(q2) and f0(q2), including statistical and systematic errors, as coefficients of a series in the variable z and the covariance matrix between these coefficients. We then fit the lattice form-factor data jointly with the experimentally measured differential decay rate from BABAR to determine the CKM matrix element, |Vcb|=(39.6 ± 1.7QCD+exp ± 0.2QED) × 10–3. As a byproduct of the joint fit we obtain the form factors with improved precision at large recoil. In conclusion, we use them to update our calculation of the ratio R(D) in the Standard Model, which yields R(D)=0.299(11).« less

  2. Review of Recent Literature Relevant to the Environmental Effects of Marine and Hydrokinetic Energy Devices Task 2.1.3: Effects on Aquatic Organisms – Fiscal Year 2011 Progress Report Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect

    Kropp, Roy K.

    2011-09-30

    A literature search was conducted by using the Web of Science® Databases component of the ISI Web of KnowledgeSM to identify recent articles that would be useful to help assess the potential environmental effects of renewable energy development in the ocean, with emphasis on marine mammals, seabirds, and fish. Several relatively recent general review articles that included possible effects of marine renewable energy devices on marine mammals and seabirds were examined to begin the search process (e.g., Boehlert et al. 2008; Thompson et al. 2008; Simas et al. 2009). From these articles, several general topics of potential environmental effects on marine mammals, seabirds, and fish were derived. These topics were used as the primary search factors. Searches were conducted with reference to the potential effects of offshore wind farms and MHK devices on marine mammals, seabirds, and fish. Additional sources were identified by cross-checking the Web of Science databases for articles that cited the review articles. It also became clear that often the potential effects were offered as hypotheses that often were not supported by the presentation of appropriate documentation. Therefore, the search was refined and focused on trying to obtain the necessary information to support or challenge a proposed potential effect to a specific concern. One of the expressed concerns regarding MHK devices is that placing wave parks in coastal waters could compromise the migration patterns of whales. Disruption of the annual migration of the gray whale (Eschrichtius robustus), which swims at least 30,000 km on its round trip from breeding grounds in Baja California to feeding areas in the Bering Sea, is of particular concern. Among the hypothesized effects on the migrating gray whales are increased predation risk by constricting migration corridor to between array and shore or by forcing the whales to swim into deeper waters, increased metabolic energy costs and delays in reaching the

  3. Is shared governance still relevant?

    PubMed

    Porter-O'Grady, T

    2001-10-01

    Is shared governance still relevant in this era of significant changes in healthcare? Requisites to support nurses and others are more important now than ever before. Shared decision-making is not only relevant, it is essential. The road to empowerment is not easy. Many patterns of organization and relationship must be changed forever through commitment and leadership today.

  4. Relationship between early diastolic intraventricular pressure gradients, an index of elastic recoil, and improvements in systolic and diastolic function

    NASA Technical Reports Server (NTRS)

    Firstenberg, M. S.; Smedira, N. G.; Greenberg, N. L.; Prior, D. L.; McCarthy, P. M.; Garcia, M. J.; Thomas, J. D.

    2001-01-01

    BACKGROUND: Early diastolic intraventricular pressure gradients (IVPGs) have been proposed to relate to left ventricular (LV) elastic recoil and early ventricular "suction." Animal studies have demonstrated relationships between IVPGs and systolic and diastolic indices during acute ischemia. However, data on the effects of improvements in LV function in humans and the relationship to IVPGs are lacking. METHODS AND RESULTS: Eight patients undergoing CABG and/or infarct exclusion surgery had a triple-sensor high-fidelity catheter placed across the mitral valve intraoperatively for simultaneous recording of left atrial (LA), basal LV, and apical LV pressures. Hemodynamic data obtained before bypass were compared with those with similar LA pressures and heart rates obtained after bypass. From each LV waveform, the time constant of LV relaxation (tau), +dP/dt(max), and -dP/dt(max) were determined. Transesophageal echocardiography was used to determined end-diastolic (EDV) and end-systolic (ESV) volumes and ejection fractions (EF). At similar LA pressures and heart rates, IVPG increased after bypass (before bypass 1.64+/-0.79 mm Hg; after bypass 2.67+/-1.25 mm Hg; P<0.01). Significant improvements were observed in ESV, as well as in apical and basal +dP/dt(max), -dP/dt(max), and tau (each P<0.05). Overall, IVPGs correlated inversely with both ESV (IVPG=-0.027[ESV]+3.46, r=-0.64) and EDV (IVPG=-0.027[EDV]+4.30, r=-0.70). Improvements in IVPGs correlated with improvements in apical tau (Deltatau =5.93[DeltaIVPG]+4.76, r=0.91) and basal tau (Deltatau =2.41[DeltaIVPG]+5.13, r=-0.67). Relative changes in IVPGs correlated with changes in ESV (DeltaESV=-0.97[%DeltaIVPG]+23.34, r=-0.79), EDV (DeltaEDV=-1.16[%DeltaIVPG]+34.92, r=-0.84), and EF (DeltaEF=0.38[%DeltaIVPG]-8.39, r=0.85). CONCLUSIONS: Improvements in LV function also increase IVPGs. These changes in IVPGs, suggestive of increases in LV suction and elastic recoil, correlate directly with improvements in LV relaxation

  5. A relevance theory of induction.

    PubMed

    Medin, Douglas L; Coley, John D; Storms, Gert; Hayes, Brett K

    2003-09-01

    A framework theory, organized around the principle of relevance, is proposed for category-based reasoning. According to the relevance principle, people assume that premises are informative with respect to conclusions. This idea leads to the prediction that people will use causal scenarios and property reinforcement strategies in inductive reasoning. These predictions are contrasted with both existing models and normative logic. Judgments of argument strength were gathered in three different countries, and the results showed the importance of both causal scenarios and property reinforcement in category-based inferences. The relation between the relevance framework and existing models of category-based inductive reasoning is discussed in the light of these findings.

  6. Overview of secondary neutron production relevant to shielding inspace

    SciTech Connect

    Heilbronn, L.; Nakamura, T.; Iwata, Y.; Kurosawa, T.; Iwase, H.; Townsend, L.W.

    2004-12-03

    An overview of experimental secondary neutron measurements relevant to space-related activities is presented. Stopping target yields and cross section measurements conducted at particle accelerators using heavy ions with energies >100 MeV per nucleon are discussed.

  7. Relevance theory: pragmatics and cognition.

    PubMed

    Wearing, Catherine J

    2015-01-01

    Relevance Theory is a cognitively oriented theory of pragmatics, i.e., a theory of language use. It builds on the seminal work of H.P. Grice(1) to develop a pragmatic theory which is at once philosophically sensitive and empirically plausible (in both psychological and evolutionary terms). This entry reviews the central commitments and chief contributions of Relevance Theory, including its Gricean commitment to the centrality of intention-reading and inference in communication; the cognitively grounded notion of relevance which provides the mechanism for explaining pragmatic interpretation as an intention-driven, inferential process; and several key applications of the theory (lexical pragmatics, metaphor and irony, procedural meaning). Relevance Theory is an important contribution to our understanding of the pragmatics of communication.

  8. Optimization of microwave-induced chemical etching for rapid development of neutron-induced recoil tracks in CR-39 detectors

    NASA Astrophysics Data System (ADS)

    Sahoo, G. S.; Tripathy, S. P.; Bandyopadhyay, T.

    2014-03-01

    A systematic investigation is carried out to optimize the recently established microwave-induced chemical etching (MICE) parameters for rapid development of neutron-induced recoil tracks in CR-39 detectors. Several combinations of all available microwave powers with different etching durations were analysed to determine the most suitable etching condition. The etching duration was found to reduce with increasing microwave power and the tracks were observed at about 18, 15, 12, and 6 min for 300, 450, 600 and 900 W of microwave powers respectively compared to a few hours in chemical etching (CE) method. However, for complete development of tracks the etching duration of 30, 40, 50 and 60 min were found to be suitable for the microwave powers of 900, 600, 450 and 300 W, respectively. Temperature profiles of the etchant for all the available microwave powers at different etching durations were generated to regulate the etching process in a controlled manner. The bulk etch rates at different microwave powers were determined by 2 methods, viz., gravimetric and removed thickness methods. A logarithmic expression was used to fit the variation of bulk etch rate with microwave power. Neutron detection efficiencies were obtained for all the cases and the results on track parameters obtained with MICE technique were compared with those obtained from another detector processed with chemical etching.

  9. Probing high areal-density cryogenic deuterium-tritium implosions using downscattered neutron spectra measured by the magnetic recoil spectrometera)

    NASA Astrophysics Data System (ADS)

    Frenje, J. A.; Casey, D. T.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Radha, P. B.; Sangster, T. C.; Meyerhofer, D. D.; Hatchett, S. P.; Haan, S. W.; Cerjan, C. J.; Landen, O. L.; Fletcher, K. A.; Leeper, R. J.

    2010-05-01

    For the first time high areal-density (ρR) cryogenic deuterium-tritium (DT) implosions have been probed using downscattered neutron spectra measured with the magnetic recoil spectrometer (MRS) [J. A. Frenje et al., Rev. Sci. Instrum. 79, 10E502 (2008)], recently installed and commissioned on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The ρR data obtained with the MRS have been essential for understanding how the fuel is assembled and for guiding the cryogenic program at the Laboratory for Laser Energetics (LLE) to ρR values up to ˜300 mg/cm2. The ρR data obtained from well-established charged particle spectrometry techniques [C. K. Li et al., Phys. Plasmas 8, 4902 (2001)] were used to authenticate the MRS data for low-ρR plastic capsule implosions, and the ρR values inferred from these techniques are in excellent agreement, indicating that the MRS technique provides high-fidelity data. Recent OMEGA-MRS data and Monte Carlo simulations have shown that the MRS on the NIF [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] will meet most of the absolute and relative requirements for determining ρR, ion temperature (Ti) and neutron yield (Yn) in both low-yield, tritium-rich, deuterium-lean, hydrogen-doped implosions and high-yield DT implosions.

  10. Dynamic measurement of the helium concentration of evolving tungsten nanostructures using Elastic Recoil Detection during plasma exposure

    NASA Astrophysics Data System (ADS)

    Woller, K. B.; Whyte, D. G.; Wright, G. M.

    2015-08-01

    Helium (He) concentration depth profiles of evolving tungsten (W) nanostructures have been measured for the first time using in situ Elastic Recoil Detection (ERD) throughout plasma irradiation. Exposures resulting in fuzzy and non-fuzzy surfaces were analyzed in order to illuminate the role of He during the development of these surface morphologies. ERD was performed on samples with surface temperatures from Ts = 530-1100 K and irradiated by He flux densities of ΓHe ∼ 1020-1022 m-2 s-1. He concentration profiles in samples that developed either non-fuzzy or fuzzy surfaces are uniformly shaped with concentrations of 1.5-7 at.%, which is presumed to be too low for pressure driven growth models. Therefore, surface morphology changes are not perpetuated by continuous bubble bursting deformation. Also, a threshold in He flux density above 1020 m-2 s-1 is suggested by using in situ ERD to monitor the depth profile evolution of the He-rich layer while changing the flux during exposure.

  11. Recoil distance transmission method: Measurement of interaction cross sections of excited states with fast rare-isotope beams

    NASA Astrophysics Data System (ADS)

    Kobayashi, N.; Whitmore, K.; Iwasaki, H.

    2016-09-01

    The possible appearance of nuclear halos in ground and excited states close to the particle-decay threshold is of great importance in the investigation of nuclear structure and few-body correlations at the limit of stability. In order to obtain direct evidence of the halo structure manifested in nuclear excited states, we have considered a new method to measure the interaction cross sections of excited states. The combination of the transmission method and the recoil distance Doppler-shift method with a plunger device enables us to measure the number of interactions of the excited states in a target. Formulae to determine the interaction cross section are derived, and key issues to realize measurements are discussed. Dominant sources of errors are uncertainties in the excited-state lifetimes and γ-ray yields. We examine prototype experiments and perform simulations to study the impact of each uncertainty on the final result. This method provides a novel opportunity to perform cross section measurements on the excited states of rare isotopes.

  12. Thermal recrystallization of alpha-recoil damaged minerals of the pyrochlore structure type

    SciTech Connect

    Lumpkin, G.R.; Ewing, R.C.; Foltyn, E.M.

    1985-10-01

    Thermal recrystallization effects (heat of recrystallization and identification of phases formed), have been determined for naturally occurring members of the pyrochlore group which have received alpha doses of up to 4 X 10{sup 16} alphas/mg. The heats of recrystallization, E{sub t}, range from 125 to 210 J/g. Release of energy decreases as a function of crystallinity (estimated on the basis of the intensity of x-ray diffraction maxima), with the fully-metamict samples approaching 210 J/g. Lower measured values (40-125 J/g) are the result of alteration of the pyrochlores. Other metamict, complex oxides with stoichiometries of ABO{sub 4} and AB{sub 2}O{sub 6} have lower heats of recrystallization (40-85 J/g), and are easily distinguished from pyrochlore group minerals. Activation energies of recrystallization, E{sub a}, range between values of 0.29 to 0.97 eV, less than those measured for Pu-doped, synthetic zirconolites.

  13. Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide ((38)ArO4) from ((38)ClO4(-)) and the evolution of chemical bonding over the nuclear transmutation reaction path.

    PubMed

    Timm, Matthew J; Matta, Chérif F

    2014-12-01

    Argon tetroxide (ArO4) is the last member of the N=50 e(-) isoelectronic and isosteric series of ions: SiO4(4-), PO4(3-), SO4(2-), and ClO4(-). A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ~298kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295-8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52-53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4(-)) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope (38)Cl to the stable rare argon isotope (38)Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar-O bond. As a result, a primary retention yield of ~1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar-O bond dissociation product ArO3+O((3)P) from which the predicted barrier to dissociation is ca. 22kcal/mol and the exothermic reaction energy is ca. 28kcal/mol [(U)MP2/6-311+G(d)].

  14. Beam-Recoil Polarization Transfer in the Nucleon Resonance Region in the Exclusive $\\vec{e}p \\to e'K^+\\vec{\\Lambda}$ and $\\vec{e}p \\to e'K^+\\vec{\\Sigma}^0$ Reactions at CLAS

    SciTech Connect

    D.S. Carman, B.A. Raue, for the CLAS Collaboration

    2009-06-01

    Beam-recoil transferred polarizations for the exclusive $\\vec{e}p \\to e'K^+ \\vec{\\Lambda},\\vec{\\Sigma}^0$ reactions have been measured using the CLAS spectrometer at Jefferson Laboratory. New measurements have been completed at beam energies of 4.261 and 5.754~GeV that span a range of momentum transfer $Q^2$ from 0.7 to 5.4~GeV$^2$, invariant energy $W$ from 1.6 to 2.6~GeV, and the full center-of-mass angular range of the $K^+$ meson. These new data add to the existing CLAS $K^+\\Lambda$ measurements at 2.567~GeV, and provide the first-ever data for the $K^+\\Sigma^0$ channel in electroproduction. Comparisons of the data with several theoretical models are used to study the sensitivity to $s$-channel resonance contributions and the underlying reaction mechanism. Interpretations within two semi-classical partonic models are made to probe the underlying reaction mechanism and the $s\\bar{s}$ quark-pair creation dynamics.

  15. Energy Levels of Hydrogen and Deuterium

    National Institute of Standards and Technology Data Gateway

    SRD 142 Energy Levels of Hydrogen and Deuterium (Web, free access)   This database provides theoretical values of energy levels of hydrogen and deuterium for principle quantum numbers n = 1 to 200 and all allowed orbital angular momenta l and total angular momenta j. The values are based on current knowledge of the revelant theoretical contributions including relativistic, quantum electrodynamic, recoil, and nuclear size effects.

  16. Evaluation of highly ionizing components in high-energy nucleon radiation fields

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Townsend, Lawrence W.; Khan, Ferdous

    1989-01-01

    The data and models for nuclear fragment recoil distribution produced by high-energy nuclear events in tissue are reviewed. Results for linear energy transfer distributions in soft tissue are derived, and a simple model is developed for use in radiation studies and risk estimates.

  17. Anatomy relevant to conservative mastectomy

    PubMed Central

    O’Connell, Rachel L.

    2015-01-01

    Knowledge of the anatomy of the nipple and breast skin is fundamental to any surgeon practicing conservative mastectomies. In this paper, the relevant clinical anatomy will be described, mainly focusing on the anatomy of the “oncoplastic plane”, the ducts and the vasculature. We will also cover more briefly the nerve supply and the arrangement of smooth muscle of the nipple. Finally the lymphatic drainage of the nipple and areola will be described. An appreciation of the relevant anatomy, together with meticulous surgical technique may minimise local recurrence and ischaemic complications. PMID:26645002

  18. Anatomy relevant to conservative mastectomy.

    PubMed

    O'Connell, Rachel L; Rusby, Jennifer E

    2015-12-01

    Knowledge of the anatomy of the nipple and breast skin is fundamental to any surgeon practicing conservative mastectomies. In this paper, the relevant clinical anatomy will be described, mainly focusing on the anatomy of the "oncoplastic plane", the ducts and the vasculature. We will also cover more briefly the nerve supply and the arrangement of smooth muscle of the nipple. Finally the lymphatic drainage of the nipple and areola will be described. An appreciation of the relevant anatomy, together with meticulous surgical technique may minimise local recurrence and ischaemic complications. PMID:26645002

  19. Inclusive production of H\\rightarrow b\\bar{b} plus a recoil for the LHC Run-II

    NASA Astrophysics Data System (ADS)

    Gutierrez, Nicolas

    2016-07-01

    This letter presents a study of the inclusive production of H→ b\\bar{b} plus a recoil, using simulated samples of pp collisions at \\sqrt{s}=14 \\text{TeV} for an integrated luminosity in the range between 30 \\text{fb}-1 and 3 \\text{ab}-1 . The case for experiments to include un-prescaled b-tag multijet triggers for this topology is made and the ideal jet thresholds are discussed. The sensitivity to the Standard Model Higgs boson with a transverse momentum of at least 200 GeV is evaluated with respect to a continuous background, dominated by multijet processes. The mass of b-jet-pairs is analysed, quoting sensitivity to cross-sections in the range from 1 to 2 pb, for 100 \\text{fb}-1 , covering the total Higgs-boson production cross-section of 1.8 pb. The trigger strategy presented in this letter is compared to triggers already in use, showing an increase on the signal efficiency for masses below 200 GeV and a performance comparable to a logical OR of all the currently available akin triggers for higher masses. The robustness of the expected sensitivity against systematic uncertainties is estimated by considering various typical sources, such as those on the fitting parameters of the continuous background, shape uncertainties affecting the signal acceptance and the background modelling. The accuracy of the Higgs-boson production cross-section measurements is also discussed, quoting sensitivity to deviations of 50% for 100 \\text{fb}-1 and 10% for 3 \\text{ab}-1 .

  20. Medical Scenarios Relevant to Spaceflight

    NASA Technical Reports Server (NTRS)

    Bacal, Kira; Hurs, Victor; Doerr, Harold

    2004-01-01

    The Medical Operational Support Team (MOST) was tasked by the JSC Space Medicine and Life Sciences Directorate (SLSD) to incorporate medical simulation into 1) medical training for astronaut-crew medical officers (CMO) and medical flight control teams and 2) evaluations of procedures and resources required for medical care aboard the International Space Station (ISS). Development of evidence-based medical scenarios that mimic the physiology observed during spaceflight will be needed for the MOST to complete these two tasks. The MOST used a human patient simulator, the ISS-like resources in the Medical Simulation Laboratory (MSL), and evidence from space operations, military operations and medical literature to develop space relevant medical scenarios. These scenarios include conditions concerning airway management, Advanced Cardiac Life Support (ACLS) and mitigating anaphylactic symptoms. The MOST has used these space relevant medical scenarios to develop a preliminary space medical training regimen for NASA flight surgeons, Biomedical Flight Controllers (Biomedical Engineers; BME) and CMO-analogs. This regimen is conducted by the MOST in the MSL. The MOST has the capability to develop evidence-based space-relevant medical scenarios that can help SLSD I) demonstrate the proficiency of medical flight control teams to mitigate space-relevant medical events and 2) validate nextgeneration medical equipment and procedures for space medicine applications.

  1. Making Plant Biology Curricula Relevant.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1992-01-01

    Reviews rationale, purposes, challenges, and relevance of hands-on, plant biology curricula that have been developed in response to the limited use of plants in biology education. Discusses methods to maintain both instructional rigor and student interest in the following topics: cut flowers, container-growing media, fertilizers, hydroponics,…

  2. What's Relevant in Classical Literature?

    ERIC Educational Resources Information Center

    Hickman, Sara

    1970-01-01

    Argues the relevance of various aspects of the Thebian trilogy, "The Iliad," The Odyssey," Great Expectations," and Hamlet" to the concerns of today's high school students; a paper presented at annual convention of National Council of Teachers of English (59th, Washington, D.C., November 29, 1969). (RD)

  3. The architectural relevance of cybernetics

    SciTech Connect

    Frazer, J.H.

    1993-12-31

    This title is taken from an article by Gordon Pask in Architectural Design September 1969. It raises a number of questions which this article attempts to answer. How did Gordon come to be writing for an architectural publication? What was his contribution to architecture? How does he now come to be on the faculty of a school of architecture? And what indeed is the architectural relevance of cybernetics? 12 refs.

  4. Helical sub-structures in energy-storing tendons provide a possible mechanism for efficient energy storage and return.

    PubMed

    Thorpe, Chavaunne T; Klemt, Christian; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2013-08-01

    The predominant function of tendons is to position the limb during locomotion. Specific tendons also act as energy stores. Energy-storing (ES) tendons are prone to injury, the incidence of which increases with age. This is likely related to their function; ES tendons are exposed to higher strains and require a greater ability to recoil than positional tendons. The specialized properties of ES tendons are thought to be achieved through structural and compositional differences. However, little is known about structure-function relationships in tendons. This study uses fascicles from the equine superficial digital flexor (SDFT) and common digital extensor (CDET) as examples of ES and positional tendons. We hypothesized that extension and recoil behaviour at the micro-level would differ between tendon types, and would alter with age in the injury-prone SDFT. Supporting this, the results show that extension in the CDET is dominated by fibre sliding. By contrast, greater rotation was observed in the SDFT, suggesting a helical component to fascicles in this tendon. This was accompanied by greater recovery and less hysteresis loss in SDFT samples. In samples from aged SDFTs, the amount of rotation and the ability to recover decreased, while hysteresis loss increased. These findings indicate that fascicles in the ES SDFT may have a helical structure, enabling the more efficient recoil observed. Further, the helix structure appears to alter with ageing; this coincides with a reduction in the ability of SDFT fascicles to recoil. This may affect tendon fatigue resistance and predispose aged tendons to injury.

  5. High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Gatu Johnson, M.; Frenje, J. A.; Bionta, R. M.; Casey, D. T.; Eckart, M. J.; Farrell, M. P.; Grim, G. P.; Hartouni, E. P.; Hatarik, R.; Hoppe, M.; Kilkenny, J. D.; Li, C. K.; Petrasso, R. D.; Reynolds, H. G.; Sayre, D. B.; Schoff, M. E.; Séguin, F. H.; Skulina, K.; Yeamans, C. B.

    2016-11-01

    The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility measures the DT neutron spectrum from cryogenically layered inertial confinement fusion implosions. Yield, areal density, apparent ion temperature, and directional fluid flow are inferred from the MRS data. This paper describes recent advances in MRS measurements of the primary peak using new, thinner, reduced-area deuterated plastic (CD) conversion foils. The new foils allow operation of MRS at yields 2 orders of magnitude higher than previously possible, at a resolution down to ˜200 keV FWHM.

  6. High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

    DOE PAGESBeta

    Gatu Johnson, M.; Frenje, J. A.; Bionta, R. M.; Casey, D. T.; Eckart, M. J.; Farrell, M. P.; Grim, G. P.; Hartouni, E. P.; Hatarik, R.; Hoppe, M.; et al

    2016-08-09

    The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility measures the DT neutron spectrum from cryogenically layered inertial confinement fusion implosions. Yield, areal density, apparent ion temperature, and directional fluid flow are inferred from the MRS data. Here, this paper describes recent advances in MRS measurements of the primary peak using new, thinner, reduced-area deuterated plastic (CD) conversion foils. The new foils allow operation of MRS at yields 2 orders of magnitude higher than previously possible, at a resolution down to ~200 keV FWHM.

  7. The self-relevance system?

    PubMed

    Conway, Martin A; Pothos, Emmanuel M; Turk, David J

    2016-01-01

    We suggest that the Self Attention Network (SAN) maybe part of a larger self-regulatory system, which we term the Self-Relevance System (SRS) of which the "core" or default network is a major part. It is within the core network that memories are generated and the future imagined. Such memories and imaginings are the basis of preoccupations. Within the SRS then preoccupations drive the emergence of attentional biases (ABs). ABs in turn are modulated by the SAN activating and inhibiting circuits that shape behavior. We consider briefly how this might function in dysfunctional appetitive behaviors, e.g., substance abuse. PMID:26305290

  8. The Constraints of Relevance on Prevocational Curriculum

    ERIC Educational Resources Information Center

    Doherty, Catherine

    2015-01-01

    This paper reflects on how relevance has been invoked as a curricular principle, both by students and teachers, in curriculum documents and in curriculum theory, to explore its variously conceived parameters and conditions. By posing the questions "relevant to whom?", "relevant to what?", "relevant how?" and…

  9. The Need for Culturally Relevant Dance Education

    ERIC Educational Resources Information Center

    McCarthy-Brown, Nyama

    2009-01-01

    There is a need for culturally relevant teaching in dance education. Many dance teachers have heard the buzz words "culturally relevant teaching methods." Yet these dance educators acknowledge that the "dance culture" is not always synonymous with "culturally relevant." This paper examines the issue of culturally relevant teaching methods in dance…

  10. Minimizing the cost of locomotion with inclined trunk predicts crouched leg kinematics of small birds at realistic levels of elastic recoil.

    PubMed

    Rode, Christian; Sutedja, Yefta; Kilbourne, Brandon M; Blickhan, Reinhard; Andrada, Emanuel

    2016-02-01

    Small birds move with pronograde trunk orientation and crouched legs. Although the pronograde trunk has been suggested to be beneficial for grounded running, the cause(s) of the specific leg kinematics are unknown. Here we show that three charadriiform bird species (northern lapwing, oystercatcher, and avocet; great examples of closely related species that differ remarkably in their hind limb design) move their leg segments during stance in a way that minimizes the cost of locomotion. We imposed measured trunk motions and ground reaction forces on a kinematic model of the birds. The model was used to search for leg configurations that minimize leg work that accounts for two factors: elastic recoil in the intertarsal joint, and cheaper negative muscle work relative to positive muscle work. A physiological level of elasticity (∼ 0.6) yielded segment motions that match the experimental data best, with a root mean square of angular deviations of ∼ 2.1 deg. This finding suggests that the exploitation of elastic recoil shapes the crouched leg kinematics of small birds under the constraint of pronograde trunk motion. Considering that an upright trunk and more extended legs likely decrease the cost of locomotion, our results imply that the cost of locomotion is a secondary movement criterion for small birds. Scaling arguments suggest that our approach may be utilized to provide new insights into the motion of extinct species such as dinosaurs.

  11. Update of |Vcb| from the B¯→D*bold">ℓν¯ form factor at zero recoil with three-flavor lattice QCD

    NASA Astrophysics Data System (ADS)

    Bailey, Jon A.; Bazavov, A.; Bernard, C.; Bouchard, C. M.; DeTar, C.; Du, Daping; El-Khadra, A. X.; Foley, J.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kronfeld, A. S.; Laiho, J.; Levkova, L.; Mackenzie, P. B.; Neil, E. T.; Qiu, Si-Wei; Simone, J.; Sugar, R.; Toussaint, D.; Van de Water, R. S.; Zhou, Ran; Fermilab Lattice; MILC Collaborations

    2014-06-01

    We compute the zero-recoil form factor for the semileptonic decay B¯0→D*+ℓ-ν¯ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. We use an improved staggered action for the light valence and sea quarks (the MILC asqtad configurations), and the Fermilab action for the heavy quarks. Our calculations incorporate higher statistics, finer lattice spacings, and lighter quark masses than our 2008 work. As a byproduct of tuning the new data set, we obtain the Ds and Bs hyperfine splittings with few-MeV accuracy. For the zero-recoil form factor, we obtain F(1)=0.906(4)(12), where the first error is statistical and the second is the sum in quadrature of all systematic errors. With the latest Heavy Flavor Averaging Group average of experimental results and a cautious treatment of QED effects, we find |Vcb|=(39.04±0.49expt±0.53QCD±0.19QED)×10-3. The QCD error is now commensurate with the experimental error.

  12. Non-perturbative dynamics of the heavy-light quark system in the non-recoil limit

    SciTech Connect

    N. Brambilla; A. Vairo

    1997-03-01

    Starting from the relativistic gauge-invariant quark-antiquark Green function the authors obtain the relevant interaction in the one-body limit, which can be interpreted as the kernel of a non-perturbative Dirac equation. They study this kernel in different kinematic regions, reproducing, in particular, for heavy quark the potential case and sum rules results. They discuss the relevance of the result for heavy-light mesons and the relation with the phenomenological Dirac equations used up to now in the literature.

  13. Macromolecules Relevant to Stone Formation

    NASA Astrophysics Data System (ADS)

    Ryall, Rosemary L.; Cook, Alison F.; Thurgood, Lauren A.; Grover, Phulwinder K.

    2007-04-01

    Despite years of research, no single macromolecule in kidney calculi or in urine has yet been shown to fulfill a specific function in stone pathogenesis. In this paper we briefly review papers investigating the urinary excretion of individual macromolecules, their effects on calcium oxalate (CaOx) crystallization and attachment of crystals to renal epithelial cells, and the influence of lithogenic conditions on their renal expression in cultured cells and animal models. Using prothrombin fragment 1 (PTF1) and human serum albumin as examples, we show the types of patterns resulting from the binding of a fluorescently tagged protein to a specific CaOx monohydrate (COM) crystal face and its incorporation into the crystal structure. Molecular modeling is also used to illustrate how PTF1 can align with the atomic array on a COM crystal surface. We conclude that although many macromolecules are, by strict definition, relevant to stone formation, very few are probably truly influential.

  14. Ancient "Observatories" - A Relevant Concept?

    NASA Astrophysics Data System (ADS)

    Belmonte, Juan Antonio

    It is quite common, when reading popular books on astronomy, to see a place referred to as "the oldest observatory in the world". In addition, numerous books on archaeoastronomy, of various levels of quality, frequently refer to the existence of "prehistoric" or "ancient" observatories when describing or citing monuments that were certainly not built with the primary purpose of observing the skies. Internet sources are also guilty of this practice. In this chapter, the different meanings of the word observatory will be analyzed, looking at how their significances can be easily confused or even interchanged. The proclaimed "ancient observatories" are a typical result of this situation. Finally, the relevance of the concept of the ancient observatory will be evaluated.

  15. Energy.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This issue focuses on the theme of "Energy," and describes several educational resources (Web sites, CD-ROMs and software, videos, books, activities, and other resources). Sidebars offer features on alternative energy, animal energy, internal combustion engines, and energy from food. Subthemes include harnessing energy, human energy, and natural…

  16. Vygotsky's Crisis: Argument, context, relevance.

    PubMed

    Hyman, Ludmila

    2012-06-01

    Vygotsky's The Historical Significance of the Crisis in Psychology (1926-1927) is an important text in the history and philosophy of psychology that has only become available to scholars in 1982 in Russian, and in 1997 in English. The goal of this paper is to introduce Vygotsky's conception of psychology to a wider audience. I argue that Vygotsky's argument about the "crisis" in psychology and its resolution can be fully understood only in the context of his social and political thinking. Vygotsky shared the enthusiasm, widespread among Russian leftist intelligentsia in the 1920s, that Soviet society had launched an unprecedented social experiment: The socialist revolution opened the way for establishing social conditions that would let the individual flourish. For Vygotsky, this meant that "a new man" of the future would become "the first and only species in biology that would create itself." He envisioned psychology as a science that would serve this humanist teleology. I propose that The Crisis is relevant today insofar as it helps us define a fundamental problem: How can we systematically account for the development of knowledge in psychology? I evaluate how Vygotsky addresses this problem as a historian of the crisis. PMID:22520196

  17. Vygotsky's Crisis: Argument, context, relevance.

    PubMed

    Hyman, Ludmila

    2012-06-01

    Vygotsky's The Historical Significance of the Crisis in Psychology (1926-1927) is an important text in the history and philosophy of psychology that has only become available to scholars in 1982 in Russian, and in 1997 in English. The goal of this paper is to introduce Vygotsky's conception of psychology to a wider audience. I argue that Vygotsky's argument about the "crisis" in psychology and its resolution can be fully understood only in the context of his social and political thinking. Vygotsky shared the enthusiasm, widespread among Russian leftist intelligentsia in the 1920s, that Soviet society had launched an unprecedented social experiment: The socialist revolution opened the way for establishing social conditions that would let the individual flourish. For Vygotsky, this meant that "a new man" of the future would become "the first and only species in biology that would create itself." He envisioned psychology as a science that would serve this humanist teleology. I propose that The Crisis is relevant today insofar as it helps us define a fundamental problem: How can we systematically account for the development of knowledge in psychology? I evaluate how Vygotsky addresses this problem as a historian of the crisis.

  18. On Relevance Weight Estimation and Query Expansion.

    ERIC Educational Resources Information Center

    Robertson, S. E.

    1986-01-01

    A Bayesian argument is used to suggest modifications to the Robertson and Jones relevance weighting formula to accommodate the addition to the query of terms taken from the relevant documents identified during the search. (Author)

  19. The Personal Relevance of the Social Studies.

    ERIC Educational Resources Information Center

    VanSickle, Ronald L.

    1990-01-01

    Conceptualizes a personal-relevance framework derived from Ronald L. VanSickle's five areas of life integrated with four general motivating goals from Abraham Maslow's hierarchy of needs and Richard and Patricia Schmuck's social motivation theory. Illustrates ways to apply the personal relevance framework to make social studies more relevant to…

  20. Differential cross sections and recoil polarizations for the reaction γpK+Σ0

    SciTech Connect

    Dey, B.; Meyer, C. A.; Bellis, M.; McCracken, M. E.; Williams, M.; Adhikari, K. P.; Aghasyan, M.; Anghinolfi, M.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Berman, B. L.; Biselli, A. S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Crede, V.; D’Angelo, A.; Daniel, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Dhamija, S.; Dickson, R.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fegan, S.; Fradi, A.; Gabrielyan, M. Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hassall, N.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Jawalkar, S. S.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Konczykowski, P.; Kubarovsky, V.; Kuleshov, S. V.; Kuznetsov, V.; Livingston, K.; MacGregor, I. J. D.; Martinez, D.; McAndrew, J.; McKinnon, B.; Mikhailov, K.; Mirazita, M.; Mokeev, V.; Moreno, B.; Moriya, K.; Morrison, B.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Nepali, C. S.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niroula, M. R.; Osipenko, M.; Ostrovidov, A. I.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Pereira, S. Anefalos; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Salamanca, J.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Strakovsky, I. I.; Strauch, S.; Tang, W.; Taylor, C. E.; Tedeschi, D. J.; Tkachenko, S.; Ungaro, M.; Watts, D. P.; Vernarsky, B.; Vineyard, M. F.; Voutier, E.; Weinstein, L. B.; Wood, M. H.; Yegneswaran, A.; Zhang, J.; Zhao, B.; Zhao, Z. W.

    2010-08-06

    Here, high-statistics measurements of differential cross sections and recoil polarizations for the reaction $\\gamma p \\rightarrow K^+ \\Sigma^0$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($\\sqrt{s}$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $K^{+}p\\pi^{-}$($\\gamma$) and $K^{+}p$($\\pi^-,\\gamma$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $\\sqrt{s}$ coverage. Above $\\sqrt{s} \\approx 2.5$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($P_\\Sigma$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $P_\\Sigma$ is of the same magnitude but opposite sign as $P_\\Lambda$, in agreement with the static SU(6) quark model prediction of $P_\\Sigma \\approx -P_\\Lambda$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $P_\\Sigma$ and $P_\\Lambda$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.

  1. Climate Relevant Processes On The Barents Shelf

    NASA Astrophysics Data System (ADS)

    Hatten, K.; Schrum, C.; Harms, I.

    The Artic Shelf, and especially the Barents Shelf , are key regions in the North At- lantic climate system. Climatic relevant processes on the shelf are on the one hand the water mass transformation and on the other hand the strong air/sea exchange. Air/sea interaction and resulting sea ice development cause water mass transformation and de- velopment of cold and salty deep water on the shelf region. The outflow of this dense water mass into the Arctic Ocean is responsible for the stabilization of the permanent halocline in the Arctic Ocean and therefore for the isolation of the cold and fresh arctic surface water from the saltier and warmer Atlantic deep water in the Arctic Ocean, and thus for preservation of the Arctic Ocean sea ice. The second climatic relevant process, the direct air/sea exchange, i.e. the annual mean heat release to the atmosphere, plays a key role as energy source for the atmosphere. Both processes are subject to strong inter-annual variability and influenced by mesoscale structures in the ice field, and thus can be assumed to be less good described by the large scale atmospheric and oceanic models. This was the background of the development of a regional eddy resolving model of the Barents Sea. Results of a multi-year model simulation will be presented and related to flux estimates from global atmospheric re-analysis, to highlight the in- fluence of mesoscale variability in the sea ice coverage on the air sea exchange and on the water mass transformation.

  2. Exact calculation of the angular momentum loss, recoil force, and radiation intensity for an arbitrary source in terms of electric, magnetic, and toroid multipoles.

    PubMed

    Radescu, E E; Vaman, G

    2002-04-01

    An exact calculation of the radiation intensity, angular momentum loss, and the recoil force for the most general type of source, characterized by electric, magnetic, and toroid multipole moments and radii of any multipolarity and an arbitrary time dependence, is presented. The results are expressed in terms of time derivatives of the multipole moments and mean radii of the corresponding distributions. Although quite cumbersome, the formulas found by us represent exact results in the correct multipole analysis of configurations of charges and currents that contain toroidal sources. So the longstanding problem in classical electrodynamics of relating the radiation properties of a system to quantities completely describing its internal electromagnetic structure is thereby exactly solved. By particularizations to the first multipole contributions, corrections to the familiar formulas from books are found, mostly on account of the toroid moments and their interference with the usual electric and magnetic ones.

  3. The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF.

    PubMed

    Casey, D T; Frenje, J A; Séguin, F H; Li, C K; Rosenberg, M J; Rinderknecht, H; Manuel, M J-E; Gatu Johnson, M; Schaeffer, J C; Frankel, R; Sinenian, N; Childs, R A; Petrasso, R D; Glebov, V Yu; Sangster, T C; Burke, M; Roberts, S

    2011-07-01

    A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.

  4. Lifetime measurement of candidate chiral doublet bands in the {sup 103,104}Rh isotopes with the recoil-distance Doppler-shift method in inverse kinematics

    SciTech Connect

    Suzuki, T.; Rainovski, G.; Koike, T.; Ahn, T.; Costin, A.; Carpenter, M. P.; Janssens, R. V. F.; Lister, C. J.; Zhu, S.; Danchev, M.; Dewald, A.; Joshi, P.; Wadsworth, R.; Moeller, O.; Pietralla, N.; Shinozuka, T.; Timar, J.; Vaman, C.

    2008-09-15

    Lifetimes of chiral candidate structures in {sup 103,104}Rh were measured using the recoil distance Doppler-shift method. The Gammasphere detector array was used in conjunction with the Cologne plunger device. Excited states of {sup 103,104}Rh were populated by the {sup 11}B({sup 96}Zr,4n){sup 103}Rh and {sup 11}B({sup 96}Zr,3n){sup 104}Rh fusion-evaporation reactions in inverse kinematics. Three and five lifetimes of levels belonging to the proposed chiral doublet bands are measured in {sup 103}Rh and {sup 104}Rh, respectively. The previously observed even-odd spin dependence of the B(M1)/B(E2) values is caused by the variation in the B(E2) values, whereas the B(M1) values decrease as a function of spin.

  5. A closer look at 40Ar/39Ar systematics of illite, recoil, retention ages, total gas ages, and a new correction method

    NASA Astrophysics Data System (ADS)

    Fitz-Diaz, E.; Hall, C. M.; van der Pluijm, B.

    2013-12-01

    One of the fundamentals of 40Ar-39Ar systematics of illite considers the effects of 39Ar recoil (ejection of 39Ar from tiny illite crystallites during the nuclear reaction 39K(n,p)39Ar), for which sample vacuum encapsulation prior to irradiation has been used since the 1990's. This technique separately measures the fraction of recoiled 39Ar and the Ar (39Ar and 40Ar) retained within illite crystals as they degas during step heating in vacuum. Total-gas ages (TGA) are calculated by using both recoiled and retained argon, while retention ages (RA) only involve retained Ar. Observations in numerous natural examples have shown that TGA fit stratigraphic constraints of geological processes when the average illite crystallite thickness (ICT) is smaller than 10nm, and that RA better matches these constrains for larger ICTs. Illite crystals with ICT >50nm show total gas and retention ages within a few My and they are identical, within analytical error, when ICT exceeds 150nm. We propose a new age correction that takes into account the average ICT and corresponding recoil for a sample , with such corrected ages (XCA) lying between the TGA and RA end-member ages. We apply this correction to samples containing one generation of illite and it particularly affects illite populations formed in the anchizone, with typical ICT values between 10-40nm. We analyzed bentonitic samples (S1, S2 and S3) from sites in Cretaceous carbonates in the front of the Monterrey salient in northern Mexico. Four size fractions (<0.05, 0.05-0.2, 0.2-1 & 1-2 μm) were separated, analyzed with XRD and dated by Ar-Ar. XRD analysis provides mineralogic characterization, illite polytype quantification, and illite crystallite thickness (ICT) determination using half-height peak width (illite crystallinity) and the Scherrer equation. All samples contain illite as the main mineral phase, ICT values between 8-27nm, from fine to coarser grain size fractions. Ages show a range in TGA among the different size

  6. The Electric Form Factor of the Neutron via Recoil Polarimetry to Q{sup 2} = 1.47 (GeV/c){sup 2}

    SciTech Connect

    Plaster, Bradley; Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Arenhovel, Hartmuth; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Brewer, Paul; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Howell, Calvin; Gueye, Paul; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Semenova, Irina; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng

    2003-07-30

    The Jefferson Laboratory E93-038 collaboration conducted measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G{sup n}E/G{sup n}M, via recoil polarimetry from the quasielastic {sup 2}H({rvec e},e/{rvec n}){sup 1}H reaction at three values of Q{sup 2} [viz., 0.45, 1.15, and 1.47 (GeV/c){sup 2}] in Hall C of the Thomas Jefferson National Accelerator Facility. The preliminary results for G{sup n}E at Q{sup 2} = 0.45 and 1.15 (GeV/c){sup 2} are consistent with the Galster parameterization; however, the preliminary result for G{sup n}E at Q{sup 2} = 1.47 (GeV/c){sup 2} lies slightly above the Galster parameterization.

  7. Measurement of the recoil polarization in the p(e-->, e'p-->)pi(0) reaction at the Delta(1232) resonance.

    PubMed

    Pospischil, T; Bartsch, P; Baumann, D; Bermuth, J; Böhm, R; Bohinc, K; Derber, S; Ding, M; Distler, M; Drechsel, D; Elsner, D; Ewald, I; Friedrich, J; Friedrich, J M; Geiges, R; Hedicke, S; Jennewein, P; Kahrau, M; Kamalov, S S; Klein, F; Krygier, K W; Lac, J; Liesenfeld, A; McIntyre, J; Merkel, H; Merle, P; Müller, U; Neuhausen, R; Potokar, M; Ransome, R D; Rohe, D; Rosner, G; Schmieden, H; Seimetz, M; Sirca, S; Sick, I; Süle, A; Tiator, L; Wagner, A; Walcher, T; Warren, G A; Weis, M

    2001-04-01

    The recoil proton polarization has been measured in the p(e-->,e'p-->)pi(0) reaction in parallel kinematics around W = 1232 MeV, Q2 = 0.121 (GeV/c)2, and epsilon = 0.718 using the polarized cw electron beam of the Mainz Microtron. All three proton polarization components, Px/P(e) = (-11.4+/-1.3+/-1.4)%, P(y) = (-43.1+/-1.3+/-2.2)%, and P(z)/P(e) = (56.2+/-1.5+/-2.6)%, could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4+/-0.7(stat)+/-0.8(syst))%, was determined from Px in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal-to-transverse response is discussed.

  8. B → Dℓν form factors at nonzero recoil and |Vcb| from 2+1-flavor lattice QCD

    SciTech Connect

    Bailey, Jon A.

    2015-08-10

    We present the first unquenched lattice-QCD calculation of the hadronic form factors for the exclusive decay B¯→Dℓν¯ at nonzero recoil. We carry out numerical simulations on 14 ensembles of gauge-field configurations generated with 2+1 flavors of asqtad-improved staggered sea quarks. The ensembles encompass a wide range of lattice spacings (approximately 0.045 to 0.12 fm) and ratios of light (up and down) to strange sea-quark masses ranging from 0.05 to 0.4. For the b and c valence quarks we use improved Wilson fermions with the Fermilab interpretation, while for the light valence quarks we use asqtad-improved staggered fermions. We extrapolate our results to the physical point using rooted staggered heavy-light meson chiral perturbation theory. We then parametrize the form factors and extend them to the full kinematic range using model-independent functions based on analyticity and unitarity. We present our final results for f+(q2) and f0(q2), including statistical and systematic errors, as coefficients of a series in the variable z and the covariance matrix between these coefficients. We then fit the lattice form-factor data jointly with the experimentally measured differential decay rate from BABAR to determine the CKM matrix element, |Vcb|=(39.6 ± 1.7QCD+exp ± 0.2QED) × 10–3. As a byproduct of the joint fit we obtain the form factors with improved precision at large recoil. In conclusion, we use them to update our calculation of the ratio R(D) in the Standard Model, which yields R(D)=0.299(11).

  9. Review of Recent Literature Relevant to the Environmental Effects of Marine and Hydrokinetic Energy Devices; Task 2.1.3: Effects on Aquatic Organisms - Fiscal Year 2012 Progress Report

    SciTech Connect

    Kropp, Roy K.

    2013-01-01

    A literature search was conducted by using the Web of Science® databases component of the ISI Web of KnowledgeSM to identify recent articles that would be useful to help assess the potential environmental effects of renewable energy development in the ocean, with emphasis on seabirds and fish. Several relatively recent general review articles that included possible effects on seabirds and fish were examined to begin the search process. From these articles, several general topics of potential environmental effects on seabirds and fish were derived. These topics were used as the primary search factors. Additional sources were identified by cross-checking the Web of Science databases for articles that cited the review articles. It also became clear that the potential effects frequently w

  10. Nuclear models relevant to evaluation

    SciTech Connect

    Arthur, E.D.; Chadwick, M.B.; Hale, G.M.; Young, P.G.

    1991-01-01

    The widespread use of nuclear models continues in the creation of data evaluations. The reasons include extension of data evaluations to higher energies, creation of data libraries for isotopic components of natural materials, and production of evaluations for radiative target species. In these cases, experimental data are often sparse or nonexistent. As this trend continues, the nuclear models employed in evaluation work move towards more microscopically-based theoretical methods, prompted in part by the availability of increasingly powerful computational resources. Advances in nuclear models applicable to evaluation will be reviewed. These include advances in optical model theory, microscopic and phenomenological state and level density theory, unified models that consistently describe both equilibrium and nonequilibrium reaction mechanism, and improved methodologies for calculation of prompt radiation from fission. 84 refs., 8 figs.

  11. "Gastric cytoprotection" is still relevant.

    PubMed

    Szabo, Sandor

    2014-12-01

    rapid vascular changes (e.g. increased VP and blood flow), followed by cellular events (e.g. infiltration by acute and chronic inflammatory cells). Thus, PG and histamine, by increasing VP create a perivascular edema that dilutes and delays toxic agents reaching the subepithelial capillaries. Otherwise, damaging chemicals may induce severe early vascular injury resulting in blood flow stasis, hypoxia, and necrosis of surrounding epithelial and mesenchymal cells. In this complex response, increased mucus and/or bicarbonate secretion seem to cause luminal dilution of gastrotoxic chemicals that is further reinforced by a perivascular, histodilutional component. This mechanistic explanation would encompass the protective actions of diverse agents as PG, small doses of histamine, motility stimulants, and dilute irritants (i.e. "adaptive cytoprotection"). Thus, although markedly increased VP is pathologic, slight increase in VP seems to be protective, that is, a key element in the complex pathophysiologic response during acute gastroprotection. Over the years, "gastroprotection" was also applied to accelerated healing of chronic gastroduodenal ulcers without reduction of acid secretion. The likely main mechanism here is the binding of angiogenic growth factors (e.g. basic fibroblast growth factor, vascular endothelial growth factor) to the heparin-like structures of sucralfate and sofalcone. Thus, despite intensive research of the last 30 years, gastroprotection is incompletely understood, and we are still far away from effectively treating Helicobacter pylori-negative ulcers and preventing nonsteroidal anti-inflammatory drugs-caused erosions and ulcers in the upper and lower gastrointestinal tract; hence "gastric cytoprotection" research is still relevant.

  12. Biology relevant to space radiation

    SciTech Connect

    Fry, R.J.M.

    1997-04-30

    There are only very limited data on the health effects to humans from the two major components of the radiations in space, namely protons and heavy ions. As a result, predictions of the accompanying effects must be based either on (1) data generated through studies of experimental systems exposed on earth at rates and fluences higher than those in space, or (2) extrapolations from studies of gamma and x rays. Better information is needed about the doses, dose rates, and the energy and LET spectra of the radiations at the organ level that are anticipated to be encountered during extended space missions. In particular, there is a need for better estimates of the relationship between radiation quality and biological effects. In the case of deterministic effects, it is the threshold that is important. The possibility of the occurrence of a large solar particle event (SPE) requires that such effects be considered during extended space missions. Analyses suggest, however, that it is feasible to provide sufficient shielding so as to reduce such effects to acceptable levels, particularly if the dose rates can be limited. If these analyses prove correct, the primary biological risks will be the stochastic effects (latent cancer induction). The contribution of one large SPE to the risk of stochastic effects while undesirable will not be large in comparison to the potential total dose on a mission of long duration.

  13. 3-Hydroxy-3-methylglutaric and 3-methylglutaric acids impair redox status and energy production and transfer in rat heart: relevance for the pathophysiology of cardiac dysfunction in 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency.

    PubMed

    da Rosa, Mateus Struecker; Seminotti, Bianca; Ribeiro, César Augusto João; Parmeggiani, Belisa; Grings, Mateus; Wajner, Moacir; Leipnitz, Guilhian

    2016-09-01

    3-Hydroxy-3-methylglutaryl-coenzyme A lyase (HL) deficiency is characterized by tissue accumulation of 3-hydroxy-3-methylglutaric (HMG), and 3-methylglutaric (MGA) acids. Affected patients present cardiomyopathy, whose pathomechanisms are not yet established. We investigated the effects of HMG and MGA on energy and redox homeostasis in rat heart using in vivo and in vitro models. In vivo experiments showed that intraperitoneal administration of HMG and MGA decreased the activities of the respiratory chain complex II and creatine kinase (CK), whereas HMG also decreased the activity of complex II-III. Furthermore, HMG and MGA injection increased reactive species production and carbonyl formation, and decreased glutathione concentrations. Regarding the enzymatic antioxidant defenses, HMG and MGA increased glutathione peroxidase (GPx) and glutathione reductase (GR) activities, while only MGA diminished the activities of superoxide dismutase (SOD) and catalase, as well as the protein content of SOD1. Pre-treatment with melatonin (MEL) prevented MGA-induced decrease of CK activity and SOD1 levels. In vitro results demonstrated that HMG and MGA increased reactive species formation, induced lipid peroxidation and decreased glutathione. We also verified that reactive species overproduction and glutathione decrease provoked by HMG and MGA were abrogated by MEL and lipoic acid (LA), while only MEL prevented HMG- and MGA-induced lipoperoxidation. Allopurinol (ALP) also prevented reactive species overproduction caused by both metabolites. Our data provide solid evidence that bioenergetics dysfunction and oxidative stress are induced by HMG and MGA in heart, which may explain the cardiac dysfunction observed in HL deficiency, and also suggest that antioxidant supplementation could be considered as adjuvant therapy for affected patients.

  14. Antioxidant relevance to human health.

    PubMed

    Wahlqvist, Mark L

    2013-01-01

    Human ecology requires both oxygen and water with the generation from food of an immediate energy source, ATP, by oxidative phosphorylation. A continuing balance between oxidation and antioxidation is necessary for longer less-disabled lives, taking account of oxidative stresses and the critical roles of oxidants in defence against infection, tissue repair and signalling. Antioxidant capacity is derived both exogenously (from food, beverage and sunlight) and endogenously (from enzymatic and non-enzymatic pathways). A number of oxidant food factors service antioxidant metallo-enzymes. The capacity operates extra- or intracellularly. Uric acid is the major antioxidant in primate blood. Uric acid synthesis is increased by dietary fructose from fruit, sugary foods and drinks. This indirect antioxidant effect of fruit is separate from that attributable to its flavonoids. Alcohol also increases serum uric acid. Urate excess and retention is associated with disease. The high prevalence of hyperuricaemia in NE Asia presents a major public health dilemma in regard to putative benefits and risks. Foods with high antioxidant activity include berries, nuts and legumes, tomatoes and sweet potato leaves. Each of the antioxidants in these foods is pleiotropic being inter-alia anti-inflammatory, anti-angiogenic or anti-neoplastic. Moreover, food matrices and patterns contribute to the safety of antioxidant consumption. There is no evidence to date that isolated antioxidants as food supplements improve health outcomes or survival; and some that indicate unacceptable risk. Their use as biomarkers of food cannot justify their isolated use. Nevertheless, a spectrum of dietary pluripotential antioxidants for tissues, metabolic and immune systems is advantageous.

  15. Processes with neutral hydrogen and deuterium molecules relevant to edge plasma in tokamaks

    NASA Astrophysics Data System (ADS)

    Cadez, I.; Markelj, S.; Rupnik, Z.; Pelicon, P.

    2008-07-01

    Detailed understanding and characterization of plasma-wall interaction and edge plasma in present tokamaks and future fusion reactors is becoming more and more important due to the ITER project. Involved processes determine the physical and chemical sputtering of the wall material, fuel retention in exposed material, edge plasma properties, disruption phenomena etc. Neutral hydrogen atoms and molecules are present in the edge plasma. They are continuously generated by ion recombination on the wall of the fusion reactor and on the other plasma facing components and subsequently reemitted in the plasma. Neutral molecules are especially important for plasma detachment in tokamak divertors. The interaction of excited neutral molecules with the walls and their importance for the edge plasma is still not well understood since there are not many experimental studies of relevant processes. Moreover, spectroscopic results from tokamak edge plasma are dominated by processes involving ions and electrons, so that direct evidence of the influence of neutrals is difficult to extract. Direct correlation of the observed phenomena to the processes with neutrals is mainly possible by numerical simulations. We have constructed a set-up for vibrational spectroscopy of hydrogen molecules (H_2 and D_2) that is based on the properties of the dissociative electron attachment in hydrogen in order to facilitate dedicated experimental studies of relevant processes with hydrogen molecules. For the same purpose we also developed a technique for in-situ hydrogen depth profiling on the samples exposed to the controlled hydrogen atmosphere. This is done by Ion Beam Analytical (IBA) method ERAD (Elastic Recoil Detection Analysis), utilizing 4.2 MeV probing beam of ^7Li^2+ ions. A short description of experimental techniques and results on chemical erosion of graphite layers, production of vibrationally excited hydrogen molecules on tungsten and isotope exchange on tungsten are to be presented in

  16. Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

    PubMed

    Gonzalez-Ballester, David; Jurado-Oller, Jose Luis; Fernandez, Emilio

    2015-09-01

    Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2.

  17. Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

    PubMed

    Gonzalez-Ballester, David; Jurado-Oller, Jose Luis; Fernandez, Emilio

    2015-09-01

    Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2. PMID:25952745

  18. Culture, Relevance, and Schooling: Exploring Uncommon Ground

    ERIC Educational Resources Information Center

    Scherff, Lisa, Ed.; Spector, Karen, Ed.

    2011-01-01

    In "Culture, Relevance, and Schooling: Exploring Uncommon Ground," Lisa Scherff, Karen Spector, and the contributing authors conceive of culturally relevant and critically minded pedagogies in terms of opening up new spatial, discursive, and/or embodied learning terrains. Readers will traverse multiple landscapes and look into a variety of spaces…

  19. The Semantic Distance Model of Relevance Assessment.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1998-01-01

    Presents the Semantic Distance Model (SDM) of Relevance Assessment, a cognitive model of the relationship between semantic distance and relevance assessment. Discusses premises of the model such as the subjective nature of information and the metaphor of semantic distance. Empirical results illustrate the effects of semantic distance and semantic…

  20. 12 CFR 308.157 - Relevant considerations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Relevant considerations. 308.157 Section 308.157 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE RULES OF PRACTICE AND PROCEDURE Procedures and Standards Applicable to an Application Pursuant to Section 19 of the FDIA § 308.157 Relevant considerations....

  1. 12 CFR 108.11 - Relevant considerations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Relevant considerations. 108.11 Section 108.11 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY REMOVALS, SUSPENSIONS, AND PROHIBITIONS WHERE A CRIME IS CHARGED OR PROVEN § 108.11 Relevant considerations. (a) In determining...

  2. 12 CFR 508.11 - Relevant considerations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Relevant considerations. 508.11 Section 508.11 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY REMOVALS, SUSPENSIONS, AND PROHIBITIONS WHERE A CRIME IS CHARGED OR PROVEN § 508.11 Relevant considerations. (a) In determining...

  3. 12 CFR 108.11 - Relevant considerations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Relevant considerations. 108.11 Section 108.11 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY REMOVALS, SUSPENSIONS, AND PROHIBITIONS WHERE A CRIME IS CHARGED OR PROVEN § 108.11 Relevant considerations. (a) In determining...

  4. 12 CFR 508.11 - Relevant considerations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Relevant considerations. 508.11 Section 508.11 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY REMOVALS, SUSPENSIONS, AND PROHIBITIONS WHERE A CRIME IS CHARGED OR PROVEN § 508.11 Relevant considerations. (a) In determining...

  5. The light ion LMF and its relevance to IFE

    SciTech Connect

    Olson, R.E.; Allshouse, G.O.; Cook, D.L.; Lockner, T.R.; Mazarakis, M.G.; Olson, C.L.; Smith, D.L.

    1993-12-01

    The inertial confinement fusion (ICF) program at Sandia National Laboratories (SNL) is directed toward validating light ions as an efficient driver for ICF defense and energy applications. The light ion laboratory microfusion facility (LMF) is envisioned as a facility in which high gain ICF targets could be developed and utilized in defense-related experiments. The relevance of LMF technology to eventual inertial fusion energy (IFE) applications is assessed via a comparison of LMF technologies with those projected in the Light Ion Beam Reactor Assessment (LIBRA) conceptual reactor design study.

  6. Physics issues relevant during stagnation phase of the Z pinch

    NASA Astrophysics Data System (ADS)

    Yu, Edmund

    2006-10-01

    Wire-array Z pinches are the most powerful laboratory x-ray sources. However, the physics driving the stagnation phase, during which the pinch collapses on axis and subsequently radiates, remains somewhat mysterious. In particular the stagnated pinch resists undergoing radiative collapse, and the radiated energy is several times the kinetic energy of the imploding plasma. In recent years, a number of theories, as well as direct 3D numerical simulation, have been developed to address these phenomena. This work will highlight some of the physics issues relevant during this complicated phase of the Z pinch. Possibilities for future work will be discussed, and, with a little luck, performed.

  7. Turbulent energy exchange: Calculation and relevance for profile prediction

    SciTech Connect

    Candy, J.

    2013-08-15

    The anomalous heat production due to turbulence is neither routinely calculated in nonlinear gyrokinetic simulations nor routinely retained in profile prediction studies. In this work, we develop a symmetrized method to compute the exchange which dramatically reduces the intermittency in the time-dependent moment, thereby improving the accuracy of the time-average. We also examine the practical impact on transport-timescale simulations, and show that the exchange has only a minor impact on profile evolution for a well-studied DIII-D discharge.

  8. Intraseasonal Variations in Tropical Energy Balance: Relevance to Climate Sensitivity?

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Ramey, Holly S.; Roberts, Jason B.

    2011-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of organization for tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, here we examine the projection of ISOs on the tropically-averaged heat and moisture budget. One unresolved question concerns the degree to which observable variations in the "fast" processes (e.g. convection, radiative / turbulent fluxes) can inform our understanding of feedback mechanisms operable in the context of climate change. Our analysis use daily data from satellite observations, the Modern Era analysis for Research and Applications (MERRA), and other model integrations to address these questions: (i) How are tropospheric temperature variations related to that tropical deep convection and the associated ice cloud fractional amount (ICF), ice water path (IWP), and properties of warmer liquid clouds? (ii) What role does moisture transport play vis-a-vis ocean latent heat flux in enabling the evolution of deep convection to mediate PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007 GRL ) whereby a composite time series of various quantities over 60+ ISO events is built using tropical mean tropospheric temperature signal as a reference to which the variables are related at various lag times (from -30 to +30 days). The area of interest encompasses the global oceans between 20oN/S. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. The decrease in net TOA radiation that develops after the peak in deep convective rainfall, is part of the response that constitutes a "discharge" / "recharge" mechanism that facilitates tropical heat balance maintenance on these time scales. However, water vapor and hydrologic scaling relationships for this mode of variability cast doubt on the utility of ISO variations as proxies for climate sensitivity response to external radiatively forced (e.g. greenhouse gas-induced) climate change.

  9. Coalescing binary systems of compact objects to (post)5/2-Newtonian order. II. Higher-order wave forms and radiation recoil

    NASA Astrophysics Data System (ADS)

    Wiseman, Alan G.

    1992-08-01

    Using formulas developed by Blanchet, Damour, and Iyer, we obtain a symmetric trace-free multipolar expansion of the gravitational radiation from a coalescing binary system which is sufficiently accurate to allow a post-Newtonian calculation of the linear momentum carried off by the gravitational radiation prior to a binary coalescence. We briefly examine the structure of the post-quadrupole corrections to the wave form for an orbiting binary system near coalescence. The post-Newtonian correction to the momentum ejection allows a more accurate calculation of the system recoil velocity (radiation rocket effect). We find that the higher-order correction actually reduces the net momentum ejection. Furthermore, the post-Newtonian correction to the momentum flux has only a weak dependence on the mass ratio of the objects in the binary, suggesting that previous test mass calculations may be quite accurate. We estimate an upper bound of the center-of-mass velocity of 1 km s-1 for neutron star binaries very near coalescence. In an appendix we give a self-contained (albeit less rigorous) derivation of the gravitational wave form using the Epstein-Wagoner formalism.

  10. Measurement of |Vcb| and the Form-Factor Slope for BBar -> Dlnu Decays on the Recoil of Fully Reconstructed B Mesons

    SciTech Connect

    Aubert, B

    2008-08-21

    We present a measurement of the CKM matrix element |V{sub cb}| and the form-factor slope {rho}{sup 2} for {bar B} {yields} D{ell}{sup -} {bar {nu}}{sub {ell}} decays based on 417 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector. The semileptonic decays are selected in B{bar B} events in which the hadronic decay of the second B meson is fully reconstructed. From the measured differential decay rate of the signal decay we determine G(1)|V{sub cb}| = (43.0 {+-} 1.9 {+-} 1.4) x 10{sup -3}, {rho}{sup 2} = 1.20 {+-} 0.09 {+-} 0.04, where G(1) is the hadronic form factor at the point of zero recoil. Using a lattice calculation for G(1) we extract |V{sub cb}| = (39.8 {+-} 1.8 {+-} 1.3 {+-} 0.9) x 10{sup -3}, where the stated errors refer to the statistical, systematic, and form factor uncertainties. We also present a measurement of the exclusive branching fractions, {Beta}(B{sup -} {yields} D{sup 0} {ell}{sup -} {bar {nu}}{sub {ell}}) = (2.31 {+-} 0.08 {+-} 0.07)% and {Beta}({bar B}{sup 0} {yields} D{sup +} {ell}{sup -} {bar {nu}}{sub {ell}}) = (2.23 {+-} 0.11 {+-} 0.08)%.

  11. Preparation of targets for the gas-filled recoil separator TASCA by electrochemical deposition and design of the TASCA target wheel assembly

    NASA Astrophysics Data System (ADS)

    Eberhardt, K.; Brüchle, W.; Düllmann, Ch. E.; Gregorich, K. E.; Hartmann, W.; Hübner, A.; Jäger, E.; Kindler, B.; Kratz, J. V.; Liebe, D.; Lommel, B.; Maier, H.-J.; Schädel, M.; Schausten, B.; Schimpf, E.; Semchenkov, A.; Steiner, J.; Szerypo, J.; Thörle, P.; Türler, A.; Yakushev, A.

    2008-06-01

    The Transactinide Separator and Chemistry Apparatus (TASCA) is a recoil separator with maximized transmission designed for performing advanced chemical studies as well as nuclear reaction and structure investigations of the transactinide elements ( Z>103) on a one-atom-at-a-time basis. TASCA will provide a very clean transactinide fraction with negligible contamination of lighter elements from nuclear side reactions in the target. For TASCA a new target chamber was designed and built at GSI including the rotating target wheel assembly ARTESIA for beam intensities up to 2 μA (particle). For the production of longer-lived isotopes of neutron-rich heavier actinide and transactinide elements, hot fusion reactions with actinide targets are required. Here, possible target materials range from thorium up to curium or even heavier elements. For the deposition of lanthanide and actinide elements on thin aluminum and titanium backings by means of Molecular Plating (MP), a new deposition cell has been constructed that allows precise temperature control of the organic solvent and stirring of the solution. The electrode geometry ensures homogeneity of the electric field inside the cell. With the new set-up, holmium and gadolinium layers (500 μg/cm 2) on 2-5 μm thin titanium backings have been produced with deposition yields of the order of 90%. Systematic investigations are under way to further optimize the deposition conditions for other lanthanide and actinide elements including uranium and plutonium on different backing materials.

  12. B{yields}D*l{nu} form factor at zero recoil from three-flavor lattice QCD: A model independent determination of |V{sub cb}|

    SciTech Connect

    Bernard, C.; DeTar, C.; Levkova, L.; Di Pierro, M.; El-Khadra, A. X.; Evans, R. T.; Gamiz, E.; Freeland, E. D.; Gottlieb, Steven; Heller, U. M.; Hetrick, J. E.; Kronfeld, A. S.; Mackenzie, P. B.; Okamoto, M.; Simone, J.; Van de Water, R. S.; Laiho, J.; Sugar, R.; Toussaint, D.

    2009-01-01

    We present the first lattice QCD calculation of the form factor for B{yields}D*l{nu} with three flavors of sea quarks. We use an improved staggered action for the light valence and sea quarks (the MILC configurations), and the Fermilab action for the heavy quarks. The form factor is computed at zero recoil using a new double ratio method that yields the form factor more directly than the previous Fermilab method. Other improvements over the previous calculation include the use of much lighter light-quark masses, and the use of lattice (staggered) chiral perturbation theory in order to control the light-quark discretization errors and chiral extrapolation. We obtain for the form factor, F{sub B{yields}}{sub D*}(1)=0.921(13)(20), where the first error is statistical and the second is the sum of all systematic errors in quadrature. Applying a 0.7% electromagnetic correction and taking the latest PDG average for F{sub B{yields}}{sub D*}(1)|V{sub cb}| leads to |V{sub cb}|=(38.7{+-}0.9{sub exp}{+-}1.0{sub theo})x10{sup -3}.

  13. Dynamic Measurements of Hydrogen and Lithium Distributions in Lithium-Cobalt-Oxide Films with Charging and Heating Using Elastic Recoil Detection Techniques

    NASA Astrophysics Data System (ADS)

    Tsuchiya, B.; Morita, K.; Iriyama, Y.; Majima, T.; Tsuchida, H.

    The migrations of lithium (Li) as well as hydrogen (H) in multi-layers thin films of Au/LiCoO2 (thickness: approximately 42 nm/80 nm), deposited onto one face of Li1.4Ti2Si0.4P2.6O12-AlPO4 (LATP) substrates, were dynamically observed with electric charging as well as isochronal annealing in vacuum by combining elastic recoil detection (ERD) analysis with Rutherford backscattering spectrometry (RBS)with 9.0-MeV O4+ ion-probe beams. The ERD spectra clearly revealed that Li atoms of approximately 9.4 at% migrated from the LiCoO2 surface to the LiCoO2/LATP interface with H absorption by a charge of approximately 0.48 e/cm2, which the acquiredvoltage was1.65 V. In addition, the diffusion of Li atoms to the LATP bulk occurred with H release by isochronal annealing at only 323 K for 10 min.The presence of H significantly influences the Li+ ion conduction for the Li-battery systems.

  14. Gas phase chemical studies of superheavy elements using the Dubna gas-filled recoil separator - Stopping range determination

    NASA Astrophysics Data System (ADS)

    Wittwer, D.; Abdullin, F. Sh.; Aksenov, N. V.; Albin, Yu. V.; Bozhikov, G. A.; Dmitriev, S. N.; Dressler, R.; Eichler, R.; Gäggeler, H. W.; Henderson, R. A.; Hübener, S.; Kenneally, J. M.; Lebedev, V. Ya.; Lobanov, Yu. V.; Moody, K. J.; Oganessian, Yu. Ts.; Petrushkin, O. V.; Polyakov, A. N.; Piguet, D.; Rasmussen, P.; Sagaidak, R. N.; Serov, A.; Shirokovsky, I. V.; Shaughnessy, D. A.; Shishkin, S. V.; Sukhov, A. M.; Stoyer, M. A.; Stoyer, N. J.; Tereshatov, E. E.; Tsyganov, Yu. S.; Utyonkov, V. K.; Vostokin, G. K.; Wegrzecki, M.; Wilk, P. A.

    2010-01-01

    Currently, gas phase chemistry experiments with heaviest elements are usually performed with the gas-jet technique with the disadvantage that all reaction products are collected in a gas-filled thermalisation chamber adjacent to the target. The incorporation of a physical preseparation device between target and collection chamber opens up the perspective to perform new chemical studies. But this approach requires detailed knowledge of the stopping force (STF) of the heaviest elements in various materials. Measurements of the energy loss of mercury (Hg), radon (Rn), and nobelium (No) in Mylar and argon (Ar) were performed at low kinetic energies of around (40-270) keV per nucleon. The experimentally obtained values were compared with STF calculations of the commonly used program for calculating stopping and ranges of ions in matter (SRIM). Using the obtained data points an extrapolation of the STF up to element 114, eka-lead, in the same stopping media was carried out. These estimations were applied to design and to perform a first chemical experiment with a superheavy element behind a physical preseparator using the nuclear fusion reaction 244Pu( 48Ca; 3n) 289114. One decay chain assigned to an atom of 285112, the α-decay product of 289114, was observed.

  15. Measurement of the proton form factors ratio G{sub E}/G{sub M} to Q{sup 2} = 5.6 GeV{sup 2} by recoil polarimetry

    SciTech Connect

    Olivier Gayou

    2002-04-01

    In this thesis, we present the results of the experiment E99-007, which measured the ratio of the electric to magnetic form factors of the proton to the four momentum transfer square Q{sup 2} = 5.6 GeV{sup 2}, by recoil polarimetry. Data were taken in 2000 at the Thomas Jefferson National Accelerator Facility in Virginia, USA. A 4.6 GeV polarized electron beam was scattered off a cryogenic hydrogen target. The polarization of the recoil proton was measured in the Focal Plane Polarimeter, located after one of the two High Resolution Spectrometers in the hall. The ratio of the transverse to longitudinal components of the recoil proton polarization is proportional to the ratio of the form factors. Elastic events were selected by detecting the scattered electron in a large acceptance lead-glass calorimeter. The main result of this experiment is the linear decrease of the form factor ratio with increasing Q{sup 2}, corresponding to different spatial distributions of the electric charge and the magnetization. Numerous theoretical calculations show that relativistic effects, such as mixing of spin states due to Lorentz boosts, are important to account for the observed data in this critical intermediate kinematic region.

  16. Meeting the Challenges of Diversity and Relevance.

    ERIC Educational Resources Information Center

    Schwan-Smith, Margaret; Silver, Edward A.

    1995-01-01

    Discusses the QUASAR Project, which has worked with middle school teachers in disadvantaged communities in order to help increase the relevance of mathematics by making connections between the mathematics taught in school and the lives of students. (16 references) (MKR)

  17. 33 CFR 51.8 - Relevant considerations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... GUARD DISCHARGE REVIEW BOARD § 51.8 Relevant considerations. In determining the equity and propriety of... applicant's capability to serve, the DRB considers such factors as the applicant's age and...

  18. Sandia programs relevant to microelectronics fabrication

    SciTech Connect

    Picraux, S.T.; Vook, F.L.; Gregory, B.L.

    1987-04-01

    This report was prepared for the Semiconductor Industry and the National Laboratories Workshop held at the National Academy of Sciences, Washington, DC, February 24, 1987. It details the current Sandia program activities relevant to microelectronics fabrication.

  19. Relevance is Primary in Secondary Chemistry.

    ERIC Educational Resources Information Center

    Zoller, Uri

    1985-01-01

    Describes how relevant aspects of environmental education can be integrated within the framework of contemporary high school chemistry. Examples which show how students can examine the chemical consequences of such social factors as smoking and drinking are provided. (JN)

  20. Mother Goose Is Alive and Culturally Relevant.

    ERIC Educational Resources Information Center

    Crawley, Sharon

    1992-01-01

    Asserts that Mother Goose rhymes are culturally relevant. Offers ways in which Mother Goose can be used in the classroom. Discusses activities for language arts, movement, art, music, science, and mathematics instruction. (PRA)

  1. Text Visualization using Light and Shadow based on Topic Relevance

    NASA Astrophysics Data System (ADS)

    Nishihara, Yoko; Sato, Keita; Sunayama, Wataru

    There are so many opportunities to transmit text information on the Web. Since texts on the Web are not always written by professional writers, those may not be coherent or may be hard to be comprehended. Therefore, we should take too much time and energy to grasp topic relevance of a text. This paper describes HINATA system that visualizes texts using light and shadow based on topic relevance. Topic is defined as a set of words such as nouns contained in a title of a text. The light expresses sentences related to a topic, and the shadow expresses sentences unrelated to a topic. This visualization method efficiently supports users for finding the parts related to a topic, and for grasping relations between sentences of a text and a topic. Experimental results showed that the proposed system could support users for understanding how a text was related to a topic.

  2. Effect of fatigue loading on structure and functional behaviour of fascicles from energy-storing tendons.

    PubMed

    Thorpe, Chavaunne T; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2014-07-01

    Tendons can broadly be categorized according to their function: those that act purely to position the limb and those that have an additional function as energy stores. Energy-storing tendons undergo many cycles of large deformations during locomotion, and so must be able to extend and recoil efficiently, rapidly and repeatedly. Our previous work has shown rotation in response to applied strain in fascicles from energy-storing tendons, indicating the presence of helical substructures which may provide greater elasticity and recovery. In the current study, we assessed how preconditioning and fatigue loading affect the ability of fascicles from the energy-storing equine superficial digital flexor tendon to extend and recoil. We hypothesized that preconditioned samples would exhibit changes in microstructural strain response, but would retain their ability to recover. We further hypothesized that fatigue loading would result in sample damage, causing further alterations in extension mechanisms and a significant reduction in sample recovery. The results broadly support these hypotheses: preconditioned samples showed some alterations in microstructural strain response, but were able to recover following the removal of load. However, fatigue loaded samples showed visual evidence of damage and exhibited further alterations in extension mechanisms, characterized by decreased rotation in response to applied strain. This was accompanied by increased hysteresis and decreased recovery. These results suggest that fatigue loading results in a compromised helix substructure, reducing the ability of energy-storing tendons to recoil. A decreased ability to recoil may lead to an impaired response to further loading, potentially increasing the likelihood of injury.

  3. Energy.

    ERIC Educational Resources Information Center

    Shanebrook, J. Richard

    This document describes a course designed to acquaint students with the many societal and technological problems facing the United States and the world due to the increasing demand for energy. The course begins with a writing assignment that involves readings on the environmental philosophy of Native Americans and the Chernobyl catastrophe.…

  4. A Search for the Rare Leptonic B- to tau- anti-neutrino Recoiling against B+ to Decays to anti-D*0 l+ Lepton-neutrino

    SciTech Connect

    Datta, Mousumi; /Wisconsin U., Madison

    2006-10-17

    This thesis describes a search for the decay B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}} in 231.8 x 10{sup 6} {Upsilon}(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B{sup +} {yields} {bar D}*{sup 0} {ell}{sup +}{nu}{sub {ell}}) is selected, and in the recoil a search for B{sup -} {yields} {tau}{sup -} {bar {nu}}{sub {tau}} signal is performed in the following {tau} decay modes: {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {tau}{sup -} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{pi}{sup 0}{nu}{sub {tau}}, and {tau}{sup -} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}}. They find no evidence of signal, and they set a preliminary upper limit on the branching fraction of {beta}(B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}}) < 2.8 x 10{sup -4} at the 90% confidence level (CL). This result is then combined with a statistically independent BABAR search for B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}} to give a combined preliminary limit of {Beta}(B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}}) < 2.6 x 10{sup -4} at 90% CL.

  5. Large-deformation analysis of the elastic recoil of fibre layers in a Brinkman medium with application to the endothelial glycocalyx

    NASA Astrophysics Data System (ADS)

    Han, Yuefeng; Weinbaum, Sheldon; Spaan, Jos A. E.; Vink, Hans

    2006-05-01

    There is wide interest in the role of the endothelial surface layer (ESL) in transmitting blood shear stress to the intracellular cytoskeleton of the endothelial cell. However, very little is known about the mechanical properties of the glycocalyx or the flexural rigidity of the core proteins that comprise it. Vink, Duling & Spaan (FASEB J., vol. 13, 1999, p. A 11) measured the time-dependent restoration of the ESL after it had been nearly completely compressed by the passage of a white blood cell (WBC) in a tightly fitting capillary. Using this initial experiment, Weinbaum et al. (Proc. Natl. Acad. Sci. USA, vol. 100, 2003, p. 7988) predicted that the core proteins have a flexural rigidity EI of 700 pN nm(2) , which is ˜1/20 the measured value for an actin filament. However, their analysis assumes small deflections and only the fibre motion is considered. In the present paper we report additional experiments and apply large-deformation theory for ‘elastica’ to describe the restoration of the fibres in a Brinkman medium which absorbs fluid as the ESL expands. We find that there are two phases in the fibre recoil: an initial phase for large compressions where the ESL thickness is <0.36 its undisturbed thickness, and the ends of the fibres overlap and are parallel to the capillary wall; and a second phase where the fibres assume a shape that is close to the solutions for an elastic bar with linearly distributed vertical loading. The predicted time-dependent change in thickness of the ESL provides remarkably good agreement with experiment and yields an estimate of 490 pN nm(2) for the flexural rigidity EI of the core protein fibres, which is unexpectedly close to that predicted by the linear theory in Weinbaum et al. (2003).

  6. Recoil Polarization Measurements for Neutral Pion Electroproduction at Q^2=1 (GeV/c)^2 Near the Delta Resonance

    SciTech Connect

    James Kelly; et. Al.

    2005-09-01

    We measured angular distributions of differential cross section, beam analyzing power, and recoil polarization for neutral pion electroproduction at Q{sup 2} = 1.0 (GeV/c){sup 2} in 10 bins of W across the Delta resonance. A total of 16 independent response functions were extracted, of which 12 were observed for the first time. Comparisons with recent model calculations show that response functions governed by real parts of interference products are determined relatively well near 1.232 GeV, but variations among models is large for response functions governed by imaginary parts and for both increases rapidly with W. We performed a nearly model-independent multipole analysis that adjusts complex multipoles with high partial waves constrained by baseline models. Parabolic fits to the W dependence of the multipole analysis around the Delta mass gives values for SMR = (-6.61 +/- 0.18)% and EMR = (-2.87 +/- 0.19)% that are distinctly larger than those from Legendre analysis of the same data. Similarly, the multipole analysis gives Re(S0+/M1+) = (+7.1 +/- 0.8)% at W=1.232 GeV, consistent with recent models, while the traditional Legendre analysis gives the opposite sign because its truncation errors are quite severe. Finally, using a unitary isobar model (UIM), we find that excitation of the Roper resonance is dominantly longitudinal with S1/2 = (0.05 +/- 0.01) GeV{sup (-1/2)} at Q{sup 2}=1. The ReS0+ and ReE0+ multipoles favor pseudovector coupling over pseudoscalar coupling or a recently proposed mixed-coupling scheme, but the UIM does not reproduce the imaginary parts of 0+ multipoles well.

  7. Time-of-flight ERD with a 200 mm2 Si3N4 window gas ionization chamber energy detector

    NASA Astrophysics Data System (ADS)

    Julin, Jaakko; Laitinen, Mikko; Sajavaara, Timo

    2014-08-01

    Low energy heavy ion elastic recoil detection work has been carried out in Jyväskylä since 2009 using home made timing detectors, a silicon energy detector and a timestamping data acquisition setup forming a time-of-flight-energy telescope. In order to improve the mass resolution of the setup a new energy detector was designed to replace the silicon solid state detector, which suffered from radiation damage and had poor resolution for heavy recoils. In this paper the construction and operation of an isobutane filled gas ionization chamber with a 14 × 14 mm2 100 nm thick silicon nitride window are described. In addition to greatly improved energy resolution for heavy ions, the detector is also able to detect hydrogen recoils simultaneously in the energy range of 100-1000 keV. Additionally the detector has position sensitivity by means of timing measurement, which can be performed without compromising the performance of the detector in any other way. The achieved position sensitivity improves the depth resolution near the surface.

  8. Relevance of saddle-splay elasticity in complex nematic geometries.

    PubMed

    Kos, Žiga; Ravnik, Miha

    2016-01-28

    We demonstrate the relevance of saddle-splay elasticity in nematic liquid crystalline fluids in the context of complex surface anchoring conditions and the complex geometrical confinement. Specifically, nematic cells with patterns of surface anchoring and colloidal knots are shown as examples where saddle-splay free energy contribution can have a notable role which originates from nonhomogeneous surface anchoring and the varying surface curvature. Patterned nematic cells are shown to exhibit various (meta)stable configurations of nematic field, with relative (meta)stability depending on the saddle-splay. We show that for high enough values of saddle-splay elastic constant K24 a previously unstable conformation can be stabilised, more generally indicating that the saddle-splay can reverse or change the (meta)stability of various nematic structures affecting their phase diagrams. Furthermore, we investigate saddle-splay elasticity in the geometry of highly curved boundaries - the colloidal particle knots in nematic - where the local curvature of the particles induces complex spatial variations of the saddle-splay contributions. Finally, a nematic order parameter tensor based saddle-splay invariant is shown, which allows for the direct calculation of saddle-splay free energy from the Q-tensor, a possibility very relevant for multiple mesoscopic modelling approaches, such as Landau-de Gennes free energy modelling.

  9. High-energy photoproduction of rho and phi vector mesons

    SciTech Connect

    Callahan, P.H.

    1983-01-01

    We have studied the photoproduction of rho and phi vector mesons from hydrogen in the Fermilab broad band neutral beam. Forward going two particle final states were detected in a multiparticle spectrometer consisting of two analyzing magnets, a multiwire-proportional-chamber tracking system and a particle identification system. Recoil protons and target fragments were observed in a recoil detector which surrounded the target. The total elastic cross-sections were measured to be independent of energy at the 10% level from 35 to 225 GeV at 10.6 ..mu..b for the rho and from 35 to 165 GeV at 0.64 ..mu..b for the phi. The elastic differential cross-sections were also measured. Approximately 20% of the diffractive rho and phi events were found to be inelastic from an analysis of the recoil detector. The t-dependence of the fraction of diffractive events which are inelastic for both the phi and the psi are consistent with a universal function determined from the rho data.

  10. Cross sections and reaction rates of relevance to aeronomy

    SciTech Connect

    Fox, J.L. )

    1991-01-01

    Experimental and theoretical data relevant to models and measurements of the chemical and thermal structures and luminosity of the thermospheres of the earth and planets published during the last four years are surveyed. Among chemical processes, attention is given to ion-molecule reactions, dissociative recombination of molecular ions, and reactions between neutral species. Both reactions between ground state species and species in excited states are considered, including energy transfer and quenching. Measured and calculated cross sections for interactions of solar radiation with atmospheric species, such as photoabsorption, photoionization, and photodissociation and related processes are surveyed.

  11. The allosteric modulation of lipases and its possible biological relevance

    PubMed Central

    Köhler, Jens; Wünsch, Bernhard

    2007-01-01

    Background During the development of an enantioselective synthesis using the lipase from Mucor miehei an unusual reaction course was observed, which was analyzed precisely. For the first time an allosteric modulation of a lipase changing its selectivity was shown. Theory Considering the biological relevance of the discovered regulation mechanism we developed a theory that describes the regulation of energy homeostasis and fat metabolism. Conclusion This theory represents a new approach to explain the cause of the metabolic syndrome and provides an innovative basis for further research activity. PMID:17825093

  12. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device

    PubMed Central

    Randers-Pehrson, Gerhard; Marino, Stephen A.; Garty, Guy; Harken, Andrew; Brenner, David J.

    2015-01-01

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)3He and D(d,n)3He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima. PMID:26273118

  13. Relevance of microelectronic education to industrial needs

    NASA Technical Reports Server (NTRS)

    Prince, J. L.; Lathrop, J. W.

    1977-01-01

    The relevance of microelectronic education to industrial needs was evaluated, and four categories were surveyed: (1) facts and rules; (2) skills; (3) personality; and (4) deductive-inductive reasoning. Examples of specific items in each category are given to illustrate their meaning and it was indicated as to which items in each category are strongly impacted by microelectronics courses and laboratories.

  14. Contingent Attentional Capture by Conceptually Relevant Images

    ERIC Educational Resources Information Center

    Wyble, Brad; Folk, Charles; Potter, Mary C.

    2013-01-01

    Attentional capture is an unintentional shift of visuospatial attention to the location of a distractor that is either highly salient, or relevant to the current task set. The latter situation is referred to as contingent capture, in that the effect is contingent on a match between characteristics of the stimuli and the task-defined…

  15. Making Chemistry Relevant to the Engineering Major

    ERIC Educational Resources Information Center

    Basu-Dutt, Sharmistha; Slappey, Charles; Bartley, Julie K.

    2010-01-01

    As part of a campus-wide, externally funded project to increase performance in, enthusiasm for, and retention within STEM disciplines, we developed an interdisciplinary, team-taught first-year seminar course. The construction and delivery of this course was designed to show the relevance of selected general chemistry topics such as matter and…

  16. Basic Structure of Work-Relevant Abilities.

    ERIC Educational Resources Information Center

    Prediger, Dale J.

    This study sought to determine whether the dimensions underlying a comprehensive set of 15 work-relevant abilities were similar to the Data/Ideas and Things/People Work Task Dimensions (D. J. Prediger, 1996) underlying J. L. Holland's (1997) hexagonal model of interest and occupational types. The work task dimensions and a general ability…

  17. The Relevance Aura of Bibliographic Records.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1997-01-01

    Analyzes relevance assessments of topical descriptors for bibliographic records for two dimensions: (1) a vertical conceptual hierarchy of broad to narrow descriptors, and (2) a horizontal linkage of related terms. The data were analyzed for a semantic distance and semantic direction effect as postulated by the Semantic Distance Model. (Author/LRW)

  18. Relevance, Pertinence and Information System Development

    ERIC Educational Resources Information Center

    Kemp, D. A.

    1974-01-01

    The difference between pertinence and relevance is discussed. Other pairs of terms and the differences between their members are examined, and the suggestion is made that such studies could increase our understanding of the theory of information systems, and thence lead to practical improvements. (Author)

  19. Achieving Relevance in Assessment through Fieldtrips

    ERIC Educational Resources Information Center

    Sutton-Brady, Catherine

    2008-01-01

    Students often bemoan the fact that they can't see the relevance of the report they are asked to write or the case study they have to analyze. This paper introduces the use of attending an industry tradeshow as a means of making assessment more interesting and meaningful. Much has been written about the need to bring reality back to management…

  20. The New FFA--Relevant, Flexible.

    ERIC Educational Resources Information Center

    Future Farmers of America, Washington, DC.

    To make education more relevant, the 1972 national seminar sought ways of integrating the Future Farmers of America (FFA) program with the broadened agricultural instruction program. Topics discussed included: (1) "Role of the FFA in the Changing Program of Agricultural Education" - William Gray (Moderator), (2) "But How Do We Get the Job Done?"…