WorldWideScience

Sample records for low-energy d-wave effects

  1. Theory of Josephson effect in d-wave superconductor/diffusive ferromagnet/d-wave superconductor junctions

    NARCIS (Netherlands)

    Yokoyama, T.; Tanaka, Y.; Golubov, Alexandre Avraamovitch

    2007-01-01

    We study Josephson effect in d-wave superconductor/diffusive ferromagnet/d-wave superconductor junctions, changing the exchange field and the angles between the normal to the interfaces and the crystal axes of d-wave superconductors. We find a 0–π transition at a certain value of the exchange field.

  2. Meissner effect in diffusive normal metal/d-wave superconductor junctions

    NARCIS (Netherlands)

    Yokoyama, Takehito; Tanaka, Yukio; Golubov, Alexandre Avraamovitch; Inoue, Jun-ichiro; Asano, Yasuhiro

    2005-01-01

    The Meissner effect in diffusive normal metal/insulator/d-wave superconductor junctions is studied theoretically in the framework of the Usadel equation under the generalized boundary condition. The effect of midgap Andreev resonant states (MARS) formed at the interface of d-wave superconductor is

  3. Effect of transparency on the Josephson junction between D-wave superconductors

    International Nuclear Information System (INIS)

    Rashedi, G

    2008-01-01

    In this paper, a dc Josephson junction between two singlet superconductors (d-wave and s-wave) with arbitrary reflection coefficient has been investigated theoretically following the famous paper [Y. Tanaka and S. Kashiwaya 1996 Phys. Rev. B 53, R11957]. For the case of High T c superconductors, the c-axes are parallel to an interface with finite transparency and their ab-planes have a mis-orientation. The effect of transparency and mis-orientation on the currents is studied both analytically and numerically. It is observed that, the current phase relations are totally different from the case of ideal transparent Josephson junctions between d-wave superconductors and two s-wave superconductors. This apparatus can be used to demonstrate d-wave order parameter in High T c superconductors

  4. Low-energy effective action for the superstring

    International Nuclear Information System (INIS)

    Burgess, C.P.; Font, A.; Quevedo, F.

    1986-01-01

    We construct the low-energy D=4, N=1 supergravity that arises in superstring theories for an arbitrary number of generations. The coupling of all massless modes that carry low-energy gauge quantum numbers are calculated by truncating the heavy Kaluza-Klein modes of the ten-dimensional effective field theory. The resulting action is compared to the most general effective action compatible with the symmetries of the underlying ten-dimensional field (and string) theories. This comparison indicates which features of the truncation correctly approximate the exact low-energy action. (orig.)

  5. Low-energy operators in effective theories

    International Nuclear Information System (INIS)

    Felline, C.; Piekarewicz, J.; Mehta, N.P.; Shepard, J.R.

    2003-01-01

    Modern effective-theory techniques are applied to the nuclear many-body problem. A novel approach is proposed for the renormalization of operators in a manner consistent with the construction of the effective potential. To test this approach, a one-dimensional, yet realistic, nucleon-nucleon potential is introduced. An effective potential is then constructed by tuning its parameters to reproduce the exact effective-range expansion and a variety of bare operators are renormalized in a fashion compatible with this construction. Predictions for the expectation values of these effective operators in the ground state reproduce the results of the exact theory with remarkable accuracy (at the 0.5% level). This represents a marked improvement over a widely practiced approach that uses effective interactions but retains bare operators. Further, it is shown that this improvement is more impressive as the operator becomes more sensitive to the short-range structure of the potential. We illustrate the main ideas of this work using the elastic form factor of the deuteron as an example

  6. Low energy effective Lagrangians in open superstring theory

    International Nuclear Information System (INIS)

    Medina, Ricardo

    2008-01-01

    The low energy effective Lagrangian describes the interactions of the massless modes of String Theory. Present work is being done to obtain all alpha' 3 terms (bosonic and fermionic) by means of the known 5-point amplitudes and SUSY

  7. Strong correlation effects on the d-wave superconductor- spectral weight analysis by variational wave functions

    International Nuclear Information System (INIS)

    Chou, C-P; Lee, T K; Ho, C-M

    2009-01-01

    We examine the strong correlation effects of the d-wave superconducting state by including the Gutzwiller projection for no electron double occupancy at each lattice site. The spectral weights (SW's) for adding and removing an electron on the projected superconducting state, the ground state of the 2-dimensional t-t'-t - J model with moderate doped holes describing the high T c cuprates, are studied numerically on finite lattices and compared with the observation made by low-temperature tunneling (particle asymmetry of tunneling conductance) and angle-resolved photoemission (SW transfer from the projected Fermi liquid state) spectroscopies. The contrast with the d-wave case without projection is alo presented.

  8. Effect of parallel transport currents on the d-wave Josephson junction

    International Nuclear Information System (INIS)

    Rashedi, Gholamreza

    2009-01-01

    In this paper, the non-local mixing of coherent current states in d-wave superconducting banks is investigated. The superconducting banks are connected via a ballistic point contact. The banks have mis-orientation and phase difference. Furthermore, they are subjected to a tangential transport current along the ab plane of d-wave crystals and parallel to the interface between the superconductors. The effects of mis-orientation and external transport current on the current-phase relations and current distributions are the subjects of this paper. It is observed that, at values of phase difference close to 0, π and 2π, the current distribution may have a vortex-like form in the vicinity of the point contact. The current distribution of the above-mentioned junction between d-wave superconductors is totally different from the junction between s-wave superconductors. The interesting result which this study shows is that spontaneous and Josephson currents are observed for the case of φ = 0.

  9. Interplay of antiferromagnetism and superconductivity in cuprates with impurity effect and d-wave pairing

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, Rasmita, E-mail: rmrmmohapatra@gmail.com [P.G. Department of Applied Physics and Ballistics, F.M. University, Balasore, Odisha 756019 (India); Rout, G.C., E-mail: gcr@iopb.res.in [Physics Enclave, Plot no-664/4825, Lane-4A, Shree Vihar, Patia, Bhubaneswar, Odisha 751024 (India)

    2015-05-15

    Highlights: • We considered here the interplay of antiferromagnetism (AFM) and Superconductivity (SC) with d-wave pairing symmetry in presence of impurity effect. • The tunneling conductance explains the multiple peaks and dip-hump structure. • It is observed that AFM coupling enhances the superconducting transition temperature. • The low temperature specific heat anomaly due to impurity atoms. - Abstract: We present here a model Hamiltonian to study the interplay between staggered magnetic field and the superconductivity with d-wave pairing symmetry in presence of hybridization between impurity f-electrons of rare-earth ions and 3d-electrons of copper ions. The staggered field and superconducting (SC) gaps are calculated by Green’s function technique and solved self-consistently. The coupling constants are compared using s-wave and d-wave pairings. The strength of hybridization suppresses the magnitude of the gaps; while antiferromagnetic coupling enhances the superconducting transition temperature, but suppresses the Neel temperature. The density of states (DOS) representing tunneling conductance shows complex character with impurity level lying at the Fermi level. The electronic specific heat explains prototype heavy fermion behavior in cuprate systems at low temperatures.

  10. Interplay of antiferromagnetism and superconductivity in cuprates with impurity effect and d-wave pairing

    International Nuclear Information System (INIS)

    Mohapatra, Rasmita; Rout, G.C.

    2015-01-01

    Highlights: • We considered here the interplay of antiferromagnetism (AFM) and Superconductivity (SC) with d-wave pairing symmetry in presence of impurity effect. • The tunneling conductance explains the multiple peaks and dip-hump structure. • It is observed that AFM coupling enhances the superconducting transition temperature. • The low temperature specific heat anomaly due to impurity atoms. - Abstract: We present here a model Hamiltonian to study the interplay between staggered magnetic field and the superconductivity with d-wave pairing symmetry in presence of hybridization between impurity f-electrons of rare-earth ions and 3d-electrons of copper ions. The staggered field and superconducting (SC) gaps are calculated by Green’s function technique and solved self-consistently. The coupling constants are compared using s-wave and d-wave pairings. The strength of hybridization suppresses the magnitude of the gaps; while antiferromagnetic coupling enhances the superconducting transition temperature, but suppresses the Neel temperature. The density of states (DOS) representing tunneling conductance shows complex character with impurity level lying at the Fermi level. The electronic specific heat explains prototype heavy fermion behavior in cuprate systems at low temperatures

  11. Two-loop disorder effects on the nematic quantum criticality in d-wave superconductors

    International Nuclear Information System (INIS)

    Wang, Jing

    2015-01-01

    The gapless nodal fermions exhibit non-Fermi liquid behaviors at the nematic quantum critical point that is supposed to exist in some d-wave cuprate superconductors. This non-Fermi liquid state may be turned into a disorder-dominated diffusive metal if the fermions also couple to a disordered potential that generates a relevant perturbation in the sense of renormalization group theory. It is therefore necessary to examine whether a specific disorder is relevant or not. We study the interplay between critical nematic fluctuation and random chemical potential by performing renormalization group analysis. The parameter that characterizes the strength of random chemical potential is marginal at the one-loop level, but becomes marginally relevant after including the two-loop corrections. Thus even weak random chemical potential leads to diffusive motion of nodal fermions and the significantly critical behaviors of physical implications, since the strength flows eventually to large values at low energies. - Highlights: • The gapless nodal fermions exhibit non-Fermi liquid behaviors at the nematic QCP. • The strength of random chemical potential is marginal at the one-loop level. • The strength becomes marginally relevant after including the two-loop corrections. • The diffusive metallic state is induced by the marginally relevant disorder. • The behaviors of some physical observables are presented at the nematic QCP

  12. Developing effective rockfall protection barriers for low energy impacts

    Science.gov (United States)

    Mentani, Alessio; Giacomini, Anna; Buzzi, Olivier; Govoni, Laura; Gottardi, Guido; Fityus, Stephen

    2016-04-01

    Recently, important progresses have been made towards the development of high capacity rockfall barriers (100 kJ - 8000 kJ). The interest of researchers and practitioners is now turning to the development of fences of minor capacity, whose use becomes essential in areas where rockfall events generally have low intensity and the use of high capacity barriers would be accompanied by excessive costs and high environmental impact. Low energy barriers can also provide a cost-effective solution even in areas where high energies events are expected. Results of full-scale tests are vital to any investigation on the behaviour of these structures. An experimental set-up has been developed at The University of Newcastle (AUS), to investigate the response of low energy rockfall barrier prototypes to low energy impacts. The Australian territory, and in particular New South Wales, is in fact characterised by rockfall events of low-to-medium intensity (50 kJ - 500 kJ) and the need of protection structures working within such energy range, is particularly felt [1]. The experiments involved the impact of a test block onto three spans, low energy barrier prototypes, made of steel structural posts, fully fixed at the base, side cables and a steel meshwork constituted by a double twist hexagonal wire net [2]. Test data enabled the development, calibration and assessment of FE models [3], on which non-linear and dynamic analyses have been performed addressing the effect of the block size. Results have shown that the response of the structure is strongly governed by the net. Data from tests conducted on the sole net and on the entire barrier showed in fact a similar trend, different to what typically observed for high capacity barriers, whose behaviour is also led by the presence of uphill cables and brakes. In particular, the numerical analyses have demonstrated a dependence of the net performance on the block size. In particular, a loss of capacity in the order of 50% occurred as the

  13. Analysis of parity violating nuclear effects at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Desplanques, B; Missimer, J [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1978-05-15

    The authors present an analysis of parity-violating nuclear effects at low energy which attempts to circumvent the uncertainties due to the weak and strong nucleon-nucleon interactions at short distances. Extending Danilov's parametrization of the parity-violating nucleon-nucleon scattering amplitude, they introduce six parameters: one for the long-range contribution due to the pion exchange and five for the shorter-range contributions. This choice gives an accurate representation of parity-violating effects in the nucleon-nucleon system up to a lab energy of 75 MeV. For calculations in nuclei, an effective two-body potential is derived in terms of the parameters. The analysis of presently measured effects shows that they are consistent, and, in particular, that the circular polarization of photons in n + p ..-->.. d + ..gamma.. is not incompatible with the other measurements. It does not imply a dominant isotensor component.

  14. Geometric low-energy effective action in a doubled spacetime

    Science.gov (United States)

    Ma, Chen-Te; Pezzella, Franco

    2018-05-01

    The ten-dimensional supergravity theory is a geometric low-energy effective theory and the equations of motion for its fields can be obtained from string theory by computing β functions. With d compact dimensions, an O (d , d ; Z) geometric structure can be added to it giving the supergravity theory with T-duality manifest. In this paper, this is constructed through the use of a suitable star product whose role is the one to implement the weak constraint on the fields and the gauge parameters in order to have a closed gauge symmetry algebra. The consistency of the action here proposed is based on the orthogonality of the momenta associated with fields in their triple star products in the cubic terms defined for d ≥ 1. This orthogonality holds also for an arbitrary number of star products of fields for d = 1. Finally, we extend our analysis to the double sigma model, non-commutative geometry and open string theory.

  15. Probing quark mass effects in low-energy hadron physics

    International Nuclear Information System (INIS)

    Ditsche, Christoph

    2012-01-01

    Since quarks are confined inside hadrons, their properties as well as their contributions to hadronic observables can be assessed by indirect methods only. As the strength of the strong interaction increases with the spatial distance, the treatment of quantum chromodynamics at low energies in general requires non-perturbative methods like dispersion relations or lattice gauge theory. Based on the fact that the light quark masses are very small with respect to the typical hadronic mass scales for mesons and baryons, furthermore effective field theories can be constructed to describe low-energy properties and dynamics of hadrons perturbatively. The present work is concerned with two particularly interesting hadronic processes that are closely related to the light quark masses. Although distinct theoretical frameworks utilizing different calculational techniques are applied, in both cases the investigations at hand are prerequisites for high-precision analyses of the respective quark-mass effects. In the first part of this thesis, we investigate higher-order isospin-breaking effects in η→3π decays, namely η→π 0 π + π - and η→3π 0 , in chiral perturbation theory. By evaluating the second-order mixed strong and electromagnetic isospin-breaking corrections, we confirm the picture that the electromagnetic contributions are small. Therefore, η→3π is perfectly suited to extract isospin-breaking ratios of light quark masses via comparing theoretical predictions with experimental results. Since for an accurate determination a detailed description of the Dalitz plot distributions is necessary, we study the different effects of higher-order isospin breaking in η→3π on a more general basis. In particular, we investigate corrections to isospin relations between both decay channels at the level of Dalitz plot parameters, showing that the branching ratio of the two partial decay widths entails sizeable uncertainties. In the second part, we develop a dispersive

  16. Channeling effect for low energy ion implantation in Si

    International Nuclear Information System (INIS)

    Cho, K.; Allen, W.R.; Finstad, T.G.; Chu, W.K.; Liu, J.; Wortman, J.J.

    1985-01-01

    Ion implantation is one of the most important processes in semiconductor device fabrication. Due to the crystalline nature of Si, channeling of implanted ions occurs during this process. Modern devices become smaller and shallower and therefore require ion implantation at lower energies. The effect of channeling on ion implantation becomes a significant problem for low energy ion implantation. The critical angle for axial and planar channeling increases with decreasing energy. This corresponds to an increased probability for channeling with lowering of ion energy. The industry approach to avoid the channeling problem is to employ a tilt angle of 7 0 between the ion implantation direction and the surface normal. We approach the problem by mapping major crystalline axes and planes near the [100] surface normal. Our analysis indicates that a 7 0 tilt is not an optimum selection in channeling reduction. Tilt angles in the range 5 0 to 6 0 combined with 7 0 +- 0.5 0 rotation from the (100) plane are better selections for the reduction of the channeling effect. The range of suitable angles is a function of the implantation energy. Implantations of boron along well specified crystallographic directions have been carried out by careful alignment and the resulting boron profiles measured by SIMS. (orig.)

  17. Effective low-energy Hamiltonians for interacting nanostructures

    Science.gov (United States)

    Kinza, Michael; Ortloff, Jutta; Honerkamp, Carsten

    2010-10-01

    We present a functional renormalization group (fRG) treatment of trigonal graphene nanodisks and composites thereof, modeled by finite-size Hubbard-like Hamiltonians with honeycomb lattice structure. At half filling, the noninteracting spectrum of these structures contains a certain number of half-filled states at the Fermi level. For the case of trigonal nanodisks, including interactions between these degenerate states was argued to lead to a large ground state spin with potential spintronics applications [M. Ezawa, Eur. Phys. J. B 67, 543 (2009)10.1140/epjb/e2009-00041-7]. Here we perform a systematic fRG flow where the excited single-particle states are integrated out with a decreasing energy cutoff, yielding a renormalized low-energy Hamiltonian for the zero-energy states that includes effects of the excited levels. The numerical implementation corroborates the results obtained with a simpler Hartree-Fock treatment of the interaction effects within the zero-energy states only. In particular, for trigonal nanodisks the degeneracy of the one-particle-states with zero energy turns out to be protected against influences of the higher levels. As an explanation, we give a general argument that within this fRG scheme the zero-energy degeneracy remains unsplit under quite general conditions and for any size of the trigonal nanodisk. We also discuss a second class of nanostructures, bow-tie-shaped systems, where the zero-energy states are not protected.

  18. Coulomb effects in low-energy nuclear fragmentation

    Science.gov (United States)

    Wilson, John W.; Chun, Sang Y.; Badavi, Francis F.; John, Sarah

    1993-01-01

    Early versions of the Langley nuclear fragmentation code NUCFRAG (and a publicly released version called HZEFRG1) assumed straight-line trajectories throughout the interaction. As a consequence, NUCFRAG and HZEFRG1 give unrealistic cross sections for large mass removal from the projectile and target at low energies. A correction for the distortion of the trajectory by the nuclear Coulomb fields is used to derive fragmentation cross sections. A simple energy-loss term is applied to estimate the energy downshifts that greatly alter the Coulomb trajectory at low energy. The results, which are far more realistic than prior versions of the code, should provide the data base for future transport calculations. The systematic behavior of charge-removal cross sections compares favorably with results from low-energy experiments.

  19. Low energy He+ irradiation effect on graphite surface

    International Nuclear Information System (INIS)

    Asari, E.; Nakamura, K.G.; Kitajima, M.; Kawabe, T.

    1992-01-01

    Study on the lattice disordering and the secondary electron emission under low energy (1-5keV) He + irradiation is reported. Real-time Raman measurements show that difference in the observed Raman spectra for different ion energies is due to the difference of the damage depth. The relation between the observed Raman spectrum and the depth profile of lattice damage is discussed. Energy dependence of the secondary electron emission coefficient are also described. (author)

  20. Effect of impurity scattering on the low temperature magnetic penetration depth of a nonlocal and nonlinear d-wave superconductor

    International Nuclear Information System (INIS)

    Yavary, H.

    2006-01-01

    The magnetic penetration depth of a quasi-two dimensional d-wave superconductor in the presence of nonlineary, nonlocality, and impurity effects is investigated by using Green's function method. It is shown that a d-wave superconductor would inevitably avoid the violation of the Nernst theorem by creating a T 2 term in its penetration depth through a competition of nonlinear, nonlocal, and impurity effects and this system may be stable at low temperatures. I also show that in the impure sample at low temperatures, T < T * ∝ γ the impurity effect determines the temperature dependence of the penetration depth, i.e., nonlocal and nonlinear effects are completely masked by impurities

  1. Does the effective Lagrangian for low-energy QCD scale?

    International Nuclear Information System (INIS)

    Birse, M.C.

    1994-01-01

    Quantum chromodynamics is not an approximately scale-invariant theory. Hence a dilaton field is not expected to provide a good description of the low-energy dynamics associated with the gluon condensate. Even if such a field is introduced, it remains almost unchanged in hadronic matter at normal densities. This is because the large glueball mass together with the size of the phenomenological gluon condensate ensure that changes to that condensate are very small at such densities. Any changes in hadronic masses and decay constants in matter generated by that condensate will be much smaller than those produced directly by changes in the quark condensate. Hence, masses and decay constants are not expected to display a universal scaling. (author)

  2. Quasiparticle conductance-voltage characteristics for break junctions involving d-wave superconductors: charge-density-wave effects.

    Science.gov (United States)

    Ekino, T; Gabovich, A M; Suan Li, Mai; Szymczak, H; Voitenko, A I

    2017-12-20

    Quasiparticle tunnel conductance-voltage characteristics (CVCs), [Formula: see text], were calculated for break junctions (BJs) made up of layered d-wave superconductors partially gapped by charge-density waves (CDWs). The current is assumed to flow in the ab-plane of electrodes. The influence of CDWs is analyzed by comparing the resulting CVCs with CVCs calculated for BJs made up of pure d-wave superconductors with relevant parameters. The main CDW-effects were found to be the appearance of new CVC peculiarities and the loss of CVC symmetry with respect to the V-sign. Tunnel directionality was shown to be one of the key factors in the formation of [Formula: see text] dependences. In particular, the orientation of electrodes with respect to the current channel becomes very important. As a result, [Formula: see text] can acquire a large variety of forms similar to those for tunnel junctions between superconductors with s-wave, d-wave, and mixed symmetry of their order parameters. The diversity of peculiarities is especially striking at finite temperatures. In the case of BJs made up of pure d-wave superconductors, the resulting CVC can include a two-peak gap-driven structure. The results were compared with the experimental BJ data for a number of high-T c oxides. It was shown that the large variety of the observed current-voltage characteristics can be interpreted in the framework of our approach. Thus, quasiparticle tunnel currents in the ab-plane can be used as an additional mean to detect CDWs competing with superconductivity in cuprates or other layered superconductors.

  3. Effect of projectile on incomplete fusion reactions at low energies

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2017-01-01

    Full Text Available Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n excess projectile 13C (as compared to 12C results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B and forward (F α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  4. Effect of projectile on incomplete fusion reactions at low energies

    Science.gov (United States)

    Sharma, Vijay R.; Shuaib, Mohd.; Yadav, Abhishek; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Singh, Devendra P.; Singh, B. P.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.; Prasad, R.

    2017-11-01

    Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF) is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n) excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B) and forward (F) α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  5. Effect of d-wave pairing symmetry in transport properties of silicene-based superconductor junction

    Science.gov (United States)

    Vosoughi-nia, S.; Rashedi, G.; hajati, Y.

    2018-06-01

    We theoretically study the tunneling conductance of a normal/d-wave superconductor silicene junction using Blonder-Tinkham-Klapwijk (BTK) formalism. We discuss how the conductance spectra are affected by changing the chemical potential (μN) in the normal silicene region. It is obtained that the amplitude of the spin/valley-dependent Andreev reflection (AR) and charge conductance (G) of the junction can be strongly modulated by the orientation angle of superconductive gap (β) and perpendicular electric field (Ez). We demonstrate that the charge conductance exhibits an oscillatory behavior as a function of β by a period of π/2. Remarkably, variation of μN strongly modifies the amplitude of the oscillations and periodically there are transport gaps in the G - β oscillations for a range of μN. These findings suggest that one may experimentally tune the transport properties of the junction through changing β, Ez and μN.

  6. Low-energy irradiation effects of gas cluster ion beams

    International Nuclear Information System (INIS)

    Houzumi, Shingo; Takeshima, Keigo; Mochiji, Kozo; Toyoda, Noriaki; Yamada, Isao

    2007-01-01

    A cluster-ion irradiation system with cluster-size selection has been developed to study the effects of the cluster size for surface processes using cluster ions. A permanent magnet with a magnetic field of 1.2 T is installed for size separation of large cluster ions. Trace formations at HOPG surface by the irradiation with size-selected Ar-cluster ions under acceleration energy of 30 keV were investigated by a scanning tunneling microscopy. Generation behavior of the crater-like traces is strongly affected by the number of constituent atoms (cluster size) of the irradiating cluster ion. When the incident cluster ion is composed of 100-3000 atoms, crater-like traces are observed on the irradiated surfaces. In contrast, such traces are not observed at all with the irradiation of the cluster-ions composed of over 5000 atoms. Such the behavior is discussed on the basis of the kinetic energy per constituent atom of the cluster ion. To study GCIB irradiation effects against macromolecule, GCIB was irradiated on DNA molecules absorbed on graphite surface. By the GCIB irradiation, much more DNA molecules was sputtered away as compared with the monomer-ion irradiation. (author)

  7. The effects of low-energy scattering on positron implantation

    Energy Technology Data Exchange (ETDEWEB)

    Ritley, K.A. (Dept. of Physics and Materials Research Laboratory, Univ. of Illinois, Urbana, IL (United States)); Lynn, K.G.; Ghosh, V.; Welch, D.O. (Brookhaven National Lab., Upton, NY (United States))

    1992-01-01

    Existing Monte Carlo models are capable of simulating the behavior of positrons incident at keV energies, then following the energy loss process to arbitrary final kinetic energies of from 20 eV to 100 eV. This work describes a Monte Carlo simulation of the final stages of positron thermalization in Al, from 25 eV to thermal energies, via the mechanisms of conduction-electron and longitudinal acoustic phonon scattering. The latter stages of thermalization can have important effects on the stopping profiles and mean depth. A novel way to obtain information about positron energy loss by considering the time-evolution of a point-concentration (delta-function distribution) of positrons is described. The effects of a positive positron work function are examined for the first time in the context of a positron Monte Carlo calculation. Finally, some issues relating to the agreement of Monte Carlo calculations with experimental data are discussed. 6 figs., 16 refs.

  8. The effects of low-energy scattering on positron implantation

    Energy Technology Data Exchange (ETDEWEB)

    Ritley, K.A. [Dept. of Physics and Materials Research Laboratory, Univ. of Illinois, Urbana, IL (United States); Lynn, K.G.; Ghosh, V.; Welch, D.O. [Brookhaven National Lab., Upton, NY (United States)

    1992-12-31

    Existing Monte Carlo models are capable of simulating the behavior of positrons incident at keV energies, then following the energy loss process to arbitrary final kinetic energies of from 20 eV to 100 eV. This work describes a Monte Carlo simulation of the final stages of positron thermalization in Al, from 25 eV to thermal energies, via the mechanisms of conduction-electron and longitudinal acoustic phonon scattering. The latter stages of thermalization can have important effects on the stopping profiles and mean depth. A novel way to obtain information about positron energy loss by considering the time-evolution of a point-concentration (delta-function distribution) of positrons is described. The effects of a positive positron work function are examined for the first time in the context of a positron Monte Carlo calculation. Finally, some issues relating to the agreement of Monte Carlo calculations with experimental data are discussed. 6 figs., 16 refs.

  9. Vacuum polarization effects in low-energy muonic atom collisions

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1995-01-01

    We estimate the vacuum polarization (VP) correction to the Coulomb interaction in collisions of muonic atoms. It is shown that the VP effect, amplified by the low-lying virtual state var-epsilon var-theta ∼10 eV, is of the order of ∼1--2 % in the S-wave cross sections for pμ+p collisions as var-epsilon ≤ var-epsilon var-theta . The VP amplitude becomes comparable to the anomalously small pure Coulomb amplitude for the singlet tμ+t scattering as var-epsilon →0 and near the Ramsauer-Townsend minima in the dμ+p and tμ+p scattering

  10. Deuteron D-wave and the non-eikonal effects in tensor asymmetries in elastic proton-deuteron scattering

    International Nuclear Information System (INIS)

    Alberi, G.; Bleszynski, M.; California Univ., Los Angeles; Santos, S.; Jaroszewicz, T.

    1980-01-01

    It is shown that the tensor asymmetries in the elastic proton-deuteron scattering at medium energies are very sensitive to the non-eikonal corrections to the Glauber model. This sensitivity originates from the fact that, in double scattering, the non-eikonal corrections affect in a different way the contributions coming from the S- and D-wave parts of the deuteron wave function. This leads to considerable change of the tensor asymmetries not only in the region of the interference between single and double scatterings, but also in the region of dominance of the double scattering. It is suggested that these effects should be taken into account in any careful analysis of the proton-deuteron polarization data, which has as a goal the extraction of the NN amplitudes. (author)

  11. The effect of low energy protons on silicon solar cells with simulated coverglass cracks

    Science.gov (United States)

    Gasner, S.; Anspaugh, B.; Francis, R.; Marvin, D.

    1991-01-01

    Results of a series of low-energy proton (LEP) tests are presented. The purpose of the tests was to investigate the effect of low-energy protons on the electrical performance of solar cells with simulated cracked covers. The results of the tests were then related to the space environment. A matrix of LEP tests was set up using solar cells with simulated cracks to determine the effect on electrical performance as a function of fluence, energy, crack width, coverglass adhesive shielding, crack location, and solar cell size. The results of the test were, for the most part, logical, and consistent.

  12. Excitation spectra of an effective d-wave model for cuprate superconductivity

    NARCIS (Netherlands)

    Yamaguchi, M; Ohta, Y; Eder, R

    An exact-diagonalization technique on finite-size clusters is used to study the ground states and some excitation spectra of the two-dimensional effective Fermi-liquid model derived from numerical studies of the t-J model. We show that there is actually a reasonable range of parameter values where

  13. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2014-05-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms.

  14. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    International Nuclear Information System (INIS)

    Thopan, P.; Thongkumkoon, P.; Prakrajang, K.; Suwannakachorn, D.; Yu, L.D.

    2014-01-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms

  15. Effect of the space-charge force on tracking at low energy

    International Nuclear Information System (INIS)

    Furman, M.A.

    1987-01-01

    The authors present tracking results for the SSC's Low Energy Booster at injection energy, including the effect of the space-charge force. The bunches are assumed to be gaussian with elliptical cross-section. Magnet errors and sextupoles are not included, but an RF cavity is. The authors compare the phase space with and without synchrotron oscillations, with and without space-charge. The effective emittance is not significantly altered. They also present results on tune shifts with amplitude

  16. Low-energy effective action in two-dimensional SQED: a two-loop analysis

    Science.gov (United States)

    Samsonov, I. B.

    2017-07-01

    We study two-loop quantum corrections to the low-energy effective actions in N=(2,2) and N=(4,4) SQED on the Coulomb branch. In the latter model, the low-energy effective action is described by a generalized Kähler potential which depends on both chiral and twisted chiral superfields. We demonstrate that this generalized Kähler potential is one-loop exact and corresponds to the N=(4,4) sigma-model with torsion presented by Roček, Schoutens and Sevrin [1]. In the N=(2,2) SQED, the effective Kähler potential is not protected against higher-loop quantum corrections. The two-loop quantum corrections to this potential and the corresponding sigma-model metric are explicitly found.

  17. The orbifolder: A tool to study the low energy effective theory of heterotic orbifolds

    International Nuclear Information System (INIS)

    Nilles, H.P.; Wingerter, A.

    2011-10-01

    The orbifolder is a program developed in C ++ that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum-configurations. (orig.)

  18. The orbifolder. A tool to study the low energy effective theory of heterotic orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Nilles, H P [Bonn Univ. (Germany). Bethe Center for Theoretical Physics and Physikalisches Institut; Ramos-Sanchez, S [Universidad Nacional Autonoma de Mexico (UNAM), Mexico City (Mexico). Dept. of Theoretical Physics; Vaudrevange, P K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Technische Univ. Muenchen, Garching (Germany). Physik-Department; Arnold-Sommerfeld-Center for Theoretical Physics, Muenchen (Germany); Wingerter, A [CNRS/IN2P3, INPG, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie

    2011-10-15

    The orbifolder is a program developed in C{sup ++} that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum-configurations. (orig.)

  19. The effective QCD theory at low energy; La theorie effective de QCD a basse energie

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, M. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    1995-12-31

    Quantum chromodynamics is studied here in the range of low energies. The Chiral perturbation theory is presented, this theory is based on a thorough study of QCD symmetry, of general field theory principles and of S-matrices. Ward identities are defined within the scope of current algebras and by using functional method. Their consequences on Chiral structure of QCD emptiness and on strong interaction at low energies are studied. The pion-pion diffusion at low energies is treated as an example. (A.C.) 70 refs.

  20. On low-energy effective action in three-dimensional = 2 and = 4 supersymmetric electrodynamics

    Science.gov (United States)

    Buchbinder, I. L.; Merzlikin, B. S.; Samsonov, I. B.

    2013-11-01

    We discuss general structure of low-energy effective actions in = 2 and = 4 three-dimensional supersymmetric electrodynamics (SQED) in gauge superfield sector. There are specific terms in the effective action having no four-dimensional analogs. Some of these terms are responsible for the moduli space metric in the Coulomb branch of the theory. We find two-loop quantum corrections to the moduli space metric in the = 2 SQED and show that in the = 4 SQED the moduli space does not receive two-loop quantum corrections.

  1. Lens effect of unipolar electrostatic steerers on low-energy ion beams and its effective reduction

    International Nuclear Information System (INIS)

    Asozu, Takuhiro; Matsuda, Makoto; Kutsukake, Kenichi

    2010-08-01

    The JAEA-Tokai tandem accelerator has two ion injectors, one is the negative ion injector placed on the ground and the other is the positive ion injector in the high voltage terminal. The electrostatic steerers in the high voltage terminal are used for ion beams from the both injectors. Because the beams from the negative ion injector gain high energy at the 20MV terminal, the electrodes of the electrostatic steerers are designed to be supplied several ten kV. The high voltages are supplied by two unipolar DC power supplies and they are controlled as the sum of the voltages keeps constant. The high electric potential between the electrodes affects the beam trajectory as an electrostatic lens. The potential must be too high for the low energy ion beams from the positive ion injector on the 100kV deck. We simulated the beam trajectory by calculation and evaluated the strength of the lens effects. The results showed that the focal distances were too short to control the beam form positive ion injector using optical devices in the downstream. If we reduce the voltages to one tenth in simulation, then the focusing effects were much less significant. We installed a multiplying factor circuit to make the voltages variable and much lower. The results of beam-handling tests using the circuit actually showed significant increase of the ion beam current. (author)

  2. The low-energy effective theory of QCD at small quark masses in a finite volume

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, Christoph

    2010-01-15

    At low energies the theory of quantum chromodynamics (QCD) can be described effectively in terms of the lightest particles of the theory, the pions. This approximation is valid for temperatures well below the mass difference of the pions to the next heavier particles. We study the low-energy effective theory at very small quark masses in a finite volume V. The corresponding perturbative expansion in 1/{radical}(V) is called {epsilon} expansion. At each order of this expansion a finite number of low-energy constants completely determine the effective theory. These low-energy constants are of great phenomenological importance. In the leading order of the {epsilon} expansion, called {epsilon} regime, the theory becomes zero-dimensional and is therefore described by random matrix theory (RMT). The dimensionless quantities of RMT are mapped to dimensionful quantities of the low-energy effective theory using the leading-order lowenergy constants {sigma} and F. In this way {sigma} and F can be obtained from lattice QCD simulations in the '' regime by a fit to RMT predictions. For typical volumes of state-of-the-art lattice QCD simulations, finite-volume corrections to the RMT prediction cannot be neglected. These corrections can be calculated in higher orders of the {epsilon} expansion. We calculate the finite-volume corrections to {sigma} and F at next-to-next-to-leading order in the {epsilon} expansion. We also discuss non-universal modifications of the theory due to the finite volume. These results are then applied to lattice QCD simulations, and we extract {sigma} and F from eigenvalue correlation functions of the Dirac operator. As a side result, we provide a proof of equivalence between the parametrization of the partially quenched low-energy effective theory without singlet particle and that of the super-Riemannian manifold used earlier in the literature. Furthermore, we calculate a special version of the massless sunset diagram at finite volume without

  3. Effect of Low-Energy Linear Shockwave Therapy on Erectile Dysfunction

    DEFF Research Database (Denmark)

    Fojecki, Grzegorz L; Thiessen, Stefan; Osther, Palle Jørn Sloth

    2017-01-01

    INTRODUCTION: Previous studies have shown that focal low-energy extracorporeal shockwave therapy (Li-ESWT) can have a positive effect in men with erectile dysfunction (ED). Linear Li-ESWT (LLi-ESWT) for ED has not been previously assessed in a randomized trial. AIM: To evaluate the treatment...... MEASURES: The primary outcome measurement was an increase of at least five points on the IIEF-EF score. The secondary outcome measurement was an increased EHS score to at least 3 in men with a score no higher than 2 at baseline. Data were analyzed by linear and logistic regression. RESULTS: Mean IIEF...

  4. Effect of passive cooling strategies on overheating in low energy residential buildings for Danish climate

    DEFF Research Database (Denmark)

    Simone, Angela; Avantaggiato, Marta; de Carli, Michele

    2014-01-01

    creating not negligible thermal discomfort. In the present work the effect of passive strategies, such as solar shading and natural night-time ventilation, are evaluated through computer simulations. The analyses are performed for 1½-storey single-family house in Copenhagen’s climate. The main result......Climate changes have progressively produced an increase of outdoors temperature resulting in tangible warmer summers even in cold climate regions. An increased interest for passive cooling strategies is rising in order to overcome the newly low energy buildings’ overheating issue. The growing level...

  5. The mass effect model of the survival rate's dose effect of organism irradiated with low energy ion beam

    International Nuclear Information System (INIS)

    Shao Chunlin; Gui Qifu; Yu Zengliang

    1995-01-01

    The main characteristic of the low energy ions mutation is its mass deposition effect. Basing on the theory of 'double strand breaking' and the 'mass deposition effect', the authors suggests that the mass deposition products can repair or further damage the double strand breaking of DNA. According to this consideration the dose effect model of the survival rate of organism irradiated by low energy of N + ion beam is deduced as: S exp{-p[αφ + βφ 2 -Rφ 2 exp(-kφ)-Lφ 3 exp(-kφ)]}, which can be called 'mass effect model'. In the low energy ion beam mutation, the dose effects of many survival rates that can not be imitated by previous models are successfully imitated by this model. The suitable application fields of the model are also discussed

  6. The orbifolder: A tool to study the low-energy effective theory of heterotic orbifolds

    Science.gov (United States)

    Nilles, H. P.; Ramos-Sánchez, S.; Vaudrevange, P. K. S.; Wingerter, A.

    2012-06-01

    The orbifolder is a program developed in C++ that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum configurations. Program summaryProgram title: orbifolder Catalogue identifier: AELR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 145 572 No. of bytes in distributed program, including test data, etc.: 930 517 Distribution format: tar.gz Programming language:C++ Computer: Personal computer Operating system: Tested on Linux (Fedora 15, Ubuntu 11, SuSE 11) Word size: 32 bits or 64 bits Classification: 11.1 External routines: Boost (http://www.boost.org/), GSL (http://www.gnu.org/software/gsl/) Nature of problem: Calculating the low-energy spectrum of heterotic orbifold compactifications. Solution method: Quadratic equations on a lattice; representation theory; polynomial algebra. Running time: Less than a second per model.

  7. Effects of low energy radiations on the stability of red palm oil

    International Nuclear Information System (INIS)

    Dzulkefly, K.; Zarida, Z.; Hamdan, S.

    1999-01-01

    Red palm oil (R-PO) is a new generation of cooking oil in which the carotenes are retained in the refined oil. In this study, the oxidative effects of low energy radiations (sunlight and ultra-violet radiation) on RPO were investigated. The red palm oil was exposed to sunlight and ultra-violet (UV) radiation for various time intervals. The concentrations of carotene, peroxide value (PV), conjugated diene value (CD) and free fatty acid (FFA) content were measured. The irradiation was also performed in the presence of antioxidant butylated hydroxytoluene (BHT). Results showed that carotene contents were significantly reduced as the irradiation doses increase. The destruction of carotenes were 23.9 % and 24.1 % respectively under sunlight and UV radiation after 5 hours exposure. Measurements of PV, CD and FFA have indicated that both UV and sunlight radiations caused deterioration of red palm oil. In the presence of antioxidant, the extent of deterioration of RPO and the destruction of carotene were suppressed. This study has shown that the natural antioxidant (carotenes and tocopherols) did not give complete protection to RPO against oxidative deterioration induced by low energy radiations. Additional antioxidant (BHT) was needed to suppress the oxidative deterioration of RPO. (Author)

  8. The temperature effect of low-energy ion beam implantation on seed

    International Nuclear Information System (INIS)

    Chang Shenghe; Su Mingjie; Qin Guangyong; Wu Yuping; Zhao Haizhen

    2005-01-01

    The temperature effects of low-energy ion beam implantation on the seed germination were studied. Maize dry seeds were covered with copy paper, aluminum foil and without cover, respectively. Results showed that the germination rate of the seeds covered with paper which was the bad heat transmitter was the highest among three treatments, while that covered with aluminum foil which can transmit heat energy well was the least. The germination rate of the seeds covered with nothing was the second. Temperature affected seeds germination markedly. Generally the temperature of the target room inhibited the seeds' germination. After minus the effects of the temperature in the target room, the germination rates of the seeds were modified in this paper. The modified germination rate curve was also provided. (authors)

  9. Damaging Effect of Low Energy N+ Implantation on Aspergillus niger Spores

    International Nuclear Information System (INIS)

    Wang Lisheng; Cai Kezhou; Cheng Maoji; Chen Lijuan; Liu Xuelan; Zhang Shuqing; Yu Zengliang

    2007-01-01

    The mutant effects of a keV range nitrogen ion (N + ) beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance (ESR) results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope (SEM). The mutagenic effect on genome indicated that N + implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms

  10. Damaging Effect of Low Energy N{sup +} Implantation on Aspergillus niger Spores

    Energy Technology Data Exchange (ETDEWEB)

    Lisheng, Wang [Department of Animal Science and Technology, Anhui Agricultural University, Hefei 230036 (China); Kezhou, Cai [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Maoji, Cheng [Department of Animal Science and Technology, Anhui Agricultural University, Hefei 230036 (China); Lijuan, Chen [Department of Animal Science and Technology, Anhui Agricultural University, Hefei 230036 (China); Xuelan, Liu [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Shuqing, Zhang [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Zengliang, Yu [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China)

    2007-06-15

    The mutant effects of a keV range nitrogen ion (N{sup +}) beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance (ESR) results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope (SEM). The mutagenic effect on genome indicated that N{sup +} implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms.

  11. Possible roles of Peccei-Quinn symmetry in an effective low energy model

    Science.gov (United States)

    Suematsu, Daijiro

    2017-12-01

    The strong C P problem is known to be solved by imposing Peccei-Quinn (PQ) symmetry. However, the domain wall problem caused by the spontaneous breaking of its remnant discrete subgroup could make models invalid in many cases. We propose a model in which the PQ charge is assigned quarks so as to escape this problem without introducing any extra colored fermions. In the low energy effective model resulting after the PQ symmetry breaking, both the quark mass hierarchy and the CKM mixing could be explained through Froggatt-Nielsen mechanism. If the model is combined with the lepton sector supplemented by an inert doublet scalar and right-handed neutrinos, the effective model reduces to the scotogenic neutrino mass model in which both the origin of neutrino masses and dark matter are closely related. The strong C P problem could be related to the quark mass hierarchy, neutrino masses, and dark matter through the PQ symmetry.

  12. Studies on biological effects of low energy N+ on ion beam implantation rice

    International Nuclear Information System (INIS)

    Wang Songli; Huang Qunce; Wang Tiegu; Qin Guangyong

    2006-01-01

    Dry seeds of five varieties of rice were implanted by 25 KeV low energy N + with doses of 2.0 x 10 17 , 2.5 x 10 17 and 3.0 x 10 17 N + /cm 2 , respectively. Mutant plants were selected from their progenies and the biological effects of the mutant plants were studied. The results showed that chlorophyll content of mutant plants was higher than that of the control, and one of those is as high as 148.67% of chlorophyll content compared with the control. Isoenzyme activities (POD, CAT and SOD) of mutant plants were different from the control plants. And AFLP analysis showed that the similarity between variant plants and feminine control plants was higher than that between variant plants and masculine control plants. (authors)

  13. Temporal characteristics and saturation effects of organic scintillators to low-energy X-rays

    International Nuclear Information System (INIS)

    Pronko, J.G.; Chase, L.F.

    1979-01-01

    Rise time, short and long term decay characteristics and possible saturation effects of the fluorescence of NE102, NE111, and doped NE111 organic scintillators were investigated using low-energy X-rays from a laser produced plasma. The laser system consisted of a pulsed Nd:glass facility operating at a pulse width of 0.2 ns at levels up to 10 J. The NE111 samples consisted of a matrix of scintillators with benzophenone, acetophenone, and piperidine each at concentrations of 0, 1, 2, 5, and 10 percent. The rise time of NE102 was measured at (640+-50) ps while that of both the doped and undoped NE111 was 2 ns) of irradiance used in this investigation. (Auth.)

  14. The effect of interatomic potential in molecular dynamics simulation of low energy ion implantation

    International Nuclear Information System (INIS)

    Chan, H.Y.; Nordlund, K.; Peltola, J.; Gossmann, H.-J.L.; Ma, N.L.; Srinivasan, M.P.; Benistant, F.; Chan, Lap

    2005-01-01

    Being able to accurately predict dopant profiles at sub-keV implant energies is critical for the microelectronic industry. Molecular Dynamics (MD), with its capability to account for multiple interactions as energy lowers, is an increasingly popular simulation method. We report our work on sub-keV implantation using MD and investigate the effect of different interatomic potentials on the range profiles. As an approximation, only pair potentials are considered in this work. Density Functional Theory (DFT) is used to calculate the pair potentials for a wide range of dopants (B, C, N, F, Si, P, Ga, Ge, As, In and Sb) in single crystalline silicon. A commonly used repulsive potential is also included in the study. Importance of the repulsive and attractive regions of the potential has been investigated with different elements and we show that a potential depicting the right attractive forces is especially important for heavy elements at low energies

  15. Can low energy experiments supply the effective information to determine the inner structure of hadrons

    International Nuclear Information System (INIS)

    Sawada, Tetsuo

    1980-01-01

    It is explained that the low energy experiments with high precision are important sources of information to determine the inner structure of hadrons. For such purpose, the magnetic monopole model of hadron due to Schwinger is reviewed. Appearance of the strong van der Waals force between hadrons is one of the most important consequences of such a model. A technique, which enables us to separate the effect of such a long range force from that of the short range force arising from the exchanges of pions, is introduced. Present status of the related experiments are summarized, and the experiments necessary to confirm the existence of the strong van der Waals force in a clear-cut way are explained. Possible impacts to the hadron physics, when the existence of such a long range force is confirmed, are discussed. (author)

  16. Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction.

    Science.gov (United States)

    Hatanaka, Kazuaki; Ito, Kenta; Shindo, Tomohiko; Kagaya, Yuta; Ogata, Tsuyoshi; Eguchi, Kumiko; Kurosawa, Ryo; Shimokawa, Hiroaki

    2016-09-01

    We have previously demonstrated that low-energy extracorporeal cardiac shock wave (SW) therapy improves myocardial ischemia through enhanced myocardial angiogenesis in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris. However, the detailed molecular mechanisms for the SW-induced angiogenesis remain unclear. In this study, we thus examined the effects of SW irradiation on intracellular signaling pathways in vitro. Cultured human umbilical vein endothelial cells (HUVECs) were treated with 800 shots of low-energy SW (1 Hz at an energy level of 0.03 mJ/mm(2)). The SW therapy significantly upregulated mRNA expression and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). The SW therapy also enhanced phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) and Akt. Furthermore, the SW therapy enhanced phosphorylation of caveolin-1 and the expression of HUTS-4 that represents β1-integrin activity. These results suggest that caveolin-1 and β1-integrin are involved in the SW-induced activation of angiogenic signaling pathways. To further examine the signaling pathways involved in the SW-induced angiogenesis, HUVECs were transfected with siRNA of either β1-integrin or caveolin-1. Knockdown of either caveolin-1 or β1-integrin suppressed the SW-induced phosphorylation of Erk1/2 and Akt and upregulation of VEGF and eNOS. Knockdown of either caveolin-1 or β1-integrin also suppressed SW-induced enhancement of HUVEC migration in scratch assay. These results suggest that activation of mechanosensors on cell membranes, such as caveolin-1 and β1-integrin, and subsequent phosphorylation of Erk and Akt may play pivotal roles in the SW-induced angiogenesis. Copyright © 2016 the American Physiological Society.

  17. Effect of low energy electron irradiation on DNA damage by Cu{sup 2+} ion

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hyung Ah; Cho, Hyuck [Dept. of Physics, Chungnam National University, Daejeon (Korea, Republic of); Park, Yeun Soo [Plasma Technology Research Center, National Fusion Research Institute, Gunsan (Korea, Republic of)

    2017-03-15

    The combined effect of the low energy electron (LEE) irradiation and Cu{sup 2+} ion on DNA damage was investigated. Lyophilized pBR322 plasmid DNA films with various concentrations (1–15 mM) of Cu{sup 2+} ion were independently irradiated by monochromatic LEEs with 5 eV. The types of DNA damage, single strand break (SSB) and double strand break (DSB), were separated and quantified by gel electrophoresis. Without electron irradiation, DNA damage was slightly increased with increasing Cu ion concentration via Fenton reaction. LEE-induced DNA damage, with no Cu ion, was only 6.6% via dissociative electron attachment (DEA) process. However, DNA damage was significantly increased through the combined effect of LEE-irradiation and Cu ion, except around 9 mM Cu ion. The possible pathways of DNA damage for each of these different cases were suggested. The combined effect of LEE-irradiation and Cu ion is likely to cause increasing dissociation after elevated transient negative ion state, resulting in the enhanced DNA damage. For the decrease of DNA damage at around 9-mM Cu ion, it is assumed to be related to the structural stabilization due to DNA inter- and intra-crosslinks via Cu ion.

  18. Impurities and conductivity in a D-wave superconductor

    International Nuclear Information System (INIS)

    Balatsky, A.V.

    1994-01-01

    Impurity scattering in the unitary limit produces low energy quasiparticles with anisotropic spectrum in a two-dimensional d-wave superconductor. The authors describe a new quasi-one-dimensional limit of the quasiparticle scattering, which might occur in a superconductor with short coherence length and with finite impurity potential range. The dc conductivity in a d-wave superconductor is predicted to be proportional to the normal state scattering rate and is impurity-dependent. They show that quasi-one-dimensional regime might occur in high-T c superconductors with Zn impurities at low temperatures T approx-lt 10 K

  19. Chemical effects of low-energy electron impact on hydrocarbons in the gas phase. II. Propene

    International Nuclear Information System (INIS)

    Derai, R.; Danon, J.

    1977-01-01

    The chemical effects of low-energy (3.5 to 15.0 eV) electron impact on propene were investigated. The setup used for the irradiations has previously been described. Appearance curves for stable products were determined, from which correlations between products and precursors were deduced. In the excitation range, the main precursors are the triplet state at 4.4 eV and various singlet states around 7.0 and 9.0 eV. Above the ionization potential, contribution from superexcited molecules and ions was noted. Superexcited molecules are formed with a much higher cross section than excited molecules. A reaction scheme was proposed to account for the chemical effects associated with excited states and the yields of excited molecules in dissociating states were derived from experimental data. Results concerning the fragmentation of propene excited in singlet states conform to photolysis data. The following new results were obtained: the decomposition of propene excited in the triplet state at 4.4 eV involves mainly C--C bond rupture; the decomposition processes of superexcited and excited molecules are similar. A higher degree of fragmentation is observed in the case of superexcited molecules

  20. Effect of low-energy hydrogen ion implantation on dendritic web silicon solar cells

    Science.gov (United States)

    Rohatgi, A.; Meier, D. L.; Rai-Choudhury, P.; Fonash, S. J.; Singh, R.

    1986-01-01

    The effect of a low-energy (0.4 keV), short-time (2-min), heavy-dose (10 to the 18th/sq cm) hydrogen ion implant on dendritic web silicon solar cells and material was investigated. Such an implant was observed to improve the cell open-circuit voltage and short-circuit current appreciably for a number of cells. In spite of the low implant energy, measurements of internal quantum efficiency indicate that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. This is supported by the observation that the measured minority-carrier diffusion length in the base did not change when the emitter was removed. In some cases, a threefold increase of the base diffusion length was observed after implantation. The effects of the hydrogen implantation were not changed by a thermal stress test at 250 C for 111 h in nitrogen. It is speculated that hydrogen enters the bulk by traveling along dislocations, as proposed recently for edge-defined film-fed growth silicon ribbon.

  1. Traversable Lorentzian wormholes in the vacuum low energy effective string theory in Einstein and Jordan frames

    International Nuclear Information System (INIS)

    Nandi, K.K.; Zhang Yuanzhong

    2004-01-01

    Three new classes (II-IV) of solutions of the vacuum low energy effective string theory in four dimensions are derived. Wormhole solutions are investigated in those solutions including the class I case both in the Einstein and in the Jordan (string) frame. It turns out that, of the eight classes of solutions investigated (four in the Einstein frame and four in the corresponding string frame), massive Lorentzian traversable wormholes exist in five classes. Nontrivial massless limit exists only in class I Einstein frame solution while none at all exists in the string frame. An investigation of test scalar charge motion in the class I solution in the two frames is carried out by using the Plebanski-Sawicki theorem. A curious consequence is that the motion around the extremal zero (Keplerian) mass configuration leads, as a result of scalar-scalar interaction, to a new hypothetical 'mass' that confines test scalar charges in bound orbits, but does not interact with neutral test particles

  2. Effects of boosting the supply temperature on pipe dimensions of low-energy district heating networks

    DEFF Research Database (Denmark)

    Tol, Hakan; Svendsen, Svend

    2015-01-01

    This paper presents a method for the dimensioning of the low-energy District Heating (DH) piping networks operating with a control philosophy of supplying heat in low-temperature such as 55 °C in supply and 25°C in return regularly while the supply temperature levels are being boosted in cold...... winter periods. The performance of the existing radiators that were formerly sized with over-dimensions was analyzed, its results being used as input data for the performance evaluation of the piping network of the low-energy DH system operating with the control philosophy in question. The optimization...

  3. A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

    International Nuclear Information System (INIS)

    Tallentire, Alan; Miller, Arne; Helt-Hansen, Jakob

    2010-01-01

    The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement with a previously published value.

  4. A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

    DEFF Research Database (Denmark)

    Tallentire, A.; Miller, Arne; Helt-Hansen, Jakob

    2010-01-01

    The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement...... with a previously published value....

  5. Track structure analysis illustrating the prominent role of low-energy electrons in radiobiological effects of low-LET radiations

    International Nuclear Information System (INIS)

    Nikjoo, H.; Goodhead, D.T.

    1991-01-01

    Monte Carlo track structure methods have been used to illustrate the importance of low-energy electrons produced by low-LET radiations. It is shown that these low-energy secondary electrons contribute substantially to the dose in all low-LET irradiations and are particularly efficient at producing highly localized clusters of atomic damage which may be responsible for a major part of the biological effectiveness of low-LET radiations. The data generated by Monte Carlo track structure techniques and by earlier semi-analytical methods based on the LET concept have been compared in terms of cumulative and differential fractions of total dose absorbed as a function of electron energy. The data show that low-energy secondary electrons account for up to nearly 50% of the total dose imparted to a medium when irradiated with electrons or photons. (author)

  6. Low-energy QCD

    International Nuclear Information System (INIS)

    Ecker, G.

    1995-11-01

    After a brief introduction to chiral perturbation theory, the effective field theory of the standard model at low energies, two recent applications are reviewed: elastic pion-pion scattering to two-loop accuracy and the complete renormalized pion-nucleon Lagrangian to O(P 3 ) in the chiral expansion. (author)

  7. Projectile Coulomb center effects on low-energy electron emission from H[sup +][yields]Ne collisions

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, S. (Centro Atomico Bariloche e Inst. Balseiro, Comision Nacional de Energia Atomica, S.C. de Bariloche, Rio Negro (Argentina)); Garibotti, C. (Centro Atomico Bariloche e Inst. Balseiro, Comision Nacional de Energia Atomica, S.C. de Bariloche, Rio Negro (Argentina) Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)); Bernardi, G. (Centro Atomico Bariloche e Inst. Balseiro, Comision Nacional de Energia Atomica, S.C. de Bariloche, Rio Negro (Argentina) Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)); Focke, P. (Centro Atomico Bariloche e Inst. Balseiro, Comision Nacional de Energia Atomica, S.C. de Bariloche, Rio Negro (Argentina)); Meckbach, W. (Centro Atomico Bariloche e Inst. Balseiro, Comision Nacional de Energia Atomica, S.C. de Bariloche, Rio Negro (Argentina) Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina))

    1994-03-01

    We present doubly differential energy distributions of low-energy electrons emitted in collisions of 106 keV H[sup +] on Ne atoms. We find a relevant dependence of the measured distribution of low-energy electrons on the physical extension of the gas target and discuss a correction procedure. Our measurements enable a quantitative analysis of the shape of the soft electron peak, which is clearly evidenced by measured contour lines. Present results indicate that ''two center effects'' must be considered in order to account for the strong asymmetry of the soft electron peak observed experimentaly. (orig.)

  8. Effects of virtual isobar admixtures on the low-energy spectrum of a complex nucleus - model calculations for 12C

    International Nuclear Information System (INIS)

    Grecksch, E.

    1978-01-01

    On the basis of a detailed analysis of the excitation spectrum of a complex nucleus in the framework of the conventional shell model theory, the paper extends this concept by adding nucleonic degrees of freedom (isobars) and by model investigations and a realistic assessment of their effects on the excited states of the low-energy spectrum. (AH) [de

  9. Immediate Dose-Response Effect of High-Energy Versus Low-Energy Extracorporeal Shock Wave Therapy on Cutaneous Microcirculation.

    Science.gov (United States)

    Kraemer, Robert; Sorg, Heiko; Forstmeier, Vinzent; Knobloch, Karsten; Liodaki, Eirini; Stang, Felix Hagen; Mailaender, Peter; Kisch, Tobias

    2016-12-01

    Elucidation of the precise mechanisms and therapeutic options of extracorporeal shock wave therapy (ESWT) is only at the beginning. Although immediate real-time effects of ESWT on cutaneous hemodynamics have recently been described, the dose response to different ESWT energies in cutaneous microcirculation has never been examined. Thirty-nine Sprague-Dawley rats were randomly assigned to three groups that received either focused high-energy shock waves (group A: total of 1000 impulses, 10 J) to the lower leg of the hind limb, focused low-energy shock waves (group B: total of 300 impulses, 1 J) or placebo shock wave treatment (group C: 0 impulses, 0 J) using a multimodality shock wave delivery system (Duolith SD-1 T-Top, Storz Medical, Tägerwilen, Switzerland). Immediate microcirculatory effects were assessed with the O2C (oxygen to see) system (LEA Medizintechnik, Giessen, Germany) before and for 20 min after application of ESWT. Cutaneous tissue oxygen saturation increased significantly higher after high-energy ESWT than after low-energy and placebo ESWT (A: 29.4% vs. B: 17.3% vs. C: 3.3%; p = 0.003). Capillary blood velocity was significantly higher after high-energy ESWT and lower after low-energy ESWT versus placebo ESWT (group A: 17.8% vs. group B: -22.1% vs. group C: -5.0%, p = 0.045). Post-capillary venous filling pressure was significantly enhanced in the high-energy ESWT group in contrast to the low-energy ESWT and placebo groups (group A: 25% vs. group B: 2% vs. group C: -4%, p = 0.001). Both high-energy and low-energy ESWT affect cutaneous hemodynamics in a standard rat model. High-energy ESWT significantly increases parameters of cutaneous microcirculation immediately after application, resulting in higher tissue oxygen saturation, venous filling pressure and blood velocity, which suggests higher tissue perfusion with enhanced oxygen saturation, in contrast to low-energy as well as placebo ESWT. Low-energy ESWT also increased tissue oxygen

  10. Effect of tissue inhomogeneity on dose distribution of point sources of low-energy electrons

    International Nuclear Information System (INIS)

    Kwok, C.S.; Bialobzyski, P.J.; Yu, S.K.; Prestwich, W.V.

    1990-01-01

    Perturbation in dose distributions of point sources of low-energy electrons at planar interfaces of cortical bone (CB) and red marrow (RM) was investigated experimentally and by Monte Carlo codes EGS and the TIGER series. Ultrathin LiF thermoluminescent dosimeters were used to measure the dose distributions of point sources of 204 Tl and 147 Pm in RM. When the point sources were at 12 mg/cm 2 from a planar interface of CB and RM equivalent plastics, dose enhancement ratios in RM averaged over the region 0--12 mg/cm 2 from the interface were measured to be 1.08±0.03 (SE) and 1.03±0.03 (SE) for 204 Tl and 147 Pm, respectively. The Monte Carlo codes predicted 1.05±0.02 and 1.01±0.02 for the two nuclides, respectively. However, EGS gave consistently 3% higher dose in the dose scoring region than the TIGER series when point sources of monoenergetic electrons up to 0.75 MeV energy were considered in the homogeneous RM situation or in the CB and RM heterogeneous situation. By means of the TIGER series, it was demonstrated that aluminum, which is normally assumed to be equivalent to CB in radiation dosimetry, leads to an overestimation of backscattering of low-energy electrons in soft tissue at a CB--soft-tissue interface by as much as a factor of 2

  11. Effect of hyperon channels in low-energy k-d scattering

    International Nuclear Information System (INIS)

    Schick, L.H.; Gibson, B.F.

    1978-01-01

    Within the framework of a Faddeev formalism and an implicit hyperon channel approximation, we have calculated K - d elastic, total, and reaction cross sections for incident kaon laboratory momenta up to 120 Mev/c. We have used as input two different (slightly modified) multichannel M matrix fits to low-energy anti KN scattering, each of which contains explicitly the πY channels, as well as a single channel representation of the anti KN interaction in which the hyperon channels appear only through their contributions to the imaginary parts of the anti KN scattering lengths. The K - d cross sections obtained with the single channel anti KN input differ by only some 10% from those for which we used the multichannel anti KN input. The D - d cross sections calculated using anti KN input parameters from each of the two separate M matrix fits differ across the entire momentum range investigated by 25-35%. (orig.) [de

  12. Low Energy Gamma Radiation Induced Effects on Ultrasonic Velocity and Acoustic Parameters in Polyvinylidene Fluoride Solution

    Directory of Open Access Journals (Sweden)

    S. S. Kulkarni

    2016-01-01

    Full Text Available The modification of polyvinylidene fluoride (PVDF polymer properties with irradiation is of interest as it possesses unique piezo-, pyro-, and ferroelectric properties. In this paper, we report the results of acoustic parameters of irradiated PVDF mixed with dimethylacetamide (DMAC solution with low energy γ-source (Cs-137. The polymer solution covered with mica film assures only γ-ray passage and the duration was increased from 18 to 50 hours to achieve the higher dose rate. The dose rate was estimated using the strength of the radioactive source and the duration of the exposure. The ultrasonic velocity (v, density (ρ, and viscosity (η of 0.2 wt% and 0.5 wt% PVDF dissolved in pure DMAC solution, irradiated with different dose rate were measured using ultrasonic interferometer (Mittal make, Pyknometer, and Oswald’s viscometer, respectively. It is observed that the values of v, ρ, and η change with dose rate. The acoustic parameters such as adiabatic compressibility (β, intermolecular free path length (Lf, acoustic impedance (Z, relative association (RA, ultrasonic attenuation (α/f2, and relaxation time (τ are calculated using the experimental data. These results are interpreted in terms of the solute-solvent interaction in a polymer solution and scissoring chain damage.

  13. The Effect of Low Energy Turbulence in Estuary Margins on Fine Sediment Settling

    Science.gov (United States)

    Allen, R. M.; MacVean, L. J.; Tse, I.; Mazzaro, L. J.; Stacey, M. T.; Variano, E. A.

    2014-12-01

    turbulent Reynolds number will enable more mechanistic predictions of sediment transport in low energy environments like protected estuary margins.

  14. Bone mineral density and bone markers in patients with a recent low-energy fracture: effect of 1 y of treatment with calcium and vitamin D

    DEFF Research Database (Denmark)

    Hitz, Mette F; Jensen, Jens-Erik B; Eskildsen, Peter C

    2007-01-01

    BACKGROUND: Low-energy fractures of the hip, forearm, shoulder, and spine are known consequences of osteoporosis. OBJECTIVE: We evaluated the effect of 1 y of treatment with calcium and vitamin D on bone mineral density (BMD) and bone markers in patients with a recent low-energy fracture. DESIGN...

  15. Effects of irradiation with low-energy nitrogen ion injection on root tip cells of broad bean

    International Nuclear Information System (INIS)

    Huang Yaqin; Li Jinzhe; Huang Qunce

    2012-01-01

    In order to study the cytogenetic effects of low-energy nitrogen ion irradiation, broad bean seed embryo was irradiated by different doses of nitrogen ions. Micronucleus rate, mitotic index and chromosome aberration in root-tip cells were analyzed. The results showed that the injection of ions inhibited mitosis of root tip cells, interfered the normal process of mitosis, caused aberrations of chromosome structure, behavior and number. The frequency of micronucleus and chromosomal aberrations increased with the increasing radiation dosage, while mitotic index decreased. (authors)

  16. Low Energy Conference 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    11 of the 19 presentations have been indexed for the database. The following national organisations jointly organised the Low-energy Conference 2009: The Norwegian Society for the Conservation of Nature, the Norwegian Society of Engineers and Technologists, Norwegian Technology, the Federation of Norwegian Industries and the Low-Energy Program. Energy efficiency is often given little attention in the ongoing debates concerning different initiatives in order to reduce greenhouse emissions. The aim of the conference was to set energy efficiency on the agenda as an important environmental instrument. Both the Intergovernmental Panel on Climate Change - IPCC and the International Energy Agency - IEA regard energy efficiency as one of the fastest and most effective ways of reducing greenhouse emissions. Despite of this little is done. Many countries are ahead of Norway - why are we lagging behind? The Low-Energy conference has a broad approach: Nigel Jollands from the International Energy Agency -IEA puts energy efficiency in a global perspective. Soeren Rise from Teqniq in Denmark informs about the Danes' energy saving agreement, which appears to have been a success. The conference increased the competencies on concrete energy efficiency solutions, how to speed up the marketing of energy-friendly buildings and technologies, possibilities through industry and the impact of EU-directives and other instruments in order to trigger the potential. The conference closed with a discussion panel of leading energy politicians. The conference contributed to raise the debate in advance of the General election in Norway and the climate negotiations in Copenhagen during the autumn 2009. (EW)

  17. The ionizing effect of low-energy cosmic rays from a class II object on its protoplanetary disc

    Science.gov (United States)

    Rodgers-Lee, D.; Taylor, A. M.; Ray, T. P.; Downes, T. P.

    2017-11-01

    We investigate the ionizing effect of low-energy cosmic rays (CRs) from a young star on its protoplanetary disc (PPD). We consider specifically the effect of ∼3 GeV protons injected at the inner edge of the PPD. An increase in the ionization fraction as a result of these CRs could allow the magnetorotational instability to operate in otherwise magnetically dead regions of the disc. For the typical values assumed we find an ionization rate of ζCR ∼ 10-17 s-1 at 1 au. The transport equation is solved by treating the propagation of the CRs as diffusive. We find for increasing diffusion coefficients the CRs penetrate further in the PPD, while varying the mass density profile of the disc is found to have little effect. We investigate the effect of an energy spectrum of CRs. The influence of a disc wind is examined by including an advective term. For advective wind speeds between 1 and 100 km s-1 diffusion dominates at all radii considered here (out to 10 au) for reasonable diffusion coefficients. Overall, we find that low-energy CRs can significantly ionize the mid-plane of PPDs out to ∼1 au. By increasing the luminosity or energy of the CRs, within plausible limits, their radial influence could increase to ∼2 au at the mid-plane but it remains challenging to significantly ionize the mid-plane further out.

  18. Low-energy effective theory, unitarity, and nondecoupling behavior in a model with heavy Higgs-triplet fields

    International Nuclear Information System (INIS)

    Chivukula, R. Sekhar; Christensen, Neil D.; Simmons, Elizabeth H.

    2008-01-01

    We discuss the properties of a model incorporating both a scalar electroweak Higgs doublet and an electroweak Higgs triplet. We construct the low-energy effective theory for the light Higgs doublet in the limit of small (but nonzero) deviations in the ρ parameter from one, a limit in which the triplet states become heavy. For Δρ>0, perturbative unitarity of WW scattering breaks down at a scale inversely proportional to the renormalized vacuum expectation value of the triplet field (or, equivalently, inversely proportional to the square root of Δρ). This result imposes an upper limit on the mass scale of the heavy triplet bosons in a perturbative theory; we show that this upper bound is consistent with dimensional analysis in the low-energy effective theory. Recent articles have shown that the triplet bosons do not decouple, in the sense that deviations in the ρ parameter from one do not necessarily vanish at one-loop in the limit of large triplet mass. We clarify that, despite the nondecoupling behavior of the Higgs triplet, this model does not violate the decoupling theorem since it incorporates a large dimensionful coupling. Nonetheless, we show that if the triplet-Higgs boson masses are of order the grand unified theory scale, perturbative consistency of the theory requires the (properly renormalized) Higgs-triplet vacuum expectation value to be so small as to be irrelevant for electroweak phenomenology

  19. Effects of impurities and vortices on the low-energy spin excitations in high-Tc materials

    DEFF Research Database (Denmark)

    Andersen, Brian Møller; Graser, S.; Schmid, M.

    2011-01-01

    We review a theoretical scenario for the origin of the spin-glass phase of underdoped cuprate materials. In particular it is shown how disorder in a correlated d-wave superconductor generates a magnetic phase by inducing local droplets of antiferromagnetic order which eventually merge and form...

  20. Effective Lagrangians and parity-conserving time-reversal violation at low energies

    International Nuclear Information System (INIS)

    Engel, J.; Frampton, P.H.; Springer, R.P.

    1996-01-01

    Using effective Lagrangians, we argue that any time-reversal-violating but parity-conserving effects are too small to be observed in flavor-conserving nuclear processes without dramatic improvement in experimental accuracy. In the process we discuss other arguments that have appeared in the literature. copyright 1996 The American Physical Society

  1. Effect of heavy particles in low-energy light-particle processes

    International Nuclear Information System (INIS)

    Chan, L.H.; Hagiwara, T.; Ovrut, B.

    1979-01-01

    The ''decoupling theorem'' of Appelquist and Carazzone is found not always to be applicable to light-scalar-particle processes in spontaneously broken theories. If the Higgs scalar is considered to be light, then Higgs-scalar processes see the effect of heavy fermions and heavy vector gauge bosons at the one-loop level. If there is more than one scalar multiplet in a spontaneously broken gauge theory, the effect of a heavy Higgs particle in light-scalar-particle processes is significant at the tree level. In the latter case, such an effect can be absorbed completely into an effective phi 4 coupling constant, lambda/sub eff/, of the light particle provided that lambda/sub eff/ is positive definite

  2. Low energy constituent quark and pion effective couplings in a weak external magnetic field

    Science.gov (United States)

    Braghin, Fábio L.

    2018-03-01

    An effective model with pions and constituent quarks in the presence of a weak external background electromagnetic field is derived by starting from a dressed one gluon exchange quark-quark interaction. By applying the auxiliary field and background field methods, the structureless pion limit is considered to extract effective pion and constituent quark couplings in the presence of a weak magnetic field. The leading terms of a large quark and gluon masses expansion are obtained by resolving effective coupling constants which turn out to depend on a weak magnetic field. Two pion field definitions are considered for that. Several relations between the effective coupling constants and parameters can be derived exactly or in the limit of very large quark mass at zero and weak constant magnetic field. Among these ratios, the Gell-Mann-Oakes-Renner and the quark level Goldberger-Treiman relations are obtained. In addition to that, in the pion sector, the leading terms of Chiral Perturbation Theory coupled to the electromagnetic field are recovered. Some numerical estimates are provided for the effective coupling constants and parameters.

  3. Low-energy effective action in nonperturbative electrodynamics in curved space-time

    International Nuclear Information System (INIS)

    Avramidi, Ivan G.; Fucci, Guglielmo

    2009-01-01

    We study the heat kernel for the Laplace-type partial differential operator acting on smooth sections of a complex spin-tensor bundle over a generic n-dimensional Riemannian manifold. Assuming that the curvature of the U(1) connection (that we call the electromagnetic field) is constant, we compute the first two coefficients of the nonperturbative asymptotic expansion of the heat kernel which are of zero and the first order in Riemannian curvature and of arbitrary order in the electromagnetic field. We apply these results to the study of the effective action in nonperturbative electrodynamics in four dimensions and derive a generalization of the Schwinger's result for the creation of scalar and spinor particles in electromagnetic field induced by the gravitational field. We discover a new infrared divergence in the imaginary part of the effective action due to the gravitational corrections, which seems to be a new physical effect.

  4. Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly

    CERN Document Server

    Ericson, M; Giunti, C; Martini, M

    2016-01-01

    We study the impact of the effect of multinucleon interactions in the reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms of neutrino oscillations. We obtain some improvement of the fit of the MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a shift of the allowed region in the $\\sin^2 2\\vartheta$--$\\Delta{m}^2$ plane towards smaller values of $\\sin^2 2\\vartheta$ and larger values of $\\Delta{m}^2$. However this effect is not enough to solve the problem of the appearance-disappearance tension in the global fit of short-baseline neutrino oscillation data.

  5. Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly

    Science.gov (United States)

    Ericson, M.; Garzelli, M. V.; Giunti, C.; Martini, M.

    2016-04-01

    We study the impact of the effect of multinucleon interactions in the reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms of neutrino oscillations. We obtain some improvement of the fit of the MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a shift of the allowed region in the sin22 ϑ -Δ m2 plane toward smaller values of sin22 ϑ and larger values of Δ m2. However, this effect is not enough to solve the problem of the appearance-disappearance tension in the global fit of short-baseline neutrino oscillation data.

  6. Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, M. [Lyon 1 Univ., CNRS/IN2P3 (France). INP Lyon; CERN Geneva (Switzerland). Theory Unit; Garzelli, M.V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Giunti, C. [INFN, Sezione di Torino (Italy); Martini, M. [ESNT, CEA-Saclay, IRFU, Gif-sur-Yvette (France). Service de Physique Nucleaire

    2016-02-15

    We study the impact of the effect of multinucleon interactions in the reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms of neutrino oscillations. We obtain some improvement of the fit of the MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a shift of the allowed region in the sin{sup 2}2θ-Δm{sup 2} plane towards smaller values of sin{sup 2}2ν and larger values of Δm{sup 2}. However this effect is not enough to solve the problem of the appearance-disappearance tension in the global fit of short-baseline neutrino oscillation data.

  7. Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly

    International Nuclear Information System (INIS)

    Ericson, M.; Martini, M.

    2016-02-01

    We study the impact of the effect of multinucleon interactions in the reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms of neutrino oscillations. We obtain some improvement of the fit of the MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a shift of the allowed region in the sin 2 2θ-Δm 2 plane towards smaller values of sin 2 2ν and larger values of Δm 2 . However this effect is not enough to solve the problem of the appearance-disappearance tension in the global fit of short-baseline neutrino oscillation data.

  8. Dramatic nondipole effects in low-energy photoionization: Experimental and theoretical study of Xe 5s

    International Nuclear Information System (INIS)

    Hemmers, O.; Lindle, D.W.; Baker, J.; Hudson, A.; Lotrakul, M.; Tran, I.C.; Guillemin, R.; Stolte, W.C.; Wolska, A.; Yu, S.W.; Kanter, E.P.; Kraessig, B.; Southworth, S.H.; Wehlitz, R.; Rolles, D.; Amusia, M.Ya.; Cheng, K.T.; Chernysheva, L.V.; Johnson, W.R.; Manson, S.T.

    2003-01-01

    The Xe 5s nondipole photoelectron parameter γ is obtained experimentally and theoretically from threshold to ∼200 eV photon energy. Significant nondipole effects are seen even in the threshold region of this valence shell photoionization. In addition, contrary to previous understanding, clear evidence of interchannel coupling among quadrupole photoionization channels is found

  9. Kaluza-Klein reduction of low-energy effective actions: geometrical approach

    Czech Academy of Sciences Publication Activity Database

    Vysoký, Jan

    2017-01-01

    Roč. 2017, č. 8 (2017), č. článku 143. ISSN 1029-8479 Institutional support: RVO:67985840 Keywords : differential and algebra ic geometry * effective field theories * supergravity models Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 6.063, year: 2016 https://link.springer.com/article/10.1007%2FJHEP08%282017%29143

  10. Study of low energy hydrogen ion implantation effects in silicon: electric properties

    International Nuclear Information System (INIS)

    Barhdadi, A.

    1985-07-01

    Several analysis methods have been developed: hydrogen distribution analysis by nuclear reaction, crystal disorder evaluation by R.B.S., chemical impurities identification by SIMS, optical measurements, electrical characterization of surface barriers, deep level spectroscopy DLTS, ... All these analyses have been made after implantation then after thermal annealing. A model explaining the effect of implantation then after thermal annealing. A model explaining the effect of implanted hydrogen is proposed, the implantation creates an important quantity of defects in a thin layer near the surface; a chemical attack removes them. In Schottky devices, this layer has a basic role on carrier transport phenomena. Other results are given, some of them allow to give an account of the passivation by hydrogen implantation [fr

  11. Low-energy effective models for two-flavor quantum chromodynamics and the universality hypothesis

    International Nuclear Information System (INIS)

    Grahl, Mara

    2014-01-01

    Our thesis is centered around the question of which order the chiral phase transition of two-flavor QCD is. First of all we outline several general aspects of phase transitions which are of central importance for the understanding of the RG approach towards them. Our focus lies on reviewing the universality hypothesis, a crucial ingredient when it comes to the construction of effective theories for order parameters, the credibility of which often heavily depends on universality arguments. We finish the chapter with an attempt to formulate the latter more precisely than usually done. The next chapter discusses the chiral phase transition from a general point of view. We supplement well-known facts with a detailed discussion of the so-called O(4) conjecture. Thereafter we introduce the nonperturbative method we use, the FRG method. Furthermore, we discuss the relation between effective models for QCD and the underlying fundamental theory making use of the FRG perspective. The next chapter is concerned with a mathematical subject indispensable for our approach towards the study of phase transitions, namely the systematic construction of polynomial invariants characterizing a given symmetry. With this thesis we point out its relevance in the context of high-energy physics. We present a simple, but novel, brute-force algorithm to effectively construct invariants of a given polynomial order. The next chapter is devoted to RG studies of several dimensionally reduced theories which are capable to either predict or to rule out the possible existence of a second-order phase transition. Of main interest for us is the linear sigma model, particularly in presence of the axial anomaly. It turns out that the fixed-point structure of the latter is rather complicated, requiring a deeper understanding of the underlying method and its preconditions. This leads us to a careful analysis of the fixed-point structure of several models, which is of great benefit for our review of the

  12. Effect of pion external distortion on low energy pion double-charge-exchange

    International Nuclear Information System (INIS)

    Khankhasaev, M.Kh.; Kurmanov, Zh.B.; Johnson, M.B.

    1993-01-01

    The effects of the external pion distortion for iso-elastic charge exchange scattering (within the framework of the isospin invariant optical model) is considered. An approximated method of taking into account the distortion based on the separable expansion of the optical potential in momentum space is developed. The result of external distortions for sequential scattering 14 C(π + , π - ) 14 O at 50 MeV is presented. It is shown that this distortion gives a small enhancement to forward and reduced the differential cross sections at large angels. 22 refs., 5 figs., 1 tab

  13. Effect of a novel low-energy pulsed-light device for home-use hair removal.

    Science.gov (United States)

    Alster, Tina S; Tanzi, Elizabeth L

    2009-03-01

    Removal of unwanted hair is the most popular skin treatment worldwide. Over the past decade, various lasers and light sources for epilation have been advocated for use in an office setting, although most people continue to treat unwanted hair with a variety of temporary physical methods (e.g., waxing, shaving) in a home setting, presumably due to cost and convenience factors. To evaluate the safety and efficacy of a low-energy pulsed-light device intended for home-use hair removal. Twenty women (skin phototypes I-IV) with dark terminal hair in nonfacial sites (axilla, forearms, inguinal region, legs) self-administered three treatments at 2-week intervals using a handheld intense-pulsed-light device. Matched untreated skin sites were also studied. Hair counts and clinical photographs were obtained pretreatment and at 1, 3, and 6 months after the third treatment. Side effects and patient satisfaction scores were recorded. All patients showed a positive clinical response to treatment, with reduction of unwanted hair. No reduction of hair was noted in untreated matched areas. Hair counts were reduced 37.8% to 53.6% 6 months after the three treatments. Skin region influenced clinical response, with lower legs exhibiting greater hair reduction than arms and inguinal and axillary areas. Mild erythema was experienced in 25% of patients, but no other side effects or complications were encountered. Patient satisfaction scores were high, with all patients stating that they would purchase the device for future home use. CONCLUSIONS Low-energy pulsed light can be applied safely and effectively for at-home hair removal in a variety of nonfacial locations and skin phototypes I-IV.

  14. Effects of low energy helium plasma irradiation on potassium doped tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xiaoyan [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu (China); Key Subject Laboratory of National Defense for Radioactive Waste and Environmental Security, Southwest University of Science and Technology, Mianyang (China); Huang, Bo [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu (China); Liu, Dongping; Fan, Hongyu [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian (China); Liu, Ning [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu (China); Tang, Jun, E-mail: tangjun@scu.edu.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu (China)

    2017-04-15

    Effects of helium plasma irradiation on spark plasma sintering (SPS) W-K, pure W and traditionally sintered commercial W-K have been studied, concerning the density, grain size and potassium content as the influence factors. Pinholes are formed under 120 eV He ions at 600 °C and 1 × 10{sup 23} m{sup −2} fluence on the surface of all samples. It is found that SPS-sintered W-K shows the best irradiation resistance among the present samples, and SPS-sintered pure W exhibits higher irradiation tolerance than commercial W-K. Different He-plasma tolerance was observed among the SPS-sintered W-K samples due to varied potassium content and grain size. In addition, the microstructure evolution under helium irradiation, the growth-migration of helium bubbles and their interactions of potassium bubbles have also been discussed.

  15. Effects of symmetry energy and momentum dependent interaction on low-energy reaction mechanisms

    Directory of Open Access Journals (Sweden)

    Zheng H.

    2016-01-01

    Full Text Available We study the dipole response associated with the Pygmy Dipole Resonance (PDR and the Isovector Giant Dipole Resonance (IVGDR, in connection with specific properties of the nuclear effective interaction (symmetry energy and momentum dependence, in the neutron-rich systems 68Ni, 132Sn and 208Pb. We perform our investigation within a microscopic transport model based on the Landau-Vlasov kinetic equation.We observe that the peak energies of PDR and IVGDR are shifted to higher values when employing momentum dependent interactions, with respect to the results obtained neglecting momentum dependence. The calculated energies are close to the experimental values and similar to the results obtained in Hartree-Fock (HF with Random Phase Approximation (RPA calculations.

  16. Space Charge Effects and Advanced Modelling for CERN Low Energy Machines

    CERN Document Server

    AUTHOR|(CDS)2088716; Rumolo, Giovanni

    The strong space charge regime of future operation of CERN’s circular particle accelerators is investigated and mitigation strategies are developed in the framework of the present thesis. The intensity upgrade of the injector chain of Large Hadron Collider (LHC) prepares the particle accelerators to meet the requirements of the High-Luminosity LHC project. Producing the specified characteristics of the future LHC beams imperatively relies on injecting brighter bunches into the Proton Synchrotron Booster (PSB), the downstream Proton Synchrotron (PS) and eventually the Super Proton Synchrotron (SPS). The increased brightness, i.e. bunch intensity per transverse emittance, entails stronger beam self-fields which can lead to harmful interaction with betatron resonances. Possible beam emittance growth and losses as a consequence thereof threaten to degrade the beam brightness. These space charge effects are partly mitigated by the upgrade of the PSB and PS injection energies. Nevertheless, the space charge tune ...

  17. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Xu Gang; Wang Xiaoteng; Gan Cailing; Fang Yanqiong; Zhang Meng

    2012-01-01

    Highlights: ► We analyzed biological effects of N + implantation on dry Jatropha curcas seed. ► N + implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 10 16 ion cm −2 , biological repair took place. ► CAT was essential for H 2 O 2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N + with energy of 25 keV was applied to treat the dry seed at six different doses. N + beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 10 16 to 15 × 10 16 ions cm −2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 10 16 ion cm −2 , biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 10 16 ions cm −2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  18. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  19. Image potential effect on the specular reflection coefficient of alkali ions scattered from a nickel surface at low energy

    International Nuclear Information System (INIS)

    Zemih, R.; Boudjema, M.; Benazeth, C.; Boudouma, Y.; Chami, A.C.

    2002-01-01

    The resonant charge exchange in the incoming path of alkali ions scattered at low energy from a polycrystalline nickel surface is studied by using the image effect occurring at glancing incidence (2-10 deg. from the surface plane) and for specular reflection. The part of the experimental artefacts (geometrical factor, surface roughness ...) is extracted from the reflection coefficient of almost completely neutralised projectiles (He + or Ne + ) compared with the coefficient obtained from numerical simulations (TRIM and MARLOWE codes). The present model explains very well the lowering of the reflection coefficient measured at grazing incidence (below 4 deg.). Furthermore, the optimised values of the charge fraction in the incoming path and the image potential are in agreement with the theoretical calculations in the case of Na + /Ni at 4 keV

  20. Low energy proton irradiation effects on InP/InGaAs DHBTs and InP-base frequency dividers

    Science.gov (United States)

    Zhang, Xingyao; Li, Yudong; Guo, Qi; Feng, Jie

    2018-03-01

    InP/InGaAs DHBTs and frequency dividers are irradiated by low energy proton, and displacement damage effect of the devices are analyzed. InP/InGaAs DHBTs has been made DC characteristics measurements, and the function measurement for frequency dividers has been done both before and after proton irradiation. The breakdown voltage of InP DHBTs drop to 3.7V When the fluence up to 5x1013 protons/cm2. Meanwhile, the function of frequency dividers get out of order. Degradation of DC characteristics of DHBTs are due to the radiation-induced defects in the quasi neutral base and the space charge region of base-collector and base-emitter junctions. The performance deterioration of DHBTs induce the fault of frequency dividers, and prescaler may be the most sensitive circuit.

  1. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Science.gov (United States)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  2. Effects of fermionic singlet neutrinos on high- and low-energy observables

    International Nuclear Information System (INIS)

    Weiland, C.

    2013-01-01

    In this doctoral thesis, we study both low- and high-energy observables related to massive neutrinos. Neutrino oscillations have provided indisputable evidence in favour of non-zero neutrino masses and mixings. However, the original formulation of the standard model cannot account for these observations, which calls for the introduction of new physics. Among many possibilities, we focus here on the inverse seesaw, a neutrino mass generation mechanism in which the standard model is extended with fermionic gauge singlets. This model offers an attractive alternative to the usual seesaw realisations since it can potentially have natural Yukawa couplings (O(1)) while keeping the new physics scale at energies within the reach of the LHC. Among the many possible effects, this scenario can lead to deviations from lepton flavour universality. We have investigated these signatures and found that the ratios R K and R π provide new, additional constraints on the inverse seesaw. We have also considered the embedding of the inverse seesaw in supersymmetric models. This leads to increased rates for various lepton flavour violating processes, due to enhanced contributions from penguin diagrams mediated by the Higgs and Z 0 bosons. Finally, we also found that the new invisible decay channels associated with the sterile neutrinos present in the super-symmetric inverse seesaw could significantly weaken the constraints on the mass and couplings of a light CP-odd Higgs boson. (author)

  3. Precise determination of total absorption coefficients for low-energy gamma-quanta with Moessbauer effect

    International Nuclear Information System (INIS)

    Bonchev, T.; Statev, S.; Nejkov, Kh.

    1980-01-01

    A new method of determining the total absorption coefficient applying the Moessbauer effect is proposed. This method enables the accuracy of the measurement increase. The coefficient is measured with practically no background on using the recoilless part of gamma radiation obtained from the Moessbauer source with and without the sample between the source of the gamma-quanta and the detector. Moessbauer sources and absorbers with a single line and without an isomeric shift are used. The recoilless part of the radiation is obtained by the ''two point'' method as a difference between the numbers of photons corresponding to the stationary source and to the vibrating one with a big mean square velocity, respectively. In the concrete measurements the sources 57 Co and 119 Sn are used. The total absorption coefficient for different samples beginning with water up to plumbum is determined. The mean square error for the mean result in all measurements is less than the mean statistical error for the coefficient. The obtained experimental data give a much smaller deviation from the theoretical data of the last issue of the Stom-Israel Tables than the one expected by their authors

  4. Solid-state effects on thermal-neutron cross sections and on low-energy resonances

    International Nuclear Information System (INIS)

    Harvey, J.A.; Mook, H.A.; Hill, N.W.; Shahal, O.

    1982-01-01

    The neutron total cross sections of several single crystals (Si, Cu, sapphire), several polycrystalline samples (Cu, Fe, Be, C, Bi, Ta), and a fine-powder copper sample have been measured from 0.002 to 5 eV. The Cu powder and polycrystalline Fe, Be and C data exhibit the expected abrupt changes in cross section. The cross section of the single crystal of Si is smooth with only small broad fluctuations. The data on two single Cu crystals, the sapphire crystal, cast Bi, and rolled samples of Ta and Cu have many narrow peaks approx. 10 -3 eV wide. High resolution (0.3%) transmission measurements were made on the 1.057-eV resonance in 240 Pu and the 0.433-eV resonance in 180 Ta, both at room and low temperatures to study the effects of crystal binding. Although the changes in Doppler broadening with temperature were apparent, no asymmetries due to a recoilless contribution were observed

  5. Antiferromagnetism and d-wave superconductivity in the Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Krahl, H.C.

    2007-07-25

    The two-dimensional Hubbard model is a promising effective model for the electronic degrees of freedom in the copper-oxide planes of high temperature superconductors. We present a functional renormalization group approach to this model with focus on antiferromagnetism and d-wave superconductivity. In order to make the relevant degrees of freedom more explicitly accessible on all length scales, we introduce composite bosonic fields mediating the interaction between the fermions. Spontaneous symmetry breaking is reflected in a non-vanishing expectation value of a bosonic field. The emergence of a coupling in the d-wave pairing channel triggered by spin wave fluctuations is demonstrated. Furthermore, the highest temperature at which the interaction strength for the electrons diverges in the renormalization flow is calculated for both antiferromagnetism and d-wave superconductivity over a wide range of doping. This ''pseudo-critical'' temperature signals the onset of local ordering. Moreover, the temperature dependence of d-wave superconducting order is studied within a simplified model characterized by a single coupling in the d-wave pairing channel. The phase transition within this model is found to be of the Kosterlitz-Thouless type. (orig.)

  6. Geometric phase effects in low-energy dynamics near conical intersections: A study of the multidimensional linear vibronic coupling model

    International Nuclear Information System (INIS)

    Joubert-Doriol, Loïc; Ryabinkin, Ilya G.; Izmaylov, Artur F.

    2013-01-01

    In molecular systems containing conical intersections (CIs), a nontrivial geometric phase (GP) appears in the nuclear and electronic wave functions in the adiabatic representation. We study GP effects in nuclear dynamics of an N-dimensional linear vibronic coupling (LVC) model. The main impact of GP on low-energy nuclear dynamics is reduction of population transfer between the local minima of the LVC lower energy surface. For the LVC model, we proposed an isometric coordinate transformation that confines non-adiabatic effects within a two-dimensional subsystem interacting with an N − 2 dimensional environment. Since environmental modes do not couple electronic states, all GP effects originate from nuclear dynamics within the subsystem. We explored when the GP affects nuclear dynamics of the isolated subsystem, and how the subsystem-environment interaction can interfere with GP effects. Comparing quantum dynamics with and without GP allowed us to devise simple rules to determine significance of the GP for nuclear dynamics in this model

  7. The effect of low-energy electrons on the response of ion chambers to ionizing photon beams

    Science.gov (United States)

    La Russa, Daniel J.

    Cavity ionization chambers are one of the most popular and widely used devices for quantifying ionizing photon beams. This popularity originates from the precision of these devices and the relative ease with which ionization measurements are converted to quantities of interest in therapeutic radiology or radiation protection, collectively referred to as radiation dosimetry. The formalisms used for these conversions, known as cavity theory, make several assumptions about the electron spectrum in the low-energy range resulting from the incident photon beam. These electrons often account for a significant fraction of the ion chamber response. An inadequate treatment of low-energy electrons can therefore significantly effect calculated quantities of interest. This thesis sets out to investigate the effect of low-energy electrons on (1) the use of Spencer-Attix cavity theory with 60Co beams; and (2) the standard temperature-pressure correction factor, P TP, used to relate the measured ionization to a set of reference temperature and pressure conditions for vented ion chambers. Problems with the PTP correction are shown to arise when used with kilovoltage x rays, where ionization measurements are due primarily to electrons that do not have enough energy to cross the cavity. A combination of measurements and Monte Carlo calculations using the EGSnrc Monte Carlo code demonstrate the breakdown of PTP in these situations when used with non-air-equivalent chambers. The extent of the breakdown is shown to depend on cavity size, energy of the incident photons, and the composition of the chamber. In the worst case, the standard P TP factor overcorrects the response of an aluminum chamber by ≈12% at an air density typical of Mexico City. The response of a more common graphite-walled chamber with similar dimensions at the same air density is undercorrected by ≈ 2%. The EGSnrc Monte Carlo code is also used to investigate Spencer-Attix cavity theory as it is used in the

  8. Possibility of a 4He2 bound state, effective range theory, and very low energy He--He scattering

    International Nuclear Information System (INIS)

    Uang, Y.; Stwalley, W.C.

    1982-01-01

    The best available intermolecular potential for helium by Aziz, Nain, Carley, Taylor, and McConville is shown here for the first time to have a 4 He 2 bound state. Two numerical analyses, namely, eigenvalue solution and effective range theory, are used to support this conclusion. Unlike usual chemically bound species, the binding energy of this very weakly bound level is found to be only 8.3 x 10 -4 K, which is four orders of magnitude smaller than the potential well depth epsilon = 10.8 K. The scattering length for He+He collisions, determined from effective range theory, is used to calculate the elastic cross section in the very low energy limit. The results (1.878 x 10 5 A 2 for 4 He+ 4 He and 6.035 x 10 2 A for 3 He+ 3 He) are consistent with measurements at the lowest velocities yet attained. In terms of the estimated uncertainties of the parameters of the potential of Aziz and co-workers, it is shown that it is very likely that a bound state of the 4 He 2 molecule does in fact exist

  9. Effects of non-implantation factors on survival rate of microbe irradiated by low-energy N+

    International Nuclear Information System (INIS)

    Yang Tianyou; Chen Linhai; Qin Guangyong; Li Zongwei; Su Mingjie; Wang Yanping; Chang Shenghe; Huo Yuping; Li Zongyi

    2006-01-01

    The effects of non-implantation factors, such as drying, vacuum and the staying time of the E.coli LE392 culture, on survival rate of E.coli LE392 were studied when E.coli LE392 was irradiated by the low-energy N + . The results show that the survival rate of E.coli LE392 does not reduce steadily all the time but rapidly drops sometime during drying. The survival rate of E.coli LE392 declines sharply as the samples are placed in vacuum, then falls in distinctively with increasing of time. the tolerance of E.coli LE392 towards vacuum increasingly strengthens when the E.coli LE392 culture is placed at room temperature. Preparing the culture in batchs can ensure the consistency of the irradiated samples and avoid errors caused by the inconsistent samples. When the non-implantation factors are controlled, E.coli is implanted by 30 kev N + of 1 x 10 14 cm -2 and 3 x 10 15 cm -2 , respectively. And the results show no difference in the E.coli's survival rates between batchs at the same dose. (authors)

  10. Low energy supersymmetry phenomenology

    International Nuclear Information System (INIS)

    Baer, H.; Chen, C.H.; Gunion, J.; Kamon, T.; Lopez, J.L.; Kao, C.

    1995-04-01

    The authors summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, they evaluate the capabilities of various e + e - , p bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, they discuss capabilities of future facilities to disentangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. The authors then comment upon the complementarity of proposed hadron and e + e - machines for a comprehensive study of low energy supersymmetry

  11. Low energy supersymmetry phenomenology

    CERN Document Server

    Baer, H.; Chen, C.H.; Eberl, H.; Feng, J.L.; Fujii, K.; Gunion, John F.; Kamon, T.; Kao, C.; Lopez, J.L.; Majerotto, W.; McIntyre, P.; Munroe, Ray B.; Murayama, H.; Paige, F.; Porod, W.; Sender, J.; Sopczak, A.; Tata, X.; Tsukamoto, T.; White, J.

    1996-01-01

    We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various e^+e^-, p\\bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and e^+e^- machines for a comprehensive study of low energy supersymmetry.

  12. Effects of low energy shock wave therapy on inflammatory moleculars, bladder pain, and bladder function in a rat cystitis model.

    Science.gov (United States)

    Wang, Hung-Jen; Lee, Wei-Chia; Tyagi, Pradeep; Huang, Chao-Cheng; Chuang, Yao-Chi

    2017-08-01

    Low energy shock wave (LESW) is known to facilitate tissue regeneration with analgesic and anti-inflammatory effects. We examined the effects of LESW on the expression of inflammatory molecules, pain behavior, and bladder function in a rat cystitis model. Control and experimental animals were injected with saline or cyclophosphamide (CYP; 75 mg/kg intraperitoneally) on day 1 and 4. After lower midline incision, the bladders were exposed to LESW (300 pulses, 0.12 mJ/mm 2 ) or sham operation on day 2. In study 1 (N = 12, 4 for each group), the nociceptive effects of CYP were evaluated for 30 min by behavioral assessment on day 4 one hour after CYP injection. In study 2 (N = 21, 7 for each group), continuous cystometry (CMG) was performed on day 8. The bladder was harvested after behavioral assessment or CMG for histology and Western blotting. CYP-induced upregulation of COX2 and IL6 expression, caused pain behavior (eye closing and hypolocomotion), and bladder inflammation was noted on days 4 and 8 along with bladder hyperactivity. LESW treatment reduced pain behavior and downregulated the NGF expression (33.3%, P < 0.05) on day 4 and IL6 (40.9%, P < 0.05). LESW treatment suppressed bladder overactivity (intercontraction interval 77.8% increase, P < 0.05) by decreasing inflammation and COX2 (38.6%, P < 0.05) expression and NGF expression (25.2%, P = 0.0812). CYP-induced bladder pain, inflammation, and overactivity involves activation of IL6, NGF, and COX2 expression. These changes are suppressed by LESW, indicating it as a potential candidate for relieving bladder inflammatory conditions and overactivity. © 2016 Wiley Periodicals, Inc.

  13. Urodynamic and molecular characteristics of detrusor underactivity in a rat cryoinjury model and effects of low energy shock wave therapy.

    Science.gov (United States)

    Chuang, Yao-Chi; Tyagi, Pradeep; Wang, Hung-Jen; Huang, Chao-Cheng; Lin, Chih-Chieh; Chancellor, Michael B

    2018-02-01

    Low energy shock wave (LESW) has been shown to facilitate tissue regeneration and reduce inflammation. We investigated the effects of LESW in an underactive (DU) model induced by cryoinjury of rat detrusor. Forty-six female Sprague-Dawley rats were divided into sham, cryoinjury with or without LESW (0.12 mJ/mm 2 ; 200 pulses). Under halothane anesthesia, a low midline incision was made and a cryoinjury of detrusor was induced by placing an aluminum rod (chilled with dry ice) for 30 s on the serosal side of the bladder filled with 1 mL sterile saline bilaterally. Awake cystometrogram (CMG), molecular and histopathology studies were performed on Day 8 or 15 after cryoinjury. Significant urodynamic, histological, and molecular changes induced by cryoinjury of rat detrusor were detected on Day 8 and decrease in the contraction amplitude (54.3%), a significant increase in wet bladder weight (64.1%), edematous changes, muscle thinning and downregulation of α-SMA, IL-6, and upregulation of COX-2. LESW reversed the cryoinjury induced histological and COX-2 expression to cause a 49.0% increase in the contraction amplitude (P < 0.05). LESW induced cell proliferation was revealed by increased CD31 and Ki67 immunostaining. The effect of cryoinjury on urodynamic and histological changes was maintained till Day 15. The cryoinjury of rat detrusor models myogenic DU, which is partially reversed by LESW. LESW may afford a simple, non-invasive modality to facilitate tissue regeneration and improve voiding function in myogenic detrusor underactivity. © 2017 Wiley Periodicals, Inc.

  14. Formulation of the low-energy effective theory of electroweak symmetry-breaking without a Higgs particle

    International Nuclear Information System (INIS)

    Hirn, J.

    2004-07-01

    The low-energy effective theory of electroweak symmetry-breaking without a Higgs particle is constructed using the methods of Chiral Perturbation Theory. Weinberg's power-counting formula demonstrates the consistency of the loop expansion, with the corresponding renormalization. We find that the suppression of effective operators by a mass scale, which was automatic in the case of the Standard Model, no longer holds in the Higgs-less case. Moreover, the incriminated operators appear at leading order in the chiral expansion, at variance with experiments. To account for their suppression, invariance under a larger symmetry is required, corresponding to the composite sector (which produces the three Goldstone modes) being decoupled from the elementary sector (quarks, leptons and Yang-Mills fields). The couplings are introduced via spurions: this reduces the symmetry to SU(2) x U(1). In the simultaneous expansion in powers of momenta and spurions, the aforementioned operators are relegated to higher orders. In addition, the method allows for a systematic treatment of weak isospin breaking. The Weinberg power-counting formula can be recovered, and small neutrino masses accounted for. The three right-handed neutrinos (lighter than the TeV), which are introduced in connection with the custodial symmetry, are quasi-sterile and stable. A constraint on the underlying theory is obtained by studying the anomaly-matching in the composite sector and generalizing the Wess-Zumino construction. The spurion formalism is also applied to open linear moose models, for which generalized Weinberg sum rules are derived. (author)

  15. Na,K-ATPase biostimulation by low-energy laser irradiation: comparative effects in membrane, solubilized and proteoliposomes enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Rigos, C.F.; Tedesco, A.C.; Ciancaglini, P. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica; Santos, H.L. [Universidade Federal de Sao Joao Del Rei (UFSJ), MG (Brazil)

    2008-07-01

    Full text: The mechanism of laser irradiation action on living cells is not yet understood. The role of membrane ATPases as possible targets has been analyzed. In our group we have been working with Na,K-ATPase. This enzyme is a member of the P-type family of active cation transport proteins. Thus, the aim of the present work was to investigate the effect of low-energy laser irradiation (685 nm, 35 mW) on the ATPase activity of different forms of the Na,K-ATPase. Membrane-bound and solubilized (ab)2 form of Na,K-ATPase was obtained from the rabbit kidney and DPPC:DPPE-proteoliposomes were prepared by the co-solubilization method. Irradiations were carried out at 685 nm. The ATPase activity of the membrane fraction was not altered with exposition to irradiation doses between 4 and 24 J/c m2. With irradiation doses ranging from 32 to 40 J/c m2, a 28% increase on the ATPase activity was observed while when using up to 50 J/c m2 no additional enhancement was observed. When bio stimulation was done using the purified or the reconstituted enzyme, an increase of about 36-40% on the ATPase activity was observed using only 4-8 J/c m2. With irradiation above these values (24 J/c m2) no additional increase in the activity appeared. These studies revealed that the bio stimulation of ATPase activity from different forms of the Na,K -ATPase is dose dependent in different ranges of irradiation exposure. The stimulation promoted by visible laser doses was modulated and the process was reverted after 2 h for the enzyme present in the membrane and after about 5 h for the solubilized or the reconstituted in DPPC:DPPE-liposomes.

  16. Na,K-ATPase biostimulation by low-energy laser irradiation: comparative effects in membrane, solubilized and proteoliposomes enzyme

    International Nuclear Information System (INIS)

    Rigos, C.F.; Tedesco, A.C.; Ciancaglini, P.

    2008-01-01

    Full text: The mechanism of laser irradiation action on living cells is not yet understood. The role of membrane ATPases as possible targets has been analyzed. In our group we have been working with Na,K-ATPase. This enzyme is a member of the P-type family of active cation transport proteins. Thus, the aim of the present work was to investigate the effect of low-energy laser irradiation (685 nm, 35 mW) on the ATPase activity of different forms of the Na,K-ATPase. Membrane-bound and solubilized (ab)2 form of Na,K-ATPase was obtained from the rabbit kidney and DPPC:DPPE-proteoliposomes were prepared by the co-solubilization method. Irradiations were carried out at 685 nm. The ATPase activity of the membrane fraction was not altered with exposition to irradiation doses between 4 and 24 J/c m2. With irradiation doses ranging from 32 to 40 J/c m2, a 28% increase on the ATPase activity was observed while when using up to 50 J/c m2 no additional enhancement was observed. When bio stimulation was done using the purified or the reconstituted enzyme, an increase of about 36-40% on the ATPase activity was observed using only 4-8 J/c m2. With irradiation above these values (24 J/c m2) no additional increase in the activity appeared. These studies revealed that the bio stimulation of ATPase activity from different forms of the Na,K -ATPase is dose dependent in different ranges of irradiation exposure. The stimulation promoted by visible laser doses was modulated and the process was reverted after 2 h for the enzyme present in the membrane and after about 5 h for the solubilized or the reconstituted in DPPC:DPPE-liposomes

  17. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  18. A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study.

    Science.gov (United States)

    White, Shane A; Reniers, Brigitte; de Jong, Evelyn E C; Rusch, Thomas; Verhaegen, Frank

    2016-01-07

    Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB  ≈  1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with

  19. EFFECT OF LOW ENERGY VERSUS MEDIUM ENERGY RADIAL SHOCK WAVE THERAPY IN THE TREATMENT OF CHRONIC PLANTER FASCIITIS

    Directory of Open Access Journals (Sweden)

    Khaled Z. Fouda

    2016-02-01

    Full Text Available Background: Plantar fasciitis (PF is the most common cause of heel pain and it can often be a challenge for clinicians to treat successfully. Radial shock wave therapy (RSWT has been introduced recently for treatment of musculoskeletal disorders. Different energy levels of shock wave therapy have been used in the literatures for treatment of PF with no clear settled parameters. Therefore, the purpose of this study was intended to investigate and compare the efficacy of two different energy levels of RSWT on PF patients. Methods: Forty patients having unilateral chronic PF were recruited for the study from orthopedic outpatient clinics of Cairo University hospitals and National Institute of Neuromotor System Cairo Egypt, with a mean age of (47.15±4.57 years. Patients were randomly assigned into two equal groups. Group (A treated with low intensity level of 1.6 bars (0.16 mJ/mm2 RSWT and group (B treated with medium intensity level of 4 bars (0.38 mJ/mm2 RSWT. Functional assessment of the foot based on Foot Function Index (FFI and Present pain intensity was measured during rest by Visual Analogue Scale (VAS. Results: There was as significant decreased in the total FFI scores from (118.42 ±6.51 to (81.37 ±3.46 for group (A and from (118.93 ±6.85 to (58.50 ±3.22 for group (B. Also regarding VAS Scores there was as significant decreased in the pain intensity from (5.11 ±0.41 to (2.85 ±0.31 for group (A and from (4.95 ±0.39 to (2.05 ±0.22 for group (B. Conclusion: Radial shock wave therapy is an effective modality that should be considered in the treatment of chronic PF, while the medium energy level RSWT is better than the low energy level RSWT in regarding to the measured treatment outcomes.

  20. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  1. Influence of low energy N+ ions pre-treatment on damage effects of UV-B irradiation on M1 rice

    International Nuclear Information System (INIS)

    Zhao Shuaipeng; Huang Qunce; Chen Xueneng

    2011-01-01

    The seedlings of rice (xindao18) were exposed to UV-B (10.08 kJ/(m 2 ·d 1 )) irradiation following the pretreatment with three different implantation dosages of low-energy N + ions. Changes in the levels of the superoxide (POD), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), glutathione (GSH) and soluble sugar were measured. The result showed that the UV-B irradiation on the seedlings of rice pretreated with low-energy ions implantation could lead to increase activities in POD and SOD, and the maximum appeared on the dose of 2.0 x 10 17 ions/cm 2 . Meanwhile, it made the content of GSH increased, and caused the activity of CAT and the content of MDA to be decreased. But there was no obvious change in soluble sugar. It was suggested that the rice pretreated by low energy ion implantation could enhance the antioxidation capacity and defensive ability when irradiated by UV-B, and the antioxidation system could be induced earlier than carbohydrate system. Therefore,the biological effects of UV-B irradiation on rice pretreated by low energy ion implantation were quite obvious. (authors)

  2. Low-energy Electro-weak Reactions

    International Nuclear Information System (INIS)

    Gazit, Doron

    2012-01-01

    Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.

  3. Extra Low ENergy Antiproton

    CERN Multimedia

    To produce dense antiproton beams at very low energies (110 keV), it has been proposed to install a small decelerator ring between the existing AD ring and the experimental area. Phase-space blowup during deceleration is compensated by electron cooling such that the final emittances are comparable to the 5MeV beam presently delivered by the AD. An immediate consequence is a significant increase in the number of trapped antiprotons at the experiments as outlined in the proposal CERN/SPSC-2009-026; SPCS-P-338. This report describes the machine parameters and layout of the proposal ELENA (Extra Low ENergy Antiproton)ring also gives an approximate estimate of cost and manpower needs. Since the initial estimate, published in 2007 (CERN-AB-2007-079), the ELENA design has evolved considerably. This is due to a new location in the AD hall to acommodate for the possibility of another experimental zone, as suggested by the SPCS, and also due to improvements in the ring optics and layout. The cost estimate that is prese...

  4. Effective and absolute cross sections for low-energy (1-30 eV) electron interactions with condensed biomolecules

    Science.gov (United States)

    Zheng, Yi; Sanche, Léon

    2018-06-01

    Ionizing radiation is intensively used for therapeutic [e.g., radiotherapy, brachytherapy, and targeted radionuclide therapy (TRT)], as well as for diagnostic medical imaging purposes. In these applications, the radiation dose given to the patient should be known and controlled. In conventional cancer treatments, absorbed dose calculations rely essentially on scattering cross sections (CSs) of the primary high-energy radiation. In more sophisticated treatments, such as combined radio- and chemo-therapy, a description of the details of energy deposits at the micro- and nano-scopic level is preferred to relate dose to radiobiological effectiveness or to evaluate doses at the biomolecular level, when radiopharmaceuticals emitting short-range radiation are delivered to critical molecular components of cancer cells (e.g., TRT). These highly radiotoxic compounds emit large densities of low-energy electrons (LEEs). More generally, LEE (0-30 eV) are emitted in large numbers by any type of high-energy radiation; i.e., about 30 000 per MeV of deposited primary energy. Thus, to optimize the effectiveness of several types of radiation treatments, the energy deposited by LEEs must be known at the level of the cell, nucleus, chromosome, or DNA. Such local doses can be evaluated by Monte Carlo (MC) calculations, which account event-by-event, for the slowing down of all generations of particles. In particular, these codes require as input parameters absolute LEE CSs for elastic scattering, energy losses, and direct damage to vital cellular molecules, particularly DNA, the main target of radiation therapy. In the last decade, such CSs have emerged in the literature. Furthermore, a method was developed to transform relative yields of damages into absolute CSs by measuring specific parameters in the experiments. In this review article, we first present a general description of dose calculations in biological media via MC simulation and give an overview of the CSs available from

  5. Validation of use of the low energies library in the GATE program: assessment of the effective mass attenuation coefficient

    International Nuclear Information System (INIS)

    Argenta, J.; Brambilla, C.R.; Marques da Silva, A.M.; Hoff, G.

    2009-01-01

    GATE (Geant4 Application for Emission Tomography) is a versatile tool kit for nuclear medicine simulations of SPECT and PET studies. GATE takes advantage of well-validated libraries of physics processes models, geometry description, tracking of particles through materials, response of detector and visualization tools offered by Geant4. One package available to simulate electromagnetic interactions is LEP (Low Energy Electromagnetic Processes). The purpose of this work was to evaluate the LEP package used by GATE 4 for nuclear medicine shielding simulations. Several simulations were made involving a mono directional and 140 keV monoenergetic point source beam, passing through barriers of variable thickness of water and lead. The results showed good agreement with the theoretical model, indicating that GATE 4 uses correctly the LEP package. (author)

  6. Validation of use of the low energies library in the GATE program: assessment of the effective mass attenuation coefficient

    International Nuclear Information System (INIS)

    Argenta, Jackson; Brambilla, Claudia R.; Silva, Ana Maria Marques da; Hoff, Gabriela

    2010-01-01

    Geant4 Application for Emission Tomography program (GATE) is a versatile toolkit for nuclear medicine simulations of SPECT and PET studies. GATE takes advantage of well-validated libraries of physics processes models, geometry description, tracking of particles through materials, response of detector and visualization tools offered by Geant4 (version 4.0). One package available to simulate electromagnetic interactions is low energy electromagnetic processes (LEP). The purpose of this work was to evaluate the LEP package used by GATE 4 for nuclear medicine shielding simulations. Several simulations were made involving a monodirectional and 140 keV monoenergetic point source beam, passing through barriers of variable thickness of water and lead. The results showed good agreement with the theoretical model, indicating that GATE 4 uses correctly the LEP package. (author)

  7. Numerical Simulation of 3-D Wave Crests

    Institute of Scientific and Technical Information of China (English)

    YU Dingyong; ZHANG Hanyuan

    2003-01-01

    A clear definition of 3-D wave crest and a description of the procedures to detect the boundary of wave crest are presented in the paper. By using random wave theory and directional wave spectrum, a MATLAB-platformed program is designed to simulate random wave crests for various directional spectral conditions in deep water. Statistics of wave crests with different directional spreading parameters and different directional functions are obtained and discussed.

  8. Inside bluetooth low energy

    CERN Document Server

    Gupta, Naresh

    2013-01-01

    Bluetooth Low Energy (LE) is one of the latest enhancement to Bluetooth technology and, as the name suggests, it is aimed at ultra low power devices, such as heart rate monitors, thermometers, and sensors. Due to very low power consumption, devices compliant with this standard can operate for several years on coin cell batteries without the need for recharging. This cutting-edge book helps you understand the whats , whys , and hows of Bluetooth LE. It includes a broad view of the technology, identifies the various building blocks, and explains how they come together. You also find discussions on Bluetooth basics, providing the background information needed to master Bluetooth LE.The book explains the architecture of Bluetooth LE stack and the functionality provided by each of the layers. You find expert guidance in setting up your own system in a quick and efficient manner with inexpensive, easily available hardware and just a couple of PCs running Linux. This unique volume features two chapters that are dedi...

  9. Solar low energy dwellings

    International Nuclear Information System (INIS)

    Hestnes, Anne Grete

    2000-01-01

    By now, a lot has been learnt about how to reduce energy use in dwellings using solar and low energy technologies, and many good examples can be found throughout Europe. Still, they are not quite the common feature we would expect them to be, i.e. they have not really penetrated the market. The reason for this is in part a result of the fact that the designers and developers of these buildings have not looked at what the market wants and needs, but rather at how to use a set of given technologies. The buildings are the result of a technology push rather than a market pull and have therefore, often, been detached or semidetached dwellings with different solar technologies added on in less than optimal ways. In order to increase market penetration, it is time to look at the market trends and relate to these. Fortunately, quite a few European architects have realized this and have started designing somewhat different residential buildings. The paper focuses on examples of the new trends in solar residential architecture and by that, hopefully, it shows that we are on the right track. (au)

  10. Very low energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

  11. Effects of high- and low-energy radial shock waves therapy combined with physiotherapy in the treatment of rotator cuff tendinopathy: a retrospective study.

    Science.gov (United States)

    Su, Xiangzheng; Li, Zhongli; Liu, Zhengsheng; Shi, Teng; Xue, Chao

    2017-06-09

    The aim of this study was to investigate the efficacy of high- and low-energy radial shock waves combined with physiotherapy for rotator cuff tendinopathy patients. Data from rotator cuff tendinopathy patients received high- or low-energy radial shock waves combined with physiotherapy or physiotherapy alone were collected. The Constant and Murley score and visual analog scale score were collected to assess the effectiveness of treatment in three groups at 4, 8, 12, and 24 weeks. In total, 94 patients were involved for our retrospective study. All groups showed remarkable improvement in the visual analog scale and Constant and Murley score compared to baseline at 24 weeks. The high-energy radial shock waves group had more marked improvement in the Constant and Murley score compared to the physiotherapy group at 4 and 8 weeks and at 4 weeks when compared with low-energy group. Furthermore, high-energy radial shock waves group had superior results on the visual analog scale at 4, 8, and 12 weeks compared to low-energy and physiotherapy groups. This retrospective study supported the usage of high-energy radial shock waves as a supplementary therapy over physiotherapy alone for rotator cuff tendinopathy by relieving the symptoms rapidly and maintaining symptoms at a satisfactory level for 24 weeks. Implications for Rehabilitation High-energy radial shock waves can be a supplemental therapy to physiotherapy for rotator cuff tendinopathy. We recommend the usage of high-energy radial shock waves during the first 5 weeks, at an interval of 7 days, of physiotherapy treatment. High-energy radial shock waves treatment combined with physiotherapy can benefit rotator cuff tendinopathy by relieving symptoms rapidly and maintain these improvements at a satisfactory level for quite a long time.

  12. Effect of laser shot peening on precipitation hardened aluminum alloy 6061-T6 using low energy laser

    Science.gov (United States)

    Sathyajith, S.; Kalainathan, S.

    2012-03-01

    Mechanical properties of engineering material can be improved by introducing compressive residual stress on the material surface and refinement of their microstructure. Variety of mechanical process such as shot peening, water jet peening, ultrasonic peening, laser shot peening were developed in the last decades on this contrast. Among these, lasers shot peening emerged as a novel industrial treatment to improve the crack resistance of turbine blades and the stress corrosion cracking (SCC) of austenic stainless steel in power plants. In this study we successfully performed laser shot peening on precipitation hardened aluminum alloy 6061-T6 with low energy (300 mJ, 1064 nm) Nd:YAG laser using different pulse densities of 22 pulses/mm 2 and 32 pulses/mm 2. Residual stress evaluation based on X-ray diffraction sin 2 ψ method indicates a maximum of 190% percentage increase on surface compressive stress. Depth profile of micro-hardness shows the impact of laser generated shock wave up to 1.2 mm from the surface. Apart from that, the crystalline size and micro-strain on the laser shot peened surfaces have been investigated and compared with the unpeened surface using X-ray diffraction in conjunction with line broadening analysis through the Williamson-Hall plot.

  13. Formation of plasmid DNA strand breaks induced by low-energy ion beam: indication of nuclear stopping effects

    International Nuclear Information System (INIS)

    Chen Yu; Jiang Bingyao; Chen Youshan; Ding Xingzhao; Liu Xianghuai; Chen Ceshi; Guo Xinyou; Yin Guanglin

    1998-01-01

    Plasmid pGEM 3zf(+) was irradiated by nitrogen ion beam with energies between 20 and 100 keV and the fluence kept as 1 x 10 12 ions/cm 2 . The irradiated plasmid was assayed by neutral electrophoresis and quantified by densitometry. The yields of DNA with single-strand and double-strand breaks first increased then decreased with increasing ion energy. There was a maximal yield value in the range of 20-100 keV. The relationship between DNA double-strand breaks (DSB) cross-section and linear energy transfer (LET) also showed a peak-shaped distribution. To understand the physical process during DNA strand breaks, a Monte Carlo calculation code known as TRIM (Transport of Ions in Matter) was used to simulate energy losses due to nuclear stopping and to electronic stopping. It can be assumed that nuclear stopping plays a more important role in DNA strand breaks than electronic stopping in this energy range. The physical mechanisms of DNA strand breaks induced by a low-energy ion beam are also discussed. (orig.)

  14. The effect of low energy helium ion irradiation on tungsten-tantalum (W-Ta) alloys under fusion relevant conditions

    Science.gov (United States)

    Gonderman, S.; Tripathi, J. K.; Novakowski, T. J.; Sizyuk, T.; Hassanein, A.

    2017-08-01

    Currently, tungsten remains the best candidate for plasma-facing components (PFCs) for future fusion devices because of its high melting point, low erosion, and strong mechanical properties. However, continued investigation has shown tungsten to undergo severe morphology changes under fusion-like conditions. These results motivate the study of innovative PFC materials which are resistant to surface morphology evolution. The goal of this work is to examine tungsten-tantalum (W-Ta) alloys, a potential PFC material, and their response to low energy helium ion irradiation. Specifically, W-Ta samples are exposed to 100 eV helium irradiations with a flux of 1.15 × 1021 ions m-2 s-1, at 873 K, 1023 K, and 1173 K for 1 h duration. Scanning electron microscopy (SEM) reveals significant changes in surface deterioration due to helium ion irradiation as a function of both temperature and tantalum concentration in W-Ta samples. X-Ray Diffraction (XRD) studies show a slight lattice parameter expansion in W-Ta alloy samples compared to pure W samples. The observed lattice parameter expansion in W-Ta alloy samples (proportional to increasing Ta wt.% concentrations) reflect significant differences observed in the evolution of surface morphology, i.e., fuzz development processes for both increasing Ta wt.% concentration and target temperature. These results suggest a correlation between the observed morphology differences and the induced crystal structure change caused by the presence of tantalum. Shifts in the XRD peaks before and after 100 eV helium irradiation with a flux of 1.15 × 1021 ions m-2 s-1, 1023 K, for 1 h showed a significant difference in the magnitude of the shift. This has suggested a possible link between the atomic spacing of the material and the accumulated damage. Ongoing research is needed on W-Ta alloys and other innovative materials for their application as irradiation resistant materials in future fusion or irradiation environments.

  15. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of 234U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Lobato, I.

    2008-01-01

    The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  16. Effect of low-energy coherent radiation with lambda=6328 A on the survival rate of Saccharomyces cerevisial of strain 14

    International Nuclear Information System (INIS)

    Abramova, N.V.

    1978-01-01

    The effect of the continuous monochromatic coherent laser radiation on the survival rate of Saccharomyces cerevisiae of strain 14 is studied. The effect of laser radiation is judged by the change in the survival rate of the yeast culture before and after the irradiation. The decrease of the number of the yeast cells in the initial moments of the irradiation was observed as a result of the laser irradiation. Then the rapid decrease of the number of cells with time changes into their constant number. It is established that the low-energy coherent radiation decreases the survival rate by 30-40%

  17. On the relationship between string low-energy effective actions and O(α'3) σ-model β-functions

    International Nuclear Information System (INIS)

    Jack, I.; Ross, D.A.; Jones, D.R.T.

    1988-01-01

    We examine in detail the connection between low-energy string effective actions and the σ-model β-functions up to O(α' 3 ) in the torsion-free case. In particular we show that the relationship between, on the one hand, the equations of motion derived from the O(α' 3 ) string effective action, and, on the other hand, the O(α' 3 ) σ-model β-functions necessarily involves derivative operators acting on the β-functions. (orig.)

  18. The effect of carbon impurities on molybdenum surface morphology evolution under high-flux low-energy helium ion irradiation

    International Nuclear Information System (INIS)

    Tripathi, J.K.; Novakowski, T.J.; Gonderman, S.; Bharadwaj, N.; Hassanein, A.

    2016-01-01

    We report on the role of carbon (C) impurities, in molybdenum (Mo) fuzz evolutions on Mo surface during 100 eV He + ion irradiations. In this study we considered 0.01, 0.05, and 0.5% C + ion impurities in He + ion irradiations. For introducing such tiny C + ion impurities, gas mixtures of He and CH 4 have been chosen in following ratios; 99.95: 0.05, 99.75: 0.25, and 97.5: 2.5. Apart from these three cases, two additional cases, 100% He + ion (for Mo fuzz growth due to only He + ions) and 100% H + ion (for confirming the significance of tiny 0.04–2.0% H + ions in terms of Mo fuzz evolutions on Mo surface, if any), have also been considered. Ion energy (100 eV), ion fluence (2.6 × 10 24  ions m −2 ), and target temperature (923 K) were kept constant for each experiment and their selections were based on our previous studies [1,2]. Our study shows homogeneously populated and highly dense Mo fuzz evolutions on entire Mo surface for 100% He + ion irradiation case. Enhancement of C + ion impurities in He + ions causes a sequential reduction in Mo fuzz evolutions, leading to almost complete prevention of Mo fuzz evolutions for 0.5% C + ion impurity concentrations. Additionally, no fuzz formation for 100% H + ion irradiation at all, were seen (apart from some tiny nano-structuring, in very limited regions). This indicates that there is no significant role of H + ions in Mo fuzz evolutions (at least for such tiny amount, 0.04–2.0% H + ions). The study is significant to understand the behavior of potential high-Z plasma facing components (PFCs), in the, presence of tiny amount of C impurities, for nuclear fusion relevant applications. - Highlights: • Mo Fuzz evolutions due to low-energy high-flux 100% He + ion irradiation. • Sequential reduction in Mo fuzz evolutions with increasing C + ion impurities in He + ions. • Almost complete prevention of Mo fuzz evolutions for 0.5% C + ion impurity in He + ions. • No Mo fuzz formation for 100% H + ion

  19. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of {sup 234}U

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Lobato, I. [Facultad de Ciencias, Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Apartado Postal 31-139, Lima (Peru)]. e-mail: mmontoya@ipen.gob.pe

    2008-07-01

    The standard deviation of the final kinetic energy distribution ({sigma}{sub e}) as a function of mass of final fragments (m) from low energy fission of {sup 234}U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution ({sigma}{sub E}) as a function of primary fragment mass (A). The second peak is attributed to a real peak on {sigma}{sub E}(A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on {sigma}{sub E}(A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on {sigma}{sub e} (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the {sigma}{sub E} (A) curve, and the observed peaks on {sigma}{sub e} (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  20. An associative and noncommutative product for the low energy effective theory of a D-brane in curved backgrounds and bi-local fields

    International Nuclear Information System (INIS)

    Hayasaka, Kiyoshi; Nakayama, Ryuichi

    2002-01-01

    We point out that when a D-brane is placed in an NS-NS B field background with nonvanishing field strength (H=dB) along the D-brane worldvolume, the coordinate of one end of the open string does not commute with that of the other in the low energy limit. The degrees of the freedom associated with both ends are not decoupled and accordingly, the effective action must be quite different from that of the ordinary noncommutative gauge theory for a constant B background. We construct an associative and noncommutative product * which operates on the coordinates of both ends of the string and propose a new type of noncommutative gauge action for the low energy effective theory of a Dp-brane. This effective theory is bi-local and lives in twice as large dimensions (2D=2(p+1)) as in the H=0 case. When viewed as a theory in the D-dimensional space, this theory is nonlocal and we must force the two ends of the string to coincide. We will then propose a prescription for reducing this bi-local effective action to that in D dimensions and obtaining a local effective action

  1. Effects of 2p-2h configurations on low-energy dipole states in neutron-rich N=80, 82 and 84 isotones

    Directory of Open Access Journals (Sweden)

    Arsenyev N. N.

    2016-01-01

    Full Text Available Starting from the Skyrme interaction SLy4 we study the effects of phonon-phonon coupling on the low-energy electric dipole response in 130−134Sn, 132−136Te and 134−138Xe. Our calculations are performed within the finite-rank separable approximation, which enables one to perform quasiparticle random phase approximation calculations in very large two-quasiparticle configuration spaces. A dependence of the pygmy dipole resonance strengths on the neutron skin thickness is found. The inclusion of the two-phonon configurations gives a considerable contribution to the low-lying strength.

  2. The effect of carbon impurities on molybdenum surface morphology evolution under high-flux low-energy helium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, J.K., E-mail: jtripat@purdue.edu; Novakowski, T.J.; Gonderman, S.; Bharadwaj, N.; Hassanein, A.

    2016-09-15

    We report on the role of carbon (C) impurities, in molybdenum (Mo) fuzz evolutions on Mo surface during 100 eV He{sup +} ion irradiations. In this study we considered 0.01, 0.05, and 0.5% C{sup +} ion impurities in He{sup +} ion irradiations. For introducing such tiny C{sup +} ion impurities, gas mixtures of He and CH{sub 4} have been chosen in following ratios; 99.95: 0.05, 99.75: 0.25, and 97.5: 2.5. Apart from these three cases, two additional cases, 100% He{sup +} ion (for Mo fuzz growth due to only He{sup +} ions) and 100% H{sup +} ion (for confirming the significance of tiny 0.04–2.0% H{sup +} ions in terms of Mo fuzz evolutions on Mo surface, if any), have also been considered. Ion energy (100 eV), ion fluence (2.6 × 10{sup 24} ions m{sup −2}), and target temperature (923 K) were kept constant for each experiment and their selections were based on our previous studies [1,2]. Our study shows homogeneously populated and highly dense Mo fuzz evolutions on entire Mo surface for 100% He{sup +} ion irradiation case. Enhancement of C{sup +} ion impurities in He{sup +} ions causes a sequential reduction in Mo fuzz evolutions, leading to almost complete prevention of Mo fuzz evolutions for 0.5% C{sup +} ion impurity concentrations. Additionally, no fuzz formation for 100% H{sup +} ion irradiation at all, were seen (apart from some tiny nano-structuring, in very limited regions). This indicates that there is no significant role of H{sup +} ions in Mo fuzz evolutions (at least for such tiny amount, 0.04–2.0% H{sup +} ions). The study is significant to understand the behavior of potential high-Z plasma facing components (PFCs), in the, presence of tiny amount of C impurities, for nuclear fusion relevant applications. - Highlights: • Mo Fuzz evolutions due to low-energy high-flux 100% He{sup +} ion irradiation. • Sequential reduction in Mo fuzz evolutions with increasing C{sup +} ion impurities in He{sup +} ions. • Almost complete prevention of Mo

  3. Charge transport in junctions between d-wave superconductors

    International Nuclear Information System (INIS)

    Barash, Y.S.; Galaktionov, A.V.; Zaikin, A.D.

    1995-01-01

    We develop a microscopic analysis of superconducting and dissipative currents in junctions between superconductors with d-wave symmetry of the order parameter. We study the proximity effect in such superconductors and show that for certain crystal orientations the superconducting order parameter can be essentially suppressed in the vicinity of a nontransparent specularly reflecting boundary. This effect strongly influences the value and the angular dependence of the dc Josephson current j S . At T∼T c it leads to a crossover between j S ∝T c -T and j S ∝(T c -T) 2 respectively for homogeneous and nonhomogeneous distribution of the order parameter in the vicinity of a tunnel junction. We show that at low temperatures the current-phase relation j S (cphi) for superconductor--normal-metal--superconductor junctions and short weak links between d-wave superconductors is essentially nonharmonic and contains a discontinuity at cphi=0. This leads to further interesting features of such systems which can be used for pairing symmetry tests in high-temperature superconductors (HTSC). We also investigated the low-temperature I-V curves of normal-metal--superconductor and superconductor-superconductor tunnel junctions and demonstrated that depending on the junction type and crystal orientation these curves show zero-bias anomalies I∝V 2 , I∝V 2 ln(1/V), and I∝V 3 caused by the gapless behavior of the order parameter in d-wave superconductors. Many of our results agree well with recent experimental findings for HTSC compounds

  4. Effects of a premolt calcium and low-energy molt program on laying hen behavior and heterophil-to-lymphocyte ratios.

    Science.gov (United States)

    Dickey, E R; Bregendahl, K; Stalder, K; Fitzgerald, R; Johnson, A K

    2010-11-01

    The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca premolt treatment and low-energy molt diets vs. a traditional feed withdrawal (FW) treatment during and after molt. A total of 144 Hy-Line W-36 hens (85 wk of age), housed 3 hens/cage (413 cm(2)/hen), were used. Hens were allotted to treatments according to a randomized complete block design, with the cage location and initial BW as the blocking criteria. Six treatments were compared in a 2 × 3 factorial arrangement with 2 Ca premolt treatments (fine or coarse) and 3 low-energy molt diets (FW, soybean hulls, or wheat middlings). The 2 Ca premolt treatments differed only in Ca particle size (fine was 0.14 mm and coarse was 2.27 mm mean diameter). Two postures and 5 behaviors were recorded and H:L was measured. Data were analyzed using the MIXED procedure of SAS, with P postures, or H:L during the premolt baseline period. The Ca premolt treatment had no carryover effects during or after molt for behaviors or postures. During molt, hens in the FW treatment were more active, and they ate and drank less compared with hens fed soybean hulls or wheat middlings, but there were no differences in aggression, nonnutritive pecking, or sitting. Drinking and aggression during and after molt were not different, but hens postmolt engaged in more sitting and feeding and less activity, nonnutritive pecking, and preening compared with during molt. There were no differences in H:L during or after molt. In conclusion, a Ca premolt treatment did not affect the behavior of the laying hen. The low-energy molt diets did not adversely affect behavior compared with FW and did not increase H:L; therefore, they could be useful alternatives for inducing molt in laying hens.

  5. On the Effects of Pickup Ion-driven Waves on the Diffusion Tensor of Low-energy Electrons in the Heliosphere

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N. Eugene, E-mail: n.eugene.engelbrecht@gmail.com [Center for Space Research, North-West University, Potchefstroom, 2522 (South Africa)

    2017-11-01

    The effects of Alfvén cyclotron waves generated due to the formation in the outer heliosphere of pickup ions on the transport coefficients of low-energy electrons is investigated here. To this end, parallel mean free path (MFP) expressions are derived from quasilinear theory, employing the damping model of dynamical turbulence. These are then used as inputs for existing expressions for the perpendicular MFP and turbulence-reduced drift coefficient. Using outputs generated by a two-component turbulence transport model, the resulting diffusion coefficients are compared with those derived using a more typically assumed turbulence spectral form, which neglects the effects of pickup ion-generated waves. It is found that the inclusion of pickup ion effects greatly leads to considerable reductions in the parallel and perpendicular MFPs of 1–10 MeV electrons beyond ∼10 au, which are argued to have significant consequences for studies of the transport of these particles.

  6. Investigating the Effect of Voltage-Switching on Low-Energy Task Scheduling in Hard Real-Time Systems

    National Research Council Canada - National Science Library

    Swaminathan, Vishnu; Chakrabarty, Krishnendu

    2005-01-01

    We investigate the effect of voltage-switching on task execution times and energy consumption for dual-speed hard real-time systems, and present a new approach for scheduling workloads containing periodic tasks...

  7. Investigating the Effect of Voltage-Switching on Low-Energy Task Scheduling in Hard Real-Time Systems

    Science.gov (United States)

    2005-01-01

    We investigate the effect of voltage-switching on task execution times and energy consumption for dual-speed hard real - time systems , and present a...scheduling algorithm and apply it to two real-life task sets. Our results show that energy can be conserved in embedded real - time systems using energy...aware task scheduling. We also show that switching times have a significant effect on the energy consumed in hard real - time systems .

  8. Low energy nuclear fission

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1982-02-01

    In these lectures we present the liquid drop model of fission and compare some of its prediction with experiment. The liquid drop analogy allows to define in a rather simple and intuitive way a number of useful concepts and possible observables. We then discuss, using the example of the oscillator model, the generality of shell effects. We show how a synthesis of the liquid drop model and of the shell model can be made using the Strutinsky shell averaging procedure. Some experimental data related to the existence of shape isomers are presented and discussed. We conclude by discussing some aspects, both experimental and theoretical, of fission dynamics

  9. Surface sterilization by low energy electron beams

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Tabei, Masae

    1989-01-01

    The germicidal effectiveness of low energy electron beams (175 KV) against bacterial cells was investigated. The dry spores of Bacillus pumilus ATCC 27142 and Bacillus globigii ATCC 9372 inoculated on carrier materials and irradiated by gamma rays showed the exponential type of survival curves whereas they showed sigmoidal ones when exposed to low energy electron beams. When similarly irradiated, the wet spores inoculated on membrane filter showed the same survival curves as the dry spores inoculated on carrier materials. The wet vegetative cells of Escherichia coli ATCC 25922 showed exponential curves when exposed to gamma and electron beam irradiation. Low energy electron beams in air showed little differences from nitrogen stream in their germicidal effectiveness against dry spores of B. pumilus. The D values of B. pumilus spores inoculated on metal plates decreased as the amounts of backscattering electrons from the plates increased. There was adequate correlation between the D value (linear region of survival curve), average D value (6D/6) and 1% survival dose and backscattering factor. Depth dose profile and backscatterig dose of low energy electron beams were measured by radiochromic dye film dosimeter (RCD). These figures were not always in accord with the observed germicidal effectiveness against B. pumilus spores because of varying thickness of RCD and spores inoculated on carrier material. The dry spores were very thin and this thinness was useful in evaluating the behavior of low energy electrons. (author)

  10. The effectiveness of the microbiological radiation decontamination process of agricultural products with the use of low energy electron beam

    Science.gov (United States)

    Gryczka, Urszula; Migdał, Wojciech; Bułka, Sylwester

    2018-02-01

    The effectiveness of the radiation decontamination process was tested for electron beam of energy 200 keV and 300 keV. The energy of electrons was controlled by the measurements of its penetration ability in stack of B3 dosimetric film. In the presented work, the reduction of total aerobic bacteria count was observed, depending on time of irradiation for samples of dried black pepper, onion flakes and bay leaves. The results were compared with the effect observed for the process where high energy electron beam was used.

  11. A study on the ranges of low energy ions in biological samples and its mechanism of biological effects

    International Nuclear Information System (INIS)

    Lu Ting; Xie Liqing; Li Junping; Xia Ji

    1993-01-01

    The seeds of wheat and bean are irradiated by iron ion beam with energy 100 keV. The RBS spectra of the samples are observed and the ranges and distributions of the iron ions in the wheat and bean are calculated theoretically by means of Monte Carlo method. The results of theory and experiment are compared and the mechanism of biological effects induced by ion is discussed

  12. On-Line Generation of 3D-Waves

    DEFF Research Database (Denmark)

    Frigaard, Peter

    1992-01-01

    The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg.......The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg....

  13. Low energy physics from superstrings

    International Nuclear Information System (INIS)

    Segre, G.C.

    1987-01-01

    The developments of the past year have resulted in growing interest in the theory of superstrings, a subject which is on the one hand extraordinarily exciting in the promise it holds for solutions of many of the outstanding problems of particle physics and on the other hand rather forbidding in the amount of new knowledge which needs to be acquired by the average theorist to understand the papers that are now being published on the recent developments. In a sense the term low energy superstrings is misleading: the work of the past fifteen years in string theory, culminating in last summer's stunning developments by Green and Schwartz have led theorists to believe a finite, consistent superstring theory can be formulated. An enormous amount of work is going on in this subject, the premise that an effective field theory in ten space-time dimensions can be obtained from the superstring theory is the start of the lectures. The lectures will cover this later stage, namely how does one proceed from the effective ten dimensional theory to an effective four dimensional theory, describing the world as we see it. 87 references, 2 tables

  14. Sputtering effect of low-energy ions on biological target: The analysis of sputtering product of urea and capsaicin

    International Nuclear Information System (INIS)

    Zhang, Lili; Xu, Xue; Wu, Yuejin

    2013-01-01

    Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. Recent years, ion implantation was successfully applied to biological research based on the fragments sputtering and form open paths in cell structure caused by ion sputtering. In this study, we focused on urea and chilli pepper pericarp samples implanted with N + and Ar + ions. To investigate the sputtering effect, we designed a collecting unit containing a disk sample and a glass pipe. The urea content and capsaicin content recovered from glass pipes were adopted to represent the sputtering product. The result of urea showed that the sputtering effect is positively correlated with the ion energy and dose, also affected by the ion type. The result of capsaicin was different from that of urea at 20 keV and possibly due to biological complex composition and structure. Therefore the sputtering yield depended on both the parameters of incident ions and the state of target materials. The sputtering yield of urea was also simulated by computational method achieved through the TRIM program. The trajectories of primary and recoiled atoms were calculated on the basis of the binary collision approximation using Monte Carlo method. The experimental results were much higher than the calculated results. The possible explanation is that in the physical model the target were assumed as a disordered lattice and independent atoms, which is much less complicated than that of the biological models

  15. Strong nondipole effects in low-energy photoionization of the 5s and 5p subshells of xenon

    International Nuclear Information System (INIS)

    Johnson, W. R.; Cheng, K. T.

    2001-01-01

    Large nondipole effects are predicted in the angular distribution of photoelectrons from the 5s and 5p subshells of xenon for photon energies below 200 eV. The nondipole parameter γ 5s exhibits a dispersion-curve variation near the first minimum of the 5s cross section at 35 eV, reaching a minimum value of -0.8 near 40 eV. Rapid variation of γ 5s is also found near the second minimum of the 5s cross section at 150 eV, where γ 5s reaches a maximum value of 1.2. Smaller, but significant, nondipole effects are also found in the parameter ζ 5p =γ 5p +3δ 5p , which has a maximum value of 0.15 near 50 eV, and a second maximum value of 0.18 near 160 eV. The higher energy maxima in γ 5s and ζ 5p arise from correlation enhanced by shape resonances in the 4p→f quadrupole photoionization channels. These predictions are based on relativistic random-phase approximation calculations in which excitations from 5p, 5s, 4d, 4p, and 4s subshells are coupled

  16. The Raman effects in γ-LiAlO2 induced by low-energy Ga ion implantation

    Science.gov (United States)

    Zhang, Jing; Song, Hong-Lian; Qiao, Mei; Wang, Tie-Jun; Yu, Xiao-Fei; Wang, Xue-Lin

    2017-10-01

    The tetragonal γ-LiAlO2 crystal, known as a promising solid breeding material in future fusion reactors, has attracted much attention for its irradiation effects. This work focused on the Raman effects in ion-implanted γ-LiAlO2. Ga ions of 30, 80 and 150 keV were implanted on the z-cut γ-LiAlO2 sample surfaces at a fluence of 1 × 1014 ions/cm2 or 1 × 1015 ions/cm2. The average ion range varied from 230 to 910 Å. The Raman spectra were collected from the implanted surfaces before and after the implantation. Evident changes were reflected in the Raman modes intensities, with abnormal increments for the most detected modes. According to the assignments of Raman modes, the Al-O vibration was enhanced to a greater extent than the Li-Al-O vibration, and the LiO4-AlO4 vibration gained a lesser enhancement. The discussion, including the factors of roughness, crystalline disorder and influence by Ga ions, attempts to explain the increments of Raman intensity.

  17. The Exergetic, Environmental and Economic Effect of the Hydrostatic Design Static Pressure Level on the Pipe Dimensions of Low-Energy District Heating Networks

    DEFF Research Database (Denmark)

    Tol, Hakan İbrahim; Svendsen, Svend

    2013-01-01

    to be used in a low-energy DH network to carry the heat produced by renewable and/or low grade energy sources to low-energy Danish buildings. In this study, a comparison of various design considerations with different levels of maximum design static pressures was performed, and their results evaluated...... in terms of energetic, exergetic, economic, and environmental perspectives....

  18. Molecular dynamics simulation of temperature effects on low energy near-surface cascades and surface damage in Cu

    Science.gov (United States)

    Zhu, Guo; Sun, Jiangping; Guo, Xiongxiong; Zou, Xixi; Zhang, Libin; Gan, Zhiyin

    2017-06-01

    The temperature effects on near-surface cascades and surface damage in Cu(0 0 1) surface under 500 eV argon ion bombardment were studied using molecular dynamics (MD) method. In present MD model, substrate system was fully relaxed for 1 ns and a read-restart scheme was introduced to save total computation time. The temperature dependence of damage production was calculated. The evolution of near-surface cascades and spatial distribution of adatoms at varying temperature were analyzed and compared. It was found that near-surface vacancies increased with temperature, which was mainly due to the fact that more atoms initially located in top two layers became adatoms with the decrease of surface binding energy. Moreover, with the increase of temperature, displacement cascades altered from channeling-like structure to branching structure, and the length of collision sequence decreased gradually, because a larger portion of energy of primary knock-on atom (PKA) was scattered out of focused chain. Furthermore, increasing temperature reduced the anisotropy of distribution of adatoms, which can be ascribed to that regular registry of surface lattice atoms was changed with the increase of thermal vibration amplitude of surface atoms.

  19. Molecular dynamics simulation of temperature effects on low energy near-surface cascades and surface damage in Cu

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Guo; Sun, Jiangping; Guo, Xiongxiong; Zou, Xixi; Zhang, Libin; Gan, Zhiyin, E-mail: ganzhiyin@126.com

    2017-06-15

    The temperature effects on near-surface cascades and surface damage in Cu(0 0 1) surface under 500 eV argon ion bombardment were studied using molecular dynamics (MD) method. In present MD model, substrate system was fully relaxed for 1 ns and a read-restart scheme was introduced to save total computation time. The temperature dependence of damage production was calculated. The evolution of near-surface cascades and spatial distribution of adatoms at varying temperature were analyzed and compared. It was found that near-surface vacancies increased with temperature, which was mainly due to the fact that more atoms initially located in top two layers became adatoms with the decrease of surface binding energy. Moreover, with the increase of temperature, displacement cascades altered from channeling-like structure to branching structure, and the length of collision sequence decreased gradually, because a larger portion of energy of primary knock-on atom (PKA) was scattered out of focused chain. Furthermore, increasing temperature reduced the anisotropy of distribution of adatoms, which can be ascribed to that regular registry of surface lattice atoms was changed with the increase of thermal vibration amplitude of surface atoms.

  20. Correlation effects on double electron capture in highly-charged, low-energy ion-atom collisions

    International Nuclear Information System (INIS)

    Meyer, F.W.; Griffin, D.C.; Havener, C.C.; Huq, M.S.; Phaneuf, R.A.; Swenson, J.K.; Stolterfoht, N.

    1987-01-01

    The method of zero-degree Auger electron spectroscopy has been used to study two-electron excited states populated in slow double capture collisions of highly charged ions with He and H 2 . The focus of this study is on production of autoionization electrons originating from the non-equivalent 1s 2 2pnl electron configurations in comparison with electron production resulting from the Auger decay of (near) equivalent 1s 2 nln'l' (with n∼n') configurations. It is shown that production of non-equivalent electron configurations is significant and involves electron-electron correlation effects whose analysis leads beyond the independent-particle model. Recent results that include a measurement at non-zero angles are presented to illustrate the angular dependence of electron emission from non-equivalent electron configurations, as well as the dependence on projectile charge state and target species. Comparison of high resolution scans over two lines of the 1s 2 2pnl sequence for the O 6+ + He system with accurate transition energy calculations shows preferential population of high angular momentum substation

  1. Technical Note: Effect of explicit M and N-shell atomic transitions on a low-energy x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Peter G. F., E-mail: peter.watson@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal, Quebec H4A 3J1 (Canada)

    2016-04-15

    Purpose: In EGSnrc, atomic transitions to and from the M and N-shells are treated in an average way by default. This approach is justified in which the energy difference between explicit and average M and N-shell binding energies is less than 1 keV, and for most applications can be considered negligible. However, for simulations of low energy x-ray sources on thin, high-Z targets, characteristic x-rays can make up a significant portion of the source spectra. As of release V4-2.4.0, EGSnrc has included an option to enable a more complete algorithm of all atomic transitions available in the EADL compilation. In this paper, the effect of M and N-shell averaging on the calculation of half-value layer (HVL) and relative depth dose (RDD) curve of a 50 kVp intraoperative x-ray tube with a thin gold target was investigated. Methods: A 50 kVp miniature x-ray source with a gold target (The INTRABEAM System, Carl Zeiss, Germany) was modeled with the EGSnrc user code cavity, both with and without M and N-shell averaging. From photon fluence spectra simulations, the source HVLs were determined analytically. The same source model was then used with egs-chamber to calculate RDD curves in water. Results: A 4% increase of HVL was reported when accounting for explicit M and N-shell transitions, and up to a 9% decrease in local relative dose for normalization at 3 mm depth in water. Conclusions: The EGSnrc default of using averaged M and N-shell binding energies has an observable effect on the HVL and RDD of a low energy x-ray source with high-Z target. For accurate modeling of this class of devices, explicit atomic transitions should be included.

  2. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Hoshi, Masaharu; Antoku, Shigetoshi; Russell, W.J.; Miller, R.C.; Nakamura, Nori; Mizuno, Masayoshi; Nishio, Shoji.

    1987-05-01

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60 Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60 Co. The RBE of 200 kVp X rays relative to 60 Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  3. Rapid Response: D-Wave Effort Debrief Welcome, Logistics

    Energy Technology Data Exchange (ETDEWEB)

    Eidenbenz, Stephan Johannes [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-11

    The main objects of this project is to develop a diverse and sizable workforce, community, interest within LANL for D-Wave and Quantum Computing; identify promising application areas/problems for future projects; and complement other D-Wave work at LANL (LDRD DR, ASC).

  4. P-odd effects in πN-scattering at low energies and determination of the isotopical structure of the weak nonleptonic interaction

    International Nuclear Information System (INIS)

    Gershtein, S.S.; Folomeshkin, V.N.; Khlopov, M.Yu.

    1974-01-01

    P-odd effects in the πN-scattering on a target polarized along and again a pion beam have been considered. The P-odd correlations are intensified by interference of weak and strong interactions, whose amplitude is great in the energy range of the order of 100 to 300 MeV. When measuring cross-section differences of the πN-scattering at meson factories, it is possible to hope that the Lobashow integral method may be used in this range. The P-odd amplitudes have been calculated in the approximation of low-energy pions from the P-odd πNN vertex. High-energy meson effects are taken account of in the model of a rho-meson exchange. A kinematic analysis shows that the P-odd effects in a backward charge exchange reaction are sensitive to the presence of neutral currents. Investigation of the P-odd effects in a forward (elastica and with charge exchange) πN-scattering makes it possible to establish the isotopic structure of the nonlepton weak interaction and in particular to check the assumption of an intensified rho-meson exchange which has been offered by. Danilov to explain the high value of circular polarization of γ-quanta in the np → dγ reaction

  5. Adenosine Receptors as a Biological Pathway for the Anti-Inflammatory and Beneficial Effects of Low Frequency Low Energy Pulsed Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Katia Varani

    2017-01-01

    Full Text Available Several studies explored the biological effects of low frequency low energy pulsed electromagnetic fields (PEMFs on human body reporting different functional changes. Much research activity has focused on the mechanisms of interaction between PEMFs and membrane receptors such as the involvement of adenosine receptors (ARs. In particular, PEMF exposure mediates a significant upregulation of A2A and A3ARs expressed in various cells or tissues involving a reduction in most of the proinflammatory cytokines. Of particular interest is the observation that PEMFs, acting as modulators of adenosine, are able to increase the functionality of the endogenous agonist. By reviewing the scientific literature on joint cells, a double role for PEMFs could be hypothesized in vitro by stimulating cell proliferation, colonization of the scaffold, and production of tissue matrix. Another effect could be obtained in vivo after surgical implantation of the construct by favoring the anabolic activities of the implanted cells and surrounding tissues and protecting the construct from the catabolic effects of the inflammatory status. Moreover, a protective involvement of PEMFs on hypoxia damage in neuron-like cells and an anti-inflammatory effect in microglial cells have suggested the hypothesis of a positive impact of this noninvasive biophysical stimulus.

  6. The Exergetic, Environmental and Economic Effect of the Hydrostatic Design Static Pressure Level on the Pipe Dimensions of Low-Energy District Heating Networks

    Directory of Open Access Journals (Sweden)

    Hakan İbrahim Tol

    2013-01-01

    Full Text Available Low-Energy District Heating (DH systems, providing great energy savings by means of very low operating temperatures of 55 °C and 25 °C for supply and return respectively, were considered to be the 4th generation of the DH systems for a low-energy future. Low-temperature operation is considered to be used in a low-energy DH network to carry the heat produced by renewable and/or low grade energy sources to low-energy Danish buildings. In this study, a comparison of various design considerations with different levels of maximum design static pressures was performed, and their results evaluated in terms of energetic, exergetic, economic, and environmental perspectives.

  7. A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

    Science.gov (United States)

    Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K.; Anuntalabhochai, S.; Yu, L. D.

    2012-02-01

    DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli ( E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

  8. A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

    International Nuclear Information System (INIS)

    Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K.; Anuntalabhochai, S.; Yu, L.D.

    2012-01-01

    DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli (E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

  9. Evaluation of the Effect of Different Doses of Low Energy Shock Wave Therapy on the Erectile Function of Streptozotocin (STZ-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Zhong-Cheng Xin

    2013-05-01

    Full Text Available To investigate the therapeutic effect of different doses of low energy shock wave therapy (LESWT on the erectile dysfunction (ED in streptozotocin (STZ induced diabetic rats. SD rats (n = 75 were randomly divided into 5 groups (normal control, diabetic control, 3 different dose LESWT treated diabetic groups. Diabetic rats were induced by intra-peritoneal injection of STZ (60 mg/kg and rats with fasting blood glucose ≥ 300 mg/dL were selected as diabetic models. Twelve weeks later, different doses of LESWT (100, 200 and 300 shocks each time treatment on penises were used to treat ED (7.33 MPa, 2 shocks/s three times a week for two weeks. The erectile function was evaluated by intracavernous pressure (ICP after 1 week washout period. Then the penises were harvested for histological study. The results showed LESWT could significantly improve the erectile function of diabetic rats, increase smooth muscle and endothelial contents, up-regulate the expression of α-SMA, vWF, nNOS and VEGF, and down- regulate the expression of RAGE in corpus cavernosum. The therapeutic effect might relate to treatment dose positively, and the maximal therapeutic effect was noted in the LESWT300 group. Consequently, 300 shocks each time might be the ideal LESWT dose for diabetic ED treatment.

  10. D-wave resonances in positronium hydride

    International Nuclear Information System (INIS)

    DiRienzi, Joseph; Drachman, Richard J.

    2002-01-01

    In a previous paper [Phys. Rev. A 65, 032721 (2002)] we reexamined a model describing the structure of the low-energy Ps-H resonances as being due to quasibound states of the positron in the perturbed Coulomb potential of the H - ion appearing in the closed, rearranged channel. In particular, we wished to understand why the lowest p-state resonance was so far away from the lowest quasibound (2p) state. We found that the lowest resonance actually corresponds to the first-excited [3p] state, while the lowest state is not recognizable as a resonance. In the present work we repeat our analysis, but this time for the lowest d state. We find that the lowest [3d] state does correspond to a resonance shifted moderately

  11. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    2012-10-05

    Oct 5, 2012 ... Abstract. Low-energy solar neutrino detection plays a fundamental role in ... the experimental point of view, there are multiple ways to shed light among the different .... compared to the two metallicity expectations [16]. ..... from the Earth; solar neutrinos; indirect dark matter searches) and GeV physics (pro-.

  12. Low-energy nuclear physics

    International Nuclear Information System (INIS)

    1985-01-01

    The 1985 annual report of the Schuster Laboratory, Manchester University, England, on low-energy nuclear physics, is presented. The report includes experiments involving: high spin states, nuclei far from stability, reactions and fission, spectroscopy and related subjects. Technical developments are also described. (U.K.)

  13. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    Low-energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND ...

  14. Coherent tunnelling conductance in normal-metal/d-wave superconductor/normal-metal double tunnel junctions

    International Nuclear Information System (INIS)

    Dong, Z C; Zheng, Z M; Xing, D Y

    2004-01-01

    Taking simultaneously into account the electron-injected current from one normal-metal (N) electrode and the hole-injected current from the other N electrode, we study the coherent tunnelling conductance and quantum interference effects in N/d-wave superconductor (S)/N double tunnel junctions. It is found that oscillations of all quasiparticle transport coefficients and the conductance spectrum with quasiparticle energy and thickness of the d-wave S depend to a great extent on the crystal orientation of the d-wave S. The zero-bias conductance peak is gradually lowered with increasing barrier strength and/or temperature, its magnitude exhibiting damped oscillatory behaviour with thickness of S

  15. Phase separation and d-wave superconductivity induced by extended electron-exciton interaction

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Ming [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, Texas 77204 (United States)], E-mail: cheng896@hotmail.com; Su Wupei [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, Texas 77204 (United States)

    2008-12-15

    Using an auxiliary-field quantum Monte Carlo (AFQMC) method, we have studied a two-dimensional tight-binding model in which the conduction electrons can polarize an adjacent layer of molecules through electron-electron repulsion. Calculated average conduction electron density as a function of chemical potential exhibits a clear break characteristic of phase separation. Compared to the noninteracting system, the d-wave pair-field correlation function shows significant enhancement. The simultaneous presence of phase separation and d-wave superconductivity suggests that an effective extended pairing force is induced by the electron-exciton coupling.

  16. Phase separation and d-wave superconductivity induced by extended electron-exciton interaction

    International Nuclear Information System (INIS)

    Cheng Ming; Su Wupei

    2008-01-01

    Using an auxiliary-field quantum Monte Carlo (AFQMC) method, we have studied a two-dimensional tight-binding model in which the conduction electrons can polarize an adjacent layer of molecules through electron-electron repulsion. Calculated average conduction electron density as a function of chemical potential exhibits a clear break characteristic of phase separation. Compared to the noninteracting system, the d-wave pair-field correlation function shows significant enhancement. The simultaneous presence of phase separation and d-wave superconductivity suggests that an effective extended pairing force is induced by the electron-exciton coupling

  17. Low Energy Neutrino Cross Sections

    International Nuclear Information System (INIS)

    Zeller, G.P.

    2004-01-01

    Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ∼ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies.Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy

  18. A low energy solar town

    Energy Technology Data Exchange (ETDEWEB)

    Svendsen, Svend; Balocco, Carla

    1998-12-31

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m{sup 2}/year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs.

  19. A low energy solar town

    International Nuclear Information System (INIS)

    Svendsen, Svend; Balocco, Carla

    1998-01-01

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m 2 /year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs

  20. Effect of low-energy extracorporeal shock wave on vascular regeneration after spinal cord injury and the recovery of motor function.

    Science.gov (United States)

    Wang, Lei; Jiang, Yuquan; Jiang, Zheng; Han, Lizhang

    2016-01-01

    Latest studies show that low-energy extracorporeal shock wave therapy (ESWT) can upregulate levels of vascular endothelial growth factor (VEGF). VEGF can ease nervous tissue harm after spinal cord injury (SCI). This study aims to explore whether low-energy ESWT can promote expression of VEGF, protect nervous tissue after SCI, and improve motor function. Ninety adult female rats were divided into the following groups: Group A (simple laminectomy), Group B (laminectomy and low-energy ESWT), Group C (spinal cord injury), and Group D (spinal cord injury and low-energy ESWT). Impinger was used to cause thoracic spinal cord injury. Low-energy ESWT was applied as treatment after injury three times a week, for 3 weeks. After SCI, the Basso, Beattie, and Bresnahan (BBB) scale was used to evaluate motor function over a period of 42 days at different time points. Hematoxylin and eosin (HE) staining was used to evaluate nerve tissue injury. Neuronal nuclear antigen (NeuN) staining was also used to evaluate loss of neurons. Polymerase chain reaction was used to detect messenger RNA (mRNA) expression of VEGF and its receptor fms-like tyrosine kinase 1 (Flt-1). Immunostaining was used to evaluate VEGF protein expression level in myeloid tissue. BBB scores of Groups A and B showed no significant result related to dyskinesia. HE and NeuN staining indicated that only using low-energy ESWT could not cause damage of nervous tissue in Group B. Recovery of motor function at 7, 35, and 42 days after SCI in Group D was better than that in Group C (Pfunction. It can be regarded as one mode of clinical routine adjunctive therapy for spinal injury.

  1. Nonmonotonic temperature dependence of critical current in diffusive d-wave junctions

    NARCIS (Netherlands)

    Yokoyama, T.; Tanaka, Y.; Golubov, Alexandre Avraamovitch; Asano, Y.

    2006-01-01

    We study the Josephson effect in D/I/DN/I/D junctions, where I, DN, and D denote an insulator, a diffusive normal metal, and a d-wave superconductor, respectively. The Josephson current is calculated based on the quasiclassical Green's function theory with a general boundary condition for

  2. Pion-nucleon interactions in low energy region

    International Nuclear Information System (INIS)

    Hiroshige, Noboru; Tsujimura, Tadakuni.

    1977-01-01

    Pion-nucleon interactions in low energy region (below 320 MeV in kinetic energy) are investigated on the basis of the one-particle-exchange model. The model is directly compared with the experimental data, i.e., differential cross sections and recoil nucleon polarizations, since phase shifts have not been uniquely determined. It is shown that these experimental data can be well reproduced by taking account of N (nucleon), Δ 33 , N 11 , N 13 , rho, f 0 and S (scalar meson) in the intermediate state. Some comments are given on the coupling constants which are determined so as to minimize chi-squared value (chi 2 ). Our predicted phase shifts for s-, p- and d-waves are also compared with other authors'. (auth.)

  3. Food irradiation by low energy electrons

    International Nuclear Information System (INIS)

    Bird, J.R.

    1985-01-01

    For some special cases, the use of low energy electrons has advantages over the use of gamma-rays or higher energy electrons for the direct irradiation of food. These advantages arise from details of the interaction processes which are responsible for the production of physical, chemical and biological effects. Factors involved include depth of penetration, dose distribution, irradiation geometry, the possible production of radioactivity and costs

  4. Effects of fusion relevant transient energetic radiation, plasma and thermal load on PLANSEE double forged tungsten samples in a low-energy plasma focus device

    Science.gov (United States)

    Javadi, S.; Ouyang, B.; Zhang, Z.; Ghoranneviss, M.; Salar Elahi, A.; Rawat, R. S.

    2018-06-01

    Tungsten is the leading candidate for plasma facing component (PFC) material for thermonuclear fusion reactors and various efforts are ongoing to evaluate its performance or response to intense fusion relevant radiation, plasma and thermal loads. This paper investigates the effects of hot dense decaying pinch plasma, highly energetic deuterium ions and fusion neutrons generated in a low-energy (3.0 kJ) plasma focus device on the structure, morphology and hardness of the PLANSEE double forged tungsten (W) samples surfaces. The tungsten samples were provided by Forschungszentrum Juelich (FZJ), Germany via International Atomic Energy Agency, Vienna, Austria. Tungsten samples were irradiated using different number of plasma focus (PF) shots (1, 5 and 10) at a fixed axial distance of 5 cm from the anode top and also at various distances from the top of the anode (5, 7, 9 and 11 cm) using fixed number (5) of plasma focus shots. The virgin tungsten sample had bcc structure (α-W phase). After PF irradiation, the XRD analysis showed (i) the presence of low intensity new diffraction peak corresponding to β-W phase at (211) crystalline plane indicating the partial structural phase transition in some of the samples, (ii) partial amorphization, and (iii) vacancy defects formation and compressive stress in irradiated tungsten samples. Field emission scanning electron microscopy showed the distinctive changes to non-uniform surface with nanometer sized particles and particle agglomerates along with large surface cracks at higher number of irradiation shots. X-ray photoelectron spectroscopy analysis demonstrated the reduction in relative tungsten oxide content and the increase in metallic tungsten after irradiation. Hardness of irradiated samples initially increased for one shot exposure due to reduction in tungsten oxide phase, but then decreased with increasing number of shots due to increasing concentration of defects. It is demonstrated that the plasma focus device provides

  5. Low energy bar pp physics

    International Nuclear Information System (INIS)

    Amsler, C.; Crowe, K.

    1989-02-01

    A detailed investigation of proton-antiproton interactions at low energy has become feasible with the commissioning of the LEAR facility in 1983. We shall shortly review the status of bar pp annihilation at rest and the physics motivations for second generation experiments with the Crystal Barrel detector. This type of detector would be adequate for the study of both Kp and bar pp interactions on an extracted beam of the KAON Factory. We shall conclude with a few remarks on the physics opportunities with bar p's at the KAON Factory which, in our opinion, will not be covered by the present LEAR facility. 11 refs., 10 figs., 2 tabs

  6. Low-energy heavy-ion reactions: Some recent developments

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1989-01-01

    We address three areas: behavior of the optical model at low energies and associated phenomena, fusion at near- and sub-barrier energies; where does fusion occur?, and recent examples of explicit coupled-channels effects at low energies. 74 refs., 18 figs

  7. Low energy dynamics of self-dual A1 strings

    International Nuclear Information System (INIS)

    Gustavsson, Andreas

    2003-01-01

    We examine the interrelation between the (2,0) supersymmetric six-dimensional effective action for the A 1 theory, and the corresponding low-energy theory for the collective coordinates associated to selfdual BPS strings. We argue that this low energy theory is a two-dimensional N=4 supersymmetric sigma model

  8. The low-energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Low-energy geothermal resources are characterized by temperatures ranging from 30 to 100 C. The principal worldwide applications are: towns and greenhouses heating, spa bathing, agriculture products drying, etc.. Sources depth ranges from 1500 to 2500 m in porous and permeable formations (sandstones, sands, conglomerates, limestones..) carrying aquifers. The worldwide installed power was of about 11500 MWth in 1990, with an annual production of about 36000 GWh (about 1% of worldwide energy consumption). The annual production rate is estimated to 10% and would represent a 30000 and 80000 MWth power in 2000 and 2010, respectively. In France, low-energy geothermal resources are encountered principally in Mesozoic sediments of the Parisian and Aquitanian basins. French geothermics has developed during the last 30 years and principally between 1980 and 1985 after the second petroleum crack. After 1985, the decay of fossil fuel costs and the development of corrosion problems in the geothermal wells have led to the abandonment of the less productive fields and to the study of technical solutions to solve the corrosion problems. (J.S.). 1 fig., 5 photos

  9. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

    and with as little energy consumption as 41.1 kWh/m2/year including heating and all building services with no use of renewable energy such as PVcells or solar heating. One of the key means of reaching the objectives was to implement mechanical ventilation with low pressure loss and therefore low energy consumption....... The project consists of two buildings, building one is 6 stories high, and building two is 4 stories high. The buildings have a gross area of 50,500 m2 including underground parking. The ventilation and indoor climate concept was to use mechanical ventilation together with mechanical cooling and fanassisted......, with an average of 1.1 kJ/m3. The yearly mean SFP based on estimated runtime is approx. 0.8 kJ/m3. The case shows the unlocked potential that lies within mechanical ventilation for nearzero energy consuming buildings....

  10. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    For a class of negative slowly decaying potentials, including with , we study the quantum mechanical scattering theory in the low-energy regime. Using modifiers of the Isozaki--Kitada type we show that scattering theory is well behaved on the {\\it whole} continuous spectrum of the Hamiltonian......, including the energy . We show that the --matrices are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use appropriate weighted spaces. These results are used...... from positive energies to the limiting energy . This change corresponds to the behaviour of the classical orbits. Under stronger conditions we extract the leading term of the asymptotics of the kernel of at its singularities; this leading term defines a Fourier integral operator in the sense...

  11. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    2009-01-01

    For a class of negative slowly decaying potentials, including V(x):=−γ|x|−μ with 0quantum mechanical scattering theory in the low-energy regime. Using appropriate modifiers of the Isozaki–Kitada type we show that scattering theory is well behaved on the whole continuous spectrum...... of the Hamiltonian, including the energy 0. We show that the modified scattering matrices S(λ) are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the modified wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use...... of the kernel of S(λ) experiences an abrupt change from passing from positive energies λ to the limiting energy λ=0 . This change corresponds to the behaviour of the classical orbits. Under stronger conditions one can extract the leading term of the asymptotics of the kernel of S(λ) at its singularities....

  12. Theory of low energy collisions

    International Nuclear Information System (INIS)

    Sparenberg, J.M.

    2007-01-01

    The basic notions of low-energy quantum scattering theory are introduced (cross sections, phase shifts, resonances,... ), in particular for positively-charged particles, in view of nuclear physics applications. An introduction to the reaction-matrix (or R-matrix) method is then proposed, as a tool to both solve the Schroedinger equation describing collisions and fit experimental data phenomenologically. Most results are established without proof but with a particular emphasis on their intuitive understanding and their possible analogs in classical mechanics. Several choices are made consequently: (i) the text starts with a detailed reminder of classical scattering theory, (ii) the concepts are first introduced in ideal theoretical cases before going to the more complicated formalism allowing the description of realistic experimental situations, (iii) a single example is used throughout nearly the whole text, (iv) all concepts are established for the elastic scattering of spinless particles, with only a brief mention of their multichannel generalization at the end of the text. (author)

  13. [Effect of low-energy 633 nm red light stimulation on proliferation and reactive oxygen species level of human epidermal cell line HaCaT].

    Science.gov (United States)

    Chen, Z Y; Li, D L; Duan, X D; Peng, D Z

    2016-09-20

    group was observed by confocal laser scanning microscope. Data were processed with one-way analysis of variance, analysis of variance for repeated measurement, and t test. (1) Irradiation distance was 10 cm. Proliferative activity of cells in blank control group and 0.082, 0.164, 0.245, 0.491, 1.472, 2.453, 4.910, and 9.810 J/cm(2) irradiation groups was 1.000, 1.116±0.031, 1.146±0.016, 1.162±0.041, 1.179±0.016, 1.207±0.016, 1.247±0.040, 1.097±0.059, and 0.951±0.118, respectively. Compared with that in blank control group, proliferative activity of cells in 0.082-2.453 J/cm(2) irradiation groups was significantly higher (with t values from -22.803 to -6.779, P values below 0.05). Proliferative activity of cells in 4.910 and 9.810 J/cm(2) irradiation groups was similar to that in blank control group (with t values respectively -2.854 and 0.711, P values above 0.05). (2) Compared with that in blank control group, reactive oxygen species level of cells was significantly enhanced at PCM 0 and 30 in 0.164-2.453 J/cm(2) irradiation groups (with t values from -12.453 to -4.684, Poxygen species level of cells was significantly enhanced at PCM 60 in 0.082-2.453 J/cm(2) irradiation groups (with t values from -11.387 to -4.717, Poxygen species level of cells was significantly enhanced at PCM 120 in 0.491-2.453 J/cm(2) irradiation groups (with t values from -10.657 to -6.644, Poxygen species of cells was increased in 0.082, 0.491, and 2.453 J/cm(2) irradiation groups and positive control group. The expression of reactive oxygen species of cells in 9.810 J/cm(2) irradiation group was attenuated when compared with the expressions in the other irradiation groups. Reactive oxygen species expressed in mitochondria of cells in each group. Low-energy 633 nm red light can enhance the proliferation of human epidermal cell line HaCaT, and the effect is closely related to the increase of reactive oxygen species produced by mitochondria after being stimulated by red light irradiation.

  14. Effect of orlistat on weight regain and cardiovascular risk factors following a very-low-energy diet in abdominally obese patients

    DEFF Research Database (Denmark)

    Richelsen, Bjørn; Tonstad, Serena; Rössner, Stephan

    2007-01-01

    OBJECTIVE: To investigate the efficacy of orlistat on the maintenance of weight loss over 3 years following a major weight loss induced by very-low-energy diet (VLED) in obese patients with metabolic risk factors such as dyslipidemia, impaired fasting glucose, and diet-treated type 2 diabetes...... circumference was significantly more reduced in the orlistat group (P risk factors were observed between the two groups. The incidences of new cases of type 2 diabetes were significantly reduced in the orlistat group (8 cases out of 153 subjects) versus placebo (17 cases...

  15. Low-energy limit of two-scale field theories

    International Nuclear Information System (INIS)

    Leon, J.; Perez-Mercader, J.; Sanchez, M.F.

    1991-01-01

    We present a full and self-contained discussion of the decoupling theorem applied to several general models in four-dimensional field theory. We compute in each case the low-energy effective action and show the explicit one-loop expressions for each of the effective parameters. We find that for suitable conditions one can always build an effective low-energy theory where the conditions of the decoupling theorem are satisfied

  16. Intense low energy positron beams

    International Nuclear Information System (INIS)

    Lynn, K.G.; Jacobsen, F.M.

    1993-01-01

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e + beams exist producing of the order of 10 8 - 10 9 e + /sec. Several laboratories are aiming at high intensity, high brightness e + beams with intensities greater than 10 9 e + /sec and current densities of the order of 10 13 - 10 14 e + sec - 1 cm -2 . Intense e + beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B + moderators or by increasing the available activity of B + particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e + collisions with atoms and molecules. Within solid state physics high intensity, high brightness e + beams are in demand in areas such as the re-emission e + microscope, two dimensional angular correlation of annihilation radiation, low energy e + diffraction and other fields. Intense e + beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies

  17. CoSi2 growth on Si(001) by reactive deposition epitaxy: Effects of high-flux, low-energy ion irradiation

    International Nuclear Information System (INIS)

    Lim, C. W.; Greene, J. E.; Petrov, I.

    2006-01-01

    CoSi 2 layers, CoSi 2 (parallel sign)(001) Si and [100] CoSi 2 (parallel sign)[100] Si , contain fourfold symmetric (111) twinned domains oriented such that (221) CoSi 2 (parallel sign)(001) Si and CoSi 2 (parallel sign)[110] Si . We demonstrate that high-flux low-energy (E Ar + =9.6 eV) Ar + ion irradiation during deposition dramatically increases the area fraction f u of untwinned regions from 0.17 in films grown under standard magnetically balanced conditions in which the ratio J Ar + /J Co of the incident Ar + to Co fluxes is 1.4 to 0.72 with J Ar + /J Co =13.3. TEM analyses show that the early stages of RDE CoSi 2 (001) film growth proceed via the Volmer-Weber mode with independent nucleation of both untwinned and twinned islands. Increasing J Ar + /J Co results in larger values of both the number density and area of untwinned with respect to twinned islands. The intense Ar + ion bombardment creates additional low-energy adsorption sites that favor the nucleation of untwinned islands while collisionally enhancing Co surface mobilities which, in turn, increases the probability of itinerant Co adatoms reaching these sites

  18. Low-energy QCD and ultraviolet renormalons

    International Nuclear Information System (INIS)

    Peris, S.

    1997-01-01

    We discuss the contribution of ultraviolet (UV) renormalons in QCD to two-point functions of quark current operators. This explicitly includes effects due to the exchange of one renormalon chain as well as two chains. It is shown that, when the external Euclidean momentum of the two-point functions becomes smaller than the scale Λ L associated with the Landau singularity of the QCD one-loop running coupling constant, the positions of the UV renormalons in the Borel plane become true singularities in the integration range of the Borel transform. This introduces ambiguities in the evaluation of the corresponding two-point functions. The ambiguities associated with the leading UV renormalon singularity are of the same type as the contribution due to the inclusion of dimension d=6 local operators in a low-energy effective Lagrangian valid at scales smaller than Λ L . We then discuss the inclusion of an infinite number of renormalon chains and argue that the previous ambiguity hints at a plausible approximation scheme for low-energy QCD, resulting in an effective Lagrangian similar to the one of the extended Nambu-Jona-Lasinio (ENJL) model of QCD at large N c . (orig.)

  19. Surface Passivation and Junction Formation Using Low Energy Hydrogen Implants

    Science.gov (United States)

    Fonash, S. J.

    1985-01-01

    New applications for high current, low energy hydrogen ion implants on single crystal and polycrystal silicon grain boundaries are discussed. The effects of low energy hydrogen ion beams on crystalline Si surfaces are considered. The effect of these beams on bulk defects in crystalline Si is addressed. Specific applications of H+ implants to crystalline Si processing are discussed. In all of the situations reported on, the hydrogen beams were produced using a high current Kaufman ion source.

  20. Low-energy hadronic interactions beyond the current algebra approach

    International Nuclear Information System (INIS)

    Ivanov, A.N.; Troitskaya, N.I.; Nagy, M.

    1993-06-01

    The new low-energy AP 3 -interaction, which is produced by convergent box-constituent-quark-loop diagrams, is obtained within chiral perturbation theory at the quark level (CHPT) q with linear realization of chiral U(3) x U(3) symmetry. Its contributions to processes of low-energy interactions of low-lying mesons are investigated. The new interaction goes beyond the framework of the low-energy current algebra approach and of the effective chiral Lagrangians with linear realization of chiral symmetry, constructed at the hadronic level. (author). 17 refs, 3 figs

  1. Low Energy Nuclear Reactions: 2007 Update

    Science.gov (United States)

    Krivit, Steven B.

    2007-03-01

    This paper presents an overview of low energy nuclear reactions, a subset of the field of condensed matter nuclear science. Condensed matter nuclear science studies nuclear effects in and/or on condensed matter, including low energy nuclear reactions, an entirely new branch of science that gained widespread attention and notoriety beginning in 1989 with the announcement of a previously unrecognized source of energy by Martin Fleischmann and Stanley Pons that came to be known as cold fusion. Two branches of LENR are recognized. The first includes a set of reactions like those observed by Fleischmann and Pons that use palladium and deuterium and yield excess heat and helium-4. Numerous mechanisms have been proposed to explain these reactions, however there is no consensus for, or general acceptance of, any of the theories. The claim of fusion is still considered speculative and, as such, is not an ideal term for this work. The other branch is a wide assortment of nuclear reactions that may occur with either hydrogen or deuterium. Anomalous nuclear transmutations are reported that involve light as well as heavy elements. The significant questions that face this field of research are: 1) Are LENRs a genuine nuclear reaction? 2) If so, is there a release of excess energy? 3) If there is, is the energy release cost-effective?

  2. Tricrystal tunneling evidence for d-wave pairing symmetry in cuprate superconductors

    International Nuclear Information System (INIS)

    Tsuei, C.C.; Kirtley, J.R.

    1997-01-01

    Strong evidence for d-wave pairing symmetry in high-temperature superconductors such as YBa 2 Cu 3 O 7 and Tl 2 Ba 2 CuO 6+δ has been obtained by monitoring the presence or absence of the half-integer flux quantum effect in various controlled - orientation tricrystal superconducting systems. New results of a tricrystal tunneling experiment with Gd Ba 2 Cu 3 O 7 will also be presented. (orig.)

  3. Safety of transvenous low energy cardioversion of atrial fibrillation in patients with a history of ventricular tachycardia: effects of rate and repolarization time on proarrhythmic risk.

    Science.gov (United States)

    Simons, G R; Newby, K H; Kearney, M M; Brandon, M J; Natale, A

    1998-02-01

    The objective of this study was to assess the safety and efficacy of transvenous low energy cardioversion of atrial fibrillation in patients with ventricular tachycardia and atrial fibrillation and to study the mechanisms of proarrhythmia. Previous studies have demonstrated that cardioversion of atrial fibrillation using low energy, R wave synchronized, direct current shocks applied between catheters in the coronary sinus and right atrium is feasible. However, few data are available regarding the risk of ventricular proarrhythmia posed by internal atrial defibrillation shocks among patients with ventricular arrhythmias or structural heart disease. Atrial defibrillation was performed on 32 patients with monomorphic ventricular tachycardia and left ventricular dysfunction. Shocks were administered during atrial fibrillation (baseline shocks), isoproterenol infusion, ventricular pacing, ventricular tachycardia, and atrial pacing. Baseline shocks were also administered to 29 patients with a history of atrial fibrillation but no ventricular arrhythmias. A total of 932 baseline shocks were administered. No ventricular proarrhythmia was observed after well-synchronized baseline shocks, although rare inductions of ventricular fibrillation occurred after inappropriate T wave sensing. Shocks administered during wide-complex rhythms (ventricular pacing or ventricular tachycardia) frequently induced ventricular arrhythmias, but shocks administered during atrial pacing at identical ventricular rates did not cause proarrhythmia. The risk of ventricular proarrhythmia after well-synchronized atrial defibrillation shocks administered during narrow-complex rhythms is low, even in patients with a history of ventricular tachycardia. The mechanism of proarrhythmia during wide-complex rhythms appears not to be related to ventricular rate per se, but rather to the temporal relationship between shock delivery and the repolarization time of the previous QRS complex.

  4. Towards Low Energy Atrial Defibrillation

    Directory of Open Access Journals (Sweden)

    Philip Walsh

    2015-09-01

    . Efficient transcutaneous power transfer and sensing of ICI during cardioversion are evidenced as key to the advancement of low-energy atrial defibrillation.

  5. Low energy accelerators for research and applications

    International Nuclear Information System (INIS)

    Bhandari, R.K.

    2013-01-01

    Charged particle accelerators are instruments for producing a variety of radiations under controlled conditions for basic and applied research as well as applications. They have helped enormously to study the matter, atoms, nuclei, sub-nuclear particles and their constituents, forces involved in the related phenomena etc. No other man-made instrument has been so effective in such studies as the accelerator. The large accelerator constructed so far is the Large Hadron Collider (LHC) housed in a tunnel of 27 km circumference, while a small accelerator can fit inside a room. Small accelerators accelerate charged particles such as electrons, protons, deuterons, alphas and, in general ions to low energy, generally, below several MeV. These particle beams are used for studies in nuclear astrophysics, atomic physics, material science, surface physics, bio sciences etc. They are used for ion beam analysis such as RBS, PIXE, NRA, AMS, CPAA etc. More importantly, the ion beams have important industrial applications like ion implantation, surface modification, isotope production etc. while electron beams are used for material processing, material modification, sterilization, food preservation, non destructive testing etc. In this talk, role of low energy accelerators in research and industry as well as medicine will be discussed. (author)

  6. Low energy theorems of hidden local symmetries

    International Nuclear Information System (INIS)

    Harada, Masayasu; Kugo, Taichiro; Yamawaki, Koichi.

    1994-01-01

    We prove to all orders of the loop expansion the low energy theorems of hidden local symmetries in four-dimensional nonlinear sigma models based on the coset space G/H, with G and H being arbitrary compact groups. Although the models are non-renormalizable, the proof is done in an analogous manner to the renormalization proof of gauge theories and two-dimensional nonlinear sigma models by restricting ourselves to the operators with two derivatives (counting a hidden gauge boson field as one derivative), i.e., with dimension 2, which are the only operators relevant to the low energy limit. Through loop-wise mathematical induction based on the Ward-Takahashi identity for the BRS symmetry, we solve renormalization equation for the effective action up to dimension-2 terms plus terms with the relevant BRS sources. We then show that all the quantum corrections to the dimension-2 operators, including the finite parts as well as the divergent ones, can be entirely absorbed into a re-definition (renormalization) of the parameters and the fields in the dimension-2 part of the tree-level Lagrangian. (author)

  7. Comment on the prediction of two-loop standard chiral perturbation theory for low-energy ππ scattering

    International Nuclear Information System (INIS)

    Girlanda, L.; Moussallam, B.; Stern, J.; Knecht, M.

    1997-03-01

    Four of the six parameters defining the two-loop ππ scattering amplitude have been determined using Roy dispersion relations. Combining this information with the Standard χ PT expressions, the threshold parameters, low-energy phases and the O(p 4 ) constants l 1 r , l 2 r are obtained. The result reproduces the correct D-waves but it is incompatible with existing Standard χ PT analyses of K 14 form factors beyond one loop. (author)

  8. TRILEX and G W +EDMFT approach to d -wave superconductivity in the Hubbard model

    Science.gov (United States)

    Vučičević, J.; Ayral, T.; Parcollet, O.

    2017-09-01

    We generalize the recently introduced TRILEX approach (TRiply irreducible local EXpansion) to superconducting phases. The method treats simultaneously Mott and spin-fluctuation physics using an Eliashberg theory supplemented by local vertex corrections determined by a self-consistent quantum impurity model. We show that, in the two-dimensional Hubbard model, at strong coupling, TRILEX yields a d -wave superconducting dome as a function of doping. Contrary to the standard cluster dynamical mean field theory (DMFT) approaches, TRILEX can capture d -wave pairing using only a single-site effective impurity model. We also systematically explore the dependence of the superconducting temperature on the bare dispersion at weak coupling, which shows a clear link between strong antiferromagnetic (AF) correlations and the onset of superconductivity. We identify a combination of hopping amplitudes particularly favorable to superconductivity at intermediate doping. Finally, we study within G W +EDMFT the low-temperature d -wave superconducting phase at strong coupling in a region of parameter space with reduced AF fluctuations.

  9. A novel setup for the determination of absolute cross sections for low-energy electron induced strand breaks in oligonucleotides - The effect of the radiosensitizer 5-fluorouracil

    International Nuclear Information System (INIS)

    Rackwitz, J.; Rankovic, M.L.; Milosavljevic, A.R.; Bald, I.

    2017-01-01

    Low-energy electrons (LEEs) play an important role in DNA radiation damage. Here we present a method to quantify LEE induced strand breakage in well-defined oligonucleotide single strands in terms of absolute cross sections. An LEE irradiation setup covering electron energies <500 eV is constructed and optimized to irradiate DNA origami triangles carrying well-defined oligonucleotide target strands. Measurements are presented for 10.0 and 5.5 eV for different oligonucleotide targets. The determination of absolute strand break cross sections is performed by atomic force microscopy analysis. An accurate fluence determination ensures small margins of error of the determined absolute single strand break cross sections σ SSB . In this way, the influence of sequence modification with the radiosensitive 5-Fluorouracil ( 5F U) is studied using an absolute and relative data analysis. We demonstrate an increase in the strand break yields of 5F U containing oligonucleotides by a factor of 1.5 to 1.6 compared with non-modified oligonucleotide sequences when irradiated with 10 eV electrons. (authors)

  10. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  11. Knowledge from the low energy results

    International Nuclear Information System (INIS)

    Gosset, J.

    1988-01-01

    Before being used at very high energies, in order to search for the quark-gluon plasma, nucleus-nucleus central collisions have been studied at low energy, between about 20 MeV per nucleon and 10 GeV per nucleon, with the same objective to explore the phase diagram of nuclear matter, but in a regime where both temperature and energy are too small for plasma formation. Approaching this very complicated problem of nuclear physics led to many difficulties. They are first reviewed, and various means developed in order to solve them are considered. These difficulties are then detailed along discussions about temperature and nuclear collective flow. Temperature is a concept which is commonly used but also a quantity which is difficult to measure. Nuclear collective flow is a very interesting compression effect; it has been observed experimentally after being predicted theoretically, but its interpretation in terms of the nuclear matter equation of state remains quite difficult [fr

  12. Theorems of low energy in Compton scattering

    International Nuclear Information System (INIS)

    Chahine, J.

    1984-01-01

    We have obtained the low energy theorems in Compton scattering to third and fouth order in the frequency of the incident photon. Next we calculated the polarized cross section to third order and the unpolarized to fourth order in terms of partial amplitudes not covered by the low energy theorems, what will permit the experimental determination of these partial amplitudes. (Author) [pt

  13. Influence of the impurity-scattering on zero-bias conductance peak in ferromagnet/insulator/d-wave superconductor junctions

    CERN Document Server

    Yoshida, N; Itoh, H; Tanaka, Y; Inoue, J I; Kashiwaya, S

    2003-01-01

    Effects of impurity-scattering on a zero-bias conductance peak in ferromagnet/insulator/d-wave superconductor junctions are theoretically studied. The impurities are introduced through the random potential in ferromagnets near the junction interface. As in the case of normal-metal/insulator/d-wave superconductor junctions, the magnitude of zero-bias conductance peak decreases with increasing the degree of disorder. However, when the magnitude of the exchange potential in ferromagnet is sufficiently large, the random potential can enhance the zero-bias conductance peak in ferromagnetic junctions. (author)

  14. Ultrafine tungsten as a plasma-facing component in fusion devices: effect of high flux, high fluence low energy helium irradiation

    International Nuclear Information System (INIS)

    El-Atwani, O.; Gonderman, Sean; Allain, J.P.; Efe, Mert; Klenosky, Daniel; Qiu, Tian; De Temmerman, Gregory; Morgan, Thomas; Bystrov, Kirill

    2014-01-01

    This work discusses the response of ultrafine-grained tungsten materials to high-flux, high-fluence, low energy pure He irradiation. Ultrafine-grained tungsten samples were exposed in the Pilot-PSI (Westerhout et al 2007 Phys. Scr. T128 18) linear plasma device at the Dutch Institute for Fundamental Energy Research (DIFFER) in Nieuwegein, the Netherlands. The He flux on the tungsten samples ranged from 1.0 × 10 23 –2.0 × 10 24  ions m −2  s −1 , the sample bias ranged from a negative (20–65) V, and the sample temperatures ranged from 600–1500 °C. SEM analysis of the exposed samples clearly shows that ultrafine-grained tungsten materials have a greater fluence threshold to the formation of fuzz by an order or magnitude or more, supporting the conjecture that grain boundaries play a major role in the mechanisms of radiation damage. Pre-fuzz damage analysis is addressed, as in the role of grain orientation on structure formation. Grains of (1 1 0) and (1 1 1) orientation showed only pore formation, while (0 0 1) oriented grains showed ripples (higher structures) decorated with pores. Blistering at the grain boundaries is also observed in this case. In situ TEM analysis during irradiation revealed facetted bubble formation at the grain boundaries likely responsible for blistering at this location. The results could have significant implications for future plasma-burning fusion devices given the He-induced damage could lead to macroscopic dust emission into the fusion plasma. (paper)

  15. Low energy demonstration accelerator technical area 53

    International Nuclear Information System (INIS)

    1996-01-01

    As part of the Department of Energy's (DOE) need to maintain the capability of producing tritium in support of its historic and near-term stewardship of the nation's nuclear weapons stockpile, the agency has recently completed a Programmatic Environmental Impact Statement for Tritium Supply and Recycling. The resulting Record of Decision (ROD) determined that over the next three years the DOE would follow a dual-track acquisition strategy that assures tritium production for the nuclear weapon stockpile in a rapid, cost effective, and safe manner. Under this strategy the DOE will further investigate and compare two options for producing tritium: (1) purchase of an existing commercial light-water reactor or irradiation services with an option to purchase the reactor for conversion to a defense facility; and (2) design, build, and test critical components of a system for accelerator production of tritium (APT). The final decision to select the primary production option will be made by the Secretary of Energy in the October 1998 time frame. The alternative not chosen as the primary production method, if feasible, would be developed as a back-up tritium supply source. This Environmental Assessment (EA) analyzes the potential environmental effects that would be expected to occur if the DOE were to design, build, and test critical prototypical components of the accelerator system for tritium production, specifically the front-end low-energy section of the accelerator, at Los Alamos National Laboratory. The Low Energy Demonstration Accelerator (LEDA) would be incrementally developed and tested in five separate stages over the next seven years. The following issues were evaluated for the proposed action: utility demands, air, human health, environmental restoration, waste management, transportation, water, threatened and endangered species, wetlands, cultural resources, and environmental justice

  16. Experimental investigation on the effect of surface electric field in the growth of tungsten nano-tendril morphology due to low energy helium irradiation

    International Nuclear Information System (INIS)

    Woller, K.B.; Whyte, D.G.; Wright, G.M.; Brunner, D.

    2016-01-01

    The mechanisms responsible for and controlling the growth of tungsten nano-tendrils (or “fuzz”) under low-energy helium plasma exposure remain unclear. For the first time in nano-tendril experiments, the plasma sheath-produced electric field and the helium (He) ion energy have been decoupled, showing that the sheath electric field has little impact on nano-tendril growth, eliminating a possible cause for tendril growth. The well-established necessary growth conditions for W fuzz were maintained with He ion flux density Γ He  > 10 21  He m −2  s −1 , surface temperature T s  = 1273 K, He ion energy E He  = 64 eV, and He ion fluence Φ He  > 10 24  He m −2 . A grid is situated between the tungsten sample and plasma, with the grid and sample potentials independently controlled in order to control the electric field at the surface of the sample while maintaining the same incident He ion energy to the surface. A calculation of the potential profile in the drift space between the grid and sample was used to account for space charge and calculate the electric field at the surface of the sample. Tungsten fuzz formed at all electric fields tested, even near zero electric field. Also, the depth of the resulting W fuzz layer was unaltered by the electric field when compared to the calculated depth determined from an empirical growth model. The conclusion is that the sheath electric field is not necessary to cause the changes in surface morphology. - Highlights: • Surface electric field is proposed as a possible driver of tungsten fuzz growth. • A method that decouples plasma sheath electric field and ion energy is described. • Tungsten fuzz is shown to grow even without direct exposure to plasma. • Tungsten fuzz grows to the same depth with and without the plasma sheath.

  17. Low energy fermion number violation

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1989-01-01

    After a brief aside on charge quantization in the standard electroweak theory, I concentrate on various aspects of anomaly induced fermion number violation in the standard model. A critical analysis of the role of sphalerons for the universe's baryon asymmetry is presented and the importance of calculating directly fermion number violating Green's functions is stressed. A physical interpretation of the recent observation of Ringwald, that coherent effects in the electroweak theory lead to catastrophic fermion number violation at 100 TeV, is discussed. Possible quantum effects which might spoil this semi-classical picture are examined

  18. Solar-assisted low energy dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, T V

    1980-02-01

    The Zero Energy House Group was formed as a subproject of the CCMS Solar Energy Pilot Study in 1974 by seven participating countries experimenting with solar-assisted low-energy dwellings for temperate and northern European climatic conditions. A Zero Energy House is one in which solar energy is used to meet the reduced energy needs of buildings incorporating various thermal energy conservation features. This final report of the Zero Energy House Group includes brief descriptions of 13 major low-energy dwellings in the participating CCMS countries. An overall assessment of the state-of-the-art in solar-assisted low-energy dwellings is also included.

  19. Low-energy limit of the extended Linear Sigma Model

    Energy Technology Data Exchange (ETDEWEB)

    Divotgey, Florian [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Kovacs, Peter [Wigner Research Center for Physics, Hungarian Academy of Sciences, Institute for Particle and Nuclear Physics, Budapest (Hungary); GSI Helmholtzzentrum fuer Schwerionenforschung, ExtreMe Matter Institute, Darmstadt (Germany); Giacosa, Francesco [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Jan-Kochanowski University, Institute of Physics, Kielce (Poland); Rischke, Dirk H. [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); University of Science and Technology of China, Interdisciplinary Center for Theoretical Study and Department of Modern Physics, Hefei, Anhui (China)

    2018-01-15

    The extended Linear Sigma Model is an effective hadronic model based on the linear realization of chiral symmetry SU(N{sub f}){sub L} x SU(N{sub f}){sub R}, with (pseudo)scalar and (axial-)vector mesons as degrees of freedom. In this paper, we study the low-energy limit of the extended Linear Sigma Model (eLSM) for N{sub f} = flavors by integrating out all fields except for the pions, the (pseudo-)Nambu-Goldstone bosons of chiral symmetry breaking. The resulting low-energy effective action is identical to Chiral Perturbation Theory (ChPT) after choosing a representative for the coset space generated by chiral symmetry breaking and expanding it in powers of (derivatives of) the pion fields. The tree-level values of the coupling constants of the effective low-energy action agree remarkably well with those of ChPT. (orig.)

  20. Fundamental physics with low-energy neutrons

    International Nuclear Information System (INIS)

    Barrón-Palos, Libertad

    2016-01-01

    Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing. (paper)

  1. Pion nucleon interaction at low energy

    International Nuclear Information System (INIS)

    Banerjee, M.K.

    1979-03-01

    A theory of the πN interaction at low energy is described. An analogy is made with an unusual approach to potential scattering theory. Phase shifts, cross sections, and scattering amplitudes and lengths are calculated. 28 references

  2. Current status of low energy EB machine

    International Nuclear Information System (INIS)

    Toshiro Nishikimi; Shuichi Taniguchi; Kenichi Mizusawa

    1999-01-01

    Electron beam processing systems have been in use in a variety of applications such as curing of paints and printing inks, crosslinking of PE products, treating of rubber tire and so on. Low energy electron processing systems have become popular as self-shielded machines, which are compact and easy to use and do not require special facility as an irradiation room. This manuscript introduces the status of low energy EB (electron beam) machine through Nissin's products current

  3. Enhancement Mechanisms of Low Energy Nuclear Reactions

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2005-01-01

    The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy o...

  4. Exploring the Hidden Sector @ Low Energies

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Over the years we have accumulated a large number of indications for physics beyond the standard model. This new physics is often sought-after at high masses and energies. Here collider experiments can bring decisive insights. However, over recent years it has become increasingly clear that new physics can also appear at low energy, but extremely weak coupling. Experiments and observations at this `low energy frontier' therefore provide a powerful tool to gain insight into fundamental physics, which is complementary to accelerators.

  5. Low energy scattering with a nontrivial pion

    International Nuclear Information System (INIS)

    Fariborz, Amir H.; Jora, Renata; Schechter, Joseph

    2007-01-01

    An earlier calculation in a generalized linear sigma model showed that the well-known current algebra formula for low energy pion-pion scattering held even though the massless Nambu Goldstone pion contained a small admixture of a two-quark two-antiquark field. Here we turn on the pion mass and note that the current algebra formula no longer holds exactly. We discuss this small deviation and also study the effects of a SU(3) symmetric quark mass type term on the masses and mixings of the eight SU(3) multiplets in the model. We calculate the s-wave scattering lengths, including the beyond current algebra theorem corrections due to the scalar mesons, and observe that the effect of the scalar mesons is to improve the agreement with experiment. In the process, we uncover the way in which linear sigma models give controlled corrections (due to the presence of scalar mesons) to the current algebra scattering formula. Such a feature is commonly thought to exist only in the nonlinear sigma model approach

  6. Ginzburg-Landau equations for a d-wave superconductor with applications to vortex structure and surface problems

    International Nuclear Information System (INIS)

    Xu, J.; Ren, Y.; Ting, C.S.

    1995-01-01

    The properties of a d x 2 -y 2 -wave superconductor in an external magnetic field are investigated on the basis of Gorkov's theory of weakly coupled superconductors. The Ginzburg-Landau (GL) equations, which govern the spatial variations of the order parameter and the supercurrent, are microscopically derived. The single vortex structure and surface problems in such a superconductor are studied using these equations. It is shown that the d-wave vortex structure is very different from the conventional s-wave vortex: the s-wave and d-wave components, with the opposite winding numbers, are found to coexist in the region near the vortex core. The supercurrent and local magnetic field around the vortex are calculated. Far away from the vortex core, both of them exhibit a fourfold symmetry, in contrast to an s-wave superconductor. The surface problem in a d-wave superconductor is also studied by solving the GL equations. The total order parameter near the surface is always a real combination of s- and d-wave components, which means that the proximity effect cannot induce a time-reversal symmetry-breaking state at the surface

  7. Low-energy physics of high-temperature superconductors

    International Nuclear Information System (INIS)

    Emery, V.J.; Kivelson, S.A.

    1992-01-01

    It is argued that the low-energy properties of high temperature superconductors are dominated by the interaction between the mobile holes and a particular class of collective modes, corresponding to local large-amplitude low-energy fluctuations in the hole density. The latter are a consequence of the competition between the effects of long-range Coulomb interactions and the tendency of a low concentration of holes in an antiferromagnet to phase separate. The low-energy behavior of the system is governed by the same fixed point as the two-channel Kondo problem, which accounts for the ''universality'' of the properties of the cuprate superconductors. Predictions of the optical properties and the spin dynamics are compared with experiment. The pairing resonance of the two Kondo problem gives a mechanism of high temperature superconductivity with an unconventional symmetry of the order parameter

  8. Low Energy Desalination Using Battery Electrode Deionization

    KAUST Repository

    Kim, Taeyoung

    2017-09-21

    New electrochemical technologies that use capacitive or battery electrodes are being developed to minimize energy requirements for desalinating brackish waters. When a pair of electrodes is charged in capacitive deionization (CDI) systems, cations bind to the cathode and anions bind to the anode, but high applied voltages (>1.2 V) result in parasitic reactions and irreversible electrode oxidation. In the battery electrode deionization (BDI) system developed here, two identical copper hexacyanoferrate (CuHCF) battery electrodes were used that release and bind cations, with anion separation occurring via an anion exchange membrane. The system used an applied voltage of 0.6 V, which avoided parasitic reactions, achieved high electrode desalination capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes between CuHCF electrodes (up to three anion and two cation exchange membranes) reduced energy consumption to only 0.02 kWh/m3 (approximately an order of magnitude lower than values reported for CDI), for an influent desalination similar to CDI (25 mM decreased to 17 mM). These results show that BDI could be effective as a very low energy method for brackish water desalination.

  9. Low energy spin excitations in chromium metal

    International Nuclear Information System (INIS)

    Pynn, R.; Azuah, R.T.; Stirling, W.G.

    1997-01-01

    Neutron scattering experiments with full polarization analysis have been performed with a single crystal of chromium to study the low-energy spin fluctuations in the transverse spin density wave (TSDW) state. A number of remarkable results have been found. Inelastic scattering observed close to the TSDW satellite positions at (1 ± δ,0,0) does not behave as expected for magnon scattering. In particular, the scattering corresponds to almost equally strong magnetization fluctuations both parallel and perpendicular to the ordered moments of the TSDW phase. As the Neel temperature is approached from below, scattering at the commensurate wavevector (1,0,0) increases in intensity as a result of critical scattering at silent satellites (1,0, ± δ) being included within the spectrometer resolution function. This effect, first observed by Sternlieb et al, does not account for all of the inelastic scattering around the (1,0,0) position, however, Rather, there are further collective excitations, apparently emanating from the TSDW satellites, which correspond to magnetic fluctuations parallel to the ordered TSDW moments. These branches have a group velocity that is close to that of (1,0,0) longitudinal acoustic (LA) phonons, but assigning their origin to magneto-elastic scattering raises other unanswered questions

  10. Low energy pion-16O scattering

    International Nuclear Information System (INIS)

    Wafelbakker, C.K.

    1981-01-01

    In spite of some outward appearances, the modern microscopic theories of the pion-nucleus (πA) interaction are not fundamentally very different from each other. They can all be derived from the same source, multiple-scattering theory. They all treat the first-order optical potential in a comparatively detailed way and in all of them it is necessary to incorporate higher-order effects in general and pion-annihilation in particular phenomenologically. Basically the same physical features can be embodied in all of them. The presentation of the theoretical scheme underlying the present thesis is designed to stress this conceptual unity of current πA theory. In this thesis the methods developed by De Kam to incorporate Pauli- and binding-corrections to the impulse-approximation first-order optical potential for 4 He are extended to a more complicated nucleus, 16 O, for the first time. In concreto two situations are considered: π- 16 O scattering at energies below nucleon-knockout threshold (13.5 MeV) - 7 and 12 MeV - and at energies 40 and 49.7 MeV, above nucleon-knockout threshold but still well within the low-energy region. (Auth.)

  11. DOD low energy model installation program

    International Nuclear Information System (INIS)

    Fournier, D.F. Jr.

    1993-01-01

    The Model Low Energy Installation Program is a demonstration of an installation-wide, comprehensive energy conservation program that meets the Department of Defense (DoD) energy management goals of reducing energy usage and costs by at least 20%. It employs the required strategies for meeting these goals, quantifies the environmental compliance benefits resulting from energy conservation and serves as a prototype for DoD wide application. This project will develop both analysis tools and implementation procedures as well as demonstrate the effectiveness of a comprehensive, coordinated energy conservation program based on state-of-the-art technologies. A military installation is in reality a small to medium sized city. It generally has a complete utilities infrastructure including water supply and distribution, sewage collection and treatment, electrical supply and distribution, central heating and cooling plants with thermal distribution, and a natural gas distribution system. These utilities are quite extensive and actually consume about 10-15% of the energy on the facility not counting the energy going into the central plants

  12. The effect of short-term low-energy ultraviolet B irradiation on bone mineral density and bone turnover markers in postmenopausal women with osteoporosis: A randomized single-blinded controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Micić Ivan

    2013-01-01

    Full Text Available Introduction. The importance of vitamin D on bone health and osteoporosis was studied by many researchers. The main role of the Vitamin D is to absorb calcium and phosphate and increase bone mineralization. Older people are at an increased risk of the inadequate vitamin D production in the skin because of lower sun exposure and reduced ability of the skin to synthesize vitamin D. Objective. The aim of this clinical trial was to evaluate the efficacy and tolerability of short-term (2 weeks low energy UVB irradiation in postmenopausal women with osteoporosis using bone mineral density and bone turnover markers. Methods. A three-month, single-blinded, randomized, placebo-controlled clinical trial was conducted at the University hospital in Daegu, Republic of Korea. Fifty-two postmenopausal Korean women (older than 65 years with osteoporosis were randomly allocated to have either low energy UVB or placebo for 30 minutes a day for two weeks of treatment during winter. Laboratory analysis and physical examination before and 4, 8 and 12 weeks after treatment were carried out and BMD was measured before and 8 and 12 weeks after treatment. The effects of time and treatment interaction between these two groups were evaluated by repeated-measure two-factor analysis, and subgroup analysis was performed to examine UVB effect on the vitamin D insufficient group [serum 25(OHD3 concentration <30 ng/mL]. Results. In vitamin D insufficient group, the effect of UVB irradiation on vitamin D and bone ALP as well as additional benefit on bone formation was confirmed. The vitamin D insufficient group showed statistically significant increment in serum 25(OHD3 compared with the normal group (p<0.05. However, there was no significant difference between two groups in the other bone turnover markers, such as serum calcium, PTH-C, serum osteocalcin, serum CTX and BMD. Conclusion. Low-energy-short-term UVB radiation for postmenopausal women may be of use in vitamin D

  13. Energy-efficient and cost-effective use of district heating bypass for improving the thermal comfort in bathrooms in low-energy buildings

    DEFF Research Database (Denmark)

    Dalla Rosa, Alessandro; Brand, Marek; Svendsen, Svend

    2012-01-01

    , in the example considered 10-35% lower than in the traditional “intermittent bypass” case; secondly, it can be used to increase the thermal comfort outside the heating-season in bathrooms through floor heating, without causing overheating. It is important that the building design foresees the use of shading......, the utilization of the bypass in bathroom floor heating is a cost-effective solution, both for the DH utilities (reduced heat loss from the DH network and higher revenues), the end-users (improved thermal comfort) and the society (reduction of greenhouse gas emissions)....... floor heating to increase the users’ comfort; its techno-economic analysis, including the modelling of the in-house space heating system; the effect of the bypass to the DH network. Some conclusions were derived. First, the “continuous bypass” guarantees low heat losses in the service pipe...

  14. Low energy p anti p strong interactions: theoretical perspective

    International Nuclear Information System (INIS)

    Dover, C.B.

    1985-01-01

    Several of the frontier problems in low energy nucleon-antinucleon phenomenology are addressed. Spin observables and dynamical selection rules in N anti N annihilation are used as examples of phenomena which offer particularly strong constraints on theoretical models, formulated either in terms of meson and baryon exchange or as effective operators in a non-perturbative quark-gluon picture. 24 refs

  15. Ground-state inversion method applied to calculation of molecular photoionization cross-sections by atomic extrapolation: Interference effects at low energies

    International Nuclear Information System (INIS)

    Hilton, P.R.; Nordholm, S.; Hush, N.S.

    1980-01-01

    The ground-state inversion method, which we have previously developed for the calculation of atomic cross-sections, is applied to the calculation of molecular photoionization cross-sections. These are obtained as a weighted sum of atomic subshell cross-sections plus multi-centre interference terms. The atomic cross-sections are calculated directly for the atomic functions which when summed over centre and symmetry yield the molecular orbital wave function. The use of the ground-state inversion method for this allows the effect of the molecular environment on the atomic cross-sections to be calculated. Multi-centre terms are estimated on the basis of an effective plane-wave expression for this contribution to the total cross-section. Finally the method is applied to the range of photon energies from 0 to 44 eV where atomic extrapolation procedures have not previously been tested. Results obtained for H 2 , N 2 and CO show good agreement with experiment, particularly when interference effects and effects of the molecular environment on the atomic cross-sections are included. The accuracy is very much better than that of previous plane-wave and orthogonalized plane-wave methods, and can stand comparison with that of recent more sophisticated approaches. It is a feature of the method that calculation of cross-sections either of atoms or of large molecules requires very little computer time, provided that good quality wave functions are available, and it is then of considerable potential practical interest for photoelectorn spectroscopy. (orig.)

  16. Patterns induced by magnetic impurities in d-wave superconductors

    International Nuclear Information System (INIS)

    Zuo Xianjun; Gong Changde; Zhou Yuan

    2010-01-01

    We investigate the modulated patterns induced by magnetic impurities in d-wave superconductors (DSCs) near optimal doping based on the t-t ' -U-V model. Modulated checkerboard patterns with periodicity of eight or four lattice constants (8a or 4a) in the spin-, charge- and DSC orders are observed. Moreover, the checkerboard modulation in the spin order appear to be robust against parameter changes, which is consistent with neutron-scattering experiments. For the two-impurity case, a modulated stripe-like spin order with periodicity 8a is induced, which coexists with the DSC order. Further experiments of magnetic impurity substitution in DSCs are expected to check these results.

  17. Patterns induced by magnetic impurities in d-wave superconductors

    Science.gov (United States)

    Zuo, Xian-Jun; Gong, Chang-De; Zhou, Yuan

    2010-07-01

    We investigate the modulated patterns induced by magnetic impurities in d-wave superconductors (DSCs) near optimal doping based on the t-t-U-V model. Modulated checkerboard patterns with periodicity of eight or four lattice constants (8 a or 4 a) in the spin-, charge- and DSC orders are observed. Moreover, the checkerboard modulation in the spin order appear to be robust against parameter changes, which is consistent with neutron-scattering experiments. For the two-impurity case, a modulated stripe-like spin order with periodicity 8 a is induced, which coexists with the DSC order. Further experiments of magnetic impurity substitution in DSCs are expected to check these results.

  18. Diffusion modelling of low-energy ion-implanted BF{sub 2} in crystalline silicon: Study of fluorine vacancy effect on boron diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Marcon, J. [Laboratoire Electronique Microtechnologie et Instrumentation (LEMI), University of Rouen, 76821 Mont Saint Aignan (France)], E-mail: Jerome.Marcon@univ-rouen.fr; Merabet, A. [Laboratoire de Physique et Mecanique des Materiaux Metalliques, Departement d' O.M.P., Faculte des Sciences de l' Ingenieur, Universite de Setif, 19000 Setif (Algeria)

    2008-12-05

    We have investigated and modelled the diffusion of boron implanted into crystalline silicon in the form of boron difluoride BF{sub 2}{sup +}. We have used published data for BF{sub 2}{sup +} implanted with an energy of 2.2 keV in crystalline silicon. Fluorine effects are considered by using vacancy-fluorine pairs which are responsible for the suppression of boron diffusion in crystalline silicon. Following Uematsu's works, the simulations satisfactory reproduce the SIMS experimental profiles in the 800-1000 deg. C temperature range. The boron diffusion model in silicon of Uematsu has been improved taking into account the last experimental data.

  19. Low energy plasma observations at synchronous orbit

    International Nuclear Information System (INIS)

    Reasoner, D.L.; Lennartsson, W.

    1977-08-01

    The University of California at San Diego Auroral Particles Experiment on the ATS-6 Satellite in synchronous orbit has detected a low-energy plasma population which is separate and distinct from both the ring current and plasma sheet populations. These observations suggest that this plasma is the outer zone of the plasmasphere. During magnetically active periods, this low energy plasma is often observed flowing sunward. In the dusk sector, enhanced plasma flow is often observed for 1-2 hours prior to the onset of a substorm-associated particle injection. (author)

  20. Low-energy meson physics (chiral theory)

    International Nuclear Information System (INIS)

    Volkov, M.K.; Pervushin, V.N.

    1976-01-01

    A quantum chiral theory which allows to obtain low-energy expansions of various hadron processes without introducing arbitrary parameters into the theory with the exception of hadron masses and interaction constants is presented. A hypothesis about the dynamic symmetry of strong interactions is suggested. The interaction lagrangian is derived which satisfies conditions of the dynamic symmetry. Examples of the use of the quantum chiral theory for describing low-energy processes of meson interaction are given. It is noted that the results obtained reproduce the actual qualitative pattern of various physical processes and in most cases result in good quantitative agreement with experiments

  1. Effects of low-energy laser irradiation on the distalization velocity during experimental canine tooth movement in humans: 'comparative clinical study'

    International Nuclear Information System (INIS)

    Cruz, Delma Rebelo

    2003-01-01

    This research investigated the effects of low level laser therapy (LLLT) upon the velocity of canine tooth movement and consequently bone remodeling. A total of eleven patients were treated with a 780 nm diode laser. One side of the upper arcade was considered control group and was not irradiated but received mechanical activation every thirty days. The opposite side received the same mechanical activation but was also irradiated at days 0, 3, 7 and 14 of each month. Data of the biometrical progress were taken on both sides on days 3,7,14,21 and 30 of each month. The results indicate that all patients showed significant acceleration of the distalization velocity on the side treated with LLLT when compared to the control. (author)

  2. Beverages containing low energy sweeteners do not differ from water in their effects on appetite, energy intake and food choices in healthy, non-obese French adults.

    Science.gov (United States)

    Fantino, Marc; Fantino, Agnès; Matray, Marie; Mistretta, Frédéric

    2018-06-01

    The usefulness of replacement of caloric sugars by low-calorie sweeteners (LCS) for weight management has been questioned on the grounds that the uncoupling of LCS sweet taste and dietary energy may confuse physiological mechanisms, leading potentially to higher energy and sugar intake. The aim of the present study was to determine whether LCS beverages compared to water, when consumed with meals, differ in their effects on energy and food intake in acute trials and after long-term habituation. Ad libitum food intake of 166 (80 women; 86 men) healthy non-obese adults (BMI between 19 and 28 kg/m2), infrequent consumers of LCS was measured in four 2-consecutive-day testing sessions (Day 1 in the laboratory, Day 2 free-living). During the first 3 sessions, held one-week apart, participants were required to drink either water or commercial non-carbonated LCS lemonade (330 ml) with their main meals (randomised cross-over design). On Day 1, motivational ratings were obtained using visual analogue scales and ad libitum food intakes (amounts and types of foods selected) were measured using the plate waste method. On Day 2, participants reported their ad libitum intakes using a food diary. After Session 3, participants were randomly assigned to the LCS habituation group or to the water control group. The habituation (660 ml LCS lemonade daily vs 660 ml water) lasted 5 weeks. The fourth and final test session measured food intakes and motivational ratings after habituation. Water and LCS beverage did not differ in their effects on total energy intake, macronutrient intakes or the selection of sweet foods and on motivational ratings. Similar results were obtained in both LCS-naïve and LCS-habituated individuals.

  3. Low-energy scattering on the lattice

    International Nuclear Information System (INIS)

    Bour Bour, Shahin

    2014-01-01

    In this thesis we present precision benchmark calculations for two-component fermions in the unitarity limit using an ab initio method, namely Hamiltonian lattice formalism. We calculate the ground state energy for unpolarized four particles (Fermi gas) in a periodic cube as a fraction of the ground state energy of the non-interacting system for two independent representations of the lattice Hamiltonians. We obtain the values 0.211(2) and 0.210(2). These results are in full agreement with the Euclidean lattice and fixed-node diffusion Monte Carlo calculations. We also give an expression for the energy corrections to the binding energy of a bound state in a moving frame. These corrections contain information about the mass and number of the constituents and are topological in origin and will have a broad applications to the lattice calculations of nucleons, nuclei, hadronic molecules and cold atoms. As one of its applications we use this expression and determine the low-energy parameters for the fermion dimer elastic scattering in shallow binding limit. For our lattice calculations we use Luescher's finite volume method. From the lattice calculations we find κa fd =1.174(9) and κr fd =-0.029(13), where κ represents the binding momentum of dimer and a fd (r fd ) denotes the scattering length (effective-range). These results are confirmed by the continuum calculations using the Skorniakov-Ter-Martirosian integral equation which gives 1.17907(1) and -0.0383(3) for the scattering length and effective range, respectively.

  4. An online low energy gaseous ion source

    International Nuclear Information System (INIS)

    Jin Shuoxue; Guo Liping; Peng Guoliang; Zhang Jiaolong; Yang Zheng; Li Ming; Liu Chuansheng; Ju Xin; Liu Shi

    2010-01-01

    The accumulation of helium and/or hydrogen in nuclear materials may cause performance deterioration of the materials. In order to provide a unique tool to investigate the He-and/or H-caused problems, such as interaction of helium with hydrogen and defects, formation of gas bubbles and its evolution, and the related effects, we designed a low energy (≤ 20 keV) cold cathode Penning ion source, which will be interfaced to a 200 kV transmission electron microscope (TEM), for monitoring continuously the evolution of micro-structure during the He + or H + ion implantation. Studies on discharge voltage-current characteristics of the ion source, and extraction and focusing of the ion beam were performed. The ion source works stably with 15-60 mA of the discharge current.Under the gas pressure of 5 x 10 -3 Pa and 1.5 x 10 -2 Pa, the discharge voltage are about 380 V and 320 V, respectively. The extracted ion current under lower gas pressure is greater than that under higher gas pressure, and it increases with the discharge current and extraction voltage. The ion lens consisting of three equal-diameter metal cylinder focus the ion beam effectively, so that the beam density at the 150 cm away from the lens exit increases by a over one order of magnitude. For ion beams of around 10 keV, the measured beam density is about 200 nA · cm -2 , which is applicable for ion implantation and in situ TEM observation for many kinds of nuclear materials. (authors)

  5. Degradation of Cu(In, Ga)Se{sub 2} thin-film solar cells due to the ionization effect of low-energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kawakita, Shirou, E-mail: kawakita.shirou@jaxa.jp [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Imaizumi, Mitsuru [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Ishizuka, Shogo; Shibata, Hajime; Niki, Shigeru [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Okuda, Shuichi [Osaka Prefecture University (OPU), Sakai, Osaka 599-8570 (Japan); Kusawake, Hiroaki [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan)

    2015-05-01

    Cu (In, Ga)Se{sub 2} (CIGS) solar cells were irradiated with 100 keV electrons to reveal the characteristics of created radiation defects. 100 keV electrons cannot produce any displacement defects in CIGS. Low-fluence electrons improve the electrical performance of the CIGS solar cells due to the change in the conductive type of donor to acceptor in a metastable defect, which is equivalent to the light-soaking effect. However, high fluence electrons cause the cell performance to decline. From analysis based on changes in carrier density and electroluminescence, defects causing the decline in performance include donor- and non-radiative types. In addition, red-on-bias experiments showed an increase in III{sub Cu} defects due to electron irradiation. Based on these results, the degradation in the electrical performance of the CIGS solar cells irradiated with high electron fluence would be attributable to a change in the conductive type of III{sub Cu} defects. - Highlights: • Cu(In,Ga)Se2 Solar cells were irradiated with 100 and 250 keV electrons at low temperature. • These electrons degraded the electrical performance of Cu(In,Ga)Se2 sola cells. • The electrons induced ⅢCu defects in Cu(In,Ga)Se2.

  6. A study on the effect of low energy ion beam irradiation on Au/TiO_2 system for its application in photoelectrochemical splitting of water

    International Nuclear Information System (INIS)

    Verma, Anuradha; Srivastav, Anupam; Sharma, Dipika; Banerjee, Anamika; Sharma, Shailja; Satsangi, Vibha Rani; Shrivastav, Rohit; Avasthi, Devesh Kumar; Dass, Sahab

    2016-01-01

    Nanostructured TiO_2 thin films were deposited on indium tin oxide (ITO) substrate via sol–gel technique and were modified by plasmonic Au layer. The plasmonic Au modified TiO_2 (Au/TiO_2) thin films were then irradiated with 500 keV Ar"2"+ ion beam at different ion fluences viz. 1 × 10"1"6, 3 × 10"1"6 and 1 × 10"1"7 to study the effect of nuclear energy deposition on the morphology, crystallinity, band gap, surface plasmon resonance (SPR) peak exhibited by Au particles and photoelectrochemical properties of the system. Prepared thin films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Rutherford backscattering spectrometry (RBS) measurements and UV–visible spectroscopy. The photoelectrochemical measurements revealed that both Au/TiO_2 and Au/TiO_2 thin film irradiated at 1 × 10"1"6 fluence exhibits enhanced photoelectrochemical response in comparison to pristine TiO_2. The film irradiated at 1 × 10"1"6 fluence offered maximum applied bias photon-to-current efficiency (ABPE) and shows 6 times increment in photocurrent density which was attributed to more negative flat band potential, maximum decrease in band gap, high open circuit voltage (V_o_c) and reduced charge transfer resistance.

  7. Low energy nuclear reactions: 2007 update

    International Nuclear Information System (INIS)

    Krivit, S. B.

    2007-01-01

    Introduction: This paper presents an overview of the field of low energy nuclear reactions (LENR), a branch of condensed matter nuclear science. It explains some of the various terminologies that have been used to describe this field since it debuted as 'cold fusion' in 1989. The paper also reviews some of the most interesting news and developments regarding low energy nuclear reaction experiments and theory, and some of the sociological and political trends that have affected the field over the last 18 years. It concludes with a list of resources and information for scientists, journalists and decision makers. Understanding the Nature of the Reactions The worldwide LENR research effort includes 200 researchers in 13 nations. Over the last 18 years, 12 international conferences have been held, as well as 7 regional conferences in Italy, 14 in Russia and 7 in Japan. The significant questions that face this field of research are: a) Are LENRs a genuine nuclear reaction? b) If so, is there a release of excess energy? and c) Are transmutations possible? If the answers to these questions turn out to be positive, the next questions will be: d) Is the energy release cost-effective? and e) Are the transmutations useful? Despite the fact that repeatability and reproducibility are challenging, the required parameters for achieving the excess heat effect are well understood. First, a high atomic loading ratio of D into Pd is required. In most conditions, 0.90 is the minimum threshold required to produce an excess heat effect. Second, a high electrical current density in the cathode is needed, 250 mA/cm 2 under most conditions. The third requirement is for some kind of dynamic trigger to impose a deuterium flux in, on or around the cathode. The challenge that researchers face is how to achieve these conditions. Some of the Most Interesting Research Developments Work by Stanislaw Szpak, Pamela Boss and Frank Gordon at the U.S. Navy's SPAWAR Systems Center in San Diego has

  8. Solid Adsorbents for Low-Temperature CO{sub 2} Capture with Low-Energy Penalties Leading to More Effective Integrated Solutions for Power Generation and Industrial Processes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Nannan [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China); Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham (United Kingdom); Tang, Zhiyong; Wei, Wei [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China); Snape, Colin Edward [Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham (United Kingdom); Sun, Yuhan, E-mail: sunyh@sari.ac.cn [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China)

    2015-03-09

    CO{sub 2} capture represents the key technology for CO{sub 2} reduction within the framework of CO{sub 2} capture, utilization, and storage (CCUS). In fact, the implementation of CO{sub 2} capture extends far beyond CCUS since it will link the CO{sub 2} emission and recycling sectors, and when renewables are used to provide necessary energy input, CO{sub 2} capture would enable a profitable zero- or even negative-emitting and integrated energy–chemical solution. To this end, highly efficient CO{sub 2} capture technologies are needed, and adsorption using solid adsorbents has the potential to be one of the ideal options. Currently, the greatest challenge in this area is the development of adsorbents with high performance that balances a range of optimization-needed factors, those including costs, efficiency, and engineering feasibility. In this review, recent advances on the development of carbon-based and immobilized organic amines-based CO{sub 2} adsorbents are summarized, the selection of these particular categories of materials is because they are among the most developed low-temperature (<100°C) CO{sub 2} adsorbents up to date, which showed important potential for practical deployment at pilot-scale in the near future. Preparation protocols, adsorption behaviors as well as pros and cons of each type of the adsorbents are presented, it was concluded that encouraging results have been achieved already, however, the development of more effective adsorbents for CO{sub 2} capture remains challenging and further innovations in the design and synthesis of adsorbents are needed.

  9. Interstellar propagation of low energy cosmic rays

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1975-01-01

    Wave particles interactions prevent low energy cosmic rays from propagating at velocities much faster than the Alfven velocity, reducing their range by a factor of order 50. Therefore, supernovae remnants cannot fill the neutral portions of the interstellar medium with 2 MeV cosmic rays [fr

  10. Virtual compton scattering at low energy

    International Nuclear Information System (INIS)

    Lhuillier, D.

    1997-09-01

    The work described in this PhD is a study of the Virtual Compton scattering (VCS) off the proton at low energy, below pion production threshold. Our experiment has been carried out at MAMI in the collaboration with the help of two high resolution spectrometers. Experimentally, the VCS process is the electroproduction of photons off a liquid hydrogen target. First results of data analysis including radiative corrections are presented and compared with low energy theorem prediction. VCS is an extension of the Real Compton Scattering. The virtuality of the incoming photon allows us to access new observables of the nucleon internal structure which are complementarity to the elastic form factors: the generalized polarizabilities (GP). They are function of the squared invariant mass of the virtual photo. The mass limit of these observables restore the usual electric and magnetic polarizabilities. Our experiment is the first measurement of the VCS process at a virtual photon mass equals 0.33 Ge V square. The experimental development presents the analysis method. The high precision needed in the absolute cross-section measurement required an accurate estimate of radiative corrections to the VCS. This new calculation, which has been performed in the dimensional regulation scheme, composes the theoretical part of this thesis. At low q', preliminary results agree with low energy theorem prediction. At higher q', substraction of low energy theorem contribution to extract GP is discussed. (author)

  11. Physics with low energy pions and muons

    International Nuclear Information System (INIS)

    Konijn, J.

    1981-01-01

    This document is a collection of texts used for a course of lectures given by the author at the Technical University of Delft (NL) in 1981. It is therefore a comprehensive, Dutch language, review article starting with the discovery of pions and muons, describing their properties and finally discussing their applications in low energy physics. (C.F.)

  12. Cooking exhaust systems for low energy dwellings

    NARCIS (Netherlands)

    Jacobs, P.; Borsboom, W.A.

    2017-01-01

    Especially in airtight low energy dwellings exhaust systems are of utmost importance as cooking can be a major source of PM2.5 exposure. Dwellings should be designed including facilities enabling extraction of at least 83 dm3/s (300 m3/h) directly to outside. Residents should be able to select an

  13. Low energy antiproton experiments - A review

    NARCIS (Netherlands)

    Jungmann, KP; Yamazaki, Y; Wada, M

    2005-01-01

    Low energy antiprotons offer excellent opportunities to study properties of fundamental forces and symmetries in nature. Experiments with them can contribute substantially to deepen our fundamental knowledge in atomic, nuclear and particle physics. Searches for new interactions can be carried out by

  14. The Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Lechner, Peter

    2009-01-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  15. The Simbol-X Low Energy Detector

    Science.gov (United States)

    Lechner, Peter

    2009-05-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  16. Low energy analysis techniques for CUORE

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Avignone, F.T.; Chott, N.; Creswick, R.J.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Alfonso, K.; Huang, H.Z.; Sakai, M.; Schmidt, J. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Artusa, D.R.; Rusconi, C. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Azzolini, O.; Camacho, A.; Keppel, G.; Palmieri, V.; Pira, C. [INFN-Laboratori Nazionali di Legnaro, Padua (Italy); Bari, G.; Deninno, M.M. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cosmelli, C.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Benato, G.; Singh, V. [University of California, Department of Physics, Berkeley, CA (United States); Bersani, A.; Caminata, A. [INFN-Sezione di Genova, Genoa (Italy); Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Fiorini, E.; Gironi, L.; Gotti, C.; Maino, M.; Nastasi, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Branca, A.; Taffarello, L. [INFN-Sezione di Padova, Padua (Italy); Bucci, C.; Cappelli, L.; D' Addabbo, A.; Gorla, P.; Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Canonica, L. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Massachusetts Institute of Technology, Cambridge, MA (United States); Cao, X.G.; Fang, D.Q.; Ma, Y.G.; Wang, H.W.; Zhang, G.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China); Cardani, L.; Casali, N.; Dafinei, I.; Morganti, S.; Mosteiro, P.J.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Copello, S.; Di Domizio, S.; Marini, L.; Pallavicini, M. [INFN-Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Cremonesi, O.; Ferri, E.; Giachero, A.; Pessina, G.; Previtali, E. [INFN-Sezione di Milano Bicocca, Milan (Italy); Cushman, J.S.; Davis, C.J.; Heeger, K.M.; Lim, K.E.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); D' Aguanno, D.; Pagliarone, C.E. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita degli Studi di Cassino e del Lazio Meridionale, Dipartimento di Ingegneria Civile e Meccanica, Cassino (Italy); Dell' Oro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); INFN-Gran Sasso Science Institute, L' Aquila (Italy); Di Vacri, M.L.; Santone, D. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, L' Aquila (Italy); Drobizhev, A.; Hennings-Yeomans, R.; Kolomensky, Yu.G.; Wagaarachchi, S.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Franceschi, M.A.; Ligi, C.; Napolitano, T. [INFN-Laboratori Nazionali di Frascati, Rome (Italy); Freedman, S.J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Fujikawa, B.K.; Mei, Y.; Schmidt, B.; Smith, A.R.; Welliver, B. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Giuliani, A.; Novati, V. [Universite Paris-Saclay, CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Orsay (France); Gladstone, L.; Leder, A.; Ouellet, J.L.; Winslow, L.A. [Massachusetts Institute of Technology, Cambridge, MA (United States); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Han, K. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Shanghai (China); Hansen, E. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Saragossa (Spain); Moggi, N.; Zucchelli, S. [INFN-Sezione di Bologna, Bologna (Italy); Universita di Bologna - Alma Mater Studiorum, Dipartimento di Fisica e Astronomia, Bologna (IT); Nones, C. [CEA/Saclay, Service de Physique des Particules, Gif-sur-Yvette (FR); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (US); University of California, Department of Nuclear Engineering, Berkeley, CA (US); O' Donnell, T. [Virginia Polytechnic Institute and State University, Center for Neutrino Physics, Blacksburg, VA (US); Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (US); Wise, T. [Yale University, Department of Physics, New Haven, CT (US); University of Wisconsin, Department of Physics, Madison, WI (US); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (GB); Zimmermann, S. [Lawrence Berkeley National Laboratory, Engineering Division, Berkeley, CA (US)

    2017-12-15

    CUORE is a tonne-scale cryogenic detector operating at the Laboratori Nazionali del Gran Sasso (LNGS) that uses tellurium dioxide bolometers to search for neutrinoless double-beta decay of {sup 130}Te. CUORE is also suitable to search for low energy rare events such as solar axions or WIMP scattering, thanks to its ultra-low background and large target mass. However, to conduct such sensitive searches requires improving the energy threshold to 10 keV. In this paper, we describe the analysis techniques developed for the low energy analysis of CUORE-like detectors, using the data acquired from November 2013 to March 2015 by CUORE-0, a single-tower prototype designed to validate the assembly procedure and new cleaning techniques of CUORE. We explain the energy threshold optimization, continuous monitoring of the trigger efficiency, data and event selection, and energy calibration at low energies in detail. We also present the low energy background spectrum of CUORE-0 below 60 keV. Finally, we report the sensitivity of CUORE to WIMP annual modulation using the CUORE-0 energy threshold and background, as well as an estimate of the uncertainty on the nuclear quenching factor from nuclear recoils in CUORE-0. (orig.)

  17. Large solid angle detectors (low energy)

    International Nuclear Information System (INIS)

    L'Hote, D.

    1988-01-01

    This lecture deals with large solid angle detectors used in low energy experiments (mainly in Nuclear Physics). The reasons for using such detectors are discussed, and several basic principles of their design are presented. Finally, two examples of data analysis from such detectors are given [fr

  18. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  19. Studies in Low-Energy Nuclear Science

    Energy Technology Data Exchange (ETDEWEB)

    Carl R. Brune; Steven M. Grimes

    2010-01-13

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187.

  20. Formulation of the low-energy effective theory of electroweak symmetry-breaking without a Higgs particle; Formulation de la theorie effective a basse energie du secteur electrofaible sans particule de Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Hirn, J

    2004-07-01

    The low-energy effective theory of electroweak symmetry-breaking without a Higgs particle is constructed using the methods of Chiral Perturbation Theory. Weinberg's power-counting formula demonstrates the consistency of the loop expansion, with the corresponding renormalization. We find that the suppression of effective operators by a mass scale, which was automatic in the case of the Standard Model, no longer holds in the Higgs-less case. Moreover, the incriminated operators appear at leading order in the chiral expansion, at variance with experiments. To account for their suppression, invariance under a larger symmetry is required, corresponding to the composite sector (which produces the three Goldstone modes) being decoupled from the elementary sector (quarks, leptons and Yang-Mills fields). The couplings are introduced via spurions: this reduces the symmetry to SU(2) x U(1). In the simultaneous expansion in powers of momenta and spurions, the aforementioned operators are relegated to higher orders. In addition, the method allows for a systematic treatment of weak isospin breaking. The Weinberg power-counting formula can be recovered, and small neutrino masses accounted for. The three right-handed neutrinos (lighter than the TeV), which are introduced in connection with the custodial symmetry, are quasi-sterile and stable. A constraint on the underlying theory is obtained by studying the anomaly-matching in the composite sector and generalizing the Wess-Zumino construction. The spurion formalism is also applied to open linear moose models, for which generalized Weinberg sum rules are derived. (author)

  1. Striped morphologies induced by magnetic impurities in d-wave superconductors

    International Nuclear Information System (INIS)

    Zuo Xianjun

    2011-01-01

    Research Highlights: → We investigate striped morphologies induced by magnetic impurities in d-wave superconductors (DSCs). → For the single-impurity and two-impurity cases, modulated checkerboard pattern and stripe-like structures are induced. → When more magnetic impurities are inserted, more complex modulated structures could be induced, including rectilinear and right-angled stripes and quantum-corral-like structures. → Impurities could induce complex striped morphologies in DSCs. - Abstract: We study striped morphologies induced by magnetic impurities in d-wave superconductors (DSCs) near optimal doping by self-consistently solving the Bogoliubov-de Gennes equations based on the t - t' - U - V model. For the single-impurity case, it is found that the stable ground state is a modulated checkerboard pattern. For the two-impurity case, the stripe-like structures in order parameters are induced due to the impurity-pinning effect. The modulations of DSC and charge orders share the same period of four lattice constants (4a), which is half the period of modulations in the coexisting spin order. Interestingly, when three or more impurities are inserted, the impurities could induce more complex striped morphologies due to quantum interference. Further experiments of magnetic impurity substitution in DSCs are expected to check these results.

  2. Asymmetric d-wave superconducting topological insulator in proximity with a magnetic order

    Science.gov (United States)

    Khezerlou, M.; Goudarzi, H.; Asgarifar, S.

    2018-02-01

    In the framework of the Dirac-Bogoliubov-de Gennes formalism, we investigate the transport properties in the surface of a 3-dimensional topological insulator-based hybrid structure, where the ferromagnetic and superconducting orders are simultaneously induced to the surface states via the proximity effect. The superconductor gap is taken to be spin-singlet d-wave symmetry. The asymmetric role of this gap respect to the electron-hole exchange, in one hand, affects the topological insulator superconducting binding excitations and, on the other hand, gives rise to forming distinct Majorana bound states at the ferromagnet/superconductor interface. We propose a topological insulator N/F/FS junction and proceed to clarify the role of d-wave asymmetry pairing in the resulting subgap and overgap tunneling conductance. The perpendicular component of magnetizations in F and FS regions can be at the parallel and antiparallel configurations leading to capture the experimentally important magnetoresistance (MR) of junction. It is found that the zero-bias conductance is strongly sensitive to the magnitude of magnetization in FS region mzfs and orbital rotated angle α of superconductor gap. The negative MR only occurs in zero orbital rotated angle. This result can pave the way to distinguish the unconventional superconducting state in the relating topological insulator hybrid structures.

  3. Low energy intense electron beams with extra-low energy spread

    International Nuclear Information System (INIS)

    Aleksandrov, A.V.; Calabrese, R.; Ciullo, G.; Dikansky, N.S.; Guidi, V.; Kot, N.C.; Kudelainen, V.I.; Lamanna, G.; Lebedev, V.A.; Logachov, P.V.; Tecchio, L.; Yang, B.

    1994-01-01

    Maximum achievable intensity for low energy electron beams is a feature that is not very often compatible with low energy spread. We show that a proper choice of the source and the acceleration optics allows one to match them together. In this scheme, a GaAs photocathode excited by a single-mode infrared laser and adiabatic acceleration in fully magnetised optics enables the production of a low-energy-spread electron beam with relatively high intensity. The technological problems associated with the method are discussed together with its limitations. (orig.)

  4. Experimentation with low-energy positron beams

    International Nuclear Information System (INIS)

    Mills, A.P. Jr.

    1983-01-01

    The capability of studying the interactions of positrons with surfaces has recently been exploited by using ultra-high-vacuum techniques. The result has been a new understanding of how positrons interact with surfaces and because of this we are now able to make much stronger fluxes of slow positrons. The higher beam strengths in turn are opening up new possibilities for experimentation on surfaces and solids and for studying the atomic physics of positronium and positron-molecule scattering at low energies. The lectures are intended to review some of the history of this subject and to outline the present state of our knowledge of experimentation with low-energy positron beams. (orig./TW)

  5. Natural gas in low energy house Zittau

    International Nuclear Information System (INIS)

    Maertens, L.; Koschack, A.

    1999-01-01

    This paper describes a low-energy house in Zittau, Germany. The house consists of two parts A and B. Part A is heated by means of gas boilers and condensed boilers, while part B is solar heated. Energy for heating and warming of tap water is an important part of the primary energy consumption in Germany. Therefore, one way of reducing the CO2 emissions is to reduce the heat losses of buildings through outer facades and air ventilation, to use regenerative energy sources, to use fuels with low CO2 emissivity like natural gas, and to install efficient heating- and hot water preparation systems. The low-energy house in Zittau is used for energy research

  6. LINAC4 low energy beam measurements

    CERN Document Server

    Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

    2012-01-01

    Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

  7. Enhancement mechanisms of low energy nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L. [Joint Institute for Nuclear Research, JINR, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation)

    2006-07-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong.

  8. Enhancement mechanisms of low energy nuclear reactions

    International Nuclear Information System (INIS)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L.

    2006-01-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong

  9. A Low-Energy Ring Lattice Design

    International Nuclear Information System (INIS)

    Cai, Yunhai

    2002-01-01

    The PEP-N project at SLAC [1] consists of a Very Low-Energy small electron Ring (VLER) that will collide with the low-energy 3.1 GeV positron beam (LER) of PEP-II, producing center-of-mass energies between the 1.1 GeV and the J/ψ. The beams will collide head-on and will be separated in the detector magnetic field which is part of the Interaction Region [2]. The IP β functions were chosen such as to optimize both luminosity and beam-beam tune shifts, while keeping the LER tune shifts small. This paper describes the lattice design of the VLER for the ''baseline'' at 500 MeV

  10. Architectural Quality of Low Energy Houses

    DEFF Research Database (Denmark)

    Lauring, Michael; Marsh, Rob

    2008-01-01

    This paper expounds a systematic vocabulary concerning architectural quality in houses in general and low energy houses in particular. The vocabulary consists of nine themes. Inside each theme, examples are given of how to achieve both architectural quality and good environmental performance....... The purpose is to provide a useful tool for communication and argumentation in order to further integrated design of houses with good architecture and good environmental performance. ...

  11. Physics with ultra-low energy antiprotons

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Holzscheiter, M.H.; Hughes, R.J.

    1989-01-01

    The experimental observation that all forms of matter experience the same gravitational acceleration is embodied in the weak equivalence principle of gravitational physics. However no experiment has tested this principle for particles of antimatter such as the antiproton or the antihydrogen atom. Clearly the question of whether antimatter is in compliance with weak equivalence is a fundamental experimental issue, which can best be addressed at an ultra-low energy antiproton facility. This paper addresses the issue. 20 refs

  12. PHYSICS WITH ULTRA-LOW ENERGY ANTIPROTONS

    Energy Technology Data Exchange (ETDEWEB)

    M. HOLZSCHEITER

    2001-02-01

    In this report the author describes the current status of the antiproton deceleration (AD) facility at CERN, and highlights the physics program with ultra-low energy antiproton at this installation. He also comments on future possibilities provided higher intensity antiproton beams become available at Fermilab, and review possibilities for initial experiments using direct degrading of high energy antiprotons in material has been developed and proven at CERN.

  13. Workshop on low energy neutrino physics

    International Nuclear Information System (INIS)

    2009-01-01

    The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

  14. The low-energy experiment on EXOSAT

    International Nuclear Information System (INIS)

    Bleeker, J.A.M.

    1975-01-01

    The present concept of the Low-Energy-Experiment (LEE) for EXOSAT was proposed by a collaboration of the X-ray astronomy groups at Mullard Space Science Laboratories at University College London, the Space Research Laboratory at Utrecht and the Cosmic Ray Working Group at Leiden. In the following paragraphs the major characteristics of the instrumentation and the expected scientific return will be discussed. The summary comprises both the approved baseline configuration and the proposed option of a small imaging telescope

  15. FLSR - The Frankfurt low energy storage ring

    International Nuclear Information System (INIS)

    Stiebing, K.E.; Alexandrov, V.; Doerner, R.; Enz, S.; Kazarinov, N.Yu.; Kruppi, T.; Schempp, A.; Schmidt Boecking, H.; Voelp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-01-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut fuer Kernphysik der Johann Wolfgang Goethe-Universitaet Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  16. Low-energy scattering data for oxygen

    International Nuclear Information System (INIS)

    Kopecky, S.; Plompen, A.J.M.

    2014-01-01

    A survey of literature data of the scattering lengths of oxygen is performed, and these values are compared to low-energy precise total cross-section data. To check the quality of the data and the correctness of the relation between coherent scattering lengths and low-energy total cross-sections the situation is examined first for carbon. A value and uncertainty for the coherent scattering length of oxygen is recommended for use in future evaluations of 16 O. This coherent scattering length is fully consistent with the high-precision, low-energy total cross-section data. The consistency requires the use of a larger uncertainty than claimed in the most accurate cross-section papers. This larger uncertainty is nevertheless very small and well within the requirements of applications of this cross-section. The recommended value is b c ( 16 O) = 5.816±0.015 fm and the associated total cross-section for the neutron-energy range 0.5 to 2 000 eV is 3.765±0.025 b. The stated uncertainties are one standard deviation total uncertainty. (authors)

  17. Targeting Low-Energy Ballistic Lunar Transfers

    Science.gov (United States)

    Parker, Jeffrey S.

    2010-01-01

    Numerous low-energy ballistic transfers exist between the Earth and Moon that require less fuel than conventional transfers, but require three or more months of transfer time. An entirely ballistic lunar transfer departs the Earth from a particular declination at some time in order to arrive at the Moon at a given time along a desirable approach. Maneuvers may be added to the trajectory in order to adjust the Earth departure to meet mission requirements. In this paper, we characterize the (Delta)V cost required to adjust a low-energy ballistic lunar transfer such that a spacecraft may depart the Earth at a desirable declination, e.g., 28.5(white bullet), on a designated date. This study identifies the optimal locations to place one or two maneuvers along a transfer to minimize the (Delta)V cost of the transfer. One practical application of this study is to characterize the launch period for a mission that aims to launch from a particular launch site, such as Cape Canaveral, Florida, and arrive at a particular orbit at the Moon on a given date using a three-month low-energy transfer.

  18. The Low-Energy Neutrino Factory

    International Nuclear Information System (INIS)

    Brass, Alan; Geer, Steve; Ellis, Malcolm; Mena, Olga; Pascoli, Silvia

    2008-01-01

    To date most studies of Neutrino Factories have focused on facilities where the energy of the muon in the storage ring has been in the range of 25-50 GeV. In this paper we present a concept for a Low-Energy (∼ 4 GeV) neutrino factory. For baselines of O(1000 km), the rich oscillation pattern at low neutrino interaction energy (0.5 - ∼3 GeV) provides the unique performance of this facility with regard to its sensitivity to CP violation and the determination of the neutrino mass hierarchy. A unique neutrino detector is needed, however, in order to exploit this oscillation pattern. We will describe the basic accelerator facility, demonstrate the methodology of the analysis and give an estimate on how well the Low-Energy neutrino factory can measure θ 13 , CP violation and the mass hierarchy. We will also describe the detector concept that is used, show a preliminary analysis regarding its performance and indicate what R and D is still needed. Finally we will show how the Low-Energy neutrino factory could be a step towards an energy frontier muon collider.

  19. d-Wave density waves in high Tc cuprates and CeCoIn5

    International Nuclear Information System (INIS)

    Maki, Kazumi; Dora, Balazs; Vanyolos, Andras; Virosztek, Attila

    2007-01-01

    Unconventional density waves (UDW) have a long history starting with the speculation of Halperin and Rice in 1968. However, a more realistic approach started around 1999 in order to clarify the nature of the pseudogap in the underdoped region of hole-doped high T c cuprates. Also d-wave density waves (dDW) evolved from early unrealistic 2D model with Z 2 symmetry to more realistic 3D mean-field condensate with U(1) gauge symmetry. More recently, the giant Nernst effect and the angle dependent magnetoresistance in LSCO, YBCO, Bi2212 and CeCoIn 5 are successfully described in terms of dDW, where the Landau quantization of the quasiparticle spectrum in dDW in a magnetic field (the Nersesyan effect) plays the crucial role

  20. Utilization of bio-resources by low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2003-01-01

    Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  1. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  2. Revealing low-energy part of the beta spectra

    International Nuclear Information System (INIS)

    Selvi, S.; Celiktas, C.

    2002-01-01

    An effective method is proposed to separate electronic noise from the beta-particle spectra revealing lower energy part of the spectra. The available methods for reducing the noise problem cut the noise along with the low-energy part of the beta spectra by using a discriminator. Our setup eliminates this undesirable effect by shifting the noise toward the lowest energy scale leaving the low-energy part of spectra undisturbed. We achieved this noise-pulse-separation by treating the noise as a pulse so that we can exploit the application of the pulse-shape analyzer equipment used for pulse shape identification of particles and rejection of defective pulses. To the best of our knowledge this method of the noise separation is a novel approach

  3. Low-energy phenomenology of a realistic composite model

    International Nuclear Information System (INIS)

    Korpa, C.; Ryzak, Z.

    1986-01-01

    The low-energy limit of the strongly coupled standard model (Abbott-Farhi composite model) is analyzed. The effects of the excited W isotriplet and isoscalar bosons are investigated and compared with experimental data. As a result, constraints on parameters (masses, coupling constants, etc.) of these vector bosons are obtained. They are not severe enough (certain cancellations are possible) to exclude the model on experimental basis

  4. Elastic scattering of low energy electrons by hydrogen molecule

    International Nuclear Information System (INIS)

    Freitas, L.C.G.; Mu-Tao, L.; Botelho, L.F.

    1987-01-01

    The coherent version of the Renormalized Multiple-Centre Potential Model (RMPM) has been extended to treat the elastic scattering of low energy electrons by H2 molecule. The intramolecular Multiple Scattering (MS) effect has also been included. The comparison against the experimental data shows that the inclusion of the MS improves significantly with experiment. The extension of the present method to study electron-polyatomic molecule interaction is also discussed. (author) [pt

  5. Dosimetry of low-energy beta radiation

    International Nuclear Information System (INIS)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

  6. Striped morphologies induced by magnetic impurities in d-wave superconductors

    Science.gov (United States)

    Zuo, Xian-Jun

    2011-05-01

    We study striped morphologies induced by magnetic impurities in d-wave superconductors (DSCs) near optimal doping by self-consistently solving the Bogoliubov-de Gennes equations based on the t - t‧ - U - V model. For the single-impurity case, it is found that the stable ground state is a modulated checkerboard pattern. For the two-impurity case, the stripe-like structures in order parameters are induced due to the impurity-pinning effect. The modulations of DSC and charge orders share the same period of four lattice constants (4 a), which is half the period of modulations in the coexisting spin order. Interestingly, when three or more impurities are inserted, the impurities could induce more complex striped morphologies due to quantum interference. Further experiments of magnetic impurity substitution in DSCs are expected to check these results.

  7. Electron spin polarization effects in low-energy electron diffraction, ion neutralization, and metastable-atom deexcitation at solid surfaces. Progress report No. 3, January 1-December 31, 1983

    International Nuclear Information System (INIS)

    Walters, G.K.; Dunning, F.B.

    1983-01-01

    The importance of electron spin polarization (ESP) effects in the various spectroscopies used to study solid surfaces has become increasingly apparent in recent years. Recent low energy electron diffraction (LEED) investigations in this laboratory and elsewhere have shown that a great deal of new information contributing to the understanding of the geometrical arrangements of atoms at a surface can be obtained if the polarization of the various LEED beams is measured, or if the incident electron beam is polarized. Polarized LEED studies have shown large polarization features that are very sensitive to the presence of adsorbed layers, surface reconstruction, etc. In addition, theory suggests that polarization measurements can provide a more sensitive test of many of the parameters used in a surface model than can conventional LEED intensity measurements alone. Polarized LEED has also been applied to the study of surface magnetism. In the present contract year, polarized LEED has been used, together with Auger analysis and LEED intensity measurements, as a diagnostic to characterize Ni(001) surfaces produced by laser annealing

  8. Hydrogen-antihydrogen interactions at low energies

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Carr, J.M.; Zeman, V.

    1999-01-01

    The main cause of loss of trapped AH is due to collisions with H 2 and He. As a first step towards treating these reactions we are studying the interaction of AH with H. We have carried out variational calculations to determine an upper bound to the smallest internuclear distance at which the light particles are still bound to the nuclei. We are currently in the process of taking into account the motion of the nuclei. This will enable us to calculate cross-sections for low energy H-AH scattering

  9. The low energy booster project status

    International Nuclear Information System (INIS)

    Tuttle, G.W.

    1993-05-01

    In order to achieve the required injection momentum, the Superconducting Super Collider (SSC) has an accelerator chain comprised of a Linear Accelerator and three synchrotrons. The Low Energy Booster (LEB) is the first synchrotron in this chain. The LEB project has made significant progress in the development of major subsystems and conventional construction. This paper briefly reviews the performance requirements of the LEB and describes significant achievements in each of the major subsystem areas. Highlighted among these achievements are the LEB foreign collaborations with the Budker Institute of Nuclear Physics (BINP) located in Novosibirsk, Russia

  10. Low energy constraints and scalar leptoquarks⋆

    Directory of Open Access Journals (Sweden)

    Fajfer Svjetlana

    2014-01-01

    Full Text Available The presence of a colored weak doublet scalar state with mass below 1 TeV can provide an explanation of the observed branching ratios in B → D(∗τντ decays. Constraints coming from Z → bb̄, muon g − 2, lepton flavor violating decays are derived. The colored scalar is accommodated within 45 representation of SU(5 group of unification. We show that presence of color scalar can improve mass relations in the up-type quark sector mass. Impact of the colored scalar embedding in 45-dimensional representation of SU(5 on low-energy phenomenology is also presented.

  11. Round Gating for Low Energy Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things....... Additionally, we discuss how to needed gating wave can be generated. Experimental results show that our technique is able to reduce the energy consumption in most block ciphers by over 60% while incurring only a minimal overhead in hardware....

  12. Low-energy phenomenological chiral Lagrangians

    International Nuclear Information System (INIS)

    Cavopol, A.V.

    1987-01-01

    We develop a phenomenological Lagrangian that satisfies the requirements of the so called alternative schemes designed to model low energy meson phenomenology. Linear and nonlinear σ type Lagrangians and symmetry breaking schemes are used to describe pions that exhibit masses proportional to the square of the symmetry breaking term's coefficient, ε. (m π 2 ∼ 0(ε 2 )). The invariance of the theory under coordinate dependent transformations is achieved by introducing gauge fields for both linear and nonlinear Lagrangians. Finally, analogies between the minimal symmetry breaking terms in Quantum Electrodynamics and in our phenomenological lagrangians are used to generate a discussion of the quark-pion mass dependence indicated by the model

  13. FLSR - The Frankfurt low energy storage ring

    Science.gov (United States)

    Stiebing, K. E.; Alexandrov, V.; Dörner, R.; Enz, S.; Kazarinov, N. Yu.; Kruppi, T.; Schempp, A.; Schmidt Böcking, H.; Völp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-02-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut für Kernphysik der Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  14. Luminescence model with quantum impact parameter for low energies

    International Nuclear Information System (INIS)

    Cruz G, H.S.; Michaelian, K.; Galindo U, S.; Martinez D, A.; Belmont M, E.

    2000-01-01

    The analytical model of induced light production in scintillator materials by energetic ions proposed by Michaelian and Menchaca (M-M) adjusts very well the luminescence substance data in a wide energy interval of the incident ions (10-100 MeV). However at low energies, that is, under to 10 MeV, the experimental deviations of the predictions of M-M model, show that the causes may be certain physical effects, all they important at low energies, which were not considered. We have modified lightly the M-M model using the basic fact that the Quantum mechanics gives to a different limit for the quantum impact parameter instead of the classic approximation. (Author)

  15. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1991-01-01

    A major accomplishment of this project in the past year is the completion of a fairly comprehensive paper describing the survey of radiative capture reactions of protons on light nuclei at low energies. In addition we have completed a preliminary set of measurements of (d,p)/(d,α) cross section ratios on the charge symmetric nuclei 6 Li and 10 B as a test of the Oppenheimer-Phillips effect. While the 6 Li data remain inconclusive, the 10 B data show solid evidence for the Oppenheimer-Phillips enhancement of the (d,p) reaction relative to the (d,α) reaction for deuteron bombarding energies below about 100 keV. We have continued our investigation of fusion reaction products from deuterium-metal systems at room temperatures with the startling observation of intense burst of energetic charged particles from deuterium gas loaded thin titaium foils subject to non-equilibrium thermal and electrical conditions. We have completed two projects involving the application of the low energy particle accelerator to material science problems; firstly a study of the transformation of crystalline to amorphous Fe-Zr systems by proton irradiation and secondly the effects of ion bombardment on the critical temperature of YBCO high-temperature superconductors. Finally we have made progress in several instrumentation projects which will be used in some of the up-coming measurements of nuclear cross sections at very low energies

  16. Radiation processing of natural polymers using low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2004-01-01

    Radiation processing is widely used in Japan and the economic scale of radiation application amounted to about 71 b$ (ratio relative to GDP: 1.7%) in total. It consisted of 60 b$ (85%) in industry, 10 b$ (14%) in medicine and 1 b$ (1%) in agriculture. Irradiation using gamma-ray from 60 Co and electron beam is commercially used for the sterilization and modification of materials. Utilization of natural polymers by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin were easily degraded by irradiation and induced various kinds of biological activities, i.e. anti-bacterial activity, elicitor activity, plant growth promotion, suppression of environmental stress on plants. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. Low energy electron beam (EB) irradiation has a variety of applications and good safety. A self-shielded low energy electron accelerator system needs an initial investment much lower than a 60 Co facility. It was demonstrated that the liquid sample irradiation system using low energy EB was effective not only for the preparation of degraded polysaccharides but also for radiation vulcanization of natural rubber latex (RVNRL). Some carbohydrate derivatives, carboxymethylcellulose (CMC), carboxymethyl-starch and carboxymethyl-chitin/chitosan, can be crosslinked under certain radiation condition and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  17. Short-term effects of black pepper (Piper nigrum) and rosemary (Rosmarinus officinalis and Rosmarinus eriocalyx) on sustained attention and on energy and fatigue mood states in young adults with low energy.

    Science.gov (United States)

    Lindheimer, Jacob B; Loy, Bryan D; O'Connor, Patrick J

    2013-08-01

    The purpose was to test whether a single dose of black pepper or rosemary produced short-term enhancements in sustained attention, motivation to perform cognitive tasks, or feelings of mental energy and fatigue. Outcomes were measured in 40 young adults with below average feelings of energy before and twice after they orally consumed capsules containing either black pepper (2.0 g), rosemary (1.7 g), or a placebo (3.1 g rice flour). Sustained attention was measured using a 16-min dual task, in which, single-digit numbers were presented every second on a screen and the participant performed both a primary task [detection of three successive, different odd digits] and a secondary task [detection of the number 6]. Feelings of energy and fatigue were measured using the vigor and fatigue subscales of the Profile of Mood States and visual analog scales (VAS). Analysis of variance showed nonsignificant condition (spice versus placebo)×time (T1, T2, & T3) effects for motivation, measured with a VAS, and the intensity of energy and fatigue feelings. Unadjusted effect sizes revealed that rosemary induced small, transient reductions in false alarm errors (d=0.21) and mental fatigue (d=0.40) at isolated time periods. Time-varying analysis of covariance, controlling for motivation to perform cognitive tasks, showed no significant effects on the primary or secondary task outcomes of correct responses (hits), errors (false alarms, misses), speed of response (reaction time), and signal detection sensitivity. It is concluded that black pepper and rosemary, consumed in a capsule form, in the doses used and while wearing a nose clip to block olfactory effects, do not induce consistent short-term improvements in sustained attention, motivation to perform cognitive tasks, or feelings of mental energy and fatigue in young adults with low energy.

  18. Analysis of low energy beta-emitters

    International Nuclear Information System (INIS)

    Murphy, D.L.

    1979-10-01

    A survey was made of the instruments used for the determination of low energy beta radioactivity. Techniques commonly used are gas flow proportional counting, liquid scintillation counting, solid scintillation counting, and internal ionization chamber counting, solid state detector counting, and radiochemical separation followed by counting using one of the preceeding techniques. The first four techniques were examined and compared with each other. The sensitivities of the techniques were compared on the basis of the detection limits quoted for instruments described in the technical and reviewed literature. The detection limits were then related to the occupational and public individual maximum levels for air and water. Attention is focused primarily on the continuous monitoring of air for 3 H and 85 Kr, a medium energy β-emitter. It is clear that several continuous air monitoring instruments are readily available for measuring low energy β concentrations, even in presence of certain other activity, at occupational levels. However, these instruments do not typically have sensitivities comparable to the public individual levels. Moreover, their capabilities for giving results in real time and for differentiating among the radionuclides actually present is limited

  19. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2010-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187. We describe here research into low-energy nuclear reactions and structure. The statistical properties of nuclei have been studied by measuring level densities and also calculating them theoretically. Our approach of measuring level densities via evaporation spectra is able to reach a very wide range of nuclei by using heavy ion beams (we expect to develop experiments using radioactive beams in the near future). Another focus of the program has been on γ-ray strength functions. These clearly impact nuclear reactions, but they are much less understood than corresponding transmission coefficients for nucleons. We have begun investigations of a new approach, using γ-γ coincidences following radiative capture. Finally, we have undertaken several measurements of cross sections involving light nuclei which are important in various applications. The 9 Be(α,n) and B(d,n) reactions have been measured at Ohio University, while neutron-induced reactions have been measured at Los Alamos (LANSCE).

  20. Low energy cyclotron for radiocarbon dating

    International Nuclear Information System (INIS)

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14 C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14 C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14 C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

  1. Experimental perspectives in low energy lepton physics

    International Nuclear Information System (INIS)

    Fiorini, E.

    1986-01-01

    Low energy nuclear physics has been and is going to be an essential tool for the study of weak interaction and neutrino physics. The use of the atomic nucleus as a ''microlaboratory'' with well defined quantum numbers is undoubtedly going to yield important and sometimes perhaps unexpected results on the symmetry laws governing the subnuclear world. These searches are however very hard experimentally and the bottleneck on obtaining more stringent results only rarely depends on the need of large and expensive apparatuses as those used in high energy physics: more limiting are technical difficulties. The author believes therefore that a real break-through to overcome the present experimental limitations can only be obtained with totally new and sometime ''non canonical'' technical approaches. This paper is an admittedly incomplete discussion of some of them. The author considers separately searches for rare decays, detection of low energy neutrinos and measurements of the neutrino mass, even if some of these new techniques are common to more than one of these subjects

  2. Beam diagnostics for low energy beams

    Directory of Open Access Journals (Sweden)

    J. Harasimowicz

    2012-12-01

    Full Text Available Low-energetic ion and antimatter beams are very attractive for a number of fundamental studies. The diagnostics of such beams, however, is a challenge due to low currents down to only a few thousands of particles per second and significant fraction of energy loss in matter at keV beam energies. A modular set of particle detectors has been developed to suit the particular beam diagnostic needs of the ultralow-energy storage ring (USR at the future facility for low-energy antiproton and ion research, accommodating very low beam intensities at energies down to 20 keV. The detectors include beam-profile monitors based on scintillating screens and secondary electron emission, sensitive Faraday cups for absolute intensity measurements, and capacitive pickups for beam position monitoring. In this paper, the design of all detectors is presented in detail and results from beam measurements are shown. The resolution limits of all detectors are described and options for further improvement summarized. Whilst initially developed for the USR, the instrumentation described in this paper is also well suited for use in other low-intensity, low-energy accelerators, storage rings, and beam lines.

  3. Occupant satisfaction with new low-energy houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Jensen, Ole Michael; Kristensen, Lars

    2012-01-01

    The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low-energy ho......The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low......-energy houses. The purpose was to study occupant satisfaction with new low-energy houses concerning i.a. the perceived indoor climate and the technical installations for heating and ventilation. The survey showed an overall satisfaction with the new low-energy houses, but also that there were problems...... occupant satisfaction in existing and future low-energy houses are given....

  4. Energy sharing and sputtering in low-energy collision cascades

    International Nuclear Information System (INIS)

    Weller, R.A.; Weller, M.R.

    1982-01-01

    Using a non-linear transport equation to describe the energy-sharing process in an isotropic collision cascade, we have numerically calculated sputtered particle velocity spectra for several very low energy (=< 10 eV) primary recoil distributions. Our formulation of the sputtering process is essentially that used in the linear model and our equations yield the familiar linear model results in the appropriate limit. Discrepancies between our calculations and the linear model results in other cases may be understood by considering the effects of the linear model assumptions on the sputtering yield at very low energies. Our calculations are also compared with recent experimental results investigating ion-explosion sputtering. The results of this comparison support the conclusion that in insulators sputtering is initiated by very low energy recoil atoms when the energy of the incident beam is high enough that the stopping power is dominated by the electronic contribution. The calculations also suggest that energy spectra similar to those for evaporation may result from non-equilibrium processes but that the apparent temperatures of evaporation are not related in a simple way to any real temperature within the target. (author)

  5. Nuclear Computational Low Energy Initiative (NUCLEI)

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Sanjay K. [University of Washington

    2017-08-14

    This is the final report for University of Washington for the NUCLEI SciDAC-3. The NUCLEI -project, as defined by the scope of work, will develop, implement and run codes for large-scale computations of many topics in low-energy nuclear physics. Physics to be studied include the properties of nuclei and nuclear decays, nuclear structure and reactions, and the properties of nuclear matter. The computational techniques to be used include Quantum Monte Carlo, Configuration Interaction, Coupled Cluster, and Density Functional methods. The research program will emphasize areas of high interest to current and possible future DOE nuclear physics facilities, including ATLAS and FRIB (nuclear structure and reactions, and nuclear astrophysics), TJNAF (neutron distributions in nuclei, few body systems, and electroweak processes), NIF (thermonuclear reactions), MAJORANA and FNPB (neutrino-less double-beta decay and physics beyond the Standard Model), and LANSCE (fission studies).

  6. Redesign of a Low Energy Probe Head

    CERN Document Server

    Rao, Yi-Nong; Ries, Thomas

    2005-01-01

    The present situation of the low energy probe LE2 in TRIUMF cyclotron is that the thickness of the finger 5 is uniform over a radial length of 3.25 inch and its weight which amounts to ~447 g is affecting its re-circulating ball mechanism and causing it to fall below the median plane over its range of movement. We therefore re-design it in order to reduce its weight. First, we made simulations and determined the optimum thickness of the probe head vs its radial length. These simulation results are found to be in good agreement with experimental measurements made. Finally, we calculated the temperature rise caused by the beam power dumped on the probe, and figured out the maximum current of beam that can be dumped on the finger.

  7. Low-energy pion-nucleon scattering

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Ai, L.; Kaufmann, W.B.

    1998-01-01

    An analysis of low-energy charged pion-nucleon data from recent π ± p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f 2 =0.0756±0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P 31 and P 13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the Σ term. Off-shell amplitudes are also provided. copyright 1998 The American Physical Society

  8. Low energy ion-molecule reactions

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, J.M. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project is concerned with elucidating the dynamics of elementary ion-molecule reactions at collision energies near and below 1 eV. From measurements of the angular and energy distributions of the reaction products, one can infer intimathe details about the nature of collisions leading to chemical reaction, the geometries and lifetimes of intermediate complexes that govern the reaction dynamics, and the collision energy dependence of these dynamical features. The author employs crossed-beam low energy mass spectrometry technology developed over the last several years, with the focus of current research on proton transfer and hydrogen atom transfer reactions of te O{sup {minus}} ion with species such as HF, H{sub 2}O, and NH{sub 3}.

  9. Windows in Low Energy Houses. Size Matters

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Mari-Louise

    2004-06-01

    A generally accepted way of building passive houses has been to have small windows facing north and a large glass facade to the south. This is to minimize losses on the north side while gaining as much solar heat as possible on the south. In spring 2001, twenty terraced houses were built outside Goeteborg partly in this way. The indoor temperature is kept at a comfortable level by passive methods, using solar gains and internal gains from household appliances and occupants. Heat losses are very low, since the building envelope is well insulated and since modern coated triple-glazed windows have been installed. The purpose of this work is to investigate how decreasing the window size facing south and increasing the window size facing north in low energy houses will influence the energy consumption and maximum power needed to keep the indoor temperature between 23 and 26 deg C. Different climates and orientations have been investigated and so have the influence of occupancy and window type. A dynamic building simulation tool, DEROB, has been used and the simulations indicate an extremely low energy demand for the houses. The results show that the size of the energy efficient windows does not have a major influence on the heating demand in winter, but is of relevant signification looking at the cooling need in summer. This indicates that instead of the traditional technique of building passive houses it is possible to enlarge the window area facing north and get better lighting conditions. To decrease the energy need for cooling, there is an optimal window size facing south that is smaller than the original size of the investigated buildings.

  10. em>d-wave superfluid with gapless edges in a cold-atom trap

    DEFF Research Database (Denmark)

    Larsen, Anne-Louise Gadsbølle; Francis Song, H.; Le Hur, Karyn

    2012-01-01

    and competing phases. In particular, at low temperatures, this allows the realization of a d-wave superfluid region surrounded by purely (gapless) normal edges. Solving the Bogoliubov–de Gennes equations and comparing them with the local density approximation, we show that the proximity to the Mott insulator...... is revealed by a downturn of the Fermi liquid order parameter at the center of the trap where the d-wave gap has a maximum. The density profile evolves linearly with distance....

  11. Antiferromagnetism and d-wave superconductivity in (doped) Mott insulators: A wave function approach

    OpenAIRE

    Weng, Z. Y.; Zhou, Y.; Muthukumar, V. N.

    2003-01-01

    We propose a class of wave functions that provide a unified description of antiferromagnetism and d-wave superconductivity in (doped) Mott insulators. The wave function has a Jastrow form and prohibits double occupancies. In the absence of holes, the wave function describes antiferromagnetism accurately. Off diagonal long range order develops at finite doping and the superconducting order parameter has d-wave symmetry. We also show how nodal quasiparticles and neutral spin excitations can be ...

  12. D-Wave's Approach to Quantum Computing: 1000-qubits and Counting!

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    In this talk I will describe D-Wave's approach to quantum computing, including the system architecture of our 1000-qubit D-Wave 2X, its programming model, and performance benchmarks. Furthermore, I will describe how the native optimization and sampling capabilities of the quantum processor can be exploited to tackle problems in a variety of fields including medicine, machine learning, physics, and computational finance.

  13. Low energy electron beam processing of YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chromik, Š., E-mail: stefan.chromik@savba.sk [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Camerlingo, C. [CNR-SPIN, Istituto Superconduttori, Materiali Innovativi e Dispositivi, via Campi Flegrei 34, 80078 Pozzuoli (Italy); Sojková, M.; Štrbík, V.; Talacko, M. [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Malka, I.; Bar, I.; Bareli, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Jung, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-02-15

    Highlights: • Improvement of superconducting properties of irradiated bridges under certain conditions. • 30 keV irradiation influence CuO{sub 2} planes as well as oxygen chains. • Direct confirmation of changes in oxygen chains using micro-Raman spectroscopy. • Possibility of electron writing. - Abstract: Effects of low energy 30 keV electron irradiation of superconducting YBa{sub 2}Cu{sub 3}O{sub 7−δ} thin films have been investigated by means of transport and micro-Raman spectroscopy measurements. The critical temperature and the critical current of 200 nm thick films initially increase with increasing fluency of the electron irradiation, reach the maximum at fluency 3 − 4 × 10{sup 20} electrons/cm{sup 2}, and then decrease with further fluency increase. In much thinner films (75 nm), the critical temperature increases while the critical current decreases after low energy electron irradiation with fluencies below 10{sup 20} electrons/cm{sup 2}. The Raman investigations suggest that critical temperature increase in irradiated films is due to healing of broken Cu−O chains that results in increased carrier’s concentration in superconducting CuO{sub 2} planes. Changes in the critical current are controlled by changes in the density of oxygen vacancies acting as effective pinning centers for flux vortices. The effects of low energy electron irradiation of YBCO turned out to result from a subtle balance of many processes involving oxygen removal, both by thermal activation and kick-off processes, and ordering of chains environment by incident electrons.

  14. Low energy electron scattering from fuels

    International Nuclear Information System (INIS)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M.

    2011-01-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  15. Low energy electron scattering from fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M. [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil). Dept. de Fisica; Yates, Brent; Hong, Ling; Khakoo, Murtadha A. [California State University at Fullerton, CA (US). Physics Department; Bettega, Marcio H.F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Costa, Romarly F. da [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Lima, Marco A.P. [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE/CNPEM), Campinas, SP (Brazil)

    2011-07-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  16. Low energy, low cost, efficient CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Trachtenberg; Lihong Bao; David A. Smith; Remy Dumortier [Carbozyme, Inc., Monmouth Junction, NJ (United States)

    2006-07-01

    This paper discusses the development and some characteristics of a new, enzyme-based, contained liquid membrane contactor to capture CO{sub 2}. The enzyme carbonic anhydrase catalyzes the removal of CO{sub 2} while the membrane contactor increases the surface area to allow the reduction of the size of the system. The modular system design is easily scaled to any required size reducing the investment costs. The system captures CO{sub 2} at a low energy and low cost promising to be a cost effective technology for CO{sub 2} capture. 5 refs., 7 figs.

  17. GEANT4 simulations for low energy proton computerized tomography

    International Nuclear Information System (INIS)

    Milhoretto, Edney; Schelin, Hugo R.; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A.; Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O.; Lopes, Ricardo T.; Vinagre Filho, Ubirajara M.

    2010-01-01

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  18. GEANT4 simulations for low energy proton computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Milhoretto, Edney [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O. [Polytechnic Institute/UERJ, Rua Alberto Rangel s/n, N. Friburgo, RJ, Brazil 28630-050 (Brazil); Lopes, Ricardo T. [Nuclear Instr. Lab./COPPE/UFRJ, Av. Horacio Macedo 2030, Rio de Janeiro-RJ (Brazil); Vinagre Filho, Ubirajara M. [Institute of Nuclear Engineering-IEN/CNEN, Rua Helio de Almeida 75, Rio de Janeiro-RJ (Brazil)

    2010-04-15

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  19. The interaction of low-energy electrons with fructose molecules

    Science.gov (United States)

    Chernyshova, I. V.; Kontrosh, E. E.; Markush, P. P.; Shpenik, O. B.

    2017-11-01

    Using a hypocycloidal electronic spectrometer, the interactions of low energy electrons (0-8.50 eV) with fructose molecules, namely, electron scattering and dissociative attachment, are studied. The results of these studies showed that the fragmentation of fructose molecules occurs effectively even at an electron energy close to zero. In the total electron-scattering cross section by molecules, resonance features (at energies 3.10 and 5.00 eV) were first observed near the formation thresholds of light ion fragments OH- and H-. The correlation of the features observed in the cross sections of electron scattering and dissociative attachment is analyzed.

  20. The EU CONCERTO project Class 1 - Demonstrating cost-effective low-energy buildings - Recent results with special focus on comparison of calculated and measured energy performance of Danish buildings

    DEFF Research Database (Denmark)

    Mørck, Ove; Thomsen, K.E.; Rose, J.

    2012-01-01

    -chip heating plant has been added. The project demonstrates the benefits of ultra-low-energy buildings integrated with biomass- and solar heating energy supply. The CLASS1 project involves 4 other countries: Estonia, France, Italy and Romania. These countries develop training activities based on the results......In 2007 the Class1 project commenced. Originally, 442 dwellings were to be designed and constructed as "low-energy class 1" houses according to requirements set by the Municipality of Egedal/Denmark. This means that the energy consumption is 50% below the existing energy regulations. 65 dwellings...... and experiences gained from the Danish housing projects. This paper describes the comparisons between measured and calculated energy consumption in a social housing settlement and in a detached single-family house. Results show relatively large discrepancies between measured and calculated results...

  1. Low energy atom-atom collisions

    International Nuclear Information System (INIS)

    Child, M.S.

    1980-01-01

    The semiclassical theory of atom-atom potential scattering and of low energy inelastic atom-atom scattering is reviewed. Particular attention is given to the origin and interpretation of rainbow structure, diffraction oscillations and exchange oscillations in the potential scattering differential cross-section, and to the glory structure and symmetry oscillations in the integral cross-section. Available methods for direct inversion of the cross-section data to recover the potential are reviewed in some detail. The theory of non-adiabatic transitions is introduced by a short discussion of interaction mechanisms and of diabetic and adiabatic representations. Analytical S matrix elements are presented for two state curve-crossing (Landau-Zener-Stuckelberg), Demkov and Nikitin models. The relation between Stuckelberg oscillations in the S matrix and in the differential cross-section is discussed in terms of interference between trajectories belonging to two different classical deflection functions. The energy dependences of the inelastic integral cross-section for curve-crossing and Demkov type transitions are also discussed. Finally the theory is reviewed in relation to a recent close-coupled study of fine structure transitions in F( 2 P) + Xe( 2 S) scattering

  2. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2006-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  3. Operating Characteristics of the low energy accelerator

    International Nuclear Information System (INIS)

    Abd El-Baki, M.M.; Abd El-Rahman, M.M.

    2000-01-01

    The main purpose of this work is to describe the construction and operation of low energy accelerator with energy in the range from (zero to 100 KeV.). This accelerator includes an ion source of the cold cathode penning type (with pierce geometry for ion beam extraction), an accelerating tube (with 8 electrodes) and faraday cup for measuring ion current. A vacuum system which gives vacuum of the order 3.0 x 10 8 torr is used. A palladium tube is used to supply the source with pure hydrogen atoms. It was possible to operate this accelerator with an energy 50 KeV. at minimum hydrogen pressure. 6.3 x 10 6 torr. The total resistance applied between the accelerating electrodes R T = 31.5 M OMEGA. These data includes the influence of the pressure in the accelerating tube, the magnetic field of the ion source, the extraction potential and the accelerating potential on the collector ion current. It was possible to accelerate protons with an energy 50 KeV with current about 100 MU A at pressure 6.3 x 10 6 Torr, the source magnetic field + 1100 gauss (I B = 2A), the current = 0.4 A and the extraction potential = 10 K. V

  4. Low-energy electron microdosimetry of CS-137

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Wrenn, M.E.

    1980-09-01

    The mass of tissue irradiated by an internal emitter depends upon the distribution of the radionuclide within the organism and the type of radiation emitted. The range (95% absorption) of low-energy electron effectively defines the sensitive volume in which the energy of the emitted electron is deposited. Accordingly, in the case of Auger electron microdosimetry of internal emitters the correct definition of the sensitive volume is of paramount importance. The amount of energy delivered by the monoenergetic electrons emitted by the decay system 137 Cs → sup(137m)Ba to spherical volumes of water-like tissue media of radii equivalent to the estimated ranges of those electrons in water is calculated and discussed as far as the variations of the estimated ranges of electrons as a function of the initial energy of emission are concerned. Although there are still many uncertainties on the actual ranges of low-energy electrons, one can state confidently that the ranges of the Auger electrons of the decay system 137 Cs → 137 sup(m) Ba → 137 Ba can be considered to be in the same order of magnitude of the diameter of a cell. The energy deposition in spherical volumes of water-like tissue media, considered equivalent to the sensitive volumes for the Auger electrons of the decay system 137 Cs → 137 sub(m) Ba → 137 Ba, range for several orders of magnitude from 10 2 to about 10 10 times higher than the energy deposition in similar media by the internal conversion electrons of this decay system. If equivalent variations of energy deposition per unit mass occur when the masses considered are cellular, and subcellular structures, then the effects into the sensitive volume should be taken into biological consideration as far as the microdosimetry of low-energy electrons (approximately equal to 10 keV) is considered, whenever there is internal localization of Auger emitters. (Author) [pt

  5. Study on the application of low energy U-window

    International Nuclear Information System (INIS)

    Li Binghai; Liu Shikai; Chen Guosheng

    2012-01-01

    For using the low energy U-window information, based on the theory and experiment, the advantage of identifying the subtle anomaly that the low energy U-window information has given is discussed, the method of drawing the low energy U-window information is stated; a method of calibration and obtaining the calibration parameters was developed which was applied to Dongsheng region. The result indicated that the anomaly of low energy U-window information upon known field is more easy identified by comparing with the standard three windows U-window information, which proved the practicability of the method of low energy U-windows information. (authors)

  6. New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field

    International Nuclear Information System (INIS)

    Gareev, F.A.; Zhidkova, I.E.

    2006-01-01

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system. (author)

  7. New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

    Science.gov (United States)

    Gareev, F. A.; Zhidkova, I. E.

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

  8. Local Density of States in a d-wave Superconductor with Stripe-Like Modulations and a Strong Impurity

    OpenAIRE

    Chen, Hong-Yi; Ting, C. S.

    2003-01-01

    Using an effective Hamiltonian with d-wave superconductivity (dSC) and competing antiferromagnetic (AF) interactions, we show that weak and one-dimensionally modulated dSC, spin density wave (SDW) and charge density wave (CDW) could coexist in the ground state configuration. With proper parameters, the SDW order exhibits a period of 8a, while for dSC and CDW orders the period is 4a. The local density of states (LDOS), which probing the behavior of quasiparticle excitations, is found to have t...

  9. Clinical application of low energy intracardiac cardioversion of atrial fibrillation

    International Nuclear Information System (INIS)

    Wu Liqun; Gu Gang; Su Kan; Su Renying; Shen Yongchu; Shen Weifeng

    2002-01-01

    Objective: To evaluate the efficacy and safety of low energy intracardiac cardioversion in persistent atria fibrillation. Methods: Low energy intracardiac cardioversion was performed by delivering R wave-synchronized biphasic shocks in 7 patients (4 men, 3 women) with persistent atrial fibrillation. Prior to the procedure, all patients underwent transesophageal echocardiographic examinations to rule out the presence of intracardiac thrombus and received subcutaneous injection of low molecular weight heparin for 3-5 days. Two custom-made 6 Fr catheters (Rhythm Technologies of Getz, USA) were used for de-fibrillation shock delivery. One catheter was positioned in the lower right atrium so that the majority of the catheter electrodes had firm contact with the right atrial free wall. The second catheter was placed randomly either in coronary sinus through right internal jugular vein or in the left pulmonary artery through femoral vein. In addition, a standard diagnostic 6-F quadrupolar catheter was placed at the right ventricular apex for ventricular synchronization and postshock ventricular pacing. Shocks were delivered by Implant Support Device (Model 4510, Teleceronics). After conversion, all patients were treated with intravenous amiodarone in the first 24 hours followed by oral administration. Results: In all 7 patients cardioversion of atrial fibrillation to sinus rhythm was successfully obtained. A mean of 2 ± 1 shocks per patient has been delivered with a total amount of 13 shocks. The average delivered energy was 7.8 ± 2.2 Joules. No complication occurred. At a mean follow-up of 18 ± 9 months, 4 of the 7 patients treated successfully showed sinus rhythm there after. Atrial fibrillation recurred in 3 patients at the second, fifth day and eighth month after cardioversion. Conclusions: Low energy intracardiac cardioversion is effective and safe, and can be easily performed in patients without general anesthesia. It offers a new option for restoring sinus

  10. Low energy x-ray spectrometer

    International Nuclear Information System (INIS)

    Woodruff, W.R.

    1981-01-01

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

  11. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  12. Low energy beam transport for HIDIF

    International Nuclear Information System (INIS)

    Meusel, O.; Pozimski, J.; Jakob, A.; Lakatos, A.

    2001-01-01

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe + beam are presented and the results of numerical simulations are shown

  13. Low energy beam transport for HIDIF

    Energy Technology Data Exchange (ETDEWEB)

    Meusel, O. E-mail: o.meusel@iap.uni-frankfurt.de; Pozimski, J.; Jakob, A.; Lakatos, A

    2001-05-21

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe{sup +} beam are presented and the results of numerical simulations are shown.

  14. Can cellulite be treated with low-energy extracorporeal shock wave therapy?

    Science.gov (United States)

    Angehrn, Fiorenzo; Kuhn, Christoph; Voss, Axel

    2007-01-01

    The present study investigates the effects of low-energy defocused extracorporeal generated shock waves on collagen structure of cellulite afflicted skin. Cellulite measurement using high-resolution ultrasound technology was performed before and after low-energy defocused extracorporeal shock wave therapy (ESWT) in 21 female subjects. ESWT was applied onto the skin at the lateral thigh twice a week for a period of six weeks. Results provide evidence that low-energy defocused ESWT caused remodeling of the collagen within the dermis of the tested region. Improving device-parameters and therapy regimes will be essential for future development of a scientific based approach to cellulite treatment. PMID:18225463

  15. Low energy description of quantum gravity and complementarity

    International Nuclear Information System (INIS)

    Nomura, Yasunori; Varela, Jaime; Weinberg, Sean J.

    2014-01-01

    We consider a framework in which low energy dynamics of quantum gravity is described preserving locality, and yet taking into account the effects that are not captured by the naive global spacetime picture, e.g. those associated with black hole complementarity. Our framework employs a “special relativistic” description of gravity; specifically, gravity is treated as a force measured by the observer tied to the coordinate system associated with a freely falling local Lorentz frame. We identify, in simple cases, regions of spacetime in which low energy local descriptions are applicable as viewed from the freely falling frame; in particular, we identify a surface called the gravitational observer horizon on which the local proper acceleration measured in the observer's coordinates becomes the cutoff (string) scale. This allows for separating between the “low-energy” local physics and “trans-Planckian” intrinsically quantum gravitational (stringy) physics, and allows for developing physical pictures of the origins of various effects. We explore the structure of the Hilbert space in which the proposed scheme is realized in a simple manner, and classify its elements according to certain horizons they possess. We also discuss implications of our framework on the firewall problem. We conjecture that the complementarity picture may persist due to properties of trans-Planckian physics.

  16. Connection between in-plane upper critical field Hc 2 and gap symmetry in layered d -wave superconductors

    Science.gov (United States)

    Wang, Jing-Rong; Liu, Guo-Zhu; Zhang, Chang-Jin

    2016-07-01

    Angle-resolved upper critical field Hc 2 provides an efficient tool to probe the gap symmetry of unconventional superconductors. We revisit the behavior of in-plane Hc 2 in d -wave superconductors by considering both the orbital effect and Pauli paramagnetic effect. After carrying out systematic analysis, we show that the maxima of Hc 2 could be along either nodal or antinodal directions of a d -wave superconducting gap, depending on the specific values of a number of tuning parameters. This behavior is in contrast to the common belief that the maxima of in-plane Hc 2 are along the direction where the superconducting gap takes its maximal value. Therefore, identifying the precise d -wave gap symmetry through fitting experiments results of angle-resolved Hc 2 with model calculations at a fixed temperature, as widely used in previous studies, is difficult and practically unreliable. However, our extensive analysis of angle-resolved Hc 2 show that there is a critical temperature T*: in-plane Hc 2 exhibits its maxima along nodal directions at T change as other parameters vary, but the existence of π /4 shift of Hc 2 at T* appears to be a general feature. Thus a better method to identify the precise d -wave gap symmetry is to measure Hc 2 at a number of different temperatures, and examine whether there is a π /4 shift in its angular dependence at certain T*. We further show that Landau level mixing does not change this general feature. However, in the presence of Fulde-Ferrell-Larkin-Ovchinnikov state, the angular dependence of Hc 2 becomes quite complicated, which makes it more difficult to determine the gap symmetry by measuring Hc 2. Our results indicate that some previous studies on the gap symmetry of CeCu2Si2 are unreliable and need to be reexamined, and also provide a candidate solution to an experimental discrepancy in the angle-resolved Hc 2 in CeCoIn5.

  17. Development of the low energy linac systems

    International Nuclear Information System (INIS)

    Cho, Yong Sub; Kwon, H. J.; Kim, Y. H.

    2005-08-01

    The project 'Development of the Low Energy Linac System' is aiming to develop the 20 MeV proton linac system. This consists of a 50 keV proton injector, a 3 MeV RFQ, and a 20 MeV DTL. We obtained the first beam signal after the 20 MeV linac. The high power switch installed in the ion source supplies the pulsed beam into the following LEBT. The pulse operation was successfully tested. The main role of the LEBT is to match the beam into the 3 MeV RFQ. The total length of the four-vane type RFQ is about 3.26m. For the field stabilization, we used the resonant coupling scheme and dipole stabilizer rods. An 1 MW klystron supplies the RF power into the RFQ. After tuning, the field deviation of the quadrupole mode is less than 2% of the design value and the dipole fraction is less than 5% of the operating mode. The following accelerating structure is DTL which accelerate 20 mA proton beams up to 20 MeV. It consists of 4 tanks and the length of each tank is less than 5 m. The lattice is FFDD type and the integrated fields of the quadrupole magnets are 1.75 T. The inner walls of the tanks are copper-plated by PR plating method. The thickness is 100m with the roughness of 0.3m. Each drift tube consists of 6 parts and assembled by e-beam welding. The tanks and drift tubes are aligned under the installation limit of 50m by using the laser-tracker. The tuning by the slug tuners and post couplers results in the field uniformity of 2% and field sensitivity of 100%/MHz. In order to detect the beam signal, we installed the Faraday cup after the RFQ or the DTL. For the RFQ, we observed the beam of 12 A under the forward RF power of 450 kW. The beam current after DTL is about 0.5 A when RF power of 150 kW was fed into each tank

  18. Effects of {Delta}-isobar degrees of freedom on the reactions {sup 3}He(n,{gamma}){sup 4}He and {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He at low-energy

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, R.

    1991-12-31

    The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

  19. Effects of. Delta. -isobar degrees of freedom on the reactions sup 3 He(n,. gamma. ) sup 4 He and sup 3 He(p,e sup +. nu. sub e ) sup 4 He at low-energy

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, R.

    1991-01-01

    The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

  20. Effects of Δ-isobar degrees of freedom on the reactions 3He(n,γ)4He and 3He(p,e+νe)4He at low-energy

    International Nuclear Information System (INIS)

    Schiavilla, R.

    1991-01-01

    The cross sections of the radiative 3 He(n,γ) 4 He and weak 3 He(p,e + ν e ) 4 He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and Δ-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + Δ Hilbert space

  1. Low-energy district heating in energy-efficient building areas

    DEFF Research Database (Denmark)

    Dalla Rosa, Alessandro; Christensen, Jørgen Erik

    2011-01-01

    of a low-energy network for low-energy houses in Denmark. We took into account the effect of human behaviour on energy demand, the effect of the number of buildings connected to the network, a socio-economic comparison with ground source heat pumps, and opportunities for the optimization of the network...... to 0.20 MWh/(m year), and that the levelized cost of energy in low-energy DH supply is competitive with a scenario based on ground source heat pumps. The investment costs represent up to three quarters of the overall expenditure, over a time horizon of 30 years; so, the implementation of an energy...... system that fully relies on renewable energy needs substantial capital investment, but in the long term this is sustainable from the environmental and socio-economic points of view. Having demonstrated the value of the low-energy DH concept, we evaluated various possible designs with the aim of finding...

  2. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1993-01-01

    This report summarizes the accomplishments of the project ''Studies of nuclear reactions at very low energies''. This project was undertaken in 1987 and completed in 1993. All but one of the major objectives of this study have been accomplished. Specifically the authors have completed their investigation of the (p,γ) on light nuclei, a study of the Oppenheimer-Phillips effect, a measurements of the astrophysically interesting reaction D(α,γ) 6 Li at low energies and an extension of the reaction D(d,γ) 4 He to lower energies than previously observed. Preliminary investigation of te reaction 7 Li( 3 He,p) 9 Be was begun and is continuing under a separate DOE grant. In addition to these tasks, they have completed some very interesting projects which were not included in the original proposal. These include a study of the (d,γ) reactions on 6 Li, 7 Li and 10 B and an investigation of the possibility of observing terrestrial antineutrinos from the beta decay chains of U and Th as a diagnostic of terrestrial heat flow

  3. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

    Directory of Open Access Journals (Sweden)

    Tanya M. S. David

    2014-01-01

    Full Text Available Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO level of −3.33 eV based on optical energy gap. The polymer was synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.

  4. Homestake result, sterile neutrinos, and low energy solar neutrino experiments

    Science.gov (United States)

    de Holanda, P. C.; Smirnov, A. Yu.

    2004-06-01

    The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E=(0.5 5) MeV thus suppressing the Be, or/and pep, CNO, as well as B electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

  5. Calculation and Measurement of Low-Energy Radiative Moller Scattering

    Science.gov (United States)

    Epstein, Charles; DarkLight Collaboration

    2017-09-01

    A number of current nuclear physics experiments have come to rely on precise knowledge of electron-electron (Moller) and positron-electron (Bhabha) scattering. Some of these experiments, having lepton beams on targets containing atomic electrons, use these purely-QED processes as normalization. In other scenarios, with electron beams at low energy and very high intensity, Moller scattering and radiative Moller scattering have such enormous cross-sections that the backgrounds they produce must be understood. In this low-energy regime, the electron mass is also not negligible in the calculation of the cross section. This is important, for example, in the DarkLight experiment (100 MeV). As a result, we have developed a new event generator for the radiative Moller and Bhabha processes, with new calculations that keep all terms of the electron mass. The MIT High Voltage Research Laboratory provides us a unique opportunity to study this process experimentally and compare it with our work, at a low beam energy of 2.5 MeV where the effects of the electron mass are significant. We are preparing a dedicated apparatus consisting of a magnetic spectrometer in order to directly measure this process. An overview of the calculation and the status of the experiment will be presented.

  6. Dynamical black holes in low-energy string theory

    Energy Technology Data Exchange (ETDEWEB)

    Aniceto, Pedro [Departamento de Matemática, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Rocha, Jorge V. [Departament de Física Quàntica i Astrofísica, Institut de Ciències del Cosmos (ICCUB),Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain)

    2017-05-08

    We investigate time-dependent spherically symmetric solutions of the four-dimensional Einstein-Maxwell-axion-dilaton system, with the dilaton coupling that occurs in low-energy effective heterotic string theory. A class of dilaton-electrovacuum radiating solutions with a trivial axion, previously found by Güven and Yörük, is re-derived in a simpler manner and its causal structure is clarified. It is shown that such dynamical spacetimes featuring apparent horizons do not possess a regular light-like past null infinity or future null infinity, depending on whether they are radiating or accreting. These solutions are then extended in two ways. First we consider a Vaidya-like generalisation, which introduces a null dust source. Such spacetimes are used to test the status of cosmic censorship in the context of low-energy string theory. We prove that — within this family of solutions — regular black holes cannot evolve into naked singularities by accreting null dust, unless standard energy conditions are violated. Secondly, we employ S-duality to derive new time-dependent dyon solutions with a nontrivial axion turned on. Although they share the same causal structure as their Einstein-Maxwell-dilaton counterparts, these solutions possess both electric and magnetic charges.

  7. Dynamics of d-wave YBa{sub 2}Cu{sub 3}O{sub 7-x} dc SQUIDs

    Energy Technology Data Exchange (ETDEWEB)

    Bauch, T [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Cedergren, K [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Johansson, J [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden); Rotoli, G [Dipartimento di Ingeneria Meccanica, Energetica e Gestionale, Universita of L' Aquila, Localita Moneluco, L' Aquila (Italy); Tafuri, F [Dipartimento Ingeneria dell' Informatione, INFM, Seconda Universita di Napoli, Aversa (Italy); Lombardi, F [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, S-41296 Goeteborg (Sweden)

    2007-02-15

    The predominant d-wave pairing symmetry in high temperature superconductors leads to an unconventional current-phase relation in Josephson junctions. This circumstance may induce new effects in the dynamics of dc SQUIDs. In this contribution we report on the measurements of the dependence of the SQUID Josephson current on the external magnetic field taken at very low temperatures, down to 20 mK. Different grain boundaries have been fabricated by using the biepitaxial and the bicrystal technique. Some of the effects which are induced by a nonsinusoidal current-phase relation can be clearly identified in the dynamics of the SQUIDs. The experimental data are also compared with theoretical simulations taking into account the inductance of the loop. The data show that, in specific conditions, a non-negligible inductance of the loop can induce effects similar to an unconventional current-phase relation, with a pronounced second harmonic sin(2{psi}) term. This fact has to be taken into account when designing d-wave SQUIDs for quantum circuitry.

  8. Dirac-fermions in graphene d-wave superconducting heterojunction with the spin orbit interaction

    Science.gov (United States)

    Wang, Juntao; Wang, Andong; Zhang, Rui; Sun, Deng; Yang, Yanling

    2017-09-01

    In this study, based on the Dirac-Bogoliubov-de Gennes equation, we theoretically investigate the interaction effect between the anisotropic d-wave pairing symmetry and the spin orbit interaction (the Rashba spin orbit interaction (RSOI) and the Dresselhaus spin orbit interaction (DSOI)) in a graphene superconducting heterojunction. We find that the spin orbit interaction (SOI) plays a critical role on the tunneling conductance in the pristine case, but minimally affecting the tunneling conductance in the heavily doped case. As for the zero bias state, in contrast to the keep intact feature in the heavily doped case, it exhibits a distinct dependence on the RSOI and the DSOI in the pristine case. In particular, the damage of the zero bias state with a slight DSOI results in the disappearance of the zero bias conductance peak. Moreover, the tunneling conductances also show a qualitative difference with respect to the RSOI when both the RSOI and the DSOI are finite. These remarkable results suggest that the SOI and the anisotropic superconducting gap can be regarded as a key tool for diagnosing the specular Andreev reflection.

  9. Heavy quark fragmentation functions for D-wave quarkonium and charmed beauty mesons

    International Nuclear Information System (INIS)

    Cheung, K.; Yuan, T.C.

    1995-09-01

    At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and anti bc mesons in high energy e + e - and hadronic collisions is dominated by parton fragmentation. The authors calculate the heavy quark fragmentation functions into the D-wave quarkonium and anti bc mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the anti bc meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a anti b antiquark to split into the D-wave anti bc mesons is about 2 x 10 -5 , which implies that only 2% of the total pseudo-scalar ground state B c comes from the cascades of these orbitally excited states

  10. Ground States of Random Spanning Trees on a D-Wave 2X

    Science.gov (United States)

    Hall, J. S.; Hobl, L.; Novotny, M. A.; Michielsen, Kristel

    The performances of two D-Wave 2 machines (476 and 496 qubits) and of a 1097-qubit D-Wave 2X were investigated. Each chip has a Chimera interaction graph calG . Problem input consists of values for the fields hj and for the two-qubit interactions Ji , j of an Ising spin-glass problem formulated on calG . Output is returned in terms of a spin configuration {sj } , with sj = +/- 1 . We generated random spanning trees (RSTs) uniformly distributed over all spanning trees of calG . On the 476-qubit D-Wave 2, RSTs were generated on the full chip with Ji , j = - 1 and hj = 0 and solved one thousand times. The distribution of solution energies and the average magnetization of each qubit were determined. On both the 476- and 1097-qubit machines, four identical spanning trees were generated on each quadrant of the chip. The statistical independence of these regions was investigated. In another study, on the D-Wave 2X, one hundred RSTs with random Ji , j ∈ { - 1 , 1 } and hj = 0 were generated on the full chip. Each RST problem was solved one hundred times and the number of times the ground state energy was found was recorded. This procedure was repeated for square subgraphs, with dimensions ranging from 7 ×7 to 11 ×11. Supported in part by NSF Grants DGE-0947419 and DMR-1206233. D-Wave time provided by D-Wave Systems and by the USRA Quantum Artificial Intelligence Laboratory Research Opportunity.

  11. Low-Energy Ballistic Transfers to Lunar Halo Orbits

    Science.gov (United States)

    Parker, Jeffrey S.

    2009-01-01

    Recent lunar missions have begun to take advantage of the benefits of low-energy ballistic transfers between the Earth and the Moon rather than implementing conventional Hohmann-like lunar transfers. Both Artemis and GRAIL plan to implement low-energy lunar transfers in the next few years. This paper explores the characteristics and potential applications of many different families of low-energy ballistic lunar transfers. The transfers presented here begin from a wide variety of different orbits at the Earth and follow several different distinct pathways to the Moon. This paper characterizes these pathways to identify desirable low-energy lunar transfers for future lunar missions.

  12. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Prasad, R; Yadav, R S [Aligarh Muslim Univ. (India). Dept. of Physics; Naqvi, T H [Z.H. Engineering Coll., Aligarh (India); Ahmed, Rais [National Council of Educational Research and Training, New Delhi (India)

    1975-12-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described.

  13. Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

    Science.gov (United States)

    Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

    2017-07-28

    We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

  14. Assessing risk from low energy radionuclide aerosol dispersal

    International Nuclear Information System (INIS)

    Waller, Edward; Perera, Sharman; Erhardt, Lorne; Cousins, Tom; Desrosiers, Marc

    2008-01-01

    Full text: When considering the potential dispersal of radionuclides into the environment, there are two broad classifications: explosive and non-explosive dispersal. An explosive dispersal relies on a violent and sudden release of energy, which may disrupt or vapourised any source containment. As such, the explosion provides the energy to both convert the source into a dispersable physical form and provides initial kinetic energy to transport the source away from the initiation point. This would be the case for sources of radiation in proximity to a steam or chemical explosion of high energy density. A low energy dispersal, on the other hand, may involve a lower energy initiator event (such as a fire or water spray) that transports particles into the near release zone, to be spread via wind or mechanical fields. For this type of dispersion to take place, the source must be in physical form ready for dispersal. In broad terms, this suggests either an ab initio powder form, or soluble/insoluble particulate form in a liquid matrix. This may be the case for radioactive material released from pressurized piping systems, material released through ventilation systems, or deliberate dispersals. To study aerosol dispersion of radionuclides and risk from low energy density initiators, there are a number of important parameters to consider. For example, particle size distribution, physicochemical form, atmospheric effects, charge effects, coagulation and agglomeration. At the University of Ontario Institute of Technology (UOIT) a unique small scale aerosol test chamber has been developed to study the low energy dispersal properties of a number of radioactive source simulant. Principle emphasis has been given to salts (CsCl and CoCl 2 ) and oxides (SrTiO 3 , CeO 2 and EuO 2 ). A planetary ball mill has been utilized to reduce particle size distributions when required. Particle sizing has been performed using Malvern Spraytec spray particle analyzers, cascade impactors, and

  15. The effects of illumination on deep levels observed in as-grown and low-energy electron irradiated high-purity semi-insulating 4H-SiC

    Science.gov (United States)

    Alfieri, G.; Knoll, L.; Kranz, L.; Sundaramoorthy, V.

    2018-05-01

    High-purity semi-insulating 4H-SiC can find a variety of applications, ranging from power electronics to quantum computing applications. However, data on the electronic properties of deep levels in this material are scarce. For this reason, we present a deep level transient spectroscopy study on HPSI 4H-SiC substrates, both as-grown and irradiated with low-energy electrons (to displace only C-atoms). Our investigation reveals the presence of four deep levels with activation energies in the 0.4-0.9 eV range. The concentrations of three of these levels increase by at least one order of magnitude after irradiation. Furthermore, we analyzed the behavior of these traps under sub- and above-band gap illumination. The nature of the traps is discussed in the light of the present data and results reported in the literature.

  16. A New Instrument Design for Imaging Low Energy Neutral Atoms

    Science.gov (United States)

    Keller, John W.; Collier, Michael R.; Chornay, Dennis; Rozmarynowski, Paul; Getty, Stephanie; Cooper, John F.; Smith, Billy

    2007-01-01

    The MidSTAR-2 satellite, to be built at the US Naval Academy as a follow-on to the successful MidSTAR-1 satellite (http://web.ew.usna.edu/midstar/), will launch in 2011 and carry three Goddard Space Flight Center (GSFC) experiments developed under Goddard's Internal Research and Development (IRAD) program. One of these GSFC instruments, the Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons (MINI-ME) builds on the heritage of the Goddard-developed Low-Energy Neutral Atom (LENA) imager launched on the IMAGE spacecraft in 2000. MINI-ME features a Venetian-blind conversion surface assembly that improves both light rejection and conversion efficiency in a smaller and lighter package than LENA making this an highly effective instrument for viewing solar wind charge exchange with terrestrial and planetary exospheres. We will describe the MINI-ME prototyping effort and its science targets.

  17. Degradation of carrageenan by low energy electron accelerator

    International Nuclear Information System (INIS)

    Relleve, L.; Aranilla, C.; Abad, L.; Dela Rosa, A.; Nagasawa, Naotsugu; Yagi, Toshiaki; Kume, Tamikazu; Yoshii, Fumio

    2004-01-01

    Degradation of κ-carrageenan using vessel-type low energy electron accelerator was investigated. Carrageenan with different molecular weights were obtained from irradiation of high molecular weight (HMW) and low molecular weight (LMW) κ-carrageenan. Other results presented were obtained from degradation studies of carrageenan by gamma rays. The decrease in molecular weight was accompanied by partial desulfation. From comparison of radiation degradation yield (Gd), it was found that the susceptibility to radiation of the three types of carrageenans in aqueous/gel forms follows the order of λ->ι->>κ- and could have been influenced by their conformational state. κ-carrageenan with molecular weight of ca. 10,000 showed strong growth promotion effect for potato in tissue culture. (author)

  18. The low-energy frontier of particle physics

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2010-02-01

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  19. A Low Energy Intelligent Clustering Protocol for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Li, Qiao; Cui, Lingguo; Zhang, Baihai

    2010-01-01

    LEACH (low-energy adaptive clustering hierarchy) is a well-known self-organizing, adaptive clustering protocol of wireless sensor networks. However it has some shortcomings when it faces such problems as the cluster construction and energy management. In this paper, LEICP (low energy intelligent...

  20. Passive and low energy cooling techniques for the Czech Republic

    NARCIS (Netherlands)

    Lain, M.; Hensen, J.L.M.; Santamouris, M.

    2005-01-01

    This paper deals with the applicability of passive and low energy cooling technologies in the Czech Republic. The work includes climate analysis as well as buildings and systems analysis in order to estimate the potential of passive and low energy cooling technologies. The latter is based on case

  1. Low-energy antiprotons physics and the FLAIR facility

    International Nuclear Information System (INIS)

    Widmann, E

    2015-01-01

    FLAIR, the Facility for low-energy antiproton and ion research has been proposed in 2004 as an extension of the planned FAIR facility at Darmstadt, Germany. FLAIR was not included into the modularized start version of FAIR, but the recent installation of the CRYRING storage ring at GSI Darmstadt has opened new perspectives for physics with low-energy antiprotons at FAIR. (paper)

  2. Positron impact ionization of atomic hydrogen at low energies

    Indian Academy of Sciences (India)

    The study of low energy ionization of atomic hydrogen has undergone a rapid ... Three distinct theories for describing low energy ionization can now .... clear evidence that the backward peak for ΘЅѕ = 180° is due to positron-nucleus scat-.

  3. Low-energy-consumption hybrid lasers for silicon photonics

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Ran, Qijiang; Mørk, Jesper

    2012-01-01

    Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed.......Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed....

  4. What is a low-energy house and who cares?

    Energy Technology Data Exchange (ETDEWEB)

    Litt, B.R.

    1994-12-01

    Most energy analysts view low-energy houses as good things, yet differ in their expectations of what exactly a low energy house is. There are two intertwining threads to this report. The first is an evaluation of 50 buildings that have been claimed to be low-energy residences, for which monitored energy performance data have been collected. These data represent the preliminary effort in the ongoing update of the Buildings Energy-Use Compilation and Analysis (BECA) data base for new residences. The second thread concerns the definition of a low-energy house. After the elements of a definition are presented, their implications for actors involved in providing housing are identified. Several more tractable definitions are applied to the houses in this compilation. The outcomes illustrate ways in which different interests are served by various definitions. Different definitions can yield very different energy rankings. No single definition of a low-energy house is universally applicable.

  5. The present state and perspectives of low-energy heavy ion biology

    International Nuclear Information System (INIS)

    Yuan Chengling; Yu Zengliang

    2004-01-01

    The interaction between low-energy ions and matter has been concerned rarely comparing to that of high-energy ions. It is even more unusual to find studies of the interaction of low-energy ions and complicated organisms. However, the discovery of bioeffects induced by ion beam implantation has opened a new branch in the field of ion beam applications in the life science--Low-energy Heavy Ion Biology. The mutagenic effect of low energy heavy ions was firstly reported in 1986 in rice. Since then, a damage mechanism involved in energy absorption, mass deposition, and charge exchange has been proposed. Accumulating evidence has indicated that these three factors are key determinants in the bioeffects induced by low energy heavy ions, which has opened new opportunities for mutational breeding, gene transferring, cell modification, and cell fusion. In recent years, the ion beam implantation technique has been widely applied in many fields, and increasing research interest in the field has been seen. The authors summarize recent advances in research on the role of low-energy ions in terms of the mechanisms and applications

  6. Neighbouring charge fragmentations in low energy fission

    International Nuclear Information System (INIS)

    Montoya, M.

    1986-10-01

    Shell and odd-even effects in fission have been largely studied until now. The structure in fragment mass, charge and kinetic energy distributions of fragments were interpreted as shell and even-odd effects. In this paper, we want to show that the discret change of fragment charge symmetry should produce also structures in those distribution. 19 refs

  7. Using the D-Wave 2X Quantum Computer to Explore the Formation of Global Terrorist Networks

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosiano, John Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Roberts, Randy Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sims, Benjamin Hayden [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-15

    Social networks with signed edges (+/-) play an important role in an area of social network theory called structural balance. In these networks, edges represent relationships that are labeled as either friendly (+) or hostile (-). A signed social network is balanced only if all cycles of three or more nodes in the graph have an odd number of hostile edges. A fundamental property of a balanced network is that it can be cleanly divided into 2 factions, where all relationships within each faction are friendly, and all relationships between members of different factions are hostile. The more unbalanced a network is, the more edges will fail to adhere to this rule, making factions more ambiguous. Social theory suggests unbalanced networks should be unstable, a finding that has been supported by research on gangs, which shows that unbalanced relationships are associated with greater violence, possibly due to this increased ambiguity about factional allegiances (Nakamura et al). One way to estimate the imbalance in a network, if only edge relationships are known, is to assign nodes to factions that minimize the number of violations of the edge rule described above. This problem is known to be computationally NP-hard. However, Facchetti et al. have pointed out that it is equivalent to an Ising model with a Hamiltonian that effectively counts the number of edge rule violations. Therefore, finding the assignment of factions that minimizes energy of the equivalent Ising system yields an estimate of the imbalance in the network. Based on the Ising model equivalence of the signed-social network balance problem, we have used the D-Wave 2X quantum annealing computer to explore some aspects of signed social networks. Because connectivity in the D-Wave computer is limited to its particular native topology, arbitrary networks cannot be represented directly. Rather, they must be “embedded” using a technique in which multiple qubits are chained together with special weights to

  8. Performance of broiler chicken fed multicarbohydrases supplemented low energy diet

    Directory of Open Access Journals (Sweden)

    Kumar Govil

    2017-07-01

    Full Text Available Aim: Objective of this study was to investigate the effect of multicarbohydrases supplementation on performance of broilers fed low energy diet. Materials and Methods: A total of 75 days old chicks were selected and randomly divided into three treatments groups (T1, T2, and T3; each group contained 25 chicks distributed in five replicates of five chicks each. T1 group (positive control was offered control ration formulated as per Bureau of Indian Standards recommendations. In T2 group (negative control ration, metabolizable energy (ME was reduced by 100 kcal/kg diet. T3 group ration was same as that of T2 except that it was supplemented with multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton. Feed intake and body weight of all experimental birds were recorded weekly. Metabolic trial was conducted for 3 days at the end of experiment to know the retention of nutrients. Results: Significant improvement (p<0.01 was observed in total weight gain, feed conversion efficiency, and performance index in broilers under supplementary group T3 as compared to T1 and T2 groups. Retention of crude protein and ether extract was significantly increased (p<0.05 in T3 group supplemented with multicarbohydrases as compared to other groups. Retention of dry matter, crude fiber, and nitrogen-free extract was comparable in all the three groups. Significantly highest dressed weight, eviscerated weight, and drawn weight (% of live body weight were observed in multicarbohydrases supplemented T3 group, however it was comparable in T1 and T2 groups. Conclusion: It was concluded that the supplementation of multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton in low energy diet improved overall performance of broilers.

  9. Nucleon-deuteron low energy parameters

    International Nuclear Information System (INIS)

    Zankel, H.; Mathelitsch, L.

    1983-01-01

    Momentum space Fadeev equations are solved for nucleon-deuteron scattering and effective range parameters are calculated. A reverse trend is found in the two spin states by 4 asub(nd) 4 asub(pd) and 2 asub(pd) 2 asub(nd) which is in agreement with a configuration space calculation, but in conflict with all existing experiments. The Coulomb contributions to the effective range are small in quartet but sizeable in doublet scattering. (Author)

  10. Competing States in the t-J Model: Uniform d-Wave State versus Stripe State versus Stripe State

    NARCIS (Netherlands)

    Corboz, P.R.; Rice, T.M.; Troyer, M.

    2014-01-01

    Variational studies of the t-J model on the square lattice based on infinite projected-entangled pair states confirm an extremely close competition between a uniform d-wave superconducting state and different stripe states. The site-centered stripe with an in-phase d-wave order has an equal or only

  11. Effect of orlistat on weight regain and cardiovascular risk factors following a very-low-energy diet in abdominally obese patients: a 3-year randomized, placebo-controlled study

    DEFF Research Database (Denmark)

    Richelsen, Bjørn; Tonstad, Serena; Rössner, Stephan

    2006-01-01

    OBJECTIVE: To investigate the efficacy of orlistat on the maintenance of weight loss over 3 years following a major weight loss induced by very-low-energy diet (VLED) in obese patients with metabolic risk factors such as dyslipidemia, impaired fasting glucose, and diet-treated type 2 diabetes....... RESEARCH DESIGN AND METHODS: Initially, weight loss was induced by an 8-week VLED (600-800 kcal/day) in 383 patients with a mean BMI of 37.5 kg/m(2) (range 30.0-45.2). Those who lost > or = 5% of their body weight (309 of 383 patients) were then randomized to receive lifestyle counseling for 3 years...... together with either orlistat 120 mg t.i.d. or matching placebo capsules. Primary end points were the maintenance of > or = 5% weight loss after 3 years. Additionally, differences in the development of type 2 diabetes between orlistat and placebo were analyzed. RESULTS: The VLED induced a mean weight loss...

  12. States of low energy on Robertson-Walker spacetimes

    International Nuclear Information System (INIS)

    Olbermann, Heiner

    2007-01-01

    We construct a new class of physical states of the free Klein-Gordon field in Robertson-Walker spacetimes. This is done by minimizing the expectation value of smeared stress-energy. We get an explicit expression for the state depending on the smearing function. We call it a state of low energy. States of low energy are an improvement of the concept of adiabatic vacua on Robertson-Walker spacetimes. The latter are approximations of the former. It is shown that states of low energy are Hadamard states

  13. DCARR: a spectrograph for measuring low-energy x rays

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    DCARR, the Differential Critical Angle Reflection Refraction detector system, is described. This detector was designed to measure low-energy x rays, 500 to 5000 eV, with a high degree of resolution, 250 eV. DCARR was developed because these low-energy measurements are of interest in the diagnostics of x-radiation in nuclear tests and available equipment could not make measurements at this low an energy in field tests. DCARR is a versatile piece of equipment that can also be used as a laboratory tool, such as in measuring the low-energy x rays emitted by lasers and various x-ray machines

  14. A primer on Higgs boson low-energy theorems

    International Nuclear Information System (INIS)

    Dawson, S.; Haber, H.E.; California Univ., Santa Cruz, CA

    1989-05-01

    We give a pedagogical review of Higgs boson low-energy theorems and their applications in the study of light Higgs boson interactions with mesons and baryons. In particular, it is shown how to combine the chiral Lagrangian method with the Higgs low-energy theorems to obtain predictions for the interaction of Higgs bosons and pseudoscalar mesons. Finally, we discuss the relation between the low-energy theorems and a technique which makes use of the trace of the QCD energy-momentum tensor. 35 refs

  15. Higgs Mode in the d -Wave Superconductor Bi2Sr2CaCu2O8 +x Driven by an Intense Terahertz Pulse

    Science.gov (United States)

    Katsumi, Kota; Tsuji, Naoto; Hamada, Yuki I.; Matsunaga, Ryusuke; Schneeloch, John; Zhong, Ruidan D.; Gu, Genda D.; Aoki, Hideo; Gallais, Yann; Shimano, Ryo

    2018-03-01

    We investigate the terahertz (THz)-pulse-driven nonlinear response in the d -wave cuprate superconductor Bi2Sr2CaCu2O8 +x (Bi2212) using a THz pump near-infrared probe scheme in the time domain. We observe an oscillatory behavior of the optical reflectivity that follows the THz electric field squared and is markedly enhanced below Tc . The corresponding third-order nonlinear effect exhibits both A1 g and B1 g symmetry components, which are decomposed from polarization-resolved measurements. A comparison with a BCS calculation of the nonlinear susceptibility indicates that the A1 g component is associated with the Higgs mode of the d -wave order parameter.

  16. Chiral models of low energy QCD

    International Nuclear Information System (INIS)

    Ripka, G.

    1993-01-01

    Two processes may be distinguished when a hadron propagates in a dense baryonic medium. The polarization of the medium and the change in the quark structure of the hadron. The polarization of the medium is better described in terms of colorless mesons and nucleons while the intrinsic change of the hadron is better described by quark models. It is shown how to couple the two processes. The scaling of effective Lagrangians, is related to changes in the quark constituent masses, based on the QCD scale anomaly. (author) 62 refs

  17. ΠN scattering at low energies

    International Nuclear Information System (INIS)

    Menezes, A.M.M.

    1985-01-01

    The pion-nucleon scattering for energies up to 300 MeV is studied by means of a theoretical model based on chiral symmetry, implemented by effective lagrangians. The interaction between the pion and the nucleon is mediated by only four particles: nucleon, delta, rho e sigma. The amplitudes associated to the delta and sigma contain free parameters, that must be extracted from experiment. The set of values obtained from fits below and above threshold disagree, indicating that, in the context of the model, a unified description in both regions is not possible. The results above threshold are sensitive to the method of unitarization employed. The method adopted in this work has a simple physical meaning and the ressonating wave associated to the delta is quite well reproduced. (Author) [pt

  18. Low energy implications of minimal superstring unification

    International Nuclear Information System (INIS)

    Khalil, S.; Vissani, F.; Masiero, A.

    1995-11-01

    We study the phenomenological implications of effective supergravities based on string vacua with spontaneously broken N =1 supersymmetry by dilation and moduli F-terms. We further require Minimal String Unification, namely that large string threshold corrections ensure the correct unification of the gauge couplings at the grand unification scale. The whole supersymmetric mass spectrum turns out to be determined in terms of only two independent parameters, the dilaton-moduli mixing angle and the gravitino mass. In particular we discuss the region of the parameter space where at least one superpartner is ''visible'' at LEPII. We find that the most likely candidates are the scalar partner of the right-handed electron and the lightest chargino, with interesting correlations between their masses and with the mass of the lightest higgs. We show how discovering SUSY particles at LEPII might rather sharply discriminate between scenarios with pure dilaton SUSY breaking and mixed dilaton-moduli breaking. (author). 10 refs, 7 figs

  19. Low-energy scattering of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, R.O.; Garibotti, C.R. (Universidad Nacional de Cuyo, San Carlos de Bariloche (Argentina). Inst. Balseiro)

    1983-04-23

    The off-energy-shell T-matrix for two charged particles is studied in the low momentum limit (k->0). The T-matrix for a Coulomb interaction (Tsub(C)) is usually considered as the limit of the amplitude for a screened potential (Tsub(s)) when the screening is removed. We show that this statement is not true for small enough energies. For an attractive interaction Tsub(C) and Tsub(s) differ significantly when k->0. Tsub(c) behaves as ksup(-1/2), while Tsub(s) keeps its k/sup -1/ behaviour even when the screening is turned off. We note that this is an effect which would be observed in ion-atom collisions when one electron is ejected from the atom and captured into a continuum state of the ion.

  20. Low-energy scattering of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, R.O.; Garibotti, C.R. (Instituto Balseiro, Argentina)

    1983-04-23

    The off-energy-shell T-matrix for two charged particles is studied in the low momentum limit ( k ->0 ). The T-matrix for a Coulomb interaction (Tsub(C)) is usually considered as the limit of the amplitude for a screened potential (Tsub(s)) when the screening is removed. This statement is not true for small enough energies. For an attractive interaction Tsub(C) and Tsub(s) differ significantly when k -> 0. Tsub(C) behaves as k sup(-0.5), while Tsub(s) keeps its k/sup -1/ behaviour even when the screening is turned off. This is an effect which would be observed in ion-atom collisions when one electron is ejected from the atom and captured into a continuum state of the ion.

  1. Electron-ion recombination at low energy

    International Nuclear Information System (INIS)

    Andersen, L.H.

    1993-01-01

    The work is based on results obtained with a merged-beams experiment. A beam of electronics with a well characterized density and energy distribution was merged with a fast, monoenergetic ion beam. Results have been obtained for radiative recombination and dielectronic recombination at low relative energies (0 to ∼70eV). The obtained energy resolution was improved by about a factor of 30. High vacuum technology was used to suppress interactions with electrons from the environments. The velocity distribution of the electron beam was determined. State-selective dielectronic-recombination measurements were performable. Recombination processes were studied. The theoretical background for radiative recombination and Kramers' theory are reviewed. The quantum mechanical result and its relation to the semiclassical theory is discussed. Radiative recombination was also measured with several different non-bare ions, and the applicability of the semiclassical theory to non-bare ions was investigated. The use of an effective charge is discussed. For dielectronic recombination, the standard theoretical approach in the isolated resonance and independent-processes approximation is debated. The applicability of this method was tested. The theory was able to reproduce most of the experimental data except when the recombination process was sensitive to couplings between different electronic configurations. The influence of external perturbing electrostatic fields is discussed. (AB) (31 refs.)

  2. Beta and low energy photon response

    International Nuclear Information System (INIS)

    Cummings, F.M.; Yoder, R.C.

    1981-01-01

    This study quantifies the observed dosimeter response for a variety of beta and photon energies. The reportable skin dose is also included in the discussion. Presently, the reportable skin dose is determined by adding the nonpenetrating and penetrating dose components together. The scheme presently used to estimate the nonpenetrating dose component for personnel at Hanford utilizes the difference in light outputs of a TLD-700 chip filtered only by the security credential (total of 88 mg/cm 2 ) and a TLD-700 chip filtered by a 0.064 cm thick aluminum filter as well as the credential. The study indicates that a maximum chip response occurs in the range of photon energies between 30 keV and 40 keV and results in an overestimation of the calculated nonpenetrating dose by a factor of approximately 2. The reportable skin dose is overestimated by a factor of approximately 2.5 following adding the nonpenetrating and penetrating dose components. The effect of removing the security credential is slight and tends to increase the steepness of slope in the photon response curve

  3. Intruder states and low energy nuclear spectroscopy

    International Nuclear Information System (INIS)

    Bengtsson, R.

    1991-01-01

    The crucial role intruder orbitals play is not limited to low spin and small deformations. In fact much of the physics at superdeformed shapes and at very high spin is a direct result of the presence of high-j intruder orbitals in the vicinity of the Fermi surface, including the introduction of intruder orbitals from still higher shells at extreme deformations. Since the intruder subshell has a larger angular momentum (j) than any other subshell close to the Fermi surface it plays an essential role for building up angular momentum in the nucleus, and the alignment of intruder shell (quasi) particles is responsible for a large variety of bandcrossings observed in discrete spectroscopy along or near the yrast line. Intruder shell orbitals are also associated with large quadrupole moments and the occupation of these orbitals may lead to significant changes of the deformation of the nucleus. Under favorable circumstances a nucleus may have totally different shapes depending on the occupation of the intruder orbitals, giving rise to a phenomenon which is usually referred to as shape coexistence. In this paper, shape coexistence in several mass regions will be discussed with specific attention focused on the relation between shape coexistence and the occupation of intruder shell levels. Shape effects associated both with spin aligned and non-aligned intruder orbitals will be investigated

  4. Low-energy buildings on mainstream market terms

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Elle, Morten; Hoffmann, Birgitte

    2008-01-01

    implementation of strict energy performance requirements in mainstream building. The paper describes how the municipality of Egedal experienced a collapse in regulation for low-energy buildings and what struggles it had to take on in order to convince the mainstream building industry and their customers......This paper looks into the challenge of actually implementing energy efficient technologies and concepts in mainstream new build. The aim of the paper is to point out some of the provisos of promoting low-energy buildings on mainstream market terms, emphasising the need to understand forces working...... against implementation of low-energy buildings. The study is based on actor-network theory, emphasising the relations and struggles that form the basis for pushing for low-energy buildings. The paper is based on a case study of the proactive attempt of a Danish municipality to force through an actual...

  5. Classification of low energy houses in Danish Building Regulations

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    The new Danish Building Regulations (Building Regulations, 2005) introduces the total energy consumption, i.e. energy use for heating, ventilation, cooling and domestic hot water, for buildings as a measure for the energy efficiency of new buildings, i.e. moving away from the former U-value demands....... In addition to the minimum requirements for new buildings, the new Building Regulations also specify requirements for characterizing a building as either low energy building class 1 or low energy building class 2. This paper describes a type-house that is presently being built in Denmark. The type......-house easily meets the requirements for being categorized as a low energy building class 1, and the paper investigates how much U-values can be increased if the type-house were to fulfil the requirements for a low energy building class 2 or a building that just fulfils the minimum demands....

  6. Biological assessments for the low energy demonstration accelerator, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1997-03-01

    This report discusses the biological impact to the area around the Los Alamos National Laboratory of the Low Energy Demonstration Accelerator. In particular the impact to the soils, water quality, vegetation, and wildlife are discussed.

  7. Low-energy nuclear reactions with double-solenoid- based ...

    Indian Academy of Sciences (India)

    solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

  8. Bag-model quantum chromodynamics for hyperons at low energy

    International Nuclear Information System (INIS)

    Weber, H.J.; Maslow, J.N.

    1980-01-01

    In a non-perturbative bag model framework, gluon exchange which mediates quark exchange scattering in conjunction with quark interchange is shown to be the basis of the OBE interactions of hyperons at low energy. (orig.)

  9. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The Ward identities of current algebra are combined with gauge invariance constraints, on-shell PCAC and the Bjorken limit to obtain the low-energy expressions of the pion photo- and electroproduction invariant amplitudes for physical pions

  10. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    International Nuclear Information System (INIS)

    Kumar, S.; Prasad, R.; Yadav, R.S.; Ahmed, Rais

    1975-01-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described. (author)

  11. Several methods and apparatus of low-energy laser therapy in veterinary practice

    Science.gov (United States)

    Svirin, Vaytcheslav N.; Rogatkin, Dmitrii A.; Barybin, Vitalii F.

    1998-12-01

    During same years various medical effect of low-energy laser therapy in veterinary were tested. We established that the laser low-energy therapy can be very effective for treatment such animal's diseases as mastitis and demodekose when certain combinations of laser beam parameters are used. This combinations were taken as the principle of a number of laser veterinary apparatus, which we started to produce at `POLUS'. It is our series of apparatus `VEGA-MB' and `VETLAS-3', which is real used today for dogs and cows treatment in Russia.

  12. Parity non-conservation in low energy scattering of nucleons by light nuclei. I. Theoretical framework

    Energy Technology Data Exchange (ETDEWEB)

    Henley, E M [Washington Univ., Seattle (USA). Dept. of Physics; Wolfenstein, L [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1978-05-15

    The low-energy scattering of nucleons by /sup 2/H, /sup 3/He and /sup 4/He is analyzed for parity nonconserving effects. The asymmetry in the total cross section of longitudinally polarized projectiles is formulated in terms of the optical theorem and a distorted-wave Born approximation. For two nucleons at low energies it is only necessary to consider l = 0 to l = 1 matrix elements of the weak nucleon-nucleon potential. The asymmetries in the scattering from nuclear targets are related to the parameters of an effective weak nucleon-nucleon potential, so that they may be used to help differentiate between various proposed theoretical potentials.

  13. Spin dynamics and implications for superconductivity. Some problems with the d-wave scenario

    International Nuclear Information System (INIS)

    Levin, K.; Zha, Y.; Radtke, R.J.; Si, Q.; Norman, M.R.; Schuettler, H.B.

    1994-01-01

    We review the spin dynamics of the normal state of the cuprates with special emphasis on neutron data in both the YBa 2 Cu 3 O 7-δ and La 2-x Sr x CuO 4 systems. When realistic models of the Fermi surface shapes are incorporated, along with a moderate degree of spin fluctuations, we find good semiquantitative agreement with experiment for both cuprates. Building on the success of this Fermi-liquid-based scheme, we explore the implications for d-wave pairing from a number of vantage points. We conclude that our present experimental and theoretical understanding is inadequate to confirm or refute the d-wave scenario. 26 refs., 6 figs

  14. p and d wave neutron strength functions for rare earth nuclei

    International Nuclear Information System (INIS)

    Kononov, V.N.; Yurlov, B.D.

    1978-01-01

    The authors obtained p and d wave neutron strength functions by analysis of average fast neutron radiative capture cross-sections for the isotopes sup(142, 144, 146, 148, 150)Nd, sup(144, 147, 148, 149, 150, 152, 154)Sm, sup(151, 153)Eu, sup(156, 158, 160)Gd and sup(166, 168, 170)Er. The data are compared with results obtained by other authors, with calculations based on the optical model and with computations based on the semi-microscopic approach. (author)

  15. Generalized hidden symmetry for low-energy hadron phsics

    International Nuclear Information System (INIS)

    Kaiser, N.; Meissner, U.G.

    1990-01-01

    We present a detailed study of an effective chiral meson lagrangian involving pseudoscalar, vector and axial-vector mesons. We employ the recently proposed technique to introduce vector and axial-vector mesons as composite gauge bosons of an extended hidden gauge symmetry of the non-linear σ-model. In particular, we write down the most general anomalous action (Wess-Zumino term) in accordance with low-energy theorems and chiral symmetry. The global flavor anomalies of QCD are given by the standard (5-dimensional) Wess-Zumino-Witten action of the pseudoscalar mesons, whereas all the processes violating natural parity for the vectors and axials are chirally (gauge) symmetric and therefore do not contribute to the Wess-Zumino anomaly equation. We find fourteen independent terms with a priori unknown (real) coefficients. We are able to fix some of these coefficients from anomalous hadronic and radiative vector/axial-vector meson decays. A comparison to the gauged Wess-Zumino action in the so-called massive Yang-Mills approach shows that both anomalous actions are indeed equivalent for a special choice of the unknown coefficients. We finally propose a realistic two-flavor chiral effective lagrangian incorporating pions, the vector mesons ρ and ω as well as the axial A 1 meson which should be used in skyrmion physics at energy scales up to about 1 GeV. (orig.)

  16. Sgoldstino-less inflation and low energy SUSY breaking

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes, Université Libre de Bruxelles, CP231, B-1050 Brussels (Belgium); Coone, Dries; Mariotti, Alberto [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Heurtier, Lucien, E-mail: rargurio@ulb.ac.be, E-mail: a.a.coone@rug.nl, E-mail: lucien.heurtier@ulb.ac.be, E-mail: alberto.mariotti@vub.ac.be [Service de Physique Théorique, Université Libre de Bruxelles, CP225, B-1050 Brussels (Belgium)

    2017-07-01

    We assess the range of validity of sgoldstino-less inflation in a scenario of low energy supersymmetry breaking. We first analyze the consistency conditions that an effective theory of the inflaton and goldstino superfields should satisfy in order to be faithfully described by a sgoldstino-less model. Enlarging the scope of previous studies, we investigate the case where the effective field theory cut-off, and hence also the sgoldstino mass, are inflaton-dependent. We then introduce a UV complete model where one can realize successfully sgoldstino-less inflation and gauge mediation of supersymmetry breaking, combining the α-attractor mechanism and a weakly coupled model of spontaneous breaking of supersymmetry. In this class of models we find that, given current limits on superpartner masses, the gravitino mass has a lower bound of the order of the MeV, i.e. we cannot reach very low supersymmetry breaking scales. On the plus side, we recognize that in this framework, one can derive the complete superpartner spectrum as well as compute inflation observables, the reheating temperature, and address the gravitino overabundance problem. We then show that further constraints come from collider results and inflation observables. Their non trivial interplay seems a staple feature of phenomenological studies of supersymmetric inflationary models.

  17. Modelling interaction cross sections for intermediate and low energy ions

    International Nuclear Information System (INIS)

    Toburen, L.H.; Shinpaugh, J.L.; Justiniano, E.L.B.

    2002-01-01

    When charged particles slow in tissue they undergo electron capture and loss processes than can have profound effects on subsequent interaction cross sections. Although a large amount of data exists for the interaction of bare charged particles with atoms and molecules, few experiments have been reported for these 'dressed' particles. Projectile electrons contribute to an impact-parameter-dependent screening of the projectile charge that precludes straightforward scaling of energy loss cross sections from those of bare charged particles. The objective of this work is to develop an analytical model for the energy-loss-dependent effects of screening on differential ionisation cross sections that can be used in track structure calculations for high LET ions. As a first step a model of differential ionisation cross sections for bare ions has been combined with a simple screening model to explore cross sections for intermediate and low energy dressed ions in collisions with atomic and molecular gas targets. The model is described briefly and preliminary results compared to measured electron energy spectra. (author)

  18. Theories of Variable Mass Particles and Low Energy Nuclear Phenomena

    Science.gov (United States)

    Davidson, Mark

    2014-02-01

    Variable particle masses have sometimes been invoked to explain observed anomalies in low energy nuclear reactions (LENR). Such behavior has never been observed directly, and is not considered possible in theoretical nuclear physics. Nevertheless, there are covariant off-mass-shell theories of relativistic particle dynamics, based on works by Fock, Stueckelberg, Feynman, Greenberger, Horwitz, and others. We review some of these and we also consider virtual particles that arise in conventional Feynman diagrams in relativistic field theories. Effective Lagrangian models incorporating variable mass particle theories might be useful in describing anomalous nuclear reactions by combining mass shifts together with resonant tunneling and other effects. A detailed model for resonant fusion in a deuterium molecule with off-shell deuterons and electrons is presented as an example. Experimental means of observing such off-shell behavior directly, if it exists, is proposed and described. Brief explanations for elemental transmutation and formation of micro-craters are also given, and an alternative mechanism for the mass shift in the Widom-Larsen theory is presented. If variable mass theories were to find experimental support from LENR, then they would undoubtedly have important implications for the foundations of quantum mechanics, and practical applications may arise.

  19. Resonant Electromagnetic Interaction in Low Energy Nuclear Reactions

    Science.gov (United States)

    Chubb, Scott

    2008-03-01

    Basic ideas about how resonant electromagnetic interaction (EMI) can take place in finite solids are reviewed. These ideas not only provide a basis for conventional, electron energy band theory (which explains charge and heat transport in solids), but they also explain how through finite size effects, it is possible to create many of the kinds of effects envisioned by Giuliano Preparata. The underlying formalism predicts that the orientation of the external fields in the SPAWAR protocolootnotetextKrivit, Steven B., New Energy Times, 2007, issue 21, item 10. http://newenergytimes.com/news/2007/NET21.htm^,ootnotetextSzpak, S.; Mosier-Boss, P.A.; Gordon, F.E. Further evidence of nuclear reactions in the Pd lattice: emission of charged particles. Naturwissenschaften 94,511(2007)..has direct bearing on the emission of high-energy particles. Resonant EMI also implies that nano-scale solids, of a particular size, provide an optimal environment for initiating Low Energy Nuclear Reactions (LENR) in the PdD system.

  20. Early Forest Fire Detection Using Low Energy Hydrogen Sensors

    Directory of Open Access Journals (Sweden)

    Jürgen Müller

    2016-08-01

    Full Text Available The North-east German Lowlands is a region with one of the highest forest fire risks in Europe. In order to keep damage levels as low as possible, it is important to have an effective early warning system. Such a system is being developed on the basis of a hydrogen sensor, which makes it possible to detect a smouldering forest fire before the development of open flames. The prototype hydrogen sensor produced at the Humboldt University Berlin has a metal/ solid electrolyte/insulator/ semiconductor (MEIS structure, which allows cost-effective production. Due to the low energy consumption, an autarchic working unit could be installed in the forest. Field trials have shown that it is possible to identify a forest fire in its early stages when hydrogen concentrations are still low. A significant change in the signal due to a fire was measured at a distance of about 100m. In view of the potential impacts of climate change, the innovative pre-ignition warning system is an important early diagnosis and monitoring module for the protection of the forests.

  1. Coupled s-wave and d-wave states in the heavy-fermion superconductor U/sub 1-//sub x/Th/sub x/Be/sub 13/

    International Nuclear Information System (INIS)

    Langner, A.; Sahu, D.; George, T.F.

    1988-01-01

    In the heavy-fermion superconductor U/sub 1-//sub x/Th/sub x/Be/sub 13/, superconducting states coexist for thorium concentrations 0 ≤ x ≤ 0.06. Assuming s-wave and d-wave symmetries for these states, we derive a Ginzburg-Landau free-energy expression which couples s- and d-wave states and is rotationally invariant, in contrast to the free-energy expression proposed by P. Kumar and P. Woelfle [Phys. Rev. Lett. 59, 1954 (1987)]. We discuss in detail the consequences that follow from our free-energy relation. In particular, we predict that in the above system there are two eigenfrequencies associated with the dynamics of phase oscillations (internal Josephson effect) which are characteristic of the s-wave and d-wave states

  2. A low-energy building under arctic conditions – a case study

    DEFF Research Database (Denmark)

    Norling, Casper Roland; Rode, Carsten; Svendsen, Svend

    2006-01-01

    Greenland is a relatively small community with limited natural resources, which results in the necessity to import all supplies, including a big share of the energy. Because of this, it is important to decrease the energy consumption. This can be done by developing new construction technology wit...... in the new Greenlandic building regulations....... with larger focus on energy efficiency. Therefore a low-energy house, located in Sisimiut, has been constructed. The low-energy house will be a forerunner for the development of new building element designs and technologies in Greenland. In the forthcoming years, the house will also be a base for scientific...... projects which will evaluate the design of the low-energy house including an assessment of the effect of the highly insulated building envelope, advanced windows and a ventilation system with heat recovery, all of which cuts the energy consumption of the building to half of what will be the requirement...

  3. A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

    Science.gov (United States)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2009-05-01

    The Simbol-X Low Energy Detector (LED), a 128×128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

  4. A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

    2009-01-01

    The Simbol-X Low Energy Detector (LED), a 128x128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

  5. Space Charge Compensation in the Linac4 Low Energy Beam Transport Line with Negative Hydrogen Ions

    CERN Document Server

    Valerio-Lizarraga, C; Leon-Monzon, I; Lettry, J; Midttun, O; Scrivens, R

    2014-01-01

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Tranport (LEBT) using the package IBSimu1, which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H- beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  6. Transport and matching of low energy space charge dominated beams

    International Nuclear Information System (INIS)

    Pandit, V.S.

    2013-01-01

    The transport and matching of low energy high intensity beams from the ion source to the subsequent accelerating structure are of considerable interest in recent years for variety of applications such as Accelerator driven system (ADSS), transmutation of nuclear waste, spallation neutron sources etc. It is essential to perform detailed simulations with experimentation to predict the beam evolution in the presence of nonlinear self as well as external fields before the design of the next accelerating structure is finalized. In order to study and settle various physics and technical issues related with transport of space charge dominated beams we have developed a 2.45 GHz microwave ion source at VECC which is now delivering more than 10 mA proton beam current at 80 keV. We have successfully transported well collimated 8 mA proton beam through the solenoid based 3 meter long transport line and studied various beam properties. We have also studied the transport of beam through spiral inflector at low beam current ∼ 1mA. In this article we will discuss the beam transport issues and describe a technique for simulation of beam envelopes in presence of linear space charge effects. We use canonical description of the motion of a single particle and then obtain first order differential equations for evolution of the moments of beam ensemble by assuming uniform distribution of the beam. We will also discuss the methodology used in the simulations to understand the observed beam behaviour during transport. (author)

  7. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report by Lawrence Berkeley National Laboratory identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most U.S. locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  8. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris; Singer, Brett C.

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two web-based meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most US locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  9. Strong interactions and electromagnetism in low-energy hadron physics

    International Nuclear Information System (INIS)

    Kubis, B.

    2002-10-01

    In the present work, we study various aspects of the entanglement of the strong and electromagnetic interactions as it is manifest in low-energy hadron physics. In the framework of chiral perturbation theory, two aspects are investigated: the test of the structure of baryons as probed by external electromagnetic currents, and the modification of reactions mediated by the strong interactions in the presence of internal (virtual) photons. In the first part of this work, we study the electromagnetic form factors of nucleons and the ground state baryon octet, as well as strangeness form factors of the nucleon. Emphasis is put on the comparison of a new relativistic scheme for the calculation of loop diagrams to the heavy-baryon formalism, and on the convergence of higher-order corrections in both schemes. The new scheme is shown to yield both a phenomenologically more successful description of the data and better convergence behaviour. In the second part, we study isospin violation in pion-kaon scattering as mediated by virtual photon effects and the light quark mass difference. This investigation is of particular importance for the extraction of scattering lengths from measurements of lifetime and energy levels in pion-kaon atoms. The isospin breaking corrections are shown to be small and sufficiently well under control. (orig.)

  10. The low-energy frontier of particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-02-15

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  11. Diagnostics for low energy buncher stability at PLF, Mumbai

    International Nuclear Information System (INIS)

    Pal, S.; Karande, J.N.; Dhumal, P.; Takke, A.N.; Nanal, V.; Pillay, R.G.

    2013-01-01

    The buncher system at Pelletron Linac Facility (PLF), Mumbai consists of room-temperature double-harmonic drift bunchers, situated at the entrance of the Pelletron accelerator and a superconducting cavity at the injection of the LINAC. Low energy (LE) bunchers operate at sub harmonic of the LINAC reference clock (∼150 MHz)) with a bunching efficiency ∼ 66% and a typical FWHM of 1.5 ns.The dark current between adjacent bunches is swept away by RF parallel plate sweeper situated at exit of the Pelletron operating at f/32. The transit time variation arising due to Pelletron terminal voltage fluctuations are compensated by locking the reference of the LE bunchers to the phase detector operating at f/4 and situated at the injection of the LINAC. For a stable injection in the LINAC, the LE bunchers, the sweeper and the phase detector need too be phase synchronized with the LINAC master clock. To achieve a better stability on the phase lock, detailed phase stability measurements of the RF subsystem consisting of various RF devices, which operate at different sub harmonic of LINAC clock (f/32, f/16, f/8, f/4 and f) have been carried out. It was observed that temperature instabilities, ground loops and poor RF/EMI shielding due to aging effects were responsible for the phase jitter and drifts. The long term drifts and phase noise in the RF control of the LE buncher system have been minimized to a level better than 50 ps. (author)

  12. Testing SO(10)-inspired leptogenesis with low energy neutrino experiments

    CERN Document Server

    Di Bari, Pasquale

    2011-01-01

    We extend the results of a previous analysis of ours showing that, when both heavy and light flavour effects are taken into account, successful minimal (type I + thermal) leptogenesis with SO(10)-inspired relations is possible. Barring fine tuned choices of the parameters, these relations enforce a hierarchical RH neutrino mass spectrum that results into a final asymmetry dominantly produced by the next-to-lightest RH neutrino decays (N_2 dominated leptogenesis). We present the constraints on the whole set of low energy neutrino parameters. Allowing a small misalignment between the Dirac basis and the charged lepton basis as in the quark sector, the allowed regions enlarge and the lower bound on the reheating temperature gets relaxed to values as low as ~ 10^10 GeV. It is confirmed that for normal ordering (NO) there are two allowed ranges of values for the lightest neutrino mass: m_1 \\simeq (1-5)\\times 10^-3 eV and m_1\\simeq (0.03-0.1) eV. For m_1\\lesssim 0.01 eV the allowed region in the plane theta_13-thet...

  13. Photon strength and the low-energy enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeking, M. [iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Bernstein, L. A.; Bleuel, D. L.; Burke, J. T.; Hatarik, R.; Lesher, S. R.; Scielzo, N. D. [Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Krtička, M. [Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, Prague 8 (Czech Republic); Allmond, J. M. [Department of Physics, University of Richmond, Virginia 23173 (United States); Basunia, M. S.; Fallon, P.; Firestone, R. B.; Lake, P. T.; Lee, I-Y.; Paschalis, S.; Petri, M.; Phair, L. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Goldblum, B. L. [Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)

    2014-08-14

    Several measurements in medium mass nuclei have reported a low-energy enhancement in the photon strength function. Although, much effort has been invested in unraveling the mysteries of this effect, its physical origin is still not conclusively understood. Here, a completely model-independent experimental approach to investigate the existence of this enhancement is presented. The experiment was designed to study statistical feeding from the quasi-continuum (below the neutron separation energy) to individual low-lying discrete levels in {sup 95}Mo produced in the (d, p) reaction. A key aspect to successfully study gamma decay from the region of high-level density is the detection and extraction of correlated particle-gamma-gamma events which was accomplished using an array of Clover HPGe detectors and large area annular silicon detectors. The entrance channel excitation energy into the residual nucleus produced in the reaction was inferred from the detected proton energies in the silicon detectors. Gating on gamma-transitions originating from low-lying discrete levels specifies the state fed by statistical gamma-rays. Any particle-gamma-gamma event in combination with specific energy sum requirements ensures a clean and unambiguous determination of the initial and final state of the observed gamma rays. With these requirements the statistical feeding to individual discrete levels is extracted on an event-by-event basis. The results are presented and compared to {sup 95}Mo photon strength function data measured at the University of Oslo.

  14. Can Low Energy Electrons Affect High Energy Physics Accelerators?

    International Nuclear Information System (INIS)

    Cimino, Roberto

    2004-01-01

    The properties of the electrons participating in the build up of an electron cloud (EC) inside the beam-pipe have become an increasingly important issue for present and future accelerators whose performance may be limited by this effect. The EC formation and evolution are determined by the wall-surface properties of the accelerator vacuum chamber. Thus, the accurate modeling of these surface properties is an indispensible input to simulation codes aimed at the correct prediction of build-up thresholds, electron-induced instability or EC heat load. In this letter, we present the results of surface measurements performed on a prototype of the beam screen adopted for the Large Hadron Collider (LHC), which presently is under construction at CERN. We have measured the total secondary electron yield (SEY) as well as the related energy distribution curves (EDC) of the secondary electrons as a function of incident electron energy. Attention has been paid, for the first time in this context, to the probability at which low-energy electrons (<∼ 20 eV) impacting on the wall create secondaries or are elastically reflected. It is shown that the ratio of reflected to true-secondary electrons increases for decreasing energy and that the SEY approaches unity in the limit of zero primary electron energy

  15. Internal defibrillation: pain perception of low energy shocks.

    Science.gov (United States)

    Steinhaus, David M; Cardinal, Debbie S; Mongeon, Luc; Musley, Shailesh Kumar; Foley, Laura; Corrigan, Susie

    2002-07-01

    Recently, device-based low energy cardoversion shocks have been used as therapy for AF. However, discomfort from internal low energy electrical shocks is poorly understood. The aim of this study was to evaluate pain perception with low energy internal discharges. Eighteen patients with ICD devices for malignant ventricular arrhythmias were recruited to receive shocks of 0.4 and 2 J in the nonsedated state. Discharges were delivered in a blinded, random order and questionnaires were used to determine discomfort levels and tolerability. Patients perceived discharges at these energies as relatively uncomfortable, averaging a score of 7.3 on a discomfort scale of 0-10, and could not distinguish 0.4-J shocks from 2-J shocks. Second shocks were perceived as more uncomfortable than initial discharges, regardless of the order in which the shocks were delivered. Despite the perceived discomfort, 83% of patients stated that they would tolerate discharges of this magnitude once per month, and 44% would tolerate weekly discharges. Patients perceive low energy discharges as painful and cannot distinguish between shocks of 0.4 and 2 J. The results suggest that ICD systems developed to treat atrial tachyarrhythmias should minimize the number of shocks delivered to terminate an atrial tachyarrhythmia episode. The majority of the patients tolerated low energy shocks provided the discharges are infrequent (once per month).

  16. European national strategies to move towards very low energy buildings

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Thomsen, Kirsten Engelund

    high energy performance. It is important to stress the need for MS to introduce a national or regional definition of very low energy buildings in their building regulation and to develop a national strategy towards this level of energy performance to become the standard. This market transformation...... the ambition in the EU Action plan - to develop an EU strategy towards very low energy houses. The current recast of the EPBD is an opportunity, which must not be missed to introduce the requirement to MS to define very low energy buildings and a national strategy towards this level of energy performance....... A strategy for improved energy efficiency of existing buildings is a necessity if the energy consumption is to be reduced significantly over a limited period of time. The life time of buildings ranges from 50 to 100 years and improvement of the existing building stock will thus have much higher impact than...

  17. Coulomb and Nuclear Breakup at Low Energies: Scaling Laws

    Directory of Open Access Journals (Sweden)

    Hussein M. S.

    2013-12-01

    Full Text Available We report on a recent work on the low-energy behavior of the breakup cross section in so far as it has important role in the fusion of weakly bound and halo nuclei at near-barrier energies. We assess the way the nuclear component of this cross section scales with the target mass. In complete accord with previous finding at higher energies we verify that the low energy behavior of the breakup cross section for a given projectile and relative center of mass energy with respect to the Coulomb barrier height scales as the cubic root of the mass number of the target. Surprisingly we find that the Coulomb component of the breakup cross section at these low energies also obeys scaling, but with a linear dependence on the target charge. Our findings are important when planning for experiments involving these exotic nuclei.

  18. Electric and Magnetic Dipole Strength at Low Energy

    Science.gov (United States)

    Sieja, K.

    2017-08-01

    A low-energy enhancement of radiative strength functions was deduced from recent experiments in several mass regions of nuclei, which is believed to impact considerably the calculated neutron capture rates. In this Letter we investigate the behavior of the low-energy γ -ray strength of the Sc 44 isotope, for the first time taking into account both electric and magnetic dipole contributions obtained coherently in the same theoretical approach. The calculations are performed using the large-scale shell-model framework in a full 1 ℏω s d -p f -g d s model space. Our results corroborate previous theoretical findings for the low-energy enhancement of the M 1 strength but show quite different behavior for the E 1 strength.

  19. A calculation of Zsub(eff) for low-energy positron-hydrogen-molecule scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Baker, D.J.

    1985-01-01

    The value of Zsub(eff), the effective number of electrons per molecule available to the positron for annihilation, is calculated for low-energy positron-hydrogen-molecule scattering using the scattering wavefunctions obtained in recent detailed ab initio calculations. The results are higher than those obtained in previous calculations but much lower than the experimental value. (author)

  20. Literature Review of Data on the Incremental Costs to Design and Build Low-Energy Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, W. D.

    2008-05-14

    This document summarizes findings from a literature review into the incremental costs associated with low-energy buildings. The goal of this work is to help establish as firm an analytical foundation as possible for the Building Technology Program's cost-effective net-zero energy goal in the year 2025.

  1. Transport of low energy electrons in water and some physico-chemical implications

    International Nuclear Information System (INIS)

    Brenner, D.J.; Zaider, M.

    1983-01-01

    Considerable effort by numerous groups is currently being devoted to measuring or calculating cross-sections for use as input to Monte-Carlo studies of radiation effects. We address the question of how well do low-energy cross-sections need to be known in order to calculate adequately quantities of interest in the radiobiological domain. 11 references, 4 figures

  2. Influence of compaction and surface roughness on low-energy ion scattering signals

    NARCIS (Netherlands)

    Jansen, W.P.A.; Knoester, A.; Maas, A.J.H.; Schmit, P.; Kytökivi, A.; Denier van der Gon, A.W.; Brongersma, H.H.

    2004-01-01

    Investigation of the surface composition of powders often requires compaction. To study the effect of compaction on surface analysis, samples have been compacted at various pressures ranging from 0 Pa (i.e. no compaction) up to 2000 MPa (2 × 104 kg cm-2) Low-energy ion scattering (LEIS) was used to

  3. Influence of trace elements in human tissue in low-energy photon brachytherapy dosimetry

    International Nuclear Information System (INIS)

    White, Shane A; Landry, Guillaume; Van Gils, Francis; Verhaegen, Frank; Reniers, Brigitte

    2012-01-01

    The aim of this paper is to determine the dosimetric impact of trace elements in human tissues for low-energy photon sources used in brachytherapy. Monte Carlo dose calculations were used to investigate the dosimetric effect of trace elements present in normal or cancerous human tissues. The effect of individual traces (atomic number Z = 11–30) was studied in soft tissue irradiated by low-energy brachytherapy sources. Three other tissue types (prostate, adipose and mammary gland) were also simulated with varying trace concentrations to quantify the contribution of each trace to the dose distribution. The dose differences between cancerous and healthy prostate tissues were calculated in single- and multi-source geometries. The presence of traces in a tissue produces a difference in the dose distribution that is dependent on Z and the concentration of the trace. Low-Z traces (Na) have a negligible effect ( 3%). There is a potentially significant difference in the dose distribution between cancerous and healthy prostate tissues (4%) and even larger if compared to the trace-free composition (15%) in both single- and multi-sourced geometries. Trace elements have a non-negligible (up to 8% in prostate D 90 ) effect on the dose in tissues irradiated with low-energy photon sources. This study underlines the need for further investigation into accurate determination of the trace composition of tissues associated with low-energy brachytherapy. Alternatively, trace elements could be incorporated as a source of uncertainty in dose calculations. (paper)

  4. Silicon passivation study under low energy electron irradiation conditions

    International Nuclear Information System (INIS)

    Cluzel, R.

    2010-01-01

    Backside illuminated thinned CMOS (Complementary Metal Oxide Semiconductor) imaging system is a technology developed to increase the signal to noise ratio and the sensibility of such sensors. This configuration is adapted to the electrons detection from the energy range of [1 - 12 keV]. The impinging electron creates by multiplication several hundreds of secondary electrons close to the surface. A P ++ highly-doped passivation layer of the rear face is required to reduce the secondary electron surface recombination rate. Thanks to the potential barrier induced by the P ++ layer, the passivation layer increases the collected charges number and so the sensor collection gain. The goal of this study is to develop some experimental methods in order to determine the effect of six different passivation processes on the collection gain. Beforehand, the energy profile deposited by an incident electron is studied with the combination of Monte-Carlo simulations and some analytical calculations. The final collection gain model shows that the mirror effect from the passivation layer is a key factor at high energies whereas the passivation layer has to be as thin as possible at low energies. A first experimental setup which consists in irradiating P ++ /N large diodes allows to study the passivation process impacts on the surface recombinations. Thanks to a second setup based on a single event upset directly on thinned CMOS sensor, passivation techniques are discriminated in term of mirror effect and the implied spreading charges. The doping atoms activation laser annealing is turn out to be a multiplication gain inhomogeneity source impacting directly the matrix uniformity. (author)

  5. Electron polarimetry at low energies in Hall C at JLab

    International Nuclear Information System (INIS)

    Gaskell, D.

    2013-01-01

    Although the majority of Jefferson Lab experiments require multi-GeV electron beams, there have been a few opportunities to make electron beam polarization measurements at rather low energies. This proceedings will discuss some of the practical difficulties encountered in performing electron polarimetry via Mo/ller scattering at energies on the order of a few hundred MeV. Prospects for Compton polarimetry at very low energies will also be discussed. While Mo/ller scattering is likely the preferred method for electron polarimetry at energies below 500 MeV, there are certain aspects of the polarimeter and experiment design that must be carefully considered

  6. A facility for low energy charged particle induced reaction studies

    International Nuclear Information System (INIS)

    Vilaithong, T.; Singkarat, S.; Yu, L.D.; Intarasiri, S.; Tippawan, U.

    2000-01-01

    In Chiang Mai, a highly stable low energy ion accelerator (0 - 350 kV) facility is being established. A subnano-second pulsing system will be incorporated into the beam transport line. The detecting system will consist of a time-of-flight charged particle spectrometer and a high resolution gamma-ray system. The new facility will be used in the studies of low energy heavy ion backscattering and charged particle induced cross section measurement in the interests of material characterization and nucleosynthesis. (author)

  7. Scattering of polarized low-energy electrons by ferromagnetic metals

    International Nuclear Information System (INIS)

    Helman, J.S.

    1981-01-01

    A source of spin polarized electrons with remarkable characteristics based on negative electron affinity (NEA) GaAs has recently been developed. It constitutes a unique tool to investigate spin dependent interactions in electron scattering processes. The characteristics and working principles of the source are briefly described. Some theoretical aspects of the scattering of polarized low-energy electrons by ferromagnetic metals are discussed. Finally, the results of the first polarized low-energy electron diffraction experiment using the NEA GaAs source are reviewed; they give information about the surface magnetization of ferromagnetic Ni (110). (Author) [pt

  8. Very low energy scanning electron microscopy in nanotechnology

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Hovorka, Miloš; Mika, Filip; Mikmeková, Eliška; Mikmeková, Šárka; Pokorná, Zuzana; Frank, Luděk

    2012-01-01

    Roč. 9, 8/9 (2012), s. 695-716 ISSN 1475-7435 R&D Projects: GA MŠk OE08012; GA MŠk ED0017/01/01; GA AV ČR IAA100650902 Institutional research plan: CEZ:AV0Z20650511 Keywords : scanning electron microscopy * very low energy electrons * cathode lens * grain contrast * strain contrast * imaging of participates * dopant contrast * very low energy STEM * graphene Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.087, year: 2012

  9. Obervations of low energy magnetospheric plasma outside the plasmasphere

    International Nuclear Information System (INIS)

    Hultqvist, B.

    1985-01-01

    After some introductory discussions about morphological concepts and limitations of various measurement techniques, existing low energy plasma data, orginating primarily from the GEOS, Dynamics Explorer, and Prognoz spacecraft, is described and discussed. The plasmasphere measurements are not included (but for some observations of plasmasphere refilling). It is finally concluded that we are very far from a complete picture of the low-energy plasma component in the magnetosphere and that this problem has to be given high priority in planning payloads of future space plasma physics missions. (Author)

  10. Progress on a spherical TPC for low energy neutrino detection

    International Nuclear Information System (INIS)

    Aune, S; Colas, P; Deschamps, H; Dolbeau, J; Fanourakis, G; Ribas, E Ferrer; Enqvist, T; Geralis, T; Giomataris, Y; Gorodetzky, P; Gounaris, G J; Gros, M; Irastorza, I G; Kousouris, K; Lepeltier, V; Morales, J; Patzak, T; Paschos, E A; Salin, P; Savvidis, I; Vergados, J D

    2006-01-01

    The new concept of the spherical TPC aims at relatively large target masses with low threshold and background, keeping an extremely simple and robust operation. Such a device would open the way to detect the neutrino-nucleus interaction, which, although a standard process, remains undetected due to the low energy of the neutrino-induced nuclear recoils. The progress in the development of the first 1 m 3 prototype at Saclay is presented. Other physics goals of such a device could include supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino, among others

  11. Universality in low energy three-body systems

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Tomio, L; Frederico, T.

    1997-01-01

    The renormalizability of the quantum theory of non-relativistic three-body system with zero range interaction, warranties that all the low-energy three-body properties are well defined and the low-energy two-body and only one three-body physical information are known. Considering this observation, we have shown that the conditions for the occurrence of Efimov states can be easily reached with any model of short range potential where the three-body ground state and the corresponding binding energy of the subsystems are kept fixed. This approach was applied to the recently discovered halo nuclei. (author)

  12. Ultra-low-energy wide electron exposure unit

    International Nuclear Information System (INIS)

    Yonago, Akinobu; Oono, Yukihiko; Tokunaga, Kazutoshi; Kishimoto, Junichi; Wakamoto, Ikuo

    2001-01-01

    Heat and ultraviolet ray processes are used in surface dryness of paint, surface treatment of construction materials and surface sterilization of food containers. A process using a low-energy wide-area electron beam (EB) has been developed that features high speed and low drive cost. EB processing is not widespread in general industry, however, due to high equipment cost and difficult maintenance. We developed an ultra-low-energy wide-area electron beam exposure unit, the Mitsubishi Wide Electron Exposure Unit (MIWEL) to solve these problems. (author)

  13. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  14. Occupant Experiences and Satisfaction with New Low-Energy Houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Thomsen, Kirsten Engelund; Mørck, Ove

    2013-01-01

    -energy houses that meet the future lower energy requirements of the planned Danish Building Regulations 2015. The purpose was to study experiences and satisfaction among occupants living in new low-energy houses. It included i.a. overall satisfaction, perceived indoor climate and experiences and satisfaction...... be addressed in order to make low-energy houses attractive to ordinary people. Occupants experienced among other things noise from the technical installations and that it was too hot in summer and too cold in winter, that there were a series of problems with the technical installations and that their use...

  15. Leptogenesis and low energy CP-violation in neutrino physics

    International Nuclear Information System (INIS)

    Pascoli, S.; Petcov, S.T.; Riotto, A.

    2007-01-01

    Taking into account the recent progress in the understanding of the lepton flavor effects in leptogenesis, we investigate in detail the possibility that the CP-violation necessary for the generation of the baryon asymmetry of the Universe is due exclusively to the Dirac and/or Majorana CP-violating phases in the PMNS neutrino mixing matrix U, and thus is directly related to the low energy CP-violation in the lepton sector (e.g., in neutrino oscillations, etc.). We first derive the conditions of CP-invariance of the neutrino Yukawa couplings λ in the see-saw Lagrangian, and of the complex orthogonal matrix R in the 'orthogonal' parametrization of λ. We show, e.g. that under certain conditions (i) real R and specific CP-conserving values of the Majorana and Dirac phases can imply CP-violation, and (ii) purely imaginary R does not necessarily imply breaking of CP-symmetry. We study in detail the case of hierarchical heavy Majorana neutrino mass spectrum, presenting results for three possible types of light neutrino mass spectrum: (i) normal hierarchical, (ii) inverted hierarchical, and (iii) quasi-degenerate. Results in the alternative case of quasi-degenerate in mass heavy Majorana neutrinos, are also derived. The minimal supersymmetric extension of the standard theory with right-handed Majorana neutrinos and see-saw mechanism of neutrino mass generation is discussed as well. We illustrate the possible correlations between the baryon asymmetry of the Universe and (i) the rephasing invariant J CP controlling the magnitude of CP-violation in neutrino oscillations, or (ii) the effective Majorana mass in neutrinoless double beta decay, in the cases when the only source of CP-violation is respectively the Dirac or the Majorana phases in the neutrino mixing matrix

  16. Role of disorder in the multi-critical region of d-wave superconductivity and antiferromagnetism

    International Nuclear Information System (INIS)

    Yanase, Youichi; Ogata, Masao

    2007-01-01

    We investigate the disorder-induced microscopic inhomogeneity in the multi-critical region of d-wave superconductivity and antiferromagnetism on the basis of the microscopic t-t ' -U-V model. We find that a small amount of point disorder induces the nano-scale inhomogeneity of spin and superconducting fluctuations when the coherence length of superconductivity is remarkably short as in the under-doped cuprates. Then, the two fluctuations spatially segregate to avoid their competition. We show the remarkable electron-hole asymmetry in high-T c cuprates where the quite different spatial structure is expected in the electron-doped materials

  17. THE PRODUCTION OF LOW-ENERGY NEUTRONS IN SOLAR FLARES AND THE IMPORTANCE OF THEIR DETECTION IN THE INNER HELIOSPHERE

    International Nuclear Information System (INIS)

    Murphy, R. J.; Kozlovsky, B.; Share, G. H.

    2012-01-01

    Neutron detectors on spacecraft in the inner heliosphere can observe the low-energy ( ion –1 ) most important for producing low-energy neutrons from these reactions. We calculate escaping-neutron spectra and neutron-capture line yields from ions propagating in a magnetic loop with various kinetic-energy spectra. This study provides the basis for planning inner-heliospheric missions having a low-energy neutron detector. The MESSENGER spacecraft orbiting Mercury has such a detector. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observation of both neutrons and gamma rays with detectors of comparable sensitivity. We find that the neutron-capture line fluence at 1 AU is comparable to the 1-10 MeV neutron fluence at 0.5 AU, and therefore as effective for revealing low-energy ion acceleration. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux allows exploration of ion acceleration in weak flares not previously observable and may reveal acceleration at other sites not previously detected where low-energy neutrons could be the only high-energy signature of ion acceleration. Also, a measurement of the low-energy neutron spectrum will provide important information about the accelerated-ion spectrum that is not available from the capture line fluence measurement alone.

  18. Charge-coupled device area detector for low energy electrons

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    2003-01-01

    Roč. 74, č. 7 (2003), s. 3379 - 3384 ISSN 0034-6748 R&D Projects: GA ČR GA102/00/P001 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy electrons * charged-coupled device * detector Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.343, year: 2003

  19. Utilization of low-energy electron accelerators in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2003-02-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  20. Corrosion behavior of low energy, high temperature nitrogen ion ...

    Indian Academy of Sciences (India)

    Corrosion behavior of low energy, high temperature nitrogen ion-implanted AISI 304 stainless steel. M GHORANNEVISS1, A SHOKOUHY1,∗, M M LARIJANI1,2,. S H HAJI HOSSEINI 1, M YARI1, A ANVARI4, M GHOLIPUR SHAHRAKI1,3,. A H SARI1 and M R HANTEHZADEH1. 1Plasma Physics Research Center, Science ...

  1. Acceleration of low energy charged particles by gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Voyatzis, G. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)]. E-mail: voyatzis@auth.gr; Vlahos, L. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Ichtiaroglou, S. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Papadopoulos, D. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)

    2006-04-03

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

  2. Acceleration of low energy charged particles by gravitational waves

    International Nuclear Information System (INIS)

    Voyatzis, G.; Vlahos, L.; Ichtiaroglou, S.; Papadopoulos, D.

    2006-01-01

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state

  3. Low energy supersymmetric models for several generations and proton decay

    International Nuclear Information System (INIS)

    Deo, B.B.; Sarkar, U.

    1983-08-01

    It is found that by invoking additional horizontal gauge symmetries required to explain the generational structure the low energy standard supersymmetric unified theories avoid the renormalizable unsuppressed baryon number violating interactions in a natural way. Theories considered here are anomaly-free by construction. (author)

  4. Low energy house in existing buildings; Niedrigenergiehaus im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Sahner, G. [BDA, Stuttgart/Augsburg (Germany)

    2008-07-01

    Presented is an energetic sanitation of residential units in the frame of a German pilot program (''low energy houses in the existing building sector'') initiated by the ministry of traffic, civil engineering and city development. (GL)

  5. Chiral symmetry and nucleon structure: Low energy aspects

    International Nuclear Information System (INIS)

    Weise, W.

    1989-01-01

    The symmetries and currents of QCD at low energy and long wavelength are realized in the form of mesons, rather than quarks and gluons. In this talk I summarize the merits, but also the limits, of chiral non-linear meson theories and their soliton solutions, in descriptions of nucleon structure and the nucleon-nucleon interaction. (orig.)

  6. Low-energy cosmic rays in the Orion region

    DEFF Research Database (Denmark)

    Pohl, M.

    1998-01-01

    The recently observed nuclear gamma-ray line emission from the Orion complex implies a high flux of low-energy cosmic rays (LECR) with unusual abundance. This cosmic ray component would dominate the energy density, pressure, and ionising power of cosmic rays, and thus would have a strong impact...

  7. Overview of the low energy accelerator scanning system

    International Nuclear Information System (INIS)

    Leo Kwee Wah; Lojius Lombigit; Muhamad Zahidee Taat; Abu Bakar Ghazali; Mohd Rizal Ibrahim; Mohd Rizal Chulan Md Chulan; Azaman Ahmad; Abdul Halim Baijan; Rokiah Mohd Sabri

    2009-01-01

    This paper describes the specification of the low energy accelerator (Baby-EBM; Electron Beam Machine) scanning system. It comprises a discussion of coil inductance measurement, power supply design and the test results. The scanning horn system was completely assembled and tested; it was found that the system is able to scan the beam across the scanning window with a required beam profile. (Author)

  8. Low-energy nuclear reactions with double-solenoid

    Indian Academy of Sciences (India)

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems ...

  9. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  10. MEIC Proton Beam Formation with a Low Energy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  11. Low-energy properties of fractional helical Luttinger liquids

    NARCIS (Netherlands)

    Meng, T.; Fritz, L.|info:eu-repo/dai/nl/371569559; Schuricht, D.|info:eu-repo/dai/nl/369284690; Loss, D.

    2014-01-01

    We investigate the low-energy properties of (quasi) helical and fractional helical Luttinger liquids. In particular, we calculate the Drude peak of the optical conductivity, the density of states, as well as charge transport properties of the interacting system with and without attached Fermi liquid

  12. Utilization of low-energy electron accelerators in Korea

    International Nuclear Information System (INIS)

    Lee, Byung Cheol

    2003-01-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  13. Elastic scattering of low energy γ-rays

    International Nuclear Information System (INIS)

    Whittingham, I.B.

    1978-01-01

    The current status of the theory of the elastic scattering of low energy γ rays is reviewed and a detailed analysis of the theoretical background to the recent calculation of Rayleigh scattering by W.R.Johnson and co-workers is presented

  14. Characterization of low energy radioactive beams using direct reactions

    DEFF Research Database (Denmark)

    Johansen, J.G.; Fraser, M.A.; Bildstein, V.

    2013-01-01

    We demonstrate a new technique to determine the beam structure of low energy radioactive beams using coincidence events from a direct reaction. The technique will be described and tested using Geant4 simulations. We use the technique to determine for the first time the width, divergence and energy...

  15. Low-energy positron beams - origins, developments and applications

    International Nuclear Information System (INIS)

    Beling, C.D.; Charlton, M.

    1987-01-01

    Over the last 15 years there have been rapid advances in the technology associated with low-energy positron beams. The origins of these advances, and some of the major developments, are discussed. Some applications from the diverse fields of surface physics, atomic scattering and positronium studies are highlighted. (author)

  16. Performance of the Low-energy House in Sisimiut

    DEFF Research Database (Denmark)

    Rode, Carsten; Kragh, Jesper; Borchersen, Egil

    2009-01-01

    A low-energy house was built in Sisimiut, Greenland in 2004-05 and since its inauguration in April 2005, its performance and operation have been object of study for researchers and students. The house is characterised by a highly insulated building envelope, advanced windows and a ventilation sys...

  17. QCD at low energy: a many-body approach

    International Nuclear Information System (INIS)

    Yépez-Martínez, T; Hess, P O; Lerma, S; Szczepaniak, A; Civitarese, O

    2011-01-01

    A review is given on recent results in the treatment of an arbitrary number of orbital levels in low energy QCD. For the pure quark part, analytic results for the dominant part of the Hamiltonian are presented. Possible extensions, including dynamic gluons, are discussed.

  18. Layout of the LER [Low Energy Ring] Arc

    International Nuclear Information System (INIS)

    Hutton, A.

    1990-01-01

    We have recently been trying to accumulate all of the information necessary to decide on the layout of the regular curved arcs of the Low Energy Ring (LER) and there have been several ABC Notes published on different aspects of the problem. This note will describe the layout that has been derived from these considerations

  19. Low energy quasi free scattering on nuclear surface

    Energy Technology Data Exchange (ETDEWEB)

    Shiyuan, S.

    1983-05-01

    The result of RGM calculation of low energy /sup 3/He(n, n)/sup 3/ He total elastic cross section does not agree well with experimental data for E/sub n/<1 MeV. This discrepancy can be improved by assuming lwo energy quasi-free scattering of particles beyond the nuclear surface.

  20. Working group report: Low energy and flavour physics

    Indian Academy of Sciences (India)

    This is a report of the low energy and flavour physics working group at ... that calculates the non-leptonic decay amplitudes including the long-distance con- tributions. There were three lectures that lasted for over seven hours, and were.

  1. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

  2. Reactions induced by low energy electrons in cryogenic films

    International Nuclear Information System (INIS)

    Bass, A.D.; Sanche, L.

    2003-01-01

    We review recent research on reactions (including dissociation) initiated by low-energy electron bombardment of monolayer and multilayer molecular solids at cryogenic temperatures. With incident electrons of energies below 20 eV, dissociation is observed by the electron stimulated desorption (ESD) of anions from target films and is attributed to the processes of dissociative electron attachment (DEA) and to dipolar dissociation. It is shown that DEA to condensed molecules is sensitive to environmental factors such as the identity of co-adsorbed species and film morphology. The effects of image-charge induced polarization on cross-sections for DEA to CH3Cl are also discussed. Taking as examples, the electron-induced production of CO within multilayer films of methanol and acetone, it is shown that the detection of electronic excited states by high resolution electron energy loss spectroscopy can be used to monitor electron beam damage. In particular, the incident energy dependence of the CO indicates that below 19 eV, dissociation proceeds via the decay of transient negative ions (TNI) into electronically excited dissociative states. The electron induced dissociation of biomolecular targets is also considered, taking as examples the ribose analog tetrahydrofuran and DNA bases adenine and thymine, cytosine and guanine. The ESD of anions from such films also show dissociation via the formation of TNI. In multilayer molecular solids, fragment species resulting from dissociation, may react with neighboring molecules, as is demonstrated in anion ESD measurements from films containing O 2 and various hydrocarbon molecules. X-ray photoelectron spectroscopy measurements reported for electron irradiated monolayers of H 2 O and CF 4 on a Si - H passivated surface further show that DEA is an important initial step in the electron-induced chemisorption of fragment species

  3. Vibrational excitation of D2 by low energy electrons

    International Nuclear Information System (INIS)

    Buckman, S.J.; Phelps, A.V.

    1985-01-01

    Excitation coefficients for the production of vibrationally exicted D 2 by low energy electrons have been determined from measurements of the intensity of infrared emission from mixtures of D 2 and small concentrations of CO 2 or CO. The measurements were made using the electron drift tube technique and covered electric field to gas density ratios (E/n) from (5 to 80) x 10 -21 V m 2 , corresponding to mean electron energies between 0.45 and 4.5 eV. The CO 2 and CO concentrations were chosen to allow efficient excitation transfer from the D 2 to the carbon containing molecule, but to minimize direct excitation of the CO 2 or CO. The measured infrared intensities were normalized to predicted values for N 2 --CO 2 and N 2 --CO mixtures at E/n where the efficiency of vibrational excitation is known to be very close to 100%. The experimental excitation coefficients are in satisfactory agreement with predictions based on electron--D 2 cross sections at mean electron energies below 1 eV, but are about 50% too high at mean energies above about 2 eV. Application of the technique to H 2 did not yield useful vibrational excitation coefficients. The effective coefficients in H 2 --CO 2 mixtures were a factor of about 3 times the predicted values. For our H 2 --CO mixtures the excitation of CO via excitation transfer from H 2 is small compared to direct electron excitation of CO molecules. Published experiments and theories on electron--H 2 and electron--D 2 collisions are reviewed to obtain the cross sections used in the predictions

  4. Detectors for low energy electron cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, F. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-15

    Low-energy operation of RHIC is of particular interest to study the location of a possible critical point in the QCD phase diagram. The performance of RHIC at energies equal to or lower than 10 GV/nucleon is limited by nonlinearities, Intra-BeamScattering (IBS) processes and space-charge effects. To successfully address the luminosity and ion store lifetime limitations imposed by IBS, the method of electron cooling has been envisaged. During electron cooling processes electrons are injected along with the ion beam at the nominal ion bunch velocities. The velocity spread of the ion beam is reduced in all planes through Coulomb interactions between the cold electron beam and the ion beam. The electron cooling system proposed for RHIC will be the first of its kind to use bunched beams for the delivery of the electron bunches, and will therefore be accompanied by the necessary challenges. The designed electron cooler will be located in IP2. The electron bunches will be accelerated by a linac before being injected along side the ion beams. Thirty consecutive electron bunches will be injected to overlap with a single ion bunch. They will first cool the yellow beam before being extracted, turned by 180-degrees, and reinjected into the blue beam for cooling. As such, both the yellow and blue beams will be cooled by the same ion bunches. This will pose considerable challenges to ensure proper electron beam quality to cool the second ion beam. Furthermore, no ondulator will be used in the electron cooler so radiative recombination between the ions and the electrons will occur.

  5. Low-energy ion beam extraction and transport: Experiment--computer comparison

    International Nuclear Information System (INIS)

    Spaedtke, P.; Brown, I.; Fojas, P.

    1994-01-01

    Ion beam formation at low energy (∼1 keV or so) is more difficult to accomplish than at high energy because of beam blowup by space-charge forces in the uncompensated region within the extractor, an effect which is yet more pronounced for heavy ions and for high beam current density. For the same reasons, the extracted ion beam is more strongly subject to space charge blowup than higher energy beams if it is not space-charge neutralized to a high degree. A version of vacuum arc ion source with an extractor that produces low-energy metal ion beams at relatively high current (∼0.5--10 kV at up to ∼100 mA) using a multi-aperture, accel--decel extractor configuration has been created. The experimentally observed beam extraction characteristics of this source is compared with those predicted using the AXCEL-INP code, and the implied downstream beam transport with theoretical expectations. It is concluded that the low-energy extractor performance is in reasonable agreement with the code, and that good downstream space charge neutralization is obtained. Here, the code and the experimental results are described, and the features that contribute to good low-energy performance are discussed

  6. The low-energy constants of the extended linear sigma model

    Energy Technology Data Exchange (ETDEWEB)

    Divotgey, Florian; Giacosa, Francesco; Kovacs, Peter; Rischke, Dirk H. [Institut fuer Theoretische Physik, Goethe-Universitaet Frankfurt am Main (Germany)

    2016-07-01

    The low-energy dynamics of Quantum Chromodynamics (QCD) is fully determined by the interactions of the (pseudo-) Nambu-Goldstone bosons of spontaneous chiral symmetry breaking, i.e., for two quark flavors, the pions. Pion dynamics is described by the low-energy effective theory of QCD, chiral perturbation theory (ChPT), which is based on the nonlinear realization of chiral symmetry. An alternative description is provided by the Linear Sigma Model, where chiral symmetry is linearly realized. An extended version of this model, the so-called extended Linear Sigma Model (eLSM) was recently developed which incorporates all J{sup P}=0{sup ±}, 1{sup ±} anti qq mesons up to 2 GeV in mass. A fit of the coupling constants of this model to experimentally measured masses and decay widths has a surprisingly good quality. In this talk, it is demonstrated that the low-energy limit of the eLSM, obtained by integrating out all fields which are heavier than the pions, assumes the same form as ChPT. Moreover, the low-energy constants (LECs) of the eLSM agree with those of ChPT.

  7. Equations for collective modes spectrum in a mixed d-wave state of unconventional superconductors

    International Nuclear Information System (INIS)

    Lee, C.Y.

    2004-01-01

    Direct observation of the collective modes in unconventional superconductors (USC) by microwave impedance technique experiments has made the very important study of the collective excitations in these systems. One of the problem is still the exact form of the order parameter of unconventional superconductors. Among the possibilities there are extended s-wave pairing, mixture of s- and d-states, as well as of different d-wave states. I consider the mixed (1-γ)d x 2 -y 2 +iγd xy state in high temperature superconductors (HTSC) and derive for the first time a full set of equations for collective modes spectrum in mixed d-wave state with arbitrary admixture of d xy state. Obtained results allow to calculate the whole collective mode spectrum, which could be used for interpretation of the sound attenuation and microwave absorption data as well as for identification of the type of pairing and order parameter in unconventional superconductors. In particular, they allow to estimate the extent of admixture of d xy state in a possible mixed state

  8. Method of distinction of pure d-wave state from the mixed state in HTSC

    International Nuclear Information System (INIS)

    Filatova, Tatiana; Brusov, Peter; Brusov, Pavel; Lee, Chong; Chaudhury, Ranjan

    2009-01-01

    Direct observation of the collective modes in unconventional superconductors (USC) by microwave impedance technique experiments has made the study of the collective excitations in these systems very important. One remaining question is the exact form of the order parameter of unconventional superconductors. Extended s-wave pairing, mixture of s- and d-states, as well as of different d-wave states are among possibilities. We have considered the mixtures of d x 2 - y 2 and d xy states in high temperature superconductors (HTSC) and have, for the first time, derived the full set of equations for the collective mode spectrum in the mixed d-wave state with an arbitrary admixture of d xy state. The results we have obtained will allow us to calculate the whole collective mode spectrum, which may then be used for interpretation of sound attenuation and microwave absorption data as well as for identification of the type of pairing and order parameter in unconventional superconductors. In particular, this will allow one to estimate the extent of admixture of d xy state in the possible mixed state.

  9. Dynamical cluster approximation plus semiclassical approximation study for a Mott insulator and d-wave pairing

    Science.gov (United States)

    Kim, SungKun; Lee, Hunpyo

    2017-06-01

    Via a dynamical cluster approximation with N c = 4 in combination with a semiclassical approximation (DCA+SCA), we study the doped two-dimensional Hubbard model. We obtain a plaquette antiferromagnetic (AF) Mott insulator, a plaquette AF ordered metal, a pseudogap (or d-wave superconductor) and a paramagnetic metal by tuning the doping concentration. These features are similar to the behaviors observed in copper-oxide superconductors and are in qualitative agreement with the results calculated by the cluster dynamical mean field theory with the continuous-time quantum Monte Carlo (CDMFT+CTQMC) approach. The results of our DCA+SCA differ from those of the CDMFT+CTQMC approach in that the d-wave superconducting order parameters are shown even in the high doped region, unlike the results of the CDMFT+CTQMC approach. We think that the strong plaquette AF orderings in the dynamical cluster approximation (DCA) with N c = 4 suppress superconducting states with increasing doping up to strongly doped region, because frozen dynamical fluctuations in a semiclassical approximation (SCA) approach are unable to destroy those orderings. Our calculation with short-range spatial fluctuations is initial research, because the SCA can manage long-range spatial fluctuations in feasible computational times beyond the CDMFT+CTQMC tool. We believe that our future DCA+SCA calculations should supply information on the fully momentum-resolved physical properties, which could be compared with the results measured by angle-resolved photoemission spectroscopy experiments.

  10. Effect of low energy diet for eight weeks to adults with overweight or obesity on folate, retinol, vitamin B12, D and e status and the degree of inflammation: a post hoc analysis of a randomized intervention trial

    DEFF Research Database (Denmark)

    Geiker, Nina Rica Wium; Veller, Mette; Kjoelbaek, Louise

    2018-01-01

    Background: Obesity is associated with vitamin insufficiency and low grade inflammation. The purpose of this study was to investigate the effect of weight loss on folate, retinol, vitamin B12, D and E status and the degree of inflammation. Methods: Out of 110, 85 individuals (75% women) aged 39...

  11. An improved theoretical value for Zsub(eff) for low-energy positron-hydrogen-molecule scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Baker, D.J.

    1986-01-01

    The value of Zsub(eff), the effective number of electrons per molecule available to the positron for annihilation, is calculated for low-energy positron-hydrogen-molecule scattering using a scattering wavefunction containing terms in which the positron-electron distance is included linearly as a factor. The results at very low energy are much closer to the experimental value than any that have been obtained previously. (author)

  12. Performance of room temperature mercuric iodide (HgI2) detectors in the ultra low energy x-ray region

    International Nuclear Information System (INIS)

    Dabrowski, A.J.; Iwanczyk, J.S.; Barton, J.B.; Huth, G.C.; Whited, R.; Ortale, C.; Economou, T.E.; Turkevich, A.L.

    1980-01-01

    Performance of room temperature mercuric iodide x-ray spectrometers has been recently improved through new fabrication techniques and further development of low noise associated electronic systems. This progress has extended the range of measurements to the ultra low energy x-ray region at room temperature. This paper reports the study of the effect of contact material on the performance of HgI 2 detectors in the low energy x-ray region

  13. Formation of nanostructures on HOPG surface in presence of surfactant atom during low energy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan, M., E-mail: ranjanm@ipr.res.in; Joshi, P.; Mukherjee, S.

    2016-07-15

    Low energy ions beam often develop periodic patterns on surfaces under normal or off-normal incidence. Formation of such periodic patterns depends on the substrate material, the ion beam parameters, and the processing conditions. Processing conditions introduce unwanted contaminant atoms, which also play strong role in pattern formation by changing the effective sputtering yield of the material. In this work we have analysed the effect of Cu, Fe and Al impurities introduced during low energy Ar{sup +} ion irradiation on HOPG substrate. It is observed that by changing the species of foreign atoms the surface topography changes drastically. The observed surface topography is co-related with the modified sputtering yield of HOPG. Presence of Cu and Fe amplify the effective sputtering yield of HOPG, so that the required threshold for the pattern formation is achieved with the given fluence, whereas Al does not lead to any significant change in the effective yield and hence no pattern formation occurs.

  14. Effect of low energy diet for eight weeks to adults with overweight or obesity on folate, retinol, vitamin B12, D and e status and the degree of inflammation: a post hoc analysis of a randomized intervention trial

    DEFF Research Database (Denmark)

    Geiker, Nina Rica Wium; Veller, Mette; Kjoelbaek, Louise

    2018-01-01

    Background: Obesity is associated with vitamin insufficiency and low grade inflammation. The purpose of this study was to investigate the effect of weight loss on folate, retinol, vitamin B12, D and E status and the degree of inflammation. Methods: Out of 110, 85 individuals (75% women) aged 39...... in folate, 13% in vitamin B12, 2% in retinol, 28% in vitamin D (72% were insufficient in vitamin D), and none were deficient in vitamin E. At baseline, BMI was inversely associated with retinol (P ... were positively associated with CRP (P associated with all vitamins but retinol (P

  15. Beyond the EPBD: The low energy residential settlement Borgo Solare

    International Nuclear Information System (INIS)

    Aste, Niccolo; Adhikari, R.S.; Buzzetti, Michela

    2010-01-01

    and technologies the higher initial embodied energy in a low energy building could quickly paid back during its life span. The economic analysis, in the same way, evidences that higher initial investment in case of energy efficient building could become economically convenient during the life span of the building. This kind of analysis is essential to determine the actual sustainability of a building.

  16. A low-energy β-function in a finite super-Yang-Mills model with multiple mass scales

    International Nuclear Information System (INIS)

    Foda, O.; Helayel-Neto, J.A.

    1985-01-01

    We compute the one-loop contribution to the low-energy light-fermion gauge coupling in a finite supersymmetric gauge theory with two mass scales: a heavy mass that breaks an initial N=4 supersymmetry down to N=2, but respects the finiteness, and a light mass that, for simplicity, is set to zero. We find that coupling grows with the mass of the heavy intermediate states. Hence the latter do not decouple at low energies, leading to large logarithms that invalidate low-energy perturbation theory. Consequently, further manipulations are required to obtain a meaningful perturbative expansion. Enforcing decoupling through finite renormalizations, that absorb the heavy mass effects into a redefinition of the parameters of the lagrangian, introduces an arbitrary subtraction mass μ. The requirement that the S-matrix elements be independent of μ leads to a non-trivial renormalization-group equation for the low-energy theory, with a non-vanishing β-function. (orig.)

  17. Low-energy. beta. -function in a finite super-Yang-Mills model with multiple mass scales

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O.; Helayel-Neto, J.A. (International Centre for Theoretical Physics, Trieste (Italy))

    1985-02-14

    We compute the one-loop contribution to the low-energy light-fermion gauge coupling in a finite supersymmetric gauge theory with two mass scales: a heavy mass that breaks an initial N=4 supersymmetry down to N=2, but respects the finiteness, and a light mass that, for simplicity, is set to zero. We find that coupling grows with the mass of the heavy intermediate states. Hence the latter do not decouple at low energies, leading to large logarithms that invalidate low-energy perturbation theory. Consequently, further manipulations are required to obtain a meaningful perturbative expansion. Enforcing decoupling through finite renormalizations, that absorb the heavy mass effects into a redefinition of the parameters of the lagrangian, introduces an arbitrary subtraction mass ..mu... The requirement that the S-matrix elements be independent of ..mu.. leads to a non-trivial renormalization-group equation for the low-energy theory, with a non-vanishing ..beta..-function.

  18. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    International Nuclear Information System (INIS)

    King, F; Kruppi, T; Müller, J; Dörner, R; Schmidt, L Ph H; Schmidt-Böcking, H; Stiebing, K E

    2015-01-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections. (paper)

  19. Radiation processing of liquid with low energy electron accelerator

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2003-01-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

  20. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  1. Low-energy restoration of parity and maximal symmetry

    International Nuclear Information System (INIS)

    Raychaudhuri, A.; Sarkar, U.

    1982-01-01

    The maximal symmetry of fermions of one generation, SU(16), which includes the left-right-symmetric Pati-Salam group, SU(4)/sub c/ x SU(2) /sub L/ x SU(2)/sub R/, as a subgroup, allows the possibility of a low-energy (M/sub R/approx.100 GeV) breaking of the left-right symmetry. It is known that such a low-energy restoration of parity can be consistent with weak-interaction phenomenology. We examine different chains of descent of SU(16) that admit a low value of M/sub R/ and determine the other intermediate symmetry-breaking mass scales associated with each of these chains. These additional mass scales provide an alternative to the ''great desert'' expected in some grand unifying models. The contributions of the Higgs fields in the renormalization-group equations are retained and are found to be important

  2. Experimental nuclear physics research challenges at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E.; Morales G, L. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Murillo O, G. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2010-02-15

    Experimental research with low energy beams of ions (a few MeV) in nuclear physics has gone through a phase transition along its evolution in fifty years because of the increasing complexity (and cost) of the equipment required to conduct meaningful investigations. Many of the small cyclotrons and Van de Graaff (single ended and tandem) accelerators have been used for the last three decades mostly in applications related to the characterization and modification of materials. Specific experimental investigations in nuclear physics with low energy accelerators are proposed in this work. Specifically we discuss the topic of nuclear radii measurements of radioactive species produced via (d,n) reactions. Some emphasis is given to the instrumentation required. (Author)

  3. Si etching with reactive neutral beams of very low energy

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Yasuhiro [Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-chou, Suita, Osaka 565-0871 (Japan); Hamagaki, Manabu; Mise, Takaya [RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan); Iwata, Naotaka; Hara, Tamio [Toyota Technological Institute, 2-12-1 Hisakata, Tenpaku-ku, Nagoya 468-8511 (Japan)

    2014-12-14

    A Si etching process has been investigated with reactive neutral beams (NBs) extracted using a low acceleration voltage of less than 100 V from CF{sub 4} and Ar mixed plasmas. The etched Si profile shows that the etching process is predominantly anisotropic. The reactive NB has a constant Si etching rate in the acceleration voltage range from 20 V to 80 V. It is considered that low-energy NBs can trigger Si etching because F radicals adsorb onto the Si surface and weaken Si–Si bonds. The etching rate per unit beam flux is 33 times higher than that with Ar NB. These results show that the low-energy reactive NB is useful for damage-free high speed Si etching.

  4. Diagnosis and dynamics of low energy electron beams using DIADYN

    International Nuclear Information System (INIS)

    Marghitu, S.; Oproiu, C.; Toader, D.; Ruset, C.; Grigore, E.; Marghitu, O.; Vasiliu, M.

    2008-01-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  5. Diagnosis and dynamics of low energy electron beams using DIADYN

    Energy Technology Data Exchange (ETDEWEB)

    Marghitu, S [Electrostatica, ICPE-CA S.A., Spaiul Unirii 313, Sector 3, RO-74204 Bucharest (Romania); Oproiu, C; Toader, D; Ruset, C; Grigore, E [National Institute for Laser, Plasma and Radiation Physics, PO Box MG-36, 409 Atomistilor Street, RO-76900 Bucharest-Magurele (Romania); Marghitu, O [Institute for Space Sciences, INCDLPFR, PO Box MG-23, RO-76911 Bucharest-Magurele (Romania); Vasiliu, M [Politehnica University, 313 Splaiul Independentei, RO-060032, Bucharest (Romania)

    2008-07-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  6. Low-energy proton increases associated with interplanetary shock waves.

    Science.gov (United States)

    Palmeira, R. A. R.; Allum, F. R.; Rao, U. R.

    1971-01-01

    Impulsive increases in the low energy proton flux observed by the Explorer 34 satellite, in very close time association with geomagnetic storm sudden commencements are described. It is shown that these events are of short duration (20-30 min) and occur only during the decay phase of a solar cosmic-ray flare event. The differential energy spectrum and the angular distribution of the direction of arrival of the particles are discussed. Two similar increases observed far away from the earth by the Pioneer 7 and 8 deep-space probes are also presented. These impulsive increases are compared with Energetic Storm Particle events and their similarities and differences are discussed. A model is suggested to explain these increases, based on the sweeping and trapping of low energy cosmic rays of solar origin by the advancing shock front responsible for the sudden commencement detected on the earth.

  7. Energy performance of the low-energy house in Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Svendsen, Svend

    2005-01-01

    by ventilation heat recovery (90% efficiency) specially designed for arctic conditions, by using thicker insulation in walls (300 mm) and roof/floor (350 mm), and by using solar hot water heating (3250 kWh/year). The building is intended to enhance sustainability in the building sector in Greenland....... energy gain, efficient ventilation system with heat recovery and solar heating. In this paper the results of a calculation of the energy consumption of low-energy house is presented. The calculation was done using the program BSim2002 [1] and a new weather test reference year based on climatic data......The object of the low-energy house in Sisimiut in Greenland was to build a house with an energy consumption less than 80 kWh/m² corresponding to half the energy frame of the coming building code. Therefore the focus in this project has been on large insulation thicknesses, windows with high net...

  8. Challenges in validating radiation sterilization with low energy electron irradiation

    International Nuclear Information System (INIS)

    Miller, A.; Helt-Hansen, J.

    2011-01-01

    Complete text of publication follows. Low energy electron irradiation (80-300 keV) is used increasingly for sterilization or decontamination in connection with isolators for aseptic filling lines in the pharmaceutical industry. It is not defined how validation for this process shall be carried out. A method can be derived from the medical device standard for radiation sterilization, ISO 11137, because the principles described in this standard can be applied to almost any industrial irradiation process. The validations elements are: Process definition, concerning specification of the dose required for the process and the maximum acceptable dose for the product. Installation qualification, concerning acceptance the irradiation facility. Operational qualification, concerning characterization of the facility. Performance qualification, concerning setting up the process. Process control, concerning routine monitoring. The limited penetration of the low energy electrons leads to problems with respect to executing these validation steps. This paper discusses these problems, and shows with examples how they can be solved.

  9. Consumer Unit for Low Energy District Heating Net

    DEFF Research Database (Denmark)

    Paulsen, Otto; Fan, Jianhua; Furbo, Simon

    2008-01-01

    to reduce heat loss in the network. The consumer’s installation is a unit type with an accumulation tank for smoothing the heat load related to the domestic hot water. The building heat load is delivered by an under-floor heating system. The heavy under-floor heating system is assumed to smooth the room...... heat load on a daily basis, having a flow temperature control based on outdoor climate. The unit is designed for a near constant district heating water flow. The paper describes two concepts. The analyses are based on TRNSYS (Klein et al., 2006) simulation, supplied with laboratory verification......A low energy/ low temperature consumer installation is designed and analyzed. The consumer type is a low energy single family house 145 m2 with annual energy consumption in the range of 7000 kWh, incl. domestic hot water in a 2800 degree day climate. The network is an extreme low temperature system...

  10. Low-energy neutral current phenomenology and grand unified theories

    International Nuclear Information System (INIS)

    Del Aguila, F.; Mendez, A.

    1981-01-01

    We derive necessary and sufficient conditions to be satisfied by any expanded electroweak gauge model in order to reproduce the standard model low-energy neutral current predictions. These conditions imply several constraints on the neutral gauge boson masses and the quantum number assignments for the ordinary fermions. Using these conditions, we prove that the popular grand unified theories based on the gauge groups SO(10) and E6 can only accommodate trivial extensions of the standard model. As a consequence, if any of these grand unified models works at some energy scale, present low-energy neutral current phenomenology implies that the Z-boson must be produced with the expected mass and couplings to the ordinary fermions. Any additional neutral gauge boson (with the possible exception of very heavy ones) could only be produced in hadronic collisions and it would not decay in e + e - . (orig.)

  11. The Phobos low energy telescope charged particle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

    1990-05-01

    The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

  12. Comparison Study on Low Energy Physics Model of GEANT4

    International Nuclear Information System (INIS)

    Park, So Hyun; Jung, Won Gyun; Suh, Tae Suk

    2010-01-01

    The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2

  13. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    Science.gov (United States)

    King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.

    2015-11-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.

  14. Negative ions as a source of low energy neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems.

  15. Low energy pion--nucleon and pion--deuteron interactions

    International Nuclear Information System (INIS)

    Burman, R.L.

    1975-01-01

    This survey concentrates upon current experiments in the fields of pion-nucleon and pion-deuteron interactions, for low-energy incident pions--below 300 MeV. The discussion is restricted to very recent work. The topics to be covered are: π +- p → π +- p, Elastic Scattering; π +- p → π +- pγ, Bremsstrahlung; π + d → pp, Absorption; π d → π + d, Elastic Scattering; and π + d → π + pn, Breakup. (14 figures) (U.S.)

  16. Low Energy Supersymmetry from the Heterotic String Landscape

    CERN Document Server

    Lebedev, O; Raby, S; Ramos-Sanchez, S; Ratz, M; Vaudrevange, P K S; Wingerter, A; Lebedev, Oleg; Nilles, Hans-Peter; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K. S.; Wingerter, Akin

    2007-01-01

    We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favoured. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

  17. Low Energy Electron Gun on Board a Scientific Satellite GEOTAIL

    OpenAIRE

    TSUTSUI, Minoru; ONISHI, Yoshiaki; MATSUMOTO, Hiroshi; KIMURA, Iwane; 筒井, 稔; 大西, 嘉昭; 松本, 紘; 木村, 磐根

    1988-01-01

    A low energy electron gun to be used for beam-plasma interaction experiments by a scientific satellite GEOTAIL has been designed and manufactured. Electrodes of the gun have been modified from the Pierce type gun because of the use of a directly heated cathode. Spatial density distributions of beam electrons emitted from the new gun have been measured in a large vacuum chamber, and characteristic curves of emission currents for some beam energies and cathode powers have been checked repeatedl...

  18. Practical Use of Scanning Low Energy Electron Microscope (SLEEM)

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Mikmeková, Eliška; Mikmeková, Šárka; Konvalina, Ivo; Frank, Luděk

    2016-01-01

    Roč. 22, S3 (2016), s. 1650-1651 ISSN 1431-9276 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : scanning low energy * SLEEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  19. The TRIUMF low energy pion spectrometer and channel

    International Nuclear Information System (INIS)

    Sobie, R.J.; Drake, T.E.; Barnett, B.M.; Erdman, K.L.; Gyles, W.; Johnson, R.R.; Roser, H.W.; Tacik, R.; Blackmore, E.W.; Gill, D.R.

    1983-08-01

    A low energy pion spectrometer has been developed for use with the TRIUMF M13 pion channel. The combined channel and spectrometer resolution is presently 1.1 MeV at T = 50 MeV. This is limited by the amount of gas and detector material in the spectrometer in addition to the inherent resolution of the channel. Improvements to both the spectrometer and channel are discussed

  20. Delayed hot spots in a low energy plasma focus

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1991-01-01

    In a low energy Mather-type plasma focus device, hot spots having temperature in the range of few keV have been observed even 1 μs after the pinch disintegration and in regions away from the pinch area. These hot spots are perhaps created by the thermal runaway due to temperature fluctuations in the background gas. (author). 12 refs., 6 figs