WorldWideScience

Sample records for energy excitations measured

  1. Plunger lifetime measurements after Coulomb excitation at intermediate beam energies

    Energy Technology Data Exchange (ETDEWEB)

    Hackstein, Matthias; Dewald, Alfred; Fransen, Christoph; Ilie, Gabriela; Jolie, Jan; Melon, Barbara; Pissulla, Thomas; Rother, Wolfram; Zell, Karl-Oskar [University of Cologne (Germany); Petkov, Pavel [University of Cologne (Germany); INRNE (Bulgaria); Chester, Aaron; Adrich, Przemyslaw; Bazin, Daniel; Bowen, Matt; Gade, Alexandra; Glasmacher, Thomas; Miller, Dave; Moeller, Victoria; Starosta, Krzysztof; Stolz, Andreas; Vaman, Constantin; Voss, Philip; Weissharr, Dirk [Michigan State Univerity (United States); Moeller, Oliver [TU Darmstadt (Germany)

    2008-07-01

    Two recoil-distance-doppler-shift (RDDS) experiments were performed at the NSCL/MSU using Coulomb excitations of the projectile nuclei {sup 110}Pd, {sup 114}Pd at beam energies of 54 MeV/u in order to investigate the evolution of deformation of neutron rich paladium isotopes. The experimental set-up consisted of a dedicated plunger device, developed at the University of Cologne, the SEGA Ge-array and the S800 spectrometer. Lifetimes of the 2{sub 1}{sup +}-states in {sup 110}Pd and {sup 114}Pd were derived from the analysis of the {gamma}-line-shapes as well as from the measured decay-curves. Special features of the data analysis, e.g. features originating from the very high recoil velocities, are discussed.

  2. On isospin excitation energy

    International Nuclear Information System (INIS)

    Li Wenfei; Zhang Fengshou; Chen Liewen

    2001-01-01

    Within the framework of Hartree-Fock theory using the extended Skyrme effective interaction, the isospin excitation energy as a function of relative neutron excess δ was investigated at different temperatures and densities. It was found that the isospin excitation energy decreased with the increment of temperature and/or the decrement of density. The authors pointed out that the decrement of isospin excitation energy was resulted from the weakening of quantum effect with increment of temperature and/or decrement of density. Meanwhile, the relationship between the isospin excitation energy and the symmetry energy was discussed and found that the symmetry energy was just a part of the isospin excitation energy. With increasing temperature and decreasing density, the contribution of the symmetry energy to the isospin excitation energy becomes more and more important. The isospin excitation energy as a function of relative neutron excess was also investigated using different potential parameters. The results shows that the isospin excitation energy is almost independent of the incompressibility and the effective mass, but strongly depends on the symmetry energy strength coefficient, which indicates that it is possible to extract the symmetry energy of the nuclear equation of state by investigating the isospin excitation energy in experiments

  3. Estimation of excitation forces for wave energy converters control using pressure measurements

    Science.gov (United States)

    Abdelkhalik, O.; Zou, S.; Robinett, R.; Bacelli, G.; Wilson, D.

    2017-08-01

    Most control algorithms of wave energy converters require prediction of wave elevation or excitation force for a short future horizon, to compute the control in an optimal sense. This paper presents an approach that requires the estimation of the excitation force and its derivatives at present time with no need for prediction. An extended Kalman filter is implemented to estimate the excitation force. The measurements in this approach are selected to be the pressures at discrete points on the buoy surface, in addition to the buoy heave position. The pressures on the buoy surface are more directly related to the excitation force on the buoy as opposed to wave elevation in front of the buoy. These pressure measurements are also more accurate and easier to obtain. A singular arc control is implemented to compute the steady-state control using the estimated excitation force. The estimated excitation force is expressed in the Laplace domain and substituted in the control, before the latter is transformed to the time domain. Numerical simulations are presented for a Bretschneider wave case study.

  4. Measurements of vibrational excitation of N2, CO, and NO by low energy proton impact

    International Nuclear Information System (INIS)

    Krutein, J.; Linder, F.

    1979-01-01

    Differential scattering experiments are reported for proton impact on N 2 , CO, and NO in the energy range E/sub lab/=30--80 eV. The measurements include the range of very small scattering angles around 0 0 as well as the rainbow region. The vibrationally resolved energy-loss spectra show a relatively low vibrational inelasticity for all three systems. Differential cross sections, transition probabilities, and the mean vibrational energy transfer are presented. Rotational excitation is indicated by the broadening of the energy-loss peaks which is most significant for H + --NO. The small-angle scattering data for vibrational excitation in CO show good agreement with the impact parameter theory using the known long-range interactions for this system

  5. A new analysis technique to measure fusion excitation functions with large beam energy dispersions

    Science.gov (United States)

    Figuera, P.; Di Pietro, A.; Fisichella, M.; Lattuada, M.; Shotter, A. C.; Ruiz, C.; Zadro, M.

    2018-01-01

    Peculiar nuclear structures of two colliding nuclei such has clustering, neutron halo/skin or very low breakup thresholds can affect the reaction dynamics below the Coulomb barrier and this may also have astrophysical consequences. In order to have a better understanding of this topic, in the last decade, several experiments were performed. A typical experimental challenge of such studies is the need to measure excitation functions below the Coulomb barrier, having a strong energy dependence, with rather large beam energy dispersions inside the target. This may easily lead to ambiguities in associating the measured cross section with a proper beam energy. In this paper a discussion on this topic is reported and a new technique to deal with the above problem will be proposed.

  6. High energy nuclear excitations

    International Nuclear Information System (INIS)

    Gogny, D.; Decharge, J.

    1983-09-01

    The main purpose of this talk is to see whether a simple description of the nuclear excitations permits one to characterize some of the high energy structures recently observed. The discussion is based on the linear response to different external fields calculated using the Random Phase Approximation. For those structure in heavy ion collisions at excitation energies above 50 MeV which cannot be explained with such a simple approach, we discuss a possible mechanism for this heavy ion scattering

  7. Hardness and excitation energy

    Indian Academy of Sciences (India)

    It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the ...

  8. Aspects of kinematical coincidence measurements of excitation energy division in damped reactions

    International Nuclear Information System (INIS)

    Toke, J.; Schroeder, W.U.; Huizenga, J.R.; Rochester Univ., NY

    1990-01-01

    It is shown that the finite resolution inherent in the kinematical coincidence method leads to systematic errors in the deduced (primary) physical quantities if the latter are calculated based on mass and linear momentum conservation equations alone. As an example, application of this method for measuring excitation energy of the fragments from damped reactions is reviewed. In such a case, finite resolution effects generate significant instrumental, or 'background' correlations between the physical quantities reconstructed in a straightforward fashion, hence, if not accounted for, they may lead to the qualitative misinterpretation of the data. Experimental measures are discussed which appear necessary in order to ensure proper accuracy of the finite resolution corrections. An alternative method of data analysis is presented which is much less susceptible to the finite resolution effects discussed. (orig.)

  9. Mean excitation energy of polystyrene extracted from proton-stopping-power measurements

    International Nuclear Information System (INIS)

    Porter, L.E.

    1980-01-01

    The measured stopping power of polystyrene for 2.2- to 5.9-MeV protons has been analyzed with the Bloch projectile-z 4 correction term and a modified low-velocity projectile-z 3 term included in the Bethe-Bloch formula. When the full-strength Walske K-shell correction was utilized, the mean excitation energy corresponding to the best fit of the measurements was (71.1 +- 1.8) eV. This result was obtained for a value of the free parameter of the low-velocity projectile-z 3 effect formalism of 1.90 +- 0.05, whether or not a Walske L-shell correction was included

  10. Inner-shell/subshell photoionization cross section measurements using a gamma excited variable energy X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Sood, B S; Allawadhi, K L; Arora, S K [Punjabi Univ., Patiala (India). Nuclear Science Labs.

    1982-02-15

    The method developed for the determination of K/L shell photoionization cross sections in various elements, 39 <= Z <= 92, in the characteristic X-ray energy region using a gamma excited variable energy X-ray source has been used for the measurement of Lsub(III) subshell photoionization cross section in Pb, Th and U. The measurements are made at the K X-ray energies of Rb, Nb and Mo, since these are able to excite selectively the Lsub(III) subshells of Pb, Th and U, respectively. The results, when compared with theoretical calculations of Scofield, are found to agree within the uncertainties of determination.

  11. High-sensitivity measurements of the excitation function for Bhabha scattering at MeV energies

    International Nuclear Information System (INIS)

    Tsertos, H.; Kozhuharov, C.; Armbruster, P.; Kienle, P.; Krusche, B.; Schreckenbach, K.

    1989-02-01

    Using a monochromatic e + beam scattered on a Be foil and a high-resolution detector device, the excitation function for elastic e + e - scattering was measured with a statistical accuracy of 0.25% in 1.4 keV steps in the c.m.-energy range between 770 keV and 840 keV (1.79 - 1.86 MeV/c 2 ) at c.m. scattering angles between 80 0 and 100 0 (FWHM). Within the experimental sensitivity of 0.5 b.eV/sr (c.m.) for the energy-integrated differential cross section no resonances were observed (97% CL). From this limit we infer that a hypothetical spinless resonant state should have a width of less than 1.9 meV corresponding to a lifetime limit of 3.5x10 -13 s. This limit establishes the most stringent bound for new particles in this mass range derived from Bhabha scattering and is independent of assumptions about the internal structure of the hypothetical particles. Less sensitivite limits were, in addition, derived around 520 keV c.m. energy (≅ 1.54 MeV/c 2 ) from an investigation with a thorium and a mylar foil as scatterers. (orig.)

  12. Measurement and analysis of excitation functions in 16O + 103Rh system in the excitation energy range ≅ 2-4 MeV/A

    International Nuclear Information System (INIS)

    Singh, Devendra P.; Unnati; Sharma, Manoj Kumar; Singh, Pushpendra P.; Singh, B.P.; Prasad, R.; Gupta, Sunita; Rakesh Kumar; Bhardwaj, H.D.

    2006-01-01

    In the present work, excitation functions for seven evaporation residues (ERs) produced via complete fusion and incomplete fusion processes in 16 O + 103 Rh system have been measured in the energy range ≅ 47-85 MeV, using recoil catcher technique followed by off-line gamma-ray spectrometry. Comparison of the experimental data with statistical model based computer code PACE 2 revealed dominance of incomplete fusion in reactions involving alpha-emission channels. To the best of our knowledge these reactions are being reported for the first time

  13. High energy magnetic excitations

    International Nuclear Information System (INIS)

    Endoh, Yasuo

    1988-01-01

    The report emphasizes that the current development in condensed matter physics opens a research field fit to inelastic neutron scattering experiments in the eV range which is easilly accessed by spallation neutron sources. Several important subjects adopted at thermal reactors are shown. It is desired to extend the implementation of the spectroscopic experiments for investigation of higher energy magnetic excitations. For La 2 CuO 4 , which is the mother crystal of the first high Tc materials found by Bednortz and Muller, it seems to be believed that the magnetism is well characterized by the two-dimensional Heisenberg antiferromagnetic Hamiltonian, and it is widely accepted that the magnetism is a most probable progenitor of high Tc superconductors. The unusual properties of spin correlations in this crystal have been studied extensively by standard neutron scattering techniques with steady neutrons at BNL. FeSi is not ordered magnetically but shows a very unique feature of temperature induced magnetism, which also has been studied extensively by using the thermal neutron scattering technique at BNL. In these experiments, polarized neutrons are indispensable to extract the clean magnetic components out of other components of non-magnetic scattering. (N.K.)

  14. Time-resolved UV-excited microarray reader for fluorescence energy transfer (FRET) measurements

    Science.gov (United States)

    Orellana, Adelina; Hokkanen, Ari P.; Pastinen, Tomi; Takkinen, Kristina; Soderlund, Hans

    2001-05-01

    Analytical systems based on immunochemistry are largely used in medical diagnostics and in biotechnology. There is a significant pressure to develop the present assay formats to become easier to use, faster, and less reagent consuming. Further developments towards high density array--like multianalyte measurement systems would be valuable. To this aim we have studied the applicability of fluorescence resonance energy transfer and time-resolved fluorescence resonance energy transfer in immunoassays on microspots and in microwells. We have used engineered recombinant antibodies detecting the pentameric protein CRP as a model analyte system, and tested different assay formats. We describe also the construction of a time-resolved scanning epifluorometer with which we could measure the FRET interaction between the slow fluorescence decay from europium chelates and its energy transfer to the rapidly decaying fluorophore Cy5.

  15. Crystal field and low energy excitations measured by high resolution RIXS at the L edge of Cu, Ni and Mn

    DEFF Research Database (Denmark)

    Ghiringhelli, G.; Piazzalunga, A.; Wang, X.

    2009-01-01

    of the 3d transition metals with unprecedented energy resolution, of the order of 100 meV for Mn, Ni and Cu. We present here some preliminary spectra on CuO, malachite, NiO, , MnO and . The dd excitations are very well resolved allowing accurate experimental evaluation of 3d state energy splitting. The low...

  16. Mean excitation energies for molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Phillip W.K.; Sauer, Stephan P.A. [Department of Chemistry, University of Copenhagen, Copenhagen (Denmark); Oddershede, Jens [Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense (Denmark); Quantum Theory Project, Departments of Physics and Chemistry, University of Florida, Gainesville, FL (United States); Sabin, John R., E-mail: sabin@qtp.ufl.edu [Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense (Denmark); Quantum Theory Project, Departments of Physics and Chemistry, University of Florida, Gainesville, FL (United States)

    2017-03-01

    The essential material constant that determines the bulk of the stopping power of high energy projectiles, the mean excitation energy, is calculated for a range of smaller molecular ions using the RPA method. It is demonstrated that the mean excitation energy of both molecules and atoms increase with ionic charge. However, while the mean excitation energies of atoms also increase with atomic number, the opposite is the case for mean excitation energies for molecules and molecular ions. The origin of these effects is explained by considering the spectral representation of the excited state contributing to the mean excitation energy.

  17. Can Measured Synergy Excitations Accurately Construct Unmeasured Muscle Excitations?

    Science.gov (United States)

    Bianco, Nicholas A; Patten, Carolynn; Fregly, Benjamin J

    2018-01-01

    Accurate prediction of muscle and joint contact forces during human movement could improve treatment planning for disorders such as osteoarthritis, stroke, Parkinson's disease, and cerebral palsy. Recent studies suggest that muscle synergies, a low-dimensional representation of a large set of muscle electromyographic (EMG) signals (henceforth called "muscle excitations"), may reduce the redundancy of muscle excitation solutions predicted by optimization methods. This study explores the feasibility of using muscle synergy information extracted from eight muscle EMG signals (henceforth called "included" muscle excitations) to accurately construct muscle excitations from up to 16 additional EMG signals (henceforth called "excluded" muscle excitations). Using treadmill walking data collected at multiple speeds from two subjects (one healthy, one poststroke), we performed muscle synergy analysis on all possible subsets of eight included muscle excitations and evaluated how well the calculated time-varying synergy excitations could construct the remaining excluded muscle excitations (henceforth called "synergy extrapolation"). We found that some, but not all, eight-muscle subsets yielded synergy excitations that achieved >90% extrapolation variance accounted for (VAF). Using the top 10% of subsets, we developed muscle selection heuristics to identify included muscle combinations whose synergy excitations achieved high extrapolation accuracy. For 3, 4, and 5 synergies, these heuristics yielded extrapolation VAF values approximately 5% lower than corresponding reconstruction VAF values for each associated eight-muscle subset. These results suggest that synergy excitations obtained from experimentally measured muscle excitations can accurately construct unmeasured muscle excitations, which could help limit muscle excitations predicted by muscle force optimizations.

  18. Mean excitation energies for molecular ions

    DEFF Research Database (Denmark)

    Jensen, Phillip W.K.; Sauer, Stephan P.A.; Oddershede, Jens

    2017-01-01

    The essential material constant that determines the bulk of the stopping power of high energy projectiles, the mean excitation energy, is calculated for a range of smaller molecular ions using the RPA method. It is demonstrated that the mean excitation energy of both molecules and atoms increase...

  19. Measurement of the rates of reaction of the ground and metastable excited states of 02+, N0+ and 0+ with atmospheric gases at thermal energy

    International Nuclear Information System (INIS)

    Glosik, J.; Rakshit, A.B.; Twiddy, N.D.; Adams, N.G.; Smith, D.

    1978-01-01

    Thermal-energy reaction rate coefficients and product ion distributions have been measured for reactions of both the ground state and metastable electronic states of 0 2 + , N0 + and 0 + with several neutral species, using a selected-ion flow tube. In general the excited-ion reaction rates are fast, frequently approaching the Langevin limit. Collisional quenching occurs for the reactions of N0 + sup(star) with N 2 ,0 2 and H 2 and the quenching rates have been determined. The ion source also provided a substantial yield of doubly charged 0 2 permitting some measurements of reaction rates of 0 2 2+ . (author)

  20. Fission lifetime measured by the blocking technique as a function of excitation energy in the 24 A.MeV 238U+28Si reaction

    International Nuclear Information System (INIS)

    Morjean, M.; Galin, J.; Goldenbaum, F.; Lienard, E.; Chevallier, M.; Dauvergne, D.; Kirsch, R.; Jacquet, D.; and others.

    1997-01-01

    The blocking technique was used to infer fission lifetimes as a function of excitation energy for uranium-like nuclei formed in the U+Si reactions at 24 MeV/nucleon. The fission lifetimes are found larger than 10 -19 s for excitation energies up to about 250 MeV. (K.A.)

  1. Dependence of the giant dipole strength function on excitation energy

    International Nuclear Information System (INIS)

    Draper, J.E.; Newton, J.O.; Sobotka, L.G.; Lindenberger, H.; Wozniak, G.J.; Moretto, L.G.; Stephens, F.S.; Diamond, R.M.; McDonald, R.J.

    1982-01-01

    Spectra of γ rays associated with deep-inelastic products from the 1150-MeV 136 Xe+ 181 Ta reaction have been measured. The yield of 10--20-MeV γ rays initially increases rapidly with the excitation energy of the products and then more slowly for excitation energies in excess of 120 MeV. Statistical-model calculations with ground-state values of the giant dipole strength function fail to reproduce the shape of the measured γ-ray spectra. This suggests a dependence of the giant dipole strength function on excitation energy

  2. PS II model based analysis of transient fluorescence yield measured on whole leaves of Arabidopsis thaliana after excitation with light flashes of different energies.

    Science.gov (United States)

    Belyaeva, N E; Schmitt, F-J; Paschenko, V Z; Riznichenko, G Yu; Rubin, A B; Renger, G

    2011-02-01

    Our recently presented PS II model (Belyaeva et al., 2008) was improved in order to permit a consistent simulation of Single Flash Induced Transient Fluorescence Yield (SFITFY) traces that were earlier measured by Steffen et al. (2005) on whole leaves of Arabidopsis (A.) thaliana at four different energies of the actinic flash. As the essential modification, the shape of the actinic flash was explicitly taken into account assuming that an exponentially decaying rate simulates the time dependent excitation of PS II by the 10 ns actinic flash. The maximum amplitude of this excitation exceeds that of the measuring light by 9 orders of magnitude. A very good fit of the SFITFY data was achieved in the time domain from 100 ns to 10s for all actinic flash energies (the maximum energy of 7.5 × 10¹⁶ photons/(cm²flash) is set to 100%, the relative energies of weaker actinic flashes were of ∼8%, 4%, ∼1%). Our model allows the calculation and visualization of the transient PS II redox state populations ranging from the dark adapted state, via excitation energy and electron transfer steps induced by pulse excitation, followed by final relaxation into the stationary state eventually attained under the measuring light. It turned out that the rate constants of electron transfer steps are invariant to intensity of the actinic laser flash. In marked contrast, an increase of the actinic flash energy by more than two orders of magnitude from 5.4×10¹⁴ photons/(cm²flash) to 7.5×10¹⁶ photons/(cm²flash), leads to an increase of the extent of fluorescence quenching due to carotenoid triplet (³Car) formation by a factor of 14 and of the recombination reaction between reduced primary pheophytin (Phe(-)) and P680(+) by a factor of 3 while the heat dissipation in the antenna complex remains virtually constant. The modified PS II model offers new opportunities to compare electron transfer and dissipative parameters for different species (e.g. for the green algae and the

  3. Review of high excitation energy structures in heavy ion collisions: target excitations and three body processes

    International Nuclear Information System (INIS)

    Frascaria, N.

    1987-09-01

    A review of experimental results on high excitation energy structures in heavy ion inelastic scattering is presented. The contribution to the spectra of the pick-up break-up mechanism is discussed in the light of the data obtained with light heavy ion projectiles. Recent results obtained with 40 Ar beams at various energies will show that target excitations contribute strongly to the measured cross section

  4. Excitation methods for energy dispersive analysis

    International Nuclear Information System (INIS)

    Jaklevic, J.M.

    1976-01-01

    The rapid development in recent years of energy dispersive x-ray fluorescence analysis has been based primarily on improvements in semiconductor detector x-ray spectrometers. However, the whole analysis system performance is critically dependent on the availability of optimum methods of excitation for the characteristic x rays in specimens. A number of analysis facilities based on various methods of excitation have been developed over the past few years. A discussion is given of the features of various excitation methods including charged particles, monochromatic photons, and broad-energy band photons. The effects of the excitation method on background and sensitivity are discussed from both theoretical and experimental viewpoints. Recent developments such as pulsed excitation and polarized photons are also discussed

  5. Study of excitation energy dependence of nuclear level density parameter

    International Nuclear Information System (INIS)

    Mohanto, G.; Nayak, B.K.; Saxena, A.

    2016-01-01

    In the present study, we have populated CN by fusion reaction and excitation energy of the intermediate nuclei is determined after first chance α-emission to investigate excitation energy dependence of the NLD parameter. Evaporated neutron spectra were measured following alpha evaporation for obtaining NLD parameter for the reaction 11 B + 197 Au, populating CN 208 Po. This CN after evaporating an α-particle populates intermediate nucleus 204 Pb. The 204 Pb has magic number of Z=82. Our aim is to study the excitation energy dependence of NLD parameter for closed shell nuclei

  6. A simple method for automatic measurement of excitation functions

    International Nuclear Information System (INIS)

    Ogawa, M.; Adachi, M.; Arai, E.

    1975-01-01

    An apparatus has been constructed to perform the sequence control of a beam-analysing magnet for automatic excitation function measurements. This device is also applied to the feedback control of the magnet to lock the beam energy. (Auth.)

  7. Measurement of nuclear potentials from fusion excitation functions

    International Nuclear Information System (INIS)

    Huizenga, J.R.; Birkelund, J.R.

    1984-01-01

    The basis for measuring nuclear potentials from fusion excitation functions at energies above barrier is reviewed. It is argued that because of experimental and conceptual problems fusion excitation functions at high energies cannot lead to model independent measurements of internuclear potential at small separations. The Al 27 + Ne 20 reaction previously analyzed by others is used as an example of problems arising from the inability to distinguish complete and incomplete fusion in experimental data

  8. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, T.R. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  9. High energy excitations in itinerant ferromagnets

    International Nuclear Information System (INIS)

    Prange, R.E.

    1984-01-01

    Itinerant magnets, those whose electrons move throughout the crystal, are described by band theory. Single particle excitations offer confirmation of band theory, but their description requires important corrections. The energetics of magnetism in iron and nickel is also described in band theory but requires complex bands. Magnetism above the critical temperature and the location of the critical temperature offer discriminants between the two major models of magnetism at high temperature and can be addressed by high energy excitations

  10. The Mean Excitation Energy of Atomic Ions

    DEFF Research Database (Denmark)

    Sauer, Stephan; Oddershede, Jens; Sabin, John R.

    2015-01-01

    A method for calculation of the mean excitation energies of atomic ions is presented, making the calculation of the energy deposition of fast ions to plasmas, warm, dense matter, and complex biological systems possible. Results are reported to all ions of helium, lithium, carbon, neon, aluminum...

  11. 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

  12. Hot nuclei, limiting temperatures and excitation energies

    International Nuclear Information System (INIS)

    Peter, J.

    1986-09-01

    Hot fusion nuclei are produced in heavy ion collisions at intermediate energies (20-100 MeV/U). Information on the maximum excitation energy per nucleon -and temperatures- indicated by the experimental data is compared to the predictions of static and dynamical calculations. Temperatures around 5-6 MeV are reached and seem to be the limit of formation of thermally equilibrated fusion nuclei

  13. Lifetime measurements of excited states in 196Pt

    International Nuclear Information System (INIS)

    Bolotin, H.H.; Katayama, Ichiro; Sakai, Hideyuki; Fujita, Yoshitaka; Fujiwara, Mamoru

    1979-01-01

    The lifetimes of six excited states in 196 Pt up to an excitation energy of 1525 keV were measured by the recoil-distance method (RDM). These levels were populated by Coulomb excitation using both 90 MeV 20 Ne and 220 MeV 58 Ni ion beams. The measured lifetimes of the 2 1 + , 4 1 + , 6 1 + , 2 2 + , 4 2 + and 0 2 + states and the B(E2) values inferred for the depopulating transitions from these levels are presented. With the exception of the 2 1 + state, the meanlives of all other levels are the first such direct experimental determinations to be reported. (author)

  14. Design and development of a parametrically excited nonlinear energy harvester

    International Nuclear Information System (INIS)

    Yildirim, Tanju; Ghayesh, Mergen H.; Li, Weihua; Alici, Gursel

    2016-01-01

    Highlights: • A parametrically broadband energy harvester was fabricated. • Strong softening-type nonlinear behaviour was observed. • Experiments were conducted showing the large bandwidth of the device. - Abstract: An energy harvester has been designed, fabricated and tested based on the nonlinear dynamical response of a parametrically excited clamped-clamped beam with a central point-mass; magnets have been used as the central point-mass which pass through a coil when parametrically excited. Experiments have been conducted for the energy harvester when the system is excited (i) harmonically near the primary resonance; (ii) harmonically near the principal parametric resonance; (iii) by means of a non-smooth periodic excitation. An electrodynamic shaker was used to parametrically excite the system and the corresponding displacement of the magnet and output voltages of the coil were measured. It has been shown that the system displays linear behaviour at the primary resonance; however, at the principal parametric resonance, the motion characteristic of the magnet substantially changed displaying a strong softening-type nonlinearity. Theoretical simulations have also been conducted in order to verify the experimental results; the comparison between theory and experiment were within very good agreement of each other. The energy harvester developed in this paper is capable of harvesting energy close to the primary resonance as well as the principal parametric resonance; the frequency-band has been broadened significantly mainly due to the nonlinear effects as well as the parametric excitation.

  15. Excitation and photon decay of giant resonances excited by intermediate energy heavy ions

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1987-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the giant resonances. In particular, recent measurements have been made of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon 17 O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the 208 Pb isovector quadrupole resonance using its gamma decay are presented. 22 refs., 19 figs., 1 tab

  16. Energies and lifetimes of excited states in copperlike Kr VIII

    International Nuclear Information System (INIS)

    Livingston, A.E.; Curtis, L.J.; Schectman, R.M.; Berry, H.G.

    1980-01-01

    The spectrum of Kr VIII has been observed between 180 and 2000 A by using foil excitation of 2.5--3.5-MeV krypton ions. Twenty new transitions have been classified and eleven new excited-state energies have been determined within the n=4 --7 shells. The ionization potential is derived to be 1 015 800 +- 200 cm -1 . The excited-state energies and fine structures are compared with recent relativistic Hartree-Fock calculations. The 4p-state lifetime has been measured by performing a simultaneous analysis of decay data for the 4p level and for its dominant cascade-repopulating levels. The 4p lifetime is found to be 30% shorter than previously measured values and is in excellent agreement with the result of a recent multiconfiguration Hartree-Fock calculation. The source of the discrepancy between this result and earlier measurements is discussed

  17. Complex fragment emission at low and high excitation energy

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1986-08-01

    Complex fragment emission has been certified as a compound nucleus process at low energies. An extension of the measurements to heavy ion reactions up to 50 MeV/u shows that most complex fragments are emitted by highly excited compound nuclei formed in incomplete fusion reactions. 12 refs., 26 figs

  18. Measurement of excitation functions and analysis of isomeric population in some reactions induced by proton on natural indium at low energy

    Science.gov (United States)

    Muhammed Shan, P. T.; Musthafa, M. M.; Najmunnisa, T.; Mohamed Aslam, P.; Rajesh, K. K.; Hajara, K.; Surendran, P.; Nair, J. P.; Shanbagh, Anil; Ghugre, S.

    2018-06-01

    The excitation functions for reaction residues populated via 115In(p , p) 115 mIn, 115In(p , pn) 114 mIn, 115In(p , p 2 n) 113 mIn, 113In(p , p) 113 mIn, 115In(p , nα) 111 mCd, 115In(p , 3 n) 113Sn and 113In(p , n) 113Sn channels were measured over the proton energy range of 8-22 MeV using stacked foil activation technique. Theoretical analysis of the data were performed within the framework of two statistical model codes EMPIRE-3.2 and TALYS-1.8. Isomeric cross section ratio for isomeric pairs m,g 115In, m,g 114In, m,g 113In, 113Sn m,g and m,g 111Cd were determined for the first time. The dependence of isomeric cross section ratio on various factors are analysed.

  19. Lifetime measurements of excited Co I levels

    CERN Document Server

    Klotz, W D; Gobel, L H

    1977-01-01

    In the region of 3500 AA the lifetimes of eight excited Cobalt I levels have been measured by means of the zero field level crossing method. The measured lifetimes belong to the odd configurations 3d/sup 7/4s4p and 3d/sup 8/4p and are of the accuracy of about 5%. The hyperfine structure of levels with I not=J has to be taken into account in evaluating lifetimes from level crossing data, because the nuclear spin of the natural isotope /sup 59/Co is I=7/2. Therefore the influence of the line profile of the exciting resonance lines on the lifetimes has been investigated. The results are compared with those of other authors. Furthermore absolute oscillator strengths were calculated with known branching ratios and a new absolute scale has been established. (23 refs).

  20. Integrated light in direct excitation and energy transfer luminescence

    OpenAIRE

    Chimczak, Eugeniusz

    2007-01-01

    Integrated light in direct excitation and energy transfer luminescence has been investigated. In the investigations reported here, monomolecular centers were taken into account. It was found that the integrated light is equal to the product of generation rate and time of duration of excitation pulse for both direct excitation and energy transfer luminescence.

  1. Neutron scattering investigation of magnetic excitations at high energy transfers

    International Nuclear Information System (INIS)

    Loong, C.K.

    1984-01-01

    With the advance of pulsed spallation neutron sources, neutron scattering investigation of elementary excitations in magnetic materials can now be extended to energies up to several hundreds of MeV. We have measured, using chopper spectrometers and time-of-flight techniques, the magnetic response functions of a series of d and f transition metals and compounds over a wide range of energy and momentum transfer. In PrO 2 , UO 2 , BaPrO 3 and CeB 6 we observed crystal-field transitions between the magnetic ground state and the excited levels in the energy range from 40 to 260 MeV. In materials exhibiting spin-fluctuation or mixed-valent character such as Ce 74 Th 26 , on the other hand, no sharp crystal-field lines but a broadened quasielastic magnetic peak was observed. The line width of the quasielastic component is thought to be connected to the spin-fluctuation energy of the 4f electrons. The significance of the neutron scattering results in relation to the ground state level structure of the magnetic ions and the spin-dynamics of the f electrons is discussed. Recently, in a study of the spin-wave excitations in itinerant magnetic systems, we have extended the spin-wave measurements in ferromagnetic iron up to about 160 MeV. Neutron scattering data at high energy transfers are of particular interest because they provide direct comparison with recent theories of itinerant magnetism. 26 references, 7 figures

  2. Lifetime measurements of excited states in 73As

    International Nuclear Information System (INIS)

    Singh, K.P.; Kavakand, T.; Hajivaliei, M.

    2004-01-01

    The excited states of 73 As have been investigated via the 73 Ge(p, nγ) 73 As reaction with proton beam energies from 2.5–4.3 MeV. The lifetimes of the levels at 769.6, 860.5, 1177.8, 1188.7, 1274.9, 1344.1, 1557.1 and 1975.2 keV excitation energies have been measured for the first time using the Doppler shift attenuation method. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for eight γ-transitions have been newly measured. (author)

  3. 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

  4. Atomic excitation and molecular dissociation by low energy electron collisions

    International Nuclear Information System (INIS)

    Weyland, Marvin

    2016-01-01

    In this work, momentum imaging experiments have been conducted for the electron impact excitation of metastable states in noble gases and for dissociative electron attachment (DEA) in polyatomic molecules. For the electron impact excitation study a new experimental technique has been developed which is able to measure the scattering angle distribution of the electrons by detection of the momentum transfer to the atoms. Momentum transfer images have been recorded for helium and neon at fixed electron impact energy close to the excitation threshold and good agreement with current R-matrix theory calculations was found. A new momentum imaging apparatus for negative ions has been built for the purpose of studying DEA in biologically relevant molecules. During this work, DEA was investigated in the molecules ammonia, water, formic acid, furan, pyridine and in two chlorofluorocarbons. Furthermore, the change of DEA resonance energies when molecules form clusters compared to monomers was investigated in ammonia and formic acid. The experimental results of most studied molecules could be compared to recent theoretical calculations and they support further development in the theoretical description of DEA. The new apparatus built in this work also delivered a superior momentum resolution compared to existing setups. This allows the momentum imaging of heavier fragments and fragments with lower kinetic energy.

  5. Atomic excitation and molecular dissociation by low energy electron collisions

    Energy Technology Data Exchange (ETDEWEB)

    Weyland, Marvin

    2016-11-16

    In this work, momentum imaging experiments have been conducted for the electron impact excitation of metastable states in noble gases and for dissociative electron attachment (DEA) in polyatomic molecules. For the electron impact excitation study a new experimental technique has been developed which is able to measure the scattering angle distribution of the electrons by detection of the momentum transfer to the atoms. Momentum transfer images have been recorded for helium and neon at fixed electron impact energy close to the excitation threshold and good agreement with current R-matrix theory calculations was found. A new momentum imaging apparatus for negative ions has been built for the purpose of studying DEA in biologically relevant molecules. During this work, DEA was investigated in the molecules ammonia, water, formic acid, furan, pyridine and in two chlorofluorocarbons. Furthermore, the change of DEA resonance energies when molecules form clusters compared to monomers was investigated in ammonia and formic acid. The experimental results of most studied molecules could be compared to recent theoretical calculations and they support further development in the theoretical description of DEA. The new apparatus built in this work also delivered a superior momentum resolution compared to existing setups. This allows the momentum imaging of heavier fragments and fragments with lower kinetic energy.

  6. Low-energy measurements of electron-photon angular correlation in electron-impact excitation of the 21P state of helium

    International Nuclear Information System (INIS)

    Steph, N.C.; Golden, D.E.

    1983-01-01

    Electron-photon angular correlations between electrons which have excited the 2 1 P state of He and photons from the 2 1 P→1 1 S transition have been studied for 27-, 30-, 35-, and 40-eV incident electrons. Values of lambda and Vertical BarchiVertical Bar obtained from these measurements are compared to values obtained in distorted-wave and R-matrix calculations. The values of lambda and Vertical BarchiVertical Bar have been combined to examine the behavior of Vertical BarO 1 /sub -//sup colvertical-bar/ [lambda(1-lambda)sinVertical BarchiVertical Bar], the nonvanishing component of orientation. At 27 eV, a substantial decrease was observed in the values of lambda and Vertical BarO 1 /sub -//sup colvertical-bar/, compared with their values for E> or =30 eV

  7. Lifetime measurements of the excited states in {sup 145} Sm

    Energy Technology Data Exchange (ETDEWEB)

    El-Badry, A M; Abdel Samie, Sh; Ahmad, A A [Depatment of Physics, Faculty of Science, ElMinia University, ElMinia, (Egypt); Kuroyanagi, T; Odahara, A; Gono, Y; Morinobu, S [Tandem Accelerator Laboratory, Department of Physics, Kyushu University, (Japan)

    1997-12-31

    Lifetime of the excited levels in {sup 145} Sm has been measured through the {sup 139} La ({sup 10} B, 4 n){sup 145} Sm nuclear reaction. The optimal beam energy of 49 MeV was determined from the measurements of the excitation function and Cascade program. With the possibility of studying lifetime of this nucleus a conventional plunger system have been designed and constructed at kyushu University tandem accelerator laboratory. A La target of 0.22 mg/cm{sup 2} thickness which was evaporated onto a Au foil of 2 mg/cm{sup 2} thickness was used. Since the recoil velocity was estimated to be 1.76 mm/ns (beta 0.00585), the measurable time range resulted in the range from 5 Ps to 5 ns. The single spectra measurements were performed at the 20 plunger positions in the range from 10 {mu} to 10 mm. Analyses of the data were carried using hypermet and/or GF2 program to obtain the lifetimes. A new list of lifetimes for 12 excited states up to 3.922 MeV excitations for {sup 145} Sm were determined for the first time. Decay curves of the these transitions are discussed. The new lifetimes of excited states in {sup 145} Sm enabled us to understand the electromagnetic properties. The deduced transition probabilities were established and compared with that of N = 83 isotones and the closed shell nucleus {sup 144} Sm. In addition, a nuclear structure of {sup 145} Sm have been discussed and proposed in framework of the shell model. 4 figs., 1 tab.

  8. Coulomb excitation of 206Hg at relativistic energies

    Science.gov (United States)

    Alexander, Tom

    The region of the nuclear chart surrounding the doubly-magic nucleus 208Pb provides a key area to constrain and develop contemporary nuclear structure models. One aspect of particular interest is the transition strength of the first excited 2+ state in even-even nuclei; this work describes the measurement of this value for the case of 206Hg, where the Z=80 line meets the N=126 shell closure. The nuclei of interest were synthesized using relativistic-energy projectile fragmentation at the GSI facility in Germany. They were produced in the fragmentation of a primary 208Pb beam at an energy of 1 GeV per nucleon, and separated and identifed using the Fragment Separator. The secondary beams with an energy of 140 MeV per nucleon were Coulomb excited on a secondary target of 400 mg/cm. 2 gold. Gamma-rays were detected with the Advanced GAmma Tracking Array (AGATA). The precise scattering angle for Doppler-correction was determined with position information from the Lund-York-Cologne-CAlorimeter(LYCCA). Using the sophisticated tracking algorithm native to AGATA in conjunction with pulse-shape analysis, a precise Doppler-correction is performed on the gamma spectra, and using a complex n-dimensional analysis, the B(E2) value for 206Hg is extracted relative to the known value also measured in 206Pb. A total of 409 million 206Hg particles were measured, and a cross-section of 50 mb was determined for the 2+ state at 1068 keV. The measurement of the B(E2) transition strength was found to be 1.109 W.u. This result is compared to a number of theoretical calculations, including two Gogny forces, and a modified shell model parametrization and is found to be smaller than all calculated estimations, implying that the first excited 2. + state in . {206}Hg is uncollective in nature.

  9. Measurement of L-XRF cross-sections and Coster–Kronig enhancement factors for {sup 62}Sm at excitation energies 6.8, 7.4 and 8 KeV

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R., E-mail: rajiv_005@rediffmail.com [Department of Physics, HCTM Technical Campus, Kaithal, Haryana 136027 (India); Rani, A., E-mail: anita_teotia@rediffmail.com [Department of Physics, University P.G. College Kurukshetra, Kurukshetra University, Kurukshetra, Haryana 136119 (India); Singh, R.M. [Department of Physics, Ch. Devi Lal University, Sirsa, Haryana 125055 (India); Tiwari, M.K.; Singh, A.K. [X-ray Optics Section, Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India)

    2016-05-15

    Highlights: • L XRF production cross-sections for {sup 62}Sm at excitation energies 6.8, 7.4 and 8 KeV were measured. • Synchrotron radiations with Peltier cooled Si(Li) detector was employed. • Experimental L XRF cross sections are in good agreement with the theoretical estimations of Puri’s data. • The present study was also carried out to examine the effect of Coster - Kronig transitions on L XRF cross section. • The measured enhancement factors are found to be smaller than the theoretical estimations. - Abstract: L{sub ℓ}, L{sub α} and L{sub β} XRF production cross-sections were measured for {sup 62}Sm at excitation energies i.e. 6.8 KeV, 7.4 KeV and 8 KeV using synchrotron radiations. Experimental measurements were also carried out to examine the effect of Coster–Kronig transitions (non-radiative transitions) on fluorescence cross section for the L{sub i} (i = 1, 2, 3) X-ray lines. The experimental cross-sections with greater accuracy and better signal to noise ratio can be measured using a polarized monoenergetic excitation beam and a high resolution detector system. A Peltier cooled vortex solid state detector with energy resolution of 138 eV at 5.959 keV X-ray was employed. Experimentally measured cross-sections have been compared with the theoretical predictions with the data of M.O. Krause [J. Phys. Chem. Ref. Data 8 (1979) 307], J.L. Campbell [At. Data Nucl. Data Tables 85 (2003) 291] and S. Puri et al. [X-Ray Spectrom. 22 (1993) 358]. The measured enhancement factors were found to be smaller than the theoretically calculated values.

  10. Electronic-excitation energy transfer in heterogeneous dye solutions under laser excitation

    International Nuclear Information System (INIS)

    Levshin, L.V.; Mukushev, B.T.; Saletskii, A.M.

    1995-01-01

    An experimental study has been made of electronic-excitation energy transfer (EEET) among dye molecules of different types for different exciting-fight wavelengths and temperatures. Upon selective laser excitation of the donor, the inhomogeneous broadening of molecular levels increases the probability of EEET from the donor to acceptor molecules. The efficiency of this process is directly proportional to the acceptor molecule concentration and is temperature dependent. The EEET is accompanied by the spectral migration of energy among donor molecules, which reduces the fluorescence quantum efficiency of the donor. Increasing the frequency of the exciting light decreases in the donor fluorescence quantum efficiency. An increase in the acceptor molecule concentration results in a decrease of the spectral migration of excitation in the donor molecule system. 5 refs., 5 figs

  11. Energy dependence of the ionization of highly excited atoms by collisions with excited atoms

    International Nuclear Information System (INIS)

    Shirai, T.; Nakai, Y.; Nakamura, H.

    1979-01-01

    Approximate analytical expressions are derived for the ionization cross sections in the high- and low-collision-energy limits using the improved impulse approximation based on the assumption that the electron-atom inelastic-scattering amplitude is a function only of the momentum transfer. Both cases of simultaneous excitation and de-excitation of one of the atoms are discussed. The formulas are applied to the collisions between two excited hydrogen atoms and are found very useful for estimating the cross sections in the wide range of collisions energies

  12. On the determination of the mean excitation energy of water

    DEFF Research Database (Denmark)

    Sabin, John R.; Oddershede, Jens; Sauer, Stephan P. A.

    2013-01-01

    Water is a ubiquitous substance in nature, and thus the mean excitation energy of water is an important quantity for understanding and prediction of the details of many fast ion/molecule collision processes such as those involved in external beam radiotherapy of tumors. There are several methods...... for determining numerical values for a mean excitation energy for water, both theoretical and experimental. Here the factors affecting the determination of the value of the mean excitation energy of water, especially from experiment, are discussed....

  13. Roles of the Excitation in Harvesting Energy from Vibrations.

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    Full Text Available The study investigated the role of excitation in energy harvesting applications. While the energy ultimately comes from the excitation, it was shown that the excitation may not always behave as a source. When the device characteristics do not perfectly match the excitation, the excitation alternately behaves as a source and a sink. The extent to which the excitation behaves as a sink determines the energy harvesting efficiency. Such contradictory roles were shown to be dictated by a generalized phase defined as the instantaneous phase angle between the velocity of the device and the excitation. An inductive prototype device with a diamagnetically levitated seismic mass was proposed to take advantage of the well established phase changing mechanism of vibro-impact to achieve a broader device bandwidth. Results suggest that the vibro-impact can generate an instantaneous, significant phase shift in response velocity that switches the role of the excitation. If introduced properly outside the resonance zone it could dramatically increase the energy harvesting efficiency.

  14. Effect of Optical Excitation Energy on the Red Luminescence of Eu(3+) in GaN

    National Research Council Canada - National Science Library

    Peng, H. Y; Lee, C. W; Everitt, H. O; Lee, D. S; Steckl, A. J; Zavada, J. M

    2005-01-01

    ...)] transition from GaN:Eu. Time-resolved PL measurements revealed that for excitation at the GaN bound exciton energy, the decay transients are almost temperature insensitive between 86 K and 300 K, indicating an efficient...

  15. Investigation of transversal nuclear excitation in 208Pb at excitation energies between 6 MeV and 8 MeV using inelastic electron scattering

    International Nuclear Information System (INIS)

    Frey, R.W.

    1978-01-01

    Using high resolution inelastic electron scattering magnitic dipole and quadrupole excitations in 208 Pb were investigated in the energy range between 6 MeV and 8 MeV. The electron energy was 50 MeV and 63.5 MeV. With a mean absolute energy resolution of 33 kev. 44 excited states were found in the above energy range. The measured angular distributions were compared with DWBA-calculations using random phase approximated wave functions. (FKS)

  16. A benchmark study of electronic excitation energies, transition moments, and excited-state energy gradients on the nicotine molecule

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, Franco, E-mail: franco.egidi@sns.it; Segado, Mireia; Barone, Vincenzo, E-mail: vincenzo.barone@sns.it [Scuola Normale Superiore, Piazza dei Cavalieri, 7 I-56126 Pisa (Italy); Koch, Henrik [Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Cappelli, Chiara [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi, 3 I-56124 Pisa (Italy)

    2014-12-14

    In this work, we report a comparative study of computed excitation energies, oscillator strengths, and excited-state energy gradients of (S)-nicotine, chosen as a test case, using multireference methods, coupled cluster singles and doubles, and methods based on time-dependent density functional theory. This system was chosen because its apparent simplicity hides a complex electronic structure, as several different types of valence excitations are possible, including n-π{sup *}, π-π{sup *}, and charge-transfer states, and in order to simulate its spectrum it is necessary to describe all of them consistently well by the chosen method.

  17. Energy-optimal electrical excitation of nerve fibers.

    Science.gov (United States)

    Jezernik, Saso; Morari, Manfred

    2005-04-01

    We derive, based on an analytical nerve membrane model and optimal control theory of dynamical systems, an energy-optimal stimulation current waveform for electrical excitation of nerve fibers. Optimal stimulation waveforms for nonleaky and leaky membranes are calculated. The case with a leaky membrane is a realistic case. Finally, we compare the waveforms and energies necessary for excitation of a leaky membrane in the case where the stimulation waveform is a square-wave current pulse, and in the case of energy-optimal stimulation. The optimal stimulation waveform is an exponentially rising waveform and necessitates considerably less energy to excite the nerve than a square-wave pulse (especially true for larger pulse durations). The described theoretical results can lead to drastically increased battery lifetime and/or decreased energy transmission requirements for implanted biomedical systems.

  18. Complete and incomplete fusion measurement and analysis of excitation functions in sup 1 sup 2 C + sup 1 sup 2 sup 8 Te system at energies near and above the coulomb barrier

    CERN Document Server

    Sharma, M K; Prasad, R; Gupta, S; Musthafa, M M; Bhardwaj, H D; Sinha, A K

    2003-01-01

    In order to study complete and incomplete fusion in heavy ion induced reactions the experiment has been carried out for measuring excitation functions (EF's) for several reactions in the system sup 1 sup 2 C + sup 1 sup 2 sup 8 Te, in the energy range approx = 42 - 82 MeV, using activation technique. To the best of our knowledge EF's for presently measured reactions are being reported for the first time. The measured EF's have been compared with those calculated theoretically using codes CASCADE and ALICE-91. Effect of variation of parameters, of the codes, on calculated EF's has also been studied. The analysis of the present data indicates presence of contributions from incomplete fusion in some cases. In general, theoretical calculations agree well with the experimental data.

  19. Energy-dependent collisional deactivation of vibrationally excited azulene

    International Nuclear Information System (INIS)

    Shi, J.; Barker, J.R.

    1988-01-01

    Collisional energy transfer parameters for highly vibrationally excited azulene have been deduced from new infrared fluorescence (IRF) emission lifetime data with an improved calibration relating IRF intensity to vibrational energy [J. Shi, D. Bernfeld, and J. R. Barker, J. Chem. Phys. 88, XXXX (1988), preceding paper]. In addition, data from previous experiments [M. J. Rossi, J. R. Pladziewicz, and J. R. Barker, J. Chem. Phys. 78, 6695 (1983)] have been reanalyzed based on the improved calibration. Inversion of the IRF decay curves produced plots of energy decay, which were analyzed to determine , the average energy transferred per collision. Master equation simulations reproduced both the original IRF decays and the deduced energy decays. A third (simple) method of determination agrees well with the other two. The results show to be nearly directly proportional to the vibrational energy of the excited azulene from ∼8000 to 33 000 cm -1 . At high energies, there are indications that the energy dependence may be slightly reduced

  20. Electron emission from materials at low excitation energies

    International Nuclear Information System (INIS)

    Urma, N.; Kijek, M.; Millar, J.J.

    1996-01-01

    Full text: An experimental system has been designed and developed with the purpose of measuring the total electron emission yield from materials at low energy excitation. In the first instance the reliability of the system was checked by measuring the total electron emission yield for a well defined surface (aluminium 99.45%). The obtained data was in the expected range given by the literature, and consequently the system will be used further for measuring the total electron yield for a range of materials with interest in the instrumentation industry. We intend to measure the total electron emission yield under electron bombardment as a function of incident electron energy up to 1200 eV, angle of incidence, state of the surface and environment to which the surface has been exposed. Dependence of emission on total electron irradiated dose is also of interest. For many practical application of the 'Secondary Electron Emission', the total electron yield is desired to be as large as possible. The above phenomenon has practical applicability in electron multiplier tube and Scanning electron microscopy - when by means of the variation of the yield of the emitted electrons one may produce visible images of small sample areas. The electron multiplier tube, is a device which utilises the above effect to detect and amplify both single particles and low currents streams of charged particles. The majority of electron tubes use electrons with low energy, hundreds of eV. Not a lot has been published in the literature about this regime and also about the emission when the impinging electrons have small energy, up to 1 KeV. The information obtained from the experimental measurements concerning the total electron emission yield is used to asses the investigated materials as a potential electron emitting surfaces or dynodes in an electron multiplier tube

  1. A scalable piezoelectric impulse-excited energy harvester for human body excitation

    International Nuclear Information System (INIS)

    Pillatsch, P; Yeatman, E M; Holmes, A S

    2012-01-01

    Harvesting energy from low-frequency and non-harmonic excitations typical of human motion presents specific challenges. While resonant devices do have an advantage in environments where the excitation frequency is constant, and while they can make use of the entire proof mass travel range in the case of excitation amplitudes that are smaller than the internal displacement limit, they are not suitable for body applications since the frequencies are random and the amplitudes tend to be larger than the device size. In this paper a piezoelectric, impulse-excited approach is presented. A cylindrical proof mass actuates an array of piezoelectric bi-morph beams through magnetic attraction. After the initial excitation these transducers are left to vibrate at their natural frequency. This increases the operational frequency range as well as the electromechanical coupling. The principle of impulse excitation is discussed and a centimetre-scale functional model is introduced as a proof of concept. The obtained data show the influence of varying the frequency, acceleration and proof mass. Finally, a commercially available integrated circuit for voltage regulation is tested. At a frequency of 2 Hz and an acceleration of 2.7 m s −2 a maximal power output of 2.1 mW was achieved. (paper)

  2. Differential cross sections for electron-impact vibrational-excitation of tetrahydrofuran at intermediate impact energies

    Energy Technology Data Exchange (ETDEWEB)

    Do, T. P. T. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); School of Education, Can Tho University, Campus II, 3/2 Street, Xuan Khanh, Ninh Kieu, Can Tho City (Viet Nam); Duque, H. V. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais (Brazil); Lopes, M. C. A. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais (Brazil); Konovalov, D. A.; White, R. D. [College of Science, Technology and Engineering, James Cook University, Townsville (Australia); Brunger, M. J., E-mail: michael.brunger@flinders.edu.au, E-mail: darryl.jones@flinders.edu.au [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Jones, D. B., E-mail: michael.brunger@flinders.edu.au, E-mail: darryl.jones@flinders.edu.au [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia)

    2015-03-28

    We report differential cross sections (DCSs) for electron-impact vibrational-excitation of tetrahydrofuran, at intermediate incident electron energies (15-50 eV) and over the 10°-90° scattered electron angular range. These measurements extend the available DCS data for vibrational excitation for this species, which have previously been obtained at lower incident electron energies (≤20 eV). Where possible, our data are compared to the earlier measurements in the overlapping energy ranges. Here, quite good agreement was generally observed where the measurements overlapped.

  3. Study of excitation energy sharing in heavy ion collisions as a function of their inelasticity

    International Nuclear Information System (INIS)

    Lott, B.

    1986-01-01

    The excitation energy sharing between the fragments of a heavy ion collision has been studied for quasi-elastic and deep inelastic mechanisms. A 32 S beam of 232 MeV incident energy has been used to bombard several targets (S, 58 Ni, 93 Nb). The evaporated charged particle multiplicities have been measured by inclusive measurements of the projectile-like nuclei and exclusive measurements of the two final nuclei. Evaporation calculations using the Hauser-Feshbach formalism allows us to deduce from the multiplicity measurements the projectile-like excitation energy. These results are compatible with the assumption of an equal sharing of excitation energies for quasi-elastic reaction products, and with the assumption of a mass ratio sharing for fully relaxed reaction products. Limiting values for the relaxation time of this mode have been deduced and are in agreement with predictions from the model developed by Randrup [fr

  4. The EDDA experiment: proton-proton elastic scattering excitation functions at intermediate energies

    International Nuclear Information System (INIS)

    Hinterberher, F.

    1996-01-01

    The EDDA experiment is designed to provide a high precision measurement of proton-proton elastic scattering excitation functions ranging from 0.5 to 2.5 GeV of (lab) incident kinetic energy. It is an internal target experiment utilizing the proton beam of the cooler synchrotron COSY operated by KFA Juelich. The excitation functions are measured during the acceleration ramp of COSY. (author)

  5. Mean excitation energies for use in Bethe's stopping-power formula

    International Nuclear Information System (INIS)

    Berger, M.J.; Seltzer, S.M.

    1983-01-01

    A review has been made of the mean excitation energies that can be derived from the analysis of stopping-power and range measurements, and from semi-empirical dipole oscillator-strength distributions for gases and dielectric-response functions for solids. On the basis of this review, mean excitation energies have been selected for 43 elemental substances and 54 compounds. Additivity rules have also been considered which allow one to estimate the mean excitation energies for compounds for which no direct data are available. These additivity rules are based on the use of mean excitation energies for atomic constituents which, to a certain extent, take into account the effects of chemical binding and physical aggregation

  6. Realistic level densities in fragment emission at high excitation energies

    International Nuclear Information System (INIS)

    Mustafa, M.G.; Blann, M.; Ignatyuk, A.V.

    1993-01-01

    Heavy fragment emission from a 44 100 Ru compound nucleus at 400 and 800 MeV of excitation is analyzed to study the influence of level density models on final yields. An approach is used in which only quasibound shell-model levels are included in calculating level densities. We also test the traditional Fermi gas model for which there is no upper energy limit to the single particle levels. We compare the influence of these two level density models in evaporation calculations of primary fragment excitations, kinetic energies and yields, and on final product yields

  7. Competition between excited core states and 1homega single-particle excitations at comparable energies in {sup 207}Pb from photon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pietralla, N., E-mail: pietralla@ikp.tu-darmstadt.d [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Li, T.C. [Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Fritzsche, M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ahmed, M.W. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Ahn, T.; Costin, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Enders, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Li, J. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Mueller, S.; Neumann-Cosel, P. von [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Pinayev, I.V. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Ponomarev, V.Yu.; Savran, D. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Tonchev, A.P.; Tornow, W.; Weller, H.R. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Werner, V. [A.W. Wright Nuclear Structure Laboratory (WNSL), Yale University, New Haven, CT (United States); Wu, Y.K. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany)

    2009-10-26

    The Pb(gamma{sup -}>,gamma{sup '}) photon scattering reaction has been studied with the nearly monochromatic, linearly polarized photon beams at the High Intensity gamma-ray Source (HIgammaS) at the DFELL. Azimuthal scattering intensity asymmetries measured with respect to the polarization plane of the beam have been used for the first time to assign both the spin and parity quantum numbers of dipole excited states of {sup 206,207,208}Pb at excitation energies in the vicinity of 5.5 MeV. Evidence for dominant particle-core coupling is deduced from these results along with information on excitation energies and electromagnetic transition matrix elements. Implications of the existence of weakly coupled states built on highly excited core states in competition with 1homega single particle (hole) excitations at comparable energies are discussed.

  8. Excitation-energy influence at the scission configuration

    Directory of Open Access Journals (Sweden)

    Ramos D.

    2017-01-01

    Full Text Available Transfer- and fusion-induced fission in inverse kinematics was proven to be a powerful tool to investigate nuclear fission, widening the information of the fission fragments and the access to unstable fissioning systems with respect to other experimental approaches. An experimental campaign for fission investigation has being carried out at GANIL with this technique since 2008. In these experiments, a beam of 238U, accelerated to 6.1 MeV/u, impinges on a 12C target. Fissioning systems from U to Cf are populated through transfer and fusion reactions, with excitation energies that range from few MeV up to 46 MeV. The use of inverse kinematics, the SPIDER telescope, and the VAMOS spectrometer permitted the characterization of the fissioning system in terms of mass, nuclear charge, and excitation energy, and the isotopic identification of the full fragment distribution. The neutron excess, the total neutron multiplicity, and the even-odd staggering in the nuclear charge of fission fragments are presented as a function of the excitation energy of the fissioning system. Structure effects are observed at Z∼50 and Z∼55, where their impact evolves with the excitation energy.

  9. El strength function at high spin and excitation energy

    International Nuclear Information System (INIS)

    Barrette, J.

    1983-04-01

    Recently giant dipole resonance-like concentration of the dipole strength function in nuclei was observed at both high excitation energies and high spins. This observation raises the possibility of obtaining new information on the shape of rapidly rotating heated nuclei. Recent experimental results on this subject are reviewed

  10. Excitation Energies of Superdeformed States in 196Pb: Towards a Systematic Study of the Second Well in Pb Isotopes

    International Nuclear Information System (INIS)

    Wilson, A.N.; Singh, A.K.; Huebel, H.; Rossbach, D.; Schonwasser, G.; Davidson, P.M.; Dracoulis, G.D.; Lane, G.J.; Goergen, A.; Korichi, A.; Hannachi, F.; Lopez-Martens, A.; Astier, A.; Azaiez, F.; Bourgeois, C.; Bazzacco, D.; Kroell, T.; Rossi-Alvarez, C.; Buforn, N.; Redon, N.

    2005-01-01

    The excitation energy of the lowest-energy superdeformed band in 196 Pb is established using the techniques of time-correlated γ-ray spectroscopy. Together with previous measurements on 192 Pb and 194 Pb, this result allows superdeformed excitation energies, binding energies, and two-proton and two-neutron separation energies to be studied systematically, providing stringent tests for current nuclear models. The results are examined for evidence of a 'superdeformed shell gap'

  11. Probing shape coexistence in neutron-deficient $^{72}$Se via low-energy Coulomb excitation

    CERN Multimedia

    We propose to study the evolution of nuclear structure in neutron-­deficient $^{72}$Se by performing a low-­energy Coulomb excitation measurement. Matrix elements will be determined for low-­lying excited states allowing for a full comparison with theoretical predictions. Furthermore, the intrinsic shape of the ground state, and the second 0$^{+}$ state, will be investigated using the quadrupole sum rules method.

  12. Lifetime and g-factor measurements of excited states using Coulomb excitation and alpha transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Guevara, Z. E., E-mail: zjguevaram@unal.edu.co; Torres, D. A., E-mail: datorresg@unal.edu.co [Physics Department, Universidad Nacional de Colombia, Bogotá D.C. (Colombia)

    2016-07-07

    In this contribution the challenges in the use of a setup to simultaneously measure lifetimes and g-factor values will be presented. The simultaneous use of the transient field technique and the Doppler Shift Attenuation Method, to measure magnetic moments and lifetimes respectively, allows to obtain a complete characterization of the currents of nucleons and the deformation in excited states close to the ground state. The technique is at the moment limited to Coulomb excitation and alpha-transfer reactions, what opens an interesting perspective to consider this type of experiments with radioactive beams. The use of deep-inelastic and fusion-evaporation reactions will be discussed. An example of a setup that makes use of a beam of {sup 106}Cd to study excited states of {sup 110}Sn and the beam nuclei itself will be presented.

  13. Mott transition: Low-energy excitations and superconductivity

    International Nuclear Information System (INIS)

    Ioffe, L.B.; Larkin, A.I.

    1988-09-01

    It is possible that metal-dielectric transition does not result in changes of magnetic or crystallographic symmetry. In this case a fermionic spectrum is not changed at the transition, but additional low-energy excitations appear which can be described as a gauge field that has the same symmetry as an electromagnetic one. In the case of a non half-filled band gapless scalar Bose excitations also appear. Due to the presence of additional gauge field the physical conductivity is determined by the lowest conductivity of the Fermi or Bose subsystems. (author). 11 refs

  14. Measurement of MOSFET LF Noise Under Large Signal RF Excitation

    NARCIS (Netherlands)

    van der Wel, A.P.; Klumperink, Eric A.M.; Nauta, Bram

    A new measurement technique is presented that allows measurement of MOSFET LF noise under large signal RF excitation. Measurements indicate that MOSFETS exhibit a reduction in LF noise when they are cycled from inversion to accummulation and that this reduction does not depend on the frequency of

  15. Time-resolved stimulated emission depletion and energy transfer dynamics in two-photon excited EGFP

    Science.gov (United States)

    Masters, T. A.; Robinson, N. A.; Marsh, R. J.; Blacker, T. S.; Armoogum, D. A.; Larijani, B.; Bain, A. J.

    2018-04-01

    Time and polarization-resolved stimulated emission depletion (STED) measurements are used to investigate excited state evolution following the two-photon excitation of enhanced green fluorescent protein (EGFP). We employ a new approach for the accurate STED measurement of the hitherto unmeasured degree of hexadecapolar transition dipole moment alignment ⟨α40 ⟩ present at a given excitation-depletion (pump-dump) pulse separation. Time-resolved polarized fluorescence measurements as a function of pump-dump delay reveal the time evolution of ⟨α40 ⟩ to be considerably more rapid than predicted for isotropic rotational diffusion in EGFP. Additional depolarization by homo-Förster resonance energy transfer is investigated for both ⟨α20 ⟩ (quadrupolar) and ⟨α40 ⟩ transition dipole alignments. These results point to the utility of higher order dipole correlation measurements in the investigation of resonance energy transfer processes.

  16. Glass-like, low-energy excitations in neutron-irradiated quartz

    International Nuclear Information System (INIS)

    Gardner, J.W.

    1980-01-01

    The specific heat and thermal conductivity of neutron-irradiated crystalline quartz have been measured for temperatures approx. = 0.1 to 5 K. Four types of low-energy excitations are observed in the irradiated samples, two of which can be removed selectively by heat treatment. One set of remaining excitations gives rise to low-temperature thermal behavior characteristic of glassy (amorphous) solids. The density of these glass-like excitations can be 50% the density observed in vitreous silica, yet the sample still retains long-range atomic order. In a less-irradiated sample, glass-like excitations may be present with a density only approx. = 2.5% that observed in vitreous silica and possess a similar broad energy spectrum over 0.1 to 1 K

  17. submitter Measurement of LYSO Intrinsic Light Yield Using Electron Excitation

    CERN Document Server

    Martinez Turtos, Rosana; Pizzichemi, Marco; Ghezzi, Alessio; Pauwels, Kristof; Auffray, Etiennette; Lecoq, Paul; Paganoni, Marco

    2016-01-01

    The determination of the intrinsic light yield $(LY_{int})$ of scintillating crystals, i.e. number of optical photons created per amount of energy deposited, constitutes a key factor in order to characterize and optimize their energy and time resolution. However, until now measurements of this quantity are affected by large uncertainties and often rely on corrections for bulk absorption and surface/edge state. The novel idea presented in this contribution is based on the confinement of the scintillation emission in the central upper part of a 10 mm cubic crystal using a 1.5 MeV electron beam with diameter of 1 mm. A black non-reflective pinhole aligned with the excitation point is used to fix the light extraction solid angle (narrower than total reflection angle), which then sets a light cone travel path through the crystal. The final number of photoelectrons detected using a Hamamatsu R2059 photomultiplier tube (PMT) was corrected for the extraction solid angle, the Fresnel reflection coefficient and quantum...

  18. Ab initio calculation of electron excitation energies in solids

    International Nuclear Information System (INIS)

    Louie, S.G.

    1996-02-01

    Progress in the first-principles calculation of electron excitation energies in solids is discussed. Quasiparticle energies are computed by expanding the electron self energy to first order in the screened Coulomb interaction in the so-called GW approximation. The method was applied to explain and predict spectroscopic properties of a variety of systems. Several illustrative applications to semiconductors, materials under pressure, chemisorption, and point defects in solids are presented. A recent reformulation of the method employing mixed- space functions and imaginary time techniques is also discussed

  19. Reaction 40Ca+natCu at 35 MeV/nucleon measured with the AMPHORA multidetector. Study of the excitation energy and angular momentum of the reconstructed projectile-like fragment

    International Nuclear Information System (INIS)

    Elhage, H.

    1992-10-01

    We have studied the reaction of 40 Ca with nat Cu at 35 MeV/nucleon with the AMPHORA multidetector. Three different reaction models were developed and we have shown that a simulation of the AMPHORA response is necessary to interpret the experimental results. Only two-body events were analyzed. Kinematic selection criterions, based on relative velocity, were used in order to isolate particles and residues coming from the de-excitation of the projectile-like fragment. The reconstitution of such a nucleus allowed to define the reaction plane and to calculate the energy balance event-by-event. We have proposed a method to determine the angular momentum based on the emission asymmetry of the light particles with respect to the normal to the reaction plane. The estimated angular momenta are in good agreement with the theoretical predictions. The projectile-like fragment temperature was estimated from the energy spectra of the light particles. The independent determination of the excitation energy, temperature and angular momentum allowed to calculate the level density parameter. This quantity does not evolve with the excitation energy and is equal to A/8. The projectile-like fragment de-excitation mode is mainly evaporation

  20. High spin spectroscopy near the N=Z line: Channel selection and excitation energy systematics

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, C.E.; Cameron, J.A.; Flibotte, S. [McMaster Univ., Ontario (Canada)] [and others

    1996-12-31

    The total {gamma}-ray and charged-particle energies emitted in fusion-evaporation reactions leading to N=Z compound systems in the A = 50-70 mass region have been measured with the 8{pi} {gamma}-ray spectrometer and the miniball charged-particle detector array. A new method of channel selection has been developed which combines particle identification with these total energy measurements and greatly improves upon the selectivity possible with particle detection alone. In addition, the event by event measurement of total {gamma}-ray energies using the BGO ball of the 8{pi} spectrometer has allowed a determination of excitation energies following particle evaporation for a large number of channels in several different reactions. The new channel selection procedure and excitation energy systematics are illustrated with data from the reaction of {sup 24}Mg on {sup 40}Ca at E{sub lab} = 80MeV.

  1. Rydberg energies using excited state density functional theory

    International Nuclear Information System (INIS)

    Cheng, C.-L.; Wu Qin; Van Voorhis, Troy

    2008-01-01

    We utilize excited state density functional theory (eDFT) to study Rydberg states in atoms. We show both analytically and numerically that semilocal functionals can give quite reasonable Rydberg energies from eDFT, even in cases where time dependent density functional theory (TDDFT) fails catastrophically. We trace these findings to the fact that in eDFT the Kohn-Sham potential for each state is computed using the appropriate excited state density. Unlike the ground state potential, which typically falls off exponentially, the sequence of excited state potentials has a component that falls off polynomially with distance, leading to a Rydberg-type series. We also address the rigorous basis of eDFT for these systems. Perdew and Levy have shown using the constrained search formalism that every stationary density corresponds, in principle, to an exact stationary state of the full many-body Hamiltonian. In the present context, this means that the excited state DFT solutions are rigorous as long as they deliver the minimum noninteracting kinetic energy for the given density. We use optimized effective potential techniques to show that, in some cases, the eDFT Rydberg solutions appear to deliver the minimum kinetic energy because the associated density is not pure state v-representable. We thus find that eDFT plays a complementary role to constrained DFT: The former works only if the excited state density is not the ground state of some potential while the latter applies only when the density is a ground state density.

  2. Experimental determination of fragment excitation energies in multifragmentation events

    International Nuclear Information System (INIS)

    Marie, N.; Natowitz, J.B.; Assenard, M.; Bacri, Ch.O.

    1998-01-01

    For 50 MeV/nucleon 129 Xe + nat Sn multifragmentation events, by means of correlation techniques, the multiplicities of the hydrogen and helium isotopes which were emitted by the hot primary excited fragments produced at the stage of the disassembly of an equilibrated hot source are determined. The relative kinetic energy distributions between the primary clusters and the light charged particles that they evaporate are also derived. From the comparison between the secondary multiplicities observed experimentally and the multiplicities predicted by the GEMINI model, it is concluded that the source breaks into primary fragments which are characterized by the same N/Z ratio as the combined system. Knowing the secondary light charged particle multiplicities and kinetic energies, the average charges of the hot fragments and are reconstructed their mean excitation energies are estimated. The fragment excitation energies are equal to 3.0 MeV/nucleon for the full range of intermediate mass fragment atomic number. This global constancy indicates that, on the average, thermodynamical equilibrium was achieved at the disassembly stage of the source. (author)

  3. Experimental determination of fragment excitation energies in multifragmentation events

    Energy Technology Data Exchange (ETDEWEB)

    Marie, N.; Natowitz, J.B. [Texas A and M Univ., College Station, TX (United States). Cyclotron Inst.; Chbihi, A.; Le Fevre, A.; Salou, S.; Wieleczko, J.P.; Gingras, L.; Auger, G. [Grand Accelerateur National d`Ions Lourds, 14 - Caen (France); Assenard, M. [Nantes Univ., 44 (France); Bacri, Ch.O. [Centre National de la Recherche Scientifique, CNRS, 91 - Orsay (France)] [and others

    1998-03-17

    For 50 MeV/nucleon {sup 129}Xe + {sup nat}Sn multifragmentation events, by means of correlation techniques, the multiplicities of the hydrogen and helium isotopes which were emitted by the hot primary excited fragments produced at the stage of the disassembly of an equilibrated hot source are determined. The relative kinetic energy distributions between the primary clusters and the light charged particles that they evaporate are also derived. From the comparison between the secondary multiplicities observed experimentally and the multiplicities predicted by the GEMINI model, it is concluded that the source breaks into primary fragments which are characterized by the same N/Z ratio as the combined system. Knowing the secondary light charged particle multiplicities and kinetic energies, the average charges of the hot fragments and are reconstructed their mean excitation energies are estimated. The fragment excitation energies are equal to 3.0 MeV/nucleon for the full range of intermediate mass fragment atomic number. This global constancy indicates that, on the average, thermodynamical equilibrium was achieved at the disassembly stage of the source. (author) 25 refs.

  4. Measurement and analysis of excitation functions in 20Ne + 27Al system

    International Nuclear Information System (INIS)

    Pachouri, Dipti; Singh, D.; Ali, R.; Afzal Ansari, M.; Rashid, M.H.

    2008-01-01

    In the present work, the excitation functions (EFs) for radioactive residues produced in the interaction of 20 Ne ion with 27 Al have been measured in order to study the reaction dynamics, particularly in the low mass region using the off-line γ-ray measurement activation technique for bombarding energies below 150 MeV

  5. General theory for environmental effects on (vertical) electronic excitation energies.

    Science.gov (United States)

    Schwabe, Tobias

    2016-10-21

    Almost 70 years ago, the first theoretical model for environmental effects on electronic excitation energies has been derived. Since then, several different interpretations and refined models have been proposed for the perichromic shift of a chromophore due to its surrounding medium. Some of these models are contradictory. Here, the contributing terms are derived within the framework of long-range perturbation theory with the least approximations so far. The derivation is based on a state-specific interpretation of the interaction energies and all terms can be identified with individual properties of either the chromophore or the surroundings, respectively. Further, the much debated contribution due to transition moments coupled to the environment can be verified in the form of a non-resonant excitonic coupling to the dynamic polarizabilities in the environment. These general insights should clarify discussions and interpretations of environmental effects on electronic excitations and should foster the development of new models for the computation of these effects.

  6. Vibrational energy transfer in selectively excited diatomic molecules

    International Nuclear Information System (INIS)

    Dasch, C.J.

    1978-09-01

    Single rovibrational states of HCl(v=2), HBr(v=2), DCl(v=2), and CO(v=2) were excited with a pulsed optical parametric oscillator (OPO). Total vibrational relaxation rates near - resonance quenchers were measured at 295 0 K using time resolved infrared fluorescence. These rates are attributed primarily to V - V energy transfer, and they generally conform to a simple energy gap law. A small deviation was found for the CO(v) + DCl(v') relaxation rates. Upper limits for the self relaxation by V - R,T of HCl(v=2) and HBr(v=2) and for the two quantum exchange between HCl and HBr were determined. The HF dimer was detected at 295 0 K and 30 torr HF pressure with an optoacoustic spectrometer using the OPO. Pulsed and chopped, resonant and non-resonant spectrophones are analyzed in detail. From experiments and first order perturbation theory, these V - V exchange rates appear to behave as a first order perturbation in the vibrational coordinates. The rotational dynamics are known to be complicated however, and the coupled rotational - vibrational dynamics were investigated theoreticaly in infinite order by the Dillon and Stephenson and the first Magnus approximations. Large ΔJ transitions appear to be important, but these calculations differ by orders of magnitude on specific rovibrational transition rates. Integration of the time dependent semiclassical equations by a modified Gordon method and a rotationally distorted wave approximation are discussed as methods which would treat the rotational motion more accurately. 225 references

  7. Excited state conformational dynamics in carotenoids: dark intermediates and excitation energy transfer.

    Science.gov (United States)

    Beck, Warren F; Bishop, Michael M; Roscioli, Jerome D; Ghosh, Soumen; Frank, Harry A

    2015-04-15

    A consideration of the excited state potential energy surfaces of carotenoids develops a new hypothesis for the nature of the conformational motions that follow optical preparation of the S2 (1(1)Bu(+)) state. After an initial displacement from the Franck-Condon geometry along bond length alternation coordinates, it is suggested that carotenoids pass over a transition-state barrier leading to twisted conformations. This hypothesis leads to assignments for several dark intermediate states encountered in femtosecond spectroscopic studies. The Sx state is assigned to the structure reached upon the onset of torsional motions near the transition state barrier that divides planar and twisted structures on the S2 state potential energy surface. The X state, detected recently in two-dimensional electronic spectra, corresponds to a twisted structure well past the barrier and approaching the S2 state torsional minimum. Lastly, the S(∗) state is assigned to a low lying S1 state structure with intramolecular charge transfer character (ICT) and a pyramidal conformation. It follows that the bent and twisted structures of carotenoids that are found in photosynthetic light-harvesting proteins yield excited-state structures that favor the development of an ICT character and optimized energy transfer yields to (bacterio)chlorophyll acceptors. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Is There Excitation Energy Transfer between Different Layers of Stacked Photosystem-II-Containing Thylakoid Membranes?

    Science.gov (United States)

    Farooq, Shazia; Chmeliov, Jevgenij; Trinkunas, Gediminas; Valkunas, Leonas; van Amerongen, Herbert

    2016-04-07

    We have compared picosecond fluorescence decay kinetics for stacked and unstacked photosystem II membranes in order to evaluate the efficiency of excitation energy transfer between the neighboring layers. The measured kinetics were analyzed in terms of a recently developed fluctuating antenna model that provides information about the dimensionality of the studied system. Independently of the stacking state, all preparations exhibited virtually the same value of the apparent dimensionality, d = 1.6. Thus, we conclude that membrane stacking does not affect the efficiency of the delivery of excitation energy toward the reaction centers but ensures a more compact organization of the thylakoid membranes within the chloroplast and separation of photosystems I and II.

  9. Cortical Excitability Measures in Patients and Unaffected Siblings

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-05-01

    Full Text Available Researchers at St Vincent's Hospital, Victoria, Australia, measured cortical excitability using transcranial magnetic stimulation in 157 patients with epilepsy (95 generalized and 62 focal and their asymptomatic siblings and results were compared to those of 12 controls and 20 of their siblings.

  10. Measurement of fusion excitation functions in the system {sup 78}Kr + {sup 100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

    1995-08-01

    Earlier measurements of fusion reactions involving {sup 78}Kr and {sup 100}Mo projectiles and Ni-targets showed surprisingly large fusion yields at low energies which could not be explained by coupled-channels calculations. The main difference to similar measurements involving the neighboring {sup 86}Kr and {sup 92}Mo isotopes was the different slope of the excitation functions at sub-barrier energies. An analysis of a variety of experiments showed a correlation between the nuclear structure and the slope of the excitation functions, with the {open_quotes}soft{close_quotes} transitional nuclei ({sup 78}Kr, {sup 100}Mo) exhibiting shallower slopes than the {open_quotes}stiff{close_quotes} nuclei ({sup 86}Kr, {sup 92}Mo) measured at the same energies with respect to the barrier. In this experiment we studied the fusion excitation function involving two transitional nuclei {sup 78}Kr + {sup 100}Mo. The measurements were performed with {sup 78}Kr beams from the ECR source at energies between 285-370 MeV. Separation of the evaporation nucleus from the elastically scattered particles was achieved by measuring time-of-flight and magnetic rigidity in the gas-filled spectrograph. The data were completely analyzed. A comparison of the cross sections with measurements for the system {sup 86}Kr + {sup 92}Mo populating the same compound nucleus {sup 178}Pt. It shows good agreement at the highest energies, but quite different falloffs of the excitation functions toward lower energies. Coupled-channels calculations, including multi-phonon excitation for the two systems, are being performed.

  11. Multi-modal highlight generation for sports videos using an information-theoretic excitability measure

    Science.gov (United States)

    Hasan, Taufiq; Bořil, Hynek; Sangwan, Abhijeet; L Hansen, John H.

    2013-12-01

    The ability to detect and organize `hot spots' representing areas of excitement within video streams is a challenging research problem when techniques rely exclusively on video content. A generic method for sports video highlight selection is presented in this study which leverages both video/image structure as well as audio/speech properties. Processing begins where the video is partitioned into small segments and several multi-modal features are extracted from each segment. Excitability is computed based on the likelihood of the segmental features residing in certain regions of their joint probability density function space which are considered both exciting and rare. The proposed measure is used to rank order the partitioned segments to compress the overall video sequence and produce a contiguous set of highlights. Experiments are performed on baseball videos based on signal processing advancements for excitement assessment in the commentators' speech, audio energy, slow motion replay, scene cut density, and motion activity as features. Detailed analysis on correlation between user excitability and various speech production parameters is conducted and an effective scheme is designed to estimate the excitement level of commentator's speech from the sports videos. Subjective evaluation of excitability and ranking of video segments demonstrate a higher correlation with the proposed measure compared to well-established techniques indicating the effectiveness of the overall approach.

  12. Coherence, energy and charge transfers in de-excitation pathways of electronic excited state of biomolecules in photosynthesis

    DEFF Research Database (Denmark)

    Bohr, Henrik; Malik, F. Bary

    2013-01-01

    The observed multiple de-excitation pathways of photo-absorbed electronic excited state in the peridinin–chlorophyll complex, involving both energy and charge transfers among its constituents, are analyzed using the bio-Auger (B-A) theory. It is also shown that the usually used F¨orster–Dexter...

  13. Measurement of excitation yields of low energy prompt γ-ray from proton bombardment of Cr-foils with energies ranging between 1.0 and 3.0 MeV

    International Nuclear Information System (INIS)

    Goncharov, A.

    2014-01-01

    The goal of this work is measurement of differential cross sections for the production of 378 keV γ-rays from the reactions 52 Cr(p,γ1) 53 Mn and 53 Cr(p,nγ1) 53 Mn for proton energies ranging between 1.0 and 3.0 MeV at the laboratory angle of 90° using foils with thickness ∼1.9×10 18 at/cm 2 (∼ 0.23 μm) of nat Cr.

  14. Energy conservation attenuates the loss of skeletal muscle excitability during intense contractions

    DEFF Research Database (Denmark)

    Macdonald, W A; Ørtenblad, N; Nielsen, Ole Bækgaard

    2007-01-01

    High-frequency stimulation of skeletal muscle has long been associated with ionic perturbations, resulting in the loss of membrane excitability, which may prevent action potential propagation and result in skeletal muscle fatigue. Associated with intense skeletal muscle contractions are large...... with control muscles, the resting metabolites ATP, phosphocreatine, creatine, and lactate, as well as the resting muscle excitability as measured by M-waves, were unaffected by treatment with BTS plus dantrolene. Following 20 or 30 s of continuous 60-Hz stimulation, BTS-plus-dantrolene-treated muscles showed...... changes in muscle metabolites. However, the role of metabolites in the loss of muscle excitability is not clear. The metabolic state of isolated rat extensor digitorum longus muscles at 30 degrees C was manipulated by decreasing energy expenditure and thereby allowed investigation of the effects of energy...

  15. Excitation of higher lying energy states in a rubidium DPAL

    Science.gov (United States)

    Wallerstein, A. J.; Perram, Glen; Rice, Christopher A.

    2018-02-01

    The spontaneous emission in a cw rubidium diode dumped alkali laser (DPAL) system was analyzed. The fluorescence from higher lying states decreases with additional buffer gas. The intermediate states (7S, 6P, 5D) decay more slowly with buffer gas and scale super-linearly with alkali density. A detailed kinetic model has been constructed, where the dominant mechanisms are energy pooling and single photon ionization. It also includes pumping into the non-Lorentzian wings of absorption profiles, fine structure mixing, collisional de-excitation, and Penning ionization. Effects of ionization in a high powered CW rubidium DPAL were assessed.

  16. Electron Energy Loss and One- and Two-Photon Excited SERS Probing of “Hot” Plasmonic Silver Nanoaggregates

    DEFF Research Database (Denmark)

    Kadkhodazadeh, Shima; Wagner, Jakob Birkedal; Joseph, Virginia

    2013-01-01

    in an optical experiment and electron energy loss intensity at energies corresponding to excitation wavelengths used for optical probing. This inverse relation exists independent on specific nanoaggregate geometries and is mainly controlled by the gap size between the particles forming the aggregate. The ratio...... between two- and one-photon excited SERS measured at different excitation wavelengths provides information about local fields in the hottest spots and their dependence on the photon energy. Our data verify experimentally the predicted increase of local optical fields in the hot spots with increasing wave...

  17. Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol

    International Nuclear Information System (INIS)

    Duque, H. V.; Chiari, L.; Jones, D. B.; Pettifer, Z.; Silva, G. B. da; Limão-Vieira, P.; Blanco, F.; García, G.; White, R. D.; Lopes, M. C. A.; Brunger, M. J.

    2014-01-01

    Differential and integral cross section measurements, for incident electron energies in the 20–50 eV range, are reported for excitation of several composite vibrational modes in α-tetrahydrofurfuryl alcohol (THFA). Optimisation and frequency calculations, using GAUSSIAN 09 at the B3LYP/aug-cc-pVDZ level, were also undertaken for the two most abundant conformers of THFA, with results being reported for their respective mode classifications and excitation energies. Those calculations assisted us in the experimental assignments of the composite features observed in our measured energy loss spectra. There are, to the best of our knowledge, no other experimental or theoretical data currently available in the literature against which we can compare the present results

  18. Intermediate energy electron impact excitation of composite vibrational modes in phenol

    Energy Technology Data Exchange (ETDEWEB)

    Neves, R. F. C. [School of Chemical and Physical Sciences, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001 (Australia); Instituto Federal do Sul de Minas Gerais, Campus Poços de Caldas, Minas Gerais (Brazil); Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, Minas Gerais (Brazil); Jones, D. B. [School of Chemical and Physical Sciences, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001 (Australia); Lopes, M. C. A.; Nixon, K. L. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, Minas Gerais (Brazil); Oliveira, E. M. de; Lima, M. A. P. [Instituto de Física ‘Gleb Wataghin,’ Universidade Estadual de Campinas, 13083-859 Campinas, São Paulo (Brazil); Costa, R. F. da [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580 Santo André, São Paulo (Brazil); Varella, M. T. do N. [Instituto de Física, Universidade de São Paulo, C.P. 66318, 05315-970 São Paulo (Brazil); Bettega, M. H. F. [Departamento de Física, Universidade Federal do Paraná, C.P. 19044, 81531-990 Curitiba, Paraná (Brazil); Silva, G. B. da [Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso (Brazil); Brunger, M. J., E-mail: Michael.Brunger@flinders.edu.au [School of Chemical and Physical Sciences, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-05-21

    We report differential cross section results from an experimental investigation into the electron impact excitation of a number of the low-lying composite (unresolved) vibrational modes in phenol (C{sub 6}H{sub 5}OH). The measurements were carried out at incident electron energies in the range 15–40 eV and for scattered-electron angles in the range 10–90°. The energy resolution of those measurements was typically ∼80 meV. Calculations, using the GAMESS code, were also undertaken with a B3LYP/aug-cc-pVDZ level model chemistry, in order to enable us to assign vibrational modes to the features observed in our energy loss spectra. To the best of our knowledge, the present cross sections are the first to be reported for vibrational excitation of the C{sub 6}H{sub 5}OH molecule by electron impact.

  19. Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Duque, H. V. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, MG (Brazil); Chiari, L.; Jones, D. B.; Pettifer, Z. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Silva, G. B. da [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso (Brazil); Limão-Vieira, P. [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Blanco, F. [Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Madrid E-28040 (Spain); García, G. [Instituto de Física Fundamental, CSIC, Madrid E-28006 (Spain); White, R. D. [School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Lopes, M. C. A. [Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, MG (Brazil); Brunger, M. J., E-mail: Michael.Brunger@flinders.edu.au [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, Kuala Lumpur (Malaysia)

    2014-06-07

    Differential and integral cross section measurements, for incident electron energies in the 20–50 eV range, are reported for excitation of several composite vibrational modes in α-tetrahydrofurfuryl alcohol (THFA). Optimisation and frequency calculations, using GAUSSIAN 09 at the B3LYP/aug-cc-pVDZ level, were also undertaken for the two most abundant conformers of THFA, with results being reported for their respective mode classifications and excitation energies. Those calculations assisted us in the experimental assignments of the composite features observed in our measured energy loss spectra. There are, to the best of our knowledge, no other experimental or theoretical data currently available in the literature against which we can compare the present results.

  20. A new recoil distance technique using low energy coulomb excitation in inverse kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Rother, W., E-mail: wolfram.rother@googlemail.com [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Dewald, A.; Pascovici, G.; Fransen, C.; Friessner, G.; Hackstein, M. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Ilie, G. [Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520 (United States); National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest-Magurele (Romania); Iwasaki, H. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Jolie, J. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Melon, B. [Dipartimento di Fisica, Universita di Firenze and INFN Sezione di Firenze, Sesto Fiorentino (Firenze) I-50019 (Italy); Petkov, P. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); INRNE-BAS, Sofia (Bulgaria); Pfeiffer, M. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Pissulla, Th. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Bundesumweltministerium, Robert-Schuman-Platz 3, D - 53175 Bonn (Germany); Zell, K.-O. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Jakobsson, U.; Julin, R.; Jones, P.; Ketelhut, S.; Nieminen, P.; Peura, P. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland); and others

    2011-10-21

    We report on the first experiment combining the Recoil Distance Doppler Shift technique and multistep Coulomb excitation in inverse kinematics at beam energies of 3-10 A MeV. The setup involves a standard plunger device equipped with a degrader foil instead of the normally used stopper foil. An array of particle detectors is positioned at forward angles to detect target-like recoil nuclei which are used as a trigger to discriminate against excitations in the degrader foil. The method has been successfully applied to measure lifetimes in {sup 128}Xe and is suited to be a useful tool for experiments with radioactive ion beams.

  1. Spin-isospin excitations induced by heavy ions at Saturne energies

    International Nuclear Information System (INIS)

    Hennino, T.

    1989-01-01

    Our program on the Spin-Isospin excitations started with the ( 3 He, 3 H) and ( 2 H, 2 He) reactions was extended with the heavy ion beams available at Saturne ( 12 C, 16 0, 20 Ne and 40 Ar) to study systematically the Δ excitation energy region. Projectile-ejectile dependences were measured. The Δ peak shift appears as a common feature in all charge exchange reactions. The first cross section calculations for the ( 12 C, 12 N) reaction are in good quantitative agreement with the data [fr

  2. Excitation functions for some evaporation residues identified in the interaction of 20Ne and 93Nb at moderate excitation energies

    International Nuclear Information System (INIS)

    Agarwal, Avinash; Rizvi, I.A.; Gupta, Meenal; Ahamad, Tauseef; Ghugre, S.S.; Sinha, A.K.; Chaubey, A.K.

    2008-01-01

    With the motivation of studying the complete and incomplete fusion reactions, excitation functions for the reactions 93 Nb(Ne, p2n) 110 Sn, 93 Nb(Ne, 2pn) 110 In, 93 Nb(Ne, 2p2n) 109 In, 93 Nb(Ne, αn) 108 In, 93 Nb(Neα2n) 107 In and 93 Nb(Ne, α p n) 107 Cd have been measured at the incident energy ranging from 91.4 MeV - 145 MeV. The well established activation technique followed by off line high purity gamma- ray spectroscopy was employed. The measured excitation functions were compared with the statistical model calculations by using the codes ALICE-91 and Pace-4. The effect of variation of different parameters including level density parameter involved in these codes has also been studied. Excellent agreement was found between theoretical and experimental values in some of the fusion evaporation reaction channels. However, significant enhancement of cross-section observed in α-emission channels may be due to incomplete fusion process. (author)

  3. Frequency and wavenumber selective excitation of spin waves through coherent energy transfer from elastic waves

    OpenAIRE

    Hashimoto, Yusuke; Bossini, Davide; Johansen, Tom H.; Saitoh, Eiji; Kirilyuk, Andrei; Rasing, Theo

    2017-01-01

    Using spin-wave tomography (SWaT), we have investigated the excitation and the propagation dynamics of optically-excited magnetoelastic waves, i.e. hybridized modes of spin waves and elastic waves, in a garnet film. By using time-resolved SWaT, we reveal the excitation dynamics of magnetoelastic waves through coherent-energy transfer between optically-excited pure-elastic waves and spin waves via magnetoelastic coupling. This process realizes frequency and wavenumber selective excitation of s...

  4. Excitation energy partition in 74Ge + 165Ho collision at energy 8.5 MeV/A

    International Nuclear Information System (INIS)

    Blocki, J.; Grotowski, K.; Planeta, R.

    1990-01-01

    The distribution of the excitation energy between both fragments in Heavy Ion Collision has been measured recently for the reaction 74 Ge + 165 Ho at 8.5 MeV/A. One can see from the experimental data a gradual transition from moreless equal partition of the heat for the peripheral collisions (small energy loss) toward equal temperatures in more central collisions (high energy loss). The similar dependence of the heat partition as a function of the energy loss was observed earlier by Vandenbosch et al for the reaction 56 Fe + 238 U at 8.5 MeV/A and by Benton et al for the 56 Fe + 165 Ho for a broad range of energy dissipation. Theoretical calculations leading to the excitation energy division between both fragments have been carried out by Randrup and by Feldmeier. In both calculations the same excitation mechanism was assumed which is the exchange of particles between colliding nuclei. Differences between results are mainly due to the different shape parametrization and calculation of the potential energy. Randrup's results are moving much faster towards equal temperatures limit if one goes to more central collisions. Both models however do not predict the direction of the experimental mass flow for the 56 Fe + 165 Ho system. In the present paper classical dynamical calculations following Feldmeir's approach with some modifications are presented for 74 Ge + 165 Ho system

  5. Photoluminescence excitation measurements using pressure-tuned laser diodes

    Science.gov (United States)

    Bercha, Artem; Ivonyak, Yurii; Medryk, Radosław; Trzeciakowski, Witold A.; Dybała, Filip; Piechal, Bernard

    2015-06-01

    Pressure-tuned laser diodes in external cavity were used as tunable sources for photoluminescence excitation (PLE) spectroscopy. The method was demonstrated in the 720 nm-1070 nm spectral range using a few commercial laser diodes. The samples for PLE measurements were quantum-well structures grown on GaAs and on InP. The method is superior to standard PLE measurements using titanium sapphire laser because it can be extended to any spectral range where anti-reflection coated laser diodes are available.

  6. Photoluminescence excitation measurements using pressure-tuned laser diodes

    International Nuclear Information System (INIS)

    Bercha, Artem; Ivonyak, Yurii; Mędryk, Radosław; Trzeciakowski, Witold A.; Dybała, Filip; Piechal, Bernard

    2015-01-01

    Pressure-tuned laser diodes in external cavity were used as tunable sources for photoluminescence excitation (PLE) spectroscopy. The method was demonstrated in the 720 nm-1070 nm spectral range using a few commercial laser diodes. The samples for PLE measurements were quantum-well structures grown on GaAs and on InP. The method is superior to standard PLE measurements using titanium sapphire laser because it can be extended to any spectral range where anti-reflection coated laser diodes are available

  7. Spectroscopic properties of the S1 state of linear carotenoids after excess energy excitation

    Science.gov (United States)

    Kuznetsova, Valentyna; Southall, June; Cogdell, Richard J.; Fuciman, Marcel; Polívka, Tomáš

    2017-09-01

    Properties of the S1 state of neurosporene, spheroidene and lycopene were studied after excess energy excitation in the S2 state. Excitation of carotenoids into higher vibronic levels of the S2 state generates excess vibrational energy in the S1 state. The vibrationally hot S1 state relaxes faster when carotenoid is excited into the S2 state with excess energy, but the S1 lifetime remains constant regardless of which vibronic level of the S2 state is excited. The S∗ signal depends on excitation energy only for spheroidene, which is likely due to asymmetry of the molecule, facilitating conformations responsible for the S∗ signal.

  8. A simplified approach for the coupling of excitation energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Shi Bo [Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei 230026 (China); Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Gao Fang, E-mail: gaofang@iim.ac.cn [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Liang Wanzhen [Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei 230026 (China); Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China)

    2012-02-06

    Highlights: Black-Right-Pointing-Pointer We propose a simple method to calculate the coupling of singlet-to-singlet and triplet-to-triplet energy transfer. Black-Right-Pointing-Pointer Coulomb term are the major contribution to the coupling of singlet-to-singlet energy transfer. Black-Right-Pointing-Pointer Effect from the intermolecular charge-transfer states dorminates in triplet-to-triplet energy transfer. Black-Right-Pointing-Pointer This method can be expanded by including correlated wavefunctions. - Abstract: A simplified approach for computing the electronic coupling of nonradiative excitation-energy transfer is proposed by following Scholes et al.'s construction on the initial and final states [G.D. Scholes, R.D. Harcourt, K.P. Ghiggino, J. Chem. Phys. 102 (1995) 9574]. The simplification is realized through defining a set of orthogonalized localized MOs, which include the polarization effect of the charge densities. The method allows calculating the coupling of both the singlet-to-singlet and triplet-to-triplet energy transfer. Numerical tests are performed for a few of dimers with different intermolecular orientations, and the results demonstrate that Coulomb term are the major contribution to the coupling of singlet-to-singlet energy transfer whereas in the case of triplet-to-triplet energy transfer, the dominant effect is arisen from the intermolecular charge-transfer states. The present application is on the Hartree-Fock level. However, the correlated wavefunctions which are normally expanded in terms of the determinant wavefunctions can be employed in the similar way.

  9. Measurement and analysis of excitation functions in (α,np) reactions on 128,130Te

    International Nuclear Information System (INIS)

    Singh, B.P.; Sankaracharyulu, M.G.V.; Ansari, M.A.; Prasad, R.; Bhardwaj, H.D.

    1992-02-01

    Excitation functions for the reactions 128 Te(α,np) 130 I, 130 Te(α,np) 132 I and 130 Te(α,np) 132m I have been measured using stacked foil technique and have also been calculated using statistical model with and without the inclusion of pre-equilibrium emission. As expected, inclusion of pre-equilibrium emission in compound nucleus calculations agree well with the experimental excitation functions. The pre-equilibrium fraction has been found to be energy and target mass number dependent. (author). 37 refs, 7 figs, 3 tabs

  10. Raman active high energy excitations in URu{sub 2}Si{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Buhot, Jonathan [Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot - Paris 7, Bât. Condorcet, 75205 Paris Cedex 13 (France); High Field Magnet Laboratory (HFML - EMFL), Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen (Netherlands); Gallais, Yann; Cazayous, Maximilien; Sacuto, Alain [Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot - Paris 7, Bât. Condorcet, 75205 Paris Cedex 13 (France); Piekarz, Przemysław [Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakòw (Poland); Lapertot, Gérard [Université Grenoble Alpes, INAC-SPSMS, F-38000 Grenoble (France); CEA, INAC-SPSMS, F-38000 Grenoble (France); Aoki, Dai [Université Grenoble Alpes, INAC-SPSMS, F-38000 Grenoble (France); CEA, INAC-SPSMS, F-38000 Grenoble (France); Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Méasson, Marie-Aude, E-mail: marie-aude.measson@univ-paris-diderot.fr [Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot - Paris 7, Bât. Condorcet, 75205 Paris Cedex 13 (France)

    2017-02-01

    We have performed Raman scattering measurements on URu{sub 2}Si{sub 2} single crystals on a large energy range up to ∼1300 cm{sup −1} and in all the Raman active symmetries as a function of temperature down to 15 K. A large excitation, active only in the E{sub g} symmetry, is reported. It has been assigned to a crystal electric field excitation on the Uranium site. We discuss how this constrains the crystal electric field scheme of the Uranium ions. Furthermore, three excitations in the A{sub 1g} symmetry are observed. They have been associated to double Raman phonon processes consistently with ab initio calculations of the phonons dispersion.

  11. Measuring industrial energy savings

    International Nuclear Information System (INIS)

    Kelly Kissock, J.; Eger, Carl

    2008-01-01

    Accurate measurement of energy savings from industrial energy efficiency projects can reduce uncertainty about the efficacy of the projects, guide the selection of future projects, improve future estimates of expected savings, promote financing of energy efficiency projects through shared-savings agreements, and improve utilization of capital resources. Many efforts to measure industrial energy savings, or simply track progress toward efficiency goals, have had difficulty incorporating changing weather and production, which are frequently major drivers of plant energy use. This paper presents a general method for measuring plant-wide industrial energy savings that takes into account changing weather and production between the pre and post-retrofit periods. In addition, the method can disaggregate savings into components, which provides additional resolution for understanding the effectiveness of individual projects when several projects are implemented together. The method uses multivariable piece-wise regression models to characterize baseline energy use, and disaggregates savings by taking the total derivative of the energy use equation. Although the method incorporates search techniques, multi-variable least-squares regression and calculus, it is easily implemented using data analysis software, and can use readily available temperature, production and utility billing data. This is important, since more complicated methods may be too complex for widespread use. The method is demonstrated using case studies of actual energy assessments. The case studies demonstrate the importance of adjusting for weather and production between the pre- and post-retrofit periods, how plant-wide savings can be disaggregated to evaluate the effectiveness of individual retrofits, how the method can identify the time-dependence of savings, and limitations of engineering models when used to estimate future savings

  12. Collective and single-particle states at high excitation energy

    International Nuclear Information System (INIS)

    Van den Berg, A.M.; Van der Molen, H.K.T.; Harakeh, M.N.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Ihara, F.; Inomata, T.

    2000-01-01

    Complete text of publication follows. Damping of high-lying single-particle states was investigated by the study of proton decay from high-lying states in 91 Nb, populated by the 90 Zr(α,t) reaction with E α = 180 MeV. In addition to decay to the ground state of 90 Zr, semi-direct decay was observed to the low-lying (2 + and 3 - ) phonon states, confirming the conclusion from other experiments that these phonon states play an important role in the damping process of the single-particle states. Furthermore, the population and decay of Isobaric Analogue States of 91 Zr, which are located at an excitation energy of about 10 - 12 MeV in 91 Nb, has been studied in the same reaction. (author)

  13. Development of the system for excitation function automatic measurement of nuclear reactions

    International Nuclear Information System (INIS)

    Sapozhnikov, A.B.

    2004-01-01

    Full text: The resonance nuclear reaction method is applied at the tandem accelerator UKP-2-1 to determinate films thickness and obtain light element depth distribution. The system for automatic measurement of the nuclear reaction excitation curve has been developed. It allowed to obtain an excitation function of nuclear reaction using continuous changing potential of the target with energy step of 6 eV. Saw-tooth voltage with amplitude up to 6 kV from the block of scanning beam is fed to a target. The amplitude is determined by constant voltage from the scanning beam block control. Nal(Tl) detector detects gamma quanta - the products of a nuclear reaction and transforms they in voltage impulses. The impulses through the amplifier income in the single-channel analyzer which forms impulses to start the analog-to-digital converter. The value of saw-tooth voltage corresponding to the moment of gamma quantum detection is read by the analog-to-digital converter, where it is transformed to digital code and transmitted to the computer. The computer program has been developed to control the process of accumulation of excitation function. The dependence a detected γ-quanta yield from a target potential is automatically plotted by the program. This dependence corresponds to the nuclear reaction excitation function. If scanning amplitude is not enough in order to scan need depth of a sample, an operator increases energy of the proton beam changing high voltage potential of the terminal up 3 keV and measures the nuclear reaction excitation function with the new energy. This procedure can be repeated some times. After that 'sewing' of excitation functions is carried out by the program under the hypothesis that nuclear reaction yield in last points be identical

  14. Radiative proton capture to the first excited state of sup 29 P nucleus at subbarrier energies

    Energy Technology Data Exchange (ETDEWEB)

    Matulewicz, T; Dabrowska, M; Decowski, P; Kicinska-Habior, M; Sikora, B [Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej; Toke, J [Rochester Univ., NY (USA). Nuclear Structure Research Lab.; Somorjai, E [Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete

    1985-08-01

    Differential cross sections at 0 deg and 90 deg measured for {sup 28}Si(p,{gamma}{sub 1}){sup 29}P reaction at proton energy range 2.3-2.9 MeV have been analyzed in terms of the direct-semidirect capture model extended by the effective potential approach. Spectroscopic factor of the first excited states of {sup 29}P nucleus was found to be 0.10+-0.05. 9 refs., 1 fig. (author).

  15. Energy risk management through self-exciting marked point process

    International Nuclear Information System (INIS)

    Herrera, Rodrigo

    2013-01-01

    Crude oil is a dynamically traded commodity that affects many economies. We propose a collection of marked self-exciting point processes with dependent arrival rates for extreme events in oil markets and related risk measures. The models treat the time among extreme events in oil markets as a stochastic process. The main advantage of this approach is its capability to capture the short, medium and long-term behavior of extremes without involving an arbitrary stochastic volatility model or a prefiltration of the data, as is common in extreme value theory applications. We make use of the proposed model in order to obtain an improved estimate for the Value at Risk in oil markets. Empirical findings suggest that the reliability and stability of Value at Risk estimates improve as a result of finer modeling approach. This is supported by an empirical application in the representative West Texas Intermediate (WTI) and Brent crude oil markets. - Highlights: • We propose marked self-exciting point processes for extreme events in oil markets. • This approach captures the short and long-term behavior of extremes. • We improve the estimates for the VaR in the WTI and Brent crude oil markets

  16. Excitation energy of the fragments produced in central collisions of Xe + Sn at intermediate energies

    International Nuclear Information System (INIS)

    Hudan, S.; Chbihi, A.; Frankland, J.D.

    2000-01-01

    Characteristics of the primary fragments produced in central collisions of Xe + Sn system from 32 to 50 AMeV have been deduced. By using the relative velocity correlation technique between the light charged particles (LCP) and detected fragments, we were able to extract the multiplicities and average kinetic energy of the secondary evaporated LCP. We then reconstructed the size and excitation energy of the primary fragments. For each bombarding energy a constant value of the excitation energy per nucleon, over the whole range of fragment charge has been found, suggesting that on the average thermodynamical equilibrium has been achieved at the freeze-out. This value increases slightly from 2.8 to 3.8 AMeV with a large increase of bombarding energy, 32 to 50 AMeV. (authors)

  17. Excitation energy of the fragments produced in central collisions of Xe + Sn at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Hudan, S.; Chbihi, A.; Frankland, J.D. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)] [and others

    2000-07-01

    Characteristics of the primary fragments produced in central collisions of Xe + Sn system from 32 to 50 AMeV have been deduced. By using the relative velocity correlation technique between the light charged particles (LCP) and detected fragments, we were able to extract the multiplicities and average kinetic energy of the secondary evaporated LCP. We then reconstructed the size and excitation energy of the primary fragments. For each bombarding energy a constant value of the excitation energy per nucleon, over the whole range of fragment charge has been found, suggesting that on the average thermodynamical equilibrium has been achieved at the freeze-out. This value increases slightly from 2.8 to 3.8 AMeV with a large increase of bombarding energy, 32 to 50 AMeV. (authors)

  18. Probing core polarization around 78Ni: intermediate energy Coulomb excitation of 74Ni

    Directory of Open Access Journals (Sweden)

    Marchi T.

    2013-12-01

    We have recently measured the B(E2; 0+ → 2+ of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2 values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes.

  19. Energy harvesting from human motion: exploiting swing and shock excitations

    International Nuclear Information System (INIS)

    Ylli, K; Hoffmann, D; Willmann, A; Becker, P; Folkmer, B; Manoli, Y

    2015-01-01

    Modern compact and low power sensors and systems are leading towards increasingly integrated wearable systems. One key bottleneck of this technology is the power supply. The use of energy harvesting techniques offers a way of supplying sensor systems without the need for batteries and maintenance. In this work we present the development and characterization of two inductive energy harvesters which exploit different characteristics of the human gait. A multi-coil topology harvester is presented which uses the swing motion of the foot. The second device is a shock-type harvester which is excited into resonance upon heel strike. Both devices were modeled and designed with the key constraint of device height in mind, in order to facilitate the integration into the shoe sole. The devices were characterized under different motion speeds and with two test subjects on a treadmill. An average power output of up to 0.84 mW is achieved with the swing harvester. With a total device volume including the housing of 21 cm 3 a power density of 40 μW cm −3 results. The shock harvester generates an average power output of up to 4.13 mW. The power density amounts to 86 μW cm −3 for the total device volume of 48 cm 3 . Difficulties and potential improvements are discussed briefly. (paper)

  20. Fission of highly excited nuclei investigated in complete kinematic measurements

    International Nuclear Information System (INIS)

    Rodriguez-Sanchez, J. L.; Benlliure, J.; Taieb, J.; Avarez-Pol, H.; Audouin, L.; Ayyad, Y.; Belier, G.; Boutoux, G.; Casarejos, E.; Chatillon, A.; Cortina-Gil, D.; Gorbinet, T.; Heinz, A.; Kelic-Heil, A.; Kurz, N.; Laurent, B.; Martin, J. F.; Paradela, C.; Pellereau, E.; Pietras, B.; Prochazka, A.; Ramos, D.; Rodriguez-Tajes, C.; Rossi, D.; Simon, H.; Tassan-Got, L.; Vargas, J.; Voss, B.

    2013-01-01

    Fission is an extremely complex mechanism that requires a dynamical approach to describe the evolution of the process in terms of intrinsic and collective excitations of the nuclear constituents. In order to determine these effects a complex experimental setup was mounted at GSI, which allowed us for the first time the full identification in charge and mass of all fission fragments thanks to a magnetic separation and the use of the inverse kinematic technique. Moreover, we also measured the neutron multiplicities and the light-charged particles emitted in coincidence with fission. These complete kinematic measurements will be used to define sensitive observables to dissipative and transient effects in fission. In this manuscript we present the first results for the total fission cross sections. (authors)

  1. Quinary excitation method for pulse compression ultrasound measurements.

    Science.gov (United States)

    Cowell, D M J; Freear, S

    2008-04-01

    A novel switched excitation method for linear frequency modulated excitation of ultrasonic transducers in pulse compression systems is presented that is simple to realise, yet provides reduced signal sidelobes at the output of the matched filter compared to bipolar pseudo-chirp excitation. Pulse compression signal sidelobes are reduced through the use of simple amplitude tapering at the beginning and end of the excitation duration. Amplitude tapering using switched excitation is realised through the use of intermediate voltage switching levels, half that of the main excitation voltages. In total five excitation voltages are used creating a quinary excitation system. The absence of analogue signal generation and power amplifiers renders the excitation method attractive for applications with requirements such as a high channel count or low cost per channel. A systematic study of switched linear frequency modulated excitation methods with simulated and laboratory based experimental verification is presented for 2.25 MHz non-destructive testing immersion transducers. The signal to sidelobe noise level of compressed waveforms generated using quinary and bipolar pseudo-chirp excitation are investigated for transmission through a 0.5m water and kaolin slurry channel. Quinary linear frequency modulated excitation consistently reduces signal sidelobe power compared to bipolar excitation methods. Experimental results for transmission between two 2.25 MHz transducers separated by a 0.5m channel of water and 5% kaolin suspension shows improvements in signal to sidelobe noise power in the order of 7-8 dB. The reported quinary switched method for linear frequency modulated excitation provides improved performance compared to pseudo-chirp excitation without the need for high performance excitation amplifiers.

  2. Empirical regularities in the excitation cross-section behavior of the lead atom (transitions from energy levels of 6pnd configurations)

    Science.gov (United States)

    Smirnov, Yu M.

    2018-03-01

    Electron-impact excitation of lead atom levels belonging to 6pnd configurations has been studied in experiment. One hundred two excitation cross-sections have been measured at an incident electron energy of 50 eV. Eleven optical excitation functions (OEFs) have been recorded in the exciting electron energy range of E = 0-200 eV. The resulting findings were used to study the excitation cross-sections dependence on the principal quantum number of upper levels for thirteen PbI spectral series.

  3. Nested variant of the method of moments of coupled cluster equations for vertical excitation energies and excited-state potential energy surfaces.

    Science.gov (United States)

    Kowalski, Karol

    2009-05-21

    In this article we discuss the problem of proper balancing of the noniterative corrections to the ground- and excited-state energies obtained with approximate coupled cluster (CC) and equation-of-motion CC (EOMCC) approaches. It is demonstrated that for a class of excited states dominated by single excitations and for states with medium doubly excited component, the newly introduced nested variant of the method of moments of CC equations provides mathematically rigorous way of balancing the ground- and excited-state correlation effects. The resulting noniterative methodology accounting for the effect of triples is tested using its parallel implementation on the systems, for which iterative CC/EOMCC calculations with full inclusion of triply excited configurations or their most important subset are numerically feasible.

  4. Lifetime measurements of excited states in 17C: Possible interplay between collectivity and halo effects

    International Nuclear Information System (INIS)

    Suzuki, D.; Iwasaki, H.; Ong, H.J.; Imai, N.; Sakurai, H.; Nakao, T.; Aoi, N.; Baba, H.; Bishop, S.; Ichikawa, Y.; Ishihara, M.; Kondo, Y.; Kubo, T.; Kurita, K.; Motobayashi, T.; Nakamura, T.; Okumura, T.; Onishi, T.K.; Ota, S.; Suzuki, M.K.

    2008-01-01

    Lifetime measurements were performed on low-lying excited states of the neutron-rich isotope 17 C using the recoil shadow method. The γ-decay mean lifetimes were determined to be 583±21(stat)±35(syst) ps for the first excited state at 212 keV and 18.9±0.6(stat)±4.7(syst) ps for the second excited state at 333 keV. Based on a comparison with the empirical upper limits for the electromagnetic transition strengths, these decays are concluded to be predominantly M1 transitions. The reduced M1 transition probabilities to the ground state were deduced to be (1.0±0.1)x10 -2 μ N 2 and (8.2 -1.8 +3.2 )x10 -2 μ N 2 , respectively, for the first and second excited states. The strongly hindered M1 strength as well as the lowered excitation energy represents unique nature of the 212-keV state

  5. Resonant states in 13C and 16,17O at high excitation energy

    International Nuclear Information System (INIS)

    Rodrigues, M R D; Borello-Lewin, T; Miyake, H; Duarte, J L M; Rodrigues, C L; Horodynski-Matsushigue, L B; Ukita, G M; Cappuzzello, F; Foti, A; Cavallaro, M; Agodi, C; Cunsolo, A; Carbone, D; Bondi, M; Napoli, M De; Roeder, B T; Linares, R; Lombardo, I

    2014-01-01

    The 9 Be( 6 Li,d) 13 C and 12,13 C( 6 Li,d) 16,17 O reactions were measured at the São Paulo Pelletron-Enge-Spectrograph facility at 25.5 MeV incident energy. The nuclear emulsion detection technique was applied. Several narrow resonances were populated up to approximately 17 MeV of excitation energy. An excellent energy resolution was obtained: 40 keV for 13 C and 15-30 keV for 16 O. The upper limit for the resonance widths were determined. Recently, d-a angular correlations were measured at θ d = 0° with incident energy of 25 MeV using the LNS Tandem-MAGNEX Spectrometer facility

  6. Resonant states in 13C and 16,17O at high excitation energy

    Science.gov (United States)

    Rodrigues, M. R. D.; Borello-Lewin, T.; Miyake, H.; Duarte, J. L. M.; Rodrigues, C. L.; Horodynski-Matsushigue, L. B.; Ukita, G. M.; Cappuzzello, F.; Cavallaro, M.; Foti, A.; Agodi, C.; Cunsolo, A.; Carbone, D.; Bondi, M.; De Napoli, M.; Roeder, B. T.; Linares, R.; Lombardo, I.

    2014-12-01

    The 9Be(6Li,d)13C and 12,13C(6Li,d)16,17O reactions were measured at the São Paulo Pelletron-Enge-Spectrograph facility at 25.5 MeV incident energy. The nuclear emulsion detection technique was applied. Several narrow resonances were populated up to approximately 17 MeV of excitation energy. An excellent energy resolution was obtained: 40 keV for 13C and 15-30 keV for 16O. The upper limit for the resonance widths were determined. Recently, d-a angular correlations were measured at θd = 0° with incident energy of 25 MeV using the LNS Tandem-MAGNEX Spectrometer facility.

  7. Fe L-shell Excitation Cross Section Measurements on EBIT-I

    Science.gov (United States)

    Chen, Hui; Beiersdorfer, P.; Brown, G.; Boyce, K.; Kelley, R.; Kilbourne, C.; Porter, F.; Gu, M. F.; Kahn, S.

    2006-09-01

    We report the measurement of electron impact excitation cross sections for the strong iron L-shell 3-2 lines of Fe XVII to Fe XXIV at the LLNL EBIT-I electron beam ion trap using a crystal spectrometer and NASA-Goddard Space Flight Center's 6x6 pixel array microcalorimeter. The cross sections were determined by direct normalization to the well-established cross sections for radiative electron capture. Our results include the excitation cross section for over 50 lines at multiple electron energies. Although we have found that for 3C line in Fe XVII the measured cross sections differ significantly from theory, in most cases the measurements and theory agree within 20%. This work was performed under the auspices of the U.S. DOE by LLNL under contract No. W-7405-Eng-48 and supported by NASA APRA grants to LLNL, GSFC, and Stanford University.

  8. Plunger lifetime measurements in {sup 128}Xe using Coulomb excitation in inverse kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Rother, Wolfram; Dewald, Alfred; Ilie, Gabriela; Pissulla, Thomas; Melon, Barbara; Jolie, Jan; Pascovici, Gheorghe; Zell, Karl-Oskar [IKP, Universitaet zu Koeln, Koeln (Germany); Julin, Rauno; Jones, Peter; Greenless, Paul; Rahkila, Panu; Scholey, Cath [JYFL, University of Jyvaeskylae, Jyvaeskylae (Finland); Harissopulos, Sotirios; Lagoyannis, Anastasios; Konstantinopoulos, T. [INP, N.C.S.R. ' ' Demokritos' ' , Athens (Greece); Grahn, Tuomas [JYFL, University of Jyvaeskylae, Jyvaeskylae (Finland)]|[Oliver Lodge Lab., University of Liverpool, Liverpool (United Kingdom); Balabanski, Dimiter [INRNE, Sofia (Bulgaria)

    2008-07-01

    We report on an experiment using Coulomb excitation in inverse kinematics in combination with the plunger technique for measuring lifetimes of excited states of the projectile. Aside from the investigation of E(2) features in {sup 128}Xe, the aim was to explore the special features of such experiments which are also suited to be used with radioactive beams. The measurement was performed at the JYFL with the Koeln coincidence plunger device and the JuroGam spectrometer using a {sup 128}Xe beam impinging on a {sup nat}Fe target at a beam energy of 525 MeV. Recoils were detected by means of 32 solar cells placed at extrem forward angles. Recoil-gated {gamma}-singles and {gamma}{gamma}-coincidences were measured at different target-degrader distances. Details of the experiment and first results are presented.

  9. Low-energy charge transfer excitations in NiO

    International Nuclear Information System (INIS)

    Sokolov, V I; Yermakov, A Ye; Uimin, M A; Gruzdev, N B; Pustovarov, V A; Churmanov, V N; Ivanov, V Yu; Sokolov, P S; Baranov, A N; Moskvin, A S

    2012-01-01

    Comparative analysis of photoluminescence (PL) and photoluminescence excitation (PLE) spectra of NiO poly- and nanocrystals in the spectral range 2-5.5 eV reveals two PLE bands peaked near 3.7 and 4.6 eV with a dramatic rise in the low-temperature PLE spectral weight of the 3.7 eV PLE band in the nanocrystalline NiO as compared with its polycrystalline counterpart. In frames of a cluster model approach we assign the 3.7 eV PLE band to the low-energy bulk-forbidden p-d (t 1g (π)-e g ) charge transfer (CT) transition which becomes the allowed one in the nanocrystalline state while the 4.6 eV PLE band is related to a bulk allowed d-d (e g -e g ) CT transition scarcely susceptible to the nanocrystallization. The PLE spectroscopy of the nanocrystalline materials appears to be a novel informative technique for inspection of different CT transitions.

  10. Measurement of light charged particles in the decay channels of medium-mass excited compound nuclei

    Directory of Open Access Journals (Sweden)

    Valdré S.

    2014-03-01

    Indeed, in this mass region (A ~ 100 models predict that shape transitions can occur at high spin values and relatively scarce data exist in the literature about coincidence measurements between evaporation residues and light charged particles. Signals of shape transitions can be found in the variations of the lineshape of high energy gamma rays emitted from the de-excitation of GDR states gated on different region of angular momenta. For this purpose it is important to keep under control the FE and FF processes, to regulate the statistical model parameters and to control the onset of possible pre-equilibrium emissions from 300 to 600 MeV bombarding energy.

  11. Excitations

    International Nuclear Information System (INIS)

    Dorner, B.

    1996-01-01

    A short introduction to instrumental resolution is followed by a discussion of visibilities of phonon modes due to their eigenvectors. High precision phonon dispersion curves in GaAs are presented together with 'ab initio' calculations. Al 2 O 3 is taken as an example of selected visibility due to group theory. By careful determination of phonon intensities eigenvectors can be determined, such as in Silicon and Diamond. The investigation of magnon modes is shown for the garnet Fe 2 Ca 3 (GeO 4 ) 3 , where also a quantum gap due to zero point spin fluctuations was observed. The study of the splitting of excitons in CsFeCl 3 in an applied magnetic field demonstrates the possibilities of neutron polarisation analysis, which made it possible to observe a mode crossing. An outlook to inelastic X-ray scattering with very high energy resolution of synchrotron radiation is given with the examples of phonons in Beryllium and in water. (author) 19 figs., 36 refs

  12. High frequency energy measurements

    International Nuclear Information System (INIS)

    Stotlar, S.C.

    1981-01-01

    High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

  13. Z-dependence of Mean Excitation Energies for Second and Third Row Atoms and Their Ions

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Sabin, John R.; Oddershede, Jens

    2018-01-01

    All mean excitations energies for second and third row atoms and their ions are calculated in the random‐phase approximation using large basis sets. To a very good approximation it turns out that mean excitation energies within an isoelectronic series is a quadratic function of the nuclear charge...

  14. Excitation energy of a helium 3 quasiparticle in the bulk mixture at constant pressure

    International Nuclear Information System (INIS)

    Yim, M.B.

    1981-01-01

    A 3 He quasiparticle excitation energy in bulk mixture at zero pressure and 6% solution is calculated to O(x) using the bulk effective interaction of Yim and Massey. The present 3 He quasiparticle excitation energy is in agreement with the experimental result of Hilton, Scherm and Stirling. (author)

  15. Exploring the vibrational fingerprint of the electronic excitation energy via molecular dynamics

    International Nuclear Information System (INIS)

    Deyne, Andy Van Yperen-De; Pauwels, Ewald; Ghysels, An; Waroquier, Michel; Van Speybroeck, Veronique; Hemelsoet, Karen; De Meyer, Thierry; De Clerck, Karen

    2014-01-01

    A Fourier-based method is presented to relate changes of the molecular structure during a molecular dynamics simulation with fluctuations in the electronic excitation energy. The method implies sampling of the ground state potential energy surface. Subsequently, the power spectrum of the velocities is compared with the power spectrum of the excitation energy computed using time-dependent density functional theory. Peaks in both spectra are compared, and motions exhibiting a linear or quadratic behavior can be distinguished. The quadratically active motions are mainly responsible for the changes in the excitation energy and hence cause shifts between the dynamic and static values of the spectral property. Moreover, information about the potential energy surface of various excited states can be obtained. The procedure is illustrated with three case studies. The first electronic excitation is explored in detail and dominant vibrational motions responsible for changes in the excitation energy are identified for ethylene, biphenyl, and hexamethylbenzene. The proposed method is also extended to other low-energy excitations. Finally, the vibrational fingerprint of the excitation energy of a more complex molecule, in particular the azo dye ethyl orange in a water environment, is analyzed

  16. Rotating permanent magnet excitation for blood flow measurement.

    Science.gov (United States)

    Nair, Sarath S; Vinodkumar, V; Sreedevi, V; Nagesh, D S

    2015-11-01

    A compact, portable and improved blood flow measurement system for an extracorporeal circuit having a rotating permanent magnetic excitation scheme is described in this paper. The system consists of a set of permanent magnets rotating near blood or any conductive fluid to create high-intensity alternating magnetic field in it and inducing a sinusoidal varying voltage across the column of fluid. The induced voltage signal is acquired, conditioned and processed to determine its flow rate. Performance analysis shows that a sensitivity of more than 250 mV/lpm can be obtained, which is more than five times higher than conventional flow measurement systems. Choice of rotating permanent magnet instead of an electromagnetic core generates alternate magnetic field of smooth sinusoidal nature which in turn reduces switching and interference noises. These results in reduction in complex electronic circuitry required for processing the signal to a great extent and enable the flow measuring device to be much less costlier, portable and light weight. The signal remains steady even with changes in environmental conditions and has an accuracy of greater than 95%. This paper also describes the construction details of the prototype, the factors affecting sensitivity and detailed performance analysis at various operating conditions.

  17. Intermediate energy cross sections for electron-impact vibrational-excitation of pyrimidine

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D. B. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Ellis-Gibbings, L.; García, G. [Instituto de Física Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); Nixon, K. L. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais (Brazil); School of Biology, Chemistry and Forensic Science, University of Wolverhampton, Wolverhampton WV1 1LY (United Kingdom); Lopes, M. C. A. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais (Brazil); Brunger, M. J., E-mail: Michael.Brunger@flinders.edu.au [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-09-07

    We report differential cross sections (DCSs) and integral cross sections (ICSs) for electron-impact vibrational-excitation of pyrimidine, at incident electron energies in the range 15–50 eV. The scattered electron angular range for the DCS measurements was 15°–90°. The measurements at the DCS-level are the first to be reported for vibrational-excitation in pyrimidine via electron impact, while for the ICS we extend the results from the only previous condensed-phase study [P. L. Levesque, M. Michaud, and L. Sanche, J. Chem. Phys. 122, 094701 (2005)], for electron energies ⩽12 eV, to higher energies. Interestingly, the trend in the magnitude of the lower energy condensed-phase ICSs is much smaller when compared to the corresponding gas phase results. As there is no evidence for the existence of any shape-resonances, in the available pyrimidine total cross sections [Baek et al., Phys. Rev. A 88, 032702 (2013); Fuss et al., ibid. 88, 042702 (2013)], between 10 and 20 eV, this mismatch in absolute magnitude between the condensed-phase and gas-phase ICSs might be indicative for collective-behaviour effects in the condensed-phase results.

  18. Investigating the fission process at high excitation energies through proton induced reactions on 181Ta

    International Nuclear Information System (INIS)

    Ayyad, Y.; Benlliure, J.; Casajeros, E.; Alvarez Pol, H.; Paradela, C.; Perez-Loureido, D.; Tarrio, D.; Bacquias, A.; Boudard, A.; Kezzar, K.; Leray, S.; Enqvist, T.; Foehr, V.; Kelic, A.; Pleskac, R.

    2010-01-01

    In this work we have investigated the total fission cross section of 181 Ta + 1 H at FRS (Fragment Separator - GSI) at 1, 0.8, 0.5 and 0.3 GeV with a specific setup, providing high accuracy measurements of the cross section values. the comparison of our data with previous results reveals a good agreement at high energies. However the situation remains unclear at lower energies. In general, our results covering a wide range of energy, are smoother. We have also compared the results obtained in this experiment, with several calculations performed with the intra-nuclear cascade model (INCL v4.1) coupled to de-excitation code (ABLAv3p), according to two different models describing fission process at high-excitation energies: statistical model of Bohr and Wheeler and the dynamical description of the fission process. We have showed that a simple statistical description largely over-predict the measured cross-section. Only a dynamical description of the fission, involving the role of the viscosity of the nuclear matter, provides a realistic result.

  19. Measurement of cross-sections for step-bystep excitation of inert gas atoms from metastable states by electron collisions

    International Nuclear Information System (INIS)

    Mityureva, A.A.; Penkin, N.P.; Smirnov, V.V.

    1989-01-01

    Excitation of argon atoms by electron collisions from metastable (MS) to high-lying states of inert gases (the so-called step-by-step excitation) is investigated. Formation of MS atoms m and their further step-by-step excitation up to k level is carried out by an electron beam with energy from 1 up to 40 eV. Time distribution of forming metastable and step-by-step electron collisions is used. The method used permits to measure the functions of step-by-step excitation and the absolute values of cross sections. Absolute values of cross-sections and functions of step-by-step excitation of some lines and argon levels are obtained

  20. Excitation of vibrational quanta in furfural by intermediate-energy electrons

    Science.gov (United States)

    Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; Blanco, F.; Brunger, M. J.

    2015-12-01

    We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

  1. Excitation of vibrational quanta in furfural by intermediate-energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D. B. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Neves, R. F. C. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Instituto Federal do Sul de Minas Gerais, Campus Poços de Caldas, Minas Gerais (Brazil); Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, MG (Brazil); Lopes, M. C. A. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, MG (Brazil); Costa, R. F. da [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo (Brazil); Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, 09210-580 São Paulo (Brazil); Varella, M. T. do N. [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, São Paulo (Brazil); Bettega, M. H. F. [Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná (Brazil); Lima, M. A. P. [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo (Brazil); García, G. [Instituto de Física Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); and others

    2015-12-14

    We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°–90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

  2. Excitation of vibrational quanta in furfural by intermediate-energy electrons

    International Nuclear Information System (INIS)

    Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; Costa, R. F. da; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.

    2015-01-01

    We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°–90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule

  3. Field-dependent molecular ionization and excitation energies: Implications for electrically insulating liquids

    Directory of Open Access Journals (Sweden)

    N. Davari

    2014-03-01

    Full Text Available The molecular ionization potential has a relatively strong electric-field dependence as compared to the excitation energies which has implications for electrical insulation since the excited states work as an energy sink emitting light in the UV/VIS region. At some threshold field, all the excited states of the molecule have vanished and the molecule is a two-state system with the ground state and the ionized state, which has been hypothesized as a possible origin of different streamer propagation modes. Constrained density-functional theory is used to calculate the field-dependent ionization potential of different types of molecules relevant for electrically insulating liquids. The low singlet-singlet excitation energies of each molecule have also been calculated using time-dependent density functional theory. It is shown that low-energy singlet-singlet excitation of the type n → π* (lone pair to unoccupied π* orbital has the ability to survive at higher fields. This type of excitation can for example be found in esters, diketones and many color dyes. For alkanes (as for example n-tridecane and cyclohexane on the other hand, all the excited states, in particular the σ → σ* excitations vanish in electric fields higher than 10 MV/cm. Further implications for the design of electrically insulating dielectric liquids based on the molecular ionization potential and excitation energies are discussed.

  4. Intensities of two-quanta cascades at different excitation energies of compound nuclei 146Nd, 174Yb, 183W

    International Nuclear Information System (INIS)

    Boneva, S.T.; Khitrov, V.A.; Sukhovoj, A.M.; Vojnov, A.V.

    1990-01-01

    Intensities of two-quanta cascades are obtained for 2-3 final low-lying levels of the following nuclei 146 Nd, 174 Yb and 183 W. These measured intensities are compared with the intensities calculated in the frame of various models at primary transition energies ranging from 0.5 MeV to the neutron binding energy. Some excitation energy intervals are revealed, experimentally obtained intensities of cascade are inconsistent with model calculations. 15 refs.; 7 figs

  5. Multi-step intramolecular excitation energy transfer in dendritic pyrene-phosphorus(V)porphyrin heptads

    International Nuclear Information System (INIS)

    Hirakawa, Kazutaka; Segawa, Hiroshi

    2016-01-01

    Dendritic heptad molecules in which four pyrenyl groups are connected at the central phosphorus atom of the edge-porphyrins of the center-to-edge type porphyrin trimers were synthesized to investigate a multi-step excitation energy transfer. As the central energy acceptor, two types porphyrins which one was phosphorus(V)tetraphenylporphyrin (H2) and another was its derivative substituted by butoxy groups at four para-position of meso-phenyl groups (H1) were used. In the photoexcited state of the pyrene units, the excitation energy transfer to the central-porphyrin unit was observed in toluene. The excitation energy transfer is considered to be through two pathways; one is a stepwise pathway through the edge-porphyrin unit and another is a direct excitation energy transfer to the central porphyrin. The direct excitation energy transfer from pyrenes to the edge-porphyrin and central-porphyrin were observed in the case for H1. From the excited state of the edge-porphyrins, the excitation energy transfer to the central-porphyrin occurs in the H1 case. In the H2 case, the excitation energy of central-porphyrin is higher than that of H1, and the electron transfer from edge-porphyrin to the central-porphyrin become predominant process. - Highlights: • Dendritic pyrene-porphyrin heptads were synthesized. • Excitation energy transfer occurs from the pyrenyl moiety to the phosphorus(V)porphyrin. • The stepwise and direct energy transfer pathways were observed. • The quantum yields of these energy transfer pathways could be determined.

  6. Multi-step intramolecular excitation energy transfer in dendritic pyrene-phosphorus(V)porphyrin heptads

    Energy Technology Data Exchange (ETDEWEB)

    Hirakawa, Kazutaka, E-mail: hirakawa.kazutaka@shizuoka.ac.jp [Applied Chemistry and Biochemical Engineering Course, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, Johoku 3-5-1, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University, Johoku 3-5-1, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Segawa, Hiroshi [Department of Multi-Disciplinary Science - General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8904 (Japan); Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8904 (Japan)

    2016-11-15

    Dendritic heptad molecules in which four pyrenyl groups are connected at the central phosphorus atom of the edge-porphyrins of the center-to-edge type porphyrin trimers were synthesized to investigate a multi-step excitation energy transfer. As the central energy acceptor, two types porphyrins which one was phosphorus(V)tetraphenylporphyrin (H2) and another was its derivative substituted by butoxy groups at four para-position of meso-phenyl groups (H1) were used. In the photoexcited state of the pyrene units, the excitation energy transfer to the central-porphyrin unit was observed in toluene. The excitation energy transfer is considered to be through two pathways; one is a stepwise pathway through the edge-porphyrin unit and another is a direct excitation energy transfer to the central porphyrin. The direct excitation energy transfer from pyrenes to the edge-porphyrin and central-porphyrin were observed in the case for H1. From the excited state of the edge-porphyrins, the excitation energy transfer to the central-porphyrin occurs in the H1 case. In the H2 case, the excitation energy of central-porphyrin is higher than that of H1, and the electron transfer from edge-porphyrin to the central-porphyrin become predominant process. - Highlights: • Dendritic pyrene-porphyrin heptads were synthesized. • Excitation energy transfer occurs from the pyrenyl moiety to the phosphorus(V)porphyrin. • The stepwise and direct energy transfer pathways were observed. • The quantum yields of these energy transfer pathways could be determined.

  7. Maximizing direct current power delivery from bistable vibration energy harvesting beams subjected to realistic base excitations

    Science.gov (United States)

    Dai, Quanqi; Harne, Ryan L.

    2017-04-01

    Effective development of vibration energy harvesters is required to convert ambient kinetic energy into useful electrical energy as power supply for sensors, for example in structural health monitoring applications. Energy harvesting structures exhibiting bistable nonlinearities have previously been shown to generate large alternating current (AC) power when excited so as to undergo snap-through responses between stable equilibria. Yet, most microelectronics in sensors require rectified voltages and hence direct current (DC) power. While researchers have studied DC power generation from bistable energy harvesters subjected to harmonic excitations, there remain important questions as to the promise of such harvester platforms when the excitations are more realistic and include both harmonic and random components. To close this knowledge gap, this research computationally and experimentally studies the DC power delivery from bistable energy harvesters subjected to such realistic excitation combinations as those found in practice. Based on the results, it is found that the ability for bistable energy harvesters to generate peak DC power is significantly reduced by introducing sufficient amount of stochastic excitations into an otherwise harmonic input. On the other hand, the elimination of a low amplitude, coexistent response regime by way of the additive noise promotes power delivery if the device was not originally excited to snap-through. The outcomes of this research indicate the necessity for comprehensive studies about the sensitivities of DC power generation from bistable energy harvester to practical excitation scenarios prior to their optimal deployment in applications.

  8. Spatial distribution of fluorescent light emitted from neon and nitrogen excited by low energy electron beams

    International Nuclear Information System (INIS)

    Morozov, A.; Kruecken, R.; Ulrich, A.; Wieser, J.

    2006-01-01

    Side-view intensity profiles of fluorescent light were measured for neon and nitrogen excited with 12 keV electron beams at gas pressures from 250 to 1400 hPa. The intensity profiles were compared with theoretical profiles calculated using the CASINO program which performs Monte Carlo simulations of electron scattering. It was assumed that the spatial distribution of fluorescent intensity is directly proportional to the spatial distribution of energy loss by primary electrons. The comparison shows good correlation of experimental data and the results of numeric simulations

  9. Predicting Atmospheric Ionization and Excitation by Precipitating SEP and Solar Wind Protons Measured By MAVEN

    Science.gov (United States)

    Jolitz, Rebecca; Dong, Chuanfei; Lee, Christina; Lillis, Rob; Brain, David; Curry, Shannon; Halekas, Jasper; Bougher, Stephen W.; Jakosky, Bruce

    2017-10-01

    Precipitating energetic particles ionize and excite planetary atmospheres, increasing electron content and producing aurora. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutral and pass the magnetosheath, and SEPs are sufficiently energetic to cross the magnetosheath unchanged. We will compare ionization and Lyman alpha emission rates for solar wind and SEP protons during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare excitation and ionization rates by SEPs and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help quantify how SEP and solar wind protons influence atmospheric energy deposition during solar minimum.

  10. Charge transfer and excitation in high-energy ion-atom collisions

    International Nuclear Information System (INIS)

    Schlachter, A.S.; Berkner, K.H.; McDonald, R.J.

    1986-11-01

    Coincidence measurements of charge transfer and simultaneous projectile electron excitation provide insight into correlated two-electron processes in energetic ion-atom collisions. Projectile excitation and electron capture can occur simultaneously in a collision of a highly charged ion with a target atom; this process is called resonant transfer and excitation (RTE). The intermediate excited state which is thus formed can subsequently decay by photon emission or by Auger-electron emission. Results are shown for RTE in both the K shell of Ca ions and the L shell of Nb ions, for simultaneous projectile electron loss and excitation, and for the effect of RTE on electron capture

  11. Luminescence decay in condensed argon under high energy excitation

    International Nuclear Information System (INIS)

    Carvalho, M.J.; Klein, G.

    1978-01-01

    α and β particles were used to study the luminescence of condensed argon. The scintillation decay has always two components independently of the phase and the kind of the exciting particles. Decay time constants are given for solid, liquid and also gaseous argon. Changes in the relative intensity values of the two components are discussed in terms of track effects

  12. Ordering and low energy excitations in strongly correlated bronzes

    NARCIS (Netherlands)

    Sagara, Dodderi Manjunatha

    2006-01-01

    Summary In any solid system, whether it is superconducting, shows a charge-density-wave behavior, or any other kind of ground state, two aspects drag the attention of the scientific community. They are order and excitations in solids. The ordering may be due to electronic, lattice, spin or orbital

  13. Energy transfer in LH2 of Rhodospirillum Molischianum, studied by subpicosecond spectroscopy and configuration interaction excition calculations.

    NARCIS (Netherlands)

    Ihalainen, J.A.; Linnanto, J.; Myllyperkiö, P.; van Stokkum, I.H.M.; Ücker, B.; Scheer, H.; Korppi-Tommola, J.E.I.

    2001-01-01

    Two color transient absorption measurements were performed on a LH2 complex from Rhodospirillum molischianum by using several excitation wavelengths (790, 800, 810, and 830 nm) and probing in the spectral region from 790 to 870 nm at room temperature. The observed energy transfer time of ∼1.0 ps

  14. Evaluation of excitation energy and spin in fission fragments using the statistical model, and the FIPPS project

    International Nuclear Information System (INIS)

    Faust, H.; Koester, U.; Kessedjian, G.; Sage, C.; Chebboubi, A.

    2013-01-01

    We review the statistical model and its application for the process of nuclear fission. The expressions for excitation energy and spin distributions for the individual fission fragments are given. We will finally emphasize the importance of measuring prompt gamma decay to further test the statistical model in nuclear fission with the FIPPS project. (authors)

  15. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W

    2015-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance...... of energy balance....

  16. Energy harvesting from coherent resonance of horizontal vibration of beam excited by vertical base motion

    Energy Technology Data Exchange (ETDEWEB)

    Lan, C. B.; Qin, W. Y. [Department of Engineering Mechanics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-09-15

    This letter investigates the energy harvesting from the horizontal coherent resonance of a vertical cantilever beam subjected to the vertical base excitation. The potential energy of the system has two symmetric potential wells. So, under vertical excitation, the system can jump between two potential wells, which will lead to the large vibration in horizontal direction. Two piezoelectric patches are pasted to harvest the energy. From experiment, it is found that the vertical excitation can make the beam turn to be bistable. The system can transform vertical vibration into horizontal vibration of low frequency when excited by harmonic motion. The horizontal coherence resonance can be observed when excited by a vertical white noise. The corresponding output voltages of piezoelectric films reach high values.

  17. Study of ionizing collisions involving excited states in a potassium-rubidium mixture at thermal energy

    International Nuclear Information System (INIS)

    Djerad, M.T.

    1987-01-01

    This study concerns mainly ionising collisions involving excited states in a saturated mixture of K-Rb vapours, at thermal energy. The experimental method consists into continuous resonant two steps laser excitation of the atoms (n ≤ 10) and mass spectrometry of ion currents. Radiative and collisional relaxation of the atoms create a complex medium. The most efficient collisional processes are Penning ionisation and Hornbeck-Molnar ionisation. In the heteronuclear system Rb(n1) + K(4P), the following exit channels may be operative: Rb(n1) + K(4P) → Rb + + e - + K Rb(n1) + K(4p) → K + + e - + Rb Rb(n1) + K(4P) → KRb + + e - . The measurements show that the first channel has an average cross section ∼ 10 -13 cm 2 . Those of the other channels are at least three orders of magnitude smaller and thus comparatively negligible. The data obtained from 5D to 10S allow to conclude that the flux in the entrance channel ionises at large separation between Rb(n1) and K(4P). The process of ionisation is dominated by polarisation forces, exchange forces being negligible. In the present mixture, Hornbeck-Molnar ionisation leads to homonuclear molecular ions K 2 + , Rb 2 + as well as the heteronuclear one KRb + . We have measured the rate coefficients for the systems: K(n1) + Rb → KRb + + e - Rb(n1) + K → KRb + + e - . The rate coefficients increase with the excitation energy of the level n1; they do not exhibit fundamental differences with those measured in pure alkali vapours [fr

  18. Ioniclike energy structure of neutral core-excited states in free Kr clusters

    International Nuclear Information System (INIS)

    Peredkov, S.; Sorensen, S.L.; Kivimaeki, A.; Schulz, J.; Maartensson, N.; Oehrwall, G.; Lundwall, M.; Rander, T.; Lindblad, A.; Bergersen, H.; Svensson, S.; Bjoerneholm, O.; Tchaplyguine, M.

    2005-01-01

    The development of electronic states in krypton clusters is investigated by high-resolution core-level electron spectroscopy. The energy ordering of bulk versus surface 3d -1 np(n>5) core-excited states in neutral clusters is demonstrated to be reversed to the 3d -1 5p level situation. The cluster 3d -1 6p,7p states are proven to be at a lower energy than the corresponding atomic levels. These findings reveal the ioniclike energy structure of the neutral cluster core-excited levels. The phenomenon is explained by a spatial spread of the excited orbitals over the cluster lattice

  19. Excitation energies from Görling-Levy perturbation theory along the range-separated adiabatic connection

    Science.gov (United States)

    Rebolini, Elisa; Teale, Andrew M.; Helgaker, Trygve; Savin, Andreas; Toulouse, Julien

    2018-06-01

    A Görling-Levy (GL)-based perturbation theory along the range-separated adiabatic connection is assessed for the calculation of electronic excitation energies. In comparison with the Rayleigh-Schrödinger (RS)-based perturbation theory this GL-based perturbation theory keeps the ground-state density constant at each order and thus gives the correct ionisation energy at each order. Excitation energies up to first order in the perturbation have been calculated numerically for the helium and beryllium atoms and the hydrogen molecule without introducing any density-functional approximations. In comparison with the RS-based perturbation theory, the present GL-based perturbation theory gives much more accurate excitation energies for Rydberg states but similar excitation energies for valence states.

  20. Energy transfer and quenching processes of excited uranyl ion and lanthanide ions in solutions

    International Nuclear Information System (INIS)

    Yamamura, Tomoo; Tomiyasu, Hiroshi

    1995-01-01

    Deactivation processes of photoexcited uranyl ion by various lanthanide ions in aqueous solution were studied. Each lanthanide ions show different interaction with excited uranyl ion depending on its lowest excited energy level, the number of 4f electrons and the acid concentration of the solution. (author)

  1. Performance of SOPPA-based methods in the calculation of vertical excitation energies and oscillator strengths

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Pitzner-Frydendahl, Henrik Frank; Buse, Mogens

    2015-01-01

    methods, the original SOPPA method as well as SOPPA(CCSD) and RPA(D) in the calculation of vertical electronic excitation energies and oscillator strengths is investigated for a large benchmark set of 28 medium-size molecules with 139 singlet and 71 triplet excited states. The results are compared...

  2. PRISMA - a spectrometer for the measurement of coherent excitations on a pulsed spallation neutron source

    International Nuclear Information System (INIS)

    Andreani, C.; Cilloco, F.; Petrillo, C.; Sacchetti, F.; Windsor, C.G.

    1986-04-01

    The measurement of nuclear and magnetic excitation spectra from single crystal samples remains central to condensed matter physics. The requirements in terms of the range and resolution of the scattering vector Q and energy transfer h/2πω are reviewed and typical experiments with a well defined cross-section are chosen. The performance and limitations of existing instruments are reviewed. A design for a new spectrometer, PRISMA, to be installed on the UK spallation neutron source, ISIS, is presented. Its performance for chosen experiments is given in terms of the Q and h/2πω range covered in a single scan, the resolution and the count rate. (author)

  3. Flow-excited acoustic resonance excitation mechanism, design guidelines, and counter measures

    International Nuclear Information System (INIS)

    Ziada, Samir; Lafon, Philippe

    2014-01-01

    The excitation mechanism of acoustic resonances has long been recognized, but the industry continues to be plagued by its undesirable consequences, manifested in severe vibration and noise problems in a wide range of industrial applications. This paper focuses on the nature of the excitation mechanism of acoustic resonances in piping systems containing impinging shear flows, such as flow over shallow and deep cavities. Since this feedback mechanism is caused by the coupling between acoustic resonators and shear flow instabilities, attention is focused first on the nature of various types of acoustic resonance modes and then on the aero-acoustic sound sources, which result from the interaction of the inherently unstable shear flow with the sound field generated by the resonant acoustic modes. Various flow-sound interaction patterns are discussed, in which the resonant sound field can be predominantly parallel or normal to the mean flow direction and the acoustic wavelength can be an order of magnitude longer than the length scale of the separated shear flow or as short as the cavity length scale. Since the state of knowledge in this field has been recently reviewed by Tonon et al. (2011, 'Aero-acoustics of Pipe Systems With Closed Branches', Int. J. Aeroacoust., 10(2), pp. 201-276), this article focuses on the more practical aspects of the phenomenon, including various flow sound interaction patterns and the resulting aero-acoustic sources, which are relevant to industrial applications. A general design guide proposal and practical means to alleviate the excitation mechanism are also presented. These are demonstrated by two examples of recent industrial case histories dealing with acoustic fatigue failure of the steam dryer in a boiling water reactor (BWR) due to acoustic resonance in the main steam piping and acoustic resonances in the roll posts of the Short Take-Off and Vertical Lift Joint Strike Fighter (JSF). (authors)

  4. NO-γ emissions from streamer discharges: direct electron impact excitation versus resonant energy transfer

    International Nuclear Information System (INIS)

    Liu Ningyu; Pasko, Victor P

    2010-01-01

    It has been established that production of NO-γ emission in pulsed corona discharges is dominated by the energy transfer from N 2 (A 3 Σ u + ) to the NO ground state NO(X 2 Π r ) while direct excitation by electron impact is negligible. However, recent studies suggest that the electron impact excitation plays a more important role. In this work, we report modelling results of NO-γ emission associated with streamer discharges using two cross section data sets available in the literature. The first set was originally reported by Mojarrabi et al (1996 Phys. Rev. A 54 2977-82) and later updated by Brunger et al (2000 J. Phys. B: At. Mol. Opt. Phys. 33 809-19); the second set was published by Hayashi (1990 Nonequilibrium Processes in Partially Ionized Gases (NATO Advanced Science Institutes Series, Series B, Physics vol 220) ed M Capitelli and J N Bardsley (New York: Plenum) pp 333-40). According to the results, the role played by the electron impact excitation in the production of NO-γ is drastically different when different cross sections are used. The results indicate that the first data set leads to better agreement with experimental measurements. (fast track communication)

  5. Vibrational and electronic excitation of hexatriacontane thin films by low energy electron impact

    International Nuclear Information System (INIS)

    Vilar, M.R.; Schott, M.; Pfluger, P.

    1990-01-01

    Thin polycrystalline films of hexatriacontane (HTC) were irradiated with low energy (E=0.5--15 eV) electrons, and off-specular backscattered electron spectra were measured. Below E∼7 eV, single and multiple vibrational excitations only are observed, which relax the electrons down to the bottom of the HTC conduction band. Due to the negative electron affinity of HTC, thermal electrons are emitted into vacuum. Structure in the backscattered electron current at kinetic energies about 1.5 and 4 eV are associated to conduction band density of states. Above E∼7 eV, the dominant losses correspond to electronic excitations, excitons, or above a threshold (energy of the electron inside the HTC film) at 9.2±0.1 eV, electron--hole pair generation. The latter process is very efficient and reaches a yield of the order of one ∼11 eV. Evidence for chemical reaction above E∼4 eV is observed

  6. Investigations of the valence-shell excitations of molecular ethane by high-energy electron scattering

    Science.gov (United States)

    Xu, Wei-Qing; Xu, Long-Quan; Qi, De-Guang; Chen, Tao; Liu, Ya-Wei; Zhu, Lin-Fan

    2018-04-01

    The differential cross sections and generalized oscillator strengths for the low-lying excitations of the valence-shell 1eg orbital electron in ethane have been measured for the first time at a high incident electron energy of 1500 eV and a scattering angular range of 1.5°-10°. A weak feature, termed X here, with a band center of about 7.5 eV has been observed, which was also announced by the previous experimental and theoretical studies. The dynamic behaviors of the generalized oscillator strengths for the 3s (8.7 eV), 3s+3p (9.31 eV, 9.41 eV), and X (˜7.5 eV) transitions on the momentum transfer squared have been obtained. The integral cross sections of these transitions from their thresholds to 5000 eV have been obtained with the aid of the BE-scaling (B is the binding energy and E is the excitation energy) method. The optical oscillator strengths of the above transitions determined by extrapolating their generalized oscillator strengths to the limit of the squared momentum transfer K2 → 0 are in good agreement with the ones from the photoabsorption spectrum [J. W. Au et al., Chem. Phys. 173, 209 (1993)], which indicates that the present differential cross sections, generalized oscillator strengths, and integral cross sections can serve as benchmark data.

  7. Hadron fragment emission in cluster excitation processes at medium energies

    International Nuclear Information System (INIS)

    Kovacs, Zs.

    1985-12-01

    An extended version of the cluster excitation model is proposed to describe the emission of various particle types in nuclear reactions in a consistent way. At first pion, proton deuteron and triton spectra from neutron-carbon interactions at 545 MeV in the angular region from deg 73 to deg 165 were tried to interpret by the model. The results are compared with model calculations. (author)

  8. Quasi-particle excitations in low energy fission

    International Nuclear Information System (INIS)

    Ashgar, M.; Djebara, M.; Bocquet, J.P.; Brissot, R.; Maurel, M.; Nifenecker, H.; Ristori, C.

    1985-05-01

    Proton odd-even effect for 229 Th(nsub(th),f) and 232 U(nsub(th),f) has been determined with a ΔE-Esub(R) gas telescope. These data indicate that the qp-particle excitation probability at the saddle point is small and most of its results, when the nucleus moves from saddle to scission and the neck ruptures into final fragments. These results are discussed in terms of the different ideas and models

  9. Quantitative multi-color FRET measurements by Fourier lifetime excitation-emission matrix spectroscopy

    Science.gov (United States)

    Zhao, Ming; Huang, Run; Peng, Leilei

    2012-01-01

    Förster resonant energy transfer (FRET) is extensively used to probe macromolecular interactions and conformation changes. The established FRET lifetime analysis method measures the FRET process through its effect on the donor lifetime. In this paper we present a method that directly probes the time-resolved FRET signal with frequency domain Fourier lifetime excitation-emission matrix (FLEEM) measurements. FLEEM separates fluorescent signals by their different phonon energy pathways from excitation to emission. The FRET process generates a unique signal channel that is initiated by donor excitation but ends with acceptor emission. Time-resolved analysis of the FRET EEM channel allows direct measurements on the FRET process, unaffected by free fluorophores that might be present in the sample. Together with time-resolved analysis on non-FRET channels, i.e. donor and acceptor EEM channels, time resolved EEM analysis allows precise quantification of FRET in the presence of free fluorophores. The method is extended to three-color FRET processes, where quantification with traditional methods remains challenging because of the significantly increased complexity in the three-way FRET interactions. We demonstrate the time-resolved EEM analysis method with quantification of three-color FRET in incompletely hybridized triple-labeled DNA oligonucleotides. Quantitative measurements of the three-color FRET process in triple-labeled dsDNA are obtained in the presence of free single-labeled ssDNA and double-labeled dsDNA. The results establish a quantification method for studying multi-color FRET between multiple macromolecules in biochemical equilibrium. PMID:23187535

  10. Measurement of Polarization Observables in the Electro-Excitation of the Proton to its First Excited State

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Rikki [Florida State Univ., Tallahassee, FL (United States)

    2003-08-01

    This thesis reports results from the Thomas Jefferson National Accelerator Facility (Jefferson Lab) Hall A experiment E91-011, which measured double-polarization observables in the pion electroproduction reaction from the proton. Specifically, the experiment measured the recoil proton polarization, polarized response functions, and cross section for the p($\\vec{e}$, e' $\\vec{p}$) π° reaction at a center-of-mass energy centered at W = 1232 MeV--the peak of the Δ(1232) resonance--and at a four-momentum transfer squared of Q2 = 1.0 GeV2/c2. Both the recoil proton polarization and polarized response function results will be presented in this thesis. Data were collected at Jefferson Lab, located in Newport News, Virginia during the summer of 2000. A 4.53 GeV polarized electron beam was scattered off of a cryogenic hydrogen target. The recoil proton polarization was measured in the Focal Plane Polarimeter (FPP), located in one of the two High Resolution Spectrometers (HRS) in Hall A. A maximum likelihood method was used to determine the polarized response functions directly from the measured polarizations and cross sections. A simultaneous fit of the cross sections, the recoil proton polarizations, and angular distributions of the polarized response functions will provide a determination of individual multipole amplitudes. Some of these multipole amplitudes are related to the concept of proton deformation. Both the recoil proton polarizations and polarized response functions were compared to two phenomenological models: MAID and SAID, which have all free parameters fixed, based on fits to previous world data. The measured helicity dependent observables, which are dominated by imaginary parts of Δ(1232)-resonance excitation multipole amplitudes, agree very well with the two models. The measured helicity independent observables, which are dominated by real parts of background multipole amplitudes, do not agree completely with

  11. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  12. Ultrafast excitation energy transfer from encapsulated quaterrylene to single-walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Takeshi, E-mail: koyama@nuap.nagoya-u.ac.jp [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Tsunekawa, Takuya [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Saito, Takeshi [Research Center for Advanced Carbon Materials, AIST, Tsukuba, Ibaraki 305-8565 (Japan); Asaka, Koji; Saito, Yahachi [Department of Quantum Engineering, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Kishida, Hideo [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Nakamura, Arao [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192 (Japan)

    2016-01-15

    We investigate excitation energy transfer from an encapsulated quaterrylene molecule to a single-walled carbon nanotube by means of femtosecond pump-probe spectroscopy. The time constant of energy transfer becomes shorter with increasing average diameter of nanotube: 1.4±0.2 ps for 1.0 nm, 1.1±0.2 ps for 1.4 nm, and 0.4±0.1 ps for 1.8 nm. The observed behavior is discussed considering the distance of less than 1 nm between the molecule and the nanotube wall. - Highlights: • Dynamical properties of excited states in quaterrylene/SWNT composites were studied. • Excitation energy transfer occurs in the time range of 0.4-1.4 ps. • The transfer rate depends on the nanotube diameter, i.e. molecule-nanotube wall distance. • This dependence indicates the feature of excitation energy transfer on the nanoscale.

  13. Optogalvanic monitoring of collisional transfer of laser excitation energy in a neon RF plasma

    International Nuclear Information System (INIS)

    Armstrong, T.D.

    1994-01-01

    The optogalvanic signals produced by pulsed laser excitation of 1s5--2p8 and 1s5-2p9 (Paschen notation) transition by a ∼29 MHz radiofrequency (rf) discharge at ∼5 torr have been investigated. The optogalvanic signal produced by 1s5-2p9 excitations indicates that there is transfer of energy from the 2p9 state to some other state. The state to which this energy is transferred is believed to be mainly the 2p8 state because of the very small energy gap between the 2p9 and 2p8 states. To verify this transfer, the 1s5-2p8 transition was investigated. The similarity of the temporal profiles of the optogalvanic signals in both excitations confirms the collisional transfer of laser excitation energy from 2p9 to 2p8

  14. Proceedings of the 1984 workshop on high-energy excitations in condensed matter. Volume II

    International Nuclear Information System (INIS)

    Silver, R.N.

    1984-12-01

    This volume covers electronic excitations, momentum distributions, high energy photons, and a wrap-up session. Abstracts of individual items from the conference were prepared separately for the data base

  15. An analytical approach for predicting the energy capture and conversion by impulsively-excited bistable vibration energy harvesters

    Science.gov (United States)

    Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.

    2016-07-01

    Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.

  16. Excitation function of elastic scattering on 12C + 4He system, at low energies

    International Nuclear Information System (INIS)

    Perez-Torres, R.; Aguilera, E. F.; Martinez-Quiroz, E.; Murillo, G.; Belyaeva, T. L.; Maldonado-Velazquez, M.

    2011-01-01

    Interactions in the 12 C + 4 He system are of great interest in astrophysics and to help determine the relative abundances of elements in stars, at the end of helium burning [1, 2]. The Instituto Nacional de Investigaciones Nucleares (ININ) in Mexico, have made measurements of elastic scattering for this system, using the inverse kinematics method with thick white gas [3, 4], for E CM (0.5 - 4 MeV) θ CM = 180 o . In this work we obtain excitation functions of elastic scattering of 12 C + 4 He system with angular and energy dependence; E CM = 0.5 - 4 MeV and θ CM 100 o -170 o .Using inverse kinematics method with thick white gas and energy loss tables. (Author)

  17. Identification of the low-energy excitations in a quantum critical system

    Directory of Open Access Journals (Sweden)

    Tom Heitmann

    2017-05-01

    Full Text Available We have identified low-energy magnetic excitations in a doped quantum critical system by means of polarized neutron scattering experiments. The presence of these excitations could explain why Ce(Fe0.76Ru0.242Ge2 displays dynamical scaling in the absence of local critical behavior or long-range spin-density wave criticality. The low-energy excitations are associated with the reorientations of the superspins of fully ordered, isolated magnetic clusters that form spontaneously upon lowering the temperature. The system houses both frozen clusters and dynamic clusters, as predicted by Hoyos and Vojta [Phys. Rev. B 74, 140401(R (2006].

  18. Excitation energy of the lowest 2+ and 3- levels in 32Mg and 146Gd

    International Nuclear Information System (INIS)

    Barranco, M.; Lombard, R.J.

    1978-06-01

    The excitation energy of the lowest 2 + and 3 - levels are calculated for neutron rich Mg-isotopes as well as for N=82 isotones. The calculations are made by assuming quadrupole-quadrupole and octupole-octupole forces. The quasi-particles energies and occupation numbers are taken from the energy density method

  19. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    The effect of external magnetic field on the excited state energies in a spherical quantum dot was studied. The impurity energy and binding energy were calculated using the variational method within the effective mass approximation and finite barrier potential. The results showed that by increasing the magnetic field, the ...

  20. Effect of magnetic field on the impurity binding energy of the excited ...

    Indian Academy of Sciences (India)

    Abstract. The effect of external magnetic field on the excited state energies in a spher- ical quantum dot was studied. The impurity energy and binding energy were calculated using the variational method within the effective mass approximation and finite barrier potential. The results showed that by increasing the magnetic ...

  1. Excitation energies, photoionization cross sections, and asymmetry parameters of the methyl and silyl radicals.

    Science.gov (United States)

    Velasco, A M; Lavín, C; Dolgounitcheva, O; Ortiz, J V

    2014-08-21

    Vertical excitation energies of the methyl and silyl radicals were inferred from ab initio electron propagator calculations on the electron affinities of CH3(+) and SiH3(+). Photoionization cross sections and angular distribution of photoelectrons for the outermost orbitals of both CH3 and SiH3 radicals have been obtained with the Molecular Quantum Defect Orbital method. The individual ionization cross sections corresponding to the Rydberg channels to which the excitation of the ground state's outermost electron gives rise are reported. Despite the relevance of methyl radical in atmospheric chemistry and combustion processes, only data for the photon energy range of 10-11 eV seem to be available. Good agreement has been found with experiment for photoionization cross section of this radical. To our knowledge, predictions of the above mentioned photoionization parameters on silyl radical are made here for the first time, and we are not aware of any reported experimental measurements. An analysis of our results reveals the presence of a Cooper minimum in the photoionization of the silyl radical. The adequacy of the two theoretical procedures employed in the present work is discussed.

  2. The structure of nuclear states at low, intermediate and high excitation energies

    International Nuclear Information System (INIS)

    Soloviev, V.G.

    1976-01-01

    It is shown that within the model based on the quasiparticle-phonon interaction one can obtain the description of few-quasiparticle components of nuclear states at low, intermediate and high excitation energies. For the low-lying states the energy of each level is calculated. The few-quasiparticle components at intermediate and high excitation energies are represented to be averaged in certain energy intervals and their characteri stics are given as the corresponding strength functions. The fragmentation of single-particle states in deformed nuclei is studied. It is shown that in the distribution of the single-particle strength alongside with a large maximum there appear local maxima and the distribution itself has a long tail. The dependence of neutron strength functions on the excitation energy is investigated for the transfer reaction of the type (d,p) and (d,t). The s,- p,- and d-wave neutron strength functions are calculated at the neutron binding energy Bn. A satisfactory agreement with experiment is obtained. The energies and Elambda-strength functions for giant multipole resonances in deformed nuclei are calculated. The energies of giant quadrupole and octupole resonances are calculated. Their widths and fine structure are being studied. It is stated that to study the structure of highly excited states it is necessary to find the values of many-quasiparticle components of the wave functions. The ways of experimental determination of these components based on the study of γ-transitions between highly excited states are discussed

  3. Experimental system to measure excitation cross-sections by electron impact. Measurements for ArI and ArII

    International Nuclear Information System (INIS)

    Blanco, F.; Sanchez, J.A.; Aguilera, J.A.; Campos, J.

    1989-01-01

    An experimental set-up to measure excitation cross-section of atomic and molecular levels by electron impact based on the optical method is reported. We also present some measurements on the excitation cross-section for ArI 5p'(1/2)0 level, and for simultaneous ionization and excitation of Ar leading to ArII levels belonging to the 3p 4 4p and 3p 4 4d configurations. (Author)

  4. Photoionization cross section measurements of the excited states of cobalt in the near-threshold region

    Directory of Open Access Journals (Sweden)

    Xianfeng Zheng

    2014-10-01

    Full Text Available We present measurements of photoionization cross-sections of the excited states of cobalt using a two-color, two-step resonance ionization technique in conjunction with a molecular beam time of flight (TOF mass spectrometer. The atoms were produced by the laser vaporization of a cobalt rod, coupled with a supersonic gas jet. The absolute photoionization cross-sections at threshold and near-threshold regions (0-1.2 eV were measured, and the measured values ranged from 4.2±0.7 Mb to 10.5±1.8 Mb. The lifetimes of four odd parity energy levels are reported for the first time.

  5. Prediction of interior noise due to random acoustic or turbulent boundary layer excitation using statistical energy analysis

    Science.gov (United States)

    Grosveld, Ferdinand W.

    1990-01-01

    The feasibility of predicting interior noise due to random acoustic or turbulent boundary layer excitation was investigated in experiments in which a statistical energy analysis model (VAPEPS) was used to analyze measurements of the acceleration response and sound transmission of flat aluminum, lucite, and graphite/epoxy plates exposed to random acoustic or turbulent boundary layer excitation. The noise reduction of the plate, when backed by a shallow cavity and excited by a turbulent boundary layer, was predicted using a simplified theory based on the assumption of adiabatic compression of the fluid in the cavity. The predicted plate acceleration response was used as input in the noise reduction prediction. Reasonable agreement was found between the predictions and the measured noise reduction in the frequency range 315-1000 Hz.

  6. Influence of donor-donor transport on excitation energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, K K; Joshi, H C; Pant, T C [Kumaun University, Nainital (India). Department of Physics

    1989-01-01

    Energy migration and transfer from acriflavine to rhodamine B and malachite green in poly (methylmethacrylate) have been investigated using the decay function analysis. It is found that the influence of energy migration in energy transfer can be described quite convincingly by making use of the theories of Loring, Andersen and Fayer (LAF) and Huber. At high acceptor concentration direct donor-acceptor transfer occurs through Forster mechanism. (author). 17 refs., 5 figs.

  7. Excited-state lifetime measurements: Linearization of the Foerster equation by the phase-plane method

    International Nuclear Information System (INIS)

    Love, J.C.; Demas, J.N.

    1983-01-01

    The Foerster equation describes excited-state decay curves involving resonance intermolecular energy transfer. A linearized solution based on the phase-plane method has been developed. The new method is quick, insensitive to the fitting region, accurate, and precise

  8. Isobar excitations and low energy spectra of light nuclei

    International Nuclear Information System (INIS)

    Czerski, P.

    1984-01-01

    The aim of this investigation is to study the possible influence of inner excitations of nucleons into the Δ(3,3)-resonance on the low lying spectra of light nuclei like 12 C and 16 O. Before we can study the effect of such exotic configurations one has to perform a reliable investigation within the normal nuclear model, which is based on a microscopic theory. This is achieved by performing RPA (Random Phase Approximation) calculations using a realistic residual interaction derived from the Brueckner G-matrix. An efficient parametrisation of the residual interaction is introduced and the reliability of the more phenomenological parametrisations which are generally used is discussed. Within such realistic calculations, the isobar effects are small. (orig.) [de

  9. σ-SCF: A direct energy-targeting method to mean-field excited states.

    Science.gov (United States)

    Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D; Van Voorhis, Troy

    2017-12-07

    The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry-a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states-ground or excited-are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H 2 , HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

  10. Measured lifetimes of states in 197Au and a critical comparison with the weak-coupling core-excitation model

    International Nuclear Information System (INIS)

    Bolotin, H.H.; Kennedy, D.L.; Linard, B.J.; Stuchbery, A.E.

    1979-01-01

    The lifetimes of five excited states in 197 Au up to an excitation energy of 885 keV were measured by the recoil-distance method (RDM). These levels were populated by Coulomb excitation using both 90 MeV 20 Ne and 120 MeV 35 Cl ion beams. The experimentally determined spectroscopy of the low-lying levels 3/2 + (ground state) and 1/2 + , (3/2) + 2 , 5/2 + and 7/2 + at 77.3, 268.8, 278.9, and 547.5 keV excitation energy, respectively, has been critically compared with the detailed predictions of the de-Shalit weak-coupling core-excitation model. When the model is taken to represent the case of a dsub(3/2) proton hole coupled to a 198 Hg core, the model parameters obtained are in accord with the criteria implicit for weak core coupling and, at the same time, are in remarkably good agreement with virtually all measured E2 and M1 transition rates. (Auth.)

  11. Radiative-lifetime measurements and calculations of odd-parity highly excited levels in Ba i

    International Nuclear Information System (INIS)

    Zhang Wei; Du Shan; Palmeri, Patrick; Quinet, Pascal; Biemont, Emile; Dai Zhenwen

    2010-01-01

    Natural radiative lifetime measurements have been performed for 70 odd-parity highly excited levels of neutral barium in the energy range from 308 15.512 to 417 59.93 cm -1 by a time-resolved laser-induced fluorescence technique in a laser-produced plasma. The lifetime values measured in this paper are in the range from 11.3 to 901 ns. They are compared with the published lifetimes of four levels. Two of them are in good agreement, whereas for the other two our measurements are slightly longer than the published data. The reasons for the discrepancies are discussed. Comparisons with theoretical results of the Hartree-Fock method with relativistic corrections illustrate the difficulties associated with the use of Cowan's codes for obtaining accurate branching fractions for transitions depopulating highly excited levels along the Rydberg series of heavy neutral elements. This work will be useful to extend the set of oscillator strengths available in Ba i.

  12. Influence of collision energy and vibrational excitation on the ...

    Indian Academy of Sciences (India)

    tions of potential energy surface (PES) for BrH2 system are more ... rier heights for both the exchange and abstraction are smaller than ... The complete picture on the dynamics of ..... Kurosaki Y and Takayanagi T private communication. 20.

  13. Application of an excited state LDA exchange energy functional for the calculation of transition energy of atoms within time-independent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Shamim, Md; Harbola, Manoj K, E-mail: sami@iitk.ac.i, E-mail: mkh@iitk.ac.i [Department of Physics, Indian Institute of Technology, Kanpur 208 016 (India)

    2010-11-14

    Transition energies of a new class of excited states (two-gap systems) of various atoms are calculated in time-independent density functional formalism by using a recently proposed local density approximation exchange energy functional for excited states. It is shown that the excitation energies calculated with this functional compare well with those calculated with exact exchange theories.

  14. Application of an excited state LDA exchange energy functional for the calculation of transition energy of atoms within time-independent density functional theory

    International Nuclear Information System (INIS)

    Shamim, Md; Harbola, Manoj K

    2010-01-01

    Transition energies of a new class of excited states (two-gap systems) of various atoms are calculated in time-independent density functional formalism by using a recently proposed local density approximation exchange energy functional for excited states. It is shown that the excitation energies calculated with this functional compare well with those calculated with exact exchange theories.

  15. Simultaneous time-space resolved reflectivity and interferometric measurements of dielectrics excited with femtosecond laser pulses

    Science.gov (United States)

    Garcia-Lechuga, M.; Haahr-Lillevang, L.; Siegel, J.; Balling, P.; Guizard, S.; Solis, J.

    2017-06-01

    Simultaneous time-and-space resolved reflectivity and interferometric measurements over a temporal span of 300 ps have been performed in fused silica and sapphire samples excited with 800 nm, 120 fs laser pulses at energies slightly and well above the ablation threshold. The experimental results have been simulated in the frame of a multiple-rate equation model including light propagation. The comparison of the temporal evolution of the reflectivity and the interferometric measurements at 400 nm clearly shows that the two techniques interrogate different material volumes during the course of the process. While the former is sensitive to the evolution of the plasma density in a very thin ablating layer at the surface, the second yields an averaged plasma density over a larger volume. It is shown that self-trapped excitons do not appreciably contribute to carrier relaxation in fused silica at fluences above the ablation threshold, most likely due to Coulomb screening effects at large excited carrier densities. For both materials, at fluences well above the ablation threshold, the maximum measured plasma reflectivity shows a saturation behavior consistent with a scattering rate proportional to the plasma density in this fluence regime. Moreover, for both materials and for pulse energies above the ablation threshold and delays in the few tens of picoseconds range, a simultaneous "low reflectivity" and "low transmission" behavior is observed. Although this behavior has been identified in the past as a signature of femtosecond laser-induced ablation, its origin is alternatively discussed in terms of the optical properties of a material undergoing strong isochoric heating, before having time to substantially expand or exchange energy with the surrounding media.

  16. Energy storage cell impedance measuring apparatus, methods and related systems

    Science.gov (United States)

    Morrison, John L.; Morrison, William H.; Christophersen, Jon P.

    2017-12-26

    Energy storage cell impedance testing devices, circuits, and related methods are disclosed. An energy storage cell impedance measuring device includes a sum of sinusoids (SOS) current excitation circuit including differential current sources configured to isolate a ground terminal of the differential current sources from a positive terminal and a negative terminal of an energy storage cell. A method includes applying an SOS signal comprising a sum of sinusoidal current signals to the energy storage cell with the SOS current excitation circuit, each of the sinusoidal current signals oscillating at a different one of a plurality of different frequencies. The method also includes measuring an electrical signal at a positive terminal and a negative terminal of the energy storage cell, and computing an impedance of the energy storage cell at each of the plurality of different frequencies using the measured electrical signal.

  17. Electron cloud density measurements in accelerator beam-pipe using resonant microwave excitation

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, John P., E-mail: jps13@cornell.edu [CLASSE, Cornell University, Ithaca, NY 14853 (United States); Carlson, Benjamin T. [Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Duggins, Danielle O. [Gordon College, Wenham, MA 01984 (United States); Hammond, Kenneth C. [Columbia University, New York, NY 10027 (United States); De Santis, Stefano [LBNL, Berkeley, CA 94720 (United States); Tencate, Alister J. [Idaho State University, Pocatello, ID 83209 (United States)

    2014-08-01

    An accelerator beam can generate low energy electrons in the beam-pipe, generally called electron cloud, that can produce instabilities in a positively charged beam. One method of measuring the electron cloud density is by coupling microwaves into and out of the beam-pipe and observing the response of the microwaves to the presence of the electron cloud. In the original technique, microwaves are transmitted through a section of beam-pipe and a change in EC density produces a change in the phase of the transmitted signal. This paper describes a variation on this technique in which the beam-pipe is resonantly excited with microwaves and the electron cloud density calculated from the change that it produces in the resonant frequency of the beam-pipe. The resonant technique has the advantage that measurements can be localized to sections of beam-pipe that are a meter or less in length with a greatly improved signal to noise ratio.

  18. Plasmon assisted control of photo-induced excitation energy transfer in a molecular chain

    Science.gov (United States)

    Wang, Luxia; May, Volkhard

    2017-08-01

    The strong and ultrafast laser pulse excitation of a molecular chain in close vicinity to a spherical metal nano-particle (MNP) is studied theoretically. Due to local-field enhancement around the MNP, pronounced excited-state formation has to be expected for the part of the chain which is in proximity to the MNP. Here, the description of this phenomenon will be based on a uniform quantum theory of the MNP-molecule system. It accounts for local-field effects due to direct consideration of the strong excitation energy transfer coupling between the MNP and the various molecules. The molecule-MNP distances are chosen in such a way as to achieve a correct description of the MNP via dipole-plasmon excitations. Short plasmon life-times are incorporated in the framework of a density matrix approach. By extending earlier work the present description allows for multi-exciton formation and multiple dipole-plasmon excitation. The region of less intense and not-too-short optical excitation is identified as being best suited for excitation energy localization in the chain.

  19. A technique for the measurement of electron attachment to short-lived excited species

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Pinnaduwage, L.A.; Bitouni, A.P.

    1990-01-01

    A technique is described for the measurement of electron attachment to short-lived (approx-lt 10 -9 s) excited species. Preliminary results are presented for photoenhanced electron attachment to short-lived electronically-excited states of triethylamine molecules produced by laser two-photon excitation. The attachment cross sections for these excited states are estimated to be >10 -11 cm 2 and are ∼10 7 larger compared to those for the unexcited (ground-state) molecules. 8 refs., 4 figs

  20. De-excitation gamma-ray technique for improved resolution in intermediate energy photonuclear reactions

    International Nuclear Information System (INIS)

    Kuzin, A.; Thompson, M.N.; Rassool, R.; Adler, J.O.; Fissum, K.; Issaksson, L.; Ruijter, H.; Schroeder, B.; Annand, J.R.M.; McGeorge, J.C.; Crawford, G.I.; Gregel, J.

    1997-01-01

    The 12 C (γ,p) reaction was studied. The experiment was done at the MAX Laboratory of Lund University, using tagged photons with energy between 50 and 70 MeV and natural carbon targets. It has been possible to detect γ-ray emitted from the residual nucleus, in coincidence with photoprotons leading to the excited residual state. The 200 KeV gamma-ray resolution permitted the identification of the residual states and allowed off-line cuts to be made in order to identify the excitation region in 11 B from what particular de-excitation gamma-ray were seen. 9 refs., 1 tab., 3 figs

  1. Singlet-triplet splittings from the virial theorem and single-particle excitation energies

    Science.gov (United States)

    Becke, Axel D.

    2018-01-01

    The zeroth-order (uncorrelated) singlet-triplet energy difference in single-particle excited configurations is 2Kif, where Kif is the Coulomb self-energy of the product of the transition orbitals. Here we present a non-empirical, virial-theorem argument that the correlated singlet-triplet energy difference should be half of this, namely, Kif. This incredibly simple result gives vertical HOMO-LUMO excitation energies in small-molecule benchmarks as good as the popular TD-B3LYP time-dependent approach to excited states. For linear acenes and nonlinear polycyclic aromatic hydrocarbons, the performance is significantly better than TD-B3LYP. In addition to the virial theorem, the derivation borrows intuitive pair-density concepts from density-functional theory.

  2. Effect of collision energy and vibrational excitation on endothermic ion-molecule reactions

    International Nuclear Information System (INIS)

    Turner, T.P.

    1984-07-01

    This thesis is divided into two major parts. In the first part an experimental study of proton and deuteron transfer in H 2 + + He and HD + + He has been carried out as a function of kinetic and vibrational energy. The data gives evidence that at lower kinetic energies, the spectator stripping mechanism indeed plays an important role when H 2 + or HD + is vibrationally excited. The second half of this thesis examines the relative efficiencies between the excitation of C-C stretching vibration and collision energy on the promotion of the H atom transfer reaction of C 2 H 2 + + H 2 → C 2 H 3 + + H

  3. σ-SCF: A direct energy-targeting method to mean-field excited states

    Science.gov (United States)

    Ye, Hong-Zhou; Welborn, Matthew; Ricke, Nathan D.; Van Voorhis, Troy

    2017-12-01

    The mean-field solutions of electronic excited states are much less accessible than ground state (e.g., Hartree-Fock) solutions. Energy-based optimization methods for excited states, like Δ-SCF (self-consistent field), tend to fall into the lowest solution consistent with a given symmetry—a problem known as "variational collapse." In this work, we combine the ideas of direct energy-targeting and variance-based optimization in order to describe excited states at the mean-field level. The resulting method, σ-SCF, has several advantages. First, it allows one to target any desired excited state by specifying a single parameter: a guess of the energy of that state. It can therefore, in principle, find all excited states. Second, it avoids variational collapse by using a variance-based, unconstrained local minimization. As a consequence, all states—ground or excited—are treated on an equal footing. Third, it provides an alternate approach to locate Δ-SCF solutions that are otherwise hardly accessible by the usual non-aufbau configuration initial guess. We present results for this new method for small atoms (He, Be) and molecules (H2, HF). We find that σ-SCF is very effective at locating excited states, including individual, high energy excitations within a dense manifold of excited states. Like all single determinant methods, σ-SCF shows prominent spin-symmetry breaking for open shell states and our results suggest that this method could be further improved with spin projection.

  4. Vibration transfers to measure the performance of vibration isolated platforms on site using background noise excitation

    NARCIS (Netherlands)

    Segerink, Franciscus B.; Korterik, Jeroen P.; Offerhaus, Herman L.

    2011-01-01

    This article demonstrates a quick and easy way of quantifying the performance of a vibration-isolated platform. We measure the vibration transfer from floor to table using background noise excitation from the floor. As no excitation device is needed, our setup only requires two identical sensors (in

  5. Generating Excitement: Build Your Own Generator to Study the Transfer of Energy

    Science.gov (United States)

    Fletcher, Kurt; Rommel-Esham, Katie; Farthing, Dori; Sheldon, Amy

    2011-01-01

    The transfer of energy from one form to another can be difficult to understand. The electrical energy that turns on a lamp may come from the burning of coal, water falling at a hydroelectric plant, nuclear reactions, or gusts of wind caused by the uneven heating of the Earth. The authors have developed and tested an exciting hands-on activity to…

  6. Optical energy transport and interactions between the excitations in a coumarin-perylene bisimide dendrimer

    NARCIS (Netherlands)

    Augulis, Ramunas; Pugzlys, Audrius; Hurenkamp, Johannes; Feringa, Ben L.; van Esch, Jan H.; van Loosdrecht, Paul H. M.

    2007-01-01

    Energy transfer properties of novel coumarin-perylene bisimide dendrimer are studied by means of steady state and time-resolved UV/vis spectroscopy. At low donor excitation density fast (transfer rate similar to 10 ps(-1)) and efficient (quantum yield similar to 99.5%) donor-acceptor energy transfer

  7. Excitation and dissociation of molecules by low-energy (0-15 eV) electrons

    International Nuclear Information System (INIS)

    Verhaart, G.J.

    1980-01-01

    The author deals with excitation and dissociation processes which result from the interaction between low-energy (0.15 eV) electrons and molecules. Low-energy electron-impact spectroscopy is used to gain a better knowledge of the electronic structure of halomethanes, ethylene and some of its halogen substituted derivatives, and some more complex organic molecules. (Auth.)

  8. Excited baryon form-factors at high momentum transfer at CEBAF at higher energies

    Energy Technology Data Exchange (ETDEWEB)

    Stoler, P. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1994-04-01

    The possibilities of measuring the properties of excited nucleons at high Q{sup 2} by means of exclusive single meson production at CEBAF with an electron energy of 8 GeV is considered. The motivation is to access short range phenomena in baryon structure, and to investigate the transition from the low Q{sup 2} non-perturbative QCD regime, where constituent quark models are valid, to higher Q{sup 2} where it is believed perturbative QCD plays an increasingly important role. It is found that high quality baryon decay angular distributions can be obtained for the most prominent states up to Q{sup 2} {approximately} 12 GeV{sup 2}/c{sup 2} using a set of moderate resolution, large solid angle magnetic spectrometers.

  9. Excitation energy transfer from dye molecules to doped graphene

    Indian Academy of Sciences (India)

    Recently, we have reported theoretical studies on the rate of energy transfer ... Dirac cone approximation and hence our conclusions are of qualitative nature. 2. .... make another change of variable to r given by r = ki q/2 to get. G1 (q) = Aq2.

  10. Range-separated density-functional theory for molecular excitation energies

    International Nuclear Information System (INIS)

    Rebolini, E.

    2014-01-01

    Linear-response time-dependent density-functional theory (TDDFT) is nowadays a method of choice to compute molecular excitation energies. However, within the usual adiabatic semi-local approximations, it is not able to describe properly Rydberg, charge-transfer or multiple excitations. Range separation of the electronic interaction allows one to mix rigorously density-functional methods at short range and wave function or Green's function methods at long range. When applied to the exchange functional, it already corrects most of these deficiencies but multiple excitations remain absent as they need a frequency-dependent kernel. In this thesis, the effects of range separation are first assessed on the excitation energies of a partially-interacting system in an analytic and numerical study in order to provide guidelines for future developments of range-separated methods for excitation energy calculations. It is then applied on the exchange and correlation TDDFT kernels in a single-determinant approximation in which the long-range part of the correlation kernel vanishes. A long-range frequency-dependent second-order correlation kernel is then derived from the Bethe-Salpeter equation and added perturbatively to the range-separated TDDFT kernel in order to take into account the effects of double excitations. (author)

  11. Use of polarization measurements in evaluating cascade contributions to optical excitation functions

    International Nuclear Information System (INIS)

    McConkey, J.W.

    1981-01-01

    Recent developments in theory and experimental measurements of rotational line polarization fractions of diatomic molecules following electron impact are used to show how in some instances cascade free optical excitation functions can be derived without additional measurements of the cascading contribution. The Lyman system of H 2 is presented as an example and some previously conflicting excitation cross-section measurements obtained by different techniques are reconciled

  12. Coherent excitation-energy transfer and quantum entanglement in a dimer

    International Nuclear Information System (INIS)

    Liao Jieqiao; Sun, C. P.; Huang Jinfeng; Kuang Leman

    2010-01-01

    We study coherent energy transfer of a single excitation and quantum entanglement in a dimer, which consists of a donor and an acceptor modeled by two two-level systems. Between the donor and the acceptor, there exists a dipole-dipole interaction, which provides the physical mechanism for coherent energy transfer and entanglement generation. The donor and the acceptor couple to two independent heat baths with diagonal couplings that do not dissipate the energy of the noncoupling dimer. Special attention is paid to the effect on single-excitation energy transfer and entanglement generation of the energy detuning between the donor and the acceptor and the temperatures of the two heat baths. It is found that, the probability for single-excitation energy transfer largely depends on the energy detuning in the low temperature limit. Concretely, the positive and negative energy detunings can increase and decrease the probability at steady state, respectively. In the high temperature limit, however, the effect of the energy detuning on the probability is negligibly small. We also find that the probability is negligibly dependent on the bath temperature difference of the two heat baths. In addition, it is found that quantum entanglement can be generated in the process of coherent energy transfer. As the bath temperature increases, the generated steady-state entanglement decreases. For a given bath temperature, the steady-state entanglement decreases with the increase of the absolute value of the energy detuning.

  13. Fusion-fission of superheavy nuclei at low excitation energies

    International Nuclear Information System (INIS)

    Itkis, M.G.; Oganesyan, Yu.Ts.; Kozulin, E.M.

    2000-01-01

    The process of fusion-fission of superheavy nuclei with Z = 102 -122 formed in the reactions with 22 Ne, 26 Mg, 48 Ca, 58 Fe and 86 Kr ions at energies near and below the Coulomb barrier has been studied. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR) using a time-of-flight spectrometer of fission fragments CORSET and a neutron multi-detector DEMON. As a result of the experiments, mass and energy distributions of fission fragments, fission and quasi-fission cross sections, multiplicities of neutrons and gamma-rays and their dependence on the mechanism of formation and decay of compound superheavy systems have been studied

  14. Comparison of sensitivities and detection limits between direct excitation and secondary excitation modes in energy dispersive x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Artz, B.E.; Short, M.A.

    1976-01-01

    A comparison was made between the direct tube excitation mode and the secondary target excitation mode using a Kevex 0810 energy dispersive x-ray fluorescence system. Relative sensitivities and detection limits were determined with two system configurations. The first configuration used a standard, high power, x-ray fluorescence tube to directly excite the specimen. Several x-ray tubes, including chromium, molybdenum, and tungsten, both filtered and not filtered, were employed. The second configuration consisted of using the x-ray tube to excite a secondary target which in turn excited the specimen. Appropriate targets were compared to the direct excitation results. Relative sensitivities and detection limits were determined for K-series lines for elements from magnesium to barium contained in a low atomic number matrix and in a high atomic number matrix

  15. Measuring transformers in energy measurement technology

    International Nuclear Information System (INIS)

    Vock, E.

    2009-01-01

    This article takes a look at the use of measurement transformers in energy measurement installations in the light of electricity market liberalisation. Such equipment is quoted as being long living and capital-intensive. Increasing requirements on the installation of measurement equipment between partners in a liberalised market are examined. The requirements placed by electricity market legislation on the systems for the various grid voltage levels are discussed. Both current and voltage measurement transformers are looked at and the requirements placed on their accuracy are discussed in detail.

  16. Magnetic measurement of soft magnetic composites material under 3D SVPWM excitation

    Science.gov (United States)

    Zhang, Changgeng; Jiang, Baolin; Li, Yongjian; Yang, Qingxin

    2018-05-01

    The magnetic properties measurement and analysis of soft magnetic material under the rotational space-vector pulse width modulation (SVPWM) excitation are key factors in design and optimization of the adjustable speed motor. In this paper, a three-dimensional (3D) magnetic properties testing system fit for SVPWM excitation is built, which includes symmetrical orthogonal excitation magnetic circuit and cubic field-metric sensor. Base on the testing system, the vector B and H loci of soft magnetic composite (SMC) material under SVPWM excitation are measured and analyzed by proposed 3D SVPWM control method. Alternating and rotating core losses under various complex excitation with different magnitude modulation ratio are calculated and compared.

  17. Solar Energy Measurement Using Arduino

    OpenAIRE

    Jumaat Siti Amely; Othman Mohamad Hilmi

    2018-01-01

    This project aims to develop a measurement of solar energy using Arduino Board technology. In this research, four parameters that been measured are temperature, light intensity, voltage and current. The temperature was measured using temperature sensor. The light intensity was measured using light dependent resistor (LDR) sensor. The voltage was measured using the voltage divider because the voltage generated by the solar panel are large for the Arduino as receiver. Lastly for the current was...

  18. Nonlinear dynamic analysis of cantilevered piezoelectric energy harvesters under simultaneous parametric and external excitations

    Science.gov (United States)

    Fang, Fei; Xia, Guanghui; Wang, Jianguo

    2018-02-01

    The nonlinear dynamics of cantilevered piezoelectric beams is investigated under simultaneous parametric and external excitations. The beam is composed of a substrate and two piezoelectric layers and assumed as an Euler-Bernoulli model with inextensible deformation. A nonlinear distributed parameter model of cantilevered piezoelectric energy harvesters is proposed using the generalized Hamilton's principle. The proposed model includes geometric and inertia nonlinearity, but neglects the material nonlinearity. Using the Galerkin decomposition method and harmonic balance method, analytical expressions of the frequency-response curves are presented when the first bending mode of the beam plays a dominant role. Using these expressions, we investigate the effects of the damping, load resistance, electromechanical coupling, and excitation amplitude on the frequency-response curves. We also study the difference between the nonlinear lumped-parameter and distributed-parameter model for predicting the performance of the energy harvesting system. Only in the case of parametric excitation, we demonstrate that the energy harvesting system has an initiation excitation threshold below which no energy can be harvested. We also illustrate that the damping and load resistance affect the initiation excitation threshold.

  19. JANUS - A setup for low-energy Coulomb excitation at ReA3

    Science.gov (United States)

    Lunderberg, E.; Belarge, J.; Bender, P. C.; Bucher, B.; Cline, D.; Elman, B.; Gade, A.; Liddick, S. N.; Longfellow, B.; Prokop, C.; Weisshaar, D.; Wu, C. Y.

    2018-03-01

    A new experimental setup for low-energy Coulomb excitation experiments was constructed in a collaboration between the National Superconducting Cyclotron Laboratory (NSCL), Lawrence Livermore National Laboratory (LLNL), and the University of Rochester and was commissioned at the general purpose beam line of NSCL's ReA3 reaccelerator facility. The so-called JANUS setup combines γ-ray detection with the Segmented Ge Array (SeGA) and scattered particle detection using a pair of segmented double-sided Si detectors (Bambino 2). The low-energy Coulomb excitation program that JANUS enables will complement intermediate-energy Coulomb excitation studies that have long been performed at NSCL by providing access to observables that quantify collectivity beyond the first excited state, including the sign and magnitude of excited-state quadrupole moments. In this work, the setup and its performance will be described based on the commissioning run that used stable 78Kr impinging onto a 1.09 mg/cm2208Pb target at a beam energy of 3.9 MeV/u.

  20. Energy principle for excitations in plasmas with counterstreaming electron flows

    Science.gov (United States)

    Kumar, Atul; Shukla, Chandrasekhar; Das, Amita; Kaw, Predhiman

    2018-05-01

    A relativistic electron beam propagating through plasma induces a return electron current in the system. Such a system of interpenetrating forward and return electron current is susceptible to a host of instabilities. The physics of such instabilities underlies the conversion of the flow kinetic energy to the electromagnetic field energy. Keeping this in view, an energy principle analysis has been enunciated in this paper. Such analyses have been widely utilized earlier in the context of conducting fluids described by MHD model [I. B. Bernstein et al., Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences 244(1236), 17-40 (1958)]. Lately, such an approach has been employed for the electrostatic two stream instability for the electron beam plasma system [C. N. Lashmore-Davies, Physics of Plasmas 14(9), 092101 (2007)]. In contrast, it has been shown here that even purely growing mode like Weibel/current filamentation instability for the electron beam plasma system is amenable to such a treatment. The treatment provides an understanding of the energetics associated with the growing mode. The growth rate expression has also been obtained from it. Furthermore, it has been conclusively demonstrated in this paper that for identical values of S4=∑αn0 αv0α 2/n0γ0 α, the growth rate is higher when the counterstreaming beams are symmetric (i.e. S3 = ∑αn0αv 0α/n0γ0α = 0) compared to the case when the two beams are asymmetric (i.e. when S3 is finite). Here, v 0α, n0α and γ0α are the equilibrium velocity, electron density and the relativistic factor for the electron species `α' respectively and n0 = ∑αn0α is the total electron density. Particle - In - Cell simulations have been employed to show that the saturated amplitude of the field energy is also higher in the symmetric case.

  1. Relativistic Energy Density Functionals: Exotic modes of excitation

    International Nuclear Information System (INIS)

    Vretenar, D.; Paar, N.; Marketin, T.

    2008-01-01

    The framework of relativistic energy density functionals has been applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of β-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure have been investigated with the relativistic quasiparticle random-phase approximation. We present results for the evolution of low-lying dipole (pygmy) strength in neutron-rich nuclei, and charged-current neutrino-nucleus cross sections.

  2. Selective excitation, relaxation, and energy channeling in molecular systems

    International Nuclear Information System (INIS)

    Rhodes, W.C.

    1993-08-01

    Research involves theoretical studies of response, relaxation, and correlated motion in time-dependent behavior of large molecular systems ranging from polyatomic molecules to protein molecules in their natural environment. Underlying theme is subsystem modulation dynamics. Main idea is that quantum mechanical correlations between components of a system develop with time, playing a major role in determining the balance between coherent and dissipative forces. Central theme is interplay of coherence and dissipation in determining the nature of dynamic structuring and energy flow in molecular transformation mechanisms. Subsystem equations of motion are being developed to show how nonlinear, dissipative dynamics of a particular subsystem arise from correlated interactions with the rest of the system (substituent groups, solvent, lattice modes, etc.); one consequence is resonance structures and networks. Quantum dynamics and thermodynamics are being applied to understand control and energy transfer mechanisms in biological functions of protein molecules; these mechanisms are both global and local. Besides the above theory, the research deals with phenomenological aspects of molecular systems

  3. An experimentally validated bimorph cantilever model for piezoelectric energy harvesting from base excitations

    International Nuclear Information System (INIS)

    Erturk, A; Inman, D J

    2009-01-01

    Piezoelectric transduction has received great attention for vibration-to-electric energy conversion over the last five years. A typical piezoelectric energy harvester is a unimorph or a bimorph cantilever located on a vibrating host structure, to generate electrical energy from base excitations. Several authors have investigated modeling of cantilevered piezoelectric energy harvesters under base excitation. The existing mathematical modeling approaches range from elementary single-degree-of-freedom models to approximate distributed parameter solutions in the sense of Rayleigh–Ritz discretization as well as analytical solution attempts with certain simplifications. Recently, the authors have presented the closed-form analytical solution for a unimorph cantilever under base excitation based on the Euler–Bernoulli beam assumptions. In this paper, the analytical solution is applied to bimorph cantilever configurations with series and parallel connections of piezoceramic layers. The base excitation is assumed to be translation in the transverse direction with a superimposed small rotation. The closed-form steady state response expressions are obtained for harmonic excitations at arbitrary frequencies, which are then reduced to simple but accurate single-mode expressions for modal excitations. The electromechanical frequency response functions (FRFs) that relate the voltage output and vibration response to translational and rotational base accelerations are identified from the multi-mode and single-mode solutions. Experimental validation of the single-mode coupled voltage output and vibration response expressions is presented for a bimorph cantilever with a tip mass. It is observed that the closed-form single-mode FRFs obtained from the analytical solution can successfully predict the coupled system dynamics for a wide range of electrical load resistance. The performance of the bimorph device is analyzed extensively for the short circuit and open circuit resonance

  4. Laser-excited fluorescence for measuring atmospheric pollution

    Science.gov (United States)

    Menzies, R. T.

    1975-01-01

    System measures amount of given pollutant at specific location. Infrared laser aimed at location has wavelength that will cause molecules of pollutant to fluoresce. Detector separates fluorescence from other radiation and measures its intensity to indicate concentration of pollutant.

  5. Lifetime measurements of odd-parity high-excitation levels of Sn I by time-resolved laser spectroscopy

    International Nuclear Information System (INIS)

    Zhang, Wei; Feng, Yanyan; Xu, Jiaxin; Dai, Zhenwen; Palmeri, Patrick; Quinet, Pascal; Biemont, Emile

    2010-01-01

    Natural radiative lifetimes of 38 odd-parity highly excited levels in neutral tin in the energy range from 43 682.737 to 56 838.68 cm -1 have been measured by a time-resolved laser-induced fluorescence technique in an atomic beam produced by laser ablation on a solid tin sample. All the levels were excited from the metastable 3 P 1, 2 and 1 D 2 levels in the ground configuration. The second and third harmonics of a dye laser were adopted as the tunable exciting source (207-250 nm). The lifetime results obtained in this paper are in the range from 4.6 to 292 ns and will be useful in extending the set of oscillator strengths available in Sn I.

  6. Lifetime measurements of odd-parity high-excitation levels of Sn I by time-resolved laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei; Feng, Yanyan; Xu, Jiaxin; Dai, Zhenwen [College of Physics, Jilin University and Key Lab of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, Changchun 130021 (China); Palmeri, Patrick; Quinet, Pascal; Biemont, Emile, E-mail: dai@jlu.edu.c [Astrophysique et Spectroscopie, Universite de Mons-UMONS, B-7000 Mons (Belgium)

    2010-10-28

    Natural radiative lifetimes of 38 odd-parity highly excited levels in neutral tin in the energy range from 43 682.737 to 56 838.68 cm{sup -1} have been measured by a time-resolved laser-induced fluorescence technique in an atomic beam produced by laser ablation on a solid tin sample. All the levels were excited from the metastable {sup 3}P{sub 1,} {sub 2} and {sup 1}D{sub 2} levels in the ground configuration. The second and third harmonics of a dye laser were adopted as the tunable exciting source (207-250 nm). The lifetime results obtained in this paper are in the range from 4.6 to 292 ns and will be useful in extending the set of oscillator strengths available in Sn I.

  7. Piezoelectric Wind Energy Harvesting from Self-Excited Vibration of Square Cylinder

    Directory of Open Access Journals (Sweden)

    Junlei Wang

    2016-01-01

    Full Text Available Self-excited vibration of a square cylinder has been considered as an effective way in harvesting piezoelectric wind energy. In present work, both of the vortex-induced vibration and unstable galloping phenomenon process are investigated in a reduced velocity (Ur=U/ωn·D range of 4≤Ur≤20 with load resistance ranging in 100 Ω≤R≤1 MΩ. The vortex-induced vibration covers presynchronization, synchronization, and postsynchronization branches. An aeroelectromechanical model is given to describe the coupling of the dynamic equation of the fluid-structure interaction and the equation of Gauss law. The effects of load resistance are investigated in both the open-circuit and close-circuit system by a linear analysis, which covers the parameters of the transverse displacement, aerodynamic force, output voltage, and harvested power utilized to measure the efficiency of the system. The highest level of the transverse displacement and the maximum value of harvested power of synchronization branch during the vortex-induced vibration and galloping are obtained. The results show that the large-amplitude galloping at high wind speeds can generate energy. Additionally, energy can be harvested by utilization of the lock-in phenomenon of vortex-induced vibration under low wind speed.

  8. Lifetime measurement of excited atomic and ionic states of some

    Indian Academy of Sciences (India)

    High-frequency deflection (HFD) technique with a delayed coincidence single photon counting arrangement is an efficient technique for radiative lifetime measurement. An apparatus for measurement of the radiative lifetime of atoms and molecules has been developed in our laboratory and measurements have been ...

  9. Multicomponent Time-Dependent Density Functional Theory: Proton and Electron Excitation Energies.

    Science.gov (United States)

    Yang, Yang; Culpitt, Tanner; Hammes-Schiffer, Sharon

    2018-04-05

    The quantum mechanical treatment of both electrons and protons in the calculation of excited state properties is critical for describing nonadiabatic processes such as photoinduced proton-coupled electron transfer. Multicomponent density functional theory enables the consistent quantum mechanical treatment of more than one type of particle and has been implemented previously for studying ground state molecular properties within the nuclear-electronic orbital (NEO) framework, where all electrons and specified protons are treated quantum mechanically. To enable the study of excited state molecular properties, herein the linear response multicomponent time-dependent density functional theory (TDDFT) is derived and implemented within the NEO framework. Initial applications to FHF - and HCN illustrate that NEO-TDDFT provides accurate proton and electron excitation energies within a single calculation. As its computational cost is similar to that of conventional electronic TDDFT, the NEO-TDDFT approach is promising for diverse applications, particularly nonadiabatic proton transfer reactions, which may exhibit mixed electron-proton vibronic excitations.

  10. Excitation of M1 resonances by medium energy protons

    International Nuclear Information System (INIS)

    Crawley, G.M.; Djalali, C.; Marty, N.

    1983-01-01

    The results of 201 MeV (p,p') studies of ΔL=0 spin-flip transitions at very forward angles are discussed. The reasons for making comparisons between (p,p'), (p,n) and electromagnetic measurements of M1 transitions are outlined. After presenting some of the experimental and theoretical uncertainties, a summary of the results on the Zr isotopes plus other nuclei to mass 140 is given. Results from 48 Ca, the N=28 nuclei 50 Ti, 51 V, 52 Cr and 54 Fe are discussed and compared with (p,n) and electromagnetic measurements. In the Ni isotopes, the T 0 and T 0 +1 components of the 1 + spin-flips transition were observed both in (p,p') and in (p,n) reactions

  11. Energy efficiency policies and measures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This document makes a review of the energy efficiency and demand side management (DSM) policies and measures in European Union countries and Norway in 1999: institutional changes, measures and programmes, budget, taxation, existence of a national DSM programme, national budgets for DSM programmes, electricity pricing: energy/environment tax, national efficiency standards and regulation for new electrical appliances, implementation of Commission directives, efficiency requirements, labelling, fiscal and economic incentives. (J.S.)

  12. Cross sections for energy transfer in collisions between two excited sodium atoms

    International Nuclear Information System (INIS)

    Huennekens, J.; Gallagher, A.

    1983-01-01

    We have measured cross sections, sigma/sub n/L, for the excitation transfer process Na(3P)+Na(3P)→Na(3S)+Na(nL), where nL is the 4D or 5S level. Our results are sigma/sub 4D/ = 23 A 2 +- 35% and sigma/sub 5S/ = 16 A 2 +- 35% at Tapprox.600 K. To obtain these cross sections we have used pulsed excitation and measured the intensities of 4D, 5S, and 3P fluorescence emissions, and the spatial distribution of excited atoms resulting from radiation diffusion, as well as the excited atom density as a function of time. Additionally, we have accounted for (time-dependent) radiation trapping of 3P and nL level radiation and for the resulting anisotropies of these fluorescence emissions. Comparisons of our results with theory have been made, and their relevance to other experiments is discussed

  13. Simultaneous measurement of quantum yield ratio and absorption ratio between acceptor and donor by linearly unmixing excitation-emission spectra.

    Science.gov (United States)

    Zhang, C; Lin, F; DU, M; Qu, W; Mai, Z; Qu, J; Chen, T

    2018-02-13

    Quantum yield ratio (Q A /Q D ) and absorption ratio (K A /K D ) in all excitation wavelengths used between acceptor and donor are indispensable to quantitative fluorescence resonance energy transfer (FRET) measurement based on linearly unmixing excitation-emission spectra (ExEm-spFRET). We here describe an approach to simultaneously measure Q A /Q D and K A /K D values by linearly unmixing the excitation-emission spectra of at least two different donor-acceptor tandem constructs with unknown FRET efficiency. To measure the Q A /Q D and K A /K D values of Venus (V) to Cerulean (C), we used a wide-field fluorescence microscope to image living HepG2 cells separately expressing each of four different C-V tandem constructs at different emission wavelengths with 435 nm and 470 nm excitation respectively to obtain the corresponding excitation-emission spectrum (S DA ). Every S DA was linearly unmixed into the contributions (weights) of three excitation-emission spectra of donor (W D ) and acceptor (W A ) as well as donor-acceptor sensitisation (W S ). Plot of W S /W D versus W A /W D for the four C-V plasmids from at least 40 cells indicated a linear relationship with 1.865 of absolute intercept (Q A /Q D ) and 0.273 of the reciprocal of slope (K A /K D ), which was validated by quantitative FRET measurements adopting 1.865 of Q A /Q D and 0.273 of K A /K D for C32V, C5V, CVC and VCV constructs respectively in living HepG2 cells. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

  14. Relative ultrasound energy measurement circuit

    OpenAIRE

    Gustafsson, E.Martin I.; Johansson, Jonny; Delsing, Jerker

    2005-01-01

    A relative ultrasound energy estimation circuit has been designed in a standard 0.35-μm CMOS process, to be a part of a thumb size internet connected wireless ultrasound measurement system. This circuit measures the relative energy between received ultrasound pulses, and presents an output signal that is linear to the received energy. Post-layout simulations indicate 7 bit linearity for 500 mV input signals, 5 μsec startup and stop times, 2.6 mW power consumption during active state. The acti...

  15. Intermolecular Modes between LH2 Bacteriochlorophylls and Protein Residues: The Effect on the Excitation Energies.

    Science.gov (United States)

    Anda, André; De Vico, Luca; Hansen, Thorsten

    2017-06-08

    Light-harvesting system 2 (LH2) executes the primary processes of photosynthesis in purple bacteria; photon absorption, and energy transportation to the reaction center. A detailed mechanistic insight into these operations is obscured by the complexity of the light-harvesting systems, particularly by the chromophore-environment interaction. In this work, we focus on the effects of the protein residues that are ligated to the bacteriochlorophylls (BChls) and construct potential energy surfaces of the ground and first optically excited state for the various BChl-residue systems where we in each case consider two degrees of freedom in the intermolecular region. We find that the excitation energies are only slightly affected by the considered modes. In addition, we see that axial ligands and hydrogen-bonded residues have opposite effects on both excitation energies and oscillator strengths by comparing to the isolated BChls. Our results indicate that only a small part of the chromophore-environment interaction can be associated with the intermolecular region between a BChl and an adjacent residue, but that it may be possible to selectively raise or lower the excitation energy at the axial and planar residue positions, respectively.

  16. Excitation-energy-dependent resonances in x-ray emissions under near-threshold electron excitation of the Ce 3d and 4d levels

    International Nuclear Information System (INIS)

    Chamberlain, M.B.; Baun, W.L.

    1975-01-01

    Soft x-ray appearance potential spectra of the 3d and 4d levels of polycrystalline cerium metal are reported in this paper. Resonant x-ray emissions are observed when the electron-excitation energy sweeps through the ionization energies of the 3d and 4d levels. The resonant x rays excited at the 3d-level onsets are considerably more intense, and are excited at a lower electron-excitation energy than the 3d-series characteristic x rays. In the neighborhood of the 4d-electron thresholds, four line-like structures extend to approx.8 eV below the 4d-electron binding energies, while two broad and more intense structures occur above the 4d onsets, with the largest one reaching a peak intensity at 12 eV above the 4d thresholds. The resonant emissions apparently arise from the decay of threshold-excited states which are bound to the inner vacancy and have core configurations nd 9 4f 3 , (n=3,4). The exchange interaction between the three 4f electrons and the respective d-orbital vacancy spreads the 4d-threshold structures over a 20 eV range of excitation energies and the 3d-threshold structures over a much smaller range

  17. Identification of an isomer in 110Ag at 1-keV excitation energy

    International Nuclear Information System (INIS)

    Clark, D.D.; Kostroun, V.O.; Siems, N.E.

    1975-01-01

    The existence of a new isomeric state in 110 Ag at approx. 1 keV excitation has been established in two experiments using a new instrument, the inner-shell-vacancy (ISV) detector. In the first experiment, a transition with a half-life of 660 plus-or-minus 40 ns was observed to follow the well-known 116-keV M4 transition that depopulates the 6 + 250-day isomeric level in 110 Ag; the energy of the new transition was deduced to be 109 Ag(n, γ) 110 Ag reaction to follow γ transitions previously assigned by others to populate a 1-keV excited state. The two results indicate the existence of a 2 - 660-ns isomer at 1.11 keV. Under the assumption that the newly observed transition is from a 2 - 1.11-keV state to the 1 + ground state, its hindrance factor with respect to the Moszkowski estimate is approx. 2.6 times 10 3 . Possible chemical-state perturbations of the measured half-life are estimated to be much smaller than the measurement error. In both experiments the approx. 1-keV transition was detected with the ISV detector, a new device based on the well-established atomic effect that within approx. 10 -14 s after the formation of an inner shell vacancy an atom will undergo a multiple loss of []lectrons ranging from several to 20 or more, the number being a function of Z and subshell. The emitted electrons, which are very soft, are collected with an accelerating and focusing electrostatic lens and detected with a plastic scintillator and a photomultiplier tube. Nuclear transitions that cause ISVs can thus be sensed. Experiments are described that show the detector is fast, sensitive, selective, and efficient in responding to ISVs.

  18. Excitation of the 4.3-μm bands of CO2 by low-energy electrons

    International Nuclear Information System (INIS)

    Bulos, R.R.; Phelps, A.V.

    1976-01-01

    Rate coefficients for the excitation of the 4.3-μm bands of CO 2 by low-energy electrons in CO 2 have been measured using a drift-tube technique. The CO 2 density [(1.5 to 7) x 10 17 molecules/cm 3 ] was chosen to maximize the radiation reaching the detector. Line-by-line transmission calculations were used to take into account the absorption of 4.3-μm radiation. A small fraction of the approximately 10 -8 W of the 4.3-μm radiation produced by the approximately 10 -7 -A electron current was incident on an InSb photovoltaic detector. The detector calibration and absorption calculations were checked by measuring the readily calculated excitation coefficients for vibrational excitation of N 2 containing a small concentration of CO 2 . For pure CO 2 the number of molecules capable of emitting 4.3-μm radiation produced per cm of electron drift and per CO 2 molecule varied from 10 -17 cm -2 at E/N = 6 x 10 -17 V cm 2 to 5.4 x 10 -16 cm -2 at E/N = 4 x 10 -16 V cm 2 . Here E is the electric field and N is total gas density. The excitation coefficients at lower E/N are much larger than estimated previously. A set of vibrational excitation cross sections is obtained for CO 2 which is consistent with the excitation coefficient data and with most of the published electron-beam data

  19. Angle-resolving time-of-flight electron spectrometer for near-threshold precision measurements of differential cross sections of electron-impact excitation of atoms and molecules

    International Nuclear Information System (INIS)

    Lange, M.; Matsumoto, J.; Setiawan, A.; Panajotovic, R.; Harrison, J.; Lower, J. C. A.; Newman, D. S.; Mondal, S.; Buckman, S. J.

    2008-01-01

    This article presents a new type of low-energy crossed-beam electron spectrometer for measuring angular differential cross sections of electron-impact excitation of atomic and molecular targets. Designed for investigations at energies close to excitation thresholds, the spectrometer combines a pulsed electron beam with the time-of-flight technique to distinguish between scattering channels. A large-area, position-sensitive detector is used to offset the low average scattering rate resulting from the pulsing duty cycle, without sacrificing angular resolution. A total energy resolution better than 150 meV (full width at half maximum) at scattered energies of 0.5-3 eV is achieved by monochromating the electron beam prior to pulsing it. The results of a precision measurement of the differential cross section for electron-impact excitation of helium, at an energy of 22 eV, are used to assess the sensitivity and resolution of the spectrometer

  20. Effect of neutron irradiation on the density of low-energy excitations in vitreous silica

    International Nuclear Information System (INIS)

    Smith, T.L.

    1979-01-01

    Systematic low-temperature measurements of the thermal conductivity, specific heat, dielectric constant, and temperature-dependent ultrasound velocity were made on a single piece of vitreous silica. These measurements were repeated after fast neutron irradiation of the material. It was found that the irradiation produced changes of the same relative magnitude in the low-temperature excess specific heat C/sub ex/, the thermal conductivity kappa, and the anomalous temperature dependence of the ultrasound velocity Δv/v. A corresponding change in the temperature dependent dielectric constant was not observed. It is therefore likely that kappa and Δv/v are determined by the same localized excitations responsible for C/sub ex/, but the temperature dependence of the dielectric constant may have a different, though possibly related, origin. A consistent account for the measured C/sub ex/, kappa, and Δv/v of unirradiated silica is given by the tunneling-state model with a single, energy-dependent density of states. Changes in these three properties due to irradiation can be explained by altering only the density of tunneling states incorporated in the model

  1. Energy measurements from betatron oscillations

    International Nuclear Information System (INIS)

    Himel, T.; Thompson, K.

    1989-03-01

    In the Stanford Linear Collider the electron beam is accelerated from 1--50 GeV in a distance of 3 km. The energy is measured and corrected at the end with an energy feedback loop. There are no bends within the linear accelerator itself, so no intermediate energy measurements are made. Errors in the energy profile due to mis-phasing of the rf, or due to calibration errors in the klystrons' rf outputs are difficult to detect. As the total betatron phase advance down the accelerator is about 30 /times/ 2π, an energy error of a few percent can cause a large error in the total phase advance. This in turn degrades the performance of auto-steering programs. We have developed a diagnostic program which generates and measures several betatron oscillations in the accelerator. It then analyzes this oscillation, looking for frequency changes which indicate energy errors. One can then compensate for or correct these energy errors. 6 refs., 1 fig

  2. High energy spin waves in iron measured by neutron scattering

    International Nuclear Information System (INIS)

    Boothroyd, A.T.; Paul, D.M.; Mook, H.A.

    1991-01-01

    We present new results for the spin were dispersion relation measured along the [ζζ0] direction in bcc iron (12% silicon) by time-of-flight, neutron inelastic scattering. The excitations were followed to the zone boundary, where they are spread over a range of energies around 300meV. 6 refs., 2 figs

  3. Radiative transport and collisional transfer of excitation energy in Cs vapors mixed with Ar or He

    International Nuclear Information System (INIS)

    Vadla, Cedomil; Horvatic, Vlasta; Niemax, Kay

    2003-01-01

    This paper is a review (with a few original additions) on the radiative transport and collisional transfer of energy in laser-excited cesium vapors in the presence of argon or helium. Narrow-band excitation of lines with Lorentz, Doppler and Voigt profiles is studied in order to calculate effective rates for pumping of spectral lines with profiles comprising inhomogeneous broadening components. The radiative transport of excitation energy is considered, and a new, simple and robust, but accurate theoretical method for quantitative treatment of radiation trapping in relatively optically thin media is presented. Furthermore, comprehensive lists of experimental values for the excitation energy transfer cross-sections related to thermal collisions in Cs-Ar and Cs-He mixtures are given. Within the collected cross-section data sets, specific regularities with respect to the energy defect, as well as the temperature, are discerned. A particular emphasis is put on the radiative and collisional processes important for the optimization of resonance-fluorescence imaging atomic filters based on Cs-noble gas systems

  4. Two types of charge transfer excitations in low dimensional cuprates: an electron energy-loss study

    Czech Academy of Sciences Publication Activity Database

    Knupfer, M.; Fink, J.; Drechsler, S.-L.; Hayn, R.; Málek, Jiří; Moskvin, A.S.

    137-140, - (2004), s. 469-473 ISSN 0368-2048 Institutional research plan: CEZ:AV0Z1010914 Keywords : cuprates * electronic excitations * electron energy-loss spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.069, year: 2004

  5. Towards an unambiguous determination of the excitation energy of the projectile in heavy-ion reactions?

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A.M.; Steckmeyer, J.C. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, G. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)] [and others

    2002-03-01

    The excitation energy of the quasi-projectiles produced in heavy-ion collisions is determined for the {sup 58}Ni+{sup 197}Au reactions at 52 and 90 AMeV. A new method is proposed for isolating unambiguously the particles evaporated by the source. It consists in observing them at small angles along the flight direction of the source. (authors)

  6. Interqubit coupling mediated by a high-excitation-energy quantum object

    NARCIS (Netherlands)

    Ashhab, S.; Niskanen, A.O.; Harrabi, K.; Nakamura, Y.; Picot, T.; De Groot, P.C.; Harmans, C.J.P.M.; Mooij, J.E.; Nori, F.

    2008-01-01

    We consider a system composed of two qubits and a high excitation energy quantum object used to mediate coupling between the qubits. We treat the entire system quantum mechanically and analyze the properties of the eigenvalues and eigenstates of the total Hamiltonian. After reproducing well known

  7. Elastic, excitation, ionization and charge transfer cross sections of current interest in fusion energy research

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, D.R.; Krstic, P.S. [Oak Ridge National Lab. TN (United States). Physics Div.

    1997-01-01

    Due to the present interest in modeling and diagnosing the edge and divertor plasma regions in magnetically confined fusion devices, we have sought to provide new calculations regarding the elastic, excitation, ionization, and charge transfer cross sections in collisions among relevant ions, neutrals, and isotopes in the low-to intermediate-energy regime. We summarize here some of our recent work. (author)

  8. Convergence of environment polarization effects in multiscale modeling of excitation energies

    DEFF Research Database (Denmark)

    Beerepoot, Maarten; Steindal, Arnfinn Hykkerud; Ruud, Kenneth

    2014-01-01

    We present a systematic investigation of the influence of polarization effects from a surrounding medium on the excitation energies of a chromophore. We use a combined molecular dynamics and polarizable embedding time-dependent density functional theory (PE-TD-DFT) approach for chromophores in pr...

  9. Restricted second random phase approximations and Tamm-Dancoff approximations for electronic excitation energy calculations

    International Nuclear Information System (INIS)

    Peng, Degao; Yang, Yang; Zhang, Peng; Yang, Weitao

    2014-01-01

    In this article, we develop systematically second random phase approximations (RPA) and Tamm-Dancoff approximations (TDA) of particle-hole and particle-particle channels for calculating molecular excitation energies. The second particle-hole RPA/TDA can capture double excitations missed by the particle-hole RPA/TDA and time-dependent density-functional theory (TDDFT), while the second particle-particle RPA/TDA recovers non-highest-occupied-molecular-orbital excitations missed by the particle-particle RPA/TDA. With proper orbital restrictions, these restricted second RPAs and TDAs have a formal scaling of only O(N 4 ). The restricted versions of second RPAs and TDAs are tested with various small molecules to show some positive results. Data suggest that the restricted second particle-hole TDA (r2ph-TDA) has the best overall performance with a correlation coefficient similar to TDDFT, but with a larger negative bias. The negative bias of the r2ph-TDA may be induced by the unaccounted ground state correlation energy to be investigated further. Overall, the r2ph-TDA is recommended to study systems with both single and some low-lying double excitations with a moderate accuracy. Some expressions on excited state property evaluations, such as 〈S ^2 〉 are also developed and tested

  10. Restricted second random phase approximations and Tamm-Dancoff approximations for electronic excitation energy calculations

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Degao; Yang, Yang; Zhang, Peng [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Yang, Weitao, E-mail: weitao.yang@duke.edu [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2014-12-07

    In this article, we develop systematically second random phase approximations (RPA) and Tamm-Dancoff approximations (TDA) of particle-hole and particle-particle channels for calculating molecular excitation energies. The second particle-hole RPA/TDA can capture double excitations missed by the particle-hole RPA/TDA and time-dependent density-functional theory (TDDFT), while the second particle-particle RPA/TDA recovers non-highest-occupied-molecular-orbital excitations missed by the particle-particle RPA/TDA. With proper orbital restrictions, these restricted second RPAs and TDAs have a formal scaling of only O(N{sup 4}). The restricted versions of second RPAs and TDAs are tested with various small molecules to show some positive results. Data suggest that the restricted second particle-hole TDA (r2ph-TDA) has the best overall performance with a correlation coefficient similar to TDDFT, but with a larger negative bias. The negative bias of the r2ph-TDA may be induced by the unaccounted ground state correlation energy to be investigated further. Overall, the r2ph-TDA is recommended to study systems with both single and some low-lying double excitations with a moderate accuracy. Some expressions on excited state property evaluations, such as 〈S{sup ^2}〉 are also developed and tested.

  11. Energy-Looping Nanoparticles: Harnessing Excited-State Absorption for Deep-Tissue Imaging.

    Science.gov (United States)

    Levy, Elizabeth S; Tajon, Cheryl A; Bischof, Thomas S; Iafrati, Jillian; Fernandez-Bravo, Angel; Garfield, David J; Chamanzar, Maysamreza; Maharbiz, Michel M; Sohal, Vikaas S; Schuck, P James; Cohen, Bruce E; Chan, Emory M

    2016-09-27

    Near infrared (NIR) microscopy enables noninvasive imaging in tissue, particularly in the NIR-II spectral range (1000-1400 nm) where attenuation due to tissue scattering and absorption is minimized. Lanthanide-doped upconverting nanocrystals are promising deep-tissue imaging probes due to their photostable emission in the visible and NIR, but these materials are not efficiently excited at NIR-II wavelengths due to the dearth of lanthanide ground-state absorption transitions in this window. Here, we develop a class of lanthanide-doped imaging probes that harness an energy-looping mechanism that facilitates excitation at NIR-II wavelengths, such as 1064 nm, that are resonant with excited-state absorption transitions but not ground-state absorption. Using computational methods and combinatorial screening, we have identified Tm(3+)-doped NaYF4 nanoparticles as efficient looping systems that emit at 800 nm under continuous-wave excitation at 1064 nm. Using this benign excitation with standard confocal microscopy, energy-looping nanoparticles (ELNPs) are imaged in cultured mammalian cells and through brain tissue without autofluorescence. The 1 mm imaging depths and 2 μm feature sizes are comparable to those demonstrated by state-of-the-art multiphoton techniques, illustrating that ELNPs are a promising class of NIR probes for high-fidelity visualization in cells and tissue.

  12. Impedance measures in analysis and characterization of multistable structures subjected to harmonic excitation

    Science.gov (United States)

    Harne, Ryan L.; Goodpaster, Benjamin A.

    2018-01-01

    Structural components susceptible to adverse, post-buckled dynamic behaviors have long challenged the success of applications requiring lightweight, slender curved structures, while researchers have begun to leverage such bistable systems in emerging applications for novel energy attenuation and shape-changing properties. To expedite development and deployment of these built-up platforms containing post-buckled constituents, efficient approaches are required to complement time-consuming full-field models in the prediction of the near- and far-from-equilibrium dynamics. This research meets the need by introducing a semi-analytical model framework to enable the characterization of steady-state responses in multi degree-of-freedom (DOF) and multistable structural systems subjected to harmonic excitation. In so doing, the pathway for assessing impedance measures is created here so as to identify how energy travels and returns within built-up multistable structures. Verified by simulations and qualitatively validated by experiments, the analysis is shown to accurately reproduce both near- and far-from-equilibrium responses including different classes of energetic snap-through dynamics that only exist in such multistable structures. A first look at the impedance measures of different dynamic regimes reveals a connection between damping in multistable structures and the sustainability of far-from-equilibrium oscillations.

  13. Excitation energy and angular momentum of quasiprojectiles produced in the Xe+Sn collisions at incident energies between 25 and 50 MeV/nucleon

    International Nuclear Information System (INIS)

    Steckmeyer, J.C.; Genouin-Duhamel, E.; Vient, E.; Colin, J.; Durand, D.; Auger, G.; Bacri, C.O.; Bellaize, N.; Borderie, B.; Bougault, R.; Bouriquet, B.; Brou, R.; Buchet, P.; Charvet, J.L.; Chbihi, A.; Cussol, D.; Dayras, R.; De Cesare, N.; Demeyer, A.; Dore, D.; Frankland, J.D.; Galichet, E.; Gerlic, E.; Guinet, D.; Hudan, S.; Lautesse, P.; Lavaud, F.; Laville, J.L.; Lecolley, J.F.; Leduc, C.; Legrain, R.; Le Neindre, N.; Lopez, O.; Louvel, M.; Maskay, A.M.; Nalpas, L.; Normand, J.; Parlog, M.; Pawlowski, P.; Plagnol, E.; Rivet, M.F.; Rosato, E.; Saint-Laurent, F.; Tabacaru, G.; Tamain, B.; Tassan-Got, L.; Tirel, O.; Turzo, K.; Vigilante, M.; Volant, C.; Wieleczko, J.P.

    2001-01-01

    The excitation energy and angular momentum transferred to quasiprojectiles have been measured in the 129 Xe+ nat Sn collisions at bombarding energies between 25 and 50 MeV/nucleon. The excitation energy of quasiprojectiles has been determined from the kinetic energy of all decay products (calorimetry). It increases with the violence of the collision, approaching 10 MeV/nucleon in the most dissipative ones. The angular momentum has been deduced from the kinetic energies and angular distributions of the emitted light charged particles (p, d, t, 3 He and α). The (apparent) spin value decreases with the violence of the collision. Larger spin values are observed at the lowest bombarding energy. Data are compared with the predictions of dynamical and statistical models. They reproduce the data in a quantitative way indicating that large spin values are transferred to quasiprojectiles during the interaction. The results show that the one-body dissipation formalism still applies at intermediate bombarding energies and low-energy dissipations. With the increase of the energy, the data seem to be better described when the two-body interaction is accounted for

  14. Determination of minimum impact parameter by modified touching spheres schemes for intermediate energy Coulomb excitation experiments

    International Nuclear Information System (INIS)

    Kumar, Rajiv; Sharma, Shagun; Singh, Pradeep; Kharab, Rajesh

    2016-01-01

    The energy-independent touching spheres schemes commonly used for the determination of the safe minimum value of the impact parameter for Coulomb excitation experiments are modified through the inclusion of an energy-dependent term. The touching spheres+3fm scheme after modification emerges out to be the best one while touching spheres+4fm scheme is found to be better in its unmodified form. (orig.)

  15. Measuring resilience to energy shocks

    OpenAIRE

    Molyneaux, Lynette; Brown, Colin; Foster, John; Wagner, Liam

    2015-01-01

    Measuring energy security or resilience in energy is, in the main, confined to indicators which are used for comparative purposes or to show trends rather than provide empirical evidence of resilience to unpredicted crises. In this paper, the electricity systems of the individual states within the United States of America are analysed for their response to the 1973-1982 and the 2003-2012 oil price shocks. Empirical evidence is sought for elements which are present in systems that experience r...

  16. Forward energy measurement with CMS

    CERN Document Server

    Kheyn, Lev

    2016-01-01

    Energy flow is measured in the forward region of CMS at pseudorapidities up to 6.6 in pp interactions at 13 TeV with forward (HF) and very forward (CASTOR) calorimeters. The results are compared to model predictions. The CMS results at different center-of-mass energies are intercompared using pseudorapidity variable shifted by beam rapidity, thus studying applicability of hypothesis of limiting fragmentation.

  17. Measurement of the Low Frequency Noise of MOSFETs under Large Signal RF Excitation

    NARCIS (Netherlands)

    van der Wel, A.P.; Klumperink, Eric A.M.; Nauta, Bram

    2002-01-01

    A measurement technique [1] is presented that allows measurement of MOSFET low frequency (LF) noise under large signal RF (Radio Frequency) excitation. Measurements indicate that MOSFETS exhibit a reduction in LF noise when they are cycled from inversion to accummulation and that this reduction does

  18. Multireference excitation energies for bacteriochlorophylls A within light harvesting system 2

    DEFF Research Database (Denmark)

    Anda, Andre; Hansen, Thorsten; De Vico, Luca

    2016-01-01

    Light-harvesting system 2 (LH2) of purple bacteria is one of the most popular antenna complexes used to study Nature's way of collecting and channeling solar energy. The dynamics of the absorbed energy is probed by ultrafast spectroscopy. Simulation of these experiments relies on fitting a range...... bacteriochlorophylls in LH2. We find that the excitation energies vary among the bacteriochlorophyll monomers and that they are regulated by the curvature of the macrocycle ring and the dihedral angle of an acetyl moiety. Increasing the curvature lifts the ground state energy, which causes a red shift...

  19. Proton-proton elastic scattering excitation functions at intermediate energies: Cross sections and analyzing powers

    CERN Document Server

    Hinterberger, F; Altmeier, M; Bauer, F; Bisplinghoff, J; Büsser, K; Busch, M; Colberg, T; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jonas, E; Krause, H; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuk, T; Meinerzhagen, A; Naehle, O; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Trelle, H J; Weise, E; Wellinghausen, A; Woller, K; Ziegler, R

    2000-01-01

    The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH sub 2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power A sub N and the polarization correlation parameters A sub N sub N , A sub S sub S and A sub S sub L are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d sigma/d OMEGA and A sub N data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.

  20. Energies and damping rates of elementary excitations in spin-1 Bose-Einstein-condensed gases

    International Nuclear Information System (INIS)

    Szirmai, Gergely; Szepfalusy, Peter; Kis-Szabo, Krisztian

    2003-01-01

    The finite temperature Green's function technique is used to calculate the energies and damping rates of the elementary excitations of homogeneous, dilute, spin-1 Bose gases below the Bose-Einstein condensation temperature in both the density and spin channels. For this purpose a self-consistent dynamical Hartree-Fock model is formulated, which takes into account the direct and exchange processes on equal footing by summing up certain classes of Feynman diagrams. The model is shown to satisfy the Goldstone theorem and to exhibit the hybridization of one-particle and collective excitations correctly. The results are applied to gases of 23 Na and 87 Rb atoms

  1. Franck--Hertz experiment with higher excitation level measurements

    International Nuclear Information System (INIS)

    Liu, F.H.

    1987-01-01

    The measurement of the higher levels of 6 3 P 2 and 6 1 P 1 of the mercury atom in the Franck--Hertz experiment has been introduced into the junior and senior laboratory course by using a homemade tetrode Franck--Hertz tube. The main structure of the tube is described. The optimum operating conditions are in the temperature range between 130 and 150 0 C and the collector currents are of the order of 10 -9 A. The additional observations of the famous Franck--Hertz experiment in the laboratory course will give the students more familiarity with the quantum behavior of atoms

  2. A low-cost approach to electronic excitation energies based on the driven similarity renormalization group

    Science.gov (United States)

    Li, Chenyang; Verma, Prakash; Hannon, Kevin P.; Evangelista, Francesco A.

    2017-08-01

    We propose an economical state-specific approach to evaluate electronic excitation energies based on the driven similarity renormalization group truncated to second order (DSRG-PT2). Starting from a closed-shell Hartree-Fock wave function, a model space is constructed that includes all single or single and double excitations within a given set of active orbitals. The resulting VCIS-DSRG-PT2 and VCISD-DSRG-PT2 methods are introduced and benchmarked on a set of 28 organic molecules [M. Schreiber et al., J. Chem. Phys. 128, 134110 (2008)]. Taking CC3 results as reference values, mean absolute deviations of 0.32 and 0.22 eV are observed for VCIS-DSRG-PT2 and VCISD-DSRG-PT2 excitation energies, respectively. Overall, VCIS-DSRG-PT2 yields results with accuracy comparable to those from time-dependent density functional theory using the B3LYP functional, while VCISD-DSRG-PT2 gives excitation energies comparable to those from equation-of-motion coupled cluster with singles and doubles.

  3. Laser wakefield excitation and measurement by femtosecond longitudinal interferometry

    International Nuclear Information System (INIS)

    Siders, C.W.; Le Blanc, S.P.; Fisher, D.; Tajima, T.; Downer, M.C.

    1996-04-01

    Plasma density oscillations (Langmuir waves) in the wake of an intense (I peak ∼ 3 x 10 17 W/cm 2 ) laser pulse (100 fs) are measured with ultrafast time resolution using a longitudinal interferometric technique. Phase shifts consistent with large amplitude (δn e /n e ∼ 1) density waves at the electron plasma frequency were observed in a fully tunnel-ionized He plasma, corresponding to longitudinal electric fields of ∼ 10 GV/m. Strong radial ponderomotive forces enhance the density oscillations. As this technique utilizes a necessary component of any laser-based plasma accelerator, it promises to be a powerful tool for on-line monitoring and control of future plasma-based particle accelerators

  4. In vivo electrophysiological measurement of the rat ulnar nerve with axonal excitability testing

    DEFF Research Database (Denmark)

    Wild, Brandon M.; Morris, Renée; Moldovan, Mihai

    2018-01-01

    Electrophysiology enables the objective assessment of peripheral nerve function in vivo. Traditional nerve conduction measures such as amplitude and latency detect chronic axon loss and demyelination, respectively. Axonal excitability techniques "by threshold tracking" expand upon these measures...... by providing information regarding the activity of ion channels, pumps and exchangers that relate to acute function and may precede degenerative events. As such, the use of axonal excitability in animal models of neurological disorders may provide a useful in vivo measure to assess novel therapeutic...... interventions. Here we describe an experimental setup for multiple measures of motor axonal excitability techniques in the rat ulnar nerve. The animals are anesthetized with isoflurane and carefully monitored to ensure constant and adequate depth of anesthesia. Body temperature, respiration rate, heart rate...

  5. Self-energy correction to the hyperfine splitting for excited states

    International Nuclear Information System (INIS)

    Wundt, B. J.; Jentschura, U. D.

    2011-01-01

    The self-energy corrections to the hyperfine splitting is evaluated for higher excited states in hydrogenlike ions using an expansion in the binding parameter Zα, where Z is the nuclear-charge number and α is the fine-structure constant. We present analytic results for D, F, and G states, and for a number of highly excited Rydberg states, with principal quantum numbers in the range 13≤n≤16, and orbital angular momenta l=n-2 and l=n-1. A closed-form analytic expression is derived for the contribution of high-energy photons, valid for any state with l≥2 and arbitrary n, l, and total angular momentum j. The low-energy contributions are written in the form of generalized Bethe logarithms and evaluated for selected states.

  6. Measurements of competing structures in neutron-deficient Pb isotopes by employing Coulomb excitation

    CERN Multimedia

    Bastin, B; Kruecken, R; Larsen, A; Rahkila, P J; Srebrny, J; Clement, E; Wadsworth, R; Syed naeemul, H; Peura, P J; Siem, S; Hadynska-klek, K; Habs, D; Napiorkowski, P J; Diriken, J V J; Iwanicki, J S

    Coulomb excitation measurements to study the shape coexistence and quadrupole collectivity of the low-lying levels in neutron-deficient Pb nuclei are proposed. Even-mass $^{188−192}$Pb nuclei will be post-accelerated at REX-ISOLDE in order to measure transition probabilities and quadrupole moments for the first excited states. In combination with results obtained in lifetime measurements, this will allow the sign of the quadrupole deformation parameter to be extracted for the first time for 2$^{+}$ states in the even-mass $^{188−192}$Pb nuclei.

  7. Measuring and Comparing Energy Flexibilities

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    2015-01-01

    induced by time and amount individually, and by their com- bination. To this end, we introduce several flexibility measures that take into account the combined effect of time and energy on flex-offer flexibility and discuss their respective pros and cons through a number of realistic examples....

  8. Measuring and monitoring energy poverty

    International Nuclear Information System (INIS)

    Pachauri, Shonali; Spreng, Daniel

    2011-01-01

    This article undertakes a review of alternative measures and indicators of energy poverty targeted to specific audiences and for particular purposes. At the national and international scales there have been some efforts for constructing measures of energy poverty. However, much more needs to be done to develop an internationally consistent measurement framework and to put in place data collection systems that will enable regular reporting. At the programme and project level, indicator systems by necessity need to be designed for specific purposes. Nevertheless, the article proposes that in many instances it is desirable to widen the scope of metrics used for designing and evaluating policies and programmes. In the past, monitoring and evaluation indicators have focused largely on outputs, service delivery or dissemination. Central to the recommendations laid out in the paper is the call for widening the focus of evaluation and necessity to design indicators that adequately assess the needs of beneficiaries and describe the living conditions of families and communities, who are targeted by such programmes and initiatives. - Highlights: ► Consistent measurement frameworks and regular data collection systems on energy poverty are needed. ► Metrics used for designing and evaluating energy access programmes should be widened. ► Indicators that adequately assess needs and describe living conditions of targeted beneficiaries are required.

  9. Lattice Boltzmann simulation for the energy and entropy of excitable systems

    Institute of Scientific and Technical Information of China (English)

    Deng Min-Yi; Tang Guo-Ning; Kong Ling-Jiang; Liu Mu-Ren

    2011-01-01

    The internal energy and the spatiotemporal entropy of excitable systems are investigated with the lattice Boltzmann method. The numerical results show that the breakup of spiral wave is attributed to the inadequate supply of energy, i.e., the internal energy of system is smaller than the energy of self-sustained spiral wave. It is observed that the average internal energy of a regular wave state reduces with its spatiotemporal entropy decreasing. Interestingly, although the energy difference between two regular wave states is very small, the different states can be distinguished obviously due to the large difference between their spatiotemporal entropies. In addition, when the unstable spiral wave converts into the spatiotemporal chaos, the internal energy of system decreases, while the spatiotemporal entropy increases, which behaves as the thermodynamic entropy in an isolated system.

  10. Inner-shell excitation in heavy ion collisions up to intermediate incident energies

    International Nuclear Information System (INIS)

    Reus, T. de.

    1987-04-01

    Electronic excitations in collisions of very heavy ions with a total nuclear charge Z greater than 1/α ≅ 137 at bombarding energies reaching from 3.6 MeV/n up to 100 MeV/n are the subject of this thesis. The dynamical behaviour of the electron-positron-field is described within a semiclassical model, which is reviewed and extended to include electronic interactions via a mean field. A detailed comparison with experimental data of K-vacancy formation, δ-electron and positron emission shows an improved agreement compared with former calculations. Structures in spectra of positrons emitted in sub- and supercritical collision are discussed in two respects: Firstly as a signal of the vacuum decay in supercritical electromagnetic fields which evolve in the vicinity of long living giant nuclear molecules. Secondly as an atomic effect, which might be related to an instaneous formation of molecular 1sσ- and 2p 1/2 σ- levels. However, beyond this speculation the emission spectra of electrons and positrons in deep inelastic reactions have proven to be a powerful tool for measuring nuclear reaction or delay times in the order of 10 -21 s. This property was transfered to the domain of intermediate energy collisions. In first order perturbation theory we derived a scaling law, exhibiting how nuclear stopping times could be extracted from the emission spectra of high energetic δ-electrons. Quantitative calculations within a coupled channel code have been carried out for the system Pb+Pb, yielding cross sections of up to 20 nb for the emission of electrons with a kinetic energy of 50 MeV in 60 MeV/n-collisions. (orig./HSI)

  11. Performance of Popular XC-Functionals for the Description of Excitation Energies in GFP-Like Chromophore Models

    DEFF Research Database (Denmark)

    List, Nanna Holmgaard; Olsen, Jógvan Magnus Haugaard; Rocha-Rinza, Tomás

    2012-01-01

    this task. We present an evaluation of the performance of commonly used XC-functionals for the prediction of excitation energies of GFP-like chromophores. In particular, we have considered the TD-DFT vertical excitation energies of chromophores displaying different charge states. We compare the quality...

  12. Measurements of electron excitation and recombination for Ne-like Ba46+

    International Nuclear Information System (INIS)

    Marrs, R.E.; Levine, M.A.; Knapp, D.A.; Henderson, J.R.

    1987-07-01

    A new facility at Lawrence Livermore National Laboratory has been used to obtain measurements for electron-impact excitation, dielectronic recombination and radiative recombination for the neon-like Ba 46+ ion. The experimental technique consists of trapping highly charged ions inside the space charge of an electron beam and measuring their x-ray emission spectra

  13. Pushing the limits of excited-state g-factor measurements

    Science.gov (United States)

    Stuchbery, Andrew E.; McCormick, Brendan P.; Gray, Timothy J.; Coombes, Ben J.

    2018-05-01

    Current developments in excited-state g-factor measurements are discussed with an emphasis on cases where the experimental methodology is being extended into new regimes. The transient-field technique, the recoil in vacuum method, and moment measurements with LaBr3 detectors are discussed.

  14. Superconducting qubit in a nonstationary transmission line cavity: Parametric excitation, periodic pumping, and energy dissipation

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, A.A. [N.L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); National Research Nuclear University (MEPhI), 115409 Moscow (Russian Federation); Shapiro, D.S., E-mail: shapiro.dima@gmail.com [N.L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); V.A. Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 125009 Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation); National University of Science and Technology MISIS, 119049 Moscow (Russian Federation); Remizov, S.V. [N.L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); V.A. Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 125009 Moscow (Russian Federation); Pogosov, W.V. [N.L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation); Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, 125412 Moscow (Russian Federation); Lozovik, Yu.E. [N.L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); National Research Nuclear University (MEPhI), 115409 Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation); Institute of Spectroscopy, Russian Academy of Sciences, 142190 Moscow Region, Troitsk (Russian Federation)

    2017-02-12

    We consider a superconducting qubit coupled to the nonstationary transmission line cavity with modulated frequency taking into account energy dissipation. Previously, it was demonstrated that in the case of a single nonadiabatical modulation of a cavity frequency there are two channels of a two-level system excitation which are due to the absorption of Casimir photons and due to the counterrotating wave processes responsible for the dynamical Lamb effect. We show that the parametric periodical modulation of the resonator frequency can increase dramatically the excitation probability. Remarkably, counterrotating wave processes under such a modulation start to play an important role even in the resonant regime. Our predictions can be used to control qubit-resonator quantum states as well as to study experimentally different channels of a parametric qubit excitation. - Highlights: • Coupled qubit-resonator system under the modulation of a resonator frequency is considered. • Counterrotating terms of the Hamiltonian are of importance even in the resonance. • Qubit excited state population is highest if driving frequency matches dressed-state energy.

  15. Low-energy excitations of the correlation-gap insulator SmB6: A light-scattering study

    International Nuclear Information System (INIS)

    Nyhus, P.; Cooper, S.L.; Fisk, Z.; Sarrao, J.

    1997-01-01

    We present the results of Raman scattering studies of single-crystal SmB 6 for temperatures down to 4 K and in magnetic fields up to 8 T. At temperatures below T * ∼50K the electronic Raman continuum exhibits an abrupt redistribution of scattering intensity around a temperature-independent (open-quotes isobesticclose quotes) energy, Δ c ∼290cm -1 , reflecting the opening of a pseudogap which is larger than previously suggested by transport measurements. Additionally, the Raman response exhibits at least four well-defined excitations within the gap below T * . The field dependencies of some of these in-gap states are consistent with the expected g factor (g eff =2/7) for the Sm 3+ Γ 8 level, suggesting that these gap edge states are crystal-electric-field excitations of the Sm 3+ ion split by magnetoelastic coupling. copyright 1997 The American Physical Society

  16. Influence of the excited states on the electron-energy distribution function in low-pressure microwave argon plasmas

    International Nuclear Information System (INIS)

    Yanguas-Gil, A.; Cotrino, J.; Gonzalez-Elipe, A.R.

    2005-01-01

    In this work the influence of the excited states on the electron-energy distribution function has been determined for an argon microwave discharge at low pressure. A collisional-radiative model of argon has been developed taking into account the most recent experimental and theoretical values of argon-electron-impact excitation cross sections. The model has been solved along with the electron Boltzmann equation in order to study the influence of the inelastic collisions from the argon excited states on the electron-energy distribution function. Results show that under certain conditions the excited states can play an important role in determining the shape of the distribution function and the mean kinetic energy of the electrons, deplecting the high-energy tail due to inelastic processes from the excited states, especially from the 4s excited configuration. It has been found that from the populations of the excited states an excitation temperature can be defined. This excitation temperature, which can be experimentally determined by optical emission spectroscopy, is lower than the electron kinetic temperature obtained from the electron-energy distribution function

  17. Measurement and analysis of excitation functions and observation of mass-asymmetry effect on incomplete fusion dynamics

    Directory of Open Access Journals (Sweden)

    Rashid M.H.

    2011-10-01

    Full Text Available Excitation functions for sixteen evaporation residues produced in the interaction of 20Ne with 165Ho have been measured in the projectile energy range ≈88-164 MeV, using catcher foil activation technique followed by gamma-ray spectrometry. It has been found in general that the excitation functions of evaporation residues produced via xn/pxn channels satisfactorily reproduced with the statistical model code PACE-2 after subtraction of precursor decay contribution. The significant enhancement in the measured excitation functions for the residues produced in alpha emission channels over the PACE-2 predictions has been observed. These alpha emission channels are attributed to incomplete fusion reaction process. The results indicate the occurrence of incomplete fusion involving break-up of projectile 20Ne into 4He + 16O and /or 8Be + 12C followed by fusion of one of the fragments with target nucleus 165Ho. The analysis of the present data suggest that probability of incomplete fusion increases with projectile energy. The ICF fraction FICF also increases with increasing mass-asymmetry of the entrance channel.

  18. Low-energy excitations in impurity substituted CuGeO3

    International Nuclear Information System (INIS)

    Jones, B. R.; Sushkov, A. B.; Musfeldt, J. L.; Wang, Y. J.; Revcolevschi, A.; Dhalenne, G.

    2001-01-01

    We report far-infrared reflectance measurements of Zn- and Si-doped CuGeO 3 single crystals as a function of applied magnetic field at low temperature. Overall, the low-energy far-infrared spectra are extraordinarily sensitive to the various phase boundaries in the H-T diagram, with the features being especially rich in the low-temperature dimerized state. Zn impurity substitution rapidly collapses the 44 cm -1 zone-boundary spin Peierls gap, although broadened magnetic excitations are observed at the lightest doping level (0.2%) and a remnant is still observable at 0.7% substitution. In a 0.7% Si-doped sample, there is no evidence of the spin gap. Impurity substitution effects on the intensity of the 98 cm -1 zone-folding mode are striking as well. The lightly doped Zn crystals display an enhanced response, and even at intermediate doping levels, the mode intensity is larger than that in the pristine material. The Si-doped sample also displays an increased intensity of the 98 cm -1 mode in the spin Peierls phase relative to the pure material. The observed trends are discussed in terms of the effect of disorder on the spin gap and 98 cm -1 mode, local oscillator strength sum rules, and broken selection rules

  19. Beyond the random-phase approximation for the electron correlation energy: the importance of single excitations.

    Science.gov (United States)

    Ren, Xinguo; Tkatchenko, Alexandre; Rinke, Patrick; Scheffler, Matthias

    2011-04-15

    The random-phase approximation (RPA) for the electron correlation energy, combined with the exact-exchange (EX) energy, represents the state-of-the-art exchange-correlation functional within density-functional theory. However, the standard RPA practice--evaluating both the EX and the RPA correlation energies using Kohn-Sham (KS) orbitals from local or semilocal exchange-correlation functionals--leads to a systematic underbinding of molecules and solids. Here we demonstrate that this behavior can be corrected by adding a "single excitation" contribution, so far not included in the standard RPA scheme. A similar improvement can also be achieved by replacing the non-self-consistent EX total energy by the corresponding self-consistent Hartree-Fock total energy, while retaining the RPA correlation energy evaluated using KS orbitals. Both schemes achieve chemical accuracy for a standard benchmark set of noncovalent intermolecular interactions.

  20. Boltzmann rovibrational collisional coarse-grained model for internal energy excitation and dissociation in hypersonic flows.

    Science.gov (United States)

    Munafò, A; Panesi, M; Magin, T E

    2014-02-01

    A Boltzmann rovibrational collisional coarse-grained model is proposed to reduce a detailed kinetic mechanism database developed at NASA Ames Research Center for internal energy transfer and dissociation in N(2)-N interactions. The coarse-grained model is constructed by lumping the rovibrational energy levels of the N(2) molecule into energy bins. The population of the levels within each bin is assumed to follow a Boltzmann distribution at the local translational temperature. Excitation and dissociation rate coefficients for the energy bins are obtained by averaging the elementary rate coefficients. The energy bins are treated as separate species, thus allowing for non-Boltzmann distributions of their populations. The proposed coarse-grained model is applied to the study of nonequilibrium flows behind normal shock waves and within converging-diverging nozzles. In both cases, the flow is assumed inviscid and steady. Computational results are compared with those obtained by direct solution of the master equation for the rovibrational collisional model and a more conventional multitemperature model. It is found that the proposed coarse-grained model is able to accurately resolve the nonequilibrium dynamics of internal energy excitation and dissociation-recombination processes with only 20 energy bins. Furthermore, the proposed coarse-grained model provides a superior description of the nonequilibrium phenomena occurring in shock heated and nozzle flows when compared with the conventional multitemperature models.

  1. Micromagnetic simulation of energy consumption and excited eigenmodes in elliptical nanomagnetic switches

    International Nuclear Information System (INIS)

    Carlotti, G.; Madami, M.; Gubbiotti, G.; Tacchi, S.

    2014-01-01

    Sub-200 nm patterned magnetic dots are key elements for the design of magnetic switches, memory cells or elementary units of nanomagnetic logic circuits. In this paper, we analyse by micromagnetic simulations the magnetization reversal, the dissipated energy and the excited spin eigenmodes in bistable magnetic switches, consisting of elliptical nanodots with 100×60 nm lateral dimensions. Two different strategies for reversal are considered and the relative results compared: (i) the irreversible switching obtained by the application of an external field along the easy axis, in the direction opposite to the initial magnetization; (ii) the precessional switching accomplished by the application of a short magnetic field pulse, oriented perpendicular to the initial magnetization direction. The obtained results are discussed in terms of deviation from the macrospin behavior, energy dissipation and characteristics of the spectrum of spin eigenmodes excited during the magnetization reversal process

  2. Evolution of collectivity in the 78Ni region: Coulomb excitation of 74Ni at intermediate energies.

    Directory of Open Access Journals (Sweden)

    Marchi T.

    2014-03-01

    Full Text Available The study of the collective properties of nuclear excitations far from stability provides information about the shell structure at extreme conditions. Spectroscopic observables such as the energy or the transition probabilities of the lowest states, in nuclei with large neutron excess, allow to probe the density and isospin dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Emblematic is the case of the evolution of the Ni isotopic chain where several features showed up moving from the most neutron rich stable isotope (64Ni towards the 78Ni nucleus where the large neutron excess coincides with a double shell closure. In this framework, we have recently performed an experiment with the goal to extract the B(E2; 0+ → 2+ value for the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment: preliminary results are discussed.

  3. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    CERN Document Server

    Mayer, J; Massalska-Arodz, M; Janik, J A; Natkaniec, I; Steinsvoll, O

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2 theta,omega) and the density of states G(omega) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  4. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    International Nuclear Information System (INIS)

    Mayer, J.; Krawczyk, J.; Massalska-Arodz, M.; Janik, J.A.; Natkaniec, I.; Steinsvoll, O.

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2θ,ω) and the density of states G(ω) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  5. Compact alpha-excited sources of low energy x-rays

    International Nuclear Information System (INIS)

    Amlauer, K.; Tuohy, I.

    1976-01-01

    A discussion is given of the use of alpha emitting isotopes, such as 210 Po and 244 Cm, for the production of low energy x-rays (less than 5.9 keV). The design of currently available sources is described, and x-ray fluxes observed from various target materials are presented. Commercial applications of the alpha excitation technique are briefly discussed

  6. Frontiers in propulsion research: Laser, matter-antimatter, excited helium, energy exchange thermonuclear fusion

    Science.gov (United States)

    Papailiou, D. D. (Editor)

    1975-01-01

    Concepts are described that presently appear to have the potential for propulsion applications in the post-1990 era of space technology. The studies are still in progress, and only the current status of investigation is presented. The topics for possible propulsion application are lasers, nuclear fusion, matter-antimatter annihilation, electronically excited helium, energy exchange through the interaction of various fields, laser propagation, and thermonuclear fusion technology.

  7. Vibrational energy transfer in selectively excited diatomic molecules. [Relaxation rates, self-relaxation, upper limits

    Energy Technology Data Exchange (ETDEWEB)

    Dasch, C.J.

    1978-09-01

    Single rovibrational states of HCl(v=2), HBr(v=2), DCl(v=2), and CO(v=2) were excited with a pulsed optical parametric oscillator (OPO). Total vibrational relaxation rates near - resonance quenchers were measured at 295/sup 0/K using time resolved infrared fluorescence. These rates are attributed primarily to V - V energy transfer, and they generally conform to a simple energy gap law. A small deviation was found for the CO(v) + DCl(v') relaxation rates. Upper limits for the self relaxation by V - R,T of HCl(v=2) and HBr(v=2) and for the two quantum exchange between HCl and HBr were determined. The HF dimer was detected at 295/sup 0/K and 30 torr HF pressure with an optoacoustic spectrometer using the OPO. Pulsed and chopped, resonant and non-resonant spectrophones are analyzed in detail. From experiments and first order perturbation theory, these V - V exchange rates appear to behave as a first order perturbation in the vibrational coordinates. The rotational dynamics are known to be complicated however, and the coupled rotational - vibrational dynamics were investigated theoreticaly in infinite order by the Dillon and Stephenson and the first Magnus approximations. Large ..delta..J transitions appear to be important, but these calculations differ by orders of magnitude on specific rovibrational transition rates. Integration of the time dependent semiclassical equations by a modified Gordon method and a rotationally distorted wave approximation are discussed as methods which would treat the rotational motion more accurately. 225 references.

  8. Low-energy Coulomb excitation of neutron-rich zinc isotopes

    CERN Document Server

    Van de Walle, J; Behrens, T; Bildstein, V; Blazhev, A; Cederkäll, J; Clément, E; Cocolios, T E; Davinson, T; Delahaye, P; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V; Fraile, L M; Franchoo, S; Gernhäuser, R; Georgiev, G; Habs, D; Heyde, K; Huber, G; Huyse, M; Ibrahim, F; Ivanov, O; Iwanicki, J; Jolie, J; Kester, O; Köster, U; Kröll, T; Krücken, R; Lauer, M; Lisetskiy, A F; Lutter, R; Marsh, B A; Mayet, P; Niedermaier, O; Pantea, M; Raabe, R; Reiter, P; Sawicka, M; Scheit, H; Schrieder, G; Schwalm, D; Seliverstov, M D; Sieber, T; Sletten, G; Smirnova, N; Stanoiu, M; Stefanescu, I; Thomas, J C; Valiente-Dobón, J J; Van Duppen, P; Verney, D; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Wolf, B H; Zielinska, M

    2009-01-01

    At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,20) values in 74-80Zn, B(E2,42) values in 74,76Zn and the determination of the energy of the first excited 2 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, i...

  9. Accurate adiabatic energy surfaces for the ground and first excited states of He2+

    International Nuclear Information System (INIS)

    Lee, E.P.F.

    1993-01-01

    Different factors affecting the accuracy of the computed energy surfaces of the ground and first excited state of He 2 + have been examined, including the choice of the one-and many-particle bases, the configurational space in the MRCI (multi-reference configuration interaction) calculations and other corrections such as the Davidson and the full counterpoise (CP) correction. From basis-variation studies, it was concluded that multi-reference direct-CI calculations (MRDCI) using CASSCF MOs and/or natural orbitals (NOs) from a smaller CISD calculation, gave results close to full CI. The computed dissociation energies, D e , for the ground and first excited state of He 2 + were 2.4670 (2.4659) eV and 17.2 (17.1) cm -1 , respectively, at the highest level [without and with CP correction for basis-set superposition errors (BSSE)] of calculation with an [11s8p3d1f] GTO contraction, in reasonably good agreement with previous calculations, and estimated correct values, where available. It is believed that the computed D e , and the energy surface for the first excited state should be reasonably accurate. However, for the ground state, the effects of multiple f functions and/or functions of higher angular momentum have not been investigated owing to limitation of the available computing resources. This is probably the only weakness is the present study. (Author)

  10. Distribution of radiative strength with excitation energy: the E1 and M1 giant resonances

    International Nuclear Information System (INIS)

    Brown, G.E.; Speth, J.

    1979-01-01

    Calculations of the giant dipole resonance in the particle-hole model, employing empirical values for the unperturbed particle and hole energies, have been unsuccessful in pushing the dipole state to a sufficiently high energy. it is argued that unperturbed levels correspondign to an effective mass of m*/m approx. 0.6 to 0.7 should be employed. The couplings of particles and holes to vibrations are the crucial ingredients in these considerations. More generally, it is argued that the effective mass relevant to excitations near the Fermi surface is that corresponding to empirical single-particle levels, m*/m greater than or equal to 1.0. For particle-hole excitations above the Fermi surface, it is a decreasing function of excitation energy, reaching the above values 0.6 to 0.7 for E greater than or equal to 2 dirac constant/b omega, dirac constant/sub omega/ being the shell spacing. This has the consequence of spreading out the M1 strength. A new interpretation of experimental strengths is proposed

  11. Excitation and charge transfer in low-energy hydrogen atom collisions with neutral oxygen

    Science.gov (United States)

    Barklem, P. S.

    2018-02-01

    Excitation and charge transfer in low-energy O+H collisions is studied; it is a problem of importance for modelling stellar spectra and obtaining accurate oxygen abundances in late-type stars including the Sun. The collisions have been studied theoretically using a previously presented method based on an asymptotic two-electron linear combination of atomic orbitals (LCAO) model of ionic-covalent interactions in the neutral atom-hydrogen-atom system, together with the multichannel Landau-Zener model. The method has been extended to include configurations involving excited states of hydrogen using an estimate for the two-electron transition coupling, but this extension was found to not lead to any remarkably high rates. Rate coefficients are calculated for temperatures in the range 1000-20 000 K, and charge transfer and (de)excitation processes involving the first excited S-states, 4s.5So and 4s.3So, are found to have the highest rates. Data are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/vizbin/qcat?J/A+A/610/A57. The data are also available at http://https://github.com/barklem/public-data

  12. Excitation and charge transfer in low-energy hydrogen atom collisions with neutral iron

    Science.gov (United States)

    Barklem, P. S.

    2018-05-01

    Data for inelastic processes due to hydrogen atom collisions with iron are needed for accurate modelling of the iron spectrum in late-type stars. Excitation and charge transfer in low-energy Fe+H collisions is studied theoretically using a previously presented method based on an asymptotic two-electron linear combination of atomic orbitals model of ionic-covalent interactions in the neutral atom-hydrogen-atom system, together with the multi-channel Landau-Zener model. An extensive calculation including 166 covalent states and 25 ionic states is presented and rate coefficients are calculated for temperatures in the range 1000-20 000 K. The largest rates are found for charge transfer processes to and from two clusters of states around 6.3 and 6.6 eV excitation, corresponding in both cases to active 4d and 5p electrons undergoing transfer. Excitation and de-excitation processes among these two sets of states are also significant. Full Tables and rate coefficient data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A90

  13. Hyperfine structure in 229gTh3+ as a probe of the 229gTh→ 229mTh nuclear excitation energy.

    Science.gov (United States)

    Beloy, K

    2014-02-14

    We identify a potential means to extract the 229gTh→ 229mTh nuclear excitation energy from precision microwave spectroscopy of the 5F(5/2,7/2) hyperfine manifolds in the ion 229gTh3+. The hyperfine interaction mixes this ground fine structure doublet with states of the nuclear isomer, introducing small but observable shifts to the hyperfine sublevels. We demonstrate how accurate atomic structure calculations may be combined with the measurement of the hyperfine intervals to quantify the effects of this mixing. Further knowledge of the magnetic dipole decay rate of the isomer, as recently reported, allows an indirect determination of the nuclear excitation energy.

  14. Temperature and excitation energy of hot nuclei in the reaction of 40Ar+197Au at 25 MeV/nucleon

    International Nuclear Information System (INIS)

    Wu, H.; Jin, G.; Li, Z.; Dai, G.; Qi, Y.; He, Z.; Luo, Q.; Duan, L.; Wen, W.; Zhang, B.

    1997-01-01

    The coincidence measurements between heavy fission fragments and light charged particles with Z ≤2 were carried out for the 40 Ar+ 197 Au reaction at 25 MeV/nucleon, to study the properties of hot nuclei in heavy ion induced reactions. The linear momentum transfers (LMTs) were deduced from the folding angle and the time-of-flight difference between two fission fragments of heavy residues. The relationship of the nuclear temperature (slope parameter of the energy spectrum) and the excitation energy was determined independently from the measurement of the kinetic energy spectra in the frames of the emitting sources and from the LMT analysis. Both the temperature and the excitation energy increase with decreasing impact parameter, which suggests that a plateau temperature of 5.5 MeV is reached at an excitation energy of 3.1 MeV/nucleon. The result was also compared with various statistical models that explain the plateau by the multifragmentation process, where the excitation energy is assumed to be stored in compression and expansion effects. (orig.)

  15. Environment-assisted Quantum Critical Effect for Excitation Energy Transfer in a LH2-type Trimer

    Science.gov (United States)

    Xu, Lan; Xu, Bo

    2015-10-01

    In this article, we are investigating excitation energy transfer (EET) in a basic unit cell of light-harvesting complex II (LH2), named a LH2-type trimer. Calculation of energy transfer efficiency (ETE) in the framework of non-Markovian environment is also implemented. With these achievements, we theoretically predict the environment-assisted quantum critical effect, where ETE exhibits a sudden change at the critical point of quantum phase transition (QPT) for the LH2-type trimer. It is found that highly efficient EET with nearly unit efficiency may occur in the vicinity of the critical point of QPT.

  16. Targeted energy transfers and passive acoustic wave redirection in a two-dimensional granular network under periodic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yijing, E-mail: yzhng123@illinois.edu; Moore, Keegan J.; Vakakis, Alexander F. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); McFarland, D. Michael [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2015-12-21

    We study passive pulse redirection and nonlinear targeted energy transfer in a granular network composed of two semi-infinite, ordered homogeneous granular chains mounted on linear elastic foundations and coupled by weak linear stiffnesses. Periodic excitation in the form of repetitive half-sine pulses is applied to one of the chains, designated as the “excited chain,” whereas the other chain is initially at rest and is regarded as the “absorbing chain.” We show that passive pulse redirection and targeted energy transfer from the excited to the absorbing chain can be achieved by macro-scale realization of the spatial analog of the Landau-Zener quantum tunneling effect. This is realized by finite stratification of the elastic foundation of the excited chain and depends on the system parameters (e.g., the percentage of stratification) and on the parameters of the periodic excitation. Utilizing empirical mode decomposition and numerical Hilbert transforms, we detect the existence of two distinct nonlinear phenomena in the periodically forced network; namely, (i) energy localization in the absorbing chain due to sustained 1:1 resonance capture leading to irreversible pulse redirection from the excited chain, and (ii) continuous energy exchanges in the form of nonlinear beats between the two chains in the absence of resonance capture. Our results extend previous findings of transient passive energy redirection in impulsively excited granular networks and demonstrate that steady state passive pulse redirection in these networks can be robustly achieved under periodic excitation.

  17. The energy structure and decay channels of the 4p6-shell excited states in Sr

    Science.gov (United States)

    Kupliauskienė, A.; Kerevičius, G.; Borovik, V.; Shafranyosh, I.; Borovik, A.

    2017-11-01

    The ejected-electron spectra arising from the decay of the 4p{}5{{nln}}{\\prime }{l}{\\prime }{n}{\\prime\\prime }{l}{\\prime\\prime } autoionizing states in Sr atoms have been studied precisely at the incident-electron energies close to excitation and ionization thresholds of the 4{{{p}}}6 subshell. The excitation behaviors for 58 lines observed between 12 and 21 eV ejected-electron kinetic energy have been investigated. Also, the ab initio calculations of excitation energies, autoionization probabilities and electron-impact excitation cross sections of the states 4p{}5{{nln}}{\\prime }{l}{\\prime }{n}{\\prime\\prime }{l}{\\prime\\prime } (nl = 4d, 5s, 5p; {n}{\\prime }{l}{\\prime } = 4d, 5s, 5p; {n}{\\prime\\prime }{l}{\\prime\\prime } = 5s, 6s, 7s, 8s, 9s, 5p, 6p, 5d, 6d, 7d, 8d, 4f, 5g) have been performed by employing the large-scale configuration-interaction method in the basis of the solutions of Dirac-Fock-Slater equations. The obtained experimental and theoretical data have been used for the accurate identification of the 60 lines in ejected-electron spectra and the 68 lines observed earlier in photoabsorption spectra. The excitation and decay processes for 105 classified states in the 4p55s{}2{nl}, 4p54d{}2{nl} and 4p55s{{nln}}{\\prime }{l}{\\prime } configurations have been considered in detail. In particular, most of the states lying below the ionization threshold of the 4p6 subshell at 26.92 eV possess up to four decay channels with formation of Sr+ in 5s{}1/2, 4d{}3/{2,5/2} and 5p{}1/{2,3/2} states. Two-step autoionization and two-electron Auger transitions with formation of Sr2+ in the 4p6 {}1{{{S}}}0 ground state are the main decay paths for high-lying autoionizing states. The excitation threshold of the 4{{{p}}}6 subshell in Sr has been established at 20.98 ± 0.05 eV.

  18. Study of some excited states of 16O by correlation measurements

    International Nuclear Information System (INIS)

    Avril, M.; Bianchi, L.; Lepareux, M.; Saunier, N.; Fotti, A.; Pappalardo, G.; Strazzeri, A.

    Angular correlation measurements were used in the study of some 16 O highly excited levels, with 32 and 34 6 Li ions. The results indicate spins of 6 and 7 for the levels at 21.8 and 20.9 MeV of 16 O [fr

  19. Iodine (p,n) and (d,2n) excitation function measurements

    International Nuclear Information System (INIS)

    West, H.I. Jr.; Nuckolls, R.M.; Mustafa, M.G.; Lanier, R.G.

    1991-01-01

    We have measured the nuclear excitation functions for the reactions 127 I (p,n) 127 Xe and 127 I(d,2n) 127 Xe. These results are being used in the interpretation of data obtained from nuclear test diagnostics. 15 refs., 3 figs., 3 tabs

  20. Measuring and analyzing excitation-induced decoherence in rare-earth-doped optical materials

    International Nuclear Information System (INIS)

    Thiel, C W; Macfarlane, R M; Cone, R L; Sun, Y; Böttger, T; Sinclair, N; Tittel, W

    2014-01-01

    A method is introduced for quantitatively analyzing photon echo decay measurements to characterize excitation-induced decoherence resulting from the phenomenon of instantaneous spectral diffusion. Detailed analysis is presented that allows fundamental material properties to be extracted that predict and describe excitation-induced decoherence for a broad range of measurements, applications and experimental conditions. Motivated by the need for a method that enables systematic studies of ultra-low decoherence systems and direct comparison of properties between optical materials, this approach employs simple techniques and analytical expressions that avoid the need for difficult to measure and often unknown material parameters or numerical simulations. This measurement and analysis approach is demonstrated for the 3 H 6 to 3 H 4 optical transition of three thulium-doped crystals, Tm 3+ :YAG, Tm 3+ :LiNbO 3 and Tm 3+ :YGG, that are currently employed in quantum information and classical signal processing demonstrations where minimizing decoherence is essential to achieve high efficiencies and large signal bandwidths. These new results reveal more than two orders of magnitude variation in sensitivity to excitation-induced decoherence among the materials studied and establish that the Tm 3+ :YGG system offers the longest optical coherence lifetimes and the lowest levels of excitation-induced decoherence yet observed for any known thulium-doped material. (paper)

  1. Measurement of the electromagnetic lifetimes of the first four excited states of /sup 192/Pt

    Energy Technology Data Exchange (ETDEWEB)

    Butt, D K; Raoof, M A; Raoof, S A [Birkbeck Coll., London (UK)

    1976-11-01

    Measurements of the electromagnetic lifetimes of the first four excited states of /sup 192/Pt have been made by the self-comparison method using electron-electron coincidences. The partial lifetimes of the gamma transitions involved have been interpreted in terms of the pairing-plus-quadrupole model of Kumar and Baranger.

  2. Stopping powers of Zr, Pd, Cd, In and Pb for 6.5 MeV protons and mean excitation energies

    International Nuclear Information System (INIS)

    Ishiwari, R.; Shiomi, N.; Sakamoto, N.

    1983-01-01

    Stopping powers of Zr, Pd, Cd, In and Pb have been measured for 6.5 MeV protons. Mean excitation energies have been extracted from the stopping power data by taking into account Bloch correction and Z 1 3 correction. For the shell correction the Bonderup shell correction has been used. The results agree fairly well with those of other authors

  3. The water-water cycle in leaves is not a major alternative electron sink for dissipation of excess excitation energy when CO2 assimilation is restricted

    NARCIS (Netherlands)

    Driever, S.M.; Baker, N.R.

    2011-01-01

    Electron flux from water via photosystem II (PSII) and PSI to oxygen (water–water cycle) may provide a mechanism for dissipation of excess excitation energy in leaves when CO2 assimilation is restricted. Mass spectrometry was used to measure O2 uptake and evolution together with CO2 uptake in leaves

  4. Solar Energy Measurement Using Arduino

    Directory of Open Access Journals (Sweden)

    Jumaat Siti Amely

    2018-01-01

    Full Text Available This project aims to develop a measurement of solar energy using Arduino Board technology. In this research, four parameters that been measured are temperature, light intensity, voltage and current. The temperature was measured using temperature sensor. The light intensity was measured using light dependent resistor (LDR sensor. The voltage was measured using the voltage divider because the voltage generated by the solar panel are large for the Arduino as receiver. Lastly for the current was measured using the current sensor module that can sense the current generated by the solar panel. These parameters as the input value for the Arduino and the output was display at the Liquid Crystal Display (LCD screen. The LCD screen display output of the temperature, the light intensity, the voltage and the current value. The purpose of Arduino to convert the analog input of parameter to the digital output and display via LCD screen. Other than that, this project also involve with a design to ensure that device case are easy to be carry around.

  5. Charge and energy dynamics in photo-excited poly(para-phenylenevinylene) systems

    International Nuclear Information System (INIS)

    Gisslen, L.; Johansson, A.; Stafstroem, S.

    2004-01-01

    We report results from simulations of charge and energy dynamics in poly(para-phenylenevinylene) (PPV) and PPV interacting with C 60 . The simulations were performed by solving the time-dependent Schroedinger equation and the lattice equation of motion simultaneously and nonadiabatically. The electronic system and the coupling of the electrons to the lattice were described by an extended three-dimensional version of the Su-Schrieffer-Heeger model, which also included an external electric field. Electron and lattice dynamics following electronic excitations at different energies have been simulated. The effect of additional lattice energy was also included in the simulations. Our results show that both exciton diffusion and transitions from high to lower lying excitations are stimulated by increasing the lattice energy. Also field induced charge separation occurs faster if the lattice energy is increased. This separation process is highly nonadiabatic and involves a significant rearrangement of the electron distribution. In the case of PPV coupled to C 60 , we observe a spontaneous charge separation. The separation time is in this case limited by the local concentration of C 60 molecules close to the PPV chain

  6. Quantitative Measurements of Electronically Excited CH Concentration in Normal Gravity and Microgravity Coflow Laminar Diffusion Flames

    Science.gov (United States)

    Giassi, D.; Cao, S.; Stocker, D. P.; Takahashi, F.; Bennett, B. A. V.; Smooke, M. D.; Long, M. B.

    2015-01-01

    With the conclusion of the SLICE campaign aboard the ISS in 2012, a large amount of data was made available for the analysis of the effect of microgravity on laminar coflow diffusion flames. Previous work focused on the study of sooty flames in microgravity as well as the ability of numerical models to predict its formation in a simplified buoyancy-free environment. The current work shifts the investigation to soot-free flames, putting an emphasis on the chemiluminescence emission from electronically excited CH (CH*). This radical species is of significant interest in combustion studies: it has been shown that the electronically excited CH spatial distribution is indicative of the flame front position and, given the relatively simple diagnostic involved with its measurement, several works have been done trying to understand the ability of electronically excited CH chemiluminescence to predict the total and local flame heat release rate. In this work, a subset of the SLICE nitrogen-diluted methane flames has been considered, and the effect of fuel and coflow velocity on electronically excited CH concentration is discussed and compared with both normal gravity results and numerical simulations. Experimentally, the spectral characterization of the DSLR color camera used to acquire the flame images allowed the signal collected by the blue channel to be considered representative of the electronically excited CH emission centered around 431 nm. Due to the axisymmetric flame structure, an Abel deconvolution of the line-of-sight chemiluminescence was used to obtain the radial intensity profile and, thanks to an absolute light intensity calibration, a quantification of the electronically excited CH concentration was possible. Results show that, in microgravity, the maximum flame electronically excited CH concentration increases with the coflow velocity, but it is weakly dependent on the fuel velocity; normal gravity flames, if not lifted, tend to follow the same trend

  7. Renewable energy: Method and measures

    International Nuclear Information System (INIS)

    Nilsen, Trond Hartvedt

    2003-01-01

    The thesis presents various possibilities for renewable energy in Norway. The wind power would give a practical and economic alternative. The external costs for the wind power would be moderate. In chapter 3 the utility cost analysis for renewable alternatives are studied relative to the macroeconomic efficiency. Some methodical problems and how these analyses are used are reviewed. In the practical utility cost analyses wind power is studied relative to gas power which is the non-renewable alternative present in Norway today. A qualitative part is included. It is not possible to determine whether wind power is preferable to gas power in the macroeconomic perspective. Wind power would be the choice if high environmental and CO2 cleaning costs are expected. The first conclusion to be drawn is that it is difficult to decide whether wind power is the best solution based on cost benefit analysis. However, the alternative seems to be quite robust in the analysis. Due to the central position the energy supplies have in the society this business should be heavily regulated. The sector is also overtaxed as a reduction in consumption is desired. The analysis shows that the system does not function perfectly. The thesis surveys various measures for improving the renewable energy supply and focuses on the wind power. A model for and analysis of the measures are carried out and resulted in a second conclusion. The measures have various properties as to the influence on the market. A subsidy is a fine measure for stimulation production of green power while a tax reduces efficiently the production of black power. A system with green licenses in combination with a subsidy and a tax would be preferable as to increasing the part of renewable energy of the total production. It is therefore necessary to have clearly defined goals and use suitable measures for achieving them. The costs of wind power is falling and it would therefore soon be macroeconomic profitable. It is also

  8. The mechanism of three-body process of energy transfer from excited xenon atoms to molecules

    International Nuclear Information System (INIS)

    Wojciechowski, K.; Forys, M.

    1999-01-01

    The mechanism of energy transfer from Xe(6 s[3/2] 1 ) resonance state (E=8.44 eV) and higher excited Xe(6p, 6p', 6 d) atoms produced in pulse radiolysis to molecules have been discussed. The analysis of the kinetic data for these processes shows that in the sensitized photolysis and radiolysis of Xe-M mixtures the excited atoms decay in 'ordinary' two-body reaction: Xe(6s[3/2] 1 0 )+M→products (r.1) and in fast 'accelerated' third order process: Xe(6s[3/2] 1 0 )+M+Xe→products (r.2) The discussion shows that three-body process occurs via reactions: Xe(6s[3/2] 1 0 )+Xe k w ↔ k d Xe 2 ** (r.2a) Xe 2 **+M k q →[Xe 2 M]*→products (r.2b) It was shown that this mechanism concerns also higher excited Xe atoms and can explain a similar process in He-M mixtures and suggests that it is a general mechanism of energy transfer in all irradiated rare gas-molecule systems

  9. Measurements of lambda and chi parameters for excitation of the 21P state of helium at 80 eV

    International Nuclear Information System (INIS)

    Slevin, J.; Porter, H.Q.; Eminyan, M.; Defrance, A.; Vassilev, G.

    1980-01-01

    Electron-photon angular correlations have been measured for excitation of the 2 1 P state of helium at an incident energy of 80 eV over the range 10-115 0 of electron scattering angles. analysis of the data yields values for the alignment and orientation parameters lambda and |chi| which are in excellent agreement with data of Hollywood et al (J. Phys. B.; 12: 819 (1979)) but the data for lambda are in marked disagreement with the results of Steph and Golden (preprint. Univ. of Oklahoma (1979)) at electron scattering angles thetasub(c)> 70 0 . (author)

  10. Construction of Vibronic Diabatic Hamiltonian for Excited-State Electron and Energy Transfer Processes.

    Science.gov (United States)

    Xie, Yu; Jiang, Shengshi; Zheng, Jie; Lan, Zhenggang

    2017-12-21

    Photoinduced excited-state electron and energy transfer processes are crucial in biological photoharvesting systems and organic photovoltaic devices. We discuss the construction of a diabatic vibronic Hamiltonian for the proper treatment of these processes involving the projection approach acting on both electronic wave functions and vibrational modes. In the electronic part, the wave function projection approach is used to construct the diabatic Hamiltonian in which both local excited states and charge-transfer states are included on the same footing. For the vibrational degrees of freedom, the vibronic couplings in the diabatic Hamiltonian are obtained in the basis of the pseudonormal modes localized on each monomer site by applying delocalized-to-localized mode projection. This systematic approach allows us to construct the vibronic diabatic Hamiltonian in molecular aggregates.

  11. Electron energy distributions and excitation rates in high-frequency argon discharges

    International Nuclear Information System (INIS)

    Ferreira, C.M.; Loureiro, J.

    1983-06-01

    The electron energy distribution functions and rate coefficients for excitation and ionisation in argon under the action of an uniform high-frequency electric field were calculated by numerically solving the homogeneous Boltzmann equation. Analytic calculations in the limiting cases ω>>νsub(c) and ω<<νsub(c), where ω is the wave angular frequency and νsub(c) is the electron-neutral collision frequency for momentum transfer, are also presented and shown to be in very good agreement with the numerical computations. The results reported here are relevant for the modelling of high-frequency discharges in argon and, in particular, for improving recent theoretical descriptions of a plasma column sustained by surface microwaves. The properties of surface wave produced plasmas make them interesting as possible substitutes for other more conventional plasma sources for such important applications as plasma chemistry laser excitation, plasma etching spectroscopic sources etc...

  12. Impact of nuclear lattice relaxation on the excitation energy transfer along a chain of pi-conjugated molecules

    NARCIS (Netherlands)

    Schmid, S.A.; Abbel, R.J.; Schenning, A.P.H.J.; Meijer, E.W.; Herz, L.M.

    2010-01-01

    We have investigated the extent to which delocalization of the ground-state and excited-state wave functions of a p-conjugated molecule affects the excitation energy transfer (EET) between such molecules. Using femtosecond photoluminescence spectroscopy, we experimentally monitored the EET along

  13. Luminescence of the SrCl2:Pr crystals under high-energy excitation

    International Nuclear Information System (INIS)

    Antonyak, O.T.; Voloshinovskii, A.S.; Vistovskyy, V.V.; Stryganyuk, G.B.; Kregel, O.P.

    2014-01-01

    The present research was carried out in order to elucidate the mechanisms of energy transfer from the crystal lattice to Pr 3+ ions in SrCl 2 . The luminescence excitation and emission spectra as well as luminescence kinetics of the SrCl 2 :Pr single crystals containing 0.2 mol% Pr were investigated at 300 and 10 K using the vacuum ultraviolet (VUV) synchrotron radiation. The X-ray excited luminescence spectra of the SrCl 2 :Pr (C Pr =0.2 and 0.5 mol%) and SrCl 2 :Pr, K (C Pr =1.5 mol%; C K =1.5 mol%) crystals were studied at 294 and 80 K. Under optical excitation of the samples in the Pr 3+ absorption bands, there were observed five fast ultraviolet emissions assigned to the 4f 1 5d→4f 2 transitions, and two long-wave bands corresponding to the f–f transitions. Furthermore, the intrinsic emission bands of SrCl 2 were observed at 10 K. The X-ray excited luminescence spectrum of the SrCl 2 :Pr crystal containing 0.2 mol% Pr, besides intrinsic emission band near 400 nm, has got a long-wave band at about 490 nm of the Pr 3+ centers. There were not observed any emission bands of the Pr 3+ centers corresponding to the 4f 1 5d–4f 2 transitions in the X-ray excited luminescence spectrum of the SrCl 2 :Pr crystal. The possible mechanisms of energy transfer from the SrCl 2 matrix to the Pr 3+ centers are discussed. -- Highlights: • Spectral-luminescent properties of SrCl 2 :Pr have been investigated. • The identification of emission 4f–4f and 5d–4f bands of Pr 3+ ions was performed. • Adding of potassium prevents clustering of the Pr 3+ centers in the SrCl 2 :Pr, K crystals. • Under X-ray excitation at 80–300 K only Pr 3+ 4f–4f and intrinsic emission is observed

  14. The Measurement of the Evaporation Residues Excitation Functions in the Fusion Reactions 144Sm (40Ar,xn) and 166Er(40Ar,xn)

    Science.gov (United States)

    Chernysheva, E. V.; Rodin, A. M.; Belozerov, A. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Novoselov, A. S.; Oganessian, Yu. Ts.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Krupa, L.; Kliman, J.; Motycak, S.; Sivacek, I.

    2015-06-01

    The evaporation residues excitation functions for the reactions 40Ar+144Sm→184Hg and 40Ar+166Er→206Rn were measured at the energies below and above the Coulomb barrier (Elab=142-207 MeV) using a mass-separator MASHA. The experimental data were compared with theoretical calculations using a Channel Coupling Model. The influence of experimental beam energy spread on the excitation functions was taking into account. It was found that structure of xn-cross sections correlate strongly with the nuclear structure of colliding nuclei.

  15. Control of base-excited dynamical systems through piezoelectric energy harvesting absorber

    Science.gov (United States)

    Abdelmoula, H.; Dai, H. L.; Abdelkefi, A.; Wang, L.

    2017-09-01

    The spring-mass absorber usually offers a good control to dynamical systems under direct base excitations for a specific value of the excitation frequency. As the vibrational energy of a primary dynamical system is transferred to the absorber, it gets dissipated. In this study, this energy is no longer dissipated but converted to available electrical power by designing efficient energy harvesters. A novel design of a piezoelectric beam installed inside an elastically-mounted dynamical system undergoing base excitations is considered. A design is carried out in order to determine the properties and dimensions of the energy harvester with the constraint of simultaneously decreasing the oscillating amplitudes of the primary dynamical system and increasing the harvested power of the energy harvesting absorber. An analytical model for the coupled system is constructed using Euler-Lagrange principle and Galerkin discretization. Different strategies for controlling the primary structure displacement and enhancing the harvested power as functions of the electrical load resistance and thickness of the beam substrate are performed. The linear polynomial approximation of the system’s key parameters as a function of the beam’s substrate thickness is first carried out. Then, the gradient method is applied to determine the adequate values of the electrical load resistance and thickness of the substrate under the constraints of minimizing the amplitudes of the primary structure or maximizing the levels of the harvested power. After that, an iterative strategy is considered in order to simultaneously minimize the amplitudes of the primary structure and maximize the levels of the harvested power as functions of the thickness of the substrate and electrical load resistance. In addition to harmonic excitations, the coupled system subjected to a white noise is explored. Through this analysis, the load resistance and thickness of the substrate of the piezoelectric energy harvester

  16. Excitation energy transfer from the bacteriochlorophyll Soret band to carotenoids in the LH2 light-harvesting complex from Ectothiorhodospira haloalkaliphila is negligible.

    Science.gov (United States)

    Razjivin, A P; Lukashev, E P; Kompanets, V O; Kozlovsky, V S; Ashikhmin, A A; Chekalin, S V; Moskalenko, A A; Paschenko, V Z

    2017-09-01

    Pathways of intramolecular conversion and intermolecular electronic excitation energy transfer (EET) in the photosynthetic apparatus of purple bacteria remain subject to debate. Here we experimentally tested the possibility of EET from the bacteriochlorophyll (BChl) Soret band to the singlet S 2 level of carotenoids using femtosecond pump-probe measurements and steady-state fluorescence excitation and absorption measurements in the near-ultraviolet and visible spectral ranges. The efficiency of EET from the Soret band of BChl to S 2 of the carotenoids in light-harvesting complex LH2 from the purple bacterium Ectothiorhodospira haloalkaliphila appeared not to exceed a few percent.

  17. Excitation energy transfer between Light-harvesting complex II and Photosystem I in reconstituted membranes.

    Science.gov (United States)

    Akhtar, Parveen; Lingvay, Mónika; Kiss, Teréz; Deák, Róbert; Bóta, Attila; Ughy, Bettina; Garab, Győző; Lambrev, Petar H

    2016-04-01

    Light-harvesting complex II (LHCII), the major peripheral antenna of Photosystem II in plants, participates in several concerted mechanisms for regulation of the excitation energy and electron fluxes in thylakoid membranes. In part, these include interaction of LHCII with Photosystem I (PSI) enhancing the latter's absorption cross-section - for example in the well-known state 1 - state 2 transitions or as a long-term acclimation to high light. In this work we examined the capability of LHCII to deliver excitations to PSI in reconstituted membranes in vitro. Proteoliposomes with native plant thylakoid membrane lipids and different stoichiometric ratios of LHCII:PSI were reconstituted and studied by steady-state and time-resolved fluorescence spectroscopy. Fluorescence emission from LHCII was strongly decreased in PSI-LHCII membranes due to trapping of excitations by PSI. Kinetic modelling of the time-resolved fluorescence data revealed the existence of separate pools of LHCII distinguished by the time scale of energy transfer. A strongly coupled pool, equivalent to one LHCII trimer per PSI, transferred excitations to PSI with near-unity efficiency on a time scale of less than 10ps but extra LHCIIs also contributed significantly to the effective antenna size of PSI, which could be increased by up to 47% in membranes containing 3 LHCII trimers per PSI. The results demonstrate a remarkable competence of LHCII to increase the absorption cross-section of PSI, given the opportunity that the two types of complexes interact in the membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Physical Meaning of Virtual Kohn-Sham Orbitals and Orbital Energies: An Ideal Basis for the Description of Molecular Excitations.

    Science.gov (United States)

    van Meer, R; Gritsenko, O V; Baerends, E J

    2014-10-14

    In recent years, several benchmark studies on the performance of large sets of functionals in time-dependent density functional theory (TDDFT) calculations of excitation energies have been performed. The tested functionals do not approximate exact Kohn-Sham orbitals and orbital energies closely. We highlight the advantages of (close to) exact Kohn-Sham orbitals and orbital energies for a simple description, very often as just a single orbital-to-orbital transition, of molecular excitations. Benchmark calculations are performed for the statistical average of orbital potentials (SAOP) functional for the potential [J. Chem. Phys. 2000, 112, 1344; 2001, 114, 652], which approximates the true Kohn-Sham potential much better than LDA, GGA, mGGA, and hybrid potentials do. An accurate Kohn-Sham potential does not only perform satisfactorily for calculated vertical excitation energies of both valence and Rydberg transitions but also exhibits appealing properties of the KS orbitals including occupied orbital energies close to ionization energies, virtual-occupied orbital energy gaps very close to excitation energies, realistic shapes of virtual orbitals, leading to straightforward interpretation of most excitations as single orbital transitions. We stress that such advantages are completely lost in time-dependent Hartree-Fock and partly in hybrid approaches. Many excitations and excitation energies calculated with local density, generalized gradient, and hybrid functionals are spurious. There is, with an accurate KS, or even the LDA or GGA potentials, nothing problematic about the "band gap" in molecules: the HOMO-LUMO gap is close to the first excitation energy (the optical gap).

  19. Excitation energy dependence of fragment-mass distributions from fission of 180,190Hg formed in fusion reactions of 36Ar + 144,154Sm

    Directory of Open Access Journals (Sweden)

    K. Nishio

    2015-09-01

    Full Text Available Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E⁎(Hg180=33–66 MeV and E⁎(Hg190=48–71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A¯L/A¯H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A¯L/A¯H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.

  20. Mechanism and models for collisional energy transfer in highly excited large polyatomic molecules

    International Nuclear Information System (INIS)

    Gilbert, R. G.

    1995-01-01

    Collisional energy transfer in highly excited molecules (say, 200-500 kJ mol -1 above the zero-point energy of reactant, or of product, for a recombination reaction) is reviewed. An understanding of this energy transfer is important in predicting and interpreting the pressure dependence of gas-phase rate coefficients for unimolecular and recombination reactions. For many years it was thought that this pressure dependence could be calculated from a single energy-transfer quantity, such as the average energy transferred per collision. However, the discovery of 'super collisions' (a small but significant fraction of collisions which transfer abnormally large amounts of energy) means that this simplistic approach needs some revision. The 'ordinary' (non-super) component of the distribution function for collisional energy transfer can be quantified either by empirical models (e.g., an exponential-down functional form) or by models with a physical basis, such as biased random walk (applicable to monatomic or diatomic collision partners) or ergodic (for polyatomic collision partners) treatments. The latter two models enable approximate expressions for the average energy transfer to be estimated from readily available molecular parameters. Rotational energy transfer, important for finding the pressure dependence for recombination reactions, can for these purposes usually be taken as transferring sufficient energy so that the explicit functional form is not required to predict the pressure dependence. The mechanism of 'ordinary' energy transfer seems to be dominated by low-frequency modes of the substrate, whereby there is sufficient time during a vibrational period for significant energy flow between the collision partners. Super collisions may involve sudden energy flow as an outer atom of the substrate is squashed between the substrate and the bath gas, and then is moved away from the interaction by large-amplitude motion such as a ring vibration or a rotation; improved

  1. Ultrafast Nonradiative Decay and Excitation Energy Transfer by Carotenoids in Photosynthetic Light-Harvesting Proteins

    Science.gov (United States)

    Ghosh, Soumen

    This dissertation investigates the photophysical and structural dynamics that allow carotenoids to serve as efficient excitation energy transfer donor to chlorophyll acceptors in photosynthetic light harvesting proteins. Femtosecond transient grating spectroscopy with optical heterodyne detection has been employed to follow the nonradiative decay pathways of carotenoids and excitation energy transfer to chlorophylls. It was found that the optically prepared S2 (11Bu+) state of beta-carotene decays in 12 fs fs to populate an intermediate electronic state, Sx, which then decays nonradiatively to the S 1 state. The ultrafast rise of the dispersion component of the heterodyne transient grating signal reports the formation of Sx intermediate since the rise of the dispersion signal is controlled by the loss of stimulated emission from the S2 state. These findings were extended to studies of peridinin, a carbonyl substituted carotenoid that serves as a photosynthetic light-harvesting chromophore in dinoflagellates. Numerical simulations using nonlinear response formalism and the multimode Brownian oscillator model assigned the Sx intermediate to a torsionally distorted structure evolving on the S2 potential surface. The decay of the Sx state is promoted by large amplitude out-of-plane torsional motions and is significantly retarded by solvent friction owing to the development of an intramolecular charge transfer character in peridinin. The slowing of the nonradiative decay allows the Sx state to transfer significant portion of the excitation energy to chlorophyll a acceptors in the peridinin-chlorophyll a protein. The results of heterodyne transient grating study on peridinin-chlorophyll a protein suggests two distinct energy transfer channels from peridinin to chlorophyll a: a 30 fs process involving quantum coherence and delocalized peridinin-Chl states and an incoherent, 2.5 ps process involving the distorted S2 state of peridinin. The torsional evolution on the S2

  2. Measurement of Polarization Observables in the Electro-Excitation of the Proton to its First Excited State

    International Nuclear Information System (INIS)

    Rikki Roche

    2003-01-01

    This thesis reports results from the Thomas Jefferson National Accelerator Facility (Jefferson Lab) Hall A experiment E91-011, which measured double-polarization observables in the pion electroproduction reaction from the proton. Specifically, the experiment measured the recoil proton polarization, polarized response functions, and cross section for the p(rvec e), e(prime) (rvec p) π o reaction at a center-of-mass energy centered at W = 1232 MeV--the peak of the Δ(1232) resonance--and at a four-momentum transfer squared of Q 2 = 1.0 GeV 2 /c 2 . Both the recoil proton polarization and polarized response function results will be presented in this thesis

  3. A new methodology for measuring time correlations and excite states of atoms and nuclei

    International Nuclear Information System (INIS)

    Cavalcante, M.A.

    1989-01-01

    A system for measuring time correlation of physical phenomena events in the range of 10 -7 to 10 5 sec is proposed, and his results presented. This system, is based on a sequential time scale which is controlled by a precision quartz oscillator; the zero time of observation is set by means of a JK Flip-Flop, which is operated by a negative transition of pulse in coincidence with the pulse from a detector which marks the time zero of the event (precedent pulse). This electronic system (named digital chronoanalizer) was used in the measurement of excited states of nuclei as well as for the determination of time fluctuations in physical phenomena, such as the time lag in a halogen Geiger counter and is the measurement of the 60 KeV excited state of N P 237 . (author)

  4. The 4p6 autoionization cross section of Rb atoms excited by low-energy electron impact

    International Nuclear Information System (INIS)

    Borovik, A; Roman, V; Kupliauskienė, A

    2012-01-01

    The autoionization cross section of rubidium atoms was obtained by measuring the total normalized intensities of ejected-electron spectra arising from the decay of the 4p 5 n 1 l 1 n 2 l 2 autoionizing levels. The electron impact energy range from the 4p 6 excitation threshold at 15.31 up to 50 eV was investigated. The cross section reaches the maximum value of (2.9 ± 0.6) × 10 −16  cm 2 at 21.8 eV impact energy. The general behaviours of the cross section and the role of particular autoionizing configurations in its formation were considered on the basis of large-scale configuration interaction calculations of energies, cross sections, autoionization probabilities in 5snl(n ⩽ 7; l ⩽ 4) and 4d nl(n ⩽ 5; l ⩽ 2) configurations as well as the measured excitation functions for the lowest levels in 5s 2 and 4d5s configurations. The resonance behaviour of the cross section between 15.3 and 18.5 eV impact energy is caused exclusively by the negative-ion resonances present close to the excitation thresholds of the (5s 2 ) 2 P and (4d5s) 4 P autoionizing levels. At higher impact energies, the autoionization cross section is composed of contributions from the high-lying quartet and doublet levels in 4d5s, 5p and 5s5p, 5d, 6s, 6p configurations. From the comparison of the present data with available experimental and calculated ionization cross sections, the 5s + 4p 6 direct ionization cross section of rubidium atoms was determined with the maximum value of (7.2 ± 2.2) × 10 −16  cm 2 at 36 eV. It was also found that the 4p 6 excitation–autoionization is the dominant indirect ionization process contributing over 30% of the total single ionization of rubidium atoms by electron impact in the 15.3–50 eV energy range. (paper)

  5. Microscopic unitary description of tidal excitations in high-energy string-brane collisions

    CERN Document Server

    D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele

    2013-01-01

    The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.

  6. Effects of Energy Dissipation on the Parametric Excitation of a Coupled Qubit-Cavity System

    Science.gov (United States)

    Remizov, S. V.; Zhukov, A. A.; Shapiro, D. S.; Pogosov, W. V.; Lozovik, Yu. E.

    2018-02-01

    We consider a parametrically driven system of a qubit coupled to a cavity taking into account different channels of energy dissipation. We focus on the periodic modulation of a single parameter of this hybrid system, which is the coupling constant between the two subsystems. Such a modulation is possible within the superconducting realization of qubit-cavity coupled systems, characterized by an outstanding degree of tunability and flexibility. Our major result is that energy dissipation in the cavity can enhance population of the excited state of the qubit in the steady state, while energy dissipation in the qubit subsystem can enhance the number of photons generated from vacuum. We find optimal parameters for the realization of such dissipation-induced amplification of quantum effects. Our results might be of importance for the full control of quantum states of coupled systems as well as for the storage and engineering of quantum states.

  7. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.

    2010-08-11

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. The unattached DCM dyes exhibit an average excitation transfer efficiency (EÌ?TE) of 96% inside TT1-covered, mesostructured TiO2 films. Further performance increases were limited by the solubility of DCM in an acetonitrile based electrolyte. This demonstration shows that energy relay dyes can be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly soluble energy relay dyes with high molar extinction coefficients. © 2010 American Chemical Society.

  8. Measured Strain of Nb3Sn Coils During Excitation and Quench

    International Nuclear Information System (INIS)

    Caspi, S.; Bartlett, S.E.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hannaford, C.R.; Hafalia, A.R.; Lietzke, S.; Mattafirri, M.; Nyman, M.; Sabbi, G.

    2005-01-01

    The strain in a high field Nb 3 Sn coil was measured during magnet assembly, cool-down, excitation and spot heater quenches. Strain was measured with a full bridge strain gauge mounted directly over the turns and impregnated with the coil. Two such coils were placed in a ''common coil'' fashion capable of reaching 11T at 4.2K. The measured steady state strain in the coil is compared with results obtained using the FEM code ANSYS. During quenches, the transient strain (due to temperature rise) was also measured and compared with the calculated mechanical time response to a quench

  9. Analyzing powers of inelastic dp-scattering in the energy region of delta and roper resonances excitation

    International Nuclear Information System (INIS)

    Malinina, L.V.; Alkhazov, G.D.; Augustyniak, W.

    2001-01-01

    A study of inelastic scattering of polarized 3.73 GeV/c deuterons on protons in the energy region of the Roper N* (1440) and the Δ(1232) resonances excitation has been performed in an exclusive experiment at LNS (Laboratoire National SATURNE, Saclay, France) using the SPES4-π setup. Tensor and vector analyzing powers of pion production for the reactions d+p→d+n+π + , d+p→d+p+π 0 , d+p→d+N+ππ have been measured as functions of the squared deuteron 4-momentum transfer t, of the effective mass of the subsystems (Nπ), (Nππ) and of the pion emission angle. A strong dependence of these analyzing powers upon the pion emission angle is observed. It is found that A yy values for the considered reaction channels are systematically larger than the known inclusive p(d,d')X world data at the nearest beam energy

  10. Analyzing Powers of Inelastic dp-Scattering in the Energy Region of Delta and Roper Resonances Excitation

    CERN Document Server

    Malinina, L V; Augustyniak, W; Boivin, M; Boyard, J L; Dahl, R; Drews, M; Ellegaard, C; Fahri, L; Gaarde, C; Hennino, T; Jourdain, J C; Kagarlis, M A; Kravtsov, A V; Künne, R A; Larsen, J C; Morsch, P; Mylnikov, V A; Orichtchin, E M; Perdrisat, C F; Piskunov, N M; Prokofiev, A N; Punjabi, V; Radvanyi, P; Ramstein, B; Razmyslovich, B V; Roy-Stephan, M; Sitnik, I M; Skousen, M; Strokovsky, E A; Tkach, I I; Tomasi-Gustafsson, E; Volkov, S S; Zhdanov, A A; Zupranski, P

    2001-01-01

    A study of inelastic scattering of polarized 3.73 GeV/c deuterons on protons in the energy region of the Roper N*(1440) and the {DELTA}(1232) resonances excitation has been performed in an exclusive experiment at LNS (Laboratoire National SATURNE, Saclay, France) using the SPES-{pi} setup.Tensor and vector analyzing powers of pion production for the reactions d + p {\\to} d + n + pi^{+}, d + p {\\to} d + p + pi^{0}, d + p {\\to} d + N + pi pi have been measured as functions of the squared deuteron 4-momentum transfer t, of the effective mass of the subsystems (N pi), (N pi pi) and of the pion emission angle. A strong dependence of these analyzing powers upon the pion emission angle is observed. It is found that A_{yy} values for the considered reaction channels are systematically larger than the known inclusive {p (d, d {\\prime}) X} world data at the nearest beam energy.

  11. Application of radionuclide sources for excitation in energy-dispersive X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Hoffmann, P.

    1986-01-01

    X-ray fluorescence (XRF) analysis is in broad application in many fields of science where elemental determinations are necessary. Solid and liquid samples are analyzed by this method. Solids are introduced in thin or thick samples as melted glass, pellets, powders or as original specimen. The excitation of X-ray spectra can be performed by specific and polychromic radiation of X-ray tubes, by protons, deuterons, α-particles, heavy ions and synchrotron radiation from accelerators and by α-particles, X- and γ-rays and by bremsstrahlung generated by β - -particles from radionuclide sources. The radionuclides are devided into groups with respect to their decay mode and the energy of the emitted radiation. The broad application of radionuclides in XRF excitation is shown in examples as semi-quantitative analysis of glasses, as quantitative analysis of coarse ceramics and as quantitative determination of heavy elements (mainly actinides) in solutions. The advantages and disadvantages of radionuclide excitation in XRF analysis are discussed. (orig.) [de

  12. Picosecond excitation energy transfer of allophycocyanin studied in solution and in crystals.

    Science.gov (United States)

    Ranjbar Choubeh, Reza; Sonani, Ravi R; Madamwar, Datta; Struik, Paul C; Bader, Arjen N; Robert, Bruno; van Amerongen, Herbert

    2018-03-01

    Cyanobacteria perform photosynthesis with the use of large light-harvesting antennae called phycobilisomes (PBSs). These hemispherical PBSs contain hundreds of open-chain tetrapyrrole chromophores bound to different peptides, providing an arrangement in which excitation energy is funnelled towards the PBS core from where it can be transferred to photosystem I and/or photosystem II. In the PBS core, many allophycocyanin (APC) trimers are present, red-light-absorbing phycobiliproteins that covalently bind phycocyanobilin (PCB) chromophores. APC trimers were amongst the first light-harvesting complexes to be crystallized. APC trimers have two spectrally different PCBs per monomer, a high- and a low-energy pigment. The crystal structure of the APC trimer reveals the close distance (~21 Å) between those two chromophores (the distance within one monomer is ~51 Å) and this explains the ultrafast (~1 ps) excitation energy transfer (EET) between them. Both chromophores adopt a somewhat different structure, which is held responsible for their spectral difference. Here we used spectrally resolved picosecond fluorescence to study EET in these APC trimers both in crystallized and in solubilized form. We found that not all closely spaced pigment couples consist of a low- and a high-energy pigment. In ~10% of the cases, a couple consists of two high-energy pigments. EET to a low-energy pigment, which can spectrally be resolved, occurs on a time scale of tens of picoseconds. This transfer turns out to be three times faster in the crystal than in the solution. The spectral characteristics and the time scale of this transfer component are similar to what have been observed in the whole cells of Synechocystis sp. PCC 6803, for which it was ascribed to EET from C-phycocyanin to APC. The present results thus demonstrate that part of this transfer should probably also be ascribed to EET within APC trimers.

  13. Strategy of ring-shaped aggregates in excitation energy transfer for removing disorder-induced shielding

    International Nuclear Information System (INIS)

    Tei, Go; Nakatani, Masatoshi; Ishihara, Hajime

    2013-01-01

    Peripheral light harvesting complex (LH2), which is found in photosynthetic antenna systems of purple photosynthetic bacteria, has important functions in the photosynthetic process, such as harvesting sunlight and transferring its energy to the photosynthetic reaction center. The key component in excitation energy transfer (EET) between LH2s is B850, which is a characteristic ring-shaped aggregate of pigments usually formed by 18 or 16 bacteriochlorophylls in LH2. We theoretically study the strategy of the ring-shaped aggregate structure, which maximizes EET efficiency, by using the standard Frenkel exciton model and the self-consistent calculation method for the Markovian quantum master equation and Maxwell equation. As a result, we have revealed a simple but ingenious strategy of the ring-shaped aggregate structure. The combination of three key properties of the ring unit system maximizes the EET efficiency, namely the large dipole moment of aggregates causes the basic improvement of EET efficiency, and the isotropic nature and the large occupying area are critically effective to remove the disorder-induced shielding that inhibits EET in the presence of the randomness of orientation and alignment of carriers of excitation energy. (paper)

  14. Influence of primary fragment excitation energy and spin distributions on fission observables

    Science.gov (United States)

    Litaize, Olivier; Thulliez, Loïc; Serot, Olivier; Chebboubi, Abdelaziz; Tamagno, Pierre

    2018-03-01

    Fission observables in the case of 252Cf(sf) are investigated by exploring several models involved in the excitation energy sharing and spin-parity assignment between primary fission fragments. In a first step the parameters used in the FIFRELIN Monte Carlo code "reference route" are presented: two parameters for the mass dependent temperature ratio law and two constant spin cut-off parameters for light and heavy fragment groups respectively. These parameters determine the initial fragment entry zone in excitation energy and spin-parity (E*, Jπ). They are chosen to reproduce the light and heavy average prompt neutron multiplicities. When these target observables are achieved all other fission observables can be predicted. We show here the influence of input parameters on the saw-tooth curve and we discuss the influence of a mass and energy-dependent spin cut-off model on gamma-rays related fission observables. The part of the model involving level densities, neutron transmission coefficients or photon strength functions remains unchanged.

  15. Strategy of ring-shaped aggregates in excitation energy transfer for removing disorder-induced shielding

    Science.gov (United States)

    Tei, Go; Nakatani, Masatoshi; Ishihara, Hajime

    2013-06-01

    Peripheral light harvesting complex (LH2), which is found in photosynthetic antenna systems of purple photosynthetic bacteria, has important functions in the photosynthetic process, such as harvesting sunlight and transferring its energy to the photosynthetic reaction center. The key component in excitation energy transfer (EET) between LH2s is B850, which is a characteristic ring-shaped aggregate of pigments usually formed by 18 or 16 bacteriochlorophylls in LH2. We theoretically study the strategy of the ring-shaped aggregate structure, which maximizes EET efficiency, by using the standard Frenkel exciton model and the self-consistent calculation method for the Markovian quantum master equation and Maxwell equation. As a result, we have revealed a simple but ingenious strategy of the ring-shaped aggregate structure. The combination of three key properties of the ring unit system maximizes the EET efficiency, namely the large dipole moment of aggregates causes the basic improvement of EET efficiency, and the isotropic nature and the large occupying area are critically effective to remove the disorder-induced shielding that inhibits EET in the presence of the randomness of orientation and alignment of carriers of excitation energy.

  16. Low-energy heavy-atom impact as a tool for production and classification of doubly excited states

    International Nuclear Information System (INIS)

    Andersen, N.

    1985-01-01

    Low-energy heavy-atom impact may be an efficient way of preferentially populating doubly excited levels. Using neon as an example, this paper discusses why this is so. The similarity of the structure of the energy level diagrams for doubly excited neon and the level scheme for neutral magnesium is pointed out, suggesting that collective quantum numbers may describe the electron pair. (orig.)

  17. Role of methylene spacer in the excitation energy transfer in europium 1- and 2- naphthylcarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravlev, K. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Tsaryuk, V., E-mail: vit225@ire216.msk.s [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Kudryashova, V.; Pekareva, I. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Sokolnicki, J. [Faculty of Chemistry, University of WrocLaw, 14 F. Joliot-Curie str., WrocLaw 50-383 (Poland); Yakovlev, Yu. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation)

    2010-08-15

    A series of compounds Ln(RCOO){sub 3}.Phen (Ln=Eu, Gd, Tb; RCOO{sup -}-1- and 2-naphthoate, 1- and 2-naphthylacetate, 1- and 2-naphthoxyacetate anions, Phen-1,10-phenanthroline) was investigated by methods of optical spectroscopy. Compounds of composition Ln(RCOO){sub 3}.nH{sub 2}O with the same carboxylate ligands are also considered. Results of studies of the effects of methylene spacer decoupling the {pi}-{pi}- or p-{pi}-conjugation in the naphthylcarboxylate ligand on the structure of Eu{sup 3+} coordination centre, on the lifetime of {sup 5}D{sub 0} (Eu{sup 3+}) state, and on processes of the excitation energy transfer to Eu{sup 3+} or Tb{sup 3+} ions are presented. Introduction of the methylene bridge in the ligand weakens the influence of the steric hindrances in forming of a crystal lattice and results in lowering the distortion of the Eu{sup 3+} luminescence centre, and in elongation of the observed {sup 5}D{sub 0} lifetime {tau}{sub obs}. The latter is caused by decrease in contribution of the radiative processes rate 1/{tau}{sub r}. This is confirmed by the correlation between the lifetimes {tau}{sub obs} and the quantities '{tau}{sub r}.const' inversely proportional to the total integral intensities of Eu(RCOO){sub 3}.Phen luminescence spectra. The methylene spacer performs a role of regulator of sensitization of the Ln{sup 3+} luminescence efficiency by means of an influence on mutual location of lowest triplet states of the ligands, the ligand-metal charge transfer (LMCT) states, and the emitting states of Ln{sup 3+} ions. The lowest triplet state in lanthanide naphthylcarboxylate adducts with Phen is related to carboxylate anion. A presence of the methylene spacer in naphthylcarboxylate ligand increases the triplet state energy. At the same time, the energy of 'carboxylic group-Eu{sup 3+} ion' charge transfer states falls, which can promote the degradation of excitation energy. In naphthylcarboxylates investigated a range of the

  18. A new analysis procedure to extract fusion excitation function with large beam energy dispersions: application to the 6Li+120Sn and 7Li+119Sn

    Directory of Open Access Journals (Sweden)

    Di Pietro Alessia

    2017-01-01

    Full Text Available In the present paper it is described an analysis procedure suited for experiments where cross-sections strongly varying with energy are measured using beams having large energy dispersion. These cross-sections are typically the sub-barrier fusion excitation function of reactions induced by radioactive beams. The large beam energy dispersion, typical of these experiments, can lead to ambiguities in the association of the effective beam energy to the reaction product yields and consequently to an error in the determination of the excitation function. As a test case, the approach is applied to the experiments 6Li+120Sn and 7Li+119Sn measured in the energy range 14 MeV ≤ Ec.m. ≤28 MeV. The complete fusion cross sections are deduced from activation measurements using the stacked target technique. The results of these experiments, that employ the two weakly-bound stable Li isotopes, show that the complete fusion cross sections above the barrier are suppressed of about 70% and 85% with respect to the Universal Fusion Function, used as a standard reference, in the 6Li and 7Li induced reactions respectively. Moreover, the excitation functions of the two systems at energies below the barrier, do not show significant differences, despite the two systems have different n-transfer Qvalue.

  19. Doping dependence of low-energy quasiparticle excitations in superconducting Bi2212.

    Science.gov (United States)

    Ino, Akihiro; Anzai, Hiroaki; Arita, Masashi; Namatame, Hirofumi; Taniguchi, Masaki; Ishikado, Motoyuki; Fujita, Kazuhiro; Ishida, Shigeyuki; Uchida, Shinichi

    2013-12-05

    : The doping-dependent evolution of the d-wave superconducting state is studied from the perspective of the angle-resolved photoemission spectra of a high-Tc cuprate, Bi2Sr2CaCu2 O8+δ (Bi2212). The anisotropic evolution of the energy gap for Bogoliubov quasiparticles is parametrized by critical temperature and superfluid density. The renormalization of nodal quasiparticles is evaluated in terms of mass enhancement spectra. These quantities shed light on the strong coupling nature of electron pairing and the impact of forward elastic or inelastic scatterings. We suggest that the quasiparticle excitations in the superconducting cuprates are profoundly affected by doping-dependent screening.

  20. Differential cross sections for intermediate-energy electron scattering from α-tetrahydrofurfuryl alcohol: Excitation of electronic-states

    Energy Technology Data Exchange (ETDEWEB)

    Chiari, L.; Jones, D. B.; Thorn, P. A.; Pettifer, Z. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Duque, H. V. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, MG (Brazil); Silva, G. B. da [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso (Brazil); Limão-Vieira, P. [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Duflot, D. [Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université Lille, F-59655 Villeneuve d’Ascq Cedex (France); Hubin-Franskin, M.-J.; Delwiche, J. [Départment de Chimie, Université de Liège, Institut de Chimie-Bât. B6C, B-4000 Liège 1 (Belgium); Blanco, F. [Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Madrid E-28040 (Spain); García, G. [Instituto de Física Fundamental, CSIC, Madrid E-28006 (Spain); and others

    2014-07-14

    We report on measurements of differential cross sections (DCSs) for electron impact excitation of a series of Rydberg electronic-states in α-tetrahydrofurfuryl alcohol (THFA). The energy range of these experiments was 20–50 eV, while the scattered electron was detected in the 10°–90° angular range. There are currently no other experimental data or theoretical computations against which we can directly compare the present measured results. Nonetheless, we are able to compare our THFA DCSs with earlier cross section measurements for Rydberg-state electronic excitation for tetrahydrofuran, a similar cyclic ether, from Do et al. [J. Chem. Phys. 134, 144302 (2011)]. In addition, “rotationally averaged” elastic DCSs, calculated using our independent atom model with screened additivity rule correction approach are also reported. Those latter results give integral cross sections consistent with the optical theorem, and supercede those from the only previous study of Milosavljević et al. [Eur. Phys. J. D 40, 107 (2006)].

  1. High mass-resolution electron-ion-ion coincidence measurements on core-excited organic molecules

    CERN Document Server

    Tokushima, T; Senba, Y; Yoshida, H; Hiraya, A

    2001-01-01

    Total electron-ion-ion coincidence measurements on core excited organic molecules have been carried out with high mass resolution by using multimode (reflectron/linear) time-of-flight mass analyzer. From the ion correlation spectra of core excited CH sub 3 OH and CD sub 3 OH, the reaction pathway to form H sub 3 sup + (D sub 3 sup +) is identified as the elimination of three H (D) atoms from the methyl group, not as the inter-group (-CH sub 3 and -OH) interactions. In a PEPIPICO spectrum of acetylacetone (CH sub 3 COCH sub 2 COCH sub 3) measured by using a reflectron TOF, correlations between ions up to mass number 70 with one-mass resolution was recorded.

  2. Fluororeflectometer for measuring the emission, excitation, reflection and transmission of materials doped with active ions

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Duverger, Aldo S., E-mail: aldo@cifus.uson.mx [Departamento de Física, Universidad de Sonora, Apdo. Postal 5-88, Hermosillo, Sonora 83000, México (Mexico); García-Llamas, Raúl, E-mail: ragal@cifus.uson.mx [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, Hermosillo, Sonora 83000, México (Mexico); Aceves, R., E-mail: raceves@cifus.uson.mx [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, Hermosillo, Sonora 83000, México (Mexico)

    2013-04-15

    The design and construction of a new hybrid instrument, which is named a fluororeflectometer, for measuring the radiation from materials doped with rare earth atoms is presented. This instrument operates in two modes. In the XL-λ mode, the instrument measures the luminescence and excitation spectra of the samples. In the RT-λ mode, the instrument measures the specular reflection and transmission spectra of thick or thin films. A photomultiplier (UV-enhanced photodiode) is used when the XL-λ (RT-λ) mode is in operation. The angle of incidence on the sample and the angle of the detected emission can be changed in both modes; the first one is changed manually and the last one is changed automatically. The reflection and transmission spectra from slabs of KCl:Eu{sup 2+} were measured to test the RT-λ mode. These data were fitted using Lorentz-type dispersion for the material, and the densities for each Eu absorption bands were obtained. In the XL-λ mode, the luminescence and excitation spectra from a slab and thin film of KCl:Eu{sup 2+} were obtained. The sensitivity of the instrument enables the luminescence from thin films with thicknesses as low as 3 μm to be measured; in this case, the signal barely exceeded the noise. The emission spectra from a slab of KCl:Eu{sup 2+} for several angles of incidence were measured in the direction parallel to the interfaces of the slab. -- Highlights: ► Develops an instrument for measuring optical properties of phosphors materials. ► Emission, excitation, transmission and reflectance are measured in KCl:Eu{sup 2+} slabs. ► The angular distribution for the emission, measured in situ, is also characterized. ► Its performance was compared with other instruments and good agreement is found. ► Capabilities are found superior to those offered by commercial fluorometers.

  3. Fluororeflectometer for measuring the emission, excitation, reflection and transmission of materials doped with active ions

    International Nuclear Information System (INIS)

    Ramírez-Duverger, Aldo S.; García-Llamas, Raúl; Aceves, R.

    2013-01-01

    The design and construction of a new hybrid instrument, which is named a fluororeflectometer, for measuring the radiation from materials doped with rare earth atoms is presented. This instrument operates in two modes. In the XL-λ mode, the instrument measures the luminescence and excitation spectra of the samples. In the RT-λ mode, the instrument measures the specular reflection and transmission spectra of thick or thin films. A photomultiplier (UV-enhanced photodiode) is used when the XL-λ (RT-λ) mode is in operation. The angle of incidence on the sample and the angle of the detected emission can be changed in both modes; the first one is changed manually and the last one is changed automatically. The reflection and transmission spectra from slabs of KCl:Eu 2+ were measured to test the RT-λ mode. These data were fitted using Lorentz-type dispersion for the material, and the densities for each Eu absorption bands were obtained. In the XL-λ mode, the luminescence and excitation spectra from a slab and thin film of KCl:Eu 2+ were obtained. The sensitivity of the instrument enables the luminescence from thin films with thicknesses as low as 3 μm to be measured; in this case, the signal barely exceeded the noise. The emission spectra from a slab of KCl:Eu 2+ for several angles of incidence were measured in the direction parallel to the interfaces of the slab. -- Highlights: ► Develops an instrument for measuring optical properties of phosphors materials. ► Emission, excitation, transmission and reflectance are measured in KCl:Eu 2+ slabs. ► The angular distribution for the emission, measured in situ, is also characterized. ► Its performance was compared with other instruments and good agreement is found. ► Capabilities are found superior to those offered by commercial fluorometers

  4. Measuring energy poverty in Greece

    International Nuclear Information System (INIS)

    Papada, Lefkothea; Kaliampakos, Dimitris

    2016-01-01

    A comprehensive research in the field of energy poverty is undertaken in this paper, in an attempt to highlight the great vulnerability of Greek households on energy poverty, in the middle of a severe economic crisis. Till now, Greek energy policy has been considered insufficient to tackle energy poverty issues, as focusing mainly on short-term rather than permanent solutions. A primary survey has been conducted, recording objective data of energy expenses as well as subjective perceptions about housing conditions. The findings showed that, under the objective expenditure-based method, 58% of Greek households are energy poor. Among households under the poverty threshold, the energy poverty rate exceeds 90%. Existing and new subjective indicators shed light on other aspects of energy poverty, such as the level of thermal comfort at home, damp problems detected, restriction of other essential needs in order to manage energy payments, etc. Some interesting conclusions are also drawn by exploring the relationship between various indicators. It appears that households considered energy poor are not identical when examined by objective and subjective indicators. However, different indicators complement each other by capturing different aspects of the problem and provide a broader overview of the issue. - Highlights: •58% of Greek households are energy poor. •75% of Greek households have reduced other essentials in favor of energy needs. •Combination of objective and subjective indicators captures better energy poverty. •Greek energy policy has failed to tackle energy poverty issues.

  5. Electron-photon angular correlation measurements for excitation of the 2P state of hydrogen at 55 and 100 eV

    International Nuclear Information System (INIS)

    Slevin, J.; Eminyan, M.; Woolsey, J.M.; Vassilev, G.; Porter, H.Q.

    1980-01-01

    Electron-photon angular correlations have been measured for excitation of the 2P state of hydrogen at incident energies of 55 and 100 eV. The data presented extend the results of Weigold and co-workers (Flinders Univ. preprint (1980)) to smaller scattering angles and reveal the existence of a deep minimum in the parameter lambda thetasub(e) = 10 0 at and incident electron energy of 100 eV. (author)

  6. Investigation of incomplete fusion dynamics by measurement of excitation functions in the 20Ne + 59Co system

    International Nuclear Information System (INIS)

    Singh, D.; Linda, Sneha Bharti; Giri, Pankaj K.; Singh, Smita Shree; Kumar, Harish; Afzal Ansari, M.; Ali, Rahbar; Rashid, M.H.; Guin, R.; Das, S.K.

    2015-01-01

    In the present work, an attempt has been made to address some important aspects of CF and ICF dynamics for the system 20 Ne + 59 Co in the projectile energy range ≈ 62–150 MeV by using recoil catcher activation technique with the following off-line γ-ray spectroscopy. Excitation Functions (EFs) for the following reactions: 59 Co(Ne, α p4n) 70 Ga, 59 Co(Ne, 3αp3n) 63 Zn, 59 Co (Ne, 3αp4n) 62 Zn and 59 Co (Ne, 4α3n) 60 Cu have been measured. No precursor decay contribution has been observed for these measured evaporation residues. The measured values of total fusion cross-sections of the above evaporation residues have been compared with the theoretical total complete fusion cross sections calculated by code PACE-2, which do not take into account ICF contribution

  7. Explanation of the observed trend in the mean excitation energy of a target as determined using several projectiles

    International Nuclear Information System (INIS)

    Cabrera-Trujillo, R.; Sabin, J.R.; Oddershede, J.

    2003-01-01

    Recently, Porter observed [L.E. Porter, Int. J. Quantum Chem. 90, 684 (2002)] that the mean excitation energy and stopping cross section of a target, obtained from fitting experimental data at given projectile charge to a modified Bethe-Block theory, gives projectile dependent results. The main result of his work is that there is a trend for the inferred target mean excitation energy, to decrease as the projectile atomic number increases. However, this result is inconsistent with the usual definition of the mean excitation energy as a function of target excitation properties only. Here we present an explanation of Porter's results based on the Bethe theory extended to take projectile electronic structure explicitly into account

  8. Measure for Measure: Urban Water and Energy

    Science.gov (United States)

    Chini, C.; Stillwell, A. S.

    2017-12-01

    Urban environments in the United States account for a majority of the population and, as such, require large volumes of treated drinking water supply and wastewater removal, both of which need energy. Despite the large share of water that urban environments demand, there is limited accounting of these water resources outside of the city itself. In this study, we provide and analyze a database of drinking water and wastewater utility flows and energy that comprise anthropogenic fluxes of water through the urban environment. We present statistical analyses of the database at an annual, spatial, and intra-annual scale. The average daily per person water flux is estimated as 563 liters of drinking water and 496 liters of wastewater, requiring 340 kWh/1000 m3 and 430 kWh/1000 m3 of energy, respectively, to treat these resources. This energy demand accounts for 1% of the total annual electricity production of the United States. Additionally, the water and embedded energy loss associated with non-revenue water (estimated at 15.8% annually) accounts for 9.1 km3of water and 3600 GWh, enough electricity to power 300,000 U.S. households annually. Through the analysis and benchmarking of the current state of urban water fluxes, we propose the term `blue city,' which promotes urban sustainability and conservation policy focusing on water resources. As the nation's water resources become scarcer and more unpredictable, it is essential to include water resources in urban sustainability planning and continue data collection of these vital resources.

  9. Energy Cascade from Internal Modes in Non-uniformly Stratified Fluid through Excitation of Superharmonic Disturbances

    Science.gov (United States)

    Sutherland, B. R.

    2016-02-01

    It is well established that two-dimensional internal plane waves and modes in uniformly stratified fluid efficiently transfer energy to smaller scale waves and ultimately turbulent mixing through parametric subharmonic instability (PSI). The numerical simulations of MacKinnon & Winters (GRL 2005) predicted PSI should act efficiently to disrupt the internal tide. However, while in situ observations showed the presence of PSI, it was not found to be appreciable. One reason for the discrepancy between simulations and observations is that the former examined an internal mode in uniformly stratified fluid whereas, in reality, the internal tide exists in non-uniform stratification and is manifest as sinusoidal oscillations of the thermocline. Through theory supported by numerical simulations, it is shown that internal modes in non-uniform stratification immediately excite superharmonics, not subharmonic disturbances. These have double the horizontal wavenumber and double the frequency of the parent mode and hence move with the same horizontal phase speed of the parent mode. As the disturbances grow in amplitude, however, they interact with the parent mode generating small-scale vertically propagating internal waves within the strongly stratified layer. The occurrence of PSI over very long times can occur, as in the simulations of Hazewinkel and Winters (JPO 2011). However, a comprehensive understanding of the energy cascade from the internal tide to small scales must consider the evolution of excited superharmonic disturbances.

  10. Excitation of high energy levels under laser exposure of suspensions of nanoparticles in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Shafeev, G.A. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation)], E-mail: shafeev@kapella.gpi.ru; Simakin, A.V. [Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow (Russian Federation); Bozon-Verduraz, F. [ITODYS, UMR CNRS 7086, Universite Paris 7-Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France); Robert, M. [Laboratoire d' Electrochimie Moleculaire, UMR CNRS 7591, Universite Paris 7 Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05 (France)

    2007-12-15

    Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D{sub 2}O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D{sub 2}O, (ii) initiation of Hg {yields} Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using {sup 196}Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed.

  11. Ab initio theoretical calculations of the electronic excitation energies of small water clusters.

    Science.gov (United States)

    Tachikawa, Hiroto; Yabushita, Akihiro; Kawasaki, Masahiro

    2011-12-14

    A direct ab initio molecular dynamics method has been applied to a water monomer and water clusters (H(2)O)(n) (n = 1-3) to elucidate the effects of zero-point energy (ZPE) vibration on the absorption spectra of water clusters. Static ab initio calculations without ZPE showed that the first electronic transitions of (H(2)O)(n), (1)B(1)←(1)A(1), are blue-shifted as a function of cluster size (n): 7.38 eV (n = 1), 7.58 eV (n = 2) and 8.01 eV (n = 3). The inclusion of the ZPE vibration strongly affects the excitation energies of a water dimer, and a long red-tail appears in the range of 6.42-6.90 eV due to the structural flexibility of a water dimer. The ultraviolet photodissociation of water clusters and water ice surfaces is relevant to these results.

  12. Excitation energy and angular momentum dependence of the nuclear level densities

    International Nuclear Information System (INIS)

    Razavi, R.; Kakavand, T.; Behkami, A. N.

    2007-01-01

    We have investigated the excitation energy (E) dependence of nuclear level density for Bethe formula and constant temperature model. The level density parameter aa nd the back shifted energy from the Bethe formula are obtained by fitting the complete level schemes. Also the level density parameters from the constant temperature model have been determined for several nuclei. we have shown that the microscopic theory provides more precise information on the nuclear level densities. On the other hand, the spin cut-off parameter and effective moment of inertia are determined by studying of the angular momentum (J) dependence of the nuclear level density, and effective moment of inertia is compared with rigid body value.

  13. Delta self-consistent field method to obtain potential energy surfaces of excited molecules on surfaces

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Olsen, Thomas; Engelund, Mads

    2008-01-01

    is a density-functional method closely resembling standard density-functional theory (DFT), the only difference being that in Delta SCF one or more electrons are placed in higher lying Kohn-Sham orbitals instead of placing all electrons in the lowest possible orbitals as one does when calculating the ground......-state energy within standard DFT. We extend the Delta SCF method by allowing excited electrons to occupy orbitals which are linear combinations of Kohn-Sham orbitals. With this extra freedom it is possible to place charge locally on adsorbed molecules in the calculations, such that resonance energies can...... be estimated, which is not possible in traditional Delta SCF because of very delocalized Kohn-Sham orbitals. The method is applied to N2, CO, and NO adsorbed on different metallic surfaces and compared to ordinary Delta SCF without our modification, spatially constrained DFT, and inverse...

  14. Calculation of 0-0 excitation energies of organic molecules by CIS(D) quantum chemical methods

    International Nuclear Information System (INIS)

    Grimme, Stefan; Izgorodina, Ekaterina I.

    2004-01-01

    The accuracy and reliability of the CIS(D) quantum chemical method and a spin-component scaled variant (SCS-CIS(D)) are tested for calculating 0-0 excitation energies of organic molecules. The ground and excited state geometries and the vibrational zero-point corrections are taken from (TD)DFT-B3LYP calculations. In total 32 valence excited states of different character are studied: π → π* states of polycyclic aromatic compounds/polyenes and n → π* states of carbonyl, thiocarbonyl and aza(azo)-aromatic compounds. This set is augmented by two systems of special interest, i.e., indole and the TICT state of dimethylaminbenzonitrile (DMABN). Both methods predict excitation energies that are on average higher than experiment by about 0.2 eV. The errors are found to be quite systematic (with a standard deviation of about 0.15 eV) and especially SCS-CIS(D) provides a more balanced treatment of π → π* vs. n → π* states. For the test suite of states, both methods clearly outperform the (TD)DFT-B3LYP approach. Opposed to previous conclusions about the performance of CIS(D), these methods can be recommended as reliable and efficient tools for computational studies of excited state problems in organic chemistry. In order to obtain conclusive results, however, the use of optimized excited state geometries and comparison with observables (0-0 excitation energies) are necessary

  15. Hybrid lead halide perovskites for light energy conversion: Excited state properties and photovoltaic applications

    Science.gov (United States)

    Manser, Joseph S.

    travel 220 nm over the course of 2 ns after photoexcitation, with an extrapolated diffusion length greater than one micrometer over the full excited state lifetime. The solution-processability of metal halide perovskites necessarily raises questions as to the properties of the solvated precursors and their connection to the final solid-state perovskite phase. Through structural and steady-state and time-resolved absorption studies, the important link between the excited state properties of the precursor components, composed of solvated and solid-state halometallate complexes, and CH3NH3PbI3 is evinced. This connection provides insight into optical nonlinearities and electronic properties of the perovskite phase. Fundamental studies of CH 3NH3PbI3 ultimately serve as a foundation for application of this and other related materials in high-performance devices. In the final chapter, the operation of CH3NH3PbI 3 solar cells in a tandem architecture is presented. The quest for economic, large scale hydrogen production has motivated the search for new materials and device designs capable of splitting water using only energy from the sun. In light of this, we introduce an all solution-processed tandem water splitting assembly composed of a BiVO4 photoanode and a single-junction CH3NH3PbI3 hybrid perovskite solar cell. This unique configuration allows efficient solar photon management, with the metal oxide photoanode selectively harvesting high energy visible photons and the underlying perovskite solar cell capturing lower energy visible-near IR wavelengths in a single-pass excitation. Operating without external bias under standard terrestrial one sun illumination, the photoanode-photovoltaic architecture, in conjunction with an earthabundant cobalt phosphate catalyst, exhibits a solar-to-hydrogen conversion efficiency of 2.5% at neutral pH. The design of low-cost tandem water splitting assemblies employing single-junction hybrid perovskite materials establishes a potentially

  16. Electron scattering by CO2: Elastic scattering, rotational excitation, and excitation of the asymmetric stretch at 10 eV impact energy

    International Nuclear Information System (INIS)

    Thirumalai, D.; Onda, K.; Truhlar, D.G.

    1981-01-01

    Coupled-channels calculations based on an effective potential are presented for electron scattering by CO 2 at 10 eV impact energy. The processes studied are pure elastic scattering, rotational excitation, and vibrational excitation of the asymmetric stretch; the vibrational excitation is always accompanied by rotational excitation. The quantities calculated are differential, partial, integral, and momentum transfer cross sections, both state to state and summed over final rotational states for a given final vibrational level. The effective potential is based on the INDOX2/1s method for the static and polarization potentials and the semiclassical exchange approximation for the exchange potential. There are no empirical parameters. The present calculations are compared to experiment and to previous calculations where available, and we also perform calculations with an altered polarization potential to further elucidate the reasons for the differences from one of the previous calculations. The agreement of the present results with the experimental rotationally summed, vibrationally inelastic differential cross section is excellent

  17. Motor excitability measurements: the influence of gender, body mass index, age and temperature in healthy controls.

    Science.gov (United States)

    Casanova, I; Diaz, A; Pinto, S; de Carvalho, M

    2014-04-01

    The technique of threshold tracking to test axonal excitability gives information about nodal and internodal ion channel function. We aimed to investigate variability of the motor excitability measurements in healthy controls, taking into account age, gender, body mass index (BMI) and small changes in skin temperature. We examined the left median nerve of 47 healthy controls using the automated threshold-tacking program, QTRAC. Statistical multiple regression analysis was applied to test relationship between nerve excitability measurements and subject variables. Comparisons between genders did not find any significant difference (P>0.2 for all comparisons). Multiple regression analysis showed that motor amplitude decreases with age and temperature, stimulus-response slope decreases with age and BMI, and that accommodation half-time decrease with age and temperature. The changes related to demographic features on TRONDE protocol parameters are small and less important than in conventional nerve conduction studies. Nonetheless, our results underscore the relevance of careful temperature control, and indicate that interpretation of stimulus-response slope and accommodation half-time should take into account age and BMI. In contrast, gender is not of major relevance to axonal threshold findings in motor nerves. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. A method of measurement of lifetimes of excited ion levels, using orientation transfer by Penning collisions

    International Nuclear Information System (INIS)

    Hamel, J.; Barrat, J.-P.

    1978-01-01

    A method for measuring the lifetimes of ionic excited levels is described. This method uses the transfer of coherence in a Penning collision using metastable optically oriented He 2 3 S 1 atoms. If R.F. transitions are induced in the (2 3 S 1 )He level, a transverse component of the magnetic moment of this level is created, which precesses coherently at the angular frequency ω of the R.F. field. The helium transverse orientation is partially transferred to the ions produced by Penning collisions. After the collision, the orientation transferred precesses around the external magnetic field at the Larmor frequency ω 0 ' of the ion excited level. The degree of orientation of the excited ion level depends, in the stationary state, on the average phase shift, during the lifetime tau prime of this level, between the Larmor precession at angular frequency ω 0 ' and the forced precession of helium (at angular frequency ω). The orientation of the ions is monitored by the modulation of the light emitted during their radiative decay. It is possible to determine the lifetime tau prime by measuring the degree of modulation of the reemitted light as a function of ω [fr

  19. Imaging-guided two-photon excitation-emission-matrix measurements of human skin tissues

    Science.gov (United States)

    Yu, Yingqiu; Lee, Anthony M. D.; Wang, Hequn; Tang, Shuo; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

    2012-07-01

    There are increased interests on using multiphoton imaging and spectroscopy for skin tissue characterization and diagnosis. However, most studies have been done with just a few excitation wavelengths. Our objective is to perform a systematic study of the two-photon fluorescence (TPF) properties of skin fluorophores, normal skin, and diseased skin tissues. A nonlinear excitation-emission-matrix (EEM) spectroscopy system with multiphoton imaging guidance was constructed. A tunable femtosecond laser was used to vary excitation wavelengths from 730 to 920 nm for EEM data acquisition. EEM measurements were performed on excised fresh normal skin tissues, seborrheic keratosis tissue samples, and skin fluorophores including: NADH, FAD, keratin, melanin, collagen, and elastin. We found that in the stratum corneum and upper epidermis of normal skin, the cells have large sizes and the TPF originates from keratin. In the lower epidermis, cells are smaller and TPF is dominated by NADH contributions. In the dermis, TPF is dominated by elastin components. The depth resolved EEM measurements also demonstrated that keratin structure has intruded into the middle sublayers of the epidermal part of the seborrheic keratosis lesion. These results suggest that the imaging guided TPF EEM spectroscopy provides useful information for the development of multiphoton clinical devices for skin disease diagnosis.

  20. Rotational temperature measurement of NO gas using two-photon excitation spectrum

    Science.gov (United States)

    Ozaki, Tadao; Matsui, Yoshihiko; Ohsawa, Toshihiko

    1981-04-01

    The rotational temperature of nitric oxide gas has been measured by means of a single-beam two-photon excitation spectrum method using a pulsed continuously tunable dye laser. The nitric oxide gas was enclosed at about 40 Torr in a quartz cell which was put in an electric oven. The NO γ (0-0) band and R11+Q21 branches were used to obtain the two-photon excitation spectrum. The rotational temperatures were determined using the fact that molecules are distributed in the rotational levels according to the Boltzmann law. The temperature range was from room temperature to about 470 K. Observed temperatures were in good agreement with cell temperatures which were obtained by using a thermocouple.

  1. Lifetime measurements in Crsub(I) by laser excitation from the metastable states

    International Nuclear Information System (INIS)

    Kwiatkowski, M.; Micali, G.; Werner, K.; Zimmermann, P.

    1981-01-01

    A combination of collisional and laser excitation was used to measure radiative lifetimes in Cr I. By a discharge an atomic beam of metastable atoms in the 3d 5 4sa 5 S, a 5 G, b 5 D, a 3 I, b 1 I and 3d 4 4s 2 a 5 D terms was produced. Spatially separated from the place of collisional excitation laser radiation selectively populated levels belonging to the 3d 5 4p z 5 P, y 5 P, u 5 F, u 5 D, x 3 I, y 1 I, 3d 5 5pz 5 G and 3d 4 4s4px 5 G terms. Time-resolved observation of the reemitted resonance fluorescence yielded the lifetimes of 28 levels. The values are compared with other experimental and theoretical results. (orig.)

  2. Observation of an energy threshold for large ΔE collisional relaxation of highly vibrationally excited pyrazine (Evib=31 000-41 000 cm-1) by CO2

    Science.gov (United States)

    Elioff, Michael S.; Wall, Mark C.; Lemoff, Andrew S.; Mullin, Amy S.

    1999-03-01

    Energy dependent studies of the collisional relaxation of highly vibrationally excited pyrazine through collisions with CO2 were performed for initial pyrazine energies Evib=31 000-35 000 cm-1. These studies are presented along with earlier results for pyrazine with Evib=36 000-41 000 cm-1. High-resolution transient IR laser absorption of individual CO2 (0000) rotational states (J=56-80) was used to investigate the magnitude and partitioning of energy gain into CO2 rotation and translation, which comprises the high energy tail of the energy transfer distribution function. Highly vibrationally excited pyrazine was prepared by absorption of pulsed UV light at seven wavelengths in the range λ=281-324 nm, followed by radiationless decay to pyrazine's ground electronic state. Nascent CO2 (0000) rotational populations were measured for each UV excitation wavelength and distributions of nascent recoil velocities for individual rotational states of CO2 (0000) were obtained from Doppler-broadened transient linewidth measurements. Measurements of energy transfer rate constants at each UV wavelength yield energy-dependent probabilities for collisions involving large ΔE values. These results reveal that the magnitude of large ΔE collisional energy gain in CO2 (0000) is fairly insensitive to the amount of vibrational energy in pyrazine for Evib=31 000-35 000 cm-1. A comparison with earlier studies on pyrazine with Evib=36 000-41 000 cm-1 indicates that the V→RT energy transfer increases both in magnitude and probability for Evib>36 000 cm-1. Implications of incomplete intramolecular vibrational relaxation, electronic state coupling, and isomerization barriers are discussed in light of these results.

  3. Measurements of shape co-existence in $^{182,184}$Hg using Coulomb excitation

    CERN Multimedia

    Voulot, D; Paul, E S; Siem, S; Czosnyka, T; Napiorkowski, P J; Iwanicki, J S

    2007-01-01

    We propose to exploit the unique capability of ISOLDE to provide post-accelerated $^{182,184}$Hg ions from the REX facility to enable the lowest states of these nuclei to be Coulomb excited. By measuring the $\\gamma$-ray yields using the MINIBALL array we can measure the transition and diagonal E2 matrix elements for these states. This will give quantitative information about the nature of the shape coexistence in these nuclei and allow the sign of the quadrupole deformation be determined for the first time. We require 24 shifts to fulfill the aims of the experiment.

  4. ESR measurement of the concentration of vibrationally excited hydrogen and deuterium molecules

    International Nuclear Information System (INIS)

    Gershenzon, Yu.M.; Ivanov, A.V.; Il'in, S.D.; Kucheryavyi, S.I.; Rozenshtein, V.B.

    1988-01-01

    A method is described for measuring the concentration of vibrationally excited H 2 and D 2 molecules using an ESR microwave spectrometer. The essence of the method is the titration of H 2 (v = 1) and D 2 (v = 1) with D and H atoms and measurement of the concentrations of the titration products H and D, respectively. Stoichiometric titration coefficients were determined in the form of proportionality coefficients between the titration signals Δ[H], Δ[D] and the concentrations of H 2 (v = 1), D 2 (v = 1)

  5. Test-retest reliability of the soleus H-reflex excitability measured during human walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Dyhre-Poulsen, Poul

    2010-01-01

    The purpose of the study was to investigate with what accuracy the soleus H-reflex modulation and excitability could be measured during human walking on two occasions separated by days. The maximal M-wave (Mmax) was measured at rest in the standing position. During treadmill walking every stimulus...... elicited an M-wave of 25+/-10% of Mmax in the soleus muscle and a supra-maximal stimulus elicited a maximal M-wave 60ms after the first stimulus. Both Mmax during rest and during walking were later used for normalization. When normalized to resting Mmax, the peak reflex amplitude during walking was 5...

  6. Analytic energy gradient of excited electronic state within TDDFT/MMpol framework: Benchmark tests and parallel implementation.

    Science.gov (United States)

    Zeng, Qiao; Liang, WanZhen

    2015-10-07

    The time-dependent density functional theory (TDDFT) has become the most popular method to calculate the electronic excitation energies, describe the excited-state properties, and perform the excited-state geometric optimization of medium and large-size molecules due to the implementation of analytic excited-state energy gradient and Hessian in many electronic structure software packages. To describe the molecules in condensed phase, one usually adopts the computationally efficient hybrid Quantum Mechanics/Molecular Mechanics (QM/MM) models. Here, we extend our previous work on the energy gradient of TDDFT/MM excited state to account for the mutual polarization effects between QM and MM regions, which is believed to hold a crucial position in the potential energy surface of molecular systems when the photoexcitation-induced charge rearrangement in the QM region is drastic. The implementation of a simple polarizable TDDFT/MM (TDDFT/MMpol) model in Q-Chem/CHARMM interface with both the linear response and the state-specific features has been realized. Several benchmark tests and preliminary applications are exhibited to confirm our implementation and assess the effects of different treatment of environmental polarization on the excited-state properties, and the efficiency of parallel implementation is demonstrated as well.

  7. Relative level populations in S VI after beam-foil excitation, obtained from ANDC analyses of measured decay curves

    International Nuclear Information System (INIS)

    Engstroem, L.

    1983-01-01

    This paper reports the relative population of the levels 3p, 3d, 4d, 5d, 4f, 5g, 6g, 6h, 7h, 7i, 8i and 8k in Na-like sulfur, S VI, after beam-foil excitation at an energy of 3 MeV. For the first time the ANDC technique has been used to obtain the relative efficiency calibration of the detection system at discrete points in the wavelength interval 400-5000 A, from the analyses of measured decay curves. The advantages and limitations of this method are discussed. The populations obtained with this new technique are compared to previous measurements in multiply ionized atoms. The preferential population of the 3p and 3d levels observed in other Na-like ions is now accurately established. For the higher lying levels an almost constant population is observed. (Auth.)

  8. A pair natural orbital implementation of the coupled cluster model CC2 for excitation energies.

    Science.gov (United States)

    Helmich, Benjamin; Hättig, Christof

    2013-08-28

    We demonstrate how to extend the pair natural orbital (PNO) methodology for excited states, presented in a previous work for the perturbative doubles correction to configuration interaction singles (CIS(D)), to iterative coupled cluster methods such as the approximate singles and doubles model CC2. The original O(N(5)) scaling of the PNO construction is reduced by using orbital-specific virtuals (OSVs) as an intermediate step without spoiling the initial accuracy of the PNO method. Furthermore, a slower error convergence for charge-transfer states is analyzed and resolved by a numerical Laplace transformation during the PNO construction, so that an equally accurate treatment of local and charge-transfer excitations is achieved. With state-specific truncated PNO expansions, the eigenvalue problem is solved by combining the Davidson algorithm with deflation to project out roots that have already been determined and an automated refresh with a generation of new PNOs to achieve self-consistency of the PNO space. For a large test set, we found that truncation errors for PNO-CC2 excitation energies are only slightly larger than for PNO-CIS(D). The computational efficiency of PNO-CC2 is demonstrated for a large organic dye, where a reduction of the doubles space by a factor of more than 1000 is obtained compared to the canonical calculation. A compression of the doubles space by a factor 30 is achieved by a unified OSV space only. Moreover, calculations with the still preliminary PNO-CC2 implementation on a series of glycine oligomers revealed an early break even point with a canonical RI-CC2 implementation between 100 and 300 basis functions.

  9. Quantitative determination of localized tissue oxygen concentration in vivo by two-photon excitation phosphorescence lifetime measurements

    NARCIS (Netherlands)

    Mik, Egbert G.; van Leeuwen, Ton G.; Raat, Nicolaas J.; Ince, Can

    2004-01-01

    This study describes the use of two-photon excitation phosphorescence lifetime measurements for quantitative oxygen determination in vivo. Doubling the excitation wavelength of Pd-porphyrin from visible light to the infrared allows for deeper tissue penetration and a more precise and confined

  10. Investigation of the energy-averaged double transition density of isoscalar monopole excitations in medium-heavy mass spherical nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gorelik, M.L.; Shlomo, S. [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation); Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Tulupov, B.A. [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation); Institute for Nuclear Research, RAS, Moscow 117312 (Russian Federation); Urin, M.H., E-mail: urin@theor.mephi.ru [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

    2016-11-15

    The particle–hole dispersive optical model, developed recently, is applied to study properties of high-energy isoscalar monopole excitations in medium-heavy mass spherical nuclei. The energy-averaged strength functions of the isoscalar giant monopole resonance and its overtone in {sup 208}Pb are analyzed. In particular, we analyze the energy-averaged isoscalar monopole double transition density, the key quantity in the description of the hadron–nucleus inelastic scattering, and studied the validity of the factorization approximation using semi classical and microscopic one body transition densities, respectively, in calculating the cross sections for the excitation of isoscalar giant resonances by inelastic alpha scattering.

  11. Energy dispersive X-ray fluorescence determination of cadmium in uranium matrix using Cd Kα line excited by continuum

    International Nuclear Information System (INIS)

    Dhara, Sangita; Misra, N.L.; Aggarwal, S.K.; Venugopal, V.

    2010-01-01

    An energy dispersive X-ray fluorescence method for determination of cadmium (Cd) in uranium (U) matrix using continuum source of excitation was developed. Calibration and sample solutions of cadmium, with and without uranium were prepared by mixing different volumes of standard solutions of cadmium and uranyl nitrate, both prepared in suprapure nitric acid. The concentration of Cd in calibration solutions and samples was in the range of 6 to 90 μg/mL whereas the concentration of Cd with respect to U ranged from 90 to 700 μg/g of U. From the calibration solutions and samples containing uranium, the major matrix uranium was selectively extracted using 30% tri-n-butyl phosphate in dodecane. Fixed volumes (1.5 mL) of aqueous phases thus obtained were taken directly in specially designed in-house fabricated leak proof Perspex sample cells for the energy dispersive X-ray fluorescence measurements and calibration plots were made by plotting Cd Kα intensity against respective Cd concentration. For the calibration solutions not having uranium, the energy dispersive X-ray fluorescence spectra were measured without any extraction and Cd calibration plots were made accordingly. The results obtained showed a precision of 2% (1σ) and the results deviated from the expected values by < 4% on average.

  12. Physical Meaning of Virtual Kohn-Sham Orbitals and Orbital Energies: An Ideal Basis for the Description of Molecular Excitations

    NARCIS (Netherlands)

    van Meer, R.; Gritsenko, O.V.; Baerends, E.J.

    2014-01-01

    In recent years, several benchmark studies on the performance of large sets of functionals in time-dependent density functional theory (TDDFT) calculations of excitation energies have been performed. The tested functionals do not approximate exact Kohn-Sham orbitals and orbital energies closely. We

  13. Fission excitation function for 19F + 194,196,198Pt at near and above barrier energies

    Directory of Open Access Journals (Sweden)

    Singh Varinderjit

    2015-01-01

    Full Text Available Fission excitation functions for 19F + 194,196,198Pt reactions populating 213,215,217Fr compound nuclei are reported. Out of these three compound nuclei, 213Fr is a shell closed (N=126 compound nucleus and the other two are away from the shell closure. From a comparison of the experimental fission cross-sections with the statistical model predictions, it is observed that the fission cross-sections are underestimated by the statistical model predictions using shell corrected finite range rotating liquid drop model (FRLDM fission barriers. Further the FRLDM fission barriers are reduced to fit the fission cross-sections over the entire measured energy range.

  14. Field-orientation dependence of low-energy quasiparticle excitations in the heavy-electron superconductor UBe(13).

    Science.gov (United States)

    Shimizu, Yusei; Kittaka, Shunichiro; Sakakibara, Toshiro; Haga, Yoshinori; Yamamoto, Etsuji; Amitsuka, Hiroshi; Tsutsumi, Yasumasa; Machida, Kazushige

    2015-04-10

    Low-energy quasiparticle excitations in the superconducting (SC) state of UBe_{13} were studied by means of specific-heat (C) measurements in a rotating field. Quite unexpectedly, the magnetic-field dependence of C(H) is linear in H with no angular dependence at low fields in the SC state, implying that the gap is fully open over the Fermi surfaces, in stark contrast to previous expectations. In addition, a characteristic cubic anisotropy of C(H) was observed above 2 T with a maximum (minimum) for H∥[001] ([111]) within the (11[over ¯]0) plane, in the normal as well as in the SC states. This oscillation possibly originates from the anisotropic response of the heavy quasiparticle bands, and might be a key to understand the unusual properties of UBe_{13}.

  15. Subsurface excitations in a metal

    DEFF Research Database (Denmark)

    Ray, M. P.; Lake, R. E.; Sosolik, C. E.

    2009-01-01

    We investigate internal hot carrier excitations in a Au thin film bombarded by hyperthermal and low energy alkali and noble gas ions. Excitations within the thin film of a metal-oxide-semiconductor device are measured revealing that ions whose velocities fall below the classical threshold given...... by the free-electron model of a metal still excite hot carriers. Excellent agreement between these results and a nonadiabatic model that accounts for the time-varying ion-surface interaction indicates that the measured excitations are due to semilocalized electrons near the metal surface....

  16. Three-fold increase of M1 strength in 40Ar at 10 MeV excitation energy

    Science.gov (United States)

    Tornow, Werner; Finch, Sean; Krishichayan, Fnu; Tonchev, Anton

    2017-09-01

    We reexamined the excitation energy region of 40Ar around 9.8 MeV with the goal of determining the known M1 strength located at 9.76 MeV more accurately. The physics motivation was based on the fact that i) the neutrino-nucleus interaction cross section is proportional to the M1 strength of a nucleus, ii) DUNE, the Deep Underground Neutrino Experiment at SURF will be using liquid argon as detector medium, iii) the energy spectrum of supernova neutrinos is peaked at approximately 10 MeV. Mono-energetic and linearly polarized photons of 9.88 MeV were produced via Compton backscattering of 548 nm FEL photons from 543 MeV electrons at the High-Intensity γ-ray Source (HI γS) facility at TUNL. The 1.25 cm diameter photon beam with energy spread of 300 keV (FWHM) interacted with argon gas contained in a high-pressure cell. The cell was viewed with HPGe detectors placed at 90o relative to the incident photon beam in the horizontal and vertical planes to distinguish between E1 and M1 de-excitation γ-rays. Our re-measurement provided an increase in M1 strength by a factor of approximately 3, mostly due to the discovery that the known level in 40Ar at 9.84 MeV is of M1 character and not of E1 character, as previously thought. In addition to the already known M1 state at 9.76 MeV, we observed weaker M1 states at 9.70, 9.81, 9.87, and 9.89 MeV.

  17. Energy dependence of isovector and isoscalar 1+ excitations in 28Si(p,p/sup '/) between 200 and 400 MeV

    International Nuclear Information System (INIS)

    Haeusser, O.; Sawafta, R.; Jeppesen, R.G.

    1988-01-01

    Forward-angle cross sections for 1 + , T = 1 and 1 + , T = 0 states in 28 Si excited by the (p,p') reaction have been measured to determine the energy dependence of important pieces of the effective nucleon-nucleus interaction. The isovector spin-transfer transitions depend on energy as expected from distorted-wave impulse approximation calculations based on the dominant V/sub Σ//sub tau/ part of the Franey-Love interaction. The parts of this interaction responsible for exciting the 9.5 MeV isosca- lar spin-flip transition predict a weaker energy dependence than is observed experimentally. The summed Gamow-Teller strength for isovector transitions below 14.5 MeV is found to be (0.89 +- 0.09) times the result of large-scale shell model calculations

  18. Low-energy d-d excitations in MnO studied by resonant x-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Butorin, S.M.; Guo, J.; Magnuson, M.

    1997-01-01

    Resonant soft X-ray emission spectroscopy has been demonstrated to possess interesting abilities for studies of electronic structure in various systems, such as symmetry probing, alignment and polarization dependence, sensitivity to channel interference, etc. In the present abstract the authors focus on the feasibility of resonant soft X-ray emission to probe low energy excitations by means of resonant electronic X-ray Raman scattering. Resonant X-ray emission can be regarded as an inelastic scattering process where a system in the ground state is transferred to a low excited state via a virtual core excitation. The energy closeness to a core excitation of the exciting radiation enhances the (generally) low probability for inelastic scattering at these wavelengths. Therefore soft X-ray emission spectroscopy (in resonant electronic Raman mode) can be used to study low energy d-d excitations in transition metal systems. The involvement of the intermediate core state allows one to use the selection rules of X-ray emission, and the appearance of the elastically scattered line in the spectra provides the reference to the ground state

  19. Low-energy d-d excitations in MnO studied by resonant x-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Butorin, S.M.; Guo, J.; Magnuson, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Resonant soft X-ray emission spectroscopy has been demonstrated to possess interesting abilities for studies of electronic structure in various systems, such as symmetry probing, alignment and polarization dependence, sensitivity to channel interference, etc. In the present abstract the authors focus on the feasibility of resonant soft X-ray emission to probe low energy excitations by means of resonant electronic X-ray Raman scattering. Resonant X-ray emission can be regarded as an inelastic scattering process where a system in the ground state is transferred to a low excited state via a virtual core excitation. The energy closeness to a core excitation of the exciting radiation enhances the (generally) low probability for inelastic scattering at these wavelengths. Therefore soft X-ray emission spectroscopy (in resonant electronic Raman mode) can be used to study low energy d-d excitations in transition metal systems. The involvement of the intermediate core state allows one to use the selection rules of X-ray emission, and the appearance of the elastically scattered line in the spectra provides the reference to the ground state.

  20. Energy dispersive soft X-ray fluorescence analysis by radioisotopic α-particle excitation

    International Nuclear Information System (INIS)

    Robertson, R.

    1977-01-01

    A Si(Li) X-ray detector system and 210 Po α-particle excitation source are combined to form a spectrometer for low energy X-rays. Its response in terms of Ksub(α) X-ray rate is shown for thick targets of elements from fluorine to copper. Potential applications of the equipment to useful quantitative elemental analysis of geological, biological and organic materials are explored. The results of analyses for oxygen and silicon in rocks and potassium in vegetation samples are included. A semi-empirical method of correcting for absorption and enhancement effects is employed. This is based upon X-ray production and photon absorption cross-sections taken from the literature and upon a minimal number of experimentally derived coefficients. (Auth.)

  1. Formation of H{sub 2} from internally heated polycyclic aromatic hydrocarbons: Excitation energy dependence

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T., E-mail: tao.chen@fysik.su.se, E-mail: henning@fysik.su.se; Gatchell, M.; Stockett, M. H.; Schmidt, H. T.; Cederquist, H.; Zettergren, H., E-mail: tao.chen@fysik.su.se, E-mail: henning@fysik.su.se [Department of Physics, Stockholm University, S-106 91 Stockholm (Sweden); Delaunay, R.; Rousseau, P.; Adoui, L. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen cedex 05 (France); Université de Caen Basse-Normandie, Esplanade de la Paix, F-14032 Caen (France); Domaracka, A.; Huber, B. A. [CIMAP, UMR 6252, CEA/CNRS/ENSICAEN/Université de Caen Basse-Normandie, bd Henri Becquerel, BP 5133, F-14070 Caen cedex 05 (France); Micelotta, E. R. [Université Paris Sud, Institut d’Astrophysique Spatiale, UMR 8617, 91405 Orsay (France); Tielens, A. G. G. M. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2015-04-14

    We have investigated the effectiveness of molecular hydrogen (H{sub 2}) formation from Polycyclic Aromatic Hydrocarbons (PAHs) which are internally heated by collisions with keV ions. The present and earlier experimental results are analyzed in view of molecular structure calculations and a simple collision model. We estimate that H{sub 2} formation becomes important for internal PAH temperatures exceeding about 2200 K, regardless of the PAH size and the excitation agent. This suggests that keV ions may effectively induce such reactions, while they are unlikely due to, e.g., absorption of single photons with energies below the Lyman limit. The present analysis also suggests that H{sub 2} emission is correlated with multi-fragmentation processes, which means that the [PAH-2H]{sup +} peak intensities in the mass spectra may not be used for estimating H{sub 2}-formation rates.

  2. Ab initio configuration interaction description of excitation energy transfer between closely packed molecules

    International Nuclear Information System (INIS)

    Fink, R.F.; Pfister, J.; Schneider, A.; Zhao, H.; Engels, B.

    2008-01-01

    We present new, generally applicable protocols for the computation of the coupling parameter, J, of excitation energy transfer with quantum chemical ab initio methods. The protocols allow to select the degree of approximation and computational demand such that they are applicable for realistic systems and still allow to control the quality of the approach. We demonstrate the capabilities of the different protocols using the CO dimer as a first example. Correlation effects are found to scale J by a factor of about 0.7 which is in good agreement to earlier results obtained for the ethene dimer. The various levels of the protocol allow to assess the influence of ionic configurations and the polarisation within the dimer. Further, the interplay between the Foerster and Dexter contribution to J is investigated. The computations also show error compensation within approximations that are widely used for extended systems as in particular the transition density cube method

  3. Photochemistry of ethylene: A multireference configuration interaction investigation of the excited-state energy surfaces

    International Nuclear Information System (INIS)

    Barbatti, M.; Paier, J.; Lischka, H.

    2004-01-01

    Multireference configuration interaction with singles and doubles (MR-CISD) calculations have been performed for the optimization of conical intersections and stationary points on the ethylene excited-state energy surfaces using recently developed methods for the computation of analytic gradients and nonadiabatic coupling terms. Basis set dependence and the effect of various choices of reference spaces for the MR-CISD calculations have been investigated. The crossing seam between the S 0 and S 1 states has been explored in detail. This seam connects all conical intersections presently known for ethylene. Major emphasis has been laid on the hydrogen-migration path. Starting in the V state of twisted-orthogonal ethylene, a barrierless path to ethylidene was found. The feasibility of ethylidene formation will be important for the explanation of the relative yield of cis and trans H 2 elimination

  4. Excitation energy deactivation funnel in 3-substituted BODIPY-porphyrin conjugate

    International Nuclear Information System (INIS)

    Nguyen, Nguyen Tran; Verbelen, Bram; Leen, Volker; Waelkens, Etienne; Dehaen, Wim; Kruk, Mikalai

    2016-01-01

    BODIPYs absorb in the visible region which is complementary to that of porphyrins and therefore can be suggested as promising antenna groups to improve the light-harvesting potential of porphyrins. A boron-dipyrromethene dye was combined at the 3-position with a Zn-porphyrin to afford a conjugate. The fluorescence of the conjugate was found to originate from the BODIPY moiety independently of the excitation wavelength due to an unique set of energy transfer rates between the BODIPY and Zn-porphyrin moieties. The fluorescence intensity was shown to be tunable over a wide range using the solvent properties. This feature makes the studied BODIPY-porphyrin conjugate a promising compound for the design of new photochromic devices.

  5. Nuclei far from stability. Individual and collective excitations at low energy

    International Nuclear Information System (INIS)

    Meyer, M.

    1984-01-01

    The low energy structure of exotic nuclei is discussed in terms of self-consistent microscopic models. The experimental striking features of the spectroscopy of these nuclei are briefly surveyed and the schematic steps performed to obtain from effective N-N interactions their spectroscopic properties are presented. Their saturation and deformation properties are given by the Hartree-Fock approximation (HF). Then it is shown how to describe the dynamics of even-even exotic nuclei excited states by solving the complete Bohr Hamiltonian, built microscopically using the HF approximation and the adiabatic limit (and its derivatives) of the time-dependent HF approximation (ATDHF). The structure of odd and doubly odd nuclei is discussed in the framework of the unified model, ie the microscopic rotor + quasiparticles model. Finally possible future directions of experimental research concerning exotic nuclei are described and improvements or new theoretical approaches discussed [fr

  6. Study on germ toxicity of exciting energy resource 147Pm of fluorescent paint

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Lun Minyue; Tao Feng

    1993-02-01

    The germ toxicity of exciting energy resource 147 Pm of fluorescent paint was studied. It was shown that the placenta was a barrier for 147 Pm entering into the fetus. The retention T 1/2 was 105 days in testes. The retention value of 147 Pm in testis was high and hardly to excrete. The results showed that 147 Pm can induce abnormal sperms, most of them were non-hock sperms. The chromosome aberrations in germ cells also can be induced. Among the type of chromosome aberrations of spermatogonia, chromatid breakage was predominant. The 147 Pm can cause the chromosome fragment and translocations of primary spermatocytes, and increasing of lethality. The dominant skeletal aberrations in offspring is proportional to the accumulated radioactivity of 147 Pm in tests

  7. Excitation energy deactivation funnel in 3-substituted BODIPY-porphyrin conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nguyen Tran [Chemistry Department, University of Education, The University of DaNang, Ton Duc Thang 459, Da Nang (Viet Nam); Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Verbelen, Bram; Leen, Volker [Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Waelkens, Etienne [Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, Box 901, 3000 Leuven (Belgium); Dehaen, Wim, E-mail: wim.dehaen@kuleuven.be [Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Kruk, Mikalai, E-mail: m.kruk@belstu.by [Belarusian State Technological University, Physics Department, Sverdlov Str., 13a, Minsk 220006 (Belarus)

    2016-11-15

    BODIPYs absorb in the visible region which is complementary to that of porphyrins and therefore can be suggested as promising antenna groups to improve the light-harvesting potential of porphyrins. A boron-dipyrromethene dye was combined at the 3-position with a Zn-porphyrin to afford a conjugate. The fluorescence of the conjugate was found to originate from the BODIPY moiety independently of the excitation wavelength due to an unique set of energy transfer rates between the BODIPY and Zn-porphyrin moieties. The fluorescence intensity was shown to be tunable over a wide range using the solvent properties. This feature makes the studied BODIPY-porphyrin conjugate a promising compound for the design of new photochromic devices.

  8. Energy levels of the single excited states in NaI and Na-like ions

    International Nuclear Information System (INIS)

    El-Sherbini, T.M.; Wahby, A.S.

    1987-08-01

    Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

  9. Ab initio configuration interaction description of excitation energy transfer between closely packed molecules

    Energy Technology Data Exchange (ETDEWEB)

    Fink, R.F. [University of Wuerzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Wuerzburg (Germany)], E-mail: reinhold.fink@rub.de; Pfister, J.; Schneider, A.; Zhao, H.; Engels, B. [University of Wuerzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Wuerzburg (Germany)

    2008-01-29

    We present new, generally applicable protocols for the computation of the coupling parameter, J, of excitation energy transfer with quantum chemical ab initio methods. The protocols allow to select the degree of approximation and computational demand such that they are applicable for realistic systems and still allow to control the quality of the approach. We demonstrate the capabilities of the different protocols using the CO dimer as a first example. Correlation effects are found to scale J by a factor of about 0.7 which is in good agreement to earlier results obtained for the ethene dimer. The various levels of the protocol allow to assess the influence of ionic configurations and the polarisation within the dimer. Further, the interplay between the Foerster and Dexter contribution to J is investigated. The computations also show error compensation within approximations that are widely used for extended systems as in particular the transition density cube method.

  10. Measurements of photoionization cross sections from the 4p, 5d and 7s excited states of potassium

    International Nuclear Information System (INIS)

    Amin, Nasir; Mahmood, S.; Haq, S.U.; Kalyar, M.A.; Rafiq, M.; Baig, M.A.

    2008-01-01

    New measurements of the photoionization cross sections from the 4p 2 P 1/2,3/2 , 5d 2 D 5/2,3/2 and 7s 2 S 1/2 excited states of potassium are presented. The cross sections have been measured by two-step excitation and ionization using a Nd:YAG laser in conjunction with a thermionic diode ion detector. By applying the saturation technique, the absolute values of the cross sections from the 4p 2 P 3/2 and 4p 2 P 1/2 states at 355 nm are determined as 7.2±1.1 and 5.6±0.8 Mb, respectively. The photoionization cross section from the 5d 2 D 5/2,3/2 excited state has been measured using two excitation paths, two-step excitation and two-photon excitation from the ground state. The measured values of the cross sections from the 5d 2 D 5/2 state by two-photon excitation from the ground state is 28.9±4.3 Mb, whereas in the two-step excitation, the cross section from the 5d 2 D 3/2 state via the 4p 2 P 1/2 state and from the 5d 2 D 5/2,3/2 states via the 4p 2 P 3/2 state are determined as 25.1±3.8 and 30.2±4.5 Mb, respectively. Besides, we have measured the photoionization cross sections from the 7s 2 S 1/2 excited state using the two-photon excitation from the ground state as 0.61±0.09 Mb

  11. Measuring energy efficiency: Is energy intensity a good evidence base?

    International Nuclear Information System (INIS)

    Proskuryakova, L.; Kovalev, A.

    2015-01-01

    Highlights: • Energy intensity measure reflects consumption, not energy efficiency. • Thermodynamic indicators should describe energy efficiency at all levels. • These indicators should have no reference to economic or financial parameters. • A set of energy efficiency indicators should satisfy several basic principles. • There are trade-offs between energy efficiency, power and costs. - Abstract: There is a widespread assumption in energy statistics and econometrics that energy intensity and energy efficiency are equivalent measures of energy performance of economies. The paper points to the discrepancy between the engineering concept of energy efficiency and the energy intensity as it is understood in macroeconomic statistics. This double discrepancy concerns definitions (while engineering concept of energy efficiency is based on the thermodynamic definition, energy intensity includes economic measures) and use. With regard to the latter, the authors conclude that energy intensity can only provide indirect and delayed evidence of technological and engineering energy efficiency of energy conversion processes, which entails shortcomings for management and policymaking. Therefore, we suggest to stop considering subsectoral, sectoral and other levels of energy intensities as aggregates of lower-level energy efficiency. It is suggested that the insufficiency of energy intensity indicators can be compensated with the introduction of thermodynamic indicators describing energy efficiency at the physical, technological, enterprise, sub-sector, sectoral and national levels without references to any economic or financial parameters. Structured statistical data on thermodynamic efficiency is offered as a better option for identifying break-through technologies and technological bottle-necks that constrain efficiency advancements. It is also suggested that macro-level thermodynamic indicators should be based on the thermodynamic first law efficiency and the energy

  12. First Double Excitation Cross Sections of Helium Measured for 100-keV Proton Impact

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A. [Laboratoire Collisions, Agregats, Reactivite, IRSAMC, UMR 5589, CNRS and Universite Paul Sabatier, 31062 Toulouse Cedex (France); Godunov, A.L.; Schipakov, V.A. [Troitsk Institute for Innovation and Fusion Research, Troitsk, Moscow region, 142092 (Russia)

    1997-12-01

    Excitation cross sections of the (2s{sup 2}){sup 1}S, (2p{sup 2}){sup 1}D , and (2s2p){sup 1}P autoionizing states of helium, produced in collisions with 100-keV protons, have been measured for the first time. Using a high resolution electron spectroscopy together with a recently proposed parametrization of autoionizing resonances distorted by Coulomb interaction in the final state makes it possible to extract from electron spectra {ital total cross sections} as well as {ital magnetic sublevel populations.} These new experimental data are briefly compared with out theoretical calculations. {copyright} {ital 1997} {ital The American Physical Society}

  13. First Double Excitation Cross Sections of Helium Measured for 100-keV Proton Impact

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.; Godunov, A.L.; Schipakov, V.A.

    1997-01-01

    Excitation cross sections of the (2s 2 ) 1 S, (2p 2 ) 1 D , and (2s2p) 1 P autoionizing states of helium, produced in collisions with 100-keV protons, have been measured for the first time. Using a high resolution electron spectroscopy together with a recently proposed parametrization of autoionizing resonances distorted by Coulomb interaction in the final state makes it possible to extract from electron spectra total cross sections as well as magnetic sublevel populations. These new experimental data are briefly compared with out theoretical calculations. copyright 1997 The American Physical Society

  14. Relative measurement of the excitation rate coefficients of the FeXI ion

    International Nuclear Information System (INIS)

    Marotta, A.

    1982-01-01

    The collision rate coefficients for the iron atoms are measured through the hot plasma obtainment. The physical model used in this determination is the crown stationary model which consider that the excitation by electronic collisions is balanced by the spontaneous emission. This work was realized in a 15Kj theta pinch device, of high pulse reproductibility. The iron-pentacarbonyl [Fe(Co) 5 ] was used as the impurity source of a hydrogen gas. The temperature and density were determined by the scattering light analysis of a rubi laser using the Thomson scattering. (L.C.) [pt

  15. Analytical Energy Gradients for Excited-State Coupled-Cluster Methods

    Science.gov (United States)

    Wladyslawski, Mark; Nooijen, Marcel

    The equation-of-motion coupled-cluster (EOM-CC) and similarity transformed equation-of-motion coupled-cluster (STEOM-CC) methods have been firmly established as accurate and routinely applicable extensions of single-reference coupled-cluster theory to describe electronically excited states. An overview of these methods is provided, with emphasis on the many-body similarity transform concept that is the key to a rationalization of their accuracy. The main topic of the paper is the derivation of analytical energy gradients for such non-variational electronic structure approaches, with an ultimate focus on obtaining their detailed algebraic working equations. A general theoretical framework using Lagrange's method of undetermined multipliers is presented, and the method is applied to formulate the EOM-CC and STEOM-CC gradients in abstract operator terms, following the previous work in [P.G. Szalay, Int. J. Quantum Chem. 55 (1995) 151] and [S.R. Gwaltney, R.J. Bartlett, M. Nooijen, J. Chem. Phys. 111 (1999) 58]. Moreover, the systematics of the Lagrange multiplier approach is suitable for automation by computer, enabling the derivation of the detailed derivative equations through a standardized and direct procedure. To this end, we have developed the SMART (Symbolic Manipulation and Regrouping of Tensors) package of automated symbolic algebra routines, written in the Mathematica programming language. The SMART toolkit provides the means to expand, differentiate, and simplify equations by manipulation of the detailed algebraic tensor expressions directly. The Lagrangian multiplier formulation establishes a uniform strategy to perform the automated derivation in a standardized manner: A Lagrange multiplier functional is constructed from the explicit algebraic equations that define the energy in the electronic method; the energy functional is then made fully variational with respect to all of its parameters, and the symbolic differentiations directly yield the explicit

  16. Measuring 13Cβ chemical shifts of invisible excited states in proteins by relaxation dispersion NMR spectroscopy

    International Nuclear Information System (INIS)

    Lundstroem, Patrik; Lin Hong; Kay, Lewis E.

    2009-01-01

    A labeling scheme is introduced that facilitates the measurement of accurate 13 C β chemical shifts of invisible, excited states of proteins by relaxation dispersion NMR spectroscopy. The approach makes use of protein over-expression in a strain of E. coli in which the TCA cycle enzyme succinate dehydrogenase is knocked out, leading to the production of samples with high levels of 13 C enrichment (30-40%) at C β side-chain carbon positions for 15 of the amino acids with little 13 C label at positions one bond removed (∼5%). A pair of samples are produced using [1- 13 C]-glucose/NaH 12 CO 3 or [2- 13 C]-glucose as carbon sources with isolated and enriched (>30%) 13 C β positions for 11 and 4 residues, respectively. The efficacy of the labeling procedure is established by NMR spectroscopy. The utility of such samples for measurement of 13 C β chemical shifts of invisible, excited states in exchange with visible, ground conformations is confirmed by relaxation dispersion studies of a protein-ligand binding exchange reaction in which the extracted chemical shift differences from dispersion profiles compare favorably with those obtained directly from measurements on ligand free and fully bound protein samples

  17. Level population measurements on analyte atom and ion excited states in the inductively coupled plasma

    International Nuclear Information System (INIS)

    Walker, Z.H.; Blades, M.W.

    1986-01-01

    During the past decade a number of publications dealing with fundamental studies of the inductively coupled plasma (ICP) have appeared in the literature. The purpose of many of these investigations has been to understand the nature of the interaction between the plasma gas and the analyte. The general conclusion drawn from these studies has been that the ICP is very close to Local Thermodynamic Equilibrium (LTE), but that some deviations from LTE do occur. Recent studies by the authors' have been directed towards the measurement of analyte atom and ion excited state level populations with the objective of obtaining a better understanding of both ionization and excitation in the ICP discharge and the extent to which such processes contribute to a non-equilibrium state. Further discussion is drawn from similar measurements made on elements with low ionization potentials, such as Barium, as well as on elements such as Iron in the presence of Easily Ionizable Elements (EIE's). The spatial and power dependences of such measurements are also discussed

  18. Direct determination of the excited state energies of the xanthophylls diadinoxanthin and diatoxanthin from Phaeodactylum tricornutum

    Science.gov (United States)

    Enriquez, Miriam M.; LaFountain, Amy M.; Budarz, James; Fuciman, Marcel; Gibson, George N.; Frank, Harry A.

    2010-06-01

    Steady-state and femtosecond time-resolved transient absorption spectra of diadinoxanthin and diatoxanthin were measured in the visible and near-infrared (NIR) regions at 293 K. The difference in energy between the visible S 0 → S 2 transitions from the steady-state absorption measurements and the S 1 → S 2 transitions observed in the transient absorption spectra in the NIR region yields precise values of the S 1 energies. The data are important for evaluating the mechanism by which excess energy is dissipated by algal systems that interconvert these xanthophylls in response to changes in photon flux levels in the marine environment.

  19. Measurement of Missing Tranverse Energy

    CERN Document Server

    The ATLAS Collaboration

    2009-01-01

    This note discusses the overall ATLAS detector performance for the reconstruction of the missing transverse energy, ETmiss. Two reconstruction algorithms are discussed and their performance is evaluated for a variety of simulated physics processes which probe different topologies and different total transverse energy regimes. In addition, effects of fake ETmiss, resulting from instrumental effects and from false reconstructions are investigated. Finally, studies with first data, corresponding to an integrated luminosity of 100 pb-1, are suggested which can be used to assess and calibrate the ETmiss performance at the startup of data taking.

  20. Optical measurement of interface movements of liquid metal excited by a pneumatic shaker

    Science.gov (United States)

    Men, Shouqiang; Zhou, Jun; Xu, Jingwen

    2015-02-01

    A model experiment was designed, and Faraday instabilities were generated in a plexiglass cylinder excited by a pneumatic shaker. A contacting distance meter and a single-point fiber-optic vibrometer were applied to measure the displacement/velocity of the shaker, both of the results are in good agreement with each other. Besides, the fibre-optic laser vibrometer was exploited to measure the velocity of the interface between potassium hydroxide aqueous solution and Galinstan. It shows that the fibre-optic vibrometer can be applied to measure the interface movements without Faraday instabilities, whereas there are strong scatter and the interface displacement can only be obtained qualitatively. In this case, a scanning vibrometer or a high-speed CCD camera should be used to record the interface movements.

  1. Ionising radiation dosimetry by measuring thermally excited currents (TEC) in irradiated highpolymers

    International Nuclear Information System (INIS)

    Shtol'ts, V.; Petermann, V.; Nigot, V.

    1976-01-01

    The first results are presented in measuring thermally excited currents (TEC) in 60 Co - gamma irradiated polyethylene and teflon. The design of measuring instruments is described. The maximum background currents in nonirradiated samples reached 10 -13 A. The TEC curves are presented which have obtained under irradiation up to 0.1-1000 rad followed by heating in the temperature range from 20 to 250 deg C. The curves exhibited maxima at about 90 deg C for polyethylene and about 200 deg C for teflon. The TEC dose range has been determined to be 0.1-1000 rad and 5-1000 rad for polyethylene and teflon, respectively. The fading at room temperature after 100 hrs has appeared to be 50% for polyethylene and 60% for teflon. The main merit of the technique is assumed to be the simplicity of the measuring instruments [ru

  2. Dissipation of the electronic excitation energy in fluorides with different type of a crystal lattice

    International Nuclear Information System (INIS)

    Lisitsyn, V.M.; Grechkina, T. V.; Korepanov, V.I.; Lisitsyna, L.A.

    2004-01-01

    Full text: In this paper we present results of comparison of efficiency creations of primary defects in crystals of fluorides of two different lattice structures: stone salt - LiF and rutile MgF 2 . We have used the methods with nanosecond time-resolved of pulse spectroscopy and found laws of creation and evolution self-trapped exciton (STE) and the F centers in a temperature range from 12.5 to 500 K and a time interval from 10 -8 to 10 -1 s after the ending of influence of a pulse electron. The density of excitation of crystals in a pulse is no more than 0.1 J·cm -3 , average energy electrons made 200 keV, duration electron pulse - 7 ns. It is established, that in crystal LiF under action of radiation are created STE two types which have various spectral-kinetic parameters absorption and emission transitions, various values of activation energy of processes of a post-industrial relaxation and different character of temperature dependences of creation efficiency under action electron pulse. In the field of low temperatures (12.5 K) created on center STE has absorption bands on 5.5 and 5.1 eV and emission band on 5.8 eV. Off-center STE has absorption on 5.3 and 4.75 eV and emission on 4.4 eV bands and are created in the interval 12.5-170 K with peak efficiency h area 60 K. In crystal MgF 2 at low temperatures (20 K) under action of radiation one STE with a nucleus occupying off-center configuration, having luminescence band on 3.2 eV and a series absorption transitions in area 4-5.5 eV is created. Concurrently with STE in both crystals under action of a pulse electron the F-centers with efficiency, not dependent on temperature of a crystal in area 20-100 K are created. There are two alternative processes under action of an irradiation with growth of temperature higher 100 K: reducing of STE creation and increasing of F centers creation. In both crystals quenching temperature of luminescence STE at T>60 K which is not accompanied by growth of efficiency of creation

  3. Energy cascades, excited state dynamics, and photochemistry in cob(III)alamins and ferric porphyrins.

    Science.gov (United States)

    Rury, Aaron S; Wiley, Theodore E; Sension, Roseanne J

    2015-03-17

    Porphyrins and the related chlorins and corrins contain a cyclic tetrapyrrole with the ability to coordinate an active metal center and to perform a variety of functions exploiting the oxidation state, reactivity, and axial ligation of the metal center. These compounds are used in optically activated applications ranging from light harvesting and energy conversion to medical therapeutics and photodynamic therapy to molecular electronics, spintronics, optoelectronic thin films, and optomagnetics. Cobalt containing corrin rings extend the range of applications through photolytic cleavage of a unique axial carbon-cobalt bond, permitting spatiotemporal control of drug delivery. The photochemistry and photophysics of cyclic tetrapyrroles are controlled by electronic relaxation dynamics including internal conversion and intersystem crossing. Typically the electronic excitation cascades through ring centered ππ* states, ligand to metal charge transfer (LMCT) states, metal to ligand charge transfer (MLCT) states, and metal centered states. Ultrafast transient absorption spectroscopy provides a powerful tool for the investigation of the electronic state dynamics in metal containing tetrapyrroles. The UV-visible spectrum is sensitive to the oxidation state, electronic configuration, spin state, and axial ligation of the central metal atom. Ultrashort broadband white light probes spanning the range from 270 to 800 nm, combined with tunable excitation pulses, permit the detailed unravelling of the time scales involved in the electronic energy cascade. State-of-the-art theoretical calculations provide additional insight required for precise assignment of the states. In this Account, we focus on recent ultrafast transient absorption studies of ferric porphyrins and corrin containing cob(III)alamins elucidating the electronic states responsible for ultrafast energy cascades, excited state dynamics, and the resulting photoreactivity or photostability of these compounds. Iron

  4. 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-.

  5. 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 ...

  6. The excited J = 01 Σu+ levels of D2: Measurements and ab initio quantum defect study

    Science.gov (United States)

    Glass-Maujean, M.; Jungen, Ch.; Dickenson, G. D.; de Oliveira, N.; Ubachs, W.

    2016-02-01

    The DESIRS beamline of the SOLEIL synchrotron facility, equipped with a vacuum ultraviolet Fourier-transform spectrometer has been used to measure P (N″ = 1) (N -N″ = - 1) absorption transitions of the D2 molecule. Some 44 P-lines were assigned and their transition frequencies determined up to excitation energies of 134,000 cm-1 above the ground state, thereby extending the earlier work by various authors, and considerably improving the spectral accuracy (<0.1 cm-1). The assignments have been aided by first principles multichannel quantum defect theory (MQDT) calculations. These calculations also provide predictions of the autoionization widths of the upper levels which agree well with the observed resonance widths.

  7. Measures for energy efficiency improvement of buildings

    Directory of Open Access Journals (Sweden)

    Vukadinović Ana V.

    2015-01-01

    Full Text Available The increase in energy consumption in buildings causes the need to propose energy efficiency improvement measures. Urban planning in accordance with micro location conditions can lead to energy consumption reduction in buildings through the passive solar design. While satisfying the thermal comfort to the user space purpose, energy efficiency can be achieved by optimizing the architectural and construction parameters such as shape of the building, envelope structure and the percentage of glazing. The improvement of the proposed measures, including the use of renewable energy sources, can meet requirements of Directive 2010/31 / EU of 'nearly zero energy buildings'.

  8. Search for aligned structure of 12C-α-12C type at high excitation energy in 28Si

    International Nuclear Information System (INIS)

    Burnereau, Nicole.

    1975-01-01

    The 16 O+ 12 C→ 12 C+α+ 12 C reaction is studied mainly at 46MeV (at this energy a state of 28 Si is presumably formed with a spin value of 14 + ; resonance of 19.7MeV c.m.). The motivation is to detect an α particle with a negligible energy in the c.m. system. This is the signature of the preformation of three aligned clusters in which the average location of the α particle is in between the two 12 C's at the center of symmetry of the system. Such a detection is performed by detecting two 12 C's in coincidence at specific angles. The data are understood by three-body calculations with a coupling of relative angular momenta governed by an unique J value. Experimentally, an α energy of 200keV is measured with good statistics, supporting the idea of aligned clusters as 28 Si intrinsic shape, related to some highly excited states [fr

  9. Ab initio calculations of dissociative excitation of water and methane molecules upon electron impact at low energies

    International Nuclear Information System (INIS)

    Gil, T.J.; McCurdy, C.W.; Rescigno, T.N.; Lengsfield, B.H. III

    1994-01-01

    The authors are reporting results of ab-initio calculations of electron-impact excitation of water and methane occurring at scattering energies up to 60 eV. The authors consider dissociative excited states of both systems since the understanding of their chemistry has considerable importance in plasma technology and atmospheric research. In the case of methane the authors are dealing with the promotion of a valence electron into Rydberg orbitals, while in water the excited states have one electron in an antibonding unoccupied valence orbital and support Feshbach resonances. The authors discuss issues related to convergence of the close-coupling expansion in the case of Rydberg excitation, where the authors have coupled up to 16 channels. The practical realization of the calculation within the framework of the complex Kohn variational principle represents merging of quantum chemistry and quantum scattering theory and is also discussed

  10. Excitation energy partition in deeply inelastic collisions between 40Ar and Ag at 27 MeV per nucleon

    International Nuclear Information System (INIS)

    Borderie, B.; Rivet, M.F.; Cabot, C.; Fuchs, H.; Gardes, D.; Hanappe, F.; Jouan, D.; Montoya, M.

    1991-01-01

    The dynamics of the two partners produced in dissipative collisions has been experimentally studied for the system 40 Ar+Ag at 27 MeV per nucleon. Primary masses of the fragments can then be calculated; the excitation energy partition between the two fragments is derived from the number of particles evaporated by each fragment. We found that this division evolves from equipartition to a repartition close to thermal equilibrium in the excitation energy range 300-350 MeV or interaction times 5-10x10 -22 s. (orig.)

  11. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

    Science.gov (United States)

    Ferreira da Silva, F.; Lange, E.; Limão-Vieira, P.; Jones, N. C.; Hoffmann, S. V.; Hubin-Franskin, M.-J.; Delwiche, J.; Brunger, M. J.; Neves, R. F. C.; Lopes, M. C. A.; de Oliveira, E. M.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Blanco, F.; García, G.; Lima, M. A. P.; Jones, D. B.

    2015-10-01

    The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

  12. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

    International Nuclear Information System (INIS)

    Ferreira da Silva, F.; Lange, E.; Limão-Vieira, P.; Jones, N. C.; Hoffmann, S. V.; Hubin-Franskin, M.-J.; Delwiche, J.; Brunger, M. J.

    2015-01-01

    The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5–10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range

  13. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira da Silva, F.; Lange, E. [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Limão-Vieira, P., E-mail: plimaovieira@fct.unl.pt, E-mail: michael.brunger@flinders.edu.au, E-mail: maplima@ifi.unicamp.br [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Jones, N. C.; Hoffmann, S. V. [ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Århus C (Denmark); Hubin-Franskin, M.-J.; Delwiche, J. [Départment de Chimie, Institut de Chimie-Bât. B6C, Université de Liège, B-4000 Liège 1 (Belgium); Brunger, M. J., E-mail: plimaovieira@fct.unl.pt, E-mail: michael.brunger@flinders.edu.au, E-mail: maplima@ifi.unicamp.br [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); and others

    2015-10-14

    The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5–10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

  14. Operation of buildings: Energy supply and energy conservation measures

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, H

    1985-01-01

    Energy saving in public administration. A list-like collection of the measures to monitor the consumption, the measures of saving energy at existing buildings, new systems and by new techniques. Examples with figures for the savings achieved in the region of Marburg-Biedenkopf (Hesse). Guidelines are set up which are mainly based on energy saving, heat recovery, use of new technologies and renewable energy sources, fluidized-bed combustion also in smaller plants of ca. 2 MW, waste management separating wastes into burnable/unburnable, information of the public administration and the people and the setting up of energy concepts. (PJH).

  15. Principal component analysis acceleration of rovibrational coarse-grain models for internal energy excitation and dissociation

    Science.gov (United States)

    Bellemans, Aurélie; Parente, Alessandro; Magin, Thierry

    2018-04-01

    The present work introduces a novel approach for obtaining reduced chemistry representations of large kinetic mechanisms in strong non-equilibrium conditions. The need for accurate reduced-order models arises from compression of large ab initio quantum chemistry databases for their use in fluid codes. The method presented in this paper builds on existing physics-based strategies and proposes a new approach based on the combination of a simple coarse grain model with Principal Component Analysis (PCA). The internal energy levels of the chemical species are regrouped in distinct energy groups with a uniform lumping technique. Following the philosophy of machine learning, PCA is applied on the training data provided by the coarse grain model to find an optimally reduced representation of the full kinetic mechanism. Compared to recently published complex lumping strategies, no expert judgment is required before the application of PCA. In this work, we will demonstrate the benefits of the combined approach, stressing its simplicity, reliability, and accuracy. The technique is demonstrated by reducing the complex quantum N2(g+1Σ) -N(S4u ) database for studying molecular dissociation and excitation in strong non-equilibrium. Starting from detailed kinetics, an accurate reduced model is developed and used to study non-equilibrium properties of the N2(g+1Σ) -N(S4u ) system in shock relaxation simulations.

  16. Rate for energy transfer from excited cyclohexane to nitrous oxide in the liquid phase

    International Nuclear Information System (INIS)

    Wada, T.; Hatano, Y.

    1975-01-01

    Pure liquid cyclohexane and cyclohexane solutions of nitrous oxide have been photolyzed at 163 nm. The quantum yield of the product hydrogen in the photolysis of pure cyclohexane is found to be 1.0. The addition of nitrous oxide results in the reduction in the yield of hydrogen and in the formation of nitrogen. The decrement of the hydrogen yield is approximately equal to the increment of the nitrogen yield. About 40 percent of the hydrogen yield in pure cyclohexane is found to be produced through a path which is not affected by the addition of nitrous oxide. The effect of the addition of nitrous oxide is attributed to energy transfer from excited cyclohexane to nitrous oxide with the rate constant of k = 1.0 x 10 11 M -1 sec -1 (at 15 0 C). This value is about a factor of 10 larger than that expected as for diffusion-controlled rate. A contribution of the energy transfer process to the formation of nitrogen in the radiolysis of cyclohexane solutions of nitrous oxide has also been discussed. (auth)

  17. Power Management of Islanded Self-Excited Induction Generator Reinforced by Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Nachat N. Nasser

    2018-02-01

    Full Text Available Self-Excited Induction Generators (SEIGs, e.g., Small-Scale Embedded wind generation, are increasingly used in electricity distribution networks. The operational stability of stand-alone SEIG is constrained by the local load conditions: stability can be achieved by maintaining the load’s active and reactive power at optimal values. Changes in power demand are dependent on customers’ requirements, and any deviation from the pre-calculated optimum setting will affect a machine’s operating voltage and frequency. This paper presents an investigation of the operation of the SEIG in islanding mode of operation under different load conditions, with the aid of batteries as an energy storage source. In this research a current-controlled voltage-source converter is proposed to regulate the power exchange between a direct current (DC energy storage source and an alternating current (AC grid, the converter’s controller is driven by any variation between machine capability and load demand. In order to prolong the system stability when the battery reaches its operation constraints, it is recommended that an ancillary generator and a dummy local load be embedded in the system. The results show the robustness and operability of the proposed system in the islanding mode of the SEIG under different load conditions.

  18. General theory of excitation energy transfer in donor-mediator-acceptor systems.

    Science.gov (United States)

    Kimura, Akihiro

    2009-04-21

    General theory of the excitation energy transfer (EET) in the case of donor-mediator-acceptor system was constructed by using generalized master equation (GME). In this theory, we consider the direct and indirect transitions in the EET consistently. Hence, our theory includes the quantum mechanical interference between the direct and indirect transitions automatically. Memory functions in the GME were expressed by the overlap integrals among the time-dependent emission spectrum of the donor, the absorption spectrum of the mediator, the time-dependent emission spectrum of the mediator, and the absorption spectrum of the acceptor. In the Markov limit of the memory functions, we obtained the rate of EET which consists of three terms due to the direct transition, the indirect transition, and the interference between them. We found that the interference works effectively in the limit of slow thermalization at the intermediate state. The formula of EET rate in this limit was expressed by the convolution of the EET interaction and optical spectra. The interference effect strongly depends on the width of the absorption spectrum of mediator molecule and the energy gap between the donor and the mediator molecules.

  19. Effect of Solvation on Electron Detachment and Excitation Energies of a Green Fluorescent Protein Chromophore Variant.

    Science.gov (United States)

    Bose, Samik; Chakrabarty, Suman; Ghosh, Debashree

    2016-05-19

    Hybrid quantum mechanics/molecular mechanics (QM/MM) is applied to the fluorinated green fluorescent protein (GFP) chromophore (DFHBDI) in its deprotonated form to understand the solvatochromic shifts in its vertical detachment energy (VDE) and vertical excitation energy (VEE). This variant of the GFP chromophore becomes fluorescent in an RNA environment and has a wide range of applications in biomedical and biochemical fields. From microsolvation studies, we benchmark (with respect to full QM) the accuracy of our QM/MM calculations with effective fragment potential (EFP) as the MM method of choice. We show that while the solvatochromic shift in the VEE is minimal (0.1 eV blue shift) and its polarization component is only 0.03 eV, the effect of the solvent on the VDE is quite large (3.85 eV). We also show by accurate calculations on the solvatochromic shift of the VDE that polarization accounts for ∼0.23 eV and therefore cannot be neglected. The effect of the counterions on the VDE of the deprotonated chromophore in solvation is studied in detail, and a charge-smearing scheme is suggested for charged chromophores.

  20. A coherent modified Redfield theory for excitation energy transfer in molecular aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Hwang-Fu, Yu-Hsien; Chen, Wei; Cheng, Yuan-Chung, E-mail: yuanchung@ntu.edu.tw

    2015-02-02

    Highlights: • A CMRT method for coherent energy transfer in molecular aggregates was developed. • Applicability of the method was verified in two-site systems with various parameters. • CMRT accurately describes population dynamics in the FMO-complex. • The method is accurate in a large parameter space and computationally efficient. - Abstract: Excitation energy transfer (EET) is crucial in photosynthetic light harvesting, and quantum coherence has been recently proven to be a ubiquitous phenomenon in photosynthetic EET. In this work, we derive a coherent modified Redfield theory (CMRT) that generalizes the modified Redfield theory to treat coherence dynamics. We apply the CMRT method to simulate the EET in a dimer system and compare the results with those obtained from numerically exact path integral calculations. The comparison shows that CMRT provides excellent computational efficiency and accuracy within a large EET parameter space. Furthermore, we simulate the EET dynamics in the FMO complex at 77 K using CMRT. The results show pronounced non-Markovian effects and long-lasting coherences in the ultrafast EET, in excellent agreement with calculations using the hierarchy equation of motion approach. In summary, we have successfully developed a simple yet powerful framework for coherent EET dynamics in photosynthetic systems and organic materials.

  1. Labor and energy impacts of energy-conservation measures

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    Three papers are presented discussing the labor and energy impacts of energy-conservation measures, namely: Generation of the Industry/Occupation Wage Matrix and Related Matters, by Carole Green; Job Shifts from Energy Conservation (Salary Distribution Effects), by Robert A. Herendeen; and Energy and Labor Implication of Improving Thermal Integrity of New Houses, by John Joseph Nangle. A separate abstract was prepared for each paper.

  2. YIELDS OF IONS AND EXCITED STATES IN NONPOLAR LIQUIDS EXPOSED TO X-RAYS OF 1 TO 30 KEV ENERGY

    International Nuclear Information System (INIS)

    HOLROYD, R.A.

    1999-01-01

    When x-rays from a synchrotron source are absorbed in a liquid, the x-ray energy (E x ) is converted by the photoelectric effect into the kinetic energy of the electrons released. For hydrocarbons, absorption by the K-electrons of carbon dominates. Thus the energy of the photoelectron (E pe ) is E x -E b , where E b is the K-shell binding energy of carbon. Additional electrons with energy equal to E b is released in the Auger process that fills the hole in the K-shell. These energetic electrons will produce many ionizations, excitations and products. The consequences of the high density of ionizations and excitations along the track of the photoelectron and special effects near the K-edge are examined here

  3. Measurement of Exciton Binding Energy of Monolayer WS2

    Science.gov (United States)

    Chen, Xi; Zhu, Bairen; Cui, Xiaodong

    Excitonic effects are prominent in monolayer crystal of transition metal dichalcogenides (TMDCs) because of spatial confinement and reduced Coulomb screening. Here we use linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE) to measure the exciton binding energy of monolayer WS2. Peaks for excitonic absorptions of the direct gap located at K valley of the Brillouin zone and transitions from multiple points near Γ point of the Brillouin zone, as well as trion side band are shown in the linear absorption spectra of WS2. But there is no gap between distinct excitons and the continuum of the interband transitions. Strong electron-phonon scattering, overlap of excitons around Γ point and the transfer of the oscillator strength from interband continuum to exciton states make it difficult to resolve the electronic interband transition edge even down to 10K. The gap between excited states of the band-edge exciton and the single-particle band is probed by TP-PLE measurements. And the energy difference between 1s exciton and the single-particle gap gives the exciton binding energy of monolayer WS2 to be about 0.71eV. The work is supported by Area of excellency (AoE/P-04/08), CRF of Hong Kong Research Grant Council (HKU9/CRF/13G) and SRT on New Materials of The University of Hong Kong.

  4. Excitation functions of proton induced reactions on {sup nat}Fe in the energy region up to 45 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwangsoo [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Khandaker, Mayeen Uddin [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Naik, Haladhara [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Radiochemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2014-03-01

    The excitation functions of various reaction products such as {sup 55,56,57}Co, {sup 52}Fe, {sup 52,54}Mn, and {sup 51}Cr in the {sup nat}Fe(p, x) reactions were measured by the stacked-foil activation technique in the energy range between their respective reaction threshold and 45 MeV at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences, Korea. The present experimental data were compared with the existing literature data. It was found that excitation function of {sup 56,57}Co and {sup 51}Cr from the {sup nat}Fe(p, x) reaction are in agreement with the literature data. However, the cross-sections for {sup nat}Fe(p, x){sup 52}Fe reactions are lower and those for {sup nat}Fe(p, x){sup 52}Mn and {sup nat}Fe(p, x){sup 54}Mn reactions are higher than the literature data. The reaction cross-sections of the above mentioned reaction products were also compared with those from the TENDL-2012 library based on the TALYS-1.4 program as a function of proton energy, which was reproduced the trend of the excitation functions of the experimental {sup nat}Fe(p, x) reaction cross-section. The integral yields for thick target of the investigated radionuclides were calculated from the excitation function.

  5. Water level response measurement in a steel cylindrical liquid storage tank using image filter processing under seismic excitation

    Science.gov (United States)

    Kim, Sung-Wan; Choi, Hyoung-Suk; Park, Dong-Uk; Baek, Eun-Rim; Kim, Jae-Min

    2018-02-01

    Sloshing refers to the movement of fluid that occurs when the kinetic energy of various storage tanks containing fluid (e.g., excitation and vibration) is continuously applied to the fluid inside the tanks. As the movement induced by an external force gets closer to the resonance frequency of the fluid, the effect of sloshing increases, and this can lead to a serious problem with the structural stability of the system. Thus, it is important to accurately understand the physics of sloshing, and to effectively suppress and reduce the sloshing. Also, a method for the economical measurement of the water level response of a liquid storage tank is needed for the exact analysis of sloshing. In this study, a method using images was employed among the methods for measuring the water level response of a liquid storage tank, and the water level response was measured using an image filter processing algorithm for the reduction of the noise of the fluid induced by light, and for the sharpening of the structure installed at the liquid storage tank. A shaking table test was performed to verify the validity of the method of measuring the water level response of a liquid storage tank using images, and the result was analyzed and compared with the response measured using a water level gauge.

  6. Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction.

    Science.gov (United States)

    Sokolowski-Tinten, K; Shen, X; Zheng, Q; Chase, T; Coffee, R; Jerman, M; Li, R K; Ligges, M; Makasyuk, I; Mo, M; Reid, A H; Rethfeld, B; Vecchione, T; Weathersby, S P; Dürr, H A; Wang, X J

    2017-09-01

    We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

  7. Effects of Isospin on Pre-scission Particle Multiplicity of Heavy Systems and Its Excitation Energy Dependence

    Institute of Scientific and Technical Information of China (English)

    YE Wei; CHEN Na

    2004-01-01

    Isospin effects on particle emission of fissioning isobaric sources 202Fr, 202po, 202Tl and isotopic sources 189,202,212Po, and its dependence on the excitation energy are studied via Smoluchowski equations. It is shown that with increasing the isospin of fissioning systems, charged-particle emission is not sensitive to the strength of nuclear dissipation. In addition, we have found that increasing the excitation energy not only increases the influence of nuclear dissipation on particle emission but also greatly enhances the sensitivity of the emission of pre-scission neutrons or charged particles to the isospin of the system. Therefore, in order to extract dissipation strength more accurately by taking light particle multiplicities it is important to choose both a highly excited compound nucleus and a proper kind of particles for systems with different isospins.

  8. Gentlest ascent dynamics for calculating first excited state and exploring energy landscape of Kohn-Sham density functionals.

    Science.gov (United States)

    Li, Chen; Lu, Jianfeng; Yang, Weitao

    2015-12-14

    We develop the gentlest ascent dynamics for Kohn-Sham density functional theory to search for the index-1 saddle points on the energy landscape of the Kohn-Sham density functionals. These stationary solutions correspond to excited states in the ground state functionals. As shown by various examples, the first excited states of many chemical systems are given by these index-1 saddle points. Our novel approach provides an alternative, more robust way to obtain these excited states, compared with the widely used ΔSCF approach. The method can be easily generalized to target higher index saddle points. Our results also reveal the physical interest and relevance of studying the Kohn-Sham energy landscape.

  9. Measurement and analysis of the excitation function and isomeric cross section ratios for α-induced reaction on Ir, Au, Re and Ta nuclei

    International Nuclear Information System (INIS)

    Ismail, M.

    1998-01-01

    Excitation functions and a few isomeric cross section ratios for production of (1) 192 Au, 193 Au, 194 Au, 195 Au and 192 Ir nuclides in α-induced reactions on 191,193 Ir, (2) 197 Tl, 197m Hg, 198m.g Tl, 199 Tl and 200 Tl nuclides in α-induced reaction in 197 Au and (3) 183 Re and 184m.g Re nuclides in α-induced reaction in 181 Ta and 185 Re are obtained from the measurements of the residual activities by the conventional stacked-foils technique from threshold to 50 MeV. The excitation function and isomeric cross section ratios for nuclear reaction 181 Ta (α,n) 184m.g Re are compared with the theoretical calculation using the code Stapre which is based on exciton model for pre-equilibrium phase and Hauser-Feshbach formalism taking angular momentum and parity into account for the equilibrium phase of the nuclear reaction. All other experimental excitation functions are compared with the calculations considering equilibrium as well as pre-equilibrium reaction mechanism according to the geometry dependent hybrid (GDH) model and hybrid model of Blann using the code Alice/91. The high energy part of the excitation functions are dominated by pre-equilibrium reaction mechanism whereas the low energy parts are dominated by equilibrium evaporation with its characteristic peak. The GDH model provides a potentially better description of the physical process (i.e. a higher probability for peripheral collisions to undergo precompound decay than for central collisions) compared to hybrid model. However in the energy range of present measurement most of the excitation functions are fitted reasonably well by both GDH model and hybrid model with initial exciton number N 0 =4 (N n =2, N p =2, N h =0). Barring a few reactions we have found the overall agreement between theory and experiment is reasonably good taking the limitations of the theory into account. (author)

  10. X-ray yields by low energy heavy ion excitation in alkali halide solid targets

    International Nuclear Information System (INIS)

    Kurup, M.B.; Prasad, K.G.; Sharma, R.P.

    1981-01-01

    Solid targets of the alkali halides KCl, NaCl and KBr are bombarded with ion beams of 35 Cl + , 40 Ar + and 63 Cu + in the energy range 165 keV to 320 keV. The MO and characteristic K X-ray yields resulting from the ion-atom collision have been systematically studied. Both MO and Cl K X-ray yields are enhanced by factors 3.5 and 2 respectively in KCl targets as compared to that in NaCl when bombarded with either Cl + or Ar + projectiles. An intercomparison of MO and K X-ray yields for a given projectile-target combination has shown that the latter increases ten times faster than the former as the energy of the projectile is increased from 165 to 320 keV indicating a correspondingly stronger velocity dependence of the K X-ray production process. The X-ray yields observed in the symmetric Cl-Cl collision are identical to those observed in the asymmetric Ar-Cl collision for the same projectile velocities in both KCl and NaCl targets. It is inferred that the multiple ionization of the projectile resulting in an increase in the binding energy of its inner shells offsets the expected enhancement in the X-ray yields in a symmetric collision. The same projectiles, Ar or Cl, incident on KBr targets have produced only Br L X-rays. Using substantially heavier projectiles than the target atoms (Na, K and Cl), like 63 Cu + ions, the inner shell excitation by recoiling atoms is shown. (orig.)

  11. Theoretical Study of the Relationships between Excited State Geometry Changes and Emission Energies of Oxyluciferin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhong Wei; Min, Chun Gang; Ren, Ai Min; Feng, Ji Kang [Jilin University, Changchun (China); Guo, Jing Fu [Northeast Normal University, Jilin (China); Goddard, John D. [University of Guelph, Ontario (Canada); Zuo, Liang [North China Mineral and Geology Testing Center of CNNC, Tianjin (China)

    2010-04-15

    In order to find a relationship between firefly luciferases structure and bioluminescence spectra, we focus on excited substrate geometries which may be affected by rigid luciferases. Density functional theory (DFT) and time dependent DFT (TDDFT) were employed. Changes in only six bond lengths of the excited substrate are important in determining the emission spectra. Analysis of these bonds suggests the mechanism whereby luciferases restrict more or less the excited substrate geometries and to produce multicolor bioluminescence.

  12. Neutron energy measurement for practical applications

    Science.gov (United States)

    Roshan, M. V.; Sadeghi, H.; Ghasabian, M.; Mazandarani, A.

    2018-03-01

    Industrial demand for neutrons constrains careful energy measurements. Elastic scattering of monoenergetic α -particles from neutron collision enables neutron energy measurement by calculating the amount of deviation from the position where collision takes place. The neutron numbers with specific energy is obtained by counting the number of α -particles in the corresponding location on the charged particle detector. Monte Carlo simulation and COMSOL Multiphysics5.2 are used to account for one-to-one collision of neutrons with α -particles.

  13. Proposal of measuring the mechanisms of nuclear excitation leading to fission with the ADONE jet-target tagged photon beam

    International Nuclear Information System (INIS)

    Lucherini, V.; Bianchi, N.; De Sanctis, E.; Guaraldo, C.; Levi Sandri, P.; Muccifora, V.; Polli, E.; Reolon, A.R.; Aiello, S.; De Filippo, E.; Lanzano', G.; Lo Nigro, S.; Milone, C.; Pagano, A.; Botvina, A.S.; Iljinov, A.S.; Mebel, M.V.

    1990-01-01

    The mechanisms of excitation with subsequent fission of heavy nuclei can be conveniently studied by means of photons, since this probe is able to interact deeply inside the nucleus. We propose the use of the (200-1200 MeV) tagged photon beam from the ADONE Jet Target in order to study the mass-energy and total momentum distributions of fission fragments, to obtain experimental information on the configurations (excitation energy and nucleonic composition) of produced compound nuclei and on their decay channels

  14. Reduced-cost second-order algebraic-diagrammatic construction method for excitation energies and transition moments

    Science.gov (United States)

    Mester, Dávid; Nagy, Péter R.; Kállay, Mihály

    2018-03-01

    A reduced-cost implementation of the second-order algebraic-diagrammatic construction [ADC(2)] method is presented. We introduce approximations by restricting virtual natural orbitals and natural auxiliary functions, which results, on average, in more than an order of magnitude speedup compared to conventional, density-fitting ADC(2) algorithms. The present scheme is the successor of our previous approach [D. Mester, P. R. Nagy, and M. Kállay, J. Chem. Phys. 146, 194102 (2017)], which has been successfully applied to obtain singlet excitation energies with the linear-response second-order coupled-cluster singles and doubles model. Here we report further methodological improvements and the extension of the method to compute singlet and triplet ADC(2) excitation energies and transition moments. The various approximations are carefully benchmarked, and conservative truncation thresholds are selected which guarantee errors much smaller than the intrinsic error of the ADC(2) method. Using the canonical values as reference, we find that the mean absolute error for both singlet and triplet ADC(2) excitation energies is 0.02 eV, while that for oscillator strengths is 0.001 a.u. The rigorous cutoff parameters together with the significantly reduced operation count and storage requirements allow us to obtain accurate ADC(2) excitation energies and transition properties using triple-ζ basis sets for systems of up to one hundred atoms.

  15. Low energy excitations in superconducting La1.86Sr0.14CuO4

    DEFF Research Database (Denmark)

    Mason, T.E.; Aeppli, G.; Hayden, S.M.

    1993-01-01

    We present magnetic neutron scattering and specific heat data on the high-T(c) superconductor La1.86Sr0.14CuO4. Even when the samples are superconducting and the magnetic response, chi'', is suppressed, there are excitations with energies well below 3.5k(B)T(c). The wave-vector dependence of chi...

  16. Voiced Excitations

    National Research Council Canada - National Science Library

    Holzricher, John

    2004-01-01

    To more easily obtain a voiced excitation function for speech characterization, measurements of skin motion, tracheal tube, and vocal fold, motions were made and compared to EM sensor-glottal derived...

  17. Molecular Excitation Energies from Time-Dependent Density Functional Theory Employing Random-Phase Approximation Hessians with Exact Exchange.

    Science.gov (United States)

    Heßelmann, Andreas

    2015-04-14

    Molecular excitation energies have been calculated with time-dependent density-functional theory (TDDFT) using random-phase approximation Hessians augmented with exact exchange contributions in various orders. It has been observed that this approach yields fairly accurate local valence excitations if combined with accurate asymptotically corrected exchange-correlation potentials used in the ground-state Kohn-Sham calculations. The inclusion of long-range particle-particle with hole-hole interactions in the kernel leads to errors of 0.14 eV only for the lowest excitations of a selection of three alkene, three carbonyl, and five azabenzene molecules, thus surpassing the accuracy of a number of common TDDFT and even some wave function correlation methods. In the case of long-range charge-transfer excitations, the method typically underestimates accurate reference excitation energies by 8% on average, which is better than with standard hybrid-GGA functionals but worse compared to range-separated functional approximations.

  18. Measurement of resonance parameters of orbitally excited narrow B0 mesons.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; González, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Rekovic, V; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-03-13

    We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width.

  19. Energies of the ground state and first excited 0 sup + state in an exactly solvable pairing model

    CERN Document Server

    Dinh Dang, N

    2003-01-01

    Several approximations are tested by calculating the ground-state energy and the energy of the first excited 0 sup + state using an exactly solvable model with two symmetric levels interacting via a pairing force. They are the BCS approximation (BCS), Lipkin-Nogami (LN) method, random-phase approximation (RPA), quasiparticle RPA (QRPA), the renormalized RPA (RRPA), and renormalized QRPA (RQRPA). It is shown that, in the strong-coupling regime, the QRPA which neglects the scattering term of the model Hamiltonian offers the best fit to the exact solutions. A recipe is proposed using the RRPA and RQRPA in combination with the pairing gap given by the LN method. Applying this recipe, it is shown that the superfluid-normal phase transition is avoided, and a reasonably good description for both of the ground-state energy and the energy of the first excited 0 sup + state is achieved. (orig.)

  20. Electron energy measurements in pulsating auroras

    International Nuclear Information System (INIS)

    McEwan, D.J.; Yee, E.; Whalen, B.A.; Yau, A.W.

    1981-01-01

    Electron spectra were obtained during two rocket flights into pulsating aurora from Southend, Saskatchewan. The first rocket launched at 1143:24 UT on February 15, 1980 flew into an aurora of background intensity 275 R of N 2 + 4278 A and showing regular pulsations with about a 17 s period. Electron spectra of Maxwellian energy distributions were observed with an average E 0 = 1.5 keV, rising to 1.8 keV during the pulsations. There was one-to-one correspondence between the electron energy modulation and the observed optical pulsations. The second rocket, launched at 1009:10 UT on February 23, flew into a diffuse auroral surface of intensity 800 R of N 2 + 4278 A and with somewhat irregular pulsations. The electron spectra were again of Maxwellian energy distribution with an average E 0 = 1.8 keV increasing to 2.1 keV during the pulsations. The results from these flights suggest that pulsating auroras occurring in the morning sector may be quite commonly excited by low energy electrons. The optical pulsations are due to periodic increases in the energy of the electrons with the source of modulation in the vicintiy of the geomagnetic equatorial plane. (auth)

  1. The surrogate-reaction method and excitation-energy sorting in nuclear fission

    International Nuclear Information System (INIS)

    Jurado, Beatriz

    2015-01-01

    This manuscript summarises the main activities that I have carried out during the last ten years of research at the Centre d'etudes Nucleaires de Bordeaux-Gradignan (CENBG). It is, to a great extent, a synthesis of nine articles. They can be consulted by the reader that would like to have more detailed information. These articles are denoted as Article I, II.. all along the manuscript. The manuscript is intended to be accessible to PhD students not familiar with the topic. Chapter 1 recalls some of the basic ideas of statistical mechanics and discusses the applicability of its concepts to nuclei. Some of these concepts, in particular the concept of statistical equilibrium, are essential for the topics covered by chapters 2 and 3. Chapter 2 summarises the studies performed by the CENBG collaboration on the surrogate-reaction method in the last ten years. Chapter 3 summarises part of the work done on the modelling of nuclear fission in collaboration with Karl-Heinz Schmidt, it considers the partition of excitation energy and unpaired nucleons in fission on the basis of statistical mechanics. Chapters 2 and 3 contain the bulk of my work, each of them has its own introduction and conclusion sections. Chapter 4 presents the medium and long-term experimental perspectives for the topics described in chapters 2 and 3. (author)

  2. Nonlinear optical measurements of conducting copolymers of aniline under CW laser excitation

    Science.gov (United States)

    Pramodini, S.; Poornesh, P.

    2015-08-01

    Synthesis and measurements of third-order optical nonlinearity and optical limiting of conducting copolymers of aniline are presented. Single beam z-scan technique was employed for the nonlinear optical studies. Continuous wave He-Ne laser operating at 633 nm was used as the source of excitation. Copolymer samples exhibited reverse saturable absorption (RSA) process. The nonlinear refraction studies depict that the copolymers exhibit self-defocusing property. The estimated values of βeff, n2 and χ(3) were found to be of the order of 10-2 cm/W, 10-5 esu and 10-7 esu respectively. Self-diffraction rings were observed due to refractive index change when exposed to the laser beam. A good optical limiting and clamping of power of ∼0.9 mW and ∼0.05 mW was observed. Therefore, copolymers of aniline emerge as a potential candidate for photonic device applications.

  3. Effective Kα x-ray excitation rates for plasma impurity measurements

    International Nuclear Information System (INIS)

    Hill, K.W.; Bitter, M.; von Goeler, S.; Hiroe, S.; Hulse, R.; Ramsey, A.T.; Sesnic, S.; Shimada, M.; Stratton, B.C.

    1986-06-01

    Metal impurity concentrations are measured by the Pulse-Height-Analyzer (PHA) diagnostic from Kα x-ray peak intensities by use of an averaged excitation rate . Low-Z impurity concentrations are inferred from the continuum enhancement (relative to a pure plasma) minus the enhancement due to metals. Since the PHA does not resolve lines from different charge states, is a weighted sum of rates; coronal equilibrium is usually assumed. The used earlier omitted the intercombination and forbidden lines from the dominant helium-like state. The result was an overestimate of metals and an underestimate of low-Z impurities in cases where metals were significant. Improved values of using recent calculations for H-, He-, and Li-like Fe range from 10 to 50% larger than the earlier rates and yield metal concentrations in better agreement with those from VUV spectroscopy

  4. Measurements of the power spectrum and dispersion relation of self-excited dust acoustic waves

    Science.gov (United States)

    Nosenko, V.; Zhdanov, S. K.; Kim, S.-H.; Heinrich, J.; Merlino, R. L.; Morfill, G. E.

    2009-12-01

    The spectrum of spontaneously excited dust acoustic waves was measured. The waves were observed with high temporal resolution using a fast video camera operating at 1000 frames per second. The experimental system was a suspension of micron-size kaolin particles in the anode region of a dc discharge in argon. Wave activity was found at frequencies as high as 450 Hz. At high wave numbers, the wave dispersion relation was acoustic-like (frequency proportional to wave number). At low wave numbers, the wave frequency did not tend to zero, but reached a cutoff frequency instead. The cutoff value declined with distance from the anode. We ascribe the observed cutoff to the particle confinement in this region.

  5. Experimental measurement of energy harvesting with backpack

    Science.gov (United States)

    Pavelkova, Radka; Vala, David; Suranek, Pavel; Mahdal, Miroslav

    2017-08-01

    This article deals with the energy harvesting systems, especially the energy harvesting backpack, which appears as a convenient means for energy harvesting for mobile sensors power. Before starting the experiment, it was necessary to verify whether this energy will be sufficient to get acquainted with the human kinematics and analyze problematics itself. For this purpose there was used motion capture technology from Xsens. Measured data on the position of a particle moving man and back when walking, these data were then used for experimental realization of energy harvesting backpack and as input data to the simulation in Simulink, which brought us a comparison between theoretical assumptions and practical implementation. When measuring characteristics of energy harvesting system we have a problem with measurements on backpack solved when redoing of the hydraulic cylinder as a source of a suitable movement corresponding to the amplitude and frequency of human walk.

  6. Excitation of short wavelength Alfven oscillations by high energy ions in tokamak

    International Nuclear Information System (INIS)

    Beasley, C.O. Jr.; Lominadze, J.G.; Mikhailovskii, A.B.

    1975-08-01

    The excitation of Alfven waves by fast untrapped ions in axisymmetric tokamaks is described by the dispersion relation epsilon 11 - c 2 k/sub parallel bars/ 2 /ω 2 = 0. Using this relation a new class of instability connected with the excitation of Alfven oscillations is described. (U.S.)

  7. Tensor numerical methods in quantum chemistry: from Hartree-Fock to excitation energies.

    Science.gov (United States)

    Khoromskaia, Venera; Khoromskij, Boris N

    2015-12-21

    We resume the recent successes of the grid-based tensor numerical methods and discuss their prospects in real-space electronic structure calculations. These methods, based on the low-rank representation of the multidimensional functions and integral operators, first appeared as an accurate tensor calculus for the 3D Hartree potential using 1D complexity operations, and have evolved to entirely grid-based tensor-structured 3D Hartree-Fock eigenvalue solver. It benefits from tensor calculation of the core Hamiltonian and two-electron integrals (TEI) in O(n log n) complexity using the rank-structured approximation of basis functions, electron densities and convolution integral operators all represented on 3D n × n × n Cartesian grids. The algorithm for calculating TEI tensor in a form of the Cholesky decomposition is based on multiple factorizations using algebraic 1D "density fitting" scheme, which yield an almost irreducible number of product basis functions involved in the 3D convolution integrals, depending on a threshold ε > 0. The basis functions are not restricted to separable Gaussians, since the analytical integration is substituted by high-precision tensor-structured numerical quadratures. The tensor approaches to post-Hartree-Fock calculations for the MP2 energy correction and for the Bethe-Salpeter excitation energies, based on using low-rank factorizations and the reduced basis method, were recently introduced. Another direction is towards the tensor-based Hartree-Fock numerical scheme for finite lattices, where one of the numerical challenges is the summation of electrostatic potentials of a large number of nuclei. The 3D grid-based tensor method for calculation of a potential sum on a L × L × L lattice manifests the linear in L computational work, O(L), instead of the usual O(L(3) log L) scaling by the Ewald-type approaches.

  8. Accurate measurement of the first excited nuclear state in 235U

    Science.gov (United States)

    Ponce, F.; Swanberg, E.; Burke, J.; Henderson, R.; Friedrich, S.

    2018-05-01

    We have used superconducting high-resolution radiation detectors to measure the energy level of metastable Um235 as 76.737 ± 0.018 eV. The Um235 isomer is created from the α decay of 239Pu and embedded directly into the detector. When the Um235 subsequently decays, the energy is fully contained within the detector and is independent of the decay mode or the chemical state of the uranium. The detector is calibrated using an energy comb from a pulsed UV laser. A comparable measurement of the metastable Thm229 nucleus would enable a laser search for the exact transition energy in 229Th-Thm229 as a step towards developing the first ever nuclear (baryonic) clock.

  9. Energy and energy width measurement in the FNAL antiproton accumulator

    International Nuclear Information System (INIS)

    Church, M.; Hsueh, S.; Rapidis, P.; Werkema, S.

    1991-10-01

    The Fermilab Antiproton Accumulator has recently been used to produce Charmonium resonances (charm quark, anti-charm quark bound states) in proton-antiproton annihilations using an internal H 2 gas jet target. A measurement of the resonance mass and width may be obtained from a precise knowledge of the antiproton beam energy and energy spread. The beam energy is measured to an accuracy of 1 part in 10 4 in the range 6.3 Gev to 4.1 Gev by measuring the orbit length and revolution frequency of the beam. The beam momentum spread is measured to an accuracy of 10% by measuring the beam frequency spread and the parameter η = (P beam /F rev )·(dF rev /dP beam ). These two measurement techniques are described in this report

  10. Energy and energy width measurement in the FNAL antiproton accumulator

    Energy Technology Data Exchange (ETDEWEB)

    Church, M.; Hsueh, S.; Rapidis, P.; Werkema, S.

    1991-10-01

    The Fermilab Antiproton Accumulator has recently been used to produce Charmonium resonances (charm quark, anti-charm quark bound states) in proton-antiproton annihilations using an internal H{sub 2} gas jet target. A measurement of the resonance mass and width may be obtained from a precise knowledge of the antiproton beam energy and energy spread. The beam energy is measured to an accuracy of 1 part in 10{sup 4} in the range 6.3 Gev to 4.1 Gev by measuring the orbit length and revolution frequency of the beam. The beam momentum spread is measured to an accuracy of 10% by measuring the beam frequency spread and the parameter {eta} = (P{sub beam}/F{sub rev}){center_dot}(dF{sub rev}/dP{sub beam}). These two measurement techniques are described in this report.

  11. Energy relaxation in IR laser excited Hg1-xCdxTe

    International Nuclear Information System (INIS)

    Storebo, A K; Brudevoll, T; Olsen, O; Norum, O C; Breivik, M

    2009-01-01

    IR laser excitation of Hg l-x Cd x Te by low-fluence femtosecond and high fluence microsecond pulses was explored for the technologically important alloy fractions x ∼ 0.2 and x ∼ 0.28. We have used first principles (LAPW) electronic structure calculations and finite element modelling, supported by Monte Carlo simulation for the description of femtosecond pulse carrier relaxation and the transport parameters. Laser wavelengths considered were 6.4 - 10.6 μm for x ∼ 0.2 and 3.8 - 4.8 μm for x ∼ 0.28, with an incident 1 microsecond pulse fluence of 2 J/cm 2 . Many energy transfer mechanisms are invoked due to the long timescales of the microsecond pulses, and a main challenge is therefore to elucidate how these interplay in situations away from thermal equilibrium. Mechanisms studied include one- and two-photon absorption (OPA and TPA) across the band gap, inter-valence band absorption (IVA) between light- and heavy hole bands, electron-hole recombination/impact ionization, band gap renormalisation, intra-band free carrier absorption (FCA), excess carrier temperatures, non-equilibrium phonon generation, and refractive index changes. In the high fluence case, lattice temperatures evolve considerably during the laser pulse in response to the heated carriers. The chosen photon energies lie just above the band gap at the starting lattice temperature of 77 K, and nonlinear effects therefore dominate as the material heats up and the band gap begins to exceed the photon energy. Because of the low photon energy we must rely on Auger recombination, inter-valence band absorption and free carrier absorption to heat the carrier plasma. Although some Hg l-x Cd x Te material parameters are now relatively well known, existing data for many of the processes are inadequate for cases far away from thermal equilibrium. Furthermore, the role of Auger recombination in relation to non-intrinsic recombination has been a matter of debate lately. In this respect, information from

  12. Three methods to measure RH bond energies

    International Nuclear Information System (INIS)

    Berkowitz, J.; Ellison, G.B.; Gutman, D.

    1993-01-01

    In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies

  13. Light and energy - daylight measurements

    Energy Technology Data Exchange (ETDEWEB)

    Christoffersen, Jens; Logadottir, A.; Traberg-Borup, S.; Barrie-Nielsen, K.

    2009-07-01

    All measurements where conducted in the spring of 2007, except the Interpane panel. The solar cell panels have been evaluated by three performance indicators to assess the daylight quantity within the room and the systems ability to maintain view to the outside. In the study, we used two performance indicators to assess the daylight quantity within the room: 1. the daylight factor (overcast sky) 2. the relative work plane illuminance (clear sky condition) Overcast sky: In general, all panels provided less daylight than the recommended requirement in the Danish Building Regulation of 2% on the work plane. This will most likely result in additional need for electric lighting. However, larger window areas and more parts of the facade with clear unobstructed glass may be one solution. Clear sky: In general, all panels provided less interior light levels than the two reference systems in the back of the room. Almost all systems aloud more or less direct sunlight in the window perimeter through the clear openings and additional needs for some kind of shading device is to be expected. Some systems blocked a large portion of the light in the majority of the room, and additional electric light in this part of the room may be needed. Only one performance indicator where used to describe the quality of the panels. View: In general, all panels, except two, obstruct the view significantly and cause figure/background confusion for a view position close to the window and the discrepancies of colour judgements. Only two systems provided a fairly clear view to the outside without to much distortion of the view. (au)

  14. On mechanism of Ar(3p54p) states excitation in low-energy Ar-Ar collisions

    International Nuclear Information System (INIS)

    Kurskov, S Y; Kashuba, A S

    2009-01-01

    The present work is devoted to study of Ar(3p 5 4p) states excitation in binary low-energy Ar-Ar collisions. The results of the experimental investigation of excitation cross sections of Ar I 4p'[l/2] 1 , 4p'[3/2] 1 , 4p'[3/2] 2 and 4p[3/2] 2 levels in the collision energy range from threshold up to 500 eV (cm) and degree of polarization for 4s[3/2] 2 0 -4p'[l/2] 1 and 4s[3/2] 2 0 -4p[3/2] 2 transitions in this energy range are represented.

  15. Procedure to Measure Indoor Lighting Energy Performance

    Energy Technology Data Exchange (ETDEWEB)

    Deru, M.; Blair, N.; Torcellini, P.

    2005-10-01

    This document provides standard definitions of performance metrics and methods to determine them for the energy performance of building interior lighting systems. It can be used for existing buildings and for proposed buildings. The primary users for whom these documents are intended are building energy analysts and technicians who design, install, and operate data acquisition systems, and who analyze and report building energy performance data. Typical results from the use of this procedure are the monthly and annual energy used for lighting, energy savings from occupancy or daylighting controls, and the percent of the total building energy use that is used by the lighting system. The document is not specifically intended for retrofit applications. However, it does complement Measurement and Verification protocols that do not provide detailed performance metrics or measurement procedures.

  16. Molecular approaches to solar energy conversion: the energetic cost of charge separation from molecular-excited states.

    Science.gov (United States)

    Durrant, James R

    2013-08-13

    This review starts with a brief overview of the technological potential of molecular-based solar cell technologies. It then goes on to focus on the core scientific challenge associated with using molecular light-absorbing materials for solar energy conversion, namely the separation of short-lived, molecular-excited states into sufficiently long-lived, energetic, separated charges capable of generating an external photocurrent. Comparisons are made between different molecular-based solar cell technologies, with particular focus on the function of dye-sensitized photoelectrochemical solar cells as well as parallels with the function of photosynthetic reaction centres. The core theme of this review is that generating charge carriers with sufficient lifetime and a high quantum yield from molecular-excited states comes at a significant energetic cost-such that the energy stored in these charge-separated states is typically substantially less than the energy of the initially generated excited state. The role of this energetic loss in limiting the efficiency of solar energy conversion by such devices is emphasized, and strategies to minimize this energy loss are compared and contrasted.

  17. Excitation function of ''7''4Ge(n, α)''7''1''mZn reaction in the energy range 13.82-14.70 MeV

    International Nuclear Information System (INIS)

    Halim, M.A.; Hafiz, M.A.; Naher, K.; Miah, R.U.; Ullah, M.R.

    2003-01-01

    The excitation function of the reaction ''7''4Ge(n, α)''7''1''mZn is measured by activation technique using high resolution HPGe detector gamma ray spectroscopy. Monoenergetic neutrons are produced via D-T reaction at J-25 neutron generator facility of the Institute of Nuclear Science and Technology, AERE, Bangladesh. The neutron flux measurement was done at different energy position in the range 13.82-14.70 MeV using the monitor reaction ''2''7Al(n, α)''2''4Na. The measured cross section values along with the literature data are plotted as a function of neutron energy to get the excitation function of the reaction. A theoretical calculation is also performed to produce the excitation function of the investigated reaction using statistical code SINCROS-II. The measured data are to be found to be in good agreement with the literature data and the theoretical cross section values. (author)

  18. Measuring and evaluating the soft energy efficiency measures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suvilehto, H.-M.; Solid, D. [AaF-Industry Ltd, Solna (Sweden); Rouhiainen, V. [Adato Energia Ltd, Helsinki (Finland); Honkasalo, N.; Sarvaranta, A. [AaF-Consult Ltd, Solna (Sweden)

    2012-07-15

    This study discusses how to quantify the energy savings related to the companies' aims to enhance their customers' energy efficiency which is one target in the Action Plan for Energy Services in the Energy Efficiency Agreement for the Industries. In Finland, a majority of the energy utilities have signed this action plan and are providing their customers services to improve their energy efficiency. Dissemination of information is the most widely used service to the customers and it is provided in a number of ways including printed material, annual energy report, and an internet tool to access and report hourly measurements. Some of the internet tools cover electricity, district heat and water. The focus of the study is in the evaluation of 'soft' measures; in other words, those measures given by energy utilities that principally rely on communication instruments. However, monitoring the impact of information and communication is far from easy. Carrying out a properly designed evaluation of programmes aiming on enhanced energy efficiency is difficult. Evaluation of the impact of a magazine article on energy efficiency is even more challenging, costly and therefore also rare. Distribution of information as measure to enhance energy efficiency is an important part of EU.s energy policy but what are the ways and even more so, are there ways to actually quantify these savings? There has been excessive work by the member states and research institutes to find a common and robust methodology within the EU to evaluate and quantify energy savings from technical measures. The ex-ante and ex-post results from these evaluations can however differ considerably, e.g. the expected energy savings from installing air to air heat pumps in Denmark did not deliver the expected energy savings. The problems with finding a common robust methodology become even more visible when the 'soft' measures are put under the evaluation loop. The &apos

  19. How Parallel Are Excited State Potential Energy Surfaces from Time-Independent and Time-Dependent DFT? A BODIPY Dye Case Study.

    Science.gov (United States)

    Komoto, Keenan T; Kowalczyk, Tim

    2016-10-06

    To support the development and characterization of chromophores with targeted photophysical properties, excited-state electronic structure calculations should rapidly and accurately predict how derivatization of a chromophore will affect its excitation and emission energies. This paper examines whether a time-independent excited-state density functional theory (DFT) approach meets this need through a case study of BODIPY chromophore photophysics. A restricted open-shell Kohn-Sham (ROKS) treatment of the S 1 excited state of BODIPY dyes is contrasted with linear-response time-dependent density functional theory (TDDFT). Vertical excitation energies predicted by the two approaches are remarkably different due to overestimation by TDDFT and underestimation by ROKS relative to experiment. Overall, ROKS with a standard hybrid functional provides the more accurate description of the S 1 excited state of BODIPY dyes, but excitation energies computed by the two methods are strongly correlated. The two approaches also make similar predictions of shifts in the excitation energy upon functionalization of the chromophore. TDDFT and ROKS models of the S 1 potential energy surface are then examined in detail for a representative BODIPY dye through molecular dynamics sampling on both model surfaces. We identify the most significant differences in the sampled surfaces and analyze these differences along selected normal modes. Differences between ROKS and TDDFT descriptions of the S 1 potential energy surface for this BODIPY derivative highlight the continuing need for validation of widely used approximations in excited state DFT through experimental benchmarking and comparison to ab initio reference data.

  20. Low-energy vibrational excitations in carbon nanotubes studied by heat capacity

    Science.gov (United States)

    Lasjaunias, J. C.; Biljakovic, K.; Monceau, P.; Sauvajol, J. L.

    2003-09-01

    We present low-temperature heat capacity measurements performed on two different kinds of single-walled carbon nanotube bundles which essentially differ in their mean number of tubes (NT) per bundle. For temperatures below a few kelvin, the vibrational heat capacity can be analysed as the sum of two contributions. The first one is a regular T3 phononic one, characteristic of the three-dimensional (3D) elastic character of the bundle for long-wavelength phonons. A crossover to a lower effective dimensionality appears at a few kelvin. From the 3D contribution, we estimate a mean sound velocity, and hence a mean shear modulus of the bundle. The difference in amplitude of the acoustic term and in the crossover temperature between the two samples is ascribed to the different bundle topology (i.e. NT). The second contribution, of similar amplitude in both kinds of samples, shows a peculiar power law Talpha variation (alpha < 1) indicative of localized excitations, very probably due to intrinsic structural defects of the nanotubes.

  1. A pair natural orbital based implementation of CCSD excitation energies within the framework of linear response theory

    Science.gov (United States)

    Frank, Marius S.; Hättig, Christof

    2018-04-01

    We present a pair natural orbital (PNO)-based implementation of coupled cluster singles and doubles (CCSD) excitation energies that builds upon the previously proposed state-specific PNO approach to the excited state eigenvalue problem. We construct the excited state PNOs for each state separately in a truncated orbital specific virtual basis and use a local density-fitting approximation to achieve an at most quadratic scaling of the computational costs for the PNO construction. The earlier reported excited state PNO construction is generalized such that a smooth convergence of the results for charge transfer states is ensured for general coupled cluster methods. We investigate the accuracy of our implementation by applying it to a large and diverse test set comprising 153 singlet excitations in organic molecules. Already moderate PNO thresholds yield mean absolute errors below 0.01 eV. The performance of the implementation is investigated through the calculations on alkene chains and reveals an at most cubic cost-scaling for the CCSD iterations with the system size.

  2. Neutron energy measurement for practical applications

    Indian Academy of Sciences (India)

    M V Roshan

    2018-02-07

    . Elastic scattering of monoenergetic α-particles from neutron collision enables neutron energy measurement by calculating the amount of deviation from the position where collision takes place. The neutron numbers with ...

  3. Priorities for energy efficiency measures in agriculture

    NARCIS (Netherlands)

    Visser, de C.L.M.

    2013-01-01

    This report provides research gaps and priorities for energy efficiency measures in agriculture across Europe, based on the analysis of the Coordination and Support Action AGREE (Agriculture & Energy Efficiency) funded by the 7th research framework of the EU (www.agree.aua.gr). The analysis from

  4. Neutron energy response measurement of scintillation detectors

    International Nuclear Information System (INIS)

    Yang Hongqiong; Peng Taiping; Yang Jianlun; Tang Zhengyuan; Yang Gaozhao; Li Linbo; Hu Mengchun; Wang Zhentong; Zhang Jianhua; Li Zhongbao; Wang Lizong

    2004-01-01

    Neutron sensitivities of detectors composed of plastic scintillator ST401, ST1422, ST1423 and phyotomultiplier tube in primary energy range of fission neutron are calibrated by direct current. The energy response curve of the detectors is obtained in this experiment. The experimental result has been compared with the theoretical calculation and they are in agreement within measuring uncertainty. (authors)

  5. Automatic energy expenditure measurement for health science

    NARCIS (Netherlands)

    Catal, Cagatay; Akbulut, Akhan

    2018-01-01

    Background and objective: It is crucial to predict the human energy expenditure in any sports activity and health science application accurately to investigate the impact of the activity. However, measurement of the real energy expenditure is not a trivial task and involves complex steps. The

  6. Dynamic properties of energy affordability measures

    International Nuclear Information System (INIS)

    Heindl, Peter; Schuessler, Rudolf

    2015-01-01

    Measures of affordability and of fuel poverty are applied in practice to assess the affordability of energy services, for example, or of water or housing. The extensive body of literature on affordability measures has little overlap with the existing literature on poverty measurement. A comprehensive assessment of the response of affordability measures as a result of changes in the distribution of income or expenditure (the dynamic properties) is missing. This paper aims to fill this gap by providing a conceptual discussion on the ‘dynamics’ of both energy affordability measures and fuel poverty measures. Several types of measures are examined in a microsimulation framework. Our results indicate that some measures exhibit odd dynamic behavior. This includes measures used in practice, such as the low income/high cost measure and the double median of expenditure share indicator. Odd dynamic behavior causes the risk of drawing false policy recommendations from the measures. Thus, an appropriate response of affordability measures to changes in relevant variables is a prerequisite for defining meaningful measures that inform about affordability or deprivation in certain domains of consumption. - Highlights: • We investigate changes in fuel poverty measures as result from changes in income and expenditure. • More generally, we investigate dynamic behavior of affordability measures using microsimulation. • We propose axioms regarding dynamic behavior of affordability measures. • Some measures which are used in practice show unintuitive dynamic behavior. • Inappropriate dynamic behavior causes a risk of false policy implications.

  7. Compton scattering artifacts in electron excited X-ray spectra measured with a silicon drift detector.

    Science.gov (United States)

    Ritchie, Nicholas W M; Newbury, Dale E; Lindstrom, Abigail P

    2011-12-01

    Artifacts are the nemesis of trace element analysis in electron-excited energy dispersive X-ray spectrometry. Peaks that result from nonideal behavior in the detector or sample can fool even an experienced microanalyst into believing that they have trace amounts of an element that is not present. Many artifacts, such as the Si escape peak, absorption edges, and coincidence peaks, can be traced to the detector. Others, such as secondary fluorescence peaks and scatter peaks, can be traced to the sample. We have identified a new sample-dependent artifact that we attribute to Compton scattering of energetic X-rays generated in a small feature and subsequently scattered from a low atomic number matrix. It seems likely that this artifact has not previously been reported because it only occurs under specific conditions and represents a relatively small signal. However, with the advent of silicon drift detectors and their utility for trace element analysis, we anticipate that more people will observe it and possibly misidentify it. Though small, the artifact is not inconsequential. Under some conditions, it is possible to mistakenly identify the Compton scatter artifact as approximately 1% of an element that is not present.

  8. Lifetime measurement of the cesium 6P3/2 state using ultrafast laser-pulse excitation and ionization

    International Nuclear Information System (INIS)

    Sell, J. F.; Patterson, B. M.; Ehrenreich, T.; Brooke, G.; Scoville, J.; Knize, R. J.

    2011-01-01

    We report a precision measurement of the cesium 6P 3/2 excited-state lifetime. Two collimated, counterpropagating thermal Cs beams cross perpendicularly to femtosecond pulsed laser beams. High timing accuracy is achieved from having excitation and ionization laser pulses which originate from the same mode-locked laser. Using pulse selection we vary the separation in time between excitation and ionization laser pulses while counting the ions produced. We obtain a Cs 6P 3/2 lifetime of 30.460(38) ns, which is a factor of two improvement from previous measurements and with an uncertainty of 0.12%, is one of the most accurate lifetime measurements on record.

  9. Excitation functions and yields of proton induced reactions at intermediate energies leading to important diagnostics radioisotopes of 52Fe, 77Br, 82Rb, 97Ru, 111In, 123I, 127Xe, 128Cs, 178Ta and 201Tl

    International Nuclear Information System (INIS)

    Rurarz, E.

    1994-01-01

    This report describes investigations of the excitation functions of the proton induced reactions on 14 targets (Mn, Co, Br, Rb, 99 Tc, 113 Cd, 114 Cd, Cd, I, Cs, Ta, 206,207,208 Pb) leading directly or indirectly to the formation of radionuclides 52 Fe, 77 Br, 82 Rb, 97 Ru, 111 In, 123 I, 127 Xe, 128 Cs, 178 Ta and 201 Tl frequently used in diagnostic procedures of nuclear medicine. The measurements of the excitation functions were made over a wide proton energy range from the reaction threshold up to 100 MeV using the stacked foil (or pellet) technique. Small energy steps were used to allow for accurate determination of the structure of excitation functions. For 97 Ru, 111 In and 127 Xe formation with protons, new reaction channels and targets were used and data concerning this method are published for the first time. The data for 52 Fe, 77 Br, 82 Rb, 123 I, 128 Cs and 201 Tl obtained in the present work for the E p =70-100 MeV region are also published for the first time. The measured excitation functions for the formation of desired (and undesired) radionuclides (altogether 28 excitation functions) are compared with the theoretical ones calculated on the basis of a hybrid model of nuclear reactions in the form of the Overlaid Alice computer code. In order to determine the contribution of the competitive reaction channels to the purity of the produced, desired radionuclide, the excitation functions of the accompanying reactions were also calculated. The 122 calculated excitation functions for the possible contaminant are given in the present work. The comparison of experimental excitation functions with the results of model calculations showed satisfactory agreement, especially if one considers, that no parameter adjustment for individual reaction products was undertaken. From the measured excitation functions the production yields for 28 radionuclides mentioned above have been determined (author). 262 refs, 65 figs, 34 tabs

  10. Gyromagnetic ratios of excited states in 198Pt; measurements and interacting boson approximation model calculations

    Science.gov (United States)

    Stuchbery, A. E.; Ryan, C. G.; Bolotin, H. H.; Morrison, I.; Sie, S. H.

    1981-07-01

    The enhanced transient hyperfine field manifest at the nuclei of swiftly recoiling ions traversing magnetized ferromagnetic materials was utilized to measure the gyromagnetic ratios of the 2 +1, 2 +2 and 4 +1 states in 198Pt by the thin-foil technique. The states of interest were populated by Coulomb excitation using a beam of 220 MeV 58Ni ions. The results obtained were: g(2 +1) = 0.324 ± 0.026; g(2 +2) = 0.34 ± 0.06; g(4 +1) = 0.34 ± 0.06. In addition, these measurements served to discriminate between the otherwise essentially equally probable values previously reported for the E2/M1 ratio of the 2 +2 → 2 +1 transition in 198Pt. We also performed interacting boson approximation (IBA) model-based calculations in the O(6) limit symmetry, with and without inclusion of a small degree of symmetry breaking, and employed the M1 operator in both first- and second-order to obtain M1 selection rules and to calculate gyromagnetic ratios of levels. When O(6) symmetry is broken, there is a predicted departure from constancy of the g-factors which provides a good test of the nuclear wave function. Evaluative comparisons are made between these experimental and predicted g-factors.

  11. Measurements and preliminary interpretation of K-Reactor foundation response to man-made seismic excitation

    International Nuclear Information System (INIS)

    Lee, R.C.; Stephenson, D.E.

    1992-01-01

    In support of the Savannah River Technology Center (SRTC) effort to develop K-Reactor seismic design basis ground motions, SRTC monitored local high-explosive tests at a ''free-field'' site adjacent to K-Reactor and on the -40 level on the foundation of K-Reactor. The high-explosive tests were part of the SRTC/United States Geological Survey (USGS) regional refraction and attenuation experiment that used deeply buried high explosive charges near New Ellenton, Snelling, and at more distant South Carolina sites. The primary purpose of the Reactor measurements are to compare the relative amplitude and frequency content of ambient noise and shot generated ground motions measured at the K-Reactor foundation level and in the ''free-field'' so that foundation effects to ground motions can be documented and possibly incorporated in the facility design basis. Data analysis indicates that one of the five high explosive tests provided sufficient excitations at K-Reactor to produce satisfactory signal-to-noise between about 1 Hz and 15 Hz. Within this frequency band, Fourier spectral amplitude ratios of motions recorded within the first 10 seconds of first motion show substantial reductions (30 endash 50%) on shot radial and transverse components for frequencies greater than about 3 to 5 Hz. Approximately 50% reductions between 10 to 15 Hz were seen on vertical component ratios, and amplifications of 100% at 4 Hz and 5 Hz endash 6 Hz

  12. Measurement and calculation of excitation cross sections and level ionization by electron impact

    International Nuclear Information System (INIS)

    Blanco Rames, F.

    1990-01-01

    The experimental and theoretical study of the atomic structure in neutral noble gases is studied in this work. It mainly deals with the determination of total cross sections by electron impact and transition probabilities, including: Chapter 1: Theoretical introduction and the intermediate coupling description obtained for 420 levels of s, p and d configurations in neutral noble gases. Chapter 2: Experimental and theoretical values for electron collision cross sections are obtained for several levels of He, Ne, Ar and Kr. Our results as well as those available from existing bibliography are sumarized and compared. By means of an intermediate coupling treatment a number of regularities is found that provides us with some useful approximate semi empirical expressions. Chapter 3: Determination of lifetime and transition probabilities. Lifetime measurements are carried out by means of laser excitation and multichannel delayed coincidences technique. The experimental setup and electronics are also described. Chapter 4: Details the experimental setup developed for electron cross sections measurement by the optical method. The difficulties of this method and their treatment are also shown. (Author)

  13. Validations of CNDOL approximate Hamiltonian as a fast and reliable method to obtain vertical excitation energies in polyatomic systems

    International Nuclear Information System (INIS)

    Montero-Alejo, Ana L.; Gonzalez-Santana, Susana; Montero-Cabrera, Luis A.; Hernandez-Rodriguez, Erix Wiliam; Fuentes-Montero, Maria Elena; Bunge-Molina, Carlos F.; Gonzalez, Augusto

    2008-01-01

    Theoretical prediction of vertical excitation energies and an estimation of charge distributions of polyatomic systems can be calculated, through the configuration interaction of single (CIS) excited determinants procedure, with the CNDOL (Complete Neglect of Differential Overlap considering the l azimuthal quantum number) Hamiltonians. This method does not use adjusted parameters to fit experimental data and only employ a priori data on atomic orbitals and simple formulas to substitute large computations of electronic integrals. In this sense, different functions for bi-electron integrals have been evaluated in order to improve the approximate Hamiltonian. The reliability of predictions and theoretical consistence has been tested with a benchmark set of organic molecules that covers important classes of chromophores including polyenes and other unsaturated aliphatic compounds, aromatic, hydrocarbons, heterocycles, carbonyl compounds, and nucleobases. The calculations are done at identical geometries (MP2) with the same basis set (6-31G) for these medium-sized molecules and the obtained results were statistically compared with other analogous methods and experimental data. The accuracy of prediction of each CNDOL vertical transitions energy increases while the active space is more complete allowing the best variational optimization of CIS matrices i.e. molecular excited states. Moreover and due to the feasible computation procedure for large polyatomic systems, the studies have been extended, as a preliminary work, in the field of optoelectronic materials for photovoltaic applications. Hence, the excitation energies of different conjugated Phenyl-cored Thiophene Dendrimers optimized by DFT (Density Functional Theory) were calculated and show good agreement with the experiment data. The predicted charge distribution during the excitation contributes to understand the photophysics process on these kind materials. (Full text)

  14. Ergodicity, configurational entropy and free energy in pigment solutions and plant photosystems: influence of excited state lifetime.

    Science.gov (United States)

    Jennings, Robert C; Zucchelli, Giuseppe

    2014-01-01

    We examine ergodicity and configurational entropy for a dilute pigment solution and for a suspension of plant photosystem particles in which both ground and excited state pigments are present. It is concluded that the pigment solution, due to the extreme brevity of the excited state lifetime, is non-ergodic and the configurational entropy approaches zero. Conversely, due to the rapid energy transfer among pigments, each photosystem is ergodic and the configurational entropy is positive. This decreases the free energy of the single photosystem pigment array by a small amount. On the other hand, the suspension of photosystems is non-ergodic and the configurational entropy approaches zero. The overall configurational entropy which, in principle, includes contributions from both the single excited photosystems and the suspension which contains excited photosystems, also approaches zero. Thus the configurational entropy upon photon absorption by either a pigment solution or a suspension of photosystem particles is approximately zero. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. New even parity energy levels of Pr I found by excitation of transitions in the region 560 - 695 nm

    Energy Technology Data Exchange (ETDEWEB)

    Syed, Tanweer Iqbal; Khan, Shamim; Imran, Siddiqui; Zaheer, Uddin; Windholz, Laurentius [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria)

    2011-07-01

    The knowledge of electronic levels is essentially needed for a description of the interactions between the electrons of an atom and for the classification of an atomic spectrum. We have studied the hyperfine structure of Praseodymium spectral lines in the region from 560 to 695 nm. The hyperfine structure of a large number of unclassified Pr I-lines have been investigated by using the method of laser induced fluorescence in a hollow cathode discharge. During this investigation, we have discovered twelve energy levels with even parity, which were previously unknown. The excitation source was a ring dye laser operated with R6G, Kiton red, or DCM. J-quantum numbers and magnetic dipole interaction constants A for upper and lower levels have been determined from the recorded hyperfine structures. The energies of new levels have been determined by using these constants, excitation and fluorescence wavelengths. Promising excitation wavelengths have been taken from Fourier transform spectra. The new levels were confirmed by at least one second laser excitation.

  16. Measurement of excitation functions and isomeric ratios of the 197Au(3He,xn)200- sup(x)Tl reactions, where x=2,3 and 4

    International Nuclear Information System (INIS)

    Vinagre Filho, U.M.

    1983-01-01

    The excitation functions and isomer ratios of the 197 Au( 3 He,xn) 200- sup(x)Tl reactions, with x = 2, 3 and 4, were measured at bombarding energies in the range from 15 to 36 MeV. The measured values were compared to those obtained with the use of the statistical an hybrid modeles, calculated by the ALICE code. Best fit was achieved using the simple statistical model. The results were also compared to those found in literature for the ( 3 He,xn) and ( 4 He,xn) reactions in gold. (Author) [pt

  17. Projectile excitation energy evolution in peripheral collisions for 16O + 197Au at 32.5, 50 and 70 MeV/N

    International Nuclear Information System (INIS)

    Pouliot, J.; Dore, D.; Houde, S.; Laforest, R.; Roy, R.; St-Pierre, C.; Chan, Y.; Horn, D.; Horn, D.

    1991-01-01

    A comparison of the multiple breakup of 16 O projectiles scattered by a Au target at three different energies (32.5, 50 and 70 MeV/N) is presented. The excitation energy spectra of the primary projectile-like nuclei decaying into specific output channels were reconstructed. The excitation energy of the target is found to increase faster with beam energy than the one for the quasi-projectile

  18. Continuum corrections to the level density and its dependence on excitation energy, n-p asymmetry, and deformation

    International Nuclear Information System (INIS)

    Charity, R.J.; Sobotka, L.G.

    2005-01-01

    In the independent-particle model, the nuclear level density is determined from the neutron and proton single-particle level densities. The single-particle level density for the positive-energy continuum levels is important at high excitation energies for stable nuclei and at all excitation energies for nuclei near the drip lines. This single-particle level density is subdivided into compound-nucleus and gas components. Two methods are considered for this subdivision: In the subtraction method, the single-particle level density is determined from the scattering phase shifts. In the Gamov method, only the narrow Gamov states or resonances are included. The level densities calculated with these two methods are similar; both can be approximated by the backshifted Fermi-gas expression with level-density parameters that are dependent on A, but with very little dependence on the neutron or proton richness of the nucleus. However, a small decrease in the level-density parameter is predicted for some nuclei very close to the drip lines. The largest difference between the calculations using the two methods is the deformation dependence of the level density. The Gamov method predicts a very strong peaking of the level density at sphericity for high excitation energies. This leads to a suppression of deformed configurations and, consequently, the fission rate predicted by the statistical model is reduced in the Gamov method

  19. Excitation of contained modes by high energy nuclei and correlated cyclotron emission

    International Nuclear Information System (INIS)

    Coppi, B.; Penn, G.; Riconda, C.

    1997-01-01

    In experiments with fusing plasmas, enhanced radiation emission at the harmonics of the cyclotron frequency of fusion reaction products has been observed. A theory is presented that explains key features of these observations and indicates the possibility of extracting significant information about the fusion product population distribution, both in velocity space and over the plasma cross section. The considered model is consistent in particular with the fact that, in DT plasmas, the radiation peaks occur at frequencies corresponding to harmonics of the α particles cyclotron frequency Ω a evaluated at the outer edge of the plasma column, and that a transition to a open-quotes continuumclose quotes spectrum at high frequencies (ω approx-gt 7Ω α ) can be identified. In this model, the radiation is the result of the excitation of radially open-quotes containedclose quotes modes which are driven unstable by the fusion products. The modes considered to be responsible for the discrete part of the spectrum are spatially localized near the plasma edge. The radial containment, which is associated mainly with the inhomogeneity of the plasma density, is in fact a fundamental characteristic since only contained modes can grow out of a relatively weak mode-particle interaction and justify the detected emission power levels. The contained mode is a solution to a set of macroscopic equations, in which the electron motion is tied to that of the magnetic field (Hall effect). The growth rate has been evaluated considering the particle orbits in a toroidal confinement configuration and modelling the distribution function of the interacting particles with the energy at birth before slowing down occurs. The growth rate depends linearly on the α-particle density and can be larger than, or of the order of, the bounce frequency of the magnetically trapped α-particles, which can have a resonant interaction with the mode. According to the theoretical model presented, the discrete

  20. Measurement of excitation, ionization, and electron temperatures and positive ion concentrations in a 144 MHz inductively coupled radiofrequency plasma

    International Nuclear Information System (INIS)

    Walters, P.E.; Chester, T.L.; Winefordner, J.D.

    1977-01-01

    Diagnostic measurements of 144 MHz radiofrequency inductively coupled plasmas at pressures between 0.5 and 14 Torr have been made. Other variables studied included the gas type (Ar or Ne) and material in plasma (Ti or Tl). Parameters measured included excitation temperatures via the atomic Boltzmann plot and the two-line method, ionization electric probes. Excitation temperatures increased as the pressure of Ar or Ne plasmas decreased and reached a maximum of approx.9000 degreeK in the latter case and approx.6700 degreeK in the former case; Tl in the Ar plasma resulted in in a smaller rate of decrease of excitation temperature with increase of pressure of Ar. The ionization temperatures were lower than the excitation temperatures and were similar for both the Ar and Ne plasmas. Electron temperatures were about 10 times higher than the excitation temperatures indicating non-LTE behavior. Again, the electron temperatures indicating in Ne were considerably higher than in Ar. With the presence of metals, the electron temperatures with a metal in the Ar plasma were higher than in the absence. Positive ion concentrations were also measured for the various plasmas and were found to be similar (approx.10 18 m -3 ) in both the Ar and Ne plasmas. The presence of metals caused significant increase in the positive ion concentrations. From the results obtained, the optimum Ar pressure for Tl electrodeless discharge lamps operated at 144 MHz would be between 2 and 4 Torr

  1. Modification of Light Emission in Si-Rich Silicon Nitride Films Versus Stoichiometry and Excitation Light Energy

    Science.gov (United States)

    Torchynska, T.; Khomenkova, L.; Slaoui, A.

    2018-04-01

    Si-rich SiN x films with different stoichiometry were grown on Si substrate by plasma-enhanced chemical vapor deposition. The Si content was varied by changing the NH3/SiH4 gas flow ratio from 0.45 up to 1.0. Conventional furnace annealing at 1100°C for 30 min was applied to produce the Si quantum dots (QDs) in the SiN x films. Spectroscopic ellipsometry was used to determine the refractive index of the SiN x films that allowed estimating the film's stoichiometry. Fourier transform infrared spectroscopy has been also used to confirm the stoichiometry and microstructure. Photoluminescence (PL) spectra of Si-rich SiN x films are complex. A non-monotonous variation of the different PL peaks versus Si excess contents testifies to the competition of different radiative channels. The analysis of PL spectra, measured at the different excitation light energies and variable temperatures, has revealed that the PL bands with the peaks within the range 2.1-3.0 eV are related to the carrier recombination via radiative native defects in the SiN x host. Simultaneously, the PL bands with the peaks at 1.5-2.0 eV are caused by the exciton recombination in the Si QDs of different sizes. The way to control the SiN x emission is discussed.

  2. Microparticle impact sensor measures energy directly

    Science.gov (United States)

    Alexander, W. M.; Berg, O. E.

    1965-01-01

    Construction of a capacitor sensor consisting of a dielectric layer between two conductive surface layers and connected across a potential source through a sensing resistor permits measurement of energy of impinging particles without degradation of sensitivity. A measurable response is produced without penetration of the dielectric layer.

  3. Testing an excited-state energy density functional and the associated potential with the ionization potential theorem

    International Nuclear Information System (INIS)

    Hemanadhan, M; Shamim, Md; Harbola, Manoj K

    2014-01-01

    The modified local spin density (MLSD) functional and the related local potential for excited states is tested by employing the ionization potential theorem. The exchange functional for an excited state is constructed by splitting k-space. Since its functional derivative cannot be obtained easily, the corresponding exchange potential is given by an analogy to its ground-state counterpart. Further, to calculate the highest occupied orbital energy ϵ max accurately, the potential is corrected for its asymptotic behaviour by employing the van Leeuwen and Baerends (LB) correction to it. ϵ max so obtained is then compared with the ΔSCF ionization energy calculated using the MLSD functional with self-interaction correction for the orbitals involved in the transition. It is shown that the two match quite accurately. The match becomes even better by tuning the LB correction with respect to a parameter in it. (paper)

  4. Lowest excited-state impurity binding energy in InGaN/GaN parabolic QWW: magnetic field effect

    International Nuclear Information System (INIS)

    Haddou El Ghazi; Anouar Jorio; Izeddine Zorkani

    2013-01-01

    In this paper, we have investigated the magnetic field effect on the lowest excited-state binding energy of hydrogenic shallow-donor impurity in wurtzite (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) using the finite-difference method within the quasi-one-dimensional effective potential model. The calculations are performed within the framework of the effective mass approximation. A cylindrical QWW effective radius is taken into account to describe the lateral confinement strength. The numerical results show that: (i) the probability density is the largest on a circularity whose radius is the effective radius and (ii) the lowest excited-state binding energy is the largest when an impurity is located on this circularity while it starts to decrease as the impurity is away from the circularity. (author)

  5. 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.

  6. Hysteretic Energy Demand in SDOF Structures Subjected to an Earthquake Excitation: Analytical and Empirical Results

    OpenAIRE

    Taner UÇAR; Onur MERTER

    2018-01-01

    In energy-based seismic design approach, earthquake ground motion is considered as an energy input to structures. The earthquake input energy is the total of energy components such as kinetic energy, damping energy, elastic strain energy and hysteretic energy, which contributes the most to structural damage. In literature, there are many empirical formulas based on the hysteretic model, damping ratio and ductility in order to estimate hysteretic energy, whereas they do not directly consider t...

  7. A vacuum-UV laser-induced fluorescence experiment for measurement of rotationally and vibrationally excited H2

    International Nuclear Information System (INIS)

    Vankan, P.; Heil, S.B.S.; Mazouffre, S.; Engeln, R.; Schram, D.C.; Doebele, H.F.

    2004-01-01

    An experimental setup is built to detect spatially resolved rovibrationally excited hydrogen molecules via laser-induced fluorescence. To excite the hydrogen molecules, laser radiation is produced in the vacuum UV part of the spectrum. The laser radiation is tunable between 120 nm and 230 nm and has a bandwith of 0.15 cm -1 . The wavelength of the laser radiation is calibrated by simultaneous recording of the two-photon laser induced fluorescence spectrum of nitric oxide. The excited hydrogen populations are calibrated on the basis of coherent anti-Stokes Raman scattering measurements. A population distribution is measured in the shock region of a pure hydrogen plasma expansion. The higher rotational levels (J>5) show overpopulation compared to a Boltzmann distribution determined from the lower rotational levels (J≤5)

  8. Collective Excitations in Protein as a Measure of Balance Between its Softness and Rigidity

    International Nuclear Information System (INIS)

    Shrestha, Utsab R.; Bhowmik, Debsindhu; Van Delinder, Kurt W.; Mamontov, Eugene; O’Neill, Hugh

    2017-01-01

    Here, we elucidate the protein activity from the perspective of protein softness and flexibility by studying the collective phonon-like excitations in a globular protein, human serum albumin (HSA), and taking advantage of the state-of-the-art inelastic X-ray scattering (IXS) technique. Such excitations demonstrate that the protein becomes softer upon thermal denaturation due to disruption of weak noncovalent bonds. On the other hand, no significant change in the local excitations is detected in ligand- (drugs) bound HSA compared to the ligand-free HSA. These results clearly suggest that the protein conformational flexibility and rigidity are balanced by the native protein structure for biological activity.

  9. Collective Excitations in Protein as a Measure of Balance Between its Softness and Rigidity

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Utsab R. [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy; Bhowmik, Debsindhu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Science and Engineering Division; Van Delinder, Kurt W. [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy; Mamontov, Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division; O’Neill, Hugh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division; Zhang, Qiu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division; Alatas, Ahmet [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source; Chu, Xiang-Qiang [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy

    2017-01-12

    Here, we elucidate the protein activity from the perspective of protein softness and flexibility by studying the collective phonon-like excitations in a globular protein, human serum albumin (HSA), and taking advantage of the state-of-the-art inelastic X-ray scattering (IXS) technique. Such excitations demonstrate that the protein becomes softer upon thermal denaturation due to disruption of weak noncovalent bonds. On the other hand, no significant change in the local excitations is detected in ligand- (drugs) bound HSA compared to the ligand-free HSA. These results clearly suggest that the protein conformational flexibility and rigidity are balanced by the native protein structure for biological activity.

  10. Fission of 255,256Es, 255-257Fm, and 258Md at moderate excitation energies

    NARCIS (Netherlands)

    Britt, H.C.; Hoffman, D.C.; Plicht, J. van der; Wilhelmy, J.; Cheifetz, E.; Dupzyk, R.J.; Lougheed, R.W.

    1984-01-01

    The fission of 255,256Es, 255-257Fm, and 258Md has been studied in the excitation energy range from threshold to 25 MeV. A target of 254Es was used in the direct reaction studies; (d,pf), (t,pf), (3He,df), (3He,pf), and in the compound induced fission reactions formed with p, d, t, and α particle

  11. Influence of excitation and ionization of the atoms on the velocity of nuclear processes at low energies

    International Nuclear Information System (INIS)

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

    2004-01-01

    We have concluded that cold transmutation of nuclei is possible in the framework of the modern physical theory - excitation and ionization of atoms and the 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. (author)

  12. A framework to characterize energy efficiency measures

    International Nuclear Information System (INIS)

    Trianni, Andrea; Cagno, Enrico; De Donatis, Alessio

    2014-01-01

    Highlights: • A novel framework to characterize energy efficiency measures is proposed. • It allows a greater knowledge sharing, facilitating the adoption of the best measures. • It supports policy-makers in developing drivers for industrial energy efficiency. - Abstract: The need to increase the diffusion of energy efficiency measures (EEMs) is of crucial importance to achieve a consistent reduction of energy consumption and green house gases (GHG) emissions. A clear comprehension of the characteristics of such EEMs could assist in gathering and capitalizing all the information needed by industrial firms in selecting and adopting technologies, as well as by policy-makers in designing appropriate policies for their diffusion. Therefore, in this study, starting from a literature review of the studies analyzing the attributes of EEMs, we aim at providing an innovative and comprehensive framework to characterize such measures, based on 17 attributes grouped according to six categories, such as: economic, energy, environmental, production-related, implementation-related and the possible interaction with other systems. We applied this scheme to an extensive range of EEMs in cross-cutting technologies, i.e. motors, compressed air, lighting and HVAC systems. The analysis provides a relevant contribution firstly to the structuring and the sharing of knowledge on EEMs and hence to the comprehension of the barriers currently hindering their adoption; secondly, it provides a structured basis for the analysis of the drivers that policy-makers should develop in order to promote industrial energy efficiency

  13. Measuring the Distribution and Excitation of Cometary CH3OH Using ALMA

    Science.gov (United States)

    Cordiner, M. A.; Charnley, S. B.; Mumma, M. J.; Bockelée-Morvan, D.; Biver, N.; Villanueva, G.; Paganini, L.; Milam, S. N.; Remijan, A. J.; Lis, D. C.; Crovisier, J.; Boissier, J.; Kuan, Y.-J.; Coulson, I. M.

    2016-10-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) was used to obtain measurements of spatially and spectrally resolved CH3OH emission from comet C/2012 K1 (PanSTARRS) on 28-29 June 2014. Detection of 12-14 emission lines of CH3OH on each day permitted the derivation of spatially-resolved rotational temperature profiles (averaged along the line of sight), for the innermost 5000 km of the coma. On each day, the CH3OH distribution was centrally peaked and approximately consistent with spherically symmetric, uniform outflow. The azimuthally-averaged CH3OH rotational temperature (T rot) as a function of sky-projected nucleocentric distance (ρ), fell by about 40 K between ρ= 0 and 2500 km on 28 June, whereas on 29 June, T rot fell by about 50 K between ρ =0 km and 1500 km. A remarkable (~50 K) rise in T rot at ρ = 1500-2500 km on 29 June was not present on 28 June. The observed variations in CH3OH rotational temperature are interpreted primarily as a result of variations in the coma kinetic temperature due to adiabatic cooling, and heating through Solar irradiation, but collisional and radiative non-LTE excitation processes also play a role.

  14. Oleate induces KATP channel-dependent hyperpolarization in mouse hypothalamic glucose-excited neurons without altering cellular energy charge.

    Science.gov (United States)

    Dadak, Selma; Beall, Craig; Vlachaki Walker, Julia M; Soutar, Marc P M; McCrimmon, Rory J; Ashford, Michael L J

    2017-03-27

    The unsaturated fatty acid, oleate exhibits anorexigenic properties reducing food intake and hepatic glucose output. However, its mechanism of action in the hypothalamus has not been fully determined. This study investigated the effects of oleate and glucose on GT1-7 mouse hypothalamic cells (a model of glucose-excited (GE) neurons) and mouse arcuate nucleus (ARC) neurons. Whole-cell and perforated patch-clamp recordings, immunoblotting and cell energy status measures were used to investigate oleate- and glucose-sensing properties of mouse hypothalamic neurons. Oleate or lowered glucose concentration caused hyperpolarization and inhibition of firing of GT1-7 cells by the activation of ATP-sensitive K + channels (K ATP ). This effect of oleate was not dependent on fatty acid oxidation or raised AMP-activated protein kinase activity or prevented by the presence of the UCP2 inhibitor genipin. Oleate did not alter intracellular calcium, indicating that CD36/fatty acid translocase may not play a role. However, oleate activation of K ATP may require ATP metabolism. The short-chain fatty acid octanoate was unable to replicate the actions of oleate on GT1-7 cells. Although oleate decreased GT1-7 cell mitochondrial membrane potential there was no change in total cellular ATP or ATP/ADP ratios. Perforated patch and whole-cell recordings from mouse hypothalamic slices demonstrated that oleate hyperpolarized a subpopulation of ARC GE neurons by K ATP activation. Additionally, in a separate small population of ARC neurons, oleate application or lowered glucose concentration caused membrane depolarization. In conclusion, oleate induces K ATP- dependent hyperpolarization and inhibition of firing of a subgroup of GE hypothalamic neurons without altering cellular energy charge. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Measuring Income and Projecting Energy Use

    International Nuclear Information System (INIS)

    Pitcher, Hugh M.

    2009-01-01

    Energy is a key requirement for a healthy, productive life and a major driver of the emissions leading to an increasingly warm planet. The implications of a doubling and redoubling of per capita incomes over the remainder of this century for energy use are a critical input into understanding the magnitude of the carbon management problem. A substantial controversy about how the Special Report on Emssions Scenarios (SRES) measured income and the potential implications of how income was measured for long term levels of energy use is revisited again in the McKibbin, Pearce and Stegman article appearing elsewhere in this issue. The recent release of a new set of purchasing power estimates of national income, and the preparations for creating new scenarios to support the IPCC's fifth assessment highlight the importance of the issues which have arisen surrounding income and energy use. Comparing the 1993 and 2005 ICP results on Purchasing Power Parity (PPP) based measures of income reveals that not only do the 2005 ICP estimates share the same issue of common growth rates for real income as measured by PPP and US $, but the lack of coherence in the estimates of PPP incomes, especially for developing countries raises yet another obstacle to resolving the best way to measure income. Further, the common use of an income term to mediate energy demand (as in the Kaya identity) obscures an underlying reality about per capita energy demands, leading to unreasonable estimates of the impact of changing income measures and of the recent high GDP growth rates in India and China. Significant new research is required to create both a reasonable set of GDP growth rates and long term levels of energy use.

  16. The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin

    International Nuclear Information System (INIS)

    Buta, A.

    2003-02-01

    During the collision between the projectile and the target nuclei in the intermediate energy regime (E < 100 MeV/nucleon) two excited nuclei are mainly observed in the exit channel, the quasi projectile (QP) and the quasi target. They disintegrate by particle emission. However, this binary picture is perturbed by the emission of particles and light fragments with velocities intermediate between the projectile velocity and the target one, all along the interaction (midrapidity component). This work aim to determine the excitation energy and the intrinsic angular momentum (or spin) of quasi-projectiles produced in the Ni+Ni and Ni+Au collisions at 52 and 90 MeV/nucleon. The excitation energy is deduced from the kinematical characteristics of particles emitted by the quasi-projectile. They have to be separated from midrapidity particles. Three different scenarios have been used for this purpose. The spin of the quasi-projectile has been extracted from the experimental data by mean of proton and alpha particles multiplicities emitted by the QP in the Ni+Au at 52 MeV/nucleon reaction. The results have been compared to the predictions of a theoretical model based on nucleon transfers. Their evolution is qualitatively reproduced as a function of the violence of the collision. (author)

  17. Analyzing power T20 measurement of backscattering d.p. vector in the Δ resonance excitation range and theoretical analysis of this reaction

    International Nuclear Information System (INIS)

    Boudard, A.

    1983-12-01

    We have measured the analysing power T 20 in the backward elastic scattering d.p. for 16 energies of the deuteron from 300 MeV to 2300 MeV. This is the region of the observed bump in the backward excitation function of the cross section. This bump is usually thought to be a signature of a Δ(3/2,3/2 + ) dynamically excited in the intermediate state. We have also measured Ay and Ayy from 70 0 to 180 0 for Tsub(d)=1200 MeV. we have compared both T 20 and the backward cross section with a coherent sum between direct neutron exchange and Δ excitation by intermediate exchanges of π and rho mesons. The overall shape of the cross section is reproduced. Unlike the earlier measurements from Argonne, there is a deep minimum in T 20 at Tsub(d)=600 MeV, in agreement with the predictions of direct exchange models. However, an additional structure producing a second minimum at Tsub(d)=1400 MeV (√S=3240 MeV) is never reproduced by our calculations. This suggests either that refinements in the Δ treatment are needed or that a new reaction mechanism (resonance) takes place in that region [fr

  18. Correlated electron capture and inner-shell excitation measurements in ion-atom collisions

    International Nuclear Information System (INIS)

    Tanis, J.A.; Bernstein, E.M.; Clark, M.W.

    1985-01-01

    In an ion-atom collision projectile excitation and charge transfer (electron capture) may occur together in a single encounter. If the excitation and capture are correlated, then the process is called resonant transfer and excitation (RTE); if they are uncorrelated, then the process is termed nonresonant transfer and excitation (NTE). Experimental work to date has shown the existence of RTE and provided strong evidence for NTE. Results presented here provide information on the relative magnitudes of RTE and NTE, the charge state dependence of RTE, the effect of the target momentum distribution on RTE, the magnitude of L-shell RTE compared to K-shell RTE, and the target Z dependences of RTE and NTE. 15 refs., 5 figs

  19. Reparameterization invariance of NRQED self-energy corrections and improved theory for excited D states in hydrogenlike systems

    International Nuclear Information System (INIS)

    Wundt, Benedikt J.; Jentschura, Ulrich D.

    2008-01-01

    Canonically, the quantum electrodynamic radiative corrections in bound systems have been evaluated in photon energy regularization, i.e., using a noncovariant overlapping parameter that separates the high-energy relativistic scales of the virtual quanta from the nonrelativistic domain. Here, we calculate the higher-order corrections to the one-photon self-energy calculation with three different overlapping parameters (photon energy, photon mass and dimensional regularization) and demonstrate the reparameterization invariance of nonrelativistic quantum electrodynamics (NRQED) using this particular example. We also present new techniques for the calculation of the low-energy part of this correction, which lead to results for the Lamb shift of highly excited states that are important for high-precision spectroscopy

  20. Reparameterization invariance of NRQED self-energy corrections and improved theory for excited D states in hydrogenlike systems

    Energy Technology Data Exchange (ETDEWEB)

    Wundt, Benedikt J. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Jentschura, Ulrich D. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Institut fuer Theoretische Physik, Philosophenweg 16, 69120 Heidelberg (Germany)], E-mail: ulrich.jentschura@mpi-hd.mpg.de

    2008-01-24

    Canonically, the quantum electrodynamic radiative corrections in bound systems have been evaluated in photon energy regularization, i.e., using a noncovariant overlapping parameter that separates the high-energy relativistic scales of the virtual quanta from the nonrelativistic domain. Here, we calculate the higher-order corrections to the one-photon self-energy calculation with three different overlapping parameters (photon energy, photon mass and dimensional regularization) and demonstrate the reparameterization invariance of nonrelativistic quantum electrodynamics (NRQED) using this particular example. We also present new techniques for the calculation of the low-energy part of this correction, which lead to results for the Lamb shift of highly excited states that are important for high-precision spectroscopy.