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Sample records for low-lying yrast spectra

  1. Microscopic study of low-lying yrast spectra and deformation ...

    Indian Academy of Sciences (India)

    73, No. 4. — journal of. October 2009 physics pp. 657–668. Microscopic study of low-lying yrast spectra and deformation systematics in neutron-rich. 98−106Sr isotopes ... with a large and rigid moment of inertia. 98Sr is predicted to have a ... 2 energy as neutron number N changes from 58 to 60. The onset of deformation in ...

  2. Microscopic study of low-lying yrast spectra and deformation systematics of even-even barium isotopes

    International Nuclear Information System (INIS)

    Sarswat, S.P.; Bharti, Arun; Khosa, S.K.

    1996-01-01

    The yrast spectra has been obtained in the variation-after-projection framework using pairing-plus-quadrupole- quadrupole model for the two body interaction. Besides the low-lying yrast spectra, the calculated values of intrinsic quadrupole moments of some of the barium isotopes i.e. 124-134 Ba are presented

  3. The low lying yrast structure of 212Po

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

    1987-07-01

    The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. the previously proposed yrast scheme below 3MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured as 1.1(3), 24.6(3) and 0.8(2)ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the 65s isomer to be identified clearly as the 18 + level arising primarily from the π(h 9/2 2 )*ν(g 9/2 i 11/2 ) configuration

  4. The low-lying yrast structure of 212Po

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

    1987-01-01

    The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. The previously proposed yrast scheme below ≅ 3 MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured at 1.1 (3), 24.6 (3) and 0.8 (2) ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the τ m = 65 s isomer to be identified clearly as the 18 + level arising primarily from the π(h 2 9/2 ) * ν(g 9/2 i 11/2 ) configuration. (orig.)

  5. Primary transitions between the yrast superdeformed band and low-lying normal deformed states in {sup 194}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Hauschild, K.; Bernstein, L.A.; Becker, J.A. [Lawrence Livermore National Lab., CA (United States)] [and others

    1996-12-31

    The observation of one-step `primary` gamma-ray transitions directly linking the superdeformed (SD) states to the normal deformed (ND) low-lying states of known excitation energies (E{sub x}), spins and parities (J{sup {pi}}) is crucial to determining the E{sub x} and J{sup {pi}} of the SD states. With this knowledge one can begin to address some of the outstanding problems associated with SD nuclei, such as the identical band issue, and one can also place more stringent restrictions on theoretical calculations which predict SD states and their properties. Brinkman, et al., used the early implementation of the GAMMASPHERE spectrometer array (32 detectors) and proposed a single, candidate {gamma} ray linking the {sup 194}Pb yrast SD band to the low-lying ND states in {sup 194}Pb. Using 55 detectors in the GAMMASPHERE array Khoo, et al., observed multiple links between the yrast SD band in {sup 194}Hg and the low-lying level scheme and conclusively determined E{sub x} and J of the yrast SD states. Here the authors report on an experiment in which Gammasphere with 88 detectors was used and the E{sub x} and J{sup {pi}} values of the yrast SD states in {sup 194}Pb were uniquely determined. Twelve one-step linking transitions between the yrast SD band and low-lying states in {sup 194}Pb have been identified, including the transition proposed by Brinkman. These transitions have been placed in the level scheme of {sup 194}Pb using coincidence relationships and agreements between the energies of the primary transitions and the energy differences in level spacings. Furthermore, measurements of angular asymmetries have yielded the multipolarities of the primaries which have allowed J{sup {pi}} assignments of the {sup 194}Pb SD states to be unambiguously determined for the first time without a priori assumptions about the character of SD bands. A study performed in parallel to this work using the EUROGAM-II array reports similar, but somewhat less extensive, results.

  6. Microscopic study of low-lying yrast spectra in Mo isotopes

    Indian Academy of Sciences (India)

    consistent calculations, which involved an optimized basis of eight major oscillator shells with the constraint of axial .... agreement with the values calculated by M¨oller et al [27] for 100 104Mo. 2. Calculational ..... [22] A Guessous, N Schulz, M Bentalab, E Lubkiewicz, J L Durell, C J Pearson, W R Phillips,. J A Shannon, W ...

  7. Systematics on the low-lying spectra in N = 78 ~ 80 isotones

    International Nuclear Information System (INIS)

    Cheng, Y.Y.; Zhang, S.Q.; Li, X.Q.

    2014-01-01

    Combining the new spectroscopy results of 144 Tb and previous spectroscopy studies of neighboring nuclei, a systematic investigation on the low-lying spectra in N = 78 ~ 80 isotones is performed. Good systematics have been found for the coupling patterns which couple the odd nucleon(s), such as πh 11/2 , νh 11/2 —1 , νh 11/2 2 , νh 11/2 —2 , νh 11/2 —1 , to the 2 + , 4 + , 6 + and 3 - core excitations. It is found that the relative excitation energies of the states formed by coupling h 11/2 proton(s) to the 2 + , 4 + core excitations are pushed up, in contrast with those formed by coupling h 11/2 neutron hole(s) to the 2 + , 4 + core excitations, which are pulled down. According to the systematics, the interpretation that the 17/2 + states observed in 141 Sm and 143 Gd are the fully aligned member of coupling the odd h 11/2 neutron hole to the octupole 3 - core excitation, is explored to the isotones 145 Dy, 142 Eu, and 144 Tb. (author)

  8. RDDS lifetime measurements of low-lying superdeformed states in {sup 194}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, R.; Dewald, A.; Kruecken, R. [Universitaet Koeln (Germany)] [and others

    1996-12-31

    The lifetimes of three low-lying states in the superdeformed (SD) yrast band of {sup 194}Hg were measured by the recoil-distance Doppler-shift method. The deduced transition quadrupole moments, Q{sub t}, equal those extracted from a DSAM measurement for the high-lying states of the band corroborate the assumption that the decay out of SD bands does not strongly affect the structure of the corresponding states. By a simple mixing-model the decay can be described assuming a very small admixture of normal-deformed (ND) states to the decaying SD states. The deduced ND mixing amplitudes for the yrast SD bands in {sup 192,194}Hg and {sup 194}Pb are presented along with average transition quadrupole moments for the lower parts of the excited SD bands.

  9. Spectroscopy high above the yrast line in rare earth nuclei

    International Nuclear Information System (INIS)

    Ramsoey, T.

    1990-01-01

    The particle-gamma coincidence technique presented in this work has proved to be a powerful tool in the study of nuclear structure. The most important feature is the ability to select well-defined excitation regions of entry states in a narrow spin window. The author has focused on the gamma-decay of low- lying descrete states and the gross structure properties in the region far above the yrast line. 6 refs., 5 figs

  10. Yrast spectroscopy: status of yrast isomers, oblate shapes and feeding of yrast states

    International Nuclear Information System (INIS)

    Khoo, T.L.

    1980-01-01

    The properties of very-high-spin states at the yrast line are addressed. Three different but related topics are discussed: the status of yrast isomers (mainly in the A approx. 150 region); the nuclear shape along the yrast line; and the feeding of the yrast states as a function of spin. A recurrent theme is the response of the core to the polarizing effects of a successively increasing number of valence particles and how the investigation of very-high-spin states bears on this problem. 10 figures, 1 table

  11. Toward yrast spectroscopy in soft vibrational nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko.

    1979-10-01

    In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of ''physical'' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the ''invariance principle of the Schroedinger equation'', which leads us to the ''maximal decoupling'' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed. (author)

  12. On the low-lying states of TiC

    Science.gov (United States)

    Bauschlicher, C. W., Jr.; Siegbahn, P. E. M.

    1984-01-01

    The ground and low-lying excited states of TiC are investigated using a CASSCF-externally contracted CI approach. The calculations yield a 3Sigma(+) ground state, but the 1Sigma(+) state is only 780/cm higher and cannot be ruled out. The low-lying states have some triple bond character. The nature of the bonding and origin of the states are discussed.

  13. The low-lying collective multipole response of atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Spieker, Mark; Derya, Vera; Hennig, Andreas; Pickstone, Simon G.; Prill, Sarah; Vielmetter, Vera; Weinert, Michael; Wilhelmy, Julius; Zilges, Andreas [Institute for Nuclear Physics, University of Cologne, Cologne (Germany); Petkov, Pavel [Institute for Nuclear Physics, University of Cologne, Cologne (Germany); INRNE, Bulgarian Academy of Sciences, Sofia (Bulgaria); National Institute for Physics and Nuclear Engineering, Bucharest (Romania)

    2016-07-01

    We present experimental results on the low-lying multipole response, which were obtained with the recently established DSA-method in Cologne. Nuclear level lifetimes in the sub-ps regime are extracted by means of centroid-shifts utilizing the (p,p{sup '}γ) reaction at the 10 MV FN-Tandem accelerator in Cologne. The scattered protons are coincidently detected with the deexciting γ rays using the SONIC rate at HORUS detector array, which allows for a precise determination of the reaction kinematics. In addition to the pioneering results on octupole and hexadecapole mixed-symmetry states of {sup 96}Ru, this contribution will feature new results on low-lying quadrupole-octupole coupled states and on the low-lying E2 strength of {sup 112,114}Sn, which was recently discussed to be generated due to a quadrupole-type oscillation of the neutron skin against the isospin-saturated core.

  14. Non-yrast states and shape co-existence in 172Os

    International Nuclear Information System (INIS)

    Davidson, P.M.; Dracoulis, G.D.; Kibedi, T.; Byrne, A.P.; Anderssen, S.S.; Baxter, A.M.; Fabricius, B.; Lane, G.J.; Stuchbery, A.E.

    1994-01-01

    Previous studies of 172 Os noted an anomaly in the behaviour of the moment of inertia of the yrast band at low spin. A phenomenological model of shape coexistence based on interacting rotational bands was proposed to explain this anomaly and this model predicted low-lying non-yrast states. In order to test these predictions, the β-decay of 172 Ir has been used to populate 172 Os. Excited states have been observed and classified into positive-parity ''quasi-β'' and ''quasi-γ'' bands and a negative-parity band. The energies of the quasi-β band states are seen to be in general agreement with the predictions of the phenomenological model and the model is refined to take into account the new data. The bands involved are determined to have significantly different moments of inertia. (orig.)

  15. Core excitations to the low lying states of thallium isotopes

    International Nuclear Information System (INIS)

    Gruenbaum, L.; Tomaselli, M.; Herold, D.

    1977-08-01

    The admixture of core excitations to the low lying states of A = 203 and A = 205 thallium isotopes has been calculated. The wave functions obtained reproduce the electromagnetic properties as well as the hyperfine splittings and the isomershifts of both thallium isotopes. (orig.) [de

  16. Properties of the low-lying levels of 122Sb

    International Nuclear Information System (INIS)

    Gunsteren, W.F. van; Rabenstein, D.

    1977-01-01

    Nanosecond lifetimes of low-lying levels in the doubly odd nucleus 122 Sb have been measured. On the basis of these results and of already published experimental material, spins and parities for most of the low-lying states are proposed. A simple theoretical description of this nucleus is presented. The model used is that of a proton coupled to a number projected neutron quasiparticle wave function, assuming a Z=N=50 core. The spectrum and transition rates were calculated in a shell model space consisting of eight subshells and using a renormalized Schiffer interaction. The shell model parameters were derived from adjadent nuclei. Good agreement with the experimental level scheme is found. Also the gamma decay properties can be accounted for rather well. Spectroscopic factors for the one-neutron transfer reactions leading to 122 Sb are predicted. Their measurement with high resolution techniques would be a helpful test for the interpretations given. (orig.) [de

  17. Low-lying level structure of 73Kr

    International Nuclear Information System (INIS)

    Moltz, D.M.; Robertson, J.D.; Norman, E.B.; Burde, J.; Beausang, C.W.

    1993-01-01

    We have used the 40 Ca( 36 Ar, 2pn) reaction to study the low-lying level structure of 73 Kr. By utilizing a bombarding energy at the Coulomb barrier, the relative cross section for this channel was enhanced to a few percent of the total reaction cross section. Levels in 73 Kr were assigned based primarily upon observed neutron-gamma-gamma coincidences and upon comparisons of these newly assigned transition cross sections with those from known nuclei. (orig.)

  18. Semirelativistic potential model for low-lying three-gluon glueballs

    International Nuclear Information System (INIS)

    Mathieu, Vincent; Semay, Claude; Silvestre-Brac, Bernard

    2006-01-01

    The three-gluon glueball states are studied with the generalization of a semirelativistic potential model giving good results for two-gluon glueballs. The Hamiltonian depends only on 3 parameters fixed on two-gluon glueball spectra: the strong coupling constant, the string tension, and a gluon size which removes singularities in the potential. The Casimir scaling determines the structure of the confinement. Low-lying J PC states are computed and compared with recent lattice calculations. A good agreement is found for 1 -- and 3 -- states, but our model predicts a 2 -- state much higher in energy than the lattice result. The 0 -+ mass is also computed

  19. Spectroscopic study of low-lying 16N levels

    International Nuclear Information System (INIS)

    Bardayan, Daniel W.; O'Malley, Patrick; Blackmon, Jeff C.; Chae, K.Y.; Chipps, K.; Cizewski, J.A.; Hatarik, Robert; Jones, K.L.; Kozub, R. L.; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D.; Pain, Steven D.; Paulauskas, Stanley; Peters, W.A.; Pittman, S.T.; Schmitt, Kyle; Shriner, J.F. Jr.; Smith, Michael Scott

    2008-01-01

    The magnitude of the 15N(n,gamma)16N reaction rate in asymptotic giant branch stars depends directly on the neutron spectroscopic factors of low-lying 16N levels. A new study of the 15N(d,p)16N reaction is reported populating the ground and first three excited states in 16N. The measured spectroscopic factors are near unity as expected from shell model calculations, resolving a long-standing discrepancy with earlier measurements that had never been confirmed or understood. Updated 15N(n,gamma)16N reaction rates are presented

  20. Low-lying levels of 129Xe and 131Xe

    International Nuclear Information System (INIS)

    Palmer, D.C.; Irving, A.D.; Forsyth, P.D.; Hall, I.; Martin, D.G.E.; Maynard, M.J.

    1978-01-01

    The nuclei 129 Xe and 131 Xe have been studied by Coulomb excitation and by (α, n) reactions on 126 Te and 128 Te. Eleven new levels for 129 Xe and six for 131 Xe and B(E2) transition values for some of the low-lying states are reported. The present Coulomb excitation experiments together with published β-decay work enable some spin-parity assignments and restrictions to be made. The data are broadly consistent with the predictions of the particle-vibrator coupling model, although a thorough comparison requires further spectroscopic measurements and more detailed theoretical calculation. (author)

  1. Competition between pairing and quadrupole deformation in the yrast sequence of sup(150,152)Dy

    International Nuclear Information System (INIS)

    Aberg, S.

    1984-05-01

    The yrast spectra are investigated for the non-collective nuclei sup(150,152)Dy using the Nilsson-Strutinsky + blocked BCS model. The separate effects from the pairing force and the quadrupole force (deformation changes) are studied. It is found that the pairing force is most important in describing the yrast line up to Iproportional30, while the quadrupole force is most important for I> or approx.20. The calculated increase of the oblate deformation with increasing spin is explained as an antipairing effect when only valence nucleons are building the total spin and as a polarization effect when the core becomes excited. (orig.)

  2. Low-lying isomeric levels in Cu75

    Science.gov (United States)

    Daugas, J. M.; Faul, T.; Grawe, H.; Pfützner, M.; Grzywacz, R.; Lewitowicz, M.; Achouri, N. L.; Angélique, J. C.; Baiborodin, D.; Bentida, R.; Béraud, R.; Borcea, C.; Bingham, C. R.; Catford, W. N.; Emsallem, A.; de France, G.; Grzywacz, K. L.; Lemmon, R. C.; Lopez Jimenez, M. J.; de Oliveira Santos, F.; Regan, P. H.; Rykaczewski, K.; Sauvestre, J. E.; Sawicka, M.; Stanoiu, M.; Sieja, K.; Nowacki, F.

    2010-03-01

    Isomeric low-lying states were identified and investigated in the Cu75 nucleus. Two states at 61.8(5)- and 128.3(7)-keV excitation energies with half-lives of 370(40)- and 170(15)-ns were assigned as Cu75m1 and Cu75m2, respectively. The measured half-lives combined with the recent spin assignment of the ground state allow one to deduce tentatively spin and parity of the two isomers and the dominant multipolarities of the isomeric transitions with respect to the systematics of the Cu isotopes. Shell-model calculations using an up-to-date effective interaction reproduce the evolution of the 1/2-, 3/2-, and 5/2- states for the neutron-rich odd-mass Cu isotopes when filling the νg9/2. The results indicate a significant change in the nuclear structure in this region, where a single-particle 5/2- state coexists with more and more collective 3/2- and 1/2- levels at low excitation energies.

  3. Low-lying excited states by constrained DFT

    Science.gov (United States)

    Ramos, Pablo; Pavanello, Michele

    2018-04-01

    Exploiting the machinery of Constrained Density Functional Theory (CDFT), we propose a variational method for calculating low-lying excited states of molecular systems. We dub this method eXcited CDFT (XCDFT). Excited states are obtained by self-consistently constraining a user-defined population of electrons, Nc, in the virtual space of a reference set of occupied orbitals. By imposing this population to be Nc = 1.0, we computed the first excited state of 15 molecules from a test set. Our results show that XCDFT achieves an accuracy in the predicted excitation energy only slightly worse than linear-response time-dependent DFT (TDDFT), but without incurring into problems of variational collapse typical of the more commonly adopted ΔSCF method. In addition, we selected a few challenging processes to test the limits of applicability of XCDFT. We find that in contrast to TDDFT, XCDFT is capable of reproducing energy surfaces featuring conical intersections (azobenzene and H3) with correct topology and correct overall energetics also away from the intersection. Venturing to condensed-phase systems, XCDFT reproduces the TDDFT solvatochromic shift of benzaldehyde when it is embedded by a cluster of water molecules. Thus, we find XCDFT to be a competitive method among single-reference methods for computations of excited states in terms of time to solution, rate of convergence, and accuracy of the result.

  4. Inelastic light scattering by low-lying excitations of electrons in low-dimensional semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, V. [NEST CNR-INFM and Scuola Normale Superiore, Pisa (Italy); Pinczuk, A. [Department of Physics, Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey (United States)

    2006-11-15

    The low-dimensional electron systems that reside in artificial semiconductor heterostructures of great perfection are a contemporary materials base for explorations of collective phenomena. Studies of low-lying elementary excitations by inelastic light scattering offer insights on properties such energetics, interactions and spin magnetization. We review here recent light scattering results obtained from two-dimensional (2D) quantum fluids in semiconductor heterostructures under extreme conditions of low temperature and large magnetic field, where the quantum Hall phases are archetypes of novel behaviors. We also consider recent light scattering experiments that have probed the excitation spectra of few-electron states in semiconductor quantum dots. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Low lying magnetic dipole strength distribution in 176Hf

    International Nuclear Information System (INIS)

    Kuliev, A. A.; Ertugral, F.; Yakut, H.; Bektasoglu, M.; Guliyev, E.

    2006-01-01

    In this study the scissors mode 1 + states are systematically investigated within the rotational invariant Quasiparticle Random Phase Approximation (QRPA) for 1 76Hf isotopes. We consider the 1 + vibrations generated by the isovector spin-spin interactions and the isoscalar (h 0 ) and isovector (h 1 ) quadrupole type separable forces restoring the broken symmetry by a deformed mean field. It has been shown that restoration of the broken rotational symmetry of the Hamiltonian essentially decreases the B(M1) value of the low lying 1 + states and increases the collectivization of the scissors mode excitations in the spectroscopic energy region. Agreement between the calculated mean excitation energies as well as the summed B(M1) value of the scissors mode excitations and the available experimental data of 1 76Hf is rather good. For instance, distributions of the calculated B(M1) transition strengths in the 1 76 Hf isotopes with respect to K π =1 + excitations is represented in Figure. Thus, we see that the models which use the Hamiltonian with broken rotational symmetry strongly overestimate the M1 strength at low energy. These results indicate an importance of the models which are free from the low-energy spurious states. The marked differences between the results for 1 + states, calculated in rotational invariant (RI) and non-rotational invariant (NRI) model indicate the importance of the approaches which are free from spurious low-energy solutions. A separation of the rotational state from the 1 + states changes somewhat the distribution of the B(M1) strength in the spectroscopic energy region and increases the fragmentation of the scissors mode 1 + excitations in agreement with the experimental data

  6. Prolate yrast cascade in 183Tl

    International Nuclear Information System (INIS)

    Reviol, W.; Carpenter, M. P.; Janssens, R. V. F.; Jenkins, D.; Toth, K. S.; Bingham, C. R.; Riedinger, L. L.; Weintraub, W.; Cizewski, J. A.; Lauritsen, T.

    2000-01-01

    The yrast sequence in 183 Tl has been studied for the first time in recoil-mass selected γ-ray spectroscopic measurements. A rotational-like cascade of seven transitions is established down to the band head with probable spin and parity (13/2 + ). Unlike in the adjacent odd-mass Tl nuclei, prompt γ decay from the yrast band to a lower lying weakly deformed (oblate) structure is not observed. These features are consistent with the predicted drop of the prolate band head in 183 Tl compared to 185 Tl. The implications for the prolate energy minimum in odd-mass Tl nuclei at the neutron i 13/2 midshell (N=103) are discussed. (c) 2000 The American Physical Society

  7. Poisson and Porter-Thomas fluctuations in off-yrast rotational transitions

    International Nuclear Information System (INIS)

    Matsuo, M.; Doessing, T.; Herskind, B.; Frauendorf, S.

    1993-01-01

    Fluctuations associated with stretched E2 transitions from high-spin levels in nuclei around 168 Yb are investigated by a cranked shell model extended to include residual two-body interactions. In the cranked mean-field model without residual interactions, it is found that gamma-ray energies behave like random variables and the energy spectra show Poisson fluctuation. With two-body residual interactions included, the discrete transition pattern with unmixed rotational bands is still valid up to around 600 keV above yrast, in good agreement with experiments. At higher excitation energy, a gradual onset of rotational damping emerges. At 1.8 MeV above yrast, complete damping is observed with GOE-type fluctuations for both energy levels and transition strengths (Porter-Thomas fluctuations). (orig.)

  8. Decay out of the yrast superdeformed band in 191Hg

    International Nuclear Information System (INIS)

    Sien, S.; Reiter, P.; Khoo, T.; Lauritsen, T.; Carpenter, M. P.; Ahmad, I.; Amro, H.; Calderin, I.; Dossing, T.; Fischer, S. M.; Garg, U.; Gassmann, D.; Hackman, G.; Hannachi, F.; Janssens, R. V. F.; Kharraja, B.; Korichi, A.; Lopez-Martens, A.; Moore, E. F.; Nisius, D.; Schuck, C.

    1999-01-01

    The excitation energies and spins of the yrast superdeformed band in 191 Hg have been determined by analyzing the quasicontinuum spectrum connecting the superdeformed and normal-deformed states. The results from this analysis, combined with that given by one-step decay lines, give confident assignments of the spins and energies of the yrast superdeformed band in 191 Hg

  9. Nuclear structure far above the yrast line

    International Nuclear Information System (INIS)

    Gaardhoeje, J.J.

    1985-01-01

    The phase space available for gamma ray spectroscopic studies has recently been extended significantly with the observation of gamma radiation produced in the decay of highly collective (isovector) giant dipole resonances (GDR), built on excited states of high spin, in nuclei produced in heavy ion induced fusion reactions. These gamma rays are predominantly emitted in competition with particles in the first few steps of the decay of compound systems and constitute an entirely new tool to study nuclei at excitation energies far above the yrast line. Some problems of current central interest are addressed. (Auth.)

  10. Low-lying charmed and charmed-strange baryon states

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bing [Anyang Normal University, Department of Physics, Anyang (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China); Wei, Ke-Wei [Anyang Normal University, Department of Physics, Anyang (China); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China); Matsuki, Takayuki [Tokyo Kasei University, Tokyo (Japan); Nishina Center, RIKEN, Theoretical Research Division, Saitama (Japan)

    2017-03-15

    In this work, we systematically study the mass spectra and strong decays of 1P and 2S charmed and charmed-strange baryons in the framework of non-relativistic constituent quark models. With the light quark cluster-heavy quark picture, the masses are simply calculated by a potential model. The strong decays are studied by the Eichten-Hill-Quigg decay formula. Masses and decay properties of the well-established 1S and 1P states can be reproduced by our method. Σ{sub c}(2800){sup 0,+,++} can be assigned as a Σ{sub c2}(3/2{sup -}) or Σ{sub c2}(5/2{sup -}) state. We prefer to interpret the signal Σ{sub c}(2850){sup 0} as a 2S(1/2{sup +}) state although at present we cannot thoroughly exclude the possibility that this is the same state as Σ{sub c}(2800){sup 0}. Λ{sub c}(2765){sup +} or Σ{sub c}(2765){sup +} could be explained as the Λ{sub c}{sup +}(2S) state or Σ{sup +}{sub c1}(1/2{sup -}) state, respectively. We propose to measure the branching ratio of B(Σ{sub c}(2455)π)/B(Σ{sub c}(2520)π) in the future, which may disentangle the puzzle of this state. Our results support Ξ{sub c}(2980){sup 0,+} as the first radial excited state of Ξ{sub c}(2470){sup 0,+} with J{sup P} = 1/2{sup +}. The assignment of Ξ{sub c}(2930){sup 0} is analogous to Σ{sub c}(2800){sup 0,+,++}, i.e., a Ξ{sup '}{sub c2}(3/2{sup -}) or Ξ{sup '}{sub c2}(5/2{sup -}) state. In addition, we predict some typical ratios among partial decay widths, which are valuable for experimental search for these missing charmed and charmed-strange baryons. (orig.)

  11. Low-lying spectra in anharmonic three-body oscillators with a strong short-range

    Czech Academy of Sciences Publication Activity Database

    Znojil, Miloslav

    2003-01-01

    Roč. 36, č. 38 (2003), s. 9929-9941 ISSN 0305-4470 R&D Projects: GA AV ČR IAA1048302 Institutional research plan: CEZ:AV0Z1048901 Keywords : three-body Schrodinger equation * limit * large repulsion Subject RIV: BE - Theoretical Physics Impact factor: 1.357, year: 2003

  12. The scaling dimension of low lying Dirac eigenmodes and of the topological charge density

    CERN Document Server

    Aubin, C.; Gottlieb, Steven; Gregory, E.B.; Heller, Urs M.; Hetrick, J.E.; Osborn, J.; Sugar, R.; Toussaint, D.; de Forcrand, Ph.; Jahn, Oliver

    2005-01-01

    As a quantitative measure of localization, the inverse participation ratio of low lying Dirac eigenmodes and topological charge density is calculated on quenched lattices over a wide range of lattice spacings and volumes. Since different topological objects (instantons, vortices, monopoles, and artifacts) have different co-dimension, scaling analysis provides information on the amount of each present and their correlation with the localization of low lying eigenmodes.

  13. High spin states and Yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1981-01-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2 - . Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  14. High spin states and yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1980-12-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2. Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  15. Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes

    International Nuclear Information System (INIS)

    Sato, Koichi; Hinohara, Nobuo

    2011-01-01

    We study the oblate-prolate shape mixing in the low-lying states of proton-rich Kr isotopes using the five-dimensional quadrupole collective Hamiltonian. The collective Hamiltonian is derived microscopically by means of the CHFB (constrained Hartree-Fock-Bogoliubov) + Local QRPA (quasiparticle random phase approximation) method, which we have developed recently on the basis of the adiabatic self-consistent collective coordinate method. The results of the numerical calculation show the importance of large-amplitude collective vibrations in the triaxial shape degree of freedom and rotational effects on the oblate-prolate shape mixing dynamics in the low-lying states of these isotopes.

  16. Energies and electric dipole transitions for low-lying levels of protactinium IV and uranium V

    Energy Technology Data Exchange (ETDEWEB)

    Uerer, Gueldem; Oezdemir, Leyla [Sakarya Univ. (Turkey). Physics Dept.

    2012-01-15

    We have reported a relativistic multiconfiguration Dirac-Fock (MCDF) study on low-lying level structures of protactinium IV (Z = 91) and uranium V (Z = 92) ions. Excitation energies and electric dipole (E1) transition parameters (wavelengths, oscillator strengths, and transition rates) for these low-lying levels have been given. We have also investigated the influence of the transverse Breit and quantum electrodynamic (QED) contributions besides correlation effects on the level structure. A comparison has been made with a few available data for these ions in the literature. (orig.)

  17. Erratum to: Quadrupole moments of low-lying baryons with spin ...

    Indian Academy of Sciences (India)

    physics pp. 1083. Erratum to: Quadrupole moments of low-lying baryons with spin-. 1. 2. +. , spin-. 3. 2. +. , and spin-. 3. 2. +. → 1. 2. + transitions. NEETIKA SHARMA and HARLEEN DAHIYA. ∗. Department of Physics, Dr. B.R. Ambedkar National Institute of Technology,. Jalandhar 144 011, India. ∗. Corresponding author.

  18. A density matrix renormalization group study of low-lying excitations ...

    Indian Academy of Sciences (India)

    Symmetrized density-matrix-renormalization-group calculations have been carried out, within Pariser-Parr-Pople Hamiltonian, to explore the nature of the ground and low-lying excited states of long polythiophene oligomers. We have exploited 2 symmetry and spin parity of the system to obtain excited states of ...

  19. More evidence of localization in the low-lying Dirac spectrum

    CERN Document Server

    Bernard, C; Gottlieb, Steven; Levkova, L.; Heller, U.M.; Hetrick, J.E.; Jahn, O.; Maresca, F.; Renner, Dru Bryant; Toussaint, D.; Sugar, R.; Forcrand, Ph. de; Gottlieb, Steven

    2006-01-01

    We have extended our computation of the inverse participation ratio of low-lying (asqtad) Dirac eigenvectors in quenched SU(3). The scaling dimension of the confining manifold is clearer and very near 3. We have also computed the 2-point correlator which further characterizes the localization.

  20. Going, Going, Gone: The Fate of Low-Lying Islands and Estuaries

    OpenAIRE

    Cairns, John

    2009-01-01

    Garrett Hardin s lifeboat metaphor is used to illustrate the problems of overpopulation and finite resources. Sea levels are rising due to excess atmospheric greenhouse gases that melt glaciers and warm the oceans. With anthropogenic greenhouse gas emissions continuing to increase, humankind has placed human culture and individuals at serious risk. Rising sea levels will soon make some low-lying islands uninhabitable.

  1. Glauber amplitudes for transitions from low lying states in hydrogen atom by charged particle impact

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Srivastava, M K [Roorkee Univ. (India). Dept. of Physics

    1977-07-01

    The Glauber amplitudes for the general transition nlm ..-->.. n'1'm' in charged particle - hydrogen atom collisions have been obtained in the form of a one-dimensional integral. The final expression involves only a few hypergeometric functions if n is not too large and is particularly suited to study excitation to highly excited states from a low lying state.

  2. A collective model description of the low lying and giant dipole resonant properties of 40424446Ca

    International Nuclear Information System (INIS)

    Weise, J.I.

    1982-01-01

    The low-lying and giant dipole resonant properties of the even-even calcium isotopes are calculated within the framework of the Gneuss-Greiner model and compared with the experimental data. In the low energy region, comparison is also made with the predictions of a coexistence model

  3. Toward yrast spectroscopy in soft vibrational nuclei. A microscopic theory of the large amplitude collective motion of soft nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko

    1980-01-01

    In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of 'physical' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the 'invariance principle of the Schroedinger equation', which leads us to the 'maximal decoupling' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed

  4. Yrast-yrare interaction strength and bandcrossing frequency

    International Nuclear Information System (INIS)

    Wu, C.S.; Zeng, J.Y.

    1991-01-01

    Accurate particle-number-conserving calculation shows that in a single-j model the yrast-yrare interaction V is always strong and no periodic oscillation of V with the degree of shell filling is found, in contrast to the results obtained by the Hartree-Fock-Bogoliubov approximation. To understand the behavior of V and bandcrossing frequency ω c , the spin-alignment, seniority structure, configuration structure, and ''quasiparticle structure'' of the yrast and yrare bands are analyzed in detail. Calculation in a two-j model (high-j intruder orbits plus normal orbits of opposite parity) was also carried out to illustrate schematically that a weak yrast-yrare interaction may occur for certain single-particle level scheme. The coexistence of normal low-j orbits with high-j intruder orbits is indispensible for a sharp backbending observed in some realistic nuclei

  5. Search for low-lying opposite parity states from a simple perspective

    International Nuclear Information System (INIS)

    Hernandez de la Pena, L.; Hess, P.O.; Levai, G.

    2003-01-01

    The low-lying spectrum of many light nuclei can be described reasonably well by assigning SU(3) quantum numbers to the states. When one focuses on basic properties of nuclei in a wide mass range, however, simplified models with fewer parameters (and thus with less arbitrary nature) can be useful. The agreement to available experimental data was found to be reasonable, expect when the nucleus is near a shell closure and has small deformation. (R.P.)

  6. Calculations of energy levels and lifetimes of low-lying states of barium and radium

    International Nuclear Information System (INIS)

    Dzuba, V. A.; Ginges, J. S. M.

    2006-01-01

    We use the configuration-interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the planning of measurements of parity- and time-invariance-violating effects which are strongly enhanced in this atom. Calculations for barium are used to control the accuracy of the calculations

  7. Low-lying Photoexcited States of a One-Dimensional Ionic Extended Hubbard Model

    Science.gov (United States)

    Yokoi, Kota; Maeshima, Nobuya; Hino, Ken-ichi

    2017-10-01

    We investigate the properties of low-lying photoexcited states of a one-dimensional (1D) ionic extended Hubbard model at half-filling. Numerical analysis by using the full and Lanczos diagonalization methods shows that, in the ionic phase, there exist low-lying photoexcited states below the charge transfer gap. As a result of comparison with numerical data for the 1D antiferromagnetic (AF) Heisenberg model, it was found that, for a small alternating potential Δ, these low-lying photoexcited states are spin excitations, which is consistent with a previous analytical study [Katsura et al., link ext-link-type="uri" xlink:href="https://doi.org/10.1103/PhysRevLett.103.177402" xlink:type="simple">Phys. Rev. Lett. 103, 177402 (2009)link>]. As Δ increases, the spectral intensity of the 1D ionic extended Hubbard model rapidly deviates from that of the 1D AF Heisenberg model and it is clarified that this deviation is due to the neutral-ionic domain wall, an elementary excitation near the neutral-ionic transition point.

  8. Study of the structure of yrast bands of neutron-rich 114-124Pd isotopes

    Science.gov (United States)

    Chaudhary, Ritu; Devi, Rani; Khosa, S. K.

    2018-02-01

    The projected shell model calculations have been carried out in the neutron-rich 114-124Pd isotopic mass chain. The results have been obtained for the deformation systematics of E(2+1) and E(4+1)/E({2}+1) values, BCS subshell occupation numbers, yrast spectra, backbending phenomena, B( E2) transition probabilities and g-factors in these nuclei. The observed systematics of E(2+1) values and R_{42} ratios in the 114-124Pd isotopic mass chain indicate that there is a decrease of collectivity as the neutron number increases from 68 to 78. The occurrence of backbending in these nuclei as well as the changes in the calculated B( E2) transition probabilities and g -factors predict that there are changes in the structure of yrast bands in these nuclei. These changes occur at the spin where there is crossing of g-band by 2-qp bands. The predicted backbendings and predicted values of B( E2)s and g-factors in some of the isotopes need to be confirmed experimentally.

  9. Study of positive-parity yrast band in 83Rb

    International Nuclear Information System (INIS)

    Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Bhattacharya, S.; Saha Sarkar, M.; Goswami, A.; Muralithar, S.; Singh, R.P.; Kumar, R.; Bhowmik, R.K.

    2005-01-01

    The properties of the positive-parity yrast band in the odd-A 81,83,85 Rb (Z=37) isotopes show remarkable changes as N increases. The objective of the present work is to study the structure of the lowest positive-parity band in 83 Rb from lifetime studies

  10. Spectroscopy of heavy nuclei: yrast states, side bands and backbending

    International Nuclear Information System (INIS)

    Sunyar, A.W.

    1979-01-01

    Some recent experimental results concerning the high spin structure of two rare earth nuclei are presented. These are 154 Er and 158 Dy. The level schemes including yrast sequences are discussed. The reactions 142 Nd( 16 O,4n) and 150 Nd( 13 C,5n) respectively, for the studied nuclei are noted. 14 references

  11. Rapid Communication: v= 2 seniority changing transitions in yrast 3 ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 5. Rapid Communication: Δ υ = 2 seniority changing transitions in yrast 3 − states and B ( E 3 ) systematics of Sn isotopes. BHOOMIKA MAHESHWARI SWATI GARG ASHOK KUMAR JAIN. Research Article Volume 89 Issue 5 November 2017 Article ID 75 ...

  12. Comprehensive ab initio calculation and simulation on the low-lying electronic states of TlX (X = F, Cl, Br, I, and At).

    Science.gov (United States)

    Zou, Wenli; Liu, Wenjian

    2009-03-01

    The low-lying electronic states of TlX (X=F, Cl, Br, I, and At) are investigated using the configuration interaction based complete active space third-order perturbation theory [CASPT3(CI)] with spin-orbit coupling accounted for. The potential energy curves and the corresponding spectroscopic constants are reported. The results are grossly in good agreement with the available experimental data. The absorption spectra are simulated as well to reassign the experimental bands. The present results are also useful for guiding future experimental measurements.

  13. Oscillator strengths and lifetimes for low-lying terms in the Al isoelectronic sequence

    International Nuclear Information System (INIS)

    Hjort-Jensen, M.; Aashamar, K.

    1988-11-01

    Using the Multiconfiguration Optimized Potential Model, calculations of oscillator strengths in the length, and velocity formulation for a large number of transitions in the Aluminium isoelectronic sequence from Si II through K VII, have been performed. The results have been used to determine the lifetimes of 14 low-lying excited terms along the sequence. Comparison is made with experiment and with other theory where results are available. The agreement between the obtained values and other theoretical results is generally good, although deviations do occur near level crossings. Some significant discrepancies between theory and experiment persist concerning lifetimes for S IV

  14. Lifetimes of low-lying states in 132Nd and 134Nd

    International Nuclear Information System (INIS)

    Kruecken, R.; Mullins, S.M.; Thornley, D.J.; Kirwan, A.J.; Nolan, P.J.; Regan, P.H.; Wadsworth, R.

    1995-01-01

    Lifetimes of low-lying states have been measured in 132 Nd and 134 Nd using the coincidence-plunger technique. The reaction 32 S+ 105 Pd was used at a bombarding energy of 152 MeV. The measurement has been performed at the NSF Daresbury using the ESSA 30 array. The differential decay-curve method (DDCM) was used to analyze the recoil-distance Doppler-shift (RDDS) data. The experimental B(E2) values in 132 Nd are well described by the predictions of the rotational model and the IBM in the O(6) limit. ((orig.))

  15. Low-lying 1/2-hidden strange pentaquark states in the constituent quark model

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Zong-Xiu Wu; Chun-Sheng An; Hong Chen

    2017-01-01

    We investigate the spectrum of the low-lying 1/2-hidden strange pentaquark states,employing the constituent quark model,and looking at two ways within that model of mediating the hyperfine interaction between quarks-Goldstone boson exchange and one gluon exchange.Numerical results show that the lowest 1/2-hidden strange pentaquark state in the Goldstone boson exchange model lies at ~ 1570 MeV,so this pentaquark configuration may form a notable component in S11(1535) if the Goldstone boson exchange model is applied.This is consistent with the prediction that S11 (1535) couples very strongly to strangeness channels.

  16. Is there a low-lying 1{sup −} state in {sup 10}He?

    Energy Technology Data Exchange (ETDEWEB)

    Chulkov, L.V. [GSI Helmholtzzentrum für Schwerionenforschung GmbH/ExtreMe Matter Institute, EMMI, D-64291 Darmstadt (Germany); Kurchatov Institute, RU-123182 Moscow (Russian Federation); Aumann, T. [Institut für Kernphysik, Technische Universität, D-64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH/ExtreMe Matter Institute, EMMI, D-64291 Darmstadt (Germany); Jonson, B., E-mail: Bjorn.Jonson@chalmers.se [Fundamental Fysik, Chalmers Tekniska Högskola, S-412 96 Göteborg (Sweden); Nilsson, T. [Fundamental Fysik, Chalmers Tekniska Högskola, S-412 96 Göteborg (Sweden); Simon, H. [GSI Helmholtzzentrum für Schwerionenforschung GmbH/ExtreMe Matter Institute, EMMI, D-64291 Darmstadt (Germany)

    2013-03-26

    In a recent paper by S.I. Sidorchuk et al., Phys. Rev. Lett. 108 (2012) 202502, angular correlations in the decay of {sup 10}He were interpreted as a coherent superposition of a 0{sup +}, 1{sup −} and 2{sup +} states. It was concluded that it is the 1{sup −} state that dominates in the energy region 4.5–6 MeV. It is here demonstrated here that the experimental data might be understood without assuming the presence of a low-lying 1{sup −} state.

  17. Low-lying eigenmodes of the Wilson-Dirac operator and correlations with topological objects

    International Nuclear Information System (INIS)

    Kusterer, Daniel-Jens; Hedditch, John; Kamleh, Waseem; Leinweber, D.B.; Williams, Anthony G.

    2002-01-01

    The probability density of low-lying eigenvectors of the hermitian Wilson-Dirac operator H(κ)=γ 5 D W (κ) is examined. Comparisons in position and size between eigenvectors, topological charge and action density are made. We do this for standard Monte-Carlo generated SU(3) background fields and for single instanton background fields. Both hot and cooled SU(3) background fields are considered. An instanton model is fitted to eigenmodes and topological charge density and the sizes and positions of these are compared

  18. Low-lying S-wave and P-wave dibaryons in a nodal structure analysis

    International Nuclear Information System (INIS)

    Liu Yuxin; Li Jingsheng; Bao Chengguang

    2003-01-01

    The inherent nodal surface structure analysis approach is proposed for six-quark clusters with u, d, and s quarks. The wave functions of the six-quark clusters are classified, and the contribution of the hidden-color channels are discussed. The quantum numbers and configurations of the wave functions of the low-lying dibaryons are obtained. The states [ΩΩ] (0,0 + ) , [ΩΩ] (0,2 - ) , [Ξ * Ω] (1/2,0 + ) , and [Σ * Σ * ] (0,4 - ) and the hidden-color channel states with the same quantum numbers are proposed to be the candidates of experimentally observable dibaryons

  19. Effective Hamiltonian and low-lying eigenenergy clustering patterns of four-sublattice antiferromagnets

    DEFF Research Database (Denmark)

    Zhang, N.G.; Henley, C.L.; Rischel, C.

    2002-01-01

    We study the low-lying eigenenergy clustering patterns of quantum antiferromagnets with p sublattices (in particular p = 4). We treat each sublattice as a large spin, and using second-order degenerate perturbation theory, we derive the effective (biquadratic) Hamiltonian coupling the p large spins....... In order to compare with exact diagonalizations, the Hamiltonian is explicitly written for a finite-size lattice, and it contains information on energies of excited states as well as the ground state. The result is applied to the face-centered-cubic Type-I antiferromagnet of spin 1/2, including second...

  20. The low-lying πσ* state and its role in the intramolecular charge transfer of aminobenzonitriles and aminobenzethyne

    International Nuclear Information System (INIS)

    Lee, Jae-Kwang; Fujiwara, Takashige; Kofron, William G.; Zgierski, Marek Z.; Lim, Edward C.

    2008-01-01

    Electronic absorption spectra of the low-lying ππ* and πσ* states of several aminobenzonitriles and 4-dimethylaminobenzethyne have been studied by time-resolved transient absorption and time-dependent density functional theory calculation. In acetonitrile, the lifetime of the πσ*-state absorption is very short (picoseconds or subpicosecond) for molecules that exhibit intramolecular charge transfer (ICT), and very long (nanoseconds) for those that do not. Where direct comparison of the temporal characteristics of the πσ*-state and the ICT-state transients could be made, the formation rate of the ICT state is identical to the decay rate of the πσ* state within the experimental uncertainty. These results are consistent with the πσ*-mediated ICT mechanism, L a (ππ*)→πσ*→ICT, in which the decay rate of the πσ* state is determined by the rate of the solvent-controlled πσ*→ICT charge-shift reaction. The ππ*→πσ* state crossing does not occur in 3-dimethylaminobenzonitrile or 2-dimethylaminobenzonitrile, as predicted by the calculation, and 4-aminobenzonitrile and 4-dimethylaminobenzethyne does not exhibit the ICT reaction, consistent with the higher energy of the ICT state relative to the πσ* state

  1. Study of yrast bands and electromagnetic properties in neutron-rich 114-128Cd isotopes

    Science.gov (United States)

    Chaudhary, Ritu; Pandit, Rakesh K.; Devi, Rani; Khosa, S. K.

    2018-02-01

    The projected shell model framework has been employed to carry out a systematic study on the deformation systematics of E (21+) and E (41+) / E (21+) values, BCS subshell occupation numbers, yrast spectra, backbending phenomena and electromagnetic quantities in 114-128Cd isotopes. Present calculations reproduce the observed systematics of the E (21+), R42 and B (E 2 ;2+ →0+) values for 114-128Cd isotopic mass chain and give the evidence that deformation increases as one moves from 114Cd to 118Cd, thereafter it decreases up to 126Cd. This in turn confirms 118Cd to be the most deformed nucleus in this set of isotopic mass chain. The emergence of backbending, decrease in B (E 2) values and change in g-factors in all these isotopes are intimately related to the crossing of g-band by 2-qp bands.

  2. Feeding of the superdeformed yrast band in sup 149 Gd

    Energy Technology Data Exchange (ETDEWEB)

    Haas, B.; Vivien, J.P.; Beck, F.A.; Benet, P.; Byrski, T.; Curien, D.; Duchene, G.; Gehringer, C.; Merdinger, J.C.; Romain, P. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires); Basu, S.K. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires Bhabha Atomic Research Centre, Calcutta (India). Variable Energy Cyclotron Centre); Kluge, H. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires Hahn-Meitner-Institut Berlin GmbH (Germany, F.R.)); Santos, D. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina)); Flibotte, S. (Hahn-Meitner-Institut Berlin GmbH (Germany, F.R.)); Gascon, J.; Taras, P. (Montreal Univ., Quebec (Canada). Lab. de Physique Nucleaire); Bozek, E.; Zuber, K. (Institute of Nuclear Physics, Krakow (Poland))

    1990-08-02

    The feeding pattern of the superdeformed yrast band in {sup 149}Gd has been found to remain essentially the same, using the {sup 124}Sn+{sup 30}Si reaction at beam energies of 150, 155 and 160 MeV leading to different input angular momenta and excitation energies in the compound nuclear system. This similarity as well as the relative yields of the superdeformed states as a function of beam energy may be understood in terms of the nuclear level density dependence on deformation and the onset of fission. In addition, it has been shown that, at all three beam energies, the selection of high-energy gamma rays does not enhance the yield of the superdeformed yrast states. (orig.).

  3. Yrast four-quasi-particle states in 182W

    International Nuclear Information System (INIS)

    Regan, P.H.; Walker, P.M.; Dracoulis, G.D.; Anderssen, S.S.; Byrne, A.P.; Davidson, P.M.; Kibedi, T.; Lane, G.J.; Stuchbery, A.E.; Yeung, K.C.

    1994-01-01

    High-spin states of the stable isotope 182 W have been studied using the reactions 176 Yb( 13 C,α3n) 182 W and 176 Yb( 9 Be,3n) 182 W at beam energies of 65 and 40 MeV, respectively. Three, possibly four, new intrinsic states at high spins have been observed corresponding to different high-K four-quasi-particle structures. The K π =15 + and 17 - levels have lifetimes of 78(15) and 25(10) ns, respectively. Rotational bands are observed built on the K π =16 + and 17 - yrast states. The coupling of Nilsson orbitals which give rise to high-K states at the yrast line and the K-forbiddenness of the K π =15 + isomeric decay are discussed. (orig.)

  4. Lifetime Measurement in the Yrast Band of 119I

    Science.gov (United States)

    Lobach, Yu. N.; Pasternak, A. A.; Srebrny, J.; Droste, Ch.; Hagemann, G. B.; Juutinen, S.; Morek, T.; Piiparinen, M.; Podsvirova, E. O.; Toermaenen, S.; Starosta, K.; Virtanen, A.; Wasilewski, A. A.

    1999-05-01

    The lifetime of levels in the yrast band of 119I were measured by DSAM and RDM using the 109Ag (13C,3n) reaction at E=54 MeV. The detailed description of data analysis including the stopping power determination and estimation of side feeding time is given. A modified method of RDM data analysis --- Recoil Distance Doppler Shape Attenuation (RDDSA) is used.

  5. Lifetime measurement in the yrast band of {sup 119}I

    Energy Technology Data Exchange (ETDEWEB)

    Lobach, Yu.N. [Institute for Nuclear Research UAS, Kiev (Ukraine); Pasternak, A.A. [A.F. Ioffe Physical Technical Institute RAS, St. Petersbourg (Russian Federation); Srebrny, J. [Nuclear Physics Division, IEP, University of Warsaw, Warsaw (Poland)] [and others

    1999-05-01

    The lifetime of levels in the yrast band of {sup 119}I were measured by DSAM and RDM using the {sup 109}Ag({sup 13}C,3n) reaction at E = 54 MeV. The detailed description of data analysis including the stopping power determination and estimation of side feeding time is given. A modified method of RDM data analysis - Recoil Distance Doppler Shape Attenuation (RDDSA) is used. (author) 17 refs, 4 figs, 1 tab

  6. Lifetime measurement in the yrast band of 119I

    International Nuclear Information System (INIS)

    Lobach, Yu.N.; Pasternak, A.A.; Srebrny, J.

    1999-01-01

    The lifetime of levels in the yrast band of 119 I were measured by DSAM and RDM using the 109 Ag( 13 C,3n) reaction at E = 54 MeV. The detailed description of data analysis including the stopping power determination and estimation of side feeding time is given. A modified method of RDM data analysis - Recoil Distance Doppler Shape Attenuation (RDDSA) is used. (author)

  7. Yrast and high spin states in 22Ne

    International Nuclear Information System (INIS)

    Szanto, E.M.; Toledo, A.S. de

    1982-08-01

    High spin states in 22 Ne have been investigated by the reactions 11 B( 13 C,d) 22 Ne and 13 C( 11 B,d) 22 Ne up to E* approximately=19 MeV. Yrast states were observed at 11.02 MeV (8 + ) and 15.46 MeV (10 + ) excitation energy. A backbending in 22 Ne is observed around spin 8 + . The location of high spin states I [pt

  8. Low-lying collective quadrupole and octupole strengths in even-even nuclei

    International Nuclear Information System (INIS)

    Raman, S.; Nestor, C.W. Jr.; Kahane, S.; Bhatt, K.H.

    1991-01-01

    The B(E2)↑ values for the first 2 + state of even-even nuclei in the Z≥50 region are compared with the predictions of several theoretical models. Comparative estimates of the overall agreement with the data are provided. Gaps and discrepancies in the data and examples that show interesting features such as shape changes are discussed. The B(E2)↑ values are examined critically to search for the dynamical Pauli effects predicted by the fermion dynamic symmetry model. The empirical B(E2)↑ and B(E3)↑ systematics are employed to obtain a measure of the harmonicity of the quadrupole and octupole vibrations. The fraction of the energy-weighted sum-rule strength exhausted by the sum of all known low-lying 2 + states below 2.3 MeV is found to be surprisingly constant in the 60< A<250 region except near closed shells

  9. Study of lifetimes of low-lying levels in {sup 53}Mn

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K.P.; Oswal, Mumtaz; Behera, B.R.; Kumar, Ashok; Singh, Gulzar [Panjab University, Cyclotron Laboratory, Department of Physics, Centre of Advance Study in Physics, Chandigarh (India)

    2015-05-15

    The properties of low-lying states of {sup 53}Mn were investigated via the {sup 53}Cr(p, n γ){sup 53}Mn reaction using 4.3 MeV proton beam energy. The lifetimes of the levels at 1289.5, 1440.8, 1620.0 and 2273.8 keV excitation energies were measured using the Doppler Shift Attenuation Method (DSAM). The reduced transition probabilities B(M1) and B(E2) were extracted using the measured values of lifetimes for these levels and the mixing ratios from the literature. These values are compared with already known experimental values as well as the shell model calculations using an effective interaction. (orig.)

  10. Low-lying intruder state of the unbound nucleus {sup 13}Be

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Y., E-mail: kondo@phys.titech.ac.j [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-Okayama, Meguro, Tokyo 152-8551 (Japan); Nakamura, T.; Satou, Y. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-Okayama, Meguro, Tokyo 152-8551 (Japan); Matsumoto, T.; Aoi, N. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Endo, N. [Department of Physics, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577 (Japan); Fukuda, N.; Gomi, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, Y. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-Okayama, Meguro, Tokyo 152-8551 (Japan); Ishihara, M. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kawai, S. [Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501 (Japan); Kitayama, M.; Kobayashi, T.; Matsuda, Y. [Department of Physics, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577 (Japan); Matsui, N. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-Okayama, Meguro, Tokyo 152-8551 (Japan); Motobayashi, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nakabayashi, T.; Okumura, T. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-Okayama, Meguro, Tokyo 152-8551 (Japan); Ong, H.J.; Onishi, T.K. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2010-06-21

    An experimental study for the unbound nucleus {sup 13}Be has been performed by means of the invariant mass method via the one-neutron removal reaction {sup 1}H({sup 14}Be,{sup 12}Be+n). A resonance has been observed at 0.51(1) MeV in the relative energy (E{sub rel}) spectrum of the {sup 12}Be+n system. The transverse momentum distribution of the {sup 12}Be+n system as well as the resonance width of 0.45(3) MeV gives evidence for the p-wave nature of the resonance. A d-wave resonance has also been observed at 2.39(5) MeV in the E{sub rel} spectrum. The observation of the low-lying p-wave resonance indicates the disappearance of the N=8 magicity in the vicinity of the neutron drip line region.

  11. Low-lying 1/2- hidden strange pentaquark states in the constituent quark model

    Science.gov (United States)

    Li, Hui; Wu, Zong-Xiu; An, Chun-Sheng; Chen, Hong

    2017-12-01

    We investigate the spectrum of the low-lying 1/2- hidden strange pentaquark states, employing the constituent quark model, and looking at two ways within that model of mediating the hyperfine interaction between quarks - Goldstone boson exchange and one gluon exchange. Numerical results show that the lowest 1/2- hidden strange pentaquark state in the Goldstone boson exchange model lies at ˜1570 MeV, so this pentaquark configuration may form a notable component in S 11(1535) if the Goldstone boson exchange model is applied. This is consistent with the prediction that S 11(1535) couples very strongly to strangeness channels. Supported by National Natural Science Foundation of China (11675131, 11645002), Chongqing Natural Science Foundation (cstc2015jcyjA00032) and Fundamental Research Funds for the Central Universities (SWU115020)

  12. Identification of low-lying proton-based intruder states in 189-193Pb

    International Nuclear Information System (INIS)

    Vel, K. van de; Andreyev, A.N.; Huyse, M.; Duppen, P. van; Cocks, J.F.C.; Dorvaux, O.; Greenlees, P.T.; Helariutta, K.; Jones, P.; Julin, R.; Juutinen, S.; Kettunen, H.; Kuusiniemi, P.; Leino, M.; Muikku, M.; Nieminen, P.; Eskola, K.; Wyss, R.

    2002-01-01

    Low-lying proton-based intruder states have been observed in the odd-mass isotopes 189,191,193 Pb in experiments at the RITU gas-filled recoil separator. The identification has been performed by observing the fine structure in the α decay of the parent 193,195,197 Po nuclei in prompt coincidence with conversion electrons and γ rays in the daughter lead isotopes. Along with the literature data these results establish a systematics of intruder states in the odd-mass lead isotopes from 197 Pb down to 185 Pb. Interpretation of these states involves the coupling of the 1i 13/2 or 3p 3/2 odd neutron to the 0 + state in the oblate minimum in the even-mass lead core. Conversion coefficients have been determined for some of the transitions, revealing mixing between the coexisting states. The experimental results are compared to potential energy surface calculations

  13. Three-body hadronic structure of low-lying 1/2+ Σ and Λ resonances

    International Nuclear Information System (INIS)

    Martinez Torres, A.; Khemchandani, K.P.; Oset, E.

    2008-01-01

    We discuss the dynamical generation of some low-lying 1/2 + Σ's and Λ's in two-meson one-baryon systems. These systems have been constructed by adding a pion in the S-wave to the anti KN pair and its coupled channels, where the 1/2 - Λ(1405)-resonance gets dynamically generated. We solve Faddeev equations in the coupled-channel approach to calculate the T-matrix for these systems as a function of the total energy and the invariant mass of one of the meson-baryon pairs. This squared T-matrix shows peaks at the energies very close to the masses of the strangeness -1,1/2 + resonances listed in the particle data book. (orig.)

  14. The low-lying electronic states of pentacene and their roles in singlet fission.

    Science.gov (United States)

    Zeng, Tao; Hoffmann, Roald; Ananth, Nandini

    2014-04-16

    We present a detailed study of pentacene monomer and dimer that serves to reconcile extant views of its singlet fission. We obtain the correct ordering of singlet excited-state energy levels in a pentacene molecule (E (S1) pentacene, we use a well-developed diabatization scheme to characterize the six low-lying singlet states of a pentacene dimer that approximates the unit cell structure of crystalline pentacene. The local, single-excitonic diabats are not directly coupled with the important multiexcitonic state but rather mix through their mutual couplings with one of the charge-transfer configurations. We analyze the mixing of diabats as a function of monomer separation and pentacene rotation. By defining an oscillator strength measure of the coherent population of the multiexcitonic diabat, essential to singlet fission, we find this population can, in principle, be increased by small compression along a specific crystal direction.

  15. High-spin isomer in 211Rn, and the shape of the yrast line

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Fahlander, C.; Poletti, A.R.

    1981-08-01

    High spin yrast states in 211 Rn have been identified. A 61/2 - , 380 ns isomer found at 8856 keV is characterised as a core-excited configuration. The average shape of the yrast line shows a smooth behaviour with spin, in contrast to its neighbour 212 Rn. This difference is attributed to the presence of the neutron hole

  16. Study of yrast structures in {sup 55,57}Cr

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Anuradha, E-mail: annu1gupta1@gmail; Kumar, Amit, E-mail: akbcw2@gmail.com [Research Scholar, University of Jammu, Jammu-180006 (India); Singh, Suram, E-mail: suramsingh@gmail.com [Assistant Professor, Department of Physics, G.D.C. Kathua, 184101 (India); Bharti, Arun, E-mail: arunbharti-2003@yahoo.co.in [Professor, University of Jammu, Jammu-180006 (India)

    2016-05-06

    The characteristic nuclear structure properties of yrast bands of {sup 55,57}Cr have been investigated by using two body effective interactions incorporated in phenomenological axial framework. In order to check the validity of the chosen framework as well as chosen valence space, the calculated results are compared with the available experimental data and a good agreement has been found from the comparison. The back-bending in moment of inertia has also been studied and attributed to the alignment of odd g{sub 9/2} neutron along the rotation axis.

  17. Conversion coefficients and yrast state spins in 180Os

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Kibedi, T.; Byrne, A.P.; Fabricius, B.; Stuchbery, A.E.

    1989-11-01

    Internal conversion coefficients of transitions in 180 Os have been measured using a superconducting, solenoidal electron spectrometer, operated in the lens mode. The high energy resolution and efficiency allow a precise measurement of the conversion coefficients of the 528 keV yrast transition. The values obtained, α K = 0.015 (2), α L = 0.004(1) define pure E2 multipolarity. Taken with the measured γ-ray angular distribution, the conversion coefficient leads to an unambiguous assignment of 16 + →14 + for the 528 keV transition. 14 refs., 5 figs., 1 tab

  18. Characterization of the low-lying 0$^{+}$ and 2$^{+}$ states of $^{68}$ Ni

    CERN Multimedia

    Recently, a number of low-lying low-spin states have been firmly identified in $^{68}$Ni; the position of the first excited state (which is a 0$^{+}$ state), the spin and parity of the second excited 0$^{+}$ state and the spin and parity of the second and third 2$^+$ states have been fixed. The identification of these three pairs of 0$^+$ and 2$^+$ states in $^{68}$Ni (Z=28 and N=40) forms ideal tests to validate shell-model calculations and the effective interactions developed for the nickel region but also hints to triple shape coexistence including even strongly deformed structures. The aim of this proposal is to collect detailed spectroscopic data of the low-spin states of $^{68}$Ni (Z=28, N=40) in order to characterize these triple pairs of 0$^+$ and 2$^+$ states. $\\gamma$-branching ratios of the 0$^+$ and 2$^+$ states and the E0 transition strengths as well as the E2 transition rate of the 0$_3^+$ will be obtained using the new ISOLDE decay station that is constructed from an efficient array of germaniu...

  19. Low-lying dipole strength of the open-shell nucleus 94Mo

    Science.gov (United States)

    Romig, C.; Beller, J.; Glorius, J.; Isaak, J.; Kelley, J. H.; Kwan, E.; Pietralla, N.; Ponomarev, V. Yu.; Sauerwein, A.; Savran, D.; Scheck, M.; Schnorrenberger, L.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Weller, H. R.; Zilges, A.; Zweidinger, M.

    2013-10-01

    The low-lying dipole strength of the open-shell nucleus 94Mo was studied via the nuclear resonance fluorescence technique up to 8.7 MeV excitation energy at the bremsstrahlung facility at the Superconducting Darmstadt Electron Linear Accelerator (S-DALINAC), and with Compton backscattered photons at the High Intensity γ-ray Source (HIγS) facility. In total, 83 excited states were identified. Exploiting polarized quasi-monoenergetic photons at HIγS, parity quantum numbers were assigned to 41 states excited by dipole transitions. The electric dipole-strength distribution was determined up to 8.7 MeV and compared to microscopic calculations within the quasiparticle phonon model. Calculations and experimental data are in good agreement for the fragmentation, as well as for the integrated strength. The average decay pattern of the excited states was investigated exploiting the HIγS measurements at five energy settings. Mean branching ratios to the ground state and first excited 21+ state were extracted from the measurements with quasi-monoenergetic photons and compared to γ-cascade simulations within the statistical model. The experimentally deduced mean branching ratios exhibit a resonance-like maximum at 6.4 MeV which cannot be reproduced within the statistical model. This indicates a nonstatistical structure in the energy range between 5.5 and 7.5 MeV.

  20. Coulomb excitations of low lying levels in 127I and 197Au

    International Nuclear Information System (INIS)

    Singh, K.P.; Tayal, D.C.; Hans, H.S.

    1988-01-01

    The low-lying levels of 127 I and 197 Au were Coulomb excited with 3.54 to 4.2 MeV protons. The reduced quadrupole transition probabilities of the 203, 374.9, 418, 618.4, 628.7, 651.1 and 745.5 keV states of 127 I, and the 268.8, 278.9, 502, and 547.5 keV states of 197 Au was measured from Coulomb excitation by observing the de-excitation gamma rays with a high resolution Ge(Li) detector. The low-energy protons were used for the first time to Coulomb-excite the two levels at 618.4 and 651.1 keV of 127 I and one level at 502 keV of 197 Au. The present experimental results are found in agreement with the existing experimental data except the B(E2) value of the level at 268.8 keV of 197 Au. (author). 4 figs., 4 tabs., 32 refs

  1. Microscopic description of low-lying M1 excitations in odd-mass actinide nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Tabar, Emre, E-mail: etabar@sakarya.edu.tr [Physics Department, Sakarya University, 54187 Sakarya (Turkey); Biomedical, Magnetic and Semiconductor Materials Research Center (BIMAS-RC), Sakarya University, 54187 Sakarya (Turkey); Yakut, Hakan, E-mail: hyakut@sakarya.edu.tr [Physics Department, Sakarya University, 54187 Sakarya (Turkey); Biomedical, Magnetic and Semiconductor Materials Research Center (BIMAS-RC), Sakarya University, 54187 Sakarya (Turkey); Kuliev, Ali Akbar [Azerbaijan National Academy of Aviation, Baku (Azerbaijan)

    2017-01-15

    A restoration method of a broken symmetry which allows self-consistent determination of the separable effective restoration forces is now adapted to odd-mass nuclei in order to restore violated rotational invariance (RI-) of the Quasiparticle Phonon Nuclear Model (QPNM) Hamiltonian. Because of the self-consistency of the method, these effective forces contain no arbitrary parameters. Within RI-QPNM, the properties of the low-lying magnetic dipole excitations in odd-mass deformed {sup 229–233}Th and {sup 233–239}U nuclei have been investigated for the first time. It has been shown that computed fragmentation of the M1 strengths below 4 MeV in these nuclei is much stronger than that in neighboring doubly even {sup 228–232}Th and {sup 232–238}U nuclei. For {sup 235}U the summed M1 strength in the energy range 1.5–2.8 MeV is in agreement with the relevant experimental data where the missing strength was extracted by means of a fluctuation analysis.

  2. The Electro-Excitation Form Factors for Low-Lying States of 7Li Nucleus

    International Nuclear Information System (INIS)

    Dakhl, Z.A.; Salih, L.; Al-Qazaz, B.S.

    2010-01-01

    The transverse electron scattering form factors have been studied for low -lying excited states of 7 L i nucleus. These states are specified by JπT= (0.478MeV),(4.63MeV) and(6.68MeV). The transitions to these states are taking place by both isoscalar and isovector components. These form factors have been analyzed in the framework of the multi-nucleon configuration mixing of harmonic oscillator shell model with size parameter b r ms=1.74fm. The universal two-body of Cohen-Kurath is used to generate the 1p-shell wave functions. The core polarization effects are included in the calculations through effective g-factors and resolved many discrepancies with experiments. A higher configuration effect outside the 1p-shell model space, such as the 2p-shell, enhances the form factors for q-values and reproduces the data. The present results are compared with other theoretical models. PACS: 25.30.Bf Elastic electron scattering - 25.30.Dh Inelastic electron scattering to specific states - 21.60.Cs Shell model - 27.20. +n 5≤ A ≥19

  3. Numerical simulation of a low-lying barrier island's morphological response to Hurricane Katrina

    Science.gov (United States)

    Lindemer, C.A.; Plant, N.G.; Puleo, J.A.; Thompson, D.M.; Wamsley, T.V.

    2010-01-01

    Tropical cyclones that enter or form in the Gulf of Mexico generate storm surge and large waves that impact low-lying coastlines along the Gulf Coast. The Chandeleur Islands, located 161. km east of New Orleans, Louisiana, have endured numerous hurricanes that have passed nearby. Hurricane Katrina (landfall near Waveland MS, 29 Aug 2005) caused dramatic changes to the island elevation and shape. In this paper the predictability of hurricane-induced barrier island erosion and accretion is evaluated using a coupled hydrodynamic and morphodynamic model known as XBeach. Pre- and post-storm island topography was surveyed with an airborne lidar system. Numerical simulations utilized realistic surge and wave conditions determined from larger-scale hydrodynamic models. Simulations included model sensitivity tests with varying grid size and temporal resolutions. Model-predicted bathymetry/topography and post-storm survey data both showed similar patterns of island erosion, such as increased dissection by channels. However, the model under predicted the magnitude of erosion. Potential causes for under prediction include (1) errors in the initial conditions (the initial bathymetry/topography was measured three years prior to Katrina), (2) errors in the forcing conditions (a result of our omission of storms prior to Katrina and/or errors in Katrina storm conditions), and/or (3) physical processes that were omitted from the model (e.g., inclusion of sediment variations and bio-physical processes). ?? 2010.

  4. Low-Lying Electronic States of AlZn Calculated by MRCI+Q Method

    Science.gov (United States)

    Zhang, Shudong; Wang, Mingxu; Wang, Zifan; Hu, Kun; Dong, Jingping

    2017-07-01

    Some low-lying electronic states of AlZn have been studied by the ab initio calculation method of multireference configuration interaction (MRCI). The complete potential energy curves (PECs) of the three lowest doublet states (X2Π, A2Σ+, and B2Π) and the two lowest quartet states (a4Σ- and b4Π) are computed in the range of R = 0.1-0.9 nm and these states are correlated to three dissociation limits, X2Π and A2Σ+ to Zn(4s2,1S) + Al(3s23p1,2P), a4Σ- and b4Π to Zn(4s2,1S) + Al(3s13p2,4P), and B2Π to Zn(4s14p1,3P) + Al(3s23p1,2P). The calculated PECs indicate that the A2Σ+ state has a very shallow potential well and the other states show significant binding-state characteristics. The equilibrium internuclear distances Re, dissociation energies De, and term energies Te for the electronic excited states were obtained. All the possible vibrational levels, rotational constants, and spectral constants for the four bound states were computed by solving the radial Schrödinger equation of nuclear motion with the Level8.0 program provided by Le Roy.

  5. Low-lying baryon spectrum with two dynamical twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, C. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Computation-based Science and Technology Research Center, Cyprus Institute, Nicosia (Cyprus); Baron, R.; Guichon, P. [CEA-Saclay, IRFU/Service de Physique Nucleaire, Gif-sur-Yvette (France); Carbonell, J.; Drach, V. [UJF/CNRS/IN2P3, Grenoble (France). Lab. de Physique Subatomique et Cosmologie; Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Korzec, T. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Pene, O. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique

    2009-10-15

    The masses of the low lying baryons are evaluated using two degenerate flavors of twisted mass sea quarks corresponding to pseudo scalar masses in the range of about 270 MeV to 500 MeV. The strange valence quark mass is tuned to reproduce the mass of the kaon in the physical limit. The tree-level Symanzik improved gauge action is employed. We use lattices of spatial size 2.1 fm and 2.7 fm at two values of the lattice spacing with r{sub 0}/a=5.22(2) and r{sub 0}/a=6.61(3). We check for both finite volume and cut-off effects on the baryon masses. We performed a detailed study of the chiral extrapolation of the octet and decuplet masses using SU(2) {chi}PT. The lattice spacings determined using the nucleon mass at the physical point are consistent with the values extracted using the pion decay constant. We examine the issue of isospin symmetry breaking for the octet and decuplet baryons and its dependence on the lattice spacing. We show that in the continuum limit isospin breaking is consistent with zero, as expected. The baryon masses that we find after taking the continuum limit and extrapolating to the physical limit are in good agreement with experiment. (orig.)

  6. Effects of pairing correlation on low-lying quasi-particle resonance in neutron drip-line nuclei

    OpenAIRE

    Kobayashi, Yoshihiko; Matsuo, Masayuki

    2015-01-01

    We discuss effects of pairing correlation on quasi-particle resonance. We analyze in detail how the width of low-lying quasi-particle resonance is governed by the pairing correlation in the neutron drip-line nuclei. We consider the 46Si + n system to discuss low-lying p wave quasi-particle resonance. Solving the Hartree-Fock-Bogoliubov equation in the coordinate space with scattering boundary condition, we calculate the phase shift, the elastic cross section, the resonance width and the reson...

  7. Three band crossings in the yrast structure of 162Hf

    International Nuclear Information System (INIS)

    Bingham, C.R.; Riedinger, L.L.; Courtney, L.H.

    1988-01-01

    The yrast sequence of 162 Hf has been observed up to a level tentatively assigned as 38 + and reveals a continuing rotational character up to that spin. Sharp backbends at rotational frequencies of 0.27 and 0.42 MeV/ℎ are attributed to isub(13/2) neutron and hsub(11/2) proton alignments, respectively. A gradual increase in the aligned angular momentum of the yrast levels between these two sharp backbends is attributed to the rotational alignment of a pair of negative parity quasineutrons (mostly hsub(9/2) in character). The interpretation of this effect is supported by the failure of the negative parity bands, which already contain this aligned hsub(9/2) neutron, to gain alignment in the same rotational frequency range. While the alignment of the hsub(9/2) quasineutrons has been predicted in the cranked shell model to occur in the rare-earth region with a large interaction strength, this represents the first clear observation of such a band crossing. (author)

  8. Testing the tetraquark structure for the X resonances in the low-lying region

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hungchong [Kookmin University, Department of General Education, Seoul (Korea, Republic of); Kim, K.S. [Korea Aerospace University, School of Liberal Arts and Science, Goyang (Korea, Republic of); Cheoun, Myung-Ki [Soongsil University, Department of Physics, Seoul (Korea, Republic of); Jido, Daisuke [Tokyo Metropolitan University, Department of Physics, Hachioji, Tokyo (Japan); Oka, Makoto [Tokyo Institute of Technology, Department of Physics, Meguro (Japan); Japan Atomic Energy Agency, Advanced Science Research Center, Tokai, Ibaraki (Japan)

    2016-07-15

    Assuming the four-quark structure for the X resonances in the low-lying region, we calculate their masses using the color-spin interaction. Specifically, the hyperfine masses of the color-spin interaction are calculated for the possible states in spin-0, spin-1, spin-2 channels. The two states in spin-0 channel as well as the two states in spin-1 channel are diagonalized in order to generate the physical hyperfine masses. By matching the difference in hyperfine masses with the splitting in corresponding hadron masses and using the X(3872) mass as an input, we estimate the masses corresponding to the states J{sup PC} = 0{sup ++}, 1{sup +-}, 2{sup ++}. We find that the masses of two states in 1{sup +-} are close to those of X(3823), X(3900), and the mass of the 2{sup ++} state is close to that of X(3940). For them, the discrepancies are about ∝ 10 MeV. This may suggest that the quantum numbers of the controversial states are X(3823) = 1{sup +-}, X(3900) = 1{sup +-}, X(3940) = 2{sup ++}. In this work, we use the same inputs parameters, the constituent quark masses and the strength of the color-spin interaction, that have been adopted in the previous work on the D- or B-meson excited states. There, it was shown that the four-quark structure can be manifested in their excited states. Thus, our results in this work provide a consistent treatment on open- and hidden-charm mesons as far as the four-quark model is concerned. (orig.)

  9. A comparative study of the spectroscopic features of the low-lying ...

    Indian Academy of Sciences (India)

    Administrator

    31G*) perturbation level of theory. Botschwina. 32,33 ... procedure (G2 theory), based on ab initio molecular orbital theory ...... Hopefully, this present work will motivate experi- mentalists to .... Huber K P and Herzberg G 1979 Molecular spectra.

  10. Low-lying qq(qq)-bar states in a relativistic model based on the Bethe-Salpeter equation

    International Nuclear Information System (INIS)

    Ram, B.; Kriss, V.

    1985-01-01

    Low-lying qq(qq)-bar states are analysed in a previously given relativistic model based on the Bethe-Salpeter equation. It is not got M-diquonia, P-mesonia, or meson molecules, but it is got T-diquonia

  11. Low-lying level structure of the neutron-rich nucleus {sup 109}Nb: A possible oblate-shape isomer

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H., E-mail: hiroshi@ribf.riken.j [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Sumikama, T. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Li, Z. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Miyashita, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Yamaguchi, K. [Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka (Japan); Baba, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Berryman, J.S. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Blasi, N. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Bracco, A.; Camera, F. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Chiba, J. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Doornenbal, P. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Go, S.; Hashimoto, T.; Hayakawa, S. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Hinke, C. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Ideguchi, E. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Isobe, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-01-31

    The neutron-rich nuclei {sup 109}Nb and {sup 109}Zr have been populated using in-flight fission of a {sup 238}U beam at 345 MeV/nucleon at the RIBF facility. A T{sub 1/2}=150(30) ns isomer at 313 keV has been identified in {sup 109}Nb for the first time. The low-lying levels in {sup 109}Nb have been also populated following the {beta}-decay of {sup 109}Zr. Based on the difference in feeding pattern between the isomeric and {beta} decays, the decay scheme from the isomeric state in {sup 109}Nb was established. The observed hindrances of the electromagnetic transitions deexciting the isomeric state are discussed in terms of possible shape coexistence. Potential energy surface calculations for single-proton configurations predict the presence of low-lying oblate-deformed states in {sup 109}Nb.

  12. Experimental study of the low-lying structure of 94Zr with the (n,n'γ) reaction

    International Nuclear Information System (INIS)

    Elhami, E.; Orce, J. N.; Scheck, M.; Mukhopadhyay, S.; Choudry, S. N.; McEllistrem, M. T.; Yates, S. W.; Angell, C.; Boswell, M.; Karwowski, H. J.; Fallin, B.; Howell, C. R.; Hutcheson, A.; Parpottas, Y.; Tonchev, A. P.; Tornow, W.; Kelley, J. H.

    2008-01-01

    The low-lying structure of 40 94 Zr was studied with the (n,n ' γ) reaction, and a level scheme was established based on excitation function and γγ coincidence measurements. Branching ratios, multipole mixing ratios, and spin assignments were determined from angular distribution measurements. Lifetimes of levels up to 3.4 MeV were measured by the Doppler-shift attenuation method, and for many transitions the reduced transition probabilities were determined. In addition to the anomalous 2 2 + state, which has a larger B(E2;2 2 + →0 1 + ) value than the B(E2;2 1 + →0 1 + ), the experimental results revealed interesting and unusual properties of the low-lying states in 94 Zr. In a simple interpretation, the excited states are classified in two distinct categories, i.e., those populating the 2 2 + state and those decaying to the 2 1 + state

  13. Present status of the microscopic study of low-lying collective states in spherical and transitional nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Takada, Kenjiro; Sakata, Fumihiko.

    1981-12-01

    The history and the present status of the microscopic study of the low-lying collective excited states in spherical and transitional nuclei are discussed by putting emphasis on explaining the rather modern microscopic investigations of the concept of collective subspace. Importance of the dynamical interplay between the pairing and the quadrupole correlations is emphasized as a crucial element to mediate coupling between the collective and non-collective subspace. (author)

  14. Seniority four admixures in the low-lying 0+ states of even-mass tin and lead nuclei

    International Nuclear Information System (INIS)

    Quesne, C.; Salmon, Y.; Spitz, S.

    1977-01-01

    New statistical measures of symmetry breaking are used to evaluate the total seniority four admixtures in the low-lying 0 + states of even-mass tin and lead nuclei. This approach is based on the centroid energies and partial widths of fixed total seniority and parity spectral distributions. Some seniority four states are found to be surprisingly low. However, the ground state is always a very pure seniority zero state

  15. Low-lying electric-dipole strengths of Ca, Ni, and Sn isotopes imprinted on total reaction cross sections

    Science.gov (United States)

    Horiuchi, W.; Hatakeyama, S.; Ebata, S.; Suzuki, Y.

    2017-08-01

    Low-lying electric-dipole (E 1 ) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on 40Ca, 120Sn, and 208Pb targets to probe the E 1 strength of neutron-rich Ca, Ni, and Sn isotopes. They exhibit large enhancement of the E 1 strength at neutron number N >28 , 50, and 82, respectively, due to a change of the single-particle orbits near the Fermi surface participating in the transitions. The density distributions and the electric-multipole strength functions of those isotopes are calculated by the Hartree-Fock+BCS and the canonical-basis-time-dependent-Hartree-Fock-Bogoliubov methods, respectively, using three kinds of Skyrme-type effective interaction. The nuclear and Coulomb breakup processes are respectively described with the Glauber model and the equivalent photon method in which the effect of finite-charge distribution is taken into account. The three Skyrme interactions give different results for the total reaction cross sections because of different Coulomb breakup contributions. The contribution of the low-lying E 1 strength is amplified when the low-incident energy is chosen. With an appropriate choice of the incident energy and target nucleus, the total reaction cross section can be complementary to the Coulomb excitation for analyzing the low-lying E 1 strength of unstable nuclei.

  16. Theoretical study of the low lying states of AmO{sub 2}{sup n+}, n = 1, 2, 3

    Energy Technology Data Exchange (ETDEWEB)

    Notter, F.P.; Dubillard, S.; Bolvin, H. [Institut de Chimie de Strasbourg, (France)

    2007-07-01

    the valence space and when possible, Fock-space coupled-cluster method. For each molecule, equilibrium distance is evaluated and the spectrum of low lying excited states is calculated. Furthermore, the results are discussed in terms of ligand field theory. References [1] R. G. Denning, T.R. Snellgrove, and D.R. Woodwark. Molec. Phys., 37, 1109, (1979); [2] Z. Zhang and R.M. Pitzer. J. Phys. Chem. A, 103, 6880, (1999); [3] S. Matsika and R.M. Pitzer. J. Phys. Chem. A, 105, 637, (2001); [4] C. Clavaguera-Sarrio, V. Vallet, D. Maynau, and C.J. Marsden. J. Chem. Phys., 123, 204309, (2005); [5] L. Gagliardi, B.O. Roos, P.A. Malmqvist, and J. M. Dyke. J. Phys. Chem. A, 105, 10602, (2001); [6] S. Matsika and R. M. Pitzer. J. Phys. Chem. A, 104, 4064, (2000); [7] L. Maron, T. Leininger, B. Schimmelpfennig, V. Vallet, J.L. Heully, C. Teichtel, O. Gropen, and U. Wahlgren. Chem. Phys., 244, 195, (1999); [8] C. Clavaguera-Sarrio, V. Vallet, D. Maynau, and C.J. Marsden. J. Chem. Phys., 121, 5312, (2004); [9] I. Invante, A. Severo Perera Gomes, and L. Visscher. J. Chem. Phys., 125, 074301, (2006)

  17. Shell evolution of stable N = 50-56 Zr and Mo nuclei with respect to low-lying octupole excitations

    Energy Technology Data Exchange (ETDEWEB)

    Gregor, E.T.; Scheck, M.; Chapman, R.; Gaffney, L.P.; Keatings, J.; Mashtakov, K.R.; O' Donnell, D.; Smith, J.F.; Spagnoletti, P.; Wiseman, C. [University of the West of Scotland, School of Engineering and Computing, Paisley (United Kingdom); SUPA, Scottish Universities Physics Alliance, Glasgow (United Kingdom); Thuerauf, M.; Werner, V. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany)

    2017-03-15

    For the N = 50-56 zirconium (Z = 40) and molybdenum (Z = 42) isotopes, the evolution of subshells is evaluated by extracting the effective single-particle energies from available particle-transfer data. The extracted systematic evolution of neutron subshells and the systematics of the excitation energy of the octupole phonons provide evidence for type-II shape coexistence in the Zr isotopes. Employing a simplistic approach, the relative effective single-particle energies are used to estimate whether the formation of low-lying octupole-isovector excitations is possible at the proposed energies. The results raise doubts about this assignment. (orig.)

  18. Low-lying dipole response in the stable 40,48Ca nuclei within the second random-phase approximation

    International Nuclear Information System (INIS)

    Gambacurta, D.; Grasso, M.; Catara, F.

    2012-01-01

    The low-lying dipole strength distributions of 40 CaCa and 48 Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle −2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle −1 hole nature and its transition densities.

  19. Low-lying dipole response in the stable 40,48Ca nuclei within the second random-phase approximation

    Science.gov (United States)

    Gambacurta, D.; Grasso, M.; Catara, F.

    2012-10-01

    The low-lying dipole strength distributions of 40CaCa and 48Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle -2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle -1 hole nature and its transition densities.

  20. Factors associated with low-lying intrauterine devices: a cross-sectional ultrasound study in a cohort of African-American women.

    Science.gov (United States)

    Moshesh, Malana; Saldana, Tina; Deans, Elizabeth; Cooper, Tracy; Baird, Donna

    2018-03-14

    The object of this study is to examine factors and symptoms associated with low-lying IUDs as defined by ultrasound. This is a cross-sectional sub-study of participants in the Study of Environment, Life-style, and Fibroids (SELF). SELF participants had screening ultrasounds for fibroids at study enrollment; those with an IUD in place are included in this sub-study. Low-lying IUDs were identified and localized. Logistic regression was used to identify factors and symptoms associated with low-lying IUDs. Among 168 women with IUDs at ultrasound, 28 (17%) had a low-lying IUD. Having a low-lying IUD was associated with low education level (≤high school: aOR 3.1 95% CI 1.14-8.55) and with increased BMI (p=.002). Women with a low-lying IUD were more likely to report a "big problem" with dysmenorrhea (the highest option of the Likert scale) as compared to women with a normally-positioned IUD (OR 3.2 95% CI 1.07-9.54). Our study found that women with a low-lying IUD are more likely to be of lower education and higher BMI, and to report more dysmenorrhea. Women who are obese may benefit from additional counseling and closer follow-up after IUD placement. Future research is warranted to investigate IUD placement and possible IUD migration among women who are obese. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Symmetrized density matrix renormalization group algorithm for low-lying excited states of conjugated carbon systems: Application to 1,12-benzoperylene and polychrysene

    Science.gov (United States)

    Prodhan, Suryoday; Ramasesha, S.

    2018-05-01

    The symmetry adapted density matrix renormalization group (SDMRG) technique has been an efficient method for studying low-lying eigenstates in one- and quasi-one-dimensional electronic systems. However, the SDMRG method had bottlenecks involving the construction of linearly independent symmetry adapted basis states as the symmetry matrices in the DMRG basis were not sparse. We have developed a modified algorithm to overcome this bottleneck. The new method incorporates end-to-end interchange symmetry (C2) , electron-hole symmetry (J ) , and parity or spin-flip symmetry (P ) in these calculations. The one-to-one correspondence between direct-product basis states in the DMRG Hilbert space for these symmetry operations renders the symmetry matrices in the new basis with maximum sparseness, just one nonzero matrix element per row. Using methods similar to those employed in the exact diagonalization technique for Pariser-Parr-Pople (PPP) models, developed in the 1980s, it is possible to construct orthogonal SDMRG basis states while bypassing the slow step of the Gram-Schmidt orthonormalization procedure. The method together with the PPP model which incorporates long-range electronic correlations is employed to study the correlated excited-state spectra of 1,12-benzoperylene and a narrow mixed graphene nanoribbon with a chrysene molecule as the building unit, comprising both zigzag and cove-edge structures.

  2. Theoretical spectroscopic studies of the atomic transitions and lifetimes of low-lying states in Ti IV

    International Nuclear Information System (INIS)

    Mandal, Subhasish; Dixit, Gopal; Majumder, Sonjoy; Sahoo, B K; Chaudhuri, R K

    2008-01-01

    The astrophysically important electric quadrupole (E2) and magnetic dipole (M1) transitions for the low-lying states of triply ionized titanium (Ti IV) are calculated very accurately using a state-of-the-art all-order many-body theory called coupled cluster (CC) method in the relativistic framework. Different many-body correlations of the CC theory has been estimated by studying the core and valence electron excitations to the unoccupied states. The calculated excitation energies of different states are in excellent agreement with the measurements. Also, we compare our calculated electric dipole (E1) amplitudes of few transitions with recent many-body calculations by others. The lifetimes of the low-lying states of Ti IV have been estimated and long lifetime is found for the first excited 3d 2 D 5/2 state, which suggested that Ti IV may be one of the useful candidates for many fundamental studies of physics. Most of the forbidden transition results reported here are not available in the literature, to the best of our knowledge

  3. Low-lying magnetic dipole strength distribution in the γ-soft even-even 130-136Ba

    International Nuclear Information System (INIS)

    Guliyev, E.; Ertugral, F.; Kuliev, A.A.

    2006-01-01

    In this study the scissors mode 1 + states are systematically investigated within the rotational invariant Quasiparticle Random Phase Approximation (QRPA) for 130-136 Ba isotopes. We consider the 1 + vibrations generated by the isovector spin-spin interactions and the isoscalar and isovector quadrupole-type separable forces restoring the broken symmetry by a deformed mean field according to A.A. Kuliev et al. (Int. J. Mod. Phys. E 9, 249 (2000)). It has been shown that the restoration of the broken rotational symmetry of the Hamiltonian essentially decreases the B(M1) value of the low-lying 1 + states and increases the collectivization of the scissors mode excitations in the spectroscopic energy region. The agreement between the calculated mean excitation energies as well as the summed B(M1) value of the scissors mode excitations and the available experimental data of 134 Ba and 136 Ba is rather good. A destructive interference between the orbit and spin part of the M1 strength has been found for barium isotopes near the shell closer. For all the nuclei under investigation, the low-lying M1 transitions have ΔK=1 character as it is the case for the well-deformed nuclei. (orig.)

  4. Isomeric and high-spin states of 94Tc and the search for yrast isomers near Napprox.50

    International Nuclear Information System (INIS)

    Lee, I.Y.; Johnson, N.R.; McGowan, F.K.; Young, G.R.; Guidry, M.W.; Yates, S.W.

    1981-01-01

    A search for isomers in the Napprox.50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94 Tc, while the yrast sequence of 94 Tc has been established to more than 5 MeV in excitation energy

  5. The Prevalence and Role of Low Lying Peroneus Brevis Muscle Belly in Patients with Peroneal Tendon Pathologies: A Potential Source for Tendon Subluxation

    OpenAIRE

    Mirmiran, Roya; Squire, Chad; Wassell, Daniel

    2015-01-01

    A low lying peroneus brevis muscle belly is a rare anomaly. There are few published studies that support presence of this anomaly as an etiology for peroneal tendon tear. However, the association between a low lying peroneus muscle belly (LLMB) and tendon subluxation is not well explored. In this retrospective study, the magnetic resonance imaging (MRI) and intraoperative findings of 50 consecutive patients undergoing a primary peroneal tendon surgery, in a five year period, were assessed. Th...

  6. The low-lying quartet electronic states of group 14 diatomic borides XB (X = C, Si, Ge, Sn, Pb)

    Science.gov (United States)

    Pontes, Marcelo A. P.; de Oliveira, Marcos H.; Fernandes, Gabriel F. S.; Da Motta Neto, Joaquim D.; Ferrão, Luiz F. A.; Machado, Francisco B. C.

    2018-04-01

    The present work focuses in the characterization of the low-lying quartet electronic and spin-orbit states of diatomic borides XB, in which X is an element of group 14 (C, Si, Ge, Sn, PB). The wavefunction was obtained at the CASSCF/MRCI level with a quintuple-ζ quality basis set. Scalar relativistic effects were also taken into account. A systematic and comparative analysis of the spectroscopic properties for the title molecular series was carried out, showing that the (1)4Π→X4Σ- transition band is expected to be measurable by emission spectroscopy to the GeB, SnB and PbB molecules, as already observed for the lighter CB and SiB species.

  7. Dielectronic recombination into excited levels of Ne-like titanium from F-like low-lying states

    International Nuclear Information System (INIS)

    Qiu Yanghui; Li Shichang; Sun Yongsheng

    1993-01-01

    The energy levels, wavelengths, oscillator strengths, Auger rates and level-to-level dielectronic recombination rate coefficients describing dielectronic recombination into excited levels of Ne-like titanium from F-like low-lying states are calculated. Our calculations are based on Dr. R.D. Cowan's semi-relativistic mass-velocity and Darwin corrections are included in the Hamiltonian, and the distorted-wave model is used for the calculation of free electron wavefunctions. In order to set the recombination rate coefficients on a level by level basis, in a manner compatible with detailed level population kinetics modelling of highly-stripped ions in plasma, the dielectronic recombination rate coefficients as a function of free electron temperatures are given in an analytical form, which is not only very convenient in practice, but also hopefully accurate compared with the exactly calculated numerical results. (orig.)

  8. Evolution of the low-lying dipole strength in deformed nuclei with extreme neutron excess with the Relativistic QRPA

    International Nuclear Information System (INIS)

    Pena Arteaga, D.; Khan, E.; Ring, P.

    2009-01-01

    Covariant density functional theory, in the framework of self-consistent Relativistic Hartree Bogoliubov (HFB) and Relativistic Quasiparticle Random Phase approximation (RQRPA), is for the first time applied to axially deformed nuclei [1]. The fully self-consistent RHB+RQRPA equations are posed for the case of axial symmetry and different energy functionals, and solved with the help of a new parallel code. As a sample application, the El strength is systematically analyzed in very neutron-rich Sn nuclei, beyond 1 32S n until 1 66S n [2]. The great neutron excess favors the appearance of a deformed ground state for 1 42-162S n. The evolution of the low-lying strength in deformed nuclei is discussed, and in particular its dependence on the interplay of two major and competing factors, isospin asymmetry and deformation.(author)

  9. Calculations of the Low-Lying Structures in the Even-Even Nd/Sm/Gd/Dy Isotopes

    Science.gov (United States)

    Lee, Su Youn; Lee, J. H.; Lee, Young Jun

    2018-05-01

    The nuclear structure of deformed nuclei has been studied using the interacting boson model (IBM). In this study, energy levels and E2 transition probabilities were determined for even nuclei in the Nd/Sm/Gd/Dy chains which have a transition characteristic between the rotational, SU(3) and vibrational, U(5) limits. The structure of the nuclei exhibits a slight breaking of the SU(3) symmetry in the direction of U(5), and therefore, we add the d-boson number operator n d , which is the main term of the U(5) symmetric Hamiltonian, to the SU(3) Hamiltonian of the IBM. The calculated results for low-lying energy levels and E2 transition rates in Nd/Sm/Gd/Dy isotopes are in reasonably good agreement with known experimental results.

  10. An ab initio study on four low-lying electronic potential energy curves for atomic cesium and rare gas pairs

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Yuki, Kenta; Matsuoka, Leo

    2016-01-01

    Using multireference configuration interaction (MRCI) calculations with single and double excitation levels, Davidson correction, and a spin-orbit (SO) effective core potential, we have developed a series of four low-lying electronic potential energy curves (PECs) for the pairs formed between a cesium atom (Cs) and a rare gas (Rg = He, Ne, Ar, Kr, and Xe). The results obtained at the MRCI level were compared with those generated at the SOCI level, which were recently reported by Blank et al. The shapes of the PECs were essentially the same when the same basis set was used. Based on this agreement, more precise PECs for Cs-Rg pairs were calculated using a larger basis set for Rg. (author)

  11. The GSAM software: A global search algorithm of minima exploration for the investigation of low lying isomers of clusters

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, Rémi; Carbonnière, Philippe; Pouchan, Claude [Université de Pau et des Pays de l' Adour, IPREM/ECP, UMR CNRS 5254 (France)

    2015-01-22

    The study of atomic clusters has become an increasingly active area of research in the recent years because of the fundamental interest in studying a completely new area that can bridge the gap between atomic and solid state physics. Due to their specific properties, such compounds are of great interest in the field of nanotechnology [1,2]. Here, we would present our GSAM algorithm based on a DFT exploration of the PES to find the low lying isomers of such compounds. This algorithm includes the generation of an intial set of structure from which the most relevant are selected. Moreover, an optimization process, called raking optimization, able to discard step by step all the non physically reasonnable configurations have been implemented to reduce the computational cost of this algorithm. Structural properties of Ga{sub n}Asm clusters will be presented as an illustration of the method.

  12. Saltwater contamination in the managed low-lying farmland of the Venice coast, Italy: An assessment of vulnerability

    Energy Technology Data Exchange (ETDEWEB)

    Da Lio, Cristina, E-mail: cristina.dalio@ve.ismar.cnr.it [Institute of Marine Sciences, National Research Council, Arsenale — Tesa 104, Castello 2737/F, 30122 Venezia (Italy); Carol, Eleonora, E-mail: eleocarol@fcnym.unlp.edu.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Cátedra de Hidrología General, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata 64 n" o3 La Plata (Argentina); Kruse, Eduardo, E-mail: kruse@fcnym.unlp.edu.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Cátedra de Hidrología General, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata 64 n" o3 La Plata (Argentina); Teatini, Pietro, E-mail: pietro.teatini@unipd.it [Institute of Marine Sciences, National Research Council, Arsenale — Tesa 104, Castello 2737/F, 30122 Venezia (Italy); Dept. of Civil, Architectural and Environmental Engineering, University of Padova, Via Trieste 63, 35121 Padova (Italy); Tosi, Luigi, E-mail: luigi.tosi@ismar.cnr.it [Institute of Marine Sciences, National Research Council, Arsenale — Tesa 104, Castello 2737/F, 30122 Venezia (Italy)

    2015-11-15

    The original morphology and hydrogeology of many low-lying coastlands worldwide have been significantly modified over the last century through river diversion, embankment built-up, and large-scale land reclamation projects. This led to a progressive shifting of the groundwater–surficial water exchanges from naturally to anthropogenically driven. In this human-influenced hydrologic landscape, the saltwater contamination usually jeopardizes the soil productivity. In the coastland south of Venice (Italy), several well log measurements, chemical and isotope analyses have been performed over the last decade to characterize the occurrence of the salt contamination. The processing of this huge dataset highlights a permanent variously-shaped saline contamination up to 20 km inland, with different conditions in relation with the various geomorphological features of the area. The results point out the important role of the land reclamation in shaping the present-day salt contamination and reveal the contribution of precipitation, river discharge, lagoon and sea water to the shallow groundwater in the various coastal sectors. Moreover, an original vulnerability map to salt contamination in relation to the farmland productivity has been developed taking into account the electrical conductivity of the upper aquifer in the worst condition, the ground elevation, and the distance from salt and fresh surface water sources. Finally, the study allows highlighting the limit of traditional investigations in monitoring saltwater contamination at the regional scale in managed Holocene coastal environments. Possible improvements are outlined. - Highlights: • Land reclamation shapes the present saltwater contamination in the Venice coastland. • Natural and anthropogenic forcings drive the seawater flow in shallow aquifers. • Hydro-geophysical–geochemical investigations highlight the groundwater origin. • The vulnerability of the farmland to salt contamination extents up to 20

  13. Saltwater contamination in the managed low-lying farmland of the Venice coast, Italy: An assessment of vulnerability

    International Nuclear Information System (INIS)

    Da Lio, Cristina; o3 La Plata (Argentina))" data-affiliation=" (Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Cátedra de Hidrología General, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata 64 no3 La Plata (Argentina))" >Carol, Eleonora; o3 La Plata (Argentina))" data-affiliation=" (Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Cátedra de Hidrología General, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata 64 no3 La Plata (Argentina))" >Kruse, Eduardo; Teatini, Pietro; Tosi, Luigi

    2015-01-01

    The original morphology and hydrogeology of many low-lying coastlands worldwide have been significantly modified over the last century through river diversion, embankment built-up, and large-scale land reclamation projects. This led to a progressive shifting of the groundwater–surficial water exchanges from naturally to anthropogenically driven. In this human-influenced hydrologic landscape, the saltwater contamination usually jeopardizes the soil productivity. In the coastland south of Venice (Italy), several well log measurements, chemical and isotope analyses have been performed over the last decade to characterize the occurrence of the salt contamination. The processing of this huge dataset highlights a permanent variously-shaped saline contamination up to 20 km inland, with different conditions in relation with the various geomorphological features of the area. The results point out the important role of the land reclamation in shaping the present-day salt contamination and reveal the contribution of precipitation, river discharge, lagoon and sea water to the shallow groundwater in the various coastal sectors. Moreover, an original vulnerability map to salt contamination in relation to the farmland productivity has been developed taking into account the electrical conductivity of the upper aquifer in the worst condition, the ground elevation, and the distance from salt and fresh surface water sources. Finally, the study allows highlighting the limit of traditional investigations in monitoring saltwater contamination at the regional scale in managed Holocene coastal environments. Possible improvements are outlined. - Highlights: • Land reclamation shapes the present saltwater contamination in the Venice coastland. • Natural and anthropogenic forcings drive the seawater flow in shallow aquifers. • Hydro-geophysical–geochemical investigations highlight the groundwater origin. • The vulnerability of the farmland to salt contamination extents up to 20

  14. Microscopic insight in the study of yrast bands in selenium isotopes

    Indian Academy of Sciences (India)

    the rotational-like energy spacings of the yrast states with I≥6. ... even–even selenium isotopes, the study of structure of high spin states through mea- ... calculations with this model can achieve a comparable quality to the large-scale ... model in that the PSM uses the angular momentum projected states as the basis.

  15. Systematics of gamma decay through low-lying vibrational levels of even--even nuclei excited by (p,p') and (n,n') reactions

    International Nuclear Information System (INIS)

    Koopman, R.P.

    1977-01-01

    A series of experiments was performed in which gamma-ray spectra were measured, using a Ge(Li) detector, for incident 7 to 26-MeV protons on the even-even vibrational nuclei 56 Fe, 62 Ni, 64 Zn, 108 Pd, 110 Cd, 114 Cd, 116 Cd, 116 Sn, 120 Sn, and 206 Pb, and for incident 14-MeV neutrons on natural Fe, Ni, Zn, Cd, Sn, and Pb. These measurements yielded gamma-ray cross sections from which it was inferred that almost all of the gamma cascades from (p,p') and (n,n') reactions passed down through the first 2 + levels. Consequently, the strength of the 2 + → 0 + gamma transitions were found to be an indirect measure of the (p,p') or (n,n') cross sections. Several types of nuclear model calculations were performed and compared with experimental results. These calculations included coupled-channel calculations to reproduce the direct, collective excitation of the low-lying levels, and statistical plus pre-equilibrium model calculations to reproduce the (p,p') and the (n,n') cross sections for comparison with the 2 + → 0 + gamma measurements. The agreement between calculation and experiment was generally good except at high energies, where pre-equilibrium processes dominate (i.e. around 26-MeV). Here discrepancies between calculations from the two different pre-equilibrium models and between the data and the calculations were found. Significant isospin mixing of T/sub greater than/ into T/sub less than/ states was necessary in order to have the calculations match the data for the (p,p') reactions, up to about 18-MeV

  16. Theoretical study of the low-lying electronic states of magnesium sulfide cation including spin-orbit interaction

    Science.gov (United States)

    Chen, Peng; Wang, Ning; Li, Song; Chen, Shan-Jun

    2017-11-01

    Highly correlated ab initio calculations have been performed for an accurate determination of electronic structures and spectroscopic features for the low-lying electronic states of the MgS+ cation. The potential energy curves for the four Λ-S states correlating to the lowest dissociation asymptote are studied for the first time. Four Λ-S states split into nine Ω states through the spin-orbit coupling effect. Accurate spectroscopic constants are deduced for all bound states. The spin-orbit couplings and the transition dipole moments, as well as the PECs, are utilized to calculate Franck-Condon factors and radiative lifetimes of the vibrational levels. To verify our computational accuracy, analogous calculations for the ground state of MgS are also carried out, and our derived results are in reasonable agreement with available experimental data. In addition, photoelectron spectrum of MgS has been simulated. The predictive results are anticipated to serve as guidelines for further researches such as assisting laboratorial detections and analyzing observed spectrum.

  17. Structure and bonding of ScCN and ScNC: Ground and low-lying states

    International Nuclear Information System (INIS)

    Kalemos, Apostolos; Metropoulos, Aristophanes; Mavridis, Aristides

    2012-01-01

    Graphical abstract: The experimentally unknown systems ScCN and ScNC have been studied through single reference CISD and CCSD(T) methods. A total of 20 = 10 (ScCN) + 10 (ScNC) states were examined. All states are quite ionic whereas ScNC(X ∼3 Δ) is stabler than ScCN(X ∼3 Δ) by ∼5 kcal/mol. Display Omitted Highlights: ► We have studied through ab initio methods the polytopic system Sc[CN]. ► A series of low lying states for both isomeric forms have been examined. ► Around equilibrium the system displays a pronounced Sc + [CN] − ionic character. - Abstract: We have studied the experimentally unknown Sc[CN] molecular system in both its isomeric forms, scandium cyanide (ScCN) and isocyanide (ScNC), through ab initio computations. We report energetics, geometries, harmonic frequencies, and dipole moments for the first 20 Sc[CN] states correlating diabatically to Sc + ( 3 D, 1 D, 3 F) + CN − (X 1 Σ + ). Both isomers have a pronounced ionic character around equilibrium due to the high electron affinity of the CN group and the low ionization energy of the Sc atom. According to our calculations the ScNC isomer (X ∼3 Δ) is stabler than the ScCN(X ∼3 Δ) by ∼5 kcal/mol.

  18. Ab initio calculation on the low-lying excited states of Si2+ cation including spin–orbit coupling

    International Nuclear Information System (INIS)

    Liu, Yanlei; Zhai, Hongsheng; Zhang, Xiaomei; Liu, Yufang

    2013-01-01

    Highlights: • 24 Λ–S states are correlated to the dissociation limit of Si( 3 P g ) + Si + ( 2 P u ) are first reported. • The dissociation energies of the calculated electronic states are predicted in our work. • It is first time that the entire 54 Ω states generated from the 24 Λ–S states have been studied. • PECs of Λ–S and Ω states are depicted with the aid of avoided crossing rule between the same symmetry. - Abstract: Ab initio all-electron relativistic calculations of the low-lying excited states of Si 2 + have been performed at MRCI+Q/AVQZ level. The calculated electronic states, including 12 doublet and 12 quartet Λ–S states, are correlated to the dissociation limit of Si( 3 P g ) + Si + ( 2 P u ). Spin–orbit interaction is taken into account via the state interaction approach with the full Breit-Pauli Hamiltonian, which causes the entire 24 Λ–S states to split into 54 Ω states. This is the first time that spin–orbit coupling (SOC) calculation has been performed on Si 2 + . The obtained potential energy curves (PECs) of Λ–S and Ω states are respectively depicted with the aid of the avoided crossing rule between the same symmetry. The spectroscopic constants of the bound Λ–S and Ω states are determined, and excellent agreements with the latest theoretical results are achieved

  19. Saltwater contamination in the managed low-lying farmland of the Venice coast, Italy: An assessment of vulnerability.

    Science.gov (United States)

    Da Lio, Cristina; Carol, Eleonora; Kruse, Eduardo; Teatini, Pietro; Tosi, Luigi

    2015-11-15

    The original morphology and hydrogeology of many low-lying coastlands worldwide have been significantly modified over the last century through river diversion, embankment built-up, and large-scale land reclamation projects. This led to a progressive shifting of the groundwater-surficial water exchanges from naturally to anthropogenically driven. In this human-influenced hydrologic landscape, the saltwater contamination usually jeopardizes the soil productivity. In the coastland south of Venice (Italy), several well log measurements, chemical and isotope analyses have been performed over the last decade to characterize the occurrence of the salt contamination. The processing of this huge dataset highlights a permanent variously-shaped saline contamination up to 20km inland, with different conditions in relation with the various geomorphological features of the area. The results point out the important role of the land reclamation in shaping the present-day salt contamination and reveal the contribution of precipitation, river discharge, lagoon and sea water to the shallow groundwater in the various coastal sectors. Moreover, an original vulnerability map to salt contamination in relation to the farmland productivity has been developed taking into account the electrical conductivity of the upper aquifer in the worst condition, the ground elevation, and the distance from salt and fresh surface water sources. Finally, the study allows highlighting the limit of traditional investigations in monitoring saltwater contamination at the regional scale in managed Holocene coastal environments. Possible improvements are outlined. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Novel Solution for Low-Lying Land Areas Safe from Natural Hazards—Toward Reconstruction of Lost Coastal Areas in Northeast Japan

    Directory of Open Access Journals (Sweden)

    Toshio Nakajima

    2015-07-01

    Full Text Available The imminent fear of water-related hazards such as flooding hangs over low-lying areas, in particular now because climate changes have led to increased hazards, like storm surges, that could result in serious harm. This paper aims to provide a novel solution—namely “the floating platform”—that can transform dangerous low-lying areas into those safeguarded against potential hazards. Additionally, by utilizing this solution as a secure base for society to build atop this new artificial reservoir, we offer a better future role for such areas. Meanwhile, we propose adoption of our concept soon at two low-lying areas in northeast Japan hard-hit by the huge 11 March 2011 tsunami: Sendai’s Arahama coastal district and the still-devastated residential harbor area of Kesennuma, both cities in need of a fresh perspective.

  1. Studies of yrast and continuum states in A=140-160 nuclei. Progress report, January 1, 1980-December 31, 1980

    International Nuclear Information System (INIS)

    Daly, P.J.

    1981-01-01

    The structure of nuclei in the A approx. 150 region was investigated by in-beam γ-ray spectroscopy using heavy-ion beams, mostly from the Argonne Tandem-Linac. Results for the nuclei 148 Dy, 149 Dy, 153 Dy, 154 Dy, 149 Ho, and 150 Ho are summarized. The feeding of yrast states in these nuclei and the link between the highest known yrast states and the continuum region were also studied. 6 figures

  2. Runoff Effect Evaluation of LID through SWMM in Typical Mountainous, Low-Lying Urban Areas: A Case Study in China

    Directory of Open Access Journals (Sweden)

    Qinghua Luan

    2017-06-01

    Full Text Available Urban flooding occurs frequently in many regions of China. To reduce the losses caused by urban flooding, sponge city (SPC and low-impact development (LID have been carried out in many Chinese cities. However, urban flooding is influenced by various factors, such as climate, land cover characteristics and nearby river networks, so it is necessary to evaluate the effectiveness of LID measures. In this study, the Storm Water Management Model (SWMM was adopted to simulate historical urban storm processes in the mountainous Fragrance Hills region of Beijing, China. Subsequently, numerical simulations were performed to evaluate how various LID measures (concave greenbelt, permeable pavement, bio-retention, vegetative swales, and comprehensive measures influenced urban runoff reduction. The results showed that the LID measures are effective in controlling the surface runoff of the storm events with return periods shorter than five years, in particular, for one-year events. Furthermore, the effectiveness on traffic congestion mitigation of several LID measures (concave greenbelt, vegetative swales, and comprehensive measures was evaluated. However, the effective return periods of storm events are shorter than two years if the effectiveness on traffic congestion relief is considered. In all evaluated aspects, comprehensive measures and concave greenbelts are the most effective, and vegetative swale is the least effective. This indicated that LID measures are less effective for removing ponding from most storm events in a mountainous, low-lying and backward pipeline infrastructure region with pressures from interval flooding and urban waterlogging. The engineering measures including water conservancy projects and pipeline infrastructure construction combined with the non-engineering measures were suggested to effectively control severe urban storms.

  3. Seawater-flooding events and impact on freshwater lenses of low-lying islands: Controlling factors, basic management and mitigation

    Science.gov (United States)

    Gingerich, Stephen B.; Voss, Clifford I.; Johnson, Adam G.

    2017-08-01

    An unprecedented set of hydrologic observations was collected after the Dec 2008 seawater-flooding event on Roi-Namur, Kwajalein Atoll, Republic of the Marshall Islands. By two days after the seawater flooding that occurred at the beginning of dry season, the observed salinity of water withdrawn by the island's main skimming well increased to 100% seawater concentration, but by ten days later already decreased to only 10-20% of seawater fraction. However, the damaging impact on the potability of the groundwater supply (when pumped water had concentrations above 1% seawater fraction) lasted 22 months longer. The data collected make possible analyses of the hydrologic factors that control recovery and management of the groundwater-supply quality on Roi-Namur and on similar low-lying islands. With the observed data as a guide, three-dimensional numerical-model simulation analyses reveal how recovery is controlled by the island's hydrology. These also allow evaluation of the efficacy of basic water-quality management/mitigation alternatives and elucidate how groundwater withdrawal and timing of the seawater-flooding event affect the length of recovery. Simulations show that, as might be expected, by adding surplus captured rainwater as artificial recharge, the freshwater-lens recovery period (after which potable groundwater may again be produced) can be shortened, with groundwater salinity remaining lower even during the dry season, a period during which no artificial recharge is applied. Simulations also show that the recovery period is not lengthened appreciably by groundwater withdrawals during recovery. Simulations further show that had the flooding event occurred at the start of the wet season, the recovery period would have been about 25% (5.5 months) shorter than actually occurred during the monitored flood that occurred at the dry-season start. Finally, analyses show that artificial recharge improves freshwater-lens water quality, making possible longer use of

  4. Constrained-path quantum Monte Carlo approach for non-yrast states within the shell model

    Energy Technology Data Exchange (ETDEWEB)

    Bonnard, J. [INFN, Sezione di Padova, Padova (Italy); LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Juillet, O. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France)

    2016-04-15

    The present paper intends to present an extension of the constrained-path quantum Monte Carlo approach allowing to reconstruct non-yrast states in order to reach the complete spectroscopy of nuclei within the interacting shell model. As in the yrast case studied in a previous work, the formalism involves a variational symmetry-restored wave function assuming two central roles. First, it guides the underlying Brownian motion to improve the efficiency of the sampling. Second, it constrains the stochastic paths according to the phaseless approximation to control sign or phase problems that usually plague fermionic QMC simulations. Proof-of-principle results in the sd valence space are reported. They prove the ability of the scheme to offer remarkably accurate binding energies for both even- and odd-mass nuclei irrespective of the considered interaction. (orig.)

  5. Systematic behavior of B(E2) values in the yrast bands of doubly even nuclei

    International Nuclear Information System (INIS)

    Andrejtscheff, W.; Rutgers - the State Univ., New Brunswick, NJ; Nadjakov, E.; Venkova, T.

    1980-01-01

    The experimental information on B(E2) transition rates in the yrast bands of doubly even nuclei (126 2 (J: moment of inertia) are plotted versus the rotational frequency squared h/2π 2 ω 2 for each nucleus. In strongly deformed nuclei (N >= 90), the Ssub(exp) curves smoothly increase for low rotational frequencies suggesting that up to spin values I approx. 8 the ratio Q 2 0 /J is nearly constant (Q 0 : quadrupole moment). This is not the case in nuclei with a soft core (N <= 88). In the relevant discussion, the hydrodynamical model as well as the CAP effect are considered. The results in the backbending region are qualitatively discussed in terms of the two-band crossing model. Evidence is found supporting the prediction of an oscillating behavior of the yrast-yrare interaction. (orig.)

  6. Yrast bands and signature inversion in double odd 162,164Lu

    International Nuclear Information System (INIS)

    Cardona, M.A.; Hojman, D.; Kreiner, A.J.; Somacal, H.; Davidson, J.; Davidson, M.; Acuna, D. de; Napoli, D.R.; Rico, J.; Burch, R.; Bazzacco, D.; Lenzi, S.M.; Rossi Alvarez, C.; Blasi, N.; Lo Bianco, G.

    1996-01-01

    High spin rotational bands in 162 Lu and 164 Lu have been studied by means of the 139 La( 28 Si,5n) and 139 La( 29(30) Si,4(5)n) reactions respectively. For both nuclei the yrast sequence which is associated with the πh 11/2 x νi 13/2 configuration shows the signature inversion feature. (orig.)

  7. High spin states in 63Cu. 17/2+ isomeric yrast state

    International Nuclear Information System (INIS)

    Tsan Ung Chan; Bruandet, J.F.; Dauchy, A.; Giorni, A.; Glasser, F.; Morand, C.; Chambon, B.; Drain, D.

    1979-01-01

    The 63 Cu nucleus has been studied via the reaction 61 Ni(α, pnγ), using different in beam γ spectroscopy techniques. An isomeric high-spin Yrast state 17/2 + (tau = 6.1 +- 0.6ns) is located at 4498 keV. The gsub(9/2) shell must be involved to explain positive high-spin states established in this work [fr

  8. Vibrational circular dichroism spectroscopy of a spin-triplet bis-(biuretato) cobaltate(III) coordination compound with low-lying electronic transitions

    DEFF Research Database (Denmark)

    Johannessen, Christian; Thulstrup, Peter W.

    2007-01-01

    . The spectroscopic results were compared to measurements performed on the free ligand and to theoretical calculations using density functional theory (B3LYP/TZVP). The results of the VCD analysis of the coordination compound identified an electronic, dipole-forbidden, magnetic dipole-allowed low-lying d-d transition...

  9. Charge transfer and relativistic effects in the low-lying electronic states of CuCl, CuBr and CuI

    NARCIS (Netherlands)

    Sousa, C; de Jong, W.A.; Broer, R.; Nieuwpoort, WC

    1997-01-01

    The spectral transitions and the character of the low-lying excited states of the copper halides, CuX (X = Cl, Br, I) are studied by means of two different relativistic computational approaches. One is based on the CASSCF/CASPT2 approach with operators accounting for scalar relativistic effects

  10. Coastline evolution of Portuguese low-lying sandy coast in the last 50 years: an integrated approach

    Science.gov (United States)

    Ponte Lira, Cristina; Nobre Silva, Ana; Taborda, Rui; Freire de Andrade, Cesar

    2016-06-01

    Regional/national-scale information on coastline rates of change and trends is extremely valuable, but these studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but it is essential to conduct an integrated and holistic approach to coastline evolution and hence support coastal management actions. Additionally, databases providing knowledge on coastline evolution are of key importance to support both coastal management experts and users.The main objective of this work is to present the first systematic, national-scale and consistent long-term coastline evolution data of Portuguese mainland low-lying sandy coasts.The methodology used quantifies coastline evolution using a unique and robust coastline indicator (the foredune toe), which is independent of short-term changes.The dataset presented comprises (1) two polyline sets, mapping the 1958 and 2010 sandy beach-dune system coastline, both optimized for working at 1 : 50 000 scale or smaller; (2) one polyline set representing long-term change rates between 1958 and 2010, each estimated at 250 m; and (3) a table with minimum, maximum and mean of evolution rates for sandy beach-dune system coastline. All science data produced here are openly accessible at https://doi.pangaea.de/10.1594/PANGAEA.859136 and can be used in other studies.Results show beach erosion as the dominant trend, with a mean change rate of -0.24 ± 0.01 m year-1 for all mainland Portuguese beach-dune systems. Although erosion is dominant, this evolution is variable in signal and magnitude in different coastal sediment cells and also within each cell. The most relevant beach erosion issues were found in the coastal stretches of Espinho-Torreira and Costa Nova-Praia de Mira, Cova da Gala-Leirosa, and Cova do Vapor-Costa da Caparica. The coastal segments Minho River-Nazaré and Costa da Caparica adjacent to the coast exhibit a history of major human interventions

  11. Seawater-flooding events and impact on freshwater lenses of low-lying islands: Controlling factors, basic management and mitigation

    Science.gov (United States)

    Gingerich, Stephen B.; Voss, Clifford I.; Johnson, Adam G.

    2017-01-01

    An unprecedented set of hydrologic observations was collected after the Dec 2008 seawater-flooding event on Roi-Namur, Kwajalein Atoll, Republic of the Marshall Islands. By two days after the seawater flooding that occurred at the beginning of dry season, the observed salinity of water withdrawn by the island’s main skimming well increased to 100% seawater concentration, but by ten days later already decreased to only 10–20% of seawater fraction. However, the damaging impact on the potability of the groundwater supply (when pumped water had concentrations above 1% seawater fraction) lasted 22 months longer. The data collected make possible analyses of the hydrologic factors that control recovery and management of the groundwater-supply quality on Roi-Namur and on similar low-lying islands.With the observed data as a guide, three-dimensional numerical-model simulation analyses reveal how recovery is controlled by the island’s hydrology. These also allow evaluation of the efficacy of basic water-quality management/mitigation alternatives and elucidate how groundwater withdrawal and timing of the seawater-flooding event affect the length of recovery. Simulations show that, as might be expected, by adding surplus captured rainwater as artificial recharge, the freshwater-lens recovery period (after which potable groundwater may again be produced) can be shortened, with groundwater salinity remaining lower even during the dry season, a period during which no artificial recharge is applied. Simulations also show that the recovery period is not lengthened appreciably by groundwater withdrawals during recovery. Simulations further show that had the flooding event occurred at the start of the wet season, the recovery period would have been about 25% (5.5 months) shorter than actually occurred during the monitored flood that occurred at the dry-season start. Finally, analyses show that artificial recharge improves freshwater-lens water quality, making possible longer

  12. Gamma-ray continuum spectra from heavy ion reactions

    International Nuclear Information System (INIS)

    Beene, J.R.; Halbert, M.L.; Hensley, D.C.; Sarantites, D.G.; Westerberg, L.W.; Geoffroy, K.; Woodward, R.

    1979-01-01

    A detailed quantitative analysis of the yrast continuum was attempted by subtracting the underlying statistical continnuum in a way that makes allowance for ignorance of its detailed shape. This procedure makes it possible to obtain the moment of inertia as a function of spin over a wide range of spins. The results of this continuum spectra shape analysis can be used to calculate the first and second moments of the continuum multiplicity distribution. Continuum spectra were taken during the bombardment of 150 Nd by 115- and 130-MeV beams of 20 Ne, also the first and second moments of the γ-ray multiplicity distribution as a function of the gamma energy. The moment of inertia versus spin and the deduced Yrast continuua are shown. 10 references

  13. The Blackwater NWR inundation model. Rising sea level on a low-lying coast: land use planning for wetlands

    Science.gov (United States)

    Larsen, Curt; Clark, Inga; Guntenspergen, Glenn; Cahoon, Don; Caruso, Vincent; Hupp, Cliff; Yanosky, Tom

    2004-01-01

    shallow water surfaces has solved this problem. Our team has developed a detailed LIDAR map of the BNWR area at a 30 centimeter (ca. 1 ft) contour interval (figure 2). The new map allows us to identify the present marsh vegetation zones and to predict the location and area of future zones on a decade-by- decade basis over the next century at increments of sea level rise on the order of 3 cm/decade (ca. 1 inch). We have developed two scenarios for the model. The first is a steady-state model that uses the historic rate of sea level rise of 3.1 mm/yr to predict marsh areas. The second is a 'global warming' scenario utilizing a conservative IPCC model with an exponentially-increasing rate of sea level rise. Under either scenario, the BNWR is progressively inundated with an expanding core of open water. Although their positions change in the future, the areas of intertidal marsh as well as those of the critical high marsh remain fairly constant until the year 2050. Beyond that time, the low-lying land surface is overtopped by rising sea level and the area is dominated by open water. Our model suggests that wetland habitat in the Blackwater area might be maintained and sustained through a combination of public and private preservation efforts through easements in combination with judicious Federal land acquisition into the predicted areas of suitable marsh formation - but for only the next 50 years. Beyond that time much of this area will become open water.

  14. Enhanced spin polarization of elastic electron scattering from alkaline-earth-metal atoms in Ramsauer-Townsend and low-lying shape resonance regions

    International Nuclear Information System (INIS)

    Yuan, J.; Zhang, Z.

    1993-01-01

    Spin polarizations (SP's) of elastic electron scattering from alkaline-earth-metal atoms in Ramsauer-Townsend (RT) and low-lying shape resonance (SR) regions are calculated using a relativistic method. The detailed SP distributions both with scattering angle and with electron energy are presented via the energy- and angle-dependent surfaces of SP parameters. It is shown that the SP effects of the collisions of electrons with Ca, Sr, and Ba atoms in the RT region are significant in a considerable area on the energy-angle plane and that the spin-orbit interaction is well increased around the low-lying p-wave SR states of Be and Mg and the d-wave SR states of Ca, Sr, and Ba

  15. Isomeric and high-spin states of 94Tc and the search for yrast isomers near N~50

    Science.gov (United States)

    Lee, I. Y.; Johnson, N. R.; McGowan, F. K.; Young, G. R.; Guidry, M. W.; Yates, S. W.

    1981-07-01

    A search for isomers in the N~50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94Tc, while the yrast sequence of 94Tc has been established to more than 5 MeV in excitation energy. [NUCLEAR REACTIONS 76Ge, 78Se(20Ne,xnypγ), E=80.9 MeV, 89Y, 93Nb(10B,xnypγ), E=52.0,58.4,62.8 MeV; measured Eγ, Iγ, γ-γ prompt and delayed coin, γ-X coin; deduced levels, t12 of 94Tc isomer, yrast states.

  16. First observation of yrast band in odd-odd 162Lu

    International Nuclear Information System (INIS)

    Zhang, Y.H.; Yuan, G.J.; Liu, X.A.

    1996-01-01

    High spin states of the odd-odd 162 Lu nucleus have been studied via 147 Sm( 19 F, 4nγ) 162 Lu reaction at 95MeV beam energy. Level scheme for yrast band based on π[h 11/2 ] υ[i 13/2 ] quasiparticle configuration was established up to I π =(23 - ) for the first time. This band shows the signature inversion in energy before backbending generally appeared in this mass region. It is stressed that the signature splitting in 162 Lu is larger than that in the 160 Tm nucleus. (orig.)

  17. Microscopical structure of the states of deformed nuclei in the neighborhood of the yrast line

    International Nuclear Information System (INIS)

    Janssen, D.; Mikhailov, I.N.

    1979-01-01

    A simple model is derived which allows one to study the structure of the nuclear states in the neighborhood of the 'yrast' band. In the present scheme the precession motion plays a role of one of the normal modes of oscillations. (The structure of the dispersion equation for this mode corresponds to the well known classical formula.) Vibrational states associated with quadrupole oscillations of the nuclear shape are determined from a general equation. At slow rotation this equation breaks up into the known equations for β-, Δ- and γ-vibrations and non-collectivized Ksup(π)=1 + excitations. (Auth.)

  18. Investigation of octupole deformations in the Fr217 nucleus by yrast spectroscopy

    International Nuclear Information System (INIS)

    Hulne, S.

    1988-01-01

    The spectroscopic characteristics of the yrast levels of Fr217 are determined. The level scheme up to a value of J = (39/2 + ) for angular momentum and parity is established. The production of the Fr217 nucleus in a heavy ion collision reaction was only possible by using a radioactive Pb210 target. The method for preparing the target is described. The Fr217 nucleus belongs to the category of nuclei showing octupole effects. Mass A = 217 seems to be the lower limit of the region where these effects occur [fr

  19. New results on the superdeformed {sup 196}Pb nucleus: The decay of the excited bands to the yrast band

    Energy Technology Data Exchange (ETDEWEB)

    Bouneau, S.; Azaiez, F.; Duprat, J. [IPN, Orsay (France)] [and others

    1996-12-31

    The study of the superdeformed (SD) {sup 196}Pb nucleus has been revisited using the EUROGAM phase 2 spectrometer. In addition to the known yrast and two lowest excited SD bands, a third excited SD band has been seen. All of the three excited bands were found to decay to the yrast SD band through, presumably, E1 transitions, allowing relative spin and excitation energy assignments. Comparisons with calculations using the random-phase approximation suggest that all three excited bands can be interpreted as octupole vibrational structures.

  20. Yrast spectroscopy in {sup 49-51}Ti via fusion-evaporation reaction induced by a radioactive beam

    Energy Technology Data Exchange (ETDEWEB)

    Niikura, M.; Ideguchi, E.; Michimasa, S.; Ota, S.; Shimoura, S.; Wakabayashi, Y. [University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Aoi, N.; Baba, H.; Fukuchi, T.; Ichikawa, Y.; Kubo, T.; Kurokawa, M.; Ohnishi, T.; Suzuki, H.; Yoshida, K. [RIKEN Nishina Center, Wako, Saitama (Japan); Iwasaki, H.; Onishi, T.K.; Suzuki, D. [University of Tokyo, Department of Physics, Tokyo (Japan); Liu, M.; Zheng, Y. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2009-12-15

    In-beam {gamma} -ray spectroscopy of high-spin states in {sup 49-51}Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and {gamma} - {gamma} coincidence analysis, yrast high-spin levels up to I=(21/2{sup -}),(11{sup +}),(17/2{sup -}) in {sup 49-51}Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N=28 shell gap at yrast states in {sup 49-51}Ti. (orig.)

  1. An accelerated conjugate gradient algorithm to compute low-lying eigenvalues - a study for the Dirac operator in SU(2) lattice QCD

    International Nuclear Information System (INIS)

    Kalkreuter, T.; Simma, H.

    1995-07-01

    The low-lying eigenvalues of a (sparse) hermitian matrix can be computed with controlled numerical errors by a conjugate gradient (CG) method. This CG algorithm is accelerated by alternating it with exact diagonalizations in the subspace spanned by the numerically computed eigenvectors. We study this combined algorithm in case of the Dirac operator with (dynamical) Wilson fermions in four-dimensional SU(2) gauge fields. The algorithm is numerically very stable and can be parallelized in an efficient way. On lattices of sizes 4 4 - 16 4 an acceleration of the pure CG method by a factor of 4 - 8 is found. (orig.)

  2. Hierarchy of the low-lying excitations for the (2+1-dimensional q=3 Potts model in the ordered phase

    Directory of Open Access Journals (Sweden)

    Yoshihiro Nishiyama

    2017-03-01

    Full Text Available The (2+1-dimensional q=3 Potts model was simulated with the exact diagonalization method. In the ordered phase, the elementary excitations (magnons are attractive, forming a series of bound states in the low-energy spectrum. We investigate the low-lying spectrum through a dynamical susceptibility, which is readily tractable with the exact diagonalization method via the continued-fraction expansion. As a result, we estimate the series of (scaled mass gaps, m2,3,4/m1 (m1: single-magnon mass, in proximity to the transition point.

  3. Low-lying dipole response in the stable {sup 40,48}Ca nuclei within the second random-phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Gambacurta, D.; Grasso, M.; Catara, F. [GANIL,CEA/DSM-CNRS/IN2P3, Caen (France); Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France); Dipartimento di Fisica e Astronomia dell' Universita di and INFN Catania (Italy)

    2012-10-20

    The low-lying dipole strength distributions of {sup 40}CaCa and {sup 48}Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle -2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle -1 hole nature and its transition densities.

  4. Feasibility of Rainwater Harvesting to fulfill potable water demand using quantitative water management in low-lying delta regions of Asia

    Science.gov (United States)

    Mahmood, A.; Hossain, F.

    2016-12-01

    Low-lying deltas of Asian region are usually densely populated and located in developing countries situated at the downstream end of major rivers. Extensive dam construction by the upstream countries has now caused water scarcity in large portions of low-lying deltas. Most inhabitants depend on shallow tube well for safe drinking water that tend to suffer from water quality issues (e.g. Arsenic contamination). In addition, people also get infected from water borne diseases like Cholera and Typhoid due to lack of safe drinking water. Developing a centralized piped network based water supply system is often not a feasible option in rural regions. Due to social acceptability, environment friendliness, lower capital and maintenance cost, rainwater harvesting can be the most sustainable option to supply safe drinking water in rural areas. In this study, first we estimate the monthly rainfall variability using long precipitation climatology from satellite precipitation data. The upper and lower bounds of monthly harvestable rainwater were estimated for each satellite precipitation grid. Taking this lower bound of monthly harvestable rainwater as input, we use quantitative water management concept to determine the percent of the time of the year potable water demand can be fulfilled. Analysis indicates that a 6 m³ reservoir tank can fulfill the potable water demand of a 6 person family throughout a year in almost all parts of this region.

  5. Effect of high lying states on the ground and few low lying excited O+ energy levels of some closed-shell nuclei

    International Nuclear Information System (INIS)

    Ayoub, N.Y.

    1980-02-01

    The ground and some excited O + (J=O, T=O positive parity) energy levels of closed-shell nuclei are examined, in an oscillator basis, using matrix techniques. The effect of states outside the mixed (O+2(h/2π)ω). model space in 4 He (namely configurations at 4(h/2π)ω excitation) are taken into account by renormalization using the generalized Rayleigh-Schroedinger perturbation expressions for a mixed multi-configurational model space, where the resultant non-symmetric energy matrices are diagonalized. It is shown that the second-order renormalized O + energy spectrum is close to the corresponding energy spectrum obtained by diagonalizing the O+2+4(h/2π)ω 4 He energy matrix. The effect, on the ground state and the first few low-lying excited O + energy levels, of renormalizing certain parts of the model space energy matrix up to second order in various approximations is also studied in 4 He and 16 O. It is found that the low-lying O + energy levels in these various approximations behave similarly in both 4 He and 16 O. (author)

  6. Change of deformation at the backbending in the yrast superdeformed band of {sup 144}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Ur, C.A.; Bolzonella, G.P.; Bazzacco, D. [dell`Universita, Padova (Italy)]|[INFN, Padova (Italy)] [and others

    1996-12-31

    A mean lifetime measurement using the Doppler shift attenuation method has been performed at GASP in order to extract the quadrupole moment of the yrast SD band of {sup 144}Gd. The extracted intrinsic quadrupole moments, being Q{sub 0}=13.7 eb above the backbending and Q{sub 0}=11.8 eb below the backbending, are consistent with a change of deformation from {beta}{sub 2}=0.51 (at {beta}{sub 4} {approx} 0.050) to {beta}{sub 2}=0.45 (at {beta}{sub 4} {approx}0.035). The experimental results are in nice agreement with the theoretical predictions, which revealed that the second well in {sup 144}Gd arises essentially from the very favored shell structure at N=80 and Z=64. The occupation at higher frequency of the aligned N=6 proton orbitals drives the nucleus to a slightly more deformed shape.

  7. Spectroscopical study of the yrast and yrare structure in far-from-stability nuclei; Etude spectroscopique de la structure yrast et yrare de noyaux loin de la stabilite

    Energy Technology Data Exchange (ETDEWEB)

    Hoellinger Fabien [Institut de Recherches Subatomiques, 23, Rue du Loess, BP 28, 67037 Strasbourg Cedex 2 (France)]|[Universite Louis Pasteur, 67 - Strasbourg (France)

    1999-01-13

    The nuclear structure study of neutron-rich nuclei was realized with the EUROGAM II array in two different experiments. The first study consisted in the analysis of the product of spontaneous fission of {sup 248}Cm. Three neutron-rich cerium isotopes {sup 147,149,151}Ce were analyzed. A level scheme for {sup 151}Ce is presented for the first time. The yrast structure of the three nuclei does not show alternative parity bands as expected in this region of octupole deformations. We studied the rotational structure of the bands and this leads to suggest Nilsson configurations to some of them. The aim of this second experiment was the study of the nuclei {sup 99}Mo, {sup 101}Tc, {sup 103}Ru. The three nuclei are situated on the neutron-rich side of the nuclear chart and are produced as fission fragments of a heavy-ion induced reaction. Some bands are extended to higher spins and some new bands are observed. The structure of the rotational bands is interpreted by means of the Hartree-Fock-Bogolyubov model. A last experiment intended to study the structure of the proton-rich nucleus {sup 223}Pa has been achieved with the JURO+RITU array located at Jyvaeskylae (Finland). In this proton-rich actinide region, the nuclei develop octupole features around Z{approx_equal}88, N{approx_equal}132. The analysis of this experiment leads to the first assignment of gamma transitions to the {sup 223}Pa. (author) 91 refs., 78 figs., 16 tabs.

  8. Vibrational Fingerprints of Low-Lying PtnP2n (n = 1–5) Cluster Structures from Global Optimization Based on Density Functional Theory Potential Energy Surfaces

    KAUST Repository

    Jedidi, Abdesslem

    2015-11-13

    Vibrational fingerprints of small PtnP2n (n = 1–5) clusters were computed from their low-lying structures located from a global exploration of their DFT potential energy surfaces with the GSAM code. Five DFT methods were assessed from the CCSD(T) wavenumbers of PtP2 species and CCSD relative energies of Pt2P4 structures. The eight first PtnP2n isomers found are reported. The vibrational computations reveal (i) the absence of clear signatures made by overtone or combination bands due to very weak mechanical and electrical anharmonicities and (ii) some significant and recurrent vibrational fingerprints in correlation with the different PP bonding situations in the PtnP2n structures.

  9. Mass spectrum of low-lying baryons in the ground state in a relativistic potential model of independent quarks with chiral symmetry

    International Nuclear Information System (INIS)

    Barik, N.; Dash, B.K.

    1986-01-01

    Under the assumption that baryons are an assembly of independent quarks, confined in a first approximation by an effective potential U(r) = 1/2(1+γ 0 )(ar 2 +V 0 ) which presumably represents the nonperturbative gluon interactions, the mass spectrum of the low-lying ground-state baryons has been calculated by considering perturbatively the contributions of the residual quark-pion coupling arising out of the requirement of chiral symmetry and that of the quark-gluon coupling due to one-gluon exchange over and above the necessary center-of-mass correction. The physical masses of the baryons so obtained agree quite well with the corresponding experimental value. The strong coupling constant α/sub c/ = 0.58 required here to describe the QCD mass splittings is quite consistent with the idea of treating one-gluon-exchange effects in lowest-order perturbation theory

  10. Vibrational Fingerprints of Low-Lying PtnP2n (n = 1–5) Cluster Structures from Global Optimization Based on Density Functional Theory Potential Energy Surfaces

    KAUST Repository

    Jedidi, Abdesslem; Li, Rui; Fornasiero, Paolo; Cavallo, Luigi; Carbonniere, Philippe

    2015-01-01

    Vibrational fingerprints of small PtnP2n (n = 1–5) clusters were computed from their low-lying structures located from a global exploration of their DFT potential energy surfaces with the GSAM code. Five DFT methods were assessed from the CCSD(T) wavenumbers of PtP2 species and CCSD relative energies of Pt2P4 structures. The eight first PtnP2n isomers found are reported. The vibrational computations reveal (i) the absence of clear signatures made by overtone or combination bands due to very weak mechanical and electrical anharmonicities and (ii) some significant and recurrent vibrational fingerprints in correlation with the different PP bonding situations in the PtnP2n structures.

  11. Hyperfine structure of six low-lying fine structure levels of 191Ir and 193Ir and the 191Δs193 hyperfine anomaly

    International Nuclear Information System (INIS)

    Buettgenbach, S.; Dicke, R.; Gebauer, H.; Kuhnen, R.; Traeber, F.

    1978-01-01

    The hyperfine interaction constants A and B of six low-lying metastable fine structure states of the two iridium isotopes 191 Ir and 193 Ir and the electronic g-factors of these levels have been measured using the atomic-beam magnetic-resonance method. From the values of the magnetic-dipole interaction constants A, corrected for off-diagonal perturbations, we extracted the hyperfine anomaly of a pure 6s-electron state: 191 Δs 193 = 0.64(7)%. Using nonrelativistic approximations for the effective radial parameters the nuclear electric-quadrupole moments were obtained: Q( 191 Ir) = 0.81(21)b, Q( 193 Ir) = 0.73(19)b (corrected for Sternheimer shielding effects). (orig.) [de

  12. Ab initio study of small He cluster ions Hen+, n=2, 3, 4, 5, and low-lying Rydberg states of He4

    International Nuclear Information System (INIS)

    Staemmler, V.

    1990-01-01

    SCF and CEPA calculations are applied to study the structure of small He cluster ions, He n 3 , n=2, 3, 4, 5 and some low-lying Rydberg states of He 4 . The effect of electron correlation upon the equilibrium structures and binding energies is discussed. He 3 + has a linear symmetric equilibrium geometry with a bond length of 2.35 a 0 and a binding energy D e =0.165 eV with respect to He 2 + +He (experimentally: D 0 =0.17 eV which corresponds to D e ≅0.20 eV). He 4 + is a very floppy molecular ion with several energetically very similar geometrical configurations. Our CEPA calculations yield a T-shaped form with a He 3 + centre (R e =2.35 a 0 ) and one inductively bound He atom (4.39 a 0 from the central He atom of He 3 + ) as equilibrium structure. Its binding energy with respect to He 3 + +He is 0.031 eV. A linear symmetric configuration consisting of a He 2 + centre with a bond length of 2.10 a 0 and two inductively bound He atoms (4.20 a 0 from the centre of He 2 + ) is only 0.02-0.03 eV higher in energy. We expect that in larger He cluster ions structures with He 2 + and He 3 + centres and n-2 or n-3 inductively bound He atoms have nearly the same energies. In He 4 a low-lying metastable Rydberg state ( 3 π symmetry for linear He 4 * , 3 B 1 for the T-shaped form) exists which is slightly stronger bound with respect to He 3 * +He than the corresponding ion. (orig.)

  13. Population of yrast states in 191Os using deep-inelastic reactions

    Science.gov (United States)

    Jones, G. A.; Podolyák, Zs; Walker, P. M.; Regan, P. H.; de Angelis, G.; Axiotis, M.; Bazzacco, D.; Bizzeti, P. G.; Brandolini, F.; Broda, R.; Bucurescu, D.; Farnea, E.; Gelletly, W.; Gadea, A.; Ionescu-Bujor, M.; Iordachescu, A.; Kröll, Th; Langdown, S. D.; Lunardi, S.; Marginean, N.; Martinez, T.; Medina, N. H.; Quintana, B.; Rubio, B.; Ur, C. A.; Valiente-Dobón, J. J.; Williams, S. J.; Zhang, Y. H.

    2005-10-01

    Several nuclei in the A ~ 190 region have been studied following deep-inelastic reactions using a 460 MeV 82Se projectile impinging upon a thick 192Os target. The GASP array (at the Legnaro National Laboratory in Italy) was used to measure the resulting γ-decays. The previously reported near-yrast structure of 191Os is extended to a t\\frac{1{2}} = 61 ns isomer, at an energy of 2640 keV. Branching ratios for ΔI = 1 and ΔI = 2 transitions in the Kπ =\\frac{11}{2}+ band have been measured, giving |(gK - gR)/Q0| = 0.022(3) and 0.024(7) for transitions from the \\frac{17}{2}+ and \\big(\\frac{19}{2}^+\\big) states respectively. These are consistent with the theoretical calculation for the proposed ν11/2+[615] configuration of the band. Nilsson plus BCS calculations reveal that the isomer is likely to have a {ν11/2+[615] π11/2-[505] π9/2-[514]} configuration with Jπ =Kπ =\\frac{31}{2}+ . This yields an implied reduced hindrance of fν= 1.9, in accordance with empirical systematics of K isomers in the A ~ 180-190 region.

  14. Study of the anharmonic effects on low-lying states of odd-mass nuclei in 1g sub(9/2)+ shell region

    International Nuclear Information System (INIS)

    Nakano, Masahiro

    1980-01-01

    Anharmonic effects on the low-lying states of the odd-mass nuclei in 1g sub(9/2)sup(+) shell region are investigated by introduction of 1, 3, 5 and 7 quasiparticle modes. Special attention is paid to the energy-lowering of anomalous coupling states in N = 41 nuclei and to the spin sequence of so-called ''one-quasiparticle-two-phonon multiplet''. It is shown that one cannot attribute the special-lowering of the energies of the anomalous coupling (j - 2) states to the dynamical effects due to the coupling between the 3-quasiparticle mode and the 5-quasiparticle mode, and is also shown that not only the kinematical effect but also the dynamical effect plays an important role in the energy-lowering of the anomalous coupling (j - 1) states in N = 41 nuclei. The second (j - 2) state is predicted to be the lowest member of one-quasiparticle-two-phonon multiplet by taking account of the kinematical effect for the 5-quasiparticle mode, which corresponds to the experimental fact. (author)

  15. Study of the β- decay of 116m1In: A new interpretation of low-lying 0+ states in 116Sn

    Science.gov (United States)

    Pore, J. L.; Cross, D. S.; Andreoiu, C.; Ashley, R.; Ball, G. C.; Bender, P. C.; Chester, A. S.; Diaz Varela, A.; Demand, G. A.; Dunlop, R.; Garnsworthy, A. B.; Garrett, P. E.; Hackman, G.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A. T.; Liblong, A.; Kanungo, R.; Noakes, B.; Petrache, C. M.; Rajabali, M. M.; Starosta, K.; Svensson, C. E.; Voss, P. J.; Wang, Z. M.; Wood, J. L.; Yates, S. W.

    2017-02-01

    The 116Sn nucleus contains a collective rotational band originating from proton π 2 p-2 h excitations across the proton Z=50 shell gap. Even though this nucleus has been extensively investigated in the past, there was still missing information on the low-energy interband transitions connecting the intruder and normal structures. The low-lying structure of 116Sn was investigated through a high-statistics study of the β- decay of 116m1In with the 8π spectrometer and its ancillary detectors at TRIUMF. These measurements are critical in order to properly characterize the π 2 p-2 h rotational band. Weak γ-decay branches are observed utilizing γ-γ coincidence spectroscopy methods, leading to the first direct observation of the 85 keV 22+→ 03+ γ ray with a transition strength of B(E2) = 99.7(84) W.u. The analysis of these results strongly suggests that the 2027 keV 03+ state should replace the previously assigned 1757 keV 02+ state as the band-head of the π 2 p-2 h rotational band.

  16. Study of the β{sup -} decay of {sup 116m1}In: A new interpretation of low-lying 0{sup +} states in {sup 116}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Pore, J.L.; Cross, D.S.; Andreoiu, C.; Ashley, R.; Chester, A.S.; Noakes, B.; Starosta, K.; Voss, P.J. [Simon Fraser University, Department of Chemistry, Burnaby BC (Canada); Ball, G.C.; Bender, P.C.; Garnsworthy, A.B.; Hackman, G.; Rajabali, M.M. [TRIUMF, Vancouver BC (Canada); Diaz Varela, A.; Demand, G.A.; Dunlop, R.; Garrett, P.E.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A.T.; Liblong, A.; Svensson, C.E. [University of Guelph, Department of Physics, Guelph ON (Canada); Kanungo, R. [Saint Mary' s University, Department of Astronomy and Physics, Halifax NS (Canada); Petrache, C.M. [Universite Paris-Saclay, CSNSM, CNRS-IN2P3, Orsay Cedex (France); Wang, Z.M. [Simon Fraser University, Department of Chemistry, Burnaby BC (Canada); TRIUMF, Vancouver BC (Canada); Wood, J.L. [Georgia Institute of Technology, School of Physics, Atlanta, GA (United States); Yates, S.W. [University of Kentucky, Departments of Chemistry and Physics and Astronomy, Lexington, KY (United States)

    2017-02-15

    The {sup 116}Sn nucleus contains a collective rotational band originating from proton π 2p-2h excitations across the proton Z = 50 shell gap. Even though this nucleus has been extensively investigated in the past, there was still missing information on the low-energy interband transitions connecting the intruder and normal structures. The low-lying structure of {sup 116}Sn was investigated through a high-statistics study of the β{sup -} decay of {sup 116m1}In with the 8π spectrometer and its ancillary detectors at TRIUMF. These measurements are critical in order to properly characterize the π 2p-2h rotational band. Weak γ-decay branches are observed utilizing γ-γ coincidence spectroscopy methods, leading to the first direct observation of the 85 keV 2{sub 2}{sup +} → 0{sub 3}{sup +} γ ray with a transition strength of B(E2) = 99.7(84) W.u. The analysis of these results strongly suggests that the 2027 keV 0{sub 3}{sup +} state should replace the previously assigned 1757 keV 0{sub 2}{sup +} state as the band-head of the π 2p-2h rotational band. (orig.)

  17. Gyromagnetic ratios of low-lying excited states in the even 192-198Pt isotopes; experimental measurements and theoretical predictions

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Ryan, C.G.; Morrison, I.; Bolotin, H.H.

    1981-01-01

    The gyromagnetic ratios of the 2 2 + and 4 1 + states in 196 Pt were measured relative to that of its 2 1 + level. The thin-foil IMPAC technique was employed utilizing the enhanced transient hyperfine magnetic field present at the nuclei of swiftly recoiling ions traversing magnetized ferromagetic materials. The states of interest were populated by Coulomb excitation using beams of 220-MeV 58 Ni ions. For g(2 1 + ) taken as 0.326+-0.014, the present measurements yielded g(2 2 + ) = 0.30+-0.06 and g(4 1 + ) 0.30+-0.05. These results and those reported by prior workers for the g-factors of corresponding levels in 192 Pt, 194 Pt, 198 Pt are used to trace the systematics of the magnetic moments of these low-lying levels in the even 192 - 198 Pt isotopes. Interacting Boson Approximation model-based calculations of the g-factors of these states were also carried out. The experimental theoretical results are compared

  18. Properties of low-lying intruder states in $^{34}$Al and $^{34}$Si sequentially populated in $\\beta$-decay of $^{34}$Mg

    CERN Multimedia

    A low-lying long-lived (26±1 ms) isomer in $^{34}$Al has been observed recently and assigned as 1$^{+}$ state of intruder character. It was populated in $^{36}$S fragmentation and feeds, in $\\beta$-decay, the 0$_{2}^{+}$ state in $^{34}$Si whose excitation energy and lifetime were determined in an electron-positron pairs spectroscopy experiment. In the present experiment we intend to measure for the first time the $\\gamma$-rays following the $\\beta$-decay of $^{34}$Mg. Despite the interest for $^{34}$Mg, the up-right corner of the “N$\\thicksim$20 island of inversion”, the only information on its $\\beta$-decay is the lifetime of 20±10 ms, determined from $\\beta$-neutron coincidences. As a result of the proposed experiment, we expect to place the first transitions in the level scheme of $^{34}$Al and to strongly populate the newly observed isomer, measuring its excitation energy, if the branching ratio to 4$^{−}$ ground state is significant. Theoretical estimations for the $\\beta$-decay of the new isome...

  19. Spectroscopic features of the low-lying electronic states of some sodium-helium and potassium-helium van der Waals systems

    Science.gov (United States)

    Chattopadhyay, Anjan

    2011-08-01

    Configuration interaction studies on MHe and MHe2 (where M = Na, K) systems have revealed several interesting characteristics in the properties of their low-lying electronic states. Binding energy values of the 12Π1/2, 3/2 states in MHe systems are found to be lower than the values of 12Πu (1/2, 3/2) states in the He-M-He systems by a margin of more than 200 cm-1, indicating better exciplex stabilities of the latter systems. Excited states of the other variety of the linear MHe2 (M-He-He) systems are almost repulsive. The characteristic energy barrier of the first excited spin-orbit state of alkali metal-helium systems is found to be only 15 cm-1 in KHe and 19 cm-1 in He-K-He. For the Na*He and K*He exciplexes, predicted radiative lifetime values of 18.5 ns and 29.8 ns, respectively, are in excellent agreement with the experimental values. The red-tail portions of their emission bands are contributed by M*He2 exciplexes with relatively high radiative lifetimes. The repulsive excited state of 2Σ+1/2 (or 2Σ+g,1/2) symmetry in these van der Waals systems is likely to play an important role in the pumping of the blue side of the ns2S1/2 → np2P3/2 transition, which eventually may give rise to the np2P1/2 → ns2S1/2 lasing transition.

  20. Spectroscopic properties of the low-lying electronic states of RbHen (n = 1, 2) and their comparison with lighter alkali metal-helium systems

    International Nuclear Information System (INIS)

    Chattopadhyay, Anjan

    2012-01-01

    Ab initio-based configuration interaction studies on RbHe and He–Rb–He have explored some key features of the low-lying electronic states of these van der Waals systems. The radiative lifetime of the Rb*He exciplex has been calculated to be around 24.5 ns, which is slightly higher than the HeRb*He lifetime (∼20 ns) and lower than the atomic fluorescence lifetime of Rb, by roughly 3.5 ns. Better exciplex stability of the symmetric triatomic system is evidenced by its higher binding energy value in comparison to the diatomic system by a substantial margin. BSSE-corrected spin–orbit calculations of RbHe have predicted a potential barrier of the 1 2 Π 1/2 state with a height of 15 cm −1 and width of 2.57 Å. The 2 Π u state of the triatomic molecule shows a conical intersection of its Renner–Teller components (1 2 A 1 and 1 2 B 2 ) near a 99° bond angle along the bending path. Their unstable higher excited states (1 2 Σ + 1/2 or 1 2 Σ + g, 1/2 ) can trigger the pumping of the blue side of the ns 2 S 1/2 → np 2 P 3/2 transition, and this may eventually lead to the np 2 P 1/2 →ns 2 S 1/2 lasing transition. The broad fluorescence band with a peak near 11 900 cm −1 is found to arise from the 1 2 Π 3/2 –X 2 Σ + 1/2 transition of RbHe. (paper)

  1. Spectroscopic features of the low-lying electronic states of some sodium-helium and potassium-helium van der Waals systems

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, Anjan, E-mail: anjan@bits-goa.ac.in, E-mail: anjan_chattopadhyay@yahoo.com [Department of Chemistry, Birla Institute of Technology and Science (BITS), Pilani -K.K. Birla Goa Campus, Goa, 403 726 (India)

    2011-08-28

    Configuration interaction studies on MHe and MHe{sub 2} (where M = Na, K) systems have revealed several interesting characteristics in the properties of their low-lying electronic states. Binding energy values of the 1{sup 2}{Pi}{sub 1/2,3/2} states in MHe systems are found to be lower than the values of 1{sup 2}{Pi}{sub u(1/2,3/2)} states in the He-M-He systems by a margin of more than 200 cm{sup -1}, indicating better exciplex stabilities of the latter systems. Excited states of the other variety of the linear MHe{sub 2} (M-He-He) systems are almost repulsive. The characteristic energy barrier of the first excited spin-orbit state of alkali metal-helium systems is found to be only 15 cm{sup -1} in KHe and 19 cm{sup -1} in He-K-He. For the Na*He and K*He exciplexes, predicted radiative lifetime values of 18.5 ns and 29.8 ns, respectively, are in excellent agreement with the experimental values. The red-tail portions of their emission bands are contributed by M*He{sub 2} exciplexes with relatively high radiative lifetimes. The repulsive excited state of {sup 2}{Sigma}{sup +}{sub 1/2} (or {sup 2}{Sigma}{sup +}{sub g,1/2}) symmetry in these van der Waals systems is likely to play an important role in the pumping of the blue side of the ns{sup 2}S{sub 1/2} {yields} np{sup 2}P{sub 3/2} transition, which eventually may give rise to the np{sup 2}P{sub 1/2} {yields} ns{sup 2}S{sub 1/2} lasing transition.

  2. Spectroscopic features of the low-lying electronic states of some sodium-helium and potassium-helium van der Waals systems

    International Nuclear Information System (INIS)

    Chattopadhyay, Anjan

    2011-01-01

    Configuration interaction studies on MHe and MHe 2 (where M = Na, K) systems have revealed several interesting characteristics in the properties of their low-lying electronic states. Binding energy values of the 1 2 Π 1/2,3/2 states in MHe systems are found to be lower than the values of 1 2 Π u(1/2,3/2) states in the He-M-He systems by a margin of more than 200 cm -1 , indicating better exciplex stabilities of the latter systems. Excited states of the other variety of the linear MHe 2 (M-He-He) systems are almost repulsive. The characteristic energy barrier of the first excited spin-orbit state of alkali metal-helium systems is found to be only 15 cm -1 in KHe and 19 cm -1 in He-K-He. For the Na*He and K*He exciplexes, predicted radiative lifetime values of 18.5 ns and 29.8 ns, respectively, are in excellent agreement with the experimental values. The red-tail portions of their emission bands are contributed by M*He 2 exciplexes with relatively high radiative lifetimes. The repulsive excited state of 2 Σ + 1/2 (or 2 Σ + g,1/2 ) symmetry in these van der Waals systems is likely to play an important role in the pumping of the blue side of the ns 2 S 1/2 → np 2 P 3/2 transition, which eventually may give rise to the np 2 P 1/2 → ns 2 S 1/2 lasing transition.

  3. Experimental determination of the lifetimes and parities of the Yrast states of 60Ni. Study of shape

    International Nuclear Information System (INIS)

    Moyat, M.-G.

    1978-01-01

    The two methods used to measure the lifetimes of the Yrast states of 60 Ni are described: the Doppler attenuation method (line deformation) and the recoil range method. The lifetimes obtained for the levels at 2505, 4262, 5345 and 6807 keV are given, together with the transition probabilities inferred. The parities of the 60 Ni high-spin levels measured by the linear polarization method are also given. Finally the recent theoretical approaches relating to the shapes of the nuclei are outlined: K. Kuman's deformed quasi-particle model and the interaction boson approximation of A. Arima and F. Iachello [fr

  4. Feeding times of high spin states in sup(152,154)Dy: Probes of nuclear structure above the yrast line

    International Nuclear Information System (INIS)

    Azgui, F.; Emling, H.; Grosse, E.; Michel, C.; Simon, R.S.; Spreng, W.; Wollersheim, H.J.; Khoo, T.L.; Chowdhury, P.; Frekers, D.; Janssens, R.V.F.; Pakkanen, A.; Daly, P.J.; Kortelahti, M.; Schwalm, D.; Seiler-Clark, G.

    1985-01-01

    Measurements of feeding times of high spin yrast states up to spin 30 (h/2π) in 154 Dy and 36 (h/2π) in 152 Dy were utilized to obtain information about possible spin dependent shape changes. The reactions 25 Mg ( 134 Xe, 5n), 124 Sn ( 34 S, 4n) and 25 Mg ( 132 Xe, 5n), 122 Sn ( 34 S, 4n) were used to populate the high spin states in 154 Dy and 152 Dy, respectively. Feeding times as well as lifetimes were determined with the recoil distance technique. In 152 Dy only long feeding times (>=10 ps) could be identified, indicating that the aligned-particle yrast states are fed through configurations of similar character, with little direct population from collective cascades in the continuum region. In 154 Dy discrete states with I<=30 (h/2π) have lifetimes which are characteristically collective, whereas the preyrast cascades exhibit both fast (< or approx.1 ps) and slow (proportional10 ps) feeding components. The latter imply a change with increasing spin from collective to aligned-particle character, probably associated with a prolate to oblate shape transition. (orig.)

  5. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. S K Khosa. Articles written in Pramana – Journal of Physics. Volume 59 Issue 4 October 2002 pp 585-598 Research Articles. Microscopic study of low-lying yrast spectra inMo isotopes · Neeru Sawhney Arun Bharti S K Khosa · More Details Abstract Fulltext PDF.

  6. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 4. Microscopic study of low-lying yrast spectra and deformation systematics in neutron-rich 98−106Sr isotopes. Anil Chandan Suram Singh Arun Bharti S K Khosa. Volume 73 Issue 4 October 2009 pp 657- ...

  7. Design of a Compton-suppression spectrometer and its application to the study of high-spin yrast states

    International Nuclear Information System (INIS)

    Aarts, H.J.M.

    1981-01-01

    Detailed γ-ray spectroscopy of high-spin states is hampered by transitions with low intensity on a high γ-ray background. An approach to enhance weak peaks in a spectrum in the reduction of the Compton background by means of a Compton-suppression spectrometer (CSS). Optimization of a CSS by means of Monte Carlo calculations is described. The investigation of high-spin states in the sd-shell nucleus 38 Ar with a Compton-suppression spectrometer is reported. With previously described techniques, in combination with p-γ coincidence measurements to establish an unambiguous level scheme, states up to Jsup(π) = 11 - could be identified and investigated. A gamma-gamma coincidence experiment on the nuclei 167 168 Hf is described with two Compton-suppression spectrometers. Yrast bands are followed, beyond the region of the first backbending, up to spin J = 37/2 and J = 28 for 167 Hf and 168 Hf, respectively. (Auth.)

  8. High-spin yrast states in the 206Po, 208Po, 209At and 210At nuclei

    International Nuclear Information System (INIS)

    Rahkonen, Vesa.

    1980-08-01

    High-spin yrast states in the 206 , 208 Po and 209 , 210 At nuclei have been studied with methods of in-beam γ-ray and conversion-electron spectroscopy and with the (α,3n), (α,4n), (p,2n) and ( 3 He,3n) reactions. Several new high-spin states have been identified up to angular momenta of 18-19 h/2π in these nuclei except in 206 Po where the highest spin was (13 - ). In the course of this work two new isomers with half-lives of 15+-3 ns and 4+-2 μs have been observed at 1689 and 4028 keV in 210 At, which have been interpreted as (10 - ) and 19 + states. The previously-known half-lives of 29+-2 and 680+-75 ns have been established for the three-proton states of Jsup(π)=21/2 - and 29/2 + at 1428 and 2429 keV in 209 At, respectively. A half-life of 1.0+-0.2 μs was measured for the 9 - isomer in 206 Po. Shell-model calculations based on the use of the empirical single- and two-particle interaction energies or of the experimental excitation energies belonging to the relevant one-, two- and three-particle states, have been carried out for these 4-6 particle nuclei. Most of the medium-spin yrast states in 206 Po, 208 Po and 209 At have been successfully described assuming the core for these nuclei being 204 Pb or 206 Pb rather than 208 Pb, and including an extra core polarization interaction described by the P 2 force. (author)

  9. Spectra of γ rays feeding superdeformed bands

    International Nuclear Information System (INIS)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G.

    1995-01-01

    The spectrum of γrays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding γrays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by ∼30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the γ cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed

  10. Spectra of {gamma} rays feeding superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

    1995-08-01

    The spectrum of {gamma}rays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding {gamma}rays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by {approximately}30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the {gamma} cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed.

  11. In-beam γ-ray spectroscopy of N=84 nuclei above Gd and the impact of the (πh11/2νh9/2)1+ attraction on their yrast lines

    International Nuclear Information System (INIS)

    Zhang Chengteng.

    1993-12-01

    In in-beam experiments using the γ-spectrometers Nordball at the Niels Bohr Institute and Osiris at the Hahn-Meitner Institute we populated the four N = 84 isotones 151 Ho, 152 Er, 153 Tm and 154 Yb through compound evaporation reactions induced with medium HI beams of masses ranging from 28 to 56. All observed γ-transitions with intensities above 1% (5% in 154 Yb) of the respective exit channel were placed in the level schemes, with spins established up to 10 MeV (8 MeV for 154 Yb) and parties up to between 5 and 7 MeV. We have found that in these N = 84 nuclei the multi-valence particle configurations πh n 11/2 νf 2 7/2 and πh n 11/2 νf 7/2 h 9/2 are strongly populated in the yrast cascades, and we have observed them up to their maximum spins of 43/2 - in Ho (at 4.8 MeV), 24 + in Er (7.5 MeV), 51/2 - in Tm (6.9 MeV), and only up to 24 + in Yb, 0.5 MeV below the fully aligned 26 + state expected at 9.1 MeV. The πh n νf 2 configuration forms smooth sections of the yrast line, while the more irregular yrast line of the πh n νfh character reflects the strong (νfh)8 + two-body attraction which gives rise to pronounced yrast line dips. We have also carried out full shell model calculations of these yrast lines, which are in excellent agreement with the experimental data. Since we take all dynamic input values, i.e. the two-body matrix elements and the single particle energies, from experiment, the calculations are free of any adjusted parameter. An interesting new result is the systematic identification in the πh n 11/2 νfh configuration of yrast states formed by specific proton couplings, where the strongly attractive (πh 11/2 νh 9/2 )1 + interaction is activated. As a consequence these states drop down to the yrast lines and in energy below the maximum aligned state of the next lower proton seniority. These seniority inverted yrast states were systematically identified in the four N = 84 nuclei, including two such states in 153 T, the first N 84

  12. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  13. Vibrational Fingerprints of Low-Lying Pt(n)P(2n) (n = 1-5) Cluster Structures from Global Optimization Based on Density Functional Theory Potential Energy Surfaces.

    Science.gov (United States)

    Jedidi, Abdesslem; Li, Rui; Fornasiero, Paolo; Cavallo, Luigi; Carbonniere, Philippe

    2015-12-03

    Vibrational fingerprints of small Pt(n)P(2n) (n = 1-5) clusters were computed from their low-lying structures located from a global exploration of their DFT potential energy surfaces with the GSAM code. Five DFT methods were assessed from the CCSD(T) wavenumbers of PtP2 species and CCSD relative energies of Pt2P4 structures. The eight first Pt(n)P(2n) isomers found are reported. The vibrational computations reveal (i) the absence of clear signatures made by overtone or combination bands due to very weak mechanical and electrical anharmonicities and (ii) some significant and recurrent vibrational fingerprints in correlation with the different PP bonding situations in the Pt(n)P(2n) structures.

  14. A model for quasi parity-doublet spectra with strong coriolis mixing

    International Nuclear Information System (INIS)

    Minkov, N.; Drenska, S.; Strecker, M.

    2013-01-01

    The model of coherent quadrupole and octupole motion (CQOM) is combined with the reflection-asymmetric deformed shell model (DSM) in a way allowing fully microscopic description of the Coriolis decoupling and K-mixing effects in the quasi parity-doublet spectra of odd-mass nuclei. In this approach the even-even core is considered within the CQOM model, while the odd nucleon is described within DSM with pairing interaction. The Coriolis decoupling/mixing factors are calculated through a parity-projection of the single-particle wave function. Expressions for the Coriolis mixed quasi parity-doublet levels are obtained in the second order of perturbation theory, while the K-mixed core plus particle wave function is obtained in the first order. Expressions for the B(E1), B(E2) and B(E3) reduced probabilities for transitions within and between different quasi-doublets are obtained by using the total K-mixed wave function. The model scheme is elaborated in a form capable of describing the yrast and non-yrast quasi parity-doublet spectra in odd-mass nuclei. (author)

  15. Decay out of the yrast and excited highly-deformed bands in the even-even nucleus {sup 134}Nd

    Energy Technology Data Exchange (ETDEWEB)

    Petrache, C.M.; Bazzacco, D.; Lunardi, S. [Sezione di Padova (Italy)] [and others

    1996-12-31

    The resolving power achieved by the new generation of {gamma}-ray detector arrays allows now to observe transitions with intensities of the order of {approximately}10{sup {minus}3} of the population of the final residual nucleus, making therefore feasible the study of the very weakly populated excited bands built on the superdeformed (SD) minimum or of the decay out of the SD bands. As a matter of fact, numerous excited SD bands have been observed in the different regions of superdeformation, which led to a deeper understanding of the single-particle excitation in the second minimum. The first experimental breakthrough in the study of the decay out process has been achieved in the odd-even {sup 133,135}Nd nuclei of the A=130 mass region. There, the observation of the discrete linking transitions has been favored by the relatively higher intensity of the highly-deformed (HD) bands ({approximately}10%), as well as by the small excitation energy with respect to the yrast line in the decay-out region ({approximately}1 MeV). No discrete linking transitions have been so far observed in the A=80, 150 mass regions. The present results suggest that the decay out of the HD bands in {sup 134}Nd is triggered by the crossing with the N=4 [402]5/2{sup +} Nilsson orbital, that has a smaller deformation than the corresponding N=6 intruder configuration. The crossing favours the mixing with the ND rotational bands strongly enhancing the decay-out process and weakening the in-band transition strength. The HD band becomes fragmented and looses part of its character. The intensity of the decay-out transitions increases when the spin of the HD state decreases, indicating enhanced ND amplitude in the wavefunction when going down the band. Lifetime measurements of the HD bands are crucial to further elucidate the decay-out process.

  16. Low lying states of Th229

    DEFF Research Database (Denmark)

    Andersen, Torkild; Maack Bisgård, K.; Hansen, P.Gregers

    1961-01-01

    The decay of 1.6 × 105y U233 has been studied by means of a six gap beta-ray spectrometer, a xenon filled proportional counter and scintillation spectrometers. Internal conversion electrons having energies below 100 keV were measured. The mixing ratios for the 42 keV and the 55 keV transitions ag...... agree with the assumed rotational character of the 42 keV and 97 keV states. Results concerning the 163 keV state indicate that this state is also a member of the ground state rotational band.......The decay of 1.6 × 105y U233 has been studied by means of a six gap beta-ray spectrometer, a xenon filled proportional counter and scintillation spectrometers. Internal conversion electrons having energies below 100 keV were measured. The mixing ratios for the 42 keV and the 55 keV transitions...

  17. Low-lying levels of 9B

    International Nuclear Information System (INIS)

    Sherr, R.; Fortune, H.T.

    2004-01-01

    We present calculations for the energies and widths of the lowest 1/2 + , 1/2 - , and 5/2 + levels of 9 B, taking into account the information known for the mirror levels in 9 Be. Comparison is made with the experimental data

  18. Spectra of nuclei 9Be and 9B in a three-cluster microscopic model

    International Nuclear Information System (INIS)

    Nesterov, A.V.; Vasilevsky, V.S.; Kovalenko, T.P.

    2012-01-01

    Within a microscopic three-cluster α + α + n(p) model, which is a three-cluster version of the algebraic approach to the Resonating Group Method (RGM), we consider the spectra of the low-lying states of mirror nuclei 9 Be and 9 B in the energy range from zero to 5 MeV excitation. The obtained theoretical results are compared with the available experimental data

  19. Observation and empirical shell-model study of new yrast excited states in the nucleus sup 1 sup 4 sup 2 Ce

    CERN Document Server

    Liu Zhong; Guo Ying Xiang; Zhou Xiao Hong; Lei Xiang Guo; LiuMinLiang; Luo Wan Ju; He Jian Jun; Zheng Yong; Pan Qiang Yan; Gan Zai Guo; Luo Yi Xiao; Hayakawa, T; Oshima, M; Toh, Y; Shizima, T; Hatsukawa, Y; Osa, A; Ishii, T; Sugawara, M

    2002-01-01

    Excited states of sup 1 sup 4 sup 2 Ce, populated in deep inelastic reactions of sup 8 sup 2 Se projectiles bombarding sup 1 sup 3 sup 9 La target, have been studied to medium spins using in-beam gamma spectroscopy techniques. Three new levels have been identified at 2625, 2995 and 3834 keV, and assigned as 8 sup + , 9 sup ( sup - sup ) and 11 sup ( sup - sup ) , respectively, based on the analysis of the properties of gamma transitions. These new yrast states follow well the level systematics of N 84 isotones. Their structures have been discussed with the help of empirical shell-model calculations

  20. Phenomenological descriptions of the Yrast bands in sup(160,162,164,166)Yb nuclei band crossings and moments of inertia

    International Nuclear Information System (INIS)

    El Zaiki, M.I.; Nafie, H.O.; Abd El Mageed, K.E.

    1992-01-01

    Two methods of calculations have been used to fit the previously presented data on rotationally aligned quasiparticle bands in sup(160,162,164,166)Yb. Backbendings of moment of inertia of the Yrast states can be reproduced reasonably well. The energy levels and the effective moment of inertia for both gs and s-band are calculated and compared with the experimental data. Band crossing interpretations are discussed for each nucleus. The interaction strength calculations are presented. (author). 17 refs., 7 figs., 4 tabs

  1. Off-Yrast low-spin structure of deformed nuclei at mass number A∼150

    Energy Technology Data Exchange (ETDEWEB)

    Krugmann, Andreas

    2014-07-14

    The present work consists of two independent parts. The first part deals with the investigation of the 0{sup +}{sub 1}→0{sup +}{sub 2} transition in {sup 150}Nd with inelastic electron scattering and in the second part a proton scattering experiment for the investigation of dipole excitations is presented. In the first part of this thesis a pioneer experiment in inelastic electron scattering is introduced. At an electron energy of 75 MeV, excitation energy spectra have been measured at the high resolution 169 spectrometer at the S-DALINAC. The aim of this investigation was the determination of the ρ{sup 2}(E0;0{sup +}{sub 1}→0{sup +}{sub 2}) transition strength in the heavy deformed nucleus {sup 150}Nd. The experimental form factor of this particular transition has been compared to a theoretical form factor that has been constructed by an effective density operator on a microscopic level with the help of the generator coordinate method. The required collective wave functions have been calculated in the Confined β soft rotor model. In this model-dependent analysis the E0 transition strength has been determined for the first time. Furthermore the evolution of the E0 transition strength as a function of the potential stiffness has been investigated from the X(5) phase shape transitional point to the Rigid Rotor limit. It has been shown, that the E0 strength is relatively high at the shape-phase transitional point and starts to decrease with increasing stiffness and vanishes completely at the Rigid Rotor limit. Additionally the wave functions of the macroscopic collective Confined β-soft rotor model have been compared to those from a microscopic mean field Hamiltonian. Good agreement has been found. The second part of this thesis covers a polarized-proton scattering experiment on the heavy deformed nucleus {sup 154}Sm, that has been performed at the RCNP in Osaka, Japan. Utilizing the method of polarization transfer observables, a separation of spinflip and non

  2. Seawater-overwash impacts on freshwater-lens water supplies of low-lying oceanic islands: example from Roi-Namur Island, Kwajalein Atoll, Republic of the Marshall Islands

    Science.gov (United States)

    Voss, C. I.; Gingerich, S. B.

    2015-12-01

    Low-lying oceanic islands host thin freshwater lenses subject to long-term aquifer salinization by seawater overwash. The lens is often the sole-source water supply for inhabitants. As maximum elevation for these islands is only a few meters above sea level, overwash can occur during high tides and storm surges. Sea level rise due to climate change will make overwash events even more common. The thin freshwater lenses, a few meters thick, are underlain by seawater, so pumping must be done carefully, often with horizontal skimming wells. Even a small amount of downward seawater infiltration from an overwash event can render the water supply non-potable. Where permeability is high, seawater infiltrates quickly, but seawater that infiltrates lower-permeability zones may remain for many months causing groundwater to remain non-potable, leaving residents without a reliable freshwater source. Initial post-overwash salinization is driven by the higher density of the invading saltwater, which sinks and mixes into the fresher water in potentially-complex patterns determined by: distribution of flooding and post-flood ponding, locations of permeable paths, and the inherently complex flow fields generated when fluid of higher density overlies lower-density fluid. The flow patterns cannot generally be measured or predicted in detail. This study develops basic understanding of overwash salinization processes impacting water supply on low-level islands, using a rare example of a monitored seawater overwash event that occurred in December 2008 at Roi-Namur Island in Kwajalein Atoll, Republic of the Marshall Islands, in which the salinity evolution of well water was measured. Due to typical lack of field data on such islands, a set of plausible alternative simulation-model descriptions of the hydrogeology and overwash event are created for analysis of the monitored salinization and recovery. Despite inability to know the 'true and complete' description of the event and the

  3. Assessing the impacts of sea-level rise and precipitation change on the surficial aquifer in the low-lying coastal alluvial plains and barrier islands, east-central Florida (USA)

    Science.gov (United States)

    Xiao, Han; Wang, Dingbao; Hagen, Scott C.; Medeiros, Stephen C.; Hall, Carlton R.

    2016-11-01

    A three-dimensional variable-density groundwater flow and salinity transport model is implemented using the SEAWAT code to quantify the spatial variation of water-table depth and salinity of the surficial aquifer in Merritt Island and Cape Canaveral Island in east-central Florida (USA) under steady-state 2010 hydrologic and hydrogeologic conditions. The developed model is referred to as the `reference' model and calibrated against field-measured groundwater levels and a map of land use and land cover. Then, five prediction/projection models are developed based on modification of the boundary conditions of the calibrated `reference' model to quantify climate change impacts under various scenarios of sea-level rise and precipitation change projected to 2050. Model results indicate that west Merritt Island will encounter lowland inundation and saltwater intrusion due to its low elevation and flat topography, while climate change impacts on Cape Canaveral Island and east Merritt Island are not significant. The SEAWAT models developed for this study are useful and effective tools for water resources management, land use planning, and climate-change adaptation decision-making in these and other low-lying coastal alluvial plains and barrier island systems.

  4. E0 and E2 decay of low-lying 0+ states in the even-even nuclei 206Pb, 208Po, 112-120 Sn and 112114Cd

    International Nuclear Information System (INIS)

    Julin, Rauno.

    1979-04-01

    Several new methods of in-beam conversion-electron and γ-ray spectrometry, applicable in the determination of E0 and E2 decay properties of low-lying 0 + states in even-mass nuclei, have been developed. The main attention has been paid to direct lifetime-measurement and coincidence methods based on the use of the natural pulsing of a cyclotron beam. With the aid of these methods, the similarity of the absolute decay rates of the two-neutron-hole 0 + 2 states in the N = 124 nuclei 206 Pb and 208 Po has been shown. A systematic investigation of the de-excitation of the 0 + 2 and 0 + 3 states in 112 , 11 4 , 116 , 118 , 120 Sn has been carried out. Twelve E0 transitions connecting the 0 + states have been observed, including very strong low-energy E0 transitions between the excited 0 + states, and several absolute transition probabilities have been determined. Furthermore, the new techniques have been applied successfully in determining the absolute E0 and E2 transition rates from the 0 + 2 and 0 + 3 states in 112 Cd and 114 Cd. The use of isotope-shift data in the calculation of the monopole strengths in 206 Pb and 208 Po is discussed. The results on even Sn and Cd nuclei are discussed within the framework of the coexistence of different shapes and of configuration mixing. (author)

  5. Effect of g-boson on spectra of high-spin states in 100Pd nucleus

    International Nuclear Information System (INIS)

    Zhao Xingzhi; Ni Shaoyong; Tong Hong; Shi Zhuyi; Second Northwest Inst. for Minority, Yinchuan; Shi Zhuya

    2007-01-01

    By using a microscopic sdgIBM-2 approach which is the accomplishment of the phenomenological sdgIBM theory and the experimental single-particle energies, the levels of the more complex ground-state band and the high-angular momentum states of y-band on 100 Pd nucleus are successfully reproduced. The ground-state band and γ-band are described well up to J π =16 + and E x =7.00 MeV, and that is larger than that J π 6 + -8 + , E x =2.00 MeV can be successfully reproduced in IBM theory. It has been proved that its yrast states up to the 16 + state are ground states, there may not exist any broken pair quasi-particle state by boson in yrast states. Theoretical analysis and numerical calculation show that to describe successfully spectra on 100 Pd nucleus under the boson approach in IBM theory, it is impossible that the g-boson has been not considered in one. According to the microscopic sdgIBM-2 approach, the 14 1 + state is understood as a result that a neutron g-boson transites into a neutron d-boson and a pair of photos is radiated at same time, and the 14 2 + state is the decoupling state of the 16 1 + state, while the 14 3 + state is the actual ground state. (authors)

  6. The geometric content of the interacting boson model for molecular spectra

    International Nuclear Information System (INIS)

    Levit, S.; Smilansky, U.

    1981-12-01

    The recently proposed algebraic model for collective spectra of diatomic molecules is analysed in terms of conventional geometrical degrees of freedom. We present a mapping of the algebraic Hamiltonian onto an exactly solvable geometrical Hamiltonian with the Morse potential. This mapping explains the success of the algebraic model in reproducing the low lying part of molecular spectra. At the same time the mapping shows that the expression for the dipole transition operator in terms of boson operators differs from the simplest IBM expression and in general must include many-body boson terms. The study also provides an insight into the problem of possible interpretations of the bosons in the nuclear IBM. (author)

  7. Raman spectra of ruthenium and tantalum trimers in argon matrices

    Science.gov (United States)

    Fang, Li; Shen, Xiaole; Chen, Xiaoyu; Lombardi, John R.

    2000-12-01

    The resonance Raman spectra of ruthenium trimers (Ru 3) in argon matrices have been obtained. Three resonance Raman transitions were observed between 570 and 590 nm. Two of them (303.4 and 603.7 cm -1) are assigned to the totally symmetric vibrational progression, giving k e=1.86 mdyne/ Å. The line at 581.5 cm-1 is assigned as the origin of a low-lying electronic state. We also report on the observation of a resonance Raman spectrum of tantalum trimers (Ta 3). Observed lines include 251.2 and 501.9 cm-1 which we assign to the fundamental and the first overtone of the symmetric stretch in Ta 3. This gives k e=2.25 mdyne/ Å.

  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. Electronic spectra from TDDFT and machine learning in chemical space

    International Nuclear Information System (INIS)

    Ramakrishnan, Raghunathan; Hartmann, Mia; Tapavicza, Enrico; Lilienfeld, O. Anatole von

    2015-01-01

    Due to its favorable computational efficiency, time-dependent (TD) density functional theory (DFT) enables the prediction of electronic spectra in a high-throughput manner across chemical space. Its predictions, however, can be quite inaccurate. We resolve this issue with machine learning models trained on deviations of reference second-order approximate coupled-cluster (CC2) singles and doubles spectra from TDDFT counterparts, or even from DFT gap. We applied this approach to low-lying singlet-singlet vertical electronic spectra of over 20 000 synthetically feasible small organic molecules with up to eight CONF atoms. The prediction errors decay monotonously as a function of training set size. For a training set of 10 000 molecules, CC2 excitation energies can be reproduced to within ±0.1 eV for the remaining molecules. Analysis of our spectral database via chromophore counting suggests that even higher accuracies can be achieved. Based on the evidence collected, we discuss open challenges associated with data-driven modeling of high-lying spectra and transition intensities

  10. Electronic spectra from TDDFT and machine learning in chemical space

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Raghunathan [Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland); Hartmann, Mia; Tapavicza, Enrico, E-mail: Enrico.Tapavicza@csulb.edu [Department of Chemistry and Biochemistry, California State University, 1250 Bellflower Boulevard, Long Beach, California 90840 (United States); Lilienfeld, O. Anatole von, E-mail: anatole.vonlilienfeld@unibas.ch [Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland); Argonne Leadership Computing Facility, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439 (United States)

    2015-08-28

    Due to its favorable computational efficiency, time-dependent (TD) density functional theory (DFT) enables the prediction of electronic spectra in a high-throughput manner across chemical space. Its predictions, however, can be quite inaccurate. We resolve this issue with machine learning models trained on deviations of reference second-order approximate coupled-cluster (CC2) singles and doubles spectra from TDDFT counterparts, or even from DFT gap. We applied this approach to low-lying singlet-singlet vertical electronic spectra of over 20 000 synthetically feasible small organic molecules with up to eight CONF atoms. The prediction errors decay monotonously as a function of training set size. For a training set of 10 000 molecules, CC2 excitation energies can be reproduced to within ±0.1 eV for the remaining molecules. Analysis of our spectral database via chromophore counting suggests that even higher accuracies can be achieved. Based on the evidence collected, we discuss open challenges associated with data-driven modeling of high-lying spectra and transition intensities.

  11. Beta spectra. II-Positron spectra

    International Nuclear Information System (INIS)

    Grau, A.; Garcia-Torano, E.

    1981-01-01

    Using the Fermi theory of beta decay, the beta spectra for 30 positron emitters have been computed, introducing a correction factor for unique forbidden transitions. The spectra are ploted vs. energy, once normalised, and tabulated with the related Fermi functions. The average and median energies are calculated. (author)

  12. Search for the discrete non-yrast states in 152Dy around 86 ns isomer, the region into which the γ-rays drain the super-deformed band

    International Nuclear Information System (INIS)

    Mansour, N.

    1991-01-01

    Further analysis of the γ-ray study of 152 Dy emitted in the decay of the super-deformed band has been performed by using the 122 Sn ( 35 Cl, P4n) reaction at low bombarding energies. Several γ-rays de-exciting non-yrast states have been identified, among these are transitions previously observed in coincidence with this super-deformed band. The lowest two members of the super-deformed cascade have also been detected, but the data is not quite good enough to make a firm connection to them. (author)

  13. Sub-nanosecond Half-life Measurement of the Yrast I{sup π}=5{sup −} State in the N=78 Nucleus {sup 136}{sub 58}Ce using Fast-timing Coincident Gamma-ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Alharbi, T. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Physics, Faculty of Science in Zulfi, Almajmaah University, P.O. Box 1712, 11932 (Saudi Arabia); Regan, P.H., E-mail: p.regan@surrey.ac.uk [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); National Physical Laboratory, Teddington, Middlesex, TW11 0LW (United Kingdom); Mărginean, N. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Podolyák, Zs.; Bajoga, A.; Britton, R. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Bucurescu, D.; Deleanu, D.; Filipescu, D.; Ghită, D.; Glodariu, T.; Mihai, C. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Mulholland, K. [School of Engineering, University of the West of Scotland, High Street, Paisley PA1 2BE (United Kingdom); Mărginean, R.; Negret, A.; Nita, C.R. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Patel, Z. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Roberts, O.J. [School of Computing Engineering and Mathematics, University of Brighton, Brighton, BN2 4GJ (United Kingdom); Stroe, L.; Sava, T. [Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); and others

    2014-06-15

    We report on the measurement of the half-life of the yrast I{sup π}=5{sup −} state in the transitional nucleus {sup 136}Ce using a combined HPGe-LaBr3(Ce) scintillator gamma-ray detection array. The measured value for the E1 decay is approximately half a nanosecond, which corresponds to an E1 decay strength of approximately 2×10{sup −6} Wu. This value is in line with single-particle type E1 decays in this mass region and suggests no sign of additional K-hindrance associated with axially symmetric quadrupole deformations observed for lighter cerium isotopes.

  14. The short range effective interaction and the spectra of calcium isotopes in (f-p) space

    International Nuclear Information System (INIS)

    Qing-ying, Z.; Shen-wu, L.; Jian-xin, W.

    1986-01-01

    In this work, the authors use a new type of extremely short range interaction, the double delta interaction (DDI) to calculate the low-lying spectra of calcium isotopes /sup 41/Ca through /sup 48/Ca. The configuration space (f-p) includes configurations ( f/sub 7/2//sup n/ ) and ( f/sub 7/2//sup n-1/2p/sub 3/2/). The calculated energies are compared with experimental data for 75 levels. For comparison, they also use usual modified surface delta interaction (MSDI) to calculate the same spectra aforementioned. It is clear that the results calculated with DDI are better than with MSDI. Therefore, in the short-range effective interaction the addition of body delta force to the modified surface delta force may improve the agreement with experiment. The authors believe that the conclusion will not be changed if one enlarges the shell model space

  15. Alpha particle spectra in coincidence with normal and superdeformed states in {sup 150}Tb

    Energy Technology Data Exchange (ETDEWEB)

    Viesti, G.; Lunardon, M.; Bazzacco, D. [dell`Universita, Padova (Italy)]|[INFN, Padova (Italy)] [and others

    1996-12-31

    The study of correlations between particle evaporation from highly excited compound nuclei at large angular momenta and the states in the final evaporation residues (ER) is a field of investigation which has been opened, in the last years, with the advent of the new large {gamma}-ray arrays. It is now possible to correlate the evaporation spectra to various bands with shapes ranging from spherical to superdeformed (SD) in the same final nucleus. It is generally accepted that the particle evaporation from the compound nucleus is chaotic and that only in the near-yrast {gamma} cascade, where the feeding of different classes of states takes place, the ordered motion is restored. The sensitivity of the particle spectra on the feeding of specific states in the residual nuclei can be taken as an indication that additional degrees of freedom might be important in the evaporation process or that particular regions of the phase space open to the decay populate preferentially some selected structures in the final cold nucleus. This latter point is important for the understanding of the feeding mechanism of SD states. Several experiments performed so far did not find a clear dependence of the shapes of the particle spectra on the excited states having different deformations in the ER. For example, the proton spectra in coincidence with transitions in the SD bands of {sup 133}Nd and {sup 152}Dy nuclei were found to be similar to those in coincidence with transitions in the normal deformed (ND) bands. Alpha particles have been proposed since long as a sensitive probe of the deformation of the emitting nucleus. Results are presented here of an experiment in which the authors have measured the energy spectra of alpha particles associated with different classes of states (ND and SD) in the {sup 150}Tb nucleus populated in the reaction {sup 37}Cl({sup 120}Sn, {alpha}3n{gamma}){sup 150}Tb.

  16. Electronic structure of some adenosine receptor antagonists. III. Quantitative investigation of the electronic absorption spectra of alkyl xanthines

    Science.gov (United States)

    Moustafa, H.; Shalaby, Samia H.; El-sawy, K. M.; Hilal, Rifaat

    2002-07-01

    Quantitative and comparative investigation of the electronic absorption spectra of theophylline, caffeine and their derivatives is reported. The spectra of theophylline, caffeine and theobromine were compared to establish the predominant tautomeric species in solution. This comparison, analysis of solvent effects and assignments of the observed transitions via MO computations indicate the exits of only one tautomeric species in solution that is the N7 form. A low-lying triplet state was identified which corresponds to a HOMO-LUMO transition. This relatively long-lived T 1 state is always less polar than the ground state and may very well underlie the photochemical reactivity of alkyl xanthines. Substituents of different electron donating or withdrawing strengths and solvent effects are investigated and analyzed. The present analysis is facilitated via computer deconvolution of the observed spectra and MO computation.

  17. Spectra of the W VIII isoelectronic sequence: III. Re IX

    International Nuclear Information System (INIS)

    Ryabtsev, A N; Kononov, E Ya; Kildiyarova, R R; Tchang-Brillet, W-Ü L; Wyart, J-F; Champion, N; Blaess, C

    2015-01-01

    Rhenium spectra excited in vacuum spark sources of different setups and electric circuits were recorded on two high resolution vacuum spectrographs: a 10 m normal incidence spectrograph with a 3600 l mm −1 grating in the Meudon Observatory and a 3 m grazing incidence spectrograph with a 3600 l mm −1 grating in the Institute of Spectroscopy in Troitsk. A total of 112 lines in the region 146–244 Å were identified as transitions from the interacting excited even configurations 4f 12 5s 2 5p 6 5d + 4f 13 5s 2 5p 5 (5d + 6s) + 4f 14 5s 2 5p 4 (5d + 6s) to the low-lying odd configurations 4f 13 5s 2 5p 6 and 4f 14 5s 2 5p 5 . A change of the ground configuration from 4f 13 5s 2 5p 6 to 4f 14 5s 2 5p 5 in a comparison with the previous spectra of the isoelectronic sequence Hf VI–W VIII was observed. Fine structure splittings and relative positions of the odd terms were established, and 83 levels of the excited even configurations were found. (paper)

  18. Spectra of Graphs

    NARCIS (Netherlands)

    Brouwer, A.E.; Haemers, W.H.

    2012-01-01

    This book gives an elementary treatment of the basic material about graph spectra, both for ordinary, and Laplace and Seidel spectra. The text progresses systematically, by covering standard topics before presenting some new material on trees, strongly regular graphs, two-graphs, association

  19. Spectra of alkali atoms

    International Nuclear Information System (INIS)

    Santoso, Budi; Arumbinang, Haryono.

    1981-01-01

    Emission spectra of alkali atoms has been determined by using spectrometer at the ultraviolet to infra red waves range. The spectra emission can be obtained by absorption spectrophotometric analysis. Comparative evaluations between experimental data and data handbook obtained by spark method were also presented. (author tr.)

  20. Yrast excitations in 191Pb

    International Nuclear Information System (INIS)

    Fotiades, N.; Andreyev, A.

    1997-01-01

    Prompt, in-beam γ rays in coincidence with evaporation residues were measured in the 164,166 Er + 164 MeV 32 S reactions. A level scheme built on the 13/2 + isomer has been deduced from four transitions assigned to 191 Pb. The states in 191 Pb are interpreted in terms of a weak coupling of the odd i 13/2 neutron-hole to the spherical states in the even-mass 192 Pb core. (orig.). With 4 figs

  1. Structure of the nucleon's low-lying excitations

    Science.gov (United States)

    Chen, Chen; El-Bennich, Bruno; Roberts, Craig D.; Schmidt, Sebastian M.; Segovia, Jorge; Wan, Shaolong

    2018-02-01

    A continuum approach to the three valence-quark bound-state problem in quantum field theory is used to perform a comparative study of the four lightest (I =1 /2 ,JP=1 /2±) baryon isospin doublets in order to elucidate their structural similarities and differences. Such analyses predict the presence of nonpointlike, electromagnetically active quark-quark (diquark) correlations within all baryons; and in these doublets, isoscalar-scalar, isovector-pseudovector, isoscalar-pseudoscalar, and vector diquarks can all play a role. In the two lightest (1 /2 ,1 /2+) doublets, however, scalar and pseudovector diquarks are overwhelmingly dominant. The associated rest-frame wave functions are largely S -wave in nature; and the first excited state in this 1 /2+ channel has the appearance of a radial excitation of the ground state. The two lightest (1 /2 ,1 /2-) doublets fit a different picture: accurate estimates of their masses are obtained by retaining only pseudovector diquarks; in their rest frames, the amplitudes describing their dressed-quark cores contain roughly equal fractions of even- and odd-parity diquarks; and the associated wave functions are predominantly P -wave in nature, but possess measurable S -wave components. Moreover, the first excited state in each negative-parity channel has little of the appearance of a radial excitation. In quantum field theory, all differences between positive- and negative-parity channels must owe to chiral symmetry breaking, which is overwhelmingly dynamical in the light-quark sector. Consequently, experiments that can validate the contrasts drawn herein between the structure of the four lightest (1 /2 ,1 /2±) doublets will prove valuable in testing links between emergent mass generation and observable phenomena and, plausibly, thereby revealing dynamical features of confinement.

  2. Comparative study of spectroscopic properties of the low-lying ...

    Indian Academy of Sciences (India)

    due to the substitutions by methyl (II), isopropyl (III) and fluoromethyl (IV) groups on nitrogen. Some theo- retical studies on PSB (I) have been earlier reported at different level of calculations. AM1/CISD, MP4, MRCI calculations have been carried out by Dobado and. Nonella,25 while MNDO-CI method has been applied.

  3. Xanadu Is Old, Rugged And Low-lying

    Science.gov (United States)

    Wood, Charles; Kirk, R. L.; Stofan, E.; Stiles, B.; Zebker, H.; Ostro, S.; Radebaugh, J.; Lorenz, R. D.; Callahan, P.; Wall, S.

    2007-10-01

    Xanadu was the first surface feature discovered on Titan. It is anomalously bright in the IR, and is also radar bright with unusual physical properties. Xanadu is continent size ( 4000 km wide) with a sharp boundary to the west against the dark dunes of Shangri-La, and less distinct boundaries in other areas. Because of its size and reflectivity it had been proposed that Xanadu is an elevated continent. But it is not. A new topography-from-SAR technique shows that along the T13 Radar swath which completely transects Xanadu, the average topographic elevation is indistinguishable from that of the surrounding terrain. There are many mountains with peaks locally rising up to 1-2 km, but the average elevation of the T13 pass is 200 m +/- 300 m lower than the radius of Titan. The highest point is near the swath center. Photogeologic interpretation suggests that Xanadu slopes to the south; three major river systems begin in the north and flow southward. The lack of significant average elevation means that it is not necessary to create models to explain how Xanadu is dynamically supported. Its eroded-looking terrain, large number of possible eroded impact craters, dune encroachment on its western edge, and apparent detached patches of similar material near its margins all suggest that Xanadu is a relict terrain, currently being disaggregated. The only sign of current activity is the river channels. We speculate that Xanadu was originally a landform of higher elevation (2 km higher if the mountain tops are remnants of an original surface) that has been modified by erosion and/or isostatic adjustment. If the observed river systems have eroded and removed the putative higher terrain there may be significant sediment deposits in the central or southern parts of Xanadu, and/or this material may have been redistributed by winds.

  4. Quadrupole moments of low-lying baryons with spin

    Indian Academy of Sciences (India)

    2015-11-27

    Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science (IWCCMP-2015). Posted on November 27, 2015. Guest Editors: Anurag Srivastava, C. S. Praveen, H. S. Tewari. © 2015 Indian Academy of Sciences, Bengaluru. Contact | Site index.

  5. Dynamic polarizabilities for the low lying states of Ca+

    International Nuclear Information System (INIS)

    Tang, Yong-Bo; Shi, Ting-Yun; Qiao, Hao-Xue; Mitroy, J

    2014-01-01

    The dynamic polarizabilities of the 4s, 3d and 4p states of Ca + are calculated using a relativistic structure model. The wavelengths at which the Stark shifts between different pairs of transitions are zero are calculated. Experimental determination of the magic wavelengths could prove useful in developing better atomic structure models and in particular lead to improved values of the polarizabilities for the Ca + (3d) states

  6. Low-lying (K π= 0+) states of gadolinium isotopes

    Indian Academy of Sciences (India)

    The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science

  7. Strange sea quark effects for low lying baryons

    International Nuclear Information System (INIS)

    Upadhyay, A.; Batra, Meenakshi

    2013-01-01

    Assuming hadrons as an ensemble of quark-gluon Fock states, contributions from sea quarks and gluons can be studied in detail for ground state baryons. Spin crisis of nucleons say that only a small fraction of proton spin is carried by valence quarks. Rest part is distributed among gluons and sea which includes both strange and non-strange quark-anti-quark pairs. This necessitates the study of strange sea quark contribution for other baryons too due to higher mass and presence of strange quark in valence part. Recent studies have also studied strange sea contribution for baryons using different models. We implement the statistical modeling techniques to compute strange sea quark content for baryon octet. Statistical model has already been applied to study sea quark content for nucleons in the form of scalar, vector and tensor sea. In our present work the same idea has been extended for strange sea to probe the structure in more detail. (author)

  8. Hyperfine splitting of low-lying heavy baryons

    Energy Technology Data Exchange (ETDEWEB)

    Harada, M.; Qamar, A.; Schechter, J. [Syracuse Univ., NY (United States). Dept. of Physics; Sannino, F. [Syracuse Univ., NY (United States). Dept. of Physics]|[Dipartimento di Scienze Fisiche and Istituto Nazionale di Fisica Nucleare, Mostra D`Oltremare Pad. 19, 80125, Napoli (Italy); Weigel, H. [Institute for Theoretical Physics, Tuebingen University, Auf der Morgenstelle 14, D-72076, Tuebingen (Germany)

    1997-11-10

    We calculate the next-to-leading order contribution to the masses of the heavy baryons in the bound-state approach for baryons containing a heavy quark. These 1/N{sub C} corrections arise when states of good spin and isospin are generated from the background soliton of the light meson fields. Our study is motivated by the previously established result that light vector meson fields are required for this soliton in order to reasonably describe the spectrum of both the light and the heavy baryons. We note that the inclusion of light vector mesons significantly improves the agreement of the predicted hyperfine splitting with experiment. A number of aspects of this somewhat complicated calculation are discussed in detail. (orig.). 33 refs.

  9. Extracting Low-Lying Lambda Resonances Using Correlation Matrix Techniques

    International Nuclear Information System (INIS)

    Menadue, Benjamin J.; Kamleh, Waseem; Leinweber, Derek B.; Mahbub, M. S.

    2011-01-01

    The lowest-lying negative-parity state of the Lambda is investigated in (2+1)-flavour full-QCD on the PACS-CS configurations made available through the ILDG. We show that a variational analysis using multiple source and sink smearings can extract a state lying lower than that obtained by using a standard fixed smeared source and sink operator alone.

  10. Low-lying (K ) states of gadolinium isotopes

    Indian Academy of Sciences (India)

    excitation on energy levels as possible as determined has become a research field ... exist and it is clearly interesting to determine how many such excitations ..... states may be common near and above the pairing gap in deformed nuclei.

  11. Low-lying (K π= 0+) states of gadolinium isotopes

    Indian Academy of Sciences (India)

    The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA ...

  12. Quadrupole moments of low-lying baryons with spin

    Indian Academy of Sciences (India)

    The chiral constituent quark model ( CQM) with general parametrization (GP) method has been formulated to calculate the quadrupole moments of the spin − 3 2 + decuplet baryons and spin − 3 2 + → 1 2 + transitions. The implications of such a model have been investigated in detail for the effects of symmetry breaking ...

  13. Franck-Condon Simulations including Anharmonicity of the Ã(1)A''-X̃(1)A' Absorption and Single Vibronic Level Emission Spectra of HSiCl and DSiCl.

    Science.gov (United States)

    Mok, Daniel W K; Lee, Edmond P F; Chau, Foo-Tim; Dyke, John M

    2009-03-10

    RCCSD(T) and/or CASSCF/MRCI calculations have been carried out on the X̃(1)A' and Ã(1)A'' states of HSiCl employing basis sets of up to the aug-cc-pV5Z quality. Contributions from core correlation and extrapolation to the complete basis set limit were included in determining the computed equilibrium geometrical parameters and relative electronic energy of these two states of HSiCl. Franck-Condon factors which include allowance for anharmonicity and Duschinsky rotation between these two states of HSiCl and DSiCl were calculated employing RCCSD(T) and CASSCF/MRCI potential energy functions, and were used to simulate the Ã(1)A'' ← X̃(1)A' absorption and Ã(1)A'' → X̃(1)A' single vibronic level (SVL) emission spectra of HSiCl and DSiCl. Simulated absorption and experimental LIF spectra, and simulated and observed Ã(1)A''(0,0,0) → X̃(1)A' SVL emission spectra, of HSiCl and DSiCl are in very good agreement. However, agreement between simulated and observed Ã(1)A''(0,1,0) → X̃(1)A' and Ã(1)A''(0,2,1) → X̃(1)A' SVL emission spectra of DSiCl is not as good. Preliminary calculations on low-lying excited states of HSiCl suggest that vibronic interaction between low-lying vibrational levels of the Ã(1)A'' state and highly excited vibrational levels of the ã(3)A'' is possible. Such vibronic interaction may change the character of the low-lying vibrational levels of the Ã(1)A'' state, which would lead to perturbation in the SVL emission spectra from these vibrational levels.

  14. Solar Energetic Particle Spectra

    Science.gov (United States)

    Ryan, J. M.; Boezio, M.; Bravar, U.; Bruno, A.; Christian, E. R.; de Nolfo, G. A.; Martucci, M.; Mergè, M.; Munini, R.; Ricci, M.; Sparvoli, R.; Stochaj, S.

    2017-12-01

    We report updated event-integrated spectra from several SEP events measured with PAMELA. The measurements were made from 2006 to 2014 in the energy range starting at 80 MeV and extending well above the neutron monitor threshold. The PAMELA instrument is in a high inclination, low Earth orbit and has access to SEPs when at high latitudes. Spectra have been assembled from these high-latitude measurements. The field of view of PAMELA is small and during the high-latitude passes it scans a wide range of asymptotic directions as the spacecraft orbits. Correcting for data gaps, solid angle effects and improved background corrections, we have compiled event-integrated intensity spectra for twenty-eight SEP events. Where statistics permit, the spectra exhibit power law shapes in energy with a high-energy exponential roll over. The events analyzed include two genuine ground level enhancements (GLE). In those cases the roll-over energy lies above the neutron monitor threshold ( 1 GV) while the others are lower. We see no qualitative difference between the spectra of GLE vs. non-GLE events, i.e., all roll over in an exponential fashion with rapidly decreasing intensity at high energies.

  15. Spectra of the W VIII isoelectronic sequence: II. Ta VII

    International Nuclear Information System (INIS)

    Ryabtsev, A N; Ya Kononov, E; Kildiyarova, R R; Tchang-Brillet, W-Ü L; Wyart, J-F; Champion, N; Blaess, C

    2014-01-01

    Tantalum spectra excited in vacuum spark sources with different set-ups and electric circuits were recorded on two high-resolution vacuum spectrographs. For the wavelength region 300–500 Å, a 10 m normal incidence spectrograph with a 3600 l mm −1 grating was used in the Meudon Observatory. In the region below 350 Å, a 3 m grazing incidence spectrograph with a 3600 l mm −1 grating was used in the Institute of Spectroscopy in Troitsk. A total of 237 lines in the region of 191–354 Å were identified as transitions from the interacting excited even configurations 4f 12 5s 2 5p 6 (5d + 6s) + 4f 13 5s 2 5p 5 (5d + 6s) + 4f 14 5s 2 5p 4 (5d + 6s) to the low-lying odd configurations 4f 13 5s 2 5p 6 and 4f 14 5s 2 5p 5 . Fine structure splittings and relative positions of the odd terms were established, and 126 levels of the excited even configurations were found. (paper)

  16. Infrared spectra of small molecular ions trapped in solid neon

    Energy Technology Data Exchange (ETDEWEB)

    Jacox, Marilyn E. [Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2015-01-22

    The infrared spectrum of a molecular ion provides a unique signature for that species, gives information on its structure, and is amenable to remote sensing. It also serves as a comparison standard for refining ab initio calculations. Experiments in this laboratory trap molecular ions in dilute solid solution in neon at 4.2 K in sufficient concentration for observation of their infrared spectra between 450 and 4000 cm{sup !1}. Discharge-excited neon atoms produce cations by photoionization and/or Penning ionization of the parent molecule. The resulting electrons are captured by other molecules, yielding anions which provide for overall charge neutrality of the deposit. Recent observations of ions produced from C{sub 2}H{sub 4} and BF{sub 3} will be discussed. Because of their relatively large possibility of having low-lying excited electronic states, small, symmetric molecular cations are especially vulnerable to breakdown of the Born-Oppenheimer approximation. Some phenomena which can result from this breakdown will be discussed. Ion-molecule reaction rates are sufficiently high that in some systems absorptions of dimer cations and anions are also observed. When H{sub 2} is introduced into the system, the initially-formed ion may react with it. Among the species resulting from such ion-molecule reactions that have recently been studied are O{sub 4}{sup +}, NH{sub 4}{sup +}, HOCO{sup +}, and HCO{sub 2}{sup !}.

  17. Parameterization of rotational spectra

    International Nuclear Information System (INIS)

    Zhou Chunmei; Liu Tong

    1992-01-01

    The rotational spectra of the strongly deformed nuclei with low rotational frequencies and weak band mixture are analyzed. The strongly deformed nuclei are commonly encountered in the rare-earth region (e. g., 150 220). A lot of rotational band knowledge are presented

  18. Atomic Spectra Database (ASD)

    Science.gov (United States)

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  19. X-ray absorption spectra and emission spectra of plasmas

    International Nuclear Information System (INIS)

    Peng Yonglun; Yang Li; Wang Minsheng; Li Jiaming

    2002-01-01

    The author reports a theoretical method to calculate the resolved absorption spectra and emission spectra (optically thin) of hot dense plasmas. Due to its fully relativistic treatment incorporated with the quantum defect theory, it calculates the absorption spectra and emission spectra for single element or multi-element plasmas with little computational efforts. The calculated absorption spectra of LTE gold plasmas agree well with the experimental ones. It also calculates the optical thin emission spectra of LTE gold plasmas, which is helpful to diagnose the plasmas of relevant ICF plasmas. It can also provide the relevant parameters such as population density of various ionic stages, precise radiative properties for ICF studies

  20. Lattice vibration spectra. 16

    International Nuclear Information System (INIS)

    Lutz, H.D.; Willich, P.

    1977-01-01

    The FIR absorption spectra of pyrite type compounds RuS 2 , RuSsub(2-x)Sesub(x), RuSe 2 , RuTe 2 , OsS 2 , OsSe 2 , and PtP 2 as well as loellingite type phosphides FeP 2 , RuP 2 , and OsP 2 are reported. For RuS 2 , RuSe 2 , RuTe 2 , OsS 2 , and PtP 2 all of the five infrared allowed modes (k = 0) are observed. As a first result of a numerical normal coordinate treatment vibration forms of pyrite structure are communicated. The spectra show that lattice forces of corresponding sulfides, tellurides, and phosphides are about the same strength, but increase strongly by substitution of iron by ruthenium and especially of ruthenium by osmium. The lattice constants of the RuSsub(2-x)Sesub(x) solid solution obey Vegard's rule. (author)

  1. Deconvoluting double Doppler spectra

    International Nuclear Information System (INIS)

    Ho, K.F.; Beling, C.D.; Fung, S.; Chan, K.L.; Tang, H.W.

    2001-01-01

    The successful deconvolution of data from double Doppler broadening of annihilation radiation (D-DBAR) spectroscopy is a promising area of endeavour aimed at producing momentum distributions of a quality comparable to those of the angular correlation technique. The deconvolution procedure we test in the present study is the constrained generalized least square method. Trials with computer simulated DDBAR spectra are generated and deconvoluted in order to find the best form of regularizer and the regularization parameter. For these trials the Neumann (reflective) boundary condition is used to give a single matrix operation in Fourier space. Experimental D-DBAR spectra are also subject to the same type of deconvolution after having carried out a background subtraction and using a symmetrize resolution function obtained from an 85 Sr source with wide coincidence windows. (orig.)

  2. Spectra, Winter 2014

    Science.gov (United States)

    2014-01-01

    additional copies or more information, please email spectra@nrl.navy.mil. LEADINGEDGE 1 Contents 30 Navy Launches UAV from Submerged Submarine 31... multitasking have become mainstream concerns. For example, the New York Times in 2005 and Time magazine in 2006 both reported stories about...interruptions and multitasking , and how they affect performance by increasing human er- ror. In 2005, the information technol- ogy research firm Basex

  3. Thermoluminescence spectra of amethyst

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q. [Suzhou Railway Teachers College (China). Dept. of Physics; Yang, B. [Beijing Normal University (China). Dept. of Physics; Wood, R.A.; White, D.R.R.; Townsend, P.D.; Luff, B.J. [Sussex Univ., Brighton (United Kingdom). School of Mathematical and Physical Sciences

    1994-04-01

    Thermoluminescence and cathodoluminescence data from natural and synthetic amethyst and synthetic quartz samples are compared. The spectra include features from the quartz host lattice and from impurity-generated recombination sites. Emission features exist throughout the wavelength range studied, 250-800 nm. The near infrared emission at 740-750 nm appears to be characteristic of the amethyst and is proposed to be due to Fe ion impurity. (Author).

  4. Auger spectra of alkanes

    International Nuclear Information System (INIS)

    Rye, R.R.; Jennison, D.R.; Houston, J.E.

    1980-01-01

    The gas-phase Auger line shapes of the linear alkanes C 1 through C 6 and of neopentane are presented and analyzed. The general shape of the spectra are characteristic of carbon in a tetrahedral environment with the major feature in all cases occurring at approx.249 eV. The relatively large spectral changes found between methane and ethane results from the direct interaction of the terminal methyl groups in ethane, and the spectra of the higher alkanes are shown to be a composite of contributions from terminal methyl and interior methylene group carbon atoms. Theoretical analysis based on a one-electron approximation is shown to be capable of making a molecular orbital assignment by comparing calculated vertical transitions to features in the Auger spectra of ethane and propane, and, in the case of ethane, of differentiating between the 2 E/sub g/ and 2 A/sub 1g/ assignment of the ground state of (C 2 H 6 ) + . A one-electron based molecular orbital treatment, however, is shown to partially break down in propane and neopentane. Analysis of neopentane and the observed absence of any noticeable major peak energy shift with increasing molecular size (as predicted by the one-electron treatment) suggests that some Auger final states occur in which both valence holes are localized on the same subunit of the molecule

  5. Pattern recognition in spectra

    International Nuclear Information System (INIS)

    Gebran, M; Paletou, F

    2017-01-01

    We present a new automated procedure that simultaneously derives the effective temperature T eff , surface gravity log g , metallicity [ Fe/H ], and equatorial projected rotational velocity v e sin i for stars. The procedure is inspired by the well-known PCA-based inversion of spectropolarimetric full-Stokes solar data, which was used both for Zeeman and Hanle effects. The efficiency and accuracy of this procedure have been proven for FGK, A, and late type dwarf stars of K and M spectral types. Learning databases are generated from the Elodie stellar spectra library using observed spectra for which fundamental parameters were already evaluated or with synthetic data. The synthetic spectra are calculated using ATLAS9 model atmospheres. This technique helped us to detect many peculiar stars such as Am, Ap, HgMn, SiEuCr and binaries. This fast and efficient technique could be used every time a pattern recognition is needed. One important application is the understanding of the physical properties of planetary surfaces by comparing aboard instrument data to synthetic ones. (paper)

  6. Deconvolution of Positrons' Lifetime spectra

    International Nuclear Information System (INIS)

    Calderin Hidalgo, L.; Ortega Villafuerte, Y.

    1996-01-01

    In this paper, we explain the iterative method previously develop for the deconvolution of Doppler broadening spectra using the mathematical optimization theory. Also, we start the adaptation and application of this method to the deconvolution of positrons' lifetime annihilation spectra

  7. Vibrational spectra of aminoacetonitrile

    International Nuclear Information System (INIS)

    Bak, B.; Hansen, E.L.; Nicolaisen, F.M.; Nielsen, O.F.

    1975-01-01

    The preparation of pure, stable aminoacetonitrile(1-amino, 1'-cyanomethane)CH 2 NH 2 CN (1) is described. The Raman spectrum, now complete, and a novel infrared spectrum extending over the 50-3600 cm -1 region are reported. A tentative normal vibration analysis is presented and supported by Raman and infrared data from the spectra of CH 2 NHDCN (2) and CH 2 ND 2 CN (3). The predominance of the trans rotamer may be attributed to intramolecular hydrogen bonding but this is too unimportant to influence the vibrational frequencies of gaseous 1, 2, and 3. However, large gas/liquid frequency shifts occur. (author)

  8. Catalogue of neutron spectra

    International Nuclear Information System (INIS)

    Buxerolle, M.; Massoutie, M.; Kurdjian, J.

    1987-09-01

    Neutron dosimetry problems have arisen as a result of developments in the applications of nuclear energy. The largest number of possible irradiation situations has been collected: they are presented in the form of a compilation of 44 neutron spectra. Diagrams show the variations of energy fluence and energy fluence weighted by the dose equivalent/fluence conversion factor, with the logarithm of the corresponding energy. The equivalent dose distributions are presented as percentages for the following energy bins: 0.01 eV/0.5 eV/50 keV/1 MeV/5 MeV/15 MeV. The dose equivalent, the mean energy and the effective energy for the dose equivalent for 1 neutron cm -2 are also given [fr

  9. Calculation of nuclear level density parameters of some light deformed medical radionuclides using collective excitation modes of observed nuclear spectra

    International Nuclear Information System (INIS)

    Okuducu, S.; Sarac, H.; Akti, N. N.; Boeluekdemir, M. H.; Tel, E.

    2010-01-01

    In this study the nuclear energy level density based on nuclear collective excitation mechanism has been identified in terms of the low-lying collective level bands at near the neutron binding energy. Nuclear level density parameters of some light deformed medical radionuclides used widely in medical applications have been calculated by using different collective excitation modes of observed nuclear spectra. The calculated parameters have been used successfully in estimation of the neutron-capture cross section basic data for the production of new medical radionuclides. The investigated radionuclides have been considered in the region of mass number 40< A< 100. The method used in the present work assumes equidistance spacing of the collective coupled state bands of the interest radionuclides. The present calculated results have been compared with the compiled values from the literatures for s-wave neutron resonance data.

  10. Design energy spectra for Turkey

    OpenAIRE

    López Almansa, Francisco; Yazgan, Ahmet Utku; Benavent Climent, Amadeo

    2012-01-01

    This work proposes design energy spectra in terms of velocity, derived through linear dynamic analyses on Turkish registers and intended for regions with design peak acceleration 0.3 g or higher. In the long and mid period ranges the analyses are linear, taking profit of the rather insensitivity of the spectra to the structural parameters other than the fundamental period; in the short period range, the spectra are more sensitive to the structural parameters and nonlinear analyses would be re...

  11. Energy spectra of vibron and cluster models in molecular and nuclear systems

    Science.gov (United States)

    Jalili Majarshin, A.; Sabri, H.; Jafarizadeh, M. A.

    2018-03-01

    The relation of the algebraic cluster model, i.e., of the vibron model and its extension, to the collective structure, is discussed. In the first section of the paper, we study the energy spectra of vibron model, for diatomic molecule then we derive the rotation-vibration spectrum of 2α, 3α and 4α configuration in the low-lying spectrum of 8Be, 12C and 16O nuclei. All vibrational and rotational states with ground and excited A, E and F states appear to have been observed, moreover the transitional descriptions of the vibron model and α-cluster model were considered by using an infinite-dimensional algebraic method based on the affine \\widehat{SU(1,1)} Lie algebra. The calculated energy spectra are compared with experimental data. Applications to the rotation-vibration spectrum for the diatomic molecule and many-body nuclear clusters indicate that there are solvable models and they can be approximated very well using the transitional theory.

  12. Theoretical study of IR and photoelectron spectra of small gallium-arsenide clusters

    Energy Technology Data Exchange (ETDEWEB)

    Pouchan, Claude; Marchal, Rémi; Hayashi, Shinsuke [Université de Pau et des Pays de l' Adour, IPREM/ECP, UMR CNRS 5254 (France)

    2015-01-22

    Relative stabilities of small Ga{sub n}As{sub m} clusters, as well as their structural electronic and vibrational properties, were computed and analysed using a CCSD(T) reference method since experimental data in this area are sparse or unknown. With the aim of investigating larger clusters, we explored several DFT functionals and basis sets able to mimic the reliable CCSD(T) approach. Among them, the PBE0/SBKJC+sp,d appears as the most efficient to describe the structural and vibrational properties since average differences of about 0.042Å and 5.1cm{sup −1} were obtained for bond lengths and fundamental vibrational frequencies, respectively for the first small clusters [1] of the series found from our GSAM method [2]. As further test, this model is used in order to investigate and revisit an experimental IR spectrum of Ga{sub n}As{sub m} mixture previously published by Li et al. [3]. More complicated is the difficulty which arises in the electronic description due to the presence of numerous low lying electronic states nearly degenerated to correctly describe the electronic structure. The case of Ga{sub 2}As will be discussed and the photoelectron spectra of the Ga{sub 2}As anion reanalyzed on the ground of our calculations [4] comparatively to the experimental spectra obtained by Neumark and co-workers [5].

  13. Spectra of chemical trees

    International Nuclear Information System (INIS)

    Balasubramanian, K.

    1982-01-01

    A method is developed for obtaining the spectra of trees of NMR and chemical interests. The characteristic polynomials of branched trees can be obtained in terms of the characteristic polynomials of unbranched trees and branches by pruning the tree at the joints. The unbranched trees can also be broken down further until a tree containing just two vertices is obtained. The effectively reduces the order of the secular determinant of the tree used at the beginning to determinants of orders atmost equal to the number of vertices in the branch containing the largest number of vertices. An illustrative example of a NMR graph is given for which the 22 x 22 secular determinant is reduced to determinants of orders atmost 4 x 4 in just the second step of the algorithm. The tree pruning algorithm can be applied even to trees with no symmetry elements and such a factoring can be achieved. Methods developed here can be elegantly used to find if two trees are cospectral and to construct cospectral trees

  14. Sequencing BPS spectra

    Energy Technology Data Exchange (ETDEWEB)

    Gukov, Sergei [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Max-Planck-Institut für Mathematik,Vivatsgasse 7, D-53111 Bonn (Germany); Nawata, Satoshi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Centre for Quantum Geometry of Moduli Spaces, University of Aarhus,Nordre Ringgade 1, DK-8000 (Denmark); Saberi, Ingmar [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Stošić, Marko [CAMGSD, Departamento de Matemática, Instituto Superior Técnico,Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Mathematical Institute SANU,Knez Mihajlova 36, 11000 Belgrade (Serbia); Sułkowski, Piotr [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland)

    2016-03-02

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincaré polynomials in numerous examples. Among these structural properties is a novel “sliding” property, which can be explained by using (refined) modular S-matrix. This leads to the identification of modular transformations in Chern-Simons theory and 3d N=2 theory via the 3d/3d correspondence. Lastly, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.

  15. Sequencing BPS spectra

    International Nuclear Information System (INIS)

    Gukov, Sergei; Nawata, Satoshi; Saberi, Ingmar; Stošić, Marko; Sułkowski, Piotr

    2016-01-01

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincaré polynomials in numerous examples. Among these structural properties is a novel “sliding” property, which can be explained by using (refined) modular S-matrix. This leads to the identification of modular transformations in Chern-Simons theory and 3d N=2 theory via the 3d/3d correspondence. Lastly, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.

  16. Raman spectra of lithium compounds

    Science.gov (United States)

    Gorelik, V. S.; Bi, Dongxue; Voinov, Y. P.; Vodchits, A. I.; Gorshunov, B. P.; Yurasov, N. I.; Yurasova, I. I.

    2017-11-01

    The paper is devoted to the results of investigating the spontaneous Raman scattering spectra in the lithium compounds crystals in a wide spectral range by the fibre-optic spectroscopy method. We also present the stimulated Raman scattering spectra in the lithium hydroxide and lithium deuteride crystals obtained with the use of powerful laser source. The symmetry properties of the lithium hydroxide, lithium hydroxide monohydrate and lithium deuteride crystals optical modes were analyzed by means of the irreducible representations of the point symmetry groups. We have established the selection rules in the Raman and infrared absorption spectra of LiOH, LiOH·H2O and LiD crystals.

  17. FSFE: Fake Spectra Flux Extractor

    Science.gov (United States)

    Bird, Simeon

    2017-10-01

    The fake spectra flux extractor generates simulated quasar absorption spectra from a particle or adaptive mesh-based hydrodynamic simulation. It is implemented as a python module. It can produce both hydrogen and metal line spectra, if the simulation includes metals. The cloudy table for metal ionization fractions is included. Unlike earlier spectral generation codes, it produces absorption from each particle close to the sight-line individually, rather than first producing an average density in each spectral pixel, thus substantially preserving more of the small-scale velocity structure of the gas. The code supports both Gadget (ascl:0003.001) and AREPO.

  18. Infrared spectra of mineral species

    CERN Document Server

    Chukanov, Nikita V

    2014-01-01

    This book details more than 3,000 IR spectra of more than 2,000 mineral species collected during last 30 years. It features full descriptions and analytical data of each sample for which IR spectrum was obtained.

  19. Correlation Functions and Power Spectra

    DEFF Research Database (Denmark)

    Larsen, Jan

    2006-01-01

    The present lecture note is a supplement to the textbook Digital Signal Processing by J. Proakis and D.G. Manolakis used in the IMM/DTU course 02451 Digital Signal Processing and provides an extended discussion of correlation functions and power spectra. The definitions of correlation functions...... and spectra for discrete-time and continuous-time (analog) signals are pretty similar. Consequently, we confine the discussion mainly to real discrete-time signals. The Appendix contains detailed definitions and properties of correlation functions and spectra for analog as well as discrete-time signals....... It is possible to define correlation functions and associated spectra for aperiodic, periodic and random signals although the interpretation is different. Moreover, we will discuss correlation functions when mixing these basic signal types. In addition, the note include several examples for the purpose...

  20. Multifractal spectra in shear flows

    Science.gov (United States)

    Keefe, L. R.; Deane, Anil E.

    1989-01-01

    Numerical simulations of three-dimensional homogeneous shear flow and fully developed channel flow, are used to calculate the associated multifractal spectra of the energy dissipation field. Only weak parameterization of the results with the nondimensional shear is found, and this only if the flow has reached its asymptotic development state. Multifractal spectra of these flows coincide with those from experiments only at the range alpha less than 1.

  1. Sequential Analysis of Gamma Spectra

    International Nuclear Information System (INIS)

    Fayez-Hassan, M.; Hella, Kh.M.

    2009-01-01

    This work shows how easy one can deal with a huge number of gamma spectra. The method can be used for radiation monitoring. It is based on the macro feature of the windows XP connected to QBASIC software. The routine was used usefully in generating accurate results free from human errors. One hundred measured gamma spectra were fully analyzed in 10 minutes using our fast and automated method controlling the Genie 2000 gamma acquisition analysis software.

  2. Response spectra in alluvial soils

    International Nuclear Information System (INIS)

    Chandrasekharan, A.R.; Paul, D.K.

    1975-01-01

    For aseismic design of structures, the ground motion data is assumed either in the form of ground acceleration as a function of time or indirectly in the form of response spectra. Though the response spectra approach has limitations like not being applicable for nonlinear problems, it is usually used for structures like nuclear power plants. Fifty accelerograms recorded at alluvial sites have been processed. Since different empirical formulas relating acceleration with magnitude and distance give a wide scatter of values, peak ground acceleration alone cannot be the parameter as is assumed by a number of authors. The spectra corresponding to 5% damping have been normalised with respect to three parameters, namely, peak ground acceleration, peak ground velocity and a nondimensional quantity ad/v 2 . Envelopee of maxima and minima as well as average response spectra has been obtained. A comparison with the USAEC spectra has been made. A relation between ground acceleration, ground velocity and ad/v 2 has been obtained which would nearly give the same magnification of the response. A design response spectra for alluvial soils has been recommended. (author)

  3. Band-head spectra of low-energy single-particle excitations in some well-deformed, odd-mass heavy nuclei within a microscopic approach

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Meng-Hock [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Duc, Dao Duy [Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Ton Duc Thang University, Faculty of Applied Sciences, Ho Chi Minh City (Viet Nam); Nhan Hao, T.V. [Duy Tan University, Center of Research and Development, Danang (Viet Nam); Hue University, Center for Theoretical and Computational Physics, College of Education, Hue City (Viet Nam); Long, Ha Thuy [Hanoi University of Sciences, Vietnam National University, Hanoi (Viet Nam); Quentin, P. [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Bonneau, L. [Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France)

    2016-01-15

    In four well-deformed heavy odd nuclei, the energies of low-lying rotational band heads have been determined microscopically within a self-consistent Hartree-Fock-plus-BCS approach with blocking. A Skyrme nucleon-nucleon effective interaction has been used together with a seniority force to describe pairing correlations. Only such states which are phenomenologically deemed to be related to single-particle excitations have been considered. The polarization effects, including those associated with the genuine time-reversal symmetry breaking have been fully taken into account within our model assumptions. The calculated spectra are in reasonably good qualitative agreement with available data for the considered odd-neutron nuclei. This is not so much the case for the odd-proton nuclei. A potential explanation for such a difference in behavior is proposed. (orig.)

  4. Interpretation of the photoelectron spectra of FeS(2)(-) by a multiconfiguration computational approach.

    Science.gov (United States)

    Clima, Sergiu; Hendrickx, Marc F A

    2007-11-01

    The ground states of FeS(2) and FeS(2)(-), and several low-lying excited electronic states of FeS(2) that are responsible for the FeS(2)(-) photoelectron spectrum, are calculated. At the B3LYP level an open, quasi-linear [SFeS](-) conformation is found as the most stable structure, which is confirmed at the ab initio CASPT2 computational level. Both the neutral and the anionic unsaturated complexes possess high-spin electronic ground states. For the first time a complete assignment of the photoelectron spectrum of FeS(2)(-) is proposed. The lowest energy band in this spectrum is ascribed to an electron detachment from the two highest-lying 3dpi antibonding orbitals (with respect to the iron-sulfur bonding) of iron. The next-lowest experimental band corresponds to an electron removal from nonbonding, nearly pure sulfur orbitals. The two highest bands in the spectra are assigned as electron detachments from pi and sigma bonding mainly sulfur orbitals.

  5. Marvel Analysis of the Measured High-resolution Rovibronic Spectra of TiO

    Science.gov (United States)

    McKemmish, Laura K.; Masseron, Thomas; Sheppard, Samuel; Sandeman, Elizabeth; Schofield, Zak; Furtenbacher, Tibor; Császár, Attila G.; Tennyson, Jonathan; Sousa-Silva, Clara

    2017-02-01

    Accurate, experimental rovibronic energy levels, with associated labels and uncertainties, are reported for 11 low-lying electronic states of the diatomic {}48{{Ti}}16{{O}} molecule, determined using the Marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. All levels are based on lines corresponding to critically reviewed and validated high-resolution experimental spectra taken from 24 literature sources. The transition data are in the 2-22,160 cm-1 region. Out of the 49,679 measured transitions, 43,885 are triplet-triplet, 5710 are singlet-singlet, and 84 are triplet-singlet transitions. A careful analysis of the resulting experimental spectroscopic network (SN) allows 48,590 transitions to be validated. The transitions determine 93 vibrational band origins of {}48{{Ti}}16{{O}}, including 71 triplet and 22 singlet ones. There are 276 (73) triplet-triplet (singlet-singlet) band-heads derived from Marvel experimental energies, 123(38) of which have never been assigned in low- or high-resolution experiments. The highest J value, where J stands for the total angular momentum, for which an energy level is validated is 163. The number of experimentally derived triplet and singlet {}48{{Ti}}16{{O}} rovibrational energy levels is 8682 and 1882, respectively. The lists of validated lines and levels for {}48{{Ti}}16{{O}} are deposited in the supporting information to this paper.

  6. Theoretical and experimental study of the electronic states and spectra of LiSb

    Science.gov (United States)

    Setzer, K. D.; Fink, E. H.; Alekseyev, A. B.; Liebermann, H.-P.; Buenker, R. J.

    2018-05-01

    Gas phase emission spectra of the hitherto unknown free radical LiSb were measured in the NIR range with a Fourier-transform spectrometer. The emissions were observed from a fast-flow system in which antimony vapor in argon carrier gas was passed through a microwave discharge and mixed with lithium vapor in an observation tube. A number of blue-degraded bands observed in the range 6200-7800 cm-1 are assigned to transitions from four excited states A21, A30+, A40- and a2 to the X10+ and/or X21 components of the X3Σ- ground state. The 0-0 bands of six transitions were measured at high spectral resolution and rotationally analysed. The rotational and vibrational analyses have yielded the spectroscopic parameters of all six states. In order to aid in the analysis of the experimental data, a series of relativistic configuration interaction calculations has been carried out to obtain potential energy curves and spectroscopic constants for the low-lying states of LiSb as well as electric-dipole transition moments and radiative lifetimes.

  7. Biological Action Spectra (invited paper)

    International Nuclear Information System (INIS)

    Gruijl, F.R. de

    2000-01-01

    Ultraviolet (UV) radiation induces a wide variety of biological responses: ranging in humans from well-known short-term effects like sunburn to long-term effects like skin cancer. The wavelength dependencies ('action spectra') of the responses can differ significantly, depending on the UV-targeted molecules (their absorption spectra), their localisation (transmission to the target depth) and the photochemical reactions involved (e.g. quantum yields, competing reaction). An action spectrum (e.g. of sunburn) is usually determined in a wavelength by wavelength analysis of the response. This is not always possible (e.g. in case of skin cancer), and an action spectrum may then be extracted mathematically from differences in responses to broadband UV sources of various spectral compositions (yielding 'biological spectral weights'). However, relative spectral weights may shift with exposure levels and contributions from different wavelengths may not always add up. Under these circumstances conventional analyses will yield different action spectra for different experimental conditions. (author)

  8. Double photoionisation spectra of molecules

    CERN Document Server

    Eland, John

    2017-01-01

    This book contains spectra of the doubly charged positive ions (dications) of some 75 molecules, including the major constituents of terrestrial and planetary atmospheres and prototypes of major chemical groups. It is intended to be a new resource for research in all areas of molecular spectroscopy involving high energy environments, both terrestrial and extra-terrestrial. All the spectra have been produced by photoionisation using laboratory lamps or synchrotron radiation and have been measured using the magnetic bottle time-of-flight technique by coincidence detection of correlated electron pairs. Full references to published work on the same species are given, though for several molecules these are the first published spectra. Double ionisation energies are listed and discussed in relation to the molecular electronic structure of the molecules. A full introduction to the field of molecular double ionisation is included and the mechanisms by which double photoionisation can occur are examined in detail. A p...

  9. QUALITATIVE INTERPRETATION OF GALAXY SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Almeida, J.; Morales-Luis, A. B. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Terlevich, R.; Terlevich, E. [Instituto Nacional de Astrofisica, Optica y Electronica, Tonantzintla, Puebla (Mexico); Cid Fernandes, R., E-mail: jos@iac.es, E-mail: abml@iac.es, E-mail: rjt@ast.cam.ac.uk, E-mail: eterlevi@inaoep.mx, E-mail: cid@astro.ufsc.br [Departamento de Fisica-CFM, Universidade Federal de Santa Catarina, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil)

    2012-09-10

    We describe a simple step-by-step guide to qualitative interpretation of galaxy spectra. Rather than an alternative to existing automated tools, it is put forward as an instrument for quick-look analysis and for gaining physical insight when interpreting the outputs provided by automated tools. Though the recipe is for general application, it was developed for understanding the nature of the Automatic Spectroscopic K-means-based (ASK) template spectra. They resulted from the classification of all the galaxy spectra in the Sloan Digital Sky Survey data release 7, thus being a comprehensive representation of the galaxy spectra in the local universe. Using the recipe, we give a description of the properties of the gas and the stars that characterize the ASK classes, from those corresponding to passively evolving galaxies, to H II galaxies undergoing a galaxy-wide starburst. The qualitative analysis is found to be in excellent agreement with quantitative analyses of the same spectra. We compare the mean ages of the stellar populations with those inferred using the code STARLIGHT. We also examine the estimated gas-phase metallicity with the metallicities obtained using electron-temperature-based methods. A number of byproducts follow from the analysis. There is a tight correlation between the age of the stellar population and the metallicity of the gas, which is stronger than the correlations between galaxy mass and stellar age, and galaxy mass and gas metallicity. The galaxy spectra are known to follow a one-dimensional sequence, and we identify the luminosity-weighted mean stellar age as the affine parameter that describes the sequence. All ASK classes happen to have a significant fraction of old stars, although spectrum-wise they are outshined by the youngest populations. Old stars are metal-rich or metal-poor depending on whether they reside in passive galaxies or in star-forming galaxies.

  10. The structure of BPS spectra

    Science.gov (United States)

    Longhi, Pietro

    In this thesis we develop and apply novel techniques for analyzing BPS spectra of supersymmetric quantum field theories of class S. By a combination of wall-crossing, spectral networks and quiver methods we explore the BPS spectra of higher rank four-dimensional N = 2 super Yang-Mills, uncovering surprising new phenomena. Focusing on the SU(3) case, we prove the existence of wild BPS spectra in field theory, featuring BPS states of higher spin whose degeneracies grow exponentially with the energy. The occurrence of wild BPS states is surprising because it appears to be in tension with physical expectations on the behavior of the entropy as a function of the energy scale. The solution to this puzzle comes from realizing that the size of wild BPS states grows rapidly with their mass, and carefully analyzing the volume-dependence of the entropy of BPS states. We also find some interesting structures underlying wild BPS spectra, such as a Regge-like relation between the maximal spin of a BPS multiplet and the square of its mass, and the existence of a universal asymptotic distribution of spin-j irreps within a multiplet of given charge. We also extend the spectral networks construction by introducing a refinement in the topological classification of 2d-4d BPS states, and identifying their spin with a topological invariant known as the "writhe of soliton paths". A careful analysis of the 2d-4d wall-crossing behavior of this refined data reveals that it is described by motivic Kontsevich-Soibelman transformations, controlled by the Protected Spin Character, a protected deformation of the BPS index encoding the spin of BPS states. Our construction opens the way for the systematic study of refined BPS spectra in class S theories. We apply it to several examples, including ones featuring wild BPS spectra, where we find an interesting relation between spectral networks and certain functional equations. For class S theories of A 1 type, we derive an alternative technique for

  11. Automatic identification of mass spectra

    International Nuclear Information System (INIS)

    Drabloes, F.

    1992-01-01

    Several approaches to preprocessing and comparison of low resolution mass spectra have been evaluated by various test methods related to library search. It is shown that there is a clear correlation between the nature of any contamination of a spectrum, the basic principle of the transformation or distance measure, and the performance of the identification system. The identification of functionality from low resolution spectra has also been evaluated using several classification methods. It is shown that there is an upper limit to the success of this approach, but also that this can be improved significantly by using a very limited amount of additional information. 10 refs

  12. Investigation of gamma spectra analysis

    International Nuclear Information System (INIS)

    Wu Huailong; Liu Suping; Hao Fanhua; Gong Jian; Liu Xiaoya

    2006-01-01

    In the investigation of radiation fingerprint comparison, it is found out that some of the popular gamma spectra analysis software have shortcomings, which decrease the radiation fingerprint comparison precision. So a new analysis software is developed for solving the problems. In order to display the advantage of developed program, some typical simulative warhead gamma spectra are analyzed respectively by present software and GAMMAVISION and GENNIE2000. Present software can be applied not only in nuclear warheads deep-cuts verification, but also in any radiation measurement field. (authors)

  13. Ultraviolet spectra of planetary nebulae

    International Nuclear Information System (INIS)

    Adams, S.; Seaton, M.J.

    1982-01-01

    Features observed in infrared spectra suggest that certain very low excitation (VLE) nebulae have low C/O abundance ratios (Cohen and Barlow 1980; Aitken and Roche 1982). Fluxes in the multiplets [O II] lambda 2470 and C II] lambda 2326 have been measured for the VLE nebula He He 2-131 = HD 138403 using IUE high-dispersion spectra. An analysis similar to that of Harrington et al. (1980) for IC 418 gives C/O = 0.3 for He 2-131, compared with C/O = 1.3 for IC 418 and 0.6 for the Sun. (author)

  14. Investigation of gamma spectra analysis

    International Nuclear Information System (INIS)

    Wu Huailong; Liu Suping; Hao Fanhua

    2006-12-01

    During the investigation of radiation fingerprint comparison, it is found out that the popular gamma spectra analysis softwares are faultful, which decrease the precision of radiation fingerprint comparison. So a new analysis software is development for solving the problems. In order to display the advantage of new program, some typical simulative gamma spectra of radiation source are analyzed respectively by our software and GAMMAVISION and GENNIE2000. The software can be applied not only in nuclear warheads deep-cuts verification, but also in any radiation measurement field. (authors)

  15. Raman spectra studies of dipeptides

    International Nuclear Information System (INIS)

    Blanchard, Simone.

    1977-10-01

    This work deals with the homogenous and heterogeneous dipeptides derived from alanine and glycine, in the solid state or in aqueous solutions, in the zwitterions or chlorhydrates form. The Raman spectra comparative study of these various forms of hydrogenated or deuterated compounds allows to specify some of the attributions which are necessary in the conformational study of the like tripeptides. These compounds contain only one peptidic group; therefore there is no possibility of intramolecular hydrogen bond which caracterise vibrations of non bonded peptidic groups and end groups. Infrared spectra of solid dipeptides will be presented and discussed in the near future [fr

  16. Study of yrast band in 155Tm

    International Nuclear Information System (INIS)

    Raut, R.; Bhowal, S.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Bhowmik, R.K.; Dasmahapatra, B.; Gangopadhyay, G.; Mukherjee, A.; Muralithar, S.; SahaSarkar, M.; Singh, R.P.; Goswami, A.

    2007-01-01

    The nucleus 155 Tm has been studied by a detailed in-beam gamma spectroscopy following the reaction 144 Sm( 14 N, 3n) 155 Tm, at a beam energy, E lab =70MeV, using a Compton suppressed gamma detector array. More than 25 new gamma transitions have been placed in the proposed scheme and the latter has been extended upto a spin-parity of (51/2 - ) at an excitation energy ∼ 6 MeV

  17. Feeding of yrast states in 89Nb

    International Nuclear Information System (INIS)

    Berinde, A.; David, I.; Trache, L.

    1986-01-01

    The level structure of 89 Nb has been investigated using the ( 19 F, xnγ) reaction and gamma-ray spectrosocpy. The measurements were performed with the γ-γ coincidence technique using Ge(Li)-detectors. The direct feeding excitation functions of the quasirotational band levels and the angular distribution of gamma-rays have been measured in the ion energy range from 50 MeV to 70 MeV. New energy levels, their spins and parities are indicated. The data are explained on the basis of the shell model

  18. Boson and fermion degrees of freedom in the orthosymplectic extension of the IVBM: Odd-odd nuclear spectra

    International Nuclear Information System (INIS)

    Ganev, H. G.; Georgieva, A. I.

    2008-01-01

    The dynamical symmetry group Sp(12, R) of the Interacting Vector Boson Model (IVBM) is extended to the orthosymplectic group OSp(2Ω/12, R) in order to incorporate fermion degrees of freedom. The structure of even-even nuclei is used as a core on which the collective excitations of the neighboring odd-mass and odd-odd nuclei are build on. Hence, the spectra of odd-mass and odd-odd nuclei arise as a result of the coupling of the fermion degrees of freedom, specified by the fermion sector SOF (2Ω) to the boson core, whose states belong to an Sp(12, R) irreducible representation. The orthosymplectic dynamical symmetry is applied for the simultaneous description of the spectra of some neighboring nuclei from rare earth region. The theoretical predictions for different low-lying collective bands with positive and negative parity are compared with the experiment. The obtained results reveal the applicability of the model and its boson-fermion extension.

  19. Classical Trajectories and Quantum Spectra

    Science.gov (United States)

    Mielnik, Bogdan; Reyes, Marco A.

    1996-01-01

    A classical model of the Schrodinger's wave packet is considered. The problem of finding the energy levels corresponds to a classical manipulation game. It leads to an approximate but non-perturbative method of finding the eigenvalues, exploring the bifurcations of classical trajectories. The role of squeezing turns out decisive in the generation of the discrete spectra.

  20. Vibrational spectra of ordered perovskites

    NARCIS (Netherlands)

    Corsmit, A.F.; Hoefdraad, H.E.; Blasse, G.

    1972-01-01

    The vibrational spectra of the molecular M6+O6 (M = Mo, Te, W) group in ordered perovskites of the type Ba2M2+M6+O6 are reported. These groups have symmetry Oh, whereas their site symmetry is also Oh. An assignment of the internal vibrations is presented.

  1. Raman spectra of graphene ribbons

    International Nuclear Information System (INIS)

    Saito, R; Furukawa, M; Dresselhaus, G; Dresselhaus, M S

    2010-01-01

    Raman spectra of graphene nanoribbons with zigzag and armchair edges are calculated within non-resonant Raman theory. Depending on the edge structure and polarization direction of the incident and scattered photon beam relative to the edge direction, a symmetry selection rule for the phonon type appears. These Raman selection rules will be useful for the identification of the edge structure of graphene nanoribbons.

  2. Explanation of earthquake response spectra

    OpenAIRE

    Douglas, John

    2017-01-01

    This is a set of five slides explaining how earthquake response spectra are derived from strong-motion records and simple models of structures and their purpose within seismic design and assessment. It dates from about 2002 and I have used it in various introductory lectures on engineering seismology.

  3. Skyshine spectra of gamma rays

    International Nuclear Information System (INIS)

    Swarup, Janardan

    1980-01-01

    A study of the spectra of gamma photons back-scattered in vertical direction by infinite air above ground (skyshine) is presented. The source for these measurements is a 650 Ci Cobalt-60 point-source and the skyshine spectra are reported for distances from 150 m to 325 m from the source, measured with a 5 cm x 5 cm NaI(Tl) detector collimated with collimators of 12 mm and 20 mm diameter and 5 cm length. These continuous spectra are unfolded with Gold's iterative technique. The photon-spectra so obtained have a distinct line at 72 keV due to multiply-scattered photons. This is an energy where photoelectric and Compton cross-sections for multiply-scattered photons balance each other. The intensity of the line(I) decreases exponentially with distance (d) from the source obeying a relation of the type I = Isub(o)esup(-μd) where μ is called as ''Multiply-Scatter Coefficient'', a constant of the medium which is air in these measurements. This relationship is explained in terms of a halo around the source comprising of multiply-scattered gamma photons, Isub(0) being the intensity of these scattered photons at the location of cobalt-source. A fraction called as ''Back-scattered Fraction'', the ratio of Isub(0) to the number of original photons from the cobalt-source entering the infinite air, is also calculated. It is shown that with a properly calibrated detector system, this fraction can be used to determine the strength of a large gamma source, viz. a nuclear explosion in air, and for mineral prospecting. These conclusions are general and can be applied to any other infinite medium. Some forward-scatter (transmission) spectra of cobalt-60 source through 10 cm of Pb and 2.5 cm of Al are also reported. (auth.)

  4. ACCELERATED FITTING OF STELLAR SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Yuan-Sen; Conroy, Charlie [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rix, Hans-Walter [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2016-07-20

    Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.

  5. Reconstruction of neutron spectra through neural networks

    International Nuclear Information System (INIS)

    Vega C, H.R.; Hernandez D, V.M.; Manzanares A, E.

    2003-01-01

    A neural network has been used to reconstruct the neutron spectra starting from the counting rates of the detectors of the Bonner sphere spectrophotometric system. A group of 56 neutron spectra was selected to calculate the counting rates that would produce in a Bonner sphere system, with these data and the spectra it was trained the neural network. To prove the performance of the net, 12 spectra were used, 6 were taken of the group used for the training, 3 were obtained of mathematical functions and those other 3 correspond to real spectra. When comparing the original spectra of those reconstructed by the net we find that our net has a poor performance when reconstructing monoenergetic spectra, this attributes it to those characteristic of the spectra used for the training of the neural network, however for the other groups of spectra the results of the net are appropriate with the prospective ones. (Author)

  6. Biological Action Spectra (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Gruijl, F.R. de

    2000-07-01

    Ultraviolet (UV) radiation induces a wide variety of biological responses: ranging in humans from well-known short-term effects like sunburn to long-term effects like skin cancer. The wavelength dependencies ('action spectra') of the responses can differ significantly, depending on the UV-targeted molecules (their absorption spectra), their localisation (transmission to the target depth) and the photochemical reactions involved (e.g. quantum yields, competing reaction). An action spectrum (e.g. of sunburn) is usually determined in a wavelength by wavelength analysis of the response. This is not always possible (e.g. in case of skin cancer), and an action spectrum may then be extracted mathematically from differences in responses to broadband UV sources of various spectral compositions (yielding 'biological spectral weights'). However, relative spectral weights may shift with exposure levels and contributions from different wavelengths may not always add up. Under these circumstances conventional analyses will yield different action spectra for different experimental conditions. (author)

  7. Gamma-Ray Emission Spectra as a Constraint on Calculations of 234,236,238U Neutron-Capture Cross Sections

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, John Leonard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kawano, Toshihiko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bredeweg, Todd Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baramsai, Bayarbadrakh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haight, Robert Cameron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jandel, Marian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mosby, Shea Morgan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); O' Donnell, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vieira, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilhelmy, Jerry B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Becker, John A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wu, Ching-Yen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Krticka, Milan [Charles Univ., Prague (Czech Republic)

    2015-05-28

    Neutron capture cross sections in the “continuum” region (>≈1 keV) and gamma-emission spectra are of importance to basic science and many applied fields. Careful measurements have been made on most common stable nuclides, but physicists must rely on calculations (or “surrogate” reactions) for rare or unstable nuclides. Calculations must be benchmarked against measurements (cross sections, gamma-ray spectra, and <Γγ>). Gamma-ray spectrum measurements from resolved resonances were made with 1 - 2 mg/cm2 thick targets; cross sections at >1 keV were measured using thicker targets. The results show that the shape of capture cross section vs neutron energy is not sensitive to the form of the strength function (although the magnitude is); the generalized Lorentzian E1 strength function is not sufficient to describe the shape of observed gamma-ray spectra; MGLO + “Oslo M1” parameters produces quantitative agreement with the measured 238U(n,γ) cross section; additional strength at low energies (~ 3 MeV) -- likely M1-- is required; and careful study of complementary results on low-lying giant resonance strength is needed to consistently describe observations.

  8. Design spectra development considering short time histories

    International Nuclear Information System (INIS)

    Weiner, E.O.

    1983-01-01

    The need for generation of seismic acceleration histories to prescribed response spectra arises several ways in structural dynamics. For example, one way of obtaining floor spectra is to generate a history from a foundation spectra and then solve for the floor motion from which a floor spectrum can be obtained. Two separate programs, MODQKE and MDOF, were written to provide a capability of obtaining equipment spectra from design spectra. MODQKE generates or modifies acceleration histories to conform with design spectra pertaining to, say, a foundation. MDOF is a simple linear modal superposition program that solves for equipment support histories using the design spectra conforming histories as input. Equipment spectra, then, are obtained from the support histories using MODQKE

  9. Gamma-ray burst spectra

    International Nuclear Information System (INIS)

    Teegarden, B.J.

    1982-01-01

    A review of recent results in gamma-ray burst spectroscopy is given. Particular attention is paid to the recent discovery of emission and absorption features in the burst spectra. These lines represent the strongest evidence to date that gamma-ray bursts originate on or near neutron stars. Line parameters give information on the temperature, magnetic field and possibly the gravitational potential of the neutron star. The behavior of the continuum spectrum is also discussed. A remarkably good fit to nearly all bursts is obtained with a thermal-bremsstrahlung-like continuum. Significant evolution is observed of both the continuum and line features within most events

  10. Wavelet spectra of JACEE events

    International Nuclear Information System (INIS)

    Suzuki, Naomichi; Biyajima, Minoru; Ohsawa, Akinori.

    1995-01-01

    Pseudo-rapidity distributions of two high multiplicity events Ca-C and Si-AgBr observed by the JACEE are analyzed by a wavelet transform. Wavelet spectra of those events are calculated and compared with the simulation calculations. The wavelet spectrum of the Ca-C event somewhat resembles that simulated with the uniform random numbers. That of Si-AgBr event, however, is not reproduced by simulation calculations with Poisson random numbers, uniform random numbers, or a p-model. (author)

  11. Uranium spectra in the ICP

    Energy Technology Data Exchange (ETDEWEB)

    Ghazi, A.A.; Qamar, S.; Atta, M.A. (Khan (A.Q.) Research Labs., Rawalpindi (Pakistan))

    1994-05-01

    Uranium spectra have been studied by inductively coupled plasma atomic emission spectroscopy (ICP-AES). In total, 8361 uranium lines were observed in the wavelength range of 235-500 nm. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hard copy text is accompanied by a disk with data files and test files for an IBM-compatible computer. The main article discusses the scientific aspects of the subject and explains the purpose of the data files. (Author).

  12. Identified hadron spectra from PHOBOS

    Science.gov (United States)

    Veres, Gábor I.; the PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wysłouch, B.; Zhang, J.

    2004-08-01

    Transverse momentum spectra of pions, kaons and protons, as well as antiparticle to particle ratios near mid-rapidity from d+Au collisions at \\sqrt{sNN} = 200 GeV have been measured by the PHOBOS experiment at RHIC. The transverse momentum range of particle identification was extended to beyond 3 GeV/c using the TOF detector and a new trigger system. The pseudorapidity dependence of the nuclear modification factor for charged hadrons in d+Au collisions is presented.

  13. Uranium spectra in the ICP

    International Nuclear Information System (INIS)

    Ghazi, A.A.; Qamar, S.; Atta, M.A.

    1994-01-01

    Uranium spectra have been studied by inductively coupled plasma atomic emission spectroscopy (ICP-AES). In total, 8361 uranium lines were observed in the wavelength range of 235-500 nm. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hard copy text is accompanied by a disk with data files and test files for an IBM-compatible computer. The main article discusses the scientific aspects of the subject and explains the purpose of the data files. (Author)

  14. Operator functions and localization of spectra

    CERN Document Server

    Gil’, Michael I

    2003-01-01

    "Operator Functions and Localization of Spectra" is the first book that presents a systematic exposition of bounds for the spectra of various linear nonself-adjoint operators in a Hilbert space, having discrete and continuous spectra. In particular bounds for the spectra of integral, differential and integro-differential operators, as well as finite and infinite matrices are established. The volume also presents a systematic exposition of estimates for norms of operator-valued functions and their applications.

  15. Raman spectra of SDW superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Rout, G.C. [Condensed Matter Physics Group, Department of Physics, Government Science College, Chatrapur, Orissa 761 020 (India)]. E-mail: gcr@iopb.res.in; Bishoyi, K.C. [P.G. Department of Physics, F.M. College (Autonomous), Balasore, Orissa 756 001 (India); Behera, S.N. [Institute of Physics, Bhubaneswar 751 005 (India)

    2005-03-15

    We report the calculation of the phonon response of the coexistent spin density wave (SDW) and superconducting (SC) state and predict the observation of SC gap in the Raman spectra of rare-earth nickel borocarbide superconductors. The SDW state normally does not couple to the lattice and hence, the phonons in the system are not expected to be affected by the SDW state. But there is a possibility of observing SC gap mode in the Raman spectra of a SDW superconductor due to the coupling of the SC gap excitation to the Raman active phonons in the system via the electron-phonon (e-p) interaction. A theoretical model is used for the coexistent phase and electron-phonon interaction. Phonon Green's function is calculated by Zubarev's technique and the phonon self-energy due to e-p interaction which is given by electron density response function in the coexistent state corresponding to the SDW wave vector q = Q is evaluated. The results so obtained exhibit agreement with the experimental observations.

  16. Raman spectra of SDW superconductors

    International Nuclear Information System (INIS)

    Rout, G.C.; Bishoyi, K.C.; Behera, S.N.

    2005-01-01

    We report the calculation of the phonon response of the coexistent spin density wave (SDW) and superconducting (SC) state and predict the observation of SC gap in the Raman spectra of rare-earth nickel borocarbide superconductors. The SDW state normally does not couple to the lattice and hence, the phonons in the system are not expected to be affected by the SDW state. But there is a possibility of observing SC gap mode in the Raman spectra of a SDW superconductor due to the coupling of the SC gap excitation to the Raman active phonons in the system via the electron-phonon (e-p) interaction. A theoretical model is used for the coexistent phase and electron-phonon interaction. Phonon Green's function is calculated by Zubarev's technique and the phonon self-energy due to e-p interaction which is given by electron density response function in the coexistent state corresponding to the SDW wave vector q = Q is evaluated. The results so obtained exhibit agreement with the experimental observations

  17. Multiscale climate emulator of multimodal wave spectra: MUSCLE-spectra

    Science.gov (United States)

    Rueda, Ana; Hegermiller, Christie A.; Antolinez, Jose A. A.; Camus, Paula; Vitousek, Sean; Ruggiero, Peter; Barnard, Patrick L.; Erikson, Li H.; Tomás, Antonio; Mendez, Fernando J.

    2017-02-01

    Characterization of multimodal directional wave spectra is important for many offshore and coastal applications, such as marine forecasting, coastal hazard assessment, and design of offshore wave energy farms and coastal structures. However, the multivariate and multiscale nature of wave climate variability makes this complex problem tractable using computationally expensive numerical models. So far, the skill of statistical-downscaling model-based parametric (unimodal) wave conditions is limited in large ocean basins such as the Pacific. The recent availability of long-term directional spectral data from buoys and wave hindcast models allows for development of stochastic models that include multimodal sea-state parameters. This work introduces a statistical downscaling framework based on weather types to predict multimodal wave spectra (e.g., significant wave height, mean wave period, and mean wave direction from different storm systems, including sea and swells) from large-scale atmospheric pressure fields. For each weather type, variables of interest are modeled using the categorical distribution for the sea-state type, the Generalized Extreme Value (GEV) distribution for wave height and wave period, a multivariate Gaussian copula for the interdependence between variables, and a Markov chain model for the chronology of daily weather types. We apply the model to the southern California coast, where local seas and swells from both the Northern and Southern Hemispheres contribute to the multimodal wave spectrum. This work allows attribution of particular extreme multimodal wave events to specific atmospheric conditions, expanding knowledge of time-dependent, climate-driven offshore and coastal sea-state conditions that have a significant influence on local nearshore processes, coastal morphology, and flood hazards.

  18. Scikit-spectra: Explorative Spectroscopy in Python

    Directory of Open Access Journals (Sweden)

    Adam Hughes

    2015-06-01

    Full Text Available Scikit-spectra is an intuitive framework for explorative spectroscopy in Python. Scikit-spectra leverages the Pandas library for powerful data processing to provide datastructures and an API designed for spectroscopy. Utilizing the new IPython Notebook widget system, scikit-spectra is headed towards a GUI when you want it, API when you need it approach to spectral analysis. As an application, analysis is presented of the surface-plasmon resonance shift in a solution of gold nanoparticles induced by proteins binding to the gold’s surface. Please refer to the scikit-spectra website for full documentation and support: http://hugadams.github.io/scikit-spectra/

  19. An RGB approach to extraordinary spectra

    Science.gov (United States)

    Grusche, Sascha; Theilmann, Florian

    2015-09-01

    After Newton had explained a series of ordinary spectra and Goethe had pointed out its complementary counterpart, Nussbaumer discovered a series of extraordinary spectra which are geometrically identical and colourwise analogous to Newton’s and Goethe’s spectra. To understand the geometry and colours of extraordinary spectra, the wavelength composition is explored with filters and spectroscopic setups. Visualized in a dispersion diagram, the wavelength composition is interpreted in terms of additive colour mixing. Finally, all spectra are simulated as the superposition of red, green, and blue images that are shifted apart. This RGB approach makes it easy to understand the complex relationship between wavelengths and colours.

  20. Different spectra with the same neutron source

    International Nuclear Information System (INIS)

    Vega C, H. R.; Ortiz R, J. M.; Hernandez D, V. M.; Martinez B, M. R.; Hernandez A, B.; Ortiz H, A. A.; Mercado, G. A.

    2010-01-01

    Using as source term the spectrum of a 239 Pu-Be source several neutron spectra have been calculated using Monte Carlo methods. The source term was located in the centre of spherical moderators made of light water, heavy water and polyethylene of different diameters. Also a 239 Pu-Be source was used to measure its neutron spectrum, bare and moderated by water. The neutron spectra were measured at 100 cm with a Bonner spheres spectrometer. Monte Carlo calculations were used to calculate the neutron spectra of bare and water-moderated spectra that were compared with those measured with the spectrometer. Resulting spectra are similar to those found in power plants with PWR, BWR and Candu nuclear reactors. Beside the spectra the dosimetric features were determined. Using moderators and a single neutron source can be produced neutron spectra alike those found in workplaces, this neutron fields can be utilized to calibrate neutron dosimeters and area monitors. (Author)

  1. Schottky spectra and crystalline beams

    International Nuclear Information System (INIS)

    Pestrikov, D.V.

    1996-01-01

    In this paper we revise the current dependence of the Schottky noise power of a cooled proton beam previously measured at NAP-M. More careful study of experimental data indicates a linear decrease in the inverse Schottky noise power with an increase in the beam intensity (N). The root of this function determines a threshold current which occurs at N = N th ≅1.2 x 10 8 particles. The inspection of measured Schottky spectra shows that this threshold does not correspond to some collective instability of the measured harmonic of the linear beam density. The found value of N th does not depend on the longitudinal beam temperature. For the case of NAP-M lattice, the study of the spectral properties of the Schottky noise in the crystalline string predicts the current dependence of the equilibrium momentum spread of the beam, which qualitatively agrees with that, recalculated from the NAP-M data. (orig.)

  2. Fractal analysis of power spectra

    International Nuclear Information System (INIS)

    Johnston, S.

    1982-01-01

    A general argument is presented concerning the Hausdorff dimension D of the power spectrum curve for a system of N weakly-coupled oscillators. Explicit upper and lower bounds for D are derived in terms of the number N of interacting modes. The mathematical reasoning relies upon the celebrated KAM theorem concerning the perturbation of Hamiltonian systems and the finite measure of the set of destroyed tori in phase space; this set can be related to Hausdorff dimension by certain mathematical theorems. An important consequence of these results is a simple empirical test for the applicability of Hamiltonian perturbation theory in the analysis of an experimentally observed spectrum. As an illustration, the theory is applied to the interpretation of a recent numerical analysis of both the power spectrum of the Sun and certain laboratory spectra of hydrodynamic turbulence. (Auth.)

  3. Spectra processing with computer graphics

    International Nuclear Information System (INIS)

    Kruse, H.

    1979-01-01

    A program of processng gamma-ray spectra in rock analysis is described. The peak search was performed by applying a cross-correlation function. The experimental data were approximated by an analytical function represented by the sum of a polynomial and a multiple peak function. The latter is Gaussian, joined with the low-energy side by an exponential. A modified Gauss-Newton algorithm is applied for the purpose of fitting the data to the function. The processing of the values derived from a lunar sample demonstrates the effect of different choices of polynomial orders for approximating the background for various fitting intervals. Observations on applications of interactive graphics are presented. 3 figures, 1 table

  4. Determination of the optical absorption spectra of thin layers from their photoacoustic spectra

    Science.gov (United States)

    Bychto, Leszek; Maliński, Mirosław; Patryn, Aleksy; Tivanov, Mikhail; Gremenok, Valery

    2018-05-01

    This paper presents a new method for computations of the optical absorption coefficient spectra from the normalized photoacoustic amplitude spectra of thin semiconductor samples deposited on the optically transparent and thermally thick substrates. This method was tested on CuIn(Te0.7Se0.3)2 thin films. From the normalized photoacoustic amplitude spectra, the optical absorption coefficient spectra were computed with the new formula as also with the numerical iterative method. From these spectra, the value of the energy gap of the thin film material and the type of the optical transitions were determined. From the experimental optical transmission spectra, the optical absorption coefficient spectra were computed too, and compared with the optical absorption coefficient spectra obtained from photoacoustic spectra.

  5. Structure of high-resolution NMR spectra

    CERN Document Server

    Corio, PL

    2012-01-01

    Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

  6. Reflectance spectra of subarctic lichens

    International Nuclear Information System (INIS)

    Petzold, D.E.; Goward, S.N.

    1988-01-01

    Lichens constitute a major portion of the ground cover of high latitude environments, but little has been reported concerning their in situ solar spectral reflectance properties. Knowledge of these properties is important for the interpretation of remotely sensed observations from high latitude regions, as well as in studies of high latitude ecology and energy balance climatology. The spectral reflectance of common boreal vascular plants is similar to that of vascular plants of the mid latitudes. The dominant lichens, in contrast, display variable reflectance patterns in visible wavelengths. The relative reflectance peak at 0.55 μm, common to green vegetation, is absent or indistinct in spectra of pervasive boreal forest and tundra lichens, despite the presence of chlorophyll in the inner algal cells. Lichens of the dominant genus, Cladina, display strong absorption of ultraviolet energy and short-wavelength blue light relative to their absorption in other visible wavelengths. Since the Cladinae dominate both the surface vegetation in open woodlands of the boreal forest and the low arctic tundra, their unusual spectral reflectance patterns will enable accurate monitoring of the boreal forest-tundra ecotone and detection of its vigor and movement in the future. (author)

  7. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  8. Reflectance spectra of subarctic lichens

    Science.gov (United States)

    Petzold, Donald E.; Goward, Samuel N.

    1988-01-01

    Lichens constitute a major portion of the ground cover of high latitude environments, but little has been reported concerning their in situ solar spectral reflectance properties. Knowledge of these properties is important for the interpretation of remotely sensed observations from high latitude regions, as well as in studies of high latitude ecology and energy balance climatology. The spectral reflectance of common boreal vascular plants is similar to that of vascular plants of the midlatitudes. The dominant lichens, in contrast, display variable reflectance patterns in visible wavelengths. The relative reflectance peak at 0.55 microns, common to green vegetation, is absent or indistinct in spectra of pervasive boreal forest and tundra lichens, despite the presence of chlorophyll in the inner algal cells. Lichens of the dominant genus, Cladina, display strong absorption of ultraviolet energy and short-wavelength blue light relative to their absorption in other visible wavelengths. Since the Cladinae dominate both the surface vegetation in open woodlands of the boreal forest and the low arctic tundra, their unusual spectral reflectance patterns will enable accurate monitoring of the boreal forest-tundra ecotone and detection of its vigor and movement in the future.

  9. Ultraviolet spectra of planetary nebulae

    International Nuclear Information System (INIS)

    Harrington, J.P.; Seaton, M.J.; Adams, S.; Lutz, J.H.

    1982-01-01

    A detailed study of NGC 7662 is based on UV results obtained from 15 IUE spectra and on observations of other workers at optical, IR and radio wavelengths. Improved techniques are used to extract IUE data for an extended source. Relative fluxes in the different apertures which have been used are obtained using the brightness contours of Coleman, Reay and Worswick. There is close agreement between the reddening deduced from the ratios He II (lambda 1640)/(lambda 4686) and (radio)/(Hβ) and the nebular continuum emission observed with the IUE large slots agrees closely with that predicted using absolute radio and Hβ fluxes. The fluxes in nebular emission lines observed with the small slots are smaller than expected from brightness distributions; it is concluded that, for an extended source, the small slots have aperture transmission factors of 0.85 for SWP and 0.46 for LWR. The central star is fainter than has been previously supposed (by more than two magnitudes). The blackbody He II Zanstra temperature of 113 000 K is consistent with the UV colour temperature. Previous work on colour temperatures of central stars is discussed critically. Two models are discussed. (author)

  10. Methodology for analyzing weak spectra

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Swainson, I.P.

    2000-02-01

    There is considerable interest in quantifying radionuclide transfer between environmental compartments. However, in many cases, it can be a challenge to detect concentrations of gamma-emitting radionuclides due to their low levels in environmental samples. As a result, it is valuable to develop analytical protocols to ensure consistent analysis of the areas under weak peaks. The current study has focused on testing how reproducibly peak areas and baselines can be determined using two analytical approaches. The first approach, which can be carried out using Maestro software, involves extracting net counts under a curve without fitting a functional form to the peak, whereas the second approach, which is used by most other peak fitting programs, determines net counts from spectra by fitting a Gaussian form to the data. It was found that the second approach produces more consistent peak area and baseline measurements, with the ability to de-convolute multiple, overlapping peaks. In addition, programs, such as Peak Fit, which can be used to fit a form to spectral data, often provide goodness of fit analyses, since the Gaussian form can be described using a characteristic equation against which peak data can be tested for their statistical significance. (author)

  11. Neutron and photon spectra in LINACs

    International Nuclear Information System (INIS)

    Vega-Carrillo, H.R.; Martínez-Ovalle, S.A.; Lallena, A.M.; Mercado, G.A.; Benites-Rengifo, J.L.

    2012-01-01

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10 –6 and 1 MeV. Neutron and the Bremsstrahlung spectra show the same features regardless of the linac voltage. - Highlights: ► With MCNPX code realistic models of two LINACs were built. ► Photon and neutron spectra below the flattening filter and at the isocenter were calculated. ► Neutron spectrum at the flattening filter was compared against the Tosi et al. source-term model. ► Tosi et al. model underestimates the neutron contribution below 1 MeV. ► Photon spectra look alike to those published in literature.

  12. Optical absorption spectra of Ag-11 isomers

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Fernandez, E. M.

    2009-01-01

    The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground-stale confi......The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground...

  13. Microscopic analysis of low-lying states in odd-A Tm isotopes

    Czech Academy of Sciences Publication Activity Database

    Alexa, P.; Hons, Zdeněk; Kvasil, J.

    2009-01-01

    Roč. 36, č. 4 (2009), 045103 /1-045103/16 ISSN 0954-3899 Institutional research plan: CEZ:AV0Z10480505 Keywords : RARE-EARTH * NUCLEI * EXCITATIONS Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.124, year: 2009

  14. A Climate Change Adaptation Planning Process for Low-Lying, Communities Vulnerable to Sea Level Rise

    Directory of Open Access Journals (Sweden)

    Kristi Tatebe

    2012-09-01

    Full Text Available While the province of British Columbia (BC, Canada, provides guidelines for flood risk management, it is local governments’ responsibility to delineate their own flood vulnerability, assess their risk, and integrate these with planning policies to implement adaptive action. However, barriers such as the lack of locally specific data and public perceptions about adaptation options mean that local governments must address the need for adaptation planning within a context of scientific uncertainty, while building public support for difficult choices on flood-related climate policy and action. This research demonstrates a process to model, visualize and evaluate potential flood impacts and adaptation options for the community of Delta, in Metro Vancouver, across economic, social and environmental perspectives. Visualizations in 2D and 3D, based on hydrological modeling of breach events for existing dike infrastructure, future sea level rise and storm surges, are generated collaboratively, together with future adaptation scenarios assessed against quantitative and qualitative indicators. This ‘visioning package’ is being used with staff and a citizens’ Working Group to assess the performance, policy implications and social acceptability of the adaptation strategies. Recommendations based on the experience of the initiative are provided that can facilitate sustainable future adaptation actions and decision-making in Delta and other jurisdictions.

  15. Search for low lying dipole strength in the neutron rich nucleus Ne{sup 26}

    Energy Technology Data Exchange (ETDEWEB)

    Gibelin, J

    2005-11-15

    We carried out the Coulomb excitation, on a lead target, of an exotic beam of neutron-rich nucleus Ne{sup 26} at 58 MeV/n, in order to study the possible existence of a pygmy dipole resonance above the neutron emission threshold. The experiment was performed at the Riken Research Facility, in Tokyo (Japan) and included a gamma-ray detector, a charged fragment hodoscope and a neutron detector. Using the invariant mass method in the Ne{sup 25} + n decay channel, and by comparing the reaction cross section on the lead target and a light target of aluminum, we observe a sizable amount of E1 strength between the one neutron and the two neutron emission thresholds. The corresponding Ne{sup 26} angular distribution confirms its nature and we deduce its reduced dipole transition probability value of B(E1) = 0.54 {+-} 0.18 e{sup 2}fm{sup 2}. Our method also enables us to extract for the first time the decay pattern of a pygmy resonance. By detecting the decay photons from the excited states below the neutron emission threshold and by analyzing the angular distribution of the inelastically scattered Ne{sup 26} we deduce the reduced transition probability of the first 2{sup +} state, from the ground state. The value obtained of B(E2) = 87 {+-} 13 e{sup 2}fm{sup 4} being in disagreement with a previous result. (author)

  16. An Overlook to Low-Lying 2+ States of Rare Earth Region Nuclei With QRPA Approach

    International Nuclear Information System (INIS)

    Ganioglu, E.

    2008-01-01

    As much as known about the nuclear wave function, as much as known about the nuclear structure. Beyond the mean field to get a better wave function it is a way to introduce correlations on top of the mean field solution by means of random phase approximation. Since QRPA is a useful tool for the collective excitations in this study we studied the first 2 + states by means of QRPA and we examine the limits of QRPA description of nuclear excitation in the rare earth region

  17. Low lying electric dipole excitations in nuclei of the rare earth region

    International Nuclear Information System (INIS)

    von Brentano, P.; Zilges, A.; Herzberg, R.D.; Kneissl, U.; Heil, R.D.; Pitz, H.H.; Wesselborg, C.

    1992-01-01

    From many experiments with low energy photon scattering on deformed rare earth nuclei we have obtained detailed information about the distribution of electric dipole strength below 4 MeV. Apart from some weaker transitions between 2 and 4 MeV we observed one, and sometimes two, very strong El-groundstate transitions around 1.5 MeV in all examined nuclei. They arise from the de-excitation of the bandheads of the (J π ,K)=(l - ,0) and (J π ,K)=(l - ,1) octupole vibrational bands. It is shown that the decay branching ratios and the absolute transition strengths of these states can be reproduced rather well with an improved T(El)-operator in the sdf-Interacting Boson Model. Another class of octupole states has been investigated in the region of the semimagic nucleus 142 Nd. Here a quintuplet of collective excitations around 3.5 MeV is expected due to the coupling of the 3--octupole vibration with the 2+-quadrupole vibration. We performed photon scattering experiments on the odd A neighboring nucleus 141 Pr and found first evidence for the existence of 3 - times 2+circle-times particle-states

  18. Numerical study of ground state and low lying excitations of quantum antiferromagnets

    International Nuclear Information System (INIS)

    Trivedi, N.; Ceperley, D.M.

    1989-01-01

    The authors have studied, via Green function Monte Carlo (GFMC), the S = 1/2 Heisenberg quantum antiferromagnet in two dimensions on a square lattice. They obtain the ground state energy with only statistical errors E 0 /J = -0.6692(2), the staggered magnetization m † = 0.31(2), and from the long wave length behavior of the structure factor, the spin wave velocity c/c o = 1.14(5). They show that the ground state wave function has long range pair correlations arising from the zero point motion of spin waves

  19. Electroexcitation of Low-Lying Particle-Hole RPA States of 16O with WBP Interaction

    International Nuclear Information System (INIS)

    Taqi, Ali H.; Radhi, R.A.; Hussein, Adil M.

    2014-01-01

    The nuclear structure of 16 O is studied in the framework of the particle-hole random phase approximation (ph RPA). The Hamiltonian is diagonalized within a model space with particle orbits {1d 5/2 ,1d 3/2 , and 2s 1/2 } and the hole orbits {1p 3/2 and 1p 1/2 } using Warburton and Brown interaction WBP. The ph RPA calculations are tested, by comparing the electron scattering form factors with the available experimental data. The results of electron scattering form factors and reduced transition strength for the states: 1 − , T = 0 (7.116 MeV); 2 − , T = 1 (12.968 MeV); 2 − , T = 1 (20.412 MeV); and 3 − , T = 0 (6.129 MeV) are interpreted in terms of the harmonic-oscillator (HO) wave functions of size parameter b. The occupation probabilities of the single particle and hole orbits are calculated. The spurious states are removed by adding the center of mass (CM) correction to the nuclear Hamiltonian. A comparison with the available experiments data is presented. (nuclear physics)

  20. Electroexcitation of Low-Lying Particle-Hole RPA States of 16O with WBP Interaction

    Science.gov (United States)

    Ali, H. Taqi; R. A., Radhi; Adil, M. Hussein

    2014-12-01

    The nuclear structure of 16O is studied in the framework of the particle-hole random phase approximation (ph RPA). The Hamiltonian is diagonalized within a model space with particle orbits {1d5/2,1d3/2, and 2s1/2} and the hole orbits {1p3/2 and 1p1/2} using Warburton and Brown interaction WBP. The ph RPA calculations are tested, by comparing the electron scattering form factors with the available experimental data. The results of electron scattering form factors and reduced transition strength for the states: 1-, T = 0 (7.116 MeV); 2-, T = 1 (12.968 MeV); 2-, T = 1 (20.412 MeV); and 3-, T = 0 (6.129 MeV) are interpreted in terms of the harmonic-oscillator (HO) wave functions of size parameter b. The occupation probabilities of the single particle and hole orbits are calculated. The spurious states are removed by adding the center of mass (CM) correction to the nuclear Hamiltonian. A comparison with the available experiments data is presented.

  1. South pacific climate variability and its impact on low-lying islands

    Directory of Open Access Journals (Sweden)

    1998-01-01

    Full Text Available VARIABILITE CLIMATIQUE DU SUD PACIFIQUE ET SES IMPACTS SUR LES ILES BASSES. L’environnement climatique du Pacifique sud est conditionné par “l’extrême océanité” de la région et l’interaction étroite entre l’atmosphère et l’océan qui conditionne la vie et l’ensemble des paramètres environnementaux des pays insulaires. Les deux principaux phénomènes climatiques qui affectent la région sont : ENSO ( El Niño - Southern Oscillation et le réchauffement global. Ces deux signaux climatiques, facteurs principaux de la variabilité climatique du Pacifique, font sentir leur action sur l’élévation du niveau moyen de l’océan qui, à terme, peut mettre en cause l’existence même de certains archipels, sur les modifications de la vie océanique et de son exploitation, sur la fréquence et l’intensité des cyclones, sur l’alternance des sécheresses et des périodes humides, sur la production agricole, et sur la santé des lagons et des formations récifales. VARIABILIDAD CLIMÁTICA EN EL PACÍFICO SUR Y SU IMPACTO EN ISLAS BAJAS. El medio ambiente climático de la región del Pacífico Sur se caracteriza por la interacción intensa del océano y la atmósfera, la cual impacta la vida y otros parámetros medioambientales de la región. Dos fenómenos principales están condicionando la variabilidad climática de la región: El Niño y la Oscilación del Sur (ENSO y el Calentamiento Global. Estos dos componentes del cambio climático están afectando la elevación del nivel del mar, la vida en el océano, la frecuencia e intensidad de los huracanes, la ocurrencia de sequías e inundaciones, la potencialidad agrícola, la salud de las regiones costeras incluyendo lagunas y arrecifes. The climatic environment of the South Pacific region is characterized by the intense ocean atmosphere interaction which impacts the life and other environmental parameters of the region. Two main phenomenons are conditioning the climate variability of the region: El Niño and the Southern Oscillation (ENSO and the global warming. These two components of the climate changes are affecting the sea level rise, the life in the ocean, the frequency and intensity of hurricanes, the occurrence of droughts and floods, the agricultural potentiality, the health of coastal regions including lagoons and reefs.

  2. Low-lying isomeric states in Ga-80 from the beta(-) decay of Zn-80

    Czech Academy of Sciences Publication Activity Database

    Lica, R.; Marginean, N.; Ghita, D. G.; Mach, H.; Simpson, G. S.; Aprahamian, A.; Bernards, C.; Briz, J. A.; Bucher, B.; Chiara, C. J.; Dlouhý, Zdeněk; Gheorghe, I.; Hoff, P.; Jolie, J.; Koster, U.; Kurcewicz, W.; Marginean, R.; Olaizola, B.; Paziy, V.; Regis, J. M.; Rudigier, M.; Sava, T.; Stanoiu, M.; Stroe, L.; Walters, W. B.

    2014-01-01

    Roč. 90, č. 1 (2014), 014320 ISSN 0556-2813 Institutional support: RVO:61389005 Keywords : picosecond lifetime measurements * neutron-rich nuclei * Zn Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders Impact factor: 3.733, year: 2014

  3. A density matrix renormalization group study of low-lying excitations ...

    Indian Academy of Sciences (India)

    Unknown

    Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 e-mail: ... has been successfully used as an active semicon- .... ing Ohno parametrization.43 The value of zC for carbon ... gated organic polymers without any heteroatoms has ..... mers can lead to addition (removal) of two electrons.

  4. Role of the low-lying isoscalar dipole modes in the polarization potential

    International Nuclear Information System (INIS)

    Bal'butsev, E.B.; Unzhakova, A.V.; Lanza, E.G.; Catania Univ.

    1994-01-01

    An analysis of the real and imaginary parts of the polarization potential in terms of the relative contributions of the single collective states for the 208 Pb + 208 Pb system has been done. The polarization potential has been calculated within the Feshbach formalism taking into account the collective states calculated with the Wigner function moments method. The contribution of the isoscalar giant dipole resonance states has been estimated being of the order of 10-20% of the total at relatively low incident energy. 14 refs., 4 figs., 1 tab

  5. Microscopic study of low-lying collective bands in 77Kr

    Indian Academy of Sciences (India)

    Extensive experimental studies of 77Kr have recently been performed by Sylvan et al [4] and Johnson et al [5] (see also refs [6,7]). These experimental studies have resulted in the identification of positive parity and negative parity collective bands up to very high spin. The ground state for 77Kr is based on K = 5/2+ with the.

  6. Effect translational invariance in low-lying electric dipole excitations in 236U and 238U

    International Nuclear Information System (INIS)

    Ertugral, F.

    2005-01-01

    In this paper the translational invariant QRPA approach suggested by Pyatov [1] for the spherical nuclei has been extended to describe the 1 - states in deformed nuclei. The role of spurious centre-of-motion state on the Pygmy dipole resonance (PDR) has been investigated in the deformed 236 U and 238 U nuclei. It has been shown that the effect of taking into account the translational invariance of the Hamiltonians in the QRPA with separation of zero energy spurious solutions are noticeable in both the low energy density of 1 - states and in the PDR. Present investigation demonstrates the advantage of the translational invariant QRPA over the non translational invariant one. Within the translational invariant model the effect of removing spurious states on the E1 strength distribution is stronger than in none invariant QRPA (∼20%) for the states up to the neutron binding energy. It is found that the spurious state is spread over many levels, the largest admixture being situated in the region of the energy spacing between nuclear shells o w h . The giant resonance states contain, as a rule, very small admixtures of the spurious state

  7. Hydrochemical and physical processes influencing salinization and freshening in Mediterranean low-lying coastal environments

    NARCIS (Netherlands)

    Mollema, P.N.; Antonelli, M.; Dinelli, E.; Gabbianelli, G.; Greggio, N.; Stuijfzand, P.J.

    2013-01-01

    Ground- and surface water chemistry and stable isotope data from the coastal zone near Ravenna (Italy) have been examined to determine the geochemical conditions and processes that occur and their implications for fresh water availability in the various brackish/saline coastal environments. Fresh

  8. Low-lying nuclear levels and radiative transitions in hadronic atoms

    International Nuclear Information System (INIS)

    Popov, V.S.; Kudryavtsev, A.E.; Lisin, V.I.; Mur, V.D.

    1985-01-01

    The analytic theory of nuclear level shifts permit the position of the nuclear level perturbing the Coulomb spectrum to be calculated on the basis of the magnitude of the level shift of a hadron atom. As an example the K -4 He atom is discussed. The experimental data on the 2p-level shift indicate that a weakly bound p-state with a binding energy and width epsilon approximately γ approximately 0.5 MeV may exist in the system. The probabilities for radiative transitions to this level and the cross section for its creation in a nuclear reaction with 6 Li are calculated. The possible existence of weakly coupled K - and anti p states for other light nuclei is discussed. An exact solution of the model Coulomb problem with short range interaction is obtained and this permits the limits of validity of the initial approximations to be determined

  9. Properties of the low-lying negative parity states in 45Sc

    International Nuclear Information System (INIS)

    Chevallier, J.; Haas, B.; Schulz, N.; Toulemonde, M.

    1975-01-01

    The electromagnetic decay of negative parity states in 45 Sc up to an excitation energy of 2107keV have been investigated via the 42 Ca(α,pγ) 45 Sc reaction at a bombarding energy of 10.5MeV. Spin and lifetime of the levels as well as branching and mixing ratios of their decay γ-rays have been obtained from proton-gamma angular correlation measurements. Calculations based on the strong coupling model have been performed. The results are compared with experiment [fr

  10. Soft rotator model and {sup 246}Cm low-lying level scheme

    Energy Technology Data Exchange (ETDEWEB)

    Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    Non-axial soft rotator nuclear model is suggested as self-consistent approach for interpretation of level schemes, {gamma}-transition probabilities and neutron interaction with even-even nuclei. (author)

  11. Large fluctuations of shallow seas in low-lying Southeast Asia driven by mantle flow

    Science.gov (United States)

    Zahirovic, Sabin; Flament, Nicolas; Dietmar Müller, R.; Seton, Maria; Gurnis, Michael

    2016-09-01

    The Sundaland continental promontory, as the core of Southeast Asia, is one of the lowest lying continental regions, with half of the continental area presently inundated by a shallow sea. The role of mantle convection in driving long-wavelength topography and vertical motion of the lithosphere in this region has often been ignored when interpreting regional stratigraphy, including a widespread Late Cretaceous-Eocene unconformity, despite a consensus that Southeast Asia is presently situated over a large-amplitude dynamic topography low resulting from long-term post-Pangea subduction. We use forward numerical models to link mantle flow with surface tectonics and compare predicted trends of dynamic topography with eustasy and regional paleogeography to determine the influence of mantle convection on regional basin histories. A Late Cretaceous collision of Gondwana-derived terranes with Sundaland choked the active margin, leading to slab breakoff and a ˜10-15 Myr-long subduction hiatus. A subduction hiatus likely resulted in several hundred meters of dynamic uplift and emergence of Sundaland between ˜80 and 60 Ma and may explain the absence of a Late Cretaceous-Eocene sedimentary record. Renewed subduction from ˜60 Ma reinitiated dynamic subsidence of Sundaland, leading to submergence from ˜40 Ma despite falling long-term global sea levels. Our results highlight a complete "down-up-down" dynamic topography cycle experienced by Sundaland, with transient dynamic topography manifesting as a major regional unconformity in sedimentary basins.

  12. Spectroscopic Parameter and Molecular Constant Investigations on Low-Lying States of BeF Radical

    Directory of Open Access Journals (Sweden)

    Jin Feng Sun

    2012-02-01

    Full Text Available The potential energy curves (PECs of X2Σ+, A2Πr and B2Σ+ states of BeF radical have been investigated using the complete active space self-consistent-field (CASSCF method, followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI approach at the correlation-consistent basis sets, cc-pV5Z for Be and aug-cc-pV6Z for F. Based on the PECs of X2Σ+, A2Πr and B2Σ+ states, the spectroscopic parameters (De, Re, ωe, ωeχe, αe and Be have also been determined in the present work. With the PECs determined at the present level of theory, vibrational states have been predicted for each state when the rotational quantum number J equals zero (J = 0. The vibrational levels, inertial rotation and centrifugal distortion constants are determined for the three states, and the classical turning points are also calculated for the X2Σ+ state. Compared with the available experiments and other theories, it can be seen that the present spectroscopic parameter and molecular constant results are more fully in agreement with the experimental findings.

  13. Nearest neighbor spacing distributions of low-lying levels of vibrational nuclei

    International Nuclear Information System (INIS)

    Abul-Magd, A.Y.; Simbel, M.H.

    1996-01-01

    Energy-level statistics are considered for nuclei whose Hamiltonian is divided into intrinsic and collective-vibrational terms. The levels are described as a random superposition of independent sequences, each corresponding to a given number of phonons. The intrinsic motion is assumed chaotic. The level spacing distribution is found to be intermediate between the Wigner and Poisson distributions and similar in form to the spacing distribution of a system with classical phase space divided into separate regular and chaotic domains. We have obtained approximate expressions for the nearest neighbor spacing and cumulative spacing distribution valid when the level density is described by a constant-temperature formula and not involving additional free parameters. These expressions have been able to achieve good agreement with the experimental spacing distributions. copyright 1996 The American Physical Society

  14. The structure of low-lying states in ${}^{140}$Sm studied by Coulomb excitation

    CERN Document Server

    Klintefjord, M.; Görgen, A.; Bauer, C.; Bello Garrote, F.L.; Bönig, S.; Bounthong, B.; Damyanova, A.; Delaroche, J.P.; Fedosseev, V.; Fink, D.A.; Giacoppo, F.; Girod, M.; Hoff, P.; Imai, N.; Korten, W.; Larsen, A.C.; Libert, J.; Lutter, R.; Marsh, B.A.; Molkanov, P.L.; Naïdja, H.; Napiorkowski, P.; Nowacki, F.; Pakarinen, J.; Rapisarda, E.; Reiter, P.; Renstrøm, T.; Rothe, S.; Seliverstov, M.D.; Siebeck, B.; Siem, S.; Srebrny, J.; Stora, T.; Thöle, P.; Tornyi, T.G.; Tveten, G.M.; Van Duppen, P.; Vermeulen, M.J.; Voulot, D.; Warr, N.; Wenander, F.; De Witte, H.; Zielińska, M.

    2016-05-02

    The electromagnetic structure of $^{140}$Sm was studied in a low-energy Coulomb excitation experiment with a radioactive ion beam from the REX-ISOLDE facility at CERN. The $2^+$ and $4^+$ states of the ground-state band and a second $2^+$ state were populated by multi-step excitation. The analysis of the differential Coulomb excitation cross sections yielded reduced transition probabilities between all observed states and the spectroscopic quadrupole moment for the $2_1^+$ state. The experimental results are compared to large-scale shell model calculations and beyond-mean-field calculations based on the Gogny D1S interaction with a five-dimensional collective Hamiltonian formalism. Simpler geometric and algebraic models are also employed to interpret the experimental data. The results indicate that $^{140}$Sm shows considerable $\\gamma$ softness, but in contrast to earlier speculation no signs of shape coexistence at low excitation energy. This work sheds more light on the onset of deformation and collectivit...

  15. Observation of a low-lying neutron-unbound state in 19C

    International Nuclear Information System (INIS)

    Thoennessen, M.; Mosby, S.; Badger, N.S.; Baumann, T.; Bazin, D.; Bennett, M.; Brown, J.; Christian, G.; DeYoung, P.A.; Finck, J.E.; Gardner, M.; Hook, E.A.; Luther, B.; Meyer, D.A.; Mosby, M.; Rogers, W.F.

    2013-01-01

    Proton removal reactions from a secondary 22 N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system 18 C+n corresponding to a state in 19 C at an excitation energy of 653(95) keV. This resonance could correspond to the first 5/2 + state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from 20 C

  16. Large scale hydrogeological modelling of a low-lying complex coastal aquifer system

    DEFF Research Database (Denmark)

    Meyer, Rena

    2018-01-01

    intrusion. In this thesis a new methodological approach was developed to combine 3D numerical groundwater modelling with a detailed geological description and hydrological, geochemical and geophysical data. It was applied to a regional scale saltwater intrusion in order to analyse and quantify...... the groundwater flow dynamics, identify the driving mechanisms that formed the saltwater intrusion to its present extent and to predict its progression in the future. The study area is located in the transboundary region between Southern Denmark and Northern Germany, adjacent to the Wadden Sea. Here, a large-scale...... parametrization schemes that accommodate hydrogeological heterogeneities. Subsequently, density-dependent flow and transport modelling of multiple salt sources was successfully applied to simulate the formation of the saltwater intrusion during the last 4200 years, accounting for historic changes in the hydraulic...

  17. M1 transitions between low-lying states in the sdg-IBM-2

    Science.gov (United States)

    Casperson, Robert; Werner, Volker

    2006-10-01

    The interplay between collective and single-particle degrees of freedom for nuclei in the A=90 region have recently been under investigation. In Molybdenum and Ruthenium nuclei, collective symmetric and mixed-symmetric structures have been identified, while in Zirconium, underlying shell-structure plays an enhanced role. Collective symmetric structures appear when protons and neutrons are in phase, whereas mixed-symmetric structures occur when they are not. The one-phonon 2^+ mixed-symmetric state was identified from strong M1 transitions to the 2^+1 state. Similar transitions were observed between higher-spin states, and are predicted by the shell model. These phenomena will be investigated within the sdg Interacting Boson Model 2 in order to obtain a better understanding about the structure of the states involved, and results from first model calculations will be presented. Work supported by US DOE under grant number DE-FG02-91ER-40609.

  18. Quadrupole moments of low-lying baryons with spin- , spin- , and ...

    Indian Academy of Sciences (India)

    2013-02-03

    Feb 3, 2013 ... boson (GB), successfully explains the 'proton spin crisis' [26], hyperon β decay parame- ters [27], strangeness content in the nucleon [28], and in the N ...... ment of India (SR/S2/HEP-0028/2008) and Department of Atomic Energy, Government of India (2010/37P/48/BRNS/1445). References. [1] R G Sachs ...

  19. Lifetimes of low-lying excited states in 50 36 86Kr

    Science.gov (United States)

    Henderson, J.; Chester, A.; Ball, G. C.; Caballero-Folch, R.; Domingo, T.; Drake, T. E.; Evitts, L. J.; Garnsworthy, A. B.; Hackman, G.; Hallam, S.; Moukaddam, M.; Ruotsalainen, P.; Smallcombe, J.; Smith, J. K.; Starosta, K.; Svensson, C. E.; Williams, J.

    2018-04-01

    Background: The evolution of nuclear magic numbers at extremes of isospin is a topic at the forefront of contemporary nuclear physics. N =50 is a prime example, with increasing experimental data coming to light on potentially doubly magic 100Sn and 78Ni at the proton-rich and proton-deficient extremes, respectively; however, experimental discrepancies exist in the data for less exotic systems. Purpose: In 86Kr the B (E 2 ;21+→01+) value—a key indicator of shell evolution—has been experimentally determined by two different methodologies, with the results deviating by 3 σ . Here, we report on a new high-precision measurement of this value, as well as the first measured lifetimes and hence transition strengths for the 22+ and 3(2) - states in the nucleus. Methods: The Doppler-shift attenuation method was implemented using the TRIUMF-ISAC γ -ray escape-suppressed spectrometer (TIGRESS) γ -ray spectrometer and the TIGRESS integrated plunger device. High-statistics Monte Carlo simulations were utilized to extract lifetimes in accordance with state-of-the-art methodologies. Results: Lifetimes of τ (21+)=336 ±4 (stat.)±20 (sys.) fs, τ (22+)=263 ±9 (stat.)±19 (sys.) fs, and τ (3(2) -)=73 ±6 (stat.)±32 (sys.) fs were extracted. This yields a transition strength for the first-excited state of B (E 2 ;21+→01+)=259 ±3 (stat.)±16 (sys.) e2 fm4. Conclusions: The measured lifetime disagrees with the previous Doppler-shift attenuation method measurement by more than 3 σ , while agreeing well with a previous value extracted from Coulomb excitation. The newly extracted B (E 2 ;21+→01+) value indicates a more significant reduction in the N =50 isotones approaching Z =40 .

  20. Investigation of low-lying dipole strength in {sup 124}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Symochko, D.; Aumann, T.; Duchene, M.; Knoerzer, M.; Pietralla, N.; Scheit, H. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Bhike, M.; Kelley, J.; Tornow, W. [Department for Physics, Duke University (United States); Derya, V.; Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); Isaak, J.; Loeher, B.; Savran, D. [ExtreMe Matter Institute EMMI and Research Division, Darmstadt (Germany); Tonchev, A. [Lawrence Livermore National Laboratory (United States); Werner, V. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); WNSL, Yale University (United States)

    2014-07-01

    Dipole excitations in the semi-magic {sup 124}Sn nucleus were studied in (γ,γ') reactions using the γ{sup 3}-high-efficiency detector setup. The experiment was carried out with quasimonoenergetic photon beams provided by the HIγS facility at the TUNL in the energy range from 5.2 to 8.6 MeV at 15 different energies. Measurements allowed to identify near 80 new transitions to the ground state, obtain reduced transition probabilities and assign parity quantum numbers to the observed excited states. Besides, the γ-γ coincidence technique gave access to the γ-decay pattern of the Pygmy Dipole Resonance, e.g. it was possible to analyse the branching ratios to the first excited 2{sup +} state. Investigations were made as a part of the experimental campaign aimed to obtain a complete picture of dipole strength function evolution in Sn isotopes - from stable {sup 112}Sn to short-lived {sup 134}Sn.

  1. Low-lying dipole strength in the well-deformed nucleus {sup 156}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Tamkas, M. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Graduate School of Natural and Applied Sciences, Yildiz Technical University, Istanbul (Turkey); Isaak, J.; Silva, J. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Frankfurt Institute for Advanced Studies (FIAS), Frankfurt (Germany); Savran, D. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Loeher, B. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Aciksoz, E. [Department of Physics, Akdeniz University (Turkey); Beck, T.; Beller, J.; Gayer, U.; Pietralla, N.; Romig, C.; Werner, V.; Zweidinger, M. [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Tornow, W.; Weller, H. [Department of Physics, Duke University, TUNL, Durham (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln (Germany)

    2016-07-01

    In this study the dipole strength has been investigated in the well-deformed nucleus {sup 156}Gd using the method of Nuclear Resonance Fluorescence (NRF). The NRF experiment was performed at the High Intensity vector γ-ray Source at Duke University in combination with the γ{sup 3} setup using a mono-energetic and linearly polarised beam. The dipole strength of {sup 156}Gd has been studied with photon beam energies between 3 MeV and 6.2 MeV. The parity quantum numbers of J=1 states have been determined for the energy region above ∝3 MeV for the first time. Recent results of the {sup 156}Gd(vector γ,γ') experiment are presented and discussed.

  2. Low-lying states of 184W and 184Os nuclei

    International Nuclear Information System (INIS)

    Sharrad, F.I.; Abdullah, Hewa Y.; Al-Dahan, N.; Umran, N.M.; Okhunov, A.A.; Abu Kassim, H.

    2013-01-01

    The energy levels, transition energy, B(E2) values, intrinsic quadrupole moment Q 0 and potential energy surface for even-even 184 W and 184 Os nuclei were calculated using IBM-1. The predicted energy levels, transition energy, B(E2) values and intrinsic quadrupole moment Q 0 results are reasonably consistent with the experimental data. A contour plot of the potential energy surfaces shows that two interesting nuclei are deformed and have rotational characters. (authors)

  3. Fluctuation analysis of rotational spectra

    International Nuclear Information System (INIS)

    Doessing, T.; Bracco, A.; Broglia, R.A.; Matsuo, M.

    1996-01-01

    The compound state rotational degree of freedom is ''damped'' in the sense that the electric quadrupole decay of a single quantum state with angular momentum I exhibits a spectrum of final states all having spin I-2. In actual experiments, the cascade of γ-rays associated with each of the members of the ensemble of compound nuclei uses each of the ''discrete'' transitions many more times than the ''continuum'' transitions. Relatively large and small fluctuations in the recorded coincidence spectrum ensue, respectively. The analysis of the fluctuations will be shown to be instrumental to gain insight into the phenomenon of rotational damping. For this purpose, two- and higher-fold coincidence spectra emitted from rotating nuclei are analyzed with respect to the count fluctuations. The coincidences from consecutive γ-rays emitted from discrete rotational bands generate ridges in the E γ1 .E γ2 spectrum, and the fluctuation analysis of the ridges is based upon the ansatz of a random selection of transition energies from band to band. This ansatz is supported by a cranked mean-field calculation for the nucleus 168 Yb, as well as by analyzing resolved bands in 168 Yb and its neighbors. The fluctuation analysis of the central valley (E γ1 =E γ2 ) is based upon the ansatz of fluctuations in the intensity of the transitions of Porter-Thomas type superposed on a smooth spectrum of transition energies. This ansatz is again supported by a mixed-band calculation. The mathematical treatment of count fluctuations is formulated in general (orig.)

  4. Area spectra of near extremal black holes

    International Nuclear Information System (INIS)

    Chen, Deyou; Yang, Haitang; Zu, Xiaotao

    2010-01-01

    Motivated by Maggiore's new interpretation of quasinormal modes, we investigate area spectra of a near extremal Schwarzschild-de Sitter black hole and a higher-dimensional near extremal Reissner-Nordstrom-de Sitter black hole. The result shows that the area spectra are equally spaced and irrelevant to the parameters of the black holes. (orig.)

  5. Composite Spectra Paper 1: HR 6902

    Indian Academy of Sciences (India)

    tribpo

    spectra; in many cases we have used the maximum width permitted by the optics of ... 10 mЕ, corresponding to 1 µm the plate, are the norm. ..... an inequality ..... on the spectra of HR 6902, we have thought it appropriate to weight the four ...

  6. Thermoluminescence spectra measured with a Michelson interferometer

    International Nuclear Information System (INIS)

    Haschberger, P.

    1991-01-01

    A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

  7. Near IR spectra of symbiotic stars

    International Nuclear Information System (INIS)

    Andrillat, Y.

    1982-01-01

    The author reports on recent observations from the near IR spectra of symbiotic stars. The helium and oxygen lines useful for the construction of theoretical models are identified. Observations for cool stars and novae (nebular phase) are outlined and the spectra of specific symbiotic stars between lambdalambda 8000-11000 are presented and discussed. (Auth./C.F.)

  8. Aircraft Measurements of Atmospheric Kinetic Energy Spectra

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Lilly, D. K.

    1983-01-01

    Wind velocity data obtained from a jet airliner are used to construct kinetic energy spectra over the range of wavelengths from 2.5 to 2500 km. The spectra exhibit an approximate -5/3 slope for wavelengths of less than about 150 km, steepening to about -2.2 at larger scales. These results support...

  9. PCA: Principal Component Analysis for spectra modeling

    Science.gov (United States)

    Hurley, Peter D.; Oliver, Seb; Farrah, Duncan; Wang, Lingyu; Efstathiou, Andreas

    2012-07-01

    The mid-infrared spectra of ultraluminous infrared galaxies (ULIRGs) contain a variety of spectral features that can be used as diagnostics to characterize the spectra. However, such diagnostics are biased by our prior prejudices on the origin of the features. Moreover, by using only part of the spectrum they do not utilize the full information content of the spectra. Blind statistical techniques such as principal component analysis (PCA) consider the whole spectrum, find correlated features and separate them out into distinct components. This code, written in IDL, classifies principal components of IRS spectra to define a new classification scheme using 5D Gaussian mixtures modelling. The five PCs and average spectra for the four classifications to classify objects are made available with the code.

  10. General Notes on Processes and Their Spectra

    Directory of Open Access Journals (Sweden)

    Gustav Cepciansky

    2012-01-01

    Full Text Available The frequency spectrum performs one of the main characteristics of a process. The aim of the paper is to show the coherence between the process and its own spectrum and how the behaviour and properties of a process itself can be deduced from its spectrum. Processes are categorized and general principles of their spectra calculation and recognition are given. The main stress is put on power spectra of electric and optic signals, as they also perform a kind of processes. These spectra can be directly measured, observed and examined by means of spectral analyzers and they are very important characteristics which can not be omitted at transmission techniques in telecommunication technologies. Further, the paper also deals with non electric processes, mainly with processes and spectra at mass servicing and how these spectra can be utilised in praxis.

  11. Design spectra development considering short time histories

    International Nuclear Information System (INIS)

    Weiner, E.O.

    1983-01-01

    Two separate programs, MODQKE and MDOF, were written to provide a capability of obtaining equipment spectra from design spectra. MODQKE generates or modifies acceleration histories to conform with design spectra pertaining to, say, a foundation. MDOF is a simple linear modal superposition program that solves for equipment support histories using the design spectra conforming histories as input. Equipment spectra, then, are obtained from the support histories using MODQKE. MODQKE was written to modify or provide new histories with special attention paid to short seismic records. A technique from the open literature was borrowed to generate an initial history that approximates a given response spectrum. Further refinement is done with smoothing cycles in which several correction signals are added to the history in a way that produces a least squares fit between actual and prescribed spectra. Provision is made for history shaping, a baseline correction, and final scaling. MODQKE performance has been demonstrated with seven examples having zero to ten percent damping ratios, and 2.5 seconds to 20 seconds durations and a variety of target spectra. The examples show the program is inexpensive to use. MDOF is a simple modal superposition program. It has no eigensolver, and the user supplies mode shapes, frequencies, and participation factors as input. Floor spectra can be generated from design spectra by using a history from MODQKE that conforms to the design spectrum as input to MDOF. Floor motions from MDOF can be fed back to MODQKE without modification to obtain the floor spectra. A simple example is given to show how equipment mass effects can be incorporated into the MDOF solution. Any transient solution capability can be used to replace MDOF. For example, a direct transient approach may be desirable if both the equipment and floor structures are to be included in the model with different damping fractions. (orig./HP)

  12. Spectra of conformal sigma models

    International Nuclear Information System (INIS)

    Tlapak, Vaclav

    2015-04-01

    In this thesis the spectra of conformal sigma models defined on (generalized) symmetric spaces are analysed. The spaces where sigma models are conformal without the addition of a Wess-Zumino term are supermanifolds, in other words spaces that include fermionic directions. After a brief review of the general construction of vertex operators and the background field expansion, we compute the diagonal terms of the one-loop anomalous dimensions of sigma models on semi-symmetric spaces. We find that the results are formally identical to the symmetric case. However, unlike for sigma models on symmetric spaces, off diagonal terms that lead to operator mixing are also present. These are not computed here. We then present a detailed analysis of the one-loop spectrum of the supersphere S 3 vertical stroke 2 sigma model as one of the simplest examples. The analysis illustrates the power and simplicity of the construction. We use this data to revisit a duality with the OSP(4 vertical stroke 2) Gross-Neveu model that was proposed by Candu and Saleur. With the help of a recent all-loop result for the anomalous dimension of (1)/(2)BPS operators of Gross-Neveu models, we are able to recover the entire zero-mode spectrum of the supersphere model. We also argue that the sigma model constraints and its equations of motion are implemented correctly in the Gross-Neveu model, including the one-loop data. The duality is further supported by a new all-loop result for the anomalous dimension of the ground states of the sigma model. However, higher-gradient operators cannot be completely recovered. It is possible that this discrepancy is related to a known instability of the sigma model. The instability of sigma models is due to symmetry preserving high-gradient operators that become relevant at arbitrarily small values of the coupling. This feature has been observed long ago in one-loop calculations of the O(N)-vector model and soon been realized to be a generic property of sigma models

  13. Statistical properties of Fermi GBM GRBs' spectra

    Science.gov (United States)

    Rácz, István I.; Balázs, Lajos G.; Horvath, Istvan; Tóth, L. Viktor; Bagoly, Zsolt

    2018-03-01

    Statistical studies of gamma-ray burst (GRB) spectra may result in important information on the physics of GRBs. The Fermi GBM catalogue contains GRB parameters (peak energy, spectral indices, and intensity) estimated fitting the gamma-ray spectral energy distribution of the total emission (fluence, flnc), and during the time of the peak flux (pflx). Using contingency tables, we studied the relationship of the models best-fitting pflx and flnc time intervals. Our analysis revealed an ordering of the spectra into a power law - Comptonized - smoothly broken power law - Band series. This result was further supported by a correspondence analysis of the pflx and flnc spectra categorical variables. We performed a linear discriminant analysis (LDA) to find a relationship between categorical (spectral) and model independent physical data. LDA resulted in highly significant physical differences among the spectral types, that is more pronounced in the case of the pflx spectra, than for the flnc spectra. We interpreted this difference as caused by the temporal variation of the spectrum during the outburst. This spectral variability is confirmed by the differences in the low-energy spectral index and peak energy, between the pflx and flnc spectra. We found that the synchrotron radiation is significant in GBM spectra. The mean low-energy spectral index is close to the canonical value of α = -2/3 during the peak flux. However, α is ˜ -0.9 for the spectra of the fluences. We interpret this difference as showing that the effect of cooling is important only for the fluence spectra.

  14. Scaling properties of the transverse mass spectra

    International Nuclear Information System (INIS)

    Schaffner-Bielich, J.

    2002-01-01

    Motivated from the formation of an initial state of gluon-saturated matter, we discuss scaling relations for the transverse mass spectra at BNL's relativistic heavy-ion collider (RHIC). We show on linear plots, that the transverse mass spectra for various hadrons can be described by an universal function in m t . The transverse mass spectra for different centralities can be rescaled into each other. Finally, we demonstrate that m t -scaling is also present in proton-antiproton collider data and compare it to m t -scaling at RHIC. (orig.)

  15. IRAS low-resolution spectra of galaxies

    International Nuclear Information System (INIS)

    Cohen, M.; Volk, K.

    1989-01-01

    The spectra of external galaxies are selected and extracted from the IRAS LRS database. Twenty-one objects present viable spectra. One is a peculiar star-forming E-S0 galaxy. The remainder are all starburst or H II region galaxies. Their average spectrum demonstrates the importance of the PAH emission bands in the 8-23-micron region and reinforces the conclusion reached from ground-based spectra, that there is a strong correlation between the PAH bands and the starburst or H II region character of a galaxy. 32 refs

  16. Parametrization relating the fermionic mass spectra

    International Nuclear Information System (INIS)

    Kleppe, A.

    1993-01-01

    When parametrizing the fermionic mass spectra in terms of the unit matrix and a recursive matrix scrR 0 , which corresponds to an underlying scaling pattern in the mass spectra, each fermionic sector is characterized by three parameters: k, α, and R. Using the set of relations displayed by the parameters of the different sectors, it is possible to formulate a ''family Lagrangian'' which for each sector encompasses all the families. Relations between quark masses are furthermore deduced from these ''family Lagrangians.'' Using the relations between the parameters of the different charge sectors, it is also possible to ''derive'' the quark mass spectra from the (charged) leptonic mass spectrum

  17. Power spectra of currents off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Current measurements were carried out using a recording current meter across the continental shelf off Bombay, Maharashtra, India at 4 stations from an anchored ship. Power spectra were computed for selected lengths of records. Spectral energy...

  18. Contribution to the study of turbulence spectra

    Science.gov (United States)

    Dumas, R.

    1979-01-01

    An apparatus suitable for turbulence measurement between ranges of 1 to 5000 cps and from 6 to 16,000 cps was developed and is described. Turbulence spectra downstream of the grills were examined with reference to their general characteristics, their LF qualities, and the effects of periodic turbulence. Medium and HF are discussed. Turbulence spectra in the boundary layers are similarly examined, with reference to their fluctuations at right angles to the wall, and to lateral fluctuations. Turbulence spectra in a boundary layer with suction to the wall is discussed. Induced turbulence, and turbulence spectra at high Reynolds numbers. Calculations are presented relating to the effect of filtering on the value of the correlations in time and space.

  19. Experimental phase diagram for random laser spectra

    International Nuclear Information System (INIS)

    El-Dardiry, Ramy G S; Mooiweer, Ronald; Lagendijk, Ad

    2012-01-01

    We systematically study the presence of narrow spectral features in a wide variety of random laser samples. Less gain or stronger scattering are shown to lead to a crossover from spiky to smooth spectra. A decomposition of random laser spectra into a set of Lorentzians provides unprecedented detail in the analysis of random laser spectra. We suggest an interpretation in terms of mode competition that enables an understanding of the observed experimental trends. In this interpretation, smooth random laser spectra are a consequence of competing modes for which the loss and gain are proportional. Spectral spikes are associated with modes that are uncoupled from the mode competition in the bulk of the sample. (paper)

  20. On two-spectra inverse problems

    OpenAIRE

    Guliyev, Namig J.

    2018-01-01

    We consider a two-spectra inverse problem for the one-dimensional Schr\\"{o}dinger equation with boundary conditions containing rational Herglotz--Nevanlinna functions of the eigenvalue parameter and provide a complete solution of this problem.

  1. Angular Spectra of Polarized Galactic Foregrounds

    OpenAIRE

    Cho, Jung; Lazarian, A.

    2003-01-01

    It is believed that magnetic field lines are twisted and bend by turbulent motions in the Galaxy. Therefore, both Galactic synchrotron emission and thermal emission from dust reflects statistics of Galactic turbulence. Our simple model of Galactic turbulence, motivated by results of our simulations, predicts that Galactic disk and halo exhibit different angular power spectra. We show that observed angular spectra of synchrotron emission are compatible with our model. We also show that our mod...

  2. Generation of synthetic gamma spectra with MATLAB

    International Nuclear Information System (INIS)

    Palmerio, Julian J.; Coppo, Anibal D.

    2009-01-01

    Objectives: The aim of this work is the simulation of gamma spectra using the MATLAB program to generate the calibration curves in efficiency, which will be used to measure radioactive waste in drums. They are necessary for the proper characterization of these drums. A Monte Carlo simulation was basically developed with the random number generator Mersenne Twister and nuclear data obtained from NIST. This paper shows the results obtained and difficulties encountered until today. The physical correction of the simulated spectra has been the only aspect we have been working, up to this moment. Procedures: A simplified representation of the 'Laboratorio de Verificacion y Control de la Calidad' was chosen. Drums with cemented liquid waste are routinely measured in this laboratory. The commercial program MCNP was also used to get a valid reference in the field of simulation of spectra. We analyzed the spectra obtained by MATLAB in the light of classical literature photon detection and the spectrum obtained by MCNP. Conclusions: Currently the program developed seems adequate to simulate a measurement in the 'Laboratorio de Verificacion y Control de la Calidad'. The spectra obtained by MATLAB seem to physically represent what is observed in real spectra. However, it is a slow program. The current development efforts are directed to improve the speed of simulation. An alternative is to use the CUDA language for NVIDIA video cards to parallelized the simulation. An adequate simulation of the electronic measuring chain is also needed to obtain better representations of the shapes of the peaks. (author)

  3. Identifying Broadband Rotational Spectra with Neural Networks

    Science.gov (United States)

    Zaleski, Daniel P.; Prozument, Kirill

    2017-06-01

    A typical broadband rotational spectrum may contain several thousand observable transitions, spanning many species. Identifying the individual spectra, particularly when the dynamic range reaches 1,000:1 or even 10,000:1, can be challenging. One approach is to apply automated fitting routines. In this approach, combinations of 3 transitions can be created to form a "triple", which allows fitting of the A, B, and C rotational constants in a Watson-type Hamiltonian. On a standard desktop computer, with a target molecule of interest, a typical AUTOFIT routine takes 2-12 hours depending on the spectral density. A new approach is to utilize machine learning to train a computer to recognize the patterns (frequency spacing and relative intensities) inherit in rotational spectra and to identify the individual spectra in a raw broadband rotational spectrum. Here, recurrent neural networks have been trained to identify different types of rotational spectra and classify them accordingly. Furthermore, early results in applying convolutional neural networks for spectral object recognition in broadband rotational spectra appear promising. Perez et al. "Broadband Fourier transform rotational spectroscopy for structure determination: The water heptamer." Chem. Phys. Lett., 2013, 571, 1-15. Seifert et al. "AUTOFIT, an Automated Fitting Tool for Broadband Rotational Spectra, and Applications to 1-Hexanal." J. Mol. Spectrosc., 2015, 312, 13-21. Bishop. "Neural networks for pattern recognition." Oxford university press, 1995.

  4. Good abundances from bad spectra - I. Techniques

    Science.gov (United States)

    Jones, J. Bryn; Gilmore, Gerard; Wyse, Rosemary F. G.

    1996-01-01

    Stellar spectra derived from multiple-object fibre-fed spectroscopic radial-velocity surveys, of the type feasible with, among other examples, AUTOFIB, 2dF, HYDRA, NESSIE, and the Sloan survey, differ significantly from those traditionally used for determination of stellar abundances. The spectra tend to be of moderate resolution (around 1A) and signal-to-noise ratio (around 10-20 per resolution element), and cannot usually have reliable continuum shapes determined over wavelength ranges in excess of a few tens of Angstroms. None the less, with care and a calibration of stellar effective temperature from photometry, independent of the spectroscopy, reliable iron abundances can be derived. We have developed techniques to extract true iron abundances and surface gravities from low-signal-to-noise ratio, intermediate-resolution spectra of G-type stars in the 4000-5000A wavelength region. Spectroscopic indices sensitive to iron abundance and gravity are defined from a set of narrow (few-several A wide) wavelength intervals. The indices are calibrated theoretically using synthetic spectra. Given adequate data and a photometrically determined effective temperature, one can derive estimates of the stellar iron abundance and surface gravity. We have also defined a single abundance indicator for the analysis of very low-signal-to-noise ratio spectra; with the further assumption of a value for the stellar surface gravity, this is able to provide useful iron abundance information from spectra having signal-to-noise ratios as low as 10 (1-A elements). The theoretical basis and calibration using synthetic spectra are described in this paper. The empirical calibration of these techniques by application to observational data is described in a separate paper (Jones, Wyse & Gilmore). The technique provides precise iron abundances, with zero-point correct to ~0.1 dex, and is reliable, with typical uncertainties being <~0.2 dex. A derivation of the in situ thick disc metallicity

  5. Differential dpa calculations with SPECTRA-PKA

    Science.gov (United States)

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

    2018-06-01

    The processing code SPECTRA-PKA produces energy spectra of primary atomic recoil events (or primary knock-on atoms, PKAs) for any material composition exposed to an irradiation spectrum. Such evaluations are vital inputs for simulations aimed at understanding the evolution of damage in irradiated material, which is generated in cascade displacement events initiated by PKAs. These PKA spectra present the full complexity of the input (to SPECTRA-PKA) nuclear data-library evaluations of recoil events. However, the commonly used displacements per atom (dpa) measure, which is an integral measure over all possible recoil events of the displacement damage dose, is still widely used and has many useful applications - as both a comparative and correlative quantity. This paper describes the methodology employed that allows the SPECTRA-PKA code to evaluate dpa rates using the energy-dependent recoil (PKA) cross section data used for the PKA distributions. This avoids the need for integral displacement kerma cross sections and also provides new insight into the relative importance of different reaction channels (and associated different daughter residual and emitted particles) to the total integrated dpa damage dose. Results are presented for Fe, Ni, W, and SS316. Fusion dpa rates are compared to those in fission, highlighting the increased contribution to damage creation in the former from high-energy threshold reactions.

  6. Climatology of tropospheric vertical velocity spectra

    Science.gov (United States)

    Ecklund, W. L.; Gage, K. S.; Balsley, B. B.; Carter, D. A.

    1986-01-01

    Vertical velocity power spectra obtained from Poker Flat, Alaska; Platteville, Colorado; Rhone Delta, France; and Ponape, East Caroline Islands using 50-MHz clear-air radars with vertical beams are given. The spectra were obtained by analyzing the quietest periods from the one-minute-resolution time series for each site. The lengths of available vertical records ranged from as long as 6 months at Poker Flat to about 1 month at Platteville. The quiet-time vertical velocity spectra are shown. Spectral period ranging from 2 minutes to 4 hours is shown on the abscissa and power spectral density is given on the ordinate. The Brunt-Vaisala (B-V) periods (determined from nearby sounding balloons) are indicated. All spectra (except the one from Platteville) exhibit a peak at periods slightly longer than the B-V period, are flat at longer periods, and fall rapidly at periods less than the B-V period. This behavior is expected for a spectrum of internal waves and is very similar to what is observed in the ocean (Eriksen, 1978). The spectral amplitudes vary by only a factor of 2 or 3 about the mean, and show that under quiet conditions vertical velocity spectra from the troposphere are very similar at widely different locations.

  7. Artificial intelligence analysis of paraspinal power spectra.

    Science.gov (United States)

    Oliver, C W; Atsma, W J

    1996-10-01

    OBJECTIVE: As an aid to discrimination of sufferers with back pain an artificial intelligence neural network was constructed to differentiate paraspinal power spectra. DESIGN: Clinical investigation using surface electromyography. METHOD: The surface electromyogram power spectra from 60 subjects, 33 non-back-pain sufferers and 27 chronic back pain sufferers were used to construct a back propagation neural network that was then tested. Subjects were placed on a test frame in 30 degrees of lumbar forward flexion. An isometric load of two-thirds maximum voluntary contraction was held constant for 30 s whilst surface electromyograms were recorded at the level of the L(4-5). Paraspinal power spectra were calculated and loaded into the input layer of a three-layer back propagation network. The neural network classified the spectra into normal or back pain type. RESULTS: The back propagation neural was shown to have satisfactory convergence with a specificity of 79% and a sensitivity of 80%. CONCLUSIONS: Artificial intelligence neural networks appear to be a useful method of differentiating paraspinal power spectra in back-pain sufferers.

  8. Background noise spectra of global seismic stations

    Energy Technology Data Exchange (ETDEWEB)

    Wada, M.M.; Claassen, J.P.

    1996-08-01

    Over an extended period of time station noise spectra were collected from various sources for use in estimating the detection and location performance of global networks of seismic stations. As the database of noise spectra enlarged and duplicate entries became available, an effort was mounted to more carefully select station noise spectra while discarding others. This report discusses the methodology and criteria by which the noise spectra were selected. It also identifies and illustrates the station noise spectra which survived the selection process and which currently contribute to the modeling efforts. The resulting catalog of noise statistics not only benefits those who model network performance but also those who wish to select stations on the basis of their noise level as may occur in designing networks or in selecting seismological data for analysis on the basis of station noise level. In view of the various ways by which station noise were estimated by the different contributors, it is advisable that future efforts which predict network performance have available station noise data and spectral estimation methods which are compatible with the statistics underlying seismic noise. This appropriately requires (1) averaging noise over seasonal and/or diurnal cycles, (2) averaging noise over time intervals comparable to those employed by actual detectors, and (3) using logarithmic measures of the noise.

  9. Seismic spectra of events at regional distances

    International Nuclear Information System (INIS)

    Springer, D.L.; Denny, M.D.

    1976-01-01

    About 40 underground nuclear explosions detonated at the Nevada Test Site (NTS) were chosen for analysis of their spectra and any relationships they might have to source parameters such as yield, depth of burial, etc. The sample covered a large yield range (less than 20 kt to greater than 1 Mt). Broadband (0.05 to 20 Hz) data recorded by the four-station seismic network operated by Lawrence Livermore Laboratory were analyzed in a search for unusual explosion signatures in their spectra. Long time windows (total wave train) as well as shorter windows (for instance, P/sub n/) were used as input to calculate the spectra. Much variation in the spectra of the long windows is typical although some gross features are similar, such as a dominant peak in the microseismic window. The variation is such that selection of corner frequencies is impractical and yield scaling could not be determined. Spectra for one NTS earthquake showed more energy in the short periods (less than 1 sec) as well as in the long periods (greater than 8 sec) compared to those for NTS explosions

  10. Laser resonant ionization spectroscopy and laser-induced resonant fluorescence spectra of samarium atom

    International Nuclear Information System (INIS)

    Jin, Changtai

    1995-01-01

    We have measured new high-lying levels of Sm atom by two-colour resonant photoionisation spectroscopy; we have observed the isotope shifts of Sm atom by laser-induced resonant fluorescence spectroscopy; the lifetime of eight low-lying levels of Sm atom were measured by using pulsed laser-Boxcar technique in atomic beam.

  11. Lowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionals

    KAUST Repository

    Pandey, Laxman; Doiron, Curtis; Sears, John S.; Bré das, Jean-Luc

    2012-01-01

    Polymers with low optical gaps are of importance to the organic photovoltaics community due to their potential for harnessing a large portion of the solar energy spectrum. The combination along their backbones of electron-rich and electron-deficient fragments contributes to the presence of low-lying excited states that are expected to display significant charge-transfer character. While conventional hybrid functionals are known to provide unsatisfactory results for charge-transfer excitations at the time-dependent DFT level, long-range corrected (LRC) functionals have been reported to give improved descriptions in a number of systems. Here, we use such LRC functionals, considering both tuned and default range-separation parameters, to characterize the absorption spectra of low-optical-gap systems of interest. Our results indicate that tuned LRC functionals lead to simulated optical-absorption properties in good agreement with experimental data. Importantly, the lowest-lying excited states (excitons) are shown to present a much more localized nature than initially anticipated. © 2012 the Owner Societies.

  12. FAST INVERSION OF SOLAR Ca II SPECTRA

    International Nuclear Information System (INIS)

    Beck, C.; Choudhary, D. P.; Rezaei, R.; Louis, R. E.

    2015-01-01

    We present a fast (<<1 s per profile) inversion code for solar Ca II lines. The code uses an archive of spectra that are synthesized prior to the inversion under the assumption of local thermodynamic equilibrium (LTE). We show that it can be successfully applied to spectrograph data or more sparsely sampled spectra from two-dimensional spectrometers. From a comparison to a non-LTE inversion of the same set of spectra, we derive a first-order non-LTE correction to the temperature stratifications derived in the LTE approach. The correction factor is close to unity up to log τ ∼ –3 and increases to values of 2.5 and 4 at log τ = –6 in the quiet Sun and the umbra, respectively

  13. Tunneling spectra of graphene on copper unraveled

    DEFF Research Database (Denmark)

    Zhang, Xin; Stradi, Daniele; Liu, Lei

    2016-01-01

    mechanisms, etc. The interpretation of the spectra can be complicated, however. Specifically for graphene grown on copper, there have been conflicting reports of tunneling spectra. A clear understanding of the mechanisms behind the variability is desired. In this work, we have revealed that the root cause...... of the variability in tunneling spectra is the variation in graphene-substrate coupling under various experimental conditions, providing a salutary perspective on the important role of 2D material-substrate interactions. The conclusions are drawn from measured data and theoretical calculations for monolayer, AB......-stacked bilayer, and twisted bilayer graphene coexisting on the same substrates in areas with and without intercalated oxygen, demonstrating a high degree of consistency. The Van Hove singularities of the twisted graphene unambiguously indicate the Dirac energy between them, lending strong evidence to our...

  14. Rotational structure in molecular infrared spectra

    CERN Document Server

    di Lauro, Carlo

    2013-01-01

    Recent advances in infrared molecular spectroscopy have resulted in sophisticated theoretical and laboratory methods that are difficult to grasp without a solid understanding of the basic principles and underlying theory of vibration-rotation absorption spectroscopy. Rotational Structure in Molecular Infrared Spectra fills the gap between these recent, complex topics and the most elementary methods in the field of rotational structure in the infrared spectra of gaseous molecules. There is an increasing need for people with the skills and knowledge to interpret vibration-rotation spectra in many scientific disciplines, including applications in atmospheric and planetary research. Consequently, the basic principles of vibration-rotation absorption spectroscopy are addressed for contemporary applications. In addition to covering operational quantum mechanical methods, spherical tensor algebra, and group theoretical methods applied to molecular symmetry, attention is also given to phase conventions and their effe...

  15. Observed and theoretical spectra in the 10-100 A interval. [of solar spectra

    Science.gov (United States)

    Brown, W. A.; Bruner, M. E.; Acton, L. W.

    1988-01-01

    The soft X-ray spectra recorded in two sounding-rocket flights in 1982 and 1985 are compared with predicted spectra. The processed densitometer trace of the full spectrum is presented, together with the new spectrum from the 1985 experiment. The intensities of the lines are then compared with predictions.

  16. BETA SPECTRA. I. Negatrons spectra; ESPECTROS BETA. I. Espectros simples de negatrones

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A; Garcia-Torano, E

    1978-07-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  17. Algorithms for classification of astronomical object spectra

    Science.gov (United States)

    Wasiewicz, P.; Szuppe, J.; Hryniewicz, K.

    2015-09-01

    Obtaining interesting celestial objects from tens of thousands or even millions of recorded optical-ultraviolet spectra depends not only on the data quality but also on the accuracy of spectra decomposition. Additionally rapidly growing data volumes demands higher computing power and/or more efficient algorithms implementations. In this paper we speed up the process of substracting iron transitions and fitting Gaussian functions to emission peaks utilising C++ and OpenCL methods together with the NOSQL database. In this paper we implemented typical astronomical methods of detecting peaks in comparison to our previous hybrid methods implemented with CUDA.

  18. Nonlinear FMR spectra in yttrium iron garnet

    Directory of Open Access Journals (Sweden)

    Yu.M. Bunkov, P.M. Vetoshko, I.G. Motygullin, T.R. Safin, M.S. Tagirov, N.A. Tukmakova

    2015-12-01

    Full Text Available Results of demagnetizing effect studies in yttrium iron garnet Y3Fe5O12 thin films are reported. Experiments were performed on X-Band of electron paramagnetic resonance spectrometer at room temperature. The ferromagnetic resonance (FMR spectra were obtained for one-layer single crystal YIG films for different values of the applied microwave power. Nonlinear FMR spectra transformation by the microwave power increasing in various directions of magnetic field sweep was observed. It is explained by the influence of the demagnetization action of nonequilibrium magnons.

  19. Virtual photon spectra for finite nuclei

    International Nuclear Information System (INIS)

    Wolynec, E.; Martins, M.N.

    1988-01-01

    The experimental results of an isochromat of the virtual photon spectrum, obtained by measuring the number of ground-state protons emitted by the 16.28 MeV isobaric analogue state in 90 Zr as a function of electron incident energy in the range 17-105 MeV, are compared with the values predicted by a calculation of the E1 DWBA virtual photon spectra for finite nuclei. It is found that the calculations are in excellent agreement with the experimental results. The DWBA virtual photon spectra for finite nuclei for E2 and M1 multipoles are also assessed. (author) [pt

  20. IUE Archival Spectra of 31 Cygni

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1991-06-01

    Full Text Available UV light curve of 31 Cygni has been made from the IUE high dispersion spectra. The depth of primary minimum of the light curve is 5.2 magnitudes because the B4 star's steep spectral gradient. The light curve has been analyzed by the method of Wilson and Devinney Differential Correction (WD. The radial velocities have been measured using the Mg II h lines. The spectroscopic elements have been determined by the method of WD. The change of the Mg II resonance doublet has been investigated based on the eight representative spectra taken at well distributed orbital phases.

  1. Approximation of Moessbauer spectra of metallic glasses

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.

    1988-01-01

    Moessbauer spectra of iron-rich metallic glasses are approximated by means of six broadened lines which have line position relations similar to those of α-Fe. It is shown via the results of the DISPA (dispersion mode vs. absorption mode) line shape analysis that each spectral peak is broadened owing to a sum of Lorentzian lines weighted by a Gaussian distribution in the peak position. Moessbauer parameters of amorphous metallic Fe 83 B 17 and Fe 40 Ni 40 B 20 alloys are presented, derived from the fitted spectra. (author). 2 figs., 2 tabs., 21 refs

  2. What can we learn from inclusive spectra

    International Nuclear Information System (INIS)

    Nagamiya, S.

    1981-05-01

    The present experimental status on single particle inclusive measurements is described. Then, the geometrical aspect of the collision is discussed from the data of total integrated cross sections of nuclear charge or mass. The dynamical aspect of the collision, especially that for the participating region is discussed in connection with proton spectra, composite fragment spectra, pion production, ratios of π - /π + , n/p and t/ 3 He, and production of strange particles. The spectator physics is described from the data on projectile fragments

  3. Photoacoustic spectra of rare earth pentaphosphates

    International Nuclear Information System (INIS)

    Strek, W.; Lukowiak, E.; Marchewka, M.; Ratajczak, H.

    1987-01-01

    The photoacoustic (PA) spectra of raee earth pentaphosphates of the general formula REP 5 O 14 , where RE = Pr,Nd,Ho,Er,Tm, are reported. The photoacoustic bands were identified and compared with the absorption spectra. For quantitative analysis of PA bands of lanthanide (III) ions, the intensity ratio vector is introduced characterizing the intensity distribution of f-f transitions. It was found that the relative intensities of photoacoustic bands are comparable with the intensities of absorption bands. It is concluded that the nonradiative relaxation mechanism leading to the PA signal is independent of the manifold-to-manifold J-J' radiationless transitions

  4. Modeling Photoelectron Spectra of CuO, Cu2O, and CuO2 Anions with Equation-of-Motion Coupled-Cluster Methods: An Adventure in Fock Space.

    Science.gov (United States)

    Orms, Natalie; Krylov, Anna I

    2018-04-12

    The experimental photoelectron spectra of di- and triatomic copper oxide anions have been reported previously. We present an analysis of the experimental spectra of the CuO - , Cu 2 O - , and CuO 2 - anions using equation-of-motion coupled-cluster (EOM-CC) methods. The open-shell electronic structure of each molecule demands a unique combination of EOM-CC methods to achieve an accurate and balanced representation of the multiconfigurational anionic- and neutral-state manifolds. Analysis of the Dyson orbitals associated with photodetachment from CuO - reveals the strong non-Koopmans character of the CuO states. For the lowest detachment energy, a good agreement between theoretical and experimental values is obtained with CCSD(T) (coupled-cluster with single and double excitations and perturbative account of triple excitations). The (T) correction is particularly important for Cu 2 O - . Use of a relativistic pseudopotential and matching basis set improves the quality of results in most cases. EOM-DIP-CCSD analysis of the low-lying states of CuO 2 - reveals multiple singlet and triplet anionic states near the triplet ground state, adding an extra layer of complexity to the interpretation of the experimental CuO 2 - photoelectron spectrum.

  5. Analysis of COSIMA spectra: Bayesian approach

    Directory of Open Access Journals (Sweden)

    H. J. Lehto

    2015-06-01

    secondary ion mass spectrometer (TOF-SIMS spectra. The method is applied to the COmetary Secondary Ion Mass Analyzer (COSIMA TOF-SIMS mass spectra where the analysis can be broken into subgroups of lines close to integer mass values. The effects of the instrumental dead time are discussed in a new way. The method finds the joint probability density functions of measured line parameters (number of lines, and their widths, peak amplitudes, integrated amplitudes and positions. In the case of two or more lines, these distributions can take complex forms. The derived line parameters can be used to further calibrate the mass scaling of TOF-SIMS and to feed the results into other analysis methods such as multivariate analyses of spectra. We intend to use the method, first as a comprehensive tool to perform quantitative analysis of spectra, and second as a fast tool for studying interesting targets for obtaining additional TOF-SIMS measurements of the sample, a property unique to COSIMA. Finally, we point out that the Bayesian method can be thought of as a means to solve inverse problems but with forward calculations, only with no iterative corrections or other manipulation of the observed data.

  6. Vibrational spectra for hydrogenated amorphous semiconductors

    International Nuclear Information System (INIS)

    Kamitakahara, W.A.; Bouchard, A.M.; Biswas, R.; Gompf, F.; Suck, J.B.

    1990-01-01

    Hydrogen vibration spectra have been measured by neutron scattering for several amorphous semiconductor materials, including a-Ge:H and a-SiC:H samples containing about 10 at. % H. The data for a-Ge:H are compared in detail with the results of realistic computer simulations

  7. RAMAN-SPECTRA OF HUMAN DENTAL CALCULUS

    NARCIS (Netherlands)

    TSUDA, H; ARENDS, J

    1993-01-01

    Raman spectra of human dental calculus have been observed for the first time by use of micro-Raman spectroscopy. The spectral features of calculus were influenced easily by heating caused by laser irradiation. Therefore, the measurements were carried out at relatively low power (5 mW, 1-mu m spot

  8. Automatic analysis of charged particle spectra

    International Nuclear Information System (INIS)

    Seres, Z.; Kiss, A.

    1975-11-01

    A computer program system is developed for off-line automatic analysis of a series of charged particle spectra measured by solid-state detectors and collected on magnetic tapes. The procedure results in complete angular distributions for the excited levels of the final nucleus up to about 15 MeV. (orig.) [de

  9. An adaptive method for γ spectra smoothing

    International Nuclear Information System (INIS)

    Xiao Gang; Zhou Chunlin; Li Tiantuo; Han Feng; Di Yuming

    2001-01-01

    Adaptive wavelet method and multinomial fitting gliding method are used for smoothing γ spectra, respectively, and then FWHM of 1332 keV peak of 60 Co and activities of 238 U standard specimen are calculated. Calculated results show that adaptive wavelet method is better than the other

  10. INTRAMOLECULAR ISOTOPE EFFECTS IN HYDROCARBON MASS SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, D. P.; Schachtschneider, J. H.

    1963-07-15

    Approximate calculations based on the quasi-equilibrium rate theory of the origin of mass spectra are shown to lead to an approximately correct magnitude for the intramolecular ( pi /sup -/) isotope effect on C--H bond dissociation probabilities of various deuterohydrocarbons. (auth)

  11. Library search with regular reflectance IR spectra

    International Nuclear Information System (INIS)

    Staat, H.; Korte, E.H.; Lampen, P.

    1989-01-01

    Characterisation in situ for coatings and other surface layers is generally favourable, but a prerequisite for precious items such as art objects. In infrared spectroscopy only reflection techniques are applicable here. However for attenuated total reflection (ATR) it is difficult to obtain the necessary optical contact of the crystal with the sample, when the latter is not perfectly plane or flexible. The measurement of diffuse reflectance demands a scattering sample and usually the reflectance is very poor. Therefore in most cases one is left with regular reflectance. Such spectra consist of dispersion-like feature instead of bands impeding their interpretation in the way the analyst is used to. Furthermore for computer search in common spectral libraries compiled from transmittance or absorbance spectra a transformation of the reflectance spectra is needed. The correct conversion is based on the Kramers-Kronig transformation. This somewhat time - consuming procedure can be speeded up by using appropriate approximations. A coarser conversion may be obtained from the first derivative of the reflectance spectrum which resembles the second derivative of a transmittance spectrum. The resulting distorted spectra can still be used successfully for the search in peak table libraries. Experiences with both transformations are presented. (author)

  12. Chaotic spectra: How to extract dynamic information

    International Nuclear Information System (INIS)

    Taylor, H.S.; Gomez Llorente, J.M.; Zakrzewski, J.; Kulander, K.C.

    1988-10-01

    Nonlinear dynamics is applied to chaotic unassignable atomic and molecular spectra with the aim of extracting detailed information about regular dynamic motions that exist over short intervals of time. It is shown how this motion can be extracted from high resolution spectra by doing low resolution studies or by Fourier transforming limited regions of the spectrum. These motions mimic those of periodic orbits (PO) and are inserts into the dominant chaotic motion. Considering these inserts and the PO as a dynamically decoupled region of space, resonant scattering theory and stabilization methods enable us to compute ladders of resonant states which interact with the chaotic quasi-continuum computed in principle from basis sets placed off the PO. The interaction of the resonances with the quasicontinuum explains the low resolution spectra seen in such experiments. It also allows one to associate low resolution features with a particular PO. The motion on the PO thereby supplies the molecular movements whose quantization causes the low resolution spectra. Characteristic properties of the periodic orbit based resonances are discussed. The method is illustrated on the photoabsorption spectrum of the hydrogen atom in a strong magnetic field and on the photodissociation spectrum of H 3 + . Other molecular systems which are currently under investigation using this formalism are also mentioned. 53 refs., 10 figs., 2 tabs

  13. Polarization Spectra of Extrasolar Giant Planets

    NARCIS (Netherlands)

    Stam, D.M.

    2004-01-01

    We present simulated spectra of the flux and degree of polarization of starlight that is reflected by extrasolar giant planets (EGPs). In particular the polarization depends strongly on the structure of the planetary atmosphere, and appears to be a valuable tool for the characterization of EGPs.

  14. Temperatures of fragment kinetic energy spectra

    International Nuclear Information System (INIS)

    Bauer, W.

    1995-01-01

    Multifragmentation reactions without large compression in the initial state (proton-induced reactions, reverse kinematics, projectile fragmentation) are examined, and it is verified quantitatively that the high temperatures obtained from fragment kinetic energy spectra and lower temperatures obtained from observables such as level population or isotope ratios can be understood in a common framework

  15. A comparison of floor response spectra techniques

    International Nuclear Information System (INIS)

    Yan, M.J.; Galford, J.E.

    1983-01-01

    Floor response spectra (FRS) conventionally have been generated using a time-history method. Babcock and Wilcox has developed a new technique, the Fast Floor Response Spectra (FFRS) method, in which dynamic analyses are done entirely in the frequency domain. This paper compares the two techniques and demonstrates that the FFRS method complies with the 'equivalency' and 'conservatism' requirements of the US NRC's Standard Review Plan. The upper end of a once-through steam generator in the B and W 205 nuclear steam supply system (NSSS) was used to demonstrate that the FFRS method is equivalent to the time-history technique. The two techniques were compared with respect to frequency content and magnitude of response for a given point on the structure. First, the specified forcing function was described in terms of an acceleration time history and an acceleration spectra enveloping that time history. The time-history forcing function was then used in a direct transient analysis to determine the response at the specified point on the NSSS. The resultant response was subsequently converted to a floor response spectra for that point. To show that the FFRS method gave equivalent and conservative results, the FFRS technique was used to determine the modal response directly from the spectral description of the forcing function. The FFRS- and time-history-generated data agreed to within 13 (worst case on conservative side) of each other with the former cutting analytical costs by 99%. (orig./HP)

  16. Microdosimetric spectra measurements of JANUS neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, I.R.; Williamson, F.S.

    1985-01-01

    Neutron radiation from the JANUS reactor at Argonne National Laboratory is being used with increasing frequency for major biological experiments. The fast neutron spectrum has a Kerma-weighted mean energy of 0.8 MeV and low gamma-ray contamination. In 1984 the JANUS fission converter plate of highly enriched uranium was replaced by one made of low-enriched uranium. We recorded microdosimetric spectra at several different positions in the high-flux irradiation room of JANUS before the change of the converter plate. Each set of measurements consisted of spectra taken at three different site diameters (0.5, 1.0, and 5.0 ..mu..m) and in both ''attenuator up'' and ''attenuator down'' configurations. At two conventional dosimetry reference positions, two sets of measurements were recorded. At three biological reference positions, measurements simulating several biological irradiation conditions, were taken. The dose rate at each position was estimated and compared with dose rates obtained previously by conventional dosimetry. Comparison of the different measurements showed no major change in spectra as a function of position or irradiation condition. First results from similar sets of measurements recorded after the installment of the new converter plate indicate no major change in the spectra. 11 refs., 4 figs., 5 tabs.

  17. Mass Spectra of Tetraselenafulvalenes, Diselenadithiafulvalenes and Tetrathiafulvalenes

    DEFF Research Database (Denmark)

    Andersen, Jan Rud; Egsgaard, Helge; Larsen, Elfinn

    1978-01-01

    fragmentation of the molecular ion, as the selenium fulvalenes lose an alkyne molecule, whereas the sulphur fulvalenes first lose an (SĊR) radical. An important feature of the spectra of the simple heterofulvalenes is the formation of a rearrangement ion by migration of a heteroatom. The mechanism...

  18. Analysis of low-intensity scintillation spectra

    International Nuclear Information System (INIS)

    Muravsky, V.; Tolstov, S.A.

    2002-01-01

    The maximum likelihood algorithms for nuclides activities estimation from low intensity scintillation γ-ray spectra have been created. The algorithms treat full energy peaks and Compton parts of spectra, and they are more effective than least squares estimators. The factors that could lead to the bias of activity estimates are taken into account. Theoretical analysis of the problem of choosing the optimal set of initial spectra for the spectrum model to minimize errors of the activities estimation has been carried out for the general case of the N-components with Gaussian or Poisson statistics. The obtained criterion allows to exclude superfluous initial spectra of nuclides from the model. A special calibration procedure for scintillation γ-spectrometers has been developed. This procedure is required for application of the maximum likelihood activity estimators processing all the channels of the scintillation γ-spectrum, including the Compton part. It allows one to take into account the influence of the sample mass density variation. The algorithm for testing the spectrum model adequacy to the processed scintillation spectrum has been developed. The algorithms are realized in Borland Pascal 7 as a library of procedures and functions. The developed library is compatible with Delphi 1.0 and higher versions. It can be used as the algorithmic basis for analysis of highly sensitive scintillation γ- and β-spectrometric devices. (author)

  19. Ultraviolet spectra of Mg in liquid helium

    International Nuclear Information System (INIS)

    Moriwaki, Y.; Morita, N.

    1999-01-01

    Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

  20. Raman spectra of lignin model compounds

    Science.gov (United States)

    Umesh P. Agarwal; Richard S. Reiner; Ashok K. Pandey; Sally A. Ralph; Kolby C. Hirth; Rajai H. Atalla

    2005-01-01

    To fully exploit the value of Raman spectroscopy for analyzing lignins and lignin containing materials, a detailed understanding of lignins’ Raman spectra needs to be achieved. Although advances made thus far have led to significant growth in application of Raman techniques, further developments are needed to improve upon the existing knowledge. Considering that lignin...

  1. Microdosimetric spectra measurements of JANUS neutrons

    International Nuclear Information System (INIS)

    Marshall, I.R.; Williamson, F.S.

    1985-01-01

    Neutron radiation from the JANUS reactor at Argonne National Laboratory is being used with increasing frequency for major biological experiments. The fast neutron spectrum has a Kerma-weighted mean energy of 0.8 MeV and low gamma-ray contamination. In 1984 the JANUS fission converter plate of highly enriched uranium was replaced by one made of low-enriched uranium. We recorded microdosimetric spectra at several different positions in the high-flux irradiation room of JANUS before the change of the converter plate. Each set of measurements consisted of spectra taken at three different site diameters (0.5, 1.0, and 5.0 μm) and in both ''attenuator up'' and ''attenuator down'' configurations. At two conventional dosimetry reference positions, two sets of measurements were recorded. At three biological reference positions, measurements simulating several biological irradiation conditions, were taken. The dose rate at each position was estimated and compared with dose rates obtained previously by conventional dosimetry. Comparison of the different measurements showed no major change in spectra as a function of position or irradiation condition. First results from similar sets of measurements recorded after the installment of the new converter plate indicate no major change in the spectra. 11 refs., 4 figs., 5 tabs

  2. Nuclear Neutrino Spectra in Late Stellar Evolution

    Science.gov (United States)

    Misch, G. Wendell; Sun, Yang; Fuller, George

    2018-05-01

    Neutrinos are the principle carriers of energy in massive stars, beginning from core carbon burning and continuing through core collapse and after the core bounce. In fact, it may be possible to detect neutrinos from nearby pre-supernova stars. Therefore, it is of great interest to understand the neutrino energy spectra from these stars. Leading up to core collapse, beginning around core silicon burning, nuclei become dominant producers of neutrinos, particularly at high neutrino energy, so a systematic study of nuclear neutrino spectra is desirable. We have done such a study, and we present our sd-shell model calculations of nuclear neutrino energy spectra for nuclei in the mass number range A = 21 - 35. Our study includes neutrinos produced by charged lepton capture, charged lepton emission, and neutral current nuclear deexcitation. Previous authors have tabulated the rates of charged current nuclear weak interactions in astrophysical conditions, but the present work expands on this not only by providing neutrino energy spectra, but also by including the heretofore untabulated neutral current de-excitation neutrino pairs.

  3. Variations on supersymmetry breaking and neutrino spectra

    International Nuclear Information System (INIS)

    Borzumati, F.; Hamaguchi, K.; Nomura, Y.; Yanagida, T.

    2000-01-01

    The problem of generating light neutrinos within supersymmetric models is discussed. It is shown that the hierarchy of scales induced by supersymmetry breaking can give rise to suppression factors of the correct order of magnitude to produce experimentally allowed neutrino spectra

  4. Autonomous System Design for Moessbauer Spectra Acquisition

    International Nuclear Information System (INIS)

    Morales, A. L.; Zuluaga, J.; Cely, A.; Tobon, J.

    2001-01-01

    An autonomous system for Moessbauer spectroscopy based in a microcontroller has been designed. A timer of the microcontroller was used to generate the control signal for the Moessbauer linear motor, and a counter for the spectra acquisition. Additionally, the system has its own memory for data storage and a serial port to transmit the data to a computer for its later processing and display

  5. Fitting PAC spectra with a hybrid algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Alves, M. A., E-mail: mauro@sepn.org [Instituto de Aeronautica e Espaco (Brazil); Carbonari, A. W., E-mail: carbonar@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (Brazil)

    2008-01-15

    A hybrid algorithm (HA) that blends features of genetic algorithms (GA) and simulated annealing (SA) was implemented for simultaneous fits of perturbed angular correlation (PAC) spectra. The main characteristic of the HA is the incorporation of a selection criterion based on SA into the basic structure of GA. The results obtained with the HA compare favorably with fits performed with conventional methods.

  6. Savannah River Site disaggregated seismic spectra

    International Nuclear Information System (INIS)

    Stephenson, D.E.

    1993-02-01

    The objective of this technical note is to characterize seismic ground motion at the Savannah River Site (SRS) by postulated earthquakes that may impact facilities at the site. This task is accomplished by reviewing the deterministic and probabilistic assessments of the seismic hazard to establish the earthquakes that control the hazard to establish the earthquakes that control the hazard at the site and then evaluate the associated seismic ground motions in terms of response spectra. For engineering design criteria of earthquake-resistant structures, response spectra serve the function of characterizing ground motions as a function of period or frequency. These motions then provide the input parameters that are used in the analysis of structural response. Because they use the maximum response, the response spectra are an inherently conservative design tool. Response spectra are described in terms of amplitude, duration, and frequency content, and these are related to source parameters, travel path, and site conditions. Studies by a number of investigators have shown by statistical analysis that for different magnitudes the response spectrum values are different for differing periods. These facts support Jennings' position that using different shapes of design spectra for earthquakes of different magnitudes and travel paths is a better practice than employing a single, general-purpose shape. All seismic ground motion characterization results indicate that the PGA is controlled by a local event with M w < 6 and R < 30km. The results also show that lower frequencies are controlled by a larger, more distant event, typically the Charleston source. The PGA of 0.2 g, based originally on the Blume study, is consistent with LLNL report UCRL-15910 (1990) and with the DOE position on LLNL/EPRI

  7. Improving interpretation of infrared spectra for OM characterization by subtraction of spectra from incinerated samples

    Science.gov (United States)

    Ellerbrock, Ruth H.; Gerke, Horst H.; Leue, Martin

    2017-04-01

    Non-destructive methods such as diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) have been applied to characterize organic matter (OM) at intact structural surfaces among others. However, it is often difficult to distinguish effects of organic components on DRIFT signal intensities from those of mineral components. The objective of this study was to re-evaluate DRIFT spectra from intact earthworm burrow walls and coated cracks to improve the interpretation of C-H and C=O bands. We compared DRIFT and transmission Fourier transform infrared (FTIR) spectra of entire samples that were from the same pedogenetic soil horizon, but different in mineral composition and texture (i.e., glacial till versus loess). Spectra of incinerated samples were subtracted from the original spectra. Transmission FTIR and DRIFT spectra were almost identical for entire soil samples. However, the DRIFT spectra were affected by the bulk mode bands (i.e., wavenumbers 2000 to 1700 cm-1) that affected spectral resolution and reproducibility. The ratios between C-H and C=O band intensities as indicator for OM quality obtained with DRIFT were smaller than those obtained from transmission FTIR. A spectral subtraction procedure was found to reduce effects of mineral absorption bands on DRIFT spectra allowing an improved interpretation. DRIFT spectroscopy as a non-destructive method for analyzing OM composition at intact surfaces in structured soils could be calibrated with information obtained with the more detailed transmission FTIR and complementary methods.

  8. Observational and theoretical spectra of supernovae

    Science.gov (United States)

    Wheeler, J. Craig; Swartz, Douglas A.; Harkness, Robert P.

    1993-05-01

    Progress in nuclear astrophysics by means of quantitative supernova spectroscopy is discussed with special concentration on type Ia, Ib and Ic and on SN 1987A. Spectral calculations continue to support an exploding C/O white dwarf as the best model of a SN Ia. Deflagration model W7 produces good maximum light spectra of SN Ia and seems to have a better composition distribution compared to delayed detonation models, but proper treatment of opacity remains a problem and the physical basis of SN Ia explosions is still not completely understood. All models for SN Ia predict large quantities of 56Co in the ejecta, but it is not clear that observations confirm this. Although the evolutionary origin of SN Ia remains uncertain, there is recent evidence that transfer of hydrogen in a binary system may be involved, as long suspected. There has been progress in comparing dynamical models with the optical/IR spectra of SN 1987A. The evolution of the [OI] λλ6300, 6364 feature and the presence of strong persistent HeI λ10 830 indicate that both the envelope and core material contribute substantially to the formation of emission lines in the nebular phase and that neither the core nor the envelope can be neglected. Blending with nearby hydrogen lines may affect both of these spectral features, thereby complicating the analysis of the lines. The effects of continuum transfer and photoionization have been included and are under study. The discrepancies between theoretical and observed spectra are due primarily to the one-dimensional hydrodynamic models. The spectral data are not consistent with the high density ``spike'' (in radial coordinate) of the core material that is predicted by all such models. Analysis of the light curves of SN Ib and SN Ic supernovae implies that there are significant differences in their physical properties. Some SN Ib have considerably more ejecta mass than SN Ic events. SN Ib require He-rich atmospheres to produce the observed strong optical lines of

  9. Remarks about the displaced spectra techniques

    International Nuclear Information System (INIS)

    Behringer, K.; Pineyro, J.

    1989-01-01

    In a recent paper a new method, called displaced spectra techniques, was presented for distinguishing between sinusoidal components and narrowband random noise contributions in otherwise random noise data. It is based on Fourier transform techniques, and uses the power spectral density (PSD) and a newly-introduced second-order displaced power spectra density (SDPSD) function. In order to distinguish between the two peak types, a validation criterion has been established. In this note, three topics are covered: a) improved numerical data for the validation criterion are given by using the refined estimation procedure of the PSD and SDPSD functions by the Welch method; b) the validation criterion requires the subtraction of the background below the peaks. A semiautomatic procedure is described; c) it was observed that peaks in the real part of the SDPSD function can be accompanied by fine structure phenomena which are unresolved in the PSD function. A few remarks are made about this problem. (author)

  10. EPR spectra of some irradiated polycrystalline perrhenate

    International Nuclear Information System (INIS)

    Zaitseva, N.G.; Constantinescu, M.; Georgescu, R.; Constantinescu, O.

    1978-10-01

    An EPR study of the paramagnetic centers formed by γ, electron and neutron irradiation of the NaReO 4 and KReO 4 was made. In the EPR spectra of the powder samples irradiated γ, with electrons and neutrons, the presence of three types of paramagnetic centers was observed. From the EPR parameters, the centers were attributed to the ReOsub(4)sup(.), ReOsub(3)sup(.) and ReOsub(2)sup(.) radicals respectively. The lower intensity of the spectra observed by KReO 4 samples irradiation showed a higher radioresistance of the KReO 4 than that of NaReO 4 . A radiolitical scheme taking into account the paramagnetic centers formation was proposed. (author)

  11. Raman spectra of filled carbon nanotubes

    International Nuclear Information System (INIS)

    Bose, S.M.; Behera, S.N.; Sarangi, S.N.; Entel, P.

    2004-01-01

    The Raman spectra of a metallic carbon nanotube filled with atoms or molecules have been investigated theoretically. It is found that there will be a three way splitting of the main Raman lines due to the interaction of the nanotube phonon with the collective excitations (plasmons) of the conduction electrons of the nanotube as well as its coupling with the phonon of the filling material. The positions and relative strengths of these Raman peaks depend on the strength of the electron-phonon interaction, phonon frequency of the filling atom and the strength of interaction of the nanotube phonon and the phonon of the filling atoms. Careful experimental studies of the Raman spectra of filled nanotubes should show these three peaks. It is also shown that in a semiconducting nanotube the Raman line will split into two and should be observed experimentally

  12. Interpreting peptide mass spectra by VEMS

    DEFF Research Database (Denmark)

    Mathiesen, Rune; Lundsgaard, M.; Welinder, Karen G.

    2003-01-01

    the calculated and the experimental mass spectrum of the called peptide. The program package includes four accessory programs. VEMStrans creates protein databases in FASTA format from EST or cDNA sequence files. VEMSdata creates a virtual peptide database from FASTA files. VEMSdist displays the distribution......Most existing Mass Spectra (MS) analysis programs are automatic and provide limited opportunity for editing during the interpretation. Furthermore, they rely entirely on publicly available databases for interpretation. VEMS (Virtual Expert Mass Spectrometrist) is a program for interactive analysis...... of peptide MS/MS spectra imported in text file format. Peaks are annotated, the monoisotopic peaks retained, and the b-and y-ion series identified in an interactive manner. The called peptide sequence is searched against a local protein database for sequence identity and peptide mass. The report compares...

  13. Benchmarking statistical averaging of spectra with HULLAC

    Science.gov (United States)

    Klapisch, Marcel; Busquet, Michel

    2008-11-01

    Knowledge of radiative properties of hot plasmas is important for ICF, astrophysics, etc When mid-Z or high-Z elements are present, the spectra are so complex that one commonly uses statistically averaged description of atomic systems [1]. In a recent experiment on Fe[2], performed under controlled conditions, high resolution transmission spectra were obtained. The new version of HULLAC [3] allows the use of the same model with different levels of details/averaging. We will take advantage of this feature to check the effect of averaging with comparison with experiment. [1] A Bar-Shalom, J Oreg, and M Klapisch, J. Quant. Spectros. Rad. Transf. 65, 43 (2000). [2] J. E. Bailey, G. A. Rochau, C. A. Iglesias et al., Phys. Rev. Lett. 99, 265002-4 (2007). [3]. M. Klapisch, M. Busquet, and A. Bar-Shalom, AIP Conference Proceedings 926, 206-15 (2007).

  14. The new NIST atomic spectra database

    International Nuclear Information System (INIS)

    Kelleher, D.E.; Martin, W.C.; Wiese, W.L.; Sugar, J.; Fuhr, J.R.; Olsen, K.; Musgrove, A.; Mohr, P.J.; Reader, J.; Dalton, G.R.

    1999-01-01

    The new atomic spectra database (ASD), Version 2.0, of the National Institute of Standards and Technology (NIST) contains significantly more data and covers a wider range of atomic and ionic transitions and energy levels than earlier versions. All data are integrated. It also has a new user interface and search engine. ASD contains spectral reference data which have been critically evaluated and compiled by NIST. Version 2.0 contains data on 900 spectra, with about 70000 energy levels and 91000 lines ranging from about 1 Aangstroem to 200 micrometers, roughly half of which have transition probabilities with estimated uncertainties. References to the NIST compilations and original data sources are listed in the ASD bibliography. A detailed ''Help'' file serves as a user's manual, and full search and filter capabilities are provided. (orig.)

  15. Graphics based PC analysis of alpha spectra

    International Nuclear Information System (INIS)

    Chapman, T.C.

    1991-01-01

    New personal computer (PC) software performs interactive analysis of alpha spectra using EGA graphics. Spectra are collected with a commercial MCA board and analyzed using the software described here. The operator is required to approve each peak integration area before analysis proceeds. Sample analysis can use detector efficiencies or spike yields or both. Background corrections are made and upper limit values are calculated when specified. Nuclide identification uses a library of up to 64 nuclides with up to 8 alpha lines for each nuclide. Any one of 32 subset libraries can be used in an analysis. Analysis time is short and is limited by interaction with the operator, not by calculation time. Utilities include nuclide library editing, library subset editing, energy calibration, efficiency calibration, and background update

  16. Predicting transmittance spectra of electrophotographic color prints

    Science.gov (United States)

    Mourad, Safer; Emmel, Patrick; Hersch, Roger D.

    2000-12-01

    For dry toner electrophotographic color printers, we present a numerical simulation model describing the color printer responses based on a physical characterization of the different electrophotographic process steps. The proposed model introduces a Cross Transfer Efficiency designed to predict the color transmittance spectra of multi-color prints by taking into account the transfer influence of each deposited color toner layer upon the other layers. The simulation model leads to a better understanding of the factors that have an impact on printing quality. In order to avoid the additional optical non-linearities produced by light reflection on paper, we have limited the present investigation to transparency prints. The proposed model succeeded to predict the transmittance spectra of printed wedges combining two color toner layers with a mean deviation less than CIE-LAB (Delta) E equals 2.5.

  17. Measurement and interpretation of plutonium spectra

    International Nuclear Information System (INIS)

    Blaise, J.; Fred, M.S.; Carnall, W.T.; Crosswhite, H.M.; Crosswhite, H.

    1982-01-01

    The atomic spectroscopic data available for plutonium are among the rickest of any in the periodic system. They include high-resolution grating and Fourier-transform spectra as well as extensive Zeeman and isotope-shift studies. We summarize the present status of the term analysis and cite the configurations that have been identified. A least-squares adjustment of a parametric Hamiltonian for configurations of both Pu I and Pu II has shown that almost all of the expected low levels are now known. The use of a model Hamiltonian applicable to both lanthanide and actinide atomic species has been applied to the low configurations of Pu I and Pu II making use of trends predicted by ab initio calculations. This same model has been used to describe the energy levels of Pu 3+ in LaCl 3 , and an extension has permitted preliminary calculations of the spectra of other valence states

  18. The XUV spectra of highly ionised molybdenum

    International Nuclear Information System (INIS)

    Mansfield, M.W.D.; Peacock, N.J.; Smith, C.C.; Hobby, M.G.; Cowan, R.D.

    1978-01-01

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible. (author)

  19. Graphics of diffraction spectra for PC

    International Nuclear Information System (INIS)

    Macias B, L.R.

    1991-09-01

    The materials can be studied by means of diffraction if these are crystalline; of the type of study will depend the technique to apply, the first step is the obtaining of a digital register that allows to build the corresponding spectra. The digital register should have well-known the initial and final angular data. The main objective of this work, is starting of a digital register of data or an arrangement CPSi type (counts per second measured by the detection system) generated by means of the diffractometer, to create the graph of the corresponding spectra in visual form in the screen of a microcomputer and if is required, to obtain the graph in printed form by means of the same computer program for microcomputer. (Author)

  20. Hadronic spectra from collisions of heavy nuclei

    International Nuclear Information System (INIS)

    Jacobs, P.

    1997-03-01

    Hadronic spectra from collisions of heavy ions at ultrarelativistic energies are discussed, concentrating on recent measurements at the SPS of central Pb+Pb collisions at 158 GeV/nucleon, which are compared to collisions of lighter ions and at lower beam energies. Baryon stopping is seen to be larger for heavier systems and lower energies. Total yields of pions and kaons scale with the number of participants in central collisions at the SPS; in particular, the K/π ratio is constant between central S+S and Pb+Pb at the SPS. Transverse mass spectra indicate significantly larger radial flow for the heavier systems. At midrapidity, an enhancement of - >/ + > and - >/ + > at low P T are best explained by final state Coulomb interaction with the residual charge of the fireball

  1. Absorption spectra of AA-stacked graphite

    International Nuclear Information System (INIS)

    Chiu, C W; Lee, S H; Chen, S C; Lin, M F; Shyu, F L

    2010-01-01

    AA-stacked graphite shows strong anisotropy in geometric structures and velocity matrix elements. However, the absorption spectra are isotropic for the polarization vector on the graphene plane. The spectra exhibit one prominent plateau at middle energy and one shoulder structure at lower energy. These structures directly reflect the unique geometric and band structures and provide sufficient information for experimental fitting of the intralayer and interlayer atomic interactions. On the other hand, monolayer graphene shows a sharp absorption peak but no shoulder structure; AA-stacked bilayer graphene has two absorption peaks at middle energy and abruptly vanishes at lower energy. Furthermore, the isotropic features are expected to exist in other graphene-related systems. The calculated results and the predicted atomic interactions could be verified by optical measurements.

  2. XUV spectra of highly ionised molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, M W.D.; Peacock, N J; Smith, C C; Hobby, M G [UKAEA, Abingdon. Culham Lab.; Cowan, R D

    1978-05-14

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible.

  3. Digital dynamic amplitude-frequency spectra analyzer

    International Nuclear Information System (INIS)

    Kalinnikov, V.A.; )

    2006-01-01

    The spectra analyzer is intended for the dynamic spectral analysis of signals physical installations and noise filtering. The recurrence Fourier transformation algorithm is used in the digital dynamic analyzer. It is realized on the basis of the fast logic FPGA matrix and the special signal ADSP microprocessor. The discretization frequency is 2 kHz-10 MHz. The number of calculated spectral coefficients is not less 512. The functional fast-action is 20 ns [ru

  4. Fourier evaluation of broad Moessbauer spectra

    International Nuclear Information System (INIS)

    Vincze, I.

    1981-01-01

    It is shown by the Fourier analysis of broad Moessbauer spectra that the even part of the distribution of the dominant hyperfine interaction (hyperfine field or quadrupole splitting) can be obtained directly without using least-square fitting procedures. Also the odd part of this distribution correlated with other hyperfine parameters (e.g. isomer shift) can be directly determined. Examples for amorphous magnetic and paramagnetic iron-based alloys are presented. (author)

  5. Fourier evaluation of broad Moessbauer spectra

    International Nuclear Information System (INIS)

    Vincze, I.

    1981-09-01

    It is shown by the Fourier analysis of broad Moessbauer spectra that the even part of the distribution of the dominant hyperfine interaction (hyperfine field or quadrupole splitting) can be obtained directly without using least-square fitting procedures. Also the odd part of this distribution correlated with other hyperfine parameters (e.g. isomer shift) can be directly determined. Examples covering the case of amorphous magnetic and paramagnetic iron-based alloys are presented. (author)

  6. Ghost lines in Moessbauer relaxation spectra

    International Nuclear Information System (INIS)

    Price, D.C.

    1985-01-01

    The appearance in Moessbauer relaxation spectra of 'ghost' lines, which are narrow lines that do not correspond to transitions between real hyperfine energy levels of the resonant system, is examined. It is shown that in many cases of interest, the appearance of these 'ghost' lines can be interpreted in terms of the relaxational averaging of one or more of the static interactions of the ion. (orig.)

  7. Automation of the Analysis of Moessbauer Spectra

    International Nuclear Information System (INIS)

    Souza, Paulo A. de Jr.; Garg, R.; Garg, V. K.

    1998-01-01

    In the present report we propose the automation of least square fitting of Moessbauer spectra, the identification of the substance, its crystal structure and the access to the references with the help of a genetic algorith, Fuzzy logic, and the artificial neural network associated with a databank of Moessbauer parameters and references. This system could be useful for specialists and non-specialists, in industry as well as in research laboratories

  8. GRETEL, Ge(Li) Gamma Spectra Unfolding

    International Nuclear Information System (INIS)

    1975-01-01

    1 - Nature of physical problem solved: The program performs the quantitative analysis of gamma-ray spectra obtained by Ge(Li) detectors, using special libraries which are prepared for each particular problem. 2 - Method of solution: The computer routines which detect and evaluate peak areas perform the following operations: - local smoothing of the spectrum; - first derivative of the smoothed spectrum, - peak location according to the change of sign of the first derivative; - computation of the net area of each peak found

  9. Electronic spectra of astrophysically interesting cations

    Energy Technology Data Exchange (ETDEWEB)

    Maier, John P., E-mail: j.p.maier@unibas.ch; Rice, Corey A., E-mail: j.p.maier@unibas.ch; Mazzotti, Fabio J., E-mail: j.p.maier@unibas.ch; Johnson, Anatoly, E-mail: j.p.maier@unibas.ch [Department of Chemistry, University of Basel, Klingelbergstr. 80, CH-4056 Basel (Switzerland)

    2015-01-22

    The electronic spectra of polyacetylene cations were recorded at 20K in the laboratory in an ion trap instrument. These can then be compared with diffuse interstellar band (DIB) absorptions. Examination of recently published data shows that the attribution of a weak DIB at ∼506.9 nm to diacetylene cation is not justified. Study of the higher excited electronic states of polyacetylene cations shows that their widths can still be sufficiently narrow for consideration as DIB carriers.

  10. Dynamical analysis of highly excited molecular spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kellman, M.E. [Univ. of Oregon, Eugene (United States)

    1993-12-01

    The goal of this program is new methods for analysis of spectra and dynamics of highly excited vibrational states of molecules. In these systems, strong mode coupling and anharmonicity give rise to complicated classical dynamics, and make the simple normal modes analysis unsatisfactory. New methods of spectral analysis, pattern recognition, and assignment are sought using techniques of nonlinear dynamics including bifurcation theory, phase space classification, and quantization of phase space structures. The emphasis is chaotic systems and systems with many degrees of freedom.

  11. The Rovibronic Spectra of the Cyclopentadienyl Radical

    Science.gov (United States)

    Sharma, Ketan; Miller, Terry A.; Stanton, John F.; Nesbitt, David

    2017-06-01

    Cyclopentadienyl (Cp) radical has been subject to numerous studies for the greater part of half a century. Experimental work has involved photo-electron spectroscopy, laser induced fluorescence excitation and emission, infrared absorption spectroscopy, and recently rotationally resolved spectra in the CH stretch region taken at JILA. Even more theoretical works appear in the literature, but substantial advances in computation have occurred since their completion. Cp's highly symmetric (D_{5h}) structure and doubly degenerate electronic ground (˜{X}^2E_1^{''}), which is subject to linear Jahn-Teller distortion, have been a great motivation for work on it. We have commenced new computational work to obtain a broad understanding of the electronic, vibrational, and rotational, i.e. rovibronic, structure of the Cp radical as revealed by its spectra, with particular emphasis on the new infrared spectra. The goal is to guide experiments and their analyses and reconcile results from spectroscopy and quantum chemistry calculations. T. Ichino, et al. J. Chem. Phys. 129, 084310 (2008) L. Yu, S. C. Foster, J. M. Williamson, M. C. Heaven and T. A. Miller J. Phys. Chem. 92, 4263 (1988) B. E. Applegate, A. J. Bezant and T. A. Miller J. Chem. Phys 114, 4869 (2001) D. Leicht, M. Kaufmann, G. Schwaab, and M. Havenith J. Chem. Phys. 145, 7 (2016), 074304.

  12. MAGNETIC ENERGY SPECTRA IN SOLAR ACTIVE REGIONS

    International Nuclear Information System (INIS)

    Abramenko, Valentyna; Yurchyshyn, Vasyl

    2010-01-01

    Line-of-sight magnetograms for 217 active regions (ARs) with different flare rates observed at the solar disk center from 1997 January until 2006 December are utilized to study the turbulence regime and its relationship to flare productivity. Data from the SOHO/MDI instrument recorded in the high-resolution mode and data from the BBSO magnetograph were used. The turbulence regime was probed via magnetic energy spectra and magnetic dissipation spectra. We found steeper energy spectra for ARs with higher flare productivity. We also report that both the power index, α, of the energy spectrum, E(k) ∼ k -α , and the total spectral energy, W = ∫E(k)dk, are comparably correlated with the flare index, A, of an AR. The correlations are found to be stronger than those found between the flare index and the total unsigned flux. The flare index for an AR can be estimated based on measurements of α and W as A = 10 b (αW) c , with b = -7.92 ± 0.58 and c = 1.85 ± 0.13. We found that the regime of the fully developed turbulence occurs in decaying ARs and in emerging ARs (at the very early stage of emergence). Well-developed ARs display underdeveloped turbulence with strong magnetic dissipation at all scales.

  13. VARIABILITY IN OPTICAL SPECTRA OF ε ORIONIS

    International Nuclear Information System (INIS)

    Thompson, Gregory B.; Morrison, Nancy D.

    2013-01-01

    We present the results of a time series analysis of 130 échelle spectra of ε Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of Hα (net) and He I λ5876 were measured and radial velocities were obtained from the central absorption of He I λ5876. Temporal variance spectra (TVS) revealed significant wind variability in both Hα and He I λ5876. The He I TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both Hα and He I, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the He I line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.

  14. Secondary charged particle spectra and kerma calculations

    International Nuclear Information System (INIS)

    Coyne, J.J.; Gerstenberg, H.M.; Hennen, L.A.

    1985-01-01

    The calculation of kerma factors from known cross sections is not as simple as is often implied. The kerma factors are strongly influenced by the reaction mechanism assumed. An important example of this dependence on the reaction mechanism is the contribution of the 12 C(n,n')3α reaction to the total kerma in carbon. First, a short review will be given of the ENDF/B-V carbon cross sections which were used in the calculation of carbon kerma factors. Using the reaction channels implied in the ENDF/B-V evaluation, the contribution of various reactions to the total kerma factors in carbon will be given. A detailed analysis of the reaction mechanisms which could contribute to the (n,n')3α reaction in carbon has been carried out. First their contribution to kerma, independent of cross section, will be calculated and then the initial spectra of alpha particles produced by the various reaction mechanisms will be given. A discussion of possible ways of experimentally distinguishing the reaction mechanisms will be made by comparing their different initial spectra and their variation in kerma with neutron energy. Finally, the event-size spectra for tissue-equivalent proportional counters will be presented, giving only the contributions from the (n,n')3α reaction and its various possible reaction channels. 3 refs., 11 figs., 4 tabs

  15. Optical spectra analysis for breast cancer diagnostics

    Science.gov (United States)

    Belkov, S. A.; Kochemasov, G. G.; Lyubynskaya, T. E.; Maslov, N. V.; Nuzhny, A. S.; da Silva, L. B.; Rubenchik, A.

    2011-11-01

    Minimally invasive probe and optical biopsy system based on optical spectra recording and analysis seem to be a promising tool for early diagnostics of breast cancer. Light scattering and absorption spectra are generated continuously as far as the needle-like probe with one emitting and several collecting optical fibers penetrates through the tissues toward to the suspicious area. That allows analyzing not only the state of local site, but also the structure of tissues along the needle trace. The suggested method has the advantages of automated on-line diagnosing and minimal tissue destruction and in parallel with the conventional diagnostic procedures provides the ground for decision-making. 165 medical trials were completed in Nizhny Novgorod Regional Oncology Centre, Russia. Independent diagnoses were the results of fine biopsy and histology. Application of wavelet expansion and clasterization techniques for spectra analysis revealed several main spectral types for malignant and benign tumors. Automatic classification algorithm demonstrated specificity ˜90% and sensitivity ˜91%. Large amount of information, fuzziness in criteria and data noisiness make neural networks to be an attractive analytic tool. The model based on three-layer perceptron was tested over the sample of 29 `cancer' and 29 `non-cancer' cases and demonstrated total separation.

  16. Photon and photoneutron spectra produced in radiotherapy Linacs

    International Nuclear Information System (INIS)

    Vega C, H. R.; Martinez O, S. A.; Benites R, J. L.; Lallena, A. M.

    2011-10-01

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10 -6 and 1 MeV. Neutron and Bremsstrahlung spectra show the same features regardless of the linac voltage. The amount of photons and neutrons produced by the 15 MV linac is smaller than that found for the 18 MV linac. As expected, Bremsstrahlung spectra ends according to the voltage used to accelerate the electrons. (Author)

  17. Time-of-flight neutron spectra measurements in Zenith

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, F R; Coates, M S; Diment, K M; Durrani, S A; Gayther, D B; Poole, M J; Reed, D L

    1962-01-15

    Neutron spectra in the second core loading of ZENITH have been measured using a neutron chopper. Spectra at two positions in the reactore core were obtained over a range of temperatures extending to 650 deg C.

  18. Quantum synchrotron spectra from semirelativistic electrons in teragauss magnetic fields

    International Nuclear Information System (INIS)

    Brainerd, J.J.

    1987-01-01

    Synchrotron spectra are calculated from quantum electrodynamic transition rates for thermal and power-law electron distributions. It is shown that quantum effects appear in thermal spectra when the photon energy is greater than the electron temperature, and in power-law spectra when the electron energy in units of the electron rest mass times the magnetic field strength in units of the critical field strength is of order unity. These spectra are compared with spectra calculated from the ultrarelativistic approximation for synchrotron emission. It is found that the approximation for the power-law spectra is good, and the approximation for thermal spectra produces the shape of the spectrum accurately but fails to give the correct normalization. Single photon pair creation masks the quantum effects for power-law distributions, so only modifications to thermal spectra are important for gamma-ray bursts. 13 references

  19. Evaluation of secondary and prompt fission neutron spectra

    Energy Technology Data Exchange (ETDEWEB)

    Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    A simple model allowing to split neutron emission spectra into reaction partials is suggested. Predicted spectra of (n,n`{gamma}), (n,n`f), etc appear to be much harder than usually evaluated. (author)

  20. Study on Moessbauer spectra of hemoglobin in thalassemia

    International Nuclear Information System (INIS)

    Guo Xuanhui; Zhao Nanming; Zhang Xiufang

    1988-01-01

    The 57 Fe Moessbauer spectra of erythrocytes in normal subjects and nine patients of different thalassemias were studied. Together with clinical analysis, the correlation between the components in the spectra and different types of anemias was discussed. (orig.)

  1. Study on Mössbauer spectra of hemoglobin in thalassemia

    Science.gov (United States)

    Xuanhui, Guo; Nanming, Zhao; Xiufang, Zhang; Naifei, Gao; Youwen, Huang; Rongxin, Wang

    1988-02-01

    The57Fe Mössbauer spectra of erythrocytes in normal subjects and nine patients of different thalassemias were studied. Together with clinical analysis, the correlation between the components in the spectra and different types of anemias was discussed.

  2. Photon and photoneutron spectra produced in radiotherapy Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte Km. 1, Via Paipa Tunja, Boyaca (Colombia); Benites R, J. L. [Universidad Autonoma de Nayarit, Postgrado CBAP, Carretera Tepic Compostela Km. 9, Xalisco, Nayarit (Mexico); Lallena, A. M., E-mail: fermineutron@yahoo.com [Universida de Granada, Departamento de Fisica Atomica, Molecular y Nuclear, E-18071 Granada (Spain)

    2011-10-15

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10{sup -6} and 1 MeV. Neutron and Bremsstrahlung spectra show the same features regardless of the linac voltage. The amount of photons and neutrons produced by the 15 MV linac is smaller than that found for the 18 MV linac. As expected, Bremsstrahlung spectra ends according to the voltage used to accelerate the electrons. (Author)

  3. Theoretical microcontact spectra of metal electron-phonon coupling

    International Nuclear Information System (INIS)

    Kulagina, T.N.; Zhernov, A.P.

    1987-01-01

    Theoretical and experimental microcontact spectra of simple and certain transition metals are discussed. The Eliashberg thermodynamic functions for the metals are considered, as well as correlations between spectra peculiarities and parameters of metals and microbridge models

  4. Development of site specific response spectra

    International Nuclear Information System (INIS)

    Bernreuter, D.L.; Chen, J.C.; Savy, J.B.

    1987-03-01

    For a number of years the US Nuclear Regulatory Commission (NRC) has employed site specific spectra (SSSP) in their evaluation of the adequacy of the Safe Shutdown Earthquake (SSE). These spectra were developed only from the spectra of the horizontal components of the ground motion and from a very limited data set. As the data set has considerably increased for Eastern North America (ENA) and as more relevant data has become available from earthquakes occurring in other parts of the world (e.g., Italy), together with the fact that recent data indicated the importance of the vertical component, it became clear that an update of the SSSP's for ENA was desirable. The methodology used in this study is similar to the previous ones in that it used actual earthquake ground motion data with magnitudes within a certain range and recorded at distances and at sites similar to those that would be chosen for the definition of an SSE. An extensive analysis of the origin and size of the uncertainty is an important part of this study. The results of this analysis of the uncertainties is used to develop criteria for selecting the earthquake records to be used in the derivation of the SSSP's. We concluded that the SSSPs were not very sensitive to the distribution of the source to site distance of the earthquake records used in the analysis. That is, the variability (uncertainty) introduced by the range of distances was relatively small compared to the variability introduced by other factors. We also concluded that the SSSP are somewhat sensitive to the distribution of the magnitudes of these earthquakes, particularly at rock sites and, by inference, at shallow soil sites. We found that one important criterion in selecting records to generate SSSP is the depth of soil at the site

  5. Characterizing Sky Spectra Using SDSS BOSS Data

    Science.gov (United States)

    Florez, Lina Maria; Strauss, Michael A.

    2018-01-01

    In the optical/near-infrared spectra gathered by a ground-based telescope observing very faint sources, the strengths of the emission lines due to the Earth’s atmosphere can be many times larger than the fluxes of the sources we are interested in. Thus the limiting factor in faint-object spectroscopy is the degree to which systematics in the sky subtraction can be minimized. Longwards of 6000 Angstroms, the night-sky spectrum is dominated by multiple vibrational/rotational transitions of the OH radical from our upper atmosphere. While the wavelengths of these lines are the same in each sky spectrum, their relative strengths vary considerably as a function of time and position on the sky. The better we can model their strengths, the better we can hope to subtract them off. We expect that the strength of lines from common upper energy levels will be correlated with one another. We used flux-calibrated sky spectra from the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (SDSS BOSS) to explore these correlations. Our aim is to use these correlations for creating improved sky subtraction algorithms for the Prime Focus Spectrograph (PFS) on the 8.2-meter Subaru Telescope. When PFS starts gathering data in 2019, it will be the most powerful multi-object spectrograph in the world. Since PFS will be gathering data on sources as faint as 24th magnitude and fainter, it's of upmost importance to be able to accurately measure and subtract sky spectra from the data that we receive.

  6. Prediction of peak overlap in NMR spectra

    International Nuclear Information System (INIS)

    Hefke, Frederik; Schmucki, Roland; Güntert, Peter

    2013-01-01

    Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

  7. Molecular geometry in the ultraviolet absorption spectra

    International Nuclear Information System (INIS)

    Albuquerque, S.F. de; Monteiro, L.S.; Adamis, L.M.B.; Baltar, M.C.P.; Silva, R.M. da

    1977-01-01

    The ultraviolet absorption spectra may be sensibly affected by steric effects. These effects can cause a lot of difficulties and unexpected changes in spectrum. The most general source of such difficulties is steric inhibition of resonance. In addition to this, ultraviolet epectra may be markedly changed by steric factors which change the positions of dipoles in the molecule with respect to each other and by the interaction of nonconjugated chromophores suitably located in space. We have studied in detail each of these effects presenting a lot of usual and importants examples in Organic Chemistry. Others relevants subjects were not considerated in this present work [pt

  8. Maximum entropy decomposition of quadrupole mass spectra

    International Nuclear Information System (INIS)

    Toussaint, U. von; Dose, V.; Golan, A.

    2004-01-01

    We present an information-theoretic method called generalized maximum entropy (GME) for decomposing mass spectra of gas mixtures from noisy measurements. In this GME approach to the noisy, underdetermined inverse problem, the joint entropies of concentration, cracking, and noise probabilities are maximized subject to the measured data. This provides a robust estimation for the unknown cracking patterns and the concentrations of the contributing molecules. The method is applied to mass spectroscopic data of hydrocarbons, and the estimates are compared with those received from a Bayesian approach. We show that the GME method is efficient and is computationally fast

  9. Spectra from foil-excited molybdenum ions

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Cecchi, J.L.; Kruse, T.H.

    1978-01-01

    The extreme-ultraviolet spectra (5 to 55 nm) for foil-excited molybdenum ions have been measured using 22 to 200 MeV beams from the Brookhaven National Laboratory MP tandem Van de Graaff accelerator facility, 20 μg/cm 2 C stripping foils, and a grazing incidence spectrometer. The mean ion charge states (13 to 28) and the narrow distribution widths (about 2 charge states) were accurately predictable from experimental parameters. Where possible, comparisons are given with Mo radiation from tokamaks, vacuum sparks, and laser-excited plasmas

  10. Perturbative description of inclusive energy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Lupia, S. [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut

    1996-03-01

    The recent LEP-1.5 data of charged particle inclusive energy spectra are analyzed within the analytical QCD approach based on modified leading log approximation plus local parton hadron duality. The shape, the position of the maximum and the cumulant moments of the inclusive energy spectrum are well described within this model. The sensitivity of the results to the running of the coupling is pointed out. A scaling law for the one-particle invariant density E dn/d{sup 3}p at small momenta is observed, consistently with the predictions of colour coherence in soft gluon bremsstrahlung. (orig.).

  11. Perturbative description of inclusive energy spectra

    International Nuclear Information System (INIS)

    Lupia, S.

    1996-01-01

    The recent LEP-1.5 data of charged particle inclusive energy spectra are analyzed within the analytical QCD approach based on modified leading log approximation plus local parton hadron duality. The shape, the position of the maximum and the cumulant moments of the inclusive energy spectrum are well described within this model. The sensitivity of the results to the running of the coupling is pointed out. A scaling law for the one-particle invariant density E dn/d 3 p at small momenta is observed, consistently with the predictions of colour coherence in soft gluon bremsstrahlung. (orig.)

  12. Process and apparatus for determining molecular spectra

    International Nuclear Information System (INIS)

    Boesl, U.; Neusser, H.J.; Schlag, E.W.

    1984-01-01

    A process for determining molecular spectra in unseparated mixtures, in particular unseparated isotopic mixtures, which comprises allowing said mixture to successively flow through a photoreactor which is irradiated by an adjustable-wavelength laser and then through a mass spectrometer wherein the concentration of particles of specified mass is determined by variation of the wavelength of the laser or variation of the mass setting of the mass spectrometer in such a manner that a two-dimensional spectrum results having the parameters of wavelength and mass

  13. Multifractal spectra in homogeneous shear flow

    Science.gov (United States)

    Deane, A. E.; Keefe, L. R.

    1988-01-01

    Employing numerical simulations of 3-D homogeneous shear flow, the associated multifractal spectra of the energy dissipation, scalar dissipation and vorticity fields were calculated. The results for (128) cubed simulations of this flow, and those obtained in recent experiments that analyzed 1- and 2-D intersections of atmospheric and laboratory flows, are in some agreement. A two-scale Cantor set model of the energy cascade process which describes the experimental results from 1-D intersections quite well, describes the 3-D results only marginally.

  14. Inelastic response spectra of simple degrading systems

    International Nuclear Information System (INIS)

    Andreaus, U.; Ceradini, G.; D'Asdia, P.; Gaudenzi, P.

    1985-01-01

    Ductility was first stated, for single-degree-of-freedom elastic-perfectly plastic systems as the ratio of maximum to yield displacements. An alternative approach, aimed to reduce design forces for ductile structures and based on the energy dissipated during earthquake allows to obtain more reliable ductility factors even when system restoring characteristics are affected by deterioration during loading history. Inelastic response of SDOF systems has been investigated under seimic excitation, assuming stable and degrading constitutive laws to model their structural behaviour. Energy spectra and ductility requirent diagrams are generated and compared with those of the corresponding elastic-perfectly plastic systems. (orig.)

  15. Beamstrahlung spectra in next generation linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.; Chen, P. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Kozanecki, W. (DAPNIA-SPP, CEN-Saclay (France))

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  16. Exclusion Statistics in Conformal Field Theory Spectra

    International Nuclear Information System (INIS)

    Schoutens, K.

    1997-01-01

    We propose a new method for investigating the exclusion statistics of quasiparticles in conformal field theory (CFT) spectra. The method leads to one-particle distribution functions, which generalize the Fermi-Dirac distribution. For the simplest SU(n) invariant CFTs we find a generalization of Gentile parafermions, and we obtain new distributions for the simplest Z N -invariant CFTs. In special examples, our approach reproduces distributions based on 'fractional exclusion statistics' in the sense of Haldane. We comment on applications to fractional quantum Hall effect edge theories. copyright 1997 The American Physical Society

  17. Far-infrared spectra of acetanilide revisited

    Science.gov (United States)

    Spire, A.; Barthes, M.; Kellouai, H.; De Nunzio, G.

    2000-03-01

    A new investigation of the temperature dependence of the far-infrared spectra of acetanilide and some isotopomers is presented. Four absorption bands are considered at 31, 42, 64, and 80 cm-1, and no significant change of their integrated intensity is observed when reducing the temperature. The temperature induced frequency shift values and other properties of these bands are consistent with an assignment as anharmonic lattice phonons. These results rule out the assignment of the 64, 80, and 106 cm-1 bands as normal modes of the polaronic excitation, as previously suggested.

  18. SIMULATION OF PARTICLE SPECTRA AT RHIC

    International Nuclear Information System (INIS)

    KAHANA, D.E.; KAHANA, S.H.

    2001-01-01

    A purely hadronic simulation is performed of the recently reported data from PHOBOS at energies of √s = 56, 130 GeV using the relativistic heavy ion cascade LUCIFER which had previously given a good description of the NA49 inclusive spectra at √s = 17.2 GeV/A. The results compare well with these early measurements at RHIC and indeed successfully predict the increase in multiplicity now seen by PHOBOS and the other RHIC detectors at the nominal maximum energy of √s = 200 GeV/A, suggesting that evidence for quark-gluon matter remains elusive

  19. Boundary layer heights derived from velocity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J.; Barthelmie, R.J. [Risoe National Lab., Roskilde (Denmark); Kaellstrand, B. [Univ. of Uppsala, Uppsala (Sweden)

    1997-10-01

    It is a well-known fact that the height of the mixed layer determines the size of the largest and most energetic eddies that can be observed in the unstable boundary layer, and consequently a peak can be observed in the power spectra of the along-wind velocity component at scales comparable to the mixed layer depth. We will now show how the mixed layer depth can be derived from the u-specta and the results will be compared with direct measurements using pibal and tethersonde measurements. (au)

  20. Photographic infrared spectra of symbiotic stars

    International Nuclear Information System (INIS)

    Andrillat, Y.; Houziaux, L.

    1982-01-01

    The authors have observed six symbiotic stars during the period 1962-1977 with a grating spectrograph attached to the newtonian focus of the 120-cm telescope at Observatoire de Haute Provence. The reciprocal dispersion is 230 A.mm -1 and the region 5800 to 8800 A has been covered using hypersensitized IN plates. The minimum equivalent width for an emission line to be seen is about 0.5 A. The spectra are displayed and the main spectral characteristics are reviewed briefly. (Auth.)

  1. The use of synthetic spectra to test the preparedness to evaluate and analyze complex gamma spectra

    International Nuclear Information System (INIS)

    Nikkinen, M

    2001-10-01

    This is the report of two exercises that were run under the NKS BOK-1.1 sub-project. In these exercises synthetic gamma spectra were developed to exercise the analysis of difficult spectra typically seen after a severe nuclear accident. The spectra were analyzed twice; first, participants were given short time to give results to resemble an actual emergency preparedness situation, then a longer period of time was allowed to tune the laboratory analysis results for quality assurance purposes. The exercise did prove that it is possible to move measurement data from one laboratory to another if second opinion of the analysis is needed. It was also felt that this kind of exercise would enhance the experience the laboratories have in analyzing accident data. Participants expressed the need for additional exercises of this type, this is inexpensive and an easy way to exercise quick emergency response situations not normally seen in daily laboratory routines. (au)

  2. Vibronic spectra of Gd3+ in metaphosphate glasses: Comparison with Raman and infrared spectra

    International Nuclear Information System (INIS)

    Hall, D.W.; Brawer, S.A.; Weber, M.J.

    1982-01-01

    Vibronic sidebands associated with the 6 P/sub 7/2/→ 8 S/sub 7/2/ transition of Gd 3+ -doped metaphosphate glasses are observed using line-narrowed fluorescence techniques. Glasses having metal cations of different mass and charge (La,Al,Mg,Ba) are examined. Vibronic spectra, which probe vibrations about the rare-earth element site, are compared with polarized Raman scattering data and the infrared dielectric constant obtained from near-normal reflectance measurements. Results indicate that in metaphosphate glasses vibronic selection rules are similar to HV (vertical height) Raman selection rules. The wavelengths and relative intensities of peaks in the high-frequency portion of the vibronic spectra change with respect to corresponding peaks in the Raman spectra when the mass and/or charge of Gd 3+ differs significantly from that of the metal cation

  3. Generate floor response spectra, Part 2: Response spectra for equipment-structure resonance

    International Nuclear Information System (INIS)

    Li, Bo; Jiang, Wei; Xie, Wei-Chau; Pandey, Mahesh D.

    2015-01-01

    Highlights: • The concept of tRS is proposed to deal with tuning of equipment and structures. • Established statistical approaches for estimating tRS corresponding to given GRS. • Derived a new modal combination rule from the theory of random vibration. • Developed efficient and accurate direct method for generating floor response spectra. - Abstract: When generating floor response spectra (FRS) using the direct spectra-to-spectra method developed in the companion paper, probability distribution of t-response spectrum (tRS), which deals with equipment-structure resonance or tuning, corresponding to a specified ground response spectrum (GRS) is required. In this paper, simulation results using a large number of horizontal and vertical ground motions are employed to establish statistical relationships between tRS and GRS. It is observed that the influence of site conditions on horizontal statistical relationships is negligible, whereas the effect of site conditions on vertical statistical relationships cannot be ignored. Considering the influence of site conditions, horizontal statistical relationship suitable for all site conditions and vertical statistical relationships suitable for hard sites and soft sites, respectively, are established. The horizontal and vertical statistical relationships are suitable to estimate tRS for design spectra in USNRC R.G. 1.60 and NUREG/CR-0098, Uniform Hazard Spectra (UHS) in Western North America (WNA), or any GRS falling inside the valid coverage of the statistical relationship. For UHS with significant high frequency spectral accelerations, such as UHS in Central and Eastern North America (CENA), an amplification ratio method is proposed to estimate tRS. Numerical examples demonstrate that the statistical relationships and the amplification ratio method are acceptable to estimate tRS for given GRS and to generate FRS using the direct method in different practical situations.

  4. Generate floor response spectra, Part 2: Response spectra for equipment-structure resonance

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo, E-mail: b68li@uwaterloo.ca; Jiang, Wei, E-mail: w46jiang@uwaterloo.ca; Xie, Wei-Chau, E-mail: xie@uwaterloo.ca; Pandey, Mahesh D., E-mail: mdpandey@uwaterloo.ca

    2015-11-15

    Highlights: • The concept of tRS is proposed to deal with tuning of equipment and structures. • Established statistical approaches for estimating tRS corresponding to given GRS. • Derived a new modal combination rule from the theory of random vibration. • Developed efficient and accurate direct method for generating floor response spectra. - Abstract: When generating floor response spectra (FRS) using the direct spectra-to-spectra method developed in the companion paper, probability distribution of t-response spectrum (tRS), which deals with equipment-structure resonance or tuning, corresponding to a specified ground response spectrum (GRS) is required. In this paper, simulation results using a large number of horizontal and vertical ground motions are employed to establish statistical relationships between tRS and GRS. It is observed that the influence of site conditions on horizontal statistical relationships is negligible, whereas the effect of site conditions on vertical statistical relationships cannot be ignored. Considering the influence of site conditions, horizontal statistical relationship suitable for all site conditions and vertical statistical relationships suitable for hard sites and soft sites, respectively, are established. The horizontal and vertical statistical relationships are suitable to estimate tRS for design spectra in USNRC R.G. 1.60 and NUREG/CR-0098, Uniform Hazard Spectra (UHS) in Western North America (WNA), or any GRS falling inside the valid coverage of the statistical relationship. For UHS with significant high frequency spectral accelerations, such as UHS in Central and Eastern North America (CENA), an amplification ratio method is proposed to estimate tRS. Numerical examples demonstrate that the statistical relationships and the amplification ratio method are acceptable to estimate tRS for given GRS and to generate FRS using the direct method in different practical situations.

  5. Comparison of fish-community size spectra based on length ...

    African Journals Online (AJOL)

    Estimates of fish-community size spectra are promising indicators of the impact of fishing on fish assemblages. Size spectra consist of logarithmic graphs of abundance plotted against fish body size. Size spectra may either be constructed from length frequency data or estimated from the mean sizes and abundances of the ...

  6. Automated element identification for EDS spectra evaluation using quantification and integrated spectra simulation approaches

    International Nuclear Information System (INIS)

    Eggert, F

    2010-01-01

    This work describes first real automated solution for qualitative evaluation of EDS spectra in X-ray microanalysis. It uses a combination of integrated standardless quantitative evaluation, computation of analytical errors to a final uncertainty, and parts of recently developed simulation approaches. Multiple spectra reconstruction assessments and peak searches of the residual spectrum are powerful enough to solve the qualitative analytical question automatically for totally unknown specimens. The integrated quantitative assessment is useful to improve the confidence of the qualitative analysis. Therefore, the qualitative element analysis becomes a part of integrated quantitative spectrum evaluation, where the quantitative results are used to iteratively refine element decisions, spectrum deconvolution, and simulation steps.

  7. Mapping SOC in a river catchment by integrating laboratory spectra wavelength with remote sensing spectra

    DEFF Research Database (Denmark)

    Peng, Yi; Xiong, Xiong; Knadel, Maria

    There is potential to use soil ·-proximal and remote sensing derived spectra concomitantly to develop soil organic carbon (SOC) models. Yet mixing spectral data from different sources and technologies to improve soil models is still in its infancy. The objective of this study was to incorporate...... soil spectral features indicative of SOC from laboratory visible near-infrared reflectance (vis-NlR) spectra and incorporate them with remote sensing (RS) images to improve predictions of top SOC in the Skjem river catchment, Denmark. The secondary objective was to improve prediction results...

  8. Study of yrast band in {sup 155}Tm

    Energy Technology Data Exchange (ETDEWEB)

    Raut, R. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Bhowal, S. [Department of Physics, Surendranath College (Evening), M.G. road, Kolkata-700009 (India); Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Bhowmik, R.K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); Dasmahapatra, B. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Gangopadhyay, G. [Department of Physics, University College of Science Technology, 92, A.P.C. road, Kolkata-700073 (India); Mukherjee, A. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Muralithar, S. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); SahaSarkar, M. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India); Singh, R.P. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); Goswami, A. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)], E-mail: asimananda.goswami@saha.ac.in

    2007-10-01

    The nucleus {sup 155}Tm has been studied by a detailed in-beam gamma spectroscopy following the reaction {sup 144}Sm({sup 14}N, 3n){sup 155}Tm, at a beam energy, E{sub lab}=70MeV, using a Compton suppressed gamma detector array. More than 25 new gamma transitions have been placed in the proposed scheme and the latter has been extended upto a spin-parity of (51/2{sup -}) at an excitation energy {approx} 6 MeV.

  9. Rapid Communication: seniority changing transitions in yrast states ...

    Indian Academy of Sciences (India)

    Bhoomika Maheshwari

    2017-10-26

    Oct 26, 2017 ... Rapid Communication: v = 2 seniority changing ... has been extensively used to understand various system- .... states. This understanding supports the previous inter- ..... Financial support from the Ministry of Human Resource.

  10. Yrast spectroscopy in the neutron-deficient nucleus 169Os

    International Nuclear Information System (INIS)

    Joss, D.T.; Simpson, J.; Appelbe, D.E.; Warner, D.D.; Page, R.D.; King, S.L.; Amzal, N.; Cullen, D.M.; Greenlees, P.T.; Keenan, A.; Baeck, T.; Cederwall, B.; Wyss, R.; Bentley, M.A.; Williams, S.J.; Cocks, J.F.C.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.

    2002-01-01

    Excited states in the neutron-deficient isotope 169 Os have been identified for the first time in an experiment using the Jurosphere γ-ray spectrometer in conjunction with the Ritu gas-filled recoil separator. The problems associated with identifying neutron-deficient isotopes produced with low fusion cross sections against a high background of competing channels, including fission, have been overcome by using the recoil-decay tagging technique. The band structures observed in 169 Os are interpreted in the context of the systematics of neighboring nuclei and the predictions of cranked Woods-Saxon calculations. The systematics of the second (i 13/2 ) 2 neutron alignment in this region are discussed

  11. High-spin structure of yrast-band in Kr

    Indian Academy of Sciences (India)

    320(70) fs was obtained from the present data at 75. ° for the 24. + level. Zeigler's stopping powers have been used for the calculation of the energy loss parameters of the recoiling nuclei. The experimental data along with the theoretical fits for the lifetimes measured can be seen in figure 1. The present lifetime values up to ...

  12. Near-yrast spectroscopy of 164Yb and neighbouring nuclei

    International Nuclear Information System (INIS)

    Jonsson, S.; Roy, H. and others.

    1983-03-01

    High-spin states in 164 Yb have been populated in the 152 Sm( 16 0,4n) and 150 Sm( 18 0,4n) reactions. From studies of γ-γ coincidences, γ-ray angular distributions and conversion electron measurements the level scheme has been constructed. The g-band and the S-band have been established to spin and parity 22(sup)+ and 26(sup)+, respectively, and the rotational sequences (π,α)=(-,1) 1 , (-,0) 1 and (-,0) 2 to 23(sup)-, 24(sup)- and 18(sup)-, respectively. The sidebands in 162 , 164 Er and 164 , 166 Yb are discussed. Constructed two-quasineutron configurations and cranked shell model (CSM) calculations are compared with the experimental results in 164 Yb. Residual interactions between quasiparticles in 164 Yb are calculated. Crossing frequencies and the gain in alignment are summarized for the Yb isotopes and the main features are discussed. (author)

  13. On statistical fluctuations in the dibaryon spectra

    International Nuclear Information System (INIS)

    Bazhanskij, I.I.; Luk'yanov, V.K.; Reznik, B.L.; Titov, A.I.

    1988-01-01

    The aim of this report is to show, that idea about statistical nature of dibaryon resonances corresponds to the present experimental data. Condition for cross section fluctuation occurrence is linked with value of decay width for isolated dibaryon in nucleon channel. Γ in terms of dibaryon potential quark model and q 6 → NN dibaryon decay for q 6 state with S 6 orbital symmetry and (S=I, I=0) deuteron quantum numbers are calculated as an example. np → ppπ - , dp → ppn and elastic pp-scattering are considered and distributions of cross sections and correlation functions obtained from these reactions are presented to investigate cross section fluctuations in spectra of effective masses of two-nucleon systems. Supposition about fluctuation pattern does not contradict the experiment. Curves, calculated with x l α < or approx. 0.05 partial amplitude parameter and full width of Γ < or approx. 20 MeV dibaryon resonances comply to the present experiment best. Fluctuation peculiarities -peaks in cross sections have approximately the same energy width (Γ ∼ 15-20 MeV) as the observed narrow peak in effective mass spectra of some reactions. 16 refs.; 3 figs

  14. [Fluorescence spectra analysis of the scrophularia soup].

    Science.gov (United States)

    Yan, Li-hua; Song, Feng; Han, Juan; Su, Jing; Qu, Fei-fei; Song, Yi-zhan; Hu, Bo-lin; Tian, Jian-guo

    2008-08-01

    The cold-water and boiled-water soaked scrophularia soups have been prepared. The emission and excitation spectra of each scrophularia soup under different conditions have been measured at room temperature. The pH values of the different scrophularia soups have been also detected. There are obvious differences between the cold-water soaked scrophularia soup and the boiled-water soaked scrophularia. For both soups the emission wavelength increases with the wavelength of the excitation, but the peaks of the emission spectra for cold-water and boiled-water soaked scrophularia soup are different, which are 441 and 532 nm, respectively. Excitation spectrum has double peaks in the cold-water soaked scrophularia soup while only one peak with longer wavelength in the boiled-water soaked one. The pH value changes from 5.5 to 4.1. According to the organic admixture fluorescence mechanism we analyzed the reasons of the experimental results. Through heating, the interaction in different fluorescence molecular and the energy transfer process in the same fluorescence molecular become more active, and the conjugate structures and the generation of hydrogen bonds, increase. The fluorescence measurement is of value for the scrophularia pharmacology analysis and provides an analytical method for the quality identification of scrophularia soup.

  15. Primordial spectra from sudden turning trajectory

    Science.gov (United States)

    Noumi, Toshifumi; Yamaguchi, Masahide

    2013-12-01

    Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the potential, the following two effects are generically induced: deformation of the inflationary background spacetime and conversion interactions between adiabatic and isocurvature perturbations, both of which can affect the primordial density perturbations. In this paper, we calculate primordial spectra in inflationary models with sudden turning potentials taking into account both of the two effects appropriately. We find that there are some non-trivial correlations between the two effects in the power spectrum and, as a consequence, the primordial scalar power spectrum has a peak around the scale exiting the horizon at the turn. Though both effects can induce parametric resonance amplifications, they are shown to be canceled out for the case with the canonical kinetic terms. The peak feature and the scale dependence of bispectra are also discussed.

  16. Interstellar dehydrogenated PAH anions: vibrational spectra

    Science.gov (United States)

    Buragohain, Mridusmita; Pathak, Amit; Sarre, Peter; Gour, Nand Kishor

    2018-03-01

    Interstellar polycyclic aromatic hydrocarbon (PAH) molecules exist in diverse forms depending on the local physical environment. Formation of ionized PAHs (anions and cations) is favourable in the extreme conditions of the interstellar medium (ISM). Besides in their pure form, PAHs are also likely to exist in substituted forms; for example, PAHs with functional groups, dehydrogenated PAHs etc. A dehydrogenated PAH molecule might subsequently form fullerenes in the ISM as a result of ongoing chemical processes. This work presents a density functional theory (DFT) calculation on dehydrogenated PAH anions to explore the infrared emission spectra of these molecules and discuss any possible contribution towards observed IR features in the ISM. The results suggest that dehydrogenated PAH anions might be significantly contributing to the 3.3 μm region. Spectroscopic features unique to dehydrogenated PAH anions are highlighted that may be used for their possible identification in the ISM. A comparison has also been made to see the size effect on spectra of these PAHs.

  17. Blind Source Separation For Ion Mobility Spectra

    International Nuclear Information System (INIS)

    Marco, S.; Pomareda, V.; Pardo, A.; Kessler, M.; Goebel, J.; Mueller, G.

    2009-01-01

    Miniaturization is a powerful trend for smart chemical instrumentation in a diversity of applications. It is know that miniaturization in IMS leads to a degradation of the system characteristics. For the present work, we are interested in signal processing solutions to mitigate limitations introduced by limited drift tube length that basically involve a loss of chemical selectivity. While blind source separation techniques (BSS) are popular in other domains, their application for smart chemical instrumentation is limited. However, in some conditions, basically linearity, BSS may fully recover the concentration time evolution and the pure spectra with few underlying hypothesis. This is extremely helpful in conditions where non-expected chemical interferents may appear, or unwanted perturbations may pollute the spectra. SIMPLISMA has been advocated by Harrington et al. in several papers. However, more modern methods of BSS for bilinear decomposition with the restriction of positiveness have appeared in the last decade. In order to explore and compare the performances of those methods a series of experiments were performed.

  18. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1976-07-01

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  19. Low resolution infrared spectra of quasars

    International Nuclear Information System (INIS)

    Soifer, B.T.; Neugebauer, G.; Oke, J.B.; Matthews, K.

    1980-01-01

    Low resolution spectra of a significant sample of quasars show that the Paschen α and Balmer line ratios do not agree with the radiative recombination case B result and vary widely within the quasars sampled. The range in Pα:Hβ ratios is a factor of approximately 6, while the range in Lyα:Hα ratios is a factor of approximately 5. For the Pα:Balmer series, the deviations from case B recombination are not consistent with reddening, but appear, within large dispersions, to be consistent with optical depth effects in the Balmer lines affecting the line ratios. The Lyα:Hα ratio is, however, correlated with the continuum spectral index, and can be explained as due to reddening affecting both the lines and continuum. Recent observational results based on a joint infrared/optical survey of the hydrogen line spectra of a significant number of the brightest low and high redshift quasars are summarised. This survey includes 12 quasars in the redshift range 0.07 1.5, where Hα and/or Hβ is redshifted into the 1.65μm or 2.2μm atmospheric windows. (Auth.)

  20. Continuous particle spectra and their angular distributions

    International Nuclear Information System (INIS)

    Sastry, Ch.V.; Jain, R.K.; Rama Rao, J.; Ernst, J.; Machner, H.

    1996-01-01

    The angular distribution of continuous particle spectra in pre-equilibrium reactions is still an unsolved problem, particularly so at forward angles. In the present work, the angular distributions of alpha particles emitted in (α, α',x) reactions in the target elements gold and rhodium have been studied in detail. Alpha particle beams of energy 60 MeV from the Variable Energy Cyclotron of Calcutta were used in these experiments. The theoretical calculations were done using an extended exciton model of Kalbach incorporated into the Computer Code PRECO-D2. The formalism used in the exciton model was modified to include division of pre equilibrium cross section into multi-step direct (MSD) and multi-step compound (MSC) components. These MSD and MSC cross sections were used to calculate the angular distributions in terms of Legendre polynomials whose coefficients are given by simple phenomenological relations. Even with a reasonable set of parameters, the agreement between theory and experiment was far from satisfactory at forward angles. Similar conclusion was also drawn in the case of continuous particle spectra of deuterons in (d, d'x) reactions at 25 MeV in various targets. (author). 10 refs., 2 figs

  1. Fourier transform spectra of quantum dots

    Science.gov (United States)

    Damian, V.; Ardelean, I.; Armăşelu, Anca; Apostol, D.

    2010-05-01

    Semiconductor quantum dots are nanometer-sized crystals with unique photochemical and photophysical properties that are not available from either isolated molecules or bulk solids. These nanocrystals absorb light over a very broad spectral range as compared to molecular fluorophores which have very narrow excitation spectra. High-quality QDs are proper to be use in different biological and medical applications (as fluorescent labels, the cancer treatment and the drug delivery). In this article, we discuss Fourier transform visible spectroscopy of commercial quantum dots. We reveal that QDs produced by Evident Technologies when are enlightened by laser or luminescent diode light provides a spectral shift of their fluorescence spectra correlated to exciting emission wavelengths, as shown by the ARCspectroNIR Fourier Transform Spectrometer. In the final part of this paper we show an important biological application of CdSe/ZnS core-shell ODs as microbial labeling both for pure cultures of cyanobacteria (Synechocystis PCC 6803) and for mixed cultures of phototrophic and heterotrophic microorganisms.

  2. Radio spectra of pulsars. Pt. 1

    International Nuclear Information System (INIS)

    Izekova, V.A.; Kuzmin, A.D.; Malofeev, V.M.; Shitov, Yu.P.

    1981-01-01

    The results of flux pulsar radioemission measurements at meter wavelength, made at Pushchino Radio Astronomical Observatory of the Lebedev Physical Institute, are presented. Flux densities at 102, 85, 61 and 39 MHz have been measured for 85, 29, 37 and 23 pulsars correspondingly. Some of them were performed at all frequencies simultaneously. On the basis of these data and high frequencies data obtained by other authors, spectra of 52 pulsars were plotted. In practically all investigated pulsars we have detected a turn-over frequency at which the flux density of pulsar radioemission attained its maximum. Its mean value is vsub(m) = 130 +- 80 MHz. Averaged on many pulsars, the spectral index is negative in the 39-61 MHz frequency range (anti ALPHA 39 sub(-) 61 = -1.4 +- 0.4) and passes through zero at frequencies of about 100 MHz, becoming positive in the 100-400 MHz frequency range. It was noticed that the spectral index in the 100-400 MHz interval depends upon such pulsar periods as α 100 sub(-) 400 = 0.7 log p + 0.9. Using the spectra, more precise radio luminosities of pulsars have been computed. (orig.)

  3. Vibration spectra of single atomic nanocontacts

    International Nuclear Information System (INIS)

    Bourahla, B; Khater, A; Rafil, O; Tigrine, R

    2006-01-01

    This paper introduces a simple model for an atomic nanocontact, where its mechanical properties are analysed by calculating numerically the local spectral properties at the contact atom and the nearby atoms. The standard methodology for calculating phonon spectral densities is extended to enable the calculation of localized contact modes and local density of states (DOS). The model system considered for the nanocontact consists of two sets of triple parallel semi-infinite atomic chains joined by a single atom in between. The matching method is used, in the harmonic approximation, to calculate the local Green's functions for the irreducible set of sites that constitute the inhomogeneous nanocontact domain. The Green's functions yield the vibration spectra and the DOS for the atomic sites. These are numerically calculated for different cases of elastic hardening and softening of the nanocontact domain. The purpose is to investigate how the local dynamics respond to local changes in the elastic environment. The analysis of the spectra and of the DOS identifies characteristic features and demonstrates the central role of a core subset of these sites for the dynamics of the nanocontact. The system models a situation which may be appropriate for contact atomic force microscopy

  4. Analysis of the FF Aqr spectra

    Science.gov (United States)

    Shimanskaya, N. N.; Bikmaev, I. F.; Shimansky, V. V.

    2011-07-01

    We determine the atmospheric parameters of the secondary in the close binary system FF Aqr and analyze its chemical composition. A series of high-resolution spectra are taken at different orbital phases using the coude echelle spectrometer of the 1.5-m Russian-Turkish Telescope (RTT150). We show that the absorption line intensity of heavy elements varies with phase due to the spotty nature of the cool component. We determine the abundances of heavy elements in the star's atmosphere by modelling the synthetic spectra and performing a differential analysis of the chemical composition of FF Aqr relative to the solar composition. Our analysis of the averaged spectrum of FF Aqr yielded 539 abundance estimates for 21 chemical elements. We found the metallicity of the star ([ Fe/H] = -0.11 ± 0.08) to be close solar, in agreement with the hypothesis that FF Aqr should belong to the Galactic disk. The inferred chemical composition of the objects exhibits no anomalous abundances of the α-, r-, and s-process elements like those earlier found in other systems (IN Com, LW Hya, V471 Tau). The lack of such anomalies in FF Aqr must be due to the fact that the elements heavier than 16 O cannot be synthesized in the core of the primary during the last stages of its evolution.

  5. Stellar parametrization from Gaia RVS spectra

    Science.gov (United States)

    Recio-Blanco, A.; de Laverny, P.; Allende Prieto, C.; Fustes, D.; Manteiga, M.; Arcay, B.; Bijaoui, A.; Dafonte, C.; Ordenovic, C.; Ordoñez Blanco, D.

    2016-01-01

    Context. Among the myriad of data collected by the ESA Gaia satellite, about 150 million spectra will be delivered by the Radial Velocity Spectrometer (RVS) for stars as faint as GRVS~ 16. A specific stellar parametrization will be performed on most of these RVS spectra, I.e. those with enough high signal-to-noise ratio (S/N), which should correspond to single stars that have a magnitude in the RVS band brighter than ~14.5. Some individual chemical abundances will also be estimated for the brightest targets. Aims: We describe the different parametrization codes that have been specifically developed or adapted for RVS spectra within the GSP-Spec working group of the analysis consortium. The tested codes are based on optimisation (FERRE and GAUGUIN), projection (MATISSE), or pattern-recognition methods (Artificial Neural Networks). We present and discuss each of their expected performances in the recovered stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity) for B- to K-type stars. The performances for determining of [α/Fe] ratios are also presented for cool stars. Methods: Each code has been homogeneously tested with a large grid of RVS simulated synthetic spectra of BAFGK-spectral types (dwarfs and giants), with metallicities varying from 10-2.5 to 10+ 0.5 the solar metallicity, and taking variations of ±0.4 dex in the composition of the α-elements into consideration. The tests were performed for S/N ranging from ten to 350. Results: For all the stellar types we considered, stars brighter than GRVS~ 12.5 are very efficiently parametrized by the GSP-Spec pipeline, including reliable estimations of [α/Fe]. Typical internal errors for FGK metal-rich and metal-intermediate stars are around 40 K in Teff, 0.10 dex in log(g), 0.04 dex in [M/H], and 0.03 dex in [α/Fe] at GRVS = 10.3. They degrade to 155 K in Teff, 0.15 dex in log(g), 0.10 dex in [M/H], and 0.1 dex in [α/Fe] at GRVS~ 12. Similar accuracies in Teff and [M/H] are

  6. An experiment on multibubble sonoluminescence spectra in sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhan; XU JunFeng; HUANG Wei; CHEN WeiZhong; MIAO GuoQing

    2008-01-01

    We investigated experimentally the spectra of MBSL in sodium chloride water solution with krypton as dissolved gas. We observed and compared the spectra of hydroxyl ion at 310 nm and that of sodium atom at 589 nm. It has been found that under the same experimental condition, the intensity of sodium atom spectra is obviously higher than that of the hydroxyl ion spectra, and is more sensitive to the experimental condition. The krypton content, the concentration of sodium chloride solution, and the driving sound pressure obviously affect the spectra intensity in certain range.

  7. Raman Spectra from Pesticides on the Surface of Fruits

    International Nuclear Information System (INIS)

    Zhang, P X; Zhou Xiaofang; Cheng, Andrew Y S; Fang Yan

    2006-01-01

    Raman spectra of several vegetables and fruits were studied by micro-Raman spectrometer (514.5 nm) and Near-infrared Fourier Transform Raman spectrometer (FTRaman). It is shown that at 514.5 nm excitation, most of the spectra are from that of carotene with some very strong fluorescence in some cases. While at 1064 nm wavelength excitation, the spectra from the different samples demonstrate different characteristic Raman spectra without fluorescence. We discuss the spectroscopic difference by the two excitation wavelengths, and the application of Raman spectra for detection of pesticides left on the surface of vegetables and fruits. Raman spectra of fruits and pesticides were successfully recorded, and using the FT-Raman spectra the pesticides left on the surface of the fruits can be detected conveniently

  8. Energetic Proton Spectra Measured by the Van Allen Probes

    Science.gov (United States)

    Summers, Danny; Shi, Run; Engebretson, Mark J.; Oksavik, Kjellmar; Manweiler, Jerry W.; Mitchell, Donald G.

    2017-10-01

    We test the hypothesis that pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves can limit ring current proton fluxes. For two chosen magnetic storms, during 17-20 March 2013 and 17-20 March 2015, we measure proton energy spectra in the region 3 ≤ L ≤ 6 using the RBSPICE-B instrument on the Van Allen Probes. The most intense proton spectra are observed to occur during the recovery periods of the respective storms. Using proton precipitation data from the POES (NOAA and MetOp) spacecraft, we deduce that EMIC wave action was prevalent at the times and L-shell locations of the most intense proton spectra. We calculate limiting ring current proton energy spectra from recently developed theory. Comparisons between the observed proton energy spectra and the theoretical limiting spectra show reasonable agreement. We conclude that the measurements of the most intense proton spectra are consistent with self-limiting by EMIC wave scattering.

  9. Running of featureful primordial power spectra

    Science.gov (United States)

    Gariazzo, Stefano; Mena, Olga; Miralles, Victor; Ramírez, Héctor; Boubekeur, Lotfi

    2017-06-01

    Current measurements of the temperature and polarization anisotropy power spectra of the cosmic microwave background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm may not be respected in nature. We show that a primordial power spectrum with localized features could in principle give rise to the observed slow-roll anarchy when fitted to a featureless power spectrum. From a model comparison perspective, and assuming that nature has chosen a featureless primordial power spectrum, we find that, while with mock Planck data there is only weak evidence against a model with localized features, upcoming CMB missions may provide compelling evidence against such a nonstandard primordial power spectrum. This evidence could be reinforced if a featureless primordial power spectrum is independently confirmed from bispectrum and/or galaxy clustering measurements.

  10. Boundary spectra in superspace σ-models

    International Nuclear Information System (INIS)

    Quella, T.; Schomerus, V.; Creutzig, T.

    2007-12-01

    In this note we compute exact boundary spectra for D-instantons in σ-models on the supergroup PSL(22). Our results are obtained through an explicit summation of the perturbative expansion for conformal dimensions to all orders in the curvature radius. The analysis exploits several remarkable properties of the perturbation series that arises from rescalings of the metric on PSL(22) relative to a fixed Wess- Zumino term. According to Berkovits, Vafa and Witten, the models are relevant in the context of string theory on AdS 3 with non-vanishing RR-flux. The note concludes with a number of comments on various possible generalizations to other supergroups and higher dimensional supercoset theories. (orig.)

  11. Automated analysis of slitless spectra. II. Quasars

    International Nuclear Information System (INIS)

    Edwards, G.; Beauchemin, M.; Borra, F.

    1988-01-01

    Automated software have been developed to process slitless spectra. The software, described in a previous paper, automatically separates stars from extended objects and quasars from stars. This paper describes the quasar search techniques and discusses the results. The performance of the software is compared and calibrated with a plate taken in a region of SA 57 that has been extensively surveyed by others using a variety of techniques: the proposed automated software performs very well. It is found that an eye search of the same plate is less complete than the automated search: surveys that rely on eye searches suffer from incompleteness at least from a magnitude brighter than the plate limit. It is shown how the complete automated analysis of a plate and computer simulations are used to calibrate and understand the characteristics of the present data. 20 references

  12. Assessment of smoothed spectra using autocorrelation function

    International Nuclear Information System (INIS)

    Urbanski, P.; Kowalska, E.

    2006-01-01

    Recently, data and signal smoothing became almost standard procedures in the spectrometric and chromatographic methods. In radiometry, the main purpose to apply smoothing is minimisation of the statistical fluctuation and avoid distortion. The aim of the work was to find a qualitative parameter, which could be used, as a figure of merit for detecting distortion of the smoothed spectra, based on the linear model. It is assumed that as long as the part of the raw spectrum removed by the smoothing procedure (v s ) will be of random nature, the smoothed spectrum can be considered as undistorted. Thanks to this feature of the autocorrelation function, drifts of the mean value in the removed noise vs as well as its periodicity can be more easily detected from the autocorrelogram than from the original data

  13. Closed N-shell alkali spectra

    International Nuclear Information System (INIS)

    Ellis, D.G.; Curtis, L.J.

    1982-01-01

    Term values and ionization potentials have been calculated for several ions in the promethium (N = 61) isoelectronic sequence. As the nuclear charge is increased, the ground configuration changes from 4f 13 5s 2 to 4f 14 5s giving the upper portion of the sequence an alkali-like character. According to our most recent Hartree-Fock calculations with first-order relativistic corrections, the ground term is 5s 2 S for Z > 77 (Ir XVII) and the first excited term is 5p 2 P 0 for Z > 84 (P 0 XXIV). Comparisons are made with calculations of Cowan in W XIV. The prospects for observation of these spectra in fast ion beams are discussed. (orig.)

  14. Dielectric spectra of proteins in conducting media

    International Nuclear Information System (INIS)

    Ruderman, G.; Xammar Oro, J.R. de

    1990-10-01

    Dielectric measurements of serum albumin and myoglobin in solutions of varying conductivities were performed. The results presented confirm that also for protein solutions, the Maxwell predictions of a threshold frequency in conducting materials holds. The threshold frequency of a serum albumin solution was experimentally determined. Attention should be recalled that, if the dielectric spectra of proteins solutions want to be measured, three distinct frequency regions are to be observed: a low frequency region, where the sample behaves like a conductor; an intermediate region centered around the threshold frequency, where the free charges partially screen the fixed ones; and a high frequency region where the sample behaves like a good dielectric. (author). 8 refs, 5 figs

  15. Conformal Symmetry Patterns in Baryon Spectra

    International Nuclear Information System (INIS)

    Kirchbach, Mariana; Compean, Cliffor B

    2011-01-01

    Attention is drawn to the fact that the spectra of the baryons of the lightest flavors, the nucleon and the Δ, carry quantum numbers characteristic for an unitary representation of the conformal group. We show that the above phenomenon is well explained for baryons whose internal structure is dominated by a quark-diquark configuration that resides in a conformally compactified Minkowski space time, R 1 x S 3 , and is described by means of the conformal scale equation there. The R 1 x S 3 space-time represents the boundary of the conformally compactified AdS 5 , on which one expects to encounter a conformal theory in accord with the gauge-gravity duality. Within this context, our model is congruent with AdS 5 /CFT 4 .

  16. Automated analysis of objective-prism spectra

    International Nuclear Information System (INIS)

    Hewett, P.C.; Irwin, M.J.; Bunclark, P.; Bridgeland, M.T.; Kibblewhite, E.J.; Smith, M.G.

    1985-01-01

    A fully automated system for the location, measurement and analysis of large numbers of low-resolution objective-prism spectra is described. The system is based on the APM facility at the University of Cambridge, and allows processing of objective-prism, grens or grism data. Particular emphasis is placed on techniques to obtain the maximum signal-to-noise ratio from the data, both in the initial spectral estimation procedure and for subsequent feature identification. Comparison of a high-quality visual catalogue of faint quasar candidates with an equivalent automated sample demonstrates the ability of the APM system to identify all the visually selected quasar candidates. In addition, a large population of new, faint (msub(J)approx. 20) candidates is identified. (author)

  17. Modeling degradation in SOEC impedance spectra

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Hauch, Anne; Knibbe, Ruth

    2013-01-01

    Solid oxide cell (SOC) performance is limited by various processes. One way to investigate these processes is by electrochemical impedance spectroscopy. In order to quantify and characterize the processes, an equivalent circuit can be used to model the SOC impedance spectra (IS). Unfortunately......, the optimal equivalent circuit is often unknown and to complicate matters further, several processes contribute to the SOC impedance - making detailed process characterization difficult. In this work we analyze and model a series of IS measured during steam electrolysis operation of an SOC. During testing......, degradation is only observed in the Ni/YSZ electrode and not in the electrolyte or the LSM/YSZ electrode. A batch fit of the differences between the IS shows that a modified Gerischer element provides a better fit to the Ni/YSZ electrode impedance than the frequently used RQ element - albeit neither...

  18. Infrared Model Spectra for Evolving Red Supergiants

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    1993-06-01

    Full Text Available The space and ground based infrared spectra of red supergiants are modeled and arranged in order of their evolutionary status with their theoretical model parameters. The chemical compositions of the dust shells around red supergiants are affected by the nuclear reaction and dredge-up processes of the cental stars. The processes are sensitively dependent on the initial mass, the initial chemical composition, and the evolutionary status. Miras, infrared carbon stars, and OH/IR stars have close link in their evolution in manu aspects, i,e., the chemical composition, the optical depths and the mass loss rates. The evolutionary tracks for the three classes of red supergiants on infrared two-color diagrams have been made from model calculations and IRAS observational data.

  19. Increased Elemental Specificity of Positron Annihilation Spectra

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Alatalo, M.; Ghosh, V.J.; Kruseman, A.C.; Nielsen, B.; Lynn, K.G.

    1996-01-01

    Positron annihilation spectroscopy (PAS) is a sensitive probe for studying the electronic structure of defects in solids. We show that the high-momentum part of the Doppler-broadened annihilation spectra can be used to distinguish different elements. This is achieved by using a new two-detector coincidence system to examine the line shape variations originating from high-momentum core electrons. Because the core electrons retain their atomic character even when atoms form a solid, these results can be directly compared to simple theoretical predictions. The new approach adds increased elemental specificity to the PAS technique, and is useful in studying the elemental variations around a defect site. copyright 1996 The American Physical Society

  20. Parameterization of MARVELS Spectra Using Deep Learning

    Science.gov (United States)

    Gilda, Sankalp; Ge, Jian; MARVELS

    2018-01-01

    Like many large-scale surveys, the Multi-Object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) was designed to operate at a moderate spectral resolution ($\\sim$12,000) for efficiency in observing large samples, which makes the stellar parameterization difficult due to the high degree of blending of spectral features. Two extant solutions to deal with this issue are to utilize spectral synthesis, and to utilize spectral indices [Ghezzi et al. 2014]. While the former is a powerful and tested technique, it can often yield strongly coupled atmospheric parameters, and often requires high spectral resolution (Valenti & Piskunov 1996). The latter, though a promising technique utilizing measurements of equivalent widths of spectral indices, has only been employed with respect to FKG dwarfs and sub-giants and not red-giant branch stars, which constitute ~30% of MARVELS targets. In this work, we tackle this problem using a convolution neural network (CNN). In particular, we train a one-dimensional CNN on appropriately processed PHOENIX synthetic spectra using supervised training to automatically distinguish the features relevant for the determination of each of the three atmospheric parameters – T_eff, log(g), [Fe/H] – and use the knowledge thus gained by the network to parameterize 849 MARVELS giants. When tested on the synthetic spectra themselves, our estimates of the parameters were consistent to within 11 K, .02 dex, and .02 dex (in terms of mean absolute errors), respectively. For MARVELS dwarfs, the accuracies are 80K, .16 dex and .10 dex, respectively.

  1. A climatology of visible surface reflectance spectra

    International Nuclear Information System (INIS)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-01-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290–740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment–2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes. - Highlights: • Our goals was visible surface reflectance for satellite trace gas measurements. • Captured the range of surface reflectance spectra through EOF analysis. • Used satellite surface reflectance products for each given scene to anchor EOFs. • Generated a climatology of time/geometry dependent surface reflectance spectra. • Demonstrated potential to

  2. Spectra of small Koronis family members

    Science.gov (United States)

    Thomas, C.; Rivkin, A.; Trilling, D.; Moskovitz, N.

    2014-07-01

    The space-weathering process and its implications for the relationships between S- and Q-type asteroids and ordinary chondrite meteorites are long-standing problems in asteroid science. Although the visible and near-infrared spectra of S- and Q-type objects qualitatively show the same absorption features and quantitatively show evidence of the same minerals, the S types display increased spectral slopes and muted absorption features compared to the Q types. This spectral mismatch is consistent with the effects of the space weathering process. Binzel et al. provided the missing link between Q- and S-type bodies in near-Earth space by showing a reddening of spectral slope in objects from 0.1 to 5 km that corresponded to the transition from Q- to S-type spectra. This result implied that size, and therefore age, is related to the relationship between Q- and S-type. The existence of Q-type objects in the main belt was not confirmed until Mothe-Diniz and Nesvorny (2008) found them in young S-type clusters. To investigate the trend from Q to S in the main belt, we examined space weathering within the old main-belt Koronis family using a spectrophotometric survey (Rivkin et al. 2011, Thomas et al. 2011). Rivkin et al. (2011) identified several potential Q-type objects within the Koronis family. Our Q-type candidates were identified using broad-band spectrophotometry and could not be taxonomically classified on that basis alone. We obtained follow-up visible and near-infrared spectral observations of our potential Q-type objects, (26970) Elias, (45610) 2000 DJ_{48}, and (37411) 2001 XF_{152}, using Gemini and Magellan. We will present the results of these spectral follow-up observations. Observations of (26970) Elias demonstrate that the object is more consistent with the average Q-type spectrum than the average S-type spectrum.

  3. Strong ground motion spectra for layered media

    International Nuclear Information System (INIS)

    Askar, A.; Cakmak, A.S.; Engin, H.

    1977-01-01

    This article presents an analytic method and calculations of strong motion spectra for the energy, displacement, velocity and acceleration based on the physical and geometric ground properties at a site. Although earthquakes occur with large deformations and high stress intensities which necessarily lead to nonlinear phenomena, most analytical efforts to date have been based on linear analyses in engineering seismology and soil dynamics. There are, however, a wealth of problems such as the shifts in frequency, dispersion due to the amplitude, the generation of harmonics, removal of resonance infinities, which cannot be accounted for by a linear theory. In the study, the stress-strain law for soil is taken as tau=G 0 γ+G 1 γ 3 +etaγ where tau is the stress, γ is the strain, G 0 and G 1 are the elasticity coefficients and eta is the damping and are different in each layer. The above stress-strain law describes soils with hysterisis where the hysterisis loops for various amplitudes of the strain are no longer concentric ellipses as for linear relations but are oval shapes rotated with respect to each other similar to the materials with the Osgood-Ramberg law. It is observed that even slight nonlinearities may drastically alter the various response spectra from that given by linear analysis. In fact, primary waves cause resonance conditions such that secondary waves are generated. As a result, a weak energy transfer from the primary to the secondary waves takes place, thus altering the wave spectrum. The mathematical technique that is utilized for the solution of the nonlinear equation is a special perturbation method as an extension of Poincare's procedure. The method considers shifts in the frequencies which are determined by the boundedness of the energy

  4. Spectroscopic modeling for tungsten EUV spectra

    International Nuclear Information System (INIS)

    Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Suzuki, Chihiro; Morita, Shigeru; Goto, Motoshi; Sasaki, Akira; Nakamura, Nobuyuki; Yamamoto, Norimasa; Koike, Fumihiro

    2014-01-01

    We have constructed an atomic model for tungsten extreme ultraviolet (EUV) spectra to reconstruct characteristic spectral feature of unresolved transition array (UTA) observed at 4-7 nm for tungsten ions. In the tungsten atomic modeling, we considered fine-structure levels with the quantum principal number n up to 6 as the atomic structure and calculated the electron-impact collision cross sections by relativistic distorted-wave method, using HULLAC atomic code. We measured tungsten EUV spectra in Large Helical Device (LHD) and Compact Electron Beam Ion Trap device (CoBIT) and compared them with the model calculation. The model successfully explain series of emission peaks at 1.5-3.5 nm as n=5-4 and 6-4 transitions of W"2"4"+ - W"3"2"+ measured in CoBIT and LHD and the charge state distributions were estimated for LHD plasma. The UTA feature observed at 4-7 nm was also successfully reconstructed with our model. The peak at ∼5 nm is produced mainly by many 4f-4d transition of W"2"2"+ - W"3"5"+ ions, and the second peak at ∼6 nm is produced by 4f-4d transition of W"2"5"+ - W"2"8"+ ions, and 4d-4p inner-shell transitions, 4p"54d"n"+"1 - 4p"64d"n, of W"2"9"+ - W"3"5"+ ions. These 4d-4p inner-shell transitions become strong since we included higher excited states such as 4p"54d"n4f state, which ADAS atomic data set does not include for spectroscopic modeling with fine structure levels. (author)

  5. Curved Radio Spectra of Weak Cluster Shocks

    Science.gov (United States)

    Kang, Hyesung; Ryu, Dongsu

    2015-08-01

    In order to understand certain observed features of arc-like giant radio relics such as the rareness, uniform surface brightness, and curved integrated spectra, we explore a diffusive shock acceleration (DSA) model for radio relics in which a spherical shock impinges on a magnetized cloud containing fossil relativistic electrons. Toward this end, we perform DSA simulations of spherical shocks with the parameters relevant for the Sausage radio relic in cluster CIZA J2242.8+5301, and calculate the ensuing radio synchrotron emission from re-accelerated electrons. Three types of fossil electron populations are considered: a delta-function like population with the shock injection momentum, a power-law distribution, and a power law with an exponential cutoff. The surface brightness profile of the radio-emitting postshock region and the volume-integrated radio spectrum are calculated and compared with observations. We find that the observed width of the Sausage relic can be explained reasonably well by shocks with speed {u}{{s}}˜ 3× {10}3 {km} {{{s}}}-1 and sonic Mach number {M}{{s}}˜ 3. These shocks produce curved radio spectra that steepen gradually over (0.1-10){ν }{br} with a break frequency {ν }{br}˜ 1 GHz if the duration of electron acceleration is ˜60-80 Myr. However, the abrupt increase in the spectral index above ˜1.5 GHz observed in the Sausage relic seems to indicate that additional physical processes, other than radiative losses, operate for electrons with {γ }{{e}}≳ {10}4.

  6. [Raman spectra of monkey cerebral cortex tissue].

    Science.gov (United States)

    Zhu, Ji-chun; Guo, Jian-yu; Cai, Wei-ying; Wang, Zu-geng; Sun, Zhen-rong

    2010-01-01

    Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.

  7. Spectra and physical properties of Taurid meteoroids

    Science.gov (United States)

    Matlovič, Pavol; Tóth, Juraj; Rudawska, Regina; Kornoš, Leonard

    2017-09-01

    Taurids are an extensive stream of particles produced by comet 2P/Encke, which can be observed mainly in October and November as a series of meteor showers rich in bright fireballs. Several near-Earth asteroids have also been linked with the meteoroid complex, and recently the orbits of two carbonaceous meteorites were proposed to be related to the stream, raising interesting questions about the origin of the complex and the composition of 2P/Encke. Our aim is to investigate the nature and diversity of Taurid meteoroids by studying their spectral, orbital, and physical properties determined from video meteor observations. Here we analyze 33 Taurid meteor spectra captured during the predicted outburst in November 2015 by stations in Slovakia and Chile, including 14 multi-station observations for which the orbital elements, material strength parameters, dynamic pressures, and mineralogical densities were determined. It was found that while orbits of the 2015 Taurids show similarities with several associated asteroids, the obtained spectral and physical characteristics point towards cometary origin with highly heterogeneous content. Observed spectra exhibited large dispersion of iron content and significant Na intensity in all cases. The determined material strengths are typically cometary in the KB classification, while PE criterion is on average close to values characteristic for carbonaceous bodies. The studied meteoroids were found to break up under low dynamic pressures of 0.02-0.10 MPa, and were characterized by low mineralogical densities of 1.3-2.5 g cm-3. The widest spectral classification of Taurid meteors to date is presented.

  8. Path spectra derived from inversion of source and site spectra for earthquakes in Southern California

    Science.gov (United States)

    Klimasewski, A.; Sahakian, V. J.; Baltay, A.; Boatwright, J.; Fletcher, J. B.; Baker, L. M.

    2017-12-01

    A large source of epistemic uncertainty in Ground Motion Prediction Equations (GMPEs) is derived from the path term, currently represented as a simple geometric spreading and intrinsic attenuation term. Including additional physical relationships between the path properties and predicted ground motions would produce more accurate and precise, region-specific GMPEs by reclassifying some of the random, aleatory uncertainty as epistemic. This study focuses on regions of Southern California, using data from the Anza network and Southern California Seismic network to create a catalog of events magnitude 2.5 and larger from 1998 to 2016. The catalog encompasses regions of varying geology and therefore varying path and site attenuation. Within this catalog of events, we investigate several collections of event region-to-station pairs, each of which share similar origin locations and stations so that all events have similar paths. Compared with a simple regional GMPE, these paths consistently have high or low residuals. By working with events that have the same path, we can isolate source and site effects, and focus on the remaining residual as path effects. We decompose the recordings into source and site spectra for each unique event and site in our greater Southern California regional database using the inversion method of Andrews (1986). This model represents each natural log record spectra as the sum of its natural log event and site spectra, while constraining each record to a reference site or Brune source spectrum. We estimate a regional, path-specific anelastic attenuation (Q) and site attenuation (t*) from the inversion site spectra and corner frequency from the inversion event spectra. We then compute the residuals between the observed record data, and the inversion model prediction (event*site spectra). This residual is representative of path effects, likely anelastic attenuation along the path that varies from the regional median attenuation. We examine the

  9. Peakr: simulating solid-state NMR spectra of proteins

    International Nuclear Information System (INIS)

    Schneider, Robert; Odronitz, Florian; Hammesfahr, Bjorn; Hellkamp, Marcel; Kollmar, Martin

    2013-01-01

    When analyzing solid-state nuclear magnetic resonance (NMR) spectra of proteins, assignment of resonances to nuclei and derivation of restraints for 3D structure calculations are challenging and time-consuming processes. Simulated spectra that have been calculated based on, for example, chemical shift predictions and structural models can be of considerable help. Existing solutions are typically limited in the type of experiment they can consider and difficult to adapt to different settings. Here, we present Peakr, a software to simulate solid-state NMR spectra of proteins. It can generate simulated spectra based on numerous common types of internuclear correlations relevant for assignment and structure elucidation, can compare simulated and experimental spectra and produces lists and visualizations useful for analyzing measured spectra. Compared with other solutions, it is fast, versatile and user friendly. (authors)

  10. Principal spectra describing magnetooptic permittivity tensor in cubic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hamrlová, Jana [Nanotechnology Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Legut, Dominik [IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Veis, Martin [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague, 121 16 Czech Republic (Czech Republic); Pištora, Jaromír [Nanotechnology Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Hamrle, Jaroslav, E-mail: jaroslav.hamrle@vsb.cz [IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague, 121 16 Czech Republic (Czech Republic); Department of Physics, VSB – Technical University of Ostrava, 17. listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic)

    2016-12-15

    We provide unified phenomenological description of magnetooptic effects being linear and quadratic in magnetization. The description is based on few principal spectra, describing elements of permittivity tensor up to the second order in magnetization. Each permittivity tensor element for any magnetization direction and any sample surface orientation is simply determined by weighted summation of the principal spectra, where weights are given by crystallographic and magnetization orientations. The number of principal spectra depends on the symmetry of the crystal. In cubic crystals owning point symmetry we need only four principal spectra. Here, the principal spectra are expressed by ab initio calculations for bcc Fe, fcc Co and fcc Ni in optical range as well as in hard and soft x-ray energy range, i.e. at the 2p- and 3p-edges. We also express principal spectra analytically using modified Kubo formula.

  11. The influence of anharmonic vibrations of the core to M2-transition between low-lying states in 115Sn

    International Nuclear Information System (INIS)

    Sy Savane, Y.

    1995-12-01

    The influence of the anharmonicity of the core vibration, on the magnetic transition 11/2 - 1 → 7/2 + 1 in 115 Sn have been investigated in the frame of the quasiparticle-phonon nuclear model. The model wave function includes a ''quasiparticle + two phonons'' component. The performed numerical calculations show that those effects cannot explain the strong reduction of the M2-transition observed in the experiment. A full agreement with the experimental value is obtained with g eff s = 0.42g free s . (author). 10 refs, 2 figs, 1 tab

  12. Theoretical study on the low-lying excited states of the phosphorus monoiodide (PI) including the spin-orbit coupling

    Science.gov (United States)

    Zhang, Xiaomei; Liu, Xiaoting; Liang, Guiying; Li, Rui; Xu, Haifeng; Yan, Bing

    2016-01-01

    The potential energy curves (PECs) of the 22 Λ-S states of the phosphorus monoiodide (PI) molecule have been calculated at the level of MRCI+Q method with correlation-consistent quadruple-ζ quality basis set. The spectroscopic constants of the bound states are determined, which well reproduce the available measurements. The metastable a1Δ state has been reported for the first time, which lies between the X3Σ- and b1Σ+ states and have much deeper well than the ground state. The R-dependent spin-orbit (SO) matrix elements are calculated with the full-electron Breit-Pauli operator. Based on the SO matrix elements, the perturbations that the 23Π state may suffer from are analyzed in detail. The SOC effect makes the original Λ-S states split into 51 Ω states. In the zero-field splitting of the ground state X3Σ-, the spin-spin coupling contribution (2.23 cm-1) is found to be much smaller compared to the spin-orbit coupling contribution (50 cm-1). The avoided crossings between the Ω states lead to much shallower potential wells and the change of dissociation relationships of the states. The Ω-state wavefunctions are analyzed depending on their Λ-S compositions, showing the strong interactions among several quasidegenerate Λ-S states of the same total SO symmetry. The transition properties including electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition moments (TMs), the Franck-Condon factors, the transition probabilities and the radiative lifetimes are computed for the transitions between Ω components of a1Δ and b1Σ+ states and ground state. The transition probabilities induced by the E1, E2, and M1 transitions are evaluated. The E2 makes little effect on transition probabilities. In contrast, the E1 transition makes the main contribution to the transition probability and the M1 transition also brings the influence that cannot be neglected. Finally, the radiative lifetimes are determined with the transition moments including E1 and M1. The lifetime of transition (2)0+-X10+ is evaluated at the level of millisecond, much smaller than that of the transition (2)0+-X21.

  13. Low-lying dipole strength of neutron-rich 'island of inversion' nuclei around n ∼ 20

    International Nuclear Information System (INIS)

    Datta Pramanik, U.; Chakraborty, S.; Ray, I.

    2009-01-01

    Magic numbers are the basic building blocks of nuclear structure since last fifty years. Recently, through various experimental results using Radioactive Ion Beam (RIB) facilities, it has been observed that those long cherished magic numbers are not valid anymore in the neutron rich nuclei like 32 Mg etc. The breakdown of magic number was hinted in the late 1980 's by Thibault et. al. in sodium nuclei ( 31,32 Na). Motobayashi et. al. showed large deformation for 32 Mg which leads to the failure of magic number at N = 20. Exploration into the cause of this breakdown shows the filling of higher pf orbitals rather than the pure lower sd orbitals in the ground state of the neutron-rich nuclei like Ne, Na, Mg in the region N∼20. Thus there is obviously an inversion in nuclear orbitals and hence the so called name 'island of inversion'. This year, we have performed an experiment at GSI, Darmstadt. The measurement of dipole threshold strength of neutron-rich nucleus (N∼20) through electromagnetic excitation was done using LAND-FRS setup. Through this dipole strength, we would like to probe directly the quantum numbers of the valence neutrons in neutron rich nuclei like 31-33 Mg, 33-35 Al, 29-30 Na, 25-27 Ne, 24 F etc.

  14. Low-lying states and structure of the exotic 8He via direct reactions on the proton

    International Nuclear Information System (INIS)

    Skaza, F.; Lapoux, V.; Keeley, N.; Alamanos, N.; Auger, F.; Beaumel, D.; Becheva, E.; Blumenfeld, Y.; Delaunay, F.; Drouart, A.; Gillibert, A.; Giot, L.; Khan, E.; Nalpas, L.; Pakou, A.; Pollacco, E.; Raabe, R.; Roussel-Chomaz, P.; Rusek, K.; Scarpaci, J.-A.; Sida, J.-L.; Stepantsov, S.; Wolski, R.

    2007-01-01

    The structure of the light exotic nucleus 8 He was investigated using direct reactions of the 8 He SPIRAL beam on a proton-rich target. The (p,p') scattering to the 2 1 + state, the (p,d) 7 He and (p,t) 6 He transfer reactions, were measured at the energy E lab =15.7 A.MeV. The light charged particles (p,d,t) were detected in the MUST Si-strip telescope array. The excitation spectrum of 8 He was extracted from the (p,p') reaction. Above the known 2 1 + excited state at 3.6 MeV, a second resonance was found around 5.4 MeV. The cross sections were analyzed within the coupled-reaction channels framework, using microscopic potentials. It is inferred that the 8 He ground state has a more complex neutron-skin structure than suggested by previous α+4n models assuming a pure (1p 3/2 ) 4 configuration

  15. Comparison of IBM-2 calculations with X(5) critical point symmetry for low lying states in 128-140Nd

    International Nuclear Information System (INIS)

    Uluer, I.; Olgun, D.; Inan, S.; Tuerkan, N.

    2006-01-01

    The X(5) would take place when moving continuously from the pure U(5) symmetry to the SU(3) symmetry and it implies a definite relations among the level energies and among the E2 transition strengths. It was recently shown that a signature of phase transition is observed in the chain of Sm, Mo and Nd isotopes, where 1 52Sm, 1 04Mo and 1 50Nd display the predicted features of the X(5) symmetry and mark therefore the critical point. However, more detailed studies and experiments are needed to get ideas about this signature. Without entering into detail we have firstly compared the results obtained in our previous study of 1 28- 1 40Nd with that of the limits in X(5) symmetry and then given a clear description about the validity of the Hamiltonian parameters used in the study. At the end, we have concluded that some of Nd isotopes display X(5) symmetry features

  16. An ab initio study of potential energy surfaces of CH 3COCN dissociation on the low-lying states

    Science.gov (United States)

    Ding, Wan-Jian; Fang, Wei-Hai; Liu, Ruo-Zhuang

    2002-01-01

    The C-CH 3 and C-CN bond dissociations of CH 3COCN on S 1 and T 1 surfaces are studied at the CAS(8,7)/cc-pVDZ level. The results show that the intersystem crossing from S 1 to T 1 is a favorable pathway of S 1 deactivation. Once on the T 1 surface, the system can dissociate adiabatically to CH3 ( X˜)+ OCCN ( X˜) or CN ( X˜)+ CH3CO ( X˜) , but the former has some preference over the latter. This mechanism is consistent with Cheng's presumption deduced from the experimental facts and theoretical considerations. A comparison with other asymmetrically substituted carbonyl compounds suggests that the selectivity of the α-bond cleavage is mainly dependent on the mechanism of dissociation.

  17. Energy relaxation between low lying tunnel split spin-states of the single molecule magnet Ni4

    Science.gov (United States)

    de Loubens, G.; Chaves-O'Flynn, G. D.; Kent, A. D.; Ramsey, C.; Del Barco, E.; Beedle, C.; Hendrickson, D. N.

    2007-03-01

    We have developed integrated magnetic sensors to study quantum tunneling of magnetization (QTM) in single molecule magnet (SMMs) single crystals. These sensors incorporate a microstrip resonator (30 GHz) and a micro-Hall effect magnetometer. They have been used to investigate the relaxation rates between the 2 lowest lying tunnel split spin-states of the SMM Ni4 (S=4). EPR spectroscopy at 30 GHz and 0.4 K and concurrent magnetization measurements of several Ni4 single crystals are presented. EPR enables measurement of the energy splitting between the 2 lowest lying superposition states as a function of the longitudinal and transverse fields. The energy relaxation rate is determined in two ways. First, in cw microwave experiments the change in spin-population together with the microwave absorption directly gives the relaxation time from energy conservation in steady-state. Second, direct time-resolved measurements of the magnetization with pulsed microwave radiation have been performed. The relaxation time is found to vary by several orders of magnitude in different crystals, from a few seconds down to smaller than 100 μs. We discuss this and the form of the relaxation found for different crystals and pulse conditions.

  18. A study of the low-lying singlet and triplet electronic states of chlorophyll A and B

    Directory of Open Access Journals (Sweden)

    Etinski Mihajlo

    2013-01-01

    Full Text Available Chlorophylls have been extensively investigated both experimentally and theoretically owing to the fact that they are essential for photosynthesis. We have studied two forms of chlorophyll, chlorophyll a and chlorophyll b, by means of density functional theory. Optimization of S0, S1 and T1 states was performed with the B3-LYP functional. The computed fluorescence lifetimes show good agreement with the available experimental data. The electronic adiabatic energies of S1 and T1 states are 2.09/2.12 and 1.19/1.29 eV for chlorophyll a and chlorophyll b respectively. We discussed the implications of this results on the triplet formation. Also, the calculated vertical ionization potentials shows good agreement with the experimental results. [Projekat Ministarstva nauke Reoublike Srbije, br. 172040

  19. Tumor vascularity evaluated by transrectal color Doppler US in predicting therapy outcome for low-lying rectal cancer

    International Nuclear Information System (INIS)

    Barbaro, Brunella; Valentini, Vincenzo; Coco, Claudio; Mancini, Anna Paola; Gambacorta, Maria Antonietta; Vecchio, Fabio Maria; Bonomo, Lorenzo

    2005-01-01

    Purpose: To evaluate the impact on T downstaging of the vasculature supplying blood flow to rectal cancer evaluated by color Doppler ultrasound. Methods and Materials: Color Doppler images were graded in 29 T3-staged rectal carcinoma patients sonographically just before chemoradiation. Any arterial vessels detected in rectal masses were assigned one of two grades: vascularity was considered as grade 1 for vessels feeding the periphery and as grade 2 for vessels coursing in all rectal masses within its peripheral and central portions. The pulsatility indices (PI = peak systolic velocity - end-diastolic velocity/time-averaged maximum velocity) were calculated in the central and peripheral portions. Results: The pathologic observations showed a change in stage in 15 of the 23 patients graded 2, positive predictive value 65.2% (p = 0.047), and in one of the six rectal cancers graded 1 (negative predictive value, 83.3%). The minimal peripheral PI values in rectal cancer graded 2 were higher in nonresponding (2.2 ± 1.3) than in responding lesions (1.6 ± 0.7) p = 0.01. Conclusion: Vascularity graded 2 associated with low peripheral PI values are indicators of therapy outcome. Vascularity graded 1 and high peripheral PI values in graded 2 have negative predictive value

  20. Low-lying electronic states of the OH radical: potential energy curves, dipole moment functions, and transition probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Qin, X.; Zhang, S. D. [Qufu Normal University, Qufu (China)

    2014-12-15

    The six doublet and the two quartet electronic states ({sup 2}Σ{sup +}(2), {sup 2}Σ{sup -}, {sup 2}Π(2), {sup 2}Δ, {sup 4}Σ{sup -}, and {sup 4}Π) of the OH radical have been studied using the multi-reference configuration interaction (MRCI) method where the Davidson correction, core-valence interaction and relativistic effect are considered with large basis sets of aug-cc-pv5z, aug-cc-pcv5z, and cc-pv5z-DK, respectively. Potential energy curves (PECs) and dipole moment functions are also calculated for these states for internuclear distances ranging from 0.05 nm to 0.80 nm. All possible vibrational levels and rotational constants for the bound state X{sup 2}Π and A{sup 2}Σ{sup +} of OH are predicted by numerical solving the radial Schroedinger equation through the Level program, and spectroscopic parameters, which are in good agreements with experimental results, are obtained. Transition dipole moments between the ground state X{sup 2}Π and other excited states are also computed using MRCI, and the transition probability, lifetime, and Franck-Condon factors for the A{sup 2}Σ{sup +} - X{sup 2}Π transition are discussed and compared with existing experimental values.