Cranking Calculation in the sdg Interacting Boson Model

NASA Astrophysics Data System (ADS)

Wang, Baolin

1998-10-01

A self-consistent cranking calculation of the intrinsic states of the sdg interacting boson model is performed. The formulae of the moment of inertia are given in a general sdg IBM multipole Hamiltonian with one- and two-body terms. In the quadrupole interaction, the intrinsic states, the quadrupole and hexadecapole deformation and the moment of inertia are investigated in the large N limit. Using a simple Hamiltonian, the results of numerical calculations for 152, 154Sm and 154-160 Gd satisfactorily reproduce the experimental data.

Theory of elastic interaction between arbitrary colloidal particles in confined nematic liquid crystals.

PubMed

Tovkach, O M; Chernyshuk, S B; Lev, B I

2012-12-01

We develop the method proposed by Chernyshuk and Lev [Phys. Rev. E 81, 041701 (2010)] for theoretical investigation of elastic interactions between colloidal particles of arbitrary shape and chirality (polar as well as azimuthal anchoring) in the confined nematic liquid crystal (NLC). General expressions for six different types of multipole elastic interactions are obtained in the confined NLC: monopole-monopole (Coulomb type), monopole-dipole, monopole-quadrupole, dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole interactions. The obtained formulas remain valid in the presence of the external electric or magnetic fields. The exact equations are found for all multipole coefficients for the weak anchoring case. For the strong anchoring coupling, the connection between the symmetry of the shape or director and multipole coefficients is obtained, which enables us to predict which multipole coefficients vanish and which remain nonzero. The particles with azimuthal helicoid anchoring are considered as an example. Dipole-dipole interactions between helicoid cylinders and cones are found in the confined NLC. In addition, the banana-shaped particles in homeotropic and planar nematic cells are considered. It is found that the dipole-dipole interaction between banana-shaped particles differs greatly from the dipole-dipole interaction between the axially symmetrical particles in the nematic cell. There is a crossover from attraction to repulsion between banana particles along some directions in nematic cells. It is shown that monopoles do not "feel" the type of nematic cell: monopole-monopole interaction turns out to be the same in homeotropic and planar nematic cells and converges to the Coulomb law as thickness increases, L→∞.

Matter-wave solitons supported by quadrupole-quadrupole interactions and anisotropic discrete lattices

NASA Astrophysics Data System (ADS)

Zhong, Rong-Xuan; Huang, Nan; Li, Huang-Wu; He, He-Xiang; Lü, Jian-Tao; Huang, Chun-Qing; Chen, Zhao-Pin

2018-04-01

We numerically and analytically investigate the formations and features of two-dimensional discrete Bose-Einstein condensate solitons, which are constructed by quadrupole-quadrupole interactional particles trapped in the tunable anisotropic discrete optical lattices. The square optical lattices in the model can be formed by two pairs of interfering plane waves with different intensities. Two hopping rates of the particles in the orthogonal directions are different, which gives rise to a linear anisotropic system. We find that if all of the pairs of dipole and anti-dipole are perpendicular to the lattice panel and the line connecting the dipole and anti-dipole which compose the quadrupole is parallel to horizontal direction, both the linear anisotropy and the nonlocal nonlinear one can strongly influence the formations of the solitons. There exist three patterns of stable solitons, namely horizontal elongation quasi-one-dimensional discrete solitons, disk-shape isotropic pattern solitons and vertical elongation quasi-continuous solitons. We systematically demonstrate the relationships of chemical potential, size and shape of the soliton with its total norm and vertical hopping rate and analytically reveal the linear dispersion relation for quasi-one-dimensional discrete solitons.

New method in muon-hadron absorption on Thx DUO2 nano material structure at 561 MHz quantum gyro-magnetic

NASA Astrophysics Data System (ADS)

Hardiyanto, M.; Ermawaty, I. R.

2018-01-01

We present an experimental of muan-hadron tunneling chain investigation with new methods of Thx DUO2 nano structure based on Josephson’s tunneling and Abrikosov-Balseiro-Russel (ABR) formulation with quantum quadrupole interacting with a strongly localized high gyro-magnetic optical field as encountered in high-resolution near-field optical microscopy for 1.2 nano meter lambda-function. The strong gradients of these localized gyro-magnetic fields suggest that higher-order multipolar interactions will affect the standard magnetic quadrupole transition rates in 1.8 x 103 currie/mm fuel energy in nuclear moderator pool and selection rules with quatum dot. For muan-hadron absorption in Josephson’s tunnelling quantum quadrupole in the strong confinement limit we calculated the inter band of gyro-magnetic quadrupole absorption rate and the associated selection rules. Founded that the magnetic quadrupole absorption rate is comparable with the absorption rate calculated in the gyro-magneticdipole approximation of ThxDUO2 nano material structure. This implies that near-field optical techniques can extend the range of spectroscopic measurements for 545 MHz at quantum gyro-magnetic field until 561 MHz deployment quantum field at B around 455-485 tesla beyond the standard dipole approximation. However, we also show that spatial resolution could be improved by the selective excitation of ABR formulation in quantum quadrupole transitions.

A -cation control of magnetoelectric quadrupole order in A (TiO)Cu 4(PO4)4(A =Ba ,Sr, and Pb)

NASA Astrophysics Data System (ADS)

Kimura, K.; Toyoda, M.; Babkevich, P.; Yamauchi, K.; Sera, M.; Nassif, V.; Rønnow, H. M.; Kimura, T.

2018-04-01

Ferroic magnetic quadrupole order exhibiting macroscopic magnetoelectric activity is discovered in the novel compound A (TiO ) Cu4(PO4)4 with A = Pb, which is in contrast with antiferroic quadrupole order observed in the isostructural compounds with A = Ba and Sr. Unlike the famous lone-pair stereochemical activity which often triggers ferroelectricity as in PbTiO3, the Pb2 + cation in Pb (TiO ) Cu4(PO4)4 is stereochemically inactive but dramatically alters specific magnetic interactions and consequently switches the quadrupole order from antiferroic to ferroic. Our first-principles calculations uncover a positive correlation between the degree of A -O bond covalency and a stability of the ferroic quadrupole order.

The Uses and Abuses of the Acoustic Analogy in Helicopter Rotor Noise Prediction

NASA Technical Reports Server (NTRS)

Farassat, F.; Brentner, Kenneth S.

1987-01-01

This paper is theoretical in nature and addresses applications of the acoustic analogy in helicopter rotor noise prediction. It is argued that in many instances the acoustic analogy has not been used with care in rotor noise studies. By this it is meant that approximate or inappropriate formulations have been used. By considering various mechanisms of noise generation, such abuses are identified and the remedy is suggested. The mechanisms discussed are thickness, loading, quadrupole, and blade-vortex interaction noise. The quadrupole term of the Ffowcs Williams-Hawkings equation is written in a new form which separates the contributions of regions of high gradients such as shock surfaces. It is shown by order of magnitude studies that such regions are capable of producing noise with the same directivity as the thickness noise. The inclusion of this part of quadrupole sources in current acoustic codes is quite practical. Some of the difficulties with the use of loading noise formulations of the first author in predictions of blade-vortex interaction noise are discussed. It appears that there is a need for development of new theoretical results based on the acoustic analogy in this area. Because of the impulsive character of the blade surface pressure, a time scale of integration different from that used in loading and thickness computations must he used in a computer code for prediction of blade-vortex interaction noise.

Spin coherent states phenomena probed by quantum state tomography in Zeeman perturbed nuclear quadrupole resonance

NASA Astrophysics Data System (ADS)

Teles, João; Auccaise, Ruben; Rivera-Ascona, Christian; Araujo-Ferreira, Arthur G.; Andreeta, José P.; Bonagamba, Tito J.

2018-07-01

Recently, we reported an experimental implementation of quantum information processing (QIP) by nuclear quadrupole resonance (NQR). In this work, we present the first quantum state tomography (QST) experimental implementation in the NQR QIP context. Two approaches are proposed, employing coherence selection by temporal and spatial averaging. Conditions for reduction in the number of cycling steps are analyzed, which can be helpful for larger spin systems. The QST method was applied to the study of spin coherent states, where the alignment-to-orientation phenomenon and the evolution of squeezed spin states show the effect of the nonlinear quadrupole interaction intrinsic to the NQR system. The quantum operations were implemented using a single-crystal sample of KClO3 and observing ^{35}Cl nuclei, which posses spin 3/2.

Support Structure Design of the $$\\hbox{Nb}_{3}\\hbox{Sn}$$ Quadrupole for the High Luminosity LHC

DOE PAGES

Juchno, M.; Ambrosio, G.; Anerella, M.; ...

2014-10-31

New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of themore » detailed 3D numerical analysis performed in preparation for the first short model test.« less

Gravitational radiation quadrupole formula is valid for gravitationally interacting systems

NASA Technical Reports Server (NTRS)

Walker, M.; Will, C. M.

1980-01-01

An argument is presented for the validity of the quadrupole formula for gravitational radiation energy loss in the far field of nearly Newtonian (e.g., binary stellar) systems. This argument differs from earlier ones in that it determines beforehand the formal accuracy of approximation required to describe gravitationally self-interacting systems, uses the corresponding approximate equation of motion explicitly, and evaluates the appropriate asymptotic quantities by matching along the correct space-time light cones.

Communication: On the isotope anomaly of nuclear quadrupole coupling in molecules

NASA Astrophysics Data System (ADS)

Filatov, Michael; Zou, Wenli; Cremer, Dieter

2012-10-01

The dependence of the nuclear quadrupole coupling constants (NQCC) on the interaction between electrons and a nucleus of finite size is theoretically analyzed. A deviation of the ratio of the NQCCs obtained from two different isotopomers of a molecule from the ratio of the corresponding bare nuclear electric quadrupole moments, known as quadrupole anomaly, is interpreted in terms of the logarithmic derivatives of the electric field gradient at the nuclear site with respect to the nuclear charge radius. Quantum chemical calculations based on a Dirac-exact relativistic methodology suggest that the effect of the changing size of the Au nucleus in different isotopomers can be observed for Au-containing molecules, for which the predicted quadrupole anomaly reaches values of the order of 0.1%. This is experimentally detectable and provides an insight into the charge distribution of non-spherical nuclei.

Laser ablated hydantoin: A high resolution rotational study.

PubMed

Alonso, Elena R; Kolesniková, Lucie; Alonso, José L

2017-09-28

Laser ablation techniques coupled with broadband and narrowband Fourier transform microwave spectroscopies have allowed the high resolution rotational study of solid hydantoin, an important target in astrochemistry as a possible precursor of glycine. The complicated hyperfine structure arising from the presence of two 14 N nuclei in non-equivalent positions has been resolved and interpreted in terms of the nuclear quadrupole coupling interactions. The results reported in this work provide a solid base for the interstellar searches of hydantoin in the astrophysical surveys. The values of the nuclear quadrupole coupling constants have been also discussed in terms of the electronic environment around the respective nitrogen atom.

First Test Results of the 150 mm Aperture IR Quadrupole Models for the High Luminosity LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ambrosio, G.; Chlachidze, G.; Wanderer, P.

2016-10-06

The High Luminosity upgrade of the LHC at CERN will use large aperture (150 mm) quadrupole magnets to focus the beams at the interaction points. The high field in the coils requires Nb3Sn superconductor technology, which has been brought to maturity by the LHC Accelerator Re-search Program (LARP) over the last 10 years. The key design targets for the new IR quadrupoles were established in 2012, and fabrication of model magnets started in 2014. This paper discusses the results from the first single short coil test and from the first short quadrupole model test. Remaining challenges and plans to addressmore » them are also presented and discussed.« less

Gyroscopic effect in low-energy classical capture of a rotating quadrupolar diatom by an ion.

PubMed

Dashevskaya, Elena; Litvin, Iliya; Nikitin, Evgueni

2006-03-09

The low-energy capture of homonuclear diatoms by ions is due mainly to the long-range part of the interpartner potential with leading terms that correspond to charge-quadrupole interaction and charge-induced dipole interaction. The capture dynamics is described by the perturbed-rotor adiabatic potentials and the Coriolis interaction between manifold of states that belong to a given value of the intrinsic angular momentum. When the latter is large enough, it can noticeably affect the capture cross section calculated in the adiabatic channel approximation due to the gyroscopic property of a rotating diatom. This paper presents the low-energy (low-temperature) state-selected partial and mean capture cross sections (rate coefficients) for the charge-quadrupole interaction that include the gyroscopic effect (decoupling of intrinsic angular momentum from the collision axis), quantum correction for the diatom rotation, and the correction for the charge-induced dipole interaction. These results complement recent studies on the gyroscopic effect in the quantum regime of diatom-ion capture (Dashevskaya, E. I.; Litvin, I.; Nikitin, E. E.; Troe, J. J. Chem. Phys. 2004, 120, 9989-9997).

Mössbauer study of Brazilian soapstone

NASA Astrophysics Data System (ADS)

Gonçalves, M. A.; de Jesus Filho, M. F.; Garg, V. K.

1991-11-01

Steatite mineral rocks, soapstone, have been studied by X-ray diffraction, optical microscopic analysis (modal analysis), electron probe micro analysis and Mössbauer spectroscopy for characterization, mineral percentages and chemical composition. Mössbauer spectra show both, magnetic interactions corresponding to magnetite and doublets corresponding to talc. chlorite, dolomite and tremolite. The temperature dependence of the quadrupole splitting in dolomite has been explained in terms of crystal field interaction.

UHB Engine Fan Broadband Noise Reduction Study

NASA Technical Reports Server (NTRS)

Gliebe, Philip R.; Ho, Patrick Y.; Mani, Ramani

1995-01-01

A study has been completed to quantify the contribution of fan broadband noise to advanced high bypass turbofan engine system noise levels. The result suggests that reducing fan broadband noise can produce 3 to 4 EPNdB in engine system noise reduction, once the fan tones are eliminated. Further, in conjunction with the elimination of fan tones and an increase in bypass ratio, a potential reduction of 7 to 10 EPNdB in system noise can be achieved. In addition, an initial assessment of engine broadband noise source mechanisms has been made, concluding that the dominant source of fan broadband noise is the interaction of incident inlet boundary layer turbulence with the fan rotor. This source has two contributors, i.e., unsteady life dipole response and steady loading quadrupole response. The quadrupole contribution was found to be the most important component, suggesting that broadband noise reduction can be achieved by the reduction of steady loading field-turbulence field quadrupole interaction. Finally, for a controlled experimental quantification and verification, the study recommends that further broadband noise tests be done on a simulated engine rig, such as the GE Aircraft Engine Universal Propulsion Simulator, rather than testing on an engine statically in an outdoor arena The rig should be capable of generating forward and aft propagating fan noise, and it needs to be tested in a large freejet or a wind tunnel.

UHB engine fan broadband noise reduction study

NASA Astrophysics Data System (ADS)

Gliebe, Philip R.; Ho, Patrick Y.; Mani, Ramani

1995-06-01

A study has been completed to quantify the contribution of fan broadband noise to advanced high bypass turbofan engine system noise levels. The result suggests that reducing fan broadband noise can produce 3 to 4 EPNdB in engine system noise reduction, once the fan tones are eliminated. Further, in conjunction with the elimination of fan tones and an increase in bypass ratio, a potential reduction of 7 to 10 EPNdB in system noise can be achieved. In addition, an initial assessment of engine broadband noise source mechanisms has been made, concluding that the dominant source of fan broadband noise is the interaction of incident inlet boundary layer turbulence with the fan rotor. This source has two contributors, i.e., unsteady life dipole response and steady loading quadrupole response. The quadrupole contribution was found to be the most important component, suggesting that broadband noise reduction can be achieved by the reduction of steady loading field-turbulence field quadrupole interaction. Finally, for a controlled experimental quantification and verification, the study recommends that further broadband noise tests be done on a simulated engine rig, such as the GE Aircraft Engine Universal Propulsion Simulator, rather than testing on an engine statically in an outdoor arena The rig should be capable of generating forward and aft propagating fan noise, and it needs to be tested in a large freejet or a wind tunnel.

Nuclear magnetic and nuclear quadrupole resonance parameters of β-carboline derivatives calculated using density functional theory

NASA Astrophysics Data System (ADS)

Ahmadinejad, Neda; Tari, Mostafa Talebi

2017-04-01

A density functional theory (DFT) calculations using B3LYP/6-311++G( d,p) method were carried out to investigate the relative stability of the molecules of β-carboline derivatives such as harmaline, harmine, harmalol, harmane and norharmane. Calculated nuclear quadrupole resonance (NQR) parameters were used to determine the 14N nuclear quadrupole coupling constant χ, asymmetry parameter η and EFG tensor ( q zz ). For better understanding of the electronic structure of β-carboline derivatives, natural bond orbital (NBO) analysis, isotropic and anisotropic NMR chemical shieldings were calculated for 14N nuclei using GIAO method for the optimized structures. The NBO analysis shows that pyrrole ring nitrogen (N9) atom has greater tendency than pyridine ring nitrogen (N2) atom to participate in resonance interactions and aromaticity development in the all of these structures. The NMR and NQR parameters were studied in order to find the correlations between electronic structure and the structural stability of the studied molecules.

Spontaneous structural distortion of the metallic Shastry-Sutherland system Dy B4 by quadrupole-spin-lattice coupling

NASA Astrophysics Data System (ADS)

Sim, Hasung; Lee, Seongsu; Hong, Kun-Pyo; Jeong, Jaehong; Zhang, J. R.; Kamiyama, T.; Adroja, D. T.; Murray, C. A.; Thompson, S. P.; Iga, F.; Ji, S.; Khomskii, D.; Park, Je-Geun

2016-11-01

Dy B4 has a two-dimensional Shastry-Sutherland (Sh-S) lattice with strong Ising character of the Dy ions. Despite the intrinsic frustrations, it undergoes two successive transitions: a magnetic ordering at TN=20 K and a quadrupole ordering at TQ=12.5 K . From high-resolution neutron and synchrotron x-ray powder diffraction studies, we have obtained full structural information on this material in all phases and demonstrate that structural modifications occurring at quadrupolar transition lead to the lifting of frustrations inherent in the Sh-S model. Our paper thus provides a complete experimental picture of how the intrinsic frustration of the Sh-S lattice can be lifted by the coupling to quadrupole moments. We show that two other factors, i.e., strong spin-orbit coupling and long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in metallic Dy B4 , play an important role in this behavior.

Nuclear quadrupole resonance lineshape analysis for different motional models: Stochastic Liouville approach

NASA Astrophysics Data System (ADS)

Kruk, D.; Earle, K. A.; Mielczarek, A.; Kubica, A.; Milewska, A.; Moscicki, J.

2011-12-01

A general theory of lineshapes in nuclear quadrupole resonance (NQR), based on the stochastic Liouville equation, is presented. The description is valid for arbitrary motional conditions (particularly beyond the valid range of perturbation approaches) and interaction strengths. It can be applied to the computation of NQR spectra for any spin quantum number and for any applied magnetic field. The treatment presented here is an adaptation of the "Swedish slow motion theory," [T. Nilsson and J. Kowalewski, J. Magn. Reson. 146, 345 (2000), 10.1006/jmre.2000.2125] originally formulated for paramagnetic systems, to NQR spectral analysis. The description is formulated for simple (Brownian) diffusion, free diffusion, and jump diffusion models. The two latter models account for molecular cooperativity effects in dense systems (such as liquids of high viscosity or molecular glasses). The sensitivity of NQR slow motion spectra to the mechanism of the motional processes modulating the nuclear quadrupole interaction is discussed.

Detection of Quadrupole Interactions by Muon Level Crossing Resonance

NASA Astrophysics Data System (ADS)

Cox, S. F. J.

1992-02-01

The positive muon proves to be a very versatile and sensitive magnetic resonance probe: implanted in virtually any material its polarisation may be monitored via the asymmetry in its radioactive decay, giving information on the sites occupied by the muon in lattices or molecules, and the local fields experienced at these sites. The scope of these experiments has been greatly extended by the development of a technique of cross relaxation or level crossing resonance which allows quadrupole splittings on nuclei adjacent to the muon to be measured. The principles of the technique and the conditions necessary for detection of the spectra are described, together with a number of applications. Of especial interest is the manner in which muons mimic the behaviour of protons in matter. In metal lattices, for instance, muons invariably adopt the same interstitial sites as do protons in the dilute hydride phases, so that they can be used to study problems of localisation and diffusion common to those of hydrogen in metals. Studies of the muon level crossing resonance in copper have given valuable information on the crystallographic site, electronic structure and low temperature mobility of the interstitial defect. In semiconductors, muons are expected to trap at other impurities - notably acceptors - in processes analogous to the passivation of dopants by hydrogen. Muon resonance offers the exciting prospect of spectroscopic study of these passivation complexes. In molecular materials, substitution of protons by muons can be thought of rather like deuteration. Muons implanted in ice produce a significant change in the quadrupole coupling constant of adjacent 17O nuclei which may be traced to the effects of the large muon zero point energy; the resonance spectrum also exhibits temperature dependent features which may be informative on the nature and lifetime of defects in the ice structure. Muon level crossing resonance has already been studied in an oxide superconductor and this relatively young field is now wide open for quadrupole interaction studies in other materials, using a variety of nuclei.

Wetting, meniscus structure, and capillary interactions of microspheres bound to a cylindrical liquid interface.

PubMed

Kim, Paul Y; Dinsmore, Anthony D; Hoagland, David A; Russell, Thomas P

2018-03-14

Wetting, meniscus structure, and capillary interactions for polystyrene microspheres deposited on constant curvature cylindrical liquid interfaces, constructed from nonvolatile ionic or oligomeric liquids, were studied by optical interferometry and optical microscopy. The liquid interface curvature resulted from the preferential wetting of finite width lines patterned onto planar silicon substrates. Key variables included sphere diameter, nominal (or average) contact angle, and deviatoric interfacial curvature. Menisci adopted the quadrupolar symmetry anticipated by theory, with interfacial deformation closely following predicted dependences on sphere diameter and nominal contact angle. Unexpectedly, the contact angle was not constant locally around the contact line, the nominal contact angle varied among seemingly identical spheres, and the maximum interface deviation did not follow the predicted dependence on deviatoric interfacial curvature. Instead, this deviation was up to an order-of-magnitude larger than predicted. Trajectories of neighboring microspheres visually manifested quadrupole-quadrupole interactions, eventually producing square sphere packings that foreshadow interfacial assembly as a potential route to hierarchical 2D particle structures.

Influence of the Pauli exclusion principle and the polarization of nuclei on the nuclear part of the interaction potential in the 40Ca +40Ca system

NASA Astrophysics Data System (ADS)

Nesterov, V. O.

2018-06-01

In the framework of the energy density method with the use of the wave function of the two-center shell model, the influence of the simultaneous account for the Pauli exclusion principle and the monopole and quadrupole polarizations of nuclei on the nuclear part of the potential of their interaction by the example of the 40Ca +40Ca system is considered. The calculations performed in the framework of the adiabatic approximation show that the consideration of the Pauli exclusion principle and the polarization of nuclei, especially the quadrupole one, essentially affects the nucleus-nucleus interaction potential.

Effect of the magnetic dipole interaction on a spin-1 system

NASA Astrophysics Data System (ADS)

Hu, Fangqi; Jia, Wei; Zhao, Qing

2018-05-01

We consider a hybrid system composed of a spin-1 triplet coupled to a nuclear spin. We study the effect of the axisymmetric and the quadrupole term of the magnetic dipole interaction between the two electrons forming the triplet on the energy spectrum in a static magnetic field. The energy spectrum obtained by directly diagonalizing the Hamiltonian of the system shows that these two terms not only remove the special crossings that appear in the absence of the magnetic dipole interaction, but also produce new (avoided) crossings by lifting the relevant levels. Specially, the gaps between the avoided crossing levels increase with the strength of the quadrupole term. In order to accurately illustrate these effects, we present the results for the discriminant and von Neumann entropy of one electron interacting with the rest of the whole system. Finally, by numerically solving the time-dependent Schrödinger equations of the system, we discover that the polarization oscillation of electron and nuclear spin is in-phase and the total average longitudinal spin is not conserved at location of avoided crossing, but the two results are opposite beyond that.

The covalent interaction between dihydrogen and gold: A rotational spectroscopic study of H2-AuCl

NASA Astrophysics Data System (ADS)

Obenchain, Daniel A.; Frank, Derek S.; Grubbs, G. S.; Pickett, Herbert M.; Novick, Stewart E.

2017-05-01

The pure rotational transitions of H2-AuCl have been measured using a pulsed-jet cavity Fourier transform microwave spectrometer equipped with a laser ablation source. The structure was found to be T-shaped, with the H-H bond interacting with the gold atom. Both 35Cl and 37Cl isotopologues have been measured for both ortho and para states of H2. Rotational constants, quartic centrifugal distortion constants, and nuclear quadrupole coupling constants for gold and chlorine have been determined. The use of the nuclear spin-nuclear spin interaction terms Daa, Dbb, and Dcc for H2 were required to fit the ortho state of hydrogen, as well as a nuclear-spin rotation constant Caa. The values of the nuclear quadrupole coupling constant of gold are χa a=-817.9929 (35 ) MHz, χb b=504.0 (27 ) MHz, and χc c=314.0 (27 ) . This is large compared to the eQq of AuCl, 9.63 312(13) MHz, which indicates a strong, covalent interaction between gold and dihydrogen.

Nanofocusing of structured light for quadrupolar light-matter interactions.

PubMed

Sakai, Kyosuke; Yamamoto, Takeaki; Sasaki, Keiji

2018-05-17

The spatial structure of an electromagnetic field can determine the characteristics of light-matter interactions. A strong gradient of light in the near field can excite dipole-forbidden atomic transitions, e.g., electric quadrupole transitions, which are rarely observed under plane-wave far-field illumination. Structured light with a higher-order orbital angular momentum state may also modulate the selection rules in which an atom can absorb two quanta of angular momentum: one from the spin and another from the spatial structure of the beam. Here, we numerically demonstrate a strong focusing of structured light with a higher-order orbital angular momentum state in the near field. A quadrupole field was confined within a gap region of several tens of nanometres in a plasmonic tetramer structure. A plasmonic crystal surrounding the tetramer structure provides a robust antenna effect, where the incident structured light can be strongly coupled to the quadrupole field in the gap region with a larger alignment tolerance. The proposed system is expected to provide a platform for light-matter interactions with strong multipolar effects.

Compensation of orbit distortion due to quadrupole motion using feed-forward control at KEK ATF

NASA Astrophysics Data System (ADS)

Bett, D. R.; Charrondière, C.; Patecki, M.; Pfingstner, J.; Schulte, D.; Tomás, R.; Jeremie, A.; Kubo, K.; Kuroda, S.; Naito, T.; Okugi, T.; Tauchi, T.; Terunuma, N.; Burrows, P. N.; Christian, G. B.; Perry, C.

2018-07-01

The high luminosity requirement for a future linear collider sets a demanding limit on the beam quality at the Interaction Point (IP). One potential source of luminosity loss is the motion of the ground itself. The resulting misalignments of the quadrupole magnets cause distortions to the beam orbit and hence an increase in the beam emittance. This paper describes a technique for compensating this orbit distortion by using seismometers to monitor the misalignment of the quadrupole magnets in real-time. The first demonstration of the technique was achieved at the Accelerator Test Facility (ATF) at KEK in Japan. The feed-forward system consisted of a seismometer-based quadrupole motion monitoring system, an FPGA-based feed-forward processor and a stripline kicker plus associated electronics. Through the application of a kick calculated from the position of a single quadruple, the system was able to remove about 80% of the component of the beam jitter that was correlated to the motion of the quadrupole. As a significant fraction of the orbit jitter in the ATF final focus is due to sources other than quadrupole misalignment, this amounted to an approximately 15% reduction in the absolute beam jitter.

Nuclear deformation in the laboratory frame

NASA Astrophysics Data System (ADS)

Gilbreth, C. N.; Alhassid, Y.; Bertsch, G. F.

2018-01-01

We develop a formalism for calculating the distribution of the axial quadrupole operator in the laboratory frame within the rotationally invariant framework of the configuration-interaction shell model. The calculation is carried out using a finite-temperature auxiliary-field quantum Monte Carlo method. We apply this formalism to isotope chains of even-mass samarium and neodymium nuclei and show that the quadrupole distribution provides a model-independent signature of nuclear deformation. Two technical advances are described that greatly facilitate the calculations. The first is to exploit the rotational invariance of the underlying Hamiltonian to reduce the statistical fluctuations in the Monte Carlo calculations. The second is to determine quadruple invariants from the distribution of the axial quadrupole operator in the laboratory frame. This allows us to extract effective values of the intrinsic quadrupole shape parameters without invoking an intrinsic frame or a mean-field approximation.

A Study of the Momentum Distributions of the Final State Hadrons in Neutrino - Nucleus Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swider, Gregory M.

1980-12-01

In an experiment using the Fermilab 15-foot Bubble Chamber/Two-Plane EMI with a 47 percent (atomic) neon-in-hydrogen fill exposed to the quadrupole-triplet neutrino beam, we have identified some 9600 neutrino charged-current events....

Wave functions of the Q .Q interaction in terms of unitary 9-j coefficients

NASA Astrophysics Data System (ADS)

Zamick, Larry; Harper, Matthew

2015-03-01

We obtain wave functions for two protons and two neutrons in the g9 /2 shell expressed as column vectors with amplitudes D (Jp,Jn) . When we use a quadrupole-quadrupole interaction (Q .Q ) we get, in many cases, a very strong overlap with wave functions given by a single set of unitary 9-j coefficients—U 9 j =<(jj ) 2 j(jjJB|(jj ) Jp(jj ) Jn) I> . Here JB=9 for even I T =0 states. For both even and odd T =1 states we take JB equal to 8 whilst for odd I ,T =0 we take JB to be 7. We compare the Q .Q results with those of a more realistic interaction.

Theory of electronic structures and nuclear quadrupole interactions in molecular solids and semiconductor surfaces

NASA Astrophysics Data System (ADS)

Pati, Ranjit

We have investigated, using the Hartree-Fock Roothaan variational procedure, the electronic structures and associated nuclear quadrupole interactions (NQI) for the molecular solids, RDX (C3H6N6O6),/ /beta- HMX(C4H8N8O8), Cocaine (C17H21NO4), Cocaine Hydrochloride (C17H21NO4HCl) and Heroin (C21H23NO5) and for the (111) surface of silicon with adsorbed radioactive 111In atom and negative cadmium ion containing the excited nucleus 111Cd/* resulting from electron capture by lllIn. Our investigations indicate that for the ring 14N NQI parameters in RDX and β-HMX there is very good agreement between theory and experiment. For the peripheral 14N nuclei in NO2 groups, while the calculated electronic structures do explain the much weaker quadrupole coupling constants for these nuclei relative to the ring 14N nuclei, there are significant differences between theory and experiment. The influence of intermolecular interactions between adjacent molecules in the solid is invoked as a possible source for these differences. For the controlled substances, Cocaine and Heroin, again very good agreement is obtained between theory and experiment. For Cocaine Hydrochloride theory is able to explain the much smaller observed 14N nuclear quadrupole resonance frequency as compared to pure Cocaine. However there are significant differences between theory and experiment for the 14N and 35Cl quadrupole resonance frequencies. The influence of intermolecular interactions is one of the factors suggested to explain the difference. For the silicon (111) surface, the observed 111Cd/* NQI parameters, with the cadmium nucleus assumed to be located at the same site as the 111In nucleus from which it is generated, can be successfully explained by theory with the indium atom located at the two distinct sites available with the DAS model for the 7 x 7 reconstructed (111) surface. Some quantitative differences still remain, one of the main factor suggested for their explanation being a need for a thorough analysis of relaxation effects in the positions of silicon atoms associated with the presence of the indium atom. Applications of the Hartree-Fock Cluster theory to other related systems is suggested to subject the DAS model to additional tests at the microscopic level as in the system studied in the present thesis. (Abstract shortened by UMI.)

Summary of Test Results of MQXFS1 - The First Short Model 150 mm Aperture $$Nb_3Sn$$ Quadrupole for the High-Luminosity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoynev, S.; et al.

The development ofmore » $$Nb_3Sn$$ quadrupole magnets for the High-Luminosity LHC upgrade is a joint venture between the US LHC Accelerator Research Program (LARP)* and CERN with the goal of fabricating large aperture quadrupoles for the LHC in-teraction regions (IR). The inner triplet (low-β) NbTi quadrupoles in the IR will be replaced by the stronger Nb3Sn magnets boosting the LHC program of having 10-fold increase in integrated luminos-ity after the foreseen upgrades. Previously LARP conducted suc-cessful tests of short and long models with up to 120 mm aperture. The first short 150 mm aperture quadrupole model MQXFS1 was assembled with coils fabricated by both CERN and LARP. The magnet demonstrated strong performance at the Fermilab’s verti-cal magnet test facility reaching the LHC operating limits. This paper reports the latest results from MQXFS1 tests with changed pre-stress levels. The overall magnet performance, including quench training and memory, ramp rate and temperature depend-ence, is also summarized.« less

Phase transition in 2-d system of quadrupoles on square lattice with anisotropic field

NASA Astrophysics Data System (ADS)

Sallabi, A. K.; Alkhttab, M.

2014-12-01

Monte Carlo method is used to study a simple model of two-dimensional interacting quadrupoles on ionic square lattice with anisotropic strength provided by the ionic lattice. Order parameter, susceptibility and correlation function data, show that this system form an ordered structure with p(2×1) symmetry at low temperature. The p(2×1) structure undergoes an order-disorder phase transition into disordered (1×1) phase at 8.3K. The two-point correlation function show exponential dependence on distance both above and below the transition temperature. At Tc the two-point correlation function shows a power law dependence on distance, e.g. C(r) ~ 1η. The value of the exponent η at Tc shows small deviation from the Ising value and indicates that this system falls into the same universality class as the XY model with cubic anisotropy. This model can be applied to prototypical quadrupoles physisorbed systems as N2 on NaCl(100).

Octupole deformations in high-K isomeric states of heavy and superheavy nuclei

NASA Astrophysics Data System (ADS)

Minkov, N.; Walker, P. M.

2016-01-01

We study the effects of quadrupole-octupole deformations on the energy and magnetic properties of high-K isomeric states in even-even heavy and superheavy nuclei. The neutron two-quasiparticle (2qp) isomeric energies and magnetic dipole moments are calculated within a deformed shell model with the Bardeen-Cooper- Schrieffer (BCS) pairing interaction over a wide range of quadrupole and octupole deformations. We found that in most cases the magnetic moments exhibit a pronounced sensitivity to the octupole deformation, while the 2qp energies indicate regions of nuclei in which the presence of high-K isomeric states may be associated with the presence of octupole softness or even with octupole deformation. In the present work we also examine the influence of the BCS pairing strength on the energy of the blocked isomer configuration. We show that the formation of 2qp energy minima in the space of quadrupole-octupole and eventually higher multipolarity deformations is a subtle effect depending on nuclear pairing correlations.

Piriformospora indica Stimulates Root Metabolism of Arabidopsis thaliana.

PubMed

Strehmel, Nadine; Mönchgesang, Susann; Herklotz, Siska; Krüger, Sylvia; Ziegler, Jörg; Scheel, Dierk

2016-07-08

Piriformospora indica is a root-colonizing fungus, which interacts with a variety of plants including Arabidopsis thaliana. This interaction has been considered as mutualistic leading to growth promotion of the host. So far, only indolic glucosinolates and phytohormones have been identified as key players. In a comprehensive non-targeted metabolite profiling study, we analyzed Arabidopsis thaliana's roots, root exudates, and leaves of inoculated and non-inoculated plants by ultra performance liquid chromatography/electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC/(ESI)-QTOFMS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS), and identified further biomarkers. Among them, the concentration of nucleosides, dipeptides, oligolignols, and glucosinolate degradation products was affected in the exudates. In the root profiles, nearly all metabolite levels increased upon co-cultivation, like carbohydrates, organic acids, amino acids, glucosinolates, oligolignols, and flavonoids. In the leaf profiles, we detected by far less significant changes. We only observed an increased concentration of organic acids, carbohydrates, ascorbate, glucosinolates and hydroxycinnamic acids, and a decreased concentration of nitrogen-rich amino acids in inoculated plants. These findings contribute to the understanding of symbiotic interactions between plant roots and fungi of the order of Sebacinales and are a valid source for follow-up mechanistic studies, because these symbioses are particular and clearly different from interactions of roots with mycorrhizal fungi or dark septate endophytes.

HYPERFINE STRUCTURES AND NUCLEAR MOMENTS OF Lu$sup 176$m, Br$sup 80$, Br$sup 80$m, AND I$sup 132$ (thesis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, M.B.

1962-09-01

The method of atomic-beam radiofrequency spectroscopy was used to determine some nuclear and atomic properties of Lu/sup 176m/, Br/sup 80/, Br/sup 80m/, and I/sup 132/. Hyperfine structure me asurements were raade to determine the magnetic dipole interaction constants and the electric quadrupole interaction constants of all these isotopes. Also the nuclear spin and the electronic g/sub J/ factor were measured for Lu/sup 176m/, and the nuclear magnetic dipole moments and the electric quadrupole moments for the isotopes were calculated. All results are listed. 62 references. (auth)

The quadrupole moments of some even–even nuclei around the mass of A ~ 80: {sup 68−80}Ge on the neighborhood of {sup 76−84}Kr and {sup 76−84}Se isotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoruk, Abdulkadir, E-mail: yorukabdulkadir@hotmail.com; Turkan, Nureddin, E-mail: nureddin.turkan@medeniyet.edu.tr

2016-09-15

We have carried out the calculation of the quadrupole moments Q(2{sub 1}{sup +}) and electromagnetic transition rates B(E2) of some levels within the framework of the interacting boson model for even-mass Ge nuclei. The presented predictions of the quadrupole moments and B(E2) ratios for Ge nuclei are compared with the results of some previous experimental and theoretical ones along with those of the neighboring Kr and Se isotopes and then it was seen that they agree well with the previous experimental and theoretical ones.

Decoupling correction system in RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trbojevic, D.; Tepikian, S.; Peggs, S.

A global linear decoupling in the Relativistic Heavy Ion Collider (RHIC) is going to be performed with the three families of skew quadrupoles. The operating horizontal and vertical betatron tunes in the RHIC will be separated by one unit [nu][sub x]=28.19 and [nu][sub y]=29.18. The linear coupling is corrected by minimizing the tune splitting [Delta][nu]-the off diagonal matrix [bold m] (defined by Edwards and Teng). The skew quadrupole correction system is located close to each of the six interaction regions. A detail study of the system is presented by the use of the TEAPOT accelerator physics code. [copyright] 1994 Americanmore » Institute of Physics« less

Atomistic simulations of CO2 and N2 within cage-type silica zeolites.

PubMed

Madison, Lindsey; Heitzer, Henry; Russell, Colin; Kohen, Daniela

2011-03-01

The behavior of CO(2) and N(2), both as single components and as binary mixtures, in two cage-type silica zeolites was studied using atomistic simulations. The zeolites considered, ITQ-3 and paradigm cage-type zeolite ZK4 (the all-silica analog of LTA), were chosen so that the principles illustrated can be generalized to other adsorbent/adsorbate systems with similar topology and types of interactions. N(2) was chosen both because of the potential uses of N(2)/CO(2) separations and because it differs from CO(2) most significantly in the magnitude of its Coulombic interactions with zeolites. Despite similarities between N(2) and CO(2) diffusion in other materials, we show here that the diffusion of CO(2) within cage-type zeolites is dominated by an energy barrier to diffusion located at the entrance to the narrow channels connecting larger cages. This barrier originates in Coulombic interactions between zeolites and CO(2)'s quadrupole and results in well-defined orientations for the diffusing molecules. Furthermore, CO(2)'s favorable electrostatic interactions with the zeolite framework result in preferential binding in the windows between cages. N(2)'s behavior, in contrast, is more consistent with that of molecules previously studied. Our analysis suggests that CO(2)'s behavior might be common for adsorbates with quadrupoles that interact strongly with a material that has narrow windows between cages.

Quench Protection of SC Quadrupole Magnets

NASA Astrophysics Data System (ADS)

Feher, S.; Bossert, R.; Dimarco, J.; Mitchell, D.; Lamm, M. J.; Limon, P. J.; Mazur, P.; Nobrega, F.; Orris, D.; Ozelis, J. P.; Strait, J. B.; Tompkins, J. C.; Zlobin, A. V.; McInturff, A. D.

1997-05-01

The energy stored in a superconducting accelerator magnet is dissipated after a quench in the coil normal zones, heating the coil and generating a turn to turn and coil to ground voltage drop. Quench heaters are used to protect the superconducting magnet by greatly increasing the coil normal zone thus allowing the energy to be dissipated over a larger conductor volume. Such heaters will be required for the Fermilab/LBNL design of the high gradient quads (HGQ) designed for the LHC interaction regions. As a first step, heaters were installed and tested in several Tevatron low-β superconducting quadrupoles. Experimental studies in normal and superfluid helium are presented which show the heater-induced quench response as a function of magnet excitation current, magnet temperature and peak heater energy density.

Model for the dynamics of two interacting axisymmetric spherical bubbles undergoing small shape oscillations

PubMed Central

Kurihara, Eru; Hay, Todd A.; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F.

2011-01-01

Interaction between acoustically driven or laser-generated bubbles causes the bubble surfaces to deform. Dynamical equations describing the motion of two translating, nominally spherical bubbles undergoing small shape oscillations in a viscous liquid are derived using Lagrangian mechanics. Deformation of the bubble surfaces is taken into account by including quadrupole and octupole perturbations in the spherical-harmonic expansion of the boundary conditions on the bubbles. Quadratic terms in the quadrupole and octupole amplitudes are retained, and surface tension and shear viscosity are included in a consistent manner. A set of eight coupled second-order ordinary differential equations is obtained. Simulation results, obtained by numerical integration of the model equations, exhibit qualitative agreement with experimental observations by predicting the formation of liquid jets. Simulations also suggest that bubble-bubble interactions act to enhance surface mode instability. PMID:22088009

Transition Quadrupole Collectivity of Ar and Cl Isotopes Near N = 28

NASA Astrophysics Data System (ADS)

Winkler, R.; Gade, A.; Brown, B. A.; Glasmacher, T.; Baugher, T. R.; Bazin, D.; Grinyer, G. F.; McDaniel, S.; Meharchand, R.; Ratkiewicz, A.; Stroberg, R.; Walsh, K.; Weisshaar, D.; Riley, L. A.

2010-11-01

Measurements of the reduced quadrupole transition strengths, B(E2; 0^+ -> 2^+) of even-even nuclei guide our understanding of the onset collectivity with the addition of valence nucleons beyond the known shell structure of the atomic nucleus. The study of the quadrupole collectivity of neutron-rich ^47,48Ar and ^45,46Cl via relativistic Coulomb excitation was performed using a cocktail of exotic beams produced by the coupled cyclotron facility at NSCL. Particle tracking and identification was achieved on an event-by-event basis using the S800 high-resolution spectrograph. Gamma rays emitted at the reaction target position in coincidence with the detection of scattered particles were observed with the segmented high-purity Germanium array SeGA, a vital tool for the Doppler reconstruction of each observed event. Results from the present work provide insight into the persistence of the N = 28 shell closure and will be discussed in the framework of the shell model utilizing modern effective interactions in the sdpf valence space. This work is supported by the National Science Foundation under Grants No. PHY-0606007 and PHY-0758099.

Whither HFI/NQI?

NASA Astrophysics Data System (ADS)

Bharuth-Ram, K.

2013-05-01

A brief review is given of the Hyperfine Interactions Conference series and, in particular, of the Joint meetings of the Hyperfine Interactions and Nuclear Quadrupole Interaction (HFI/NQI) Conferences, with respect to number of participants, contributed papers and participant countries. Trends are traced and recommendations are offered to attract a wider participation at future HFI/NQI conferences.

The effective way

NASA Astrophysics Data System (ADS)

Fruchart, Michel; Vitelli, Vincenzo

2018-03-01

A theoretical framework for the design of so-called perturbative metamaterials, based on weakly interacting unit cells, has led to the experimental demonstration of a quadrupole topological insulator.

Theoretical study of the hyperfine-interaction constants and the isotope-shift factors for the 3 s21S0-3 s 3 p 3,1P1o transitions in Al+

NASA Astrophysics Data System (ADS)

Zhang, Tingxian; Xie, Luyou; Li, Jiguang; Lu, Zehuang

2017-07-01

We calculated the magnetic dipole and the electric quadrupole hyperfine interaction constants of 3 s 3 p 3,1P1o states and the isotope shift, including mass and field shift, factors for transitions from these two states to the ground state 3 s 2 1S0 in Al+ ions using the multiconfiguration Dirac-Hartree-Fock method. The effects of the electron correlations and the Breit interaction on these physical quantities were investigated in detail based on the active space approach. It is found that the core-core and the higher order correlations are considerable for evaluating the uncertainties of the atomic parameters concerned. The uncertainties of the hyperfine interaction constants in this work are less than 1.6%. Although the isotope shift factors are highly sensitive to the electron correlations, reasonable uncertainties were obtained by exploring the effects of the electron correlations. Moreover, we found that the relativistic nuclear recoil corrections to the mass shift factors are very small and insensitive to the electron correlations for Al+. These atomic parameters present in this work are valuable for extracting the nuclear electric quadrupole moments and the mean-square charge radii of Al isotopes.

Quadrupole collectivity beyond N = 50 in neutron- rich Se and Kr isotopes

NASA Astrophysics Data System (ADS)

Elman, Brandon; Gade, A.; Barofsky, D.; Bender, P. C.; Bowry, M.; Hjorth-Jensen, M.; Kemper, K. W.; Lipschutz, S.; Lunderberg, E.; Sachmpazidi, N.; Terpstra, N.; Walters, W. B.; Weisshaar, D.; Westerberg, A.; Williams, S. J.; Wimmer, K.

2017-09-01

We will present results on measuring the B (E 2 ;01+ ->2n+) strength for the neutron-rich 88,90Kr and 86Se isotopes from intermediate-energy Coulomb excitation. The electric quadrupole transition strengths to the first 2+ state complete, with considerably improved uncertainties, the evolution of quadrupole collectivity in the Kr and Se isotopes approaching N = 60 , for which 90Kr and 86Se had previously been the most uncertain. We also report significant excitation strength to several higher lying 2+ states in the krypton isotopes. The results confirm shell model calculations in the π (fpg) - ν (sdg) shell with only a minimally tuned shell model setup that is based on a nucleon-nucleon interaction derived from effective field theory with effective charges adjusted to 86Kr.

Resonance energy transfer: when a dipole fails.

PubMed

Andrews, David L; Leeder, Jamie M

2009-05-14

The Coulombic coupling of electric dipole (E1) transition moments is the most commonly studied and widely operative mechanism for energy migration in multichromophore systems. However a significant number of exceptions exist, in which donor decay and/or acceptor excitation processes are E1-forbidden. The alternative transfer mechanisms that can apply in such cases include roles for higher multipole transitions, exciton- or phonon-assisted interactions, and non-Coulombic interactions based on electron exchange. A quantum electrodynamical formulation provides a rigorous basis to assess the first of these, specifically addressing the relative significance of higher multipole contributions to the process of energy transfer in donor-acceptor systems where electric dipole transitions are precluded by symmetry. Working within the near-zone limit, where donor-acceptor separations are small in comparison to the chromophore scale, the analysis highlights the contributions of both electric quadrupole-electric quadrupole (E2-E2) coupling and the seldom considered second-order electric dipole-electric dipole (E1(2)-E1(2)) coupling. For both forms of interaction, experimentally meaningful rate equations are secured by the use of orientational averaging, and the mechanisms are analyzed with reference to systems in which E1-forbidden transitions are commonly reported.

Electrodynamical forbiddance of a strong quadrupole interaction in surface enhanced optical processes. Experimental confirmation of the existence in fullerene C{sub 60}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polubotko, A. M., E-mail: alex.marina@mail.ioffe.ru; Chelibanov, V. P., E-mail: Chelibanov@gmail.com

2017-02-15

It is demonstrated that in the SERS and SEIRA spectra of the fullerene C{sub 60}, the lines, which are forbidden in usual Raman and IR spectra and allowed in SERS and SEIRA, are absent. In addition the enhancement SERS coefficient in a single molecule detection regime is ~10{sup 8} instead of the value 10{sup 14}–10{sup 15}, characteristic for this phenomenon. These results are explained by the existence of so-called electrodynamical forbiddance of a strong quadrupole light-molecule interaction, which arises because of belonging of C{sup 60} to the icosahedral symmetry group and due to the electrodynamical law divE = 0.

Control of Screening of a Charged Particle in Electrolytic Aqueous Paul Trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jae Hyun nmn; Krstic, Predrag S

2011-01-01

Individual charged particles could be trapped and confined in the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Applying molecular dynamics simulation we show that the quadrupole field has a different affects at the electrolyte ions and at muchmore » heavier charged particle, effectively eliminating the screening effect and reinstating the electrophoretic confinement.« less

Control Of Screening Of A Charged Particle In Electrolytic Aqueous Paul Trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jae Hyun; Krstic, Predrag S.

2011-06-01

Individual charged particles could be trapped and confined by the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Applying molecular dynamics simulation we show that the quadrupole field has a different effect at the electrolyte ions and at muchmore » heavier charged particle, effectively eliminating the screening by electrolyte ions and reinstating the electrophoretic confinement.« less

Calculation of yrast spectra in the doubly even cadmium isotopes

NASA Astrophysics Data System (ADS)

Khosa, S. K.; Mattu, P. K.

1991-02-01

The observed systematics of the low-lying states in 98-110Cd nuclei and the high-spin yrast spectra with Jπmax<=14+ are examined by carrying out Hartree-Fock-Bogoliubov calculations employing a pairing-plus-quadrupole-quadrupole effective interaction operating in a reasonably large valence space outside an inert 80Zr core. Our calculations reveal that the systematics of the low-lying yrast states in 98-110Cd are intricately linked with the deformation producing tendency of the n-p interaction when operating between spin-orbit-partner (SOP) orbits. Our results indicate that such systematics depend crucially on the simultaneous increase of relative occupation probabilities of the (d5/2)-proton and (d3/2)-neutron orbits in the 98-100Cd isotopes.

Higher-order electric multipole contributions to retarded non-additive three-body dispersion interaction energies between atoms: Equilateral triangle and collinear configurations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salam, A., E-mail: salama@wfu.edu

2013-12-28

The theory of molecular quantum electrodynamics (QED) is used to calculate higher electric multipole contributions to the dispersion energy shift between three atoms or molecules arranged in a straight line or in an equilateral triangle configuration. As in two-body potentials, three-body dispersion interactions are viewed in the QED formalism to arise from exchange of virtual photons between coupled pairs of particles. By employing an interaction Hamiltonian that is quadratic in the electric displacement field means that third-order perturbation theory can be used to yield the energy shift for a particular combination of electric multipole polarizable species, with only six time-orderedmore » diagrams needing to be summed over. Specific potentials evaluated include dipole-dipole-quadrupole (DDQ), dipole-quadrupole-quadrupole (DQQ), and dipole-dipole-octupole (DDO) terms. For the geometries of interest, near-zone limiting forms are found to exhibit an R{sup −11} dependence on separation distance for the DDQ interaction, and an R{sup −13} behaviour for DQQ and DDO shifts, agreeing with an earlier semi-classical computation. Retardation weakens the potential in each case by R{sup −1} in the far-zone. It is found that by decomposing the octupole moment into its irreducible components of weights-1 and -3 that the former contribution to the DDO potential may be taken to be a higher-order correction to the leading triple dipole energy shift.« less

Electron configuration and hydrogen-bonding pattern in several thymine and uracil analogues studied by 1H-14N NQDR and DFT/QTAIM.

PubMed

Seliger, Janez; Žagar, Veselko; Latosińska, Magdalena; Latosińska, Jolanta Natalia

2012-08-02

Some thio- and aza-derivatives of natural nucleobases uracil and thymine: 2-thiouracil, 4-thiouracil, 6-methyl-2-thiouracil, 6-azauracil, and 6-aza-2-thiothymine have been studied experimentally in solid state by (1)H-(14)N NMR-NQR double resonance (NQDR) and theoretically by the Density Functional Theory (DFT)/Quantum Theory of Atoms in Molecules (QTAIM). The (14)N resonance frequencies have been measured at 173 and 295 K and assigned to particular nitrogen sites (-N═ and -NH-). The temperature factor has been found negligible. The changes in the molecular skeletons, electric charge distribution, intermolecular interactions pattern, and molecular aggregations caused by oxygen replacement with sulfur and carbon replacement with nitrogen are discussed in detail. Correlations between all the principal components of the (14)N quadrupole coupling tensor have been found helpful in the search for the experimental (14)N NQR frequencies, their assignment to a particular nitrogen positions and estimation of the strength of the inter- and intramolecular interactions. The variation in the NQR parameters have been mainly related to the variation in the population of π-electron orbital. For thiouracil derivatives a general trend is that the stronger the hydrogen bond is, the lower is the asymmetry parameter, while for thymine and 6-aza-2-thiotymine, the opposite relation holds. Differences in correlations of the principal components of the (14)N quadrupole coupling tensor at the amino and iminonitrogen positions in heterocyclic rings are discussed. The effect of C→H and C→N substitution at the amino nitrogen position and C→N substitution at the iminonitrogen position on the quadrupole coupling tensor is analyzed. This study also demonstrates the advantages of combining NQR and DFT/QTAIM to predict an unsolved crystalline structure of 4-thiouracil.

Ab initio correlated calculations of rare-gas dimer quadrupoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donchev, Alexander G.

2007-10-15

This paper reports ab initio calculations of rare gas (RG=Kr, Ar, Ne, and He) dimer quadrupoles at the second order of Moeller-Plesset perturbation theory (MP2). The study reveals the crucial role of the dispersion contribution to the RG{sub 2} quadrupole in the neighborhood of the equilibrium dimer separation. The magnitude of the dispersion quadrupole is found to be much larger than that predicted by the approximate model of Hunt. As a result, the total MP2 quadrupole moment is significantly smaller than was assumed in virtually all previous related studies. An analytical model for the distance dependence of the RG{sub 2}more » quadrupole is proposed. The model is based on the effective-electron approach of Jansen, but replaces the original Gaussian approximation to the electron density in an RG atom by an exponential one. The role of the nonadditive contribution in RG{sub 3} quadrupoles is discussed.« less

Photonuclear absorption cross sections

NASA Technical Reports Server (NTRS)

Norbury, John W.

1989-01-01

Neutron multiplicity in photonuclear reactions; invariance of classical electromagnetism; momentum transfer models in ion collisions; cosmic ray electromagnetic interactions; quadrupole excitations in nucleus-nucleus collisons and Y-89 interactions with relativistic nuclei; and the Weizsacker-Williams theory for nucleon emission via electromagnetic excitations in nucleus-nucleus collisions are discussed.

Chemical interaction between Lilium brownii and Rhizoma Anemarrhenae, the herbal constituents of Baihe Zhimu decoction, by liquid chromatography coupled to hybrid triple quadrupole linear ion trap mass spectrometer.

PubMed

Yang, Bo; Liu, Zhirui; Wang, Qian; Xia, Peiyuan

2018-03-01

During the course of decoction, the components of herbal formula interact with each other, such that chemical extraction characteristics are altered. The crude drugs, Lilium brownii (Baihe) and Rhizoma Anemarrhenae (Zhimu), are the herbal constituents of Baihe Zhimu decoction, a traditional herbal formula. To investigate the chemical interaction between Baihe and Zhimu when decocting together, eight marker components in Baihe Zhimu decoction were simultaneously characterized and quantified in one run by a hybrid triple quadrupole linear ion trap mass spectrometer in the multiple reactions monitoring-information dependent acquisition-enhanced product ion mode. The results showed that Zhimu significantly suppressed the extraction of phenolic glycosides (the components from Baihe) when co-decocting, and Baihe clearly suppressed the extraction of xanthones and steroidal saponins (the components from Zhimu). Overall, the presently developed method would be a preferred candidate for the investigation of the chemical interaction between herbal medicines. Copyright © 2017 John Wiley & Sons, Ltd.

Magnetic Measurements of the First Nb 3Sn Model Quadrupole (MQXFS) for the High-Luminosity LHC

DOE PAGES

DiMarco, J.; Ambrosio, G.; Chlachidze, G.; ...

2016-12-12

The US LHC Accelerator Research Program (LARP) and CERN are developing high-gradient Nb 3Sn magnets for the High Luminosity LHC interaction regions. Magnetic measurements of the first 1.5 m long, 150 mm aperture model quadrupole, MQXFS1, were performed during magnet assembly at LBNL, as well as during cryogenic testing at Fermilab’s Vertical Magnet Test Facility. This paper reports on the results of these magnetic characterization measurements, as well as on the performance of new probes developed for the tests.

New ortho-para conversion mechanism in dense solid hydrogen.

PubMed

Strzhemechny, M A; Hemley, R J

2000-12-25

Analysis of recent measurements of striking changes in the rate of ortho-para conversion of solid H(2) up to 58 GPa shows that the conversion mechanism must differ from that at ambient pressure. A new conversion mechanism is identified in which the emerging excitations are coupled to the converting molecules via electric quadrupole-quadrupole rather than nuclear spin-spin interactions. The latter only initiates conversion while the coupling enhancement associated with the new mechanism is ensured by high compression and a gap closing, with the conversion energy diminishing strongly with increasing pressure.

LHC interaction region quadrupole cryostat design

NASA Astrophysics Data System (ADS)

Nicol, T. H.; Darve, Ch.; Huang, Y.; Page, T. M.

2002-05-01

The cryostat of a Large Hadron Collider (LHC) Interaction Region (IR) quadrupole magnet consists of all components of the inner triplet except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, to house all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations, and must be able to be manufactured at low cost. The major components of the cryostat are the vacuum vessel, thermal shield, multi-layer insulation system, cryogenic piping, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course of their expected operating lifetime. This paper describes the current LHC IR inner triplet quadrupole magnet cryostats being designed and manufactured at Fermilab as part of the US-LHC collaboration, and includes discussions on the structural and thermal considerations involved in the development of each of the major systems.

Cd-binding to model membranes

NASA Astrophysics Data System (ADS)

Geszner, R.; Saibene, S.; Butz, T.; Lerf, A.

1990-08-01

The binding of Cd2+ to the model membranes Di-myristoyl L-α-phosphatidic acid (DMPA) and Di-myristoyl L-α-phosphatidylcholine (DMPC) was studied by time differential perturbed angular correlation (TDPAC) on111mCd, via its nuclear quadrupole interaction. Whereas Cd2+ does not bind to the neutral DMPC, it binds to charged DMPA up to a 0.8∶1 Cd/lipid ratio.

Fluorine Scan of Inhibitors of the Cysteine Protease Human Cathepsin L: Dipolar and Quadrupolar Effects in the π-Stacking of Fluorinated Phenyl Rings on Peptide Amide Bonds.

PubMed

Giroud, Maude; Harder, Michael; Kuhn, Bernd; Haap, Wolfgang; Trapp, Nils; Schweizer, W Bernd; Schirmeister, Tanja; Diederich, François

2016-05-19

The π-stacking of fluorinated benzene rings on protein backbone amide groups was investigated, using a dual approach comprising enzyme-ligand binding studies complemented by high-level quantum chemical calculations. In the experimental study, the phenyl substituent of triazine nitrile inhibitors of human cathepsin L (hCatL), which stacks onto the peptide amide bond Gly67-Gly68 at the entrance of the S3 pocket, was systematically fluorinated, and differences in inhibitory potency were measured in a fluorimetric assay. Binding affinity is influenced by lipophilicity (clog P), the dipole and quadrupole moments of the fluorinated rings, but also by additional interactions of the introduced fluorine atoms with the local environment of the pocket. Generally, the higher the degree of fluorination, the better the binding affinities. Gas phase calculations strongly support the contributions of the molecular quadrupole moments of the fluorinated phenyl rings to the π-stacking interaction with the peptide bond. These findings provide useful guidelines for enhancing π-stacking on protein amide fragments. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

27 Al MAS NMR Studies of HBEA Zeolite at Low to High Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Jian Zhi; Wan, Chuan; Vjunov, Aleksei

27Al single pulse (SP) MAS NMR spectra of HBEA zeolites with high Si/Al ratios of 71 and 75 were obtained at three magnetic field strengths of 7.05, 11.75 and 19.97 T. High field 27Al MAS NMR spectra acquired at 19.97 T show significantly improved spectral resolution, resulting in at least two well-resolved tetrahedral-Al NMR peaks. Based on the results obtained from 27Al MAS and MQMAS NMR acquired at 19.97 T, four different quadrupole peaks are used to deconvolute the 27Al SP MAS spectra acquired at vari-ous fields by using the same set of quadrupole coupling constants, asymmetric parameters and relativemore » integrated peak intensities for the tetrahedral Al peaks. The line shapes of individual peaks change from typical quadrupole line shape at low field to essentially symmetrical line shapes at high field. We demonstrate that for fully hydrated HBEA zeolites the effect of second order quadrupole interaction can be ignored and quantitative spectral analysis can be performed by directly fitting the high field spectra using mixed Gaussian/Lorentzian line shapes. Also, the analytical steps described in our work allow direct assignment of spectral intensity to individual Al tetrahedral sites (T-sites) of zeolite HBEA. Finally, the proposed concept is suggested generally applicable to other zeo-lite framework types, thus, allowing a direct probing of Al distributions by NMR spectroscopic methods in zeolites with high confi-dence.« less

Larp Nb3Sn Quadrupole Magnets for the Lhc Luminosity Upgrade

NASA Astrophysics Data System (ADS)

Ferracin, P.

2010-04-01

The US LHC Accelerator Research Program (LARP) is a collaboration between four US laboratories (BNL, FNAL, LBNL, and SLAC) aimed at contributing to the commissioning and operation of the LHC and conducting R&D on its luminosity upgrade. Within LARP, the Magnet Program's main goal is to demonstrate that Nb3Sn superconducting magnets are a viable option for a future upgrade of the LHC Interaction Regions. Over the past four years, LARP has successfully fabricated and tested several R&D magnets: 1) the subscale quadrupole magnet SQ, to perform technology studies with 300 mm long racetrack coils, 2) the technology quadrupole TQ, to investigate support structure behavior with 1 m long cos 2θ coils, and 3) the long racetrack magnet LR, to test 3.6 m long racetrack coils. The next milestone consists in the fabrication and test of the 3.7 m long quadrupole magnet LQ, with the goal of demonstrating that Nb3Sn technology is mature for use in high energy accelerators. After an overview of design features and test result of the LARP magnets fabricated so far, this paper focuses on the status of the fabrication of LQ: we describe the production of the 3.4 m long cos 2θ coils, and the of the qualification support structure. Finally, the status of the development of the next 1 m long model HQ, conceived to explore stress and field limits of Nb3Sn superconducting, magnets, is presented.

Mechanical Design Studies of the MQXF Long Model Quadrupole for the HiLumi LHC

DOE PAGES

Pan, Heng; Anderssen, Eric; Ambrosio, Giorgio; ...

2016-12-20

The Large Hadron Collider Luminosity upgrade (HiLumi) program requires new low-β triplet quadrupole magnets, called MQXF, in the Interaction Region (IR) to increase the LHC peak and integrated luminosity. The MQXF magnets, designed and fabricated in collaboration between CERN and the U.S. LARP, will all have the same cross section. The MQXF long model, referred as MQXFA, is a quadrupole using the Nb3Sn superconducting technology with 150 mm aperture and a 4.2 m magnetic length and is the first long prototype of the final MQXF design. The MQXFA magnet is based on the previous LARP HQ and MQXFS designs. Inmore » this paper we present the baseline design of the MQXFA structure with detailed 3D numerical analysis. A detailed tolerance analysis of the baseline case has been performed by using a 3D finite element model, which allows fast computation of structures modelled with actual tolerances. Tolerance sensitivity of each component is discussed to verify the actual tolerances to be achieved by vendors. In conclusion, tolerance stack-up analysis is presented in the end of this paper.« less

Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nosochkov, Yuri; Cai, Y.; Jiao, Y.

2012-06-25

It has been proposed to implement the so-called Achromatic Telescopic Squeezing (ATS) scheme in the LHC high luminosity (HL) lattice to reduce beta functions at the Interaction Points (IP) up to a factor of 8. As a result, the nominal 4.5 km peak beta functions reached in the Inner Triplets (IT) at collision will be increased by the same factor. This, therefore, justifies the installation of new, larger aperture, superconducting IT quadrupoles. The higher beta functions will enhance the effects of the triplet quadrupole field errors leading to smaller beam dynamic aperture (DA). To maintain the acceptable DA, the effectsmore » of the triplet field errors must be re-evaluated, thus specifying new tolerances. Such a study has been performed for the so-called '4444' collision option of the HL-LHC layout version SLHCV3.01, where the IP beta functions are reduced by a factor of 4 in both planes with respect to a pre-squeezed value of 60 cm at two collision points. The dynamic aperture calculations were performed using SixTrack. The impact on the triplet field quality is presented.« less

LARP Long Quadrupole: A "Long" Step Toward an LHC

ScienceCinema

Giorgio Ambrosio

2017-12-09

The beginning of the development of Nb3Sn magnets for particle accelerators goes back to the 1960’s. But only very recently has this development begun to face the challenges of fabricating Nb3Sn magnets which can meet the requirements of modern particle accelerators. LARP (the LHC Accelerator Research Program) is leading this effort focusing on long models of the Interaction Region quadrupoles for a possible luminosity upgrade of the Large Hadron Collider. A major milestone in this development is to test, by the end of 2009, 4m-long quadrupole models, which will be the first Nb3Sn accelerator-type magnets approaching the length of real accelerator magnets. The Long Quadrupoles (LQ) are “Proof-of-Principle” magnets which are to demonstrate that Nb3Sn technology is sufficiently mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, under development at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. Several challenges must be addressed for the successful fabrication of long Nb3Sn coils and magnets. These challenges and the solutions adopted will be presented together with the main features of the LQ magnets. Several R&D lines are participating to this effort and their contributions will be also presented.

Intermolecular configurations dominated by quadrupole-quadrupole electrostatic interactions: explicit correlation treatment of the five-dimensional potential energy surface and infrared spectra for the CO-N2 complex.

PubMed

Liu, Jing-Min; Zhai, Yu; Zhang, Xiao-Long; Li, Hui

2018-01-17

A thorough understanding of the intermolecular configurations of van der Waals complexes is a great challenge due to their weak interactions, floppiness and anharmonic nature. Although high-resolution microwave or infrared spectroscopy provides one of the most direct and precise pieces of experimental evidence, the origin and key role in determining such intermolecular configurations of a van der Waals system strongly depend on its highly accurate potential energy surface (PES) and a detailed analysis of its ro-vibrational wavefunctions. Here, a new five-dimensional potential energy surface for the van der Waals complex of CO-N 2 which explicitly incorporates the dependence on the stretch coordinate of the CO monomer is generated using the explicitly correlated couple cluster (CCSD(T)-F12) method in conjunction with a large basis set. Analytic four-dimensional PESs are obtained by the least-squares fitting of vibrationally averaged interaction energies for v = 0 and v = 1 to the Morse/Long-Range potential mode (V MLR ). These fits to 7966 points have root-mean-square deviations (RMSD) of 0.131 cm -1 and 0.129 cm -1 for v = 0 and v = 1, respectively, with only 315 parameters. Energy decomposition analysis is carried out, and it reveals that the dominant factor in controlling intermolecular configurations is quadrupole-quadrupole electrostatic interactions. Moreover, the rovibrational levels and wave functions are obtained for the first time. The predicted infrared transitions and intensities for the ortho-N 2 -CO complex as well as the calculated energy levels for para-N 2 -CO are in good agreement with the available experimental data with RMSD discrepancies smaller than 0.068 cm -1 . The calculated infrared band origin shift associated with the fundamental band frequency of CO is -0.721 cm -1 for ortho-N 2 -CO which is in excellent agreement with the experimental value of -0.739 cm -1 . The agreement with experimental values validates the high quality of the PESs and enhances our confidence to explain the observed mystery lines around 2163 cm -1 .

Transmission of singularities through a shock wave and the sound generation

NASA Technical Reports Server (NTRS)

Ting, L.

1974-01-01

The interaction of a plane shock wave of finite strength with a vortex line, point vortex, doublet or quadrupole of weak strength is studied. Based upon the physical condition that a free vortex line cannot support a pressure difference, rules are established which define the change of the linear intensity of the segment of the vortex line after its passage through the shock. The rules for point vortex, doublet, and quadrupole are then established as limiting cases. These rules can be useful for the construction of the solution of the entire flow field and for its physical interpretation. However, the solution can be obtained directly by the technique developed for shock diffraction problems. Explicit solutions and the associated sound generation are obtained for the passage of a point vortex through the shock wave.

Are neutron stars crushed? Gravitomagnetic tidal fields as a mechanism for binary-induced collapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favata, Marc

Numerical simulations of binary neutron stars by Wilson, Mathews, and Marronetti indicated that neutron stars that are stable in isolation can be made to collapse to black holes when placed in a binary. This claim was surprising as it ran counter to the Newtonian expectation that a neutron star in a binary should be more stable, not less. After correcting an error found by Flanagan, Wilson and Mathews found that the compression of the neutron stars was significantly reduced but not eliminated. This has motivated us to ask the following general question: Under what circumstances can general-relativistic tidal interactions causemore » an otherwise stable neutron star to be compressed? We have found that if a nonrotating neutron star possesses a current-quadrupole moment, interactions with a gravitomagnetic tidal field can lead to a compressive force on the star. If this current quadrupole is induced by the gravitomagnetic tidal field, it is related to the tidal field by an equation-of-state-dependent constant called the gravitomagnetic Love number. This is analogous to the Newtonian Love number that relates the strength of a Newtonian tidal field to the induced mass quadrupole moment of a star. The compressive force is almost never larger than the Newtonian tidal interaction that stabilizes the neutron star against collapse. In the case in which a current quadrupole is already present in the star (perhaps as an artifact of a numerical simulation), the compressive force can exceed the stabilizing one, leading to a net increase in the central density of the star. This increase is small (< or approx. 1%) but could, in principle, cause gravitational collapse in a star that is close to its maximum mass. This paper also reviews the history of the Wilson-Mathews-Marronetti controversy and, in an appendix, extends the discussion of tidally induced changes in the central density to rotating stars.« less

Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals

NASA Astrophysics Data System (ADS)

Xia, S. Y.; Tao, H.; Lu, Y.; Li, Z. P.; Nikšić, T.; Vretenar, D.

2017-11-01

Quadrupole and octupole deformation energy surfaces, low-energy excitation spectra, and transition rates in 14 isotopic chains: Xe, Ba, Ce, Nd, Sm, Gd, Rn, Ra, Th, U, Pu, Cm, Cf, and Fm, are systematically analyzed using a theoretical framework based on a quadrupole-octupole collective Hamiltonian (QOCH), with parameters determined by constrained reflection-asymmetric and axially symmetric relativistic mean-field calculations. The microscopic QOCH model based on the PC-PK1 energy density functional and δ -interaction pairing is shown to accurately describe the empirical trend of low-energy quadrupole and octupole collective states, and predicted spectroscopic properties are consistent with recent microscopic calculations based on both relativistic and nonrelativistic energy density functionals. Low-energy negative-parity bands, average octupole deformations, and transition rates show evidence for octupole collectivity in both mass regions, for which a microscopic mechanism is discussed in terms of evolution of single-nucleon orbitals with deformation.

First determination of ground state electromagnetic moments of Fe 53

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, A. J.; Minamisono, K.; Rossi, D. M.

Here, the hyperfine coupling constants of neutron deficient 53Fe were deduced from the atomic hyperfine spectrum measured using the bunched-beam collinear laser spectroscopy technique. The low-energy 53Fe beam was produced by projectile-fragmentation reactions followed by gas stopping, and used for the first time for laser spectroscopy. Ground state magnetic-dipole and electric-quadrupole moments were determined as μ= –0.65(1)μ N and Q=+35(15)e 2fm 2, respectively. The multiconfiguration Dirac-Fock method was used to calculate the electric field gradient to deduce Q from the quadrupole hyperfine coupling constant, since the quadrupole coupling constant has not been determined for any Fe isotopes. Both experimental valuesmore » agree well with nuclear shell model calculations using the GXPF1A effective interaction performed in a full fp shell model space, which support the soft nature of the 56Ni nucleus.« less

First determination of ground state electromagnetic moments of Fe 53

DOE PAGES

Miller, A. J.; Minamisono, K.; Rossi, D. M.; ...

2017-11-16

Here, the hyperfine coupling constants of neutron deficient 53Fe were deduced from the atomic hyperfine spectrum measured using the bunched-beam collinear laser spectroscopy technique. The low-energy 53Fe beam was produced by projectile-fragmentation reactions followed by gas stopping, and used for the first time for laser spectroscopy. Ground state magnetic-dipole and electric-quadrupole moments were determined as μ= –0.65(1)μ N and Q=+35(15)e 2fm 2, respectively. The multiconfiguration Dirac-Fock method was used to calculate the electric field gradient to deduce Q from the quadrupole hyperfine coupling constant, since the quadrupole coupling constant has not been determined for any Fe isotopes. Both experimental valuesmore » agree well with nuclear shell model calculations using the GXPF1A effective interaction performed in a full fp shell model space, which support the soft nature of the 56Ni nucleus.« less

Connections between the dynamical symmetries in the microscopic shell model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Georgieva, A. I., E-mail: anageorg@issp.bas.bg; Drumev, K. P.

2016-03-25

The dynamical symmetries of the microscopic shell model appear as the limiting cases of a symmetry adapted Pairing-Plus-Quadrupole Model /PQM/, with a Hamiltonian containing isoscalar and isovector pairing and quadrupole interactions. We establish a correspondence between each of the three types of pairing bases and Elliott’s SU(3) basis, that describes collective rotation of nuclear systems with quadrupole deformation. It is derived from their complementarity to the same LS coupling chain of the shell model number conserving algebra. The probability distribution of the S U(3) basis states within the pairing eigenstates is also obtained through a numerical diagonalization of the PQMmore » Hamiltonian in each limit. We introduce control parameters, which define the phase diagram of the model and determine the role of each term of the Hamiltonian in the correct reproduction of the experimental data for the considered nuclei.« less

Reexamining the nuclear structure of 154Gd in the dynamic pairing plus quadrupole model

NASA Astrophysics Data System (ADS)

Gupta, J. B.; Hamilton, J. H.

2017-05-01

In a previous study of the collective multiphonon bands in 154Gd, using the microscopic dynamic pairing plus quadrupole model, data for eight K bands were analyzed. In the last four decades, its decay scheme is significantly revised and the nuclear theory has undergone a significant change. Special focus is on new weak intensity transitions in several bands and on the reassigned levels in its decay scheme. The present study represents a detailed revised analysis of the collective even parity bands below 2.1 MeV. Also, a discussion is given on the nature of the Kπ=0+ excited bands, validity of band mixing approach, and of the assumption of shape coexistence of β band with ground band. Comparison is made with the X (5) analytical symmetry and the algebraic interacting boson model predictions. Discussion of the 2 n transfer reactions is given. The validity of the multiphonon view of the Kπ=4+ and 22+ bands is also studied.

Modeling the physisorption of graphene on metals

NASA Astrophysics Data System (ADS)

Tao, Jianmin; Tang, Hong; Patra, Abhirup; Bhattarai, Puskar; Perdew, John P.

2018-04-01

Many processes of technological and fundamental importance occur on surfaces. Adsorption is one of these phenomena that has received the most attention. However, it presents a great challenge to conventional density functional theory. Starting with the Lifshitz-Zaremba-Kohn second-order perturbation theory, here we develop a long-range van der Waals (vdW) correction for physisorption of graphene on metals. The model importantly includes quadrupole-surface interaction and screening effects. The results show that, when the vdW correction is combined with the Perdew-Burke-Enzerhof functional, it yields adsorption energies in good agreement with the random-phase approximation, significantly improving upon other vdW methods. We also find that, compared with the leading-order interaction, the higher-order quadrupole-surface correction accounts for about 25 % of the total vdW correction, suggesting the importance of the higher-order term.

Implementation of Magnetic Dipole Interaction in the Planewave-Basis Approach for Slab Systems

NASA Astrophysics Data System (ADS)

Oda, Tatsuki; Obata, Masao

2018-06-01

We implemented the magnetic dipole interaction (MDI) in a first-principles planewave-basis electronic structure calculation based on spin density functional theory. This implementation, employing the two-dimensional Ewald summation, enables us to obtain the total magnetic anisotropy energy of slab materials with contributions originating from both spin-orbit and magnetic dipole-dipole couplings on the same footing. The implementation was demonstrated using an iron square lattice. The result indicates that the magnetic anisotropy of the MDI is much less than that obtained from the atomic magnetic moment model due to the prolate quadrupole component of the spin magnetic moment density. We discuss the reduction in the anisotropy of the MDI in the case of modulation of the quadrupole component and the effect of magnetic field arising from the MDI on atomic scale.

Discriminating the structure of exo-2-aminonorbornane using nuclear quadrupole coupling interactions.

PubMed

Écija, Patricia; Cocinero, Emilio J; Lesarri, Alberto; Millán, Judith; Basterretxea, Francisco; Fernández, José A; Castaño, Fernando

2011-04-28

The intrinsic conformational and structural properties of the bicycle exo-2-aminonorbornane have been probed in a supersonic jet expansion using Fourier-transform microwave (FT-MW) spectroscopy and quantum chemical calculations. The rotational spectrum revealed two different conformers arising from the internal rotation of the amino group, exhibiting small (MHz) hyperfine patterns originated by the (14)N nuclear quadrupole coupling interaction. Complementary ab initio (MP2) and DFT (B3LYP and M05-2X) calculations provided comparative predictions for the structural properties, rotational and centrifugal distortion data, hyperfine parameters, and isomerization barriers. Due to the similarity of the rotational constants, the structural assignment of the observed rotamers and the calculation of the torsion angles of the amino group were based on the conformational dependence of the (14)N nuclear quadrupole coupling hyperfine tensor. In the most stable conformation (ss), the two amino N-H bonds are staggered with respect to the adjacent C-H bond. In the second conformer (st), only one of the N-H bonds is staggered and the other is trans. A third predicted conformer (ts) was not detected, consistent with a predicted conformational relaxation to conformer ss through a low barrier of 5.2 kJ mol(-1).

Manifestation of a strong quadrupole interaction and peculiarities in the SERS and SEHRS spectra of 4,4'-bipyridine

NASA Astrophysics Data System (ADS)

Golovin, A. V.; Polubotko, A. M.

2017-07-01

The paper analyzes Surface Enhanced Raman Scattering (SERS) and Surface Enhanced Hyper Raman Scattering (SEHRS) spectra of 4,4'-bypiridine molecule for two possible geometries, which are described by D 2 and D 2 h symmetry groups. It is pointed out on appearance of sufficiently strong lines, caused by vibrations with the unit irreducible representation for both possible configurations. Appearance of these lines in the SEHRS spectrum points out the existence of a strong quadrupole light-molecule interaction. In addition one observes the lines, caused by vibrations both with the unit irreducible representations A or A g and the irreducible representation B 1 or B 1 u . The last ones describe transformational properties of the d z component of the dipole moment, which is perpendicular to the surface. This property of the spectrum is caused by peculiarity of the geometry of the molecule, which consists of two benzene rings, which are weakly connected with each other. The linear combinations of the vibrations of the rings create two nearly degenerated symmetric and anti symmetrical states, which cannot be identified in the experimental spectra. The result is in a full agreement with the dipole-quadrupole theory of SERS and SEHRS.

Quantum correction to classical gravitational interaction between two polarizable objects

NASA Astrophysics Data System (ADS)

Wu, Puxun; Hu, Jiawei; Yu, Hongwei

2016-12-01

When gravity is quantized, there inevitably exist quantum gravitational vacuum fluctuations which induce quadrupole moments in gravitationally polarizable objects and produce a quantum correction to the classical Newtonian interaction between them. Here, based upon linearized quantum gravity and the leading-order perturbation theory, we study, from a quantum field-theoretic prospect, this quantum correction between a pair of gravitationally polarizable objects treated as two-level harmonic oscillators. We find that the interaction potential behaves like r-11 in the retarded regime and r-10 in the near regime. Our result agrees with what were recently obtained in different approaches. Our study seems to indicate that linearized quantum gravity is robust in dealing with quantum gravitational effects at low energies.

Three-photon Gaussian-Gaussian-Laguerre-Gaussian excitation of a localized atom to a highly excited Rydberg state

NASA Astrophysics Data System (ADS)

Mashhadi, L.

2017-12-01

Optical vortices are currently one of the most intensively studied topics in light-matter interaction. In this work, a three-step axial Doppler- and recoil-free Gaussian-Gaussian-Laguerre-Gaussian (GGLG) excitation of a localized atom to the highly excited Rydberg state is presented. By assuming a large detuning for intermediate states, an effective quadrupole excitation related to the Laguerre-Gaussian (LG) excitation to the highly excited Rydberg state is obtained. This special excitation system radially confines the single highly excited Rydberg atom independently of the trapping system into a sharp potential landscape into the so-called ‘far-off-resonance optical dipole-quadrupole trap’ (FORDQT). The key parameters of the Rydberg excitation to the highly excited state, namely the effective Rabi frequency and the effective detuning including a position-dependent AC Stark shift, are calculated in terms of the basic parameters of the LG beam and of the polarization of the excitation lasers. It is shown that the obtained parameters can be tuned to have a precise excitation of a single atom to the desired Rydberg state as well. The features of transferring the optical orbital and spin angular momentum of the polarized LG beam to the atom via quadrupole Rydberg excitation offer a long-lived and controllable qudit quantum memory. In addition, in contrast to the Gaussian laser beam, the doughnut-shaped LG beam makes it possible to use a high intensity laser beam to increase the signal-to-noise ratio in quadrupole excitation with minimized perturbations coming from stray light broadening in the last Rydberg excitation process.

Characterization, stoichiometry, and stability of salivary protein-tannin complexes by ESI-MS and ESI-MS/MS.

PubMed

Canon, Francis; Paté, Franck; Meudec, Emmanuelle; Marlin, Thérèse; Cheynier, Véronique; Giuliani, Alexandre; Sarni-Manchado, Pascale

2009-12-01

Numerous protein-polyphenol interactions occur in biological and food domains particularly involving proline-rich proteins, which are representative of the intrinsically unstructured protein group (IUP). Noncovalent protein-ligand complexes are readily detected by electrospray ionization mass spectrometry (ESI-MS), which also gives access to ligand binding stoichiometry. Surprisingly, the study of interactions between polyphenolic molecules and proteins is still an area where ESI-MS has poorly benefited, whereas it has been extensively applied to the detection of noncovalent complexes. Electrospray ionization mass spectrometry has been applied to the detection and the characterization of the complexes formed between tannins and a human salivary proline-rich protein (PRP), namely IB5. The study of the complex stability was achieved by low-energy collision-induced dissociation (CID) measurements, which are commonly implemented using triple quadrupole, hybrid quadrupole time-of-flight, or ion trap instruments. Complexes composed of IB5 bound to a model polyphenol EgCG have been detected by ESI-MS and further analyzed by MS/MS. Mild ESI interface conditions allowed us to observe intact noncovalent PRP-tannin complexes with stoichiometries ranging from 1:1 to 1:5. Thus, ESI-MS shows its efficiency for (1) the study of PRP-tannin interactions, (2) the determination of stoichiometry, and (3) the study of complex stability. We were able to establish unambiguously both their stoichiometries and their overall subunit architecture via tandem mass spectrometry and solution disruption experiments. Our results prove that IB5.EgCG complexes are maintained intact in the gas phase.

Prediction of thermodynamic properties of coal derivatives. Progress report, September 1, 1981-August 31, 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donohue, M.D.

It is the purpose of this research program to develop a model to predict the thermodynamic properties of coal derivatives. Unlike natural gas and petroleum, coal and its gasification and liquefaction products are predominantly aromatic and have substantial quadrupole moments. Because of these quadrupole forces, the numerous correlational techniques that have been developed for petroleum products cannot be used to predict the thermodynamic properties of coal derivatives. We are presently developing a correlation that will be useful in predicting the thermodynamic properties of coal derivatives. This theory is based on the Perturbed-Hard-Chain theory, but is different from PHCT in twomore » respects. First, PHCT uses a square-well to describe the intermolecular potential energy between two molecules. In our new theory, the Lennard-Jones potential energy function is used. The second difference is that we take into account the effect of quadrupole forces on the intermolecular potential energy. In PHCT these forces were ignored. In PHCT the contributions to the partition function (or equation of state) that arise from the attractive forces between molecules (regardless of whether these forces are treated as a square-well or by Lennard-Jones) are calculated by assuming that they are perturbations on a hard sphere. In calculating the contributions to the partition function that arise from the quadrupole-quadrupole interactions, we use a second order perturbation about the Lennard-Jones. For aromatic molecules, the effect of this additional perturbation is significant.« less

Hexadecapolar Colloids

DOE PAGES

Senyuk, Bohdan; Puls, Owen; Tovkach, Oleh M.; ...

2016-02-11

Outermost occupied electron shells of chemical elements can have symmetries resembling that of monopoles, dipoles, quadrupoles and octupoles corresponding to filled s-, p-, d- and forbitals. Theoretically, elements with hexadecapolar outer shells could also exist, but none of the known elements have filled g-orbitals. On the other hand, the research paradigm of ‘colloidal atoms’ displays complexity of particle behaviour exceeding that of atomic counterparts, which is driven by DNA functionalization, geometric shape and topology and weak external stimuli. We describe elastic hexadecapoles formed by polymer microspheres dispersed in a liquid crystal, a nematic fluid of orientationally ordered molecular rods. Becausemore » of conically degenerate boundary conditions, the solid microspheres locally perturb the alignment of the nematic host, inducing hexadecapolar distortions that drive anisotropic colloidal interactions. We uncover physical underpinnings of formation of colloidal elastic hexadecapoles and report the ensuing bonding inaccessible to elastic dipoles, quadrupoles and other nematic colloids studied previously.« less

Damping of spin-dipole mode and generation of quadrupole mode excitations in a spin-orbit coupled Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Li, Chuan-Hsun; Blasing, David; Chen, Yong

2017-04-01

In cold atom systems, spin excitations have been shown to be a sensitive probe of interactions and quantum statistical effects, and can be used to study spin transport in both Fermi and Bose gases. In particular, spin-dipole mode (SDM) is a type of excitation that can generate a spin current without a net mass current. We present recent measurements and analysis of SDM in a disorder-free, interacting three-dimensional (3D) 87Rb Bose-Einstein condensate (BEC) by applying spin-dependent synthetic electric fields to actuate head-on collisions between two BECs of different spin states. We experimentally study and compare the behaviors of the system following SDM excitations in the presence as well as absence of synthetic 1D spin-orbit coupling (SOC). We find that in the absence of SOC, SDM is relatively weakly damped, accompanied with collision-induced thermalization which heats up the atomic cloud. However, in the presence of SOC, we find that SDM is more strongly damped with reduced thermalization, and observe excitation of a quadrupole mode that exhibits BEC shape oscillation even after SDM is damped out. Such a mode conversion bears analogies with the Beliaev coupling process or the parametric frequency down conversion of light in nonlinear optics.

Interacting Boson Model and nucleons

NASA Astrophysics Data System (ADS)

Otsuka, Takaharu

2012-10-01

An overview on the recent development of the microscopic derivation of the Interacting Boson Model is presented with some remarks not found elsewhere. The OAI mapping is reviewed very briefly, including the basic correspondence from nucleon-pair to boson. The new fermionboson mapping method is introduced, where intrinsic states of nucleons and bosons for a wide variation of shapes play an important role. Nucleon intrinsic states are obtained from mean field models, which is Skyrme model in examples to be shown. This method generates IBM-2 Hamiltonian which can describe and predict various situations of quadrupole collective states, including U(5), SU(3), O(6) and E(5) limits. The method is extended so that rotational response (cranking) can be handled, which enables us to describe rotational bands of strongly deformed nuclei. Thus, we have obtained a unified framework for the microscopic derivation of the IBM covering all known situations of quadrupole collectivity at low energy.

Interaction of Strain and Nuclear Spins in Silicon: Quadrupolar Effects on Ionized Donors

NASA Astrophysics Data System (ADS)

Franke, David P.; Hrubesch, Florian M.; Künzl, Markus; Becker, Hans-Werner; Itoh, Kohei M.; Stutzmann, Martin; Hoehne, Felix; Dreher, Lukas; Brandt, Martin S.

2015-07-01

The nuclear spins of ionized donors in silicon have become an interesting quantum resource due to their very long coherence times. Their perfect isolation, however, comes at a price, since the absence of the donor electron makes the nuclear spin difficult to control. We demonstrate that the quadrupolar interaction allows us to effectively tune the nuclear magnetic resonance of ionized arsenic donors in silicon via strain and determine the two nonzero elements of the S tensor linking strain and electric field gradients in this material to S11=1.5 ×1022 V /m2 and S44=6 ×1022 V /m2 . We find a stronger benefit of dynamical decoupling on the coherence properties of transitions subject to first-order quadrupole shifts than on those subject to only second-order shifts and discuss applications of quadrupole physics including mechanical driving of magnetic resonance, cooling of mechanical resonators, and strain-mediated spin coupling.

Multipolar Kondo effect in a S10-P32 mixture of 173Yb atoms

NASA Astrophysics Data System (ADS)

Kuzmenko, Igor; Kuzmenko, Tetyana; Avishai, Yshai; Jo, Gyu-Boong

2018-02-01

Whereas in the familiar Kondo effect the exchange interaction is dipolar, there are systems in which the exchange interaction is multipolar, as has been realized in a recent experiment. Here, we study multipolar Kondo effect in a Fermi gas of cold 173Yb atoms. Making use of different ac polarizabilities of the electronic ground state Yb (S10 ) and the long-lived metastable state Yb*(P32 ), it is suggested that the latter atoms can be localized and serve as a dilute concentration of magnetic impurities while the former ones remain itinerant. The exchange mechanism between the itinerant Yb and the localized Yb* atoms is analyzed and shown to be antiferromagnetic. The quadrupole and octupole interactions act to enhance the Kondo temperature TK that is found to be experimentally accessible. The bare exchange Hamiltonian needs to be decomposed into dipole (d), quadrupole (q), and octupole (o) interactions in order to retain its form under renormalization group (RG) analysis, in which the corresponding exchange constants (λd,λq, and λo) flow independently. Numerical solution of the RG scaling equations reveals a few finite fixed points. Arguments are presented that the Fermi-liquid fixed point at low temperature is unstable, indicating that the impurity is overscreened, which suggests a non-Fermi-liquid phase. The impurity contributions to the specific heat, entropy, and the magnetic susceptibility are calculated in the weak coupling regime (T ≫TK ), and are compared with the analogous results obtained for the standard case of dipolar exchange interaction (the s -d Hamiltonian).

Nature of isomerism of solid isothiourea salts, inhibitors of nitric oxide synthases, as studied by 1H-14N nuclear quadrupole double resonance, X-ray, and density functional theory/quantum theory of atoms in molecules.

PubMed

Latosińska, J N; Latosińska, M; Seliger, J; Žagar, V; Maurin, J K; Kazimierczuk, Z

2012-02-09

Isothioureas, inhibitors of nitric oxide synthases, have been studied experimentally in solid state by nuclear quadrupole double resonance (NQDR) and X-ray methods and theoretically by the quantum theory of atoms in molecules/density functional theory. Resonance frequencies on (14)N have been detected and assigned to particular nitrogen sites in each molecule. The crystal packings of (S)-3,4-dichlorobenzyl-N-methylisothiouronium chloride with the disordered chlorine positions in benzene ring and (S)-butyloisothiouronium bromide have been resolved in X-ray diffraction studies. (14)N NQDR spectra have been found good indicators of isomer type and strength of intra- or intermolecular N-H···X (X = Cl, Br) interactions. From among all salts studied, only for (S)-2,3,4,5,6-pentabromobenzylisothiouronium chloride are both nitrogen sites equivalent, which has been explained by the slow exchange. This unique structural feature can be a key factor in the high biological activity of (S)-2,3,4,5,6-pentabromobenzylisothiouronium salts.

Dynamics of charged particles in a Paul radio-frequency quadrupole trap

NASA Technical Reports Server (NTRS)

Prestage, J. D.; Williams, A.; Maleki, L.; Djomehri, M. J.; Harabetian, E.

1991-01-01

A molecular-dynamics simulation of hundreds of ions confined in a Paul trap has been performed. The simulation includes the trapped particles' micromotion and interparticle Coulomb interactions. A random walk in velocity was implemented to bring the secular motion to a given temperature which was numerically measured. When the coupling Gamma is large the ions from concentric shells which undergo a quadrupole oscillation at the RF frequency, while the ions within a shell form a 2D hexagonal lattice. Ion clouds at 5 mK show no RF heating for q(z) less than about 0.6, whereas rapid heating is seen for qz = 0.8.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lackner, Friedrich; Ferracin, Paolo; Todesco, Ezio

The High luminosity LHC upgrade target is to increase the integrated luminosity by a factor 10, resulting in an integrated luminosity of 3000 fb-1. One major improvement foreseen is the reduction of the beam size at the collision points. This requires the development of 150 mm single aperture quadrupoles for the interaction regions. These quadrupoles are under development in a joint collaboration between CERN and the US-LHC Accelerator Research Program (LARP). The chosen approach for achieving a nominal quadrupole field gradient of 132.6 T/m is based on the Nb3Sn technology. The coils with a length of 7281 mm will bemore » the longest Nb3Sn coils fabricated so far for accelerator magnets. The production of the long coils was launched in 2016 based on practise coils made from copper. This paper provides a status of the production of the first low grade and full performance coils and describes the production process and applied quality control. Furthermore an outlook for the prototype assembly is provided.« less

First determination of ground state electromagnetic moments of 53Fe

NASA Astrophysics Data System (ADS)

Miller, A. J.; Minamisono, K.; Rossi, D. M.; Beerwerth, R.; Brown, B. A.; Fritzsche, S.; Garand, D.; Klose, A.; Liu, Y.; Maaß, B.; Mantica, P. F.; Müller, P.; Nörtershäuser, W.; Pearson, M. R.; Sumithrarachchi, C.

2017-11-01

The hyperfine coupling constants of neutron deficient 53Fe were deduced from the atomic hyperfine spectrum of the 3 d64 s25D4↔3 d64 s 4 p 5F5 transition, measured using the bunched-beam collinear laser spectroscopy technique. The low-energy 53Fe beam was produced by projectile-fragmentation reactions followed by gas stopping, and used for the first time for laser spectroscopy. Ground state magnetic-dipole and electric-quadrupole moments were determined as μ =-0.65 (1 ) μN and Q =+35 (15 ) e2fm2 , respectively. The multiconfiguration Dirac-Fock method was used to calculate the electric field gradient to deduce Q from the quadrupole hyperfine coupling constant, since the quadrupole coupling constant has not been determined for any Fe isotopes. Both experimental values agree well with nuclear shell model calculations using the GXPF1A effective interaction performed in a full f p shell model space, which support the soft nature of the 56Ni nucleus.

Geometry and mechanics of two-dimensional defects in amorphous materials

PubMed Central

Moshe, Michael; Levin, Ido; Aharoni, Hillel; Kupferman, Raz; Sharon, Eran

2015-01-01

We study the geometry of defects in amorphous materials and their elastic interactions. Defects are defined and characterized by deviations of the material’s intrinsic metric from a Euclidian metric. This characterization makes possible the identification of localized defects in amorphous materials, the formulation of a corresponding elastic problem, and its solution in various cases of physical interest. We present a multipole expansion that covers a large family of localized 2D defects. The dipole term, which represents a dislocation, is studied analytically and experimentally. Quadrupoles and higher multipoles correspond to fundamental strain-carrying entities. The interactions between those entities, as well as their interaction with external stress fields, are fundamental to the inelastic behavior of solids. We develop analytical tools to study those interactions. The model, methods, and results presented in this work are all relevant to the study of systems that involve a distribution of localized sources of strain. Examples are plasticity in amorphous materials and mechanical interactions between cells on a flexible substrate. PMID:26261331

Numerical simulation of NQR/NMR: Applications in quantum computing.

PubMed

Possa, Denimar; Gaudio, Anderson C; Freitas, Jair C C

2011-04-01

A numerical simulation program able to simulate nuclear quadrupole resonance (NQR) as well as nuclear magnetic resonance (NMR) experiments is presented, written using the Mathematica package, aiming especially applications in quantum computing. The program makes use of the interaction picture to compute the effect of the relevant nuclear spin interactions, without any assumption about the relative size of each interaction. This makes the program flexible and versatile, being useful in a wide range of experimental situations, going from NQR (at zero or under small applied magnetic field) to high-field NMR experiments. Some conditions specifically required for quantum computing applications are implemented in the program, such as the possibility of use of elliptically polarized radiofrequency and the inclusion of first- and second-order terms in the average Hamiltonian expansion. A number of examples dealing with simple NQR and quadrupole-perturbed NMR experiments are presented, along with the proposal of experiments to create quantum pseudopure states and logic gates using NQR. The program and the various application examples are freely available through the link http://www.profanderson.net/files/nmr_nqr.php. Copyright © 2011 Elsevier Inc. All rights reserved.

Isotropic–Nematic Phase Transitions in Gravitational Systems. II. Higher Order Multipoles

NASA Astrophysics Data System (ADS)

Takács, Ádám; Kocsis, Bence

2018-04-01

The gravitational interaction among bodies orbiting in a spherical potential leads to the rapid relaxation of the orbital planes’ distribution, a process called vector resonant relaxation. We examine the statistical equilibrium of this process for a system of bodies with similar semimajor axes and eccentricities. We extend the previous model of Roupas et al. by accounting for the multipole moments beyond the quadrupole, which dominate the interaction for radially overlapping orbits. Nevertheless, we find no qualitative differences between the behavior of the system with respect to the model restricted to the quadrupole interaction. The equilibrium distribution resembles a counterrotating disk at low temperature and a spherical structure at high temperature. The system exhibits a first-order phase transition between the disk and the spherical phase in the canonical ensemble if the total angular momentum is below a critical value. We find that the phase transition erases the high-order multipoles, i.e., small-scale structure in angular momentum space, most efficiently. The system admits a maximum entropy and a maximum energy, which lead to the existence of negative temperature equilibria.

Radiation drag in the field of a non-spherical source

NASA Astrophysics Data System (ADS)

Bini, D.; Geralico, A.; Passamonti, A.

2015-01-01

The motion of a test particle in the gravitational field of a non-spherical source endowed with both mass and mass quadrupole moment is investigated when a test radiation field is also present. The background is described by the Erez-Rosen solution, which is a static space-time belonging to the Weyl class of solutions to the vacuum Einstein's field equations, and reduces to the familiar Schwarzschild solution when the quadrupole parameter vanishes. The radiation flux has a fixed but arbitrary (non-zero) angular momentum. The interaction with the radiation field is assumed to be Thomson-like, i.e. the particles absorb and re-emit radiation, thus suffering for a friction-like drag force. Such an additional force is responsible for the Poynting-Robertson effect, which is well established in the framework of Newtonian gravity and has been recently extended to the general theory of relativity. The balance between gravitational attraction, centrifugal force and radiation drag leads to the occurrence of equilibrium circular orbits which are attractors for the surrounding matter for every fixed value of the interaction strength. The presence of the quadrupolar structure of the source introduces a further degree of freedom: there exists a whole family of equilibrium orbits parametrized by the quadrupole parameter, generalizing previous works. This scenario is expected to play a role in the context of accretion matter around compact objects.

Excitation of transverse dipole and quadrupole modes in a pure ion plasma in a linear Paul trap to study collective processes in intense beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.

Transverse dipole and quadrupole modes have been excited in a one-component cesium ion plasma trapped in the Paul Trap Simulator Experiment (PTSX) in order to characterize their properties and understand the effect of their excitation on equivalent long-distance beam propagation. The PTSX device is a compact laboratory Paul trap that simulates the transverse dynamics of a long, intense charge bunch propagating through an alternating-gradient transport system by putting the physicist in the beam's frame of reference. A pair of arbitrary function generators was used to apply trapping voltage waveform perturbations with a range of frequencies and, by changing which electrodesmore » were driven with the perturbation, with either a dipole or quadrupole spatial structure. The results presented in this paper explore the dependence of the perturbation voltage's effect on the perturbation duration and amplitude. Perturbations were also applied that simulate the effect of random lattice errors that exist in an accelerator with quadrupole magnets that are misaligned or have variance in their field strength. The experimental results quantify the growth in the equivalent transverse beam emittance that occurs due to the applied noise and demonstrate that the random lattice errors interact with the trapped plasma through the plasma's internal collective modes. Coherent periodic perturbations were applied to simulate the effects of magnet errors in circular machines such as storage rings. The trapped one component plasma is strongly affected when the perturbation frequency is commensurate with a plasma mode frequency. The experimental results, which help to understand the physics of quiescent intense beam propagation over large distances, are compared with analytic models.« less

Corrections to atomic ground state energy due to interaction between atomic electric quadrupole and optical field

NASA Astrophysics Data System (ADS)

Hu, Jie; Chen, Yu; Bai, Yi-Xiu; He, Pei-Song; Sun, Qing; Ji, An-Chun

2018-04-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 21503138, 11247324, 61405003, 11604225, 11404225, and 11474205) and the Fund from Beijing Education Committees, China (Grant No. KM201710028004).

Isolated rotor noise due to inlet distortion or turbulence

NASA Technical Reports Server (NTRS)

Mani, R.

1974-01-01

Theoretical formulation, analysis, and results are presented that are necessary to analyze quadrupole noise generated from a loaded, subsonic rotor because of its interaction with an inflow distortion or inlet turbulence. The ratio of quadrupole to dipole noise is largely a function of the axial Mach number, wheel tip Mach number, rotor solidity, and total pressure ratio across the rotor. It is relatively independent of the specific form of the inflow distortion or inlet turbulence. Comparisons with experimental data only succeed in predicting gross levels at a given speed and fail to predict the variation of noise at fixed speed with flow and pressure ratio. Likely sources of this discrepancy are discussed.

Covariant spectator theory of np scattering: Deuteron quadrupole moment

DOE PAGES

Gross, Franz

2015-01-26

The deuteron quadrupole moment is calculated using two CST model wave functions obtained from the 2007 high precision fits to np scattering data. Included in the calculation are a new class of isoscalar np interaction currents automatically generated by the nuclear force model used in these fits. The prediction for model WJC-1, with larger relativistic P-state components, is 2.5% smaller that the experiential result, in common with the inability of models prior to 2014 to predict this important quantity. However, model WJC-2, with very small P-state components, gives agreement to better than 1%, similar to the results obtained recently frommore » XEFT predictions to order N 3LO.« less

Transverse-rapidity yt dependence of the nonjet azimuth quadrupole from 62- and 200-GeV Au-Au collisions

NASA Astrophysics Data System (ADS)

Kettler, David T.; Prindle, Duncan J.; Trainor, Thomas A.

2015-06-01

Previous measurements of a quadrupole component of azimuth correlations denoted by symbol v2 have been interpreted to represent elliptic flow, a hydrodynamic phenomenon conjectured to play a major role in noncentral nucleus-nucleus collisions. v2 measurements provide the main support for conclusions that a "perfect liquid" is formed in heavy-ion collisions at the Relativistic Heavy Ion Collider. However, conventional v2 methods based on one-dimensional (1D) azimuth correlations give inconsistent results and may include a jet contribution. In some cases the data trends appear to be inconsistent with hydrodynamic interpretations. In this study we distinguish several components of 2D angular correlations and isolate a nonjet (NJ) azimuth quadrupole denoted by v2{2D} . We establish systematic variations of the NJ quadrupole on yt, centrality, and collision energy. We adopt transverse-rapidity yt as both a velocity measure and a logarithmic alternative to transverse momentum pt. Based on NJ-quadrupole trends, we derive a completely factorized universal parametrization of quantity v2{2D} (yt,b ,√{sN N}) which describes the centrality, yt, and energy dependence. From yt-differential v2(yt) data we isolate a quadrupole spectrum and infer a quadrupole source boost having unexpected properties. NJ quadrupole v2 trends obtained with 2D model fits are remarkably simple. The centrality trend appears to be uncorrelated with a sharp transition in jet-related structure that may indicate rapid change of Au-Au medium properties. The lack of correspondence suggests that the NJ quadrupole may be insensitive to such a medium. Several quadrupole trends have interesting implications for hydro interpretations.

STM imaging ortho- and para-fluorothiophenol self-assembled monolayers on Au(111).

PubMed

Jiang, Peng; Deng, Ke; Fichou, Denis; Xie, Si-Shen; Nion, Aymeric; Wang, Chen

2009-05-05

Self-assembled monolayers (SAMs) of para- and ortho-fluorothiophenol (p- and o-FTP) spontaneously formed on Au(111) substrate have been contrasted through investigation by a scanning tunneling microscope (STM) at room temperature. High-resolution STM imaging reveals that p-FTP adopts a 6 x radical3R30 degrees molecule arrangement containing six molecules. Two different kinds of p-FTP molecule dimer line structures have been formed on Au(111) by intermolecular pi-pi stacking along 112 substrate directions, besides a single p-FTP molecule line. In contrast, o-FTP molecules self-assemble into a much looser wave-like SAM, which can be described as a 5 x 3 radical3R30 degrees structure containing two molecules. Periodic density functional theory (DFT) calculations for the two systems suggest that these kinds of FTP molecules preferentially take the asymmetrical positions between 3-fold face-centered cubic (fcc) hollow and bridge sites on Au(111), tilting from the substrate surface. Theoretical simulation gives apparent average tilted angles of 58 degrees and 68 degrees for p-FTP and o-FTP with respect to the surface normal, respectively. This simulation shows that o-FTP is more inclined to lie down toward the Au(111) surface compared to p-FTP. The difference between p-FTP and o-FTP SAM structures can be qualitatively understood in terms of the variation of intermolecular dipole-dipole orientation. This suggests that, besides well-known Au-S and pi-pi interactions, electrostatic interactions including dipole-dipole, quadrupole-quadrupole, and dipole-quadrupole interactions might also play an important role in influencing the SAM structures formed by aromatic thiols with a permanent dipole moment.

Measurement of the orientation of buffer-gas-cooled, electrostatically-guided ammonia molecules

NASA Astrophysics Data System (ADS)

Steer, Edward W.; Petralia, Lorenzo S.; Western, Colin M.; Heazlewood, Brianna R.; Softley, Timothy P.

2017-02-01

The extent to which the spatial orientation of internally and translationally cold ammonia molecules can be controlled as molecules pass out of a quadrupole guide and through different electric field regions is examined. Ammonia molecules are collisionally cooled in a buffer gas cell, and are subsequently guided by a three-bend electrostatic quadrupole into a detection chamber. The orientation of ammonia molecules is probed using (2 + 1) resonance-enhanced multiphoton ionisation (REMPI), with the laser polarisation axis aligned both parallel and perpendicular to the time-of-flight axis. Even with the presence of a near-zero field region, the ammonia REMPI spectra indicate some retention of orientation. Monte Carlo simulations propagating the time-dependent Schrödinger equation in a full basis set including the hyperfine interaction enable the orientation of ammonia molecules to be calculated - with respect to both the local field direction and a space-fixed axis - as the molecules pass through different electric field regions. The simulations indicate that the orientation of ∼95% of ammonia molecules in JK =11 could be achieved with the application of a small bias voltage (17 V) to the mesh separating the quadrupole and detection regions. Following the recent combination of the buffer gas cell and quadrupole guide apparatus with a linear Paul ion trap, this result could enable one to examine the influence of molecular orientation on ion-molecule reaction dynamics and kinetics.

Molecular near-field antenna effect in resonance hyper-Raman scattering: Intermolecular vibronic intensity borrowing of solvent from solute through dipole-dipole and dipole-quadrupole interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimada, Rintaro; Hamaguchi, Hiro-o, E-mail: hhama@nctu.edu.tw

2014-05-28

We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-β-carotene (β-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute β-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by more than 5 orders of magnitude under the presence of β-carotene. We have called this phenomenon the molecular-near field effect. Resonance HR spectra of β-carotene in benzene, deuterated benzene, cyclohexane, and deuterated cyclohexane have been measured precisely for a quantitative analysis of this effect. The assignments of themore » observed peaks are made by referring to the infrared, Raman, and HR spectra of neat solvents. It has been revealed that infrared active and some Raman active vibrations are active in the HR molecular near-field effect. The observed spectra in the form of difference spectra (between benzene/deuterated benzene and cyclohexane/deuterated cyclohexane) are quantitatively analyzed on the basis of the extended vibronic theory of resonance HR scattering. The theory incorporates the coupling of excited electronic states of β-carotene with the vibrations of a proximate solvent molecule through solute–solvent dipole–dipole and dipole–quadrupole interactions. It is shown that the infrared active modes arise from the dipole–dipole interaction, whereas Raman active modes from the dipole–quadrupole interaction. It is also shown that vibrations that give strongly polarized Raman bands are weak in the HR molecular near-field effect. The observed solvent HR spectra are simulated with the help of quantum chemical calculations for various orientations and distances of a solvent molecule with respect to the solute. The observed spectra are best simulated with random orientations of the solvent molecule at an intermolecular distance of 10 Å.« less

Conformational study of 2-phenylethylamine by molecular-beam Fourier transform microwave spectroscopy.

PubMed

López, Juan C; Cortijo, Vanessa; Blanco, Susana; Alonso, Jose L

2007-08-28

The conformational preferences of the simplest amine neurotransmitter 2-phenylethylamine have been investigated using molecular beam Fourier transform microwave (MB-FTMW) spectroscopy. Two new conformers have been observed together with the two previously reported by Godfrey et al. [J. Am. Chem. Soc., 1995, 117, 8204]. The (14)N nuclear quadrupole hyperfine structure has been resolved for all four conformers. Comparison of the experimental rotational and quadrupole coupling constants with those calculated theoretically provides a conclusive test for the identification of all conformers. The two most stable conformers present a gauche (folded) disposition of the alkyl-amine chain and are stabilised by a weak NH...pi interaction between the amino group and the aromatic ring. The other two conformers show an anti (extended) arrangement of the alkyl-amine chain. Tunnelling splittings have been observed in the spectrum of one of the anti conformers. The post expansion relative abundances in the supersonic jet have been also investigated and related to the conformer energies.

A microscopic explanation of the isotonic multiplet at N=90

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, J. B., E-mail: jbgupta2011@gmail.com

2014-08-14

The shape phase transition from spherical to soft deformed at N=88-90 was observed long ago. After the prediction of the X(5) symmetry, for which analytical solution of the nuclear Hamiltonian is given [1], good examples of X(5) nuclei were identified in the N=90 isotones of Nd, Sm, Gd and Dy, in the recent works. The N=90 isotones have almost the similar deformed level structure, forming the isotonic multiplet in Z=50-66, N=82-104 quadrant. This is explained microscopically in terms of the Nilsson level diagram. Using the Dynamic Pairing-Plus-Quadrupole model of Kumar-Baranger, the quadrupole deformation and the occupancies of the neutrons andmore » protons in these nuclei have been calculated, which support the formation of N=88, 90 isotonic multiplets. The existence of F-spin multiplets in Z=66-82, N=82-104 quadrant, identified in earlier works on the Interacting Boson Model, is also explained in our study.« less

Second-generation coil design of the Nb 3Sn low-β quadrupole for the high luminosity LHC

DOE PAGES

Bermudez, S. Izquierdo; Ambrosio, G.; Ballarino, A.; ...

2016-01-18

As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb 3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with amore » fine tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this study, we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.« less

Non-target screening of Allura Red AC photodegradation products in a beverage through ultra high performance liquid chromatography coupled with hybrid triple quadrupole/linear ion trap mass spectrometry.

PubMed

Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Calabrese, Giorgio; Gennaro, Maria Carla; Marengo, Emilio

2013-01-15

The study deals with the identification of the degradation products formed by simulated sunlight photoirradiation in a commercial beverage that contains Allura Red AC dye. An UHPLC-MS/MS method, that makes use of hybrid triple quadrupole/linear ion trap, was developed. In the identification step the software tool information dependent acquisition (IDA) was used to automatically obtain information about the species present and to build a multiple reaction monitoring (MRM) method with the MS/MS fragmentation pattern of the species considered. The results indicate that the identified degradation products are formed from side-reactions and/or interactions among the dye and other ingredients present in the beverage (ascorbic acid, citric acid, sucrose, aromas, strawberry juice, and extract of chamomile flowers). The presence of aromatic amine or amide functionalities in the chemical structures proposed for the degradation products might suggest potential hazards to consumer health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Control of systematic uncertainties in the storage ring search for an electric dipole moment by measuring the electric quadrupole moment

NASA Astrophysics Data System (ADS)

Magiera, Andrzej

2017-09-01

Measurements of electric dipole moment (EDM) for light hadrons with use of a storage ring have been proposed. The expected effect is very small, therefore various subtle effects need to be considered. In particular, interaction of particle's magnetic dipole moment and electric quadrupole moment with electromagnetic field gradients can produce an effect of a similar order of magnitude as that expected for EDM. This paper describes a very promising method employing an rf Wien filter, allowing to disentangle that contribution from the genuine EDM effect. It is shown that both these effects could be separated by the proper setting of the rf Wien filter frequency and phase. In the EDM measurement the magnitude of systematic uncertainties plays a key role and they should be under strict control. It is shown that particles' interaction with field gradients offers also the possibility to estimate global systematic uncertainties with the precision necessary for an EDM measurement with the planned accuracy.

Influence of the electron density on the characteristics of terahertz waves generated under laser–cluster interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, A. A., E-mail: frolov@ihed.ras.ru

2016-12-15

A theory of generation of terahertz radiation under laser–cluster interaction, developed earlier for an overdense cluster plasma [A. A. Frolov, Plasma Phys. Rep. 42. 637 (2016)], is generalized for the case of arbitrary electron density. The spectral composition of radiation is shown to substantially depend on the density of free electrons in the cluster. For an underdense cluster plasma, there is a sharp peak in the terahertz spectrum at the frequency of the quadrupole mode of a plasma sphere. As the electron density increases to supercritical values, this spectral line vanishes and a broad maximum at the frequency comparable withmore » the reciprocal of the laser pulse duration appears in the spectrum. The dependence of the total energy of terahertz radiation on the density of free electrons is analyzed. The radiation yield is shown to increase significantly under resonance conditions, when the laser frequency is close to the eigenfrequency of the dipole or quadrupole mode of a plasma sphere.« less

Rapid Quantification of Four Anthocyanins in Red Grape Wine by Hydrophilic Interaction Liquid Chromatography/Triple Quadrupole Linear Ion Trap Mass Spectrometry.

PubMed

Sun, Yongming; Xia, Biqi; Chen, Xiangzhun; Duanmu, Chuansong; Li, Denghao; Han, Chao

2015-01-01

The identification and quantification of four anthocyanins (cyanidin-3-O-glucoside, peonidin-3-O-glucoside, delphinidin-3-O-glucoside, and malvidin-3-O-glucoside) in red grape wine were carried out by hydrophilic interaction liquid chromatography/triple quadrupole linear ion trap MS (HILIC/QTrap-MS/MS). Samples were diluted directly and separated on a Merck ZIC HILIC column with 20 mM ammonium acetate solution-acetonitrile mobile phase. Quantitative data acquisition was carried out in the multiple reaction monitoring mode. Additional identification and confirmation of target compounds were performed using the enhanced product ion mode of the linear ion trap. The LOQs were in the range 0.05-1.0 ng/mL. The average recoveries were in the range 94.6 to 104.5%. The HILIC/QTrap-MS/MS platform offers the best sensitivity and specificity for characterization and quantitative determination of the four anthocyanins in red grape wines and fulfills the quality criteria for routine laboratory application.

Superfluid quenching of the moment of inertia in a strongly interacting Fermi gas

NASA Astrophysics Data System (ADS)

Riedl, S.; Sánchez Guajardo, E. R.; Kohstall, C.; Hecker Denschlag, J.; Grimm, R.

2011-03-01

We report on the observation of a quenched moment of inertia resulting from superfluidity in a strongly interacting Fermi gas. Our method is based on setting the hydrodynamic gas in slow rotation and determining its angular momentum by detecting the precession of a radial quadrupole excitation. The measurements distinguish between the superfluid and collisional origins of hydrodynamic behavior, and show the phase transition.

The Distribution of Galaxies’ Gravitational Field Stemming from Their Tidal Interaction

NASA Astrophysics Data System (ADS)

Stephanovich, Vladimir; Godłowski, Włodzimierz

2015-09-01

We calculate the distribution function of astronomical objects’ (like galaxies and/or smooth halos of different kinds) gravitational fields due to their tidal interaction. For that we apply the statistical method of Chandrasekhar, used originally to calculate the famous Holtzmark distribution. We show that in our approach the distribution function is never Gaussian, its form being dictated by the potential of interaction between objects. This calculation permits us to perform a theoretical analysis of the relation between angular momentum and mass (richness) of the galaxy clusters. To do so, we follow the ideas of Catelan & Theuns and Heavens & Peacock. The main difference is that here we reduce the problem to a discrete many-body case, where all physical properties of the system are determined by the interaction potential V({{\\boldsymbol{r}}}{ij}). The essence of reduction is that we use the multipole (up to quadrupole here) expansion of Newtonian potential so that all hydrodynamic, “extended” characteristics of an object, such as its density mass, are “integrated out,” leaving its “point-like” characteristics, such as mass and quadrupole moment. In that sense we do not distinguish between galaxies and smooth components such as halos. We compare our theoretical results with observational data.

The 57Fe hyperfine interactions in human liver ferritin and its iron-polymaltose analogues: the heterogeneous iron core model

NASA Astrophysics Data System (ADS)

Oshtrakh, M. I.; Alenkina, I. V.; Semionkin, V. A.

2016-12-01

Human liver ferritin and its iron-polymaltose pharmaceutical analogues Ferrum Lek, Maltofer® and Ferrifol® were studied using Mössbauer spectroscopy at 295 and 90 K. The Mössbauer spectra were fitted on the basis of a new model of heterogeneous iron core structure using five quadrupole doublets. These components were related to the corresponding more or less close-packed iron core layers/regions demonstrating some variations in the 57Fe hyperfine parameters for the studied samples.

Mössbauer Study of Hexavalent Iron Compounds

NASA Astrophysics Data System (ADS)

Dedushenko, S. K.; Perfiliev, Yu. D.; Goldfeld, M. G.; Tsapin, A. I.

2001-11-01

Six crystalline ferrates(VI): K3Na(FeO4)2, K2FeO4, Rb2FeO4, Cs2FeO4, K2Sr(FeO4)2 and BaFeO4, were studied by Mössbauer spectroscopy. Room-temperature spectra of potassium, rubidium and cesium ferrates are single lines, but spectra of barium, potassium strontium and potassium sodium ferrates show a presence of quadrupole interactions. Most of these salts display an antiferromagnetic transition with a Néel temperature within 2 to 8 K range.

Probing the Electronic Environment of Methylindoles using Internal Rotation and (14)N Nuclear Quadrupole Coupling.

PubMed

Gurusinghe, Ranil M; Tubergen, Michael J

2016-05-26

High-resolution rotational spectra were recorded in the 10.5-21.0 GHz frequency range for seven singly methylated indoles. (14)N nuclear quadrupole hyperfine structure and spectral splittings arising from tunneling along the internal rotation of the methyl group were resolved for all indole species. The nuclear quadrupole coupling constants were used to characterize the electronic environment of the nitrogen atom, and the program XIAM was used to fit the barrier to internal rotation to the measured transition frequencies. The best fit barriers were found to be 277.1(2), 374.32(4), 414.(5), 331.6(2), 126.8675(15), 121.413(4), and 426(3) cm(-1) for 1-methylindole through 7-methylindole, respectively. The fitted barriers were found to be in good agreement with barriers calculated at the ωB97XD/6-311++G(d,p) level. The complete set of experimental barriers is compared to theoretical investigations of the origins of methyl torsional barriers and confirms that the magnitude of these barriers is an overall effect of individual hyperconjugative and structural interactions of many bonding/antibonding orbitals.

Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry

PubMed Central

Martín-Ortiz, A.; Salcedo, J.; Barile, D.; Bunyatratchata, A.; Moreno, F.J.; Martin-García, I.; Clemente, A.; Sanz, M.L.; Ruiz-Matute, A.I.

2016-01-01

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography-quadrupole-time of flight mass spectrometry (Nano-LC-Chip-Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or N-glycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 °C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO. PMID:26427327

Pocket formula for nuclear deformations of actinides

NASA Astrophysics Data System (ADS)

Manjunatha, H. C.; Sridhar, K. N.

2018-06-01

We have formulated a pocket formula for quadrupole (β2), octupole (β3), hexadecapole (β4) and hexacontatetrapole (β6) deformation of the nuclear ground state of all isotopes of actinide nuclei (89 < Z < 103). This formula is first of its kind and produces a nuclear deformation of all isotopes actinide nuclei 89 < Z < 103 with simple inputs of Z and A. Hence, this formula is useful in the fields of nuclear physics to study the structure and interaction of nuclei.

Quench protection study of the updated MQXF for the LHC luminosity upgrade (HiLumi LHC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marinozzi, Vittorio; Ambrosio, Giorgio; Ferracin, Paolo

In 2023, the LHC luminosity will be increased, aiming at reaching 3000 fb-1 integrated over ten years. To obtain this target, new Nb 3Sn low-β quadrupoles (MQXF) have been designed for the interaction regions. These magnets present a very large aperture (150 mm, to be compared with the 70 mm of the present NbTi quadrupoles) and a very large stored energy density (120 MJ/m 3). For these reasons, quench protection is one of the most challenging aspects of the design of these magnets. In fact, protection studies of a previous design showed that the simulated hot spot temperature was verymore » close to the maximum allowed limit of 350 K; this challenge motivated improvements in the current discharge modeling, taking into account the so-called dynamic effects on the apparent magnet inductance. Moreover, quench heaters design has been studied to be going into more details. In this study, a protection study of the updated MQXF is presented, benefiting from the experience gained by studying the previous design. As a result, a study of the voltages between turns in the magnet is also presented during both normal operation and most important failure scenarios.« less

Quench protection study of the updated MQXF for the LHC luminosity upgrade (HiLumi LHC)

DOE PAGES

Marinozzi, Vittorio; Ambrosio, Giorgio; Ferracin, Paolo; ...

2016-06-01

In 2023, the LHC luminosity will be increased, aiming at reaching 3000 fb-1 integrated over ten years. To obtain this target, new Nb 3Sn low-β quadrupoles (MQXF) have been designed for the interaction regions. These magnets present a very large aperture (150 mm, to be compared with the 70 mm of the present NbTi quadrupoles) and a very large stored energy density (120 MJ/m 3). For these reasons, quench protection is one of the most challenging aspects of the design of these magnets. In fact, protection studies of a previous design showed that the simulated hot spot temperature was verymore » close to the maximum allowed limit of 350 K; this challenge motivated improvements in the current discharge modeling, taking into account the so-called dynamic effects on the apparent magnet inductance. Moreover, quench heaters design has been studied to be going into more details. In this study, a protection study of the updated MQXF is presented, benefiting from the experience gained by studying the previous design. As a result, a study of the voltages between turns in the magnet is also presented during both normal operation and most important failure scenarios.« less

Machine Imperfection Studies of the RAON Superconducting Linac

NASA Astrophysics Data System (ADS)

Jeon, D.; Jang, J.-H.; Jin, H.

2018-05-01

Studies of the machine imperfections in the RAON superconducting linac (SCL) that employs normal conducting (NC) quadrupoles were done to assess the tolerable error budgets of the machine imperfections that ensure operation of the beam. The studies show that the beam loss requirement is met even before the orbit correction and that the beam loss requirement is met even without the MHB (multi-harmonic buncher) and VE (velocity equalizer) thanks to the RAON's radio-frequency quadrupole (RFQ) design feature. For the low energy section of the linac (SCL3), a comparison is made between the two superconducting linac lattice types: one lattice that employs NC quadrupoles and the other that employs SC solenoids. The studies show that both lattices meet the beam loss requirement after the orbit correction. However, before the orbit correction, the lattice employing SC solenoids does not meet the beam loss requirement and can cause a significant beam loss, while the lattice employing NC quadrupoles meets the requirement. For the lattice employing SC solenoids, care must be taken during the beam commissioning.

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE PAGES

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

2017-01-27

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Theoretical design of twelve-band infrared metamaterial perfect absorber by combining the dipole, quadrupole, and octopole plasmon resonance modes of four different ring-strip resonators.

PubMed

Zhao, Lei; Liu, Han; He, Zhihong; Dong, Shikui

2018-05-14

Multiband metamaterial perfect absorbers (MPAs) have promising applications in many fields like microbolometers, infrared detection, biosensing, and thermal emitters. In general, the single resonator can only excite a fundamental mode and achieve single absorption band. The multiband MPA can be achieved by combining several different sized resonators together. However, it's still challenging to design the MPA with absorption bands of more than four and average absorptivity of more than 90% due to the interaction between differently sized resonators. In this paper, three absorption bands are successfully achieved with average absorptivity up to 98.5% only utilizing single one our designed ring-strip resonator, which can simultaneously excite a fundamental electric dipole mode, a higher-order electric quadrupole mode, and a higher-order electric octopole mode. As the biosensor, the sensing performance of the higher-order modes is higher than the fundamental modes. Then we try to increase the absorption bands by combining different sized ring-strip resonators together and make the average absorptivity above 90% by optimizing the geometry parameters. A six-band MPA is achieved by combining two different sized ring-strip resonators with average absorptivity up to 98.8%, which can excite two dipole modes, two quadrupole modes, and two octopole modes. A twelve-band MPA is achieved by combining four different sized ring-strip resonators with average absorptivity up to 93.7%, which can excite four dipole modes, four quadrupole modes, and four octopole modes.

Complementary π-π interactions induce multicomponent coassembly into functional fibrils.

PubMed

Ryan, Derek M; Doran, Todd M; Nilsson, Bradley L

2011-09-06

Noncovalent self-assembled materials inspired by amyloid architectures are useful for biomedical applications ranging from regenerative medicine to drug delivery. The selective coassembly of complementary monomeric units to provide ordered multicomponent fibrils is a possible strategy for enhancing the sophistication of these noncovalent materials. Herein we report that complementary π-π interactions can be exploited to promote the coassembly of phenylalanine (Phe) derivatives that possess complementary aromatic side-chain functionality. Specifically, equimolar mixtures of Fmoc-Phe and Fmoc-F(5)-Phe, which possess side-chain groups with complementary quadrupole electronics, readily coassemble to form two-component fibrils and hydrogels under conditions where Fmoc-Phe alone fails to self-assemble. In addition, it was found that equimolar mixtures of Fmoc-Phe with monohalogenated (F, Cl, and Br) Fmoc-Phe derivatives also coassembled into two-component fibrils. These results collectively indicate that face-to-face quadrupole stacking between benzyl side-chain groups does not account for the molecular recognition between Phe and halogenated Phe derivatives that promote cofibrillization but that coassembly is mediated by more subtle π-π effects arising from the halogenation of the benzyl side chain. The use of complementary π-π interactions to promote the coassembly of two distinct monomeric units into ordered two-component fibrils dramatically expands the repertoire of noncovalent interactions that can be used in the development of sophisticated noncovalent materials. © 2011 American Chemical Society

Stability of an aqueous quadrupole micro-trap

DOE PAGES

Park, Jae Hyun; Krstić, Predrag S.

2012-03-30

Recently demonstrated functionality of an aqueous quadrupole micro- or nano-trap opens a new avenue for applications of the Paul traps, like is confinement of a charged biomolecule which requires water environment for its chemical stability. Besides strong viscosity forces, motion of a charged particle in the aqueous trap is subject to dielectrophoretic and electrophoretic forces. In this study, we describe the general conditions for stability of a charged particle in an aqueous quadrupole trap. We find that for the typical micro-trap parameters, effects of both dielectrophoresis and electrophoresis significantly influence the trap stability. In particular, the aqueous quadrupole trap couldmore » play of a role of a synthetic virtual nanopore for the 3rd generation of DNA sequencing technology.« less

Synthesis and energy transfer studies of LaMgAl{sub 11}O{sub 19}:Cr{sup 3+}, Nd{sup 3+} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Jicheng; Xia, Zhiguo; Liu, Quanlin, E-mail: qlliu@ustb.edu.cn

2016-02-15

Highlights: • Cr{sup 3+}/Nd{sup 3+} co-doped LaMgAl{sub 11}O{sub 19} phosphors were synthesized. • The energy transfer mechanism is ascribed to the dipole–quadrupole interaction. • The materials can convert the UV–vis light into near-infrared emission. - Abstract: Cr{sup 3+}/Nd{sup 3+} co-activated LaMgAl{sub 11}O{sub 19} phosphors have been synthesized by high temperature solid-state method. In the LaMgAl{sub 11}O{sub 19}:Cr{sup 3+}/Nd{sup 3+} system, Cr{sup 3+} can absorb the UV–vis photons (350–650 nm), and then energy transfer takes place between Cr{sup 3+} and Nd{sup 3+}, and finally the samples give near infrared emission originated from Nd{sup 3+}. Energy transfer from Cr{sup 3+} to Nd{supmore » 3+} is discussed via the variations of the lifetime values of Cr{sup 3+}, and the mechanism has been ascribed to the dipole–quadrupole interaction. The absorption of Cr{sup 3+} in the visible region and the following energy transfer from Cr{sup 3+} to Nd{sup 3+} indicated that the material can potentially serve as spectral convertors to improve the photovoltaic conversion efficiency of silicon-based solar cell.« less

Development of MQXF: The Nb 3Sn low-β quadrupole for the HiLumi LHC

DOE PAGES

Ferracin, P.; G. Ambrosio; Anerella, M.; ...

2015-12-18

The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating atmore » magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.« less

Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry.

PubMed

Martín-Ortiz, A; Salcedo, J; Barile, D; Bunyatratchata, A; Moreno, F J; Martin-García, I; Clemente, A; Sanz, M L; Ruiz-Matute, A I

2016-01-08

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography-quadrupole-time of flight mass spectrometry (Nano-LC-Chip-Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or N-glycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2-0.6min) and good symmetry (As: 0.8-1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40°C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315mgL(-1) for neutral oligosaccharides and from 83 to 251mgL(-1) for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO. Copyright © 2015 Elsevier B.V. All rights reserved.

The129I hyperfine interaction in fatty acids studied by Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Burda, K.; Strzałka, K.; Stanek, J.

1993-12-01

Oleic acid substituted by iodine and saponified by Ca2+ cations has been studied by129I Mössbauer spectroscopy. The quadrupole coupling constants and isomer shifts, determined from the γ-resonance spectra recorded at 4.2 K, have been described by 5p and 5s orbital populations of iodine. It was also found that saponification of the fatty acid has no significant influence on the measured iodine bonds. However, the increased order of fatty acids in soap form is reflected by narrowing of the resonant linewidth due to the reduction of the electric field gradient distribution.

Effects of the quadrupole wakefields in a passive streaker

DOE PAGES

Craievich, Paolo; Lutman, Alberto A.

2016-10-05

A novel method based on transverse wakefields has been recently proposed to characterize the temporal profile of a relativistic electron bunch. The electron bunch is streaked by the interaction with the transverse wakefield excited when the electrons travel off-axis in a device called the passive streaker. Furthermore, for the large transverse off-axis offsets required to effectively streak the electron bunch, higher order modes can be excited. The time-dependent quadrupole wakefield of the dielectric-lined structure can cause a significant enlargement of the transverse profile at the screen. Consequently, the measurement resolution is decreased also at the bunch tail. We report onmore » how the temporal profile can be effectively reconstructed also including the defocusing effect for a given transverse beam distribution at the passive streaker.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Chi; Arvapally, Ravi K.; Tekarli, Sammer M.

The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal- interactions affords the supramolecular assemblies [1PtOEP] or [1H(2)OEP] (2a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes.

17O nuclear quadrupole coupling constants of water bound to a metal ion: A gadolinium(III) case study

NASA Astrophysics Data System (ADS)

Yazyev, Oleg V.; Helm, Lothar

2006-08-01

Rotational correlation times of metal ion aqua complexes can be determined from O17 NMR relaxation rates if the quadrupole coupling constant of the bound water oxygen-17 nucleus is known. The rotational correlation time is an important parameter for the efficiency of Gd3+ complexes as magnetic resonance imaging contrast agents. Using a combination of density functional theory with classical and Car-Parrinello molecular dynamics simulations we performed a computational study of the O17 quadrupole coupling constants in model aqua ions and the [Gd(DOTA)(H2O)]- complex used in clinical diagnostics. For the inner sphere water molecule in the [Gd(DOTA)(H2O)]- complex the determined quadrupole coupling parameter χ√1+η2/3 of 8.7MHz is very similar to that of the liquid water (9.0MHz ). Very close values were also predicted for the the homoleptic aqua ions of Gd3+ and Ca2+. We conclude that the O17 quadrupole coupling parameters of water molecules coordinated to closed shell and lanthanide metal ions are similar to water molecules in the liquid state.

A Laboratory Study of the Charging/Discharging Mechanisms of a Dust Particle Exposed to an Electron Beam

NASA Technical Reports Server (NTRS)

Venturini, C. C.; Spann, J. F.; Comfort, R. H.

1999-01-01

The interaction of micron sized particles or "dust particles" with different space and planetary environments has become an important area of research. One particular area of interest is how dust particles interact with plasmas. Studies have shown that charged dust particles immersed in plasmas can alter plasma characteristics, while ions and electrons in plasmas can affect a particle's potential and thereby, its interaction with other particles. The basis for understanding these phenomena is the charging mechanisms of the dust particle, specifically, how the particle's charge and characteristics are affected when exposed to ions and electrons. At NASA Marshall Space Flight Center, a laboratory experiment has been developed to study the interaction of dust particles with electrons. Using a unique laboratory technique known as electrodynamic suspension, a single charged particle is suspended in a modified quadrupole trap. Once suspended, the particle is then exposed to an electron beam to study the charging/discharging mechanisms due to collisions of energetic electrons. The change in the particle's charge, approximations of the charging/discharging currents, and the charging/discharging yield are calculated.

Isoscalar neutron-proton pairing and SU(4)-symmetry breaking in Gamow-Teller transitions

NASA Astrophysics Data System (ADS)

Kaneko, K.; Sun, Y.; Mizusaki, T.

2018-05-01

The isoscalar neutron-proton pairing is thought to be important for nuclei with equal number of protons and neutrons but its manifestation in structure properties remains to be understood. We investigate the Gamow-Teller (GT) transitions for the f7 /2-shell nuclei in large-scale shell-model calculations with the realistic Hamiltonian. We show that the isoscalar T =0 ,Jπ=1+ neutron-proton pairing interaction plays a decisive role for the concentration of GT strengths at the first-excited 11+ state in 42Sc, and that the suppression of these strengths in 46V, 50Mn, and 54Co is mainly caused by the spin-orbit force supplemented by the quadrupole-quadrupole interaction. Based on the good reproduction of the charge-exchange reaction data, we further analyze the interplay between the isoscalar and isovector pairing correlations. We conclude that even for the most promising A =42 nuclei where the SU(4) isoscalar-isovector-pairing symmetry is less broken, the probability of forming an isoscalar neutron-proton pairing condensation is less than 60% as compared to the expectation at the SU(4)-symmetry limit.

Energy levels, wavelengths, and transition rates of multipole transitions (E1, E2, M1, M2) in Au{sup 67+} and Au{sup 66+} ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamasha, Safeia, E-mail: safeia@hu.edu.jo

2013-11-15

The fully relativistic configuration interaction method of the FAC code is used to calculate atomic data for multipole transitions in Mg-like Au (Au{sup 67+}) and Al-like Au (Au{sup 66+}) ions. Generated atomic data are important in the modeling of M-shell spectra for heavy Au ions and Au plasma diagnostics. Energy levels, oscillator strengths and transition rates are calculated for electric-dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) for transitions between excited and ground states 3l−nl{sup ′}, such that n=4,5,6,7. The local central potential is derived using the Dirac–Fock–Slater method. Correlation effects to all orders are consideredmore » by the configuration interaction expansion. All relativistic effects are included in the calculations. Calculated energy levels are compared against published values that were calculated using the multi-reference many body perturbation theory, which includes higher order QED effects. Favorable agreement was observed, with less than 0.15% difference.« less

Novel tunable green-red-emitting oxynitride phosphors co-activated with Ce3+, Tb3+, and Eu3+: photoluminescence and energy transfer.

PubMed

Huo, Jiansheng; Dong, Langping; Lü, Wei; Shao, Baiqi; You, Hongpeng

2017-07-14

A series of novel Ce 3+ , Tb 3+ and Eu 3+ ion doped Y 4 SiAlO 8 N-based oxynitride phosphors were synthesized by the solid-state method and characterized by X-ray powder diffraction, scanning electron microscopy, photoluminescence, lifetimes and thermo-luminescence. The excitation of the Ce 3+ /Tb 3+ co-doped and Ce 3+ /Tb 3+ /Eu 3+ tri-doped phosphor with near-UV radiation results in strong linear Tb 3+ green and Eu 3+ red emission. The occurrence of Ce 3+ -Tb 3+ and Ce 3+ -Tb 3+ -Eu 3+ energy transfer processes is responsible for the bright green or red luminescence. The Tb 3+ ion acting as an energy transfer bridge can alleviate MMCT quenching between the Ce 3+ -Eu 3+ ion pairs. The lifetime measurements demonstrated that the energy-transfer mechanisms of Ce 3+ → Tb 3+ and Tb 3+ → Eu 3+ are dipole-quadrupole and quadrupole-quadrupole interactions, respectively. The temperature dependent luminescence measurements showed that as-prepared green/red phosphors have good thermal stability against temperature quenching. The obtained results indicate that these phosphors might serve as promising candidates for n-UV LEDs.

Fabrication of First 4-m Coils for the LARP MQXFA Quadrupole and Assembly in Mirror Structure

DOE PAGES

Holik, Eddie Frank; Ambrosio, Giorgio; Anerella, Michael; ...

2017-01-23

The US LHC Accelerator Research Program is constructing prototype interaction region quadrupoles as part of the US in-kind contribution to the Hi-Lumi LHC project. The low-beta MQXFA Q1/Q3 coils have a 4-m length and a 150 mm bore. The design is first validated on short, one meter models (MQXFS) developed as part of the longstanding Nb3Sn quadrupole R&D by LARP in collaboration with CERN. In parallel, facilities and tooling are being developed and refined at BNL, LBNL, and FNAL to enable long coil production, assembly, and cold testing. Long length scale-up is based on the experience from the LARP 90more » mm aperture (TQ-LQ) and 120 mm aperture (HQ and Long HQ) programs. A 4-m long MQXF practice coil was fabricated, water jet cut and analyzed to verify procedures, parts, and tooling. In parallel, the first complete prototype coil (QXFP01a) was fabricated and assembled in a long magnetic mirror, MQXFPM1, to provide early feedback on coil design and fabrication following the successful experience of previous LARP mirror tests.« less

Ultrahigh-resolution γ-ray spectroscopy of 156Gd: a test of tetrahedral symmetry.

PubMed

Jentschel, M; Urban, W; Krempel, J; Tonev, D; Dudek, J; Curien, D; Lauss, B; de Angelis, G; Petkov, P

2010-06-04

Tetrahedral symmetry in strongly interacting systems would establish a new class of quantum effects at subatomic scale. Excited states in 156Gd that could carry the information about the tetrahedral symmetry were populated in the 155Gd(n,γ)156Gd reaction and studied using the GAMS4/5 Bragg spectrometers at the Institut Laue-Langevin. We have identified the 5(1)- → 3(1)- transition of 131.983(12) keV in 156Gd and determined its intensity to be 1.9(3)x10(-6) per neutron capture. The lifetime τ=220(-30)(+180) fs of the 5(1)- state in 156Gd has been measured using the GRID technique. The resulting B(E2)=293(-134)(+6) Weisskopf unit rate of the 131.983 keV transition provides the intrinsic quadrupole moment of the 5(1)- state in 156Gd to be Q0=7.1(-1.6)(+0.7) b. This large value, comparable to the quadrupole moment of the ground state in 156Gd, gives strong evidence against tetrahedral symmetry in the lowest odd-spin, negative-parity band of 156Gd.

A scale-bridging modeling approach for anisotropic organic molecules at patterned semiconductor surfaces

NASA Astrophysics Data System (ADS)

Kleppmann, Nicola; Klapp, Sabine H. L.

2015-02-01

Hybrid systems consisting of organic molecules at inorganic semiconductor surfaces are gaining increasing importance as thin film devices for optoelectronics. The efficiency of such devices strongly depends on the collective behavior of the adsorbed molecules. In the present paper, we propose a novel, coarse-grained model addressing the condensed phases of a representative hybrid system, that is, para-sexiphenyl (6P) at zinc-oxide (ZnO). Within our model, intermolecular interactions are represented via a Gay-Berne potential (describing steric and van-der-Waals interactions) combined with the electrostatic potential between two linear quadrupoles. Similarly, the molecule-substrate interactions include a coupling between a linear molecular quadrupole to the electric field generated by the line charges characterizing ZnO(10-10). To validate our approach, we perform equilibrium Monte Carlo simulations, where the lateral positions are fixed to a 2D lattice, while the rotational degrees of freedom are continuous. We use these simulations to investigate orientational ordering in the condensed state. We reproduce various experimentally observed features such as the alignment of individual molecules with the line charges on the surface, the formation of a standing uniaxial phase with a herringbone structure, as well as the formation of a lying nematic phase.

Long range intermolecular interactions between the alkali diatomics Na2, K2, and NaK

NASA Astrophysics Data System (ADS)

Zemke, Warren T.; Byrd, Jason N.; Michels, H. Harvey; Montgomery, John A.; Stwalley, William C.

2010-06-01

Long range interactions between the ground state alkali diatomics Na2-Na2, K2-K2, Na2-K2, and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential ELR=Eelec+Edisp+Eind is shown to accurately represent the intermolecular interactions for these systems at long range.

Long range intermolecular interactions between the alkali diatomics Na(2), K(2), and NaK.

PubMed

Zemke, Warren T; Byrd, Jason N; Michels, H Harvey; Montgomery, John A; Stwalley, William C

2010-06-28

Long range interactions between the ground state alkali diatomics Na(2)-Na(2), K(2)-K(2), Na(2)-K(2), and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential E(LR)=E(elec)+E(disp)+E(ind) is shown to accurately represent the intermolecular interactions for these systems at long range.

Leakage of power from dipole to higher multipoles due to non-symmetric beam shape of the CMB missions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Santanu; Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in

2015-05-01

A number of studies of WMAP and Planck claimed the low multipole (specially quadrupole) power deficiency in CMB power spectrum. Anomaly in the orientations of the low multipoles have also been claimed. There is a possibility that the power deficiency at low multipoles may not be of primordial origin and is only an observation artifact coming from the scan procedure adapted in the WMAP or Planck satellites. Therefore, it is always important to investigate all the observational artifacts that can mimic them. The CMB dipole which is much higher than the quadrupole can leak to the higher multipoles due tomore » the non-symmetric beam shape of the WMAP or Planck. We observe that a non-negligible amount of power from the dipole can get transferred to the quadrupole and the higher multipoles due to the non-symmetric beam shapes and contaminate the observed measurements. The orientation of the quadrupole generated by this power transfer is surprisingly very close to the quadrupole observed from the WMAP and Planck maps. However, our analysis shows that the orientation of the quadrupole can not be explained using only the dipole power leakage. In this paper we calculate the amount of quadrupole power leakage for different WMAP bands. For Planck we present the results in terms of upper limits on asymmetric beam parameters that can lead to significant amount of power leakage.« less

Proton-neutron sdg boson model and spherical-deformed phase transition

NASA Astrophysics Data System (ADS)

Otsuka, Takaharu; Sugita, Michiaki

1988-12-01

The spherical-deformed phase transition in nuclei is described in terms of the proton-neutron sdg interacting boson model. The sdg hamiltonian is introduced to model the pairing+quadrupole interaction. The phase transition is reproduced in this framework as a function of the boson number in the Sm isotopes, while all parameters in the hamiltonian are kept constant at values reasonable from the shell-model point of view. The sd IBM is derived from this model through the renormalization of g-boson effects.

Test results of the LARP Nb$$_3$$Sn quadrupole HQ03a

DOE PAGES

DiMarco, J.; G. Ambrosio; Chlachidze, G.; ...

2016-03-09

The US LHC Accelerator Research Program (LARP) has been developingmore » $$Nb_3Sn$$ quadrupoles of progressively increasing performance for the high luminosity upgrade of the Large Hadron Collider. The 120 mm aperture High-field Quadrupole (HQ) models are the last step in the R&D phase supporting the development of the new IR Quadrupoles (MQXF). Three series of HQ coils were fabricated and assembled in a shell-based support structure, progressively optimizing the design and fabrication process. The final set of coils consistently applied the optimized design solutions, and was assembled in the HQ03a model. Furthermore, this paper reports a summary of the HQ03a test results, including training, mechanical performance, field quality and quench studies.« less

Structure and orientational ordering in a fluid of elongated quadrupolar molecules

NASA Astrophysics Data System (ADS)

Singh, Ram Chandra

2013-01-01

A second-order density-functional theory is used to study the effect of quadrupolar interactions on the isotropic-nematic transition in a system of fluids of elongated molecules interacting via the Gay-Berne potential. The direct pair-correlation functions of the coexisting isotropic fluid that enter in the theory as input information are obtained by solving the Ornstein-Zernike equation using the Percus-Yevick integral equation theory in the (reduced) temperature range of 1.6≤T∗≤3.0 for different densities, temperatures and quadrupole moments. Using the harmonic coefficients of the direct pair-correlation functions, isotropic-nematic phase coexistence and thermodynamic parameters have been calculated. The theoretical results have been compared with the available computer simulation results.

CFD Modelling of a Quadrupole Vortex Inside a Cylindrical Channel for Research into Advanced Hybrid Rocket Designs

NASA Astrophysics Data System (ADS)

Godfrey, B.; Majdalani, J.

2014-11-01

This study relies on computational fluid dynamics (CFD) tools to analyse a possible method for creating a stable quadrupole vortex within a simulated, circular-port, cylindrical rocket chamber. A model of the vortex generator is created in a SolidWorks CAD program and then the grid is generated using the Pointwise mesh generation software. The non-reactive flowfield is simulated using an open source computational program, Stanford University Unstructured (SU2). Subsequent analysis and visualization are performed using ParaView. The vortex generation approach that we employ consists of four tangentially injected monopole vortex generators that are arranged symmetrically with respect to the center of the chamber in such a way to produce a quadrupole vortex with a common downwash. The present investigation focuses on characterizing the flow dynamics so that future investigations can be undertaken with increasing levels of complexity. Our CFD simulations help to elucidate the onset of vortex filaments within the monopole tubes, and the evolution of quadrupole vortices downstream of the injection faceplate. Our results indicate that the quadrupole vortices produced using the present injection pattern can become quickly unstable to the extent of dissipating soon after being introduced into simulated rocket chamber. We conclude that a change in the geometrical configuration will be necessary to produce more stable quadrupoles.

Multiple shadows from distorted static black holes

NASA Astrophysics Data System (ADS)

Grover, Jai; Kunz, Jutta; Nedkova, Petya; Wittig, Alexander; Yazadjiev, Stoytcho

2018-04-01

We study the local shadow of the Schwarzschild black hole with a quadrupole distortion and the influence of the external gravitational field on the photon dynamics. The external matter sources modify the light ring structure and lead to the appearance of multiple shadow images. In the case of negative quadrupole moments we identify the most prominent mechanism causing multiple shadow formation. Furthermore, we obtain a condition under which this mechanism can be realized. This condition depends on the quadrupole moment, but also on the position of the observer and the celestial sphere.

Eight piece quadrupole magnet, method for aligning quadrupole magent pole tips

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaski, Mark S.; Liu, Jie; Donnelly, Aric T.

The invention provides an alternative to the standard 2-piece or 4-piece quadrupole. For example, an 8-piece and a 10-piece quadrupole are provided whereby the tips of each pole may be adjustable. Also provided is a method for producing a quadrupole using standard machining techniques but which results in a final tolerance accuracy of the resulting construct which is better than that obtained using standard machining techniques.

Dissymmetry effects on the laser spectroscopy of supersonically expanded rare gas/chiral arene heteroclusters.

PubMed

Filippi, Antonello; Giardini, Anna; Marcantoni, Enrico; Paladini, Alessandra; Piccirillo, Susanna; Renzi, Gabriele; Rondino, Flaminia; Roselli, Graziella; Satta, Mauro; Speranza, Maurizio

2007-04-14

The R2PI-TOF spectra of supersonically expanded rare gas/chiral arene heteroclusters have been rationalized in terms of the distortion of the pi-electron density reflecting the different dipole and quadrupole momenta induced in the rare gas atoms by interaction with the opposite pi-faces of the chiral arene itself.

Electron cloud generation and trapping in a quadrupole magnet at the Los Alamos proton storage ring

NASA Astrophysics Data System (ADS)

Macek, Robert J.; Browman, Andrew A.; Ledford, John E.; Borden, Michael J.; O'Hara, James F.; McCrady, Rodney C.; Rybarcyk, Lawrence J.; Spickermann, Thomas; Zaugg, Thomas J.; Pivi, Mauro T. F.

2008-01-01

Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the “prompt” electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the “swept” electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100μs. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole.

Theoretical level energies and transition data for 4p64d4, 4p64d34f and 4p54d5 configurations of W34+ ion

NASA Astrophysics Data System (ADS)

Karpuškienė, R.; Bogdanovich, P.; Kisielius, R.

2017-05-01

The ab initio quasirelativistic approach developed specifically for the calculation of spectral parameters of highly charged ions was used to derive transition data for the tungsten ion W34+. The configuration interaction method was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit-Pauli approximation. The level energies, radiative lifetimes τ, Landé g-factors are determined for the ground configuration 4p64d4 and two excited configurations 4p64d34f and 4p54d5. The radiative transition wavelengths λ and emission transition probabilities A for the electric dipole, electric quadrupole, electric octupole, magnetic dipole, and magnetic quadrupole transitions among the levels of these configurations are produced.

Multipole induced splitting of metal-cage vibrations in crystalline endohedral D2d-M2@C84 dimetallofullerenes.

PubMed

Krause, M; Popov, V N; Inakuma, M; Tagmatarchis, N; Shinohara, H; Georgi, P; Dunsch, L; Kuzmany, H

2004-01-22

Metal-carbon cage vibrations of crystalline endohedral D2d-M2@C84 (M=Sc,Y,Dy) dimetallofullerenes were analyzed by temperature dependent Raman scattering and a dynamical force field model. Three groups of metal-carbon cage modes were found at energies of 35-200 cm(-1) and assigned to metal-cage stretching and deformation vibrations. They exhibit a textbook example for the splitting of molecular vibrations in a crystal field. Induced dipole-dipole and quadrupole-quadrupole interactions account quantitatively for the observed mode splitting. Based on the metal-cage vibrational structure it is demonstrated that D2d-Y2@C84 dimetallofullerene retains a monoclinic crystal structure up to 550 K and undergoes a transition from a disordered to an ordered orientational state at a temperature of approximately 150 K.

Magnetic analysis of the Nb$$_3$$Sn low-beta quadrupole for the high luminosity LHC

DOE PAGES

Bermudez, Susana Izquierdo; Ambrosio, G.; Chlachidze, G.; ...

2017-01-10

As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build 150 mm aperture Nb 3Sn quadrupoles for the LHC interaction regions. A first series of 1.5 m long coils were fabricated, assembled and tested in the first short model. This paper presents the magnetic analysis, comparing magnetic field measurements with the expectations and the field quality requirements. The analysis is focused on the geometrical harmonics, iron saturation effect and cold-warm correlation. Three dimensional effects such as the variability of the field harmonics along the magnet axismore » and the contribution of the coil ends are also discussed. Furthemore, we present the influence of the conductor magnetization and the dynamic effects.« less

Energy levels and radiative rates for Ne-like ions from Cu to Ga

NASA Astrophysics Data System (ADS)

Singh, Narendra; Aggarwal, Sunny

2017-11-01

Energy levels, lifetimes and wave function compositions are computed for 127 fine structural levels in Ne-like ions (Z=29{-}31). Configuration interaction has been included among 51 configurations (generating 1016 levels) and multiconfigurational Dirac-Fock method is used to generate the wave functions. Similar calculations have also been performed using the fully relativistic flexible atomic code (FAC). Transition wavelength, oscillator strength, transition probabilities and line strength are reported for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions from the ground level. We compared our calculated results with the available data in the literature. The calculated results are found to be in close agreement with the previous results. Further, we predict some new atomic data which may be important for plasma diagnostics.

A Vibrating Wire System For Quadrupole Fiducialization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, Zachary

2010-12-13

A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization stepmore » of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method of choice. We then give an overview of the measurement system showing how the vibrating wire is positioned onto the quadrupole axis, how the wire position detectors locate the wire relative to tooling balls without touching the wire, and how the tooling ball positions are all measured. The novel feature of this system is the vibrating wire which we discuss in depth. We analyze the wire dynamics and calculate the expected sensitivity of the system. The note should be an aid in debugging the system by providing calculations to compare measurements to.« less

Supersonic Quadrupole Noise Theory for High-Speed Helicopter Rotors

NASA Technical Reports Server (NTRS)

Farassat, F.; Brentner, Kenneth S.

1997-01-01

High-speed helicopter rotor impulsive noise prediction is an important problem of aeroacoustics. The deterministic quadrupoles have been shown to contribute significantly to high-speed impulsive (HSI) noise of rotors, particularly when the phenomenon of delocalization occurs. At high rotor-tip speeds, some of the quadrupole sources lie outside the sonic circle and move at supersonic speed. Brentner has given a formulation suitable for efficient prediction of quadrupole noise inside the sonic circle. In this paper, we give a simple formulation based on the acoustic analogy that is valid for both subsonic and supersonic quadrupole noise prediction. Like the formulation of Brentner, the model is exact for an observer in the far field and in the rotor plane and is approximate elsewhere. We give the full analytic derivation of this formulation in the paper. We present the method of implementation on a computer for supersonic quadrupoles using marching cubes for constructing the influence surface (Sigma surface) of an observer space- time variable (x; t). We then present several examples of noise prediction for both subsonic and supersonic quadrupoles. It is shown that in the case of transonic flow over rotor blades, the inclusion of the supersonic quadrupoles improves the prediction of the acoustic pressure signature. We show the equivalence of the new formulation to that of Brentner for subsonic quadrupoles. It is shown that the regions of high quadrupole source strength are primarily produced by the shock surface and the flow over the leading edge of the rotor. The primary role of the supersonic quadrupoles is to increase the width of a strong acoustic signal.

Comprehensive analysis of a multidimensional liquid chromatography mass spectrometry dataset acquired on a quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometer: I. How much of the data is theoretically interpretable by search engines?

PubMed

Chalkley, Robert J; Baker, Peter R; Hansen, Kirk C; Medzihradszky, Katalin F; Allen, Nadia P; Rexach, Michael; Burlingame, Alma L

2005-08-01

An in-depth analysis of a multidimensional chromatography-mass spectrometry dataset acquired on a quadrupole selecting, quadrupole collision cell, time-of-flight (QqTOF) geometry instrument was carried out. A total of 3269 CID spectra were acquired. Through manual verification of database search results and de novo interpretation of spectra 2368 spectra could be confidently determined as predicted tryptic peptides. A detailed analysis of the non-matching spectra was also carried out, highlighting what the non-matching spectra in a database search typically are composed of. The results of this comprehensive dataset study demonstrate that QqTOF instruments produce information-rich data of which a high percentage of the data is readily interpretable.

Evolution of the Carter constant for inspirals into a black hole: Effect of the black hole quadrupole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flanagan, Eanna E.; Laboratory for Elementary Particle Physics, Cornell University, Ithaca, New York 14853; Hinderer, Tanja

2007-06-15

We analyze the effect of gravitational radiation reaction on generic orbits around a body with an axisymmetric mass quadrupole moment Q to linear order in Q, to the leading post-Newtonian order, and to linear order in the mass ratio. This system admits three constants of the motion in absence of radiation reaction: energy, angular momentum along the symmetry axis, and a third constant analogous to the Carter constant. We compute instantaneous and time-averaged rates of change of these three constants. For a point particle orbiting a black hole, Ryan has computed the leading order evolution of the orbit's Carter constant,more » which is linear in the spin. Our result, when combined with an interaction quadratic in the spin (the coupling of the black hole's spin to its own radiation reaction field), gives the next to leading order evolution. The effect of the quadrupole, like that of the linear spin term, is to circularize eccentric orbits and to drive the orbital plane towards antialignment with the symmetry axis. In addition we consider a system of two point masses where one body has a single mass multipole or current multipole of order l. To linear order in the mass ratio, to linear order in the multipole, and to the leading post-Newtonian order, we show that there does not exist an analog of the Carter constant for such a system (except for the cases of an l=1 current moment and an l=2 mass moment). Thus, the existence of the Carter constant in Kerr depends on interaction effects between the different multipoles. With mild additional assumptions, this result falsifies the conjecture that all vacuum, axisymmetric spacetimes possess a third constant of the motion for geodesic motion.« less

The influence of quadrupole sources in the boundary layer and wake of a blade on helicopter rotor noise

NASA Technical Reports Server (NTRS)

Farassat, F.; Brentner, Kenneth S.

1991-01-01

It is presently noted that, for an observer in or near the plane containing a helicopter rotor disk, and in the far field, part of the volume quadrupole sources, and the blade and wake surface quadrupole sources, completely cancel out. This suggests a novel quadrupole source description for the Ffowcs Williams-Hawkings equation which retain quadrupoles with axes parallel to the rotor disk; in this case, the volume and shock surface sourse terms are dominant.

Charge Dependence and Electric Quadrupole Effects on Single-Nucleon Removal in Relativistic and Intermediate Energy Nuclear Collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.

1992-01-01

Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.

Charge dependence and electric quadrupole effects on single-nucleon removal in relativistic and intermediate energy nuclear collisions

NASA Technical Reports Server (NTRS)

Norbury, J. W.; Townsend, L. W. (Principal Investigator)

1990-01-01

Single-nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.

Higher order parametric excitation modes for spaceborne quadrupole mass spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gershman, D. J.; Block, B. P.; Rubin, M.

This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and themore » ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system. When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.« less

An analytical study of double bend achromat lattice.

PubMed

Fakhri, Ali Akbar; Kant, Pradeep; Singh, Gurnam; Ghodke, A D

2015-03-01

In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented.

The quadrupole moments of Cd and Zn isotopes - an apology

NASA Astrophysics Data System (ADS)

Haas, H.; Barbosa, M. B.; Correia, J. G.

2016-12-01

In 2010 we presented an update of the nuclear quadrupole moments (Q) for the Cd and Zn isotopes, based essentially on straightforward density functional (DF) calculations (H. Haas and J.G. Correia, Hyperfine Interact 198, 133-137 (2010)). It has been apparent for some years that the standard DF procedure obviously fails, however, to reproduce the known electric-field gradient (EFG) for various systems, typical cases being Cu2O, As and Sb, and the solid halogens. Recently a cure for this deficiency has been found in the hybrid DF technique. This method is now applied to solid Cd and Zn, and the resultant quadrupole moments are about 15 % smaller than in our earlier report. Also nuclear systematics, using the recently revised values of Q for the long-lived 11/2 isomers in111Cd to129Cd, together with earlier PAD data for107,109Cd, leads to the same conclusion. In addition, EFG calculations for the cadmium dimethyl molecule further support the new values: Q(111Cd, 5/2+) = .683(20) b, Q(67Zn, gs) = .132(5) b. This implies, that the value for the atomic EFG in the 3it {P}1 state of Zn must be revised, as it has been for Cd.

The quadrupole model for rigid-body gravity simulations

NASA Astrophysics Data System (ADS)

Dobrovolskis, Anthony R.; Korycansky, D. G.

2013-07-01

We introduce two new models for gravitational simulations of systems of non-spherical bodies, such as comets and asteroids. In both models, one body (the "primary") may be represented by any convenient means, to arbitrary accuracy. In our first model, all of the other bodies are represented by small gravitational "molecules" consisting of a few point masses, rigidly linked together. In our second model, all of the other bodies are treated as point quadrupoles, with gravitational potentials including spherical harmonic terms up to the third degree (rather than only the first degree, as for ideal spheres or point masses). This quadrupole formulation may be regarded as a generalization of MacCullagh's approximation. Both models permit the efficient calculation of the interaction energy, the force, and the torque acting on a small body in an arbitrary external gravitational potential. We test both models for the cases of a triaxial ellipsoid, a rectangular parallelepiped, and "duplex" combinations of two spheres, all in a point-mass potential. These examples were chosen in order to compare the accuracy of our technique with known analytical results, but the ellipsoid and duplex are also useful models for comets and asteroids. We find that both approaches show significant promise for more efficient gravitational simulations of binary asteroids, for example. An appendix also describes the duplex model in detail.

Study of a micro chamber quadrupole mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Jinchan; Zhang Xiaobing; Mao Fuming

The design of a micro chamber quadrupole mass spectrometer (MCQMS) having a small total volume of only 20 cm{sup 3}, including Faraday cup ion detector and ion source, is described. This MCQMS can resist a vacuum baking temperature of 400-500 deg. C. The quadrupole elements with a hyperbolic surface are made of a ceramic material and coated with a thin metal layer. The quadrupole mass filter has a field radius of 3 mm and a length of 100 mm. Prototypes of this new MCQMS can detect a minimum partial pressure of 10{sup -8} Pa, have a peak width of {delta}M=1more » at 10% peak height from mass number 1 to 60, and show an excellent long-term stability. The new MCQMS is intended to be used in residual gas analyses of electron devices during a mutual pumping and baking process.« less

Mass peak shape improvement of a quadrupole mass filter when operating with a rectangular wave power supply.

PubMed

Luo, Chan; Jiang, Dan; Ding, Chuan-Fan; Konenkov, Nikolai V

2009-09-01

Numeric experiments were performed to study the first and second stability regions and find the optimal configurations of a quadrupole mass filter constructed of circular quadrupole rods with a rectangular wave power supply. The ion transmission contours were calculated using ion trajectory simulations. For the first stability region, the optimal rod set configuration and the ratio r/r(0) is 1.110-1.115; for the second stability region, it is 1.128-1.130. Low-frequency direct current (DC) modulation with the parameters of m = 0.04-0.16 and nu = omega/Omega = 1/8-1/14 improves the mass peak shape of the circular rod quadrupole mass filter at the optimal r/r(0) ratio of 1.130. The amplitude modulation does not improve mass peak shape. Copyright (c) 2009 John Wiley & Sons, Ltd.

Physical origin of the quadrupole out-of-plane magnetic field in Hall-magnetohydrodynamic reconnection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uzdensky, Dmitri A.; Kulsrud, Russell M.

2006-06-15

A quadrupole pattern of the out-of-plane component of the magnetic field inside a reconnection region is seen as an important signature of the Hall-magnetohydrodynamic regime of reconnection. It has been first observed in numerical simulations and just recently confirmed in the Magnetic Reconnection Experiment [Y. Ren, M. Yamada, S. Gerhardt, H. Ji, R. Kulsrud, and A. Kuritsin, Phys. Rev. Lett. 95, 055003 (2005)] and also seen in spacecraft observations of Earth's magnetosphere. In this study, the physical origin of the quadrupole field is analyzed and traced to a current of electrons that flows along the lines in and out ofmore » the inner reconnection region to maintain charge neutrality. The role of the quadrupole magnetic field in the overall dynamics of the reconnection process is discussed. In addition, the bipolar poloidal electric field is estimated and its effect on ion motions is emphasized.« less

Calculations with spectroscopic accuracy for energies, transition rates, hyperfine interaction constants, and Landé gJ-factors in nitrogen-like Kr XXX

NASA Astrophysics Data System (ADS)

Wang, K.; Li, S.; Jönsson, P.; Fu, N.; Dang, W.; Guo, X. L.; Chen, C. Y.; Yan, J.; Chen, Z. B.; Si, R.

2017-01-01

Extensive self-consistent multi-configuration Dirac-Fock (MCDF) calculations and second-order many-body perturbation theory (MBPT) calculations are performed for the lowest 272 states belonging to the 2s22p3, 2s2p4, 2p5, 2s22p23l, and 2s2p33l (l=s, p, d) configurations of N-like Kr XXX. Complete and consistent data sets of level energies, wavelengths, line strengths, oscillator strengths, lifetimes, AJ, BJ hyperfine interaction constants, Landé gJ-factors, and electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), magnetic quadrupole (M2) transition rates among all these levels are given. The present MCDF and MBPT results are compared with each other and with other available experimental and theoretical results. The mean relative difference between our two sets of level energies is only about 0.003% for these 272 levels. The accuracy of the present calculations are high enough to facilitate identification of many observed spectral lines. These accurate data can be served as benchmark for other calculations and can be useful for fusion plasma research and astrophysical applications.

Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

PubMed

Zhou, Guisheng; Pang, Hanqing; Tang, Yuping; Yao, Xin; Mo, Xuan; Zhu, Shaoqing; Guo, Sheng; Qian, Dawei; Qian, Yefei; Su, Shulan; Zhang, Li; Jin, Chun; Qin, Yong; Duan, Jin-ao

2013-05-01

This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

Comparison of conventional and novel quadrupole drift tube magnets inspired by Klaus Halbach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feinberg, B.

1995-02-01

Quadrupole drift tube magnets for a heavy-ion linac provide a demanding application of magnet technology. A comparison is made of three different solutions to the problem of providing an adjustable high-field-strength quadrupole magnet in a small volume. A conventional tape-wound electromagnet quadrupole magnet (conventional) is compared with an adjustable permanent-magnet/iron quadrupole magnet (hybrid) and a laced permanent-magnet/iron/electromagnet (laced). Data is presented from magnets constructed for the SuperHILAC heavy-ion linear accelerator, and conclusions are drawn for various applications.

Quantum phases of quadrupolar Fermi gases in coupled one-dimensional systems

NASA Astrophysics Data System (ADS)

Huang, Wen-Min; Lahrz, M.; Mathey, L.

2014-01-01

Following the recent proposal to create quadrupolar gases [Bhongale et al., Phys. Rev. Lett. 110, 155301 (2013), 10.1103/PhysRevLett.110.155301], we investigate what quantum phases can be created in these systems in one dimension. We consider a geometry of two coupled one-dimensional (1D) systems, and derive the quantum phase diagram of ultracold fermionic atoms interacting via quadrupole-quadrupole interactions within a Tomonaga-Luttinger-liquid framework. We map out the phase diagram as a function of the distance between the two tubes and the angle between the direction of the tubes and the quadrupolar moments. The latter can be controlled by an external field. We show that there are two magic angles θB,1c and θB,2c between 0 and π /2, where the intratube quadrupolar interactions vanish and change signs. Adopting a pseudospin language with regard to the two 1D systems, the system undergoes a spin-gap transition and displays a zigzag density pattern, above θB,2c and below θB,1c. Between the two magic angles, we show that polarized triplet superfluidity and a planar spin-density-wave order compete with each other. The latter corresponds to a bond-order solid in higher dimensions. We demonstrate that this order can be further stabilized by applying a commensurate periodic potential along the tubes.

Fermilab Booster Transition Crossing Simulations and Beam Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhat, C. M.; Tan, C. Y.

2016-01-01

The Fermilab Booster accelerates beam from 400 MeV to 8 GeV at 15 Hz. In the PIP (Proton Improvement Plan) era, it is required that Booster deliver 4.2 xmore » $$10^{12}$$ protons per pulse to extraction. One of the obstacles for providing quality beam to the users is the longitudinal quadrupole oscillation that the beam suffers from right after transition. Although this oscillation is well taken care of with quadrupole dampers, it is important to understand the source of these oscillations in light of the PIP II requirements that require 6.5 x $$10^{12}$$ protons per pulse at extraction. This paper explores the results from machine studies, computer simulations and solutions to prevent the quadrupole oscillations after transition.« less

Ion-mobility study of two functionalized pentacene structural isomers using a modified electrospray/triple quadrupole mass spectrometer

NASA Astrophysics Data System (ADS)

Prada, Svitlana V.; Bohme, Diethard K.; Baranov, Vladimir I.

2007-03-01

We report ion-mobility measurements with a modified triple quadrupole mass spectrometer fitted with an ion molecule reactor (IMR) designed to investigate ion molecule reactivity in organic mass spectrometry. Functionalized pentacene ions, which are generally unreactive were chosen for study to decouple drift/diffusion effects from reactivity (including clustering). The IMR is equipped with a variable axial electrostatic drift field (ADF) and is able to trap ions. These capabilities were successfully employed in the measurement of ion mobilities in different modes of IMR operation. Theoretical modeling of the drift dynamics and the special localization of the large ion packet was successfully implemented. The contribution of the quadrupole RF field to the drift dynamics also was taken into consideration.

Large-scale shell-model calculations for 32-39P isotopes

NASA Astrophysics Data System (ADS)

Srivastava, P. C.; Hirsch, J. G.; Ermamatov, M. J.; Kota, V. K. B.

2012-10-01

In this work, the structure of 32-39P isotopes is described in the framework of stateof-the-art large-scale shell-model calculations, employing the code ANTOINE with three modern effective interactions: SDPF-U, SDPF-NR and the extended pairing plus quadrupole-quadrupoletype forces with inclusion of monopole interaction (EPQQM). Protons are restricted to fill the sd shell, while neutrons are active in the sd - pf valence space. Results for positive and negative level energies and electromagnetic observables are compared with the available experimental data.

Higher-order dielectrophoretic effects: levitation at a field null.

PubMed

Washizu, M; Jones, T B; Kaler, K V

1993-08-20

Experiments with certain new micro-electrode structures used to achieve passive dielectrophoretic levitation of small particles and biological cells reveal a pronounced size-dependent effect not anticipated by the conventional dipole-based model. The conventional theory fails to predict this size effect because it neglects higher-order moments such as the quadrupole, hexapole, and octupole. These higher-order moments are in fact responsible for the levitation force achieved by azimuthally periodic electrode structures because, in such geometries, the electric field is zero along the axis so that the induced dipole moment must be zero. For example, the planar quadrupole levitates particles passively along the central axis through the interaction of its field with the induced quadrupolar moment of the particle. The size effect reported with this structure is readily explained in terms of this quadrupolar component of the ponderomotive force exerted on the particle.

Formation of a Fluorous/Organic Biphasic Supramolecular Octopus Assembly for Enhanced Porphyrin Phosphorescence in Air

DOE PAGES

Yang, Chi; Arvapally, Ravi K.; Tekarli, Sammer M.; ...

2015-03-03

The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal- interactions affords the supramolecular assemblies [1PtOEP] or [1H(2)OEP] (2a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes.

Fourier transform microwave spectroscopy of the SiCl+ ion

NASA Astrophysics Data System (ADS)

Tanaka, Keiichi; Harada, Kensuke; Cabezas, Carlos; Endo, Yasuki

2018-03-01

Fourier transform microwave spectra for the J = 1 ← 0 and 2 ← 1 rotational transitions of the SiCl+ ion were observed for two isotopologues (35 Cl and 37 Cl) in the ground and the first excited vibrational states of the ground 1Σ+ electronic state. Thanks to the high resolution of the FTMW spectrometer, hyperfine structures due to the quadrupole moment of the chlorine nucleus and the nuclear spin-rotation interaction were fully resolved. The observed FTMW spectra were combined with previously reported MMW and diode laser spectra in an analysis to determine the mass-independent Dunham coefficients Uk,l as well as a mass scaling parameter Δ01Cl = - 0.856 (30) . The equilibrium bond length of SiCl+ determined is re = 1.9439729 (10) Å and the nuclear quadrupole coupling constant of Si35 Cl+ is eQqe = - 11.8788 (23) MHz.

Benchmarking Atomic Data for Astrophysics: Be-like Ions between B II and Ne VII

NASA Astrophysics Data System (ADS)

Wang, Kai; Chen, Zhan Bin; Zhang, Chun Yu; Si, Ran; Jönsson, Per; Hartman, Henrik; Gu, Ming Feng; Chen, Chong Yang; Yan, Jun

2018-02-01

Large-scale self-consistent multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction calculations are reported for the n≤slant 6 levels in Be-like ions from B II to Ne VII. Effects from electron correlation are taken into account by means of large expansions in terms of a basis of configuration state functions, and a complete and accurate data set of excitation energies; lifetimes; wavelengths; electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole line strengths; transition rates; and oscillator strengths for these levels is provided for each ion. Comparisons are made with available experimental and theoretical results. The uncertainty of excitation energies is assessed to be 0.01% on average, which makes it possible to find and rule out misidentifications and aid new line identifications involving high-lying levels in astrophysical spectra. The complete data set is also useful for modeling and diagnosing astrophysical plasmas.

Measuring the Magnetic Center Behavior of an ILC Superconducting Quadrupole Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spencer, Cherrill M.; Adolphsen, Chris; Berndt, Martin

2011-02-07

The main linacs of the proposed International Linear Collider (ILC) consist of superconducting cavities operated at 2K. The accelerating cavities are contained in a contiguous series of cryogenic modules that also house the main linac quadrupoles, thus the quadrupoles also need to be superconducting. In an early ILC design, these magnets are about 0.6 m long, have cos (2{theta}) coils, and operate at constant field gradients up to 60 T/m. In order to preserve the small beam emittances in the ILC linacs, the e+ and e- beams need to traverse the quadrupoles near their magnetic centers. A quadrupole shunting techniquemore » is used to measure the quadrupole alignment with the beams; this process requires the magnetic centers move by no more than about 5 micrometers when their strength is changed. To determine if such tight stability is achievable in a superconducting quadrupole, we at SLAC measured the magnetic center motions in a prototype ILC quadrupole built at CIEMAT in Spain. A rotating coil technique was used with a better than 0.1 micrometer precision in the relative field center position, and less than a 2 micrometer systematic error over 30 minutes. This paper describes the warm-bore cryomodule that houses the quadrupole in its Helium vessel, the magnetic center measurement system, the measured center data and strength and harmonics magnetic data.« less

Calculation of total cross sections for charge exchange in molecular collisions

NASA Technical Reports Server (NTRS)

Ioup, J.

1979-01-01

Areas of investigation summarized include nitrogen ion-nitrogen molecule collisions; molecular collisions with surfaces; molecular identification from analysis of cracking patterns of selected gases; computer modelling of a quadrupole mass spectrometer; study of space charge in a quadrupole; transmission of the 127 deg cylindrical electrostatic analyzer; and mass spectrometer data deconvolution.

Tolerance analyses of a quadrupole magnet for advanced photon source upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J., E-mail: Jieliu@aps.anl.gov; Jaski, M., E-mail: jaski@aps.anl.gov; Borland, M., E-mail: borland@aps.anl.gov

2016-07-27

Given physics requirements, the mechanical fabrication and assembly tolerances for storage ring magnets can be calculated using analytical methods [1, 2]. However, this method is not easy for complicated magnet designs [1]. In this paper, a novel method is proposed to determine fabrication and assembly tolerances consistent with physics requirements, through a combination of magnetic and mechanical tolerance analyses. In this study, finite element analysis using OPERA is conducted to estimate the effect of fabrication and assembly errors on the magnetic field of a quadrupole magnet and to determine the allowable tolerances to achieve the specified magnetic performances. Based onmore » the study, allowable fabrication and assembly tolerances for the quadrupole assembly are specified for the mechanical design of the quadrupole magnet. Next, to achieve the required assembly level tolerances, mechanical tolerance stackup analyses using a 3D tolerance analysis package are carried out to determine the part and subassembly level fabrication tolerances. This method can be used to determine the tolerances for design of other individual magnets and of magnet strings.« less

Tidal coupling of a Schwarzschild black hole and circularly orbiting moon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang Hua; Lovelace, Geoffrey

2005-12-15

We describe the possibility of using the laser interferometer space antenna (LISA) 's gravitational-wave observations to study, with high precision, the response of a massive central body (e.g. a black hole or a soliton star) to the tidal gravitational pull of an orbiting, compact, small-mass object (a white dwarf, neutron star, or small-mass black hole). Motivated by this LISA application, we use first-order perturbation theory to study tidal coupling for a special, idealized case: a Schwarzschild black hole of mass M, tidally perturbed by a 'moon' with mass {mu}<>M with orbital angularmore » velocity {omega}. We investigate the details of how the tidal deformation of the hole gives rise to an induced quadrupole moment I{sub ij} in the hole's external gravitational field at large radii, including the vicinity of the moon. In the limit that the moon is static, we find, in Schwarzschild coordinates and Regge-Wheeler gauge, the surprising result that there is no induced quadrupole moment. We show that this conclusion is gauge dependent and that the static, induced quadrupole moment for a black hole is inherently ambiguous, and we contrast this with an earlier result of Suen, which gave, in a very different gauge, a nonzero static induced quadrupole moment with a sign opposite to what one would get for a fluid central body. For the orbiting moon and the central Schwarzschild hole, we find (in agreement with a recent result of Poisson) a time-varying induced quadrupole moment that is proportional to the time derivative of the moon's tidal field, I{sub ij}=(32/45)M{sup 6}E{sub ij} and that therefore is out of phase with the tidal field by a spatial angle {pi}/4 and by a temporal phase shift {pi}/2. This induced quadrupole moment produces a gravitational force on the moon that reduces its orbital energy and angular momentum at the same rate as the moon's tidal field sends energy and angular momentum into the hole's horizon. As a partial analog of a result derived long ago by Hartle for a spinning hole and a static distant companion, we show that the orbiting moon's tidal field induces a tidal bulge on the hole's horizon, and that the rate of change of the horizon shape (i.e. the horizon shear) leads the perturbing tidal field at the horizon by an angle 4M{omega}. We prefer to avoid introducing an ingoing null geodesic, as Hartle did in his definition of the phase shift, because the moon is in the central body's near zone (b<<1/{omega}) and thus should interact with the horizon instantaneously, not causally. We discuss the implications of these results for LISA's future observations of tidal coupling, including the inappropriateness of using the concepts of tidal polarizability and tidal lag or lead angle, for the massive central body, when discussing LISA's observations.« less

Organization of model helical peptides in lipid bilayers: insight into the behavior of single-span protein transmembrane domains.

PubMed Central

Sharpe, Simon; Barber, Kathryn R; Grant, Chris W M; Goodyear, David; Morrow, Michael R

2002-01-01

Selectively deuterated transmembrane peptides comprising alternating leucine-alanine subunits were examined in fluid bilayer membranes by solid-state nuclear magnetic resonance (NMR) spectroscopy in an effort to gain insight into the behavior of membrane proteins. Two groups of peptides were studied: 21-mers having a 17-amino-acid hydrophobic domain calculated to be close in length to the hydrophobic thickness of 1-palmitoyl-2-oleoyl phosphatidylcholine and 26-mers having a 22-amino-acid hydrophobic domain calculated to exceed the membrane hydrophobic thickness. (2)H NMR spectral features similar to ones observed for transmembrane peptides from single-span receptors of higher animal cells were identified which apparently correspond to effectively monomeric peptide. Spectral observations suggested significant distortion of the transmembrane alpha-helix, and/or potential for restriction of rotation about the tilted helix long axis for even simple peptides. Quadrupole splittings arising from the 26-mer were consistent with greater peptide "tilt" than were those of the analogous 21-mer. Quadrupole splittings associated with monomeric peptide were relatively insensitive to concentration and temperature over the range studied, indicating stable average conformations, and a well-ordered rotation axis. At high peptide concentration (6 mol% relative to phospholipid) it appeared that the peptide predicted to be longer than the membrane thickness had a particular tendency toward reversible peptide-peptide interactions occurring on a timescale comparable with or faster than approximately 10(-5) s. This interaction may be direct or lipid-mediated and was manifest as line broadening. Peptide rotational diffusion rates within the membrane, calculated from quadrupolar relaxation times, T(2e), were consistent with such interactions. In the case of the peptide predicted to be equal to the membrane thickness, at low peptide concentration spectral lineshape indicated the additional presence of a population of peptide having rotational motion that was restricted on a timescale of 10(-5) s. PMID:12080125

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Chutjian, Ara (Inventor); Brennen, Reid A. (Inventor); Hecht, Michael (Inventor); Wiberg, Dean (Inventor); Orient, Otto (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Fuerstenau, Stephen D. (Inventor); Yee, Karl Y. (Inventor); Chutjian, Ara (Inventor); Orient, Otto J. (Inventor); Rice, John T. (Inventor)

2002-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Chutjian, Ara (Inventor); Rice, John T. (Inventor); Fuerstenau, Stephen D. (Inventor); Orient, Otto J. (Inventor); Yee, Karl Y. (Inventor)

2000-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Yee, Karl Y. (Inventor); Fuerstenau, Stephen D. (Inventor); Orient, Otto J. (Inventor); Rice, John T. (Inventor); Chutjian, Ara (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Hecht, Michael (Inventor); Wiberg, Dean (Inventor); Orient, Otto (Inventor); Brennen, Reid A. (Inventor); Chutjian, Ara (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and aligrnent for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Orient, Otto (Inventor); Wiberg, Dean (Inventor); Brennen, Reid A. (Inventor); Hecht, Michael (Inventor); Chutjian, Ara (Inventor)

2000-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Mechanical performance of short models for MQXF, the Nb3Sn low-β quadrupole for the Hi-Lumi LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vallone, Giorgio; Ambrosio, Giorgio; Anderssen, Eric

In the framework of the Hi-Lumi LHC Project, CERN and U.S. LARP are jointly developing MQXF, a 150-mm aperture high-field Nb3Sn quadrupole for the upgrade of the inner triplet of the low-beta interaction regions. The magnet is supported by a shell-based structure, providing the preload by means of bladder-key technology and differential thermal contraction of the various components. Two short models have been produced using the same cross section currently considered for the final magnet. The structures were preliminarily tested replacing the superconducting coils with blocks of aluminum. This procedure allows for model validation and calibration, and also to setmore » performance goals for the real magnet. Strain gauges were used to monitor the behavior of the structure during assembly, cool down and also excitation in the case of the magnets. The various structures differ for the shell partitioning strategies adopted and for the presence of thick or thin laminations. This study presents the results obtained and discusses the mechanical performance of all the short models produced up to now.« less

Blue and white light emission in Tm3+ and Tm3+/Dy3+ doped zinc phosphate glasses upon UV light excitation

NASA Astrophysics Data System (ADS)

Meza-Rocha, A. N.; Speghini, A.; Lozada-Morales, R.; Caldiño, U.

2016-08-01

A spectroscopic study based on photoluminescence spectra and decay time profiles in Tm3+ and Tm3+/Dy3+ doped Zn(PO3)2 glasses is reported. The Tm3+ doped Zn(PO3)2 glass, upon 357 nm excitation, exhibits blue emission with CIE1931 chromaticity coordinates, x = 0.157 and y = 0.030, and color purity of about 96%. Under excitations at 348, 352 and 363 nm, which match with the emissions of AlGaN and GaN based LEDs, the Tm3+/Dy3+ co-doped Zn(PO3)2 glass displays natural white, bluish white and cool white overall emissions, with correlated color temperature values of 4523, 10700 and 7788 K, respectively, depending strongly on the excitation wavelength. The shortening of the Dy3+ emission decay time in presence of Tm3+ suggests that Dy3+→Tm3+ non-radiative energy transfer occurs. By using the Inokuti-Hirayama model, it is inferred that an electric quadrupole-quadrupole interaction might be the dominant mechanism involved in the energy transfer. The efficiency and probability of this energy transfer are 0.12 and 126.70 s-1, respectively.

Mechanical performance of short models for MQXF, the Nb3Sn low-β quadrupole for the Hi-Lumi LHC

DOE PAGES

Vallone, Giorgio; Ambrosio, Giorgio; Anderssen, Eric; ...

2016-12-23

In the framework of the Hi-Lumi LHC Project, CERN and U.S. LARP are jointly developing MQXF, a 150-mm aperture high-field Nb3Sn quadrupole for the upgrade of the inner triplet of the low-beta interaction regions. The magnet is supported by a shell-based structure, providing the preload by means of bladder-key technology and differential thermal contraction of the various components. Two short models have been produced using the same cross section currently considered for the final magnet. The structures were preliminarily tested replacing the superconducting coils with blocks of aluminum. This procedure allows for model validation and calibration, and also to setmore » performance goals for the real magnet. Strain gauges were used to monitor the behavior of the structure during assembly, cool down and also excitation in the case of the magnets. The various structures differ for the shell partitioning strategies adopted and for the presence of thick or thin laminations. This study presents the results obtained and discusses the mechanical performance of all the short models produced up to now.« less

Selective Isobar Suppression for Accelerator Mass Spectrometry and Radioactive Ion Beam Science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galindo-Uribarri, Alfredo; Havener, Charles C; Lewis, Thomas L.

2010-01-01

Several applications of AMS will benefit from pushing further the detection limits of AMS isotopes. A new method of selective isobar suppression by photodetachment in a radio-frequency quadrupole ion cooler is being developed at HRIBF with a two-fold purpose: (1) increasing the AMS sensitivity for certain isotopes of interest and (2) purifying radioactive ion beams for nuclear science. The potential of suppressing the 36S contaminants in a 36Cl beam using this method has been explored with stable S- and Cl- ions and a Nd:YLF laser. In the study, the laser beam was directed along the experiment's beam line and throughmore » a RF quadrupole ion cooler. Negative 32S and 35Cl ions produced by a Cs sputter ion source were focused into the ion cooler where they were slowed by collisions with He buffer gas; this increased the interaction time between the negative ion beam and the laser beam. As a result, suppression of S- by a factor of 3000 was obtained with about 2.5 W average laser power in the cooler while no reduction in Cl- current was observed.« less

Second rank direction cosine spherical tensor operators and the nuclear electric quadrupole hyperfine structure Hamiltonian of rotating molecules

NASA Astrophysics Data System (ADS)

di Lauro, C.

2018-03-01

Transformations of vector or tensor properties from a space-fixed to a molecule-fixed axis system are often required in the study of rotating molecules. Spherical components λμ,ν of a first rank irreducible tensor can be obtained from the direction cosines between the two axis systems, and a second rank tensor with spherical components λμ,ν(2) can be built from the direct product λ × λ. It is shown that the treatment of the interaction between molecular rotation and the electric quadrupole of a nucleus is greatly simplified, if the coefficients in the axis-system transformation of the gradient of the electric field of the outer charges at the coupled nucleus are arranged as spherical components λμ,ν(2). Then the reduced matrix elements of the field gradient operators in a symmetric top eigenfunction basis, including their dependence on the molecule-fixed z-angular momentum component k, can be determined from the knowledge of those of λ(2) . The hyperfine structure Hamiltonian Hq is expressed as the sum of terms characterized each by a value of the molecule-fixed index ν, whose matrix elements obey the rule Δk = ν. Some of these terms may vanish because of molecular symmetry, and the specific cases of linear and symmetric top molecules, orthorhombic molecules, and molecules with symmetry lower than orthorhombic are considered. Each ν-term consists of a contraction of the rotational tensor λ(2) and the nuclear quadrupole tensor in the space-fixed frame, and its matrix elements in the rotation-nuclear spin coupled representation can be determined by the standard spherical tensor methods.

High-resolution molecular-beam spectroscopy of NaCN and Na 13CN

NASA Astrophysics Data System (ADS)

van Vaals, J. J.; Meerts, W. Leo; Dymanus, A.

The sodium cyanide molecule was studied by molecular-beam electric-resonance spectroscopy in the microwave region. We used the seeded-beam technique to produce a supersonic beam with strong translational, rotational and vibrational cooling. In the frequency range 9.5-40 GHz we observed and identified for NaCN 186 and for Na 13CN 107 hyperfine transitions in 20 and 16 rotational transitions, respectively, all in the ground vibrational state. The rotational, the five quartic and three sextic centrifugal distortion constants of NaCN are: A″ = 57921.954(7) MHz; B″ = 8369.312(2) MHz, C″ = 7272.712(2) MHz. All quadrupole and several spin-rotation coupling constants for the hyperfine interaction were evaluated. The quadrupole coupling constants (in MHz) for NaCN are: eQq12(Na) = -5.344(5), eQq12 = 2.397(7). eQq12(N) = 2.148(4), eQq12(N) = -4.142(5). From these constants and those of Na 13CN we have determined the principal components of the quadrupole coupling tensor for potassium and nitrogen. The structure of sodium cyanide evaluated from the rotational constants of NaCN and Na 13CN was found to be T shaped, similar to the structure of KCN but completely different from the linear isocyanide configuration of LiNC. The effective structural parameters for sodium cyanide in the ground vibrational state are: rCN = 1.170(4) Å, rNaC = 2.379(15) Å, rN12N = 2.233(15) Å, in gratifying agreement with ab initio calculations. Both the geometrical structure and the hyperfine coupling justify the conclusion that the CN group in gaseous sodium cyanide approximately can be considered as a free CN - ion.

High energy proton induced radiation damage of rare earth permanent magnet quadrupoles

NASA Astrophysics Data System (ADS)

Schanz, M.; Endres, M.; Löwe, K.; Lienig, T.; Deppert, O.; Lang, P. M.; Varentsov, D.; Hoffmann, D. H. H.; Gutfleisch, O.

2017-12-01

Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material—single wedges and a fully assembled PMQ module—were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

High energy proton induced radiation damage of rare earth permanent magnet quadrupoles.

PubMed

Schanz, M; Endres, M; Löwe, K; Lienig, T; Deppert, O; Lang, P M; Varentsov, D; Hoffmann, D H H; Gutfleisch, O

2017-12-01

Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material-single wedges and a fully assembled PMQ module-were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

Nuclear Quadrupole Moments and Nuclear Shell Structure

DOE R&D Accomplishments Database

Townes, C. H.; Foley, H. M.; Low, W.

1950-06-23

Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

Coulomb-like elastic interaction induced by symmetry breaking in nematic liquid crystal colloids.

PubMed

Lee, Beom-Kyu; Kim, Sung-Jo; Kim, Jong-Hyun; Lev, Bohdan

2017-11-21

It is generally thought that colloidal particles in a nematic liquid crystal do not generate the first multipole term called deformation elastic charge as it violates the mechanical equilibrium. Here, we demonstrate theoretically and experimentally that this is not the case, and deformation elastic charges, as well as dipoles and quadrupoles, can be induced through anisotropic boundary conditions. We report the first direct observation of Coulomb-like elastic interactions between colloidal particles in a nematic liquid crystal. The behaviour of two spherical colloidal particles with asymmetric anchoring conditions induced by asymmetric alignment is investigated experimentally; the interaction of two particles located at the boundary of twist and parallel aligned regions is observed. We demonstrate that such particles produce deformation elastic charges and interact by Coulomb-like interactions.

Means and method for the focusing and acceleration of parallel beams of charged particles

DOEpatents

Maschke, Alfred W.

1983-07-05

A novel apparatus and method for focussing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The quadrupole arrays may comprise electrodes which are shared by two or more quadrupoles. Such quadrupole arrays are particularly adapted to providing strong focussing forces for high current, high brightness, beams of charged particles, said beams further comprising a plurality of parallel beams, or beamlets, each such beamlet being focussed by one quadrupole of the array. Such arrays may be incorporated in various devices wherein beams of charged particles are accelerated or transported, such as linear accelerators, klystron tubes, beam transport lines, etc.

Noise reduction in negative-ion quadrupole mass spectrometry

DOEpatents

Chastagner, P.

1993-04-20

A quadrupole mass spectrometer (QMS) system is described having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Noise reduction in negative-ion quadrupole mass spectrometry

DOEpatents

Chastagner, Philippe

1993-01-01

A quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Particle beam injector system and method

DOEpatents

Guethlein, Gary

2013-06-18

Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

Tuneable complementary metamaterial structures based on graphene for single and multiple transparency windows

PubMed Central

Ding, Jun; Arigong, Bayaner; Ren, Han; Zhou, Mi; Shao, Jin; Lu, Meng; Chai, Yang; Lin, Yuankun; Zhang, Hualiang

2014-01-01

Novel graphene-based tunable plasmonic metamaterials featuring single and multiple transparency windows are numerically studied in this paper. The designed structures consist of a graphene layer perforated with quadrupole slot structures and dolmen-like slot structures printed on a substrate. Specifically, the graphene-based quadrupole slot structure can realize a single transparency window, which is achieved without breaking the structure symmetry. Further investigations have shown that the single transparency window in the proposed quadrupole slot structure is more likely originated from the quantum effect of Autler-Townes splitting. Then, by introducing a dipole slot to the quadrupole slot structure to form the dolmen-like slot structure, an additional transmission dip could occur in the transmission spectrum, thus, a multiple-transparency-window system can be achieved (for the first time for graphene-based devices). More importantly, the transparency windows for both the quadrupole slot and the dolmen-like slot structures can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer (through electrostatic gating). The proposed slot metamaterial structures with tunable single and multiple transparency windows could find potential applications in many areas such as multiple-wavelength slow-light devices, active plasmonic switching, and optical sensing. PMID:25146672

Tuneable complementary metamaterial structures based on graphene for single and multiple transparency windows.

PubMed

Ding, Jun; Arigong, Bayaner; Ren, Han; Zhou, Mi; Shao, Jin; Lu, Meng; Chai, Yang; Lin, Yuankun; Zhang, Hualiang

2014-08-22

Novel graphene-based tunable plasmonic metamaterials featuring single and multiple transparency windows are numerically studied in this paper. The designed structures consist of a graphene layer perforated with quadrupole slot structures and dolmen-like slot structures printed on a substrate. Specifically, the graphene-based quadrupole slot structure can realize a single transparency window, which is achieved without breaking the structure symmetry. Further investigations have shown that the single transparency window in the proposed quadrupole slot structure is more likely originated from the quantum effect of Autler-Townes splitting. Then, by introducing a dipole slot to the quadrupole slot structure to form the dolmen-like slot structure, an additional transmission dip could occur in the transmission spectrum, thus, a multiple-transparency-window system can be achieved (for the first time for graphene-based devices). More importantly, the transparency windows for both the quadrupole slot and the dolmen-like slot structures can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer (through electrostatic gating). The proposed slot metamaterial structures with tunable single and multiple transparency windows could find potential applications in many areas such as multiple-wavelength slow-light devices, active plasmonic switching, and optical sensing.

Low-frequency quadrupole impedance of undulators and wigglers

DOE PAGES

Blednykh, A.; Bassi, G.; Hidaka, Y.; ...

2016-10-25

An analytical expression of the low-frequency quadrupole impedance for undulators and wigglers is derived and benchmarked against beam-based impedance measurements done at the 3 GeV NSLS-II storage ring. The adopted theoretical model, valid for an arbitrary number of electromagnetic layers with parallel geometry, allows to calculate the quadrupole impedance for arbitrary values of the magnetic permeability μ r. Here, in the comparison of the analytical results with the measurements for variable magnet gaps, two limit cases of the permeability have been studied: the case of perfect magnets (μ r → ∞), and the case in which the magnets are fullymore » saturated (μ r = 1).« less

Influence of Pt substitution on magnetic properties of multipolar ordering compounds Ce(Pd,Pt)3S4

NASA Astrophysics Data System (ADS)

Michimura, S.; Nishikawa, Ushio; Shimizu, Akihide; Kosaka, Masashi; Numakura, Ryosuke; Iizuka, Ryosuke; Katano, Susumu

2018-05-01

We have studied the magnetic properties of the multipolar ordering compounds Ce(Pd1-xPtx) 3S4 with 0.00 ≤ x ≤ 0.53 by means of magnetic susceptibility and magnetization measurements. In CePd3S4 , a simultaneous phase transition of the antiferro quadrupolar (AFQ) ordering and ferro magnetic (FM) ordering has been observed at 6.3 K. It has been suggested that the primary order parameter of CePd3S4 is the quadrupole moments, and it has not been understood why the FM ordering occurs at very high temperature which is almost the same magnetic transition temperature of GdPd3S4 . GdPd3S4 shows an antiferromagnetic (AFM) transition at 5.8 K. With increasing Pt substitution in CePd3S4 , the FM transition temperature TC (x) is rapidly suppressed to 2.4 K for x ≃ 0.3 and approaches asymptotically to 1.9 K (x = 0.53) . The results of magnetization curve suggest that the ordered state below TC (x) remains FM and AFQ ordered state for the whole range of x. For x ≥ 0.29 , TC (x) reaches at around 2 K, a new AFM transition was observed at TN (x) ≃ 7 K . We determined the T - x phase diagram, and discuss the phase transitions at TC (x) and TN (x) . The results suggest the possibility of the presence of the correlation between the magnetic interaction and the quadrupole interaction, and the correlation is not understood based on the previous multipolar model.

Klystron having electrostatic quadrupole focusing arrangement

DOEpatents

Maschke, Alfred W.

1983-08-30

A klystron includes a source for emitting at least one electron beam, and an accelerator for accelarating the beam in a given direction through a number of drift tube sections successively aligned relative to one another in the direction of the beam. A number of electrostatic quadrupole arrays are successively aligned relative to one another along at least one of the drift tube sections in the beam direction for focusing the electron beam. Each of the electrostatic quadrupole arrays forms a different quadrupole for each electron beam. Two or more electron beams can be maintained in parallel relationship by the quadrupole arrays, thereby enabling space charge limitations encountered with conventional single beam klystrons to be overcome.

Klystron having electrostatic quadrupole focusing arrangement

DOEpatents

Maschke, A.W.

1983-08-30

A klystron includes a source for emitting at least one electron beam, and an accelerator for accelerating the beam in a given direction through a number of drift tube sections successively aligned relative to one another in the direction of the beam. A number of electrostatic quadrupole arrays are successively aligned relative to one another along at least one of the drift tube sections in the beam direction for focusing the electron beam. Each of the electrostatic quadrupole arrays forms a different quadrupole for each electron beam. Two or more electron beams can be maintained in parallel relationship by the quadrupole arrays, thereby enabling space charge limitations encountered with conventional single beam klystrons to be overcome. 4 figs.

A modified quadrupole mass spectrometer with custom RF link rods driver for remote operation

NASA Technical Reports Server (NTRS)

Tashbar, P. W.; Nisen, D. B.; Moore, W. W., Jr.

1973-01-01

A commercial quadrupole residual gas analyzer system has been upgraded for operation at extended cable lengths. Operation inside a vacuum chamber for the standard quadrupole nude head is limited to approximately 2 m from its externally located rf/dc generator because of the detuning of the rf oscillator circuits by the coaxial cable reactance. The advance of long distance remote operation inside a vacuum chamber for distances of 45 and 60 m was made possible without altering the quadrupole's rf/dc generator circuit by employing an rf link to drive the quadrupole rods. Applications of the system have been accomplished for in situ space simulation thermal/vacuum testing of sophisticated payloads.

Constrained Hartree-Fock Theory and Study of Deformed Structures of Closed Shell Nuclei

NASA Astrophysics Data System (ADS)

Praharaj, Choudhury

2016-03-01

We have studied some N or Z = 50 nuclei in a microscopic model with effective interaction in a reasonably large shell model space. Excitation of particles across 50 shell closure leads to well-deformed excited prolate configurations. The potential energy surfaces of nuclei are studied using Hartree-Fock theory with quadrupole constraint to explore the various deformed configurations of N = 50 nuclei 82Ge , 84Se and 86Kr . Energy spectra are calculated from various intrinsic states using Peierls-Yoccoz angular momentum projection technique. Results of spectra and electromagnetic moments and transitions will be presented for N = 50 nuclei and for Z = 50 114Sn nucleus. Supported by Grant No SB/S2/HEP-06/2013 of DST.

Relativistic many-body bound systems: electromagnetic properties. Monograph report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danos, M.; Gillet, V.

1977-04-01

The formulae for the calculation of the electron scattering form factors, and of the static magnetic dipole and electric quadrupole moments, of relativistic many-body bound systems are derived. The framework, given in NBS Monograph 147, is relativistic quantum field theory in the Schrodinger picture; the physical particles, i.e., the solutions of the interacting fields, are given as linear combinations of the solutions of the free fields, called the parton fields. The parton--photon interaction is taken as given by minimal coupling. In addition, the contribution of the photon--vector meson vertex of the vector dominance model is derived.

HZEFRG1: An energy-dependent semiempirical nuclear fragmentation model

NASA Technical Reports Server (NTRS)

Townsend, Lawrence W.; Wilson, John W.; Tripathi, Ram K.; Norbury, John W.; Badavi, Francis F.; Khan, Ferdous

1993-01-01

Methods for calculating cross sections for the breakup of high-energy heavy ions by the combined nuclear and coulomb fields of the interacting nuclei are presented. The nuclear breakup contributions are estimated with an abrasion-ablation model of heavy ion fragmentation that includes an energy-dependent, mean free path. The electromagnetic dissociation contributions arising from the interacting coulomb fields are estimated by using Weizsacker-Williams theory extended to include electric dipole and electric quadrupole contributions. The complete computer code that implements the model is included as an appendix. Extensive comparisons of cross section predictions with available experimental data are made.

A theoretical study on the characteristics of the intermolecular interactions in the active site of human androsterone sulphotransferase: DFT calculations of NQR and NMR parameters and QTAIM analysis.

PubMed

Astani, Elahe K; Heshmati, Emran; Chen, Chun-Jung; Hadipour, Nasser L

2016-07-01

A theoretical study at the level of density functional theory (DFT) was performed to characterize noncovalent intermolecular interactions, especially hydrogen bond interactions, in the active site of enzyme human androsterone sulphotransferase (SULT2A1/ADT). Geometry optimization, interaction energy, (2)H, (14)N, and (17)O electric field gradient (EFG) tensors, (1)H, (13)C, (17)O, and (15)N chemical shielding (CS) tensors, Natural Bonding Orbital (NBO) analysis, and quantum theory of atoms in molecules (QTAIM) analysis of this active site were investigated. It was found that androsterone (ADT) is able to form hydrogen bonds with residues Ser80, Ile82, and His99 of the active site. The interaction energy calculations and NBO analysis revealed that the ADT molecule forms the strongest hydrogen bond with Ser80. Results revealed that ADT interacts with the other residues through electrostatic and Van der Waals interactions. Results showed that these hydrogen bonds influence on the calculated (2)H, (14)N, and (17)O quadrupole coupling constants (QCCs), as well as (1)H, (13)C, (17)O, and (15)N CS tensors. The magnitude of the QCC and CS changes at each nucleus depends directly on its amount of contribution to the hydrogen bond interaction. Copyright © 2016 Elsevier Inc. All rights reserved.

Tunable Luminescence in Sr2MgSi2O7:Tb3+, Eu3+Phosphors Based on Energy Transfer

PubMed Central

Li, Minhong; Wang, Lili; Ran, Weiguang; Deng, Zhihan; Shi, Jinsheng; Ren, Chunyan

2017-01-01

A series of Tb3+, Eu3+-doped Sr2MgSi2O7 (SMSO) phosphors were synthesized by high temperature solid-state reaction. X-ray diffraction (XRD) patterns, Rietveld refinement, photoluminescence spectra (PL), and luminescence decay curves were utilized to characterize each sample’s properties. Intense green emission due to Tb3+ 5D4→7F5 transition was observed in the Tb3+ single-doped SMSO sample, and the corresponding concentration quenching mechanism was demonstrated to be a diople-diople interaction. A wide overlap between Tb3+ emission and Eu3+ excitationspectraresults in energy transfer from Tb3+ to Eu3+. This has been demonstrated by the emission spectra and decay curves of Tb3+ in SMSO:Tb3+, Eu3+ phosphors. Energy transfer mechanism was determined to be a quadrupole-quadrupole interaction. And critical distance of energy transfer from Tb3+ to Eu3+ ions is calculated to be 6.7 Å on the basis of concentration quenching method. Moreover, white light emission was generated via adjusting concentration ratio of Tb3+ and Eu3+ in SMSO:Tb3+, Eu3+ phosphors. All the results indicate that SMSO:Tb3+, Eu3+ is a promising single-component white light emitting phosphor. PMID:28772587

Characterization of the ELIMED prototype permanent magnet quadrupole system

NASA Astrophysics Data System (ADS)

Russo, A. D.; Schillaci, F.; Pommarel, L.; Romano, F.; Amato, A.; Amico, A. G.; Calanna, A.; Cirrone, G. A. P.; Costa, M.; Cuttone, G.; Amato, C.; De Luca, G.; Flacco, F. A.; Gallo, G.; Giove, D.; Grmek, A.; La Rosa, G.; Leanza, R.; Maggiore, M.; Malka, V.; Milluzzo, G.; Petringa, G.; Pipek, J.; Scuderi, V.; Vauzour, B.; Zappalà, E.

2017-01-01

The system described in this work is meant to be a prototype of a more performing one that will be installed at ELI-Beamlines in Prague for the collection of ions produced after the interaction Laser-target, [1]. It has been realized by the researchers of INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) and SIGMAPHI, a French company, using a system of Permanent Magnet Quadrupoles (PMQs), [2]. The final system that will be installed in Prague is designed for protons and carbons up to 60 MeV/u, around 10 times more than the energies involved in the present work. The prototype, shown in this work, has been tested in collaboration with the SAPHIR experimental facility group at LOA (Laboratoire d'Optique Appliqueé) in Paris using a 200 TW Ti:Sapphire laser system. The purpose of this work is to validate the design and the performances of this large and compact bore system and to characterize the beam produced after the interaction laser-target and its features. Moreover, the optics simulations have been compared with a real beam shape on a GAFChromic film. The procedure used during the experimental campaign and the most relevant results are reported here demonstrating a good agreement with the simulations and a good control on the beam optics.

A study of the semiconductor compound СuAlO2 by the method of nuclear quadrupole resonance of Cu

NASA Astrophysics Data System (ADS)

Matukhin, V. L.; Khabibulin, I. Kh.; Shul'gin, D. A.; Smidt, S. V.

2012-07-01

The method of nuclear quadrupole resonance of Cu (NQR Cu) is used to study the samples of a semiconductor compound CuAlO2. The crystal structure of CuAlO2 belongs to the family of delafossite - the mineral of a basic CuFeO2 structure. Transparent semiconductor oxides, such as CuAlO2, have attracted recent attention as promising thermoelectric materials.

Targeted Proteomic Quantification on Quadrupole-Orbitrap Mass Spectrometer*

PubMed Central

Gallien, Sebastien; Duriez, Elodie; Crone, Catharina; Kellmann, Markus; Moehring, Thomas; Domon, Bruno

2012-01-01

There is an immediate need for improved methods to systematically and precisely quantify large sets of peptides in complex biological samples. To date protein quantification in biological samples has been routinely performed on triple quadrupole instruments operated in selected reaction monitoring mode (SRM), and two major challenges remain. Firstly, the number of peptides to be included in one survey experiment needs to be increased to routinely reach several hundreds, and secondly, the degree of selectivity should be improved so as to reliably discriminate the targeted analytes from background interferences. High resolution and accurate mass (HR/AM) analysis on the recently developed Q-Exactive mass spectrometer can potentially address these issues. This instrument presents a unique configuration: it is constituted of an orbitrap mass analyzer equipped with a quadrupole mass filter as the front-end for precursor ion mass selection. This configuration enables new quantitative methods based on HR/AM measurements, including targeted analysis in MS mode (single ion monitoring) and in MS/MS mode (parallel reaction monitoring). The ability of the quadrupole to select a restricted m/z range allows one to overcome the dynamic range limitations associated with trapping devices, and the MS/MS mode provides an additional stage of selectivity. When applied to targeted protein quantification in urine samples and benchmarked with the reference SRM technique, the quadrupole-orbitrap instrument exhibits similar or better performance in terms of selectivity, dynamic range, and sensitivity. This high performance is further enhanced by leveraging the multiplexing capability of the instrument to design novel acquisition methods and apply them to large targeted proteomic studies for the first time, as demonstrated on 770 tryptic yeast peptides analyzed in one 60-min experiment. The increased quality of quadrupole-orbitrap data has the potential to improve existing protein quantification methods in complex samples and address the pressing demand of systems biology or biomarker evaluation studies. PMID:22962056

Cd hyperfine interactions in DNA bases and DNA of mouse strains infected with Trypanosoma cruzi investigated by perturbed angular correlation spectroscopy and ab initio calculations.

PubMed

Petersen, Philippe A D; Silva, Andreia S; Gonçalves, Marcos B; Lapolli, André L; Ferreira, Ana Maria C; Carbonari, Artur W; Petrilli, Helena M

2014-06-03

In this work, perturbed angular correlation (PAC) spectroscopy is used to study differences in the nuclear quadrupole interactions of Cd probes in DNA molecules of mice infected with the Y-strain of Trypanosoma cruzi. The possibility of investigating the local genetic alterations in DNA, which occur along generations of mice infected with T. cruzi, using hyperfine interactions obtained from PAC measurements and density functional theory (DFT) calculations in DNA bases is discussed. A comparison of DFT calculations with PAC measurements could determine the type of Cd coordination in the studied molecules. To the best of our knowledge, this is the first attempt to use DFT calculations and PAC measurements to investigate the local environment of Cd ions bound to DNA bases in mice infected with Chagas disease. The obtained results also allowed the detection of local changes occurring in the DNA molecules of different generations of mice infected with T. cruzi, opening the possibility of using this technique as a complementary tool in the characterization of complicated biological systems.

Some aspects of self-consistent higher-order interactions

NASA Astrophysics Data System (ADS)

Sakamoto, Hideo

2018-05-01

After a brief review of the formalism of the self-consistent higher-order interactions, applications of a ([Q 3 Q 3](2) · Q 2) type of three-body interaction to the quadrupole moment of the 3‑ state in 208Pb and the energy splitting of the septuplet of states (h 9/23‑)I with I = 3/2, 5/2, …, 15/2 in 209Bi are discussed. It is shown that if the contribution of the three-body interaction is included, the theoretical value of the Qel (3‑) moment becomes rather small compared to the experiment, but the observed small energy splitting of the septuplet can essentially be understood within the particle-vibration coupling model. Roles of non-linear field couplings provided by the self-consistent higher-order interactions are also discussed.

Conceptual Design Study of Nb(3)Sn Low-beta Quadrupoles for 2nd Generation LHC IRs

NASA Astrophysics Data System (ADS)

Zlobin, A. V.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bauer, P.

2002-10-01

Conceptual designs of 90-mm aperture high gradient quadrupoles based on the Nb3Sn superconductor, are being developed at Fermilab for possible 2nd generation IRs with the similar optics as in the current low-beta insertions. Magnet designs and results of magnetic, mechanical, thermal and quench protection analysis for these magnets are presented and discussed.

137 Ba Double Gamma Decay Measurement with GAMMASPHERE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merchán, E.; Moran, K.; Lister, C. J.

2015-05-28

The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0 + → 0 + transitions, where a single gamma transition is forbidden, the simultaneous emission of two γ-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via β-decay, the J π = 11/2 - isomericmore » state at 662 keV in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.« less

Determination of nuclear quadrupole moments – An example of the synergy of ab initio calculations and microwave spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kellö, Vladimir

Highly correlated scalar relativistic calculations of electric field gradients at nuclei in diatomic molecules in combination with accurate nuclear quadrupole coupling constants obtained from microwave spectroscopy are used for determination of nuclear quadrupole moments.

Unusual Enhancement of Magnetization by Pressure in the Antiferro-Quadrupole-Ordered Phase in CeB6

NASA Astrophysics Data System (ADS)

Ikeda, Suguru; Sera, Masafumi; Hane, Shingo; Uwatoko, Yoshiya; Kosaka, Masashi; Kunii, Satoru

2007-06-01

The effect of pressure on CeB6 was investigated by the measurement of the magnetization (M) under pressure, and we obtained the following results. The effect of pressure on M in phase I is very small. By applying pressure, TQ is enhanced, but TN and the critical field from the antiferromagnetic (AFM) phase III to the antiferro-quadrupole (AFQ) phase II (HcIII--II) are suppressed, as previously reported. The magnetization curve in phase III shows the characteristic shoulder at H˜ HcIII--II/2 at ambient pressure. This shoulder becomes much more pronounced by applying pressure. Both HcIII--II and the magnetic field, where a shoulder is seen in the magnetization curve in phase III, are largely suppressed by pressure. In phase II, the M-T curve at a low magnetic field exhibits an unusual concave temperature dependence below TQ down to TN. Thus, we found that the lower the magnetic field, the larger the enhancement of M in both phases III and II. To clarify the origin of the unusual pressure effect of M, we performed a mean-field calculation for the 4-sublattice model using the experimental results of dTQ/dP>0 and dTN/dP<0 and assuming the positive pressure dependence of the Txyz-antiferro-octupole (AFO) interaction. The characteristic features of the pressure effect of M obtained by the experiments could be reproduced well by the mean-field calculation. We found that the origin of the characteristic effect of pressure on CeB6 is the change in the subtle balance between the AFM interaction and the magnetic field-induced-effective FM interaction induced by the coexistence of the Oxy-AFQ and Txyz-AFO interactions under pressure.

Summary of the Persistent Current Effect Measurements in Nb 3 Sn and NbTi Accelerator Magnets at Fermilab

DOE PAGES

Velev, G. V.; Chlachidze, G.; DiMarco, J.; ...

2016-01-06

In the past 10 years, Fermilab has been executing an intensive R&D program on accelerator magnets based on Nb 3Sn superconductor technology. This R&D effort includes dipole and quadrupole models for different programs, such as LARP and 11 T dipoles for the LHC high-luminosity upgrade. Before the Nb 3Sn R&D program, Fermilab was involved in the production of the low-beta quadrupole magnets for LHC based on the NbTi superconductor. Additionally, during the 2003-2005 campaign to optimize the operation of the Tevatron, a large number of Tevatron magnets were re-measured. As a result of this field analysis, a systematic study ofmore » the persistent current decay and snapback effect in these magnets was performed. This paper summarizes the result of this study and presents a comparison between Nb 3Sn and NbTi dipoles and quadrupoles.« less

Rapid Quadrupole-Time-of-Flight Mass Spectrometry Method Quantifies Oxygen-Rich Lignin Compound in Complex Mixtures

NASA Astrophysics Data System (ADS)

Boes, Kelsey S.; Roberts, Michael S.; Vinueza, Nelson R.

2018-03-01

Complex mixture analysis is a costly and time-consuming task facing researchers with foci as varied as food science and fuel analysis. When faced with the task of quantifying oxygen-rich bio-oil molecules in a complex diesel mixture, we asked whether complex mixtures could be qualitatively and quantitatively analyzed on a single mass spectrometer with mid-range resolving power without the use of lengthy separations. To answer this question, we developed and evaluated a quantitation method that eliminated chromatography steps and expanded the use of quadrupole-time-of-flight mass spectrometry from primarily qualitative to quantitative as well. To account for mixture complexity, the method employed an ionization dopant, targeted tandem mass spectrometry, and an internal standard. This combination of three techniques achieved reliable quantitation of oxygen-rich eugenol in diesel from 300 to 2500 ng/mL with sufficient linearity (R2 = 0.97 ± 0.01) and excellent accuracy (percent error = 0% ± 5). To understand the limitations of the method, it was compared to quantitation attained on a triple quadrupole mass spectrometer, the gold standard for quantitation. The triple quadrupole quantified eugenol from 50 to 2500 ng/mL with stronger linearity (R2 = 0.996 ± 0.003) than the quadrupole-time-of-flight and comparable accuracy (percent error = 4% ± 5). This demonstrates that a quadrupole-time-of-flight can be used for not only qualitative analysis but also targeted quantitation of oxygen-rich lignin molecules in complex mixtures without extensive sample preparation. The rapid and cost-effective method presented here offers new possibilities for bio-oil research, including: (1) allowing for bio-oil studies that demand repetitive analysis as process parameters are changed and (2) making this research accessible to more laboratories. [Figure not available: see fulltext.

Conceptual design of a compact high gradient quadrupole magnet of varying strength using permanent magnets

NASA Astrophysics Data System (ADS)

Sinha, Gautam

2018-02-01

A concept is presented to design magnets using cylindrical-shaped permanent-magnet blocks, where various types of magnetic fields can be produced by either rotating or varying the size of the magnetic blocks within a given mechanical structure. A general method is introduced to calculate the 3D magnetic field produced by a set of permanent magnets. An analytical expression of the 2D field and the condition to generate various magnetic fields like dipole, quadrupole, and sextupole are derived. Using the 2D result as a starting point, a computer code is developed to get the optimum orientation of the magnets to obtain the user-specific target field profile over a given volume in 3D. Designs of two quadrupole magnets are presented, one using 12 and the other using 24 permanent-magnet blocks. Variation of the quadrupole strength is achieved using tuning coils of a suitable current density and specially designed end tubes. A new concept is introduced to reduce the integrated quadrupole field strength by inserting two hollow cylindrical tubes made of iron, one at each end. This will not affect the field gradient at the center but reduce the integrated field strength by shielding the magnetic field near the ends where the tubes are inserted. The advantages of this scheme are that it is easy to implement, the magnetic axis will not shift, and it will prevent interference with nearby devices. Around 40% integrated field variation is achieved using this method in the present example. To get a realistic estimation of the field quality, a complete 3D model using a nonlinear B -H curve is also studied using a finite-element-based computer code. An example to generate around an 80 T /m quadrupole field gradient is also presented.

Rapid Quadrupole-Time-of-Flight Mass Spectrometry Method Quantifies Oxygen-Rich Lignin Compound in Complex Mixtures

NASA Astrophysics Data System (ADS)

Boes, Kelsey S.; Roberts, Michael S.; Vinueza, Nelson R.

2017-12-01

Complex mixture analysis is a costly and time-consuming task facing researchers with foci as varied as food science and fuel analysis. When faced with the task of quantifying oxygen-rich bio-oil molecules in a complex diesel mixture, we asked whether complex mixtures could be qualitatively and quantitatively analyzed on a single mass spectrometer with mid-range resolving power without the use of lengthy separations. To answer this question, we developed and evaluated a quantitation method that eliminated chromatography steps and expanded the use of quadrupole-time-of-flight mass spectrometry from primarily qualitative to quantitative as well. To account for mixture complexity, the method employed an ionization dopant, targeted tandem mass spectrometry, and an internal standard. This combination of three techniques achieved reliable quantitation of oxygen-rich eugenol in diesel from 300 to 2500 ng/mL with sufficient linearity (R2 = 0.97 ± 0.01) and excellent accuracy (percent error = 0% ± 5). To understand the limitations of the method, it was compared to quantitation attained on a triple quadrupole mass spectrometer, the gold standard for quantitation. The triple quadrupole quantified eugenol from 50 to 2500 ng/mL with stronger linearity (R2 = 0.996 ± 0.003) than the quadrupole-time-of-flight and comparable accuracy (percent error = 4% ± 5). This demonstrates that a quadrupole-time-of-flight can be used for not only qualitative analysis but also targeted quantitation of oxygen-rich lignin molecules in complex mixtures without extensive sample preparation. The rapid and cost-effective method presented here offers new possibilities for bio-oil research, including: (1) allowing for bio-oil studies that demand repetitive analysis as process parameters are changed and (2) making this research accessible to more laboratories. [Figure not available: see fulltext.

Rapid Quadrupole-Time-of-Flight Mass Spectrometry Method Quantifies Oxygen-Rich Lignin Compound in Complex Mixtures.

PubMed

Boes, Kelsey S; Roberts, Michael S; Vinueza, Nelson R

2018-03-01

Complex mixture analysis is a costly and time-consuming task facing researchers with foci as varied as food science and fuel analysis. When faced with the task of quantifying oxygen-rich bio-oil molecules in a complex diesel mixture, we asked whether complex mixtures could be qualitatively and quantitatively analyzed on a single mass spectrometer with mid-range resolving power without the use of lengthy separations. To answer this question, we developed and evaluated a quantitation method that eliminated chromatography steps and expanded the use of quadrupole-time-of-flight mass spectrometry from primarily qualitative to quantitative as well. To account for mixture complexity, the method employed an ionization dopant, targeted tandem mass spectrometry, and an internal standard. This combination of three techniques achieved reliable quantitation of oxygen-rich eugenol in diesel from 300 to 2500 ng/mL with sufficient linearity (R 2 = 0.97 ± 0.01) and excellent accuracy (percent error = 0% ± 5). To understand the limitations of the method, it was compared to quantitation attained on a triple quadrupole mass spectrometer, the gold standard for quantitation. The triple quadrupole quantified eugenol from 50 to 2500 ng/mL with stronger linearity (R 2 = 0.996 ± 0.003) than the quadrupole-time-of-flight and comparable accuracy (percent error = 4% ± 5). This demonstrates that a quadrupole-time-of-flight can be used for not only qualitative analysis but also targeted quantitation of oxygen-rich lignin molecules in complex mixtures without extensive sample preparation. The rapid and cost-effective method presented here offers new possibilities for bio-oil research, including: (1) allowing for bio-oil studies that demand repetitive analysis as process parameters are changed and (2) making this research accessible to more laboratories. Graphical Abstract ᅟ.

The ab initio Calculation of Electric Field Gradient at the Site of P Impurity in α-Al3O2

NASA Astrophysics Data System (ADS)

Zhang, Qiao-Li; Yuan, Da-Qing; Zhang, Huan-Qiao; Fan, Ping; Zuo, Yi; Zheng, Yong-Nan; Masuta, K.; Fukuda, M.; Mihara, M.; Minamisono, T.; Kitagawa, A.; Zhu, Sheng-Yun

2012-09-01

An ab initio calculation of the electric-field gradient (EFG) at the site of a phosphorous impurity substituting an Al atom in α-Al2O3 is carried out using the WIEN2k code with the full-potential linearized augmented plane wave plus local orbital method (LAPW+lo) in the frame of density functional theory. The atomic lattice relaxations caused by the implanted impurities were calculated for two different charged states to well describe the electronic structure of the doped system. The EFG at the site of the phosphorous impurity in the charged supercell calculated with the exchange-correlation potential of the Wu-Cohen generalized gradient approximation (WC-GGA) is 0.573 × 1021 V/m2. Then, the nuclear quadrupole moment of the I = 3 state in 28P is deduced to be 137 mb from the quadrupole interaction frequency of 190 kHz measured recently by the β-NQR method.

Analysis of fast boundary-integral approximations for modeling electrostatic contributions of molecular binding

PubMed Central

Kreienkamp, Amelia B.; Liu, Lucy Y.; Minkara, Mona S.; Knepley, Matthew G.; Bardhan, Jaydeep P.; Radhakrishnan, Mala L.

2013-01-01

We analyze and suggest improvements to a recently developed approximate continuum-electrostatic model for proteins. The model, called BIBEE/I (boundary-integral based electrostatics estimation with interpolation), was able to estimate electrostatic solvation free energies to within a mean unsigned error of 4% on a test set of more than 600 proteins—a significant improvement over previous BIBEE models. In this work, we tested the BIBEE/I model for its capability to predict residue-by-residue interactions in protein–protein binding, using the widely studied model system of trypsin and bovine pancreatic trypsin inhibitor (BPTI). Finding that the BIBEE/I model performs surprisingly less well in this task than simpler BIBEE models, we seek to explain this behavior in terms of the models’ differing spectral approximations of the exact boundary-integral operator. Calculations of analytically solvable systems (spheres and tri-axial ellipsoids) suggest two possibilities for improvement. The first is a modified BIBEE/I approach that captures the asymptotic eigenvalue limit correctly, and the second involves the dipole and quadrupole modes for ellipsoidal approximations of protein geometries. Our analysis suggests that fast, rigorous approximate models derived from reduced-basis approximation of boundary-integral equations might reach unprecedented accuracy, if the dipole and quadrupole modes can be captured quickly for general shapes. PMID:24466561

Removal of two large-scale cosmic microwave background anomalies after subtraction of the integrated Sachs-Wolfe effect

NASA Astrophysics Data System (ADS)

Rassat, A.; Starck, J.-L.; Dupé, F.-X.

2013-09-01

Context. Although there is currently a debate over the significance of the claimed large-scale anomalies in the cosmic microwave background (CMB), their existence is not totally dismissed. In parallel to the debate over their statistical significance, recent work has also focussed on masks and secondary anisotropies as potential sources of these anomalies. Aims: In this work we investigate simultaneously the impact of the method used to account for masked regions as well as the impact of the integrated Sachs-Wolfe (ISW) effect, which is the large-scale secondary anisotropy most likely to affect the CMB anomalies. In this sense, our work is an update of previous works. Our aim is to identify trends in CMB data from different years and with different mask treatments. Methods: We reconstruct the ISW signal due to 2 Micron All-Sky Survey (2MASS) and NRAO VLA Sky Survey (NVSS) galaxies, effectively reconstructing the low-redshift ISW signal out to z ~ 1. We account for regions of missing data using the sparse inpainting technique. We test sparse inpainting of the CMB, large scale structure and ISW and find that it constitutes a bias-free reconstruction method suitable to study large-scale statistical isotropy and the ISW effect. Results: We focus on three large-scale CMB anomalies: the low quadrupole, the quadrupole/octopole alignment, and the octopole planarity. After sparse inpainting, the low quadrupole becomes more anomalous, whilst the quadrupole/octopole alignment becomes less anomalous. The significance of the low quadrupole is unchanged after subtraction of the ISW effect, while the trend amongst the CMB maps is that both the low quadrupole and the quadrupole/octopole alignment have reduced significance, yet other hypotheses remain possible as well (e.g. exotic physics). Our results also suggest that both of these anomalies may be due to the quadrupole alone. While the octopole planarity significance is reduced after inpainting and after ISW subtraction, however, we do not find that it was very anomalous to start with. In the spirit of participating in reproducible research, we make all codes and resulting products which constitute main results of this paper public here: http://www.cosmostat.org/anomaliesCMB.html

Differentially pumped dual linear quadrupole ion trap mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owen, Benjamin C.; Kenttamaa, Hilkka I.

The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

Evaluation of asymmetric quadrupoles for a non-scaling fixed field alternating gradient accelerator

NASA Astrophysics Data System (ADS)

Lee, Sang-Hun; Park, Sae-Hoon; Kim, Yu-Seok

2017-12-01

A non-scaling fixed field alternating gradient (NS-FFAG) accelerator was constructed, which employs conventional quadrupoles. The possible demerit is the beam instability caused by the variable focusing strength when the orbit radius of the beam changes. To overcome this instability, it was suggested that the asymmetric quadrupole has different current flows in each coil. The magnetic field of the asymmetric quadrupole was found to be more similar to the magnetic field required for the FFAG accelerator than the constructed NS-FFAG accelerator. In this study, a simulation of the beam dynamics was carried out to evaluate the improvement to the beam stability for the NS-FFAG accelerator using the SIMION program. The beam dynamics simulation was conducted with the `hard edge' model; it ignored the fringe field at the end of the magnet. The magnetic field map of the suggested magnet was created using the SIMION program. The lattices for the simulation combined the suggested magnets. The magnets were evaluated for beam stability in the lattices through the SIMION program.

Relativistic all-order many-body calculation of energies, wavelengths, and M 1 and E 2 transition rates for the 3 dn configurations in tungsten ions

NASA Astrophysics Data System (ADS)

Safronova, M. S.; Safronova, U. I.; Porsev, S. G.; Kozlov, M. G.; Ralchenko, Yu.

2018-01-01

Energy levels, wavelengths, magnetic-dipole and electric-quadrupole transition rates between the low-lying states are evaluated for W51 + to W54 + ions with 3 dn (n =2 to 5) electronic configurations by using an approach combining configuration interaction with the linearized coupled-cluster single-double method. The QED corrections are directly incorporated into the calculations and their effect is studied in detail. Uncertainties of the calculations are discussed. This study of such highly charged ions with the present method opens the way for future applications allowing an accurate prediction of properties for a very wide range of highly charged ions aimed at providing precision benchmarks for various applications.

A theoretical study on directivity control of multiple-loudspeaker system with a quadrupole radiation pattern in low frequency range

NASA Astrophysics Data System (ADS)

Irwansyah, Kuse, Naoyuki; Usagawa, Tsuyoshi

2017-08-01

Directivity pattern of an ordinary loudspeaker becomes more directive at higher frequencies. However, because a single loudspeaker tends to radiate uniformly in all directions at low frequencies, reverberation from surrounding building walls may affect speech intelligibility when installing a multiple-loudspeaker system at crossroads. As an alternative, a sharply directive sound source is recommended to be used, but in many cases the directivity of an ordinary loudspeaker is less sharp at lower frequencies. Therefore, in order to overcome such a limitation, this paper discusses the possibility of using four loudspeakers under active control to realize a quadrupole radiation pattern in low frequency range. In this study, the radiation pattern of a primary loudspeaker and three secondary loudspeakers has been modelled. By placing the loudspeakers close together in the direction of 0°, 90°, 180°, and 270°, it was theoretically demonstrated that a quadrupole radiation pattern can be shaped in the target frequency range up to 600 Hz by simply controlling the directivity in three of four directions which are 45°, 135°, 225°, and 315°. Although, the radiation pattern model is far from realistic configurations and conditions, it is possible to realize a quadrupole radiation pattern in the low frequency range.

Synthetic Landau Levels and Spinor Vortex Matter on a Haldane Spherical Surface with a Magnetic Monopole.

PubMed

Zhou, Xiang-Fa; Wu, Congjun; Guo, Guang-Can; Wang, Ruquan; Pu, Han; Zhou, Zheng-Wei

2018-03-30

We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by applying the Floquet engineering of a magnetic quadrupole field to create a synthetic monopole field in real space. The system can be exactly mapped to the electron-monopole system on a sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. This method works for either bosons or fermions. We investigate the ground-state vortex pattern for an s-wave interacting atomic condensate by mapping this system to the classical Thompson's problem. The distortion and stability of the vortex pattern are further studied in the presence of dipolar interaction. Our scheme is compatible with the current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.

Molecular simulation study of the competitive adsorption of H2O and CO2 in zeolite 13X.

PubMed

Joos, Lennart; Swisher, Joseph A; Smit, Berend

2013-12-23

The presence of H2O in postcombustion gas streams is an important technical issue for deploying CO2-selective adsorbents. Because of its permanent dipole, H2O can interact strongly with materials where the selectivity for CO2 is a consequence of its quadrupole interacting with charges in the material. We performed molecular simulations to model the adsorption of pure H2O and CO2 as well as H2O/CO2 mixtures in 13X, a popular zeolite for CO2 capture processes that is commercially available. The simulations show that H2O reduces the capacity of these materials for adsorbing CO2 by an order of magnitude and that at the partial pressures of H2O relevant for postcombustion capture, 13X will be essentially saturated with H2O .

Synthetic Landau Levels and Spinor Vortex Matter on a Haldane Spherical Surface with a Magnetic Monopole

NASA Astrophysics Data System (ADS)

Zhou, Xiang-Fa; Wu, Congjun; Guo, Guang-Can; Wang, Ruquan; Pu, Han; Zhou, Zheng-Wei

2018-03-01

We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by applying the Floquet engineering of a magnetic quadrupole field to create a synthetic monopole field in real space. The system can be exactly mapped to the electron-monopole system on a sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. This method works for either bosons or fermions. We investigate the ground-state vortex pattern for an s -wave interacting atomic condensate by mapping this system to the classical Thompson's problem. The distortion and stability of the vortex pattern are further studied in the presence of dipolar interaction. Our scheme is compatible with the current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.

Low-energy nuclear spectroscopy in a microscopic multiphonon approach

NASA Astrophysics Data System (ADS)

Lo Iudice, N.; Ponomarev, V. Yu; Stoyanov, Ch; Sushkov, A. V.; Voronov, V. V.

2012-04-01

The low-lying spectra of heavy nuclei are investigated within the quasiparticle-phonon model. This microscopic approach goes beyond the quasiparticle random-phase approximation by treating a Hamiltonian of separable form in a microscopic multiphonon basis. It is therefore able to describe the anharmonic features of collective modes as well as the multiphonon states, whose experimental evidence is continuously growing. The method can be put in close correspondence with the proton-neutron interacting boson model. By associating the microscopic isoscalar and isovector quadrupole phonons with proton-neutron symmetric and mixed-symmetry quadrupole bosons, respectively, the microscopic states can be classified, just as in the algebraic model, according to their phonon content and their symmetry. In addition, these states disclose the nuclear properties which are to be ascribed to genuine shell effects, not included in the algebraic approach. Due to its flexibility, the method can be implemented numerically for systematic studies of spectroscopic properties throughout entire regions of vibrational nuclei. The spectra and multipole transition strengths so computed are in overall good agreement with the experimental data. By exploiting the correspondence of the method with the interacting boson model, it is possible to embed the microscopic states into this algebraic frame and, therefore, face the study of nuclei far from shell closures, not directly accessible to merely microscopic approaches. Here, it is shown how this task is accomplished through systematic investigations of magnetic dipole and, especially, electric dipole modes along paths moving from the vibrational to the transitional regions. The method is very well suited to the study of well-deformed nuclei. It provides reliable descriptions of low-lying magnetic as well as electric multipole modes of nuclei throughout the rare-earth and actinide regions. Attention is focused here on the low-lying 0+ states produced in large abundance in recent experiments. The analysis shows that the quasiparticle-phonon model accounts for the occurrence of so many 0+ levels and discloses their nature.

Study of the in vitro metabolism of TJ0711 using ultra high performance liquid chromatography with quadrupole time-of-flight and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry.

PubMed

Hu, Lei; Lv, Zhenhua; Li, Gao; Xu, Xiaolong; Zhang, Chenghao; Cao, Peng; Huang, Jiangeng; Si, Luqin

2015-06-01

TJ0711 (1-[4-(2-methoxyethyl)phenoxy]-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanol) is a novel β-adrenoreceptor blocker with vasodilating activity. The aim of this study was to investigate the in vitro metabolic properties of TJ0711 from both qualitative and quantitative aspects using mouse, rat, dog, and human liver microsomes as well as rat hepatocytes. Two modern liquid chromatography with tandem mass spectrometry systems, ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry, were utilized for the analysis. To better characterize the metabolic pathways of TJ0711, two major metabolites were incubated under the same conditions as that for TJ0711. TJ0711 was extensively metabolized in vitro, and a total of 34 metabolites, including 19 phase I and 15 phase II metabolites, were identified. Similar metabolite profiles were observed among species, and demethylation, hydroxylation, carboxylic acid formation, and glucuronidation were proposed as the major metabolic routes. Significant interspecies differences were observed in the metabolic stability studies of TJ0711. Furthermore, gender differences were significant in mice, rats, and dogs, but were negligible in humans. The valuable information provided in this work will be useful in planning and interpreting further pharmacokinetic, in vivo metabolism and toxicological studies of this novel β-blocker. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aharonov–Anandan quantum phases and Landau quantization associated with a magnetic quadrupole moment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fonseca, I.C.; Bakke, K., E-mail: kbakke@fisica.ufpb.br

The arising of geometric quantum phases in the wave function of a moving particle possessing a magnetic quadrupole moment is investigated. It is shown that an Aharonov–Anandan quantum phase (Aharonov and Anandan, 1987) can be obtained in the quantum dynamics of a moving particle with a magnetic quadrupole moment. In particular, it is obtained as an analogue of the scalar Aharonov–Bohm effect for a neutral particle (Anandan, 1989). Besides, by confining the quantum particle to a hard-wall confining potential, the dependence of the energy levels on the geometric quantum phase is discussed and, as a consequence, persistent currents can arisemore » from this dependence. Finally, an analogue of the Landau quantization is discussed. -- Highlights: •Scalar Aharonov–Bohm effect for a particle possessing a magnetic quadrupole moment. •Aharonov–Anandan quantum phase for a particle with a magnetic quadrupole moment. •Dependence of the energy levels on the Aharonov–Anandan quantum phase. •Landau quantization associated with a particle possessing a magnetic quadrupole moment.« less

Curvature-induced capillary interaction of spherical particles at a liquid interface.

PubMed

Würger, Alois

2006-10-01

We consider a liquid interface with different principal curvatures +/-c and find that the mere presence of a spherical particle leads to a deformation field of quadrupolar symmetry; the corresponding "capillary quadrupole moment" is given by the ratio of the particle size and the curvature radius. The resulting pair interaction of nearby particles is anisotropic and favors the formation of aggregates of cubic symmetry. Since the single-particle trapping energy depends quadratically on curvature with a negative prefactor, a curvature gradient induces a lateral force that pushes the particles towards strongly curved regions of the interface. As an illustration we discuss the effects occurring on a catenoid.

The interaction of O(plus) ions with the interior surface of a copper chamber

NASA Technical Reports Server (NTRS)

Siegel, M. W.; Boring, J. W.

1971-01-01

Modulated beams of 0(+), Ar(+), and Kr(+) in the 100-300 eV range are directed into a copper box simulating the ante-chamber of an orbiting mass spectrometer. An RF quadrupole mass spectrometer and phase sensitive detection extract the component of the internal mass spectrum correlated with the beam. Intense Ar and Kr signals are observed; however, no O or O2 is detectable, indicating loss of the primary O(+) beam to surface interactions. All four primary ions stimulate sizeable signals at masses 26 and 28. The relevance of these experiments to the interpretation of mass spectra obtained by orbiting satellites is discussed.

Nucleon and Elastic and Transition Form Factors

NASA Astrophysics Data System (ADS)

Segovia, Jorge; Cloët, Ian C.; Roberts, Craig D.; Schmidt, Sebastian M.

2014-12-01

We present a unified study of nucleon and elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a symmetry-preserving treatment of a vector vector contact-interaction. The comparison emphasises that experiments are sensitive to the momentum dependence of the running couplings and masses in the strong interaction sector of the Standard Model and highlights that the key to describing hadron properties is a veracious expression of dynamical chiral symmetry breaking in the bound-state problem. Amongst the results we describe, the following are of particular interest: possesses a zero at Q 2 = 9.5 GeV2; any change in the interaction which shifts a zero in the proton ratio to larger Q 2 relocates a zero in to smaller Q 2; there is likely a value of momentum transfer above which ; and the presence of strong diquark correlations within the nucleon is sufficient to understand empirical extractions of the flavour-separated form factors. Regarding the -baryon, we find that, inter alia: the electric monopole form factor exhibits a zero; the electric quadrupole form factor is negative, large in magnitude, and sensitive to the nature and strength of correlations in the Faddeev amplitude; and the magnetic octupole form factor is negative so long as rest-frame P- and D-wave correlations are included. In connection with the transition, the momentum-dependence of the magnetic transition form factor, , matches that of once the momentum transfer is high enough to pierce the meson-cloud; and the electric quadrupole ratio is a keen measure of diquark and orbital angular momentum correlations, the zero in which is obscured by meson-cloud effects on the domain currently accessible to experiment. Importantly, within each framework, identical propagators and vertices are sufficient to describe all properties discussed herein. Our analysis and predictions should therefore serve as motivation for measurement of elastic and transition form factors involving the nucleon and its resonances at high photon virtualities using modern electron-beam facilities.

Nonuniform radiation damage in permanent magnet quadrupoles.

PubMed

Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

2014-08-01

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

Exact cancellation of emittance growth due to coupled transverse dynamics in solenoids and rf couplers

NASA Astrophysics Data System (ADS)

Dowell, David H.; Zhou, Feng; Schmerge, John

2018-01-01

Weak, rotated magnetic and radio frequency quadrupole fields in electron guns and injectors can couple the beam's horizontal with vertical motion, introduce correlations between otherwise orthogonal transverse momenta, and reduce the beam brightness. This paper discusses two important sources of coupled transverse dynamics common to most electron injectors. The first is quadrupole focusing followed by beam rotation in a solenoid, and the second coupling comes from a skewed high-power rf coupler or cavity port which has a rotated rf quadrupole field. It is shown that a dc quadrupole field can correct for both types of couplings and exactly cancel their emittance growths. The degree of cancellation of the rf skew quadrupole emittance is limited by the electron bunch length. Analytic expressions are derived and compared with emittance simulations and measurements.

Presence of 3d quadrupole moment in LaTiO3 studied by 47,49Ti NMR.

PubMed

Kiyama, Takashi; Itoh, Masayuki

2003-10-17

47,49Ti NMR spectra of LaTiO3 are reexamined and the orbital state of this compound is discussed. The NMR spectra of LaTiO3 taken at 1.5 K under zero external field indicate a large nuclear quadrupole splitting. This splitting is ascribed to the presence of the rather large quadrupole moment of 3d electrons at Ti sites, suggesting that the orbital liquid model proposed for LaTiO3 is inappropriate. The NMR spectra are well explained by the orbital ordering model expressed approximately as 1/square root of 3(d(xy)+d(yz)+d(zx)) originating from a crystal field effect. It is also shown that most of the orbital moment is quenched.

Rotationally adiabatic pair interactions of para- and ortho-hydrogen with the halogen molecules F2, Cl2, and Br2.

PubMed

Berg, Matthias; Accardi, Antonio; Paulus, Beate; Schmidt, Burkhard

2014-08-21

The present work is concerned with the weak interactions between hydrogen and halogen molecules, i.e., the interactions of pairs H2-X2 with X = F, Cl, Br, which are dominated by dispersion and quadrupole-quadrupole forces. The global minimum of the four-dimensional (4D) coupled cluster with singles and doubles and perturbative triples (CCSD(T)) pair potentials is always a T shaped structure where H2 acts as the hat of the T, with well depths (De) of 1.3, 2.4, and 3.1 kJ/mol for F2, Cl2, and Br2, respectively. MP2/AVQZ results, in reasonable agreement with CCSD(T) results extrapolated to the basis set limit, are used for detailed scans of the potentials. Due to the large difference in the rotational constants of the monomers, in the adiabatic approximation, one can solve the rotational Schrödinger equation for H2 in the potential of the X2 molecule. This yields effective two-dimensional rotationally adiabatic potential energy surfaces where pH2 and oH2 are point-like particles. These potentials for the H2-X2 complexes have global and local minima for effective linear and T-shaped complexes, respectively, which are separated by 0.4-1.0 kJ/mol, where oH2 binds stronger than pH2 to X2, due to higher alignment to minima structures of the 4D-pair potential. Further, we provide fits of an analytical function to the rotationally adiabatic potentials.

Separation and characterization of chemical constituents in Ginkgo biloba extract by off-line hydrophilic interaction×reversed-phase two-dimensional liquid chromatography coupled with quadrupole-time of flight mass spectrometry.

PubMed

Ji, Shuai; He, Dan-Dan; Wang, Tian-Yun; Han, Jie; Li, Zheng; Du, Yan; Zou, Jia-Hui; Guo, Meng-Zhe; Tang, Dao-Quan

2017-11-30

Ginkgo biloba extract (GBE), derived from the leaves of Ginkgo biloba L., is one of the most widely used traditional Chinese medicines worldwide. Due to high structural diversity and low abundance of chemical constituents in GBE, conventional reversed-phase liquid chromatography has limited power to meet the needs of its quality control. In this study, an off-line hydrophilic interaction×reversed-phase two-dimensional liquid chromatography (HILIC×RP 2D-LC) system coupled with diode array detection (DAD) and quadrupole time-of-flight mass spectrometry (qTOF-MS) was established to comprehensively analyze the chemical constituents of GBE. After optimizing the chromatographic columns and mobile phase of 2D-LC, a Waters XBridge Amide column using acetonitrile/water/formic acid as the mobile phase was selected as the first dimension to fractionate GBE, and the obtained fractions were further separated on an Agilent Zorbax XDB-C18 column with methanol/water/formic acid as the mobile phase. As a result, a total of 125 compounds were detected in GBE. The orthogonality of the 2D-LC system was 69.5%, and the practical peak capacity was 3864 and 2994, respectively, calculated by two different methods. The structures of 104 compounds were tentatively characterized by qTOF-MS analysis, and 21 of them were further confirmed by comparing with reference standards. This established HILIC×RP 2D-LC-qTOF/MS system can greatly improve the separation and characterization of natural products in GBE or other complicated herbal extracts. Copyright © 2017 Elsevier B.V. All rights reserved.

Nitro-Fatty Acid Detection in Plants by High-Pressure Liquid Chromatography Coupled to Triple Quadrupole Mass Spectrometry.

PubMed

Mata-Pérez, Capilla; Padilla, María N; Sánchez-Calvo, Beatriz; Begara-Morales, Juan C; Valderrama, Raquel; Corpas, Francisco J; Barroso, Juan B

2018-01-01

In the last few years, the role of nitric oxide (NO) and NO-related molecules has attracted attention in the field of plant systems. In this sense, the ability of NO to mediate several posttranslational modifications (NO-PTM) in different biomolecules, such as protein tyrosine nitration or S-nitrosylation, has shown the involvement of these reactive nitrogen species in a wide range of functions in plant physiology such as the antioxidant response or the involvement in processes such as germination, growth, development, or senescence. However, growing interest has focused on the interaction of these NO-derived molecules with unsaturated fatty acids, yielding nitro-fatty acids (NO 2 -FAs). It has recently been shown that these molecules are involved in key signaling pathways in animal systems through the implementation of antioxidant and anti-inflammatory responses. Nevertheless, this interaction has been poorly studied in plant systems. Very recently, the endogenous presence of NO 2 -FAs in the model plant Arabidopsis thaliana has been demonstrated as well as the significant involvement of nitro-linolenic acid (NO 2 -Ln) in the defence response against several abiotic and oxidative stress conditions. In this respect, the detection of NO 2 -FAs in plant systems can be a useful tool to determine the importance of these molecules in the regulation of different biochemical pathways. Using high-pressure liquid chromatography coupled to triple quadrupole mass spectrometry (LC-MS/MS), the methods described in this chapter enable the determination of the NO 2 -FA content in a pM range as well as the characterization of these nitrated derivatives of unsaturated fatty acids in plant tissues.

Measurement of Aqueous Foam Rheology by Acoustic Levitation

NASA Technical Reports Server (NTRS)

McDaniel, J. Gregory; Holt, R. Glynn; Rogers, Rich (Technical Monitor)

2000-01-01

An experimental technique is demonstrated for acoustically levitating aqueous foam drops and exciting their spheroidal modes. This allows fundamental studies of foam-drop dynamics that provide an alternative means of estimating the viscoelastic properties of the foam. One unique advantage of the technique is the lack of interactions between the foam and container surfaces, which must be accounted for in other techniques. Results are presented in which a foam drop with gas volume fraction phi = 0.77 is levitated at 30 kHz and excited into its first quadrupole resonance at 63 +/- 3 Hz. By modeling the drop as an elastic sphere, the shear modulus of the foam was estimated at 75 +/- 3 Pa.

Quantitative study of interactions between oxygen lone pair and aromatic rings: substituent effect and the importance of closeness of contact.

PubMed

Gung, Benjamin W; Zou, Yan; Xu, Zhigang; Amicangelo, Jay C; Irwin, Daniel G; Ma, Shengqian; Zhou, Hong-Cai

2008-01-18

Current models describe aromatic rings as polar groups based on the fact that benzene and hexafluorobenzene are known to have large and permanent quadrupole moments. This report describes a quantitative study of the interactions between oxygen lone pair and aromatic rings. We found that even electron-rich aromatic rings and oxygen lone pairs exhibit attractive interactions. Free energies of interactions are determined using the triptycene scaffold and the equilibrium constants were determined by low-temperature 1H NMR spectroscopy. An X-ray structure analysis for one of the model compounds confirms the close proximity between the oxygen and the center of the aromatic ring. Theoretical calculations at the MP2/aug-cc-pVTZ level corroborate the experimental results. The origin of attractive interactions was explored by using aromatic rings with a wide range of substituents. The interactions between an oxygen lone pair and an aromatic ring are attractive at van der Waals' distance even with electron-donating substituents. Electron-withdrawing groups increase the strength of the attractive interactions. The results from this study can be only partly rationalized by using the current models of aromatic system. Electrostatic-based models are consistent with the fact that stronger electron-withdrawing groups lead to stronger attractions, but fail to predict or rationalize the fact that weak attractions even exist between electron-rich arenes and oxygen lone pairs. The conclusion from this study is that aromatic rings cannot be treated as a simple quadrupolar functional group at van der Waals' distance. Dispersion forces and local dipole should also be considered.

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

DOEpatents

Maschke, A.W.

1984-04-16

A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow through the assembly.

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

DOEpatents

Maschke, Alfred W.

1985-01-01

A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly.

Small Aperture BPM to Quadrupole Assembly Tolerance Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fong, K. W.

2010-12-07

The LCLS injector and linac systems utilize a series of quadrupole magnets with a beam position monitor (BPM) captured in the magnet pole tips. The BPM measures the electron beam position by comparing the electrical signal from 4 electrodes and interpolating beam position from these signals. The manufacturing tolerances of the magnet and BPM are critical in determining the mechanical precision of the electrodes relative to the nominal electron beam Z-axis. This study evaluates the statistical uncertainty of the electrodes center axis relative to the nominal electron beam axis.

The Columbia University Sub-micron Charged Particle Beam

PubMed Central

Randers-Pehrson, Gerhard; Johnson, Gary W.; Marino, Stephen A.; Xu, Yanping; Dymnikov, Alexander D.; Brenner, David J.

2009-01-01

A lens system consisting of two electrostatic quadrupole triplets has been designed and constructed at the Radiological Research Accelerator Facility (RARAF) of Columbia University. The lens system has been used to focus 6-MeV 4He ions to a beam spot in air with a diameter of 0.8 µm. The quadrupole electrodes can withstand voltages high enough to focus 4He ions up to 10 MeV and protons up to 5 MeV. The quadrupole triplet design is novel in that alignment is made through precise construction and the relative strengths of the quadrupoles are accomplished by the lengths of the elements, so that the magnitudes of the voltages required for focusing are nearly identical. The insulating sections between electrodes have had ion implantation to improve the voltage stability of the lens. The lens design employs Russian symmetry for the quadrupole elements. PMID:20161365

Exact cancellation of emittance growth due to coupled transverse dynamics in solenoids and rf couplers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dowell, David H.; Zhou, Feng; Schmerge, John

Weak, rotated magnetic and radio frequency quadrupole fields in electron guns and injectors can couple the beam’s horizontal with vertical motion, introduce correlations between otherwise orthogonal transverse momenta, and reduce the beam brightness. This paper discusses two important sources of coupled transverse dynamics common to most electron injectors. The first is quadrupole focusing followed by beam rotation in a solenoid, and the second coupling comes from a skewed high-power rf coupler or cavity port which has a rotated rf quadrupole field. It is shown that a dc quadrupole field can correct for both types of couplings and exactly cancel theirmore » emittance growths. The degree of cancellation of the rf skew quadrupole emittance is limited by the electron bunch length. Analytic expressions are derived and compared with emittance simulations and measurements.« less

Exact cancellation of emittance growth due to coupled transverse dynamics in solenoids and rf couplers

DOE PAGES

Dowell, David H.; Zhou, Feng; Schmerge, John

2018-01-17

Weak, rotated magnetic and radio frequency quadrupole fields in electron guns and injectors can couple the beam’s horizontal with vertical motion, introduce correlations between otherwise orthogonal transverse momenta, and reduce the beam brightness. This paper discusses two important sources of coupled transverse dynamics common to most electron injectors. The first is quadrupole focusing followed by beam rotation in a solenoid, and the second coupling comes from a skewed high-power rf coupler or cavity port which has a rotated rf quadrupole field. It is shown that a dc quadrupole field can correct for both types of couplings and exactly cancel theirmore » emittance growths. The degree of cancellation of the rf skew quadrupole emittance is limited by the electron bunch length. Analytic expressions are derived and compared with emittance simulations and measurements.« less

High spin states of 72-74Kr

NASA Astrophysics Data System (ADS)

Kaushik, M.; Kumawat, M.; Singh, U. K.; Saxena, G.

2018-05-01

A theoretical investigation has made on the structure of high spin states of 72-74Kr within the framework of cranked Hartree-Fock-Bogoliubov (CHFB) theory employing a pairing + quadrupole + hexadecapole model interaction. Dependence of shape with the spin, excitation energy, alignment of proton as well as neutron 0g9/2 orbital along with backbending phenomenon are discussed upto a high spin J = 26. We found reasonable agreement with the experimental values and other theoretical calculations.

Distal and proximal ligand interactions in heme proteins: Correlations between C-O and Fe-C vibrational frequencies, oxygen-17 and carbon-13 nuclear magnetic resonance chemical shifts, and oxygen-17 nuclear quadrupole coupling constants in C sup 17 O- and sup 13 CO-labeled species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ki Deok Park; Guo, K.; Adebodun, F.

1991-03-05

The authors have obtained the oxygen-17 nuclear magnetic resonance (NMR) spectra of a variety of C{sup 17}O-labeled heme proteins, including sperm whale (Physeter catodon) myoglobin, two synthetic sperm whale myoglobin mutants (His E7 {yields} Val E7; His E7 {yields} Phe E7), adult human hemoglobin, rabbit (Oryctolagus cuniculus) hemoglobin, horseradish (Cochlearia armoracia) peroxidase isoenzymes A and C, and Caldariomyces fumago chloroperoxidase, in some cases as a function of pH, and have determined their isotropic {sup 17}O NMR chemical shifts, {delta}{sub i}, and spin-lattice relaxation times, T{sub 1}. They have also obtained similar results on a picket fence prophyrin. The results showmore » an excellent correlation between the infrared C-O vibrational frequencies, {nu}(C-O), and {delta}{sub i}, between {nu}(C-O) and the {sup 17}O nuclear quadrupole coupling constant, and as expected between e{sup 2}qQ/h and {delta}{sub i}. The results suggest the IR and NMR measurements reflect the same interaction, which is thought to be primarily the degree of {pi}-back-bonding from Fe d to CO {pi}* orbitals, as outlined previously.« less

Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

NASA Astrophysics Data System (ADS)

Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

2012-10-01

A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

Quadrupole Magnetic Sorting of Porcine Islets of Langerhans

PubMed Central

Shenkman, Rustin M.; Chalmers, Jeffrey J.; Hering, Bernhard J.; Kirchhof, Nicole

2009-01-01

Islet transplantation is emerging as a treatment option for selected patients with type 1 diabetes. Inconsistent isolation, purification, and recovery of large numbers of high-quality islets remain substantial impediments to progress in the field. Removing islets as soon as they are liberated from the pancreas during digestion and circumventing the need for density gradient purification is likely to result in substantially increased viable islet yields by minimizing exposure to proteolytic enzymes, reactive oxygen intermediates, and mechanical stress associated with centrifugation. This study capitalized on the hypervascularity of islets compared with acinar tissue to explore their preferential enrichment with magnetic beads to enable immediate separation in a magnetic field utilizing a quadrupole magnetic sorting. The results demonstrate that (1) preferential enrichment of porcine islets is achievable, but homogeneous bead distribution within the pancreas is difficult to achieve with current protocols; (2) greater than 70% of islets in the dissociated pancreatic tissue were recovered by quadrupole magnetic sorting, but their purity was low; and (3) infused islets purified by density gradients and subsequently passed through quadrupole magnetic sorting had similar potency as uninfused islets. These results demonstrate proof of concept and define the steps for implementation of this technology in pig and human islet isolation. PMID:19505179

Photoionization of Ne8+

NASA Astrophysics Data System (ADS)

Pindzola, M. S.; Abdel-Naby, Sh. A.; Robicheaux, F.; Colgan, J.

2014-05-01

Single and double photoionization cross sections for Ne8+ are calculated using a non-perturbative fully relativistic time-dependent close-coupling method. A Bessel function expansion is used to include both dipole and quadrupole effects in the radiation field interaction and the repulsive interaction between electrons includes both the Coulomb and Gaunt interactions. The fully correlated ground state of Ne8+ is obtained by solving a time-independent inhomogeneous set of close-coupled equations. Propagation of the time-dependent close-coupled equations yields single and double photoionization cross sections for Ne8+ at energies easily accessible at advanced free electron laser facilities. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California, NICS in Knoxville, Tennessee, and OLCF in Oak Ridge, Tennessee.

Permanent magnet edge-field quadrupole

DOEpatents

Tatchyn, R.O.

1997-01-21

Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis. 10 figs.

Permanent magnet edge-field quadrupole

DOEpatents

Tatchyn, Roman O.

1997-01-01

Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis.

Investigating a Quadrant Surface Coil Array for NQR Remote Sensing

DTIC Science & Technology

2014-10-23

UNCLASSIFIED 1  Abstract—this paper is on the design and fabrication of a surface coil array in a quadrant layout for NQR (Nuclear Quadrupole...coupling and SNR (Signal-to-Noise Ratio) at standoff distances perpendicular from each coil. Index Terms— Nuclear Quadrupole Resonance, NQR ...Coil Array, probe, Nuclear Magnetic Resonance, tuning, decoupling, RLC, mutual coupling, RLC I. INTRODUCTION N Nuclear quadrupole resonance ( NQR

Chemical (knight) shift distortions of quadrupole-split deuteron powder spectra in solids

NASA Astrophysics Data System (ADS)

Torgeson, D. R.; Schoenberger, R. J.; Barnes, R. G.

In strong magnetic fields (e.g., 8 Tesla) anisotropy of the shift tensor (chemical or Knight shift) can alter the spacings of the features of quadrupole-split deuteron spectra of polycrystalline samples. Analysis of powder spectra yields both correct quadrupole coupling and symmetry parameters and all the components of the shift tensor. Synthetic and experimental examples are given to illustrate such behavior.

Identification of human hnRNP C1/C2 as a dengue virus NS1-interacting protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noisakran, Sansanee; Medical Molecular Biology Unit, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Adulyadejvikrom Building; Sengsai, Suchada

Dengue virus nonstructural protein 1 (NS1) is a key glycoprotein involved in the production of infectious virus and the pathogenesis of dengue diseases. Very little is known how NS1 interacts with host cellular proteins and functions in dengue virus-infected cells. This study aimed at identifying NS1-interacting host cellular proteins in dengue virus-infected cells by employing co-immunoprecipitation, two-dimensional gel electrophoresis, and mass spectrometry. Using lysates of dengue virus-infected human embryonic kidney cells (HEK 293T), immunoprecipitation with an anti-NS1 monoclonal antibody revealed eight isoforms of dengue virus NS1 and a 40-kDa protein, which was subsequently identified by quadrupole time-of-flight tandem mass spectrometrymore » (Q-TOF MS/MS) as human heterogeneous nuclear ribonucleoprotein (hnRNP) C1/C2. Further investigation by co-immunoprecipitation and co-localization confirmed the association of hnRNP C1/C2 and dengue virus NS1 proteins in dengue virus-infected cells. Their interaction may have implications in virus replication and/or cellular responses favorable to survival of the virus in host cells.« less

Are the low-lying isovector 1 + states scissors vibrations?

NASA Astrophysics Data System (ADS)

Faessler, A.

At the Technische Hochschule in Darmstadt the group of Richter and coworkers found in 1983/84 in deformed rare earth nuclei low-lying isovector 1 + states. Such states have been predicted in the generalized Bohr-Mottelson model and in the interacting boson model no. 2 (IBA2). In the generalized Bohr-Mottelson model one allows for proton and neutron quadrupole deformations separately. If one includes only static proton and neutron deformations the generalized Bohr-Mottelson model reduces to the two rotor model. It describes the excitation energy of these states in good agreement with the data but overestimates the magnetic dipole transition probabilities by a factor 5. In the interacting boson model (IBA2) where only the outermost nucleons participate in the excitation the magnetic dipole transition probability is only overestimated by a factor 2. The too large collectivity in both models results from the fact that they concentrate the whole strength of the scissors vibrations into one state. A microscopic description is needed to describe the spreading of the scissors strength over several states. For a microscopic determination of these scissors states one uses the Quasi-particle Random Phase Approximation (QRPA). But this approach has a serious difficulty. Since one rotates for the calculation the nucleus into the intrinsic system the state corresponding to the rotation of the whole nucleus is a spurious state. The usual procedure to remove this spuriosity is to use the Thouless theorem which says that a spurious state created by an operator which commutes with the total hamiltonian (here the total angular momentum, corresponding to a rotation of the whole system) produces the spurious state if applied to the ground state. It says further the energy of this spurious state lies at zero excitation energy (it is degenerate with the ground state) and is orthogonal to all physical states. Thus the usual approach is to vary the quadrupole-quadrupole force strength so that a state lies at zero excitation energy and to identify that with the spuríous state. This procedure assumes that a total angular momentum commutes with a total hamiltonian. But this is not the case since the total hamiltonian contains a deformed Saxon-Woods potential. Thus one has to take care explicitly that the spurious state is removed. This we do in our approach by introducing Lagrange multipliers for each excited states and requesting that these states are orthogonal to the spurious state which is explicitly constructed by applying the total angular momentum operator to the ground state. To reduce the number of free parameters in the hamiltonian we take the Saxon-Woods potential for the deformed nuclei from the literature (with minor adjustments) and determine the proton-proton, neutron-neutron and the proton-neutron quadrupole force constant by requesting that the hamiltonian commutes with the total angular momentum in the (QRPA) ground state. This yields equations fixing all three coupling constants for the quadrupole-quadrupole force allowing even for isospin symmetry violation. The spin-spin force is taken from the Reid soft core potential. A possible spin-quadrupole force has been taken from the work of Soloviev but it turns out that this is not important. The calculation shows that the strength of the scissors vibrations are spread over many states. The main 1 + state at around 3 MeV has an overlap of the order of 14 % of the scissors state. 50% of that state are spread over the physical states up to an excitation energy of 6 MeV. The rest is distributed over higher lying states. The expectation value of the many-body hamiltonian in the scissors vibrational state shows roughly an excitation energy of 7 MeV above the ground state. The results also support the experimental findings that these states are mainly orbital excitations. States are not very collective. Normally only a proton and neutron particle-hole pair are with a large amplitude participating in forming these states. But those protons and neutrons which are excited perform scissors type vibrations.

Energetic ion mass analysis using a radio-frequency quadrupole filter.

PubMed

Medley, S S

1978-06-01

In conventional applications of the radio-frequency quadrupole mass analyzer, the ion injection energy is usually limited to less than the order of 100 eV due to constraints on the dimensions and power supply of the device. However, requirements often arise, for example in fusion plasma ion diagnostics, for mass analysis of much more energetic ions. A technique easily adaptable to any conventional quadrupole analyzer which circumvents the limitation on injection energy is documented in this paper. Briefly, a retarding potential applied to the pole assembly is shown to facilitate mass analysis of multikiloelectron volt ions without altering the salient characteristics of either the quadrupole filter or the ion beam.

An overview of the evaluation of oxygen interaction with materials-third phase (EOIM-III) experiment - Space Shuttle Mission 46

NASA Technical Reports Server (NTRS)

Leger, Lubert J.; Koontz, Steven L.; Visentine, James T.; Hunton, Donald

1993-01-01

An overview of EOIM-III, designed to produce benchmark atomic oxygen reactivity data is presented. Ambient density measurements are conducted using a quadrupole mass spectrometer calibrated for atomic oxygen measurements in a unique ground-based test facility. The combination of these data with the predictions of ambient density models permits an assessment of the accuracy of measured reaction rates on a variety of materials, many of which have never been tested in LEO previously.

Phase transitions in the sdg interacting boson model

NASA Astrophysics Data System (ADS)

Van Isacker, P.; Bouldjedri, A.; Zerguine, S.

2010-05-01

A geometric analysis of the sdg interacting boson model is performed. A coherent state is used in terms of three types of deformation: axial quadrupole ( β), axial hexadecapole ( β) and triaxial ( γ). The phase-transitional structure is established for a schematic sdg Hamiltonian which is intermediate between four dynamical symmetries of U(15), namely the spherical U(5)⊗U(9), the (prolate and oblate) deformed SU(3) and the γ-soft SO(15) limits. For realistic choices of the Hamiltonian parameters the resulting phase diagram has properties close to what is obtained in the sd version of the model and, in particular, no transition towards a stable triaxial shape is found.

Sources of sound in fluid flows

NASA Technical Reports Server (NTRS)

Williams, J. E. F.

1974-01-01

Some features of a flow that produce acoustic radiation, particularly when the flow is turbulent and interacting with solid surfaces such as turbine or compressor blades are discussed. Early theoretical ideas on the subject are reviewed and are shown to be inadequate at high Mach number. Some recent theoretical developments that form the basis of a description of sound generation by supersonic flows interacting with surfaces are described. At high frequencies the problem is treated as one of describing the surface-induced diffraction field of adjacent aerodynamic quadrupole sources. This approach has given rise to distinctly new features of the problem that seem to have bearing on the radiating properties of relatively large aerodynamic surfaces.

Higher Order Multipole Potentials and Electrostatic Screening Effects on Cohesive Energy and Bulk Modulus of Metallic Nanoparticles

NASA Astrophysics Data System (ADS)

Barakat, T.

2011-12-01

Higher order multipole potentials and electrostatic screening effects are introduced to incorporate the dangling bonds on the surface of a metallic nanopaticle and to modify the coulomb like potential energy terms, respectively. The total interaction energy function for any metallic nanoparticle is represented in terms of two- and three-body potentials. The two-body part is described by dipole-dipole interaction potential, and in the three-body part, triple-dipole (DDD) and dipole-dipole-quadrupole (DDQ) terms are included. The size-dependent cohesive energy and bulk modulus are observed to decrease with decreasing sizes, a result which is in good agreement with the experimental values of Mo and W nanoparticles.

Octupole correlations in the 144Ba nucleus described with symmetry-conserving configuration-mixing calculations

NASA Astrophysics Data System (ADS)

Bernard, Rémi N.; Robledo, Luis M.; Rodríguez, Tomás R.

2016-06-01

We study the interplay of quadrupole and octupole degrees of freedom in the structure of the isotope 144Ba. A symmetry-conserving configuration-mixing method (SCCM) based on a Gogny energy density functional (EDF) has been used. The method includes particle number, parity, and angular momentum restoration as well as axial quadrupole and octupole shape mixing within the generator coordinate method. Predictions both for excitation energies and electromagnetic transition probabilities are in good agreement with the most recent experimental data.

An energy-filtering device coupled to a quadrupole mass spectrometer for soft-landing molecular ions on surfaces with controlled energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bodin, A.; Laloo, R.; Abeilhou, P.

2013-09-15

We have developed an energy-filtering device coupled to a quadrupole mass spectrometer to deposit ionized molecules on surfaces with controlled energy in ultra high vacuum environment. Extensive numerical simulations as well as direct measurements show that the ion beam flying out of a quadrupole exhibits a high-energy tail decreasing slowly up to several hundred eV. This energy distribution renders impossible any direct soft-landing deposition of molecular ions. To remove this high-energy tail by energy filtering, a 127° electrostatic sector and a specific triplet lenses were designed and added after the last quadrupole of a triple quadrupole mass spectrometer. The resultsmore » obtained with this energy-filtering device show clearly the elimination of the high-energy tail. The ion beam that impinges on the sample surface satisfies now the soft-landing criterion for molecular ions, opening new research opportunities in the numerous scientific domains involving charges adsorbed on insulating surfaces.« less

Evaluating Mass Analyzers as Candidates for Small, Portable, Rugged Single Point Mass Spectrometers for Analysis of Permanent Gases

NASA Technical Reports Server (NTRS)

Arkin, C. Richard; Ottens, Andrew K.; Diaz, Jorge A.; Griffin, Timothy P.; Follestein, Duke; Adams, Fredrick; Steinrock, T. (Technical Monitor)

2001-01-01

For Space Shuttle launch safety, there is a need to monitor the concentration Of H2, He, O2, and Ar around the launch vehicle. Currently a large mass spectrometry system performs this task, using long transport lines to draw in samples. There is great interest in replacing this stationary system with several miniature, portable, rugged mass spectrometers which act as point sensors which can be placed at the sampling point. Five commercial and two non-commercial analyzers are evaluated. The five commercial systems include the Leybold Inficon XPR-2 linear quadrupole, the Stanford Research (SRS-100) linear quadrupole, the Ferran linear quadrupole array, the ThermoQuest Polaris-Q quadrupole ion trap, and the IonWerks Time-of-Flight (TOF). The non-commercial systems include a compact double focusing sector (CDFMS) developed at the University of Minnesota, and a quadrupole ion trap (UF-IT) developed at the University of Florida.

Triple Quadrupole Versus High Resolution Quadrupole-Time-of-Flight Mass Spectrometry for Quantitative LC-MS/MS Analysis of 25-Hydroxyvitamin D in Human Serum

NASA Astrophysics Data System (ADS)

Geib, Timon; Sleno, Lekha; Hall, Rabea A.; Stokes, Caroline S.; Volmer, Dietrich A.

2016-08-01

We describe a systematic comparison of high and low resolution LC-MS/MS assays for quantification of 25-hydroxyvitamin D3 in human serum. Identical sample preparation, chromatography separations, electrospray ionization sources, precursor ion selection, and ion activation were used; the two assays differed only in the implemented final mass analyzer stage; viz. high resolution quadrupole-quadrupole-time-of-flight (QqTOF) versus low resolution triple quadrupole instruments. The results were assessed against measured concentration levels from a routine clinical chemiluminescence immunoassay. Isobaric interferences prevented the simple use of TOF-MS spectra for extraction of accurate masses and necessitated the application of collision-induced dissociation on the QqTOF platform. The two mass spectrometry assays provided very similar analytical figures of merit, reflecting the lack of relevant isobaric interferences in the MS/MS domain, and were successfully applied to determine the levels of 25-hydroxyvitamin D for patients with chronic liver disease.

Nuclear quadrupole resonance studies project. [spectrometer design and spectrum analysis

NASA Technical Reports Server (NTRS)

Murty, A. N.

1978-01-01

The participation of undergraduates in nuclear quadrupole resonance research at Grambling University was made possible by NASA grants. Expanded laboratory capabilities include (1) facilities for high and low temperature generation and measurement; (2) facilities for radio frequency generation and measurement with the modern spectrum analyzers, precision frequency counters and standard signal generators; (3) vacuum and glass blowing facilities; and (4) miscellaneous electronic and machine shop facilities. Experiments carried out over a five year period are described and their results analyzed. Theoretical studies on solid state crystalline electrostatic fields, field gradients, and antishielding factors are included.

Production and installation of the LHC low-beta triplets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feher, S.; Bossert, R.; DiMarco, J.

2005-09-01

The LHC performance depends critically on the low-{beta}, triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was formed in 1996 to design and build the triplet systems, and after nine years of joint effort the production has been completed in 2005. We retrace the main events of the project and present the design features and performance of the low-{beta} quadrupoles, built by KEKmore » and Fermilab, as well as of other vital elements of the triplet. The tunnel installation of the first triplet and plans for commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-{beta} triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of high energy physics experiment collaborations, and rarely before achieved in construction of an accelerator.« less

Energy levels, lifetimes, and transition rates for the selenium isoelectronic sequence Pd XIII-Te XIX, Xe XXI-Nd XXVII, W XLI

NASA Astrophysics Data System (ADS)

Wang, K.; Yang, X.; Chen, Z. B.; Si, R.; Chen, C. Y.; Yan, J.; Zhao, X. H.; Dang, W.

2017-09-01

Energy levels, wavelengths, lifetimes, oscillator strengths, and electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), magnetic quadrupole (M2) transition rates among the 46 fine structure levels belonging to the ([ Ar ] 3d10) 4s2 4p4, ([ Ar ] 3d10) 4s2 4p3 4 d, and ([ Ar ] 3d10) 4 s 4p5 configurations for the selenium isoelectronic sequence Pd XIII-Te XIX, Xe XXI-Nd XXVII, W XLI are reported. These data are determined in the multi-configuration Dirac-Fock (MCDF) approach, in which relativistic effects, main electron correlations within the n = 7 complex, Breit interaction (BI), and quantum electrodynamic (QED) corrections are included. The many-body perturbation theory (MBPT) method is also employed as an independent calculation to confirm the present accuracy, taking W XLI as an example. Comparisons and analysis are made between the present results and available experimental and theoretical ones, and good agreements are obtained. These accurate data are expected to be useful in nuclear fusion research and astrophysical applications.

Comprehensive two-dimensional gas chromatography in combination with rapid scanning quadrupole mass spectrometry in perfume analysis.

PubMed

Mondello, Luigi; Casillia, Alessandro; Tranchida, Peter Quinto; Dugo, Giovanni; Dugo, Paola

2005-03-04

Single column gas chromatography (GC) in combination with a flame ionization detector (FID) and/or a mass spectrometer is routinely employed in the determination of perfume profiles. The latter are to be considered medium to highly complex matrices and, as such, can only be partially separated even on long capillaries. Inevitably, several monodimensional peaks are the result of two or more overlapping components, often hindering reliable identification and quantitation. The present investigation is based on the use of a comprehensive GC (GC x GC) method, in vacuum outlet conditions, for the near to complete resolution of a complex perfume sample. A rapid scanning quadrupole mass spectrometry (qMS) system, employed for the assignment of GC x GC peaks, supplied high quality mass spectra. The validity of the three-dimensional (3D) GC x GC-qMS application was measured and compared to that of GC-qMS analysis on the same matrix. Peak identification, in all applications, was achieved through MS spectra library matching and the interactive use of linear retention indices (LRI).

1H NMR relaxometry and quadrupole relaxation enhancement as a sensitive probe of dynamical properties of solids—[C(NH2)3]3Bi2I9 as an example

NASA Astrophysics Data System (ADS)

Florek-Wojciechowska, M.; Wojciechowski, M.; Jakubas, R.; Brym, Sz.; Kruk, D.

2016-02-01

1H nuclear magnetic resonance relaxometry has been applied to reveal information on dynamics and structure of Gu3Bi2I9 ([Gu = C(NH2)3] denotes guanidinium cation). The data have been analyzed in terms of a theory of quadrupole relaxation enhancement, which has been extended here by including effects associated with quadrupole (14N) spin relaxation caused by a fast fluctuating component of the electric field gradient tensor. Two motional processes have been identified: a slow one occurring on a timescale of about 8 × 10-6 s which has turned out to be (almost) temperature independent, and a fast process in the range of 10-9 s. From the 1H-14N relaxation contribution (that shows "quadrupole peaks") the quadrupole parameters, which are a fingerprint of the arrangement of the anionic network, have been determined. It has been demonstrated that the magnitude of the quadrupole coupling considerably changes with temperature and the changes are not caused by phase transitions. At the same time, it has been shown that there is no evidence of abrupt changes in the cationic dynamics and the anionic substructure upon the phase transitions.

Paul Trap Simulator Experiment (PTSX) to simulate intense beam propagation through a periodic focusing quadrupole field

NASA Astrophysics Data System (ADS)

Davidson, Ronald C.; Efthimion, Philip C.; Gilson, Erik; Majeski, Richard; Qin, Hong

2002-01-01

The Paul Trap Simulator Experiment (PTSX) is under construction at the Princeton Plasma Physics Laboratory to simulate intense beam propagation through a periodic quadrupole magnetic field. In the Paul trap configuration, a long nonneutral plasma column is confined axially by dc voltages on end cylinders at z=+L and z=-L, and transverse confinement is provided by segmented cylindrical electrodes with applied oscillatory voltages ±V0(t) over 90° segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the Paul trap configuration offers the possibility of simulating intense beam propagation in a compact laboratory facility. The experimental layout is described, together with the planned experiments to study beam mismatch, envelope instabilities, halo particle production, and collective wave excitations.

Quantum self-organization and nuclear collectivities

NASA Astrophysics Data System (ADS)

Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

2018-02-01

The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The outcome of the collective mode is determined basically by the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger gaps between relevant single particle states. Thus, the single-particle state and the collective mode are “enemies” each other. However, the nuclear forces are demonstrated to be rich enough so as to enhance relevant collective mode by reducing the resistance power by changing singleparticle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, when the quantum self-organization occurs, single-particle energies can be self-organized, being enhanced by (i) two quantum liquids, e.g., protons and neutrons, (ii) two major force components, e.g., quadrupole interaction (to drive collective mode) and monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger. The quantum self-organization is a general phenomenon, and is expected to be found in other quantum systems.

Exploring the Angstrom Excursion of Au Nanoparticles Excited away from a Metal Surface by an Impulsive Acoustic Perturbation.

PubMed

Kim, Ji-Wan; Kovalenko, Oleksandr; Liu, Yu; Bigot, Jean-Yves

2016-12-27

We report the anharmonic angstrom dynamics of self-assembled Au nanoparticles (Au:NPs) away from a nickel surface on top of which they are coupled by their near-field interaction. The deformation and the oscillatory excursion away from the surface are induced by picosecond acoustic pulses and probed at the surface plasmon resonance with femtosecond laser pulses. The overall dynamics are due to an efficient transfer of translational momentum from the Ni surface to the Au:NPs, therefore avoiding usual thermal effects and energy redistribution among the electronic states. Two modes are clearly revealed by the oscillatory shift of the Au:NPs surface plasmon resonance-the quadrupole deformation mode due to the transient ellipsoid shape and the excursion mode when the Au:NPs bounce away from the surface. We find that, contrary to the quadrupole mode, the excursion mode is sensitive to the distance between Au:NPs and Ni. Importantly, the excursion dynamics display a nonsinusoidal motion that cannot be explained by a standard harmonic potential model. A detailed modeling of the dynamics using a Hamaker-type Lennard-Jones potential between two media is performed, showing that each Au:NPs coherently evolves in a nearly one-dimensional anharmonic potential with a total excursion of ∼1 Å. This excursion induces a shift of the surface plasmon resonance detectable because of the strong near-field interaction. This general method of observing the spatiotemporal dynamics with angstrom and picosecond resolutions can be directly transposed to many nanostructures or biosystems to reveal the interaction and contact mechanism with their surrounding medium while remaining in their fundamental electronic states.

Scissors Modes and Spin Excitations in Light Nuclei Including ΔN=2 Excitations: Behaviour of 8Be and 10Be

NASA Astrophysics Data System (ADS)

Fayache, M. S.; Sharma, S. Shelley; Zamick, L.

1996-10-01

Shell model calculations are performed for magnetic dipole excitations in8Be and10Be, first with a quadrupole-quadrupole interaction (Q·Q) and then with a realistic interaction. The calculations are performed both in a 0pspace and in a large space which includes all 2ℏωexcitations. In the 0pwithQ·Qwe have an analytic expression for the energies of all states. In this limit we find that in10Be theL=1S=0 scissors mode with isospinT=1 is degenerate with that ofT=2. By projection from an intrinsic state we can obtain simple expressions forB(M1) to the scissors modes in8Be and10Be. We plot cumulative sums for energy-weighted isovector orbital transitions fromJ=0+ground states to the 1+excited states. These have the structure of a low-energy plateau and a steep rise to a high-energy plateau. The relative magnitudes of these plateaux are discussed. By comparing8Be and10Be we find that contrary to the behaviour in heavy deformed nuclei,B(M1)orbitalis not proportional toB(E2). On the other hand, a sum rule which relatesB(M1) to the difference (B(E2)isoscalar-B(E2)isovector) succeeds in describing the difference in behaviours in the two nuclei. The results forQ·Qand the realistic interactions are compared, as are the results in the 0pspace and the large (0p+2ℏω) space. The Wigner supermultiplet scheme is a very useful guide in analyzing the shell model results.

Mass resolution of linear quadrupole ion traps with round rods.

PubMed

Douglas, D J; Konenkov, N V

2014-11-15

Auxiliary dipole excitation is widely used to eject ions from linear radio-frequency quadrupole ion traps for mass analysis. Linear quadrupoles are often constructed with round rod electrodes. The higher multipoles introduced to the electric potential by round rods might be expected to change the ion ejection process. We have therefore investigated the optimum ratio of rod radius, r, to field radius, r0, for excitation and ejection of ions. Trajectory calculations are used to determine the excitation contour, S(q), the fraction of ions ejected when trapped at q values close to the ejection (or excitation) q. Initial conditions are randomly selected from Gaussian distributions of the x and y coordinates and a thermal distribution of velocities. The N = 6 (12 pole) and N = 10 (20 pole) multipoles are added to the quadrupole potential. Peak shapes and resolution were calculated for ratios r/r0 from 1.09 to 1.20 with an excitation time of 1000 cycles of the trapping radio-frequency. Ratios r/r0 in the range 1.140 to 1.160 give the highest resolution and peaks with little tailing. Ratios outside this range give lower resolution and peaks with tails on either the low-mass side or the high-mass side of the peaks. This contrasts with the optimum ratio of 1.126-1.130 for a quadrupole mass filter operated conventionally at the tip of the first stability region. With the optimum geometry the resolution is 2.7 times greater than with an ideal quadrupole field. Adding only a 2.0% hexapole field to a quadrupole field increases the resolution by a factor of 1.6 compared with an ideal quadrupole field. Addition of a 2.0% octopole lowers resolution and degrades peak shape. With the optimum value of r/r0 , the resolution increases with the ejection time (measured in cycles of the trapping rf, n) approximately as R0.5 = 6.64n, in contrast to a pure quadrupole field where R0.5 = 1.94n. Adding weak nonlinear fields to a quadrupole field can improve the resolution with mass-selective ejection of ions by up to a factor of 2.7. The optimum ratio r/r0 is 1.14 to 1.16, which differs from the optimum ratio for a mass filter of 1.128-1.130. Copyright © 2014 John Wiley & Sons, Ltd.

ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu Zhe; Lin, W. P.; Yang Xiaofeng, E-mail: chuzhe@shao.ac.cn, E-mail: linwp@shao.ac.cn

Using an analytical method, we study the singular isothermal quadrupole (SIQ) lens system, which is the simplest lens model that can produce four images. In this case, the radial mass distribution is in accord with the profile of the singular isothermal sphere lens, and the tangential distribution is given by adding a quadrupole on the monopole component. The basic properties of the SIQ lens have been studied in this Letter, including the deflection potential, deflection angle, magnification, critical curve, caustic, pseudo-caustic, and transition locus. Analytical solutions of the image positions and magnifications for the source on axes are derived. Wemore » find that naked cusps will appear when the relative intensity k of quadrupole to monopole is larger than 0.6. According to the magnification invariant theory of the SIQ lens, the sum of the signed magnifications of the four images should be equal to unity, as found by Dalal. However, if a source lies in the naked cusp, the summed magnification of the left three images is smaller than the invariant 1. With this simple lens system, we study the situations where a point source infinitely approaches a cusp or a fold. The sum of the magnifications of the cusp image triplet is usually not equal to 0, and it is usually positive for major cusps while negative for minor cusps. Similarly, the sum of magnifications of the fold image pair is usually not equal to 0 either. Nevertheless, the cusp and fold relations are still equal to 0 in that the sum values are divided by infinite absolute magnifications by definition.« less

Design and fabrication of a basic mass analyzer and vacuum system

NASA Technical Reports Server (NTRS)

Judson, C. M.; Josias, C.; Lawrence, J. L., Jr.

1977-01-01

A two-inch hyperbolic rod quadrupole mass analyzer with a mass range of 400 to 200 amu and a sensitivity exceeding 100 packs per billion has been developed and tested. This analyzer is the basic hardware portion of a microprocessor-controlled quadrupole mass spectrometer for a Gas Analysis and Detection System (GADS). The development and testing of the hyperbolic-rod quadrupole mass spectrometer and associated hardware are described in detail.

Ellipsoidal universe can solve the cosmic microwave background quadrupole problem.

PubMed

Campanelli, L; Cea, P; Tedesco, L

2006-09-29

The recent 3 yr Wilkinson Microwave Anisotropy Probe data have confirmed the anomaly concerning the low quadrupole amplitude compared to the best-fit Lambda-cold dark matter prediction. We show that by allowing the large-scale spatial geometry of our universe to be plane symmetric with eccentricity at decoupling or order 10(-2), the quadrupole amplitude can be drastically reduced without affecting higher multipoles of the angular power spectrum of the temperature anisotropy.

SU-E-T-590: Optimizing Magnetic Field Strengths with Matlab for An Ion-Optic System in Particle Therapy Consisting of Two Quadrupole Magnets for Subsequent Simulations with the Monte-Carlo Code FLUKA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumann, K; Weber, U; Simeonov, Y

Purpose: Aim of this study was to optimize the magnetic field strengths of two quadrupole magnets in a particle therapy facility in order to obtain a beam quality suitable for spot beam scanning. Methods: The particle transport through an ion-optic system of a particle therapy facility consisting of the beam tube, two quadrupole magnets and a beam monitor system was calculated with the help of Matlab by using matrices that solve the equation of motion of a charged particle in a magnetic field and field-free region, respectively. The magnetic field strengths were optimized in order to obtain a circular andmore » thin beam spot at the iso-center of the therapy facility. These optimized field strengths were subsequently transferred to the Monte-Carlo code FLUKA and the transport of 80 MeV/u C12-ions through this ion-optic system was calculated by using a user-routine to implement magnetic fields. The fluence along the beam-axis and at the iso-center was evaluated. Results: The magnetic field strengths could be optimized by using Matlab and transferred to the Monte-Carlo code FLUKA. The implementation via a user-routine was successful. Analyzing the fluence-pattern along the beam-axis the characteristic focusing and de-focusing effects of the quadrupole magnets could be reproduced. Furthermore the beam spot at the iso-center was circular and significantly thinner compared to an unfocused beam. Conclusion: In this study a Matlab tool was developed to optimize magnetic field strengths for an ion-optic system consisting of two quadrupole magnets as part of a particle therapy facility. These magnetic field strengths could subsequently be transferred to and implemented in the Monte-Carlo code FLUKA to simulate the particle transport through this optimized ion-optic system.« less

Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gulyuz, Kerim; Stedwell, Corey N.; Wang Da

2011-05-15

We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure ({approx}10{sup -5} Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarilymore » increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH{sup +}, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.« less

Development of a radio-frequency quadrupole cooler for high beam currents

NASA Astrophysics Data System (ADS)

Boussaid, Ramzi; Ban, G.; Quéméner, G.; Merrer, Y.; Lorry, J.

2017-12-01

The SHIRaC prototype is a recently developed radio-frequency quadrupole (RFQ) beam cooler with an improved optics design to deliver the required beam quality to a high resolution separator (HRS). For an isobaric separation of isotopes, the HRS demands beams with emittance not exceeding 3 π mm mrad and longitudinal energy spread ˜1 eV . Simulation studies showed a significant contribution of the buffer gas diffusion, space charge effect and mainly the rf fringe field to degrade the achieved beam quality at the RFQ exit. A miniature rf quadrupole (μ RFQ ) has been implemented at that exit to remove the degrading effects and provide beams with 1 eV of energy spread and around 1.75 π mm mrad of emittance for 4 Pa gas pressure. This solution enables also to transmit more than 60% of the incoming ions for currents up to 1 μ A . Detailed studies of this development are presented and discussed in this paper. Transport of beams from SHIRaC towards the HRS has been done with an electrostatic quadrupole triplet. Simulations and first experimental tests showed that more than 95% of ions can reach the HRS. Because SPIRAL-2 beams are of high current and very radioactive, the buffer gas will be highly contaminated. Safe maintenance of the SHIRaC beam line needs exceptional treatment of radioactive contaminants. For that, special vinyl sleep should be mounted on elements to be maintained. A detailed maintenance process will be presented.

Use of a Designed Peptide Array To Infer Dissociation Trends for Nontryptic Peptides in Quadrupole Ion Trap and Quadrupole Time-of-Flight Mass Spectrometry

DOE PAGES

Gaucher, Sara P.; Morrow, Jeffrey A.; Faulon, Jean-Loup M.

2007-09-14

Observed peptide gas-phase fragmentation patterns are a complex function of many variables. In order to systematically probe this phenomenon, an array of 40 peptides was synthesized for study. The array of sequences was designed to hold certain variables (peptide length) constant and randomize or balance others (peptide amino acid distribution and position). A high-quality tandem mass spectrometry (MS/MS) data set was acquired for each peptide for all observed charge states on multiple MS instruments, quadrupole-time-of-flight and quadrupole ion trap. The data were analyzed as a function of total charge state and number of mobile protons. Previously known dissociation trends weremore » observed, validating our approach. In addition, the general influence of basic amino acids on dissociation could be determined because, in contrast to the more widely studied tryptic peptides, the amino acids H, K, and R were positionally distributed. Interestingly, our results suggest that cleavage at all basic amino acids is suppressed when a mobile proton is available. Cleavage at H becomes favored only under conditions where a partially mobile proton is present, a caveat to the previously reported trend of enhanced cleavage at H. In conclusion, all acquired data were used as a benchmark to determine how well these sequences would have been identified in a database search using a common algorithm, Mascot.« less

Analysis and correction of linear optics errors, and operational improvements in the Indus-2 storage ring

NASA Astrophysics Data System (ADS)

Husain, Riyasat; Ghodke, A. D.

2017-08-01

Estimation and correction of the optics errors in an operational storage ring is always vital to achieve the design performance. To achieve this task, the most suitable and widely used technique, called linear optics from closed orbit (LOCO) is used in almost all storage ring based synchrotron radiation sources. In this technique, based on the response matrix fit, errors in the quadrupole strengths, beam position monitor (BPM) gains, orbit corrector calibration factors etc. can be obtained. For correction of the optics, suitable changes in the quadrupole strengths can be applied through the driving currents of the quadrupole power supplies to achieve the desired optics. The LOCO code has been used at the Indus-2 storage ring for the first time. The estimation of linear beam optics errors and their correction to minimize the distortion of linear beam dynamical parameters by using the installed number of quadrupole power supplies is discussed. After the optics correction, the performance of the storage ring is improved in terms of better beam injection/accumulation, reduced beam loss during energy ramping, and improvement in beam lifetime. It is also useful in controlling the leakage in the orbit bump required for machine studies or for commissioning of new beamlines.

Simple Model for the Benzene Hexafluorobenzene Interaction

DOE PAGES

Tillack, Andreas F.; Robinson, Bruce H.

2017-06-05

While the experimental intermolecular distance distribution functions of pure benzene and pure hexafluorobenzene are well described by transferable all-atom force fields, the interaction between the two molecules (in a 1:1 mixture) is not well simulated. We demonstrate that the parameters of the transferable force fields are adequate to describe the intermolecular distance distribution if the charges are replaced by a set of charges that are not located at the atoms. Here, the simplest model that well describes the experimental distance distribution, between benzene and hexafluorobenzene, is that of a single ellipsoid for each molecule, representing the van der Waals interactions,more » and a set of three point charges (on the axis perpendicular to the arene plane) which give the same quadrupole moment as do the all atom charges from the transferable force fields.« less

Twisted-Light-Ion Interaction: The Role of Longitudinal Fields

NASA Astrophysics Data System (ADS)

Quinteiro, G. F.; Schmidt-Kaler, Ferdinand; Schmiegelow, Christian T.

2017-12-01

The propagation of light beams is well described using the paraxial approximation, where field components along the propagation direction are usually neglected. For strongly inhomogeneous or shaped light fields, however, this approximation may fail, leading to intriguing variations of the light-matter interaction. This is the case of twisted light having opposite orbital and spin angular momenta. We compare experimental data for the excitation of a quadrupole transition in a single trapped 40Ca+ ion from Schmiegelow et al. [Nat. Commun. 7, 12998 (2016), 10.1038/ncomms12998] with a complete model where longitudinal components of the electric field are taken into account. Our model matches the experimental data and excludes by 11 standard deviations the approximation of a complete transverse field. This demonstrates the relevance of all field components for the interaction of twisted light with matter.

Simple Model for the Benzene Hexafluorobenzene Interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tillack, Andreas F.; Robinson, Bruce H.

While the experimental intermolecular distance distribution functions of pure benzene and pure hexafluorobenzene are well described by transferable all-atom force fields, the interaction between the two molecules (in a 1:1 mixture) is not well simulated. We demonstrate that the parameters of the transferable force fields are adequate to describe the intermolecular distance distribution if the charges are replaced by a set of charges that are not located at the atoms. Here, the simplest model that well describes the experimental distance distribution, between benzene and hexafluorobenzene, is that of a single ellipsoid for each molecule, representing the van der Waals interactions,more » and a set of three point charges (on the axis perpendicular to the arene plane) which give the same quadrupole moment as do the all atom charges from the transferable force fields.« less

Extension of the quasistatic far-wing line shape theory to multicomponent anisotropic potentials

NASA Technical Reports Server (NTRS)

Ma, Q.; Tipping, R. H.

1994-01-01

The formalism developed previously for the calculation of the far-wing line shape function and the corresponding absorption coefficient using a single-component anisotropic interaction term and the binary collision and quasistatic approximations is generalized to multicomponent anisotropic potential functions. Explicit expressions are presented for several common cases, including the long-range dipole-dipole plus dipole-quadrupole interaction and a linear molecule interacting with a perturber atom. After determining the multicomponent functional representation for the interaction between the CO2 and Ar from previously published data, we calculate the theoretical line shape function and the corresponding absorption due to the nu(sub 3) band of CO2 in the frequency range 2400-2580 cm(exp -1) and compare our results with previous calculations carried out using a single-component anisotropic interaction, and with the results obtained assuming Lorentzian line shapes. The principal uncertainties in the present results, possible refinements of the theoretical formalism, and the applicability to other systems are discussed briefly.

Study of Nonlinear Dynamics of Intense Charged Particle Beams in the Paul Trap Simulator Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hua

The Paul Trap Simulator Experiment (PTSX) is a compact laboratory device that simulates the nonlinear dynamics of intense charged particle beams propagating over a large distance in an alternating-gradient magnetic transport system. The radial quadrupole electric eld forces on the charged particles in the Paul Trap are analogous to the radial forces on the charged particles in the quadrupole magnetic transport system. The amplitude of oscillating voltage applied to the cylindrical electrodes in PTSX is equivalent to the quadrupole magnetic eld gradient in accelerators. The temporal periodicity in PTSX corresponds to the spatial periodicity in magnetic transport system. This thesismore » focuses on investigations of envelope instabilities and collective mode excitations, properties of high-intensity beams with significant space-charge effects, random noise-induced beam degradation and a laser-induced-fluorescence diagnostic. To better understand the nonlinear dynamics of the charged particle beams, it is critical to understand the collective processes of the charged particles. Charged particle beams support a variety of collective modes, among which the quadrupole mode and the dipole mode are of the greatest interest. We used quadrupole and dipole perturbations to excite the quadrupole and dipole mode respectively and study the effects of those collective modes on the charge bunch. The experimental and particle-in-cell (PIC) simulation results both show that when the frequency and the spatial structure of the external perturbation are matched with the corresponding collective mode, that mode will be excited to a large amplitude and resonates strongly with the external perturbation, usually causing expansion of the charge bunch and loss of particles. Machine imperfections are inevitable for accelerator systems, and we use random noise to simulate the effects of machine imperfection on the charged particle beams. The random noise can be Fourier decomposed into various frequency components and experimental results show that when the random noise has a large frequency component that matches a certain collective mode, the mode will also be excited and cause heating of the charge bunch. It is also noted that by rearranging the order of the random noise, the adverse effects of the random noise may be eliminated. As a non-destructive diagnostic method, a laser-induced- fluorescence (LIF) diagnostic is developed to study the transverse dynamics of the charged particle beams. The accompanying barium ion source and dye laser system are developed and tested.« less

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

PubMed

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

[Determination of hydroxyproline in liver tissue by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry].

PubMed

Liu, Wei; Qi, Shenglan; Xu, Ying; Xiao, Zhun; Fu, Yadong; Chen, Jiamei; Yang, Tao; Liu, Ping

2017-12-08

A method for the determination of hydroxyproline (Hyp) in liver tissue of mice by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (HILIC-HRMS) was developed. The liver tissue samples of normal mice and liver fibrosis mice induced by carbon tetrachloride were hydrolyzed by concentrated hydrochloric acid. After filtrated and diluted by solution, the diluent was separated on an Hypersil GOLD HILIC column (100 mm×2.1 mm, 3 μm). Water-acetonitrile (28:72, v/v)were used as the mobile phases with isocratic elution. Finally, the target analytes were detected in positive model by HRMS equipped with an electrospray ionization source. The linear range of hydroxyproline was from 0.78 to 100.00 μg/L with the correlation coefficient ( R 2 ) of 0.9983. The limit of quantification was 0.78 μg/L. By detecting the spiked samples, the recoveries were in the range of 97.4%-100.9% with the relative standard deviations (RSDs) between 1.4% and 2.0%. In addition, comparison of the measurement results by this method and the chloramine T method was proceeded. It was found that the linear correlation between the two methods was very good, and the Pearson correlation coefficient was 0.927. And this method had simpler operation procedure and higher accuracy than chloramine T method. This method can be used for the quick determination of hydroxyproline in liver tissue samples.

Excited State Atom-Ion Charge-Exchange

NASA Astrophysics Data System (ADS)

Li, Ming; Makrides, Constantinos; Petrov, Alexander; Kotochigova, Svetlana

2017-04-01

We theoretically investigate the exothermic charge-exchange reaction between an excited atom and a ground-state positive ion. In particular, we focus on MOT-excited Ca*(4s4p 1P) atoms colliding with ground-state Yb+ ions, which are under active study by the experimental group of E. Hudson at UCLA. Collisions between an excited atom and an ion are guided by two major contributions to the long-range interaction potentials, the induction C4 /R4 and charge-quadrupole C3 /R3 potentials, and their coupling by the electron-exchange interaction. Our model of these forces leads to close-coupling equations for multiple reaction channels. We find several avoided crossings between the potentials that couple to the nearby asymptotic limits of Yb*+Ca+, some of which can possibly provide large charge exchange rate coefficients above 10-10 cm3 / s. We acknowledge support from the US Army Research Office, MURI Grants W911NF-14-1-0378 and the US National Science Foundation, Grant PHY-1619788.

Hyperfine coupling of the iodine {\\boldsymbol{D}}{0}_{{\\boldsymbol{u}}}^{+} and β1 g ion-pair states

NASA Astrophysics Data System (ADS)

Baturo, V. V.; Cherepanov, I. N.; Lukashov, S. S.; Petrov, A. N.; Poretsky, S. A.; Pravilov, A. M.

2018-05-01

Detailed studies of I2(β1 g , v β = 13, J β ∼ D{0}u+, v D = 12, J D and D, 48, J D ∼ β, 47, J β ) rovibronic state coupling have been carried out using two-step two-color, hν 1 + hν 2 and hν 1 + 2hν 2, optical–optical double resonance excitation schemes, respectively. The hyperfine interaction satisfying the | {{Δ }}J| = 0, 1 selection rules (magnetic-dipole interaction) has been observed. No electric-quadrupole hyperfine coupling (| {{Δ }}J| = 2) has been found. The dependences of ratios of luminescence intensities from the rovibronic states populated due to the hyperfine coupling to those from optically populated ones on energy gaps between these states have been experimentally determined. The matrix elements as well as the hyperfine structure constant have been obtained using these dependences. It is shown that they increase slightly with the vibrational quantum number of the states.

Clustering fossil from primordial gravitational waves in anisotropic inflation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emami, Razieh; Firouzjahi, Hassan, E-mail: emami@ipm.ir, E-mail: firouz@ipm.ir

2015-10-01

Inflationary models can correlate small-scale density perturbations with the long-wavelength gravitational waves (GW) in the form of the Tensor-Scalar-Scalar (TSS) bispectrum. This correlation affects the mass-distribution in the Universe and leads to the off-diagonal correlations of the density field modes in the form of the quadrupole anisotropy. Interestingly, this effect survives even after the tensor mode decays when it re-enters the horizon, known as the fossil effect. As a result, the off-diagonal correlation function between different Fourier modes of the density fluctuations can be thought as a way to probe the large-scale GW and the mechanism of inflation behind themore » fossil effect. Models of single field slow roll inflation generically predict a very small quadrupole anisotropy in TSS while in models of multiple fields inflation this effect can be observable. Therefore this large scale quadrupole anisotropy can be thought as a spectroscopy for different inflationary models. In addition, in models of anisotropic inflation there exists quadrupole anisotropy in curvature perturbation power spectrum. Here we consider TSS in models of anisotropic inflation and show that the shape of quadrupole anisotropy is different than in single field models. In fact, in these models, quadrupole anisotropy is projected into the preferred direction and its amplitude is proportional to g{sub *} N{sub e} where N{sub e} is the number of e-folds and g{sub *} is the amplitude of quadrupole anisotropy in curvature perturbation power spectrum. We use this correlation function to estimate the large scale GW as well as the preferred direction and discuss the detectability of the signal in the galaxy surveys like Euclid and 21 cm surveys.« less

On the inter-instrument and the inter-laboratory transferability of a tandem mass spectral reference library: 2. Optimization and characterization of the search algorithm.

PubMed

Oberacher, Herbert; Pavlic, Marion; Libiseller, Kathrin; Schubert, Birthe; Sulyok, Michael; Schuhmacher, Rainer; Csaszar, Edina; Köfeler, Harald C

2009-04-01

A sophisticated matching algorithm developed for highly efficient identity search within tandem mass spectral libraries is presented. For the optimization of the search procedure a collection of 410 tandem mass spectra corresponding to 22 compounds was used. The spectra were acquired in three different laboratories on four different instruments. The following types of tandem mass spectrometric instruments were used: quadrupole-quadrupole-time-of-flight (QqTOF), quadrupole-quadrupole-linear ion trap (QqLIT), quadrupole-quadrupole-quadrupole (QqQ), and linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer (LIT-FTICR). The obtained spectra were matched to an established MS/MS-spectral library that contained 3759 MS/MS-spectra corresponding to 402 different reference compounds. All 22 test compounds were part of the library. A dynamic intensity cut-off, the search for neutral losses, and optimization of the formula used to calculate the match probability were shown to significantly enhance the performance of the presented library search approach. With the aid of these features the average number of correct assignments was increased to 98%. For statistical evaluation of the match reliability the set of fragment ion spectra was extended with 300 spectra corresponding to 100 compounds not included in the reference library. Performance was checked with the aid of receiver operating characteristic (ROC) curves. Using the magnitude of the match probability as well as the precursor ion mass as benchmarks to rate the obtained top hit, overall correct classification of a compound being included or not included in the mass spectrometric library, was obtained in more than 95% of cases clearly indicating a high predictive accuracy of the established matching procedure. Copyright (c) 2009 John Wiley & Sons, Ltd.

Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy.

PubMed

Vento, V Thatar; Bergueiro, J; Cartelli, D; Valda, A A; Kreiner, A J

2011-12-01

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam. Copyright © 2011 Elsevier Ltd. All rights reserved.

{sup 1}H NMR relaxometry and quadrupole relaxation enhancement as a sensitive probe of dynamical properties of solids—[C(NH{sub 2}){sub 3}]{sub 3}Bi{sub 2}I{sub 9} as an example

DOE Office of Scientific and Technical Information (OSTI.GOV)

Florek-Wojciechowska, M.; Wojciechowski, M.; Brym, Sz.

{sup 1}H nuclear magnetic resonance relaxometry has been applied to reveal information on dynamics and structure of Gu{sub 3}Bi{sub 2}I{sub 9} ([Gu = C(NH{sub 2}){sub 3}] denotes guanidinium cation). The data have been analyzed in terms of a theory of quadrupole relaxation enhancement, which has been extended here by including effects associated with quadrupole ({sup 14}N) spin relaxation caused by a fast fluctuating component of the electric field gradient tensor. Two motional processes have been identified: a slow one occurring on a timescale of about 8 × 10{sup −6} s which has turned out to be (almost) temperature independent, andmore » a fast process in the range of 10{sup −9} s. From the {sup 1}H-{sup 14}N relaxation contribution (that shows “quadrupole peaks”) the quadrupole parameters, which are a fingerprint of the arrangement of the anionic network, have been determined. It has been demonstrated that the magnitude of the quadrupole coupling considerably changes with temperature and the changes are not caused by phase transitions. At the same time, it has been shown that there is no evidence of abrupt changes in the cationic dynamics and the anionic substructure upon the phase transitions.« less

Induced CMB quadrupole from pointing offsets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moss, Adam; Scott, Douglas; Sigurdson, Kris, E-mail: adammoss@phas.ubc.ca, E-mail: dscott@phas.ubc.ca, E-mail: krs@phas.ubc.ca

2011-01-01

Recent claims in the literature have suggested that the WMAP quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than the WMAP value. We discuss reasons why the WMAP data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between themore » pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here — the dipole signal lies close to the Ecliptic Plane, and its direction, together with the WMAP scan strategy, results in a strong coupling to the Y{sub 2,−1} component in Ecliptic co-ordinates. The dominant strength of this component in the measured quadrupole suggests that one should exercise increased caution in interpreting its estimated amplitude. The Planck satellite has a different scan strategy which does not so directly couple the dipole and quadrupole in this way and will soon provide an independent measurement.« less

Theoretical study of NMR, infrared and Raman spectra on triple-decker phthalocyanines

NASA Astrophysics Data System (ADS)

Suzuki, Atsushi; Oku, Takeo

2016-02-01

Electronic structures and magnetic properties of multi-decker phthalocyanines were studied by theoretical calculation. Electronic structures, excited processes at multi-states, isotropic chemical shifts of 13C, 14N and 1H-nuclear magnetic resonance (NMR), principle V-tensor in electronic field gradient (EFG) tensor and asymmetry parameters (η), vibration mode in infrared (IR) and Raman spectra of triple-decker phthalocyanines were calculated by density functional theory (DFT) and time-dependent DFT using B3LYP as basis function. Electron density distribution was delocalized on the phthalocyanine rings with electron static potential. Considerable separation of chemical shifts in 13C, 14N and 1H-NMR was originated from nuclear spin interaction between nitrogen and carbon atoms, nuclear quadrupole interaction based on EFG and η of central metal under crystal field. Calculated optical absorption at multi-excited process was derived from overlapping π-orbital on the phthalocyanine rings. The vibration modes in IR and Raman spectra were based on in-plane deformation and stretching vibrations of metal-ligand coordination bond on the deformed structure.

HIGH ENERGY, HIGH BRIGHTNESS X-RAYS PRODUCED BY COMPTON BACKSCATTERING AT THE LIVERMORE PLEIADES FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tremaine, A M; Anderson, S G; Betts, S

2005-05-19

PLEIADES (Picosecond Laser Electron Interaction for the Dynamic Evaluation of Structures) produces tunable 30-140 keV x-rays with 0.3-5 ps pulse lengths and up to 10{sup 7} photons/pulse by colliding a high brightness electron beam with a high power laser. The electron beam is created by an rf photo-injector system, accelerated by a 120 MeV linac, and focused to 20 {micro}m with novel permanent magnet quadrupoles. To produce Compton back scattered x-rays, the electron bunch is overlapped with a Ti:Sapphire laser that delivers 500 mJ, 100 fs, pulses to the interaction point. K-edge radiography at 115 keV on Uranium has verifiedmore » the angle correlated energy spectrum inherent in Compton scattering and high-energy tunability of the Livermore source. Current upgrades to the facility will allow laser pumping of targets synchronized to the x-ray source enabling dynamic diffraction and time-resolved studies of high Z materials. Near future plans include extending the radiation energies to >400 keV, allowing for nuclear fluorescence studies of materials.« less

An efficient and robust method for predicting helicopter rotor high-speed impulsive noise

NASA Technical Reports Server (NTRS)

Brentner, Kenneth S.

1996-01-01

A new formulation for the Ffowcs Williams-Hawkings quadrupole source, which is valid for a far-field in-plane observer, is presented. The far-field approximation is new and unique in that no further approximation of the quadrupole source strength is made and integrands with r(exp -2) and r(exp -3) dependence are retained. This paper focuses on the development of a retarded-time formulation in which time derivatives are analytically taken inside the integrals to avoid unnecessary computational work when the observer moves with the rotor. The new quadrupole formulation is similar to Farassat's thickness and loading formulation 1A. Quadrupole noise prediction is carried out in two parts: a preprocessing stage in which the previously computed flow field is integrated in the direction normal to the rotor disk, and a noise computation stage in which quadrupole surface integrals are evaluated for a particular observer position. Preliminary predictions for hover and forward flight agree well with experimental data. The method is robust and requires computer resources comparable to thickness and loading noise prediction.

Measurements of the microwave spectrum, Re-H bond length, and Re quadrupole coupling for HRe(CO)5

NASA Astrophysics Data System (ADS)

Kukolich, Stephen G.; Sickafoose, Shane M.

1993-11-01

Rotational transition frequencies for rhenium pentacarbonyl hydride were measured in the 4-10 GHz range using a Flygare-Balle type microwave spectrometer. The rotational constants and Re nuclear quadrupole coupling constants for the four isotopomers, (1) H187Re(CO)5, (2) H185Re(CO)5, (3) D187Re(CO)5, and (4) D185Re(CO)5, were obtained from the spectra. For the most common isotopomer, B(1)=818.5464(2) MHz and eq Q(187Re)=-900.13(3) MHz. The Re-H bond length (r0) determined by fitting the rotational constants is 1.80(1) Å. Although the Re atom is located at a site of near-octahedral symmetry, the quadrupole coupling is large due to the large Re nuclear moments. A 2.7% increase in Re quadrupole coupling was observed for D-substituted isotopomers, giving a rather large isotope effect on the quadrupole coupling. The Cax-Re-Ceq angle is 96(1)°, when all Re-C-O angles are constrained to 180°.

Use of a Linear Paul Trap to Study Random Noise-Induced Beam Degradation in High-Intensity Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Moses; Gilson, Erik P.; Davidson, Ronald C.

2009-04-10

A random noise-induced beam degradation that can affect intense beam transport over long propagation distances has been experimentally studied by making use of the transverse beam dynamics equivalence between an alternating-gradient (AG) focusing system and a linear Paul trap system. For the present studies, machine imperfections in the quadrupole focusing lattice are considered, which are emulated by adding small random noise on the voltage waveform of the quadrupole electrodes in the Paul trap. It is observed that externally driven noise continuously produces a nonthermal tail of trapped ions, and increases the transverse emittance almost linearly with the duration of themore » noise.« less

Electrostatic atomization--Experiment, theory and industrial applications

NASA Astrophysics Data System (ADS)

Okuda, H.; Kelly, Arnold J.

1996-05-01

Experimental and theoretical research has been initiated at the Princeton Plasma Physics Laboratory on the electrostatic atomization process in collaboration with Charged Injection Corporation. The goal of this collaboration is to set up a comprehensive research and development program on the electrostatic atomization at the Princeton Plasma Physics Laboratory so that both institutions can benefit from the collaboration. Experimental, theoretical and numerical simulation approaches are used for this purpose. An experiment consisting of a capillary sprayer combined with a quadrupole mass filter and a charge detector was installed at the Electrostatic Atomization Laboratory to study fundamental properties of the charged droplets such as the distribution of charges with respect to the droplet radius. In addition, a numerical simulation model is used to study interaction of beam electrons with atmospheric pressure water vapor, supporting an effort to develop an electrostatic water mist fire-fighting nozzle.

The Rhic Azimuth Quadrupole:. "perfect Liquid" or Gluonic Radiation?

NASA Astrophysics Data System (ADS)

Trainor, Thomas A.

Large elliptic flow at RHIC seems to indicate that ideal hydrodynamics provides a good description of Au-Au collisions, at least at the maximum RHIC energy. The medium formed has been interpreted as a nearly perfect (low-viscosity) liquid, and connections have been made to gravitation through string theory. Recently, claimed observations of large flow fluctuations comparable to participant eccentricity fluctuations seem to confirm the ideal hydro scenario. However, determination of the azimuth quadrupole with 2D angular autocorrelations, which accurately distinguish "flow" (quadrupole) from "nonflow" (minijets), contradicts conventional interpretations. Centrality trends may depend only on the initial parton geometry, and methods used to isolate flow fluctuations are sensitive instead mainly to minijet correlations. The results presented in this paper suggest that the azimuth quadrupole may be a manifestation of gluonic multipole radiation.

Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

DOE PAGES

Cho, Herman

2016-02-28

Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2,5/2,7/2, and 9/2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Furthermore, applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

Mass Spectral Studies of 1-(2-Chloroethoxy)-2-[(2-chloroethyl)thio] Ethane and Related Compounds Using Gas ChromatographyMass Spectrometry and Gas ChromatographyTriple-Quadrupole Mass Spectrometry

DTIC Science & Technology

2016-02-01

NOTES 14. ABSTRACT: The electron impact and collision-induced- dissociation mass spectra of 1-(2-chloroethoxy)-2-[(2-chloroethyl)thio] ethane and 10...Collision-ion dissociation (CID) Triple-quadrupole mass spectrometry (QQQ) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...ratio, 10:1), and a 1.0 µL volume of sample was placed on the column. Nitrogen was used as the collision gas for the collision-induced dissociation (CID

Stress fields and energy of disclination-type defects in zones of localized elastic distortions

NASA Astrophysics Data System (ADS)

Sukhanov, Ivan I.; Tyumentsev, Alexander N.; Ditenberg, Ivan A.

2016-11-01

This paper studies theoretically the elastically deformed state and analyzes deformation mechanisms in nanocrystals in the zones of localized elastic distortions and related disclination-type defects, such as dipole, quadrupole and multipole of partial disclinations. Significant differences in the energies of quadrupole and multipole configurations in comparison with nanodipole are revealed. The mechanism of deformation localization in the field of elastic distortions is proposed, which is a quasi-periodic sequence of formation and relaxation of various disclination ensembles with a periodic change in the energy of the defect.

Dynamical quadrupole structure factor of frustrated ferromagnetic chain

NASA Astrophysics Data System (ADS)

Onishi, Hiroaki

2018-05-01

We investigate the dynamical quadrupole structure factor of a spin-1/2 J1-J2 Heisenberg chain with competing ferromagnetic J1 and antiferromagnetic J2 in a magnetic field by exploiting density-matrix renormalization group techniques. In a field-induced spin nematic regime, we observe gapless excitations at q = π according to quasi-long-range antiferro-quadrupole correlations. The gapless excitation mode has a quadratic form at the saturation, while it changes into a linear dispersion as the magnetization decreases.

Nuclear Quadrupole Resonance (NQR) Method and Probe for Generating RF Magnetic Fields in Different Directions to Distinguish NQR from Acoustic Ringing Induced in a Sample

DTIC Science & Technology

1997-08-01

77,719 TITLE OF THE INVENTION NUCLEAR QUADRUPOLE RESONANCE ( NQR ) METHOD AND PROBE FOR GENERATING RF MAGNETIC FIELDS IN DIFFERENT DIRECTIONS TO...DISTINGUISH NQR FROM ACOUSTIC RINGING INDUCED IN A SAMPLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a...nuclear quadrupole 15 resonance ( NQR ) method and probe for generating RF magnetic fields in different directions towards a sample. More specifically

γ-unstable nuclei in the sdg boson model

NASA Astrophysics Data System (ADS)

Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barrett, B. R.

1991-07-01

Following the recent Pt(p, p‧) experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to include g bosons. It is shown that a γ-unstable hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the γ-unstable nature of the hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions. Applications are made to the Xe and Pt isotopes.

Where's water? The many binding sites of hydantoin.

PubMed

Gruet, Sébastien; Pérez, Cristóbal; Steber, Amanda L; Schnell, Melanie

2018-02-21

Prebiotic hydantoin and its complexes with one and two water molecules are investigated using high-resolution broadband rotational spectroscopy in the 2-8 GHz frequency range. The hyperfine structure due to the nuclear quadrupole coupling of the two 14 N atoms is analysed for the monomer and the complexes. This characteristic hyperfine structure will support a definitive assignment from low frequency radioastronomy data. Experiments with H 2 18 O provide accurate experimental information on the preferred binding sites of water, which are compared with quantum-chemically calculated coordinates. In the 2-water complexes, the water molecules bind to hydantoin as a dimer instead of individually, indicating the strong water-water interactions. This information provides first insight on how hydantoin interacts with water on the molecular level.

Open sd-shell nuclei from first principles

DOE PAGES

Jansen, Gustav R.; Signoracci, Angelo J.; Hagen, Gaute; ...

2016-07-05

We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space, and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory formore » deformed nuclei, thereby demonstrating that collective phenomena in sd-shell nuclei emerge from complex ab initio calculations.« less

Open sd-shell nuclei from first principles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, Gustav R.; Signoracci, Angelo J.; Hagen, Gaute

We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space, and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory formore » deformed nuclei, thereby demonstrating that collective phenomena in sd-shell nuclei emerge from complex ab initio calculations.« less

Characterization of the hyperfine interaction of the excited D50 state of Eu3 +:Y2SiO5

NASA Astrophysics Data System (ADS)

Cruzeiro, Emmanuel Zambrini; Etesse, Jean; Tiranov, Alexey; Bourdel, Pierre-Antoine; Fröwis, Florian; Goldner, Philippe; Gisin, Nicolas; Afzelius, Mikael

2018-03-01

We characterize the europium (Eu3 +) hyperfine interaction of the excited state (D50) and determine its effective spin Hamiltonian parameters for the Zeeman and quadrupole tensors. An optical free induction decay method is used to measure all hyperfine splittings under a weak external magnetic field (up to 10 mT) for various field orientations. On the basis of the determined Hamiltonian, we discuss the possibility to predict optical transition probabilities between hyperfine levels for the F70⟷D50 transition. The obtained results provide necessary information to realize an optical quantum memory scheme which utilizes long spin coherence properties of 3 + 151Eu :Y2SiO5 material under external magnetic fields.

A Survey of Aspartate Phenylalanine and Glutamate Phenylalanine Interactions in the Protein Data Bank: Searching for Anion Pairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip, Vivek M; Harris, Jason B; Adams, Rachel M

Protein structures are stabilized using noncovalent interactions. In addition to the traditional noncovalent interactions, newer types of interactions are thought to be present in proteins. One such interaction, an anion pair, in which the positively charged edge of an aromatic ring interacts with an anion, forming a favorable anion quadrupole interaction, has been previously proposed [Jackson, M. R., et al. (2007) J. Phys. Chem. B111, 8242 8249]. To study the role of anion interactions in stabilizing protein structure, we analyzed pairwise interactions between phenylalanine (Phe) and the anionic amino acids, aspartate (Asp) and glutamate (Glu). Particular emphasis was focused onmore » identification of Phe Asp or Glu pairs separated by less than 7 in the high-resolution, nonredundant Protein Data Bank. Simplifying Phe to benzene and Asp or Glu to formate molecules facilitated in silico analysis of the pairs. Kitaura Morokuma energy calculations were performed on roughly 19000 benzene formate pairs and the resulting energies analyzed as a function of distance and angle. Edgewise interactions typically produced strongly stabilizing interaction energies (2 to 7.3 kcal/mol), while interactions involving the ring face resulted in weakly stabilizing to repulsive interaction energies. The strongest, most stabilizing interactions were identified as preferentially occurring in buried residues. Anion pairs are found throughout protein structures, in helices as well as strands. Numerous pairs also had nearby cation interactions as well as potential stacking. While more than 1000 structures did not contain an anion pair, the 3134 remaining structures contained approximately 2.6 anion pairs per protein, suggesting it is a reasonably common motif that could contribute to the overall structural stability of a protein.« less

A Survey of Aspartate-Phenylalanine and Glutamate-Phenylalanine Interactions in the Protein Data Bank: Searching for Anion-pi Pairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip, Vivek M; Harris, Jason B; Adams, Rachel M

Protein structures are stabilized using noncovalent interactions. In addition to the traditional noncovalent interactions, newer types of interactions are thought to be present in proteins. One such interaction, an anion-{pi} pair, in which the positively charged edge of an aromatic ring interacts with an anion, forming a favorable anion-quadrupole interaction, has been previously proposed [Jackson, M. R., et al. (2007) J. Phys. Chem. B111, 8242-8249]. To study the role of anion-{pi} interactions in stabilizing protein structure, we analyzed pairwise interactions between phenylalanine (Phe) and the anionic amino acids, aspartate (Asp) and glutamate (Glu). Particular emphasis was focused on identification ofmore » Phe-Asp or -Glu pairs separated by less than 7 {angstrom} in the high-resolution, nonredundant Protein Data Bank. Simplifying Phe to benzene and Asp or Glu to formate molecules facilitated in silico analysis of the pairs. Kitaura-Morokuma energy calculations were performed on roughly 19000 benzene-formate pairs and the resulting energies analyzed as a function of distance and angle. Edgewise interactions typically produced strongly stabilizing interaction energies (-2 to -7.3 kcal/mol), while interactions involving the ring face resulted in weakly stabilizing to repulsive interaction energies. The strongest, most stabilizing interactions were identified as preferentially occurring in buried residues. Anion-{pi} pairs are found throughout protein structures, in helices as well as {beta} strands. Numerous pairs also had nearby cation-{pi} interactions as well as potential {pi}-{pi} stacking. While more than 1000 structures did not contain an anion-{pi} pair, the 3134 remaining structures contained approximately 2.6 anion-{pi} pairs per protein, suggesting it is a reasonably common motif that could contribute to the overall structural stability of a protein.« less

A survey of aspartate-phenylalanine and glutamate-phenylalanine interactions in the protein data bank: searching for anion-π pairs.

PubMed

Philip, Vivek; Harris, Jason; Adams, Rachel; Nguyen, Don; Spiers, Jeremy; Baudry, Jerome; Howell, Elizabeth E; Hinde, Robert J

2011-04-12

Protein structures are stabilized using noncovalent interactions. In addition to the traditional noncovalent interactions, newer types of interactions are thought to be present in proteins. One such interaction, an anion-π pair, in which the positively charged edge of an aromatic ring interacts with an anion, forming a favorable anion-quadrupole interaction, has been previously proposed [Jackson, M. R., et al. (2007) J. Phys. Chem. B111, 8242-8249]. To study the role of anion-π interactions in stabilizing protein structure, we analyzed pairwise interactions between phenylalanine (Phe) and the anionic amino acids, aspartate (Asp) and glutamate (Glu). Particular emphasis was focused on identification of Phe-Asp or -Glu pairs separated by less than 7 Å in the high-resolution, nonredundant Protein Data Bank. Simplifying Phe to benzene and Asp or Glu to formate molecules facilitated in silico analysis of the pairs. Kitaura-Morokuma energy calculations were performed on roughly 19000 benzene-formate pairs and the resulting energies analyzed as a function of distance and angle. Edgewise interactions typically produced strongly stabilizing interaction energies (-2 to -7.3 kcal/mol), while interactions involving the ring face resulted in weakly stabilizing to repulsive interaction energies. The strongest, most stabilizing interactions were identified as preferentially occurring in buried residues. Anion-π pairs are found throughout protein structures, in helices as well as β strands. Numerous pairs also had nearby cation-π interactions as well as potential π-π stacking. While more than 1000 structures did not contain an anion-π pair, the 3134 remaining structures contained approximately 2.6 anion-π pairs per protein, suggesting it is a reasonably common motif that could contribute to the overall structural stability of a protein.

Elastic and transition form factors of the Δ(1232)

DOE PAGES

Segovia, Jorge; Chen, Chen; Cloet, Ian C.; ...

2013-12-10

Predictions obtained with a confining, symmetry-preserving treatment of a vector Ⓧ vector contact interaction at leading-order in a widely used truncation of QCD’s Dyson–Schwinger equations are presented for Δ and Ω baryon elastic form factors and the γN → Δ transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest.more » The Δ elastic form factors are very sensitive to m Δ. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce Δ-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the Δ(1232). Considering the Δ-baryon’s quadrupole moment, whilst all computations produce a negative value, the conflict between theoretical predictions entails that it is currently impossible to reach a sound conclusion on the nature of the Δ-baryon’s deformation in the infinite momentum frame. Furthermore, results for analogous properties of the Ω baryon are less contentious. In connection with the N → Δ transition, the Ash-convention magnetic transition form factor falls faster than the neutron’s magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ; and, furthermore, these quadrupole ratios do slowly approach their anticipated asymptotic limits.« less

NMR spectrum analysis for CrAs at ambient pressure

NASA Astrophysics Data System (ADS)

Kotegawa, H.; Nakahara, S.; Matsushima, K.; Tou, H.; Matsuoka, E.; Sugawara, H.; Harima, H.

2018-05-01

We report NMR spectrum analysis for CrAs, which was recently reported to be superconducting under pressure. The NMR spectrum obtained by the powdered single crystals shows a typical powder pattern reproduced by the electric field gradient (EFG) parameters and isotropic Knight shift, indicating anisotropy of Knight shift is not remarkable in CrAs. For the oriented sample, the spectrum can be understood by considering that the crystals are aligned for H ∥ b . The temperature dependence of Knight shift was successfully obtained from NMR spectrum with large nuclear quadrupole interaction.

Structure of the Lightest Tin Isotopes

NASA Astrophysics Data System (ADS)

Morris, T. D.; Simonis, J.; Stroberg, S. R.; Stumpf, C.; Hagen, G.; Holt, J. D.; Jansen, G. R.; Papenbrock, T.; Roth, R.; Schwenk, A.

2018-04-01

We link the structure of nuclei around 100Sn, the heaviest doubly magic nucleus with equal neutron and proton numbers (N =Z =50 ), to nucleon-nucleon (N N ) and three-nucleon (N N N ) forces constrained by data of few-nucleon systems. Our results indicate that 100Sn is doubly magic, and we predict its quadrupole collectivity. We present precise computations of 101Sn based on three-particle-two-hole excitations of 100Sn, and we find that one interaction accurately reproduces the small splitting between the lowest Jπ=7 /2+ and 5 /2+ states.

Spin temperature concept verified by optical magnetometry of nuclear spins

NASA Astrophysics Data System (ADS)

Vladimirova, M.; Cronenberger, S.; Scalbert, D.; Ryzhov, I. I.; Zapasskii, V. S.; Kozlov, G. G.; Lemaître, A.; Kavokin, K. V.

2018-01-01

We develop a method of nonperturbative optical control over adiabatic remagnetization of the nuclear spin system and apply it to verify the spin temperature concept in GaAs microcavities. The nuclear spin system is shown to exactly follow the predictions of the spin temperature theory, despite the quadrupole interaction that was earlier reported to disrupt nuclear spin thermalization. These findings open a way for the deep cooling of nuclear spins in semiconductor structures, with the prospect of realizing nuclear spin-ordered states for high-fidelity spin-photon interfaces.

Mass spectra stimulated by O+ and Ar+ interacting with a surface.

NASA Technical Reports Server (NTRS)

Siegel, M. W.; Krauss, R. H.; Boring, J. W.

1972-01-01

Beams of O(+) and Ar(+) in the energy range from 100 to 300 eV were directed into an aperture in one face of a copper box. The mass spectrum from a similar aperture in an adjacent face was observed with the aid of a commercial RF quadrupole spectrometer. On the basis of the results obtained it is reported that O(+) beams at about 200 eV may be essentially lost after a few collisions with a surface, in agreement with similar conclusions about atomic oxygen at thermal energies.

Hyperfine-Structure-Induced Depolarization of Impulsively Aligned I2 Molecules

NASA Astrophysics Data System (ADS)

Thomas, Esben F.; Søndergaard, Anders A.; Shepperson, Benjamin; Henriksen, Niels E.; Stapelfeldt, Henrik

2018-04-01

A moderately intense 450 fs laser pulse is used to create rotational wave packets in gas phase I2 molecules. The ensuing time-dependent alignment, measured by Coulomb explosion imaging with a delayed probe pulse, exhibits the characteristic revival structures expected for rotational wave packets but also a complex nonperiodic substructure and decreasing mean alignment not observed before. A quantum mechanical model attributes the phenomena to coupling between the rotational angular momenta and the nuclear spins through the electric quadrupole interaction. The calculated alignment trace agrees very well with the experimental results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishev, S., E-mail: mishev@theor.jinr.ru; Voronov, V. V., E-mail: voronov@theor.jinr.ru

The role of the nucleon correlations in the ground states of even–even nuclei on the properties of low-lying states in odd–even spherical and transitional nuclei is studied. We reason about this subject using the language of the quasiparticle–phonon model which we extend to take account of the existence of quasiparticle⊗phonon configurations in the wave functions of the ground states of the even–even cores. Of paramount importance to the structure of the low-lying states happens to be the quasiparticle–phonon interaction in the ground states which we evaluated using both the standard and the extended random phase approximations. Numerical calculations for nucleimore » in the barium and cadmium regions are performed using pairing and quadrupole–quadrupole interaction modes which have the dominant impact on the lowest-lying states’ structure. It is found that states with same angular momentum and parity become closer in energy as compared to the predictions of models disregarding the backward amplitudes, which turns out to be in accord with the experimental data. In addition we found that the interaction between the last quasiparticle and the ground-state phonon admixtures produces configurations which contribute significantly to the magnetic dipolemoment of odd-A nuclei. It also reveals a potential for reproducing their experimental values which proves impossible if this interaction is neglected.« less

Development of a systematic strategy for the global identification and classification of the chemical constituents and metabolites of Kai-Xin-San based on liquid chromatography with quadrupole time-of-flight mass spectrometry combined with multiple data-processing approaches.

PubMed

Wang, Xiaotong; Liu, Jing; Yang, Xiaomei; Zhang, Qian; Zhang, Yiwen; Li, Qing; Bi, Kaishun

2018-03-30

To rapidly identify and classify complicated components and metabolites for traditional Chinese medicines, a liquid chromatography with quadrupole time-of-flight mass spectrometry method combined with multiple data-processing approaches was established. In this process, Kai-Xin-San, a widely used classic traditional Chinese medicine preparation, was chosen as a model prescription. Initially, the fragmentation patterns, diagnostic product ions and neutral loss of each category of compounds were summarized by collision-induced dissociation analysis of representative standards. In vitro, the multiple product ions filtering technique was utilized to identify the chemical constituents for globally covering trace components. With this strategy, 108 constituents were identified, and compounds database was successfully established. In vivo, the prototype compounds were extracted based on the established database, and the neutral loss filtering technique combined with the drug metabolism reaction rules was employed to identify metabolites. Overall, 69 constituents including prototype and metabolites were characterized in rat plasma and nine constituents were firstly characterized in rat brain, which may be the potential active constituents resulting in curative effects by synergistic interaction. In conclusion, this study provides a generally applicable strategy to global metabolite identification for the complicated components in complex matrix and a chemical basis for further pharmacological research of Kai-Xin-San. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence

NASA Astrophysics Data System (ADS)

Krishnendu, N. V.; Arun, K. G.; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

The importance of quadrupole sources in prediction of transonic tip speed propeller noise

NASA Technical Reports Server (NTRS)

Hanson, D. B.; Fink, M. R.

1978-01-01

A theoretical analysis is presented for the harmonic noise of high speed, open rotors. Far field acoustic radiation equations based on the Ffowcs-Williams/Hawkings theory are derived for a static rotor with thin blades and zero lift. Near the plane of rotation, the dominant sources are the volume displacement and the rho U(2) quadrupole, where u is the disturbance velocity component in the direction blade motion. These sources are compared in both the time domain and the frequency domain using two dimensional airfoil theories valid in the subsonic, transonic, and supersonic speed ranges. For nonlifting parabolic arc blades, the two sources are equally important at speeds between the section critical Mach number and a Mach number of one. However, for moderately subsonic or fully supersonic flow over thin blade sections, the quadrupole term is negligible. It is concluded for thin blades that significant quadrupole noise radiation is strictly a transonic phenomenon and that it can be suppressed with blade sweep. Noise calculations are presented for two rotors, one simulating a helicopter main rotor and the other a model propeller. For the latter, agreement with test data was substantially improved by including the quadrupole source term.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

PubMed

Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

Nuclear scissors modes and hidden angular momenta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balbutsev, E. B., E-mail: balbuts@theor.jinr.ru; Molodtsova, I. V.; Schuck, P.

The coupled dynamics of low-lying modes and various giant resonances are studied with the help of the Wigner Function Moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. The method is based on Time-Dependent Hartree–Fock–Bogoliubov equations. The model of the harmonic oscillator including spin–orbit potential plus quadrupole–quadrupole and spin–spin interactions is considered. New low-lying spin-dependent modes are analyzed. Special attention is paid to the scissors modes. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theorymore » allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes.« less

Photodissociation spectroscopy of the Mg + -CO2 complex and its isotopic analogs

NASA Astrophysics Data System (ADS)

Yeh, C. S.; Willey, K. F.; Robbins, D. L.; Pilgrim, J. S.; Duncan, M. A.

1993-02-01

Mg+-CO2 ion-molecule cluster complexes are produced by laser vaporization in a pulsed nozzle cluster source. The vibronic spectroscopy in these complexes is studied with mass-selected photodissociation spectroscopy in a reflectron time-of-flight mass spectrometer. Two excited electronic states are observed (2) 2Σ+ and 2Π. The 2Π state has a vibrational progression in the metal-CO2 stretching mode (ωe'=381.8 cm-1). The complexes are linear (Mg+-OCO) and are bound by the charge-quadrupole interaction. The dissociation energy (D0`) is 14.7 kcal/mol. Corresponding spectra are measured for each of the 24, 25, and 26 isotopes of magnesium. These results are compared to theoretical predictions made by Bauschlicher and co-workers.

Error Correction for the JLEIC Ion Collider Ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Guohui; Morozov, Vasiliy; Lin, Fanglei

2016-05-01

The sensitivity to misalignment, magnet strength error, and BPM noise is investigated in order to specify design tolerances for the ion collider ring of the Jefferson Lab Electron Ion Collider (JLEIC) project. Those errors, including horizontal, vertical, longitudinal displacement, roll error in transverse plane, strength error of main magnets (dipole, quadrupole, and sextupole), BPM noise, and strength jitter of correctors, cause closed orbit distortion, tune change, beta-beat, coupling, chromaticity problem, etc. These problems generally reduce the dynamic aperture at the Interaction Point (IP). According to real commissioning experiences in other machines, closed orbit correction, tune matching, beta-beat correction, decoupling, andmore » chromaticity correction have been done in the study. Finally, we find that the dynamic aperture at the IP is restored. This paper describes that work.« less

Plasmonic-Field Interactions at Nanoparticle Interfaces for Infrared Thermal-Shielding Applications Based on Transparent Oxide Semiconductors.

PubMed

Matsui, Hiroaki; Furuta, Shinya; Hasebe, Takayuki; Tabata, Hitoshi

2016-05-11

This paper describes infrared plasmonic responses in three-dimensional (3D) assembled films of In2O3:Sn nanoparticles (NPs). The introduction of surface modifications to NPs can facilitate the production of electric-field interactions between NPs due to the creation of narrow crevices in the NP interfaces. In particular, the electric-field interactions along the in-plane and out-of-plane directions in the 3D assembled NP films allow for resonant splitting of plasmon excitations to the quadrupole and dipole modes, thereby realizing selective high reflections in the near- and mid-infrared range, respectively. The origins of these plasmonic properties were revealed from electric-field distributions calculated by electrodynamic simulations that agreed well with experimental results. The interparticle gaps and their derived plasmon couplings play an important role in producing high reflective performances in assembled NP films. These 3D assemblies of NPs can be further extended to produce large-size flexible films with high infrared reflectance, which simultaneously exhibit microwave transmittance essential for telecommunications. This study provides important insights for harnessing infrared optical responses using plasmonic technology for the fabrication of infrared thermal-shielding applications.

Numerical study of the 3-D effect on FEL performance and its application to the APS LEUTL FEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chae, Y.C.

A Low-Energy Undulator Test Line (LEUTL) is under construction at the Advanced Photon Source (APS). In LEUTL periodic focusing is provided by external quadrupoles. This results in an elliptical beam with its betatron oscillation envelope varying along the undulators. The free-electron laser (FEL) interaction with such a beam will exhibit truly 3-D effects. Thus the investigation of 3-D effects is important in optimizing the FEL performance. The programs GINGER and TDA3D, coupled with theoretically known facts, have been used for this purpose. Both programs are fully 3-D in moving the particle, but model the interaction between particles and axially symmetricmore » electromagnetic waves. Even though TDA3D can include a few azimuthal modes in the interaction, it is still not a fully 3-D FEL code. However, they show that these 2-D programs can still be used for an elliptical beam whose aspect ratio is within certain limits. The author presents numerical results of FEL performance for the circular beam, the elliptical beam, and finally for the beam in the realistic LEUTL lattice.« less

Mechanical qualification of the support structure for MQXF, the Nb 3Sn low-β quadrupole for the high luminosity LHC

DOE PAGES

Juchno, M.; Ambrosio, G.; Anerella, M.; ...

2016-01-26

Within the scope of the High Luminosity LHC project, the collaboration between CERN and U.S. LARP is developing new low-β quadrupoles using the Nb 3Sn superconducting technology for the upgrade of the LHC interaction regions. The magnet support structure of the first short model was designed and two units were fabricated and tested at CERN and at LBNL. The structure provides the preload to the collars-coils subassembly by an arrangement of outer aluminum shells pre-tensioned with water-pressurized bladders. For the mechanical qualification of the structure and the assembly procedure, superconducting coils were replaced with solid aluminum “dummy coils”, the structuremore » was preloaded at room temperature, and then cooled-down to 77 K. Mechanical behavior of the magnet structure was monitored with the use of strain gauges installed on the aluminum shells, the dummy coils and the axial preload system. As a result, this paper reports on the outcome of the assembly and the cool-down tests with dummy coils, which were performed at CERN and at LBNL, and presents the strain gauge measurements compared to the 3D finite element model predictions.« less

Modeling Aerodynamically Generated Sound of Helicopter Rotors

NASA Technical Reports Server (NTRS)

Brentner, Kenneth S.; Farassat, F.

2002-01-01

A great deal of progress has been made in the modeling of aerodynamically generated sound of rotors over the past decade. Although the modeling effort has focused on helicopter main rotors, the theory is generally valid for a wide range of rotor configurations. The Ffowcs Williams Hawkings (FW-H) equation has been the foundation for much of the development. The monopole and dipole source terms of the FW-H equation account for the thickness and loading noise, respectively. Bladevortex-interaction noise and broadband noise are important types of loading noise, hence much research has been directed toward the accurate modeling of these noise mechanisms. Both subsonic and supersonic quadrupole noise formulations have been developed for the prediction of high-speed impulsive noise. In an effort to eliminate the need to compute the quadrupole contribution, the FW-H equation has also been utilized on permeable surfaces surrounding all physical noise sources. Comparisons of the Kirchhoff formulation for moving surfaces with the FW-H equation have shown that the Kirchhoff formulation for moving surfaces can give erroneous results for aeroacoustic problems. Finally, significant progress has been made incorporating the rotor noise models into full vehicle noise prediction tools.

Instrumentation status of the low-b magnet systems at the Large Hadron Collider (LHC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, C.; /Fermilab; Balle, C.

2011-05-01

The low-{beta} magnet systems are located in the Large Hadron Collider (LHC) insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process allowing proton collisions at luminosity up to 10{sup 34}cm{sup -2}s{sup -1}. Those systems are a contribution of the US-LHC Accelerator project. The systems are mainly composed of the quadrupole magnets (triplets), the separation dipoles and their respective electrical feed-boxes (DFBX). The low-{beta} magnet systems operate in an environment of extreme radiation, high gradient magnetic field and high heat load to the cryogenic system due to the beam dynamic effect. Due tomore » the severe environment, the robustness of the diagnostics is primordial for the operation of the triplets. The hardware commissioning phase of the LHC was completed in February 2010. In the sake of a safer and more user-friendly operation, several consolidations and instrumentation modifications were implemented during this commissioning phase. This paper presents the instrumentation used to optimize the engineering process and operation of the final focusing/defocusing quadrupole magnets for the first years of operation.« less

CALCULATIONS WITH SPECTROSCOPIC ACCURACY: ENERGIES AND TRANSITION RATES IN THE NITROGEN ISOELECTRONIC SEQUENCE FROM Ar XII TO Zn XXIV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, K.; Dang, W.; Si, R.

2016-03-15

Combined relativistic configuration interaction and many-body perturbation calculations are performed for the 359 fine-structure levels of the 2s{sup 2} 2p{sup 3}, 2 s2p{sup 4}, 2p{sup 5}, 2s{sup 2} 2p{sup 2} 3l, 2 s2p{sup 3} 3l, 2p{sup 4} 3l, and 2s{sup 2} 2p{sup 2} 4l configurations in N-like ions from Ar xii to Zn xxiv. Complete and consistent data sets of energies, wavelengths, radiative rates, oscillator strengths, and line strengths for all possible electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among the 359 levels are given for each ion. The present work significantly increases the amount of accuratemore » data for ions in the nitrogen-like sequence, and the accuracy of the energy levels is high enough to enable the identification and interpretation of observed spectra involving the n = 3, 4 levels, for which experimental values are largely scarce. Meanwhile, the results should be of great help for modeling and diagnosing astrophysical and fusion plasmas.« less

Characterization of magnetic nanoparticles using programmed quadrupole magnetic field-flow fractionation

PubMed Central

Williams, P. Stephen; Carpino, Francesca; Zborowski, Maciej

2010-01-01

Quadrupole magnetic field-flow fractionation is a relatively new technique for the separation and characterization of magnetic nanoparticles. Magnetic nanoparticles are often of composite nature having a magnetic component, which may be a very finely divided material, and a polymeric or other material coating that incorporates this magnetic material and stabilizes the particles in suspension. There may be other components such as antibodies on the surface for specific binding to biological cells, or chemotherapeutic drugs for magnetic drug delivery. Magnetic field-flow fractionation (MgFFF) has the potential for determining the distribution of the magnetic material among the particles in a given sample. MgFFF differs from most other forms of field-flow fractionation in that the magnetic field that brings about particle separation induces magnetic dipole moments in the nanoparticles, and these potentially can interact with one another and perturb the separation. This aspect is examined in the present work. Samples of magnetic nanoparticles were analysed under different experimental conditions to determine the sensitivity of the method to variation of conditions. The results are shown to be consistent and insensitive to conditions, although magnetite content appeared to be somewhat higher than expected. PMID:20732895

The nuclear electric quadrupole moment of copper.

PubMed

Santiago, Régis Tadeu; Teodoro, Tiago Quevedo; Haiduke, Roberto Luiz Andrade

2014-06-21

The nuclear electric quadrupole moment (NQM) of the (63)Cu nucleus was determined from an indirect approach by combining accurate experimental nuclear quadrupole coupling constants (NQCCs) with relativistic Dirac-Coulomb coupled cluster calculations of the electric field gradient (EFG). The data obtained at the highest level of calculation, DC-CCSD-T, from 14 linear molecules containing the copper atom give rise to an indicated NQM of -198(10) mbarn. Such result slightly deviates from the previously accepted standard value given by the muonic method, -220(15) mbarn, although the error bars are superimposed.

Deformation effect on spectral statistics of nuclei

NASA Astrophysics Data System (ADS)

Sabri, H.; Jalili Majarshin, A.

2018-02-01

In this study, we tried to get significant relations between the spectral statistics of atomic nuclei and their different degrees of deformations. To this aim, the empirical energy levels of 109 even-even nuclei in the 22 ≤ A ≤ 196 mass region are classified as their experimental and calculated quadrupole, octupole, hexadecapole and hexacontatetrapole deformations values and analyzed by random matrix theory. Our results show an obvious relation between the regularity of nuclei and strong quadrupole, hexadecapole and hexacontatetrapole deformations and but for nuclei that their octupole deformations are nonzero, we have observed a GOE-like statistics.

Nuclear spin warm up in bulk n -GaAs

NASA Astrophysics Data System (ADS)

Kotur, M.; Dzhioev, R. I.; Vladimirova, M.; Jouault, B.; Korenev, V. L.; Kavokin, K. V.

2016-08-01

We show that the spin-lattice relaxation in n -type insulating GaAs is dramatically accelerated at low magnetic fields. The origin of this effect, which cannot be explained in terms of well-known diffusion-limited hyperfine relaxation, is found in the quadrupole relaxation, induced by fluctuating donor charges. Therefore, quadrupole relaxation, which governs low field nuclear spin relaxation in semiconductor quantum dots, but was so far supposed to be harmless to bulk nuclei spins in the absence of optical pumping, can be studied and harnessed in the much simpler model environment of n -GaAs bulk crystal.

A Superstrong Adjustable Permanent Magnet for the Final Focus Quadrupole in a Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihara, T.

A super strong permanent magnet quadrupole (PMQ) was fabricated and tested. It has an integrated strength of 28.5T with overall length of 10 cm and a 7mm bore radius. The final focus quadrupole of a linear collider needs a variable focal length. This can be obtained by slicing the magnet into pieces along the beamline direction and rotating these slices. But this technique may lead to movement of the magnetic center and introduction of a skew quadrupole component when the strength is varied. A ''double ring structure'' can ease these effects. A second prototype PMQ, containing thermal compensation materials andmore » with a double ring structure, has been fabricated. Worm gear is selected as the mechanical rotating scheme because the double ring structure needs a large torque to rotate magnets. The structure of the second prototype PMQ is shown.« less

Development of a GC/Quadrupole-Orbitrap Mass Spectrometer, Part I: Design and Characterization

PubMed Central

2015-01-01

Identification of unknown compounds is of critical importance in GC/MS applications (metabolomics, environmental toxin identification, sports doping, petroleomics, and biofuel analysis, among many others) and remains a technological challenge. Derivation of elemental composition is the first step to determining the identity of an unknown compound by MS, for which high accuracy mass and isotopomer distribution measurements are critical. Here, we report on the development of a dedicated, applications-grade GC/MS employing an Orbitrap mass analyzer, the GC/Quadrupole-Orbitrap. Built from the basis of the benchtop Orbitrap LC/MS, the GC/Quadrupole-Orbitrap maintains the performance characteristics of the Orbitrap, enables quadrupole-based isolation for sensitive analyte detection, and includes numerous analysis modalities to facilitate structural elucidation. We detail the design and construction of the instrument, discuss its key figures-of-merit, and demonstrate its performance for the characterization of unknown compounds and environmental toxins. PMID:25208235

Microfluidic quadrupole and floating concentration gradient.

PubMed

Qasaimeh, Mohammad A; Gervais, Thomas; Juncker, David

2011-09-06

The concept of fluidic multipoles, in analogy to electrostatics, has long been known as a particular class of solutions of the Navier-Stokes equation in potential flows; however, experimental observations of fluidic multipoles and of their characteristics have not been reported yet. Here we present a two-dimensional microfluidic quadrupole and a theoretical analysis consistent with the experimental observations. The microfluidic quadrupole was formed by simultaneously injecting and aspirating fluids from two pairs of opposing apertures in a narrow gap formed between a microfluidic probe and a substrate. A stagnation point was formed at the centre of the microfluidic quadrupole, and its position could be rapidly adjusted hydrodynamically. Following the injection of a solute through one of the poles, a stationary, tunable, and movable-that is, 'floating'-concentration gradient was formed at the stagnation point. Our results lay the foundation for future combined experimental and theoretical exploration of microfluidic planar multipoles including convective-diffusive phenomena.

Reconstruction of CMB temperature anisotropies with primordial CMB induced polarization in galaxy clusters

NASA Astrophysics Data System (ADS)

Liu, Guo-Chin; Ichiki, Kiyotomo; Tashiro, Hiroyuki; Sugiyama, Naoshi

2016-07-01

Scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces polarization signals determined by the quadrupole anisotropy in the photon distribution at the location of clusters. This `remote quadrupole' derived from the measurements of the induced polarization in galaxy clusters provides an opportunity to reconstruct local CMB temperature anisotropies. In this Letter, we develop an algorithm of the reconstruction through the estimation of the underlying primordial gravitational potential, which is the origin of the CMB temperature and polarization fluctuations and CMB induced polarization in galaxy clusters. We found a nice reconstruction for the quadrupole and octopole components of the CMB temperature anisotropies with the assistance of the CMB induced polarization signals. The reconstruction can be an important consistency test on the puzzles of CMB anomalies, especially for the low-quadrupole and axis-of-evil problems reported in Wilkinson Microwave Anisotropy Probe and Planck data.

Extended nuclear quadrupole resonance study of the heavy-fermion superconductor PuCoGa5

NASA Astrophysics Data System (ADS)

Koutroulakis, G.; Yasuoka, H.; Tobash, P. H.; Mitchell, J. N.; Bauer, E. D.; Thompson, J. D.

2016-10-01

PuCoGa5 has emerged as a prototypical heavy-fermion superconductor, with its transition temperature (Tc≃18.5 K) being the highest amongst such materials. Nonetheless, a clear description as to what drives the superconducting pairing is still lacking, rendered complicated by the notoriously intricate nature of plutonium's 5 f valence electrons. Here, we present a detailed Ga,7169 nuclear quadrupole resonance (NQR) study of PuCoGa5, concentrating on the system's normal state properties near to Tc and aiming to detect distinct signatures of possible pairing mechanisms. In particular, the quadrupole frequency and spin-lattice relaxation rate were measured for the two crystallographically inequivalent Ga sites and for both Ga isotopes, in the temperature range 1.6-300 K. No evidence of significant charge fluctuations is found from the NQR observables. On the contrary, the low-energy dynamics is dominated by anisotropic spin fluctuations with strong, nearly critical, in-plane character, which are effectively identical to the case of the sister compound PuCoIn5. These findings are discussed within the context of different theoretical proposals for the unconventional pairing mechanism in heavy-fermion superconductors.

Extended nuclear quadrupole resonance study of the heavy-fermion superconductor PuCoGa 5

DOE PAGES

Koutroulakis, Georgios; Yasuoka, Hiroshi; Tobash, Paul H.; ...

2016-10-10

PuCoGa 5 has emerged as a prototypical heavy-fermion superconductor, with its transition temperature (T c ≃ 18.5 K) being the highest amongst such materials. Nonetheless, a clear description as to what drives the superconducting pairing is still lacking, rendered complicated by the notoriously intricate nature of plutonium's 5f valence electrons. Here, we present a detailed 69,71Ga nuclear quadrupole resonance (NQR) study of PuCoGa 5, concentrating on the system's normal state properties near to T c and aiming to detect distinct signatures of possible pairing mechanisms. In particular, the quadrupole frequency and spin-lattice relaxation rate were measured for the two crystallographicallymore » inequivalent Ga sites and for both Ga isotopes, in the temperature range 1.6–300 K. No evidence of significant charge fluctuations is found from the NQR observables. On the contrary, the low-energy dynamics is dominated by anisotropic spin fluctuations with strong, nearly critical, in-plane character, which are effectively identical to the case of the sister compound PuCoIn 5. Lastly, these findings are discussed within the context of different theoretical proposals for the unconventional pairing mechanism in heavy-fermion superconductors.« less

Spectroscopic Factors from the Single Neutron Transfer Reaction 111Cd(d,p)112Cd

NASA Astrophysics Data System (ADS)

Jamieson, D. S.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Svensson, C. E.; Sumithrarachchi, C. S.; Triambak, S.; Wong, J.; Ball, G.; Faestermann, T.; Krücken, R.; Hertenberger, R.; Wirth, H.-F.

2013-03-01

The cadmium isotopes have been cited as excellent examples of vibrational nuclei for decades, with multi-phonon quadrupole, quadrupole-octupole, and mixed-symmetry states proposed. From a variety of experimental studies, a large amount of spectroscopic data has been obtained, recently focused on γ-ray studies. In the present work, the single-particle structure of 112Cd has been investigated using the 111Cd(ěcd, p)112Cd reaction. The investigation was carried out using a 22 MeV beam of polarized deuterons obtained from the Maier-Leibnitz Laboratory at Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 115 levels have been identified up to 4.2 MeV of excitation energy. Spin-parity has been assigned to each analyzed level, and angular distributions for the reaction cross sections and analyzing powers were obtained. Many additional levels have been observed compared with the previous (d,p) study performed with 8 MeV deuterons,1 including strongly populated 5- and 6- states. The former was previously assigned as a member of the quadrupole-octupole quintuplet, based on a strongly enhanced B(E2) value to the 3- state, but is now re-assigned as being predominately s1/2 ⊗ h11/2 configuration.

A fragmentation study of dihydroquercetin using triple quadrupole mass spectrometry and its application for identification of dihydroflavonols in Citrus juices.

PubMed

Abad-García, Beatriz; Garmón-Lobato, Sergio; Berrueta, Luis A; Gallo, Blanca; Vicente, Francisca

2009-09-01

A mass spectrometric method using electrospray ionization with triple quadrupole and quadrupole time-of-flight hybrid (Q-Tof) mass spectrometry has been applied to the structural characterization of dihydroflavonols. This family of compounds has been studied by liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the first time in this work. A comprehensive study of the product ion MS spectra of the [M+H](+) ion of a commercially available standard has been performed. The most useful fragmentations in terms of structural identification are those that involve cleavage of the C-ring, resulting in diagnostic ions of dihydroflavonol family: (1,3)A(0) (+), (1,2)B(0) (+), (1,2)B(0) (+)-CO, (0,2)A(0) (+), (0,2)A(0) (+)-H(2)O, (0,2)A(0) (+)-CO, and (0,2)A(0) (+)-H(2)O-CO, that allow the characterization of the substituents in the A- and B-rings. In addition to those ions, other product ions due to losses of H(2)O and CO molecules from the Y(0) (+) ion were observed. Their fragmentation mechanisms and ion structures have been proposed. The established fragmentation patterns have been used to successfully identity three dihydroflavonols found in tangerine juices for the first time. Copyright (c) 2009 John Wiley & Sons, Ltd.

Modulated magnetic structure of F e3P O7 as seen by 57Fe Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Sobolev, A. V.; Akulenko, A. A.; Glazkova, I. S.; Pankratov, D. A.; Presniakov, I. A.

2018-03-01

The paper reports results of the 57Fe Mössbauer measurements on an F e3P O4O3 powder sample recorded at various temperatures, including the point of magnetic phase transition TN≈163 K . The spectra measured above TN consist of a quadrupole doublet with high quadrupole splitting of Δ300 K≈1.10 mm /s , emphasizing that F e3 + ions are located in crystal positions with a strong electric-field gradient (EFG). To predict the sign and orientation of the main components of the EFG tensor, we calculated the EFG using the density-functional-theory approach. In the temperature range T

Heavy metal coordination chemistry in mercaptides and enzymes studied by TDPAC

NASA Astrophysics Data System (ADS)

Butz, T.

1993-03-01

Time differential perturbed angular correlation (TDPAC) studies of the coordination chemistry of the heavy metal atoms Cd and Hg via the nuclear quadrupole interaction are presented for the following systems; (i) mercury complexes with mercaptides, polymers with thiol groups, and ferrocenethiols. Mercury has a strong tendency to form linear or almost linear bonds with sulfur ligands. Evidence for 1,3-dithia-2-mercura[3]ferrocenophane formation is presented. (ii)111mCd-derivatives of the small electron transport proteins azurin, including a his 117gly mutant, and stellacyanin. The titration of the his 117gly mutant of azurin with imidazole was monitored in situ. (iii)111mCd- and199mHg-derivatives of the multi-Cu enzymes ascorbate oxidase and laccase. Reconstitution probabilities for Hg-reconstitution will be given as well as information on selective depletion and blocking of Cu-sites.

Gamma-unstable nuclei in the sdg boson model

NASA Astrophysics Data System (ADS)

Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barret, B. R.

Following the recent Pt(p,p') experiments which indicated the need for high angular momentum (g) bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a gamma-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the gamma-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4(sup +) states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes.

New General Relativistic Contribution to Mercury's Perihelion Advance

NASA Astrophysics Data System (ADS)

Will, Clifford M.

2018-05-01

We point out the existence of a new general relativistic contribution to the perihelion advance of Mercury that, while smaller than the contributions arising from the solar quadrupole moment and angular momentum, is 100 times larger than the second-post-Newtonian contribution. It arises in part from relativistic "crossterms" in the post-Newtonian equations of motion between Mercury's interaction with the Sun and with the other planets, and in part from an interaction between Mercury's motion and the gravitomagnetic field of the moving planets. At a few parts in 1 06 of the leading general relativistic precession of 42.98 arcseconds per century, these effects are likely to be detectable by the BepiColombo mission to place and track two orbiters around Mercury, scheduled for launch around 2018.

New General Relativistic Contribution to Mercury's Perihelion Advance.

PubMed

Will, Clifford M

2018-05-11

We point out the existence of a new general relativistic contribution to the perihelion advance of Mercury that, while smaller than the contributions arising from the solar quadrupole moment and angular momentum, is 100 times larger than the second-post-Newtonian contribution. It arises in part from relativistic "crossterms" in the post-Newtonian equations of motion between Mercury's interaction with the Sun and with the other planets, and in part from an interaction between Mercury's motion and the gravitomagnetic field of the moving planets. At a few parts in 10^{6} of the leading general relativistic precession of 42.98 arcseconds per century, these effects are likely to be detectable by the BepiColombo mission to place and track two orbiters around Mercury, scheduled for launch around 2018.

Microscopic derivation of IBM and structural evolution in nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nomura, Kosuke

A Hamiltonian of the interacting boson model (IBM) is derived based on the mean-field calculations with nuclear energy density functionals (EDFs). The multi-nucleon dynamics of the surface deformation is simulated in terms of the boson degrees of freedom. The interaction strengths of the IBM Hamiltonian are determined by mapping the potential energy surfaces (PESs) of a given EDF with quadrupole degrees of freedom onto the corresponding PES of IBM. A fermion-to-boson mapping for a rotational nucleus is discussed in terms of the rotational response, which reflects a specific time-dependent feature. Ground-state correlation energy is evaluated as a signature of structuralmore » evolution. Some examples resulting from the present spectroscopic calculations are shown for neutron-rich Pt, Os and W isotopes including exotic ones.« less

Rotational Quenching Study in Isovalent H+ + CO and H+ + CS Systems

NASA Astrophysics Data System (ADS)

Kaur, Rajwant; Dhilip Kumar, T. J.

2016-06-01

Cooling and trapping of polar molecules has attracted attention at cold and ultracold temperatures. Extended study of molecular inelastic collision processes of polar interstellar species with proton finds an important astrophysical application to model interstellar medium. Present study includes computation of rate coefficient for molecular rotational quenching process in proton collision with isovalent CO and CS molecules using quantum dynamical close-coupling calculations. Full dimensional ab initio potential energy surfaces have been computed for the ground state for both the systems using internally contracted multireference configuration interaction method and basis sets. Quantum scattering calculations for rotational quenching of isovalent species are studied in the rigid-rotor approximation with CX (X=O, S) bond length fixed at an experimental equilibrium value of 2.138 and 2.900 a.u., respectively. Asymptotic potentials are computed using the dipole and quadrupole moments, and the dipole polarizability components. The resulting long-range potentials with the short-range ab initio interaction potentials have been fitted to study the anisotropy of the rigid-rotor surface using the multipolar expansion coefficients. Rotational quenching cross-section and corresponding rates from j=4 level of CX to lower j' levels have been obtained and found to obey Wigner's threshold law at ultra cold temperatures.

Investigation of Ion Transmission Effects on Intact Protein Quantification in a Triple Quadrupole Mass Spectrometer

NASA Astrophysics Data System (ADS)

Wang, Evelyn H.; Appulage, Dananjaya Kalu; McAllister, Erin A.; Schug, Kevin A.

2017-09-01

Recently, direct intact protein quantitation using triple quadrupole mass spectrometry (QqQ-MS) and multiple reaction monitoring (MRM) was demonstrated (J. Am. Soc. Mass Spectrom. 27, 886-896 (2016)). Even though QqQ-MS is known to provide extraordinary detection sensitivity for quantitative analysis, we found that intact proteins exhibited a less than 5% ion transmission from the first quadrupole to the third quadrupole mass analyzer in the presence of zero collision energy (ZCE). With the goal to enhance intact protein quantitation sensitivity, ion scattering effects, proton transfer effects, and mass filter resolution widths were examined for their contributions to the lost signal. Protein standards myoglobin and ubiquitin along with small molecules reserpine and vancomycin were analyzed together with various collision induced dissociation (CID) gases (N2, He, and Ar) at different gas pressures. Mass resolution settings played a significant role in reducing ion transmission signal. By narrowing the mass resolution window by 0.35 m/z on each side, roughly 75%-90% of the ion signal was lost. The multiply charged proteins experienced additional proton transfer effects, corresponding to 10-fold signal reduction. A study of increased sensitivity of the method was also conducted with various MRM summation techniques. Although the degree of enhancement was analyte-dependent, an up to 17-fold increase in sensitivity was observed for ubiquitin using a summation of multiple MRM transitions. Biological matrix, human urine, and equine plasma were spiked with proteins to demonstrate the specificity of the method. This study provides additional insight into optimizing the use and sensitivity of QqQ-MS for intact protein quantification. [Figure not available: see fulltext.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owen, Benjamin C.; Kenttamaa, Hilkka I.

The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

The nuclear electric quadrupole moment of antimony from the molecular method.

PubMed

Haiduke, Roberto L A; da Silva, Albérico B F; Visscher, Lucas

2006-08-14

Relativistic Dirac-Coulomb (DC) Hartree-Fock calculations are employed to obtain the analytic electric field gradient (EFG) on the antimony nucleus in the SbN, SbP, SbF, and SbCl molecules. The electronic correlation contribution to the EFGs is included with the DC-CCSD(T) and DC-CCSD-T approaches, also in the four-component framework, using a finite-difference method. The total EFG results, along with the experimental nuclear quadrupole coupling constants from microwave spectroscopy, allow to derive the nuclear quadrupole moments of (121)Sb and (123)Sb, respectively, as -543(11) and -692(14) mb.

Observation of Excited Quadrupole-Bound States in Cold Anions

NASA Astrophysics Data System (ADS)

Zhu, Guo-Zhu; Liu, Yuan; Wang, Lai-Sheng

2017-07-01

We report the first observation of an excited quadrupole-bound state (QBS) in an anion. High-resolution photoelectron imaging of cryogenically cooled 4-cyanophenoxide (4 CP- ) anions yields an electron detachment threshold of 24 927 cm-1 . The photodetachment spectrum reveals a resonant transition 20 cm-1 below the detachment threshold, which is attributed to an excited QBS of 4 CP- because neutral 4CP has a large quadrupole moment with a negligible dipole moment. The QBS is confirmed by observation of seventeen above-threshold resonances due to autodetachment from vibrational levels of the QBS.

Method and apparatus for measuring the gas permeability of a solid sample

DOEpatents

Carstens, D.H.W.

1984-01-27

The disclosure is directed to an apparatus and method for measuring the permeability of a gas in a sample. The gas is allowed to reach a steady flow rate through the sample. A measurable amount of the gas is collected during a given time period and then delivered to a sensitive quadrupole. The quadrupole signal, adjusted for background, is proportional to the amount of gas collected during the time period. The quadrupole can be calibrated with a standard helium leak. The gas can be deuterium and the sample can be polyvinyl alcohol.

Variable energy constant current accelerator structure

DOEpatents

Anderson, Oscar A.

1990-01-01

A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90.degree. intervals with opposing electrodes maintained at the same potential. Adjacent cylinder electrodes of the quadrupole structure are maintained at different potentials to thereby reshape the cross section of the charged particle beam to an ellipse in cross section at the mid point along each quadrupole electrode unit in the accelerator modules. The beam is maintained in focus by alternating the major axis of the ellipse along the x and y axis respectively at adjacent quadrupoles. In another embodiment, electrostatic ring electrodes may be utilized instead of the quadrupole electrodes.

Electrostatic Properties of Aqueous Salt Solution Interfaces: A Comparison of Polarizable and Non-Polarizable Ion Models

PubMed Central

Warren, G. Lee; Patel, Sandeep

2014-01-01

The effects of ion force field polarizability on the interfacial electrostatic properties of ~1 M aqueous solutions of NaCl, CsCl and NaI are investigated using molecular dynamics simulations employing both non-polarizable and Drude-polarizable ion sets. Differences in computed depth-dependent orientational distributions, “permanent” and induced dipole and quadrupole moment profiles, and interfacial potentials are obtained for both ion sets to further elucidate how ion polarizability affects interfacial electrostatic properties among the various salts relative to pure water. We observe that the orientations and induced dipoles of water molecules are more strongly perturbed in the presence of polarizable ions via a stronger ionic double layer effect arising from greater charge separation. Both anions and cations exhibit enhanced induced dipole moments and strong z alignment in the vicinity of the Gibbs dividing surface (GDS) with the magnitude of the anion induced dipoles being nearly an order of magnitude larger than those of the cations and directed into the vapor phase. Depth-dependent profiles for the trace and zz components of the water molecular quadrupole moment tensors reveal 40% larger quadrupole moments in the bulk phase relative to the vapor mimicking a similar observed 40% increase in the average water dipole moment. Across the GDS, the water molecular quadrupole moments increase non-monotonically (in contrast to the water dipoles) and exhibit a locally reduced contribution just below the surface due to both orientational and polarization effects. Computed interfacial potentials for the non-polarizable salts yield values 20 to 60 mV more positive than pure water and increase by an additional 30 to 100 mV when ion polarizability is included. A rigorous decomposition of the total interfacial potential into ion monopole, water and ion dipole, and water quadrupole components reveals that a very strong, positive ion monopole contribution is offset by negative contributions from all other potential sources. Water quadrupole components modulated by the water density contribute significantly to the observed interfacial potential increments and almost entirely explain observed differences in the interfacial potentials for the two chloride salts. By lumping all remaining non-quadrupole interfacial potential contributions into a single “effective” dipole potential, we observe that the ratio of quadrupole to “effective” dipole contributions range from 2:1 in CsCl to 1:1.5 in NaI suggesting that both contributions are comparably important in determining the interfacial potential increments. We also find that oscillations in the quadrupole potential in the double layer region are opposite in sign and partially cancel those of the “effective” dipole potential. PMID:18712908

Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Sel, Sabriye; Öztürk Er, Elif; Bakırdere, Sezgin

2017-12-01

A highly sensitive and simple diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time-of-flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high-performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90-105% in tap water and 94-97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward a Micro Gas Chromatograph/Mass Spectrometer (GC/MS) System

NASA Technical Reports Server (NTRS)

Wiberg, D. V.; Eyre, F. B.; Orient, O.; Chutjian, A.; Garkarian, V.

2001-01-01

Miniature mass filters (e.g., quadrupoles, ion traps) have been the subject of several miniaturization efforts. A project is currently in progress at JPL to develop a miniaturized Gas Chromatograph/Mass Spectrometer (GC/MS) system, incorporating and/or developing miniature system components including turbomolecular pumps, scroll type roughing pump, quadrupole mass filter, gas chromatograph, precision power supply and other electronic components. The preponderance of the system elements will be fabricated using microelectromechanical systems (MEMS) techniques. The quadrupole mass filter will be fabricated using an X-ray lithography technique producing high precision, 5x5 arrays of quadrupoles with pole lengths of about 3 mm and a total volume of 27 cubic mm. The miniature scroll pump will also be fabricated using X-ray lithography producing arrays of scroll stages about 3 mm in diameter. The target detection range for the mass spectrometer is 1 to 300 atomic mass units (AMU) with are solution of 0.5 AMU. This resolution will allow isotopic characterization for geochronology, atmospheric studies and other science efforts dependant on the understanding of isotope ratios of chemical species. This paper will discuss the design approach, the current state-of-the art regarding the system components and the progress toward development of key elements. The full system is anticipated to be small enough in mass, volume and power consumption to allow in situ chemical analysis on highly miniaturized science craft for geochronology, atmospheric characterization and detection of life experiments applicable to outer planet roadmap missions.

The Assessment of Selectivity in Different Quadrupole-Orbitrap Mass Spectrometry Acquisition Modes

NASA Astrophysics Data System (ADS)

Berendsen, Bjorn J. A.; Wegh, Robin S.; Meijer, Thijs; Nielen, Michel W. F.

2015-02-01

Selectivity of the confirmation of identity in liquid chromatography (tandem) mass spectrometry using Q-Orbitrap instrumentation was assessed using different acquisition modes based on a representative experimental data set constructed from 108 samples, including six different matrix extracts and containing over 100 analytes each. Single stage full scan, all ion fragmentation, and product ion scanning were applied. By generating reconstructed ion chromatograms using unit mass window in targeted MS2, selected reaction monitoring (SRM), regularly applied using triple-quadrupole instruments, was mimicked. This facilitated the comparison of single stage full scan, all ion fragmentation, (mimicked) SRM, and product ion scanning applying a mass window down to 1 ppm. Single factor Analysis of Variance was carried out on the variance (s2) of the mass error to determine which factors and interactions are significant parameters with respect to selectivity. We conclude that selectivity is related to the target compound (mainly the mass defect), the matrix, sample clean-up, concentration, and mass resolution. Selectivity of the different instrumental configurations was quantified by counting the number of interfering peaks observed in the chromatograms. We conclude that precursor ion selection significantly contributes to selectivity: monitoring of a single product ion at high mass accuracy with a 1 Da precursor ion window proved to be equally selective or better to monitoring two transition products in mimicked SRM. In contrast, monitoring a single fragment in all ion fragmentation mode results in significantly lower selectivity versus mimicked SRM. After a thorough inter-laboratory evaluation study, the results of this study can be used for a critical reassessment of the current identification points system and contribute to the next generation of evidence-based and robust performance criteria in residue analysis and sports doping.

Intermolecular interactions between imidazole derivatives intercalated in layered solids. Substituent group effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

González, M.; Lemus-Santana, A.A.; Rodríguez-Hernández, J.

2013-08-15

This study sheds light on the intermolecular interactions between imidazole derive molecules (2-methyl-imidazole, 2-ethyl-imidazole and benzimidazole) intercalated in T[Ni(CN){sub 4}] layers to form a solid of formula unit T(ImD){sub 2}[Ni(CN){sub 4}]. These hybrid inorganic–organic solids were prepared by soft chemical routes and their crystal structures solved and refined from X-ray powder diffraction data. The involved imidazole derivative molecules were found coordinated through the pyridinic N atom to the axial positions for the metal T in the T[Ni(CN){sub 4}] layer. In the interlayers region ligand molecules from neighboring layers remain stacked in a face-to-face configuration through dipole–dipole and quadrupole–quadrupole interactions. Thesemore » intermolecular interactions show a pronounced dependence on the substituent group and are responsible for an ImD-pillaring concatenation of adjacent layers. This is supported by the structural information and the recorded magnetic data in the 2–300 K temperature range. The samples containing Co and Ni are characterized by presence of spin–orbit coupling and pronounced temperature dependence for the effective magnetic moment except for 2-ethyl-imidazole related to the local distortion for the metal coordination environment. For this last one ligand a weak ferromagnetic ordering ascribed to a super-exchange interaction between T metals from neighboring layers through the ligands π–π interaction was detected. - Graphical abstract: In the interlayers region imidazole derivative molecules are oriented according to their dipolar and quadrupolar interactions and minimizing the steric impediment. Highlights: • Imidazole derivatives intercalation compounds. • Intermolecular interaction between intercalated imidazole derivatives. • Hybrid inorganic–organic solids. • Pi–pi interactions and ferromagnetic coupling. • Dipolar and quadrupolar interactions between intercalated imidazole derivatives.« less

Unexpected matching insensitivity in DTL of GTA accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, V.W.; Gilpatrick, J.D.; Johnson, K.F.

1995-05-01

The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) contains four variable-field quadrupoles (VFQs) and is designed to match beam exiting the Radio-Frequency Quadrupole to the first tank of the Drift-tube LINAC (DTL-1). By varying the VFQ field strengths to create a range of beam mismatches at the entrance to DTL-1, one can test the sensitivity of the DTL-1 output beam to variations in the DTL-1 input beam. Experimental studies made during commissioning of the GTA indicate an unexpected result: the beam exiting DTL-1 shows little variation for a range of mismatches produced at the entrance. Results ofmore » the experiment and simulation studies are presented.« less

How water interacts with halogenated anesthetics: the rotational spectrum of isoflurane-water.

PubMed

Gou, Qian; Feng, Gang; Evangelisti, Luca; Vallejo-López, Montserrat; Spada, Lorenzo; Lesarri, Alberto; Cocinero, Emilio J; Caminati, Walther

2014-02-10

The rotational spectra of several isotopologues of the 1:1 complex between the inhaled anesthetic isoflurane and water have been recorded and analyzed by using Fourier transform microwave spectroscopy. The rotational spectrum showed a single rotamer, corresponding to the configuration in which the most stable conformer of isolated isoflurane is linked to the water molecule through an almost linear C-H⋅⋅⋅O weak hydrogen bond. All transitions display a hyperfine structure due to the (35)Cl (or (37)Cl) nuclear quadrupole effects. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Internal energy transfer phenomenon and light-emission properties of γ-LiAlO2 phosphor doped with Mn2+

NASA Astrophysics Data System (ADS)

Wang, Bai-Bin; Chang, Chi-Fen; Yang, Wein-Duo

2013-07-01

γ-LiAlO2:Mn2+ phosphor was synthesized using the cellulose-citric acid sol-gel method, and its light emission and energy transfer properties were investigated. Excitation and emission spectrum analysis revealed a decrease in intensity of the spectrum as the amount of Mn2+ doping increased. Blasse's equation determined the maximum distance for energy transfer between Mn2+ ions as 4.3142 nm. Dexter's theory verifies that the mechanism of energy transfer between Mn2+ ions conforms to an electric dipole and electric quadrupole interaction.

Main regularities of SERS on semiconductors and dielectrics

NASA Astrophysics Data System (ADS)

Chelibanov, V. P.; Polubotko, A. M.

2018-04-01

The paper demonstrates that the reason of SERS on dielectrics and semiconductors is the enhancement of the electric field in the regions of the tops of the surface roughness with a very large positive curvature. The enhancement in many ways depends on the dielectric constant of the substrate and is stronger for a larger dielectric constant. The theoretical result points out that on dielectrics and semiconductors it is weaker than on metals. Experimentally it is demonstrated that there are forbidden lines on hydroquinone, adsorbed on TiO2 , which indicate on the existence of strong quadrupole light-molecule interaction in such systems.

Use of liquid chromatography hybrid triple-quadrupole mass spectrometry for the detection of emodin metabolites in rat bile and urine.

PubMed

Wu, Songyan; Zhang, Yaqing; Zhang, Zunjian; Song, Rui

2017-10-01

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti-inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Owing to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple-quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which included four phase I and 18 phase II metabolites. The major metabolites in rat biosamples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple-quadrupole mass spectrometry analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway. Copyright © 2017 John Wiley & Sons, Ltd.

FORWARD MODELING OF STANDING KINK MODES IN CORONAL LOOPS. I. SYNTHETIC VIEWS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Ding; Doorsselaere, Tom Van, E-mail: DYuan2@uclan.ac.uk

2016-04-15

Kink magnetohydrodynamic (MHD) waves are frequently observed in various magnetic structures of the solar atmosphere. They may contribute significantly to coronal heating and could be used as a tool to diagnose the solar plasma. In this study, we synthesize the Fe ix λ171.073 Å emission of a coronal loop supporting a standing kink MHD mode. The kink MHD wave solution of a plasma cylinder is mapped into a semi-torus structure to simulate a curved coronal loop. We decompose the solution into a quasi-rigid kink motion and a quadrupole term, which dominate the plasma inside and outside of the flux tube, respectively.more » At the loop edges, the line of sight integrates relatively more ambient plasma, and the background emission becomes significant. The plasma motion associated with the quadrupole term causes spectral line broadening and emission suppression. The periodic intensity suppression will modulate the integrated intensity and the effective loop width, which both exhibit oscillatory variations at half of the kink period. The quadrupole term can be directly observed as a pendular motion at the front view.« less

Implementation of the incremental scheme for one-electron first-order properties in coupled-cluster theory.

PubMed

Friedrich, Joachim; Coriani, Sonia; Helgaker, Trygve; Dolg, Michael

2009-10-21

A fully automated parallelized implementation of the incremental scheme for coupled-cluster singles-and-doubles (CCSD) energies has been extended to treat molecular (unrelaxed) first-order one-electron properties such as the electric dipole and quadrupole moments. The convergence and accuracy of the incremental approach for the dipole and quadrupole moments have been studied for a variety of chemically interesting systems. It is found that the electric dipole moment can be obtained to within 5% and 0.5% accuracy with respect to the exact CCSD value at the third and fourth orders of the expansion, respectively. Furthermore, we find that the incremental expansion of the quadrupole moment converges to the exact result with increasing order of the expansion: the convergence of nonaromatic compounds is fast with errors less than 16 mau and less than 1 mau at third and fourth orders, respectively (1 mau=10(-3)ea(0)(2)); the aromatic compounds converge slowly with maximum absolute deviations of 174 and 72 mau at third and fourth orders, respectively.

Shape transition with temperature of the pear-shaped nuclei in covariant density functional theory

DOE PAGES

Zhang, Wei; Niu, Yi-Fei

2017-11-10

The shape evolutions of the pear-shaped nucleimore » $$^{224}$$Ra and even-even $$^{144-154}$$Ba with temperature are investigated by the finite-temperature relativistic mean field theory with the treatment of pairing correlations by the BCS approach. We study the free energy surfaces as well as the bulk properties including deformations, pairing gaps, excitation energy, and specific heat for the global minimum. For $$^{224}$$Ra, three discontinuities found in the specific heat curve indicate the pairing transition at temperature 0.4 MeV, and two shape transitions at temperatures 0.9 and 1.0 MeV, namely one from quadrupole-octupole deformed to quadrupole deformed, and the other from quadrupole deformed to spherical. Furthermore, the gaps at $N$=136 and $Z$=88 are responsible for stabilizing the octupole-deformed global minimum at low temperatures. Similar pairing transition at $$T\\sim$$0.5 MeV and shape transitions at $T$=0.5-2.2 MeV are found for even-even $$^{144-154}$$Ba. Finally, the transition temperatures are roughly proportional to the corresponding deformations at the ground states.« less

Ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples.

PubMed

Prothmann, Jens; Sun, Mingzhe; Spégel, Peter; Sandahl, Margareta; Turner, Charlotta

2017-12-01

The conversion of lignin to potentially high-value low molecular weight compounds often results in complex mixtures of monomeric and oligomeric compounds. In this study, a method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) has been developed. Seven different columns were explored for maximum selectivity. Makeup solvent composition and ion source settings were optimised using a D-optimal design of experiment (DoE). Differently processed lignin samples were analysed and used for the method validation. The new UHPSFC/QTOF-MS method showed good separation of the 40 compounds within only 6-min retention time, and out of these, 36 showed high ionisation efficiency in negative electrospray ionisation mode. Graphical abstract A rapid and selective method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS).

Quadrupole collectivity in 42Ca from low-energy Coulomb excitation with AGATA

NASA Astrophysics Data System (ADS)

Hadyńska-Klęk, K.; Napiorkowski, P. J.; Zielińska, M.; Srebrny, J.; Maj, A.; Azaiez, F.; Valiente Dobón, J. J.; Kicińska-Habior, M.; Nowacki, F.; Naïdja, H.; Bounthong, B.; Rodríguez, T. R.; de Angelis, G.; Abraham, T.; Anil Kumar, G.; Bazzacco, D.; Bellato, M.; Bortolato, D.; Bednarczyk, P.; Benzoni, G.; Berti, L.; Birkenbach, B.; Bruyneel, B.; Brambilla, S.; Camera, F.; Chavas, J.; Cederwall, B.; Charles, L.; Ciemała, M.; Cocconi, P.; Coleman-Smith, P.; Colombo, A.; Corsi, A.; Crespi, F. C. L.; Cullen, D. M.; Czermak, A.; Désesquelles, P.; Doherty, D. T.; Dulny, B.; Eberth, J.; Farnea, E.; Fornal, B.; Franchoo, S.; Gadea, A.; Giaz, A.; Gottardo, A.; Grave, X.; Grębosz, J.; Görgen, A.; Gulmini, M.; Habermann, T.; Hess, H.; Isocrate, R.; Iwanicki, J.; Jaworski, G.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Kmiecik, M.; Karpiński, D.; Kisieliński, M.; Kondratyev, N.; Korichi, A.; Komorowska, M.; Kowalczyk, M.; Korten, W.; Krzysiek, M.; Lehaut, G.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lunardi, S.; Maron, G.; Mazurek, K.; Menegazzo, R.; Mengoni, D.; Merchán, E.; Męczyński, W.; Michelagnoli, C.; Million, B.; Myalski, S.; Napoli, D. R.; Niikura, M.; Obertelli, A.; Özmen, S. F.; Palacz, M.; Próchniak, L.; Pullia, A.; Quintana, B.; Rampazzo, G.; Recchia, F.; Redon, N.; Reiter, P.; Rosso, D.; Rusek, K.; Sahin, E.; Salsac, M.-D.; Söderström, P.-A.; Stefan, I.; Stézowski, O.; Styczeń, J.; Theisen, Ch.; Toniolo, N.; Ur, C. A.; Wadsworth, R.; Wasilewska, B.; Wiens, A.; Wood, J. L.; Wrzosek-Lipska, K.; Ziębliński, M.

2018-02-01

A Coulomb-excitation experiment to study electromagnetic properties of 42Ca was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in 42Ca were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E 2 matrix elements coupling six low-lying states in 42Ca, including the diagonal E 2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E 2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2 + and 21,2 + states, as well as triaxiality for 01,2 + states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in 42Ca. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in 42Ca.

a Molecular Fountain

NASA Astrophysics Data System (ADS)

Cheng, Cunfeng; van der Poel, Aernout P. P.; Ubachs, Wim; Bethlem, Hendrick

2017-06-01

The resolution of any spectroscopic experiment is limited by the coherent interaction time between the probe radiation and the particle that is being studied. The introduction of cooling techniques for atoms and ions has resulted in a dramatic increase of interaction times and accuracy, it is hoped that molecular cooling techniques will lead to a similar increase. Here we demonstrate the first molecular fountain, a development which permits hitherto unattainably long interrogation times with molecules. In our experiment, beams of ammonia molecules are decelerated, trapped and cooled using inhomogeneous electric fields and subsequently launched. Using a combination of quadrupole lenses and buncher elements, the beam is shaped such that it has a large position spread and a small velocity spread (corresponding to a transverse temperature of less than 10μK and a longitudinal temperature of less than 1μK) while the molecules are in free fall, but strongly focused at the detection region. The molecules are in free fall for up to 266 milliseconds, making it possible, in principle, to perform sub-Hz measurements in molecular systems and paving the way for stringent tests of fundamental physics theories.

Design of an rf quadrupole for Landau damping

NASA Astrophysics Data System (ADS)

Papke, K.; Grudiev, A.

2017-08-01

The recently proposed superconducting quadrupole resonator for Landau damping in accelerators is subjected to a detailed design study. The optimization process of two different cavity types is presented following the requirements of the High Luminosity Large Hadron Collider (HL-LHC) with the main focus on quadrupolar strength, surface peak fields, and impedance. The lower order and higher order mode (LOM and HOM) spectrum of the optimized cavities is investigated and different approaches for their damping are proposed. On the basis of an example the first two higher order multipole errors are calculated. Likewise on this example the required rf power and optimal external quality factor for the input coupler is derived.

Lifetime Measurements in Neutron-Rich Xe Isotopes — Evolution of Quadrupole Collectivity Beyond 132Sn

NASA Astrophysics Data System (ADS)

Ilieva, S.; Bönig, S.; Hartig, A.-L.; Henrich, C.; Ignatov, A.; Kröll, Th.; Thürauf, M.; Jolie, J.; Régis, J.-M.; Saed-Samii, N.; Blanc, A.; de France, G.; Jentschel, M.; Köster, U.; Mutti, P.; Simpson, G. S.; Soldner, T.; Urban, W.; Mǎrginean, N.; Ur, C. A.; Mach, H.; Fraile, L. M.; Paziy, V.; Regan, P. H.; Bruce, A. M.; Lalkovski, S.; Korten, W.

Picosecond lifetimes of excited states in neutron-rich Xe isotopes were measured at the Institut Laue-Langevin via γ-ray spectroscopy of fission fragments from neutron-induced fission of 235U and 241Pu targets. The data collected with the recently installed fast timing array FATIMA in combination with the EXOGAM Ge array were analysed using the new generalized centroid difference method. Our aim is to study the quadrupole and octupole collectivity, arising in the mass region beyond the doubly magic 132Sn, by means of transition probabilities. These can be calculated from the directly measured lifetimes.

Superdeformed shapes and configurations in thallium nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reviol, W.; Mueller, W.F.; Riedinger, L.L.

1997-09-01

Superdeformation studies in {sup 189,191,192}Tl at Gammasphere are discussed. New results on {sup 191}Tl are the observation of interband transitions between the signature partner E2 bands and the measurement of an average quadrupole moment (Q{sub 0} = 18 {+-} 1 eb) for these superdeformed structures. These data enable them to derive absolute M1 strengths and confirm that the 81st proton occupies the [642]5/2 orbital. Tentative data for one superdeformed sequence in {sup 189}Tl are consistent with the prediction of a decrease in quadrupole deformation for the lightest nuclei at the limit of this island of superdeformation.

Quadrupolar asymmetry in shifted-stem vane-shaped-rod radio frequency quadrupole accelerator

NASA Astrophysics Data System (ADS)

Mehrotra, Nitin

2018-04-01

Quadrupolar Asymmetry (QA), which has been a rampant problem for rod-type Radio Frequency Quadrupole (RFQ) Linacs, arises due to the geometry of resonant structure. A systematic parametric simulation study has been performed to unravel their effect on Figure of Merit (FoM) quantities namely Quality Factor (Q), Shunt Impedance (Rsh) and Quadrupolar Asymmetry (QA). A novel stem and cavity shape is proposed, which caters to the profile of electromagnetic fields of the resonant structure. A design methodology is formulated, which demonstrates that Quadrupolar Asymmetry can be annihilated, and a symmetric electric field can be produced in all four quadrants of rod-type RFQ accelerator.

The neutral mass spectrometer on Dynamics Explorer B

NASA Technical Reports Server (NTRS)

Carignan, G. R.; Block, B. P.; Maurer, J. C.; Hedin, A. E.; Reber, C. A.; Spencer, N. W.

1981-01-01

A neutral gas mass spectrometer has been developed to satisfy the measurement requirements of the Dynamics Explorer mission. The mass spectrometer, a quadrupole, will measure the abundances of neutral species in the region 300-500 km in the earth's atmosphere. These measurements will be used in concert with other simultaneous observations on Dynamics Explorer to study the physical processes involved in the interactions of the magnetosphere-ionosphere-atmosphere system. The instrument, which is similar to that flown on Atmosphere Explorer, employs an electron beam ion source operating in the closed mode and a discrete dynode multiplier as a detector. The mass range is 22 to 50 amu. The abundances of atomic oxygen, molecular nitrogen, helium, argon, and possibly atomic nitrogen will be measured to an accuracy of about + or - 15% over the specified altitude range, with a temporal resolution of one second.

Spectral and spatial shaping of a laser-produced ion beam for radiation-biology experiments

NASA Astrophysics Data System (ADS)

Pommarel, L.; Vauzour, B.; Mégnin-Chanet, F.; Bayart, E.; Delmas, O.; Goudjil, F.; Nauraye, C.; Letellier, V.; Pouzoulet, F.; Schillaci, F.; Romano, F.; Scuderi, V.; Cirrone, G. A. P.; Deutsch, E.; Flacco, A.; Malka, V.

2017-03-01

The study of radiation biology on laser-based accelerators is most interesting due to the unique irradiation conditions they can produce, in terms of peak current and duration of the irradiation. In this paper we present the implementation of a beam transport system to transport and shape the proton beam generated by laser-target interaction for in vitro irradiation of biological samples. A set of four permanent magnet quadrupoles is used to transport and focus the beam, efficiently shaping the spectrum and providing a large and relatively uniform irradiation surface. Real time, absolutely calibrated, dosimetry is installed on the beam line, to enable shot-to-shot control of dose deposition in the irradiated volume. Preliminary results of cell sample irradiation are presented to validate the robustness of the full system.

A reference map of the Arabidopsis thaliana mature pollen proteome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noir, Sandra; Braeutigam, Anne; Colby, Thomas

The male gametophyte (or pollen) plays an obligatory role during sexual reproduction of higher plants. The extremely reduced complexity of this organ renders pollen a valuable experimental system for studying fundamental aspects of plant biology such as cell fate determination, cell-cell interactions, cell polarity, and tip-growth. Here, we present the first reference map of the mature pollen proteome of the dicotyledonous model plant species, Arabidopsis thaliana. Based on two-dimensional gel electrophoresis, matrix-assisted laser desorption/ionization time-of-flight, and electrospray quadrupole time-of-flight mass spectrometry, we reproducibly identified 121 different proteins in 145 individual spots. The presence, subcellular localization, and functional classification of themore » identified proteins are discussed in relation to the pollen transcriptome and the full protein complement encoded by the nuclear Arabidopsis genome.« less

Self-consistent Hartree-Fock RPA calculations in 208Pb

NASA Astrophysics Data System (ADS)

Taqi, Ali H.; Ali, Mohammed S.

2018-01-01

The nuclear structure of 208Pb is studied in the framework of the self-consistent random phase approximation (SCRPA). The Hartree-Fock mean field and single particle states are used to implement a completely SCRPA with Skyrme-type interactions. The Hamiltonian is diagonalised within a model space using five Skyrme parameter sets, namely LNS, SkI3, SkO, SkP and SLy4. In view of the huge number of the existing Skyrme-force parameterizations, the question remains which of them provide the best description of data. The approach attempts to accurately describe the structure of the spherical even-even nucleus 208Pb. To illustrate our approach, we compared the binding energy, charge density distribution, excitation energy levels scheme with the available experimental data. Moreover, we calculated isoscalar and isovector monopole, dipole, and quadrupole transition densities and strength functions.

The exact calculation of quadrupole sources for some incompressible flows

NASA Technical Reports Server (NTRS)

Brentner, Kenneth S.

1988-01-01

This paper is concerned with the application of the acoustic analogy of Lighthill to the acoustic and aerodynamic problems associated with moving bodies. The Ffowcs Williams-Hawkings equation, which is an interpretation of the acoustic analogy for sound generation by moving bodies, manipulates the source terms into surface and volume sources. Quite often in practice the volume sources, or quadrupoles, are neglected for various reasons. Recently, Farassat, Long and others have attempted to use the FW-H equation with the quadrupole source and neglected to solve for the surface pressure on the body. The purpose of this paper is to examine the contribution of the quadrupole source to the acoustic pressure and body surface pressure for some problems for which the exact solution is known. The inviscid, incompressible, 2-D flow, calculated using the velocity potential, is used to calculate the individual contributions of the various surface and volume source terms in the FW-H equation. The relative importance of each of the sources is then assessed.

Stochastic hyperfine interactions modeling library-Version 2

NASA Astrophysics Data System (ADS)

Zacate, Matthew O.; Evenson, William E.

2016-02-01

The stochastic hyperfine interactions modeling library (SHIML) provides a set of routines to assist in the development and application of stochastic models of hyperfine interactions. The library provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental techniques that measure hyperfine interactions can be calculated. The optimized vector and matrix operations of the BLAS and LAPACK libraries are utilized. The original version of SHIML constructed and solved Blume matrices for methods that measure hyperfine interactions of nuclear probes in a single spin state. Version 2 provides additional support for methods that measure interactions on two different spin states such as Mössbauer spectroscopy and nuclear resonant scattering of synchrotron radiation. Example codes are provided to illustrate the use of SHIML to (1) generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A22 can be neglected and (2) generate Mössbauer spectra for polycrystalline samples for pure dipole or pure quadrupole transitions.

Investigation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput liquid chromatography/tandem mass spectrometry assays.

PubMed

Yang, Liyu; Amad, Ma'an; Winnik, Witold M; Schoen, Alan E; Schweingruber, Hans; Mylchreest, Iain; Rudewicz, Patrick J

2002-01-01

Triple quadrupole mass spectrometers, when operated in multiple reaction monitoring (MRM) mode, offer a unique combination of sensitivity, specificity, and dynamic range. Consequently, the triple quadrupole is the workhorse for high-throughput quantitation within the pharmaceutical industry. However, in the past, the unit mass resolution of quadrupole instruments has been a limitation when interference from matrix or metabolites cannot be eliminated. With recent advances in instrument design, triple quadrupole instruments now afford mass resolution of less than 0.1 Dalton (Da) full width at half maximum (FWHM). This paper describes the evaluation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput bioanalysis with emphasis on comparison of selectivity, sensitivity, dynamic range, precision, accuracy, and stability under both unit mass (1 Da FWHM) and enhanced (

Theory for nanoparticle retention time in the helical channel of quadrupole magnetic field-flow fractionation

NASA Astrophysics Data System (ADS)

Williams, P. Stephen; Carpino, Francesca; Zborowski, Maciej

2009-05-01

Quadrupole magnetic field-flow fractionation (QMgFFF) is a separation and characterization technique for magnetic nanoparticles such as those used for cell labeling and for targeted drug therapy. A helical separation channel is used to efficiently exploit the quadrupole magnetic field. The fluid and sample components therefore have angular and longitudinal components to their motion in the thin annular space occupied by the helical channel. The retention ratio is defined as the ratio of the times for non-retained and a retained material to pass through the channel. Equations are derived for the respective angular and longitudinal components to retention ratio.

Search for Quadrupole Strength in the Electroexcitation of the Delta+ (1232)

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. Mertz; C. Vellidis; Ricardo Alarcon

2001-04-01

High precision 1H(e, e'p)pi0 measurements at Q2 = 0.126. (GeV/c)2 are reported, which allow the determination of quadrupole amplitudes in the gamma*N --> Delta transition; they simultaneously test the reliability of electroproduction models. The derived quadrupole-to-dipole (I = 3/2) amplitude ratios, RSM = (-6.5 +/- 0.2stat+sys+/-2.5mod)% and REM = 9-2.1 +/-0.2stat+sys +/-2.0mod)%, are dominated by model error. Previous RSM and REM results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account.

Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

NASA Astrophysics Data System (ADS)

Kennedy, David J.; Todd, Paul; Logan, Sam; Becker, Matthew; Papas, Klearchos K.; Moore, Lee R.

2007-04-01

Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 μm) to the isolation of pancreatic islets (150-350 μm) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation.

On the sound field radiated by a tuning fork

NASA Astrophysics Data System (ADS)

Russell, Daniel A.

2000-12-01

When a sounding tuning fork is brought close to the ear, and rotated about its long axis, four distinct maxima and minima are heard. However, when the same tuning fork is rotated while being held at arm's length from the ear only two maxima and minima are heard. Misconceptions concerning this phenomenon are addressed and the fundamental mode of the fork is described in terms of a linear quadrupole source. Measured directivity patterns in the near field and far field of several forks agree very well with theoretical predictions for a linear quadrupole. Other modes of vibration are shown to radiate as dipole and lateral quadrupole sources.

An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas

NASA Technical Reports Server (NTRS)

De, B. R.; Srnka, L. J.

1978-01-01

Consideration of the nuclear electric quadrupole terms in the expression for the fusion Coulomb barrier suggests that this electrostatic barrier may be substantially modified from that calculated under the usual plasma assumption that the nuclei are electric monopoles. This effect is a result of the nonspherical potential shape and the spatial quantization of the nuclear spins of the fully stripped ions in the presence of a magnetic field. For monopole-quadrupole fuel cycles like p-B-11, the fusion cross-section may be substantially increased at low energies if the protons are injected at a small angle relative to the confining magnetic field.

Liquid chromatography coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry and post-column addition of metal salt solutions as a powerful tool for the metabolic profiling of Fusarium oxysporum.

PubMed

Cirigliano, Adriana M; Rodriguez, M Alejandra; Gagliano, M Laura; Bertinetti, Brenda V; Godeas, Alicia M; Cabrera, Gabriela M

2016-03-25

Fusarium oxysporum L11 is a non-pathogenic soil-borne fungal strain that yielded an extract that showed antifungal activity against phytopathogens. In this study, reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry (API-QTOF-MS) was applied for the comprehensive profiling of the metabolites from the extract. The employed sources were electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Post-column addition of metal solutions of Ca, Cu and Zn(II) was also tested using ESI. A total of 137 compounds were identified or tentatively identified by matching their accurate mass signals, suggested molecular formulae and MS/MS analysis with previously reported data. Some compounds were isolated and identified by NMR. The extract was rich in cyclic peptides like cyclosporins, diketopiperazines and sansalvamides, most of which were new, and are reported here for the first time. The use of post-column addition of metals resulted in a useful strategy for the discrimination of compound classes since specific adducts were observed for the different compound families. This technique also allowed the screening for compounds with metal binding properties. Thus, the applied methodology is a useful choice for the metabolic profiling of extracts and also for the selection of metabolites with potential biological activities related to interactions with metal ions. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental and theoretical studies of dipole and quadrupole contributions to the vanadium K-edge XANES for VOPO4.2H2O xerogel

NASA Astrophysics Data System (ADS)

Poumellec, B.; Kraizman, V.; Aifa, Y.; Cortès, R.; Novakovich, A.; Vedrinskii, R.

1998-09-01

Angular dependence of the vanadium K-edge x-ray appearance near-edge structure (XANES) for the VOPO4.2H2O xerogel is thoroughly studied both experimentally and theoretically. The main attention is paid to the pre-edge fine structure (PEFS) of the spectra which was shown earlier to be a useful tool for the atomic short order investigations. Good quantitative agreement between theory and experiment obtained for both dipole and quadrupole contributions to the spectra proves validity of the calculation method developed and enables us to ascertain the nature of all the features in the PEFS's. The p-d mixture effect due to distortion of the central coordination octahedron and the quadrupole transitions are proved to be the only mechanisms responsible for the PEFS formation in the case considered. We show that in order to achieve quantitative agreement between experimental and theoretical spectra, it is necessary to include the effect of atomic vibrations, which makes the forbidden transitions to molecular orbitals of the central octahedron (MOCO's) dipole allowed, and to take into account deviation of the crystal layers from the substrate plane, which is not a single crystal but a texture.

Correlation between y-type ions observed in ion trap and triple quadrupole mass spectrometers.

PubMed

Sherwood, Carly A; Eastham, Ashley; Lee, Lik Wee; Risler, Jenni; Vitek, Olga; Martin, Daniel B

2009-09-01

Multiple reaction monitoring mass spectrometry (MRM-MS) is a technique for high-sensitivity targeted analysis. In proteomics, MRM-MS can be used to monitor and quantify a peptide based on the production of expected fragment peaks from the selected peptide precursor ion. The choice of which fragment ions to monitor in order to achieve maximum sensitivity in MRM-MS can potentially be guided by existing MS/MS spectra. However, because the majority of discovery experiments are performed on ion trap platforms, there is concern in the field regarding the generalizability of these spectra to MRM-MS on a triple quadrupole instrument. In light of this concern, many operators perform an optimization step to determine the most intense fragments for a target peptide on a triple quadrupole mass spectrometer. We have addressed this issue by targeting, on a triple quadrupole, the top six y-ion peaks from ion trap-derived consensus library spectra for 258 doubly charged peptides from three different sample sets and quantifying the observed elution curves. This analysis revealed a strong correlation between the y-ion peak rank order and relative intensity across platforms. This suggests that y-type ions obtained from ion trap-based library spectra are well-suited for generating MRM-MS assays for triple quadrupoles and that optimization is not required for each target peptide.

Coarse-grained electrostatic interactions of coronene: Towards the crystalline phase

NASA Astrophysics Data System (ADS)

Heinemann, Thomas; Palczynski, Karol; Dzubiella, Joachim; Klapp, Sabine H. L.

2015-11-01

In this article, we present and compare two different, coarse-grained approaches to model electrostatic interactions of disc-shaped aromatic molecules, specifically coronene. Our study builds on our previous work [T. Heinemann et al., J. Chem. Phys. 141, 214110 (2014)], where we proposed, based on a systematic coarse-graining procedure starting from the atomistic level, an anisotropic effective (Gay-Berne-like) potential capable of describing van der Waals contributions to the interaction energy. To take into account electrostatics, we introduce, first, a linear quadrupole moment along the symmetry axis of the coronene disc. The second approach takes into account the fact that the partial charges within the molecules are distributed in a ring-like fashion. We then reparametrize the effective Gay-Berne-like potential such that it matches, at short distances, the ring-ring potential. To investigate the validity of these two approaches, we perform many-particle molecular dynamics simulations, focusing on the crystalline phase (karpatite) where electrostatic interaction effects are expected to be particularly relevant for the formation of tilted stacked columns. Specifically, we investigate various structural parameters as well as the melting transition. We find that the second approach yields consistent results with those from experiments despite the fact that the underlying potential decays with the wrong distance dependence at large molecule separations. Our strategy can be transferred to a broader class of molecules, such as benzene or hexabenzocoronene.

Coarse-grained electrostatic interactions of coronene: Towards the crystalline phase.

PubMed

Heinemann, Thomas; Palczynski, Karol; Dzubiella, Joachim; Klapp, Sabine H L

2015-11-07

In this article, we present and compare two different, coarse-grained approaches to model electrostatic interactions of disc-shaped aromatic molecules, specifically coronene. Our study builds on our previous work [T. Heinemann et al., J. Chem. Phys. 141, 214110 (2014)], where we proposed, based on a systematic coarse-graining procedure starting from the atomistic level, an anisotropic effective (Gay-Berne-like) potential capable of describing van der Waals contributions to the interaction energy. To take into account electrostatics, we introduce, first, a linear quadrupole moment along the symmetry axis of the coronene disc. The second approach takes into account the fact that the partial charges within the molecules are distributed in a ring-like fashion. We then reparametrize the effective Gay-Berne-like potential such that it matches, at short distances, the ring-ring potential. To investigate the validity of these two approaches, we perform many-particle molecular dynamics simulations, focusing on the crystalline phase (karpatite) where electrostatic interaction effects are expected to be particularly relevant for the formation of tilted stacked columns. Specifically, we investigate various structural parameters as well as the melting transition. We find that the second approach yields consistent results with those from experiments despite the fact that the underlying potential decays with the wrong distance dependence at large molecule separations. Our strategy can be transferred to a broader class of molecules, such as benzene or hexabenzocoronene.

Dimeric Fe (II, III) complex of quinoneoxime as functional model of PAP enzyme: Mössbauer, magneto-structural and DNA cleavage studies

NASA Astrophysics Data System (ADS)

Salunke-Gawali, Sunita; Ahmed, Khursheed; Varret, François; Linares, Jorge; Zaware, Santosh; Date, Sadgopal; Rane, Sandhya

2008-07-01

Purple acid phosphatase, ( PAP), is known to contain dinuclear Fe2 + 2, + 3 site with characteristic Fe + 3 ← Tyr ligand to metal charge transfer in coordination. Phthiocoloxime (3-methyl-2-hydroxy-1,4-naphthoquinone-1-oxime) ligand L, mimics (His/Tyr) ligation with controlled and unique charge transfers resulting in valence tautomeric coordination with mixed valent diiron site in model compound Fe-1: [μ-OH-Fe2 + 2, + 3 ( o-NQCH3ox) ( o-NSQCH3ox)2 (CAT) H2O]. Fe-2: [Fe + 3( o-NQCH3ox) ( p-NQCH3ox)2]2 a molecularly associated dimer of phthiocoloxime synthesized for comparison of charge transfer. 57Fe Mössbauer studies was used to quantitize unusual valences due to ligand in dimeric Fe-1 and Fe-2 complexes which are supported by EPR and SQUID studies. 57Fe Mössbauer spectra for Fe-1 at 300 K indicates the presence of two quadrupole split asymmetric doublets due to the differences in local coordination geometries of [Fe + 3]A and [Fe + 2]B sites. The hyperfine interaction parameters are δ A = 0.152, (Δ E Q)A = 0.598 mm/s with overlapping doublet at δ B = 0.410 and (Δ E Q)B = 0.468 mm/s. Due to molecular association tendency of ligand, dimer Fe-2 possesses 100% Fe + 3(h.s.) hexacoordinated configuration with isomer shift δ = 0.408 mm/s. Slightly distorted octahedral symmetry created by NQCH3ox ligand surrounding Fe + 3(h.s.) state generates small field gradient indicated by quadrupole split Δ E Q = 0.213 mm/s. Decrease of isomer shifts together with variation of quadrupole splits with temperature in Fe-1 dimer compared to Fe-2 is result of charge transfers in [Fe2 + 2, + 3 SQ] complexes. EPR spectrum of Fe-1 shows two strong signals at g 1 = 4.17 and g 2 = 2.01 indicative of S = 3/2 spin state with an intermediate spin of Fe + 3(h.s.) configuration. SQUID data of χ _m^{corr} .T were best fitted by using HDVV spin pair model S = 2, 3/2 resulting in antiferromagnetic exchange ( J = -13.5 cm - 1 with an agreement factor of R = 1.89 × 10 - 5). The lower J value of antiferromagnetic exchange leads to Fe+3μ-(OH) Fe + 2 bridging in Fe-1 dimer instead of μ-oxo bridge. The intermolecular association through H-bonds may lead to weakly coupled antiferromagnetic interaction between two Fe-2 molecules having Fe + 3(h.s.) centers. Using S = 5/2, 5/2 spin pair model we obtained best-fitted parameters such as J = -12.4 cm - 1, g = 2.3 with R = 3.58 × 10 - 5. Synthetic strategy results in non-equivalent iron sites in Fe-1 dimer analogues to PAP enzyme hence its reconstitution results in pUC-19 DNA cleavage activity, as physiological functionality of APase. It is compared with nuclease activity of Fe-2 RAPase.

Emission of terahertz waves in the interaction of a laser pulse with clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, A. A., E-mail: frolov@ihed.ras.ru

2016-07-15

A theory of generation of terahertz radiation in the interaction of a femtosecond laser pulse with a spherical cluster is developed for the case in which the density of free electrons in the cluster plasma exceeds the critical value. The spectral, angular, and energy characteristics of the emitted terahertz radiation are investigated, as well as its spatiotemporal structure. It is shown that the directional pattern of radiation has a quadrupole structure and that the emission spectrum has a broad maximum at a frequency nearly equal to the reciprocal of the laser pulse duration. It is found that the total radiatedmore » energy depends strongly on the cluster size. Analysis of the spatiotemporal profile of the terahertz signal shows that it has a femtosecond duration and contains only two oscillation cycles.« less

Analytical approach to chromatic correction in the final focus system of circular colliders

DOE PAGES

Cai, Yunhai

2016-11-28

Here, a conventional final focus system in particle accelerators is systematically analyzed. We find simple relations between the parameters of two focus modules in the final telescope. Using the relations, we derive the chromatic Courant-Snyder parameters for the telescope. The parameters are scaled approximately according to (L*/βmore » $$*\\atop{y}$$)δ, where L* is the distance from the interaction point to the first quadrupole, β$$*\\atop{y}$$ the vertical beta function at the interaction point, and δ the relative momentum deviation. Most importantly, we show how to compensate its chromaticity order by order in δ by a traditional correction module flanked by an asymmetric pair of harmonic multipoles. The method enables a circular Higgs collider with 2% momentum aperture and illuminates a path forward to 4% in the future.« less

Millimeter wave spectrum of nitromethane

NASA Astrophysics Data System (ADS)

Ilyushin, Vadim

2018-03-01

A new study of the millimeter wave spectrum of nitromethane, CH3NO2, is reported. The new measurements covering the frequency range from 49 GHz to 237 GHz have been carried out using the spectrometer in IRA NASU (Ukraine). Transitions belonging to the |m| ≤ 8 torsional states have been analyzed using the Rho-axis-method and the RAM36 program, which has been modified for this study to take into account the quadrupole hyperfine structure due to presence of the nitrogen atom. A data set consisting of 5925 microwave line frequencies and including transitions with J up to 55 was fit using a model consisting of 97 parameters, and a weighted root-mean-square deviation of 0.84 was achieved. The analysis of the spectrum covers the m torsional states lying below the lowest small amplitude vibration in nitromethane molecule, which is the NO2 in plane rock at 475 cm-1. It serves as a preparatory step in further studies of intervibrational interactions in this molecule.

Microwave spectroscopy of biomolecular building blocks.

PubMed

Alonso, José L; López, Juan C

2015-01-01

Microwave spectroscopy, considered as the most definitive gas phase structural probe, is able to distinguish between different conformational structures of a molecule, because they have unique spectroscopic constants and give rise to distinct individual rotational spectra.Previously, application of this technique was limited to molecular specimens possessing appreciable vapor pressures, thus discarding the possibility of studying many other molecules of biological importance, in particular those with high melting points, which had a tendency to undergo thermal reactions, and ultimately degradation, upon heating.Nowadays, the combination of laser ablation with Fourier transform microwave spectroscopy techniques, in supersonic jets, has enabled the gas-phase study of such systems. In this chapter, these techniques, including broadband spectroscopy, as well as results of their application into the study of the conformational panorama and structure of biomolecular building blocks, such as amino acids, nucleic bases, and monosaccharides, are briefly discussed, and with them, the tools for conformational assignation - rotational constants, nuclear quadrupole coupling interaction, and dipole moment.

Computer programs of information processing of nuclear physical methods as a demonstration material in studying nuclear physics and numerical methods

NASA Astrophysics Data System (ADS)

Bateev, A. B.; Filippov, V. P.

2017-01-01

The principle possibility of using computer program Univem MS for Mössbauer spectra fitting as a demonstration material at studying such disciplines as atomic and nuclear physics and numerical methods by students is shown in the article. This program is associated with nuclear-physical parameters such as isomer (or chemical) shift of nuclear energy level, interaction of nuclear quadrupole moment with electric field and of magnetic moment with surrounded magnetic field. The basic processing algorithm in such programs is the Least Square Method. The deviation of values of experimental points on spectra from the value of theoretical dependence is defined on concrete examples. This value is characterized in numerical methods as mean square deviation. The shape of theoretical lines in the program is defined by Gaussian and Lorentzian distributions. The visualization of the studied material on atomic and nuclear physics can be improved by similar programs of the Mössbauer spectroscopy, X-ray Fluorescence Analyzer or X-ray diffraction analysis.

The large-scale microwave background anisotropy in decaying particle cosmology

NASA Technical Reports Server (NTRS)

Panek, Miroslaw

1988-01-01

The quadrupole anisotropy of the microwave background radiation in cosmological models with decaying particles is investigated. A conservative upper limit on value of the quadrupole moment combined with other constraints gives an upper limit on the redshift of the decay z(d) of less than 3-6.

Multi-configuration Dirac-Hartree-Fock (MCDHF) calculations for Ni XXV

NASA Astrophysics Data System (ADS)

Singh, Narendra; Aggarwal, Sunny

2018-03-01

We present accurate 165 fine-structure energy levels related to the configurations 1s22s2, 1s22p2, 1s2nƖn‧l‧ (n = 2, n‧ = 2, 3, 4, 5, Ɩ = s,p Ɩ‧ = s, p, d, f, g) of Ni XXV which may be useful ion for astrophysical and fusion plasma. For the calculations of energy levels and radiative rates, we have used the multiconfiguration Dirac-Hartree-Fock (MCDHF) method employed in GRASP2K code. The calculations are carried out in the active space approximation with the inclusion of the Breit interaction, the finite nuclear size effect, and quantum electrodynamic corrections. The transition wavelengths, transition probabilities, line strengths, and absorption oscillator strengths are reported for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), magnetic quadrupole (M2) transitions from the ground state. We have compared our calculated results with available theoretical and experimental data and good agreement is achieved. We predict new energy levels, oscillator strengths, line strengths and transition probabilities, where no other experimental or theoretical results are available. The present complete set of results should be of great help in line identification and the interpretation of spectra, as well as in the modelling and diagnostics of astrophysical and fusion plasmas.

Hyperfine interactions and electric dipole moments in the [16.0]1.5(v = 6), [16.0]3.5(v = 7), and X2Δ(5/2) states of iridium monosilicide, IrSi.

PubMed

Le, Anh; Steimle, Timothy C; Morse, Michael D; Garcia, Maria A; Cheng, Lan; Stanton, John F

2013-12-19

The (6,0)[16.0]1.5-X(2)Δ(5/2) and (7,0)[16.0]3.5-X(2)Δ(5/2) bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The field-free spectra of the (191)IrSi and (193)IrSi isotopologues were modeled to generate a set of fine, magnetic hyperfine, and nuclear quadrupole hyperfine parameters for the X(2)Δ(5/2)(v = 0), [16.0]1.5(v = 6), and [16.0]3.5 (v = 7) states. The observed optical Stark shifts for the (193)IrSi and (191)IrSi isotopologues were analyzed to produce the permanent electric dipole moments, μ(el), of -0.414(6) D and 0.782(6) D for the X(2)Δ(5/2) and [16.0]1.5 (v = 6) states, respectively. Properties of the X(2)Δ(5/2) state computed using relativistic coupled-cluster methods clearly indicate that electron correlation plays an essential role. Specifically, inclusion of correlation changes the sign of the dipole moment and is essential for achieving good accuracy for the nuclear quadrupole coupling parameter eQq0.

Calculation of levels, transition rates, and lifetimes for the arsenic isoelectronic sequence Sn XVIII-Ba XXIV, W XLII

NASA Astrophysics Data System (ADS)

Wang, K.; Chen, Z. B.; Chen, C. Y.; Yan, J.; Dang, W.; Zhao, X. H.; Yang, X.

2017-09-01

Multi-configuration Dirac-Fock (MCDF) calculations of energy levels, wavelengths, oscillator strengths, lifetimes, and electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), magnetic quadrupole (M2) transition rates are reported for the arsenic isoelectronic sequence Sn XVIII-Ba XXIV, W XLII. Results are presented among the 86 levels of the 4s2 4p3, 4 s 4p4, 4p5, 4s2 4p2 4 d, and 4 s 4p3 4 d configurations in each ion. The relativistic atomic structure package GRASP2K is adopted for the calculations, in which the contributions from the correlations within the n ≤ 7 complexes, Breit interaction (BI) and quantum electrodynamics (QED) effects are taking into account. The many-body perturbation theory (MBPT) method is also employed as an independent calculation for comparison purposes, taking W XLII as an example. Calculated results are compared with data from other calculations and the observed values from the Atomic Spectra Database (ASD) of the National Institute of Standards and Technology (NIST). Good agreements are obtained. i.e, the accuracy of our energy levels is assessed to be better than 0.6%. These accurate theoretical data should be useful for diagnostics of hot plasmas in fusion devices.

Hyperfine induced transition probabilities from 4{f}^{14}5s5p{}^{3}{{\\rm{P}}}_{0,2}^{o} states in Sm-like ions

NASA Astrophysics Data System (ADS)

Zhou, Fuyang; Li, Jiguang; Qu, Yizhi; Wang, Jianguo

2017-11-01

The hyperfine induced 4{f}145s5p{}3{{{P}}}0,2o-4{f}145{s}2{}1{{{S}}}0 transition probabilities for highly charged Sm-like ions are calculated within the framework of the multiconfiguration Dirac-Hartree-Fock method. Electron correlation, the Breit interaction and quantum electrodynamical effects are taken into account. For ions ranging from Z = 79 to Z=94,4{f}145s5p{}3{{{P}}}0o is the first excited state, and the hyperfine induced transition (HIT) is a dominant decay channel. For the 4{f}145s5p{}3{{{P}}}2o state, the HIT rates of Sm-like ions with Z=82-94 are reported as well as the magnetic dipole (M1) {}3{{{P}}}2o-{}3{{{P}}}1o, the electric quadrupole (E2) {}3{{{P}}}2o-{}3{{{P}}}0,1o, and the magnetic quadrupole (M2) {}3{{{P}}}2o-{}1{{{S}}}0 transition probabilities. It is found that M1 transition from the 4{f}145s5p{}3{{{P}}}2o state is the most important decay channel in this range on Z≥slant 82.

Tunable luminescence mediated by energy transfer in Tm3+/Dy3+ co-doped phosphate glasses under UV excitation

NASA Astrophysics Data System (ADS)

Chen, Yong; Chen, Guohua; Liu, Xiangyu; Yuan, Changlai; Zhou, Changrong

2017-11-01

Tm3+/Dy3+ co-doped phosphate glasses for white light-emitting diodes were synthesized by a conventional melting-quenching method. A spectroscopic research based on optical, photoluminescence spectrum and decay time curves in Tm3+/Dy3+ co-doped phosphate glasses was carried out. The color of luminescence could be tuned by altering the concentrations of Tm3+ ions. Under UV light excitation, the CIE chromaticity coordinates (0.3471, 0.3374) and color correlate temperature (CCT = 4866.21 K) close to the standard white-light illumination (0.333, 0.333 and CCT = 5454.12 K) could be achieved in 0.4 Tm3+/0.6 Dy3+ (mol %) co-doped glass sample. The decrease of the Dy3+ emission decay time in existence of Tm3+ ascertained that non-radiative energy transfer from Dy3+ to Tm3+ occurred. Moreover, the research of energy transfers between Dy3+ and Tm3+ based on the Inokuti-Hirayama model revealed that an electric quadrupole-quadrupole interaction might be the predominant mechanism participated in the energy transfer. This finding suggests that the as-prepared Tm3+/Dy3+ co-doped phosphate glasses may be promising candidate for white LEDs and other display devices.

Quantification of sterol lipids in plants by quadrupole time-of-flight mass spectrometry

PubMed Central

Wewer, Vera; Dombrink, Isabel; vom Dorp, Katharina; Dörmann, Peter

2011-01-01

Glycerolipids, sphingolipids, and sterol lipids constitute the major lipid classes in plants. Sterol lipids are composed of free and conjugated sterols, i.e., sterol esters, sterol glycosides, and acylated sterol glycosides. Sterol lipids play crucial roles during adaption to abiotic stresses and plant-pathogen interactions. Presently, no comprehensive method for sterol lipid quantification in plants is available. We used nanospray ionization quadrupole-time-of-flight mass spectrometry (Q-TOF MS) to resolve and identify the molecular species of all four sterol lipid classes from Arabidopsis thaliana. Free sterols were derivatized with chlorobetainyl chloride. Sterol esters, sterol glycosides, and acylated sterol glycosides were ionized as ammonium adducts. Quantification of molecular species was achieved in the positive mode after fragmentation in the presence of internal standards. The amounts of sterol lipids quantified by Q-TOF MS/MS were validated by comparison with results obtained with TLC/GC. Quantification of sterol lipids from leaves and roots of phosphate-deprived A. thaliana plants revealed changes in the amounts and molecular species composition. The Q-TOF method is far more sensitive than GC or HPLC. Therefore, Q-TOF MS/MS provides a comprehensive strategy for sterol lipid quantification that can be adapted to other tandem mass spectrometers. PMID:21382968

Pulsed EPR investigations of systems modeling molybdenum enzymes: hyperfine and quadrupole parameters of oxo-17O in [Mo 17O(SPh)4]-.

PubMed

Astashkin, Andrei V; Neese, Frank; Raitsimring, Arnold M; Cooney, J Jon A; Bultman, Eric; Enemark, John H

2005-11-30

Ka band ESEEM spectroscopy was used to determine the hyperfine (hfi) and nuclear quadrupole (nqi) interaction parameters for the oxo-17O ligand in [Mo 17O(SPh)4]-, a spectroscopic model of the oxo-Mo(V) centers of enzymes. The isotropic hfi constant of 6.5 MHz found for the oxo-17O is much smaller than the values of approximately 20-40 MHz typical for the 17O nucleus of an equatorial OH(2) ligand in molybdenum enzymes. The 17O nqi parameter (e2qQ/h = 1.45 MHz, eta approximately = 0) is the first to be obtained for an oxo group in a metal complex. The parameters of the oxo-17O ligand, as well as other magnetic resonance parameters of [Mo 17O(SPh)4]- predicted by quasi-relativistic DFT calculations, were in good agreement with those obtained in experiment. From the electronic structure of the complex revealed by DFT, it follows that the SOMO is almost entirely molybdenum d(xy) and sulfur p, while the spin density on the oxo-17O is negative, determined by spin polarization mechanisms. The results of this work will enable direct experimental identification of the oxo ligand in a variety of chemical and biological systems.

Precision PEP-II optics measurement with an SVD-enhanced Least-Square fitting

NASA Astrophysics Data System (ADS)

Yan, Y. T.; Cai, Y.

2006-03-01

A singular value decomposition (SVD)-enhanced Least-Square fitting technique is discussed. By automatic identifying, ordering, and selecting dominant SVD modes of the derivative matrix that responds to the variations of the variables, the converging process of the Least-Square fitting is significantly enhanced. Thus the fitting speed can be fast enough for a fairly large system. This technique has been successfully applied to precision PEP-II optics measurement in which we determine all quadrupole strengths (both normal and skew components) and sextupole feed-downs as well as all BPM gains and BPM cross-plane couplings through Least-Square fitting of the phase advances and the Local Green's functions as well as the coupling ellipses among BPMs. The local Green's functions are specified by 4 local transfer matrix components R12, R34, R32, R14. These measurable quantities (the Green's functions, the phase advances and the coupling ellipse tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a high-resolution model-independent analysis (MIA). Once all of the quadrupoles and sextupole feed-downs are determined, we obtain a computer virtual accelerator which matches the real accelerator in linear optics. Thus, beta functions, linear coupling parameters, and interaction point (IP) optics characteristics can be measured and displayed.

Jupiter's Magnetic Field. Magnetosphere, and Interaction with the Solar Wind: Pioneer 11.

PubMed

Smith, E J; Davis, L; Jones, D E; Coleman, P J; Colburn, D S; Dyal, P; Sonett, C P

1975-05-02

The Pioneer 11 vector helium magnetometer provided precise, contititious measurements of the magnetic fields in interplanetary space, inside Jupiter's magnetosphere, and in the near vicinity of Jupiter. As with the Pioneer 10 data, evidence was seen of the dynanmic interaction of Jupiter with the solar wind which leads to a variety of phenomena (bow shock, upstream waves, nonlinear magnetosheath impulses) and to changes in the dimension of the dayside magnetosphere by as much as a factor of 2. The magnetosphere clearly appears to be blunt, not disk-shaped, with a well-defined outer boundary. In the outer magnetosphere, the magnetic field is irregular but exhibits a persistent southward component indicative of a closed magnetosphere. The data contain the first clear evidence in the dayside magnetosphere of the current sheet, apparently associated with centrifugal forces, that was a donminatnt feature of the outbound Pionieer 10 data. A modest westward spiraling of the field was again evident inbound but not outbound at higher latitudes and nearer the Sun-Jupiter direction. Measurements near periapsis, which were nearer the planet and provide better latitude and longitude coverage than Pioneer 10, have revealed a 5 percent discrepancy with the Pioneer 10 offset dipole mnodel (D(2)). A revised offset dipole (6-parameter fit) is presented as well as the results of a spherical harmonic analysis (23 parameters) consisting of an interior dipole, quadrupole, and octopole and an external dipole and quadrupole. The dipole moment and the composite field appear moderately larger than inferred from Pioneer 10. Maximum surface fields of 14 and 11 gauss in the northern and southern hemispheres are inferred. Jupiter's planetary field is found to be slightly more irregular than that of Earth.

Beam-based calibrations of the BPM offset at C-ADS Injector II

NASA Astrophysics Data System (ADS)

Chen, Wei-Long; Wang, Zhi-Jun; Feng, Chi; Dou, Wei-Ping; Tao, Yue; Jia, Huan; Wang, Wang-Sheng; Liu, Shu-Hui; He, Yuan

2016-07-01

Beam-based BPM offset calibration was carried out for Injector II at the C-ADS demonstration facility at the Institute of Modern Physics (IMP), Chinese Academy of Science (CAS). By using the steering coils integrated in the quadrupoles, the beam orbit can be effectively adjusted and BPM positions recorded at the Medium Energy Beam Transport of the Injector II Linac. The studies were done with a 2 mA, 2.1 MeV proton beam in pulsed mode. During the studies, the “null comparison method” was applied for the calibration. This method is less sensitive to errors compared with the traditional transmission matrix method. In addition, the quadrupole magnet’s center can also be calibrated with this method. Supported by National Natural Science Foundation of China (91426303, 11525523)

Implementation of dipolar direct current (DDC) collision-induced dissociation in storage and transmission modes on a quadrupole/time-of-flight tandem mass spectrometer.

PubMed

Webb, Ian K; Londry, Frank A; McLuckey, Scott A

2011-09-15

Means for effecting dipolar direct current collision-induced dissociation (DDC CID) on a quadrupole/time-of-flight in a mass spectrometer have been implemented for the broadband dissociation of a wide range of analyte ions. The DDC fragmentation method in electrodynamic storage and transmission devices provides a means for inducing fragmentation of ions over a large mass-to-charge range simultaneously. It can be effected within an ion storage step in a quadrupole collision cell that is operated as a linear ion trap or as ions are continuously transmitted through the collision cell. A DDC potential is applied across one pair of rods in the quadrupole collision cell of a QqTOF hybrid mass spectrometer to effect fragmentation. In this study, ions derived from a small drug molecule, a model peptide, a small protein, and an oligonucleotide were subjected to the DDC CID method in either an ion trapping or an ion transmission mode (or both). Several key experimental parameters that affect DDC CID results, such as time, voltage, low mass cutoff, and bath gas pressure, are illustrated with protonated leucine enkephalin. The DDC CID dissociation method gives a readily tunable, broadband tool for probing the primary structures of a wide range of analyte ions. The method provides an alternative to the narrow resonance conditions of conventional ion trap CID and it can access more extensive sequential fragmentation, depending upon conditions. The DDC CID approach constitutes a collision analog to infrared multiphoton dissociation (IRMPD). Copyright © 2011 John Wiley & Sons, Ltd.

Simultaneous analysis by Quadrupole-Orbitrap mass spectrometry and UHPLC-MS/MS for the determination of sedative-hypnotics and sleep inducers in adulterated products.

PubMed

Lee, Ji Hyun; Park, Han Na; Choi, Ji Yeon; Kim, Nam Sook; Park, Hyung-Joon; Park, Seong Soo; Baek, Sun Young

2017-12-01

Adulterated products are continuously detected in society and cause problems. In this study, we developed and validated a method for determining synthetic sedative-hypnotics and sleep inducers, including barbital, benzodiazepam, zolpidem, and first-generation antihistamines, in adulterated products using Quadrupole-Orbitrap mass spectrometry and ultrahigh performance liquid chromatography with tandem mass spectrometry. In Quadrupole-Orbitrap mass spectrometry analysis, target compounds were confirmed using a combination of retention time, mass tolerance, mass accuracy, and fragment ions. For quantification, several validation parameters were employed using ultrahigh performance liquid chromatography with tandem mass spectrometry. The limit of detection and limit of quantitation was 0.05-53 and 0.17-177 ng/mL, respectively. The correlation coefficient for linearity was more than 0.995. The intra- and interassay accuracies were 86-110 and 84-111%, respectively. Their precision values were evaluated as within 4.0 (intraday) and 10.7% (interday). Mean recoveries of target compounds in adulterated products ranged from 85 to 116%. The relative standard deviation of stability was less than 10.7% at 4°C for 48 h. The 144 adulterated products obtained over 3 years (2014-2016) from online and in-person vendors were tested using established methods. After rapidly screening with Quadrupole-Orbitrap mass spectrometry, the detected samples were quantified using ultrahigh performance liquid chromatography with tandem mass spectrometry. Two of them were adulterated with phenobarbital. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Coherent production of single pions and ρ mesons in charged-current interactions of neutrinos and antineutrinos on neon nuclei at the Fermilab Tevatron

NASA Astrophysics Data System (ADS)

Willocq, S.; Aderholz, M.; Akbari, H.; Allport, P. P.; Badyal, S. K.; Ballagh, H. C.; Barth, M.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Cence, R. J.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; de Prospo, D.; Devanand; de Wolf, E.; Faulkner, P. J.; Foeth, H.; Fretter, W. B.; Gupta, V. K.; Hanlon, J.; Harigel, G.; Harris, F. A.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Kafka, T.; Kalelkar, M.; Kohli, J. M.; Koller, E. L.; Krawiec, R. J.; Lauko, M.; Lys, J. E.; Marage, P.; Milburn, R. H.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Sacton, J.; Sambyal, S. S.; Schmitz, N.; Schneps, J.; Singh, J. B.; Singh, S.; Smart, W.; Stamer, P.; Varvell, K. E.; Verluyten, L.; Wachsmuth, H.; Wainstein, S.; Yost, G. P.

1993-04-01

The coherent production of π and ρ mesons in νμ(ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Teva- tron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53+/-9) μ+/-π-/+ coherent events and (19+/-7) μ+/-π-/+π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2+/-0.7)×10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1+/-0.8)×10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at ||t||<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.

Simulation of Crab Waist Collisions In DA$$\\Phi$$NE With KLOE-2 Interaction Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zobov, M.; Drago, A.; Gallo, A.

2015-06-24

After the successful completion of the SIDDHARTA experiment run with crab waist collisions, the electron-positron collider DAΦNE has started routine operations for the KLOE-2 detector. The new interaction region also exploits the crab waist collision scheme, but features certain complications including the experimental detector solenoid, compensating anti-solenoids, and tilted quadrupole magnets. We have performed simulations of the beam-beam collisions in the collider taking into account the real DAΦNE nonlinear lattice. In particular, we have evaluated the effect of crab waist sextupoles and beam-beam interactions on the DAΦNE dynamical aperture and energy acceptance, and estimated the luminosity that can be potentiallymore » achieved with and without crab waist sextupoles in the present working conditions. A numerical analysis has been performed in order to propose possible steps for further luminosity increase in DAΦNE such as a better working point choice, crab sextupole strength optimization, correction of the phase advance between the sextupoles and the interaction region. The proposed change of the e- ring working point was implemented and resulted in a significant performance increase.« less

Influence of stereoelectronic effects on the non-opioid analgesics gaboxadol and gaboxadol hydrochloride: Spectral and DFT study

NASA Astrophysics Data System (ADS)

Leenaraj, D. R.; Joe, I. Hubert

2018-05-01

The stereoelectronic properties of the molecular structure of most stable conformers of gaboxadol and gaboxadol hydrochloride have been studied using DFT/B3P86-LANL2DZ methodology. The energies of stable conformers of gaboxadol and gaboxadol hydrochloride are -494.2689 and -510.0117 hartrees, respectively. The stability of the molecules arising from stereoelectronic interactions, leading to its bioactivity, has been confirmed using natural bond orbital analysis. The natural bond orbital analysis of donor-acceptor (σ→σ* and n→σ*) interactions showed that the stereoelectronic hyperconjugative and anomeric interactions are exhibited in gaboxadol hydrochloride and gaboxadol, respectively. Lengthening of the axial and equatorial C-H bond lengths and natural population analysis support these results. Spectral features of gaboxadol hydrochloride have been explored by the Fourier transform infrared, Raman and Nuclear magnetic resonance spectroscopic techniques combined with density functional theory computations. NH+ … Cl- hydrogen bonding has been noticeable as a broad and strong absorption in the 2800-2400 cm-1 region. Broad peaks obtained by proton NMR are a result of the quadrupole effect of the N+ atom. Docking studies using representative GABA receptor crystal structures revealed that molecules containing azinane and isoxazole cores fit within the ligand binding domains, and the gaboxadol hydrochloride molecule shows the best binding energy with the 3D32 GABA receptor. Also, gaboxadol hydrochloride has obtained a high value of HOMO energy and a narrow HOMO- LUMO energy gap, which enhances reactivity.

The MQXA quadrupoles for the LHC low-beta insertions

NASA Astrophysics Data System (ADS)

Ajima, Y.; Higashi, N.; Iida, M.; Kimura, N.; Nakamoto, T.; Ogitsu, T.; Ohhata, H.; Ohuchi, N.; Shintomi, T.; Sugawara, S.; Sugita, K.; Tanaka, K.; Taylor, T.; Terashima, A.; Tsuchiya, K.; Yamamoto, A.

2005-09-01

High-performance superconducting quadrupole magnets, MQXA, for the LHC low-beta insertions have been designed, manufactured in series and tested. The design field gradient of the quadrupole, which has a coil aperture of diameter 70 mm, was 240 T/m at 1.9 K; its effective length is 6.37 m, and it is required to operate reliably at up to 215 T/m when subjected to radiation heat deposit in the coils of up to 5 W/m. The series of 20 magnets has been produced in industry, and tested at KEK. The magnet design is explained, and the construction and performance of the series units, in terms of training, field quality and geometry, are presented.

Air broadening of the hydrogen halides. I - N2-broadening and shifting in the HCl fundamental

NASA Technical Reports Server (NTRS)

Looney, J. P.; Herman, R. M.

1987-01-01

The resolvent operator formalism of Kolb, Griem (1964), and Baranger (1962) is used to determine the widths and shifts of the fundamental band vibration-rotation lines of HCl under N2 pressure. Time-development operator matrix elements are evaluated accounting for all bilinear and second order anisotropic terms, in addition to isotropic effects to all orders. The method employs the use of a parabolic trajectory model and explicit velocity averaging. The major contributions to the linewidths are found to arise from dipole-quadrupole, quadrupole-quadrupole, and vibrationally dependent isotropic dispersion forces. Good overall agreement is found between calculated and measured widths and linewidths over a 163-295 K temperature range.

The argon nuclear quadrupole moments

NASA Astrophysics Data System (ADS)

Sundholm, Dage; Pyykkö, Pekka

2018-07-01

New standard values -116(2) mb and 76(3) mb are suggested for the nuclear quadrupole moments (Q) of the 39Ar and 37Ar nuclei, respectively. The Q values were obtained by combining optical measurements of the quadrupole coupling constant (B or eqQ/h) of the 3s23p54s[3/2]2 (3Po) and 3s23p54p[5/2]3 (3De) states of argon with large scale numerical complete active space self-consistent field and restricted active space self-consistent field calculations of the electric field gradient at the nucleus (q) using the LUCAS code, which is a finite-element based multiconfiguration Hartree-Fock program for atomic structure calculations.

RFQ device for accelerating particles

DOEpatents

Shepard, Kenneth W.; Delayen, Jean R.

1995-01-01

A superconducting radio frequency quadrupole (RFQ) device includes four spaced elongated, linear, tubular rods disposed parallel to a charged particle beam axis, with each rod supported by two spaced tubular posts oriented radially with respect to the beam axis. The rod and post geometry of the device has four-fold rotation symmetry, lowers the frequency of the quadrupole mode below that of the dipole mode, and provides large dipole-quadrupole mode isolation to accommodate a range of mechanical tolerances. The simplicity of the geometry of the structure, which can be formed by joining eight simple T-sections, provides a high degree of mechanical stability, is insensitive to mechanical displacement, and is particularly adapted for fabrication with superconducting materials such as niobium.

Electron radiography

DOEpatents

Merrill, Frank E.; Morris, Christopher

2005-05-17

A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

Electric Quadrupole E2- Transitions of 170-174 Yb Isotopes

NASA Astrophysics Data System (ADS)

Abu El Sheikh, Mohd Kh. M.; Okhunov, Abdurahim A.; Usmanov, Ph. N.; Hassan, Torla HJ

2017-12-01

The non-adiabatic effects which is manifested in the electric properties of low-lying states of even-even deformed nuclei are studied. A simple phenomenological model which takes into account the Coriolis mixing of {K}π ={0}n+,{2}n+ and {K}π ={1}ν + state bands. The Calculations for isotopes 170-174 Yb, are carried out. The reduced probability of electric quadrupole transitions from the states {0}ν + and {2}ν + - bands to the ground (gr) state band is calculated and non adiabatic effect is discussed. The ratio of E2- transitions RIK from {0}2+, {0}3+, {2}1+, and {2}2+ bands are calculated and compared with the experimental data.

Using Hyperfine Structure to Quantify the Effects of Substitution on the Electron Distribution Within a Pyridine Ring: a Study of 2-, 3-, and 4-PICOLYLAMINE

NASA Astrophysics Data System (ADS)

McDivitt, Lindsey M.; Himes, Korrina M.; Bailey, Josiah R.; McMahon, Timothy J.; Bird, Ryan G.

2017-06-01

The ground state rotational spectra of the three methylamine substituted pyridines, 2-, 3-, and 4-picolylamine, were collected and analyzed over the frequency range of 7-17.5 GHz using chirped-pulsed Fourier transform microwave spectroscopy. All three molecules show a distinctive quadrupole splitting, which is representative of the local electronic environment around the two different ^{14}N nuclei, with the pyridine nitrogen being particularly sensitive to the pi-electron distribution within the ring. The role that the position of the methylamine group plays on the quadrupole coupling constants on both nitrogens will be discussed and compared to other substituted pyridines.

a Fascinating Two-Photon Process: Magnetically Induced Quadrupole Second Harmonic Genaration

NASA Astrophysics Data System (ADS)

Matsuoka, Masahiro

1990-10-01

After a short prologue, recalling the memory of the first meeting with Professor Bloembergen, the author reviews a topic of a second harmonic generation in centrosymmetric medium, that is, magnetically induced quadrupole SHG. A pictorial description of the process is presented together with a few suggestions for future experiment.

Electrodynamic Aerosol Concentrating and Sampling

DTIC Science & Technology

2006-06-16

flat-plate AC electrode ...................................................................................................9 Figure 4. Corona needle ...Figure 4 shows a fine hypodermic needle used as a corona wire within the first quadrupole. The quadrupole electrodes would serve as the collecting...carefully expanded to better approximate hyperbolas. It is shown here with the inner needle corona electrode in place. Once it was determined that the

Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

USGS Publications Warehouse

Wolf, Ruth E.; Adams, Monique

2015-01-01

Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

Phenolic profiling of the skin, pulp and seeds of Albariño grapes using hybrid quadrupole time-of-flight and triple-quadrupole mass spectrometry.

PubMed

Di Lecce, Giuseppe; Arranz, Sara; Jáuregui, Olga; Tresserra-Rimbau, Anna; Quifer-Rada, Paola; Lamuela-Raventós, Rosa M

2014-02-15

This paper describes for the first time a complete characterisation of the phenolic compounds in different anatomical parts of the Albariño grape. The application of high-performance liquid chromatography coupled with two complementary techniques, hybrid quadrupole time-of-flight and triple-quadrupole mass spectrometry, allowed the phenolic composition of the Albariño grape to be unambiguously identified and quantified. A more complete phenolic profile was obtained by product ion and precursor ion scans, while a neutral loss scan at 152 u enabled a fast screening of procyanidin dimers, trimers and their galloylated derivatives. The compounds were confirmed by accurate mass measurements in QqToF-MS and QqToF-MS/MS modes at high resolution, and good fits were obtained for all investigated ions, with errors ranging from 0.2 to 4.5 mDa. To the best of our knowledge, two flavanol monomer hexosides were detected in the grape berry for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Electric quadrupole moment of the 5d {sup 2}D{sub 3/2} state in {sup 171}Yb{sup +}: A relativistic coupled-cluster analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latha, K. V. P.; Chaudhuri, R. K.; Das, B. P.

2007-12-15

The electric quadrupole moment for the 5d {sup 2}D{sub 3/2} state of {sup 171}Yb{sup +}, has been calculated using the relativistic coupled-cluster method. Earlier a similar calculation was performed for the 4d {sup 2}D{sub 5/2} state of {sup 88}Sr{sup +} which is the most accurate determination to date [Sur et al., Phys. Rev. Lett. 96, 193001 (2006)]. The present calculation of the electric quadrupole moment of {sup 171}Yb{sup +} yielded a value 2.157ea{sub 0}{sup 2} where the experimental value is 2.08(11)ea{sub 0}{sup 2}; a{sub 0} is the Bohr radius and e the elementary charge. We discuss in this paper ourmore » results for {sup 171}Yb{sup +} in detail and highlight the dominant correlation effects present. We have presented the effect of inner core excitations and their contribution to the electric quadrupole moment, which is a property sensitive to regions away from the nucleus.« less

Simulation of Thermographic Responses of Delaminations in Composites with Quadrupole Method

NASA Technical Reports Server (NTRS)

Winfree, William P.; Zalameda, Joseph N.; Howell, Patricia A.; Cramer, K. Elliott

2016-01-01

The application of the quadrupole method for simulating thermal responses of delaminations in carbon fiber reinforced epoxy composites materials is presented. The method solves for the flux at the interface containing the delamination. From the interface flux, the temperature at the surface is calculated. While the results presented are for single sided measurements, with ash heating, expansion of the technique to arbitrary temporal flux heating or through transmission measurements is simple. The quadrupole method is shown to have two distinct advantages relative to finite element or finite difference techniques. First, it is straight forward to incorporate arbitrary shaped delaminations into the simulation. Second, the quadrupole method enables calculation of the thermal response at only the times of interest. This, combined with a significant reduction in the number of degrees of freedom for the same simulation quality, results in a reduction of the computation time by at least an order of magnitude. Therefore, it is a more viable technique for model based inversion of thermographic data. Results for simulations of delaminations in composites are presented and compared to measurements and finite element method results.

Final 6D Muon Ionization Colling using Strong Focusing Quadrupoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, T. L.; Acosta, J. G.; Cremaldi, L. M.

2016-11-15

Abstract Low emittance muon beam lines and muon colliders are potentially a rich source of BSM physics for future exper- imenters. A muon beam normalized emittance of ax,y,z = (280, 280, 1570)µm has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to achieve a normalized transverse emittance of 100 µm and complete 6D cooling. The low beta regions, as low as 5 mm, produced by the quadrupoles are occupied by dense, low Z absorbers, such asmore » lithium hydride or beryllium, that cool the beam transversely. Equilibrium transverse emittance is linearly proportional to the transverse betatron function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 µm at the expense of longitudinal emittance for a high energy lepton collider. Cooling challenges include chromaticity correction, ssband overlap, quadrupole acceptance, and staying in phase with RF.« less

40Ar/36Ar geochronology on a quadrupole mass spectrometer: Where are we going?

NASA Astrophysics Data System (ADS)

Schneider, B.; Wijbrans, J. R.; Kuiper, K. F.; Fenton, C. R.; Williams, A. J.

2009-04-01

40Ar/39Ar analysis has passed many milestones since its first application (Wänke & König, 1959). From the early all-glass Reynolds-type vacuum system to today's high quality, bakeable all-metal piping and valve systems, the evolution of ultra high vacuum systems has been considerable. Extraction systems have faced similar changes over time. Early furnaces made partially of glass were later replaced by full metal constructs containing a high temperature resistant molybdenum alloy tube and heating mechanism, sometimes contained within an insulating secondary vacuum chamber. Laser extraction techniques further refined the approach allowing very small samples or sample parts to be analyzed. The principal type of mass spectrometer used for 40Ar/36Ar geochronology is the magnetic sector instrument, which has the resolution and sensitivity necessary for measuring argon isotopes and achieving high precision over a large age range. We present 40Ar/39Ar data from basalt samples collected from a number of different locations, all obtained using the Hiden HAL Series 1000 quadrupole mass spectrometer at Vrije University, Amsterdam. We show that quadrupole technology is not only a viable option in K-Ar geochronology (Rouchon et al., 2008) but also in 40Ar/39Ar geochronology. The data was obtained from groundmass hand-picked from 200-500 um size fractions. Sample amounts of 200 to 500 mg were used for incremental heating experiments. The quality of the data is demonstrated by convergence of plateau and isochron ages, replicate analyses and by comparison to results of independent studies. Sample ages range from 40 ka to 400 ka, demonstrating the potential of quadrupole instruments for dating even very young rocks using the 40Ar/39Ar incremental heating technique. Rouchon, V., Lefevre, J.-C., Quidelleur, X., Guerin, G., Gillot, P.-Y. (2008): Nonspiked 40Ar and 36Ar quantification using a quadrupole mass spectrometer: A potential for K-Ar geochronology. International Journal of Mass Spectrometry 270, 52-61. Wänke H., König H. (1959): Eine neue Methode zur Kalium-Argon-Altersbestimmung und ihre Anwendung auf Steinmeteorite. Z. Naturforschung, 14a, 860 - 866.

Inductively coupled plasma mass spectrometer with axial field in a quadrupole reaction cell.

PubMed

Bandura, Dmitry R; Baranov, Vladimir I; Tanner, Scott D

2002-10-01

A novel reaction cell for ICP-MS with an electric field provided inside the quadrupole along its axis is described. The field is implemented via a DC bias applied to additional auxiliary electrodes inserted between the rods of the quadrupole. The field reduces the settling time of the pressurized quadrupole when its mass bandpass is dynamically tuned. It also improves the transmission of analyte ions. It is shown that for the pressurized cell with the field activated, the recovery time for a change in quadrupole operating parameters is reduced to <4 ms, which allows fast tuning of the mass bandpass in concert with and at the speed of the analyzing quadrupole. When the cell is operated with ammonia, the field reduces ion-ammonia cluster formation, further enhancing the transmission of atomic ions that have a high cluster formation rate. Ni x (NH3)n+ cluster formation in a cell operated with a wide bandpass (i.e., Ni+ precursors are stable in the cell) is shown to be dependent on the axial field strength. Clusters at n = 2-4 can be suppressed by 9, 1200, and >610 times, respectively. The use of a retarding axial field for in-situ energy discrimination against cluster and polyatomic ions is shown. When the cell is pressurized with O2 for suppression of 129Xe+, the formation of 127IH2+ by reactions with gas impurities limits the detection of 129I to isotopic abundance of approximately 10(-6). In-cell energy discrimination against 127IH2+ utilizing a retarding axial field is shown to reduce the abundance of the background at m/z = 129 to ca. 3 x 10(-8) of the 127I+ signal. In-cell energy discrimination against 127IH2+ is shown to cause less I+ loss than a post-cell potential energy barrier for the same degree of 127IH2+ suppression.

Magnetic quench antenna for MQXF quadrupoles

DOE PAGES

Marchevsky, Maxim; Sabbi, GianLuca; Prestemon, Soren; ...

2016-12-21

High-field MQXF-series quadrupoles are presently under development by LARP and CERN for the upcoming LHC luminosity upgrade. Quench training and protection studies on MQXF prototypes require a capability to accurately localize quenches and measure their propagation velocity in the magnet coils. The voltage tap technique commonly used for such purposes is not a convenient option for the 4.2-m-long MQXF-A prototype, nor can it be implemented in the production model. We have developed and tested a modular inductive magnetic antenna for quench localization. The base element of our quench antenna is a round-shaped printed circuit board containing two orthogonal pairs ofmore » flat coils integrated with low-noise preamplifiers. The elements are aligned axially and spaced equidistantly in 8-element sections using a supporting rod structure. The sections are installed in the warm bore of the magnet, and can be stacked together to adapt for the magnet length. We discuss the design, operational characteristics and preliminary qualification of the antenna. Lastly, axial quench localization capability with an accuracy of better than 2 cm has been validated during training test campaign of the MQXF-S1 quadrupole.« less

Magnetic quench antenna for MQXF quadrupoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marchevsky, Maxim; Sabbi, GianLuca; Prestemon, Soren

High-field MQXF-series quadrupoles are presently under development by LARP and CERN for the upcoming LHC luminosity upgrade. Quench training and protection studies on MQXF prototypes require a capability to accurately localize quenches and measure their propagation velocity in the magnet coils. The voltage tap technique commonly used for such purposes is not a convenient option for the 4.2-m-long MQXF-A prototype, nor can it be implemented in the production model. We have developed and tested a modular inductive magnetic antenna for quench localization. The base element of our quench antenna is a round-shaped printed circuit board containing two orthogonal pairs ofmore » flat coils integrated with low-noise preamplifiers. The elements are aligned axially and spaced equidistantly in 8-element sections using a supporting rod structure. The sections are installed in the warm bore of the magnet, and can be stacked together to adapt for the magnet length. We discuss the design, operational characteristics and preliminary qualification of the antenna. Lastly, axial quench localization capability with an accuracy of better than 2 cm has been validated during training test campaign of the MQXF-S1 quadrupole.« less

Form factors of the d*(2380 ) resonance

NASA Astrophysics Data System (ADS)

Dong, Yubing; Shen, Pengnian; Zhang, Zongye

2018-06-01

In order to explore the possible physical quantities for judging different structures of the newly observed resonance d*(2380 ), we study its electromagnetic form factors. In addition to the electric charge monopole C 0 , we calculate its electric quadrupole E 2 , magnetic dipole M 1 , and magnetic octupole M 3 form factors on the base of the realistic coupled Δ Δ +C8C8 channel d* wave function with both the S - and D -partial waves. The results show that the magnetic dipole moment and electric quadrupole deformation of d* are 7.602 and 2.53 ×10-2 fm2 , respectively. The calculated magnetic dipole moment in the naive constituent quark model is also compared with the result of D12π picture. By comparing with partial results where the d* state is considered with a single Δ Δ and with a D12π structures, we find that in addition to the charge distribution of d*, the magnetic dipole moment and magnetic radius can be used to discriminate different structures of d*. Moreover, a quite small electric quadrupole deformation indicates that d* is more inclined to a slightly oblate shape due to our compact hexaquark dominated structure of d*.

Comparative analysis of the heme iron electronic structure and stereochemistry in tetrameric rabbit hemoglobin and monomeric soybean leghemoglobin a using Mössbauer spectroscopy with a high velocity resolution

NASA Astrophysics Data System (ADS)

Alenkina, I. V.; Kumar, A.; Berkovsky, A. L.; Oshtrakh, M. I.

2018-02-01

A comparative study of tetrameric rabbit hemoglobin and monomeric soybean leghemoglobin a in the oxy- and deoxy-forms was carried out using 57Fe Mössbauer spectroscopy with a high velocity resolution in order to analyze the heme iron electronic structure and stereochemistry in relation to the Mössbauer hyperfine parameters. The Mössbauer spectra of tetrameric rabbit hemoglobin in both forms were fitted using two quadrupole doublets related to the 57Fe in ɑ- and β-subunits. In contrast, the Mössbauer spectra of monomeric soybean leghemoglobin a were fitted using: (i) two quadrupole doublets for the oxy-form related to two conformational states of the distal His E7 imidazole ring and different hydrogen bonding of oxygen molecule in the oxy-form and (ii) using three quadrupole doublets for deoxy-form related to three conformational states of the proximal His F8 imidazole ring. Small variations of Mössbauer hyperfine parameters related to small differences in the heme iron electronic structure and stereochemistry in tetrameric rabbit hemoglobin and monomeric soybean leghemoglobin a are discussed.

Rapid characterisation and identification of compounds in Saposhnikoviae Radix by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry.

PubMed

Chen, Luxiao; Chen, Xiangyang; Su, Lei; Jiang, Yanyan; Liu, Bin

2018-04-01

Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3'-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation.

Tidal waves in 102Pd: a rotating condensate of multiple d bosons.

PubMed

Ayangeakaa, A D; Garg, U; Caprio, M A; Carpenter, M P; Ghugre, S S; Janssens, R V F; Kondev, F G; Matta, J T; Mukhopadhyay, S; Patel, D; Seweryniak, D; Sun, J; Zhu, S; Frauendorf, S

2013-03-08

Low-lying collective excitations in even-even vibrational and transitional nuclei may be described semiclassically as quadrupole running waves on the surface of the nucleus ("tidal waves"), and the observed vibrational-rotational behavior can be thought of as resulting from a rotating condensate of interacting d bosons. These concepts have been investigated by measuring lifetimes of the levels in the yrast band of the (102)Pd nucleus with the Doppler shift attenuation method. The extracted B(E2) reduced transition probabilities for the yrast band display a monotonic increase with spin, in agreement with the interpretation based on rotation-induced condensation of aligned d bosons.

Inorganic biochemistry with short-lived radioisotopes as nuclear probes

NASA Astrophysics Data System (ADS)

Tröger, W.; Butz, T.

2000-12-01

Metal ions are ubiquitous in the biosphere. In living organisms metalloproteins with specifically designed metal cores perform vital chemical processes. On the other hand, several heavy metals are detrimental to living organisms and nature has developed effective enzymatic detoxification systems which convert toxic metal ions to less toxic species. The nuclear spectroscopy technique Time Differential Perturbed Angular Correlation (TDPAC) of γ-rays uses radioactive isotopes as nuclear probes in these metal cores to obtain a better understanding of the structural and functional significance of these metal cores by monitoring the nuclear quadrupole interaction of the TDPAC probe. Since this technique is based on the nuclear decay, it is also applicable under physiological conditions, i.e., especially at picomolar concentrations. For these studies an indispensable prerequisite is the production of the TDPAC probes with highest possible specific activity and purity as is done by the on-line mass separator ISOLDE at CERN in Geneva.

The pharmacokinetic characters of simvastatin after co-administration with Shexiang Baoxin Pill in healthy volunteers' plasma.

PubMed

Tao, Jianfei; Jiang, Peng; Peng, Chengcheng; Li, Min; Liu, Runhui; Zhang, Weidong

2016-07-15

To investigate the effect of Shexiang Baoxin Pill (SBP), a tranditional Chinese medicine, on the pharmacokinetic (PK) parameters of simvastatin in healthy volunteers' plasma, a quantitative method was developed using an Agilent G6410A rapid performance liquid chromatography (RPLC) coupled with triple quadrupole mass spectrometry system. The established method was rapid with high extraction recovery and successfully applied for the determination of simvastatin in plasma of 16 healthy volunteers. The results demonstrated that the MRT(0-∞), T1/2 and Tmax value of simvastatin were significantly decreased, while the AUC(0-t) and Cmax values of smivastatin were increased by SBP. The pharmacokinetic study demonstrated that the metabolism parameters of simvastatin could be affected by SBP and the potential drug-drug interaction should be noted in the future clinical practice. Copyright © 2016 Elsevier B.V. All rights reserved.

Infinite lattices of vortex molecules in Rabi-coupled condensates

NASA Astrophysics Data System (ADS)

Mencia Uranga, B.; Lamacraft, Austen

2018-04-01

Vortex molecules can form in a two-component superfluid when a Rabi field drives transitions between the two components. We study the ground state of an infinite system of vortex molecules in two dimensions, using a numerical scheme which makes no use of the lowest Landau level approximation. We find the ground state lattice geometry for different values of intercomponent interactions and strength of the Rabi field. In the limit of large field when molecules are tightly bound, we develop a complementary analytical description. The energy governing the alignment of molecules on a triangular lattice is found to correspond to that of an infinite system of two-dimensional quadrupoles, which may be written in terms of an elliptic function Q (zi j;ω1,ω2) . This allows for a numerical evaluation of the energy which enables us to find the ground state configuration of the molecules.

Beam echoes in the presence of coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross, Axel

2017-10-03

Transverse beam echoes could provide a new technique of measuring diusion characteristics orders of magnitude faster than the current methods; however, their interaction with many accelerator parameters is poorly understood. Using a program written in C, we explored the relationship between coupling and echo strength. We found that echoes could be generated in both dimensions, even with a dipole kick in only one dimension. We found that the echo eects are not destroyed even when there is strong coupling, falling o only at extremely high coupling values. We found that at intermediate values of skew quadrupole strength, the decoherence timemore » of the beam is greatly increased, causing a destruction of the echo eects. We found that this is caused by a narrowing of the tune width of the particles. Results from this study will help to provide recommendations to IOTA (Integrable Optics Test Accelerator) for their upcoming echo experiment.« less

In-plane nuclear field formation investigated in single self-assembled quantum dots

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Matsusaki, R.; Kaji, R.; Adachi, S.

2018-02-01

We studied the formation mechanism of the in-plane nuclear field in single self-assembled In0.75Al0.25As /Al0.3Ga0.7As quantum dots. The Hanle curves with an anomalously large width and hysteretic behavior at the critical transverse magnetic field were observed in many single quantum dots grown in the same sample. In order to explain the anomalies in the Hanle curve indicating the formation of a large nuclear field perpendicular to the photo-injected electron spin polarization, we propose a new model based on the current phenomenological model for dynamic nuclear spin polarization. The model includes the effects of the nuclear quadrupole interaction and the sign inversion between in-plane and out-of-plane components of nuclear g factors, and the model calculations reproduce successfully the characteristics of the observed anomalies in the Hanle curves.

Valence fluctuating compound α-YbAlB4 studied by 174Yb Mössbauer spectroscopy and X-ray diffraction using synchrotron radiation

NASA Astrophysics Data System (ADS)

Oura, Momoko; Ikeda, Shugo; Masuda, Ryo; Kobayashi, Yasuhiro; Seto, Makoto; Yoda, Yoshitaka; Hirao, Naohisa; Kawaguchi, Saori I.; Ohishi, Yasuo; Suzuki, Shintaro; Kuga, Kentaro; Nakatsuji, Satoru; Kobayashi, Hisao

2018-05-01

The structural properties and the Yb 4 f electronic state of the valence fluctuating α-YbAlB4 have been investigated by powder X-ray diffraction under pressure and 174Yb Mössbauer spectroscopy with magnetic fields at low temperature, respectively, using synchrotron radiation. Powder X-ray diffraction patterns showed that the crystal structure does not change up to p ∼ 18 GPa at 8 K and the volume decreases smoothly. However, the pressure dependence of the difference in the structure factor between the (060) and (061) diffraction lines changes at ∼ 3.4 GPa, indicating the change of atomic coordination parameters. The 174Yb Mössbauer spectroscopy measurements at 2 K with 10 and 50 kOe suggest that the electrical quadrupole interaction changes by applied magnetic fields.

Molecular microelectrostatic view on electronic states near pentacene grain boundaries

NASA Astrophysics Data System (ADS)

Verlaak, Stijn; Heremans, Paul

2007-03-01

Grain boundaries are the most inevitable and pronounced structural defects in pentacene films. To study the effect of those structural defects on the electronic state distribution, the energy levels of a hole on molecules at and near the defect have been calculated using a submolecular self-consistent-polarization-field approach in combination with atomic charge-quadrupole interaction energy calculations. This method has been benchmarked prior to application on four idealized grain boundaries: a grain boundary void, a void with molecules squeezed in between two grains, a boundary between two grains with different crystallographic orientations, and a grain boundary void in which a permanent dipole (e.g., a water molecule) has nested. While idealized, those views highlight different aspects of real grain boundaries. Implications on macroscopic charge transport models are discussed, as well as some relation between growth conditions and the formation of the grain boundary.

Interstitial Fe in MgO

NASA Astrophysics Data System (ADS)

Mølholt, T. E.; Mantovan, R.; Gunnlaugsson, H. P.; Svane, A.; Masenda, H.; Naidoo, D.; Bharuth-Ram, K.; Fanciulli, M.; Gislason, H. P.; Johnston, K.; Langouche, G.; Ólafsson, S.; Sielemann, R.; Weyer, G.

2014-01-01

Isolated 57Fe atoms were studied in MgO single-crystals by emission Mössbauer spectroscopy following implantation of 57Mn decaying to 57Fe. Four Mössbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

An integrated study of thermal treatment effects on the microstructure and magnetic properties of Zn-ferrite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antic, Bratislav; Perovic, Marija; Kremenovic, Aleksandar

2015-09-30

The evolution of the magnetic state, crystal structure and microstructure parameters of nanocrystalline zinc–ferrite, tuned by thermal annealing of ~4 nm nanoparticles, was systematically studied by complementary characterization methods. Structural analysis of neutron and synchrotron x-ray radiation data revealed a mixed cation distribution in the nanoparticle samples, with the degree of inversion systematically decreasing from 0.25 in an as-prepared nanocrystalline sample to a non-inverted spinel structure with a normal cation distribution in the bulk counterpart. The results of DC magnetization and Mossbauer spectroscopy experiments indicated a superparamagnetic relaxation in ~4 nm nanoparticles, albeit with different freezing temperatures T f ofmore » 27.5 K and 46 K, respectively. The quadrupole splitting parameter decreases with the annealing temperature due to cation redistribution between the tetrahedral and octahedral sites of the spinel structure and the associated defects. DC magnetization measurements indicated the existence of significant interparticle interactions among nanoparticles (‘superspins’). Additional confirmation for the presence of interparticle interactions was found from the fit of the T f(H) dependence to the AT line, from which a value of the anisotropy constant of K eff = 5.6 × 10 5 erg cm -3 was deduced. Further evidence for strong interparticle interactions was found from AC susceptibility measurements, where the frequency dependence of the freezing temperature T f(ƒ) was satisfactory described by both Vogel–Fulcher and dynamic scaling theory, both applicable for interacting systems. The parameters obtained from these fits suggest collective freezing of magnetic moments at T f .« less

Protecting LHC components against radiation resulting from an unsynchronized beam abort

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolai V. Mokhov et al.

2001-06-26

The effect of possible accidental beam loss in the LHC on the IP5 and IP6 insertion elements is studied via realistic Monte Carlo simulations. The scenario studied is beam loss due to unsynchronized abort at an accidental prefire of one of the abort kicker modules. Simulations show that this beam loss would result in severe heating of the IP5 and IP6 superconducting (SC) quadrupoles. Contrary to the previous considerations with a stationary set of collimators in IP5, collimators in IP6 close to the cause are proposed: a movable collimator upstream of the Q4 quadrupole and a stationary one upstream ofmore » the extraction septumMSD. The calculated temperature rise in the optimal set of collimators is quite acceptable. All SC magnets are protected by these collimators against damage.« less

The effect of the cosmological constant on a quadrupole signal in the linearized approximation

NASA Astrophysics Data System (ADS)

Somlai, László Ábel; Vasúth, Mátyás

In this study the effects of a nonzero cosmological constant Λ on a quadrupole gravitational wave (GW) signal are analyzed. The linearized approximation of general relativity was used, so the perturbed metric can be written as the sum of hGW GWs and hΛ background term, originated from Λ. The ΛhGW term was also included in this study. To derive physically relevant consequences of Λ≠0 comoving coordinates are used. In these coordinates, the equations of motion (EoMs) are not self-consistent so the result of the linearized theory has to be transformed to the FRW frame. The luminosity distance and the same order of the magnitude of frequency in accordance with the detected GWs were used to demonstrate the effects of the cosmological constant.

Profiling the indole alkaloids in yohimbe bark with ultra-performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry

USDA-ARS?s Scientific Manuscript database

An ultra-high performance liquid chromatography-ion mobility- quadrupole time-of-flight mass spectrometry (UHPLC-IM-QTOF-MS) method was developed for profiling the indole alkaloids in yohimbe bark. Many indole alkaloids with the yohimbine core structure, plus methylated, oxidized, and reduced speci...

Metabolic profiling of Hoodia, Chamomile, Terminalia Species and evaluation of commercial preparations using Ultra-High Performance Quadrupole Time of Flight-Mass Spectrometry

USDA-ARS?s Scientific Manuscript database

Ultra-High Performance-Quadrupole Time of Flight Mass Spectrometr(UHPLC-QToF-MS)profiling has become an impattant tool for identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. Chemometric approaches can be used to ana...

Variable Permanent Magnet Quadrupole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mihara, T.; Iwashita, Y.; /Kyoto U.

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four partsmore » and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.« less

Modeling of Dipole and Quadrupole Fringe-Field Effects for the Advanced Photon Source Upgrade Lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borland, M.; Lindberg, R.

2017-06-01

The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice requires shorter and much stronger quadrupole magnets than are present in the existing ring. This results in longitudinal gradient profiles that differ significantly from a hard-edge model. Additionally, the lattice assumes the use of five-segment longitudinal gradient dipoles. Under these circumstances, the effects of fringe fields and detailed field distributions are of interest. We evaluated the effect of soft-edge fringe fields on the linear optics and chromaticity, finding that compensation for these effects is readily accomplished. In addition, we evaluated the reliability of standard methods of simulatingmore » hardedge nonlinear fringe effects in quadrupoles.« less

RFQ device for accelerating particles

DOEpatents

Shepard, K.W.; Delayen, J.R.

1995-06-06

A superconducting radio frequency quadrupole (RFQ) device includes four spaced elongated, linear, tubular rods disposed parallel to a charged particle beam axis, with each rod supported by two spaced tubular posts oriented radially with respect to the beam axis. The rod and post geometry of the device has four-fold rotation symmetry, lowers the frequency of the quadrupole mode below that of the dipole mode, and provides large dipole-quadrupole mode isolation to accommodate a range of mechanical tolerances. The simplicity of the geometry of the structure, which can be formed by joining eight simple T-sections, provides a high degree of mechanical stability, is insensitive to mechanical displacement, and is particularly adapted for fabrication with superconducting materials such as niobium. 5 figs.

Magnetic fringe field interference between the quadrupole and corrector magnets in the CSNS/RCS

NASA Astrophysics Data System (ADS)

Yang, Mei; Kang, Wen; Deng, Changdong; Sun, Xianjing; Li, Li; Wu, Xi; Gong, Lingling; Cheng, Da; Zhu, Yingshun; Chen, Fusan

2017-03-01

The Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) employs large aperture quadrupole and corrector magnets with small aspect ratios and relatively short iron to iron separations; so the fringe field interference becomes serious which results in integral field strength reduction and extra field harmonics. We have performed 3D magnetic field simulations to investigate the magnetic field interference in the magnet assemblies and made some adjustments on the magnet arrangement. The Fourier analysis is used to quantify the integral gradient reduction and field harmonic changes of the quadrupole magnets. Some magnetic field measurements are undertaken to verify the simulation results. The simulation details and the major results are presented in this paper.

Analysis of field errors for LARP Nb 3Sn HQ03 quadrupole magnet

DOE PAGES

Wang, Xiaorong; Ambrosio, Giorgio; Chlachidze, Guram; ...

2016-12-01

The U.S. LHC Accelerator Research Program, in close collaboration with CERN, has developed three generations of high-gradient quadrupole (HQ) Nb 3Sn model magnets, to support the development of the 150 mm aperture Nb 3Sn quadrupole magnets for the High-Luminosity LHC. The latest generation, HQ03, featured coils with better uniformity of coil dimensions and properties than the earlier generations. We tested the HQ03 magnet at FNAL, including the field quality study. The profiles of low-order harmonics along the magnet aperture observed at 15 kA, 1.9 K can be traced back to the assembled coil pack before the magnet assembly. Based onmore » the measured harmonics in the magnet center region, the coil block positioning tolerance was analyzed and compared with earlier HQ01 and HQ02 magnets to correlate with coil and magnet fabrication. Our study the capability of correcting the low-order non-allowed field errors, magnetic shims were installed in HQ03. Furthermore, the expected shim contribution agreed well with the calculation. For the persistent-current effect, the measured a4 can be related to 4% higher in the strand magnetization of one coil with respect to the other three coils. Lastly, we compare the field errors due to the inter-strand coupling currents between HQ03 and HQ02.« less

Diverse trends of electron correlation effects for properties with different radial and angular factors in an atomic system: a case study in Ca+

NASA Astrophysics Data System (ADS)

Kumar, Pradeep; Li, Cheng-Bin; Sahoo, B. K.

2018-03-01

Dependencies of electron correlation effects with the rank and radial behavior of spectroscopic properties are analyzed in the singly charged calcium ion (Ca+). To demonstrate these trends, we have determined field shift constants, magnetic dipole and electric quadrupole hyperfine structure constants, Landé g J factors, and electric quadrupole moments that are described by electronic operators with different radial and angular factors. Radial dependencies are investigated by comparing correlation trends among the properties that have similar angular factors and vice versa. To highlight these observations, we present results from the mean-field approach to all-orders along with intermediate contributions. Contributions from higher relativistic corrections are also given. These findings suggest that sometime lower-order approximations can give results agreeing with the experimental results, but inclusion of some of higher-order correlation effects can cause large disagreement with the experimental values. Therefore, validity of a method for accurate evaluation of atomic properties can be tested by performing calculations of several properties simultaneously that have diverse dependencies on the angular and radial factors and comparing with the available experimental results. Nevertheless, it is imperative to include full triple and quadrupole excitations in the all-order many-body methods for high-precision calculations that are yet to be developed adopting spherical coordinate system for atomic studies.

Particle- γ coincidence spectroscopy of the N = 90 nucleus 154Gd by (p,tγ)

NASA Astrophysics Data System (ADS)

Allmond, J. M.; Beausang, C. W.; Ross, T. J.; Humby, P.; Basunia, M. S.; Bernstein, L. A.; Bleuel, D. L.; Brooks, W.; Brown, N.; Burke, J. T.; Darakchieva, B. K.; Dudziak, K. R.; Evans, K. E.; Fallon, P.; Jeppesen, H. B.; LeBlanc, J. D.; Lesher, S. R.; McMahan, M. A.; Meyer, D. A.; Phair, L.; Rasmussen, J. O.; Scielzo, N. D.; Stroberg, S. R.; Wiedeking, M.

2017-03-01

A segmented Si-telescope and HPGe array, STARS-LIBERACE, was used to study the 156Gd(p,tγ)154Gd direct reaction by particle- γ coincidence spectroscopy. New cross sections with a 25MeV proton beam are reported and compared to previous (p,t) and (t,p) studies. Furthermore, additional evidence for coexisting K^{π}=01+,21+ and 02+, 22+ configurations at N = 90 is presented. Direct and indirect population patterns of the low-lying states are also explored. Review of the new and existing evidence favors an interpretation based on a configuration-dependent pairing interaction. The weakening of monopole pairing strength and an increase in quadrupole pairing strength could bring 2p-2h 0+ states below 2Δ. This may account for a large number of the low-lying 0+ states observed in two-nucleon transfer reactions. A hypothesis for the origin of the 02+ and 03+ states is provided.

Planck CMB Anomalies: Astrophysical and Cosmological Secondary Effects and the Curse of Masking

NASA Astrophysics Data System (ADS)

Rassat, Anais

2016-07-01

Large-scale anomalies have been reported in CMB data with both WMAP and Planck data. These could be due to foreground residuals and or systematic effects, though their confirmation with Planck data suggests they are not due to a problem in the WMAP or Planck pipelines. If these anomalies are in fact primordial, then understanding their origin is fundamental to either validate the standard model of cosmology or to explore new physics. We investigate three other possible issues: 1) the trade-off between minimising systematics due to foreground contamination (with a conservative mask) and minimising systematics due to masking, 2) astrophysical secondary effects (the kinetic Doppler quadrupole and kinetic Sunyaev-Zel'dovich effect), and 3) secondary cosmological signals (the integrated Sachs-Wolfe effect). We address the masking issue by considering new procedures that use both WMAP and Planck to produce higher quality full-sky maps using the sparsity methodology (LGMCA maps). We show the impact of masking is dominant over that of residual foregrounds, and the LGMCA full-sky maps can be used without further processing to study anomalies. We consider four official Planck PR1 and two LGMCA CMB maps. Analysis of the observed CMB maps shows that only the low quadrupole and quadrupole-octopole alignment seem significant, but that the planar octopole, Axis of Evil, mirror parity and cold spot are not significant in nearly all maps considered. After subtraction of astrophysical and cosmological secondary effects, only the low quadrupole may still be considered anomalous, meaning the significance of only one anomaly is affected by secondary effect subtraction out of six anomalies considered. In the spirit of reproducible research all reconstructed maps and codes are available online.

Planck CMB anomalies: astrophysical and cosmological secondary effects and the curse of masking

NASA Astrophysics Data System (ADS)

Rassat, A.; Starck, J.-L.; Paykari, P.; Sureau, F.; Bobin, J.

2014-08-01

Large-scale anomalies have been reported in CMB data with both WMAP and Planck data. These could be due to foreground residuals and or systematic effects, though their confirmation with Planck data suggests they are not due to a problem in the WMAP or Planck pipelines. If these anomalies are in fact primordial, then understanding their origin is fundamental to either validate the standard model of cosmology or to explore new physics. We investigate three other possible issues: 1) the trade-off between minimising systematics due to foreground contamination (with a conservative mask) and minimising systematics due to masking, 2) astrophysical secondary effects (the kinetic Doppler quadrupole and kinetic Sunyaev-Zel'dovich effect), and 3) secondary cosmological signals (the integrated Sachs-Wolfe effect). We address the masking issue by considering new procedures that use both WMAP and Planck to produce higher quality full-sky maps using the sparsity methodology (LGMCA maps). We show the impact of masking is dominant over that of residual foregrounds, and the LGMCA full-sky maps can be used without further processing to study anomalies. We consider four official Planck PR1 and two LGMCA CMB maps. Analysis of the observed CMB maps shows that only the low quadrupole and quadrupole-octopole alignment seem significant, but that the planar octopole, Axis of Evil, mirror parity and cold spot are not significant in nearly all maps considered. After subtraction of astrophysical and cosmological secondary effects, only the low quadrupole may still be considered anomalous, meaning the significance of only one anomaly is affected by secondary effect subtraction out of six anomalies considered. In the spirit of reproducible research all reconstructed maps and codes will be made available for download here http://www.cosmostat.org/anomaliesCMB.html.

Lifetimes of excited states in 196, 198Pt; Application of interacting boson approximation model to even Pt isotopes systematics

NASA Astrophysics Data System (ADS)

Bolotin, H. H.; Stuchbery, A. E.; Morrison, I.; Kennedy, D. L.; Ryan, C. G.; Sie, S. H.

1981-11-01

The lifetimes and lifetime limits of the low-lying excited states up to and including the 6 1+ levels in 196, 198Pt were determined by the recoil-distance method (RDM). Gamma-ray angular distributions in 198Pt were also measured. These states were populated by multiple Coulomb excitation using 220 MeV 58Ni ion beams and the measurements were carried out in coincidence with back-scattered projectiles. The measured mean lives of the states and B(E2) values inferred for the transitions between levels are presented. These specific findings, and the observed structure systematics obtained from the combination of the present results and those of prior workers for the even 194-198Pt isotopes, are critically compared with our structure calculations employing the interacting boson approximation (IBA) model incorporating a symmetry-breaking quadrupole force; evaluative comparisons are also made with boson expansion theory (BET) calculations.